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-rw-r--r--com32/lib/MCONFIG12
-rw-r--r--com32/lib/Makefile7
-rw-r--r--com32/lib/libpng/ANNOUNCE32
-rw-r--r--com32/lib/libpng/CHANGES1419
-rw-r--r--com32/lib/libpng/KNOWNBUG11
-rw-r--r--com32/lib/libpng/LICENSE113
-rw-r--r--com32/lib/libpng/README262
-rw-r--r--com32/lib/libpng/TODO24
-rw-r--r--com32/lib/libpng/Y2KINFO55
-rw-r--r--com32/lib/libpng/example.c808
-rw-r--r--com32/lib/libpng/libpng.txt2959
-rw-r--r--com32/lib/libpng/png.c828
-rw-r--r--com32/lib/libpng/png.h3419
-rw-r--r--com32/lib/libpng/pngconf.h1437
-rw-r--r--com32/lib/libpng/pngerror.c295
-rw-r--r--com32/lib/libpng/pnggccrd.c5408
-rw-r--r--com32/lib/libpng/pngget.c934
-rw-r--r--com32/lib/libpng/pngmem.c595
-rw-r--r--com32/lib/libpng/pngpread.c1573
-rw-r--r--com32/lib/libpng/pngread.c1456
-rw-r--r--com32/lib/libpng/pngrio.c161
-rw-r--r--com32/lib/libpng/pngrtran.c4177
-rw-r--r--com32/lib/libpng/pngrutil.c3124
-rw-r--r--com32/lib/libpng/pngset.c1219
-rw-r--r--com32/lib/libpng/pngtest.c1554
-rw-r--r--com32/lib/libpng/pngtrans.c650
-rw-r--r--com32/lib/libpng/pngvcrd.c3903
-rw-r--r--com32/lib/libpng/pngwio.c228
-rw-r--r--com32/lib/libpng/pngwrite.c1464
-rw-r--r--com32/lib/libpng/pngwtran.c563
-rw-r--r--com32/lib/libpng/pngwutil.c2730
31 files changed, 41417 insertions, 3 deletions
diff --git a/com32/lib/MCONFIG b/com32/lib/MCONFIG
index 50150975..e740ed5e 100644
--- a/com32/lib/MCONFIG
+++ b/com32/lib/MCONFIG
@@ -1,3 +1,6 @@
+# -*- makefile -*-
+# $Id$
+
CC = gcc
LD = ld
INCLUDE = -I.
@@ -8,13 +11,18 @@ PERL = perl
STRIP = strip --strip-all -R .comment -R .note
OBJCOPY = objcopy
+# zlib and libpng configuration flags
+LIBFLAGS = -DDYNAMIC_CRC_TABLE -DPNG_NO_CONSOLE_IO \
+ -DPNG_NO_MNG_FEATURES -DPNG_NO_FLOATING_POINT_SUPPORTED \
+ -DPNG_NO_WRITE_FLUSH -DPNG_NO_WRITE_tIME -DPNG_NO_READ_tIME
+
REQFLAGS = -g -m32 -mregparm=3 -DREGPARM=3 -D__COM32__ -I. -I./sys -I../include
OPTFLAGS = -Os -march=i386 -falign-functions=0 -falign-jumps=0 \
- -falign-labels=0 -DDYNAMIC_CRC_TABLE
+ -falign-labels=0
WARNFLAGS = -W -Wall -Wpointer-arith -Wwrite-strings -Wstrict-prototypes -Winline
CFLAGS = -Wp,-MT,$@,-MD,$(dir $@).$(notdir $@).d $(OPTFLAGS) \
- $(REQFLAGS) $(WARNFLAGS)
+ $(REQFLAGS) $(WARNFLAGS) $(LIBFLAGS)
LDFLAGS = -m elf32_i386
.SUFFIXES: .c .o .a .so .lo .i .S .s .ls .ss .lss
diff --git a/com32/lib/Makefile b/com32/lib/Makefile
index d4df7a17..29f0cecd 100644
--- a/com32/lib/Makefile
+++ b/com32/lib/Makefile
@@ -30,7 +30,12 @@ LIBOBJS = abort.o atexit.o atoi.o atol.o atoll.o calloc.o creat.o \
pci/writeb.o pci/writew.o pci/writel.o \
zlib/adler32.o zlib/compress.o zlib/crc32.o zlib/gzio.o \
zlib/uncompr.o zlib/deflate.o zlib/trees.o zlib/zutil.o \
- zlib/inflate.o zlib/infback.o zlib/inftrees.o zlib/inffast.o
+ zlib/inflate.o zlib/infback.o zlib/inftrees.o zlib/inffast.o \
+ libpng/png.o libpng/pngset.o libpng/pngrutil.o \
+ libpng/pngtrans.o libpng/pngwutil.o libpng/pngread.o \
+ libpng/pngrio.o libpng/pngwio.o libpng/pngwrite.o \
+ libpng/pngrtran.o libpng/pngwtran.o libpng/pngmem.o \
+ libpng/pngerror.o libpng/pngpread.o
BINDIR = /usr/bin
LIBDIR = /usr/lib
diff --git a/com32/lib/libpng/ANNOUNCE b/com32/lib/libpng/ANNOUNCE
new file mode 100644
index 00000000..e40b94a0
--- /dev/null
+++ b/com32/lib/libpng/ANNOUNCE
@@ -0,0 +1,32 @@
+
+Libpng 1.2.8 - December 3, 2004
+
+This is a public release of libpng, intended for use in production codes.
+
+Changes since the last public release (1.2.7):
+
+ Fixed bug in png_text_compress() that would fail to complete a large block.
+ Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during
+ strip alpha operation in png_do_strip_filler().
+ Added PNG_1_2_X definition in pngconf.h
+ #ifdef out png_info_init in png.c and png_read_init in pngread.c (as of 1.3.0)
+ Reduce color_type to a nonalpha type after strip alpha operation in
+ png_do_strip_filler().
+ Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM
+ Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin).
+ Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin).
+ Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection
+ of data type in deflate (Cosmin).
+ Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of
+ PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
+ Despammed mailing addresses by masking "@" with "at".
+ Added scripts/makefile.elf with supporting code in pngconf.h for symbol
+ versioning (John Bowler).
+ Added projects/visualc71 (Simon-pierre).
+
+Send comments/corrections/commendations to
+png-implement at ccrc.wustl.edu (subscription required; write to
+majordomo at ccrc.wustl.edu with "subscribe png-implement" in the message)
+or to glennrp at users.sourceforge.net
+
+Glenn R-P
diff --git a/com32/lib/libpng/CHANGES b/com32/lib/libpng/CHANGES
new file mode 100644
index 00000000..90c816e3
--- /dev/null
+++ b/com32/lib/libpng/CHANGES
@@ -0,0 +1,1419 @@
+
+CHANGES - changes for libpng
+
+version 0.2
+ added reader into png.h
+ fixed small problems in stub file
+
+version 0.3
+ added pull reader
+ split up pngwrite.c to several files
+ added pnglib.txt
+ added example.c
+ cleaned up writer, adding a few new tranformations
+ fixed some bugs in writer
+ interfaced with zlib 0.5
+ added K&R support
+ added check for 64 KB blocks for 16 bit machines
+
+version 0.4
+ cleaned up code and commented code
+ simplified time handling into png_time
+ created png_color_16 and png_color_8 to handle color needs
+ cleaned up color type defines
+ fixed various bugs
+ made various names more consistant
+ interfaced with zlib 0.71
+ cleaned up zTXt reader and writer (using zlib's Reset functions)
+ split transformations into pngrtran.c and pngwtran.c
+
+version 0.5
+ interfaced with zlib 0.8
+ fixed many reading and writing bugs
+ saved using 3 spaces instead of tabs
+
+version 0.6
+ added png_large_malloc() and png_large_free()
+ added png_size_t
+ cleaned up some compiler warnings
+ added png_start_read_image()
+
+version 0.7
+ cleaned up lots of bugs
+ finished dithering and other stuff
+ added test program
+ changed name from pnglib to libpng
+
+version 0.71 [June, 1995]
+ changed pngtest.png for zlib 0.93
+ fixed error in libpng.txt and example.c
+
+version 0.8
+ cleaned up some bugs
+ added png_set_filler()
+ split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
+ added #define's to remove unwanted code
+ moved png_info_init() to png.c
+ added old_size into png_realloc()
+ added functions to manually set filtering and compression info
+ changed compression parameters based on image type
+ optimized filter selection code
+ added version info
+ changed external functions passing floats to doubles (k&r problems?)
+ put all the configurable stuff in pngconf.h
+ enabled png_set_shift to work with paletted images on read
+ added png_read_update_info() - updates info structure with
+ transformations
+
+version 0.81 [August, 1995]
+ incorporated Tim Wegner's medium model code (thanks, Tim)
+
+version 0.82 [September, 1995]
+ [unspecified changes]
+
+version 0.85 [December, 1995]
+ added more medium model code (almost everything's a far)
+ added i/o, error, and memory callback functions
+ fixed some bugs (16 bit, 4 bit interlaced, etc.)
+ added first run progressive reader (barely tested)
+
+version 0.86 [January, 1996]
+ fixed bugs
+ improved documentation
+
+version 0.87 [January, 1996]
+ fixed medium model bugs
+ fixed other bugs introduced in 0.85 and 0.86
+ added some minor documentation
+
+version 0.88 [January, 1996]
+ fixed progressive bugs
+ replaced tabs with spaces
+ cleaned up documentation
+ added callbacks for read/write and warning/error functions
+
+version 0.89 [July, 1996]
+ added new initialization API to make libpng work better with shared libs
+ we now have png_create_read_struct(), png_create_write_struct(),
+ png_create_info_struct(), png_destroy_read_struct(), and
+ png_destroy_write_struct() instead of the separate calls to
+ malloc and png_read_init(), png_info_init(), and png_write_init()
+ changed warning/error callback functions to fix bug - this means you
+ should use the new initialization API if you were using the old
+ png_set_message_fn() calls, and that the old API no longer exists
+ so that people are aware that they need to change their code
+ changed filter selection API to allow selection of multiple filters
+ since it didn't work in previous versions of libpng anyways
+ optimized filter selection code
+ fixed png_set_background() to allow using an arbitrary RGB color for
+ paletted images
+ fixed gamma and background correction for paletted images, so
+ png_correct_palette is not needed unless you are correcting an
+ external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
+ in pngconf.h) - if nobody uses this, it may disappear in the future.
+ fixed bug with Borland 64K memory allocation (Alexander Lehmann)
+ fixed bug in interlace handling (Smarasderagd, I think)
+ added more error checking for writing and image to reduce invalid files
+ separated read and write functions so that they won't both be linked
+ into a binary when only reading or writing functionality is used
+ new pngtest image also has interlacing and zTXt
+ updated documentation to reflect new API
+
+version 0.90 [January, 1997]
+ made CRC errors/warnings on critical and ancillary chunks configurable
+ libpng will use the zlib CRC routines by (compile-time) default
+ changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
+ added external C++ wrapper statements to png.h (Gilles Dauphin)
+ allow PNG file to be read when some or all of file signature has already
+ been read from the beginning of the stream. ****This affects the size
+ of info_struct and invalidates all programs that use a shared libpng****
+ fixed png_filler() declarations
+ fixed? background color conversions
+ fixed order of error function pointers to match documentation
+ current chunk name is now available in png_struct to reduce the number
+ of nearly identical error messages (will simplify multi-lingual
+ support when available)
+ try to get ready for unknown-chunk callback functions:
+ - previously read critical chunks are flagged, so the chunk handling
+ routines can determine if the chunk is in the right place
+ - all chunk handling routines have the same prototypes, so we will
+ be able to handle all chunks via a callback mechanism
+ try to fix Linux "setjmp" buffer size problems
+ removed png_large_malloc, png_large_free, and png_realloc functions.
+
+version 0.95 [March, 1997]
+ fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
+ fixed bug in PNG file signature compares when start != 0
+ changed parameter type of png_set_filler(...filler...) from png_byte
+ to png_uint_32
+ added test for MACOS to ensure that both math.h and fp.h are not #included
+ added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
+ added "packswap" transformation, which changes the endianness of
+ packed-pixel bytes (Kevin Bracey)
+ added "strip_alpha" transformation, which removes the alpha channel of
+ input images without using it (not neccesarily a good idea)
+ added "swap_alpha" transformation, which puts the alpha channel in front
+ of the color bytes instead of after
+ removed all implicit variable tests which assume NULL == 0 (I think)
+ changed several variables to "png_size_t" to show 16/32-bit limitations
+ added new pCAL chunk read/write support
+ added experimental filter selection weighting (Greg Roelofs)
+ removed old png_set_rgbx() and png_set_xrgb() functions that have been
+ obsolete for about 2 years now (use png_set_filler() instead)
+ added macros to read 16- and 32-bit ints directly from buffer, to be
+ used only on those systems that support it (namely PowerPC and 680x0)
+ With some testing, this may become the default for MACOS/PPC systems.
+ only calculate CRC on data if we are going to use it
+ added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
+ added macros for simple libpng debugging output selectable at compile time
+ removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
+ more description of info_struct in libpng.txt and png.h
+ more instructions in example.c
+ more chunk types tested in pngtest.c
+ renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
+ png_set_<chunk>. We now have corresponding png_get_<chunk>
+ functions in pngget.c to get infomation in info_ptr. This isolates
+ the application from the internal organization of png_info_struct
+ (good for shared library implementations).
+
+version 0.96 [May, 1997]
+ fixed serious bug with < 8bpp images introduced in 0.95
+ fixed 256-color transparency bug (Greg Roelofs)
+ fixed up documentation (Greg Roelofs, Laszlo Nyul)
+ fixed "error" in pngconf.h for Linux setjmp() behaviour
+ fixed DOS medium model support (Tim Wegner)
+ fixed png_check_keyword() for case with error in static string text
+ added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
+ added typecasts to quiet compiler errors
+ added more debugging info
+
+version 0.97 [January, 1998]
+ removed PNG_USE_OWN_CRC capability
+ relocated png_set_crc_action from pngrutil.c to pngrtran.c
+ fixed typecasts of "new_key", etc. (Andreas Dilger)
+ added RFC 1152 [sic] date support
+ fixed bug in gamma handling of 4-bit grayscale
+ added 2-bit grayscale gamma handling (Glenn R-P)
+ added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
+ minor corrections in libpng.txt
+ added simple sRGB support (Glenn R-P)
+ easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
+ all configurable options can be selected from command-line instead
+ of having to edit pngconf.h (Glenn R-P)
+ fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
+ added more conditions for png_do_background, to avoid changing
+ black pixels to background when a background is supplied and
+ no pixels are transparent
+ repaired PNG_NO_STDIO behaviour
+ tested NODIV support and made it default behaviour (Greg Roelofs)
+ added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
+ regularized version numbering scheme and bumped shared-library major
+ version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)
+
+version 0.98 [January, 1998]
+ cleaned up some typos in libpng.txt and in code documentation
+ fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
+ cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
+ changed recommendation about file_gamma for PC images to .51 from .45,
+ in example.c and libpng.txt, added comments to distinguish between
+ screen_gamma, viewing_gamma, and display_gamma.
+ changed all references to RFC1152 to read RFC1123 and changed the
+ PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
+ added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
+ changed srgb_intent from png_byte to int to avoid compiler bugs
+
+version 0.99 [January 30, 1998]
+ free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
+ fixed a longstanding "packswap" bug in pngtrans.c
+ fixed some inconsistencies in pngconf.h that prevented compiling with
+ PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
+ fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
+ changed recommendation about file_gamma for PC images to .50 from .51 in
+ example.c and libpng.txt, and changed file_gamma for sRGB images to .45
+ added a number of functions to access information from the png structure
+ png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
+ added TARGET_MACOS similar to zlib-1.0.8
+ define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
+ added type casting to all png_malloc() function calls
+version 0.99a [January 31, 1998]
+ Added type casts and parentheses to all returns that return a value.(Tim W.)
+version 0.99b [February 4, 1998]
+ Added type cast png_uint_32 on malloc function calls where needed.
+ Changed type of num_hist from png_uint_32 to int (same as num_palette).
+ Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
+ Renamed makefile.elf to makefile.lnx.
+version 0.99c [February 7, 1998]
+ More type casting. Removed erroneous overflow test in pngmem.c.
+ Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
+ Added UNIX manual pages libpng.3 (incorporating libpng.txt) and png.5.
+version 0.99d [February 11, 1998]
+ Renamed "far_to_near()" "png_far_to_near()"
+ Revised libpng.3
+ Version 99c "buffered" operations didn't work as intended. Replaced them
+ with png_memcpy_check() and png_memset_check().
+ Added many "if (png_ptr == NULL) return" to quell compiler warnings about
+ unused png_ptr, mostly in pngget.c and pngset.c.
+ Check for overlength tRNS chunk present when indexed-color PLTE is read.
+ Cleaned up spelling errors in libpng.3/libpng.txt
+ Corrected a problem with png_get_tRNS() which returned undefined trans array
+version 0.99e [February 28, 1998]
+ Corrected png_get_tRNS() again.
+ Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
+ Touched up example.c to make more of it compileable, although the entire
+ file still can't be compiled (Willem van Schaik)
+ Fixed a bug in png_do_shift() (Bryan Tsai)
+ Added a space in png.h prototype for png_write_chunk_start()
+ Replaced pngtest.png with one created with zlib 1.1.1
+ Changed pngtest to report PASS even when file size is different (Jean-loup G.)
+ Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
+version 0.99f [March 5, 1998]
+ Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
+ Moved makefiles into a "scripts" directory, and added INSTALL instruction file
+ Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
+ Added pointers to "note on libpng versions" in makefile.lnx and README
+ Added row callback feature when reading and writing nonprogressive rows
+ and added a test of this feature in pngtest.c
+ Added user transform callbacks, with test of the feature in pngtest.c
+version 0.99g [March 6, 1998, morning]
+ Minor changes to pngtest.c to suppress compiler warnings.
+ Removed "beta" language from documentation.
+version 0.99h [March 6, 1998, evening]
+ Minor changes to previous minor changes to pngtest.c
+ Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
+ and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
+ Added user transform capability
+
+version 1.00 [March 7, 1998]
+ Changed several typedefs in pngrutil.c
+ Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
+ replaced "while(1)" with "for(;;)"
+ added PNGARG() to prototypes in pngtest.c and removed some prototypes
+ updated some of the makefiles (Tom Lane)
+ changed some typedefs (s_start, etc.) in pngrutil.c
+ fixed dimensions of "short_months" array in pngwrite.c
+ Replaced ansi2knr.c with the one from jpeg-v6
+
+version 1.0.0 [March 8, 1998]
+ Changed name from 1.00 to 1.0.0 (Adam Costello)
+ Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
+version 1.0.0a [March 9, 1998]
+ Fixed three bugs in pngrtran.c to make gamma+background handling consistent
+ (Greg Roelofs)
+ Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
+ for major, minor, and bugfix releases. This is 10001. (Adam Costello,
+ Tom Lane)
+ Make months range from 1-12 in png_convert_to_rfc1123
+version 1.0.0b [March 13, 1998]
+ Quieted compiler complaints about two empty "for" loops in pngrutil.c
+ Minor changes to makefile.s2x
+ Removed #ifdef/#endif around a png_free() in pngread.c
+
+version 1.0.1 [March 14, 1998]
+ Changed makefile.s2x to reduce security risk of using a relative pathname
+ Fixed some typos in the documentation (Greg).
+ Fixed a problem with value of "channels" returned by png_read_update_info()
+version 1.0.1a [April 21, 1998]
+ Optimized Paeth calculations by replacing abs() function calls with intrinsics
+ plus other loop optimizations. Improves avg decoding speed by about 20%.
+ Commented out i386istic "align" compiler flags in makefile.lnx.
+ Reduced the default warning level in some makefiles, to make them consistent.
+ Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
+ Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
+ Added grayscale and 16-bit capability to png_do_read_filler().
+ Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
+ too large when writing an image with bit_depth < 8 (Bob Dellaca).
+ Corrected some bugs in the experimental weighted filtering heuristics.
+ Moved a misplaced pngrutil code block that truncates tRNS if it has more
+ than num_palette entries -- test was done before num_palette was defined.
+ Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
+ Changed compiler flags in makefile.wat for better optimization (Pawel Mrochen).
+version 1.0.1b [May 2, 1998]
+ Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
+ Relocated the png_composite macros from pngrtran.c to png.h (Greg).
+ Added makefile.sco (contributed by Mike Hopkirk).
+ Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
+ Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
+ More work on the Paeth-filtering, achieving imperceptible speedup (A Kleinert).
+ More work on loop optimization which may help when compiled with C++ compilers.
+ Added warnings when people try to use transforms they've defined out.
+ Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
+ Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
+version 1.0.1c [May 11, 1998]
+ Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
+ filler bytes should have been 0xff instead of 0xf.
+ Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
+ Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
+ out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
+ Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
+ for consistency, in pngconf.h
+ Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
+ to remove unwanted capabilities via the compile line
+ Made some corrections to grammar (which, it's) in documentation (Greg).
+ Corrected example.c, use of row_pointers in png_write_image().
+version 1.0.1d [May 24, 1998]
+ Corrected several statements that used side effects illegally in pngrutil.c
+ and pngtrans.c, that were introduced in version 1.0.1b
+ Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
+ More corrections to example.c, use of row_pointers in png_write_image()
+ and png_read_rows().
+ Added pngdll.mak and pngdef.pas to scripts directory, contributed by
+ Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
+ Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
+ Changed several loops from count-down to count-up, for consistency.
+version 1.0.1e [June 6, 1998]
+ Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
+ added warnings when people try to set png_read_fn and png_write_fn in
+ the same structure.
+ Added a test such that png_do_gamma will be done when num_trans==0
+ for truecolor images that have defined a background. This corrects an
+ error that was introduced in libpng-0.90 that can cause gamma processing
+ to be skipped.
+ Added tests in png.h to include "trans" and "trans_values" in structures
+ when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
+ Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
+ Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
+ Added capability for user-provided malloc_fn() and free_fn() functions,
+ and revised pngtest.c to demonstrate their use, replacing the
+ PNGTEST_DEBUG_MEM feature.
+ Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
+
+version 1.0.2 [June 14, 1998]
+ Fixed two bugs in makefile.bor .
+version 1.0.2a [December 30, 1998]
+ Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
+ Fixed a bug in png_do_filler() that made it fail to write filler bytes in
+ the left-most pixel of each row (Kevin Bracey).
+ Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
+ in pngtest.c (Duncan Simpson).
+ Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
+ even when no tIME chunk was present in the source file.
+ Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
+ Fixed a problem in png_read_push_finish_row(), which would not skip some
+ passes that it should skip, for images that are less than 3 pixels high.
+ Interchanged the order of calls to png_do_swap() and png_do_shift()
+ in pngwtran.c (John Cromer).
+ Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
+ Changed "bad adaptive filter type" from error to warning in pngrutil.c .
+ Fixed a documentation error about default filtering with 8-bit indexed-color.
+ Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
+ (L. Peter Deutsch).
+ Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
+ Added png_get_copyright() and png_get_header_version() functions.
+ Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
+ Added information about debugging in libpng.txt and libpng.3 .
+ Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and makefile.sco.
+ Removed lines after Dynamic Dependencies" in makefile.aco .
+ Revised makefile.dec to make a shared library (Jeremie Petit).
+ Removed trailing blanks from all files.
+version 1.0.2a [January 6, 1999]
+ Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
+ Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
+ Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
+ Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
+ which is obsolete.
+
+version 1.0.3 [January 14, 1999]
+ Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
+ Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.
+version 1.0.3a [August 12, 1999]
+ Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
+ if an attempt is made to read an interlaced image when it's not supported.
+ Added check if png_ptr->trans is defined before freeing it in pngread.c
+ Modified the Y2K statement to include versions back to version 0.71
+ Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
+ Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
+ Replaced leading blanks with tab characters in makefile.hux
+ Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
+ Changed (float)red and (float)green to (double)red, (double)green
+ in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
+ Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
+ Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
+ Updated documentation to refer to the PNG-1.2 specification.
+ Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
+ in makefile.knr, INSTALL, and README (L. Peter Deutsch)
+ Fixed bugs in calculation of the length of rowbytes when adding alpha
+ channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
+ Added function png_set_user_transform_info() to store user_transform_ptr,
+ user_depth, and user_channels into the png_struct, and a function
+ png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
+ Added function png_set_empty_plte_permitted() to make libpng useable
+ in MNG applications.
+ Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
+ Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
+ consistent with PNG-1.2, and allow variance of 500 before complaining.
+ Added assembler code contributed by Intel in file pngvcrd.c and modified
+ makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation, Gilles Vollant)
+ Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
+ Added some aliases for png_set_expand() in pngrtran.c, namely
+ png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
+ (Greg Roelofs, in "PNG: The Definitive Guide").
+ Added makefile.beo for BEOS on X86, contributed by Sander Stok.
+version 1.0.3b [August 26, 1999]
+ Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
+ Changed leading blanks to tabs in all makefiles.
+ Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
+ Made alternate versions of png_set_expand() in pngrtran.c, namely
+ png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
+ (Greg Roelofs, in "PNG: The Definitive Guide"). Deleted the 1.0.3a aliases.
+ Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
+ Revised calculation of num_blocks in pngmem.c to avoid a potentially
+ negative shift distance, whose results are undefined in the C language.
+ Added a check in pngset.c to prevent writing multiple tIME chunks.
+ Added a check in pngwrite.c to detect invalid small window_bits sizes.
+version 1.0.3d [September 4, 1999]
+ Fixed type casting of igamma in pngrutil.c
+ Added new png_expand functions to scripts/pngdef.pas and pngos2.def
+ Added a demo read_user_transform_fn that examines the row filters in pngtest.c
+
+version 1.0.4 [September 24, 1999]
+ Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
+ Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
+ Made several minor corrections to pngtest.c
+ Renamed the makefiles with longer but more user friendly extensions.
+ Copied the PNG copyright and license to a separate LICENSE file.
+ Revised documentation, png.h, and example.c to remove reference to
+ "viewing_gamma" which no longer appears in the PNG specification.
+ Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
+ Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
+ Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
+ assembler code) and makefile.vcwin32 (doesn't).
+ Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
+ Added a copy of pngnow.png to the distribution.
+version 1.0.4a [September 25, 1999]
+ Increase max_pixel_depth in pngrutil.c if a user transform needs it.
+ Changed several division operations to right-shifts in pngvcrd.c
+version 1.0.4b [September 30, 1999]
+ Added parentheses in line 3732 of pngvcrd.c
+ Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
+version 1.0.4c [October 1, 1999]
+ Added a "png_check_version" function in png.c and pngtest.c that will generate
+ a helpful compiler error if an old png.h is found in the search path.
+ Changed type of png_user_transform_depth|channels from int to png_byte.
+version 1.0.4d [October 6, 1999]
+ Changed 0.45 to 0.45455 in png_set_sRGB()
+ Removed unused PLTE entries from pngnow.png
+ Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
+version 1.0.4e [October 10, 1999]
+ Fixed sign error in pngvcrd.c (Greg Roelofs)
+ Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
+version 1.0.4f [October 15, 1999]
+ Surrounded example.c code with #if 0 .. #endif to prevent people from
+ inadvertently trying to compile it.
+ Changed png_get_header_version() from a function to a macro in png.h
+ Added type casting mostly in pngrtran.c and pngwtran.c
+ Removed some pointless "ptr = NULL" in pngmem.c
+ Added a "contrib" directory containing the source code from Greg's book.
+
+version 1.0.5 [October 15, 1999]
+ Minor editing of the INSTALL and README files.
+version 1.0.5a [October 23, 1999]
+ Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
+ Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
+ Further optimization and bugfix of pngvcrd.c
+ Revised pngset.c so that it does not allocate or free memory in the user's
+ text_ptr structure. Instead, it makes its own copy.
+ Created separate write_end_info_struct in pngtest.c for a more severe test.
+ Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
+version 1.0.5b [November 23, 1999]
+ Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
+ PNG_FLAG_WROTE_tIME from flags to mode.
+ Added png_write_info_before_PLTE() function.
+ Fixed some typecasting in contrib/gregbook/*.c
+ Updated scripts/makevms.com and added makevms.com to contrib/gregbook
+ and contrib/pngminus (Martin Zinser)
+version 1.0.5c [November 26, 1999]
+ Moved png_get_header_version from png.h to png.c, to accomodate ansi2knr.
+ Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
+ accomodate making DLL's: Moved usr_png_ver from global variable to function
+ png_get_header_ver() in png.c. Moved png_sig to png_sig_bytes in png.c and
+ eliminated use of png_sig in pngwutil.c. Moved the various png_CHNK arrays
+ into pngtypes.h. Eliminated use of global png_pass arrays. Declared the
+ png_CHNK and png_pass arrays to be "const". Made the global arrays
+ available to applications (although none are used in libpng itself) when
+ PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
+ Removed some extraneous "-I" from contrib/pngminus/makefile.std
+ Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
+ Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
+version 1.0.5d [November 29, 1999]
+ Add type cast (png_const_charp) two places in png.c
+ Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
+ Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
+ to applications a macro "PNG_USE_LOCAL_ARRAYS".
+ #ifdef out all the new declarations when PNG_USE_GLOBAL_ARRAYS is defined.
+ Added PNG_EXPORT_VAR macro to accommodate making DLL's.
+version 1.0.5e [November 30, 1999]
+ Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
+ structure; refactored the inflate/deflate support to make adding new chunks
+ with trailing compressed parts easier in the future, and added new functions
+ png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
+ png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
+ NOTE: Applications that write text chunks MUST define png_text->lang
+ before calling png_set_text(). It must be set to NULL if you want to
+ write tEXt or zTXt chunks. If you want your application to be able to
+ run with older versions of libpng, use
+
+ #ifdef PNG_iTXt_SUPPORTED
+ png_text[i].lang = NULL;
+ #endif
+
+ Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
+ offsets (Eric S. Raymond).
+ Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
+ PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
+ macros, leaving the separate macros also available.
+ Removed comments on #endifs at the end of many short, non-nested #if-blocks.
+version 1.0.5f [December 6, 1999]
+ Changed makefile.solaris to issue a warning about potential problems when
+ the ucb "ld" is in the path ahead of the ccs "ld".
+ Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
+ Added sCAL chunk support (Eric S. Raymond).
+version 1.0.5g [December 7, 1999]
+ Fixed "png_free_spallettes" typo in png.h
+ Added code to handle new chunks in pngpread.c
+ Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
+ Added "translated_key" to png_text structure and png_write_iTXt().
+ Added code in pngwrite.c to work around a newly discovered zlib bug.
+version 1.0.5h [December 10, 1999]
+ NOTE: regarding the note for version 1.0.5e, the following must also
+ be included in your code:
+ png_text[i].translated_key = NULL;
+ Unknown chunk handling is now supported.
+ Option to eliminate all floating point support was added. Some new
+ fixed-point functions such as png_set_gAMA_fixed() were added.
+ Expanded tabs and removed trailing blanks in source files.
+version 1.0.5i [December 13, 1999]
+ Added some type casts to silence compiler warnings.
+ Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
+ Removed leading blanks from a #define in pngvcrd.c
+ Added some parameters to the new png_set_keep_unknown_chunks() function.
+ Added a test for up->location != 0 in the first instance of writing
+ unknown chunks in pngwrite.c
+ Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
+ prevent recursion.
+ Added png_free_hIST() function.
+ Various patches to fix bugs in the sCAL and integer cHRM processing,
+ and to add some convenience macros for use with sCAL.
+version 1.0.5j [December 21, 1999]
+ Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
+ around buggy compilers.
+ Added new type "png_fixed_point" for integers that hold float*100000 values
+ Restored backward compatibility of tEXt/zTXt chunk processing:
+ Restored the first four members of png_text to the same order as v.1.0.5d.
+ Added members "lang_key" and "itxt_length" to png_text struct. Set
+ text_length=0 when "text" contains iTXt data. Use the "compression"
+ member to distinguish among tEXt/zTXt/iTXt types. Added
+ PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
+ The "Note" above, about backward incompatibility of libpng-1.0.5e, no
+ longer applies.
+ Fixed png_read|write_iTXt() to read|write parameters in the right order,
+ and to write the iTXt chunk after IDAT if it appears in the end_ptr.
+ Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
+ Reversed the order of trying to write floating-point and fixed-point gAMA.
+version 1.0.5k [December 27, 1999]
+ Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
+ Added png_handle_as_unknown() function (Glenn)
+ Added png_free_chunk_list() function and chunk_list and num_chunk_list members
+ of png_ptr.
+ Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
+ Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
+ about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
+ Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
+ Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
+ Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
+version 1.0.5l [January 1, 2000]
+ Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
+ for setting a callback function to handle unknown chunks and for
+ retrieving the associated user pointer (Glenn).
+version 1.0.5m [January 7, 2000]
+ Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
+version 1.0.5n [January 9, 2000]
+ Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
+ own memory for info_ptr->palette. This makes it safe for the calling
+ application to free its copy of the palette any time after it calls
+ png_set_PLTE().
+version 1.0.5o [January 20, 2000]
+ Cosmetic changes only (removed some trailing blanks and TABs)
+version 1.0.5p [January 31, 2000]
+ Renamed pngdll.mak to makefile.bd32
+ Cosmetic changes in pngtest.c
+version 1.0.5q [February 5, 2000]
+ Relocated the makefile.solaris warning about PATH problems.
+ Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
+ Revised makefile.gcmmx
+ Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
+version 1.0.5r [February 7, 2000]
+ Removed superfluous prototype for png_get_itxt from png.h
+ Fixed a bug in pngrtran.c that improperly expanded the background color.
+ Return *num_text=0 from png_get_text() when appropriate, and fix documentation
+ of png_get_text() in libpng.txt/libpng.3.
+version 1.0.5s [February 18, 2000]
+ Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
+ new error handler that's planned for the next libpng release, and changed
+ example.c, pngtest.c, and contrib programs to use this macro.
+ Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
+ Fixed a bug in png_read_png() that caused it to fail to expand some images
+ that it should have expanded.
+ Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
+ in pngget.c
+ Changed the allocation of palette, history, and trans arrays back to
+ the version 1.0.5 method (linking instead of copying) which restores
+ backward compatibility with version 1.0.5. Added some remarks about
+ that in example.c. Added "free_me" member to info_ptr and png_ptr
+ and added png_free_data() function.
+ Updated makefile.linux and makefile.gccmmx to make directories conditionally.
+ Made cosmetic changes to pngasmrd.h
+ Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
+ Modified png_read_png() to allocate info_ptr->row_pointers only if it
+ hasn't already been allocated.
+version 1.0.5t [March 4, 2000]
+ Changed png_jmp_env() migration aiding macro to png_jmpbuf().
+ Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
+ Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
+ PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
+ Files in contrib/gregbook were revised to use png_jmpbuf() and to select
+ a 24-bit visual if one is available, and to allow abbreviated options.
+ Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
+ Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
+version 1.0.5u [March 5, 2000]
+ Simplified the code that detects old png.h in png.c and pngtest.c
+ Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
+ Increased precision of rgb_to_gray calculations from 8 to 15 bits and
+ added png_set_rgb_to_gray_fixed() function.
+ Added makefile.bc32 (32-bit Borland C++, C mode)
+version 1.0.5v [March 11, 2000]
+ Added some parentheses to the png_jmpbuf macro definition.
+ Updated references to the zlib home page, which has moved to freesoftware.com.
+ Corrected bugs in documentation regarding png_read_row() and png_write_row().
+ Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
+ Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
+ revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
+
+version 1.0.6 [March 20, 2000]
+ Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
+ Added makefile.sggcc (SGI IRIX with gcc)
+version 1.0.6d [April 7, 2000]
+ Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
+ Added data_length parameter to png_decompress_chunk() function
+ Revised documentation to remove reference to abandoned png_free_chnk functions
+ Fixed an error in png_rgb_to_gray_fixed()
+ Revised example.c, usage of png_destroy_write_struct().
+ Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
+ Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c
+ Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
+version 1.0.6e [April 9, 2000]
+ Added png_data_freer() function.
+ In the code that checks for over-length tRNS chunks, added check of
+ info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
+ Minor revisions of libpng.txt/libpng.3.
+ Check for existing data and free it if the free_me flag is set, in png_set_*()
+ and png_handle_*().
+ Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED
+ is defined.
+ Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
+ and mentioned the purposes of the two macros in libpng.txt/libpng.3.
+version 1.0.6f [April 14, 2000]
+ Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data.
+ Add checks in png_set_text() for NULL members of the input text structure.
+ Revised libpng.txt/libpng.3.
+ Removed superfluous prototype for png_set_itxt from png.h
+ Removed "else" from pngread.c, after png_error(), and changed "0" to "length".
+ Changed several png_errors about malformed ancillary chunks to png_warnings.
+version 1.0.6g [April 24, 2000]
+ Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined.
+ Relocated paragraph about png_set_background() in libpng.3/libpng.txt
+ and other revisions (Matthias Benckmann)
+ Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and
+ png_ptr members to restore binary compatibility with libpng-1.0.5
+ (breaks compatibility with libpng-1.0.6).
+version 1.0.6h [April 24, 2000]
+ Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds
+ libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h)
+ This is a temporary change for test purposes.
+version 1.0.6i [May 2, 2000]
+ Rearranged some members at the end of png_info and png_struct, to put
+ unknown_chunks_num and free_me within the original size of the png_structs
+ and free_me, png_read_user_fn, and png_free_fn within the original png_info,
+ because some old applications allocate the structs directly instead of
+ using png_create_*().
+ Added documentation of user memory functions in libpng.txt/libpng.3
+ Modified png_read_png so that it will use user_allocated row_pointers
+ if present, unless free_me directs that it be freed, and added description
+ of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3.
+ Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version
+ 1.00) members of png_struct and png_info, to regain binary compatibility
+ when you define this macro. Capabilities lost in this event
+ are user transforms (new in version 1.0.0),the user transform pointer
+ (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT,
+ the high-level interface, and unknown chunks support (all new in 1.0.6).
+ This was necessary because of old applications that allocate the structs
+ directly as authors were instructed to do in libpng-0.88 and earlier,
+ instead of using png_create_*().
+ Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which
+ can be used to detect codes that directly allocate the structs, and
+ code to check these modes in png_read_init() and png_write_init() and
+ generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED
+ was not defined.
+ Added makefile.intel and updated makefile.watcom (Pawel Mrochen)
+version 1.0.6j [May 3, 2000]
+ Overloaded png_read_init() and png_write_init() with macros that convert
+ calls to png_read_init_2() or png_write_init_2() that check the version
+ and structure sizes.
+version 1.0.7beta11 [May 7, 2000]
+ Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
+ which are no longer used.
+ Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
+ defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXT_SUPPORTED
+ is defined.
+ Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
+ overrun when old applications fill the info_ptr->text structure directly.
+ Added PNGAPI macro, and added it to the definitions of all exported functions.
+ Relocated version macro definitions ahead of the includes of zlib.h and
+ pngconf.h in png.h.
+version 1.0.7beta12 [May 12, 2000]
+ Revised pngset.c to avoid a problem with expanding the png_debug macro.
+ Deleted some extraneous defines from pngconf.h
+ Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
+ Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined.
+ Added png_access_version_number() function.
+ Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
+ Expanded libpng.3/libpng.txt information about png_data_freer().
+version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
+ Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
+ warnings instead of errors, as pngrutil.c does.
+ Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png()
+ will actually write IDATs.
+ Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32.
+ Make png_free_data() ignore its final parameter except when freeing data
+ that can have multiple instances (text, sPLT, unknowns).
+ Fixed a new bug in png_set_rows().
+ Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5.
+ Added png_set_invalid() function.
+ Fixed incorrect illustrations of png_destroy_write_struct() in example.c.
+version 1.0.7beta15 [May 30, 2000]
+ Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce
+ fewer error messages.
+ Rearranged checks for Z_OK to check the most likely path first in pngpread.c
+ and pngwutil.c.
+ Added checks in pngtest.c for png_create_*() returning NULL, and mentioned
+ in libpng.txt/libpng.3 the need for applications to check this.
+ Changed names of png_default_*() functions in pngtest to pngtest_*().
+ Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32.
+ Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c
+ Set each pointer to NULL after freeing it in png_free_data().
+ Worked around a problem in pngconf.h; AIX's strings.h defines an "index"
+ macro that conflicts with libpng's png_color_16.index. (Dimitri Papadapoulos)
+ Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux).
+version 1.0.7beta16 [June 4, 2000]
+ Revised the workaround of AIX string.h "index" bug.
+ Added a check for overlength PLTE chunk in pngrutil.c.
+ Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer
+ indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler.
+ Added a warning in png_decompress_chunk() when it runs out of data, e.g.
+ when it tries to read an erroneous PhotoShop iCCP chunk.
+ Added PNG_USE_DLL macro.
+ Revised the copyright/disclaimer/license notice.
+ Added contrib/msvctest directory
+version 1.0.7rc1 [June 9, 2000]
+ Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA (0x0400 not 0x0200)
+ Added contrib/visupng directory (Willem van Schaik)
+version 1.0.7beta18 [June 23, 2000]
+ Revised PNGAPI definition, and pngvcrd.c to work with __GCC__
+ and do not redefine PNGAPI if it is passed in via a compiler directive.
+ Revised visupng/PngFile.c to remove returns from within the Try block.
+ Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros.
+ Updated contrib/visupng/cexcept.h to version 1.0.0.
+ Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks.
+version 1.0.7rc2 [June 28, 2000]
+ Updated license to include disclaimers required by UCITA.
+ Fixed "DJBPP" typo in pnggccrd.c introduced in beta18.
+
+version 1.0.7 [July 1, 2000]
+ Revised the definition of "trans_values" in libpng.3/libpng.txt
+version 1.0.8beta1 [July 8, 2000]
+ Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
+ Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
+ pngwutil.c.
+ Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
+ Removed unused "#include <assert.h>" from png.c
+ Added WindowsCE support.
+ Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment.
+version 1.0.8beta2 [July 10, 2000]
+ Added project files to the wince directory and made further revisions
+ of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
+version 1.0.8beta3 [July 11, 2000]
+ Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
+ for indexed-color input files to avoid potential double-freeing trans array
+ under some unusual conditions; problem was introduced in version 1.0.6f.
+ Further revisions to pngtest.c and files in the wince subdirectory.
+version 1.0.8beta4 [July 14, 2000]
+ Added the files pngbar.png and pngbar.jpg to the distribution.
+ Added makefile.cygwin, and cygwin support in pngconf.h
+ Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)
+version 1.0.8rc1 [July 16, 2000]
+ Revised png_debug() macros and statements to eliminate compiler warnings.
+
+version 1.0.8 [July 24, 2000]
+ Added png_flush() in pngwrite.c, after png_write_IEND().
+ Updated makefile.hpux to build a shared library.
+version 1.0.9beta1 [November 10, 2000]
+ Fixed typo in scripts/makefile.hpux
+ Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
+ Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
+ Changed "cdrom.com" in documentation to "libpng.org"
+ Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
+ Changed type of "params" from voidp to png_voidp in png_read|write_png().
+ Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h.
+ Revised the 3 instances of WRITEFILE in pngtest.c.
+ Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory.
+ Updated png.rc in dll/msvc project
+ Revised makefile.dec to define and use LIBPATH and INCPATH
+ Increased size of global png_libpng_ver[] array from 12 to 18 chars.
+ Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const.
+ Removed duplicate png_crc_finish() from png_handle_bKGD() function.
+ Added a warning when application calls png_read_update_info() multiple times.
+ Revised makefile.cygwin
+ Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
+ Replaced png_set_empty_plte_permitted() with png_permit_mng_features().
+version 1.0.9beta2 [November 19, 2000]
+ Renamed the "dll" subdirectory "projects".
+ Added borland project files to "projects" subdirectory.
+ Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
+ Add error message in png_set_compression_buffer_size() when malloc fails.
+version 1.0.9beta3 [November 23, 2000]
+ Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
+ Removed the png_flush() in pngwrite.c that crashes some applications
+ that don't set png_output_flush_fn.
+ Added makefile.macosx and makefile.aix to scripts directory.
+version 1.0.9beta4 [December 1, 2000]
+ Change png_chunk_warning to png_warning in png_check_keyword().
+ Increased the first part of msg buffer from 16 to 18 in png_chunk_error().
+version 1.0.9beta5 [December 15, 2000]
+ Added support for filter method 64 (for PNG datastreams embedded in MNG).
+version 1.0.9beta6 [December 18, 2000]
+ Revised png_set_filter() to accept filter method 64 when appropriate.
+ Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
+ help prevent applications from using MNG features in PNG datastreams.
+ Added png_permit_mng_features() function.
+ Revised libpng.3/libpng.txt. Changed "filter type" to "filter method".
+version 1.0.9rc1 [December 23, 2000]
+ Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c
+ Fixed error handling of unknown compression type in png_decompress_chunk().
+ In pngconf.h, define __cdecl when _MSC_VER is defined.
+version 1.0.9beta7 [December 28, 2000]
+ Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
+ Revised memory management in png_set_hIST and png_handle_hIST in a backward
+ compatible manner. PLTE and tRNS were revised similarly.
+ Revised the iCCP chunk reader to ignore trailing garbage.
+version 1.0.9beta8 [January 12, 2001]
+ Moved pngasmrd.h into pngconf.h.
+ Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.
+version 1.0.9beta9 [January 15, 2001]
+ Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to
+ wince and msvc project module definition files.
+ Minor revision of makefile.cygwin.
+ Fixed bug with progressive reading of narrow interlaced images in pngpread.c
+version 1.0.9beta10 [January 16, 2001]
+ Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined.
+ Fixed "png_mmx_supported" typo in project definition files.
+version 1.0.9beta11 [January 19, 2001]
+ Updated makefile.sgi to make shared library.
+ Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED
+ by default, for the benefit of DLL forward compatibility. These will
+ be re-enabled in version 1.2.0.
+version 1.0.9rc2 [January 22, 2001]
+ Revised cygwin support.
+
+version 1.0.9 [January 31, 2001]
+ Added check of cygwin's ALL_STATIC in pngconf.h
+ Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
+version 1.0.10beta1 [March 14, 2001]
+ Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
+ Reformatted libpng.3 to eliminate bad line breaks.
+ Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
+ Added prototype for png_mmx_support() near the top of pnggccrd.c
+ Moved some error checking from png_handle_IHDR to png_set_IHDR.
+ Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
+ Revised png_mmx_support() function in pnggccrd.c
+ Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
+ Fixed memory leak in contrib/visupng/PngFile.c
+ Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
+ Added warnings when retrieving or setting gamma=0.
+ Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().
+version 1.0.10rc1 [March 23, 2001]
+ Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy,
+ and png_strlen.
+ Revised png_mmx_supported() function in pnggccrd.c to return proper value.
+ Fixed bug in progressive reading (pngpread.c) with small images (height < 8).
+
+version 1.0.10 [March 30, 2001]
+ Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
+ Added beos project files (Chris Herborth)
+version 1.0.11beta1 [April 3, 2001]
+ Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
+ Removed a no-longer needed AIX work-around from pngconf.h
+ Changed several "//" single-line comments to C-style in pnggccrd.c
+version 1.0.11beta2 [April 11, 2001]
+ Removed PNGAPI from several functions whose prototypes did not have PNGAPI.
+ Updated scripts/pngos2.def
+version 1.0.11beta3 [April 14, 2001]
+ Added checking the results of many instances of png_malloc() for NULL
+version 1.0.11beta4 [April 20, 2001]
+ Undid the changes from version 1.0.11beta3. Added a check for NULL return
+ from user's malloc_fn().
+ Removed some useless type casts of the NULL pointer.
+ Added makefile.netbsd
+
+version 1.0.11 [April 27, 2001]
+ Revised makefile.netbsd
+version 1.0.12beta1 [May 14, 2001]
+ Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot)
+ Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h
+ Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings.
+ Eliminated the png_error about apps using png_read|write_init(). Instead,
+ libpng will reallocate the png_struct and info_struct if they are too small.
+ This retains future binary compatibility for old applications written for
+ libpng-0.88 and earlier.
+version 1.2.0beta1 [May 6, 2001]
+ Bumped DLLNUM to 2.
+ Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED
+ by default.
+ Added runtime selection of MMX features.
+ Added png_set_strip_error_numbers function and related macros.
+version 1.2.0beta2 [May 7, 2001]
+ Finished merging 1.2.0beta1 with version 1.0.11
+ Added a check for attempts to read or write PLTE in grayscale PNG datastreams.
+version 1.2.0beta3 [May 17, 2001]
+ Enabled user memory function by default.
+ Modified png_create_struct so it passes user mem_ptr to user memory allocator.
+ Increased png_mng_features flag from png_byte to png_uint_32.
+ Bumped shared-library (so-number) and dll-number to 3.
+version 1.2.0beta4 [June 23, 2001]
+ Check for missing profile length field in iCCP chunk and free chunk_data
+ in case of truncated iCCP chunk.
+ Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc
+ Bumped dll-number from 2 to 3 in makefile.cygwin
+ Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly
+ if user attempts to run it on an 8-bit display.
+ Updated contrib/gregbook
+ Use png_malloc instead of png_zalloc to allocate palette in pngset.c
+ Updated makefile.ibmc
+ Added some typecasts to eliminate gcc 3.0 warnings. Changed prototypes
+ of png_write_oFFS width and height from png_uint_32 to png_int_32.
+ Updated example.c
+ Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c
+version 1.2.0beta5 [August 8, 2001]
+ Revised contrib/gregbook
+ Revised makefile.gcmmx
+ Revised pnggccrd.c to conditionally compile some thread-unsafe code only
+ when PNG_THREAD_UNSAFE_OK is defined.
+ Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with
+ value exceeding 2^bit_depth-1
+ Revised makefile.sgi and makefile.sggcc
+ Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c
+ Removed restriction that do_invert_mono only operate on 1-bit opaque files
+
+version 1.2.0 [September 1, 2001]
+ Changed a png_warning() to png_debug() in pnggccrd.c
+ Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC().
+version 1.2.1beta1 [October 19, 2001]
+ Revised makefile.std in contrib/pngminus
+ Include background_1 in png_struct regardless of gamma support.
+ Revised makefile.netbsd and makefile.macosx, added makefile.darwin.
+ Revised example.c to provide more details about using row_callback().
+version 1.2.1beta2 [October 25, 2001]
+ Added type cast to each NULL appearing in a function call, except for
+ WINCE functions.
+ Added makefile.so9.
+version 1.2.1beta3 [October 27, 2001]
+ Removed type casts from all NULLs.
+ Simplified png_create_struct_2().
+version 1.2.1beta4 [November 7, 2001]
+ Revised png_create_info_struct() and png_creat_struct_2().
+ Added error message if png_write_info() was omitted.
+ Type cast NULLs appearing in function calls when _NO_PROTO or
+ PNG_TYPECAST_NULL is defined.
+version 1.2.1rc1 [November 24, 2001]
+ Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL
+ is defined.
+ Changed typecast of "size" argument to png_size_t in pngmem.c calls to
+ the user malloc_fn, to agree with the prototype in png.h
+ Added a pop/push operation to pnggccrd.c, to preserve Eflag (Maxim Sobolev)
+ Updated makefile.sgi to recognize LIBPATH and INCPATH.
+ Updated various makefiles so "make clean" does not remove previous major
+ version of the shared library.
+version 1.2.1rc2 [December 4, 2001]
+ Always allocate 256-entry internal palette, hist, and trans arrays, to
+ avoid out-of-bounds memory reference caused by invalid PNG datastreams.
+ Added a check for prefix_length > data_length in iCCP chunk handler.
+
+version 1.2.1 [December 7, 2001]
+ None.
+version 1.2.2beta1 [February 22, 2002]
+ Fixed a bug with reading the length of iCCP profiles (Larry Reeves).
+ Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate
+ libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h
+ Revised makefile.darwin to remove "-undefined suppress" option.
+ Added checks for gamma and chromaticity values over 21474.83, which exceed
+ the limit for PNG unsigned 32-bit integers when encoded.
+ Revised calls to png_create_read_struct() and png_create_write_struct()
+ for simpler debugging.
+ Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK)
+version 1.2.2beta2 [February 23, 2002]
+ Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths.
+ Check for invalid image dimensions in png_get_IHDR.
+ Added missing "fi;" in the install target of the SGI makefiles.
+ Added install-static to all makefiles that make shared libraries.
+ Always do gamma compensation when image is partially transparent.
+version 1.2.2beta3 [March 7, 2002]
+ Compute background.gray and background_1.gray even when color_type is RGB
+ in case image gets reduced to gray later.
+ Modified shared-library makefiles to install pkgconfig/libpngNN.pc.
+ Export (with PNGAPI) png_zalloc, png_zfree, and png_handle_as_unknown
+ Removed unused png_write_destroy_info prototype from png.h
+ Eliminated incorrect use of width_mmx from pnggccrd.c in pixel_bytes == 8 case
+ Added install-shared target to all makefiles that make shared libraries.
+ Stopped a double free of palette, hist, and trans when not using free_me.
+ Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64.
+version 1.2.2beta4 [March 8, 2002]
+ Compute background.gray and background_1.gray even when color_type is RGB
+ in case image gets reduced to gray later (Jason Summers).
+ Relocated a misplaced /bin/rm in the "install-shared" makefile targets
+ Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library.
+version 1.2.2beta5 [March 26, 2002]
+ Added missing PNGAPI to several function definitions.
+ Check for invalid bit_depth or color_type in png_get_IHDR(), and
+ check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen).
+ Revised iTXt support to accept NULL for lang and lang_key.
+ Compute gamma for color components of background even when color_type is gray.
+ Changed "()" to "{}" in scripts/libpng.pc.in.
+ Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN
+ Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so
+version 1.2.2beta6 [March 31, 2002]
+version 1.0.13beta1 [March 31, 2002]
+ Prevent png_zalloc() from trying to memset memory that it failed to acquire.
+ Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate).
+ Ensure that the right function (user or default) is used to free the
+ png_struct after an error in png_create_read_struct_2().
+version 1.2.2rc1 [April 7, 2002]
+version 1.0.13rc1 [April 7, 2002]
+ Save the ebx register in pnggccrd.c (Sami Farin)
+ Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner).
+ Updated makefiles to put headers in include/libpng and remove old include/*.h.
+
+version 1.2.2 [April 15, 2002]
+version 1.0.13 [April 15, 2002]
+ Revised description of png_set_filter() in libpng.3/libpng.txt.
+ Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd
+version 1.0.13patch01 [April 17, 2002]
+version 1.2.2patch01 [April 17, 2002]
+ Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and makefile.sggcc
+ Fixed VER -> PNGVER typo in makefile.macosx and added install-static to install
+ Added install: target to makefile.32sunu and makefile.64sunu
+version 1.0.13patch03 [April 18, 2002]
+version 1.2.2patch03 [April 18, 2002]
+ Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng
+ subdirectory to libpngNN subdirectory without the full pathname.
+ Moved generation of libpng.pc from "install" to "all" in 15 makefiles.
+version 1.2.3rc1 [April 28, 2002]
+ Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos).
+ Added $(DESTDIR) feature to 24 makefiles (Tim Mooney)
+ Fixed bug with $prefix, should be $(prefix) in makefile.hpux.
+ Updated cygwin-specific portion of pngconf.h and revised makefile.cygwin
+ Added a link from libpngNN.pc to libpng.pc in 15 makefiles.
+ Added links from include/libpngNN/*.h to include/*.h in 24 makefiles.
+ Revised makefile.darwin to make relative links without full pathname.
+ Added setjmp() at the end of png_create_*_struct_2() in case user forgets
+ to put one in their application.
+ Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and
+ removed them from module definition files.
+version 1.2.3rc2 [May 1, 2002]
+ Fixed bug in reporting number of channels in pngget.c and pngset.c,
+ that was introduced in version 1.2.2beta5.
+ Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(),
+ png_default_flush(), and png_push_fill_buffer() and included them in
+ module definition files.
+ Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles.
+version 1.2.3rc3 [May 1, 2002]
+ Revised prototype for png_default_flush()
+ Remove old libpng.pc and libpngNN.pc before installing new ones.
+version 1.2.3rc4 [May 2, 2002]
+ Typos in *.def files (png_default_read|write -> png_default_read|write_data)
+ In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc
+ Added libpng-config and libpngNN-config and modified makefiles to install them.
+ Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles
+ Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp
+version 1.2.3rc5 [May 11, 2002]
+ Changed "error" and "message" in prototypes to "error_message" and
+ "warning_message" to avoid namespace conflict.
+ Revised 15 makefiles to build libpng-config from libpng-config-*.in
+ Once more restored png_zalloc and png_zfree to regular nonexported form.
+ Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer
+ to nonexported form, but with PNGAPI, and removed them from module def files.
+version 1.2.3rc6 [May 14, 2002]
+ Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c
+ Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp.
+ Removed leftover libpng-config "sed" script from four makefiles.
+ Revised libpng-config creating script in 16 makefiles.
+
+version 1.2.3 [May 22, 2002]
+ Revised libpng-config target in makefile.cygwin.
+ Removed description of png_set_mem_fn() from documentation.
+ Revised makefile.freebsd.
+ Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR).
+ Revised projects/msvc/README.txt
+ Changed -lpng to -lpngNN in LDFLAGS in several makefiles.
+version 1.2.4beta1 [May 24, 2002]
+ Added libpng.pc and libpng-config to "all:" target in 16 makefiles.
+ Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH)
+ Added missing "\" before closing double quote in makefile.gcmmx.
+ Plugged various memory leaks; added png_malloc_warn() and png_set_text_2()
+ functions.
+version 1.2.4beta2 [June 25, 2002]
+ Plugged memory leak of png_ptr->current_text (Matt Holgate).
+ Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison)
+ Added -soname to the loader flags in makefile.dec, makefile.sgi, and
+ makefile.sggcc.
+ Added "test-installed" target to makefile.linux, makefile.gcmmx,
+ makefile.sgi, and makefile.sggcc.
+version 1.2.4beta3 [June 28, 2002]
+ Plugged memory leak of row_buf in pngtest.c when there is a png_error().
+ Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data.
+ Added "test-installed" target to makefile.32sunu, makefile.64sunu,
+ makefile.beos, makefile.darwin, makefile.dec, makefile.macosx,
+ makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9.
+version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002]
+ Added "test-installed" target to makefile.cygwin and makefile.sco.
+ Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro.
+
+version 1.2.4 and 1.0.14 [July 8, 2002]
+ Changed png_warning() to png_error() when width is too large to process.
+version 1.2.4patch01 [July 20, 2002]
+ Revised makefile.cygwin to use DLL number 12 instead of 13.
+version 1.2.5beta1 [August 6, 2002]
+ Added code to contrib/gregbook/readpng2.c to ignore unused chunks.
+ Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11)
+ Removed some stray *.o files from contrib/gregbook.
+ Changed png_error() to png_warning() about "Too much data" in pngpread.c
+ and about "Extra compressed data" in pngrutil.c.
+ Prevent png_ptr->pass from exceeding 7 in png_push_finish_row().
+ Updated makefile.hpgcc
+ Updated png.c and pnggccrd.c handling of return from png_mmx_support()
+version 1.2.5beta2 [August 15, 2002]
+ Only issue png_warning() about "Too much data" in pngpread.c when avail_in
+ is nonzero.
+ Updated makefiles to install a separate libpng.so.3 with its own rpath.
+version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002]
+ Revised makefiles to not remove previous minor versions of shared libraries.
+version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002]
+ Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared
+ library loader directive.
+ Added missing "$OBJSDLL" line to makefile.gcmmx.
+ Added missing "; fi" to makefile.32sunu.
+version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002]
+ Revised libpng-config script.
+
+version 1.2.5 and 1.0.15 [October 3, 2002]
+ Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux,
+ and makefile.aix.
+ Relocated two misplaced PNGAPI lines in pngtest.c
+version 1.2.6beta1 [October 22, 2002]
+ Commented out warning about uninitialized mmx_support in pnggccrd.c.
+ Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h.
+ Relocated two more misplaced PNGAPI lines in pngtest.c
+ Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams,
+ introduced in version 1.0.2.
+ Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu.
+version 1.2.6beta2 [November 1, 2002]
+ Added libpng-config "--ldopts" output.
+ Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)"
+ in makefiles.
+version 1.2.6beta3 [July 18, 2004]
+ Reverted makefile changes from version 1.2.6beta2 and some of the changes
+ from version 1.2.6beta1; these will be postponed until version 1.2.7.
+ Version 1.2.6 is going to be a simple bugfix release.
+ Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile.
+ Fixed potential overrun in pngerror.c by using strncpy instead of memcpy.
+ Added "#!/bin/sh" at the top of configure, for recognition of the
+ 'x' flag under Cygwin (Cosmin).
+ Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin).
+ Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin).
+ Fixed the special memory handler for Borland C under DOS, in pngmem.c
+ (Cosmin).
+ Removed some spurious assignments in pngrutil.c (Cosmin).
+ Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings
+ on 16-bit platforms (Cosmin).
+ Enclosed shift op expressions in parentheses, to silence warnings (Cosmin).
+ Used proper type png_fixed_point, to avoid problems on 16-bit platforms,
+ in png_handle_sRGB() (Cosmin).
+ Added compression_type to png_struct, and optimized the window size
+ inside the deflate stream (Cosmin).
+ Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin).
+ Fixed handling of unknown chunks that come after IDAT (Cosmin).
+ Allowed png_error() and png_warning() to work even if png_ptr == NULL
+ (Cosmin).
+ Replaced row_info->rowbytes with row_bytes in png_write_find_filter()
+ (Cosmin).
+ Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre).
+ Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded
+ values in png.c (Simon-Pierre, Cosmin).
+ Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre).
+ Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc
+ (Simon-Pierre).
+ Moved the definition of PNG_HEADER_VERSION_STRING near the definitions
+ of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin).
+ Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin).
+ Updated scripts/makefile.vc(a)win32 (Cosmin).
+ Updated the MSVC project (Simon-Pierre, Cosmin).
+ Updated the Borland C++ Builder project (Cosmin).
+ Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin).
+ Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin).
+ Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin).
+ Added extra guard around inclusion of Turbo C memory headers, in pngconf.h
+ (Cosmin).
+ Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to
+ projects/cbuilder5/ (Cosmin).
+ Moved projects/visualc6/png32ms.def to scripts/pngw32.def,
+ and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin).
+ Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin).
+ Changed line endings to DOS style in cbuilder5 and visualc6 files, even
+ in the tar.* distributions (Cosmin).
+ Updated contrib/visupng/VisualPng.dsp (Cosmin).
+ Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin).
+ Added a separate distribution with "configure" and supporting files (Junichi).
+version 1.2.6beta4 [July 28, 2004]
+ Added user ability to change png_size_t via a PNG_SIZE_T macro.
+ Added png_sizeof() and png_convert_size() functions.
+ Added PNG_SIZE_MAX (maximum value of a png_size_t variable.
+ Added check in png_malloc_default() for (size_t)size != (png_uint_32)size
+ which would indicate an overflow.
+ Changed sPLT failure action from png_error to png_warning and abandon chunk.
+ Changed sCAL and iCCP failures from png_error to png_warning and abandon.
+ Added png_get_uint_31(png_ptr, buf) function.
+ Added PNG_UINT_32_MAX macro.
+ Renamed PNG_MAX_UINT to PNG_UINT_31_MAX.
+ Made png_zalloc() issue a png_warning and return NULL on potential
+ overflow.
+ Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x
+ Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4.
+ Revised Borland portion of png_malloc() to return NULL or issue
+ png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK.
+ Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove
+ sequential read support.
+ Added some "#if PNG_WRITE_SUPPORTED" blocks.
+ #ifdef'ed out some redundancy in png_malloc_default().
+ Use png_malloc instead of png_zalloc to allocate the pallete.
+version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
+ Fixed buffer overflow vulnerability in png_handle_tRNS()
+ Fixed integer arithmetic overflow vulnerability in png_read_png().
+ Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
+ duplicate chunk types to go undetected.
+ Fixed some timestamps in the -config version
+ Rearranged order of processing of color types in png_handle_tRNS().
+ Added ROWBYTES macro to calculate rowbytes without integer overflow.
+ Updated makefile.darwin and removed makefile.macosx from scripts directory.
+ Imposed default one million column, one-million row limits on the image
+ dimensions, and added png_set_user_limits() function to override them.
+ Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro.
+ Fixed wrong cast of returns from png_get_user_width|height_max().
+ Changed some "keep the compiler happy" from empty statements to returns,
+ Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution
+version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
+ Revised makefile.darwin and makefile.solaris. Removed makefile.macosx.
+ Revised pngtest's png_debug_malloc() to use png_malloc() instead of
+ png_malloc_default() which is not supposed to be exported.
+ Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in
+ pngpread.c. Bug was introduced in 1.2.6rc1.
+ Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1.
+ Fixed old bug in RGB to Gray transformation.
+ Fixed problem with 64-bit compilers by casting arguments to abs()
+ to png_int_32.
+ Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9).
+ Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin)
+ Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles.
+ Added code to update the row_info->colortype in png_do_read_filler() (MSB).
+version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004]
+ Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid
+ trouble with some 64-bit compilers. Created PNG_OUT_OF_RANGE() macro.
+ Revised documentation of png_set_keep_unknown_chunks().
+ Check handle_as_unknown status in pngpread.c, as in pngread.c previously.
+ Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h
+ Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c
+version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]
+ Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of
+ "pinfo" was out of place).
+version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
+ Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
+ section of png.h where they were inadvertently placed in version rc3.
+
+version 1.0.16 and 1.2.6 [August 15, 2004]
+ Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
+version 1.2.7beta1 [August 26, 2004]
+ Removed unused pngasmrd.h file.
+ Removed references to uu.net for archived files. Added references to
+ PNG Spec (second edition) and the PNG ISO/IEC Standard.
+ Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR.
+ Fixed bug with "optimized window size" in the IDAT datastream, that
+ causes libpng to write PNG files with incorrect zlib header bytes.
+version 1.2.7beta2 [August 28, 2004]
+ Fixed bug with sCAL chunk and big-endian machines (David Munro).
+ Undid new code added in 1.2.6rc2 to update the color_type in
+ png_set_filler().
+ Added png_set_add_alpha() that updates color type.
+version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004]
+ Revised png_set_strip_filler() to not remove alpha if color_type has alpha.
+version 1.0.17 and 1.2.7 [September 12, 2004]
+ Added makefile.hp64
+ Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin
+version 1.2.8beta1 [November 1, 2004]
+ Fixed bug in png_text_compress() that would fail to complete a large block.
+ Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during
+ strip alpha operation in png_do_strip_filler().
+ Added PNG_1_2_X definition in pngconf.h
+ #ifdef out png_info_init in png.c and png_read_init in pngread.c (as of 1.3.0)
+version 1.2.8beta2 [November 2, 2004]
+ Reduce color_type to a nonalpha type after strip alpha operation in
+ png_do_strip_filler().
+version 1.2.8beta3 [November 3, 2004]
+ Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM
+version 1.2.8beta4 [November 12, 2004]
+ Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin).
+ Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin).
+ Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection
+ of data type in deflate (Cosmin).
+ Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of
+ PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
+version 1.2.8beta5 [November 20, 2004]
+ Use png_ptr->flags instead of png_ptr->transformations to pass
+ PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI
+ compatibility.
+ Revised handling of SPECIALBUILD, PRIVATEBUILD,
+ PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
+version 1.2.8rc1 [November 24, 2004]
+ Moved handling of BUILD macros from pngconf.h to png.h
+ Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently
+ omitted from beta5.
+ Revised scripts/pngw32.rc
+ Despammed mailing addresses by masking "@" with "at".
+ Inadvertently installed a supposedly faster test version of pngrutil.c
+version 1.2.8rc2 [November 26, 2004]
+ Added two missing "\" in png.h
+ Change tests in pngread.c and pngpread.c to
+ if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
+ png_do_read_transformations(png_ptr);
+version 1.2.8rc3 [November 28, 2004]
+ Reverted pngrutil.c to version libpng-1.2.8beta5.
+ Added scripts/makefile.elf with supporting code in pngconf.h for symbol
+ versioning (John Bowler).
+version 1.2.8rc4 [November 29, 2004]
+ Added projects/visualc7 (Simon-pierre).
+version 1.2.8rc5 [November 29, 2004]
+ Fixed new typo in scripts/pngw32.rc
+version 1.2.8 [December 3, 2004]
+ Removed projects/visualc7, added projects/visualc71.
+
+Send comments/corrections/commendations to
+png-implement at ccrc.wustl.edu (subscription required; write to
+majordomo at ccrc.wustl.edu with "subscribe png-implement" in the message)
+or to glennrp at users.sourceforge.net
+
+Glenn R-P
diff --git a/com32/lib/libpng/KNOWNBUG b/com32/lib/libpng/KNOWNBUG
new file mode 100644
index 00000000..620296f6
--- /dev/null
+++ b/com32/lib/libpng/KNOWNBUG
@@ -0,0 +1,11 @@
+
+Known bugs in libpng version 1.2.8
+
+1. April 22, 2001: pnggccrd.c has been reported to crash on NetBSD when
+ reading interlaced PNG files, when assembler code is enabled but running
+ on a non-MMX i386 platform.
+
+ STATUS: Under investigation. The change to pnggccrd.c in libpng-1.2.1
+ fixed a problem under FreeBSD but not the problem with NetBSD, which
+ still fails as of libpng-1.2.2rc1.
+
diff --git a/com32/lib/libpng/LICENSE b/com32/lib/libpng/LICENSE
new file mode 100644
index 00000000..7ef36674
--- /dev/null
+++ b/com32/lib/libpng/LICENSE
@@ -0,0 +1,113 @@
+
+This copy of the libpng notices is provided for your convenience. In case of
+any discrepancy between this copy and the notices in the file png.h that is
+included in the libpng distribution, the latter shall prevail.
+
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+
+If you modify libpng you may insert additional notices immediately following
+this sentence.
+
+*** This version of libpng has been slightly modified to fit into the
+ libcom32 framework. In particular, it uses the libcom32 Makefile
+ system instead of its own.
+
+libpng version 1.2.6, December 3, 2004, is
+Copyright (c) 2004 Glenn Randers-Pehrson, and is
+distributed according to the same disclaimer and license as libpng-1.2.5
+with the following individual added to the list of Contributing Authors
+
+ Cosmin Truta
+
+libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
+Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.0.6
+with the following individuals added to the list of Contributing Authors
+
+ Simon-Pierre Cadieux
+ Eric S. Raymond
+ Gilles Vollant
+
+and with the following additions to the disclaimer:
+
+ There is no warranty against interference with your enjoyment of the
+ library or against infringement. There is no warranty that our
+ efforts or the library will fulfill any of your particular purposes
+ or needs. This library is provided with all faults, and the entire
+ risk of satisfactory quality, performance, accuracy, and effort is with
+ the user.
+
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-0.96,
+with the following individuals added to the list of Contributing Authors:
+
+ Tom Lane
+ Glenn Randers-Pehrson
+ Willem van Schaik
+
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996, 1997 Andreas Dilger
+Distributed according to the same disclaimer and license as libpng-0.88,
+with the following individuals added to the list of Contributing Authors:
+
+ John Bowler
+ Kevin Bracey
+ Sam Bushell
+ Magnus Holmgren
+ Greg Roelofs
+ Tom Tanner
+
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+
+ Andreas Dilger
+ Dave Martindale
+ Guy Eric Schalnat
+ Paul Schmidt
+ Tim Wegner
+
+The PNG Reference Library is supplied "AS IS". The Contributing Authors
+and Group 42, Inc. disclaim all warranties, expressed or implied,
+including, without limitation, the warranties of merchantability and of
+fitness for any purpose. The Contributing Authors and Group 42, Inc.
+assume no liability for direct, indirect, incidental, special, exemplary,
+or consequential damages, which may result from the use of the PNG
+Reference Library, even if advised of the possibility of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+
+1. The origin of this source code must not be misrepresented.
+
+2. Altered versions must be plainly marked as such and must not
+ be misrepresented as being the original source.
+
+3. This Copyright notice may not be removed or altered from any
+ source or altered source distribution.
+
+The Contributing Authors and Group 42, Inc. specifically permit, without
+fee, and encourage the use of this source code as a component to
+supporting the PNG file format in commercial products. If you use this
+source code in a product, acknowledgment is not required but would be
+appreciated.
+
+
+A "png_get_copyright" function is available, for convenient use in "about"
+boxes and the like:
+
+ printf("%s",png_get_copyright(NULL));
+
+Also, the PNG logo (in PNG format, of course) is supplied in the
+files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+
+Libpng is OSI Certified Open Source Software. OSI Certified Open Source is a
+certification mark of the Open Source Initiative.
+
+Glenn Randers-Pehrson
+glennrp at users.sourceforge.net
+December 3, 2004
diff --git a/com32/lib/libpng/README b/com32/lib/libpng/README
new file mode 100644
index 00000000..06f9fe4d
--- /dev/null
+++ b/com32/lib/libpng/README
@@ -0,0 +1,262 @@
+README for libpng version 1.2.8 - December 3, 2004 (shared library 12.0)
+See the note about version numbers near the top of png.h
+
+See INSTALL for instructions on how to install libpng.
+
+Libpng comes in several distribution formats. Get libpng-*.tar.gz
+or libpng-*.tar.bz2 if you want UNIX-style line endings in the text
+files, or lpng*.zip if you want DOS-style line endings.
+
+Version 0.89 was the first official release of libpng. Don't let the
+fact that it's the first release fool you. The libpng library has been in
+extensive use and testing since mid-1995. By late 1997 it had
+finally gotten to the stage where there hadn't been significant
+changes to the API in some time, and people have a bad feeling about
+libraries with versions < 1.0. Version 1.0.0 was released in
+March 1998.
+
+****
+Note that some of the changes to the png_info structure render this
+version of the library binary incompatible with libpng-0.89 or
+earlier versions if you are using a shared library. The type of the
+"filler" parameter for png_set_filler() has changed from png_byte to
+png_uint_32, which will affect shared-library applications that use
+this function.
+
+To avoid problems with changes to the internals of png_info_struct,
+new APIs have been made available in 0.95 to avoid direct application
+access to info_ptr. These functions are the png_set_<chunk> and
+png_get_<chunk> functions. These functions should be used when
+accessing/storing the info_struct data, rather than manipulating it
+directly, to avoid such problems in the future.
+
+It is important to note that the APIs do not make current programs
+that access the info struct directly incompatible with the new
+library. However, it is strongly suggested that new programs use
+the new APIs (as shown in example.c and pngtest.c), and older programs
+be converted to the new format, to facilitate upgrades in the future.
+****
+
+Additions since 0.90 include the ability to compile libpng as a
+Windows DLL, and new APIs for accessing data in the info struct.
+Experimental functions include the ability to set weighting and cost
+factors for row filter selection, direct reads of integers from buffers
+on big-endian processors that support misaligned data access, faster
+methods of doing alpha composition, and more accurate 16->8 bit color
+conversion.
+
+The additions since 0.89 include the ability to read from a PNG stream
+which has had some (or all) of the signature bytes read by the calling
+application. This also allows the reading of embedded PNG streams that
+do not have the PNG file signature. As well, it is now possible to set
+the library action on the detection of chunk CRC errors. It is possible
+to set different actions based on whether the CRC error occurred in a
+critical or an ancillary chunk.
+
+The changes made to the library, and bugs fixed are based on discussions
+on the PNG-implement mailing list
+and not on material submitted privately to Guy, Andreas, or Glenn. They will
+forward any good suggestions to the list.
+
+For a detailed description on using libpng, read libpng.txt. For
+examples of libpng in a program, see example.c and pngtest.c. For usage
+information and restrictions (what little they are) on libpng, see
+png.h. For a description on using zlib (the compression library used by
+libpng) and zlib's restrictions, see zlib.h
+
+I have included a general makefile, as well as several machine and
+compiler specific ones, but you may have to modify one for your own needs.
+
+You should use zlib 1.0.4 or later to run this, but it MAY work with
+versions as old as zlib 0.95. Even so, there are bugs in older zlib
+versions which can cause the output of invalid compression streams for
+some images. You will definitely need zlib 1.0.4 or later if you are
+taking advantage of the MS-DOS "far" structure allocation for the small
+and medium memory models. You should also note that zlib is a
+compression library that is useful for more things than just PNG files.
+You can use zlib as a drop-in replacement for fread() and fwrite() if
+you are so inclined.
+
+zlib should be available at the same place that libpng is, or at.
+ftp://ftp.info-zip.org/pub/infozip/zlib
+
+You may also want a copy of the PNG specification. It is available
+as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find
+these at http://www.libpng.org/pub/png/documents/
+
+This code is currently being archived at libpng.sf.net in the
+[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT)
+at GO GRAPHSUP. If you can't find it in any of those places,
+e-mail me, and I'll help you find it.
+
+If you have any code changes, requests, problems, etc., please e-mail
+them to me. Also, I'd appreciate any make files or project files,
+and any modifications you needed to make to get libpng to compile,
+along with a #define variable to tell what compiler/system you are on.
+If you needed to add transformations to libpng, or wish libpng would
+provide the image in a different way, drop me a note (and code, if
+possible), so I can consider supporting the transformation.
+Finally, if you get any warning messages when compiling libpng
+(note: not zlib), and they are easy to fix, I'd appreciate the
+fix. Please mention "libpng" somewhere in the subject line. Thanks.
+
+This release was created and will be supported by myself (of course
+based in a large way on Guy's and Andreas' earlier work), and the PNG group.
+
+glennrp at users.sourceforge.net
+png-implement at ccrc.wustl.edu (subscription required; write to
+majordomo at ccrc.wustl.edu with "subscribe png-implement" in the message).
+
+You can't reach Guy, the original libpng author, at the addresses
+given in previous versions of this document. He and Andreas will read mail
+addressed to the png-implement list, however.
+
+Please do not send general questions about PNG. Send them to
+the (png-list at ccrc.wustl.edu, subscription required, write to
+majordomo at ccrc.wustl.edu with "subscribe png-list" in your message).
+On the other hand,
+please do not send libpng questions to that address, send them to me
+or to the png-implement list. I'll
+get them in the end anyway. If you have a question about something
+in the PNG specification that is related to using libpng, send it
+to me. Send me any questions that start with "I was using libpng,
+and ...". If in doubt, send questions to me. I'll bounce them
+to others, if necessary.
+
+Please do not send suggestions on how to change PNG. We have
+been discussing PNG for nine years now, and it is official and
+finished. If you have suggestions for libpng, however, I'll
+gladly listen. Even if your suggestion is not used immediately,
+it may be used later.
+
+Files in this distribution:
+
+ ANNOUNCE => Announcement of this version, with recent changes
+ CHANGES => Description of changes between libpng versions
+ KNOWNBUG => List of known bugs and deficiencies
+ LICENSE => License to use and redistribute libpng
+ README => This file
+ TODO => Things not implemented in the current library
+ Y2KINFO => Statement of Y2K compliance
+ example.c => Example code for using libpng functions
+ libpng.3 => manual page for libpng (includes libpng.txt)
+ libpng.txt => Description of libpng and its functions
+ libpngpf.3 => manual page for libpng's private functions
+ png.5 => manual page for the PNG format
+ png.c => Basic interface functions common to library
+ png.h => Library function and interface declarations
+ pngconf.h => System specific library configuration
+ pngasmrd.h => Header file for assembler-coded functions
+ pngerror.c => Error/warning message I/O functions
+ pngget.c => Functions for retrieving info from struct
+ pngmem.c => Memory handling functions
+ pngbar.png => PNG logo, 88x31
+ pngnow.png => PNG logo, 98x31
+ pngpread.c => Progressive reading functions
+ pngread.c => Read data/helper high-level functions
+ pngrio.c => Lowest-level data read I/O functions
+ pngrtran.c => Read data transformation functions
+ pngrutil.c => Read data utility functions
+ pngset.c => Functions for storing data into the info_struct
+ pngtest.c => Library test program
+ pngtest.png => Library test sample image
+ pngtrans.c => Common data transformation functions
+ pngwio.c => Lowest-level write I/O functions
+ pngwrite.c => High-level write functions
+ pngwtran.c => Write data transformations
+ pngwutil.c => Write utility functions
+ contrib => Contributions
+ gregbook => source code for PNG reading and writing, from
+ Greg Roelofs' "PNG: The Definitive Guide",
+ O'Reilly, 1999
+ msvctest => Builds and runs pngtest using a MSVC workspace
+ pngminus => Simple pnm2png and png2pnm programs
+ pngsuite => Test images
+ visupng => Contains a MSVC workspace for VisualPng
+ projects => Contains project files and workspaces for building DLL
+ beos => Contains a Beos workspace for building libpng
+ c5builder => Contains a Borland workspace for building libpng
+ and zlib
+ visualc6 => Contains a Microsoft Visual C++ (MSVC) workspace
+ for building libpng and zlib
+ netware.txt => Contains instructions for downloading a set of
+ project files for building libpng and zlib on
+ Netware.
+ wince.txt => Contains instructions for downloading a Microsoft
+ Visual C++ (Windows CD Toolkit) workspace for
+ building libpng and zlib on WindowsCE
+ scripts => Directory containing scripts for building libpng:
+ descrip.mms => VMS makefile for MMS or MMK
+ makefile.std => Generic UNIX makefile (cc, creates static libpng.a)
+ makefile.elf => Linux/ELF makefile symbol versioning,
+ gcc, creates libpng12.so.0.1.2.8)
+ makefile.linux => Linux/ELF makefile
+ (gcc, creates libpng12.so.0.1.2.8)
+ makefile.gcmmx => Linux/ELF makefile
+ (gcc, creates libpng12.so.0.1.2.8,
+ uses assembler code tuned for Intel MMX platform)
+ makefile.gcc => Generic makefile (gcc, creates static libpng.a)
+ makefile.knr => Archaic UNIX Makefile that converts files with
+ ansi2knr (Requires ansi2knr.c from
+ ftp://ftp.cs.wisc.edu/ghost)
+ makefile.aix => AIX makefile
+ makefile.cygwin => Cygwin/gcc makefile
+ makefile.darwin => Darwin makefile
+ makefile.dec => DEC Alpha UNIX makefile
+ makefile.freebsd => FreeBSD makefile
+ makefile.hpgcc => HPUX makefile using gcc
+ makefile.hpux => HPUX (10.20 and 11.00) makefile
+ makefile.hp64 => HPUX (10.20 and 11.00) makefile, 64 bit
+ makefile.ibmc => IBM C/C++ version 3.x for Win32 and OS/2 (static)
+ makefile.intel => Intel C/C++ version 4.0 and later
+ libpng.icc => Project file, IBM VisualAge/C++ 4.0 or later
+ makefile.netbsd => NetBSD/cc makefile, PNGGCCRD, makes libpng.so.
+ makefile.ne12bsd => NetBSD/cc makefile, PNGGCCRD, makes libpng12.so
+ makefile.openbsd => OpenBSD makefile
+ makefile.sgi => Silicon Graphics IRIX (cc, creates static lib)
+ makefile.sggcc => Silicon Graphics
+ (gcc, creates libpng12.so.0.1.2.8)
+ makefile.sunos => Sun makefile
+ makefile.solaris => Solaris 2.X makefile
+ (gcc, creates libpng12.so.0.1.2.8)
+ makefile.so9 => Solaris 9 makefile
+ (gcc, creates libpng12.so.0.1.2.8)
+ makefile.32sunu => Sun Ultra 32-bit makefile
+ makefile.64sunu => Sun Ultra 64-bit makefile
+ makefile.sco => For SCO OSr5 ELF and Unixware 7 with Native cc
+ makefile.mips => MIPS makefile
+ makefile.acorn => Acorn makefile
+ makefile.amiga => Amiga makefile
+ smakefile.ppc => AMIGA smakefile for SAS C V6.58/7.00 PPC
+ compiler (Requires SCOPTIONS, copied from
+ scripts/SCOPTIONS.ppc)
+ makefile.atari => Atari makefile
+ makefile.beos => BEOS makefile for X86
+ makefile.bor => Borland makefile (uses bcc)
+ makefile.bc32 => 32-bit Borland C++ (all modules compiled in C mode)
+ makefile.tc3 => Turbo C 3.0 makefile
+ makefile.dj2 => DJGPP 2 makefile
+ makefile.msc => Microsoft C makefile
+ makefile.vcawin32=> makefile for Microsoft Visual C++ 5.0 and
+ later (uses assembler code tuned for Intel MMX
+ platform)
+ makefile.vcwin32 => makefile for Microsoft Visual C++ 4.0 and
+ later (does not use assembler code)
+ makefile.os2 => OS/2 Makefile (gcc and emx, requires pngos2.def)
+ pngos2.def => OS/2 module definition file used by makefile.os2
+ makefile.watcom => Watcom 10a+ Makefile, 32-bit flat memory model
+ makevms.com => VMS build script
+ SCOPTIONS.ppc => Used with smakefile.ppc
+
+Good luck, and happy coding.
+
+-Glenn Randers-Pehrson (current maintainer)
+ Internet: glennrp at users.sourceforge.net
+
+-Andreas Eric Dilger (former maintainer, 1996-1997)
+ Internet: adilger at enel.ucalgary.ca
+ Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
+
+-Guy Eric Schalnat (original author and former maintainer, 1995-1996)
+ (formerly of Group 42, Inc)
+ Internet: gschal at infinet.com
diff --git a/com32/lib/libpng/TODO b/com32/lib/libpng/TODO
new file mode 100644
index 00000000..a5f63957
--- /dev/null
+++ b/com32/lib/libpng/TODO
@@ -0,0 +1,24 @@
+TODO - list of things to do for libpng:
+
+Final bug fixes.
+Improve API by hiding the png_struct and png_info structs.
+Finish work on the no-floating-point version (including gamma compensation)
+Better C++ wrapper/full C++ implementation?
+Fix problem with C++ and EXTERN "C".
+cHRM transformation.
+Improve setjmp/longjmp usage or remove it in favor of returning error codes.
+Add "grayscale->palette" transformation and "palette->grayscale" detection.
+Improved dithering.
+Multi-lingual error and warning message support.
+Complete sRGB transformation (presently it simply uses gamma=0.45455).
+Man pages for function calls.
+Better documentation.
+Better filter selection
+ (counting huffman bits/precompression? filter inertia? filter costs?).
+Histogram creation.
+Text conversion between different code pages (Latin-1 -> Mac and DOS).
+Should we always malloc 2^bit_depth PLTE/tRNS/hIST entries for safety?
+Build gamma tables using fixed point (and do away with floating point entirely).
+Use greater precision when changing to linear gamma for compositing against
+ background and doing rgb-to-gray transformation.
+Investigate pre-incremented loop counters and other loop constructions.
diff --git a/com32/lib/libpng/Y2KINFO b/com32/lib/libpng/Y2KINFO
new file mode 100644
index 00000000..4db294fb
--- /dev/null
+++ b/com32/lib/libpng/Y2KINFO
@@ -0,0 +1,55 @@
+ Y2K compliance in libpng:
+ =========================
+
+ December 3, 2004
+
+ Since the PNG Development group is an ad-hoc body, we can't make
+ an official declaration.
+
+ This is your unofficial assurance that libpng from version 0.71 and
+ upward through 1.2.8 are Y2K compliant. It is my belief that earlier
+ versions were also Y2K compliant.
+
+ Libpng only has three year fields. One is a 2-byte unsigned integer
+ that will hold years up to 65535. The other two hold the date in text
+ format, and will hold years up to 9999.
+
+ The integer is
+ "png_uint_16 year" in png_time_struct.
+
+ The strings are
+ "png_charp time_buffer" in png_struct and
+ "near_time_buffer", which is a local character string in png.c.
+
+ There are seven time-related functions:
+
+ png_convert_to_rfc_1123() in png.c
+ (formerly png_convert_to_rfc_1152() in error)
+ png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+ png_convert_from_time_t() in pngwrite.c
+ png_get_tIME() in pngget.c
+ png_handle_tIME() in pngrutil.c, called in pngread.c
+ png_set_tIME() in pngset.c
+ png_write_tIME() in pngwutil.c, called in pngwrite.c
+
+ All appear to handle dates properly in a Y2K environment. The
+ png_convert_from_time_t() function calls gmtime() to convert from system
+ clock time, which returns (year - 1900), which we properly convert to
+ the full 4-digit year. There is a possibility that applications using
+ libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+ function, or that they are incorrectly passing only a 2-digit year
+ instead of "year - 1900" into the png_convert_from_struct_tm() function,
+ but this is not under our control. The libpng documentation has always
+ stated that it works with 4-digit years, and the APIs have been
+ documented as such.
+
+ The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
+ integer to hold the year, and can hold years as large as 65535.
+
+ zlib, upon which libpng depends, is also Y2K compliant. It contains
+ no date-related code.
+
+
+ Glenn Randers-Pehrson
+ libpng maintainer
+ PNG Development Group
diff --git a/com32/lib/libpng/example.c b/com32/lib/libpng/example.c
new file mode 100644
index 00000000..ba0ecc5b
--- /dev/null
+++ b/com32/lib/libpng/example.c
@@ -0,0 +1,808 @@
+
+#if 0 /* in case someone actually tries to compile this */
+
+/* example.c - an example of using libpng */
+
+/* This is an example of how to use libpng to read and write PNG files.
+ * The file libpng.txt is much more verbose then this. If you have not
+ * read it, do so first. This was designed to be a starting point of an
+ * implementation. This is not officially part of libpng, is hereby placed
+ * in the public domain, and therefore does not require a copyright notice.
+ *
+ * This file does not currently compile, because it is missing certain
+ * parts, like allocating memory to hold an image. You will have to
+ * supply these parts to get it to compile. For an example of a minimal
+ * working PNG reader/writer, see pngtest.c, included in this distribution;
+ * see also the programs in the contrib directory.
+ */
+
+#include "png.h"
+
+ /* The png_jmpbuf() macro, used in error handling, became available in
+ * libpng version 1.0.6. If you want to be able to run your code with older
+ * versions of libpng, you must define the macro yourself (but only if it
+ * is not already defined by libpng!).
+ */
+
+#ifndef png_jmpbuf
+# define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+
+/* Check to see if a file is a PNG file using png_sig_cmp(). png_sig_cmp()
+ * returns zero if the image is a PNG and nonzero if it isn't a PNG.
+ *
+ * The function check_if_png() shown here, but not used, returns nonzero (true)
+ * if the file can be opened and is a PNG, 0 (false) otherwise.
+ *
+ * If this call is successful, and you are going to keep the file open,
+ * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once
+ * you have created the png_ptr, so that libpng knows your application
+ * has read that many bytes from the start of the file. Make sure you
+ * don't call png_set_sig_bytes() with more than 8 bytes read or give it
+ * an incorrect number of bytes read, or you will either have read too
+ * many bytes (your fault), or you are telling libpng to read the wrong
+ * number of magic bytes (also your fault).
+ *
+ * Many applications already read the first 2 or 4 bytes from the start
+ * of the image to determine the file type, so it would be easiest just
+ * to pass the bytes to png_sig_cmp() or even skip that if you know
+ * you have a PNG file, and call png_set_sig_bytes().
+ */
+#define PNG_BYTES_TO_CHECK 4
+int check_if_png(char *file_name, FILE **fp)
+{
+ char buf[PNG_BYTES_TO_CHECK];
+
+ /* Open the prospective PNG file. */
+ if ((*fp = fopen(file_name, "rb")) == NULL)
+ return 0;
+
+ /* Read in some of the signature bytes */
+ if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK)
+ return 0;
+
+ /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature.
+ Return nonzero (true) if they match */
+
+ return(!png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
+}
+
+/* Read a PNG file. You may want to return an error code if the read
+ * fails (depending upon the failure). There are two "prototypes" given
+ * here - one where we are given the filename, and we need to open the
+ * file, and the other where we are given an open file (possibly with
+ * some or all of the magic bytes read - see comments above).
+ */
+#ifdef open_file /* prototype 1 */
+void read_png(char *file_name) /* We need to open the file */
+{
+ png_structp png_ptr;
+ png_infop info_ptr;
+ unsigned int sig_read = 0;
+ png_uint_32 width, height;
+ int bit_depth, color_type, interlace_type;
+ FILE *fp;
+
+ if ((fp = fopen(file_name, "rb")) == NULL)
+ return (ERROR);
+#else no_open_file /* prototype 2 */
+void read_png(FILE *fp, unsigned int sig_read) /* file is already open */
+{
+ png_structp png_ptr;
+ png_infop info_ptr;
+ png_uint_32 width, height;
+ int bit_depth, color_type, interlace_type;
+#endif no_open_file /* only use one prototype! */
+
+ /* Create and initialize the png_struct with the desired error handler
+ * functions. If you want to use the default stderr and longjump method,
+ * you can supply NULL for the last three parameters. We also supply the
+ * the compiler header file version, so that we know if the application
+ * was compiled with a compatible version of the library. REQUIRED
+ */
+ png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
+ png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+
+ if (png_ptr == NULL)
+ {
+ fclose(fp);
+ return (ERROR);
+ }
+
+ /* Allocate/initialize the memory for image information. REQUIRED. */
+ info_ptr = png_create_info_struct(png_ptr);
+ if (info_ptr == NULL)
+ {
+ fclose(fp);
+ png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
+ return (ERROR);
+ }
+
+ /* Set error handling if you are using the setjmp/longjmp method (this is
+ * the normal method of doing things with libpng). REQUIRED unless you
+ * set up your own error handlers in the png_create_read_struct() earlier.
+ */
+
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ /* Free all of the memory associated with the png_ptr and info_ptr */
+ png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
+ fclose(fp);
+ /* If we get here, we had a problem reading the file */
+ return (ERROR);
+ }
+
+ /* One of the following I/O initialization methods is REQUIRED */
+#ifdef streams /* PNG file I/O method 1 */
+ /* Set up the input control if you are using standard C streams */
+ png_init_io(png_ptr, fp);
+
+#else no_streams /* PNG file I/O method 2 */
+ /* If you are using replacement read functions, instead of calling
+ * png_init_io() here you would call:
+ */
+ png_set_read_fn(png_ptr, (void *)user_io_ptr, user_read_fn);
+ /* where user_io_ptr is a structure you want available to the callbacks */
+#endif no_streams /* Use only one I/O method! */
+
+ /* If we have already read some of the signature */
+ png_set_sig_bytes(png_ptr, sig_read);
+
+#ifdef hilevel
+ /*
+ * If you have enough memory to read in the entire image at once,
+ * and you need to specify only transforms that can be controlled
+ * with one of the PNG_TRANSFORM_* bits (this presently excludes
+ * dithering, filling, setting background, and doing gamma
+ * adjustment), then you can read the entire image (including
+ * pixels) into the info structure with this call:
+ */
+ png_read_png(png_ptr, info_ptr, png_transforms, png_voidp_NULL);
+#else
+ /* OK, you're doing it the hard way, with the lower-level functions */
+
+ /* The call to png_read_info() gives us all of the information from the
+ * PNG file before the first IDAT (image data chunk). REQUIRED
+ */
+ png_read_info(png_ptr, info_ptr);
+
+ png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+ &interlace_type, int_p_NULL, int_p_NULL);
+
+/* Set up the data transformations you want. Note that these are all
+ * optional. Only call them if you want/need them. Many of the
+ * transformations only work on specific types of images, and many
+ * are mutually exclusive.
+ */
+
+ /* tell libpng to strip 16 bit/color files down to 8 bits/color */
+ png_set_strip_16(png_ptr);
+
+ /* Strip alpha bytes from the input data without combining with the
+ * background (not recommended).
+ */
+ png_set_strip_alpha(png_ptr);
+
+ /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
+ * byte into separate bytes (useful for paletted and grayscale images).
+ */
+ png_set_packing(png_ptr);
+
+ /* Change the order of packed pixels to least significant bit first
+ * (not useful if you are using png_set_packing). */
+ png_set_packswap(png_ptr);
+
+ /* Expand paletted colors into true RGB triplets */
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ png_set_palette_rgb(png_ptr);
+
+ /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */
+ if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+ png_set_gray_1_2_4_to_8(png_ptr);
+
+ /* Expand paletted or RGB images with transparency to full alpha channels
+ * so the data will be available as RGBA quartets.
+ */
+ if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+ png_set_tRNS_to_alpha(png_ptr);
+
+ /* Set the background color to draw transparent and alpha images over.
+ * It is possible to set the red, green, and blue components directly
+ * for paletted images instead of supplying a palette index. Note that
+ * even if the PNG file supplies a background, you are not required to
+ * use it - you should use the (solid) application background if it has one.
+ */
+
+ png_color_16 my_background, *image_background;
+
+ if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+ png_set_background(png_ptr, image_background,
+ PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+ else
+ png_set_background(png_ptr, &my_background,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+
+ /* Some suggestions as to how to get a screen gamma value */
+
+ /* Note that screen gamma is the display_exponent, which includes
+ * the CRT_exponent and any correction for viewing conditions */
+ if (/* We have a user-defined screen gamma value */)
+ {
+ screen_gamma = user-defined screen_gamma;
+ }
+ /* This is one way that applications share the same screen gamma value */
+ else if ((gamma_str = getenv("SCREEN_GAMMA")) != NULL)
+ {
+ screen_gamma = atof(gamma_str);
+ }
+ /* If we don't have another value */
+ else
+ {
+ screen_gamma = 2.2; /* A good guess for a PC monitors in a dimly
+ lit room */
+ screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */
+ }
+
+ /* Tell libpng to handle the gamma conversion for you. The final call
+ * is a good guess for PC generated images, but it should be configurable
+ * by the user at run time by the user. It is strongly suggested that
+ * your application support gamma correction.
+ */
+
+ int intent;
+
+ if (png_get_sRGB(png_ptr, info_ptr, &intent))
+ png_set_gamma(png_ptr, screen_gamma, 0.45455);
+ else
+ {
+ double image_gamma;
+ if (png_get_gAMA(png_ptr, info_ptr, &image_gamma))
+ png_set_gamma(png_ptr, screen_gamma, image_gamma);
+ else
+ png_set_gamma(png_ptr, screen_gamma, 0.45455);
+ }
+
+ /* Dither RGB files down to 8 bit palette or reduce palettes
+ * to the number of colors available on your screen.
+ */
+ if (color_type & PNG_COLOR_MASK_COLOR)
+ {
+ int num_palette;
+ png_colorp palette;
+
+ /* This reduces the image to the application supplied palette */
+ if (/* we have our own palette */)
+ {
+ /* An array of colors to which the image should be dithered */
+ png_color std_color_cube[MAX_SCREEN_COLORS];
+
+ png_set_dither(png_ptr, std_color_cube, MAX_SCREEN_COLORS,
+ MAX_SCREEN_COLORS, png_uint_16p_NULL, 0);
+ }
+ /* This reduces the image to the palette supplied in the file */
+ else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette))
+ {
+ png_uint_16p histogram = NULL;
+
+ png_get_hIST(png_ptr, info_ptr, &histogram);
+
+ png_set_dither(png_ptr, palette, num_palette,
+ max_screen_colors, histogram, 0);
+ }
+ }
+
+ /* invert monochrome files to have 0 as white and 1 as black */
+ png_set_invert_mono(png_ptr);
+
+ /* If you want to shift the pixel values from the range [0,255] or
+ * [0,65535] to the original [0,7] or [0,31], or whatever range the
+ * colors were originally in:
+ */
+ if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
+ {
+ png_color_8p sig_bit;
+
+ png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+ png_set_shift(png_ptr, sig_bit);
+ }
+
+ /* flip the RGB pixels to BGR (or RGBA to BGRA) */
+ if (color_type & PNG_COLOR_MASK_COLOR)
+ png_set_bgr(png_ptr);
+
+ /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+ png_set_swap_alpha(png_ptr);
+
+ /* swap bytes of 16 bit files to least significant byte first */
+ png_set_swap(png_ptr);
+
+ /* Add filler (or alpha) byte (before/after each RGB triplet) */
+ png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
+
+ /* Turn on interlace handling. REQUIRED if you are not using
+ * png_read_image(). To see how to handle interlacing passes,
+ * see the png_read_row() method below:
+ */
+ number_passes = png_set_interlace_handling(png_ptr);
+
+ /* Optional call to gamma correct and add the background to the palette
+ * and update info structure. REQUIRED if you are expecting libpng to
+ * update the palette for you (ie you selected such a transform above).
+ */
+ png_read_update_info(png_ptr, info_ptr);
+
+ /* Allocate the memory to hold the image using the fields of info_ptr. */
+
+ /* The easiest way to read the image: */
+ png_bytep row_pointers[height];
+
+ for (row = 0; row < height; row++)
+ {
+ row_pointers[row] = png_malloc(png_ptr, png_get_rowbytes(png_ptr,
+ info_ptr));
+ }
+
+ /* Now it's time to read the image. One of these methods is REQUIRED */
+#ifdef entire /* Read the entire image in one go */
+ png_read_image(png_ptr, row_pointers);
+
+#else no_entire /* Read the image one or more scanlines at a time */
+ /* The other way to read images - deal with interlacing: */
+
+ for (pass = 0; pass < number_passes; pass++)
+ {
+#ifdef single /* Read the image a single row at a time */
+ for (y = 0; y < height; y++)
+ {
+ png_read_rows(png_ptr, &row_pointers[y], png_bytepp_NULL, 1);
+ }
+
+#else no_single /* Read the image several rows at a time */
+ for (y = 0; y < height; y += number_of_rows)
+ {
+#ifdef sparkle /* Read the image using the "sparkle" effect. */
+ png_read_rows(png_ptr, &row_pointers[y], png_bytepp_NULL,
+ number_of_rows);
+#else no_sparkle /* Read the image using the "rectangle" effect */
+ png_read_rows(png_ptr, png_bytepp_NULL, &row_pointers[y],
+ number_of_rows);
+#endif no_sparkle /* use only one of these two methods */
+ }
+
+ /* if you want to display the image after every pass, do
+ so here */
+#endif no_single /* use only one of these two methods */
+ }
+#endif no_entire /* use only one of these two methods */
+
+ /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
+ png_read_end(png_ptr, info_ptr);
+#endif hilevel
+
+ /* At this point you have read the entire image */
+
+ /* clean up after the read, and free any memory allocated - REQUIRED */
+ png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
+
+ /* close the file */
+ fclose(fp);
+
+ /* that's it */
+ return (OK);
+}
+
+/* progressively read a file */
+
+int
+initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
+{
+ /* Create and initialize the png_struct with the desired error handler
+ * functions. If you want to use the default stderr and longjump method,
+ * you can supply NULL for the last three parameters. We also check that
+ * the library version is compatible in case we are using dynamically
+ * linked libraries.
+ */
+ *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
+ png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+
+ if (*png_ptr == NULL)
+ {
+ *info_ptr = NULL;
+ return (ERROR);
+ }
+
+ *info_ptr = png_create_info_struct(png_ptr);
+
+ if (*info_ptr == NULL)
+ {
+ png_destroy_read_struct(png_ptr, info_ptr, png_infopp_NULL);
+ return (ERROR);
+ }
+
+ if (setjmp(png_jmpbuf((*png_ptr))))
+ {
+ png_destroy_read_struct(png_ptr, info_ptr, png_infopp_NULL);
+ return (ERROR);
+ }
+
+ /* This one's new. You will need to provide all three
+ * function callbacks, even if you aren't using them all.
+ * If you aren't using all functions, you can specify NULL
+ * parameters. Even when all three functions are NULL,
+ * you need to call png_set_progressive_read_fn().
+ * These functions shouldn't be dependent on global or
+ * static variables if you are decoding several images
+ * simultaneously. You should store stream specific data
+ * in a separate struct, given as the second parameter,
+ * and retrieve the pointer from inside the callbacks using
+ * the function png_get_progressive_ptr(png_ptr).
+ */
+ png_set_progressive_read_fn(*png_ptr, (void *)stream_data,
+ info_callback, row_callback, end_callback);
+
+ return (OK);
+}
+
+int
+process_data(png_structp *png_ptr, png_infop *info_ptr,
+ png_bytep buffer, png_uint_32 length)
+{
+ if (setjmp(png_jmpbuf((*png_ptr))))
+ {
+ /* Free the png_ptr and info_ptr memory on error */
+ png_destroy_read_struct(png_ptr, info_ptr, png_infopp_NULL);
+ return (ERROR);
+ }
+
+ /* This one's new also. Simply give it chunks of data as
+ * they arrive from the data stream (in order, of course).
+ * On Segmented machines, don't give it any more than 64K.
+ * The library seems to run fine with sizes of 4K, although
+ * you can give it much less if necessary (I assume you can
+ * give it chunks of 1 byte, but I haven't tried with less
+ * than 256 bytes yet). When this function returns, you may
+ * want to display any rows that were generated in the row
+ * callback, if you aren't already displaying them there.
+ */
+ png_process_data(*png_ptr, *info_ptr, buffer, length);
+ return (OK);
+}
+
+info_callback(png_structp png_ptr, png_infop info)
+{
+/* do any setup here, including setting any of the transformations
+ * mentioned in the Reading PNG files section. For now, you _must_
+ * call either png_start_read_image() or png_read_update_info()
+ * after all the transformations are set (even if you don't set
+ * any). You may start getting rows before png_process_data()
+ * returns, so this is your last chance to prepare for that.
+ */
+}
+
+row_callback(png_structp png_ptr, png_bytep new_row,
+ png_uint_32 row_num, int pass)
+{
+/*
+ * This function is called for every row in the image. If the
+ * image is interlaced, and you turned on the interlace handler,
+ * this function will be called for every row in every pass.
+ *
+ * In this function you will receive a pointer to new row data from
+ * libpng called new_row that is to replace a corresponding row (of
+ * the same data format) in a buffer allocated by your application.
+ *
+ * The new row data pointer new_row may be NULL, indicating there is
+ * no new data to be replaced (in cases of interlace loading).
+ *
+ * If new_row is not NULL then you need to call
+ * png_progressive_combine_row() to replace the corresponding row as
+ * shown below:
+ */
+ /* Check if row_num is in bounds. */
+ if((row_num >= 0) && (row_num < height))
+ {
+ /* Get pointer to corresponding row in our
+ * PNG read buffer.
+ */
+ png_bytep old_row = ((png_bytep *)our_data)[row_num];
+
+ /* If both rows are allocated then copy the new row
+ * data to the corresponding row data.
+ */
+ if((old_row != NULL) && (new_row != NULL))
+ png_progressive_combine_row(png_ptr, old_row, new_row);
+ }
+/*
+ * The rows and passes are called in order, so you don't really
+ * need the row_num and pass, but I'm supplying them because it
+ * may make your life easier.
+ *
+ * For the non-NULL rows of interlaced images, you must call
+ * png_progressive_combine_row() passing in the new row and the
+ * old row, as demonstrated above. You can call this function for
+ * NULL rows (it will just return) and for non-interlaced images
+ * (it just does the png_memcpy for you) if it will make the code
+ * easier. Thus, you can just do this for all cases:
+ */
+
+ png_progressive_combine_row(png_ptr, old_row, new_row);
+
+/* where old_row is what was displayed for previous rows. Note
+ * that the first pass (pass == 0 really) will completely cover
+ * the old row, so the rows do not have to be initialized. After
+ * the first pass (and only for interlaced images), you will have
+ * to pass the current row as new_row, and the function will combine
+ * the old row and the new row.
+ */
+}
+
+end_callback(png_structp png_ptr, png_infop info)
+{
+/* this function is called when the whole image has been read,
+ * including any chunks after the image (up to and including
+ * the IEND). You will usually have the same info chunk as you
+ * had in the header, although some data may have been added
+ * to the comments and time fields.
+ *
+ * Most people won't do much here, perhaps setting a flag that
+ * marks the image as finished.
+ */
+}
+
+/* write a png file */
+void write_png(char *file_name /* , ... other image information ... */)
+{
+ FILE *fp;
+ png_structp png_ptr;
+ png_infop info_ptr;
+ png_colorp palette;
+
+ /* open the file */
+ fp = fopen(file_name, "wb");
+ if (fp == NULL)
+ return (ERROR);
+
+ /* Create and initialize the png_struct with the desired error handler
+ * functions. If you want to use the default stderr and longjump method,
+ * you can supply NULL for the last three parameters. We also check that
+ * the library version is compatible with the one used at compile time,
+ * in case we are using dynamically linked libraries. REQUIRED.
+ */
+ png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+ png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+
+ if (png_ptr == NULL)
+ {
+ fclose(fp);
+ return (ERROR);
+ }
+
+ /* Allocate/initialize the image information data. REQUIRED */
+ info_ptr = png_create_info_struct(png_ptr);
+ if (info_ptr == NULL)
+ {
+ fclose(fp);
+ png_destroy_write_struct(&png_ptr, png_infopp_NULL);
+ return (ERROR);
+ }
+
+ /* Set error handling. REQUIRED if you aren't supplying your own
+ * error handling functions in the png_create_write_struct() call.
+ */
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ /* If we get here, we had a problem reading the file */
+ fclose(fp);
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+ return (ERROR);
+ }
+
+ /* One of the following I/O initialization functions is REQUIRED */
+#ifdef streams /* I/O initialization method 1 */
+ /* set up the output control if you are using standard C streams */
+ png_init_io(png_ptr, fp);
+#else no_streams /* I/O initialization method 2 */
+ /* If you are using replacement read functions, instead of calling
+ * png_init_io() here you would call */
+ png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn,
+ user_IO_flush_function);
+ /* where user_io_ptr is a structure you want available to the callbacks */
+#endif no_streams /* only use one initialization method */
+
+#ifdef hilevel
+ /* This is the easy way. Use it if you already have all the
+ * image info living info in the structure. You could "|" many
+ * PNG_TRANSFORM flags into the png_transforms integer here.
+ */
+ png_write_png(png_ptr, info_ptr, png_transforms, png_voidp_NULL);
+#else
+ /* This is the hard way */
+
+ /* Set the image information here. Width and height are up to 2^31,
+ * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
+ * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
+ * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB,
+ * or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or
+ * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST
+ * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
+ */
+ png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, PNG_COLOR_TYPE_???,
+ PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ /* set the palette if there is one. REQUIRED for indexed-color images */
+ palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
+ * png_sizeof (png_color));
+ /* ... set palette colors ... */
+ png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
+ /* You must not free palette here, because png_set_PLTE only makes a link to
+ the palette that you malloced. Wait until you are about to destroy
+ the png structure. */
+
+ /* optional significant bit chunk */
+ /* if we are dealing with a grayscale image then */
+ sig_bit.gray = true_bit_depth;
+ /* otherwise, if we are dealing with a color image then */
+ sig_bit.red = true_red_bit_depth;
+ sig_bit.green = true_green_bit_depth;
+ sig_bit.blue = true_blue_bit_depth;
+ /* if the image has an alpha channel then */
+ sig_bit.alpha = true_alpha_bit_depth;
+ png_set_sBIT(png_ptr, info_ptr, sig_bit);
+
+
+ /* Optional gamma chunk is strongly suggested if you have any guess
+ * as to the correct gamma of the image.
+ */
+ png_set_gAMA(png_ptr, info_ptr, gamma);
+
+ /* Optionally write comments into the image */
+ text_ptr[0].key = "Title";
+ text_ptr[0].text = "Mona Lisa";
+ text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr[1].key = "Author";
+ text_ptr[1].text = "Leonardo DaVinci";
+ text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr[2].key = "Description";
+ text_ptr[2].text = "<long text>";
+ text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
+#ifdef PNG_iTXt_SUPPORTED
+ text_ptr[0].lang = NULL;
+ text_ptr[1].lang = NULL;
+ text_ptr[2].lang = NULL;
+#endif
+ png_set_text(png_ptr, info_ptr, text_ptr, 3);
+
+ /* other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs, */
+ /* note that if sRGB is present the gAMA and cHRM chunks must be ignored
+ * on read and must be written in accordance with the sRGB profile */
+
+ /* Write the file header information. REQUIRED */
+ png_write_info(png_ptr, info_ptr);
+
+ /* If you want, you can write the info in two steps, in case you need to
+ * write your private chunk ahead of PLTE:
+ *
+ * png_write_info_before_PLTE(write_ptr, write_info_ptr);
+ * write_my_chunk();
+ * png_write_info(png_ptr, info_ptr);
+ *
+ * However, given the level of known- and unknown-chunk support in 1.1.0
+ * and up, this should no longer be necessary.
+ */
+
+ /* Once we write out the header, the compression type on the text
+ * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
+ * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
+ * at the end.
+ */
+
+ /* set up the transformations you want. Note that these are
+ * all optional. Only call them if you want them.
+ */
+
+ /* invert monochrome pixels */
+ png_set_invert_mono(png_ptr);
+
+ /* Shift the pixels up to a legal bit depth and fill in
+ * as appropriate to correctly scale the image.
+ */
+ png_set_shift(png_ptr, &sig_bit);
+
+ /* pack pixels into bytes */
+ png_set_packing(png_ptr);
+
+ /* swap location of alpha bytes from ARGB to RGBA */
+ png_set_swap_alpha(png_ptr);
+
+ /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
+ * RGB (4 channels -> 3 channels). The second parameter is not used.
+ */
+ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+
+ /* flip BGR pixels to RGB */
+ png_set_bgr(png_ptr);
+
+ /* swap bytes of 16-bit files to most significant byte first */
+ png_set_swap(png_ptr);
+
+ /* swap bits of 1, 2, 4 bit packed pixel formats */
+ png_set_packswap(png_ptr);
+
+ /* turn on interlace handling if you are not using png_write_image() */
+ if (interlacing)
+ number_passes = png_set_interlace_handling(png_ptr);
+ else
+ number_passes = 1;
+
+ /* The easiest way to write the image (you may have a different memory
+ * layout, however, so choose what fits your needs best). You need to
+ * use the first method if you aren't handling interlacing yourself.
+ */
+ png_uint_32 k, height, width;
+ png_byte image[height][width*bytes_per_pixel];
+ png_bytep row_pointers[height];
+
+ if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+ png_error (png_ptr, "Image is too tall to process in memory");
+
+ for (k = 0; k < height; k++)
+ row_pointers[k] = image + k*width*bytes_per_pixel;
+
+ /* One of the following output methods is REQUIRED */
+#ifdef entire /* write out the entire image data in one call */
+ png_write_image(png_ptr, row_pointers);
+
+ /* the other way to write the image - deal with interlacing */
+
+#else no_entire /* write out the image data by one or more scanlines */
+ /* The number of passes is either 1 for non-interlaced images,
+ * or 7 for interlaced images.
+ */
+ for (pass = 0; pass < number_passes; pass++)
+ {
+ /* Write a few rows at a time. */
+ png_write_rows(png_ptr, &row_pointers[first_row], number_of_rows);
+
+ /* If you are only writing one row at a time, this works */
+ for (y = 0; y < height; y++)
+ {
+ png_write_rows(png_ptr, &row_pointers[y], 1);
+ }
+ }
+#endif no_entire /* use only one output method */
+
+ /* You can write optional chunks like tEXt, zTXt, and tIME at the end
+ * as well. Shouldn't be necessary in 1.1.0 and up as all the public
+ * chunks are supported and you can use png_set_unknown_chunks() to
+ * register unknown chunks into the info structure to be written out.
+ */
+
+ /* It is REQUIRED to call this to finish writing the rest of the file */
+ png_write_end(png_ptr, info_ptr);
+#endif hilevel
+
+ /* If you png_malloced a palette, free it here (don't free info_ptr->palette,
+ as recommended in versions 1.0.5m and earlier of this example; if
+ libpng mallocs info_ptr->palette, libpng will free it). If you
+ allocated it with malloc() instead of png_malloc(), use free() instead
+ of png_free(). */
+ png_free(png_ptr, palette);
+ palette=NULL;
+
+ /* Similarly, if you png_malloced any data that you passed in with
+ png_set_something(), such as a hist or trans array, free it here,
+ when you can be sure that libpng is through with it. */
+ png_free(png_ptr, trans);
+ trans=NULL;
+
+ /* clean up after the write, and free any memory allocated */
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+
+ /* close the file */
+ fclose(fp);
+
+ /* that's it */
+ return (OK);
+}
+
+#endif /* if 0 */
diff --git a/com32/lib/libpng/libpng.txt b/com32/lib/libpng/libpng.txt
new file mode 100644
index 00000000..9360f33b
--- /dev/null
+++ b/com32/lib/libpng/libpng.txt
@@ -0,0 +1,2959 @@
+libpng.txt - A description on how to use and modify libpng
+
+ libpng version 1.2.8 - December 3, 2004
+ Updated and distributed by Glenn Randers-Pehrson
+ <glennrp at users.sourceforge.net>
+ Copyright (c) 1998-2004 Glenn Randers-Pehrson
+ For conditions of distribution and use, see copyright
+ notice in png.h.
+
+ based on:
+
+ libpng 1.0 beta 6 version 0.96 May 28, 1997
+ Updated and distributed by Andreas Dilger
+ Copyright (c) 1996, 1997 Andreas Dilger
+
+ libpng 1.0 beta 2 - version 0.88 January 26, 1996
+ For conditions of distribution and use, see copyright
+ notice in png.h. Copyright (c) 1995, 1996 Guy Eric
+ Schalnat, Group 42, Inc.
+
+ Updated/rewritten per request in the libpng FAQ
+ Copyright (c) 1995, 1996 Frank J. T. Wojcik
+ December 18, 1995 & January 20, 1996
+
+I. Introduction
+
+This file describes how to use and modify the PNG reference library
+(known as libpng) for your own use. There are five sections to this
+file: introduction, structures, reading, writing, and modification and
+configuration notes for various special platforms. In addition to this
+file, example.c is a good starting point for using the library, as
+it is heavily commented and should include everything most people
+will need. We assume that libpng is already installed; see the
+INSTALL file for instructions on how to install libpng.
+
+Libpng was written as a companion to the PNG specification, as a way
+of reducing the amount of time and effort it takes to support the PNG
+file format in application programs.
+
+The PNG specification (second edition), November 2003, is available as
+a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
+<http://www.w3.org/TR/2003/REC-PNG-20031110/
+The W3C and ISO documents have identical technical content.
+
+The PNG-1.2 specification is available at
+<http://www.libpng.org/pub/png/documents/>
+
+The PNG-1.0 specification is available
+as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a
+W3C Recommendation <http://www.w3.org/TR/REC.png.html>. Some
+additional chunks are described in the special-purpose public chunks
+documents at <http://www.libpng.org/pub/png/documents/>.
+
+Other information
+about PNG, and the latest version of libpng, can be found at the PNG home
+page, <http://www.libpng.org/pub/png/>.
+
+Most users will not have to modify the library significantly; advanced
+users may want to modify it more. All attempts were made to make it as
+complete as possible, while keeping the code easy to understand.
+Currently, this library only supports C. Support for other languages
+is being considered.
+
+Libpng has been designed to handle multiple sessions at one time,
+to be easily modifiable, to be portable to the vast majority of
+machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy
+to use. The ultimate goal of libpng is to promote the acceptance of
+the PNG file format in whatever way possible. While there is still
+work to be done (see the TODO file), libpng should cover the
+majority of the needs of its users.
+
+Libpng uses zlib for its compression and decompression of PNG files.
+Further information about zlib, and the latest version of zlib, can
+be found at the zlib home page, <http://www.info-zip.org/pub/infozip/zlib/>.
+The zlib compression utility is a general purpose utility that is
+useful for more than PNG files, and can be used without libpng.
+See the documentation delivered with zlib for more details.
+You can usually find the source files for the zlib utility wherever you
+find the libpng source files.
+
+Libpng is thread safe, provided the threads are using different
+instances of the structures. Each thread should have its own
+png_struct and png_info instances, and thus its own image.
+Libpng does not protect itself against two threads using the
+same instance of a structure. Note: thread safety may be defeated
+by use of some of the MMX assembler code in pnggccrd.c, which is only
+compiled when the user defines PNG_THREAD_UNSAFE_OK.
+
+II. Structures
+
+There are two main structures that are important to libpng, png_struct
+and png_info. The first, png_struct, is an internal structure that
+will not, for the most part, be used by a user except as the first
+variable passed to every libpng function call.
+
+The png_info structure is designed to provide information about the
+PNG file. At one time, the fields of png_info were intended to be
+directly accessible to the user. However, this tended to cause problems
+with applications using dynamically loaded libraries, and as a result
+a set of interface functions for png_info (the png_get_*() and png_set_*()
+functions) was developed. The fields of png_info are still available for
+older applications, but it is suggested that applications use the new
+interfaces if at all possible.
+
+Applications that do make direct access to the members of png_struct (except
+for png_ptr->jmpbuf) must be recompiled whenever the library is updated,
+and applications that make direct access to the members of png_info must
+be recompiled if they were compiled or loaded with libpng version 1.0.6,
+in which the members were in a different order. In version 1.0.7, the
+members of the png_info structure reverted to the old order, as they were
+in versions 0.97c through 1.0.5. Starting with version 2.0.0, both
+structures are going to be hidden, and the contents of the structures will
+only be accessible through the png_get/png_set functions.
+
+The png.h header file is an invaluable reference for programming with libpng.
+And while I'm on the topic, make sure you include the libpng header file:
+
+#include <png.h>
+
+III. Reading
+
+We'll now walk you through the possible functions to call when reading
+in a PNG file sequentially, briefly explaining the syntax and purpose
+of each one. See example.c and png.h for more detail. While
+progressive reading is covered in the next section, you will still
+need some of the functions discussed in this section to read a PNG
+file.
+
+Setup
+
+You will want to do the I/O initialization(*) before you get into libpng,
+so if it doesn't work, you don't have much to undo. Of course, you
+will also want to insure that you are, in fact, dealing with a PNG
+file. Libpng provides a simple check to see if a file is a PNG file.
+To use it, pass in the first 1 to 8 bytes of the file to the function
+png_sig_cmp(), and it will return 0 if the bytes match the corresponding
+bytes of the PNG signature, or nonzero otherwise. Of course, the more bytes
+you pass in, the greater the accuracy of the prediction.
+
+If you are intending to keep the file pointer open for use in libpng,
+you must ensure you don't read more than 8 bytes from the beginning
+of the file, and you also have to make a call to png_set_sig_bytes_read()
+with the number of bytes you read from the beginning. Libpng will
+then only check the bytes (if any) that your program didn't read.
+
+(*): If you are not using the standard I/O functions, you will need
+to replace them with custom functions. See the discussion under
+Customizing libpng.
+
+
+ FILE *fp = fopen(file_name, "rb");
+ if (!fp)
+ {
+ return (ERROR);
+ }
+ fread(header, 1, number, fp);
+ is_png = !png_sig_cmp(header, 0, number);
+ if (!is_png)
+ {
+ return (NOT_PNG);
+ }
+
+
+Next, png_struct and png_info need to be allocated and initialized. In
+order to ensure that the size of these structures is correct even with a
+dynamically linked libpng, there are functions to initialize and
+allocate the structures. We also pass the library version, optional
+pointers to error handling functions, and a pointer to a data struct for
+use by the error functions, if necessary (the pointer and functions can
+be NULL if the default error handlers are to be used). See the section
+on Changes to Libpng below regarding the old initialization functions.
+The structure allocation functions quietly return NULL if they fail to
+create the structure, so your application should check for that.
+
+ png_structp png_ptr = png_create_read_struct
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn);
+ if (!png_ptr)
+ return (ERROR);
+
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+ if (!info_ptr)
+ {
+ png_destroy_read_struct(&png_ptr,
+ (png_infopp)NULL, (png_infopp)NULL);
+ return (ERROR);
+ }
+
+ png_infop end_info = png_create_info_struct(png_ptr);
+ if (!end_info)
+ {
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_read_struct_2() instead of png_create_read_struct():
+
+ png_structp png_ptr = png_create_read_struct_2
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn, (png_voidp)
+ user_mem_ptr, user_malloc_fn, user_free_fn);
+
+The error handling routines passed to png_create_read_struct()
+and the memory alloc/free routines passed to png_create_struct_2()
+are only necessary if you are not using the libpng supplied error
+handling and memory alloc/free functions.
+
+When libpng encounters an error, it expects to longjmp back
+to your routine. Therefore, you will need to call setjmp and pass
+your png_jmpbuf(png_ptr). If you read the file from different
+routines, you will need to update the jmpbuf field every time you enter
+a new routine that will call a png_*() function.
+
+See your documentation of setjmp/longjmp for your compiler for more
+information on setjmp/longjmp. See the discussion on libpng error
+handling in the Customizing Libpng section below for more information
+on the libpng error handling. If an error occurs, and libpng longjmp's
+back to your setjmp, you will want to call png_destroy_read_struct() to
+free any memory.
+
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ &end_info);
+ fclose(fp);
+ return (ERROR);
+ }
+
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+
+Now you need to set up the input code. The default for libpng is to
+use the C function fread(). If you use this, you will need to pass a
+valid FILE * in the function png_init_io(). Be sure that the file is
+opened in binary mode. If you wish to handle reading data in another
+way, you need not call the png_init_io() function, but you must then
+implement the libpng I/O methods discussed in the Customizing Libpng
+section below.
+
+ png_init_io(png_ptr, fp);
+
+If you had previously opened the file and read any of the signature from
+the beginning in order to see if this was a PNG file, you need to let
+libpng know that there are some bytes missing from the start of the file.
+
+ png_set_sig_bytes(png_ptr, number);
+
+Setting up callback code
+
+You can set up a callback function to handle any unknown chunks in the
+input stream. You must supply the function
+
+ read_chunk_callback(png_ptr ptr,
+ png_unknown_chunkp chunk);
+ {
+ /* The unknown chunk structure contains your
+ chunk data: */
+ png_byte name[5];
+ png_byte *data;
+ png_size_t size;
+ /* Note that libpng has already taken care of
+ the CRC handling */
+
+ /* put your code here. Return one of the
+ following: */
+
+ return (-n); /* chunk had an error */
+ return (0); /* did not recognize */
+ return (n); /* success */
+ }
+
+(You can give your function another name that you like instead of
+"read_chunk_callback")
+
+To inform libpng about your function, use
+
+ png_set_read_user_chunk_fn(png_ptr, user_chunk_ptr,
+ read_chunk_callback);
+
+This names not only the callback function, but also a user pointer that
+you can retrieve with
+
+ png_get_user_chunk_ptr(png_ptr);
+
+At this point, you can set up a callback function that will be
+called after each row has been read, which you can use to control
+a progress meter or the like. It's demonstrated in pngtest.c.
+You must supply a function
+
+ void read_row_callback(png_ptr ptr, png_uint_32 row,
+ int pass);
+ {
+ /* put your code here */
+ }
+
+(You can give it another name that you like instead of "read_row_callback")
+
+To inform libpng about your function, use
+
+ png_set_read_status_fn(png_ptr, read_row_callback);
+
+Width and height limits
+
+The PNG specification allows the width and height of an image to be as
+large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
+Since very few applications really need to process such large images,
+we have imposed an arbitrary 1-million limit on rows and columns.
+Larger images will be rejected immediately with a png_error() call. If
+you wish to override this limit, you can use
+
+ png_set_user_limits(png_ptr, width_max, height_max);
+
+to set your own limits, or use width_max = height_max = 0x7fffffffL
+to allow all valid dimensions (libpng may reject some very large images
+anyway because of potential buffer overflow conditions).
+
+You should put this statement after you create the PNG structure and
+before calling png_read_info(), png_read_png(), or png_process_data().
+If you need to retrieve the limits that are being applied, use
+
+ width_max = png_get_user_width_max(png_ptr);
+ height_max = png_get_user_height_max(png_ptr);
+
+Unknown-chunk handling
+
+Now you get to set the way the library processes unknown chunks in the
+input PNG stream. Both known and unknown chunks will be read. Normal
+behavior is that known chunks will be parsed into information in
+various info_ptr members; unknown chunks will be discarded. To change
+this, you can call:
+
+ png_set_keep_unknown_chunks(png_ptr, keep,
+ chunk_list, num_chunks);
+ keep - 0: do not handle as unknown
+ 1: do not keep
+ 2: keep only if safe-to-copy
+ 3: keep even if unsafe-to-copy
+ You can use these definitions:
+ PNG_HANDLE_CHUNK_AS_DEFAULT 0
+ PNG_HANDLE_CHUNK_NEVER 1
+ PNG_HANDLE_CHUNK_IF_SAFE 2
+ PNG_HANDLE_CHUNK_ALWAYS 3
+ chunk_list - list of chunks affected (a byte string,
+ five bytes per chunk, NULL or '\0' if
+ num_chunks is 0)
+ num_chunks - number of chunks affected; if 0, all
+ unknown chunks are affected. If nonzero,
+ only the chunks in the list are affected
+
+Unknown chunks declared in this way will be saved as raw data onto a
+list of png_unknown_chunk structures. If a chunk that is normally
+known to libpng is named in the list, it will be handled as unknown,
+according to the "keep" directive. If a chunk is named in successive
+instances of png_set_keep_unknown_chunks(), the final instance will
+take precedence. The IHDR and IEND chunks should not be named in
+chunk_list; if they are, libpng will process them normally anyway.
+
+The high-level read interface
+
+At this point there are two ways to proceed; through the high-level
+read interface, or through a sequence of low-level read operations.
+You can use the high-level interface if (a) you are willing to read
+the entire image into memory, and (b) the input transformations
+you want to do are limited to the following set:
+
+ PNG_TRANSFORM_IDENTITY No transformation
+ PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to
+ 8 bits
+ PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel
+ PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit
+ samples to bytes
+ PNG_TRANSFORM_PACKSWAP Change order of packed
+ pixels to LSB first
+ PNG_TRANSFORM_EXPAND Perform set_expand()
+ PNG_TRANSFORM_INVERT_MONO Invert monochrome images
+ PNG_TRANSFORM_SHIFT Normalize pixels to the
+ sBIT depth
+ PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
+ to BGRA
+ PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
+ to AG
+ PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
+ to transparency
+ PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
+
+(This excludes setting a background color, doing gamma transformation,
+dithering, and setting filler.) If this is the case, simply do this:
+
+ png_read_png(png_ptr, info_ptr, png_transforms, NULL)
+
+where png_transforms is an integer containing the logical OR of
+some set of transformation flags. This call is equivalent to png_read_info(),
+followed the set of transformations indicated by the transform mask,
+then png_read_image(), and finally png_read_end().
+
+(The final parameter of this call is not yet used. Someday it might point
+to transformation parameters required by some future input transform.)
+
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_read_png().
+
+After you have called png_read_png(), you can retrieve the image data
+with
+
+ row_pointers = png_get_rows(png_ptr, info_ptr);
+
+where row_pointers is an array of pointers to the pixel data for each row:
+
+ png_bytep row_pointers[height];
+
+If you know your image size and pixel size ahead of time, you can allocate
+row_pointers prior to calling png_read_png() with
+
+ if (height > PNG_UINT_32_MAX/png_sizeof(png_byte))
+ png_error (png_ptr,
+ "Image is too tall to process in memory");
+ if (width > PNG_UINT_32_MAX/pixel_size)
+ png_error (png_ptr,
+ "Image is too wide to process in memory");
+ row_pointers = png_malloc(png_ptr,
+ height*png_sizeof(png_bytep));
+ for (int i=0; i<height, i++)
+ row_pointers[i]=png_malloc(png_ptr,
+ width*pixel_size);
+ png_set_rows(png_ptr, info_ptr, &row_pointers);
+
+Alternatively you could allocate your image in one big block and define
+row_pointers[i] to point into the proper places in your block.
+
+If you use png_set_rows(), the application is responsible for freeing
+row_pointers (and row_pointers[i], if they were separately allocated).
+
+If you don't allocate row_pointers ahead of time, png_read_png() will
+do it, and it'll be free'ed when you call png_destroy_*().
+
+The low-level read interface
+
+If you are going the low-level route, you are now ready to read all
+the file information up to the actual image data. You do this with a
+call to png_read_info().
+
+ png_read_info(png_ptr, info_ptr);
+
+This will process all chunks up to but not including the image data.
+
+Querying the info structure
+
+Functions are used to get the information from the info_ptr once it
+has been read. Note that these fields may not be completely filled
+in until png_read_end() has read the chunk data following the image.
+
+ png_get_IHDR(png_ptr, info_ptr, &width, &height,
+ &bit_depth, &color_type, &interlace_type,
+ &compression_type, &filter_method);
+
+ width - holds the width of the image
+ in pixels (up to 2^31).
+ height - holds the height of the image
+ in pixels (up to 2^31).
+ bit_depth - holds the bit depth of one of the
+ image channels. (valid values are
+ 1, 2, 4, 8, 16 and depend also on
+ the color_type. See also
+ significant bits (sBIT) below).
+ color_type - describes which color/alpha channels
+ are present.
+ PNG_COLOR_TYPE_GRAY
+ (bit depths 1, 2, 4, 8, 16)
+ PNG_COLOR_TYPE_GRAY_ALPHA
+ (bit depths 8, 16)
+ PNG_COLOR_TYPE_PALETTE
+ (bit depths 1, 2, 4, 8)
+ PNG_COLOR_TYPE_RGB
+ (bit_depths 8, 16)
+ PNG_COLOR_TYPE_RGB_ALPHA
+ (bit_depths 8, 16)
+
+ PNG_COLOR_MASK_PALETTE
+ PNG_COLOR_MASK_COLOR
+ PNG_COLOR_MASK_ALPHA
+
+ filter_method - (must be PNG_FILTER_TYPE_BASE
+ for PNG 1.0, and can also be
+ PNG_INTRAPIXEL_DIFFERENCING if
+ the PNG datastream is embedded in
+ a MNG-1.0 datastream)
+ compression_type - (must be PNG_COMPRESSION_TYPE_BASE
+ for PNG 1.0)
+ interlace_type - (PNG_INTERLACE_NONE or
+ PNG_INTERLACE_ADAM7)
+ Any or all of interlace_type, compression_type, of
+ filter_method can be NULL if you are
+ not interested in their values.
+
+ channels = png_get_channels(png_ptr, info_ptr);
+ channels - number of channels of info for the
+ color type (valid values are 1 (GRAY,
+ PALETTE), 2 (GRAY_ALPHA), 3 (RGB),
+ 4 (RGB_ALPHA or RGB + filler byte))
+ rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+ rowbytes - number of bytes needed to hold a row
+
+ signature = png_get_signature(png_ptr, info_ptr);
+ signature - holds the signature read from the
+ file (if any). The data is kept in
+ the same offset it would be if the
+ whole signature were read (i.e. if an
+ application had already read in 4
+ bytes of signature before starting
+ libpng, the remaining 4 bytes would
+ be in signature[4] through signature[7]
+ (see png_set_sig_bytes())).
+
+
+ width = png_get_image_width(png_ptr,
+ info_ptr);
+ height = png_get_image_height(png_ptr,
+ info_ptr);
+ bit_depth = png_get_bit_depth(png_ptr,
+ info_ptr);
+ color_type = png_get_color_type(png_ptr,
+ info_ptr);
+ filter_method = png_get_filter_type(png_ptr,
+ info_ptr);
+ compression_type = png_get_compression_type(png_ptr,
+ info_ptr);
+ interlace_type = png_get_interlace_type(png_ptr,
+ info_ptr);
+
+
+These are also important, but their validity depends on whether the chunk
+has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and
+png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the
+data has been read, or zero if it is missing. The parameters to the
+png_get_<chunk> are set directly if they are simple data types, or a pointer
+into the info_ptr is returned for any complex types.
+
+ png_get_PLTE(png_ptr, info_ptr, &palette,
+ &num_palette);
+ palette - the palette for the file
+ (array of png_color)
+ num_palette - number of entries in the palette
+
+ png_get_gAMA(png_ptr, info_ptr, &gamma);
+ gamma - the gamma the file is written
+ at (PNG_INFO_gAMA)
+
+ png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
+ srgb_intent - the rendering intent (PNG_INFO_sRGB)
+ The presence of the sRGB chunk
+ means that the pixel data is in the
+ sRGB color space. This chunk also
+ implies specific values of gAMA and
+ cHRM.
+
+ png_get_iCCP(png_ptr, info_ptr, &name,
+ &compression_type, &profile, &proflen);
+ name - The profile name.
+ compression - The compression type; always
+ PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+ You may give NULL to this argument to
+ ignore it.
+ profile - International Color Consortium color
+ profile data. May contain NULs.
+ proflen - length of profile data in bytes.
+
+ png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+ sig_bit - the number of significant bits for
+ (PNG_INFO_sBIT) each of the gray,
+ red, green, and blue channels,
+ whichever are appropriate for the
+ given color type (png_color_16)
+
+ png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans,
+ &trans_values);
+ trans - array of transparent entries for
+ palette (PNG_INFO_tRNS)
+ trans_values - graylevel or color sample values of
+ the single transparent color for
+ non-paletted images (PNG_INFO_tRNS)
+ num_trans - number of transparent entries
+ (PNG_INFO_tRNS)
+
+ png_get_hIST(png_ptr, info_ptr, &hist);
+ (PNG_INFO_hIST)
+ hist - histogram of palette (array of
+ png_uint_16)
+
+ png_get_tIME(png_ptr, info_ptr, &mod_time);
+ mod_time - time image was last modified
+ (PNG_VALID_tIME)
+
+ png_get_bKGD(png_ptr, info_ptr, &background);
+ background - background color (PNG_VALID_bKGD)
+ valid 16-bit red, green and blue
+ values, regardless of color_type
+
+ num_comments = png_get_text(png_ptr, info_ptr,
+ &text_ptr, &num_text);
+ num_comments - number of comments
+ text_ptr - array of png_text holding image
+ comments
+ text_ptr[i].compression - type of compression used
+ on "text" PNG_TEXT_COMPRESSION_NONE
+ PNG_TEXT_COMPRESSION_zTXt
+ PNG_ITXT_COMPRESSION_NONE
+ PNG_ITXT_COMPRESSION_zTXt
+ text_ptr[i].key - keyword for comment. Must contain
+ 1-79 characters.
+ text_ptr[i].text - text comments for current
+ keyword. Can be empty.
+ text_ptr[i].text_length - length of text string,
+ after decompression, 0 for iTXt
+ text_ptr[i].itxt_length - length of itxt string,
+ after decompression, 0 for tEXt/zTXt
+ text_ptr[i].lang - language of comment (empty
+ string for unknown).
+ text_ptr[i].lang_key - keyword in UTF-8
+ (empty string for unknown).
+ num_text - number of comments (same as
+ num_comments; you can put NULL here
+ to avoid the duplication)
+ Note while png_set_text() will accept text, language,
+ and translated keywords that can be NULL pointers, the
+ structure returned by png_get_text will always contain
+ regular zero-terminated C strings. They might be
+ empty strings but they will never be NULL pointers.
+
+ num_spalettes = png_get_sPLT(png_ptr, info_ptr,
+ &palette_ptr);
+ palette_ptr - array of palette structures holding
+ contents of one or more sPLT chunks
+ read.
+ num_spalettes - number of sPLT chunks read.
+
+ png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y,
+ &unit_type);
+ offset_x - positive offset from the left edge
+ of the screen
+ offset_y - positive offset from the top edge
+ of the screen
+ unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+
+ png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y,
+ &unit_type);
+ res_x - pixels/unit physical resolution in
+ x direction
+ res_y - pixels/unit physical resolution in
+ x direction
+ unit_type - PNG_RESOLUTION_UNKNOWN,
+ PNG_RESOLUTION_METER
+
+ png_get_sCAL(png_ptr, info_ptr, &unit, &width,
+ &height)
+ unit - physical scale units (an integer)
+ width - width of a pixel in physical scale units
+ height - height of a pixel in physical scale units
+ (width and height are doubles)
+
+ png_get_sCAL_s(png_ptr, info_ptr, &unit, &width,
+ &height)
+ unit - physical scale units (an integer)
+ width - width of a pixel in physical scale units
+ height - height of a pixel in physical scale units
+ (width and height are strings like "2.54")
+
+ num_unknown_chunks = png_get_unknown_chunks(png_ptr,
+ info_ptr, &unknowns)
+ unknowns - array of png_unknown_chunk
+ structures holding unknown chunks
+ unknowns[i].name - name of unknown chunk
+ unknowns[i].data - data of unknown chunk
+ unknowns[i].size - size of unknown chunk's data
+ unknowns[i].location - position of chunk in file
+
+ The value of "i" corresponds to the order in which the
+ chunks were read from the PNG file or inserted with the
+ png_set_unknown_chunks() function.
+
+The data from the pHYs chunk can be retrieved in several convenient
+forms:
+
+ res_x = png_get_x_pixels_per_meter(png_ptr,
+ info_ptr)
+ res_y = png_get_y_pixels_per_meter(png_ptr,
+ info_ptr)
+ res_x_and_y = png_get_pixels_per_meter(png_ptr,
+ info_ptr)
+ res_x = png_get_x_pixels_per_inch(png_ptr,
+ info_ptr)
+ res_y = png_get_y_pixels_per_inch(png_ptr,
+ info_ptr)
+ res_x_and_y = png_get_pixels_per_inch(png_ptr,
+ info_ptr)
+ aspect_ratio = png_get_pixel_aspect_ratio(png_ptr,
+ info_ptr)
+
+ (Each of these returns 0 [signifying "unknown"] if
+ the data is not present or if res_x is 0;
+ res_x_and_y is 0 if res_x != res_y)
+
+The data from the oFFs chunk can be retrieved in several convenient
+forms:
+
+ x_offset = png_get_x_offset_microns(png_ptr, info_ptr);
+ y_offset = png_get_y_offset_microns(png_ptr, info_ptr);
+ x_offset = png_get_x_offset_inches(png_ptr, info_ptr);
+ y_offset = png_get_y_offset_inches(png_ptr, info_ptr);
+
+ (Each of these returns 0 [signifying "unknown" if both
+ x and y are 0] if the data is not present or if the
+ chunk is present but the unit is the pixel)
+
+For more information, see the png_info definition in png.h and the
+PNG specification for chunk contents. Be careful with trusting
+rowbytes, as some of the transformations could increase the space
+needed to hold a row (expand, filler, gray_to_rgb, etc.).
+See png_read_update_info(), below.
+
+A quick word about text_ptr and num_text. PNG stores comments in
+keyword/text pairs, one pair per chunk, with no limit on the number
+of text chunks, and a 2^31 byte limit on their size. While there are
+suggested keywords, there is no requirement to restrict the use to these
+strings. It is strongly suggested that keywords and text be sensible
+to humans (that's the point), so don't use abbreviations. Non-printing
+symbols are not allowed. See the PNG specification for more details.
+There is also no requirement to have text after the keyword.
+
+Keywords should be limited to 79 Latin-1 characters without leading or
+trailing spaces, but non-consecutive spaces are allowed within the
+keyword. It is possible to have the same keyword any number of times.
+The text_ptr is an array of png_text structures, each holding a
+pointer to a language string, a pointer to a keyword and a pointer to
+a text string. The text string, language code, and translated
+keyword may be empty or NULL pointers. The keyword/text
+pairs are put into the array in the order that they are received.
+However, some or all of the text chunks may be after the image, so, to
+make sure you have read all the text chunks, don't mess with these
+until after you read the stuff after the image. This will be
+mentioned again below in the discussion that goes with png_read_end().
+
+Input transformations
+
+After you've read the header information, you can set up the library
+to handle any special transformations of the image data. The various
+ways to transform the data will be described in the order that they
+should occur. This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths. Even though each transformation
+checks to see if it has data that it can do something with, you should
+make sure to only enable a transformation if it will be valid for the
+data. For example, don't swap red and blue on grayscale data.
+
+The colors used for the background and transparency values should be
+supplied in the same format/depth as the current image data. They
+are stored in the same format/depth as the image data in a bKGD or tRNS
+chunk, so this is what libpng expects for this data. The colors are
+transformed to keep in sync with the image data when an application
+calls the png_read_update_info() routine (see below).
+
+Data will be decoded into the supplied row buffers packed into bytes
+unless the library has been told to transform it into another format.
+For example, 4 bit/pixel paletted or grayscale data will be returned
+2 pixels/byte with the leftmost pixel in the high-order bits of the
+byte, unless png_set_packing() is called. 8-bit RGB data will be stored
+in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
+is called to insert filler bytes, either before or after each RGB triplet.
+16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
+byte of the color value first, unless png_set_strip_16() is called to
+transform it to regular RGB RGB triplets, or png_set_filler() or
+png_set_add alpha() is called to insert filler bytes, either before or
+after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can
+be modified with
+png_set_filler(), png_set_add_alpha(), or png_set_strip_16().
+
+The following code transforms grayscale images of less than 8 to 8 bits,
+changes paletted images to RGB, and adds a full alpha channel if there is
+transparency information in a tRNS chunk. This is most useful on
+grayscale images with bit depths of 2 or 4 or if there is a multiple-image
+viewing application that wishes to treat all images in the same way.
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ png_set_palette_to_rgb(png_ptr);
+
+ if (color_type == PNG_COLOR_TYPE_GRAY &&
+ bit_depth < 8) png_set_gray_1_2_4_to_8(png_ptr);
+
+ if (png_get_valid(png_ptr, info_ptr,
+ PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
+
+These three functions are actually aliases for png_set_expand(), added
+in libpng version 1.0.4, with the function names expanded to improve code
+readability. In some future version they may actually do different
+things.
+
+PNG can have files with 16 bits per channel. If you only can handle
+8 bits per channel, this will strip the pixels down to 8 bit.
+
+ if (bit_depth == 16)
+ png_set_strip_16(png_ptr);
+
+If, for some reason, you don't need the alpha channel on an image,
+and you want to remove it rather than combining it with the background
+(but the image author certainly had in mind that you *would* combine
+it with the background, so that's what you should probably do):
+
+ if (color_type & PNG_COLOR_MASK_ALPHA)
+ png_set_strip_alpha(png_ptr);
+
+In PNG files, the alpha channel in an image
+is the level of opacity. If you need the alpha channel in an image to
+be the level of transparency instead of opacity, you can invert the
+alpha channel (or the tRNS chunk data) after it's read, so that 0 is
+fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit
+images) is fully transparent, with
+
+ png_set_invert_alpha(png_ptr);
+
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit
+files. This code expands to 1 pixel per byte without changing the
+values of the pixels:
+
+ if (bit_depth < 8)
+ png_set_packing(png_ptr);
+
+PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels
+stored in a PNG image have been "scaled" or "shifted" up to the next
+higher possible bit depth (e.g. from 5 bits/sample in the range [0,31] to
+8 bits/sample in the range [0, 255]). However, it is also possible to
+convert the PNG pixel data back to the original bit depth of the image.
+This call reduces the pixels back down to the original bit depth:
+
+ png_color_8p sig_bit;
+
+ if (png_get_sBIT(png_ptr, info_ptr, &sig_bit))
+ png_set_shift(png_ptr, sig_bit);
+
+PNG files store 3-color pixels in red, green, blue order. This code
+changes the storage of the pixels to blue, green, red:
+
+ if (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ png_set_bgr(png_ptr);
+
+PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
+into 4 or 8 bytes for windowing systems that need them in this format:
+
+ if (color_type == PNG_COLOR_TYPE_RGB)
+ png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
+
+where "filler" is the 8 or 16-bit number to fill with, and the location is
+either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
+you want the filler before the RGB or after. This transformation
+does not affect images that already have full alpha channels. To add an
+opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
+will generate RGBA pixels.
+
+Note that png_set_filler() does not change the color type. If you want
+to do that, you can add a true alpha channel with
+
+ if (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_GRAY)
+ png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
+
+where "filler" contains the alpha value to assign to each pixel.
+This function was added in libpng-1.2.7.
+
+If you are reading an image with an alpha channel, and you need the
+data as ARGB instead of the normal PNG format RGBA:
+
+ if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ png_set_swap_alpha(png_ptr);
+
+For some uses, you may want a grayscale image to be represented as
+RGB. This code will do that conversion:
+
+ if (color_type == PNG_COLOR_TYPE_GRAY ||
+ color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ png_set_gray_to_rgb(png_ptr);
+
+Conversely, you can convert an RGB or RGBA image to grayscale or grayscale
+with alpha.
+
+ if (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ png_set_rgb_to_gray_fixed(png_ptr, error_action,
+ int red_weight, int green_weight);
+
+ error_action = 1: silently do the conversion
+ error_action = 2: issue a warning if the original
+ image has any pixel where
+ red != green or red != blue
+ error_action = 3: issue an error and abort the
+ conversion if the original
+ image has any pixel where
+ red != green or red != blue
+
+ red_weight: weight of red component times 100000
+ green_weight: weight of green component times 100000
+ If either weight is negative, default
+ weights (21268, 71514) are used.
+
+If you have set error_action = 1 or 2, you can
+later check whether the image really was gray, after processing
+the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
+It will return a png_byte that is zero if the image was gray or
+1 if there were any non-gray pixels. bKGD and sBIT data
+will be silently converted to grayscale, using the green channel
+data, regardless of the error_action setting.
+
+With red_weight+green_weight<=100000,
+the normalized graylevel is computed:
+
+ int rw = red_weight * 65536;
+ int gw = green_weight * 65536;
+ int bw = 65536 - (rw + gw);
+ gray = (rw*red + gw*green + bw*blue)/65536;
+
+The default values approximate those recommended in the Charles
+Poynton's Color FAQ, <http://www.inforamp.net/~poynton/>
+Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net>
+
+ Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+
+Libpng approximates this with
+
+ Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
+
+which can be expressed with integers as
+
+ Y = (6969 * R + 23434 * G + 2365 * B)/32768
+
+The calculation is done in a linear colorspace, if the image gamma
+is known.
+
+If you have a grayscale and you are using png_set_expand_depth(),
+png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to
+a higher bit-depth, you must either supply the background color as a gray
+value at the original file bit-depth (need_expand = 1) or else supply the
+background color as an RGB triplet at the final, expanded bit depth
+(need_expand = 0). Similarly, if you are reading a paletted image, you
+must either supply the background color as a palette index (need_expand = 1)
+or as an RGB triplet that may or may not be in the palette (need_expand = 0).
+
+ png_color_16 my_background;
+ png_color_16p image_background;
+
+ if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+ png_set_background(png_ptr, image_background,
+ PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+ else
+ png_set_background(png_ptr, &my_background,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+
+The png_set_background() function tells libpng to composite images
+with alpha or simple transparency against the supplied background
+color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
+you may use this color, or supply another color more suitable for
+the current display (e.g., the background color from a web page). You
+need to tell libpng whether the color is in the gamma space of the
+display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file
+(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one
+that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't
+know why anyone would use this, but it's here).
+
+To properly display PNG images on any kind of system, the application needs
+to know what the display gamma is. Ideally, the user will know this, and
+the application will allow them to set it. One method of allowing the user
+to set the display gamma separately for each system is to check for a
+SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be
+correctly set.
+
+Note that display_gamma is the overall gamma correction required to produce
+pleasing results, which depends on the lighting conditions in the surrounding
+environment. In a dim or brightly lit room, no compensation other than
+the physical gamma exponent of the monitor is needed, while in a dark room
+a slightly smaller exponent is better.
+
+ double gamma, screen_gamma;
+
+ if (/* We have a user-defined screen
+ gamma value */)
+ {
+ screen_gamma = user_defined_screen_gamma;
+ }
+ /* One way that applications can share the same
+ screen gamma value */
+ else if ((gamma_str = getenv("SCREEN_GAMMA"))
+ != NULL)
+ {
+ screen_gamma = (double)atof(gamma_str);
+ }
+ /* If we don't have another value */
+ else
+ {
+ screen_gamma = 2.2; /* A good guess for a
+ PC monitor in a bright office or a dim room */
+ screen_gamma = 2.0; /* A good guess for a
+ PC monitor in a dark room */
+ screen_gamma = 1.7 or 1.0; /* A good
+ guess for Mac systems */
+ }
+
+The png_set_gamma() function handles gamma transformations of the data.
+Pass both the file gamma and the current screen_gamma. If the file does
+not have a gamma value, you can pass one anyway if you have an idea what
+it is (usually 0.45455 is a good guess for GIF images on PCs). Note
+that file gammas are inverted from screen gammas. See the discussions
+on gamma in the PNG specification for an excellent description of what
+gamma is, and why all applications should support it. It is strongly
+recommended that PNG viewers support gamma correction.
+
+ if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+ png_set_gamma(png_ptr, screen_gamma, gamma);
+ else
+ png_set_gamma(png_ptr, screen_gamma, 0.45455);
+
+If you need to reduce an RGB file to a paletted file, or if a paletted
+file has more entries then will fit on your screen, png_set_dither()
+will do that. Note that this is a simple match dither that merely
+finds the closest color available. This should work fairly well with
+optimized palettes, and fairly badly with linear color cubes. If you
+pass a palette that is larger then maximum_colors, the file will
+reduce the number of colors in the palette so it will fit into
+maximum_colors. If there is a histogram, it will use it to make
+more intelligent choices when reducing the palette. If there is no
+histogram, it may not do as good a job.
+
+ if (color_type & PNG_COLOR_MASK_COLOR)
+ {
+ if (png_get_valid(png_ptr, info_ptr,
+ PNG_INFO_PLTE))
+ {
+ png_uint_16p histogram = NULL;
+
+ png_get_hIST(png_ptr, info_ptr,
+ &histogram);
+ png_set_dither(png_ptr, palette, num_palette,
+ max_screen_colors, histogram, 1);
+ }
+ else
+ {
+ png_color std_color_cube[MAX_SCREEN_COLORS] =
+ { ... colors ... };
+
+ png_set_dither(png_ptr, std_color_cube,
+ MAX_SCREEN_COLORS, MAX_SCREEN_COLORS,
+ NULL,0);
+ }
+ }
+
+PNG files describe monochrome as black being zero and white being one.
+The following code will reverse this (make black be one and white be
+zero):
+
+ if (bit_depth == 1 && color_type == PNG_COLOR_TYPE_GRAY)
+ png_set_invert_mono(png_ptr);
+
+This function can also be used to invert grayscale and gray-alpha images:
+
+ if (color_type == PNG_COLOR_TYPE_GRAY ||
+ color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ png_set_invert_mono(png_ptr);
+
+PNG files store 16 bit pixels in network byte order (big-endian,
+ie. most significant bits first). This code changes the storage to the
+other way (little-endian, i.e. least significant bits first, the
+way PCs store them):
+
+ if (bit_depth == 16)
+ png_set_swap(png_ptr);
+
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+
+ if (bit_depth < 8)
+ png_set_packswap(png_ptr);
+
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs. This is done by setting a callback
+with
+
+ png_set_read_user_transform_fn(png_ptr,
+ read_transform_fn);
+
+You must supply the function
+
+ void read_transform_fn(png_ptr ptr, row_info_ptr
+ row_info, png_bytep data)
+
+See pngtest.c for a working example. Your function will be called
+after all of the other transformations have been processed.
+
+You can also set up a pointer to a user structure for use by your
+callback function, and you can inform libpng that your transform
+function will change the number of channels or bit depth with the
+function
+
+ png_set_user_transform_info(png_ptr, user_ptr,
+ user_depth, user_channels);
+
+The user's application, not libpng, is responsible for allocating and
+freeing any memory required for the user structure.
+
+You can retrieve the pointer via the function
+png_get_user_transform_ptr(). For example:
+
+ voidp read_user_transform_ptr =
+ png_get_user_transform_ptr(png_ptr);
+
+The last thing to handle is interlacing; this is covered in detail below,
+but you must call the function here if you want libpng to handle expansion
+of the interlaced image.
+
+ number_of_passes = png_set_interlace_handling(png_ptr);
+
+After setting the transformations, libpng can update your png_info
+structure to reflect any transformations you've requested with this
+call. This is most useful to update the info structure's rowbytes
+field so you can use it to allocate your image memory. This function
+will also update your palette with the correct screen_gamma and
+background if these have been given with the calls above.
+
+ png_read_update_info(png_ptr, info_ptr);
+
+After you call png_read_update_info(), you can allocate any
+memory you need to hold the image. The row data is simply
+raw byte data for all forms of images. As the actual allocation
+varies among applications, no example will be given. If you
+are allocating one large chunk, you will need to build an
+array of pointers to each row, as it will be needed for some
+of the functions below.
+
+Reading image data
+
+After you've allocated memory, you can read the image data.
+The simplest way to do this is in one function call. If you are
+allocating enough memory to hold the whole image, you can just
+call png_read_image() and libpng will read in all the image data
+and put it in the memory area supplied. You will need to pass in
+an array of pointers to each row.
+
+This function automatically handles interlacing, so you don't need
+to call png_set_interlace_handling() or call this function multiple
+times, or any of that other stuff necessary with png_read_rows().
+
+ png_read_image(png_ptr, row_pointers);
+
+where row_pointers is:
+
+ png_bytep row_pointers[height];
+
+You can point to void or char or whatever you use for pixels.
+
+If you don't want to read in the whole image at once, you can
+use png_read_rows() instead. If there is no interlacing (check
+interlace_type == PNG_INTERLACE_NONE), this is simple:
+
+ png_read_rows(png_ptr, row_pointers, NULL,
+ number_of_rows);
+
+where row_pointers is the same as in the png_read_image() call.
+
+If you are doing this just one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+
+ png_bytep row_pointer = row;
+ png_read_row(png_ptr, row_pointer, NULL);
+
+If the file is interlaced (interlace_type != 0 in the IHDR chunk), things
+get somewhat harder. The only current (PNG Specification version 1.2)
+interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7)
+is a somewhat complicated 2D interlace scheme, known as Adam7, that
+breaks down an image into seven smaller images of varying size, based
+on an 8x8 grid.
+
+libpng can fill out those images or it can give them to you "as is".
+If you want them filled out, there are two ways to do that. The one
+mentioned in the PNG specification is to expand each pixel to cover
+those pixels that have not been read yet (the "rectangle" method).
+This results in a blocky image for the first pass, which gradually
+smooths out as more pixels are read. The other method is the "sparkle"
+method, where pixels are drawn only in their final locations, with the
+rest of the image remaining whatever colors they were initialized to
+before the start of the read. The first method usually looks better,
+but tends to be slower, as there are more pixels to put in the rows.
+
+If you don't want libpng to handle the interlacing details, just call
+png_read_rows() seven times to read in all seven images. Each of the
+images is a valid image by itself, or they can all be combined on an
+8x8 grid to form a single image (although if you intend to combine them
+you would be far better off using the libpng interlace handling).
+
+The first pass will return an image 1/8 as wide as the entire image
+(every 8th column starting in column 0) and 1/8 as high as the original
+(every 8th row starting in row 0), the second will be 1/8 as wide
+(starting in column 4) and 1/8 as high (also starting in row 0). The
+third pass will be 1/4 as wide (every 4th pixel starting in column 0) and
+1/8 as high (every 8th row starting in row 4), and the fourth pass will
+be 1/4 as wide and 1/4 as high (every 4th column starting in column 2,
+and every 4th row starting in row 0). The fifth pass will return an
+image 1/2 as wide, and 1/4 as high (starting at column 0 and row 2),
+while the sixth pass will be 1/2 as wide and 1/2 as high as the original
+(starting in column 1 and row 0). The seventh and final pass will be as
+wide as the original, and 1/2 as high, containing all of the odd
+numbered scanlines. Phew!
+
+If you want libpng to expand the images, call this before calling
+png_start_read_image() or png_read_update_info():
+
+ if (interlace_type == PNG_INTERLACE_ADAM7)
+ number_of_passes
+ = png_set_interlace_handling(png_ptr);
+
+This will return the number of passes needed. Currently, this
+is seven, but may change if another interlace type is added.
+This function can be called even if the file is not interlaced,
+where it will return one pass.
+
+If you are not going to display the image after each pass, but are
+going to wait until the entire image is read in, use the sparkle
+effect. This effect is faster and the end result of either method
+is exactly the same. If you are planning on displaying the image
+after each pass, the "rectangle" effect is generally considered the
+better looking one.
+
+If you only want the "sparkle" effect, just call png_read_rows() as
+normal, with the third parameter NULL. Make sure you make pass over
+the image number_of_passes times, and you don't change the data in the
+rows between calls. You can change the locations of the data, just
+not the data. Each pass only writes the pixels appropriate for that
+pass, and assumes the data from previous passes is still valid.
+
+ png_read_rows(png_ptr, row_pointers, NULL,
+ number_of_rows);
+
+If you only want the first effect (the rectangles), do the same as
+before except pass the row buffer in the third parameter, and leave
+the second parameter NULL.
+
+ png_read_rows(png_ptr, NULL, row_pointers,
+ number_of_rows);
+
+Finishing a sequential read
+
+After you are finished reading the image through either the high- or
+low-level interfaces, you can finish reading the file. If you are
+interested in comments or time, which may be stored either before or
+after the image data, you should pass the separate png_info struct if
+you want to keep the comments from before and after the image
+separate. If you are not interested, you can pass NULL.
+
+ png_read_end(png_ptr, end_info);
+
+When you are done, you can free all memory allocated by libpng like this:
+
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ &end_info);
+
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+
+ png_free_data(png_ptr, info_ptr, mask, seq)
+ mask - identifies data to be freed, a mask
+ containing the logical OR of one or
+ more of
+ PNG_FREE_PLTE, PNG_FREE_TRNS,
+ PNG_FREE_HIST, PNG_FREE_ICCP,
+ PNG_FREE_PCAL, PNG_FREE_ROWS,
+ PNG_FREE_SCAL, PNG_FREE_SPLT,
+ PNG_FREE_TEXT, PNG_FREE_UNKN,
+ or simply PNG_FREE_ALL
+ seq - sequence number of item to be freed
+ (-1 for all items)
+
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user and not by libpng, and will in those
+cases do nothing. The "seq" parameter is ignored if only one item
+of the selected data type, such as PLTE, is allowed. If "seq" is not
+-1, and multiple items are allowed for the data type identified in
+the mask, such as text or sPLT, only the n'th item in the structure
+is freed, where n is "seq".
+
+The default behavior is only to free data that was allocated internally
+by libpng. This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+
+ png_data_freer(png_ptr, info_ptr, freer, mask)
+ mask - which data elements are affected
+ same choices as in png_free_data()
+ freer - one of
+ PNG_DESTROY_WILL_FREE_DATA
+ PNG_SET_WILL_FREE_DATA
+ PNG_USER_WILL_FREE_DATA
+
+This function only affects data that has already been allocated.
+You can call this function after reading the PNG data but before calling
+any png_set_*() functions, to control whether the user or the png_set_*()
+function is responsible for freeing any existing data that might be present,
+and again after the png_set_*() functions to control whether the user
+or png_destroy_*() is supposed to free the data. When the user assumes
+responsibility for libpng-allocated data, the application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+
+If you allocated your row_pointers in a single block, as suggested above in
+the description of the high level read interface, you must not transfer
+responsibility for freeing it to the png_set_rows or png_read_destroy function,
+because they would also try to free the individual row_pointers[i].
+
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key. Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+
+The png_free_data() function will turn off the "valid" flag for anything
+it frees. If you need to turn the flag off for a chunk that was freed by your
+application instead of by libpng, you can use
+
+ png_set_invalid(png_ptr, info_ptr, mask);
+ mask - identifies the chunks to be made invalid,
+ containing the logical OR of one or
+ more of
+ PNG_INFO_gAMA, PNG_INFO_sBIT,
+ PNG_INFO_cHRM, PNG_INFO_PLTE,
+ PNG_INFO_tRNS, PNG_INFO_bKGD,
+ PNG_INFO_hIST, PNG_INFO_pHYs,
+ PNG_INFO_oFFs, PNG_INFO_tIME,
+ PNG_INFO_pCAL, PNG_INFO_sRGB,
+ PNG_INFO_iCCP, PNG_INFO_sPLT,
+ PNG_INFO_sCAL, PNG_INFO_IDAT
+
+For a more compact example of reading a PNG image, see the file example.c.
+
+Reading PNG files progressively
+
+The progressive reader is slightly different then the non-progressive
+reader. Instead of calling png_read_info(), png_read_rows(), and
+png_read_end(), you make one call to png_process_data(), which calls
+callbacks when it has the info, a row, or the end of the image. You
+set up these callbacks with png_set_progressive_read_fn(). You don't
+have to worry about the input/output functions of libpng, as you are
+giving the library the data directly in png_process_data(). I will
+assume that you have read the section on reading PNG files above,
+so I will only highlight the differences (although I will show
+all of the code).
+
+png_structp png_ptr;
+png_infop info_ptr;
+
+ /* An example code fragment of how you would
+ initialize the progressive reader in your
+ application. */
+ int
+ initialize_png_reader()
+ {
+ png_ptr = png_create_read_struct
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn);
+ if (!png_ptr)
+ return (ERROR);
+ info_ptr = png_create_info_struct(png_ptr);
+ if (!info_ptr)
+ {
+ png_destroy_read_struct(&png_ptr, (png_infopp)NULL,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+ /* This one's new. You can provide functions
+ to be called when the header info is valid,
+ when each row is completed, and when the image
+ is finished. If you aren't using all functions,
+ you can specify NULL parameters. Even when all
+ three functions are NULL, you need to call
+ png_set_progressive_read_fn(). You can use
+ any struct as the user_ptr (cast to a void pointer
+ for the function call), and retrieve the pointer
+ from inside the callbacks using the function
+
+ png_get_progressive_ptr(png_ptr);
+
+ which will return a void pointer, which you have
+ to cast appropriately.
+ */
+ png_set_progressive_read_fn(png_ptr, (void *)user_ptr,
+ info_callback, row_callback, end_callback);
+
+ return 0;
+ }
+
+ /* A code fragment that you call as you receive blocks
+ of data */
+ int
+ process_data(png_bytep buffer, png_uint_32 length)
+ {
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+ /* This one's new also. Simply give it a chunk
+ of data from the file stream (in order, of
+ course). On machines with segmented memory
+ models machines, don't give it any more than
+ 64K. The library seems to run fine with sizes
+ of 4K. Although you can give it much less if
+ necessary (I assume you can give it chunks of
+ 1 byte, I haven't tried less then 256 bytes
+ yet). When this function returns, you may
+ want to display any rows that were generated
+ in the row callback if you don't already do
+ so there.
+ */
+ png_process_data(png_ptr, info_ptr, buffer, length);
+ return 0;
+ }
+
+ /* This function is called (as set by
+ png_set_progressive_read_fn() above) when enough data
+ has been supplied so all of the header has been
+ read.
+ */
+ void
+ info_callback(png_structp png_ptr, png_infop info)
+ {
+ /* Do any setup here, including setting any of
+ the transformations mentioned in the Reading
+ PNG files section. For now, you _must_ call
+ either png_start_read_image() or
+ png_read_update_info() after all the
+ transformations are set (even if you don't set
+ any). You may start getting rows before
+ png_process_data() returns, so this is your
+ last chance to prepare for that.
+ */
+ }
+
+ /* This function is called when each row of image
+ data is complete */
+ void
+ row_callback(png_structp png_ptr, png_bytep new_row,
+ png_uint_32 row_num, int pass)
+ {
+ /* If the image is interlaced, and you turned
+ on the interlace handler, this function will
+ be called for every row in every pass. Some
+ of these rows will not be changed from the
+ previous pass. When the row is not changed,
+ the new_row variable will be NULL. The rows
+ and passes are called in order, so you don't
+ really need the row_num and pass, but I'm
+ supplying them because it may make your life
+ easier.
+
+ For the non-NULL rows of interlaced images,
+ you must call png_progressive_combine_row()
+ passing in the row and the old row. You can
+ call this function for NULL rows (it will just
+ return) and for non-interlaced images (it just
+ does the memcpy for you) if it will make the
+ code easier. Thus, you can just do this for
+ all cases:
+ */
+
+ png_progressive_combine_row(png_ptr, old_row,
+ new_row);
+
+ /* where old_row is what was displayed for
+ previously for the row. Note that the first
+ pass (pass == 0, really) will completely cover
+ the old row, so the rows do not have to be
+ initialized. After the first pass (and only
+ for interlaced images), you will have to pass
+ the current row, and the function will combine
+ the old row and the new row.
+ */
+ }
+
+ void
+ end_callback(png_structp png_ptr, png_infop info)
+ {
+ /* This function is called after the whole image
+ has been read, including any chunks after the
+ image (up to and including the IEND). You
+ will usually have the same info chunk as you
+ had in the header, although some data may have
+ been added to the comments and time fields.
+
+ Most people won't do much here, perhaps setting
+ a flag that marks the image as finished.
+ */
+ }
+
+
+
+IV. Writing
+
+Much of this is very similar to reading. However, everything of
+importance is repeated here, so you won't have to constantly look
+back up in the reading section to understand writing.
+
+Setup
+
+You will want to do the I/O initialization before you get into libpng,
+so if it doesn't work, you don't have anything to undo. If you are not
+using the standard I/O functions, you will need to replace them with
+custom writing functions. See the discussion under Customizing libpng.
+
+ FILE *fp = fopen(file_name, "wb");
+ if (!fp)
+ {
+ return (ERROR);
+ }
+
+Next, png_struct and png_info need to be allocated and initialized.
+As these can be both relatively large, you may not want to store these
+on the stack, unless you have stack space to spare. Of course, you
+will want to check if they return NULL. If you are also reading,
+you won't want to name your read structure and your write structure
+both "png_ptr"; you can call them anything you like, such as
+"read_ptr" and "write_ptr". Look at pngtest.c, for example.
+
+ png_structp png_ptr = png_create_write_struct
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn);
+ if (!png_ptr)
+ return (ERROR);
+
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+ if (!info_ptr)
+ {
+ png_destroy_write_struct(&png_ptr,
+ (png_infopp)NULL);
+ return (ERROR);
+ }
+
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_write_struct_2() instead of png_create_write_struct():
+
+ png_structp png_ptr = png_create_write_struct_2
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ user_error_fn, user_warning_fn, (png_voidp)
+ user_mem_ptr, user_malloc_fn, user_free_fn);
+
+After you have these structures, you will need to set up the
+error handling. When libpng encounters an error, it expects to
+longjmp() back to your routine. Therefore, you will need to call
+setjmp() and pass the png_jmpbuf(png_ptr). If you
+write the file from different routines, you will need to update
+the png_jmpbuf(png_ptr) every time you enter a new routine that will
+call a png_*() function. See your documentation of setjmp/longjmp
+for your compiler for more information on setjmp/longjmp. See
+the discussion on libpng error handling in the Customizing Libpng
+section below for more information on the libpng error handling.
+
+ if (setjmp(png_jmpbuf(png_ptr)))
+ {
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+ fclose(fp);
+ return (ERROR);
+ }
+ ...
+ return;
+
+If you would rather avoid the complexity of setjmp/longjmp issues,
+you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
+errors will result in a call to PNG_ABORT() which defaults to abort().
+
+Now you need to set up the output code. The default for libpng is to
+use the C function fwrite(). If you use this, you will need to pass a
+valid FILE * in the function png_init_io(). Be sure that the file is
+opened in binary mode. Again, if you wish to handle writing data in
+another way, see the discussion on libpng I/O handling in the Customizing
+Libpng section below.
+
+ png_init_io(png_ptr, fp);
+
+Write callbacks
+
+At this point, you can set up a callback function that will be
+called after each row has been written, which you can use to control
+a progress meter or the like. It's demonstrated in pngtest.c.
+You must supply a function
+
+ void write_row_callback(png_ptr, png_uint_32 row,
+ int pass);
+ {
+ /* put your code here */
+ }
+
+(You can give it another name that you like instead of "write_row_callback")
+
+To inform libpng about your function, use
+
+ png_set_write_status_fn(png_ptr, write_row_callback);
+
+You now have the option of modifying how the compression library will
+run. The following functions are mainly for testing, but may be useful
+in some cases, like if you need to write PNG files extremely fast and
+are willing to give up some compression, or if you want to get the
+maximum possible compression at the expense of slower writing. If you
+have no special needs in this area, let the library do what it wants by
+not calling this function at all, as it has been tuned to deliver a good
+speed/compression ratio. The second parameter to png_set_filter() is
+the filter method, for which the only valid values are 0 (as of the
+July 1999 PNG specification, version 1.2) or 64 (if you are writing
+a PNG datastream that is to be embedded in a MNG datastream). The third
+parameter is a flag that indicates which filter type(s) are to be tested
+for each scanline. See the PNG specification for details on the specific filter
+types.
+
+
+ /* turn on or off filtering, and/or choose
+ specific filters. You can use either a single
+ PNG_FILTER_VALUE_NAME or the logical OR of one
+ or more PNG_FILTER_NAME masks. */
+ png_set_filter(png_ptr, 0,
+ PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE |
+ PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB |
+ PNG_FILTER_UP | PNG_FILTER_VALUE_UP |
+ PNG_FILTER_AVE | PNG_FILTER_VALUE_AVE |
+ PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH|
+ PNG_ALL_FILTERS);
+
+If an application
+wants to start and stop using particular filters during compression,
+it should start out with all of the filters (to ensure that the previous
+row of pixels will be stored in case it's needed later), and then add
+and remove them after the start of compression.
+
+If you are writing a PNG datastream that is to be embedded in a MNG
+datastream, the second parameter can be either 0 or 64.
+
+The png_set_compression_*() functions interface to the zlib compression
+library, and should mostly be ignored unless you really know what you are
+doing. The only generally useful call is png_set_compression_level()
+which changes how much time zlib spends on trying to compress the image
+data. See the Compression Library (zlib.h and algorithm.txt, distributed
+with zlib) for details on the compression levels.
+
+ /* set the zlib compression level */
+ png_set_compression_level(png_ptr,
+ Z_BEST_COMPRESSION);
+
+ /* set other zlib parameters */
+ png_set_compression_mem_level(png_ptr, 8);
+ png_set_compression_strategy(png_ptr,
+ Z_DEFAULT_STRATEGY);
+ png_set_compression_window_bits(png_ptr, 15);
+ png_set_compression_method(png_ptr, 8);
+ png_set_compression_buffer_size(png_ptr, 8192)
+
+extern PNG_EXPORT(void,png_set_zbuf_size)
+
+Setting the contents of info for output
+
+You now need to fill in the png_info structure with all the data you
+wish to write before the actual image. Note that the only thing you
+are allowed to write after the image is the text chunks and the time
+chunk (as of PNG Specification 1.2, anyway). See png_write_end() and
+the latest PNG specification for more information on that. If you
+wish to write them before the image, fill them in now, and flag that
+data as being valid. If you want to wait until after the data, don't
+fill them until png_write_end(). For all the fields in png_info and
+their data types, see png.h. For explanations of what the fields
+contain, see the PNG specification.
+
+Some of the more important parts of the png_info are:
+
+ png_set_IHDR(png_ptr, info_ptr, width, height,
+ bit_depth, color_type, interlace_type,
+ compression_type, filter_method)
+ width - holds the width of the image
+ in pixels (up to 2^31).
+ height - holds the height of the image
+ in pixels (up to 2^31).
+ bit_depth - holds the bit depth of one of the
+ image channels.
+ (valid values are 1, 2, 4, 8, 16
+ and depend also on the
+ color_type. See also significant
+ bits (sBIT) below).
+ color_type - describes which color/alpha
+ channels are present.
+ PNG_COLOR_TYPE_GRAY
+ (bit depths 1, 2, 4, 8, 16)
+ PNG_COLOR_TYPE_GRAY_ALPHA
+ (bit depths 8, 16)
+ PNG_COLOR_TYPE_PALETTE
+ (bit depths 1, 2, 4, 8)
+ PNG_COLOR_TYPE_RGB
+ (bit_depths 8, 16)
+ PNG_COLOR_TYPE_RGB_ALPHA
+ (bit_depths 8, 16)
+
+ PNG_COLOR_MASK_PALETTE
+ PNG_COLOR_MASK_COLOR
+ PNG_COLOR_MASK_ALPHA
+
+ interlace_type - PNG_INTERLACE_NONE or
+ PNG_INTERLACE_ADAM7
+ compression_type - (must be
+ PNG_COMPRESSION_TYPE_DEFAULT)
+ filter_method - (must be PNG_FILTER_TYPE_DEFAULT
+ or, if you are writing a PNG to
+ be embedded in a MNG datastream,
+ can also be
+ PNG_INTRAPIXEL_DIFFERENCING)
+
+ png_set_PLTE(png_ptr, info_ptr, palette,
+ num_palette);
+ palette - the palette for the file
+ (array of png_color)
+ num_palette - number of entries in the palette
+
+ png_set_gAMA(png_ptr, info_ptr, gamma);
+ gamma - the gamma the image was created
+ at (PNG_INFO_gAMA)
+
+ png_set_sRGB(png_ptr, info_ptr, srgb_intent);
+ srgb_intent - the rendering intent
+ (PNG_INFO_sRGB) The presence of
+ the sRGB chunk means that the pixel
+ data is in the sRGB color space.
+ This chunk also implies specific
+ values of gAMA and cHRM. Rendering
+ intent is the CSS-1 property that
+ has been defined by the International
+ Color Consortium
+ (http://www.color.org).
+ It can be one of
+ PNG_sRGB_INTENT_SATURATION,
+ PNG_sRGB_INTENT_PERCEPTUAL,
+ PNG_sRGB_INTENT_ABSOLUTE, or
+ PNG_sRGB_INTENT_RELATIVE.
+
+
+ png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr,
+ srgb_intent);
+ srgb_intent - the rendering intent
+ (PNG_INFO_sRGB) The presence of the
+ sRGB chunk means that the pixel
+ data is in the sRGB color space.
+ This function also causes gAMA and
+ cHRM chunks with the specific values
+ that are consistent with sRGB to be
+ written.
+
+ png_set_iCCP(png_ptr, info_ptr, name, compression_type,
+ profile, proflen);
+ name - The profile name.
+ compression - The compression type; always
+ PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+ You may give NULL to this argument to
+ ignore it.
+ profile - International Color Consortium color
+ profile data. May contain NULs.
+ proflen - length of profile data in bytes.
+
+ png_set_sBIT(png_ptr, info_ptr, sig_bit);
+ sig_bit - the number of significant bits for
+ (PNG_INFO_sBIT) each of the gray, red,
+ green, and blue channels, whichever are
+ appropriate for the given color type
+ (png_color_16)
+
+ png_set_tRNS(png_ptr, info_ptr, trans, num_trans,
+ trans_values);
+ trans - array of transparent entries for
+ palette (PNG_INFO_tRNS)
+ trans_values - graylevel or color sample values of
+ the single transparent color for
+ non-paletted images (PNG_INFO_tRNS)
+ num_trans - number of transparent entries
+ (PNG_INFO_tRNS)
+
+ png_set_hIST(png_ptr, info_ptr, hist);
+ (PNG_INFO_hIST)
+ hist - histogram of palette (array of
+ png_uint_16)
+
+ png_set_tIME(png_ptr, info_ptr, mod_time);
+ mod_time - time image was last modified
+ (PNG_VALID_tIME)
+
+ png_set_bKGD(png_ptr, info_ptr, background);
+ background - background color (PNG_VALID_bKGD)
+
+ png_set_text(png_ptr, info_ptr, text_ptr, num_text);
+ text_ptr - array of png_text holding image
+ comments
+ text_ptr[i].compression - type of compression used
+ on "text" PNG_TEXT_COMPRESSION_NONE
+ PNG_TEXT_COMPRESSION_zTXt
+ PNG_ITXT_COMPRESSION_NONE
+ PNG_ITXT_COMPRESSION_zTXt
+ text_ptr[i].key - keyword for comment. Must contain
+ 1-79 characters.
+ text_ptr[i].text - text comments for current
+ keyword. Can be NULL or empty.
+ text_ptr[i].text_length - length of text string,
+ after decompression, 0 for iTXt
+ text_ptr[i].itxt_length - length of itxt string,
+ after decompression, 0 for tEXt/zTXt
+ text_ptr[i].lang - language of comment (NULL or
+ empty for unknown).
+ text_ptr[i].translated_keyword - keyword in UTF-8 (NULL
+ or empty for unknown).
+ num_text - number of comments
+
+ png_set_sPLT(png_ptr, info_ptr, &palette_ptr,
+ num_spalettes);
+ palette_ptr - array of png_sPLT_struct structures
+ to be added to the list of palettes
+ in the info structure.
+ num_spalettes - number of palette structures to be
+ added.
+
+ png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y,
+ unit_type);
+ offset_x - positive offset from the left
+ edge of the screen
+ offset_y - positive offset from the top
+ edge of the screen
+ unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
+
+ png_set_pHYs(png_ptr, info_ptr, res_x, res_y,
+ unit_type);
+ res_x - pixels/unit physical resolution
+ in x direction
+ res_y - pixels/unit physical resolution
+ in y direction
+ unit_type - PNG_RESOLUTION_UNKNOWN,
+ PNG_RESOLUTION_METER
+
+ png_set_sCAL(png_ptr, info_ptr, unit, width, height)
+ unit - physical scale units (an integer)
+ width - width of a pixel in physical scale units
+ height - height of a pixel in physical scale units
+ (width and height are doubles)
+
+ png_set_sCAL_s(png_ptr, info_ptr, unit, width, height)
+ unit - physical scale units (an integer)
+ width - width of a pixel in physical scale units
+ height - height of a pixel in physical scale units
+ (width and height are strings like "2.54")
+
+ png_set_unknown_chunks(png_ptr, info_ptr, &unknowns,
+ num_unknowns)
+ unknowns - array of png_unknown_chunk
+ structures holding unknown chunks
+ unknowns[i].name - name of unknown chunk
+ unknowns[i].data - data of unknown chunk
+ unknowns[i].size - size of unknown chunk's data
+ unknowns[i].location - position to write chunk in file
+ 0: do not write chunk
+ PNG_HAVE_IHDR: before PLTE
+ PNG_HAVE_PLTE: before IDAT
+ PNG_AFTER_IDAT: after IDAT
+
+The "location" member is set automatically according to
+what part of the output file has already been written.
+You can change its value after calling png_set_unknown_chunks()
+as demonstrated in pngtest.c. Within each of the "locations",
+the chunks are sequenced according to their position in the
+structure (that is, the value of "i", which is the order in which
+the chunk was either read from the input file or defined with
+png_set_unknown_chunks).
+
+A quick word about text and num_text. text is an array of png_text
+structures. num_text is the number of valid structures in the array.
+Each png_text structure holds a language code, a keyword, a text value,
+and a compression type.
+
+The compression types have the same valid numbers as the compression
+types of the image data. Currently, the only valid number is zero.
+However, you can store text either compressed or uncompressed, unlike
+images, which always have to be compressed. So if you don't want the
+text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE.
+Because tEXt and zTXt chunks don't have a language field, if you
+specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt
+any language code or translated keyword will not be written out.
+
+Until text gets around 1000 bytes, it is not worth compressing it.
+After the text has been written out to the file, the compression type
+is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR,
+so that it isn't written out again at the end (in case you are calling
+png_write_end() with the same struct.
+
+The keywords that are given in the PNG Specification are:
+
+ Title Short (one line) title or
+ caption for image
+ Author Name of image's creator
+ Description Description of image (possibly long)
+ Copyright Copyright notice
+ Creation Time Time of original image creation
+ (usually RFC 1123 format, see below)
+ Software Software used to create the image
+ Disclaimer Legal disclaimer
+ Warning Warning of nature of content
+ Source Device used to create the image
+ Comment Miscellaneous comment; conversion
+ from other image format
+
+The keyword-text pairs work like this. Keywords should be short
+simple descriptions of what the comment is about. Some typical
+keywords are found in the PNG specification, as is some recommendations
+on keywords. You can repeat keywords in a file. You can even write
+some text before the image and some after. For example, you may want
+to put a description of the image before the image, but leave the
+disclaimer until after, so viewers working over modem connections
+don't have to wait for the disclaimer to go over the modem before
+they start seeing the image. Finally, keywords should be full
+words, not abbreviations. Keywords and text are in the ISO 8859-1
+(Latin-1) character set (a superset of regular ASCII) and can not
+contain NUL characters, and should not contain control or other
+unprintable characters. To make the comments widely readable, stick
+with basic ASCII, and avoid machine specific character set extensions
+like the IBM-PC character set. The keyword must be present, but
+you can leave off the text string on non-compressed pairs.
+Compressed pairs must have a text string, as only the text string
+is compressed anyway, so the compression would be meaningless.
+
+PNG supports modification time via the png_time structure. Two
+conversion routines are provided, png_convert_from_time_t() for
+time_t and png_convert_from_struct_tm() for struct tm. The
+time_t routine uses gmtime(). You don't have to use either of
+these, but if you wish to fill in the png_time structure directly,
+you should provide the time in universal time (GMT) if possible
+instead of your local time. Note that the year number is the full
+year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and
+that months start with 1.
+
+If you want to store the time of the original image creation, you should
+use a plain tEXt chunk with the "Creation Time" keyword. This is
+necessary because the "creation time" of a PNG image is somewhat vague,
+depending on whether you mean the PNG file, the time the image was
+created in a non-PNG format, a still photo from which the image was
+scanned, or possibly the subject matter itself. In order to facilitate
+machine-readable dates, it is recommended that the "Creation Time"
+tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
+although this isn't a requirement. Unlike the tIME chunk, the
+"Creation Time" tEXt chunk is not expected to be automatically changed
+by the software. To facilitate the use of RFC 1123 dates, a function
+png_convert_to_rfc1123(png_timep) is provided to convert from PNG
+time to an RFC 1123 format string.
+
+Writing unknown chunks
+
+You can use the png_set_unknown_chunks function to queue up chunks
+for writing. You give it a chunk name, raw data, and a size; that's
+all there is to it. The chunks will be written by the next following
+png_write_info_before_PLTE, png_write_info, or png_write_end function.
+Any chunks previously read into the info structure's unknown-chunk
+list will also be written out in a sequence that satisfies the PNG
+specification's ordering rules.
+
+The high-level write interface
+
+At this point there are two ways to proceed; through the high-level
+write interface, or through a sequence of low-level write operations.
+You can use the high-level interface if your image data is present
+in the info structure. All defined output
+transformations are permitted, enabled by the following masks.
+
+ PNG_TRANSFORM_IDENTITY No transformation
+ PNG_TRANSFORM_PACKING Pack 1, 2 and 4-bit samples
+ PNG_TRANSFORM_PACKSWAP Change order of packed
+ pixels to LSB first
+ PNG_TRANSFORM_INVERT_MONO Invert monochrome images
+ PNG_TRANSFORM_SHIFT Normalize pixels to the
+ sBIT depth
+ PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
+ to BGRA
+ PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
+ to AG
+ PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
+ to transparency
+ PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
+ PNG_TRANSFORM_STRIP_FILLER Strip out filler bytes.
+
+If you have valid image data in the info structure (you can use
+png_set_rows() to put image data in the info structure), simply do this:
+
+ png_write_png(png_ptr, info_ptr, png_transforms, NULL)
+
+where png_transforms is an integer containing the logical OR of some set of
+transformation flags. This call is equivalent to png_write_info(),
+followed the set of transformations indicated by the transform mask,
+then png_write_image(), and finally png_write_end().
+
+(The final parameter of this call is not yet used. Someday it might point
+to transformation parameters required by some future output transform.)
+
+You must use png_transforms and not call any png_set_transform() functions
+when you use png_write_png().
+
+The low-level write interface
+
+If you are going the low-level route instead, you are now ready to
+write all the file information up to the actual image data. You do
+this with a call to png_write_info().
+
+ png_write_info(png_ptr, info_ptr);
+
+Note that there is one transformation you may need to do before
+png_write_info(). In PNG files, the alpha channel in an image is the
+level of opacity. If your data is supplied as a level of
+transparency, you can invert the alpha channel before you write it, so
+that 0 is fully transparent and 255 (in 8-bit or paletted images) or
+65535 (in 16-bit images) is fully opaque, with
+
+ png_set_invert_alpha(png_ptr);
+
+This must appear before png_write_info() instead of later with the
+other transformations because in the case of paletted images the tRNS
+chunk data has to be inverted before the tRNS chunk is written. If
+your image is not a paletted image, the tRNS data (which in such cases
+represents a single color to be rendered as transparent) won't need to
+be changed, and you can safely do this transformation after your
+png_write_info() call.
+
+If you need to write a private chunk that you want to appear before
+the PLTE chunk when PLTE is present, you can write the PNG info in
+two steps, and insert code to write your own chunk between them:
+
+ png_write_info_before_PLTE(png_ptr, info_ptr);
+ png_set_unknown_chunks(png_ptr, info_ptr, ...);
+ png_write_info(png_ptr, info_ptr);
+
+After you've written the file information, you can set up the library
+to handle any special transformations of the image data. The various
+ways to transform the data will be described in the order that they
+should occur. This is important, as some of these change the color
+type and/or bit depth of the data, and some others only work on
+certain color types and bit depths. Even though each transformation
+checks to see if it has data that it can do something with, you should
+make sure to only enable a transformation if it will be valid for the
+data. For example, don't swap red and blue on grayscale data.
+
+PNG files store RGB pixels packed into 3 or 6 bytes. This code tells
+the library to strip input data that has 4 or 8 bytes per pixel down
+to 3 or 6 bytes (or strip 2 or 4-byte grayscale+filler data to 1 or 2
+bytes per pixel).
+
+ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+
+where the 0 is unused, and the location is either PNG_FILLER_BEFORE or
+PNG_FILLER_AFTER, depending upon whether the filler byte in the pixel
+is stored XRGB or RGBX.
+
+PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
+they can, resulting in, for example, 8 pixels per byte for 1 bit files.
+If the data is supplied at 1 pixel per byte, use this code, which will
+correctly pack the pixels into a single byte:
+
+ png_set_packing(png_ptr);
+
+PNG files reduce possible bit depths to 1, 2, 4, 8, and 16. If your
+data is of another bit depth, you can write an sBIT chunk into the
+file so that decoders can recover the original data if desired.
+
+ /* Set the true bit depth of the image data */
+ if (color_type & PNG_COLOR_MASK_COLOR)
+ {
+ sig_bit.red = true_bit_depth;
+ sig_bit.green = true_bit_depth;
+ sig_bit.blue = true_bit_depth;
+ }
+ else
+ {
+ sig_bit.gray = true_bit_depth;
+ }
+ if (color_type & PNG_COLOR_MASK_ALPHA)
+ {
+ sig_bit.alpha = true_bit_depth;
+ }
+
+ png_set_sBIT(png_ptr, info_ptr, &sig_bit);
+
+If the data is stored in the row buffer in a bit depth other than
+one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG),
+this will scale the values to appear to be the correct bit depth as
+is required by PNG.
+
+ png_set_shift(png_ptr, &sig_bit);
+
+PNG files store 16 bit pixels in network byte order (big-endian,
+ie. most significant bits first). This code would be used if they are
+supplied the other way (little-endian, i.e. least significant bits
+first, the way PCs store them):
+
+ if (bit_depth > 8)
+ png_set_swap(png_ptr);
+
+If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
+need to change the order the pixels are packed into bytes, you can use:
+
+ if (bit_depth < 8)
+ png_set_packswap(png_ptr);
+
+PNG files store 3 color pixels in red, green, blue order. This code
+would be used if they are supplied as blue, green, red:
+
+ png_set_bgr(png_ptr);
+
+PNG files describe monochrome as black being zero and white being
+one. This code would be used if the pixels are supplied with this reversed
+(black being one and white being zero):
+
+ png_set_invert_mono(png_ptr);
+
+Finally, you can write your own transformation function if none of
+the existing ones meets your needs. This is done by setting a callback
+with
+
+ png_set_write_user_transform_fn(png_ptr,
+ write_transform_fn);
+
+You must supply the function
+
+ void write_transform_fn(png_ptr ptr, row_info_ptr
+ row_info, png_bytep data)
+
+See pngtest.c for a working example. Your function will be called
+before any of the other transformations are processed.
+
+You can also set up a pointer to a user structure for use by your
+callback function.
+
+ png_set_user_transform_info(png_ptr, user_ptr, 0, 0);
+
+The user_channels and user_depth parameters of this function are ignored
+when writing; you can set them to zero as shown.
+
+You can retrieve the pointer via the function png_get_user_transform_ptr().
+For example:
+
+ voidp write_user_transform_ptr =
+ png_get_user_transform_ptr(png_ptr);
+
+It is possible to have libpng flush any pending output, either manually,
+or automatically after a certain number of lines have been written. To
+flush the output stream a single time call:
+
+ png_write_flush(png_ptr);
+
+and to have libpng flush the output stream periodically after a certain
+number of scanlines have been written, call:
+
+ png_set_flush(png_ptr, nrows);
+
+Note that the distance between rows is from the last time png_write_flush()
+was called, or the first row of the image if it has never been called.
+So if you write 50 lines, and then png_set_flush 25, it will flush the
+output on the next scanline, and every 25 lines thereafter, unless
+png_write_flush() is called before 25 more lines have been written.
+If nrows is too small (less than about 10 lines for a 640 pixel wide
+RGB image) the image compression may decrease noticeably (although this
+may be acceptable for real-time applications). Infrequent flushing will
+only degrade the compression performance by a few percent over images
+that do not use flushing.
+
+Writing the image data
+
+That's it for the transformations. Now you can write the image data.
+The simplest way to do this is in one function call. If you have the
+whole image in memory, you can just call png_write_image() and libpng
+will write the image. You will need to pass in an array of pointers to
+each row. This function automatically handles interlacing, so you don't
+need to call png_set_interlace_handling() or call this function multiple
+times, or any of that other stuff necessary with png_write_rows().
+
+ png_write_image(png_ptr, row_pointers);
+
+where row_pointers is:
+
+ png_byte *row_pointers[height];
+
+You can point to void or char or whatever you use for pixels.
+
+If you don't want to write the whole image at once, you can
+use png_write_rows() instead. If the file is not interlaced,
+this is simple:
+
+ png_write_rows(png_ptr, row_pointers,
+ number_of_rows);
+
+row_pointers is the same as in the png_write_image() call.
+
+If you are just writing one row at a time, you can do this with
+a single row_pointer instead of an array of row_pointers:
+
+ png_bytep row_pointer = row;
+
+ png_write_row(png_ptr, row_pointer);
+
+When the file is interlaced, things can get a good deal more
+complicated. The only currently (as of the PNG Specification
+version 1.2, dated July 1999) defined interlacing scheme for PNG files
+is the "Adam7" interlace scheme, that breaks down an
+image into seven smaller images of varying size. libpng will build
+these images for you, or you can do them yourself. If you want to
+build them yourself, see the PNG specification for details of which
+pixels to write when.
+
+If you don't want libpng to handle the interlacing details, just
+use png_set_interlace_handling() and call png_write_rows() the
+correct number of times to write all seven sub-images.
+
+If you want libpng to build the sub-images, call this before you start
+writing any rows:
+
+ number_of_passes =
+ png_set_interlace_handling(png_ptr);
+
+This will return the number of passes needed. Currently, this
+is seven, but may change if another interlace type is added.
+
+Then write the complete image number_of_passes times.
+
+ png_write_rows(png_ptr, row_pointers,
+ number_of_rows);
+
+As some of these rows are not used, and thus return immediately,
+you may want to read about interlacing in the PNG specification,
+and only update the rows that are actually used.
+
+Finishing a sequential write
+
+After you are finished writing the image, you should finish writing
+the file. If you are interested in writing comments or time, you should
+pass an appropriately filled png_info pointer. If you are not interested,
+you can pass NULL.
+
+ png_write_end(png_ptr, info_ptr);
+
+When you are done, you can free all memory used by libpng like this:
+
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+
+It is also possible to individually free the info_ptr members that
+point to libpng-allocated storage with the following function:
+
+ png_free_data(png_ptr, info_ptr, mask, seq)
+ mask - identifies data to be freed, a mask
+ containing the logical OR of one or
+ more of
+ PNG_FREE_PLTE, PNG_FREE_TRNS,
+ PNG_FREE_HIST, PNG_FREE_ICCP,
+ PNG_FREE_PCAL, PNG_FREE_ROWS,
+ PNG_FREE_SCAL, PNG_FREE_SPLT,
+ PNG_FREE_TEXT, PNG_FREE_UNKN,
+ or simply PNG_FREE_ALL
+ seq - sequence number of item to be freed
+ (-1 for all items)
+
+This function may be safely called when the relevant storage has
+already been freed, or has not yet been allocated, or was allocated
+by the user and not by libpng, and will in those
+cases do nothing. The "seq" parameter is ignored if only one item
+of the selected data type, such as PLTE, is allowed. If "seq" is not
+-1, and multiple items are allowed for the data type identified in
+the mask, such as text or sPLT, only the n'th item in the structure
+is freed, where n is "seq".
+
+If you allocated data such as a palette that you passed
+in to libpng with png_set_*, you must not free it until just before the call to
+png_destroy_write_struct().
+
+The default behavior is only to free data that was allocated internally
+by libpng. This can be changed, so that libpng will not free the data,
+or so that it will free data that was allocated by the user with png_malloc()
+or png_zalloc() and passed in via a png_set_*() function, with
+
+ png_data_freer(png_ptr, info_ptr, freer, mask)
+ mask - which data elements are affected
+ same choices as in png_free_data()
+ freer - one of
+ PNG_DESTROY_WILL_FREE_DATA
+ PNG_SET_WILL_FREE_DATA
+ PNG_USER_WILL_FREE_DATA
+
+For example, to transfer responsibility for some data from a read structure
+to a write structure, you could use
+
+ png_data_freer(read_ptr, read_info_ptr,
+ PNG_USER_WILL_FREE_DATA,
+ PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+ png_data_freer(write_ptr, write_info_ptr,
+ PNG_DESTROY_WILL_FREE_DATA,
+ PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+
+thereby briefly reassigning responsibility for freeing to the user but
+immediately afterwards reassigning it once more to the write_destroy
+function. Having done this, it would then be safe to destroy the read
+structure and continue to use the PLTE, tRNS, and hIST data in the write
+structure.
+
+This function only affects data that has already been allocated.
+You can call this function before calling after the png_set_*() functions
+to control whether the user or png_destroy_*() is supposed to free the data.
+When the user assumes responsibility for libpng-allocated data, the
+application must use
+png_free() to free it, and when the user transfers responsibility to libpng
+for data that the user has allocated, the user must have used png_malloc()
+or png_zalloc() to allocate it.
+
+If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
+separately, do not transfer responsibility for freeing text_ptr to libpng,
+because when libpng fills a png_text structure it combines these members with
+the key member, and png_free_data() will free only text_ptr.key. Similarly,
+if you transfer responsibility for free'ing text_ptr from libpng to your
+application, your application must not separately free those members.
+For a more compact example of writing a PNG image, see the file example.c.
+
+V. Modifying/Customizing libpng:
+
+There are three issues here. The first is changing how libpng does
+standard things like memory allocation, input/output, and error handling.
+The second deals with more complicated things like adding new chunks,
+adding new transformations, and generally changing how libpng works.
+Both of those are compile-time issues; that is, they are generally
+determined at the time the code is written, and there is rarely a need
+to provide the user with a means of changing them. The third is a
+run-time issue: choosing between and/or tuning one or more alternate
+versions of computationally intensive routines; specifically, optimized
+assembly-language (and therefore compiler- and platform-dependent)
+versions.
+
+Memory allocation, input/output, and error handling
+
+All of the memory allocation, input/output, and error handling in libpng
+goes through callbacks that are user-settable. The default routines are
+in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively. To change
+these functions, call the appropriate png_set_*_fn() function.
+
+Memory allocation is done through the functions png_malloc()
+and png_free(). These currently just call the standard C functions. If
+your pointers can't access more then 64K at a time, you will want to set
+MAXSEG_64K in zlib.h. Since it is unlikely that the method of handling
+memory allocation on a platform will change between applications, these
+functions must be modified in the library at compile time. If you prefer
+to use a different method of allocating and freeing data, you can use
+png_create_read_struct_2() or png_create_write_struct_2() to register
+your own functions as described above.
+These functions also provide a void pointer that can be retrieved via
+
+ mem_ptr=png_get_mem_ptr(png_ptr);
+
+Your replacement memory functions must have prototypes as follows:
+
+ png_voidp malloc_fn(png_structp png_ptr,
+ png_size_t size);
+ void free_fn(png_structp png_ptr, png_voidp ptr);
+
+Your malloc_fn() must return NULL in case of failure. The png_malloc()
+function will normally call png_error() if it receives a NULL from the
+system memory allocator or from your replacement malloc_fn().
+
+Input/Output in libpng is done through png_read() and png_write(),
+which currently just call fread() and fwrite(). The FILE * is stored in
+png_struct and is initialized via png_init_io(). If you wish to change
+the method of I/O, the library supplies callbacks that you can set
+through the function png_set_read_fn() and png_set_write_fn() at run
+time, instead of calling the png_init_io() function. These functions
+also provide a void pointer that can be retrieved via the function
+png_get_io_ptr(). For example:
+
+ png_set_read_fn(png_structp read_ptr,
+ voidp read_io_ptr, png_rw_ptr read_data_fn)
+
+ png_set_write_fn(png_structp write_ptr,
+ voidp write_io_ptr, png_rw_ptr write_data_fn,
+ png_flush_ptr output_flush_fn);
+
+ voidp read_io_ptr = png_get_io_ptr(read_ptr);
+ voidp write_io_ptr = png_get_io_ptr(write_ptr);
+
+The replacement I/O functions must have prototypes as follows:
+
+ void user_read_data(png_structp png_ptr,
+ png_bytep data, png_size_t length);
+ void user_write_data(png_structp png_ptr,
+ png_bytep data, png_size_t length);
+ void user_flush_data(png_structp png_ptr);
+
+Supplying NULL for the read, write, or flush functions sets them back
+to using the default C stream functions. It is an error to read from
+a write stream, and vice versa.
+
+Error handling in libpng is done through png_error() and png_warning().
+Errors handled through png_error() are fatal, meaning that png_error()
+should never return to its caller. Currently, this is handled via
+setjmp() and longjmp() (unless you have compiled libpng with
+PNG_SETJMP_NOT_SUPPORTED, in which case it is handled via PNG_ABORT()),
+but you could change this to do things like exit() if you should wish.
+
+On non-fatal errors, png_warning() is called
+to print a warning message, and then control returns to the calling code.
+By default png_error() and png_warning() print a message on stderr via
+fprintf() unless the library is compiled with PNG_NO_CONSOLE_IO defined
+(because you don't want the messages) or PNG_NO_STDIO defined (because
+fprintf() isn't available). If you wish to change the behavior of the error
+functions, you will need to set up your own message callbacks. These
+functions are normally supplied at the time that the png_struct is created.
+It is also possible to redirect errors and warnings to your own replacement
+functions after png_create_*_struct() has been called by calling:
+
+ png_set_error_fn(png_structp png_ptr,
+ png_voidp error_ptr, png_error_ptr error_fn,
+ png_error_ptr warning_fn);
+
+ png_voidp error_ptr = png_get_error_ptr(png_ptr);
+
+If NULL is supplied for either error_fn or warning_fn, then the libpng
+default function will be used, calling fprintf() and/or longjmp() if a
+problem is encountered. The replacement error functions should have
+parameters as follows:
+
+ void user_error_fn(png_structp png_ptr,
+ png_const_charp error_msg);
+ void user_warning_fn(png_structp png_ptr,
+ png_const_charp warning_msg);
+
+The motivation behind using setjmp() and longjmp() is the C++ throw and
+catch exception handling methods. This makes the code much easier to write,
+as there is no need to check every return code of every function call.
+However, there are some uncertainties about the status of local variables
+after a longjmp, so the user may want to be careful about doing anything after
+setjmp returns non-zero besides returning itself. Consult your compiler
+documentation for more details. For an alternative approach, you may wish
+to use the "cexcept" facility (see http://cexcept.sourceforge.net).
+
+Custom chunks
+
+If you need to read or write custom chunks, you may need to get deeper
+into the libpng code. The library now has mechanisms for storing
+and writing chunks of unknown type; you can even declare callbacks
+for custom chunks. Hoewver, this may not be good enough if the
+library code itself needs to know about interactions between your
+chunk and existing `intrinsic' chunks.
+
+If you need to write a new intrinsic chunk, first read the PNG
+specification. Acquire a first level of
+understanding of how it works. Pay particular attention to the
+sections that describe chunk names, and look at how other chunks were
+designed, so you can do things similarly. Second, check out the
+sections of libpng that read and write chunks. Try to find a chunk
+that is similar to yours and use it as a template. More details can
+be found in the comments inside the code. It is best to handle unknown
+chunks in a generic method, via callback functions, instead of by
+modifying libpng functions.
+
+If you wish to write your own transformation for the data, look through
+the part of the code that does the transformations, and check out some of
+the simpler ones to get an idea of how they work. Try to find a similar
+transformation to the one you want to add and copy off of it. More details
+can be found in the comments inside the code itself.
+
+Configuring for 16 bit platforms
+
+You will want to look into zconf.h to tell zlib (and thus libpng) that
+it cannot allocate more then 64K at a time. Even if you can, the memory
+won't be accessible. So limit zlib and libpng to 64K by defining MAXSEG_64K.
+
+Configuring for DOS
+
+For DOS users who only have access to the lower 640K, you will
+have to limit zlib's memory usage via a png_set_compression_mem_level()
+call. See zlib.h or zconf.h in the zlib library for more information.
+
+Configuring for Medium Model
+
+Libpng's support for medium model has been tested on most of the popular
+compilers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
+defined, and FAR gets defined to far in pngconf.h, and you should be
+all set. Everything in the library (except for zlib's structure) is
+expecting far data. You must use the typedefs with the p or pp on
+the end for pointers (or at least look at them and be careful). Make
+note that the rows of data are defined as png_bytepp, which is an
+unsigned char far * far *.
+
+Configuring for gui/windowing platforms:
+
+You will need to write new error and warning functions that use the GUI
+interface, as described previously, and set them to be the error and
+warning functions at the time that png_create_*_struct() is called,
+in order to have them available during the structure initialization.
+They can be changed later via png_set_error_fn(). On some compilers,
+you may also have to change the memory allocators (png_malloc, etc.).
+
+Configuring for compiler xxx:
+
+All includes for libpng are in pngconf.h. If you need to add/change/delete
+an include, this is the place to do it. The includes that are not
+needed outside libpng are protected by the PNG_INTERNAL definition,
+which is only defined for those routines inside libpng itself. The
+files in libpng proper only include png.h, which includes pngconf.h.
+
+Configuring zlib:
+
+There are special functions to configure the compression. Perhaps the
+most useful one changes the compression level, which currently uses
+input compression values in the range 0 - 9. The library normally
+uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests
+have shown that for a large majority of images, compression values in
+the range 3-6 compress nearly as well as higher levels, and do so much
+faster. For online applications it may be desirable to have maximum speed
+(Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also
+specify no compression (Z_NO_COMPRESSION = 0), but this would create
+files larger than just storing the raw bitmap. You can specify the
+compression level by calling:
+
+ png_set_compression_level(png_ptr, level);
+
+Another useful one is to reduce the memory level used by the library.
+The memory level defaults to 8, but it can be lowered if you are
+short on memory (running DOS, for example, where you only have 640K).
+Note that the memory level does have an effect on compression; among
+other things, lower levels will result in sections of incompressible
+data being emitted in smaller stored blocks, with a correspondingly
+larger relative overhead of up to 15% in the worst case.
+
+ png_set_compression_mem_level(png_ptr, level);
+
+The other functions are for configuring zlib. They are not recommended
+for normal use and may result in writing an invalid PNG file. See
+zlib.h for more information on what these mean.
+
+ png_set_compression_strategy(png_ptr,
+ strategy);
+ png_set_compression_window_bits(png_ptr,
+ window_bits);
+ png_set_compression_method(png_ptr, method);
+ png_set_compression_buffer_size(png_ptr, size);
+
+Controlling row filtering
+
+If you want to control whether libpng uses filtering or not, which
+filters are used, and how it goes about picking row filters, you
+can call one of these functions. The selection and configuration
+of row filters can have a significant impact on the size and
+encoding speed and a somewhat lesser impact on the decoding speed
+of an image. Filtering is enabled by default for RGB and grayscale
+images (with and without alpha), but not for paletted images nor
+for any images with bit depths less than 8 bits/pixel.
+
+The 'method' parameter sets the main filtering method, which is
+currently only '0' in the PNG 1.2 specification. The 'filters'
+parameter sets which filter(s), if any, should be used for each
+scanline. Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS
+to turn filtering on and off, respectively.
+
+Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB,
+PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise
+ORed together with '|' to specify one or more filters to use.
+These filters are described in more detail in the PNG specification.
+If you intend to change the filter type during the course of writing
+the image, you should start with flags set for all of the filters
+you intend to use so that libpng can initialize its internal
+structures appropriately for all of the filter types. (Note that this
+means the first row must always be adaptively filtered, because libpng
+currently does not allocate the filter buffers until png_write_row()
+is called for the first time.)
+
+ filters = PNG_FILTER_NONE | PNG_FILTER_SUB
+ PNG_FILTER_UP | PNG_FILTER_AVE |
+ PNG_FILTER_PAETH | PNG_ALL_FILTERS;
+
+ png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE,
+ filters);
+ The second parameter can also be
+ PNG_INTRAPIXEL_DIFFERENCING if you are
+ writing a PNG to be embedded in a MNG
+ datastream. This parameter must be the
+ same as the value of filter_method used
+ in png_set_IHDR().
+
+It is also possible to influence how libpng chooses from among the
+available filters. This is done in one or both of two ways - by
+telling it how important it is to keep the same filter for successive
+rows, and by telling it the relative computational costs of the filters.
+
+ double weights[3] = {1.5, 1.3, 1.1},
+ costs[PNG_FILTER_VALUE_LAST] =
+ {1.0, 1.3, 1.3, 1.5, 1.7};
+
+ png_set_filter_heuristics(png_ptr,
+ PNG_FILTER_HEURISTIC_WEIGHTED, 3,
+ weights, costs);
+
+The weights are multiplying factors that indicate to libpng that the
+row filter should be the same for successive rows unless another row filter
+is that many times better than the previous filter. In the above example,
+if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
+"sum of absolute differences" 1.5 x 1.3 times higher than other filters
+and still be chosen, while the NONE filter could have a sum 1.1 times
+higher than other filters and still be chosen. Unspecified weights are
+taken to be 1.0, and the specified weights should probably be declining
+like those above in order to emphasize recent filters over older filters.
+
+The filter costs specify for each filter type a relative decoding cost
+to be considered when selecting row filters. This means that filters
+with higher costs are less likely to be chosen over filters with lower
+costs, unless their "sum of absolute differences" is that much smaller.
+The costs do not necessarily reflect the exact computational speeds of
+the various filters, since this would unduly influence the final image
+size.
+
+Note that the numbers above were invented purely for this example and
+are given only to help explain the function usage. Little testing has
+been done to find optimum values for either the costs or the weights.
+
+Removing unwanted object code
+
+There are a bunch of #define's in pngconf.h that control what parts of
+libpng are compiled. All the defines end in _SUPPORTED. If you are
+never going to use a capability, you can change the #define to #undef
+before recompiling libpng and save yourself code and data space, or
+you can turn off individual capabilities with defines that begin with
+PNG_NO_.
+
+You can also turn all of the transforms and ancillary chunk capabilities
+off en masse with compiler directives that define
+PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
+or all four,
+along with directives to turn on any of the capabilities that you do
+want. The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable
+the extra transformations but still leave the library fully capable of reading
+and writing PNG files with all known public chunks
+Use of the PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive
+produces a library that is incapable of reading or writing ancillary chunks.
+If you are not using the progressive reading capability, you can
+turn that off with PNG_NO_PROGRESSIVE_READ (don't confuse
+this with the INTERLACING capability, which you'll still have).
+
+All the reading and writing specific code are in separate files, so the
+linker should only grab the files it needs. However, if you want to
+make sure, or if you are building a stand alone library, all the
+reading files start with pngr and all the writing files start with
+pngw. The files that don't match either (like png.c, pngtrans.c, etc.)
+are used for both reading and writing, and always need to be included.
+The progressive reader is in pngpread.c
+
+If you are creating or distributing a dynamically linked library (a .so
+or DLL file), you should not remove or disable any parts of the library,
+as this will cause applications linked with different versions of the
+library to fail if they call functions not available in your library.
+The size of the library itself should not be an issue, because only
+those sections that are actually used will be loaded into memory.
+
+Requesting debug printout
+
+The macro definition PNG_DEBUG can be used to request debugging
+printout. Set it to an integer value in the range 0 to 3. Higher
+numbers result in increasing amounts of debugging information. The
+information is printed to the "stderr" file, unless another file
+name is specified in the PNG_DEBUG_FILE macro definition.
+
+When PNG_DEBUG > 0, the following functions (macros) become available:
+
+ png_debug(level, message)
+ png_debug1(level, message, p1)
+ png_debug2(level, message, p1, p2)
+
+in which "level" is compared to PNG_DEBUG to decide whether to print
+the message, "message" is the formatted string to be printed,
+and p1 and p2 are parameters that are to be embedded in the string
+according to printf-style formatting directives. For example,
+
+ png_debug1(2, "foo=%d\n", foo);
+
+is expanded to
+
+ if(PNG_DEBUG > 2)
+ fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+
+When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
+can still use PNG_DEBUG to control your own debugging:
+
+ #ifdef PNG_DEBUG
+ fprintf(stderr, ...
+ #endif
+
+When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
+having level = 0 will be printed. There aren't any such statements in
+this version of libpng, but if you insert some they will be printed.
+
+VI. Runtime optimization
+
+A new feature in libpng 1.2.0 is the ability to dynamically switch between
+standard and optimized versions of some routines. Currently these are
+limited to three computationally intensive tasks when reading PNG files:
+decoding row filters, expanding interlacing, and combining interlaced or
+transparent row data with previous row data. Currently the optimized
+versions are available only for x86 (Intel, AMD, etc.) platforms with
+MMX support, though this may change in future versions. (For example,
+the non-MMX assembler optimizations for zlib might become similarly
+runtime-selectable in future releases, in which case libpng could be
+extended to support them. Alternatively, the compile-time choice of
+floating-point versus integer routines for gamma correction might become
+runtime-selectable.)
+
+Because such optimizations tend to be very platform- and compiler-dependent,
+both in how they are written and in how they perform, the new runtime code
+in libpng has been written to allow programs to query, enable, and disable
+either specific optimizations or all such optimizations. For example, to
+enable all possible optimizations (bearing in mind that some "optimizations"
+may actually run more slowly in rare cases):
+
+ #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+ png_uint_32 mask, flags;
+
+ flags = png_get_asm_flags(png_ptr);
+ mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
+ png_set_asm_flags(png_ptr, flags | mask);
+ #endif
+
+To enable only optimizations relevant to reading PNGs, use PNG_SELECT_READ
+by itself when calling png_get_asm_flagmask(); similarly for optimizing
+only writing. To disable all optimizations:
+
+ #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+ flags = png_get_asm_flags(png_ptr);
+ mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
+ png_set_asm_flags(png_ptr, flags & ~mask);
+ #endif
+
+To enable or disable only MMX-related features, use png_get_mmx_flagmask()
+in place of png_get_asm_flagmask(). The mmx version takes one additional
+parameter:
+
+ #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+ int selection = PNG_SELECT_READ | PNG_SELECT_WRITE;
+ int compilerID;
+
+ mask = png_get_mmx_flagmask(selection, &compilerID);
+ #endif
+
+On return, compilerID will indicate which version of the MMX assembler
+optimizations was compiled. Currently two flavors exist: Microsoft
+Visual C++ (compilerID == 1) and GNU C (a.k.a. gcc/gas, compilerID == 2).
+On non-x86 platforms or on systems compiled without MMX optimizations, a
+value of -1 is used.
+
+Note that both png_get_asm_flagmask() and png_get_mmx_flagmask() return
+all valid, settable optimization bits for the version of the library that's
+currently in use. In the case of shared (dynamically linked) libraries,
+this may include optimizations that did not exist at the time the code was
+written and compiled. It is also possible, of course, to enable only known,
+specific optimizations; for example:
+
+ #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+ flags = PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
+ | PNG_ASM_FLAG_MMX_READ_INTERLACE \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_UP \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ;
+ png_set_asm_flags(png_ptr, flags);
+ #endif
+
+This method would enable only the MMX read-optimizations available at the
+time of libpng 1.2.0's release, regardless of whether a later version of
+the DLL were actually being used. (Also note that these functions did not
+exist in versions older than 1.2.0, so any attempt to run a dynamically
+linked app on such an older version would fail.)
+
+To determine whether the processor supports MMX instructions at all, use
+the png_mmx_support() function:
+
+ #if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+ mmxsupport = png_mmx_support();
+ #endif
+
+It returns -1 if MMX support is not compiled into libpng, 0 if MMX code
+is compiled but MMX is not supported by the processor, or 1 if MMX support
+is fully available. Note that png_mmx_support(), png_get_mmx_flagmask(),
+and png_get_asm_flagmask() all may be called without allocating and ini-
+tializing any PNG structures (for example, as part of a usage screen or
+"about" box).
+
+The following code can be used to prevent an application from using the
+thread_unsafe features, even if libpng was built with PNG_THREAD_UNSAFE_OK
+defined:
+
+#if defined(PNG_USE_PNGGCCRD) && defined(PNG_ASSEMBLER_CODE_SUPPORTED) \
+ && defined(PNG_THREAD_UNSAFE_OK)
+ /* Disable thread-unsafe features of pnggccrd */
+ if (png_access_version() >= 10200)
+ {
+ png_uint_32 mmx_disable_mask = 0;
+ png_uint_32 asm_flags;
+
+ mmx_disable_mask |= ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
+ asm_flags = png_get_asm_flags(png_ptr);
+ png_set_asm_flags(png_ptr, asm_flags & ~mmx_disable_mask);
+ }
+#endif
+
+For more extensive examples of runtime querying, enabling and disabling
+of optimized features, see contrib/gregbook/readpng2.c in the libpng
+source-code distribution.
+
+VII. MNG support
+
+The MNG specification (available at http://www.libpng.org/pub/mng) allows
+certain extensions to PNG for PNG images that are embedded in MNG datastreams.
+Libpng can support some of these extensions. To enable them, use the
+png_permit_mng_features() function:
+
+ feature_set = png_permit_mng_features(png_ptr, mask)
+ mask is a png_uint_32 containing the logical OR of the
+ features you want to enable. These include
+ PNG_FLAG_MNG_EMPTY_PLTE
+ PNG_FLAG_MNG_FILTER_64
+ PNG_ALL_MNG_FEATURES
+ feature_set is a png_uint_32 that is the logical AND of
+ your mask with the set of MNG features that is
+ supported by the version of libpng that you are using.
+
+It is an error to use this function when reading or writing a standalone
+PNG file with the PNG 8-byte signature. The PNG datastream must be wrapped
+in a MNG datastream. As a minimum, it must have the MNG 8-byte signature
+and the MHDR and MEND chunks. Libpng does not provide support for these
+or any other MNG chunks; your application must provide its own support for
+them. You may wish to consider using libmng (available at
+http://www.libmng.com) instead.
+
+VIII. Changes to Libpng from version 0.88
+
+It should be noted that versions of libpng later than 0.96 are not
+distributed by the original libpng author, Guy Schalnat, nor by
+Andreas Dilger, who had taken over from Guy during 1996 and 1997, and
+distributed versions 0.89 through 0.96, but rather by another member
+of the original PNG Group, Glenn Randers-Pehrson. Guy and Andreas are
+still alive and well, but they have moved on to other things.
+
+The old libpng functions png_read_init(), png_write_init(),
+png_info_init(), png_read_destroy(), and png_write_destroy() have been
+moved to PNG_INTERNAL in version 0.95 to discourage their use. These
+functions will be removed from libpng version 2.0.0.
+
+The preferred method of creating and initializing the libpng structures is
+via the png_create_read_struct(), png_create_write_struct(), and
+png_create_info_struct() because they isolate the size of the structures
+from the application, allow version error checking, and also allow the
+use of custom error handling routines during the initialization, which
+the old functions do not. The functions png_read_destroy() and
+png_write_destroy() do not actually free the memory that libpng
+allocated for these structs, but just reset the data structures, so they
+can be used instead of png_destroy_read_struct() and
+png_destroy_write_struct() if you feel there is too much system overhead
+allocating and freeing the png_struct for each image read.
+
+Setting the error callbacks via png_set_message_fn() before
+png_read_init() as was suggested in libpng-0.88 is no longer supported
+because this caused applications that do not use custom error functions
+to fail if the png_ptr was not initialized to zero. It is still possible
+to set the error callbacks AFTER png_read_init(), or to change them with
+png_set_error_fn(), which is essentially the same function, but with a new
+name to force compilation errors with applications that try to use the old
+method.
+
+Starting with version 1.0.7, you can find out which version of the library
+you are using at run-time:
+
+ png_uint_32 libpng_vn = png_access_version_number();
+
+The number libpng_vn is constructed from the major version, minor
+version with leading zero, and release number with leading zero,
+(e.g., libpng_vn for version 1.0.7 is 10007).
+
+You can also check which version of png.h you used when compiling your
+application:
+
+ png_uint_32 application_vn = PNG_LIBPNG_VER;
+
+IX. Y2K Compliance in libpng
+
+December 3, 2004
+
+Since the PNG Development group is an ad-hoc body, we can't make
+an official declaration.
+
+This is your unofficial assurance that libpng from version 0.71 and
+upward through 1.2.8 are Y2K compliant. It is my belief that earlier
+versions were also Y2K compliant.
+
+Libpng only has three year fields. One is a 2-byte unsigned integer that
+will hold years up to 65535. The other two hold the date in text
+format, and will hold years up to 9999.
+
+The integer is
+ "png_uint_16 year" in png_time_struct.
+
+The strings are
+ "png_charp time_buffer" in png_struct and
+ "near_time_buffer", which is a local character string in png.c.
+
+There are seven time-related functions:
+
+ png_convert_to_rfc_1123() in png.c
+ (formerly png_convert_to_rfc_1152() in error)
+ png_convert_from_struct_tm() in pngwrite.c, called
+ in pngwrite.c
+ png_convert_from_time_t() in pngwrite.c
+ png_get_tIME() in pngget.c
+ png_handle_tIME() in pngrutil.c, called in pngread.c
+ png_set_tIME() in pngset.c
+ png_write_tIME() in pngwutil.c, called in pngwrite.c
+
+All appear to handle dates properly in a Y2K environment. The
+png_convert_from_time_t() function calls gmtime() to convert from system
+clock time, which returns (year - 1900), which we properly convert to
+the full 4-digit year. There is a possibility that applications using
+libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+function, or that they are incorrectly passing only a 2-digit year
+instead of "year - 1900" into the png_convert_from_struct_tm() function,
+but this is not under our control. The libpng documentation has always
+stated that it works with 4-digit years, and the APIs have been
+documented as such.
+
+The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
+integer to hold the year, and can hold years as large as 65535.
+
+zlib, upon which libpng depends, is also Y2K compliant. It contains
+no date-related code.
+
+
+ Glenn Randers-Pehrson
+ libpng maintainer
+ PNG Development Group
diff --git a/com32/lib/libpng/png.c b/com32/lib/libpng/png.c
new file mode 100644
index 00000000..608ea2ce
--- /dev/null
+++ b/com32/lib/libpng/png.c
@@ -0,0 +1,828 @@
+
+/* png.c - location for general purpose libpng functions
+ *
+ * libpng version 1.2.8 - December 3, 2004
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2004 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ */
+
+#define PNG_INTERNAL
+#define PNG_NO_EXTERN
+#include "png.h"
+
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef version_1_2_8 Your_png_h_is_not_version_1_2_8;
+
+/* Version information for C files. This had better match the version
+ * string defined in png.h. */
+
+#ifdef PNG_USE_GLOBAL_ARRAYS
+/* png_libpng_ver was changed to a function in version 1.0.5c */
+const char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING;
+
+/* png_sig was changed to a function in version 1.0.5c */
+/* Place to hold the signature string for a PNG file. */
+const png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+/* Invoke global declarations for constant strings for known chunk types */
+PNG_IHDR;
+PNG_IDAT;
+PNG_IEND;
+PNG_PLTE;
+PNG_bKGD;
+PNG_cHRM;
+PNG_gAMA;
+PNG_hIST;
+PNG_iCCP;
+PNG_iTXt;
+PNG_oFFs;
+PNG_pCAL;
+PNG_sCAL;
+PNG_pHYs;
+PNG_sBIT;
+PNG_sPLT;
+PNG_sRGB;
+PNG_tEXt;
+PNG_tIME;
+PNG_tRNS;
+PNG_zTXt;
+
+/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+/* start of interlace block */
+const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+
+/* offset to next interlace block */
+const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+
+/* start of interlace block in the y direction */
+const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+
+/* offset to next interlace block in the y direction */
+const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+
+/* width of interlace block (used in assembler routines only) */
+#ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
+const int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
+#endif
+
+/* Height of interlace block. This is not currently used - if you need
+ * it, uncomment it here and in png.h
+const int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+*/
+
+/* Mask to determine which pixels are valid in a pass */
+const int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
+
+/* Mask to determine which pixels to overwrite while displaying */
+const int FARDATA png_pass_dsp_mask[]
+ = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
+
+#endif /* PNG_USE_GLOBAL_ARRAYS */
+
+/* Tells libpng that we have already handled the first "num_bytes" bytes
+ * of the PNG file signature. If the PNG data is embedded into another
+ * stream we can set num_bytes = 8 so that libpng will not attempt to read
+ * or write any of the magic bytes before it starts on the IHDR.
+ */
+
+void PNGAPI
+png_set_sig_bytes(png_structp png_ptr, int num_bytes)
+{
+ png_debug(1, "in png_set_sig_bytes\n");
+ if (num_bytes > 8)
+ png_error(png_ptr, "Too many bytes for PNG signature.");
+
+ png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
+}
+
+/* Checks whether the supplied bytes match the PNG signature. We allow
+ * checking less than the full 8-byte signature so that those apps that
+ * already read the first few bytes of a file to determine the file type
+ * can simply check the remaining bytes for extra assurance. Returns
+ * an integer less than, equal to, or greater than zero if sig is found,
+ * respectively, to be less than, to match, or be greater than the correct
+ * PNG signature (this is the same behaviour as strcmp, memcmp, etc).
+ */
+int PNGAPI
+png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
+{
+ png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+ if (num_to_check > 8)
+ num_to_check = 8;
+ else if (num_to_check < 1)
+ return (0);
+
+ if (start > 7)
+ return (0);
+
+ if (start + num_to_check > 8)
+ num_to_check = 8 - start;
+
+ return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
+}
+
+/* (Obsolete) function to check signature bytes. It does not allow one
+ * to check a partial signature. This function might be removed in the
+ * future - use png_sig_cmp(). Returns true (nonzero) if the file is a PNG.
+ */
+int PNGAPI
+png_check_sig(png_bytep sig, int num)
+{
+ return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
+}
+
+/* Function to allocate memory for zlib and clear it to 0. */
+#ifdef PNG_1_0_X
+voidpf PNGAPI
+#else
+voidpf /* private */
+#endif
+png_zalloc(voidpf png_ptr, uInt items, uInt size)
+{
+ png_voidp ptr;
+ png_structp p=png_ptr;
+ png_uint_32 save_flags=p->flags;
+ png_uint_32 num_bytes;
+
+ if (items > PNG_UINT_32_MAX/size)
+ {
+ png_warning (png_ptr, "Potential overflow in png_zalloc()");
+ return (NULL);
+ }
+ num_bytes = (png_uint_32)items * size;
+
+ p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
+ ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
+ p->flags=save_flags;
+
+#if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
+ if (ptr == NULL)
+ return ((voidpf)ptr);
+
+ if (num_bytes > (png_uint_32)0x8000L)
+ {
+ png_memset(ptr, 0, (png_size_t)0x8000L);
+ png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
+ (png_size_t)(num_bytes - (png_uint_32)0x8000L));
+ }
+ else
+ {
+ png_memset(ptr, 0, (png_size_t)num_bytes);
+ }
+#endif
+ return ((voidpf)ptr);
+}
+
+/* function to free memory for zlib */
+#ifdef PNG_1_0_X
+void PNGAPI
+#else
+void /* private */
+#endif
+png_zfree(voidpf png_ptr, voidpf ptr)
+{
+ png_free((png_structp)png_ptr, (png_voidp)ptr);
+}
+
+/* Reset the CRC variable to 32 bits of 1's. Care must be taken
+ * in case CRC is > 32 bits to leave the top bits 0.
+ */
+void /* PRIVATE */
+png_reset_crc(png_structp png_ptr)
+{
+ png_ptr->crc = crc32(0, Z_NULL, 0);
+}
+
+/* Calculate the CRC over a section of data. We can only pass as
+ * much data to this routine as the largest single buffer size. We
+ * also check that this data will actually be used before going to the
+ * trouble of calculating it.
+ */
+void /* PRIVATE */
+png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
+{
+ int need_crc = 1;
+
+ if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+ (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ need_crc = 0;
+ }
+ else /* critical */
+ {
+ if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
+ need_crc = 0;
+ }
+
+ if (need_crc)
+ png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
+}
+
+/* Allocate the memory for an info_struct for the application. We don't
+ * really need the png_ptr, but it could potentially be useful in the
+ * future. This should be used in favour of malloc(png_sizeof(png_info))
+ * and png_info_init() so that applications that want to use a shared
+ * libpng don't have to be recompiled if png_info changes size.
+ */
+png_infop PNGAPI
+png_create_info_struct(png_structp png_ptr)
+{
+ png_infop info_ptr;
+
+ png_debug(1, "in png_create_info_struct\n");
+ if(png_ptr == NULL) return (NULL);
+#ifdef PNG_USER_MEM_SUPPORTED
+ info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
+ png_ptr->malloc_fn, png_ptr->mem_ptr);
+#else
+ info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
+#endif
+ if (info_ptr != NULL)
+ png_info_init_3(&info_ptr, png_sizeof(png_info));
+
+ return (info_ptr);
+}
+
+/* This function frees the memory associated with a single info struct.
+ * Normally, one would use either png_destroy_read_struct() or
+ * png_destroy_write_struct() to free an info struct, but this may be
+ * useful for some applications.
+ */
+void PNGAPI
+png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
+{
+ png_infop info_ptr = NULL;
+
+ png_debug(1, "in png_destroy_info_struct\n");
+ if (info_ptr_ptr != NULL)
+ info_ptr = *info_ptr_ptr;
+
+ if (info_ptr != NULL)
+ {
+ png_info_destroy(png_ptr, info_ptr);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
+ png_ptr->mem_ptr);
+#else
+ png_destroy_struct((png_voidp)info_ptr);
+#endif
+ *info_ptr_ptr = NULL;
+ }
+}
+
+/* Initialize the info structure. This is now an internal function (0.89)
+ * and applications using it are urged to use png_create_info_struct()
+ * instead.
+ */
+#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
+#undef png_info_init
+void PNGAPI
+png_info_init(png_infop info_ptr)
+{
+ /* We only come here via pre-1.0.12-compiled applications */
+ png_info_init_3(&info_ptr, 0);
+}
+#endif
+
+void PNGAPI
+png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
+{
+ png_infop info_ptr = *ptr_ptr;
+
+ png_debug(1, "in png_info_init_3\n");
+
+ if(png_sizeof(png_info) > png_info_struct_size)
+ {
+ png_destroy_struct(info_ptr);
+ info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
+ *ptr_ptr = info_ptr;
+ }
+
+ /* set everything to 0 */
+ png_memset(info_ptr, 0, png_sizeof (png_info));
+}
+
+#ifdef PNG_FREE_ME_SUPPORTED
+void PNGAPI
+png_data_freer(png_structp png_ptr, png_infop info_ptr,
+ int freer, png_uint_32 mask)
+{
+ png_debug(1, "in png_data_freer\n");
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+ if(freer == PNG_DESTROY_WILL_FREE_DATA)
+ info_ptr->free_me |= mask;
+ else if(freer == PNG_USER_WILL_FREE_DATA)
+ info_ptr->free_me &= ~mask;
+ else
+ png_warning(png_ptr,
+ "Unknown freer parameter in png_data_freer.");
+}
+#endif
+
+void PNGAPI
+png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
+ int num)
+{
+ png_debug(1, "in png_free_data\n");
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+#if defined(PNG_TEXT_SUPPORTED)
+/* free text item num or (if num == -1) all text items */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_TEXT)
+#endif
+{
+ if (num != -1)
+ {
+ if (info_ptr->text && info_ptr->text[num].key)
+ {
+ png_free(png_ptr, info_ptr->text[num].key);
+ info_ptr->text[num].key = NULL;
+ }
+ }
+ else
+ {
+ int i;
+ for (i = 0; i < info_ptr->num_text; i++)
+ png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
+ png_free(png_ptr, info_ptr->text);
+ info_ptr->text = NULL;
+ info_ptr->num_text=0;
+ }
+}
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED)
+/* free any tRNS entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
+#else
+if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
+#endif
+{
+ png_free(png_ptr, info_ptr->trans);
+ info_ptr->valid &= ~PNG_INFO_tRNS;
+#ifndef PNG_FREE_ME_SUPPORTED
+ png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
+#endif
+ info_ptr->trans = NULL;
+}
+#endif
+
+#if defined(PNG_sCAL_SUPPORTED)
+/* free any sCAL entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_SCAL)
+#endif
+{
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+ png_free(png_ptr, info_ptr->scal_s_width);
+ png_free(png_ptr, info_ptr->scal_s_height);
+ info_ptr->scal_s_width = NULL;
+ info_ptr->scal_s_height = NULL;
+#endif
+ info_ptr->valid &= ~PNG_INFO_sCAL;
+}
+#endif
+
+#if defined(PNG_pCAL_SUPPORTED)
+/* free any pCAL entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_PCAL)
+#endif
+{
+ png_free(png_ptr, info_ptr->pcal_purpose);
+ png_free(png_ptr, info_ptr->pcal_units);
+ info_ptr->pcal_purpose = NULL;
+ info_ptr->pcal_units = NULL;
+ if (info_ptr->pcal_params != NULL)
+ {
+ int i;
+ for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
+ {
+ png_free(png_ptr, info_ptr->pcal_params[i]);
+ info_ptr->pcal_params[i]=NULL;
+ }
+ png_free(png_ptr, info_ptr->pcal_params);
+ info_ptr->pcal_params = NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_pCAL;
+}
+#endif
+
+#if defined(PNG_iCCP_SUPPORTED)
+/* free any iCCP entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_ICCP)
+#endif
+{
+ png_free(png_ptr, info_ptr->iccp_name);
+ png_free(png_ptr, info_ptr->iccp_profile);
+ info_ptr->iccp_name = NULL;
+ info_ptr->iccp_profile = NULL;
+ info_ptr->valid &= ~PNG_INFO_iCCP;
+}
+#endif
+
+#if defined(PNG_sPLT_SUPPORTED)
+/* free a given sPLT entry, or (if num == -1) all sPLT entries */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_SPLT)
+#endif
+{
+ if (num != -1)
+ {
+ if(info_ptr->splt_palettes)
+ {
+ png_free(png_ptr, info_ptr->splt_palettes[num].name);
+ png_free(png_ptr, info_ptr->splt_palettes[num].entries);
+ info_ptr->splt_palettes[num].name = NULL;
+ info_ptr->splt_palettes[num].entries = NULL;
+ }
+ }
+ else
+ {
+ if(info_ptr->splt_palettes_num)
+ {
+ int i;
+ for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+ png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
+
+ png_free(png_ptr, info_ptr->splt_palettes);
+ info_ptr->splt_palettes = NULL;
+ info_ptr->splt_palettes_num = 0;
+ }
+ info_ptr->valid &= ~PNG_INFO_sPLT;
+ }
+}
+#endif
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_UNKN)
+#endif
+{
+ if (num != -1)
+ {
+ if(info_ptr->unknown_chunks)
+ {
+ png_free(png_ptr, info_ptr->unknown_chunks[num].data);
+ info_ptr->unknown_chunks[num].data = NULL;
+ }
+ }
+ else
+ {
+ int i;
+
+ if(info_ptr->unknown_chunks_num)
+ {
+ for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
+ png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
+
+ png_free(png_ptr, info_ptr->unknown_chunks);
+ info_ptr->unknown_chunks = NULL;
+ info_ptr->unknown_chunks_num = 0;
+ }
+ }
+}
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+/* free any hIST entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
+#else
+if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
+#endif
+{
+ png_free(png_ptr, info_ptr->hist);
+ info_ptr->hist = NULL;
+ info_ptr->valid &= ~PNG_INFO_hIST;
+#ifndef PNG_FREE_ME_SUPPORTED
+ png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
+#endif
+}
+#endif
+
+/* free any PLTE entry that was internally allocated */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
+#else
+if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
+#endif
+{
+ png_zfree(png_ptr, info_ptr->palette);
+ info_ptr->palette = NULL;
+ info_ptr->valid &= ~PNG_INFO_PLTE;
+#ifndef PNG_FREE_ME_SUPPORTED
+ png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
+#endif
+ info_ptr->num_palette = 0;
+}
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+/* free any image bits attached to the info structure */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_ROWS)
+#endif
+{
+ if(info_ptr->row_pointers)
+ {
+ int row;
+ for (row = 0; row < (int)info_ptr->height; row++)
+ {
+ png_free(png_ptr, info_ptr->row_pointers[row]);
+ info_ptr->row_pointers[row]=NULL;
+ }
+ png_free(png_ptr, info_ptr->row_pointers);
+ info_ptr->row_pointers=NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_IDAT;
+}
+#endif
+
+#ifdef PNG_FREE_ME_SUPPORTED
+ if(num == -1)
+ info_ptr->free_me &= ~mask;
+ else
+ info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
+#endif
+}
+
+/* This is an internal routine to free any memory that the info struct is
+ * pointing to before re-using it or freeing the struct itself. Recall
+ * that png_free() checks for NULL pointers for us.
+ */
+void /* PRIVATE */
+png_info_destroy(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_info_destroy\n");
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+ if (png_ptr->num_chunk_list)
+ {
+ png_free(png_ptr, png_ptr->chunk_list);
+ png_ptr->chunk_list=NULL;
+ png_ptr->num_chunk_list=0;
+ }
+#endif
+
+ png_info_init_3(&info_ptr, png_sizeof(png_info));
+}
+
+/* This function returns a pointer to the io_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy() or png_read_destroy() are called.
+ */
+png_voidp PNGAPI
+png_get_io_ptr(png_structp png_ptr)
+{
+ return (png_ptr->io_ptr);
+}
+
+#if !defined(PNG_NO_STDIO)
+/* Initialize the default input/output functions for the PNG file. If you
+ * use your own read or write routines, you can call either png_set_read_fn()
+ * or png_set_write_fn() instead of png_init_io(). If you have defined
+ * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
+ * necessarily available.
+ */
+void PNGAPI
+png_init_io(png_structp png_ptr, png_FILE_p fp)
+{
+ png_debug(1, "in png_init_io\n");
+ png_ptr->io_ptr = (png_voidp)fp;
+}
+#endif
+
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Convert the supplied time into an RFC 1123 string suitable for use in
+ * a "Creation Time" or other text-based time string.
+ */
+png_charp PNGAPI
+png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
+{
+ static PNG_CONST char short_months[12][4] =
+ {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+
+ if (png_ptr->time_buffer == NULL)
+ {
+ png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
+ png_sizeof(char)));
+ }
+
+#if defined(_WIN32_WCE)
+ {
+ wchar_t time_buf[29];
+ wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
+ ptime->day % 32, short_months[(ptime->month - 1) % 12],
+ ptime->year, ptime->hour % 24, ptime->minute % 60,
+ ptime->second % 61);
+ WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
+ NULL, NULL);
+ }
+#else
+#ifdef USE_FAR_KEYWORD
+ {
+ char near_time_buf[29];
+ sprintf(near_time_buf, "%d %s %d %02d:%02d:%02d +0000",
+ ptime->day % 32, short_months[(ptime->month - 1) % 12],
+ ptime->year, ptime->hour % 24, ptime->minute % 60,
+ ptime->second % 61);
+ png_memcpy(png_ptr->time_buffer, near_time_buf,
+ 29*png_sizeof(char));
+ }
+#else
+ sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000",
+ ptime->day % 32, short_months[(ptime->month - 1) % 12],
+ ptime->year, ptime->hour % 24, ptime->minute % 60,
+ ptime->second % 61);
+#endif
+#endif /* _WIN32_WCE */
+ return ((png_charp)png_ptr->time_buffer);
+}
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+
+#if 0
+/* Signature string for a PNG file. */
+png_bytep PNGAPI
+png_sig_bytes(void)
+{
+ return ((png_bytep)"\211\120\116\107\015\012\032\012");
+}
+#endif
+
+png_charp PNGAPI
+png_get_copyright(png_structp png_ptr)
+{
+ if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+ return ((png_charp) "\n libpng version 1.2.8 - December 3, 2004\n\
+ Copyright (c) 1998-2004 Glenn Randers-Pehrson\n\
+ Copyright (c) 1996-1997 Andreas Dilger\n\
+ Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n");
+ return ((png_charp) "");
+}
+
+/* The following return the library version as a short string in the
+ * format 1.0.0 through 99.99.99zz. To get the version of *.h files
+ * used with your application, print out PNG_LIBPNG_VER_STRING, which
+ * is defined in png.h.
+ * Note: now there is no difference between png_get_libpng_ver() and
+ * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
+ * it is guaranteed that png.c uses the correct version of png.h.
+ */
+png_charp PNGAPI
+png_get_libpng_ver(png_structp png_ptr)
+{
+ /* Version of *.c files used when building libpng */
+ if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+ return ((png_charp) PNG_LIBPNG_VER_STRING);
+ return ((png_charp) "");
+}
+
+png_charp PNGAPI
+png_get_header_ver(png_structp png_ptr)
+{
+ /* Version of *.h files used when building libpng */
+ if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+ return ((png_charp) PNG_LIBPNG_VER_STRING);
+ return ((png_charp) "");
+}
+
+png_charp PNGAPI
+png_get_header_version(png_structp png_ptr)
+{
+ /* Returns longer string containing both version and date */
+ if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+ return ((png_charp) PNG_HEADER_VERSION_STRING);
+ return ((png_charp) "");
+}
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+int PNGAPI
+png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
+{
+ /* check chunk_name and return "keep" value if it's on the list, else 0 */
+ int i;
+ png_bytep p;
+ if((png_ptr == NULL && chunk_name == NULL) || png_ptr->num_chunk_list<=0)
+ return 0;
+ p=png_ptr->chunk_list+png_ptr->num_chunk_list*5-5;
+ for (i = png_ptr->num_chunk_list; i; i--, p-=5)
+ if (!png_memcmp(chunk_name, p, 4))
+ return ((int)*(p+4));
+ return 0;
+}
+#endif
+
+/* This function, added to libpng-1.0.6g, is untested. */
+int PNGAPI
+png_reset_zstream(png_structp png_ptr)
+{
+ return (inflateReset(&png_ptr->zstream));
+}
+
+/* This function was added to libpng-1.0.7 */
+png_uint_32 PNGAPI
+png_access_version_number(void)
+{
+ /* Version of *.c files used when building libpng */
+ return((png_uint_32) PNG_LIBPNG_VER);
+}
+
+
+#if !defined(PNG_1_0_X)
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+ /* GRR: could add this: && defined(PNG_MMX_CODE_SUPPORTED) */
+/* this INTERNAL function was added to libpng 1.2.0 */
+void /* PRIVATE */
+png_init_mmx_flags (png_structp png_ptr)
+{
+ png_ptr->mmx_rowbytes_threshold = 0;
+ png_ptr->mmx_bitdepth_threshold = 0;
+
+# if (defined(PNG_USE_PNGVCRD) || defined(PNG_USE_PNGGCCRD))
+
+ png_ptr->asm_flags |= PNG_ASM_FLAG_MMX_SUPPORT_COMPILED;
+
+ if (png_mmx_support() > 0) {
+ png_ptr->asm_flags |= PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
+# ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
+ | PNG_ASM_FLAG_MMX_READ_COMBINE_ROW
+# endif
+# ifdef PNG_HAVE_ASSEMBLER_READ_INTERLACE
+ | PNG_ASM_FLAG_MMX_READ_INTERLACE
+# endif
+# ifndef PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
+ ;
+# else
+ | PNG_ASM_FLAG_MMX_READ_FILTER_SUB
+ | PNG_ASM_FLAG_MMX_READ_FILTER_UP
+ | PNG_ASM_FLAG_MMX_READ_FILTER_AVG
+ | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ;
+
+ png_ptr->mmx_rowbytes_threshold = PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT;
+ png_ptr->mmx_bitdepth_threshold = PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT;
+# endif
+ } else {
+ png_ptr->asm_flags &= ~( PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
+ | PNG_MMX_READ_FLAGS
+ | PNG_MMX_WRITE_FLAGS );
+ }
+
+# else /* !((PNGVCRD || PNGGCCRD) && PNG_ASSEMBLER_CODE_SUPPORTED)) */
+
+ /* clear all MMX flags; no support is compiled in */
+ png_ptr->asm_flags &= ~( PNG_MMX_FLAGS );
+
+# endif /* ?(PNGVCRD || PNGGCCRD) */
+}
+
+#endif /* !(PNG_ASSEMBLER_CODE_SUPPORTED) */
+
+/* this function was added to libpng 1.2.0 */
+#if !defined(PNG_USE_PNGGCCRD) && \
+ !(defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_USE_PNGVCRD))
+int PNGAPI
+png_mmx_support(void)
+{
+ return -1;
+}
+#endif
+#endif /* PNG_1_0_X */
+
+#ifdef PNG_SIZE_T
+/* Added at libpng version 1.2.6 */
+ PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
+png_size_t PNGAPI
+png_convert_size(size_t size)
+{
+ if (size > (png_size_t)-1)
+ PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */
+ return ((png_size_t)size);
+}
+#endif /* PNG_SIZE_T */
diff --git a/com32/lib/libpng/png.h b/com32/lib/libpng/png.h
new file mode 100644
index 00000000..e87a3011
--- /dev/null
+++ b/com32/lib/libpng/png.h
@@ -0,0 +1,3419 @@
+/* png.h - header file for PNG reference library
+ *
+ * libpng version 1.2.8 - December 3, 2004
+ * Copyright (c) 1998-2004 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * Authors and maintainers:
+ * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
+ * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
+ * libpng versions 0.97, January 1998, through 1.2.8 - December 3, 2004: Glenn
+ * See also "Contributing Authors", below.
+ *
+ * Note about libpng version numbers:
+ *
+ * Due to various miscommunications, unforeseen code incompatibilities
+ * and occasional factors outside the authors' control, version numbering
+ * on the library has not always been consistent and straightforward.
+ * The following table summarizes matters since version 0.89c, which was
+ * the first widely used release:
+ *
+ * source png.h png.h shared-lib
+ * version string int version
+ * ------- ------ ----- ----------
+ * 0.89c "1.0 beta 3" 0.89 89 1.0.89
+ * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
+ * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
+ * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
+ * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
+ * 0.97c 0.97 97 2.0.97
+ * 0.98 0.98 98 2.0.98
+ * 0.99 0.99 98 2.0.99
+ * 0.99a-m 0.99 99 2.0.99
+ * 1.00 1.00 100 2.1.0 [100 should be 10000]
+ * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
+ * 1.0.1 png.h string is 10001 2.1.0
+ * 1.0.1a-e identical to the 10002 from here on, the shared library
+ * 1.0.2 source version) 10002 is 2.V where V is the source code
+ * 1.0.2a-b 10003 version, except as noted.
+ * 1.0.3 10003
+ * 1.0.3a-d 10004
+ * 1.0.4 10004
+ * 1.0.4a-f 10005
+ * 1.0.5 (+ 2 patches) 10005
+ * 1.0.5a-d 10006
+ * 1.0.5e-r 10100 (not source compatible)
+ * 1.0.5s-v 10006 (not binary compatible)
+ * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
+ * 1.0.6d-f 10007 (still binary incompatible)
+ * 1.0.6g 10007
+ * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
+ * 1.0.6i 10007 10.6i
+ * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
+ * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
+ * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
+ * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
+ * 1.0.7 1 10007 (still compatible)
+ * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
+ * 1.0.8rc1 1 10008 2.1.0.8rc1
+ * 1.0.8 1 10008 2.1.0.8
+ * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
+ * 1.0.9rc1 1 10009 2.1.0.9rc1
+ * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
+ * 1.0.9rc2 1 10009 2.1.0.9rc2
+ * 1.0.9 1 10009 2.1.0.9
+ * 1.0.10beta1 1 10010 2.1.0.10beta1
+ * 1.0.10rc1 1 10010 2.1.0.10rc1
+ * 1.0.10 1 10010 2.1.0.10
+ * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
+ * 1.0.11rc1 1 10011 2.1.0.11rc1
+ * 1.0.11 1 10011 2.1.0.11
+ * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
+ * 1.0.12rc1 2 10012 2.1.0.12rc1
+ * 1.0.12 2 10012 2.1.0.12
+ * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
+ * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
+ * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
+ * 1.2.0rc1 3 10200 3.1.2.0rc1
+ * 1.2.0 3 10200 3.1.2.0
+ * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
+ * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
+ * 1.2.1 3 10201 3.1.2.1
+ * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
+ * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
+ * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
+ * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
+ * 1.0.13 10 10013 10.so.0.1.0.13
+ * 1.2.2 12 10202 12.so.0.1.2.2
+ * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
+ * 1.2.3 12 10203 12.so.0.1.2.3
+ * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
+ * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
+ * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
+ * 1.0.14 10 10014 10.so.0.1.0.14
+ * 1.2.4 13 10204 12.so.0.1.2.4
+ * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
+ * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
+ * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
+ * 1.0.15 10 10015 10.so.0.1.0.15
+ * 1.2.5 13 10205 12.so.0.1.2.5
+ * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4
+ * 1.0.16 10 10016 10.so.0.1.0.16
+ * 1.2.6 13 10206 12.so.0.1.2.6
+ * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2
+ * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1
+ * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1
+ * 1.0.17 10 10017 12.so.0.1.0.17
+ * 1.2.7 13 10207 12.so.0.1.2.7
+ * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5
+ * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5
+ * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5
+ * 1.0.18 10 10018 12.so.0.1.0.18
+ * 1.2.8 13 10208 12.so.0.1.2.8
+ *
+ * Henceforth the source version will match the shared-library major
+ * and minor numbers; the shared-library major version number will be
+ * used for changes in backward compatibility, as it is intended. The
+ * PNG_LIBPNG_VER macro, which is not used within libpng but is available
+ * for applications, is an unsigned integer of the form xyyzz corresponding
+ * to the source version x.y.z (leading zeros in y and z). Beta versions
+ * were given the previous public release number plus a letter, until
+ * version 1.0.6j; from then on they were given the upcoming public
+ * release number plus "betaNN" or "rcN".
+ *
+ * Binary incompatibility exists only when applications make direct access
+ * to the info_ptr or png_ptr members through png.h, and the compiled
+ * application is loaded with a different version of the library.
+ *
+ * DLLNUM will change each time there are forward or backward changes
+ * in binary compatibility (e.g., when a new feature is added).
+ *
+ * See libpng.txt or libpng.3 for more information. The PNG specification
+ * is available as a W3C Recommendation and as an ISO Specification,
+ * <http://www.w3.org/TR/2003/REC-PNG-20031110/
+ */
+
+/*
+ * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+ *
+ * If you modify libpng you may insert additional notices immediately following
+ * this sentence.
+ *
+ * libpng versions 1.2.6, August 15, 2004, through 1.2.8, December 3, 2004, are
+ * Copyright (c) 2004 Glenn Randers-Pehrson, and are
+ * distributed according to the same disclaimer and license as libpng-1.2.5
+ * with the following individual added to the list of Contributing Authors:
+ *
+ * Cosmin Truta
+ *
+ * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
+ * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+ * distributed according to the same disclaimer and license as libpng-1.0.6
+ * with the following individuals added to the list of Contributing Authors:
+ *
+ * Simon-Pierre Cadieux
+ * Eric S. Raymond
+ * Gilles Vollant
+ *
+ * and with the following additions to the disclaimer:
+ *
+ * There is no warranty against interference with your enjoyment of the
+ * library or against infringement. There is no warranty that our
+ * efforts or the library will fulfill any of your particular purposes
+ * or needs. This library is provided with all faults, and the entire
+ * risk of satisfactory quality, performance, accuracy, and effort is with
+ * the user.
+ *
+ * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
+ * distributed according to the same disclaimer and license as libpng-0.96,
+ * with the following individuals added to the list of Contributing Authors:
+ *
+ * Tom Lane
+ * Glenn Randers-Pehrson
+ * Willem van Schaik
+ *
+ * libpng versions 0.89, June 1996, through 0.96, May 1997, are
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Distributed according to the same disclaimer and license as libpng-0.88,
+ * with the following individuals added to the list of Contributing Authors:
+ *
+ * John Bowler
+ * Kevin Bracey
+ * Sam Bushell
+ * Magnus Holmgren
+ * Greg Roelofs
+ * Tom Tanner
+ *
+ * libpng versions 0.5, May 1995, through 0.88, January 1996, are
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * For the purposes of this copyright and license, "Contributing Authors"
+ * is defined as the following set of individuals:
+ *
+ * Andreas Dilger
+ * Dave Martindale
+ * Guy Eric Schalnat
+ * Paul Schmidt
+ * Tim Wegner
+ *
+ * The PNG Reference Library is supplied "AS IS". The Contributing Authors
+ * and Group 42, Inc. disclaim all warranties, expressed or implied,
+ * including, without limitation, the warranties of merchantability and of
+ * fitness for any purpose. The Contributing Authors and Group 42, Inc.
+ * assume no liability for direct, indirect, incidental, special, exemplary,
+ * or consequential damages, which may result from the use of the PNG
+ * Reference Library, even if advised of the possibility of such damage.
+ *
+ * Permission is hereby granted to use, copy, modify, and distribute this
+ * source code, or portions hereof, for any purpose, without fee, subject
+ * to the following restrictions:
+ *
+ * 1. The origin of this source code must not be misrepresented.
+ *
+ * 2. Altered versions must be plainly marked as such and
+ * must not be misrepresented as being the original source.
+ *
+ * 3. This Copyright notice may not be removed or altered from
+ * any source or altered source distribution.
+ *
+ * The Contributing Authors and Group 42, Inc. specifically permit, without
+ * fee, and encourage the use of this source code as a component to
+ * supporting the PNG file format in commercial products. If you use this
+ * source code in a product, acknowledgment is not required but would be
+ * appreciated.
+ */
+
+/*
+ * A "png_get_copyright" function is available, for convenient use in "about"
+ * boxes and the like:
+ *
+ * printf("%s",png_get_copyright(NULL));
+ *
+ * Also, the PNG logo (in PNG format, of course) is supplied in the
+ * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+ */
+
+/*
+ * Libpng is OSI Certified Open Source Software. OSI Certified is a
+ * certification mark of the Open Source Initiative.
+ */
+
+/*
+ * The contributing authors would like to thank all those who helped
+ * with testing, bug fixes, and patience. This wouldn't have been
+ * possible without all of you.
+ *
+ * Thanks to Frank J. T. Wojcik for helping with the documentation.
+ */
+
+/*
+ * Y2K compliance in libpng:
+ * =========================
+ *
+ * December 3, 2004
+ *
+ * Since the PNG Development group is an ad-hoc body, we can't make
+ * an official declaration.
+ *
+ * This is your unofficial assurance that libpng from version 0.71 and
+ * upward through 1.2.8 are Y2K compliant. It is my belief that earlier
+ * versions were also Y2K compliant.
+ *
+ * Libpng only has three year fields. One is a 2-byte unsigned integer
+ * that will hold years up to 65535. The other two hold the date in text
+ * format, and will hold years up to 9999.
+ *
+ * The integer is
+ * "png_uint_16 year" in png_time_struct.
+ *
+ * The strings are
+ * "png_charp time_buffer" in png_struct and
+ * "near_time_buffer", which is a local character string in png.c.
+ *
+ * There are seven time-related functions:
+ * png.c: png_convert_to_rfc_1123() in png.c
+ * (formerly png_convert_to_rfc_1152() in error)
+ * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+ * png_convert_from_time_t() in pngwrite.c
+ * png_get_tIME() in pngget.c
+ * png_handle_tIME() in pngrutil.c, called in pngread.c
+ * png_set_tIME() in pngset.c
+ * png_write_tIME() in pngwutil.c, called in pngwrite.c
+ *
+ * All handle dates properly in a Y2K environment. The
+ * png_convert_from_time_t() function calls gmtime() to convert from system
+ * clock time, which returns (year - 1900), which we properly convert to
+ * the full 4-digit year. There is a possibility that applications using
+ * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+ * function, or that they are incorrectly passing only a 2-digit year
+ * instead of "year - 1900" into the png_convert_from_struct_tm() function,
+ * but this is not under our control. The libpng documentation has always
+ * stated that it works with 4-digit years, and the APIs have been
+ * documented as such.
+ *
+ * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
+ * integer to hold the year, and can hold years as large as 65535.
+ *
+ * zlib, upon which libpng depends, is also Y2K compliant. It contains
+ * no date-related code.
+ *
+ * Glenn Randers-Pehrson
+ * libpng maintainer
+ * PNG Development Group
+ */
+
+#ifndef PNG_H
+#define PNG_H
+
+/* This is not the place to learn how to use libpng. The file libpng.txt
+ * describes how to use libpng, and the file example.c summarizes it
+ * with some code on which to build. This file is useful for looking
+ * at the actual function definitions and structure components.
+ */
+
+/* Version information for png.h - this should match the version in png.c */
+#define PNG_LIBPNG_VER_STRING "1.2.8"
+#define PNG_HEADER_VERSION_STRING \
+ " libpng version 1.2.8 - December 3, 2004 (header)\n"
+
+#define PNG_LIBPNG_VER_SONUM 0
+#define PNG_LIBPNG_VER_DLLNUM 13
+
+/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
+#define PNG_LIBPNG_VER_MAJOR 1
+#define PNG_LIBPNG_VER_MINOR 2
+#define PNG_LIBPNG_VER_RELEASE 8
+/* This should match the numeric part of the final component of
+ * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
+
+#define PNG_LIBPNG_VER_BUILD 0
+
+/* Release Status */
+#define PNG_LIBPNG_BUILD_ALPHA 1
+#define PNG_LIBPNG_BUILD_BETA 2
+#define PNG_LIBPNG_BUILD_RC 3
+#define PNG_LIBPNG_BUILD_STABLE 4
+#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
+
+/* Release-Specific Flags */
+#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
+ PNG_LIBPNG_BUILD_STABLE only */
+#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
+ PNG_LIBPNG_BUILD_SPECIAL */
+#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
+ PNG_LIBPNG_BUILD_PRIVATE */
+
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
+
+/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
+ * We must not include leading zeros.
+ * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
+ * version 1.0.0 was mis-numbered 100 instead of 10000). From
+ * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release */
+#define PNG_LIBPNG_VER 10208 /* 1.2.8 */
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* include the compression library's header */
+#include "zlib.h"
+#endif
+
+/* include all user configurable info, including optional assembler routines */
+#include "pngconf.h"
+
+/*
+ * Added at libpng-1.2.8 */
+/* Ref MSDN: Private as priority over Special
+ * VS_FF_PRIVATEBUILD File *was not* built using standard release
+ * procedures. If this value is given, the StringFileInfo block must
+ * contain a PrivateBuild string.
+ *
+ * VS_FF_SPECIALBUILD File *was* built by the original company using
+ * standard release procedures but is a variation of the standard
+ * file of the same version number. If this value is given, the
+ * StringFileInfo block must contain a SpecialBuild string.
+ */
+
+#if defined(PNG_USER_PRIVATEBUILD)
+# define PNG_LIBPNG_BUILD_TYPE PNG_LIBPNG_BUILD_BASE_TYPE | \
+ PNG_LIBPNG_BUILD_PRIVATE
+#else
+# if defined(PNG_LIBPNG_SPECIALBUILD)
+# define PNG_LIBPNG_BUILD_TYPE PNG_LIBPNG_BUILD_BASE_TYPE | \
+ PNG_LIBPNG_BUILD_SPECIAL
+# else
+# define PNG_LIBPNG_BUILD_TYPE PNG_LIBPNG_BUILD_BASE_TYPE
+# endif
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/* This file is arranged in several sections. The first section contains
+ * structure and type definitions. The second section contains the external
+ * library functions, while the third has the internal library functions,
+ * which applications aren't expected to use directly.
+ */
+
+#ifndef PNG_NO_TYPECAST_NULL
+#define int_p_NULL (int *)NULL
+#define png_bytep_NULL (png_bytep)NULL
+#define png_bytepp_NULL (png_bytepp)NULL
+#define png_doublep_NULL (png_doublep)NULL
+#define png_error_ptr_NULL (png_error_ptr)NULL
+#define png_flush_ptr_NULL (png_flush_ptr)NULL
+#define png_free_ptr_NULL (png_free_ptr)NULL
+#define png_infopp_NULL (png_infopp)NULL
+#define png_malloc_ptr_NULL (png_malloc_ptr)NULL
+#define png_read_status_ptr_NULL (png_read_status_ptr)NULL
+#define png_rw_ptr_NULL (png_rw_ptr)NULL
+#define png_structp_NULL (png_structp)NULL
+#define png_uint_16p_NULL (png_uint_16p)NULL
+#define png_voidp_NULL (png_voidp)NULL
+#define png_write_status_ptr_NULL (png_write_status_ptr)NULL
+#else
+#define int_p_NULL NULL
+#define png_bytep_NULL NULL
+#define png_bytepp_NULL NULL
+#define png_doublep_NULL NULL
+#define png_error_ptr_NULL NULL
+#define png_flush_ptr_NULL NULL
+#define png_free_ptr_NULL NULL
+#define png_infopp_NULL NULL
+#define png_malloc_ptr_NULL NULL
+#define png_read_status_ptr_NULL NULL
+#define png_rw_ptr_NULL NULL
+#define png_structp_NULL NULL
+#define png_uint_16p_NULL NULL
+#define png_voidp_NULL NULL
+#define png_write_status_ptr_NULL NULL
+#endif
+
+/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
+#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
+/* Version information for C files, stored in png.c. This had better match
+ * the version above.
+ */
+#ifdef PNG_USE_GLOBAL_ARRAYS
+PNG_EXPORT_VAR (const char) png_libpng_ver[18];
+ /* need room for 99.99.99beta99z */
+#else
+#define png_libpng_ver png_get_header_ver(NULL)
+#endif
+
+#ifdef PNG_USE_GLOBAL_ARRAYS
+/* This was removed in version 1.0.5c */
+/* Structures to facilitate easy interlacing. See png.c for more details */
+PNG_EXPORT_VAR (const int FARDATA) png_pass_start[7];
+PNG_EXPORT_VAR (const int FARDATA) png_pass_inc[7];
+PNG_EXPORT_VAR (const int FARDATA) png_pass_ystart[7];
+PNG_EXPORT_VAR (const int FARDATA) png_pass_yinc[7];
+PNG_EXPORT_VAR (const int FARDATA) png_pass_mask[7];
+PNG_EXPORT_VAR (const int FARDATA) png_pass_dsp_mask[7];
+#ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
+PNG_EXPORT_VAR (const int FARDATA) png_pass_width[7];
+#endif
+/* This isn't currently used. If you need it, see png.c for more details.
+PNG_EXPORT_VAR (const int FARDATA) png_pass_height[7];
+*/
+#endif
+
+#endif /* PNG_NO_EXTERN */
+
+/* Three color definitions. The order of the red, green, and blue, (and the
+ * exact size) is not important, although the size of the fields need to
+ * be png_byte or png_uint_16 (as defined below).
+ */
+typedef struct png_color_struct
+{
+ png_byte red;
+ png_byte green;
+ png_byte blue;
+} png_color;
+typedef png_color FAR * png_colorp;
+typedef png_color FAR * FAR * png_colorpp;
+
+typedef struct png_color_16_struct
+{
+ png_byte index; /* used for palette files */
+ png_uint_16 red; /* for use in red green blue files */
+ png_uint_16 green;
+ png_uint_16 blue;
+ png_uint_16 gray; /* for use in grayscale files */
+} png_color_16;
+typedef png_color_16 FAR * png_color_16p;
+typedef png_color_16 FAR * FAR * png_color_16pp;
+
+typedef struct png_color_8_struct
+{
+ png_byte red; /* for use in red green blue files */
+ png_byte green;
+ png_byte blue;
+ png_byte gray; /* for use in grayscale files */
+ png_byte alpha; /* for alpha channel files */
+} png_color_8;
+typedef png_color_8 FAR * png_color_8p;
+typedef png_color_8 FAR * FAR * png_color_8pp;
+
+/*
+ * The following two structures are used for the in-core representation
+ * of sPLT chunks.
+ */
+typedef struct png_sPLT_entry_struct
+{
+ png_uint_16 red;
+ png_uint_16 green;
+ png_uint_16 blue;
+ png_uint_16 alpha;
+ png_uint_16 frequency;
+} png_sPLT_entry;
+typedef png_sPLT_entry FAR * png_sPLT_entryp;
+typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
+
+/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
+ * occupy the LSB of their respective members, and the MSB of each member
+ * is zero-filled. The frequency member always occupies the full 16 bits.
+ */
+
+typedef struct png_sPLT_struct
+{
+ png_charp name; /* palette name */
+ png_byte depth; /* depth of palette samples */
+ png_sPLT_entryp entries; /* palette entries */
+ png_int_32 nentries; /* number of palette entries */
+} png_sPLT_t;
+typedef png_sPLT_t FAR * png_sPLT_tp;
+typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
+
+#ifdef PNG_TEXT_SUPPORTED
+/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
+ * and whether that contents is compressed or not. The "key" field
+ * points to a regular zero-terminated C string. The "text", "lang", and
+ * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
+ * However, the * structure returned by png_get_text() will always contain
+ * regular zero-terminated C strings (possibly empty), never NULL pointers,
+ * so they can be safely used in printf() and other string-handling functions.
+ */
+typedef struct png_text_struct
+{
+ int compression; /* compression value:
+ -1: tEXt, none
+ 0: zTXt, deflate
+ 1: iTXt, none
+ 2: iTXt, deflate */
+ png_charp key; /* keyword, 1-79 character description of "text" */
+ png_charp text; /* comment, may be an empty string (ie "")
+ or a NULL pointer */
+ png_size_t text_length; /* length of the text string */
+#ifdef PNG_iTXt_SUPPORTED
+ png_size_t itxt_length; /* length of the itxt string */
+ png_charp lang; /* language code, 0-79 characters
+ or a NULL pointer */
+ png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
+ chars or a NULL pointer */
+#endif
+} png_text;
+typedef png_text FAR * png_textp;
+typedef png_text FAR * FAR * png_textpp;
+#endif
+
+/* Supported compression types for text in PNG files (tEXt, and zTXt).
+ * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
+#define PNG_TEXT_COMPRESSION_NONE_WR -3
+#define PNG_TEXT_COMPRESSION_zTXt_WR -2
+#define PNG_TEXT_COMPRESSION_NONE -1
+#define PNG_TEXT_COMPRESSION_zTXt 0
+#define PNG_ITXT_COMPRESSION_NONE 1
+#define PNG_ITXT_COMPRESSION_zTXt 2
+#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
+
+/* png_time is a way to hold the time in an machine independent way.
+ * Two conversions are provided, both from time_t and struct tm. There
+ * is no portable way to convert to either of these structures, as far
+ * as I know. If you know of a portable way, send it to me. As a side
+ * note - PNG has always been Year 2000 compliant!
+ */
+typedef struct png_time_struct
+{
+ png_uint_16 year; /* full year, as in, 1995 */
+ png_byte month; /* month of year, 1 - 12 */
+ png_byte day; /* day of month, 1 - 31 */
+ png_byte hour; /* hour of day, 0 - 23 */
+ png_byte minute; /* minute of hour, 0 - 59 */
+ png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
+} png_time;
+typedef png_time FAR * png_timep;
+typedef png_time FAR * FAR * png_timepp;
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+/* png_unknown_chunk is a structure to hold queued chunks for which there is
+ * no specific support. The idea is that we can use this to queue
+ * up private chunks for output even though the library doesn't actually
+ * know about their semantics.
+ */
+typedef struct png_unknown_chunk_t
+{
+ png_byte name[5];
+ png_byte *data;
+ png_size_t size;
+
+ /* libpng-using applications should NOT directly modify this byte. */
+ png_byte location; /* mode of operation at read time */
+}
+png_unknown_chunk;
+typedef png_unknown_chunk FAR * png_unknown_chunkp;
+typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
+#endif
+
+/* png_info is a structure that holds the information in a PNG file so
+ * that the application can find out the characteristics of the image.
+ * If you are reading the file, this structure will tell you what is
+ * in the PNG file. If you are writing the file, fill in the information
+ * you want to put into the PNG file, then call png_write_info().
+ * The names chosen should be very close to the PNG specification, so
+ * consult that document for information about the meaning of each field.
+ *
+ * With libpng < 0.95, it was only possible to directly set and read the
+ * the values in the png_info_struct, which meant that the contents and
+ * order of the values had to remain fixed. With libpng 0.95 and later,
+ * however, there are now functions that abstract the contents of
+ * png_info_struct from the application, so this makes it easier to use
+ * libpng with dynamic libraries, and even makes it possible to use
+ * libraries that don't have all of the libpng ancillary chunk-handing
+ * functionality.
+ *
+ * In any case, the order of the parameters in png_info_struct should NOT
+ * be changed for as long as possible to keep compatibility with applications
+ * that use the old direct-access method with png_info_struct.
+ *
+ * The following members may have allocated storage attached that should be
+ * cleaned up before the structure is discarded: palette, trans, text,
+ * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
+ * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
+ * are automatically freed when the info structure is deallocated, if they were
+ * allocated internally by libpng. This behavior can be changed by means
+ * of the png_data_freer() function.
+ *
+ * More allocation details: all the chunk-reading functions that
+ * change these members go through the corresponding png_set_*
+ * functions. A function to clear these members is available: see
+ * png_free_data(). The png_set_* functions do not depend on being
+ * able to point info structure members to any of the storage they are
+ * passed (they make their own copies), EXCEPT that the png_set_text
+ * functions use the same storage passed to them in the text_ptr or
+ * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
+ * functions do not make their own copies.
+ */
+typedef struct png_info_struct
+{
+ /* the following are necessary for every PNG file */
+ png_uint_32 width; /* width of image in pixels (from IHDR) */
+ png_uint_32 height; /* height of image in pixels (from IHDR) */
+ png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
+ png_uint_32 rowbytes; /* bytes needed to hold an untransformed row */
+ png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
+ png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
+ png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
+ png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
+ png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
+ /* The following three should have been named *_method not *_type */
+ png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
+ png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
+ png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+
+ /* The following is informational only on read, and not used on writes. */
+ png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */
+ png_byte pixel_depth; /* number of bits per pixel */
+ png_byte spare_byte; /* to align the data, and for future use */
+ png_byte signature[8]; /* magic bytes read by libpng from start of file */
+
+ /* The rest of the data is optional. If you are reading, check the
+ * valid field to see if the information in these are valid. If you
+ * are writing, set the valid field to those chunks you want written,
+ * and initialize the appropriate fields below.
+ */
+
+#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
+ /* The gAMA chunk describes the gamma characteristics of the system
+ * on which the image was created, normally in the range [1.0, 2.5].
+ * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
+ */
+ float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
+#endif
+
+#if defined(PNG_sRGB_SUPPORTED)
+ /* GR-P, 0.96a */
+ /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
+ png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
+#endif
+
+#if defined(PNG_TEXT_SUPPORTED)
+ /* The tEXt, and zTXt chunks contain human-readable textual data in
+ * uncompressed, compressed, and optionally compressed forms, respectively.
+ * The data in "text" is an array of pointers to uncompressed,
+ * null-terminated C strings. Each chunk has a keyword that describes the
+ * textual data contained in that chunk. Keywords are not required to be
+ * unique, and the text string may be empty. Any number of text chunks may
+ * be in an image.
+ */
+ int num_text; /* number of comments read/to write */
+ int max_text; /* current size of text array */
+ png_textp text; /* array of comments read/to write */
+#endif /* PNG_TEXT_SUPPORTED */
+
+#if defined(PNG_tIME_SUPPORTED)
+ /* The tIME chunk holds the last time the displayed image data was
+ * modified. See the png_time struct for the contents of this struct.
+ */
+ png_time mod_time;
+#endif
+
+#if defined(PNG_sBIT_SUPPORTED)
+ /* The sBIT chunk specifies the number of significant high-order bits
+ * in the pixel data. Values are in the range [1, bit_depth], and are
+ * only specified for the channels in the pixel data. The contents of
+ * the low-order bits is not specified. Data is valid if
+ * (valid & PNG_INFO_sBIT) is non-zero.
+ */
+ png_color_8 sig_bit; /* significant bits in color channels */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
+defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* The tRNS chunk supplies transparency data for paletted images and
+ * other image types that don't need a full alpha channel. There are
+ * "num_trans" transparency values for a paletted image, stored in the
+ * same order as the palette colors, starting from index 0. Values
+ * for the data are in the range [0, 255], ranging from fully transparent
+ * to fully opaque, respectively. For non-paletted images, there is a
+ * single color specified that should be treated as fully transparent.
+ * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
+ */
+ png_bytep trans; /* transparent values for paletted image */
+ png_color_16 trans_values; /* transparent color for non-palette image */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* The bKGD chunk gives the suggested image background color if the
+ * display program does not have its own background color and the image
+ * is needs to composited onto a background before display. The colors
+ * in "background" are normally in the same color space/depth as the
+ * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
+ */
+ png_color_16 background;
+#endif
+
+#if defined(PNG_oFFs_SUPPORTED)
+ /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
+ * and downwards from the top-left corner of the display, page, or other
+ * application-specific co-ordinate space. See the PNG_OFFSET_ defines
+ * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
+ */
+ png_int_32 x_offset; /* x offset on page */
+ png_int_32 y_offset; /* y offset on page */
+ png_byte offset_unit_type; /* offset units type */
+#endif
+
+#if defined(PNG_pHYs_SUPPORTED)
+ /* The pHYs chunk gives the physical pixel density of the image for
+ * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
+ * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
+ */
+ png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
+ png_uint_32 y_pixels_per_unit; /* vertical pixel density */
+ png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+ /* The hIST chunk contains the relative frequency or importance of the
+ * various palette entries, so that a viewer can intelligently select a
+ * reduced-color palette, if required. Data is an array of "num_palette"
+ * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
+ * is non-zero.
+ */
+ png_uint_16p hist;
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+ /* The cHRM chunk describes the CIE color characteristics of the monitor
+ * on which the PNG was created. This data allows the viewer to do gamut
+ * mapping of the input image to ensure that the viewer sees the same
+ * colors in the image as the creator. Values are in the range
+ * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
+ */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float x_white;
+ float y_white;
+ float x_red;
+ float y_red;
+ float x_green;
+ float y_green;
+ float x_blue;
+ float y_blue;
+#endif
+#endif
+
+#if defined(PNG_pCAL_SUPPORTED)
+ /* The pCAL chunk describes a transformation between the stored pixel
+ * values and original physical data values used to create the image.
+ * The integer range [0, 2^bit_depth - 1] maps to the floating-point
+ * range given by [pcal_X0, pcal_X1], and are further transformed by a
+ * (possibly non-linear) transformation function given by "pcal_type"
+ * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
+ * defines below, and the PNG-Group's PNG extensions document for a
+ * complete description of the transformations and how they should be
+ * implemented, and for a description of the ASCII parameter strings.
+ * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
+ */
+ png_charp pcal_purpose; /* pCAL chunk description string */
+ png_int_32 pcal_X0; /* minimum value */
+ png_int_32 pcal_X1; /* maximum value */
+ png_charp pcal_units; /* Latin-1 string giving physical units */
+ png_charpp pcal_params; /* ASCII strings containing parameter values */
+ png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
+ png_byte pcal_nparams; /* number of parameters given in pcal_params */
+#endif
+
+/* New members added in libpng-1.0.6 */
+#ifdef PNG_FREE_ME_SUPPORTED
+ png_uint_32 free_me; /* flags items libpng is responsible for freeing */
+#endif
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+ /* storage for unknown chunks that the library doesn't recognize. */
+ png_unknown_chunkp unknown_chunks;
+ png_size_t unknown_chunks_num;
+#endif
+
+#if defined(PNG_iCCP_SUPPORTED)
+ /* iCCP chunk data. */
+ png_charp iccp_name; /* profile name */
+ png_charp iccp_profile; /* International Color Consortium profile data */
+ /* Note to maintainer: should be png_bytep */
+ png_uint_32 iccp_proflen; /* ICC profile data length */
+ png_byte iccp_compression; /* Always zero */
+#endif
+
+#if defined(PNG_sPLT_SUPPORTED)
+ /* data on sPLT chunks (there may be more than one). */
+ png_sPLT_tp splt_palettes;
+ png_uint_32 splt_palettes_num;
+#endif
+
+#if defined(PNG_sCAL_SUPPORTED)
+ /* The sCAL chunk describes the actual physical dimensions of the
+ * subject matter of the graphic. The chunk contains a unit specification
+ * a byte value, and two ASCII strings representing floating-point
+ * values. The values are width and height corresponsing to one pixel
+ * in the image. This external representation is converted to double
+ * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
+ */
+ png_byte scal_unit; /* unit of physical scale */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ double scal_pixel_width; /* width of one pixel */
+ double scal_pixel_height; /* height of one pixel */
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_charp scal_s_width; /* string containing height */
+ png_charp scal_s_height; /* string containing width */
+#endif
+#endif
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+ /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
+ /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
+ png_bytepp row_pointers; /* the image bits */
+#endif
+
+#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
+ png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
+#endif
+
+#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
+ png_fixed_point int_x_white;
+ png_fixed_point int_y_white;
+ png_fixed_point int_x_red;
+ png_fixed_point int_y_red;
+ png_fixed_point int_x_green;
+ png_fixed_point int_y_green;
+ png_fixed_point int_x_blue;
+ png_fixed_point int_y_blue;
+#endif
+
+} png_info;
+
+typedef png_info FAR * png_infop;
+typedef png_info FAR * FAR * png_infopp;
+
+/* Maximum positive integer used in PNG is (2^31)-1 */
+#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
+#define PNG_UINT_32_MAX ((png_uint_32)(-1))
+#define PNG_SIZE_MAX ((png_size_t)(-1))
+/* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
+#define PNG_MAX_UINT PNG_UINT_31_MAX
+
+/* These describe the color_type field in png_info. */
+/* color type masks */
+#define PNG_COLOR_MASK_PALETTE 1
+#define PNG_COLOR_MASK_COLOR 2
+#define PNG_COLOR_MASK_ALPHA 4
+
+/* color types. Note that not all combinations are legal */
+#define PNG_COLOR_TYPE_GRAY 0
+#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
+#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
+#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
+#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
+/* aliases */
+#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
+#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
+
+/* This is for compression type. PNG 1.0-1.2 only define the single type. */
+#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
+#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
+
+/* This is for filter type. PNG 1.0-1.2 only define the single type. */
+#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
+#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
+#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
+
+/* These are for the interlacing type. These values should NOT be changed. */
+#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
+#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
+#define PNG_INTERLACE_LAST 2 /* Not a valid value */
+
+/* These are for the oFFs chunk. These values should NOT be changed. */
+#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
+#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
+#define PNG_OFFSET_LAST 2 /* Not a valid value */
+
+/* These are for the pCAL chunk. These values should NOT be changed. */
+#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
+#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
+#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
+#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
+#define PNG_EQUATION_LAST 4 /* Not a valid value */
+
+/* These are for the sCAL chunk. These values should NOT be changed. */
+#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
+#define PNG_SCALE_METER 1 /* meters per pixel */
+#define PNG_SCALE_RADIAN 2 /* radians per pixel */
+#define PNG_SCALE_LAST 3 /* Not a valid value */
+
+/* These are for the pHYs chunk. These values should NOT be changed. */
+#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
+#define PNG_RESOLUTION_METER 1 /* pixels/meter */
+#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
+
+/* These are for the sRGB chunk. These values should NOT be changed. */
+#define PNG_sRGB_INTENT_PERCEPTUAL 0
+#define PNG_sRGB_INTENT_RELATIVE 1
+#define PNG_sRGB_INTENT_SATURATION 2
+#define PNG_sRGB_INTENT_ABSOLUTE 3
+#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
+
+/* This is for text chunks */
+#define PNG_KEYWORD_MAX_LENGTH 79
+
+/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
+#define PNG_MAX_PALETTE_LENGTH 256
+
+/* These determine if an ancillary chunk's data has been successfully read
+ * from the PNG header, or if the application has filled in the corresponding
+ * data in the info_struct to be written into the output file. The values
+ * of the PNG_INFO_<chunk> defines should NOT be changed.
+ */
+#define PNG_INFO_gAMA 0x0001
+#define PNG_INFO_sBIT 0x0002
+#define PNG_INFO_cHRM 0x0004
+#define PNG_INFO_PLTE 0x0008
+#define PNG_INFO_tRNS 0x0010
+#define PNG_INFO_bKGD 0x0020
+#define PNG_INFO_hIST 0x0040
+#define PNG_INFO_pHYs 0x0080
+#define PNG_INFO_oFFs 0x0100
+#define PNG_INFO_tIME 0x0200
+#define PNG_INFO_pCAL 0x0400
+#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
+#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
+#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
+#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
+#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
+
+/* This is used for the transformation routines, as some of them
+ * change these values for the row. It also should enable using
+ * the routines for other purposes.
+ */
+typedef struct png_row_info_struct
+{
+ png_uint_32 width; /* width of row */
+ png_uint_32 rowbytes; /* number of bytes in row */
+ png_byte color_type; /* color type of row */
+ png_byte bit_depth; /* bit depth of row */
+ png_byte channels; /* number of channels (1, 2, 3, or 4) */
+ png_byte pixel_depth; /* bits per pixel (depth * channels) */
+} png_row_info;
+
+typedef png_row_info FAR * png_row_infop;
+typedef png_row_info FAR * FAR * png_row_infopp;
+
+/* These are the function types for the I/O functions and for the functions
+ * that allow the user to override the default I/O functions with his or her
+ * own. The png_error_ptr type should match that of user-supplied warning
+ * and error functions, while the png_rw_ptr type should match that of the
+ * user read/write data functions.
+ */
+typedef struct png_struct_def png_struct;
+typedef png_struct FAR * png_structp;
+
+typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
+typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
+typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
+typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
+ int));
+typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
+ int));
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
+typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
+typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
+ png_uint_32, int));
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_LEGACY_SUPPORTED)
+typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
+ png_row_infop, png_bytep));
+#endif
+
+#if defined(PNG_USER_CHUNKS_SUPPORTED)
+typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
+#endif
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
+#endif
+
+/* Transform masks for the high-level interface */
+#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
+#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
+#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
+#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
+#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
+#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
+#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
+#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
+#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
+#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
+#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
+#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
+#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* WRITE only */
+
+/* Flags for MNG supported features */
+#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
+#define PNG_FLAG_MNG_FILTER_64 0x04
+#define PNG_ALL_MNG_FEATURES 0x05
+
+typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
+typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
+
+/* The structure that holds the information to read and write PNG files.
+ * The only people who need to care about what is inside of this are the
+ * people who will be modifying the library for their own special needs.
+ * It should NOT be accessed directly by an application, except to store
+ * the jmp_buf.
+ */
+
+struct png_struct_def
+{
+#ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf jmpbuf; /* used in png_error */
+#endif
+ png_error_ptr error_fn; /* function for printing errors and aborting */
+ png_error_ptr warning_fn; /* function for printing warnings */
+ png_voidp error_ptr; /* user supplied struct for error functions */
+ png_rw_ptr write_data_fn; /* function for writing output data */
+ png_rw_ptr read_data_fn; /* function for reading input data */
+ png_voidp io_ptr; /* ptr to application struct for I/O functions */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+ png_user_transform_ptr read_user_transform_fn; /* user read transform */
+#endif
+
+#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+ png_user_transform_ptr write_user_transform_fn; /* user write transform */
+#endif
+
+/* These were added in libpng-1.0.2 */
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+ png_voidp user_transform_ptr; /* user supplied struct for user transform */
+ png_byte user_transform_depth; /* bit depth of user transformed pixels */
+ png_byte user_transform_channels; /* channels in user transformed pixels */
+#endif
+#endif
+
+ png_uint_32 mode; /* tells us where we are in the PNG file */
+ png_uint_32 flags; /* flags indicating various things to libpng */
+ png_uint_32 transformations; /* which transformations to perform */
+
+ z_stream zstream; /* pointer to decompression structure (below) */
+ png_bytep zbuf; /* buffer for zlib */
+ png_size_t zbuf_size; /* size of zbuf */
+ int zlib_level; /* holds zlib compression level */
+ int zlib_method; /* holds zlib compression method */
+ int zlib_window_bits; /* holds zlib compression window bits */
+ int zlib_mem_level; /* holds zlib compression memory level */
+ int zlib_strategy; /* holds zlib compression strategy */
+
+ png_uint_32 width; /* width of image in pixels */
+ png_uint_32 height; /* height of image in pixels */
+ png_uint_32 num_rows; /* number of rows in current pass */
+ png_uint_32 usr_width; /* width of row at start of write */
+ png_uint_32 rowbytes; /* size of row in bytes */
+ png_uint_32 irowbytes; /* size of current interlaced row in bytes */
+ png_uint_32 iwidth; /* width of current interlaced row in pixels */
+ png_uint_32 row_number; /* current row in interlace pass */
+ png_bytep prev_row; /* buffer to save previous (unfiltered) row */
+ png_bytep row_buf; /* buffer to save current (unfiltered) row */
+ png_bytep sub_row; /* buffer to save "sub" row when filtering */
+ png_bytep up_row; /* buffer to save "up" row when filtering */
+ png_bytep avg_row; /* buffer to save "avg" row when filtering */
+ png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
+ png_row_info row_info; /* used for transformation routines */
+
+ png_uint_32 idat_size; /* current IDAT size for read */
+ png_uint_32 crc; /* current chunk CRC value */
+ png_colorp palette; /* palette from the input file */
+ png_uint_16 num_palette; /* number of color entries in palette */
+ png_uint_16 num_trans; /* number of transparency values */
+ png_byte chunk_name[5]; /* null-terminated name of current chunk */
+ png_byte compression; /* file compression type (always 0) */
+ png_byte filter; /* file filter type (always 0) */
+ png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+ png_byte pass; /* current interlace pass (0 - 6) */
+ png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
+ png_byte color_type; /* color type of file */
+ png_byte bit_depth; /* bit depth of file */
+ png_byte usr_bit_depth; /* bit depth of users row */
+ png_byte pixel_depth; /* number of bits per pixel */
+ png_byte channels; /* number of channels in file */
+ png_byte usr_channels; /* channels at start of write */
+ png_byte sig_bytes; /* magic bytes read/written from start of file */
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+#ifdef PNG_LEGACY_SUPPORTED
+ png_byte filler; /* filler byte for pixel expansion */
+#else
+ png_uint_16 filler; /* filler bytes for pixel expansion */
+#endif
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED)
+ png_byte background_gamma_type;
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+ float background_gamma;
+# endif
+ png_color_16 background; /* background color in screen gamma space */
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ png_color_16 background_1; /* background normalized to gamma 1.0 */
+#endif
+#endif /* PNG_bKGD_SUPPORTED */
+
+#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+ png_flush_ptr output_flush_fn;/* Function for flushing output */
+ png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
+ png_uint_32 flush_rows; /* number of rows written since last flush */
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ int gamma_shift; /* number of "insignificant" bits 16-bit gamma */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float gamma; /* file gamma value */
+ float screen_gamma; /* screen gamma value (display_exponent) */
+#endif
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ png_bytep gamma_table; /* gamma table for 8-bit depth files */
+ png_bytep gamma_from_1; /* converts from 1.0 to screen */
+ png_bytep gamma_to_1; /* converts from file to 1.0 */
+ png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
+ png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
+ png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
+ png_color_8 sig_bit; /* significant bits in each available channel */
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+ png_color_8 shift; /* shift for significant bit tranformation */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
+ || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ png_bytep trans; /* transparency values for paletted files */
+ png_color_16 trans_values; /* transparency values for non-paletted files */
+#endif
+
+ png_read_status_ptr read_row_fn; /* called after each row is decoded */
+ png_write_status_ptr write_row_fn; /* called after each row is encoded */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+ png_progressive_info_ptr info_fn; /* called after header data fully read */
+ png_progressive_row_ptr row_fn; /* called after each prog. row is decoded */
+ png_progressive_end_ptr end_fn; /* called after image is complete */
+ png_bytep save_buffer_ptr; /* current location in save_buffer */
+ png_bytep save_buffer; /* buffer for previously read data */
+ png_bytep current_buffer_ptr; /* current location in current_buffer */
+ png_bytep current_buffer; /* buffer for recently used data */
+ png_uint_32 push_length; /* size of current input chunk */
+ png_uint_32 skip_length; /* bytes to skip in input data */
+ png_size_t save_buffer_size; /* amount of data now in save_buffer */
+ png_size_t save_buffer_max; /* total size of save_buffer */
+ png_size_t buffer_size; /* total amount of available input data */
+ png_size_t current_buffer_size; /* amount of data now in current_buffer */
+ int process_mode; /* what push library is currently doing */
+ int cur_palette; /* current push library palette index */
+
+# if defined(PNG_TEXT_SUPPORTED)
+ png_size_t current_text_size; /* current size of text input data */
+ png_size_t current_text_left; /* how much text left to read in input */
+ png_charp current_text; /* current text chunk buffer */
+ png_charp current_text_ptr; /* current location in current_text */
+# endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
+
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+
+#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
+/* for the Borland special 64K segment handler */
+ png_bytepp offset_table_ptr;
+ png_bytep offset_table;
+ png_uint_16 offset_table_number;
+ png_uint_16 offset_table_count;
+ png_uint_16 offset_table_count_free;
+#endif
+
+#if defined(PNG_READ_DITHER_SUPPORTED)
+ png_bytep palette_lookup; /* lookup table for dithering */
+ png_bytep dither_index; /* index translation for palette files */
+#endif
+
+#if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
+ png_uint_16p hist; /* histogram */
+#endif
+
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
+ png_byte heuristic_method; /* heuristic for row filter selection */
+ png_byte num_prev_filters; /* number of weights for previous rows */
+ png_bytep prev_filters; /* filter type(s) of previous row(s) */
+ png_uint_16p filter_weights; /* weight(s) for previous line(s) */
+ png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
+ png_uint_16p filter_costs; /* relative filter calculation cost */
+ png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
+#endif
+
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+ png_charp time_buffer; /* String to hold RFC 1123 time text */
+#endif
+
+/* New members added in libpng-1.0.6 */
+
+#ifdef PNG_FREE_ME_SUPPORTED
+ png_uint_32 free_me; /* flags items libpng is responsible for freeing */
+#endif
+
+#if defined(PNG_USER_CHUNKS_SUPPORTED)
+ png_voidp user_chunk_ptr;
+ png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
+#endif
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+ int num_chunk_list;
+ png_bytep chunk_list;
+#endif
+
+/* New members added in libpng-1.0.3 */
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ png_byte rgb_to_gray_status;
+ /* These were changed from png_byte in libpng-1.0.6 */
+ png_uint_16 rgb_to_gray_red_coeff;
+ png_uint_16 rgb_to_gray_green_coeff;
+ png_uint_16 rgb_to_gray_blue_coeff;
+#endif
+
+/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
+#if defined(PNG_MNG_FEATURES_SUPPORTED) || \
+ defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
+ defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
+/* changed from png_byte to png_uint_32 at version 1.2.0 */
+#ifdef PNG_1_0_X
+ png_byte mng_features_permitted;
+#else
+ png_uint_32 mng_features_permitted;
+#endif /* PNG_1_0_X */
+#endif
+
+/* New member added in libpng-1.0.7 */
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ png_fixed_point int_gamma;
+#endif
+
+/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+ png_byte filter_type;
+#endif
+
+#if defined(PNG_1_0_X) || (defined(PNG_DEBUG) && defined(PNG_USE_PNGGCCRD))
+/* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
+ png_uint_32 row_buf_size;
+#endif
+
+/* New members added in libpng-1.2.0 */
+#if !defined(PNG_1_0_X) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+ png_byte mmx_bitdepth_threshold;
+ png_uint_32 mmx_rowbytes_threshold;
+ png_uint_32 asm_flags;
+#endif
+
+/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_voidp mem_ptr; /* user supplied struct for mem functions */
+ png_malloc_ptr malloc_fn; /* function for allocating memory */
+ png_free_ptr free_fn; /* function for freeing memory */
+#endif
+
+/* New member added in libpng-1.0.13 and 1.2.0 */
+ png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
+
+#if defined(PNG_READ_DITHER_SUPPORTED)
+/* The following three members were added at version 1.0.14 and 1.2.4 */
+ png_bytep dither_sort; /* working sort array */
+ png_bytep index_to_palette; /* where the original index currently is */
+ /* in the palette */
+ png_bytep palette_to_index; /* which original index points to this */
+ /* palette color */
+#endif
+
+/* New members added in libpng-1.0.16 and 1.2.6 */
+ png_byte compression_type;
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ png_uint_32 user_width_max;
+ png_uint_32 user_height_max;
+#endif
+
+};
+
+
+/* This triggers a compiler error in png.c, if png.c and png.h
+ * do not agree upon the version number.
+ */
+typedef png_structp version_1_2_8;
+
+typedef png_struct FAR * FAR * png_structpp;
+
+/* Here are the function definitions most commonly used. This is not
+ * the place to find out how to use libpng. See libpng.txt for the
+ * full explanation, see example.c for the summary. This just provides
+ * a simple one line description of the use of each function.
+ */
+
+/* Returns the version number of the library */
+extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
+
+/* Tell lib we have already handled the first <num_bytes> magic bytes.
+ * Handling more than 8 bytes from the beginning of the file is an error.
+ */
+extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
+ int num_bytes));
+
+/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
+ * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
+ * signature, and non-zero otherwise. Having num_to_check == 0 or
+ * start > 7 will always fail (ie return non-zero).
+ */
+extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
+ png_size_t num_to_check));
+
+/* Simple signature checking function. This is the same as calling
+ * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
+ */
+extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
+
+/* Allocate and initialize png_ptr struct for reading, and any other memory. */
+extern PNG_EXPORT(png_structp,png_create_read_struct)
+ PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn));
+
+/* Allocate and initialize png_ptr struct for writing, and any other memory */
+extern PNG_EXPORT(png_structp,png_create_write_struct)
+ PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn));
+
+#ifdef PNG_WRITE_SUPPORTED
+extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
+ PNGARG((png_structp png_ptr));
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+extern PNG_EXPORT(void,png_set_compression_buffer_size)
+ PNGARG((png_structp png_ptr, png_uint_32 size));
+#endif
+
+/* Reset the compression stream */
+extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
+
+/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
+#ifdef PNG_USER_MEM_SUPPORTED
+extern PNG_EXPORT(png_structp,png_create_read_struct_2)
+ PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+extern PNG_EXPORT(png_structp,png_create_write_struct_2)
+ PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+#endif
+
+/* Write a PNG chunk - size, type, (optional) data, CRC. */
+extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
+ png_bytep chunk_name, png_bytep data, png_size_t length));
+
+/* Write the start of a PNG chunk - length and chunk name. */
+extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
+ png_bytep chunk_name, png_uint_32 length));
+
+/* Write the data of a PNG chunk started with png_write_chunk_start(). */
+extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
+ png_bytep data, png_size_t length));
+
+/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
+extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
+
+/* Allocate and initialize the info structure */
+extern PNG_EXPORT(png_infop,png_create_info_struct)
+ PNGARG((png_structp png_ptr));
+
+/* Initialize the info structure (old interface - DEPRECATED) */
+extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
+#undef png_info_init
+#define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
+ png_sizeof(png_info));
+extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
+ png_size_t png_info_struct_size));
+
+/* Writes all the PNG information before the image. */
+extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
+/* read the information before the actual image data. */
+extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
+ PNGARG((png_structp png_ptr, png_timep ptime));
+#endif
+
+#if !defined(_WIN32_WCE)
+/* "time.h" functions are not supported on WindowsCE */
+#if defined(PNG_WRITE_tIME_SUPPORTED)
+/* convert from a struct tm to png_time */
+extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
+ struct tm FAR * ttime));
+
+/* convert from time_t to png_time. Uses gmtime() */
+extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
+ time_t ttime));
+#endif /* PNG_WRITE_tIME_SUPPORTED */
+#endif /* _WIN32_WCE */
+
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
+extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Use blue, green, red order for pixels. */
+extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+/* Expand the grayscale to 24-bit RGB if necessary. */
+extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+/* Reduce RGB to grayscale. */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
+ int error_action, double red, double green ));
+#endif
+extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
+ int error_action, png_fixed_point red, png_fixed_point green ));
+extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
+ png_ptr));
+#endif
+
+extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
+ png_colorp palette));
+
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
+extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
+ png_uint_32 filler, int flags));
+/* The values of the PNG_FILLER_ defines should NOT be changed */
+#define PNG_FILLER_BEFORE 0
+#define PNG_FILLER_AFTER 1
+/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
+#if !defined(PNG_1_0_X)
+extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
+ png_uint_32 filler, int flags));
+#endif
+#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swap bytes in 16-bit depth files. */
+extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
+extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Swap packing order of pixels in bytes. */
+extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+/* Converts files to legal bit depths. */
+extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
+ png_color_8p true_bits));
+#endif
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+ defined(PNG_WRITE_INTERLACING_SUPPORTED)
+/* Have the code handle the interlacing. Returns the number of passes. */
+extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+/* Invert monochrome files */
+extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+/* Handle alpha and tRNS by replacing with a background color. */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
+ png_color_16p background_color, int background_gamma_code,
+ int need_expand, double background_gamma));
+#endif
+#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
+#define PNG_BACKGROUND_GAMMA_SCREEN 1
+#define PNG_BACKGROUND_GAMMA_FILE 2
+#define PNG_BACKGROUND_GAMMA_UNIQUE 3
+#endif
+
+#if defined(PNG_READ_16_TO_8_SUPPORTED)
+/* strip the second byte of information from a 16-bit depth file. */
+extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_DITHER_SUPPORTED)
+/* Turn on dithering, and reduce the palette to the number of colors available. */
+extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
+ png_colorp palette, int num_palette, int maximum_colors,
+ png_uint_16p histogram, int full_dither));
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+/* Handle gamma correction. Screen_gamma=(display_exponent) */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
+ double screen_gamma, double default_file_gamma));
+#endif
+#endif
+
+#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
+ defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
+/* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
+/* Deprecated and will be removed. Use png_permit_mng_features() instead. */
+extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
+ int empty_plte_permitted));
+#endif
+
+#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+/* Set how many lines between output flushes - 0 for no flushing */
+extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
+/* Flush the current PNG output buffer */
+extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
+#endif
+
+/* optional update palette with requested transformations */
+extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
+
+/* optional call to update the users info structure */
+extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
+/* read one or more rows of image data. */
+extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
+ png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
+#endif
+
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
+/* read a row of data. */
+extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
+ png_bytep row,
+ png_bytep display_row));
+#endif
+
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
+/* read the whole image into memory at once. */
+extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
+ png_bytepp image));
+#endif
+
+/* write a row of image data */
+extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
+ png_bytep row));
+
+/* write a few rows of image data */
+extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
+ png_bytepp row, png_uint_32 num_rows));
+
+/* write the image data */
+extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
+ png_bytepp image));
+
+/* writes the end of the PNG file. */
+extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
+/* read the end of the PNG file. */
+extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+
+/* free any memory associated with the png_info_struct */
+extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
+ png_infopp info_ptr_ptr));
+
+/* free any memory associated with the png_struct and the png_info_structs */
+extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
+ png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
+
+/* free all memory used by the read (old method - NOT DLL EXPORTED) */
+extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_infop end_info_ptr));
+
+/* free any memory associated with the png_struct and the png_info_structs */
+extern PNG_EXPORT(void,png_destroy_write_struct)
+ PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
+
+/* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
+extern void png_write_destroy PNGARG((png_structp png_ptr));
+
+/* set the libpng method of handling chunk CRC errors */
+extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
+ int crit_action, int ancil_action));
+
+/* Values for png_set_crc_action() to say how to handle CRC errors in
+ * ancillary and critical chunks, and whether to use the data contained
+ * therein. Note that it is impossible to "discard" data in a critical
+ * chunk. For versions prior to 0.90, the action was always error/quit,
+ * whereas in version 0.90 and later, the action for CRC errors in ancillary
+ * chunks is warn/discard. These values should NOT be changed.
+ *
+ * value action:critical action:ancillary
+ */
+#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
+#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
+#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
+#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
+#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
+#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
+
+/* These functions give the user control over the scan-line filtering in
+ * libpng and the compression methods used by zlib. These functions are
+ * mainly useful for testing, as the defaults should work with most users.
+ * Those users who are tight on memory or want faster performance at the
+ * expense of compression can modify them. See the compression library
+ * header file (zlib.h) for an explination of the compression functions.
+ */
+
+/* set the filtering method(s) used by libpng. Currently, the only valid
+ * value for "method" is 0.
+ */
+extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
+ int filters));
+
+/* Flags for png_set_filter() to say which filters to use. The flags
+ * are chosen so that they don't conflict with real filter types
+ * below, in case they are supplied instead of the #defined constants.
+ * These values should NOT be changed.
+ */
+#define PNG_NO_FILTERS 0x00
+#define PNG_FILTER_NONE 0x08
+#define PNG_FILTER_SUB 0x10
+#define PNG_FILTER_UP 0x20
+#define PNG_FILTER_AVG 0x40
+#define PNG_FILTER_PAETH 0x80
+#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
+ PNG_FILTER_AVG | PNG_FILTER_PAETH)
+
+/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
+ * These defines should NOT be changed.
+ */
+#define PNG_FILTER_VALUE_NONE 0
+#define PNG_FILTER_VALUE_SUB 1
+#define PNG_FILTER_VALUE_UP 2
+#define PNG_FILTER_VALUE_AVG 3
+#define PNG_FILTER_VALUE_PAETH 4
+#define PNG_FILTER_VALUE_LAST 5
+
+#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
+/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
+ * defines, either the default (minimum-sum-of-absolute-differences), or
+ * the experimental method (weighted-minimum-sum-of-absolute-differences).
+ *
+ * Weights are factors >= 1.0, indicating how important it is to keep the
+ * filter type consistent between rows. Larger numbers mean the current
+ * filter is that many times as likely to be the same as the "num_weights"
+ * previous filters. This is cumulative for each previous row with a weight.
+ * There needs to be "num_weights" values in "filter_weights", or it can be
+ * NULL if the weights aren't being specified. Weights have no influence on
+ * the selection of the first row filter. Well chosen weights can (in theory)
+ * improve the compression for a given image.
+ *
+ * Costs are factors >= 1.0 indicating the relative decoding costs of a
+ * filter type. Higher costs indicate more decoding expense, and are
+ * therefore less likely to be selected over a filter with lower computational
+ * costs. There needs to be a value in "filter_costs" for each valid filter
+ * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
+ * setting the costs. Costs try to improve the speed of decompression without
+ * unduly increasing the compressed image size.
+ *
+ * A negative weight or cost indicates the default value is to be used, and
+ * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
+ * The default values for both weights and costs are currently 1.0, but may
+ * change if good general weighting/cost heuristics can be found. If both
+ * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
+ * to the UNWEIGHTED method, but with added encoding time/computation.
+ */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
+ int heuristic_method, int num_weights, png_doublep filter_weights,
+ png_doublep filter_costs));
+#endif
+#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+
+/* Heuristic used for row filter selection. These defines should NOT be
+ * changed.
+ */
+#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
+#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
+#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
+#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
+
+/* Set the library compression level. Currently, valid values range from
+ * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
+ * (0 - no compression, 9 - "maximal" compression). Note that tests have
+ * shown that zlib compression levels 3-6 usually perform as well as level 9
+ * for PNG images, and do considerably fewer caclulations. In the future,
+ * these values may not correspond directly to the zlib compression levels.
+ */
+extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
+ int level));
+
+extern PNG_EXPORT(void,png_set_compression_mem_level)
+ PNGARG((png_structp png_ptr, int mem_level));
+
+extern PNG_EXPORT(void,png_set_compression_strategy)
+ PNGARG((png_structp png_ptr, int strategy));
+
+extern PNG_EXPORT(void,png_set_compression_window_bits)
+ PNGARG((png_structp png_ptr, int window_bits));
+
+extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
+ int method));
+
+/* These next functions are called for input/output, memory, and error
+ * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
+ * and call standard C I/O routines such as fread(), fwrite(), and
+ * fprintf(). These functions can be made to use other I/O routines
+ * at run time for those applications that need to handle I/O in a
+ * different manner by calling png_set_???_fn(). See libpng.txt for
+ * more information.
+ */
+
+#if !defined(PNG_NO_STDIO)
+/* Initialize the input/output for the PNG file to the default functions. */
+extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
+#endif
+
+/* Replace the (error and abort), and warning functions with user
+ * supplied functions. If no messages are to be printed you must still
+ * write and use replacement functions. The replacement error_fn should
+ * still do a longjmp to the last setjmp location if you are using this
+ * method of error handling. If error_fn or warning_fn is NULL, the
+ * default function will be used.
+ */
+
+extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
+ png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
+
+/* Return the user pointer associated with the error functions */
+extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
+
+/* Replace the default data output functions with a user supplied one(s).
+ * If buffered output is not used, then output_flush_fn can be set to NULL.
+ * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
+ * output_flush_fn will be ignored (and thus can be NULL).
+ */
+extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
+ png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
+
+/* Replace the default data input function with a user supplied one. */
+extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
+ png_voidp io_ptr, png_rw_ptr read_data_fn));
+
+/* Return the user pointer associated with the I/O functions */
+extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
+
+extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
+ png_read_status_ptr read_row_fn));
+
+extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
+ png_write_status_ptr write_row_fn));
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* Replace the default memory allocation functions with user supplied one(s). */
+extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
+ png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+/* Return the user pointer associated with the memory functions */
+extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_LEGACY_SUPPORTED)
+extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
+ png_ptr, png_user_transform_ptr read_user_transform_fn));
+#endif
+
+#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_LEGACY_SUPPORTED)
+extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
+ png_ptr, png_user_transform_ptr write_user_transform_fn));
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_LEGACY_SUPPORTED)
+extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
+ png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
+ int user_transform_channels));
+/* Return the user pointer associated with the user transform functions */
+extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
+ PNGARG((png_structp png_ptr));
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
+ png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
+extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
+ png_ptr));
+#endif
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+/* Sets the function callbacks for the push reader, and a pointer to a
+ * user-defined structure available to the callback functions.
+ */
+extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
+ png_voidp progressive_ptr,
+ png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+ png_progressive_end_ptr end_fn));
+
+/* returns the user pointer associated with the push read functions */
+extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
+ PNGARG((png_structp png_ptr));
+
+/* function to be called when data becomes available */
+extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
+
+/* function that combines rows. Not very much different than the
+ * png_combine_row() call. Is this even used?????
+ */
+extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
+ png_bytep old_row, png_bytep new_row));
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+
+extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
+ png_uint_32 size));
+
+#if defined(PNG_1_0_X)
+# define png_malloc_warn png_malloc
+#else
+/* Added at libpng version 1.2.4 */
+extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
+ png_uint_32 size));
+#endif
+
+/* frees a pointer allocated by png_malloc() */
+extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
+
+#if defined(PNG_1_0_X)
+/* Function to allocate memory for zlib. */
+extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
+ uInt size));
+
+/* Function to free memory for zlib */
+extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
+#endif
+
+/* Free data that was allocated internally */
+extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 free_me, int num));
+#ifdef PNG_FREE_ME_SUPPORTED
+/* Reassign responsibility for freeing existing data, whether allocated
+ * by libpng or by the application */
+extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int freer, png_uint_32 mask));
+#endif
+/* assignments for png_data_freer */
+#define PNG_DESTROY_WILL_FREE_DATA 1
+#define PNG_SET_WILL_FREE_DATA 1
+#define PNG_USER_WILL_FREE_DATA 2
+/* Flags for png_ptr->free_me and info_ptr->free_me */
+#define PNG_FREE_HIST 0x0008
+#define PNG_FREE_ICCP 0x0010
+#define PNG_FREE_SPLT 0x0020
+#define PNG_FREE_ROWS 0x0040
+#define PNG_FREE_PCAL 0x0080
+#define PNG_FREE_SCAL 0x0100
+#define PNG_FREE_UNKN 0x0200
+#define PNG_FREE_LIST 0x0400
+#define PNG_FREE_PLTE 0x1000
+#define PNG_FREE_TRNS 0x2000
+#define PNG_FREE_TEXT 0x4000
+#define PNG_FREE_ALL 0x7fff
+#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
+
+#ifdef PNG_USER_MEM_SUPPORTED
+extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
+ png_uint_32 size));
+extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
+ png_voidp ptr));
+#endif
+
+extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
+ png_voidp s1, png_voidp s2, png_uint_32 size));
+
+extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
+ png_voidp s1, int value, png_uint_32 size));
+
+#if defined(USE_FAR_KEYWORD) /* memory model conversion function */
+extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
+ int check));
+#endif /* USE_FAR_KEYWORD */
+
+/* Fatal error in PNG image of libpng - can't continue */
+extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
+ png_const_charp error_message));
+
+/* The same, but the chunk name is prepended to the error string. */
+extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
+ png_const_charp error_message));
+
+/* Non-fatal error in libpng. Can continue, but may have a problem. */
+extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
+ png_const_charp warning_message));
+
+/* Non-fatal error in libpng, chunk name is prepended to message. */
+extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
+ png_const_charp warning_message));
+
+/* The png_set_<chunk> functions are for storing values in the png_info_struct.
+ * Similarly, the png_get_<chunk> calls are used to read values from the
+ * png_info_struct, either storing the parameters in the passed variables, or
+ * setting pointers into the png_info_struct where the data is stored. The
+ * png_get_<chunk> functions return a non-zero value if the data was available
+ * in info_ptr, or return zero and do not change any of the parameters if the
+ * data was not available.
+ *
+ * These functions should be used instead of directly accessing png_info
+ * to avoid problems with future changes in the size and internal layout of
+ * png_info_struct.
+ */
+/* Returns "flag" if chunk data is valid in info_ptr. */
+extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
+png_infop info_ptr, png_uint_32 flag));
+
+/* Returns number of bytes needed to hold a transformed row. */
+extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+/* Returns row_pointers, which is an array of pointers to scanlines that was
+returned from png_read_png(). */
+extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+/* Set row_pointers, which is an array of pointers to scanlines for use
+by png_write_png(). */
+extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_bytepp row_pointers));
+#endif
+
+/* Returns number of color channels in image. */
+extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Returns image width in pixels. */
+extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image height in pixels. */
+extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image bit_depth. */
+extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image color_type. */
+extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image filter_type. */
+extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image interlace_type. */
+extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image compression_type. */
+extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns image resolution in pixels per meter, from pHYs chunk data. */
+extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+/* Returns pixel aspect ratio, computed from pHYs chunk data. */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+#endif
+
+/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
+extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
+png_ptr, png_infop info_ptr));
+
+#endif /* PNG_EASY_ACCESS_SUPPORTED */
+
+/* Returns pointer to signature string read from PNG header */
+extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
+png_infop info_ptr));
+
+#if defined(PNG_bKGD_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_color_16p *background));
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED)
+extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_color_16p background));
+#endif
+
+#if defined(PNG_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, double *white_x, double *white_y, double *red_x,
+ double *red_y, double *green_x, double *green_y, double *blue_x,
+ double *blue_y));
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
+ *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
+ png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
+ *int_blue_x, png_fixed_point *int_blue_y));
+#endif
+#endif
+
+#if defined(PNG_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, double white_x, double white_y, double red_x,
+ double red_y, double green_x, double green_y, double blue_x, double blue_y));
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
+ png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
+ int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
+ png_fixed_point int_blue_y));
+#endif
+#endif
+
+#if defined(PNG_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, double *file_gamma));
+#endif
+extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_fixed_point *int_file_gamma));
+#endif
+
+#if defined(PNG_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, double file_gamma));
+#endif
+extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_fixed_point int_file_gamma));
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_16p *hist));
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_16p hist));
+#endif
+
+extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
+ int *bit_depth, int *color_type, int *interlace_method,
+ int *compression_method, int *filter_method));
+
+extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_method, int compression_method,
+ int filter_method));
+
+#if defined(PNG_oFFs_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
+ int *unit_type));
+#endif
+
+#if defined(PNG_oFFs_SUPPORTED)
+extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
+ int unit_type));
+#endif
+
+#if defined(PNG_pCAL_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
+ int *type, int *nparams, png_charp *units, png_charpp *params));
+#endif
+
+#if defined(PNG_pCAL_SUPPORTED)
+extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
+ int type, int nparams, png_charp units, png_charpp params));
+#endif
+
+#if defined(PNG_pHYs_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
+#endif
+
+#if defined(PNG_pHYs_SUPPORTED)
+extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
+#endif
+
+extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_colorp *palette, int *num_palette));
+
+extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_colorp palette, int num_palette));
+
+#if defined(PNG_sBIT_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_color_8p *sig_bit));
+#endif
+
+#if defined(PNG_sBIT_SUPPORTED)
+extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_color_8p sig_bit));
+#endif
+
+#if defined(PNG_sRGB_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int *intent));
+#endif
+
+#if defined(PNG_sRGB_SUPPORTED)
+extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int intent));
+extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int intent));
+#endif
+
+#if defined(PNG_iCCP_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_charpp name, int *compression_type,
+ png_charpp profile, png_uint_32 *proflen));
+ /* Note to maintainer: profile should be png_bytepp */
+#endif
+
+#if defined(PNG_iCCP_SUPPORTED)
+extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_charp name, int compression_type,
+ png_charp profile, png_uint_32 proflen));
+ /* Note to maintainer: profile should be png_bytep */
+#endif
+
+#if defined(PNG_sPLT_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_sPLT_tpp entries));
+#endif
+
+#if defined(PNG_sPLT_SUPPORTED)
+extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_sPLT_tp entries, int nentries));
+#endif
+
+#if defined(PNG_TEXT_SUPPORTED)
+/* png_get_text also returns the number of text chunks in *num_text */
+extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_textp *text_ptr, int *num_text));
+#endif
+
+/*
+ * Note while png_set_text() will accept a structure whose text,
+ * language, and translated keywords are NULL pointers, the structure
+ * returned by png_get_text will always contain regular
+ * zero-terminated C strings. They might be empty strings but
+ * they will never be NULL pointers.
+ */
+
+#if defined(PNG_TEXT_SUPPORTED)
+extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_textp text_ptr, int num_text));
+#endif
+
+#if defined(PNG_tIME_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_timep *mod_time));
+#endif
+
+#if defined(PNG_tIME_SUPPORTED)
+extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_timep mod_time));
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED)
+extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_bytep *trans, int *num_trans,
+ png_color_16p *trans_values));
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED)
+extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_bytep trans, int num_trans,
+ png_color_16p trans_values));
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED)
+#endif
+
+#if defined(PNG_sCAL_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int *unit, double *width, double *height));
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
+#endif
+#endif
+#endif /* PNG_sCAL_SUPPORTED */
+
+#if defined(PNG_sCAL_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int unit, double width, double height));
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
+#endif
+#endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+/* provide a list of chunks and how they are to be handled, if the built-in
+ handling or default unknown chunk handling is not desired. Any chunks not
+ listed will be handled in the default manner. The IHDR and IEND chunks
+ must not be listed.
+ keep = 0: follow default behavour
+ = 1: do not keep
+ = 2: keep only if safe-to-copy
+ = 3: keep even if unsafe-to-copy
+*/
+extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
+ png_ptr, int keep, png_bytep chunk_list, int num_chunks));
+extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
+extern PNG_EXPORT(void, png_set_unknown_chunk_location)
+ PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
+extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
+ png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
+#endif
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
+ chunk_name));
+#endif
+
+/* Png_free_data() will turn off the "valid" flag for anything it frees.
+ If you need to turn it off for a chunk that your application has freed,
+ you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
+extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
+ png_infop info_ptr, int mask));
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+/* The "params" pointer is currently not used and is for future expansion. */
+extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
+ png_infop info_ptr,
+ int transforms,
+ png_voidp params));
+extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
+ png_infop info_ptr,
+ int transforms,
+ png_voidp params));
+#endif
+
+/* Define PNG_DEBUG at compile time for debugging information. Higher
+ * numbers for PNG_DEBUG mean more debugging information. This has
+ * only been added since version 0.95 so it is not implemented throughout
+ * libpng yet, but more support will be added as needed.
+ */
+#ifdef PNG_DEBUG
+#if (PNG_DEBUG > 0)
+#if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
+#include <crtdbg.h>
+#if (PNG_DEBUG > 1)
+#define png_debug(l,m) _RPT0(_CRT_WARN,m)
+#define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m,p1)
+#define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m,p1,p2)
+#endif
+#else /* PNG_DEBUG_FILE || !_MSC_VER */
+#ifndef PNG_DEBUG_FILE
+#define PNG_DEBUG_FILE stderr
+#endif /* PNG_DEBUG_FILE */
+#if (PNG_DEBUG > 1)
+#define png_debug(l,m) \
+{ \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
+}
+#define png_debug1(l,m,p1) \
+{ \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
+}
+#define png_debug2(l,m,p1,p2) \
+{ \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
+}
+#endif /* (PNG_DEBUG > 1) */
+#endif /* _MSC_VER */
+#endif /* (PNG_DEBUG > 0) */
+#endif /* PNG_DEBUG */
+#ifndef png_debug
+#define png_debug(l, m)
+#endif
+#ifndef png_debug1
+#define png_debug1(l, m, p1)
+#endif
+#ifndef png_debug2
+#define png_debug2(l, m, p1, p2)
+#endif
+
+extern PNG_EXPORT(png_bytep,png_sig_bytes) PNGARG((void));
+
+extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
+ png_ptr, png_uint_32 mng_features_permitted));
+#endif
+
+/* For use in png_set_keep_unknown, added to version 1.2.6 */
+#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
+#define PNG_HANDLE_CHUNK_NEVER 1
+#define PNG_HANDLE_CHUNK_IF_SAFE 2
+#define PNG_HANDLE_CHUNK_ALWAYS 3
+
+/* Added to version 1.2.0 */
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+#define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED 0x01 /* not user-settable */
+#define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 0x02 /* not user-settable */
+#define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 0x04
+#define PNG_ASM_FLAG_MMX_READ_INTERLACE 0x08
+#define PNG_ASM_FLAG_MMX_READ_FILTER_SUB 0x10
+#define PNG_ASM_FLAG_MMX_READ_FILTER_UP 0x20
+#define PNG_ASM_FLAG_MMX_READ_FILTER_AVG 0x40
+#define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
+#define PNG_ASM_FLAGS_INITIALIZED 0x80000000 /* not user-settable */
+
+#define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
+ | PNG_ASM_FLAG_MMX_READ_INTERLACE \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_UP \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
+ | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
+#define PNG_MMX_WRITE_FLAGS ( 0 )
+
+#define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
+ | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU \
+ | PNG_MMX_READ_FLAGS \
+ | PNG_MMX_WRITE_FLAGS )
+
+#define PNG_SELECT_READ 1
+#define PNG_SELECT_WRITE 2
+
+#if !defined(PNG_1_0_X)
+/* pngget.c */
+extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
+ PNGARG((int flag_select, int *compilerID));
+
+/* pngget.c */
+extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
+ PNGARG((int flag_select));
+
+/* pngget.c */
+extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
+ PNGARG((png_structp png_ptr));
+
+/* pngget.c */
+extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
+ PNGARG((png_structp png_ptr));
+
+/* pngget.c */
+extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
+ PNGARG((png_structp png_ptr));
+
+/* pngset.c */
+extern PNG_EXPORT(void,png_set_asm_flags)
+ PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
+
+/* pngset.c */
+extern PNG_EXPORT(void,png_set_mmx_thresholds)
+ PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
+ png_uint_32 mmx_rowbytes_threshold));
+
+#endif /* PNG_1_0_X */
+#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
+
+#if !defined(PNG_1_0_X)
+/* png.c, pnggccrd.c, or pngvcrd.c */
+extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
+
+/* Strip the prepended error numbers ("#nnn ") from error and warning
+ * messages before passing them to the error or warning handler. */
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
+ png_ptr, png_uint_32 strip_mode));
+#endif
+
+#endif /* PNG_1_0_X */
+
+/* Added at libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
+ png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
+extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
+ png_ptr));
+extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
+ png_ptr));
+#endif
+
+/* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
+
+#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
+/* With these routines we avoid an integer divide, which will be slower on
+ * most machines. However, it does take more operations than the corresponding
+ * divide method, so it may be slower on a few RISC systems. There are two
+ * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
+ *
+ * Note that the rounding factors are NOT supposed to be the same! 128 and
+ * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
+ * standard method.
+ *
+ * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
+ */
+
+ /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
+
+# define png_composite(composite, fg, alpha, bg) \
+ { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
+ + (png_uint_16)(bg)*(png_uint_16)(255 - \
+ (png_uint_16)(alpha)) + (png_uint_16)128); \
+ (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
+
+# define png_composite_16(composite, fg, alpha, bg) \
+ { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
+ + (png_uint_32)(bg)*(png_uint_32)(65535L - \
+ (png_uint_32)(alpha)) + (png_uint_32)32768L); \
+ (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
+
+#else /* standard method using integer division */
+
+# define png_composite(composite, fg, alpha, bg) \
+ (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
+ (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
+ (png_uint_16)127) / 255)
+
+# define png_composite_16(composite, fg, alpha, bg) \
+ (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
+ (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
+ (png_uint_32)32767) / (png_uint_32)65535L)
+
+#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
+
+/* These next functions are used internally in the code. They generally
+ * shouldn't be used unless you are writing code to add or replace some
+ * functionality in libpng. More information about most functions can
+ * be found in the files where the functions are located.
+ */
+
+#if defined(PNG_INTERNAL)
+
+/* Various modes of operation. Note that after an init, mode is set to
+ * zero automatically when the structure is created.
+ */
+#define PNG_HAVE_IHDR 0x01
+#define PNG_HAVE_PLTE 0x02
+#define PNG_HAVE_IDAT 0x04
+#define PNG_AFTER_IDAT 0x08
+#define PNG_HAVE_IEND 0x10
+#define PNG_HAVE_gAMA 0x20
+#define PNG_HAVE_cHRM 0x40
+#define PNG_HAVE_sRGB 0x80
+#define PNG_HAVE_CHUNK_HEADER 0x100
+#define PNG_WROTE_tIME 0x200
+#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
+#define PNG_BACKGROUND_IS_GRAY 0x800
+#define PNG_HAVE_PNG_SIGNATURE 0x1000
+
+/* flags for the transformations the PNG library does on the image data */
+#define PNG_BGR 0x0001
+#define PNG_INTERLACE 0x0002
+#define PNG_PACK 0x0004
+#define PNG_SHIFT 0x0008
+#define PNG_SWAP_BYTES 0x0010
+#define PNG_INVERT_MONO 0x0020
+#define PNG_DITHER 0x0040
+#define PNG_BACKGROUND 0x0080
+#define PNG_BACKGROUND_EXPAND 0x0100
+ /* 0x0200 unused */
+#define PNG_16_TO_8 0x0400
+#define PNG_RGBA 0x0800
+#define PNG_EXPAND 0x1000
+#define PNG_GAMMA 0x2000
+#define PNG_GRAY_TO_RGB 0x4000
+#define PNG_FILLER 0x8000L
+#define PNG_PACKSWAP 0x10000L
+#define PNG_SWAP_ALPHA 0x20000L
+#define PNG_STRIP_ALPHA 0x40000L
+#define PNG_INVERT_ALPHA 0x80000L
+#define PNG_USER_TRANSFORM 0x100000L
+#define PNG_RGB_TO_GRAY_ERR 0x200000L
+#define PNG_RGB_TO_GRAY_WARN 0x400000L
+#define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
+ /* 0x800000L Unused */
+#define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
+ /* 0x2000000L unused */
+ /* 0x4000000L unused */
+ /* 0x8000000L unused */
+ /* 0x10000000L unused */
+ /* 0x20000000L unused */
+ /* 0x40000000L unused */
+
+/* flags for png_create_struct */
+#define PNG_STRUCT_PNG 0x0001
+#define PNG_STRUCT_INFO 0x0002
+
+/* Scaling factor for filter heuristic weighting calculations */
+#define PNG_WEIGHT_SHIFT 8
+#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
+#define PNG_COST_SHIFT 3
+#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
+
+/* flags for the png_ptr->flags rather than declaring a byte for each one */
+#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
+#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
+#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
+#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
+#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
+#define PNG_FLAG_ZLIB_FINISHED 0x0020
+#define PNG_FLAG_ROW_INIT 0x0040
+#define PNG_FLAG_FILLER_AFTER 0x0080
+#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
+#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
+#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
+#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
+#define PNG_FLAG_FREE_PLTE 0x1000
+#define PNG_FLAG_FREE_TRNS 0x2000
+#define PNG_FLAG_FREE_HIST 0x4000
+#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
+#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
+#define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
+#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
+#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
+#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
+#define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */
+#define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */
+ /* 0x800000L unused */
+ /* 0x1000000L unused */
+ /* 0x2000000L unused */
+ /* 0x4000000L unused */
+ /* 0x8000000L unused */
+ /* 0x10000000L unused */
+ /* 0x20000000L unused */
+ /* 0x40000000L unused */
+
+#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
+ PNG_FLAG_CRC_ANCILLARY_NOWARN)
+
+#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
+ PNG_FLAG_CRC_CRITICAL_IGNORE)
+
+#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
+ PNG_FLAG_CRC_CRITICAL_MASK)
+
+/* save typing and make code easier to understand */
+
+#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
+ abs((int)((c1).green) - (int)((c2).green)) + \
+ abs((int)((c1).blue) - (int)((c2).blue)))
+
+/* Added to libpng-1.2.6 JB */
+#define PNG_ROWBYTES(pixel_bits, width) \
+ ((pixel_bits) >= 8 ? \
+ ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
+ (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
+
+/* PNG_OUT_OF_RANGE returns true if value is outside the range
+ ideal-delta..ideal+delta. Each argument is evaluated twice.
+ "ideal" and "delta" should be constants, normally simple
+ integers, "value" a variable. Added to libpng-1.2.6 JB */
+#define PNG_OUT_OF_RANGE(value, ideal, delta) \
+ ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
+
+/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
+#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
+/* place to hold the signature string for a PNG file. */
+#ifdef PNG_USE_GLOBAL_ARRAYS
+ PNG_EXPORT_VAR (const png_byte FARDATA) png_sig[8];
+#else
+#define png_sig png_sig_bytes(NULL)
+#endif
+#endif /* PNG_NO_EXTERN */
+
+/* Constant strings for known chunk types. If you need to add a chunk,
+ * define the name here, and add an invocation of the macro in png.c and
+ * wherever it's needed.
+ */
+#define PNG_IHDR const png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
+#define PNG_IDAT const png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
+#define PNG_IEND const png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
+#define PNG_PLTE const png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
+#define PNG_bKGD const png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
+#define PNG_cHRM const png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
+#define PNG_gAMA const png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
+#define PNG_hIST const png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
+#define PNG_iCCP const png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
+#define PNG_iTXt const png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
+#define PNG_oFFs const png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
+#define PNG_pCAL const png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
+#define PNG_sCAL const png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
+#define PNG_pHYs const png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
+#define PNG_sBIT const png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
+#define PNG_sPLT const png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
+#define PNG_sRGB const png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
+#define PNG_tEXt const png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
+#define PNG_tIME const png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
+#define PNG_tRNS const png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
+#define PNG_zTXt const png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
+
+#ifdef PNG_USE_GLOBAL_ARRAYS
+PNG_EXPORT_VAR (const png_byte FARDATA) png_IHDR[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_IDAT[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_IEND[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_PLTE[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_bKGD[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_cHRM[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_gAMA[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_hIST[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_iCCP[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_iTXt[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_oFFs[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_pCAL[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_sCAL[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_pHYs[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_sBIT[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_sPLT[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_sRGB[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_tEXt[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_tIME[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_tRNS[5];
+PNG_EXPORT_VAR (const png_byte FARDATA) png_zTXt[5];
+#endif /* PNG_USE_GLOBAL_ARRAYS */
+
+
+/* Inline macros to do direct reads of bytes from the input buffer. These
+ * require that you are using an architecture that uses PNG byte ordering
+ * (MSB first) and supports unaligned data storage. I think that PowerPC
+ * in big-endian mode and 680x0 are the only ones that will support this.
+ * The x86 line of processors definitely do not. The png_get_int_32()
+ * routine also assumes we are using two's complement format for negative
+ * values, which is almost certainly true.
+ */
+#if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
+# if defined(PNG_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
+# define png_get_int_32(buf) ( *((png_int_32p) (buf)))
+# endif
+# define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
+# define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
+#else
+# if defined(PNG_pCAL_SUPPORTED) || defined(PNG_oFFs_SUPPORTED)
+PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf));
+# endif
+PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf));
+PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf));
+#endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
+PNG_EXTERN png_uint_32 png_get_uint_31 PNGARG((png_structp png_ptr,
+ png_bytep buf));
+
+/* Initialize png_ptr struct for reading, and allocate any other memory.
+ * (old interface - DEPRECATED - use png_create_read_struct instead).
+ */
+extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
+#undef png_read_init
+#define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
+ PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
+extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
+ png_const_charp user_png_ver, png_size_t png_struct_size));
+extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
+ png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
+ png_info_size));
+
+/* Initialize png_ptr struct for writing, and allocate any other memory.
+ * (old interface - DEPRECATED - use png_create_write_struct instead).
+ */
+extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
+#undef png_write_init
+#define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
+ PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
+extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
+ png_const_charp user_png_ver, png_size_t png_struct_size));
+extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
+ png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
+ png_info_size));
+
+/* Allocate memory for an internal libpng struct */
+PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
+
+/* Free memory from internal libpng struct */
+PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
+
+PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
+ malloc_fn, png_voidp mem_ptr));
+PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
+ png_free_ptr free_fn, png_voidp mem_ptr));
+
+/* Free any memory that info_ptr points to and reset struct. */
+PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+#ifndef PNG_1_0_X
+/* Function to allocate memory for zlib. */
+PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
+
+/* Function to free memory for zlib */
+PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
+
+#ifdef PNG_SIZE_T
+/* Function to convert a sizeof an item to png_sizeof item */
+ PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
+#endif
+
+/* Next four functions are used internally as callbacks. PNGAPI is required
+ * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3. */
+
+PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
+ png_bytep data, png_size_t length));
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
+ png_bytep buffer, png_size_t length));
+#endif
+
+PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
+ png_bytep data, png_size_t length));
+
+#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+#if !defined(PNG_NO_STDIO)
+PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
+#endif
+#endif
+#else /* PNG_1_0_X */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
+ png_bytep buffer, png_size_t length));
+#endif
+#endif /* PNG_1_0_X */
+
+/* Reset the CRC variable */
+PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
+
+/* Write the "data" buffer to whatever output you are using. */
+PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
+ png_size_t length));
+
+/* Read data from whatever input you are using into the "data" buffer */
+PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
+ png_size_t length));
+
+/* Read bytes into buf, and update png_ptr->crc */
+PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
+ png_size_t length));
+
+/* Decompress data in a chunk that uses compression */
+#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
+ defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
+PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
+ int comp_type, png_charp chunkdata, png_size_t chunklength,
+ png_size_t prefix_length, png_size_t *data_length));
+#endif
+
+/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
+PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
+
+/* Read the CRC from the file and compare it to the libpng calculated CRC */
+PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
+
+/* Calculate the CRC over a section of data. Note that we are only
+ * passing a maximum of 64K on systems that have this as a memory limit,
+ * since this is the maximum buffer size we can specify.
+ */
+PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
+ png_size_t length));
+
+#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
+#endif
+
+
+/* Place a 32-bit number into a buffer in PNG byte order (big-endian).
+ * The only currently known PNG chunks that use signed numbers are
+ * the ancillary extension chunks, oFFs and pCAL.
+ */
+PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
+
+#if defined(PNG_WRITE_pCAL_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i));
+#endif
+
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, unsigned int i));
+
+/* simple function to write the signature */
+PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
+
+/* write various chunks */
+
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information.
+ */
+PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
+ png_uint_32 height,
+ int bit_depth, int color_type, int compression_method, int filter_method,
+ int interlace_method));
+
+PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
+ png_uint_32 num_pal));
+
+PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
+ png_size_t length));
+
+PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
+
+#if defined(PNG_WRITE_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
+ file_gamma));
+#endif
+#endif
+
+#if defined(PNG_WRITE_sBIT_SUPPORTED)
+PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
+ int color_type));
+#endif
+
+#if defined(PNG_WRITE_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
+ double white_x, double white_y,
+ double red_x, double red_y, double green_x, double green_y,
+ double blue_x, double blue_y));
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
+ png_fixed_point int_white_x, png_fixed_point int_white_y,
+ png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
+ int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
+ png_fixed_point int_blue_y));
+#endif
+#endif
+
+#if defined(PNG_WRITE_sRGB_SUPPORTED)
+PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
+ int intent));
+#endif
+
+#if defined(PNG_WRITE_iCCP_SUPPORTED)
+PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
+ png_charp name, int compression_type,
+ png_charp profile, int proflen));
+ /* Note to maintainer: profile should be png_bytep */
+#endif
+
+#if defined(PNG_WRITE_sPLT_SUPPORTED)
+PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
+ png_sPLT_tp palette));
+#endif
+
+#if defined(PNG_WRITE_tRNS_SUPPORTED)
+PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
+ png_color_16p values, int number, int color_type));
+#endif
+
+#if defined(PNG_WRITE_bKGD_SUPPORTED)
+PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
+ png_color_16p values, int color_type));
+#endif
+
+#if defined(PNG_WRITE_hIST_SUPPORTED)
+PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
+ int num_hist));
+#endif
+
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
+ defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
+ png_charp key, png_charpp new_key));
+#endif
+
+#if defined(PNG_WRITE_tEXt_SUPPORTED)
+PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
+ png_charp text, png_size_t text_len));
+#endif
+
+#if defined(PNG_WRITE_zTXt_SUPPORTED)
+PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
+ png_charp text, png_size_t text_len, int compression));
+#endif
+
+#if defined(PNG_WRITE_iTXt_SUPPORTED)
+PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
+ int compression, png_charp key, png_charp lang, png_charp lang_key,
+ png_charp text));
+#endif
+
+#if defined(PNG_TEXT_SUPPORTED) /* Added at version 1.0.14 and 1.2.4 */
+PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_textp text_ptr, int num_text));
+#endif
+
+#if defined(PNG_WRITE_oFFs_SUPPORTED)
+PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
+ png_int_32 x_offset, png_int_32 y_offset, int unit_type));
+#endif
+
+#if defined(PNG_WRITE_pCAL_SUPPORTED)
+PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
+ png_int_32 X0, png_int_32 X1, int type, int nparams,
+ png_charp units, png_charpp params));
+#endif
+
+#if defined(PNG_WRITE_pHYs_SUPPORTED)
+PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
+ png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
+ int unit_type));
+#endif
+
+#if defined(PNG_WRITE_tIME_SUPPORTED)
+PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
+ png_timep mod_time));
+#endif
+
+#if defined(PNG_WRITE_sCAL_SUPPORTED)
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
+PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
+ int unit, double width, double height));
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
+ int unit, png_charp width, png_charp height));
+#endif
+#endif
+#endif
+
+/* Called when finished processing a row of data */
+PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
+
+/* Internal use only. Called before first row of data */
+PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
+
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
+#endif
+
+/* combine a row of data, dealing with alpha, etc. if requested */
+PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
+ int mask));
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED)
+/* expand an interlaced row */
+/* OLD pre-1.0.9 interface:
+PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
+ png_bytep row, int pass, png_uint_32 transformations));
+ */
+PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
+#endif
+
+/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
+
+#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
+/* grab pixels out of a row for an interlaced pass */
+PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
+ png_bytep row, int pass));
+#endif
+
+/* unfilter a row */
+PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
+ png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
+
+/* Choose the best filter to use and filter the row data */
+PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
+ png_row_infop row_info));
+
+/* Write out the filtered row. */
+PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
+ png_bytep filtered_row));
+/* finish a row while reading, dealing with interlacing passes, etc. */
+PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
+
+/* initialize the row buffers, etc. */
+PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
+/* optional call to update the users info structure */
+PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+
+/* these are the functions that do the transformations */
+#if defined(PNG_READ_FILLER_SUPPORTED)
+PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
+ png_bytep row, png_uint_32 filler, png_uint_32 flags));
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
+PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
+PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+ defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
+ png_bytep row, png_uint_32 flags));
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
+ row_info, png_bytep row));
+#endif
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED)
+PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED)
+PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
+ png_color_8p sig_bits));
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#if defined(PNG_READ_16_TO_8_SUPPORTED)
+PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#if defined(PNG_READ_DITHER_SUPPORTED)
+PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
+ png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
+
+# if defined(PNG_CORRECT_PALETTE_SUPPORTED)
+PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
+ png_colorp palette, int num_palette));
+# endif
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
+#endif
+
+#if defined(PNG_WRITE_PACK_SUPPORTED)
+PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
+ png_bytep row, png_uint_32 bit_depth));
+#endif
+
+#if defined(PNG_WRITE_SHIFT_SUPPORTED)
+PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
+ png_color_8p bit_depth));
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
+ png_color_16p trans_values, png_color_16p background,
+ png_color_16p background_1,
+ png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
+ png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
+ png_uint_16pp gamma_16_to_1, int gamma_shift));
+#else
+PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
+ png_color_16p trans_values, png_color_16p background));
+#endif
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
+ png_bytep gamma_table, png_uint_16pp gamma_16_table,
+ int gamma_shift));
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
+ png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
+PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
+ png_bytep row, png_color_16p trans_value));
+#endif
+
+/* The following decodes the appropriate chunks, and does error correction,
+ * then calls the appropriate callback for the chunk if it is valid.
+ */
+
+/* decode the IHDR chunk */
+PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+
+#if defined(PNG_READ_bKGD_SUPPORTED)
+PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_cHRM_SUPPORTED)
+PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_gAMA_SUPPORTED)
+PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_hIST_SUPPORTED)
+PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_iCCP_SUPPORTED)
+extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif /* PNG_READ_iCCP_SUPPORTED */
+
+#if defined(PNG_READ_iTXt_SUPPORTED)
+PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_oFFs_SUPPORTED)
+PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_pCAL_SUPPORTED)
+PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_pHYs_SUPPORTED)
+PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_sBIT_SUPPORTED)
+PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_sCAL_SUPPORTED)
+PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_sPLT_SUPPORTED)
+extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif /* PNG_READ_sPLT_SUPPORTED */
+
+#if defined(PNG_READ_sRGB_SUPPORTED)
+PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_tEXt_SUPPORTED)
+PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_tIME_SUPPORTED)
+PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_tRNS_SUPPORTED)
+PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+#if defined(PNG_READ_zTXt_SUPPORTED)
+PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
+ png_uint_32 length));
+#endif
+
+PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+
+PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
+ png_bytep chunk_name));
+
+/* handle the transformations for reading and writing */
+PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
+
+PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
+ png_uint_32 length));
+PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
+ png_bytep buffer, png_size_t buffer_length));
+PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
+ png_bytep buffer, png_size_t buffer_length));
+PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
+PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
+PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
+#if defined(PNG_READ_tEXt_SUPPORTED)
+PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr, png_uint_32 length));
+PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
+ png_infop info_ptr));
+#endif
+
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
+ png_bytep row));
+PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
+ png_bytep row));
+#endif
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+/* png.c */ /* PRIVATE */
+PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
+#endif
+/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+
+#endif /* PNG_INTERNAL */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PNG_VERSION_INFO_ONLY */
+/* do not put anything past this line */
+#endif /* PNG_H */
diff --git a/com32/lib/libpng/pngconf.h b/com32/lib/libpng/pngconf.h
new file mode 100644
index 00000000..7f4cbede
--- /dev/null
+++ b/com32/lib/libpng/pngconf.h
@@ -0,0 +1,1437 @@
+
+/* pngconf.h - machine configurable file for libpng
+ *
+ * libpng version 1.2.8 - December 3, 2004
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2004 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ */
+
+/* Any machine specific code is near the front of this file, so if you
+ * are configuring libpng for a machine, you may want to read the section
+ * starting here down to where it starts to typedef png_color, png_text,
+ * and png_info.
+ */
+
+#ifndef PNGCONF_H
+#define PNGCONF_H
+
+#define PNG_1_2_X
+
+/*
+ * PNG_USER_CONFIG has to be defined on the compiler command line. This
+ * includes the resource compiler for Windows DLL configurations.
+ */
+#ifdef PNG_USER_CONFIG
+#include "pngusr.h"
+#endif
+
+/*
+ * Added at libpng-1.2.8
+ *
+ * If you create a private DLL you need to define in "pngusr.h" the followings:
+ * #define PNG_USER_PRIVATEBUILD <Describes by whom and why this version of
+ * the DLL was built>
+ * e.g. #define PNG_USER_PRIVATEBUILD "Build by MyCompany for xyz reasons."
+ * #define PNG_USER_DLLFNAME_POSTFIX <two-letter postfix that serve to
+ * distinguish your DLL from those of the official release. These
+ * correspond to the trailing letters that come after the version
+ * number and must match your private DLL name>
+ * e.g. // private DLL "libpng13gx.dll"
+ * #define PNG_USER_DLLFNAME_POSTFIX "gx"
+ *
+ * The following macros are also at your disposal if you want to complete the
+ * DLL VERSIONINFO structure.
+ * - PNG_USER_VERSIONINFO_COMMENTS
+ * - PNG_USER_VERSIONINFO_COMPANYNAME
+ * - PNG_USER_VERSIONINFO_LEGALTRADEMARKS
+ */
+
+#ifdef __STDC__
+#ifdef SPECIALBUILD
+# pragma message("PNG_LIBPNG_SPECIALBUILD (and deprecated SPECIALBUILD)\
+ are now LIBPNG reserved macros. Use PNG_USER_PRIVATEBUILD instead.")
+#endif
+
+#ifdef PRIVATEBUILD
+# pragma message("PRIVATEBUILD is deprecated. Use\
+ PNG_USER_PRIVATEBUILD instead.")
+# define PNG_USER_PRIVATEBUILD PRIVATEBUILD
+#endif
+#endif /* __STDC__ */
+
+#ifndef PNG_VERSION_INFO_ONLY
+
+/* End of material added to libpng-1.2.8 */
+
+/* This is the size of the compression buffer, and thus the size of
+ * an IDAT chunk. Make this whatever size you feel is best for your
+ * machine. One of these will be allocated per png_struct. When this
+ * is full, it writes the data to the disk, and does some other
+ * calculations. Making this an extremely small size will slow
+ * the library down, but you may want to experiment to determine
+ * where it becomes significant, if you are concerned with memory
+ * usage. Note that zlib allocates at least 32Kb also. For readers,
+ * this describes the size of the buffer available to read the data in.
+ * Unless this gets smaller than the size of a row (compressed),
+ * it should not make much difference how big this is.
+ */
+
+#ifndef PNG_ZBUF_SIZE
+# define PNG_ZBUF_SIZE 8192
+#endif
+
+/* Enable if you want a write-only libpng */
+
+#ifndef PNG_NO_READ_SUPPORTED
+# define PNG_READ_SUPPORTED
+#endif
+
+/* Enable if you want a read-only libpng */
+
+#ifndef PNG_NO_WRITE_SUPPORTED
+# define PNG_WRITE_SUPPORTED
+#endif
+
+/* Enabled by default in 1.2.0. You can disable this if you don't need to
+ support PNGs that are embedded in MNG datastreams */
+#if !defined(PNG_1_0_X) && !defined(PNG_NO_MNG_FEATURES)
+# ifndef PNG_MNG_FEATURES_SUPPORTED
+# define PNG_MNG_FEATURES_SUPPORTED
+# endif
+#endif
+
+#ifndef PNG_NO_FLOATING_POINT_SUPPORTED
+# ifndef PNG_FLOATING_POINT_SUPPORTED
+# define PNG_FLOATING_POINT_SUPPORTED
+# endif
+#endif
+
+/* If you are running on a machine where you cannot allocate more
+ * than 64K of memory at once, uncomment this. While libpng will not
+ * normally need that much memory in a chunk (unless you load up a very
+ * large file), zlib needs to know how big of a chunk it can use, and
+ * libpng thus makes sure to check any memory allocation to verify it
+ * will fit into memory.
+#define PNG_MAX_MALLOC_64K
+ */
+#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
+# define PNG_MAX_MALLOC_64K
+#endif
+
+/* Special munging to support doing things the 'cygwin' way:
+ * 'Normal' png-on-win32 defines/defaults:
+ * PNG_BUILD_DLL -- building dll
+ * PNG_USE_DLL -- building an application, linking to dll
+ * (no define) -- building static library, or building an
+ * application and linking to the static lib
+ * 'Cygwin' defines/defaults:
+ * PNG_BUILD_DLL -- (ignored) building the dll
+ * (no define) -- (ignored) building an application, linking to the dll
+ * PNG_STATIC -- (ignored) building the static lib, or building an
+ * application that links to the static lib.
+ * ALL_STATIC -- (ignored) building various static libs, or building an
+ * application that links to the static libs.
+ * Thus,
+ * a cygwin user should define either PNG_BUILD_DLL or PNG_STATIC, and
+ * this bit of #ifdefs will define the 'correct' config variables based on
+ * that. If a cygwin user *wants* to define 'PNG_USE_DLL' that's okay, but
+ * unnecessary.
+ *
+ * Also, the precedence order is:
+ * ALL_STATIC (since we can't #undef something outside our namespace)
+ * PNG_BUILD_DLL
+ * PNG_STATIC
+ * (nothing) == PNG_USE_DLL
+ *
+ * CYGWIN (2002-01-20): The preceding is now obsolete. With the advent
+ * of auto-import in binutils, we no longer need to worry about
+ * __declspec(dllexport) / __declspec(dllimport) and friends. Therefore,
+ * we don't need to worry about PNG_STATIC or ALL_STATIC when it comes
+ * to __declspec() stuff. However, we DO need to worry about
+ * PNG_BUILD_DLL and PNG_STATIC because those change some defaults
+ * such as CONSOLE_IO and whether GLOBAL_ARRAYS are allowed.
+ */
+#if defined(__CYGWIN__)
+# if defined(ALL_STATIC)
+# if defined(PNG_BUILD_DLL)
+# undef PNG_BUILD_DLL
+# endif
+# if defined(PNG_USE_DLL)
+# undef PNG_USE_DLL
+# endif
+# if defined(PNG_DLL)
+# undef PNG_DLL
+# endif
+# if !defined(PNG_STATIC)
+# define PNG_STATIC
+# endif
+# else
+# if defined (PNG_BUILD_DLL)
+# if defined(PNG_STATIC)
+# undef PNG_STATIC
+# endif
+# if defined(PNG_USE_DLL)
+# undef PNG_USE_DLL
+# endif
+# if !defined(PNG_DLL)
+# define PNG_DLL
+# endif
+# else
+# if defined(PNG_STATIC)
+# if defined(PNG_USE_DLL)
+# undef PNG_USE_DLL
+# endif
+# if defined(PNG_DLL)
+# undef PNG_DLL
+# endif
+# else
+# if !defined(PNG_USE_DLL)
+# define PNG_USE_DLL
+# endif
+# if !defined(PNG_DLL)
+# define PNG_DLL
+# endif
+# endif
+# endif
+# endif
+#endif
+
+/* This protects us against compilers that run on a windowing system
+ * and thus don't have or would rather us not use the stdio types:
+ * stdin, stdout, and stderr. The only one currently used is stderr
+ * in png_error() and png_warning(). #defining PNG_NO_CONSOLE_IO will
+ * prevent these from being compiled and used. #defining PNG_NO_STDIO
+ * will also prevent these, plus will prevent the entire set of stdio
+ * macros and functions (FILE *, printf, etc.) from being compiled and used,
+ * unless (PNG_DEBUG > 0) has been #defined.
+ *
+ * #define PNG_NO_CONSOLE_IO
+ * #define PNG_NO_STDIO
+ */
+
+#if defined(_WIN32_WCE)
+# include <windows.h>
+ /* Console I/O functions are not supported on WindowsCE */
+# define PNG_NO_CONSOLE_IO
+# ifdef PNG_DEBUG
+# undef PNG_DEBUG
+# endif
+#endif
+
+#ifdef PNG_BUILD_DLL
+# ifndef PNG_CONSOLE_IO_SUPPORTED
+# ifndef PNG_NO_CONSOLE_IO
+# define PNG_NO_CONSOLE_IO
+# endif
+# endif
+#endif
+
+# ifdef PNG_NO_STDIO
+# ifndef PNG_NO_CONSOLE_IO
+# define PNG_NO_CONSOLE_IO
+# endif
+# ifdef PNG_DEBUG
+# if (PNG_DEBUG > 0)
+# include <stdio.h>
+# endif
+# endif
+# else
+# if !defined(_WIN32_WCE)
+/* "stdio.h" functions are not supported on WindowsCE */
+# include <stdio.h>
+# endif
+# endif
+
+/* This macro protects us against machines that don't have function
+ * prototypes (ie K&R style headers). If your compiler does not handle
+ * function prototypes, define this macro and use the included ansi2knr.
+ * I've always been able to use _NO_PROTO as the indicator, but you may
+ * need to drag the empty declaration out in front of here, or change the
+ * ifdef to suit your own needs.
+ */
+#ifndef PNGARG
+
+#ifdef OF /* zlib prototype munger */
+# define PNGARG(arglist) OF(arglist)
+#else
+
+#ifdef _NO_PROTO
+# define PNGARG(arglist) ()
+# ifndef PNG_TYPECAST_NULL
+# define PNG_TYPECAST_NULL
+# endif
+#else
+# define PNGARG(arglist) arglist
+#endif /* _NO_PROTO */
+
+#endif /* OF */
+
+#endif /* PNGARG */
+
+/* Try to determine if we are compiling on a Mac. Note that testing for
+ * just __MWERKS__ is not good enough, because the Codewarrior is now used
+ * on non-Mac platforms.
+ */
+#ifndef MACOS
+# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
+ defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
+# define MACOS
+# endif
+#endif
+
+/* enough people need this for various reasons to include it here */
+#if !defined(MACOS) && !defined(RISCOS) && !defined(_WIN32_WCE)
+# include <sys/types.h>
+#endif
+
+#if !defined(PNG_SETJMP_NOT_SUPPORTED) && !defined(PNG_NO_SETJMP_SUPPORTED)
+# define PNG_SETJMP_SUPPORTED
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This is an attempt to force a single setjmp behaviour on Linux. If
+ * the X config stuff didn't define _BSD_SOURCE we wouldn't need this.
+ */
+
+# ifdef __linux__
+# ifdef _BSD_SOURCE
+# define PNG_SAVE_BSD_SOURCE
+# undef _BSD_SOURCE
+# endif
+# ifdef _SETJMP_H
+ /* If you encounter a compiler error here, see the explanation
+ * near the end of INSTALL.
+ */
+ __png.h__ already includes setjmp.h;
+ __dont__ include it again.;
+# endif
+# endif /* __linux__ */
+
+ /* include setjmp.h for error handling */
+# include <setjmp.h>
+
+# ifdef __linux__
+# ifdef PNG_SAVE_BSD_SOURCE
+# define _BSD_SOURCE
+# undef PNG_SAVE_BSD_SOURCE
+# endif
+# endif /* __linux__ */
+#endif /* PNG_SETJMP_SUPPORTED */
+
+#ifdef BSD
+# include <strings.h>
+#else
+# include <string.h>
+#endif
+
+/* Other defines for things like memory and the like can go here. */
+#ifdef PNG_INTERNAL
+
+#include <stdlib.h>
+
+/* The functions exported by PNG_EXTERN are PNG_INTERNAL functions, which
+ * aren't usually used outside the library (as far as I know), so it is
+ * debatable if they should be exported at all. In the future, when it is
+ * possible to have run-time registry of chunk-handling functions, some of
+ * these will be made available again.
+#define PNG_EXTERN extern
+ */
+#define PNG_EXTERN
+
+/* Other defines specific to compilers can go here. Try to keep
+ * them inside an appropriate ifdef/endif pair for portability.
+ */
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED)
+# if defined(MACOS)
+ /* We need to check that <math.h> hasn't already been included earlier
+ * as it seems it doesn't agree with <fp.h>, yet we should really use
+ * <fp.h> if possible.
+ */
+# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
+# include <fp.h>
+# endif
+# else
+# include <math.h>
+# endif
+# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
+ /* Amiga SAS/C: We must include builtin FPU functions when compiling using
+ * MATH=68881
+ */
+# include <m68881.h>
+# endif
+#endif
+
+/* Codewarrior on NT has linking problems without this. */
+#if (defined(__MWERKS__) && defined(WIN32)) || defined(__STDC__)
+# define PNG_ALWAYS_EXTERN
+#endif
+
+/* This provides the non-ANSI (far) memory allocation routines. */
+#if defined(__TURBOC__) && defined(__MSDOS__)
+# include <mem.h>
+# include <alloc.h>
+#endif
+
+/* I have no idea why is this necessary... */
+#if defined(_MSC_VER) && (defined(WIN32) || defined(_Windows) || \
+ defined(_WINDOWS) || defined(_WIN32) || defined(__WIN32__))
+# include <malloc.h>
+#endif
+
+/* This controls how fine the dithering gets. As this allocates
+ * a largish chunk of memory (32K), those who are not as concerned
+ * with dithering quality can decrease some or all of these.
+ */
+#ifndef PNG_DITHER_RED_BITS
+# define PNG_DITHER_RED_BITS 5
+#endif
+#ifndef PNG_DITHER_GREEN_BITS
+# define PNG_DITHER_GREEN_BITS 5
+#endif
+#ifndef PNG_DITHER_BLUE_BITS
+# define PNG_DITHER_BLUE_BITS 5
+#endif
+
+/* This controls how fine the gamma correction becomes when you
+ * are only interested in 8 bits anyway. Increasing this value
+ * results in more memory being used, and more pow() functions
+ * being called to fill in the gamma tables. Don't set this value
+ * less then 8, and even that may not work (I haven't tested it).
+ */
+
+#ifndef PNG_MAX_GAMMA_8
+# define PNG_MAX_GAMMA_8 11
+#endif
+
+/* This controls how much a difference in gamma we can tolerate before
+ * we actually start doing gamma conversion.
+ */
+#ifndef PNG_GAMMA_THRESHOLD
+# define PNG_GAMMA_THRESHOLD 0.05
+#endif
+
+#endif /* PNG_INTERNAL */
+
+/* The following uses const char * instead of char * for error
+ * and warning message functions, so some compilers won't complain.
+ * If you do not want to use const, define PNG_NO_CONST here.
+ */
+
+#ifndef PNG_NO_CONST
+# define PNG_CONST const
+#else
+# define PNG_CONST
+#endif
+
+/* The following defines give you the ability to remove code from the
+ * library that you will not be using. I wish I could figure out how to
+ * automate this, but I can't do that without making it seriously hard
+ * on the users. So if you are not using an ability, change the #define
+ * to and #undef, and that part of the library will not be compiled. If
+ * your linker can't find a function, you may want to make sure the
+ * ability is defined here. Some of these depend upon some others being
+ * defined. I haven't figured out all the interactions here, so you may
+ * have to experiment awhile to get everything to compile. If you are
+ * creating or using a shared library, you probably shouldn't touch this,
+ * as it will affect the size of the structures, and this will cause bad
+ * things to happen if the library and/or application ever change.
+ */
+
+/* Any features you will not be using can be undef'ed here */
+
+/* GR-P, 0.96a: Set "*TRANSFORMS_SUPPORTED as default but allow user
+ * to turn it off with "*TRANSFORMS_NOT_SUPPORTED" or *PNG_NO_*_TRANSFORMS
+ * on the compile line, then pick and choose which ones to define without
+ * having to edit this file. It is safe to use the *TRANSFORMS_NOT_SUPPORTED
+ * if you only want to have a png-compliant reader/writer but don't need
+ * any of the extra transformations. This saves about 80 kbytes in a
+ * typical installation of the library. (PNG_NO_* form added in version
+ * 1.0.1c, for consistency)
+ */
+
+/* The size of the png_text structure changed in libpng-1.0.6 when
+ * iTXt is supported. It is turned off by default, to support old apps
+ * that malloc the png_text structure instead of calling png_set_text()
+ * and letting libpng malloc it. It will be turned on by default in
+ * libpng-1.3.0.
+ */
+
+#ifndef PNG_iTXt_SUPPORTED
+# if !defined(PNG_READ_iTXt_SUPPORTED) && !defined(PNG_NO_READ_iTXt)
+# define PNG_NO_READ_iTXt
+# endif
+# if !defined(PNG_WRITE_iTXt_SUPPORTED) && !defined(PNG_NO_WRITE_iTXt)
+# define PNG_NO_WRITE_iTXt
+# endif
+#endif
+
+/* The following support, added after version 1.0.0, can be turned off here en
+ * masse by defining PNG_LEGACY_SUPPORTED in case you need binary compatibility
+ * with old applications that require the length of png_struct and png_info
+ * to remain unchanged.
+ */
+
+#ifdef PNG_LEGACY_SUPPORTED
+# define PNG_NO_FREE_ME
+# define PNG_NO_READ_UNKNOWN_CHUNKS
+# define PNG_NO_WRITE_UNKNOWN_CHUNKS
+# define PNG_NO_READ_USER_CHUNKS
+# define PNG_NO_READ_iCCP
+# define PNG_NO_WRITE_iCCP
+# define PNG_NO_READ_iTXt
+# define PNG_NO_WRITE_iTXt
+# define PNG_NO_READ_sCAL
+# define PNG_NO_WRITE_sCAL
+# define PNG_NO_READ_sPLT
+# define PNG_NO_WRITE_sPLT
+# define PNG_NO_INFO_IMAGE
+# define PNG_NO_READ_RGB_TO_GRAY
+# define PNG_NO_READ_USER_TRANSFORM
+# define PNG_NO_WRITE_USER_TRANSFORM
+# define PNG_NO_USER_MEM
+# define PNG_NO_READ_EMPTY_PLTE
+# define PNG_NO_MNG_FEATURES
+# define PNG_NO_FIXED_POINT_SUPPORTED
+#endif
+
+/* Ignore attempt to turn off both floating and fixed point support */
+#if !defined(PNG_FLOATING_POINT_SUPPORTED) || \
+ !defined(PNG_NO_FIXED_POINT_SUPPORTED)
+# define PNG_FIXED_POINT_SUPPORTED
+#endif
+
+#ifndef PNG_NO_FREE_ME
+# define PNG_FREE_ME_SUPPORTED
+#endif
+
+#if defined(PNG_READ_SUPPORTED)
+
+#if !defined(PNG_READ_TRANSFORMS_NOT_SUPPORTED) && \
+ !defined(PNG_NO_READ_TRANSFORMS)
+# define PNG_READ_TRANSFORMS_SUPPORTED
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+# ifndef PNG_NO_READ_EXPAND
+# define PNG_READ_EXPAND_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_SHIFT
+# define PNG_READ_SHIFT_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_PACK
+# define PNG_READ_PACK_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_BGR
+# define PNG_READ_BGR_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_SWAP
+# define PNG_READ_SWAP_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_PACKSWAP
+# define PNG_READ_PACKSWAP_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_INVERT
+# define PNG_READ_INVERT_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_DITHER
+# define PNG_READ_DITHER_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_BACKGROUND
+# define PNG_READ_BACKGROUND_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_16_TO_8
+# define PNG_READ_16_TO_8_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_FILLER
+# define PNG_READ_FILLER_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_GAMMA
+# define PNG_READ_GAMMA_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_GRAY_TO_RGB
+# define PNG_READ_GRAY_TO_RGB_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_SWAP_ALPHA
+# define PNG_READ_SWAP_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_INVERT_ALPHA
+# define PNG_READ_INVERT_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_STRIP_ALPHA
+# define PNG_READ_STRIP_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_USER_TRANSFORM
+# define PNG_READ_USER_TRANSFORM_SUPPORTED
+# endif
+# ifndef PNG_NO_READ_RGB_TO_GRAY
+# define PNG_READ_RGB_TO_GRAY_SUPPORTED
+# endif
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
+
+#if !defined(PNG_NO_PROGRESSIVE_READ) && \
+ !defined(PNG_PROGRESSIVE_READ_NOT_SUPPORTED) /* if you don't do progressive */
+# define PNG_PROGRESSIVE_READ_SUPPORTED /* reading. This is not talking */
+#endif /* about interlacing capability! You'll */
+ /* still have interlacing unless you change the following line: */
+
+#define PNG_READ_INTERLACING_SUPPORTED /* required for PNG-compliant decoders */
+
+#ifndef PNG_NO_READ_COMPOSITE_NODIV
+# ifndef PNG_NO_READ_COMPOSITED_NODIV /* libpng-1.0.x misspelling */
+# define PNG_READ_COMPOSITE_NODIV_SUPPORTED /* well tested on Intel, SGI */
+# endif
+#endif
+
+/* Deprecated, will be removed from version 2.0.0.
+ Use PNG_MNG_FEATURES_SUPPORTED instead. */
+#ifndef PNG_NO_READ_EMPTY_PLTE
+# define PNG_READ_EMPTY_PLTE_SUPPORTED
+#endif
+
+#endif /* PNG_READ_SUPPORTED */
+
+#if defined(PNG_WRITE_SUPPORTED)
+
+# if !defined(PNG_WRITE_TRANSFORMS_NOT_SUPPORTED) && \
+ !defined(PNG_NO_WRITE_TRANSFORMS)
+# define PNG_WRITE_TRANSFORMS_SUPPORTED
+#endif
+
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+# ifndef PNG_NO_WRITE_SHIFT
+# define PNG_WRITE_SHIFT_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_PACK
+# define PNG_WRITE_PACK_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_BGR
+# define PNG_WRITE_BGR_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_SWAP
+# define PNG_WRITE_SWAP_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_PACKSWAP
+# define PNG_WRITE_PACKSWAP_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_INVERT
+# define PNG_WRITE_INVERT_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_FILLER
+# define PNG_WRITE_FILLER_SUPPORTED /* same as WRITE_STRIP_ALPHA */
+# endif
+# ifndef PNG_NO_WRITE_SWAP_ALPHA
+# define PNG_WRITE_SWAP_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_INVERT_ALPHA
+# define PNG_WRITE_INVERT_ALPHA_SUPPORTED
+# endif
+# ifndef PNG_NO_WRITE_USER_TRANSFORM
+# define PNG_WRITE_USER_TRANSFORM_SUPPORTED
+# endif
+#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
+
+#define PNG_WRITE_INTERLACING_SUPPORTED /* not required for PNG-compliant
+ encoders, but can cause trouble
+ if left undefined */
+
+#if !defined(PNG_NO_WRITE_WEIGHTED_FILTER) && \
+ defined(PNG_FLOATING_POINT_SUPPORTED)
+# define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+#endif
+
+#ifndef PNG_NO_WRITE_FLUSH
+# define PNG_WRITE_FLUSH_SUPPORTED
+#endif
+
+/* Deprecated, see PNG_MNG_FEATURES_SUPPORTED, above */
+#ifndef PNG_NO_WRITE_EMPTY_PLTE
+# define PNG_WRITE_EMPTY_PLTE_SUPPORTED
+#endif
+
+#endif /* PNG_WRITE_SUPPORTED */
+
+#ifndef PNG_1_0_X
+# ifndef PNG_NO_ERROR_NUMBERS
+# define PNG_ERROR_NUMBERS_SUPPORTED
+# endif
+#endif /* PNG_1_0_X */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+# ifndef PNG_NO_USER_TRANSFORM_PTR
+# define PNG_USER_TRANSFORM_PTR_SUPPORTED
+# endif
+#endif
+
+#ifndef PNG_NO_STDIO
+# define PNG_TIME_RFC1123_SUPPORTED
+#endif
+
+/* This adds extra functions in pngget.c for accessing data from the
+ * info pointer (added in version 0.99)
+ * png_get_image_width()
+ * png_get_image_height()
+ * png_get_bit_depth()
+ * png_get_color_type()
+ * png_get_compression_type()
+ * png_get_filter_type()
+ * png_get_interlace_type()
+ * png_get_pixel_aspect_ratio()
+ * png_get_pixels_per_meter()
+ * png_get_x_offset_pixels()
+ * png_get_y_offset_pixels()
+ * png_get_x_offset_microns()
+ * png_get_y_offset_microns()
+ */
+#if !defined(PNG_NO_EASY_ACCESS) && !defined(PNG_EASY_ACCESS_SUPPORTED)
+# define PNG_EASY_ACCESS_SUPPORTED
+#endif
+
+/* PNG_ASSEMBLER_CODE was enabled by default in version 1.2.0
+ even when PNG_USE_PNGVCRD or PNG_USE_PNGGCCRD is not defined */
+#if defined(PNG_READ_SUPPORTED) && !defined(PNG_NO_ASSEMBLER_CODE)
+# ifndef PNG_ASSEMBLER_CODE_SUPPORTED
+# define PNG_ASSEMBLER_CODE_SUPPORTED
+# endif
+# if !defined(PNG_MMX_CODE_SUPPORTED) && !defined(PNG_NO_MMX_CODE)
+# define PNG_MMX_CODE_SUPPORTED
+# endif
+#endif
+
+/* If you are sure that you don't need thread safety and you are compiling
+ with PNG_USE_PNGCCRD for an MMX application, you can define this for
+ faster execution. See pnggccrd.c.
+#define PNG_THREAD_UNSAFE_OK
+*/
+
+#if !defined(PNG_1_0_X)
+#if !defined(PNG_NO_USER_MEM) && !defined(PNG_USER_MEM_SUPPORTED)
+# define PNG_USER_MEM_SUPPORTED
+#endif
+#endif /* PNG_1_0_X */
+
+/* Added at libpng-1.2.6 */
+#if !defined(PNG_1_0_X)
+#ifndef PNG_SET_USER_LIMITS_SUPPORTED
+#if !defined(PNG_NO_SET_USER_LIMITS) && !defined(PNG_SET_USER_LIMITS_SUPPORTED)
+# define PNG_SET_USER_LIMITS_SUPPORTED
+#endif
+#endif
+#endif /* PNG_1_0_X */
+
+/* Added at libpng-1.0.16 and 1.2.6. To accept all valid PNGS no matter
+ * how large, set these limits to 0x7fffffffL
+ */
+#ifndef PNG_USER_WIDTH_MAX
+# define PNG_USER_WIDTH_MAX 1000000L
+#endif
+#ifndef PNG_USER_HEIGHT_MAX
+# define PNG_USER_HEIGHT_MAX 1000000L
+#endif
+
+/* These are currently experimental features, define them if you want */
+
+/* very little testing */
+/*
+#ifdef PNG_READ_SUPPORTED
+# ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+# define PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+# endif
+#endif
+*/
+
+/* This is only for PowerPC big-endian and 680x0 systems */
+/* some testing */
+/*
+#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
+# define PNG_READ_BIG_ENDIAN_SUPPORTED
+#endif
+*/
+
+/* Buggy compilers (e.g., gcc 2.7.2.2) need this */
+/*
+#define PNG_NO_POINTER_INDEXING
+*/
+
+/* These functions are turned off by default, as they will be phased out. */
+/*
+#define PNG_USELESS_TESTS_SUPPORTED
+#define PNG_CORRECT_PALETTE_SUPPORTED
+*/
+
+/* Any chunks you are not interested in, you can undef here. The
+ * ones that allocate memory may be expecially important (hIST,
+ * tEXt, zTXt, tRNS, pCAL). Others will just save time and make png_info
+ * a bit smaller.
+ */
+
+#if defined(PNG_READ_SUPPORTED) && \
+ !defined(PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED) && \
+ !defined(PNG_NO_READ_ANCILLARY_CHUNKS)
+# define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+#endif
+
+#if defined(PNG_WRITE_SUPPORTED) && \
+ !defined(PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED) && \
+ !defined(PNG_NO_WRITE_ANCILLARY_CHUNKS)
+# define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#endif
+
+#ifdef PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+
+#ifdef PNG_NO_READ_TEXT
+# define PNG_NO_READ_iTXt
+# define PNG_NO_READ_tEXt
+# define PNG_NO_READ_zTXt
+#endif
+#ifndef PNG_NO_READ_bKGD
+# define PNG_READ_bKGD_SUPPORTED
+# define PNG_bKGD_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_cHRM
+# define PNG_READ_cHRM_SUPPORTED
+# define PNG_cHRM_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_gAMA
+# define PNG_READ_gAMA_SUPPORTED
+# define PNG_gAMA_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_hIST
+# define PNG_READ_hIST_SUPPORTED
+# define PNG_hIST_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_iCCP
+# define PNG_READ_iCCP_SUPPORTED
+# define PNG_iCCP_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_iTXt
+# ifndef PNG_READ_iTXt_SUPPORTED
+# define PNG_READ_iTXt_SUPPORTED
+# endif
+# ifndef PNG_iTXt_SUPPORTED
+# define PNG_iTXt_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_READ_oFFs
+# define PNG_READ_oFFs_SUPPORTED
+# define PNG_oFFs_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_pCAL
+# define PNG_READ_pCAL_SUPPORTED
+# define PNG_pCAL_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sCAL
+# define PNG_READ_sCAL_SUPPORTED
+# define PNG_sCAL_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_pHYs
+# define PNG_READ_pHYs_SUPPORTED
+# define PNG_pHYs_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sBIT
+# define PNG_READ_sBIT_SUPPORTED
+# define PNG_sBIT_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sPLT
+# define PNG_READ_sPLT_SUPPORTED
+# define PNG_sPLT_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sRGB
+# define PNG_READ_sRGB_SUPPORTED
+# define PNG_sRGB_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_tEXt
+# define PNG_READ_tEXt_SUPPORTED
+# define PNG_tEXt_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_tIME
+# define PNG_READ_tIME_SUPPORTED
+# define PNG_tIME_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_tRNS
+# define PNG_READ_tRNS_SUPPORTED
+# define PNG_tRNS_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_zTXt
+# define PNG_READ_zTXt_SUPPORTED
+# define PNG_zTXt_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_UNKNOWN_CHUNKS
+# define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+# ifndef PNG_UNKNOWN_CHUNKS_SUPPORTED
+# define PNG_UNKNOWN_CHUNKS_SUPPORTED
+# endif
+# ifndef PNG_NO_HANDLE_AS_UNKNOWN
+# define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# endif
+#endif
+#if !defined(PNG_NO_READ_USER_CHUNKS) && \
+ defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+# define PNG_READ_USER_CHUNKS_SUPPORTED
+# define PNG_USER_CHUNKS_SUPPORTED
+# ifdef PNG_NO_READ_UNKNOWN_CHUNKS
+# undef PNG_NO_READ_UNKNOWN_CHUNKS
+# endif
+# ifdef PNG_NO_HANDLE_AS_UNKNOWN
+# undef PNG_NO_HANDLE_AS_UNKNOWN
+# endif
+#endif
+#ifndef PNG_NO_READ_OPT_PLTE
+# define PNG_READ_OPT_PLTE_SUPPORTED /* only affects support of the */
+#endif /* optional PLTE chunk in RGB and RGBA images */
+#if defined(PNG_READ_iTXt_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) || \
+ defined(PNG_READ_zTXt_SUPPORTED)
+# define PNG_READ_TEXT_SUPPORTED
+# define PNG_TEXT_SUPPORTED
+#endif
+
+#endif /* PNG_READ_ANCILLARY_CHUNKS_SUPPORTED */
+
+#ifdef PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+
+#ifdef PNG_NO_WRITE_TEXT
+# define PNG_NO_WRITE_iTXt
+# define PNG_NO_WRITE_tEXt
+# define PNG_NO_WRITE_zTXt
+#endif
+#ifndef PNG_NO_WRITE_bKGD
+# define PNG_WRITE_bKGD_SUPPORTED
+# ifndef PNG_bKGD_SUPPORTED
+# define PNG_bKGD_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_cHRM
+# define PNG_WRITE_cHRM_SUPPORTED
+# ifndef PNG_cHRM_SUPPORTED
+# define PNG_cHRM_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_gAMA
+# define PNG_WRITE_gAMA_SUPPORTED
+# ifndef PNG_gAMA_SUPPORTED
+# define PNG_gAMA_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_hIST
+# define PNG_WRITE_hIST_SUPPORTED
+# ifndef PNG_hIST_SUPPORTED
+# define PNG_hIST_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_iCCP
+# define PNG_WRITE_iCCP_SUPPORTED
+# ifndef PNG_iCCP_SUPPORTED
+# define PNG_iCCP_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_iTXt
+# ifndef PNG_WRITE_iTXt_SUPPORTED
+# define PNG_WRITE_iTXt_SUPPORTED
+# endif
+# ifndef PNG_iTXt_SUPPORTED
+# define PNG_iTXt_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_oFFs
+# define PNG_WRITE_oFFs_SUPPORTED
+# ifndef PNG_oFFs_SUPPORTED
+# define PNG_oFFs_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_pCAL
+# define PNG_WRITE_pCAL_SUPPORTED
+# ifndef PNG_pCAL_SUPPORTED
+# define PNG_pCAL_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_sCAL
+# define PNG_WRITE_sCAL_SUPPORTED
+# ifndef PNG_sCAL_SUPPORTED
+# define PNG_sCAL_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_pHYs
+# define PNG_WRITE_pHYs_SUPPORTED
+# ifndef PNG_pHYs_SUPPORTED
+# define PNG_pHYs_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_sBIT
+# define PNG_WRITE_sBIT_SUPPORTED
+# ifndef PNG_sBIT_SUPPORTED
+# define PNG_sBIT_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_sPLT
+# define PNG_WRITE_sPLT_SUPPORTED
+# ifndef PNG_sPLT_SUPPORTED
+# define PNG_sPLT_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_sRGB
+# define PNG_WRITE_sRGB_SUPPORTED
+# ifndef PNG_sRGB_SUPPORTED
+# define PNG_sRGB_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_tEXt
+# define PNG_WRITE_tEXt_SUPPORTED
+# ifndef PNG_tEXt_SUPPORTED
+# define PNG_tEXt_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_tIME
+# define PNG_WRITE_tIME_SUPPORTED
+# ifndef PNG_tIME_SUPPORTED
+# define PNG_tIME_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_tRNS
+# define PNG_WRITE_tRNS_SUPPORTED
+# ifndef PNG_tRNS_SUPPORTED
+# define PNG_tRNS_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_zTXt
+# define PNG_WRITE_zTXt_SUPPORTED
+# ifndef PNG_zTXt_SUPPORTED
+# define PNG_zTXt_SUPPORTED
+# endif
+#endif
+#ifndef PNG_NO_WRITE_UNKNOWN_CHUNKS
+# define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+# ifndef PNG_UNKNOWN_CHUNKS_SUPPORTED
+# define PNG_UNKNOWN_CHUNKS_SUPPORTED
+# endif
+# ifndef PNG_NO_HANDLE_AS_UNKNOWN
+# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# endif
+# endif
+#endif
+#if defined(PNG_WRITE_iTXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \
+ defined(PNG_WRITE_zTXt_SUPPORTED)
+# define PNG_WRITE_TEXT_SUPPORTED
+# ifndef PNG_TEXT_SUPPORTED
+# define PNG_TEXT_SUPPORTED
+# endif
+#endif
+
+#endif /* PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED */
+
+/* Turn this off to disable png_read_png() and
+ * png_write_png() and leave the row_pointers member
+ * out of the info structure.
+ */
+#ifndef PNG_NO_INFO_IMAGE
+# define PNG_INFO_IMAGE_SUPPORTED
+#endif
+
+/* need the time information for reading tIME chunks */
+#if defined(PNG_tIME_SUPPORTED)
+# if !defined(_WIN32_WCE) && !defined(__COM32__)
+ /* "time.h" functions are not supported on WindowsCE */
+# include <time.h>
+# endif
+#endif
+
+/* Some typedefs to get us started. These should be safe on most of the
+ * common platforms. The typedefs should be at least as large as the
+ * numbers suggest (a png_uint_32 must be at least 32 bits long), but they
+ * don't have to be exactly that size. Some compilers dislike passing
+ * unsigned shorts as function parameters, so you may be better off using
+ * unsigned int for png_uint_16. Likewise, for 64-bit systems, you may
+ * want to have unsigned int for png_uint_32 instead of unsigned long.
+ */
+
+typedef unsigned long png_uint_32;
+typedef long png_int_32;
+typedef unsigned short png_uint_16;
+typedef short png_int_16;
+typedef unsigned char png_byte;
+
+/* This is usually size_t. It is typedef'ed just in case you need it to
+ change (I'm not sure if you will or not, so I thought I'd be safe) */
+#ifdef PNG_SIZE_T
+ typedef PNG_SIZE_T png_size_t;
+# define png_sizeof(x) png_convert_size(sizeof (x))
+#else
+ typedef size_t png_size_t;
+# define png_sizeof(x) sizeof (x)
+#endif
+
+/* The following is needed for medium model support. It cannot be in the
+ * PNG_INTERNAL section. Needs modification for other compilers besides
+ * MSC. Model independent support declares all arrays and pointers to be
+ * large using the far keyword. The zlib version used must also support
+ * model independent data. As of version zlib 1.0.4, the necessary changes
+ * have been made in zlib. The USE_FAR_KEYWORD define triggers other
+ * changes that are needed. (Tim Wegner)
+ */
+
+/* Separate compiler dependencies (problem here is that zlib.h always
+ defines FAR. (SJT) */
+#ifdef __BORLANDC__
+# if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__)
+# define LDATA 1
+# else
+# define LDATA 0
+# endif
+ /* GRR: why is Cygwin in here? Cygwin is not Borland C... */
+# if !defined(__WIN32__) && !defined(__FLAT__) && !defined(__CYGWIN__)
+# define PNG_MAX_MALLOC_64K
+# if (LDATA != 1)
+# ifndef FAR
+# define FAR __far
+# endif
+# define USE_FAR_KEYWORD
+# endif /* LDATA != 1 */
+ /* Possibly useful for moving data out of default segment.
+ * Uncomment it if you want. Could also define FARDATA as
+ * const if your compiler supports it. (SJT)
+# define FARDATA FAR
+ */
+# endif /* __WIN32__, __FLAT__, __CYGWIN__ */
+#endif /* __BORLANDC__ */
+
+
+/* Suggest testing for specific compiler first before testing for
+ * FAR. The Watcom compiler defines both __MEDIUM__ and M_I86MM,
+ * making reliance oncertain keywords suspect. (SJT)
+ */
+
+/* MSC Medium model */
+#if defined(FAR)
+# if defined(M_I86MM)
+# define USE_FAR_KEYWORD
+# define FARDATA FAR
+# include <dos.h>
+# endif
+#endif
+
+/* SJT: default case */
+#ifndef FAR
+# define FAR
+#endif
+
+/* At this point FAR is always defined */
+#ifndef FARDATA
+# define FARDATA
+#endif
+
+/* Typedef for floating-point numbers that are converted
+ to fixed-point with a multiple of 100,000, e.g., int_gamma */
+typedef png_int_32 png_fixed_point;
+
+/* Add typedefs for pointers */
+typedef void FAR * png_voidp;
+typedef png_byte FAR * png_bytep;
+typedef png_uint_32 FAR * png_uint_32p;
+typedef png_int_32 FAR * png_int_32p;
+typedef png_uint_16 FAR * png_uint_16p;
+typedef png_int_16 FAR * png_int_16p;
+typedef PNG_CONST char FAR * png_const_charp;
+typedef char FAR * png_charp;
+typedef png_fixed_point FAR * png_fixed_point_p;
+
+#ifndef PNG_NO_STDIO
+#if defined(_WIN32_WCE)
+typedef HANDLE png_FILE_p;
+#else
+typedef FILE * png_FILE_p;
+#endif
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double FAR * png_doublep;
+#endif
+
+/* Pointers to pointers; i.e. arrays */
+typedef png_byte FAR * FAR * png_bytepp;
+typedef png_uint_32 FAR * FAR * png_uint_32pp;
+typedef png_int_32 FAR * FAR * png_int_32pp;
+typedef png_uint_16 FAR * FAR * png_uint_16pp;
+typedef png_int_16 FAR * FAR * png_int_16pp;
+typedef PNG_CONST char FAR * FAR * png_const_charpp;
+typedef char FAR * FAR * png_charpp;
+typedef png_fixed_point FAR * FAR * png_fixed_point_pp;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double FAR * FAR * png_doublepp;
+#endif
+
+/* Pointers to pointers to pointers; i.e., pointer to array */
+typedef char FAR * FAR * FAR * png_charppp;
+
+#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
+/* SPC - Is this stuff deprecated? */
+/* It'll be removed as of libpng-1.3.0 - GR-P */
+/* libpng typedefs for types in zlib. If zlib changes
+ * or another compression library is used, then change these.
+ * Eliminates need to change all the source files.
+ */
+typedef charf * png_zcharp;
+typedef charf * FAR * png_zcharpp;
+typedef z_stream FAR * png_zstreamp;
+#endif /* (PNG_1_0_X) || defined(PNG_1_2_X) */
+
+/*
+ * Define PNG_BUILD_DLL if the module being built is a Windows
+ * LIBPNG DLL.
+ *
+ * Define PNG_USE_DLL if you want to *link* to the Windows LIBPNG DLL.
+ * It is equivalent to Microsoft predefined macro _DLL that is
+ * automatically defined when you compile using the share
+ * version of the CRT (C Run-Time library)
+ *
+ * The cygwin mods make this behavior a little different:
+ * Define PNG_BUILD_DLL if you are building a dll for use with cygwin
+ * Define PNG_STATIC if you are building a static library for use with cygwin,
+ * -or- if you are building an application that you want to link to the
+ * static library.
+ * PNG_USE_DLL is defined by default (no user action needed) unless one of
+ * the other flags is defined.
+ */
+
+#if !defined(PNG_DLL) && (defined(PNG_BUILD_DLL) || defined(PNG_USE_DLL))
+# define PNG_DLL
+#endif
+/* If CYGWIN, then disallow GLOBAL ARRAYS unless building a static lib.
+ * When building a static lib, default to no GLOBAL ARRAYS, but allow
+ * command-line override
+ */
+#if defined(__CYGWIN__)
+# if !defined(PNG_STATIC)
+# if defined(PNG_USE_GLOBAL_ARRAYS)
+# undef PNG_USE_GLOBAL_ARRAYS
+# endif
+# if !defined(PNG_USE_LOCAL_ARRAYS)
+# define PNG_USE_LOCAL_ARRAYS
+# endif
+# else
+# if defined(PNG_USE_LOCAL_ARRAYS) || defined(PNG_NO_GLOBAL_ARRAYS)
+# if defined(PNG_USE_GLOBAL_ARRAYS)
+# undef PNG_USE_GLOBAL_ARRAYS
+# endif
+# endif
+# endif
+# if !defined(PNG_USE_LOCAL_ARRAYS) && !defined(PNG_USE_GLOBAL_ARRAYS)
+# define PNG_USE_LOCAL_ARRAYS
+# endif
+#endif
+
+/* Do not use global arrays (helps with building DLL's)
+ * They are no longer used in libpng itself, since version 1.0.5c,
+ * but might be required for some pre-1.0.5c applications.
+ */
+#if !defined(PNG_USE_LOCAL_ARRAYS) && !defined(PNG_USE_GLOBAL_ARRAYS)
+# if defined(PNG_NO_GLOBAL_ARRAYS) || (defined(__GNUC__) && defined(PNG_DLL))
+# define PNG_USE_LOCAL_ARRAYS
+# else
+# define PNG_USE_GLOBAL_ARRAYS
+# endif
+#endif
+
+#if defined(__CYGWIN__)
+# undef PNGAPI
+# define PNGAPI __cdecl
+# undef PNG_IMPEXP
+# define PNG_IMPEXP
+#endif
+
+/* If you define PNGAPI, e.g., with compiler option "-DPNGAPI=__stdcall",
+ * you may get warnings regarding the linkage of png_zalloc and png_zfree.
+ * Don't ignore those warnings; you must also reset the default calling
+ * convention in your compiler to match your PNGAPI, and you must build
+ * zlib and your applications the same way you build libpng.
+ */
+
+#if defined(__MINGW32__) && !defined(PNG_MODULEDEF)
+# ifndef PNG_NO_MODULEDEF
+# define PNG_NO_MODULEDEF
+# endif
+#endif
+
+#if !defined(PNG_IMPEXP) && defined(PNG_BUILD_DLL) && !defined(PNG_NO_MODULEDEF)
+# define PNG_IMPEXP
+#endif
+
+#if defined(PNG_DLL) || defined(_DLL) || defined(__DLL__ ) || \
+ (( defined(_Windows) || defined(_WINDOWS) || \
+ defined(WIN32) || defined(_WIN32) || defined(__WIN32__) ))
+
+# ifndef PNGAPI
+# if defined(__GNUC__) || (defined (_MSC_VER) && (_MSC_VER >= 800))
+# define PNGAPI __cdecl
+# else
+# define PNGAPI _cdecl
+# endif
+# endif
+
+# if !defined(PNG_IMPEXP) && (!defined(PNG_DLL) || \
+ 0 /* WINCOMPILER_WITH_NO_SUPPORT_FOR_DECLIMPEXP */)
+# define PNG_IMPEXP
+# endif
+
+# if !defined(PNG_IMPEXP)
+
+# define PNG_EXPORT_TYPE1(type,symbol) PNG_IMPEXP type PNGAPI symbol
+# define PNG_EXPORT_TYPE2(type,symbol) type PNG_IMPEXP PNGAPI symbol
+
+ /* Borland/Microsoft */
+# if defined(_MSC_VER) || defined(__BORLANDC__)
+# if (_MSC_VER >= 800) || (__BORLANDC__ >= 0x500)
+# define PNG_EXPORT PNG_EXPORT_TYPE1
+# else
+# define PNG_EXPORT PNG_EXPORT_TYPE2
+# if defined(PNG_BUILD_DLL)
+# define PNG_IMPEXP __export
+# else
+# define PNG_IMPEXP /*__import */ /* doesn't exist AFAIK in
+ VC++ */
+# endif /* Exists in Borland C++ for
+ C++ classes (== huge) */
+# endif
+# endif
+
+# if !defined(PNG_IMPEXP)
+# if defined(PNG_BUILD_DLL)
+# define PNG_IMPEXP __declspec(dllexport)
+# else
+# define PNG_IMPEXP __declspec(dllimport)
+# endif
+# endif
+# endif /* PNG_IMPEXP */
+#else /* !(DLL || non-cygwin WINDOWS) */
+# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
+# ifndef PNGAPI
+# define PNGAPI _System
+# endif
+# else
+# if 0 /* ... other platforms, with other meanings */
+# endif
+# endif
+#endif
+
+#ifndef PNGAPI
+# define PNGAPI
+#endif
+#ifndef PNG_IMPEXP
+# define PNG_IMPEXP
+#endif
+
+#ifdef PNG_BUILDSYMS
+# ifndef PNG_EXPORT
+# define PNG_EXPORT(type,symbol) PNG_FUNCTION_EXPORT symbol END
+# endif
+# ifdef PNG_USE_GLOBAL_ARRAYS
+# ifndef PNG_EXPORT_VAR
+# define PNG_EXPORT_VAR(type) PNG_DATA_EXPORT
+# endif
+# endif
+#endif
+
+#ifndef PNG_EXPORT
+# define PNG_EXPORT(type,symbol) PNG_IMPEXP type PNGAPI symbol
+#endif
+
+#ifdef PNG_USE_GLOBAL_ARRAYS
+# ifndef PNG_EXPORT_VAR
+# define PNG_EXPORT_VAR(type) extern PNG_IMPEXP type
+# endif
+#endif
+
+/* User may want to use these so they are not in PNG_INTERNAL. Any library
+ * functions that are passed far data must be model independent.
+ */
+
+#ifndef PNG_ABORT
+# define PNG_ABORT() abort()
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+# define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#else
+# define png_jmpbuf(png_ptr) \
+ (LIBPNG_WAS_COMPILED_WITH__PNG_SETJMP_NOT_SUPPORTED)
+#endif
+
+#if defined(USE_FAR_KEYWORD) /* memory model independent fns */
+/* use this to make far-to-near assignments */
+# define CHECK 1
+# define NOCHECK 0
+# define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
+# define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
+# define png_strcpy _fstrcpy
+# define png_strncpy _fstrncpy /* Added to v 1.2.6 */
+# define png_strlen _fstrlen
+# define png_memcmp _fmemcmp /* SJT: added */
+# define png_memcpy _fmemcpy
+# define png_memset _fmemset
+#else /* use the usual functions */
+# define CVT_PTR(ptr) (ptr)
+# define CVT_PTR_NOCHECK(ptr) (ptr)
+# define png_strcpy strcpy
+# define png_strncpy strncpy /* Added to v 1.2.6 */
+# define png_strlen strlen
+# define png_memcmp memcmp /* SJT: added */
+# define png_memcpy memcpy
+# define png_memset memset
+#endif
+/* End of memory model independent support */
+
+/* Just a little check that someone hasn't tried to define something
+ * contradictory.
+ */
+#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
+# undef PNG_ZBUF_SIZE
+# define PNG_ZBUF_SIZE 65536L
+#endif
+
+#ifdef PNG_READ_SUPPORTED
+/* Prior to libpng-1.0.9, this block was in pngasmrd.h */
+#if defined(PNG_INTERNAL)
+
+/* These are the default thresholds before the MMX code kicks in; if either
+ * rowbytes or bitdepth is below the threshold, plain C code is used. These
+ * can be overridden at runtime via the png_set_mmx_thresholds() call in
+ * libpng 1.2.0 and later. The values below were chosen by Intel.
+ */
+
+#ifndef PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT
+# define PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT 128 /* >= */
+#endif
+#ifndef PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT
+# define PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT 9 /* >= */
+#endif
+
+/* Set this in the makefile for VC++ on Pentium, not here. */
+/* Platform must be Pentium. Makefile must assemble and load pngvcrd.c .
+ * MMX will be detected at run time and used if present.
+ */
+#ifdef PNG_USE_PNGVCRD
+# define PNG_HAVE_ASSEMBLER_COMBINE_ROW
+# define PNG_HAVE_ASSEMBLER_READ_INTERLACE
+# define PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
+#endif
+
+/* Set this in the makefile for gcc/as on Pentium, not here. */
+/* Platform must be Pentium. Makefile must assemble and load pnggccrd.c .
+ * MMX will be detected at run time and used if present.
+ */
+#ifdef PNG_USE_PNGGCCRD
+# define PNG_HAVE_ASSEMBLER_COMBINE_ROW
+# define PNG_HAVE_ASSEMBLER_READ_INTERLACE
+# define PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
+#endif
+/* - see pnggccrd.c for info about what is currently enabled */
+
+#endif /* PNG_INTERNAL */
+#endif /* PNG_READ_SUPPORTED */
+
+/* Added at libpng-1.2.8 */
+#endif /* PNG_VERSION_INFO_ONLY */
+
+#endif /* PNGCONF_H */
diff --git a/com32/lib/libpng/pngerror.c b/com32/lib/libpng/pngerror.c
new file mode 100644
index 00000000..6fa40123
--- /dev/null
+++ b/com32/lib/libpng/pngerror.c
@@ -0,0 +1,295 @@
+
+/* pngerror.c - stub functions for i/o and memory allocation
+ *
+ * libpng version 1.2.8 - December 3, 2004
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2004 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This file provides a location for all error handling. Users who
+ * need special error handling are expected to write replacement functions
+ * and use png_set_error_fn() to use those functions. See the instructions
+ * at each function.
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+static void /* PRIVATE */
+png_default_error PNGARG((png_structp png_ptr,
+ png_const_charp error_message));
+static void /* PRIVATE */
+png_default_warning PNGARG((png_structp png_ptr,
+ png_const_charp warning_message));
+
+/* This function is called whenever there is a fatal error. This function
+ * should not be changed. If there is a need to handle errors differently,
+ * you should supply a replacement error function and use png_set_error_fn()
+ * to replace the error function at run-time.
+ */
+void PNGAPI
+png_error(png_structp png_ptr, png_const_charp error_message)
+{
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ char msg[16];
+ if (png_ptr->flags&(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+ {
+ if (*error_message == '#')
+ {
+ int offset;
+ for (offset=1; offset<15; offset++)
+ if (*(error_message+offset) == ' ')
+ break;
+ if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+ {
+ int i;
+ for (i=0; i<offset-1; i++)
+ msg[i]=error_message[i+1];
+ msg[i]='\0';
+ error_message=msg;
+ }
+ else
+ error_message+=offset;
+ }
+ else
+ {
+ if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+ {
+ msg[0]='0';
+ msg[1]='\0';
+ error_message=msg;
+ }
+ }
+ }
+#endif
+ if (png_ptr != NULL && png_ptr->error_fn != NULL)
+ (*(png_ptr->error_fn))(png_ptr, error_message);
+
+ /* If the custom handler doesn't exist, or if it returns,
+ use the default handler, which will not return. */
+ png_default_error(png_ptr, error_message);
+}
+
+/* This function is called whenever there is a non-fatal error. This function
+ * should not be changed. If there is a need to handle warnings differently,
+ * you should supply a replacement warning function and use
+ * png_set_error_fn() to replace the warning function at run-time.
+ */
+void PNGAPI
+png_warning(png_structp png_ptr, png_const_charp warning_message)
+{
+ int offset = 0;
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if (png_ptr->flags&(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+#endif
+ {
+ if (*warning_message == '#')
+ {
+ for (offset=1; offset<15; offset++)
+ if (*(warning_message+offset) == ' ')
+ break;
+ }
+ }
+ if (png_ptr != NULL && png_ptr->warning_fn != NULL)
+ (*(png_ptr->warning_fn))(png_ptr, warning_message+offset);
+ else
+ png_default_warning(png_ptr, warning_message+offset);
+}
+
+/* These utilities are used internally to build an error message that relates
+ * to the current chunk. The chunk name comes from png_ptr->chunk_name,
+ * this is used to prefix the message. The message is limited in length
+ * to 63 bytes, the name characters are output as hex digits wrapped in []
+ * if the character is invalid.
+ */
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+static PNG_CONST char png_digit[16] = {
+ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+ 'A', 'B', 'C', 'D', 'E', 'F'
+};
+
+static void /* PRIVATE */
+png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
+ error_message)
+{
+ int iout = 0, iin = 0;
+
+ while (iin < 4)
+ {
+ int c = png_ptr->chunk_name[iin++];
+ if (isnonalpha(c))
+ {
+ buffer[iout++] = '[';
+ buffer[iout++] = png_digit[(c & 0xf0) >> 4];
+ buffer[iout++] = png_digit[c & 0x0f];
+ buffer[iout++] = ']';
+ }
+ else
+ {
+ buffer[iout++] = (png_byte)c;
+ }
+ }
+
+ if (error_message == NULL)
+ buffer[iout] = 0;
+ else
+ {
+ buffer[iout++] = ':';
+ buffer[iout++] = ' ';
+ png_strncpy(buffer+iout, error_message, 63);
+ buffer[iout+63] = 0;
+ }
+}
+
+void PNGAPI
+png_chunk_error(png_structp png_ptr, png_const_charp error_message)
+{
+ char msg[18+64];
+ png_format_buffer(png_ptr, msg, error_message);
+ png_error(png_ptr, msg);
+}
+
+void PNGAPI
+png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
+{
+ char msg[18+64];
+ png_format_buffer(png_ptr, msg, warning_message);
+ png_warning(png_ptr, msg);
+}
+
+/* This is the default error handling function. Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash. This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static void /* PRIVATE */
+png_default_error(png_structp png_ptr, png_const_charp error_message)
+{
+#ifndef PNG_NO_CONSOLE_IO
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if (*error_message == '#')
+ {
+ int offset;
+ char error_number[16];
+ for (offset=0; offset<15; offset++)
+ {
+ error_number[offset] = *(error_message+offset+1);
+ if (*(error_message+offset) == ' ')
+ break;
+ }
+ if((offset > 1) && (offset < 15))
+ {
+ error_number[offset-1]='\0';
+ fprintf(stderr, "libpng error no. %s: %s\n", error_number,
+ error_message+offset);
+ }
+ else
+ fprintf(stderr, "libpng error: %s, offset=%d\n", error_message,offset);
+ }
+ else
+#endif
+ fprintf(stderr, "libpng error: %s\n", error_message);
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+# ifdef USE_FAR_KEYWORD
+ {
+ jmp_buf jmpbuf;
+ png_memcpy(jmpbuf,png_ptr->jmpbuf,png_sizeof(jmp_buf));
+ longjmp(jmpbuf, 1);
+ }
+# else
+ longjmp(png_ptr->jmpbuf, 1);
+# endif
+#else
+ /* make compiler happy */ ;
+ if (png_ptr)
+ PNG_ABORT();
+#endif
+#ifdef PNG_NO_CONSOLE_IO
+ /* make compiler happy */ ;
+ if (&error_message != NULL)
+ return;
+#endif
+}
+
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway. Replacement functions don't have to do anything
+ * here if you don't want them to. In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void /* PRIVATE */
+png_default_warning(png_structp png_ptr, png_const_charp warning_message)
+{
+#ifndef PNG_NO_CONSOLE_IO
+# ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if (*warning_message == '#')
+ {
+ int offset;
+ char warning_number[16];
+ for (offset=0; offset<15; offset++)
+ {
+ warning_number[offset]=*(warning_message+offset+1);
+ if (*(warning_message+offset) == ' ')
+ break;
+ }
+ if((offset > 1) && (offset < 15))
+ {
+ warning_number[offset-1]='\0';
+ fprintf(stderr, "libpng warning no. %s: %s\n", warning_number,
+ warning_message+offset);
+ }
+ else
+ fprintf(stderr, "libpng warning: %s\n", warning_message);
+ }
+ else
+# endif
+ fprintf(stderr, "libpng warning: %s\n", warning_message);
+#else
+ /* make compiler happy */ ;
+ if (warning_message)
+ return;
+#endif
+ /* make compiler happy */ ;
+ if (png_ptr)
+ return;
+}
+
+/* This function is called when the application wants to use another method
+ * of handling errors and warnings. Note that the error function MUST NOT
+ * return to the calling routine or serious problems will occur. The return
+ * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
+ */
+void PNGAPI
+png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warning_fn)
+{
+ png_ptr->error_ptr = error_ptr;
+ png_ptr->error_fn = error_fn;
+ png_ptr->warning_fn = warning_fn;
+}
+
+
+/* This function returns a pointer to the error_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_error_ptr(png_structp png_ptr)
+{
+ return ((png_voidp)png_ptr->error_ptr);
+}
+
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+void PNGAPI
+png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
+{
+ if(png_ptr != NULL)
+ {
+ png_ptr->flags &=
+ ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
+ }
+}
+#endif
diff --git a/com32/lib/libpng/pnggccrd.c b/com32/lib/libpng/pnggccrd.c
new file mode 100644
index 00000000..248e1b3b
--- /dev/null
+++ b/com32/lib/libpng/pnggccrd.c
@@ -0,0 +1,5408 @@
+/* pnggccrd.c - mixed C/assembler version of utilities to read a PNG file
+ *
+ * For Intel x86 CPU (Pentium-MMX or later) and GNU C compiler.
+ *
+ * See http://www.intel.com/drg/pentiumII/appnotes/916/916.htm
+ * and http://www.intel.com/drg/pentiumII/appnotes/923/923.htm
+ * for Intel's performance analysis of the MMX vs. non-MMX code.
+ *
+ * libpng version 1.2.8 - December 3, 2004
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2004 Glenn Randers-Pehrson
+ * Copyright (c) 1998, Intel Corporation
+ *
+ * Based on MSVC code contributed by Nirav Chhatrapati, Intel Corp., 1998.
+ * Interface to libpng contributed by Gilles Vollant, 1999.
+ * GNU C port by Greg Roelofs, 1999-2001.
+ *
+ * Lines 2350-4300 converted in place with intel2gas 1.3.1:
+ *
+ * intel2gas -mdI pnggccrd.c.partially-msvc -o pnggccrd.c
+ *
+ * and then cleaned up by hand. See http://hermes.terminal.at/intel2gas/ .
+ *
+ * NOTE: A sufficiently recent version of GNU as (or as.exe under DOS/Windows)
+ * is required to assemble the newer MMX instructions such as movq.
+ * For djgpp, see
+ *
+ * ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bnu281b.zip
+ *
+ * (or a later version in the same directory). For Linux, check your
+ * distribution's web site(s) or try these links:
+ *
+ * http://rufus.w3.org/linux/RPM/binutils.html
+ * http://www.debian.org/Packages/stable/devel/binutils.html
+ * ftp://ftp.slackware.com/pub/linux/slackware/slackware/slakware/d1/
+ * binutils.tgz
+ *
+ * For other platforms, see the main GNU site:
+ *
+ * ftp://ftp.gnu.org/pub/gnu/binutils/
+ *
+ * Version 2.5.2l.15 is definitely too old...
+ */
+
+/*
+ * TEMPORARY PORTING NOTES AND CHANGELOG (mostly by Greg Roelofs)
+ * =====================================
+ *
+ * 19991006:
+ * - fixed sign error in post-MMX cleanup code (16- & 32-bit cases)
+ *
+ * 19991007:
+ * - additional optimizations (possible or definite):
+ * x [DONE] write MMX code for 64-bit case (pixel_bytes == 8) [not tested]
+ * - write MMX code for 48-bit case (pixel_bytes == 6)
+ * - figure out what's up with 24-bit case (pixel_bytes == 3):
+ * why subtract 8 from width_mmx in the pass 4/5 case?
+ * (only width_mmx case) (near line 1606)
+ * x [DONE] replace pixel_bytes within each block with the true
+ * constant value (or are compilers smart enough to do that?)
+ * - rewrite all MMX interlacing code so it's aligned with
+ * the *beginning* of the row buffer, not the end. This
+ * would not only allow one to eliminate half of the memory
+ * writes for odd passes (that is, pass == odd), it may also
+ * eliminate some unaligned-data-access exceptions (assuming
+ * there's a penalty for not aligning 64-bit accesses on
+ * 64-bit boundaries). The only catch is that the "leftover"
+ * pixel(s) at the end of the row would have to be saved,
+ * but there are enough unused MMX registers in every case,
+ * so this is not a problem. A further benefit is that the
+ * post-MMX cleanup code (C code) in at least some of the
+ * cases could be done within the assembler block.
+ * x [DONE] the "v3 v2 v1 v0 v7 v6 v5 v4" comments are confusing,
+ * inconsistent, and don't match the MMX Programmer's Reference
+ * Manual conventions anyway. They should be changed to
+ * "b7 b6 b5 b4 b3 b2 b1 b0," where b0 indicates the byte that
+ * was lowest in memory (e.g., corresponding to a left pixel)
+ * and b7 is the byte that was highest (e.g., a right pixel).
+ *
+ * 19991016:
+ * - Brennan's Guide notwithstanding, gcc under Linux does *not*
+ * want globals prefixed by underscores when referencing them--
+ * i.e., if the variable is const4, then refer to it as const4,
+ * not _const4. This seems to be a djgpp-specific requirement.
+ * Also, such variables apparently *must* be declared outside
+ * of functions; neither static nor automatic variables work if
+ * defined within the scope of a single function, but both
+ * static and truly global (multi-module) variables work fine.
+ *
+ * 19991023:
+ * - fixed png_combine_row() non-MMX replication bug (odd passes only?)
+ * - switched from string-concatenation-with-macros to cleaner method of
+ * renaming global variables for djgpp--i.e., always use prefixes in
+ * inlined assembler code (== strings) and conditionally rename the
+ * variables, not the other way around. Hence _const4, _mask8_0, etc.
+ *
+ * 19991024:
+ * - fixed mmxsupport()/png_do_read_interlace() first-row bug
+ * This one was severely weird: even though mmxsupport() doesn't touch
+ * ebx (where "row" pointer was stored), it nevertheless managed to zero
+ * the register (even in static/non-fPIC code--see below), which in turn
+ * caused png_do_read_interlace() to return prematurely on the first row of
+ * interlaced images (i.e., without expanding the interlaced pixels).
+ * Inspection of the generated assembly code didn't turn up any clues,
+ * although it did point at a minor optimization (i.e., get rid of
+ * mmx_supported_local variable and just use eax). Possibly the CPUID
+ * instruction is more destructive than it looks? (Not yet checked.)
+ * - "info gcc" was next to useless, so compared fPIC and non-fPIC assembly
+ * listings... Apparently register spillage has to do with ebx, since
+ * it's used to index the global offset table. Commenting it out of the
+ * input-reg lists in png_combine_row() eliminated compiler barfage, so
+ * ifdef'd with __PIC__ macro: if defined, use a global for unmask
+ *
+ * 19991107:
+ * - verified CPUID clobberage: 12-char string constant ("GenuineIntel",
+ * "AuthenticAMD", etc.) placed in ebx:ecx:edx. Still need to polish.
+ *
+ * 19991120:
+ * - made "diff" variable (now "_dif") global to simplify conversion of
+ * filtering routines (running out of regs, sigh). "diff" is still used
+ * in interlacing routines, however.
+ * - fixed up both versions of mmxsupport() (ORIG_THAT_USED_TO_CLOBBER_EBX
+ * macro determines which is used); original not yet tested.
+ *
+ * 20000213:
+ * - when compiling with gcc, be sure to use -fomit-frame-pointer
+ *
+ * 20000319:
+ * - fixed a register-name typo in png_do_read_interlace(), default (MMX) case,
+ * pass == 4 or 5, that caused visible corruption of interlaced images
+ *
+ * 20000623:
+ * - Various problems were reported with gcc 2.95.2 in the Cygwin environment,
+ * many of the form "forbidden register 0 (ax) was spilled for class AREG."
+ * This is explained at http://gcc.gnu.org/fom_serv/cache/23.html, and
+ * Chuck Wilson supplied a patch involving dummy output registers. See
+ * http://sourceforge.net/bugs/?func=detailbug&bug_id=108741&group_id=5624
+ * for the original (anonymous) SourceForge bug report.
+ *
+ * 20000706:
+ * - Chuck Wilson passed along these remaining gcc 2.95.2 errors:
+ * pnggccrd.c: In function `png_combine_row':
+ * pnggccrd.c:525: more than 10 operands in `asm'
+ * pnggccrd.c:669: more than 10 operands in `asm'
+ * pnggccrd.c:828: more than 10 operands in `asm'
+ * pnggccrd.c:994: more than 10 operands in `asm'
+ * pnggccrd.c:1177: more than 10 operands in `asm'
+ * They are all the same problem and can be worked around by using the
+ * global _unmask variable unconditionally, not just in the -fPIC case.
+ * Reportedly earlier versions of gcc also have the problem with more than
+ * 10 operands; they just don't report it. Much strangeness ensues, etc.
+ *
+ * 20000729:
+ * - enabled png_read_filter_row_mmx_up() (shortest remaining unconverted
+ * MMX routine); began converting png_read_filter_row_mmx_sub()
+ * - to finish remaining sections:
+ * - clean up indentation and comments
+ * - preload local variables
+ * - add output and input regs (order of former determines numerical
+ * mapping of latter)
+ * - avoid all usage of ebx (including bx, bh, bl) register [20000823]
+ * - remove "$" from addressing of Shift and Mask variables [20000823]
+ *
+ * 20000731:
+ * - global union vars causing segfaults in png_read_filter_row_mmx_sub()?
+ *
+ * 20000822:
+ * - ARGH, stupid png_read_filter_row_mmx_sub() segfault only happens with
+ * shared-library (-fPIC) version! Code works just fine as part of static
+ * library. Damn damn damn damn damn, should have tested that sooner.
+ * ebx is getting clobbered again (explicitly this time); need to save it
+ * on stack or rewrite asm code to avoid using it altogether. Blargh!
+ *
+ * 20000823:
+ * - first section was trickiest; all remaining sections have ebx -> edx now.
+ * (-fPIC works again.) Also added missing underscores to various Shift*
+ * and *Mask* globals and got rid of leading "$" signs.
+ *
+ * 20000826:
+ * - added visual separators to help navigate microscopic printed copies
+ * (http://pobox.com/~newt/code/gpr-latest.zip, mode 10); started working
+ * on png_read_filter_row_mmx_avg()
+ *
+ * 20000828:
+ * - finished png_read_filter_row_mmx_avg(): only Paeth left! (930 lines...)
+ * What the hell, did png_read_filter_row_mmx_paeth(), too. Comments not
+ * cleaned up/shortened in either routine, but functionality is complete
+ * and seems to be working fine.
+ *
+ * 20000829:
+ * - ahhh, figured out last(?) bit of gcc/gas asm-fu: if register is listed
+ * as an input reg (with dummy output variables, etc.), then it *cannot*
+ * also appear in the clobber list or gcc 2.95.2 will barf. The solution
+ * is simple enough...
+ *
+ * 20000914:
+ * - bug in png_read_filter_row_mmx_avg(): 16-bit grayscale not handled
+ * correctly (but 48-bit RGB just fine)
+ *
+ * 20000916:
+ * - fixed bug in png_read_filter_row_mmx_avg(), bpp == 2 case; three errors:
+ * - "_ShiftBpp.use = 24;" should have been "_ShiftBpp.use = 16;"
+ * - "_ShiftRem.use = 40;" should have been "_ShiftRem.use = 48;"
+ * - "psllq _ShiftRem, %%mm2" should have been "psrlq _ShiftRem, %%mm2"
+ *
+ * 20010101:
+ * - added new png_init_mmx_flags() function (here only because it needs to
+ * call mmxsupport(), which should probably become global png_mmxsupport());
+ * modified other MMX routines to run conditionally (png_ptr->asm_flags)
+ *
+ * 20010103:
+ * - renamed mmxsupport() to png_mmx_support(), with auto-set of mmx_supported,
+ * and made it public; moved png_init_mmx_flags() to png.c as internal func
+ *
+ * 20010104:
+ * - removed dependency on png_read_filter_row_c() (C code already duplicated
+ * within MMX version of png_read_filter_row()) so no longer necessary to
+ * compile it into pngrutil.o
+ *
+ * 20010310:
+ * - fixed buffer-overrun bug in png_combine_row() C code (non-MMX)
+ *
+ * 20020304:
+ * - eliminated incorrect use of width_mmx in pixel_bytes == 8 case
+ *
+ * 20040724:
+ * - more tinkering with clobber list at lines 4529 and 5033, to get
+ * it to compile on gcc-3.4.
+ *
+ * STILL TO DO:
+ * - test png_do_read_interlace() 64-bit case (pixel_bytes == 8)
+ * - write MMX code for 48-bit case (pixel_bytes == 6)
+ * - figure out what's up with 24-bit case (pixel_bytes == 3):
+ * why subtract 8 from width_mmx in the pass 4/5 case?
+ * (only width_mmx case) (near line 1606)
+ * - rewrite all MMX interlacing code so it's aligned with beginning
+ * of the row buffer, not the end (see 19991007 for details)
+ * x pick one version of mmxsupport() and get rid of the other
+ * - add error messages to any remaining bogus default cases
+ * - enable pixel_depth == 8 cases in png_read_filter_row()? (test speed)
+ * x add support for runtime enable/disable/query of various MMX routines
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+#if defined(PNG_USE_PNGGCCRD)
+
+int PNGAPI png_mmx_support(void);
+
+#ifdef PNG_USE_LOCAL_ARRAYS
+static const int FARDATA png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+static const int FARDATA png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+static const int FARDATA png_pass_width[7] = {8, 4, 4, 2, 2, 1, 1};
+#endif
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+/* djgpp, Win32, and Cygwin add their own underscores to global variables,
+ * so define them without: */
+#if defined(__DJGPP__) || defined(WIN32) || defined(__CYGWIN__)
+# define _mmx_supported mmx_supported
+# define _const4 const4
+# define _const6 const6
+# define _mask8_0 mask8_0
+# define _mask16_1 mask16_1
+# define _mask16_0 mask16_0
+# define _mask24_2 mask24_2
+# define _mask24_1 mask24_1
+# define _mask24_0 mask24_0
+# define _mask32_3 mask32_3
+# define _mask32_2 mask32_2
+# define _mask32_1 mask32_1
+# define _mask32_0 mask32_0
+# define _mask48_5 mask48_5
+# define _mask48_4 mask48_4
+# define _mask48_3 mask48_3
+# define _mask48_2 mask48_2
+# define _mask48_1 mask48_1
+# define _mask48_0 mask48_0
+# define _LBCarryMask LBCarryMask
+# define _HBClearMask HBClearMask
+# define _ActiveMask ActiveMask
+# define _ActiveMask2 ActiveMask2
+# define _ActiveMaskEnd ActiveMaskEnd
+# define _ShiftBpp ShiftBpp
+# define _ShiftRem ShiftRem
+#ifdef PNG_THREAD_UNSAFE_OK
+# define _unmask unmask
+# define _FullLength FullLength
+# define _MMXLength MMXLength
+# define _dif dif
+# define _patemp patemp
+# define _pbtemp pbtemp
+# define _pctemp pctemp
+#endif
+#endif
+
+
+/* These constants are used in the inlined MMX assembly code.
+ Ignore gcc's "At top level: defined but not used" warnings. */
+
+/* GRR 20000706: originally _unmask was needed only when compiling with -fPIC,
+ * since that case uses the %ebx register for indexing the Global Offset Table
+ * and there were no other registers available. But gcc 2.95 and later emit
+ * "more than 10 operands in `asm'" errors when %ebx is used to preload unmask
+ * in the non-PIC case, so we'll just use the global unconditionally now.
+ */
+#ifdef PNG_THREAD_UNSAFE_OK
+static int _unmask;
+#endif
+
+static unsigned long long _mask8_0 = 0x0102040810204080LL;
+
+static unsigned long long _mask16_1 = 0x0101020204040808LL;
+static unsigned long long _mask16_0 = 0x1010202040408080LL;
+
+static unsigned long long _mask24_2 = 0x0101010202020404LL;
+static unsigned long long _mask24_1 = 0x0408080810101020LL;
+static unsigned long long _mask24_0 = 0x2020404040808080LL;
+
+static unsigned long long _mask32_3 = 0x0101010102020202LL;
+static unsigned long long _mask32_2 = 0x0404040408080808LL;
+static unsigned long long _mask32_1 = 0x1010101020202020LL;
+static unsigned long long _mask32_0 = 0x4040404080808080LL;
+
+static unsigned long long _mask48_5 = 0x0101010101010202LL;
+static unsigned long long _mask48_4 = 0x0202020204040404LL;
+static unsigned long long _mask48_3 = 0x0404080808080808LL;
+static unsigned long long _mask48_2 = 0x1010101010102020LL;
+static unsigned long long _mask48_1 = 0x2020202040404040LL;
+static unsigned long long _mask48_0 = 0x4040808080808080LL;
+
+static unsigned long long _const4 = 0x0000000000FFFFFFLL;
+//static unsigned long long _const5 = 0x000000FFFFFF0000LL; // NOT USED
+static unsigned long long _const6 = 0x00000000000000FFLL;
+
+// These are used in the row-filter routines and should/would be local
+// variables if not for gcc addressing limitations.
+// WARNING: Their presence probably defeats the thread safety of libpng.
+
+#ifdef PNG_THREAD_UNSAFE_OK
+static png_uint_32 _FullLength;
+static png_uint_32 _MMXLength;
+static int _dif;
+static int _patemp; // temp variables for Paeth routine
+static int _pbtemp;
+static int _pctemp;
+#endif
+
+void /* PRIVATE */
+png_squelch_warnings(void)
+{
+#ifdef PNG_THREAD_UNSAFE_OK
+ _dif = _dif;
+ _patemp = _patemp;
+ _pbtemp = _pbtemp;
+ _pctemp = _pctemp;
+ _MMXLength = _MMXLength;
+#endif
+ _const4 = _const4;
+ _const6 = _const6;
+ _mask8_0 = _mask8_0;
+ _mask16_1 = _mask16_1;
+ _mask16_0 = _mask16_0;
+ _mask24_2 = _mask24_2;
+ _mask24_1 = _mask24_1;
+ _mask24_0 = _mask24_0;
+ _mask32_3 = _mask32_3;
+ _mask32_2 = _mask32_2;
+ _mask32_1 = _mask32_1;
+ _mask32_0 = _mask32_0;
+ _mask48_5 = _mask48_5;
+ _mask48_4 = _mask48_4;
+ _mask48_3 = _mask48_3;
+ _mask48_2 = _mask48_2;
+ _mask48_1 = _mask48_1;
+ _mask48_0 = _mask48_0;
+}
+#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
+
+
+static int _mmx_supported = 2;
+
+/*===========================================================================*/
+/* */
+/* P N G _ C O M B I N E _ R O W */
+/* */
+/*===========================================================================*/
+
+#if defined(PNG_HAVE_ASSEMBLER_COMBINE_ROW)
+
+#define BPP2 2
+#define BPP3 3 /* bytes per pixel (a.k.a. pixel_bytes) */
+#define BPP4 4
+#define BPP6 6 /* (defined only to help avoid cut-and-paste errors) */
+#define BPP8 8
+
+/* Combines the row recently read in with the previous row.
+ This routine takes care of alpha and transparency if requested.
+ This routine also handles the two methods of progressive display
+ of interlaced images, depending on the mask value.
+ The mask value describes which pixels are to be combined with
+ the row. The pattern always repeats every 8 pixels, so just 8
+ bits are needed. A one indicates the pixel is to be combined; a
+ zero indicates the pixel is to be skipped. This is in addition
+ to any alpha or transparency value associated with the pixel.
+ If you want all pixels to be combined, pass 0xff (255) in mask. */
+
+/* Use this routine for the x86 platform - it uses a faster MMX routine
+ if the machine supports MMX. */
+
+void /* PRIVATE */
+png_combine_row(png_structp png_ptr, png_bytep row, int mask)
+{
+ png_debug(1, "in png_combine_row (pnggccrd.c)\n");
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+ if (_mmx_supported == 2) {
+#if !defined(PNG_1_0_X)
+ /* this should have happened in png_init_mmx_flags() already */
+ png_warning(png_ptr, "asm_flags may not have been initialized");
+#endif
+ png_mmx_support();
+ }
+#endif
+
+ if (mask == 0xff)
+ {
+ png_debug(2,"mask == 0xff: doing single png_memcpy()\n");
+ png_memcpy(row, png_ptr->row_buf + 1,
+ (png_size_t)PNG_ROWBYTES(png_ptr->row_info.pixel_depth,png_ptr->width));
+ }
+ else /* (png_combine_row() is never called with mask == 0) */
+ {
+ switch (png_ptr->row_info.pixel_depth)
+ {
+ case 1: /* png_ptr->row_info.pixel_depth */
+ {
+ png_bytep sp;
+ png_bytep dp;
+ int s_inc, s_start, s_end;
+ int m;
+ int shift;
+ png_uint_32 i;
+
+ sp = png_ptr->row_buf + 1;
+ dp = row;
+ m = 0x80;
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 7;
+ s_inc = 1;
+ }
+ else
+#endif
+ {
+ s_start = 7;
+ s_end = 0;
+ s_inc = -1;
+ }
+
+ shift = s_start;
+
+ for (i = 0; i < png_ptr->width; i++)
+ {
+ if (m & mask)
+ {
+ int value;
+
+ value = (*sp >> shift) & 0x1;
+ *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+ else
+ shift += s_inc;
+
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+
+ case 2: /* png_ptr->row_info.pixel_depth */
+ {
+ png_bytep sp;
+ png_bytep dp;
+ int s_start, s_end, s_inc;
+ int m;
+ int shift;
+ png_uint_32 i;
+ int value;
+
+ sp = png_ptr->row_buf + 1;
+ dp = row;
+ m = 0x80;
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 6;
+ s_inc = 2;
+ }
+ else
+#endif
+ {
+ s_start = 6;
+ s_end = 0;
+ s_inc = -2;
+ }
+
+ shift = s_start;
+
+ for (i = 0; i < png_ptr->width; i++)
+ {
+ if (m & mask)
+ {
+ value = (*sp >> shift) & 0x3;
+ *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+ else
+ shift += s_inc;
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+
+ case 4: /* png_ptr->row_info.pixel_depth */
+ {
+ png_bytep sp;
+ png_bytep dp;
+ int s_start, s_end, s_inc;
+ int m;
+ int shift;
+ png_uint_32 i;
+ int value;
+
+ sp = png_ptr->row_buf + 1;
+ dp = row;
+ m = 0x80;
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 4;
+ s_inc = 4;
+ }
+ else
+#endif
+ {
+ s_start = 4;
+ s_end = 0;
+ s_inc = -4;
+ }
+ shift = s_start;
+
+ for (i = 0; i < png_ptr->width; i++)
+ {
+ if (m & mask)
+ {
+ value = (*sp >> shift) & 0xf;
+ *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+ else
+ shift += s_inc;
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+
+ case 8: /* png_ptr->row_info.pixel_depth */
+ {
+ png_bytep srcptr;
+ png_bytep dstptr;
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_THREAD_UNSAFE_OK)
+#if !defined(PNG_1_0_X)
+ if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
+ /* && _mmx_supported */ )
+#else
+ if (_mmx_supported)
+#endif
+ {
+ png_uint_32 len;
+ int diff;
+ int dummy_value_a; // fix 'forbidden register spilled' error
+ int dummy_value_d;
+ int dummy_value_c;
+ int dummy_value_S;
+ int dummy_value_D;
+ _unmask = ~mask; // global variable for -fPIC version
+ srcptr = png_ptr->row_buf + 1;
+ dstptr = row;
+ len = png_ptr->width &~7; // reduce to multiple of 8
+ diff = (int) (png_ptr->width & 7); // amount lost
+
+ __asm__ __volatile__ (
+ "movd _unmask, %%mm7 \n\t" // load bit pattern
+ "psubb %%mm6, %%mm6 \n\t" // zero mm6
+ "punpcklbw %%mm7, %%mm7 \n\t"
+ "punpcklwd %%mm7, %%mm7 \n\t"
+ "punpckldq %%mm7, %%mm7 \n\t" // fill reg with 8 masks
+
+ "movq _mask8_0, %%mm0 \n\t"
+ "pand %%mm7, %%mm0 \n\t" // nonzero if keep byte
+ "pcmpeqb %%mm6, %%mm0 \n\t" // zeros->1s, v versa
+
+// preload "movl len, %%ecx \n\t" // load length of line
+// preload "movl srcptr, %%esi \n\t" // load source
+// preload "movl dstptr, %%edi \n\t" // load dest
+
+ "cmpl $0, %%ecx \n\t" // len == 0 ?
+ "je mainloop8end \n\t"
+
+ "mainloop8: \n\t"
+ "movq (%%esi), %%mm4 \n\t" // *srcptr
+ "pand %%mm0, %%mm4 \n\t"
+ "movq %%mm0, %%mm6 \n\t"
+ "pandn (%%edi), %%mm6 \n\t" // *dstptr
+ "por %%mm6, %%mm4 \n\t"
+ "movq %%mm4, (%%edi) \n\t"
+ "addl $8, %%esi \n\t" // inc by 8 bytes processed
+ "addl $8, %%edi \n\t"
+ "subl $8, %%ecx \n\t" // dec by 8 pixels processed
+ "ja mainloop8 \n\t"
+
+ "mainloop8end: \n\t"
+// preload "movl diff, %%ecx \n\t" // (diff is in eax)
+ "movl %%eax, %%ecx \n\t"
+ "cmpl $0, %%ecx \n\t"
+ "jz end8 \n\t"
+// preload "movl mask, %%edx \n\t"
+ "sall $24, %%edx \n\t" // make low byte, high byte
+
+ "secondloop8: \n\t"
+ "sall %%edx \n\t" // move high bit to CF
+ "jnc skip8 \n\t" // if CF = 0
+ "movb (%%esi), %%al \n\t"
+ "movb %%al, (%%edi) \n\t"
+
+ "skip8: \n\t"
+ "incl %%esi \n\t"
+ "incl %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz secondloop8 \n\t"
+
+ "end8: \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=a" (dummy_value_a), // output regs (dummy)
+ "=d" (dummy_value_d),
+ "=c" (dummy_value_c),
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "3" (srcptr), // esi // input regs
+ "4" (dstptr), // edi
+ "0" (diff), // eax
+// was (unmask) "b" RESERVED // ebx // Global Offset Table idx
+ "2" (len), // ecx
+ "1" (mask) // edx
+
+#if 0 /* MMX regs (%mm0, etc.) not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm4", "%mm6", "%mm7" // clobber list
+#endif
+ );
+ }
+ else /* mmx _not supported - Use modified C routine */
+#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
+ {
+ register png_uint_32 i;
+ png_uint_32 initial_val = png_pass_start[png_ptr->pass];
+ /* png.c: png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; */
+ register int stride = png_pass_inc[png_ptr->pass];
+ /* png.c: png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; */
+ register int rep_bytes = png_pass_width[png_ptr->pass];
+ /* png.c: png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; */
+ png_uint_32 len = png_ptr->width &~7; /* reduce to mult. of 8 */
+ int diff = (int) (png_ptr->width & 7); /* amount lost */
+ register png_uint_32 final_val = len; /* GRR bugfix */
+
+ srcptr = png_ptr->row_buf + 1 + initial_val;
+ dstptr = row + initial_val;
+
+ for (i = initial_val; i < final_val; i += stride)
+ {
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ if (diff) /* number of leftover pixels: 3 for pngtest */
+ {
+ final_val+=diff /* *BPP1 */ ;
+ for (; i < final_val; i += stride)
+ {
+ if (rep_bytes > (int)(final_val-i))
+ rep_bytes = (int)(final_val-i);
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ }
+
+ } /* end of else (_mmx_supported) */
+
+ break;
+ } /* end 8 bpp */
+
+ case 16: /* png_ptr->row_info.pixel_depth */
+ {
+ png_bytep srcptr;
+ png_bytep dstptr;
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_THREAD_UNSAFE_OK)
+#if !defined(PNG_1_0_X)
+ if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
+ /* && _mmx_supported */ )
+#else
+ if (_mmx_supported)
+#endif
+ {
+ png_uint_32 len;
+ int diff;
+ int dummy_value_a; // fix 'forbidden register spilled' error
+ int dummy_value_d;
+ int dummy_value_c;
+ int dummy_value_S;
+ int dummy_value_D;
+ _unmask = ~mask; // global variable for -fPIC version
+ srcptr = png_ptr->row_buf + 1;
+ dstptr = row;
+ len = png_ptr->width &~7; // reduce to multiple of 8
+ diff = (int) (png_ptr->width & 7); // amount lost //
+
+ __asm__ __volatile__ (
+ "movd _unmask, %%mm7 \n\t" // load bit pattern
+ "psubb %%mm6, %%mm6 \n\t" // zero mm6
+ "punpcklbw %%mm7, %%mm7 \n\t"
+ "punpcklwd %%mm7, %%mm7 \n\t"
+ "punpckldq %%mm7, %%mm7 \n\t" // fill reg with 8 masks
+
+ "movq _mask16_0, %%mm0 \n\t"
+ "movq _mask16_1, %%mm1 \n\t"
+
+ "pand %%mm7, %%mm0 \n\t"
+ "pand %%mm7, %%mm1 \n\t"
+
+ "pcmpeqb %%mm6, %%mm0 \n\t"
+ "pcmpeqb %%mm6, %%mm1 \n\t"
+
+// preload "movl len, %%ecx \n\t" // load length of line
+// preload "movl srcptr, %%esi \n\t" // load source
+// preload "movl dstptr, %%edi \n\t" // load dest
+
+ "cmpl $0, %%ecx \n\t"
+ "jz mainloop16end \n\t"
+
+ "mainloop16: \n\t"
+ "movq (%%esi), %%mm4 \n\t"
+ "pand %%mm0, %%mm4 \n\t"
+ "movq %%mm0, %%mm6 \n\t"
+ "movq (%%edi), %%mm7 \n\t"
+ "pandn %%mm7, %%mm6 \n\t"
+ "por %%mm6, %%mm4 \n\t"
+ "movq %%mm4, (%%edi) \n\t"
+
+ "movq 8(%%esi), %%mm5 \n\t"
+ "pand %%mm1, %%mm5 \n\t"
+ "movq %%mm1, %%mm7 \n\t"
+ "movq 8(%%edi), %%mm6 \n\t"
+ "pandn %%mm6, %%mm7 \n\t"
+ "por %%mm7, %%mm5 \n\t"
+ "movq %%mm5, 8(%%edi) \n\t"
+
+ "addl $16, %%esi \n\t" // inc by 16 bytes processed
+ "addl $16, %%edi \n\t"
+ "subl $8, %%ecx \n\t" // dec by 8 pixels processed
+ "ja mainloop16 \n\t"
+
+ "mainloop16end: \n\t"
+// preload "movl diff, %%ecx \n\t" // (diff is in eax)
+ "movl %%eax, %%ecx \n\t"
+ "cmpl $0, %%ecx \n\t"
+ "jz end16 \n\t"
+// preload "movl mask, %%edx \n\t"
+ "sall $24, %%edx \n\t" // make low byte, high byte
+
+ "secondloop16: \n\t"
+ "sall %%edx \n\t" // move high bit to CF
+ "jnc skip16 \n\t" // if CF = 0
+ "movw (%%esi), %%ax \n\t"
+ "movw %%ax, (%%edi) \n\t"
+
+ "skip16: \n\t"
+ "addl $2, %%esi \n\t"
+ "addl $2, %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz secondloop16 \n\t"
+
+ "end16: \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=a" (dummy_value_a), // output regs (dummy)
+ "=c" (dummy_value_c),
+ "=d" (dummy_value_d),
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "0" (diff), // eax // input regs
+// was (unmask) " " RESERVED // ebx // Global Offset Table idx
+ "1" (len), // ecx
+ "2" (mask), // edx
+ "3" (srcptr), // esi
+ "4" (dstptr) // edi
+
+#if 0 /* MMX regs (%mm0, etc.) not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1", "%mm4" // clobber list
+ , "%mm5", "%mm6", "%mm7"
+#endif
+ );
+ }
+ else /* mmx _not supported - Use modified C routine */
+#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
+ {
+ register png_uint_32 i;
+ png_uint_32 initial_val = BPP2 * png_pass_start[png_ptr->pass];
+ /* png.c: png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; */
+ register int stride = BPP2 * png_pass_inc[png_ptr->pass];
+ /* png.c: png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; */
+ register int rep_bytes = BPP2 * png_pass_width[png_ptr->pass];
+ /* png.c: png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; */
+ png_uint_32 len = png_ptr->width &~7; /* reduce to mult. of 8 */
+ int diff = (int) (png_ptr->width & 7); /* amount lost */
+ register png_uint_32 final_val = BPP2 * len; /* GRR bugfix */
+
+ srcptr = png_ptr->row_buf + 1 + initial_val;
+ dstptr = row + initial_val;
+
+ for (i = initial_val; i < final_val; i += stride)
+ {
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ if (diff) /* number of leftover pixels: 3 for pngtest */
+ {
+ final_val+=diff*BPP2;
+ for (; i < final_val; i += stride)
+ {
+ if (rep_bytes > (int)(final_val-i))
+ rep_bytes = (int)(final_val-i);
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ }
+ } /* end of else (_mmx_supported) */
+
+ break;
+ } /* end 16 bpp */
+
+ case 24: /* png_ptr->row_info.pixel_depth */
+ {
+ png_bytep srcptr;
+ png_bytep dstptr;
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_THREAD_UNSAFE_OK)
+#if !defined(PNG_1_0_X)
+ if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
+ /* && _mmx_supported */ )
+#else
+ if (_mmx_supported)
+#endif
+ {
+ png_uint_32 len;
+ int diff;
+ int dummy_value_a; // fix 'forbidden register spilled' error
+ int dummy_value_d;
+ int dummy_value_c;
+ int dummy_value_S;
+ int dummy_value_D;
+ _unmask = ~mask; // global variable for -fPIC version
+ srcptr = png_ptr->row_buf + 1;
+ dstptr = row;
+ len = png_ptr->width &~7; // reduce to multiple of 8
+ diff = (int) (png_ptr->width & 7); // amount lost //
+
+ __asm__ __volatile__ (
+ "movd _unmask, %%mm7 \n\t" // load bit pattern
+ "psubb %%mm6, %%mm6 \n\t" // zero mm6
+ "punpcklbw %%mm7, %%mm7 \n\t"
+ "punpcklwd %%mm7, %%mm7 \n\t"
+ "punpckldq %%mm7, %%mm7 \n\t" // fill reg with 8 masks
+
+ "movq _mask24_0, %%mm0 \n\t"
+ "movq _mask24_1, %%mm1 \n\t"
+ "movq _mask24_2, %%mm2 \n\t"
+
+ "pand %%mm7, %%mm0 \n\t"
+ "pand %%mm7, %%mm1 \n\t"
+ "pand %%mm7, %%mm2 \n\t"
+
+ "pcmpeqb %%mm6, %%mm0 \n\t"
+ "pcmpeqb %%mm6, %%mm1 \n\t"
+ "pcmpeqb %%mm6, %%mm2 \n\t"
+
+// preload "movl len, %%ecx \n\t" // load length of line
+// preload "movl srcptr, %%esi \n\t" // load source
+// preload "movl dstptr, %%edi \n\t" // load dest
+
+ "cmpl $0, %%ecx \n\t"
+ "jz mainloop24end \n\t"
+
+ "mainloop24: \n\t"
+ "movq (%%esi), %%mm4 \n\t"
+ "pand %%mm0, %%mm4 \n\t"
+ "movq %%mm0, %%mm6 \n\t"
+ "movq (%%edi), %%mm7 \n\t"
+ "pandn %%mm7, %%mm6 \n\t"
+ "por %%mm6, %%mm4 \n\t"
+ "movq %%mm4, (%%edi) \n\t"
+
+ "movq 8(%%esi), %%mm5 \n\t"
+ "pand %%mm1, %%mm5 \n\t"
+ "movq %%mm1, %%mm7 \n\t"
+ "movq 8(%%edi), %%mm6 \n\t"
+ "pandn %%mm6, %%mm7 \n\t"
+ "por %%mm7, %%mm5 \n\t"
+ "movq %%mm5, 8(%%edi) \n\t"
+
+ "movq 16(%%esi), %%mm6 \n\t"
+ "pand %%mm2, %%mm6 \n\t"
+ "movq %%mm2, %%mm4 \n\t"
+ "movq 16(%%edi), %%mm7 \n\t"
+ "pandn %%mm7, %%mm4 \n\t"
+ "por %%mm4, %%mm6 \n\t"
+ "movq %%mm6, 16(%%edi) \n\t"
+
+ "addl $24, %%esi \n\t" // inc by 24 bytes processed
+ "addl $24, %%edi \n\t"
+ "subl $8, %%ecx \n\t" // dec by 8 pixels processed
+
+ "ja mainloop24 \n\t"
+
+ "mainloop24end: \n\t"
+// preload "movl diff, %%ecx \n\t" // (diff is in eax)
+ "movl %%eax, %%ecx \n\t"
+ "cmpl $0, %%ecx \n\t"
+ "jz end24 \n\t"
+// preload "movl mask, %%edx \n\t"
+ "sall $24, %%edx \n\t" // make low byte, high byte
+
+ "secondloop24: \n\t"
+ "sall %%edx \n\t" // move high bit to CF
+ "jnc skip24 \n\t" // if CF = 0
+ "movw (%%esi), %%ax \n\t"
+ "movw %%ax, (%%edi) \n\t"
+ "xorl %%eax, %%eax \n\t"
+ "movb 2(%%esi), %%al \n\t"
+ "movb %%al, 2(%%edi) \n\t"
+
+ "skip24: \n\t"
+ "addl $3, %%esi \n\t"
+ "addl $3, %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz secondloop24 \n\t"
+
+ "end24: \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=a" (dummy_value_a), // output regs (dummy)
+ "=d" (dummy_value_d),
+ "=c" (dummy_value_c),
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "3" (srcptr), // esi // input regs
+ "4" (dstptr), // edi
+ "0" (diff), // eax
+// was (unmask) "b" RESERVED // ebx // Global Offset Table idx
+ "2" (len), // ecx
+ "1" (mask) // edx
+
+#if 0 /* MMX regs (%mm0, etc.) not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1", "%mm2" // clobber list
+ , "%mm4", "%mm5", "%mm6", "%mm7"
+#endif
+ );
+ }
+ else /* mmx _not supported - Use modified C routine */
+#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
+ {
+ register png_uint_32 i;
+ png_uint_32 initial_val = BPP3 * png_pass_start[png_ptr->pass];
+ /* png.c: png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; */
+ register int stride = BPP3 * png_pass_inc[png_ptr->pass];
+ /* png.c: png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; */
+ register int rep_bytes = BPP3 * png_pass_width[png_ptr->pass];
+ /* png.c: png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; */
+ png_uint_32 len = png_ptr->width &~7; /* reduce to mult. of 8 */
+ int diff = (int) (png_ptr->width & 7); /* amount lost */
+ register png_uint_32 final_val = BPP3 * len; /* GRR bugfix */
+
+ srcptr = png_ptr->row_buf + 1 + initial_val;
+ dstptr = row + initial_val;
+
+ for (i = initial_val; i < final_val; i += stride)
+ {
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ if (diff) /* number of leftover pixels: 3 for pngtest */
+ {
+ final_val+=diff*BPP3;
+ for (; i < final_val; i += stride)
+ {
+ if (rep_bytes > (int)(final_val-i))
+ rep_bytes = (int)(final_val-i);
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ }
+ } /* end of else (_mmx_supported) */
+
+ break;
+ } /* end 24 bpp */
+
+ case 32: /* png_ptr->row_info.pixel_depth */
+ {
+ png_bytep srcptr;
+ png_bytep dstptr;
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_THREAD_UNSAFE_OK)
+#if !defined(PNG_1_0_X)
+ if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
+ /* && _mmx_supported */ )
+#else
+ if (_mmx_supported)
+#endif
+ {
+ png_uint_32 len;
+ int diff;
+ int dummy_value_a; // fix 'forbidden register spilled' error
+ int dummy_value_d;
+ int dummy_value_c;
+ int dummy_value_S;
+ int dummy_value_D;
+ _unmask = ~mask; // global variable for -fPIC version
+ srcptr = png_ptr->row_buf + 1;
+ dstptr = row;
+ len = png_ptr->width &~7; // reduce to multiple of 8
+ diff = (int) (png_ptr->width & 7); // amount lost //
+
+ __asm__ __volatile__ (
+ "movd _unmask, %%mm7 \n\t" // load bit pattern
+ "psubb %%mm6, %%mm6 \n\t" // zero mm6
+ "punpcklbw %%mm7, %%mm7 \n\t"
+ "punpcklwd %%mm7, %%mm7 \n\t"
+ "punpckldq %%mm7, %%mm7 \n\t" // fill reg with 8 masks
+
+ "movq _mask32_0, %%mm0 \n\t"
+ "movq _mask32_1, %%mm1 \n\t"
+ "movq _mask32_2, %%mm2 \n\t"
+ "movq _mask32_3, %%mm3 \n\t"
+
+ "pand %%mm7, %%mm0 \n\t"
+ "pand %%mm7, %%mm1 \n\t"
+ "pand %%mm7, %%mm2 \n\t"
+ "pand %%mm7, %%mm3 \n\t"
+
+ "pcmpeqb %%mm6, %%mm0 \n\t"
+ "pcmpeqb %%mm6, %%mm1 \n\t"
+ "pcmpeqb %%mm6, %%mm2 \n\t"
+ "pcmpeqb %%mm6, %%mm3 \n\t"
+
+// preload "movl len, %%ecx \n\t" // load length of line
+// preload "movl srcptr, %%esi \n\t" // load source
+// preload "movl dstptr, %%edi \n\t" // load dest
+
+ "cmpl $0, %%ecx \n\t" // lcr
+ "jz mainloop32end \n\t"
+
+ "mainloop32: \n\t"
+ "movq (%%esi), %%mm4 \n\t"
+ "pand %%mm0, %%mm4 \n\t"
+ "movq %%mm0, %%mm6 \n\t"
+ "movq (%%edi), %%mm7 \n\t"
+ "pandn %%mm7, %%mm6 \n\t"
+ "por %%mm6, %%mm4 \n\t"
+ "movq %%mm4, (%%edi) \n\t"
+
+ "movq 8(%%esi), %%mm5 \n\t"
+ "pand %%mm1, %%mm5 \n\t"
+ "movq %%mm1, %%mm7 \n\t"
+ "movq 8(%%edi), %%mm6 \n\t"
+ "pandn %%mm6, %%mm7 \n\t"
+ "por %%mm7, %%mm5 \n\t"
+ "movq %%mm5, 8(%%edi) \n\t"
+
+ "movq 16(%%esi), %%mm6 \n\t"
+ "pand %%mm2, %%mm6 \n\t"
+ "movq %%mm2, %%mm4 \n\t"
+ "movq 16(%%edi), %%mm7 \n\t"
+ "pandn %%mm7, %%mm4 \n\t"
+ "por %%mm4, %%mm6 \n\t"
+ "movq %%mm6, 16(%%edi) \n\t"
+
+ "movq 24(%%esi), %%mm7 \n\t"
+ "pand %%mm3, %%mm7 \n\t"
+ "movq %%mm3, %%mm5 \n\t"
+ "movq 24(%%edi), %%mm4 \n\t"
+ "pandn %%mm4, %%mm5 \n\t"
+ "por %%mm5, %%mm7 \n\t"
+ "movq %%mm7, 24(%%edi) \n\t"
+
+ "addl $32, %%esi \n\t" // inc by 32 bytes processed
+ "addl $32, %%edi \n\t"
+ "subl $8, %%ecx \n\t" // dec by 8 pixels processed
+ "ja mainloop32 \n\t"
+
+ "mainloop32end: \n\t"
+// preload "movl diff, %%ecx \n\t" // (diff is in eax)
+ "movl %%eax, %%ecx \n\t"
+ "cmpl $0, %%ecx \n\t"
+ "jz end32 \n\t"
+// preload "movl mask, %%edx \n\t"
+ "sall $24, %%edx \n\t" // low byte => high byte
+
+ "secondloop32: \n\t"
+ "sall %%edx \n\t" // move high bit to CF
+ "jnc skip32 \n\t" // if CF = 0
+ "movl (%%esi), %%eax \n\t"
+ "movl %%eax, (%%edi) \n\t"
+
+ "skip32: \n\t"
+ "addl $4, %%esi \n\t"
+ "addl $4, %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz secondloop32 \n\t"
+
+ "end32: \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=a" (dummy_value_a), // output regs (dummy)
+ "=d" (dummy_value_d),
+ "=c" (dummy_value_c),
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "3" (srcptr), // esi // input regs
+ "4" (dstptr), // edi
+ "0" (diff), // eax
+// was (unmask) "b" RESERVED // ebx // Global Offset Table idx
+ "2" (len), // ecx
+ "1" (mask) // edx
+
+#if 0 /* MMX regs (%mm0, etc.) not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1", "%mm2", "%mm3" // clobber list
+ , "%mm4", "%mm5", "%mm6", "%mm7"
+#endif
+ );
+ }
+ else /* mmx _not supported - Use modified C routine */
+#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
+ {
+ register png_uint_32 i;
+ png_uint_32 initial_val = BPP4 * png_pass_start[png_ptr->pass];
+ /* png.c: png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; */
+ register int stride = BPP4 * png_pass_inc[png_ptr->pass];
+ /* png.c: png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; */
+ register int rep_bytes = BPP4 * png_pass_width[png_ptr->pass];
+ /* png.c: png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; */
+ png_uint_32 len = png_ptr->width &~7; /* reduce to mult. of 8 */
+ int diff = (int) (png_ptr->width & 7); /* amount lost */
+ register png_uint_32 final_val = BPP4 * len; /* GRR bugfix */
+
+ srcptr = png_ptr->row_buf + 1 + initial_val;
+ dstptr = row + initial_val;
+
+ for (i = initial_val; i < final_val; i += stride)
+ {
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ if (diff) /* number of leftover pixels: 3 for pngtest */
+ {
+ final_val+=diff*BPP4;
+ for (; i < final_val; i += stride)
+ {
+ if (rep_bytes > (int)(final_val-i))
+ rep_bytes = (int)(final_val-i);
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ }
+ } /* end of else (_mmx_supported) */
+
+ break;
+ } /* end 32 bpp */
+
+ case 48: /* png_ptr->row_info.pixel_depth */
+ {
+ png_bytep srcptr;
+ png_bytep dstptr;
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_THREAD_UNSAFE_OK)
+#if !defined(PNG_1_0_X)
+ if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)
+ /* && _mmx_supported */ )
+#else
+ if (_mmx_supported)
+#endif
+ {
+ png_uint_32 len;
+ int diff;
+ int dummy_value_a; // fix 'forbidden register spilled' error
+ int dummy_value_d;
+ int dummy_value_c;
+ int dummy_value_S;
+ int dummy_value_D;
+ _unmask = ~mask; // global variable for -fPIC version
+ srcptr = png_ptr->row_buf + 1;
+ dstptr = row;
+ len = png_ptr->width &~7; // reduce to multiple of 8
+ diff = (int) (png_ptr->width & 7); // amount lost //
+
+ __asm__ __volatile__ (
+ "movd _unmask, %%mm7 \n\t" // load bit pattern
+ "psubb %%mm6, %%mm6 \n\t" // zero mm6
+ "punpcklbw %%mm7, %%mm7 \n\t"
+ "punpcklwd %%mm7, %%mm7 \n\t"
+ "punpckldq %%mm7, %%mm7 \n\t" // fill reg with 8 masks
+
+ "movq _mask48_0, %%mm0 \n\t"
+ "movq _mask48_1, %%mm1 \n\t"
+ "movq _mask48_2, %%mm2 \n\t"
+ "movq _mask48_3, %%mm3 \n\t"
+ "movq _mask48_4, %%mm4 \n\t"
+ "movq _mask48_5, %%mm5 \n\t"
+
+ "pand %%mm7, %%mm0 \n\t"
+ "pand %%mm7, %%mm1 \n\t"
+ "pand %%mm7, %%mm2 \n\t"
+ "pand %%mm7, %%mm3 \n\t"
+ "pand %%mm7, %%mm4 \n\t"
+ "pand %%mm7, %%mm5 \n\t"
+
+ "pcmpeqb %%mm6, %%mm0 \n\t"
+ "pcmpeqb %%mm6, %%mm1 \n\t"
+ "pcmpeqb %%mm6, %%mm2 \n\t"
+ "pcmpeqb %%mm6, %%mm3 \n\t"
+ "pcmpeqb %%mm6, %%mm4 \n\t"
+ "pcmpeqb %%mm6, %%mm5 \n\t"
+
+// preload "movl len, %%ecx \n\t" // load length of line
+// preload "movl srcptr, %%esi \n\t" // load source
+// preload "movl dstptr, %%edi \n\t" // load dest
+
+ "cmpl $0, %%ecx \n\t"
+ "jz mainloop48end \n\t"
+
+ "mainloop48: \n\t"
+ "movq (%%esi), %%mm7 \n\t"
+ "pand %%mm0, %%mm7 \n\t"
+ "movq %%mm0, %%mm6 \n\t"
+ "pandn (%%edi), %%mm6 \n\t"
+ "por %%mm6, %%mm7 \n\t"
+ "movq %%mm7, (%%edi) \n\t"
+
+ "movq 8(%%esi), %%mm6 \n\t"
+ "pand %%mm1, %%mm6 \n\t"
+ "movq %%mm1, %%mm7 \n\t"
+ "pandn 8(%%edi), %%mm7 \n\t"
+ "por %%mm7, %%mm6 \n\t"
+ "movq %%mm6, 8(%%edi) \n\t"
+
+ "movq 16(%%esi), %%mm6 \n\t"
+ "pand %%mm2, %%mm6 \n\t"
+ "movq %%mm2, %%mm7 \n\t"
+ "pandn 16(%%edi), %%mm7 \n\t"
+ "por %%mm7, %%mm6 \n\t"
+ "movq %%mm6, 16(%%edi) \n\t"
+
+ "movq 24(%%esi), %%mm7 \n\t"
+ "pand %%mm3, %%mm7 \n\t"
+ "movq %%mm3, %%mm6 \n\t"
+ "pandn 24(%%edi), %%mm6 \n\t"
+ "por %%mm6, %%mm7 \n\t"
+ "movq %%mm7, 24(%%edi) \n\t"
+
+ "movq 32(%%esi), %%mm6 \n\t"
+ "pand %%mm4, %%mm6 \n\t"
+ "movq %%mm4, %%mm7 \n\t"
+ "pandn 32(%%edi), %%mm7 \n\t"
+ "por %%mm7, %%mm6 \n\t"
+ "movq %%mm6, 32(%%edi) \n\t"
+
+ "movq 40(%%esi), %%mm7 \n\t"
+ "pand %%mm5, %%mm7 \n\t"
+ "movq %%mm5, %%mm6 \n\t"
+ "pandn 40(%%edi), %%mm6 \n\t"
+ "por %%mm6, %%mm7 \n\t"
+ "movq %%mm7, 40(%%edi) \n\t"
+
+ "addl $48, %%esi \n\t" // inc by 48 bytes processed
+ "addl $48, %%edi \n\t"
+ "subl $8, %%ecx \n\t" // dec by 8 pixels processed
+
+ "ja mainloop48 \n\t"
+
+ "mainloop48end: \n\t"
+// preload "movl diff, %%ecx \n\t" // (diff is in eax)
+ "movl %%eax, %%ecx \n\t"
+ "cmpl $0, %%ecx \n\t"
+ "jz end48 \n\t"
+// preload "movl mask, %%edx \n\t"
+ "sall $24, %%edx \n\t" // make low byte, high byte
+
+ "secondloop48: \n\t"
+ "sall %%edx \n\t" // move high bit to CF
+ "jnc skip48 \n\t" // if CF = 0
+ "movl (%%esi), %%eax \n\t"
+ "movl %%eax, (%%edi) \n\t"
+
+ "skip48: \n\t"
+ "addl $4, %%esi \n\t"
+ "addl $4, %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz secondloop48 \n\t"
+
+ "end48: \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=a" (dummy_value_a), // output regs (dummy)
+ "=d" (dummy_value_d),
+ "=c" (dummy_value_c),
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "3" (srcptr), // esi // input regs
+ "4" (dstptr), // edi
+ "0" (diff), // eax
+// was (unmask) "b" RESERVED // ebx // Global Offset Table idx
+ "2" (len), // ecx
+ "1" (mask) // edx
+
+#if 0 /* MMX regs (%mm0, etc.) not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1", "%mm2", "%mm3" // clobber list
+ , "%mm4", "%mm5", "%mm6", "%mm7"
+#endif
+ );
+ }
+ else /* mmx _not supported - Use modified C routine */
+#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
+ {
+ register png_uint_32 i;
+ png_uint_32 initial_val = BPP6 * png_pass_start[png_ptr->pass];
+ /* png.c: png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; */
+ register int stride = BPP6 * png_pass_inc[png_ptr->pass];
+ /* png.c: png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; */
+ register int rep_bytes = BPP6 * png_pass_width[png_ptr->pass];
+ /* png.c: png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; */
+ png_uint_32 len = png_ptr->width &~7; /* reduce to mult. of 8 */
+ int diff = (int) (png_ptr->width & 7); /* amount lost */
+ register png_uint_32 final_val = BPP6 * len; /* GRR bugfix */
+
+ srcptr = png_ptr->row_buf + 1 + initial_val;
+ dstptr = row + initial_val;
+
+ for (i = initial_val; i < final_val; i += stride)
+ {
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ if (diff) /* number of leftover pixels: 3 for pngtest */
+ {
+ final_val+=diff*BPP6;
+ for (; i < final_val; i += stride)
+ {
+ if (rep_bytes > (int)(final_val-i))
+ rep_bytes = (int)(final_val-i);
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ }
+ } /* end of else (_mmx_supported) */
+
+ break;
+ } /* end 48 bpp */
+
+ case 64: /* png_ptr->row_info.pixel_depth */
+ {
+ png_bytep srcptr;
+ png_bytep dstptr;
+ register png_uint_32 i;
+ png_uint_32 initial_val = BPP8 * png_pass_start[png_ptr->pass];
+ /* png.c: png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; */
+ register int stride = BPP8 * png_pass_inc[png_ptr->pass];
+ /* png.c: png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; */
+ register int rep_bytes = BPP8 * png_pass_width[png_ptr->pass];
+ /* png.c: png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; */
+ png_uint_32 len = png_ptr->width &~7; /* reduce to mult. of 8 */
+ int diff = (int) (png_ptr->width & 7); /* amount lost */
+ register png_uint_32 final_val = BPP8 * len; /* GRR bugfix */
+
+ srcptr = png_ptr->row_buf + 1 + initial_val;
+ dstptr = row + initial_val;
+
+ for (i = initial_val; i < final_val; i += stride)
+ {
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ if (diff) /* number of leftover pixels: 3 for pngtest */
+ {
+ final_val+=diff*BPP8;
+ for (; i < final_val; i += stride)
+ {
+ if (rep_bytes > (int)(final_val-i))
+ rep_bytes = (int)(final_val-i);
+ png_memcpy(dstptr, srcptr, rep_bytes);
+ srcptr += stride;
+ dstptr += stride;
+ }
+ }
+
+ break;
+ } /* end 64 bpp */
+
+ default: /* png_ptr->row_info.pixel_depth != 1,2,4,8,16,24,32,48,64 */
+ {
+ /* this should never happen */
+ png_warning(png_ptr, "Invalid row_info.pixel_depth in pnggccrd");
+ break;
+ }
+ } /* end switch (png_ptr->row_info.pixel_depth) */
+
+ } /* end if (non-trivial mask) */
+
+} /* end png_combine_row() */
+
+#endif /* PNG_HAVE_ASSEMBLER_COMBINE_ROW */
+
+
+
+
+/*===========================================================================*/
+/* */
+/* P N G _ D O _ R E A D _ I N T E R L A C E */
+/* */
+/*===========================================================================*/
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED)
+#if defined(PNG_HAVE_ASSEMBLER_READ_INTERLACE)
+
+/* png_do_read_interlace() is called after any 16-bit to 8-bit conversion
+ * has taken place. [GRR: what other steps come before and/or after?]
+ */
+
+void /* PRIVATE */
+png_do_read_interlace(png_structp png_ptr)
+{
+ png_row_infop row_info = &(png_ptr->row_info);
+ png_bytep row = png_ptr->row_buf + 1;
+ int pass = png_ptr->pass;
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ png_uint_32 transformations = png_ptr->transformations;
+#endif
+
+ png_debug(1, "in png_do_read_interlace (pnggccrd.c)\n");
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+ if (_mmx_supported == 2) {
+#if !defined(PNG_1_0_X)
+ /* this should have happened in png_init_mmx_flags() already */
+ png_warning(png_ptr, "asm_flags may not have been initialized");
+#endif
+ png_mmx_support();
+ }
+#endif
+
+ if (row != NULL && row_info != NULL)
+ {
+ png_uint_32 final_width;
+
+ final_width = row_info->width * png_pass_inc[pass];
+
+ switch (row_info->pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp, dp;
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ png_byte v;
+ png_uint_32 i;
+ int j;
+
+ sp = row + (png_size_t)((row_info->width - 1) >> 3);
+ dp = row + (png_size_t)((final_width - 1) >> 3);
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (transformations & PNG_PACKSWAP)
+ {
+ sshift = (int)((row_info->width + 7) & 7);
+ dshift = (int)((final_width + 7) & 7);
+ s_start = 7;
+ s_end = 0;
+ s_inc = -1;
+ }
+ else
+#endif
+ {
+ sshift = 7 - (int)((row_info->width + 7) & 7);
+ dshift = 7 - (int)((final_width + 7) & 7);
+ s_start = 0;
+ s_end = 7;
+ s_inc = 1;
+ }
+
+ for (i = row_info->width; i; i--)
+ {
+ v = (png_byte)((*sp >> sshift) & 0x1);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+ else
+ dshift += s_inc;
+ }
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+
+ case 2:
+ {
+ png_bytep sp, dp;
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ png_uint_32 i;
+
+ sp = row + (png_size_t)((row_info->width - 1) >> 2);
+ dp = row + (png_size_t)((final_width - 1) >> 2);
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (transformations & PNG_PACKSWAP)
+ {
+ sshift = (png_size_t)(((row_info->width + 3) & 3) << 1);
+ dshift = (png_size_t)(((final_width + 3) & 3) << 1);
+ s_start = 6;
+ s_end = 0;
+ s_inc = -2;
+ }
+ else
+#endif
+ {
+ sshift = (png_size_t)((3 - ((row_info->width + 3) & 3)) << 1);
+ dshift = (png_size_t)((3 - ((final_width + 3) & 3)) << 1);
+ s_start = 0;
+ s_end = 6;
+ s_inc = 2;
+ }
+
+ for (i = row_info->width; i; i--)
+ {
+ png_byte v;
+ int j;
+
+ v = (png_byte)((*sp >> sshift) & 0x3);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+ else
+ dshift += s_inc;
+ }
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp, dp;
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ png_uint_32 i;
+
+ sp = row + (png_size_t)((row_info->width - 1) >> 1);
+ dp = row + (png_size_t)((final_width - 1) >> 1);
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (transformations & PNG_PACKSWAP)
+ {
+ sshift = (png_size_t)(((row_info->width + 1) & 1) << 2);
+ dshift = (png_size_t)(((final_width + 1) & 1) << 2);
+ s_start = 4;
+ s_end = 0;
+ s_inc = -4;
+ }
+ else
+#endif
+ {
+ sshift = (png_size_t)((1 - ((row_info->width + 1) & 1)) << 2);
+ dshift = (png_size_t)((1 - ((final_width + 1) & 1)) << 2);
+ s_start = 0;
+ s_end = 4;
+ s_inc = 4;
+ }
+
+ for (i = row_info->width; i; i--)
+ {
+ png_byte v;
+ int j;
+
+ v = (png_byte)((*sp >> sshift) & 0xf);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+ else
+ dshift += s_inc;
+ }
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+
+ /*====================================================================*/
+
+ default: /* 8-bit or larger (this is where the routine is modified) */
+ {
+#if 0
+// static unsigned long long _const4 = 0x0000000000FFFFFFLL; no good
+// static unsigned long long const4 = 0x0000000000FFFFFFLL; no good
+// unsigned long long _const4 = 0x0000000000FFFFFFLL; no good
+// unsigned long long const4 = 0x0000000000FFFFFFLL; no good
+#endif
+ png_bytep sptr, dp;
+ png_uint_32 i;
+ png_size_t pixel_bytes;
+ int width = (int)row_info->width;
+
+ pixel_bytes = (row_info->pixel_depth >> 3);
+
+ /* point sptr at the last pixel in the pre-expanded row: */
+ sptr = row + (width - 1) * pixel_bytes;
+
+ /* point dp at the last pixel position in the expanded row: */
+ dp = row + (final_width - 1) * pixel_bytes;
+
+ /* New code by Nirav Chhatrapati - Intel Corporation */
+
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+#if !defined(PNG_1_0_X)
+ if ((png_ptr->asm_flags & PNG_ASM_FLAG_MMX_READ_INTERLACE)
+ /* && _mmx_supported */ )
+#else
+ if (_mmx_supported)
+#endif
+ {
+ //--------------------------------------------------------------
+ if (pixel_bytes == 3)
+ {
+ if (((pass == 0) || (pass == 1)) && width)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $21, %%edi \n\t"
+ // (png_pass_inc[pass] - 1)*pixel_bytes
+
+ ".loop3_pass0: \n\t"
+ "movd (%%esi), %%mm0 \n\t" // x x x x x 2 1 0
+ "pand _const4, %%mm0 \n\t" // z z z z z 2 1 0
+ "movq %%mm0, %%mm1 \n\t" // z z z z z 2 1 0
+ "psllq $16, %%mm0 \n\t" // z z z 2 1 0 z z
+ "movq %%mm0, %%mm2 \n\t" // z z z 2 1 0 z z
+ "psllq $24, %%mm0 \n\t" // 2 1 0 z z z z z
+ "psrlq $8, %%mm1 \n\t" // z z z z z z 2 1
+ "por %%mm2, %%mm0 \n\t" // 2 1 0 2 1 0 z z
+ "por %%mm1, %%mm0 \n\t" // 2 1 0 2 1 0 2 1
+ "movq %%mm0, %%mm3 \n\t" // 2 1 0 2 1 0 2 1
+ "psllq $16, %%mm0 \n\t" // 0 2 1 0 2 1 z z
+ "movq %%mm3, %%mm4 \n\t" // 2 1 0 2 1 0 2 1
+ "punpckhdq %%mm0, %%mm3 \n\t" // 0 2 1 0 2 1 0 2
+ "movq %%mm4, 16(%%edi) \n\t"
+ "psrlq $32, %%mm0 \n\t" // z z z z 0 2 1 0
+ "movq %%mm3, 8(%%edi) \n\t"
+ "punpckldq %%mm4, %%mm0 \n\t" // 1 0 2 1 0 2 1 0
+ "subl $3, %%esi \n\t"
+ "movq %%mm0, (%%edi) \n\t"
+ "subl $24, %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz .loop3_pass0 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width), // ecx
+ "rim" (_const4) // %1(?) (0x0000000000FFFFFFLL)
+
+#if 0 /* %mm0, ..., %mm4 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1", "%mm2" // clobber list
+ , "%mm3", "%mm4"
+#endif
+ );
+ }
+ else if (((pass == 2) || (pass == 3)) && width)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $9, %%edi \n\t"
+ // (png_pass_inc[pass] - 1)*pixel_bytes
+
+ ".loop3_pass2: \n\t"
+ "movd (%%esi), %%mm0 \n\t" // x x x x x 2 1 0
+ "pand _const4, %%mm0 \n\t" // z z z z z 2 1 0
+ "movq %%mm0, %%mm1 \n\t" // z z z z z 2 1 0
+ "psllq $16, %%mm0 \n\t" // z z z 2 1 0 z z
+ "movq %%mm0, %%mm2 \n\t" // z z z 2 1 0 z z
+ "psllq $24, %%mm0 \n\t" // 2 1 0 z z z z z
+ "psrlq $8, %%mm1 \n\t" // z z z z z z 2 1
+ "por %%mm2, %%mm0 \n\t" // 2 1 0 2 1 0 z z
+ "por %%mm1, %%mm0 \n\t" // 2 1 0 2 1 0 2 1
+ "movq %%mm0, 4(%%edi) \n\t"
+ "psrlq $16, %%mm0 \n\t" // z z 2 1 0 2 1 0
+ "subl $3, %%esi \n\t"
+ "movd %%mm0, (%%edi) \n\t"
+ "subl $12, %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz .loop3_pass2 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width), // ecx
+ "rim" (_const4) // (0x0000000000FFFFFFLL)
+
+#if 0 /* %mm0, ..., %mm2 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1", "%mm2" // clobber list
+#endif
+ );
+ }
+ else if (width) /* && ((pass == 4) || (pass == 5)) */
+ {
+ int width_mmx = ((width >> 1) << 1) - 8; // GRR: huh?
+ if (width_mmx < 0)
+ width_mmx = 0;
+ width -= width_mmx; // 8 or 9 pix, 24 or 27 bytes
+ if (width_mmx)
+ {
+ // png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+ // sptr points at last pixel in pre-expanded row
+ // dp points at last pixel position in expanded row
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $3, %%esi \n\t"
+ "subl $9, %%edi \n\t"
+ // (png_pass_inc[pass] + 1)*pixel_bytes
+
+ ".loop3_pass4: \n\t"
+ "movq (%%esi), %%mm0 \n\t" // x x 5 4 3 2 1 0
+ "movq %%mm0, %%mm1 \n\t" // x x 5 4 3 2 1 0
+ "movq %%mm0, %%mm2 \n\t" // x x 5 4 3 2 1 0
+ "psllq $24, %%mm0 \n\t" // 4 3 2 1 0 z z z
+ "pand _const4, %%mm1 \n\t" // z z z z z 2 1 0
+ "psrlq $24, %%mm2 \n\t" // z z z x x 5 4 3
+ "por %%mm1, %%mm0 \n\t" // 4 3 2 1 0 2 1 0
+ "movq %%mm2, %%mm3 \n\t" // z z z x x 5 4 3
+ "psllq $8, %%mm2 \n\t" // z z x x 5 4 3 z
+ "movq %%mm0, (%%edi) \n\t"
+ "psrlq $16, %%mm3 \n\t" // z z z z z x x 5
+ "pand _const6, %%mm3 \n\t" // z z z z z z z 5
+ "por %%mm3, %%mm2 \n\t" // z z x x 5 4 3 5
+ "subl $6, %%esi \n\t"
+ "movd %%mm2, 8(%%edi) \n\t"
+ "subl $12, %%edi \n\t"
+ "subl $2, %%ecx \n\t"
+ "jnz .loop3_pass4 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx), // ecx
+ "rim" (_const4), // 0x0000000000FFFFFFLL
+ "rim" (_const6) // 0x00000000000000FFLL
+
+#if 0 /* %mm0, ..., %mm3 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1" // clobber list
+ , "%mm2", "%mm3"
+#endif
+ );
+ }
+
+ sptr -= width_mmx*3;
+ dp -= width_mmx*6;
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+
+ png_memcpy(v, sptr, 3);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ png_memcpy(dp, v, 3);
+ dp -= 3;
+ }
+ sptr -= 3;
+ }
+ }
+ } /* end of pixel_bytes == 3 */
+
+ //--------------------------------------------------------------
+ else if (pixel_bytes == 1)
+ {
+ if (((pass == 0) || (pass == 1)) && width)
+ {
+ int width_mmx = ((width >> 2) << 2);
+ width -= width_mmx; // 0-3 pixels => 0-3 bytes
+ if (width_mmx)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $3, %%esi \n\t"
+ "subl $31, %%edi \n\t"
+
+ ".loop1_pass0: \n\t"
+ "movd (%%esi), %%mm0 \n\t" // x x x x 3 2 1 0
+ "movq %%mm0, %%mm1 \n\t" // x x x x 3 2 1 0
+ "punpcklbw %%mm0, %%mm0 \n\t" // 3 3 2 2 1 1 0 0
+ "movq %%mm0, %%mm2 \n\t" // 3 3 2 2 1 1 0 0
+ "punpcklwd %%mm0, %%mm0 \n\t" // 1 1 1 1 0 0 0 0
+ "movq %%mm0, %%mm3 \n\t" // 1 1 1 1 0 0 0 0
+ "punpckldq %%mm0, %%mm0 \n\t" // 0 0 0 0 0 0 0 0
+ "punpckhdq %%mm3, %%mm3 \n\t" // 1 1 1 1 1 1 1 1
+ "movq %%mm0, (%%edi) \n\t"
+ "punpckhwd %%mm2, %%mm2 \n\t" // 3 3 3 3 2 2 2 2
+ "movq %%mm3, 8(%%edi) \n\t"
+ "movq %%mm2, %%mm4 \n\t" // 3 3 3 3 2 2 2 2
+ "punpckldq %%mm2, %%mm2 \n\t" // 2 2 2 2 2 2 2 2
+ "punpckhdq %%mm4, %%mm4 \n\t" // 3 3 3 3 3 3 3 3
+ "movq %%mm2, 16(%%edi) \n\t"
+ "subl $4, %%esi \n\t"
+ "movq %%mm4, 24(%%edi) \n\t"
+ "subl $32, %%edi \n\t"
+ "subl $4, %%ecx \n\t"
+ "jnz .loop1_pass0 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx) // ecx
+
+#if 0 /* %mm0, ..., %mm4 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1", "%mm2" // clobber list
+ , "%mm3", "%mm4"
+#endif
+ );
+ }
+
+ sptr -= width_mmx;
+ dp -= width_mmx*8;
+ for (i = width; i; i--)
+ {
+ int j;
+
+ /* I simplified this part in version 1.0.4e
+ * here and in several other instances where
+ * pixel_bytes == 1 -- GR-P
+ *
+ * Original code:
+ *
+ * png_byte v[8];
+ * png_memcpy(v, sptr, pixel_bytes);
+ * for (j = 0; j < png_pass_inc[pass]; j++)
+ * {
+ * png_memcpy(dp, v, pixel_bytes);
+ * dp -= pixel_bytes;
+ * }
+ * sptr -= pixel_bytes;
+ *
+ * Replacement code is in the next three lines:
+ */
+
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ *dp-- = *sptr;
+ }
+ --sptr;
+ }
+ }
+ else if (((pass == 2) || (pass == 3)) && width)
+ {
+ int width_mmx = ((width >> 2) << 2);
+ width -= width_mmx; // 0-3 pixels => 0-3 bytes
+ if (width_mmx)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $3, %%esi \n\t"
+ "subl $15, %%edi \n\t"
+
+ ".loop1_pass2: \n\t"
+ "movd (%%esi), %%mm0 \n\t" // x x x x 3 2 1 0
+ "punpcklbw %%mm0, %%mm0 \n\t" // 3 3 2 2 1 1 0 0
+ "movq %%mm0, %%mm1 \n\t" // 3 3 2 2 1 1 0 0
+ "punpcklwd %%mm0, %%mm0 \n\t" // 1 1 1 1 0 0 0 0
+ "punpckhwd %%mm1, %%mm1 \n\t" // 3 3 3 3 2 2 2 2
+ "movq %%mm0, (%%edi) \n\t"
+ "subl $4, %%esi \n\t"
+ "movq %%mm1, 8(%%edi) \n\t"
+ "subl $16, %%edi \n\t"
+ "subl $4, %%ecx \n\t"
+ "jnz .loop1_pass2 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx) // ecx
+
+#if 0 /* %mm0, %mm1 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1" // clobber list
+#endif
+ );
+ }
+
+ sptr -= width_mmx;
+ dp -= width_mmx*4;
+ for (i = width; i; i--)
+ {
+ int j;
+
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ *dp-- = *sptr;
+ }
+ --sptr;
+ }
+ }
+ else if (width) /* && ((pass == 4) || (pass == 5)) */
+ {
+ int width_mmx = ((width >> 3) << 3);
+ width -= width_mmx; // 0-3 pixels => 0-3 bytes
+ if (width_mmx)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $7, %%esi \n\t"
+ "subl $15, %%edi \n\t"
+
+ ".loop1_pass4: \n\t"
+ "movq (%%esi), %%mm0 \n\t" // 7 6 5 4 3 2 1 0
+ "movq %%mm0, %%mm1 \n\t" // 7 6 5 4 3 2 1 0
+ "punpcklbw %%mm0, %%mm0 \n\t" // 3 3 2 2 1 1 0 0
+ "punpckhbw %%mm1, %%mm1 \n\t" // 7 7 6 6 5 5 4 4
+ "movq %%mm1, 8(%%edi) \n\t"
+ "subl $8, %%esi \n\t"
+ "movq %%mm0, (%%edi) \n\t"
+ "subl $16, %%edi \n\t"
+ "subl $8, %%ecx \n\t"
+ "jnz .loop1_pass4 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (none)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx) // ecx
+
+#if 0 /* %mm0, %mm1 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1" // clobber list
+#endif
+ );
+ }
+
+ sptr -= width_mmx;
+ dp -= width_mmx*2;
+ for (i = width; i; i--)
+ {
+ int j;
+
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ *dp-- = *sptr;
+ }
+ --sptr;
+ }
+ }
+ } /* end of pixel_bytes == 1 */
+
+ //--------------------------------------------------------------
+ else if (pixel_bytes == 2)
+ {
+ if (((pass == 0) || (pass == 1)) && width)
+ {
+ int width_mmx = ((width >> 1) << 1);
+ width -= width_mmx; // 0,1 pixels => 0,2 bytes
+ if (width_mmx)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $2, %%esi \n\t"
+ "subl $30, %%edi \n\t"
+
+ ".loop2_pass0: \n\t"
+ "movd (%%esi), %%mm0 \n\t" // x x x x 3 2 1 0
+ "punpcklwd %%mm0, %%mm0 \n\t" // 3 2 3 2 1 0 1 0
+ "movq %%mm0, %%mm1 \n\t" // 3 2 3 2 1 0 1 0
+ "punpckldq %%mm0, %%mm0 \n\t" // 1 0 1 0 1 0 1 0
+ "punpckhdq %%mm1, %%mm1 \n\t" // 3 2 3 2 3 2 3 2
+ "movq %%mm0, (%%edi) \n\t"
+ "movq %%mm0, 8(%%edi) \n\t"
+ "movq %%mm1, 16(%%edi) \n\t"
+ "subl $4, %%esi \n\t"
+ "movq %%mm1, 24(%%edi) \n\t"
+ "subl $32, %%edi \n\t"
+ "subl $2, %%ecx \n\t"
+ "jnz .loop2_pass0 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx) // ecx
+
+#if 0 /* %mm0, %mm1 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1" // clobber list
+#endif
+ );
+ }
+
+ sptr -= (width_mmx*2 - 2); // sign fixed
+ dp -= (width_mmx*16 - 2); // sign fixed
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ sptr -= 2;
+ png_memcpy(v, sptr, 2);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ dp -= 2;
+ png_memcpy(dp, v, 2);
+ }
+ }
+ }
+ else if (((pass == 2) || (pass == 3)) && width)
+ {
+ int width_mmx = ((width >> 1) << 1) ;
+ width -= width_mmx; // 0,1 pixels => 0,2 bytes
+ if (width_mmx)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $2, %%esi \n\t"
+ "subl $14, %%edi \n\t"
+
+ ".loop2_pass2: \n\t"
+ "movd (%%esi), %%mm0 \n\t" // x x x x 3 2 1 0
+ "punpcklwd %%mm0, %%mm0 \n\t" // 3 2 3 2 1 0 1 0
+ "movq %%mm0, %%mm1 \n\t" // 3 2 3 2 1 0 1 0
+ "punpckldq %%mm0, %%mm0 \n\t" // 1 0 1 0 1 0 1 0
+ "punpckhdq %%mm1, %%mm1 \n\t" // 3 2 3 2 3 2 3 2
+ "movq %%mm0, (%%edi) \n\t"
+ "subl $4, %%esi \n\t"
+ "movq %%mm1, 8(%%edi) \n\t"
+ "subl $16, %%edi \n\t"
+ "subl $2, %%ecx \n\t"
+ "jnz .loop2_pass2 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx) // ecx
+
+#if 0 /* %mm0, %mm1 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1" // clobber list
+#endif
+ );
+ }
+
+ sptr -= (width_mmx*2 - 2); // sign fixed
+ dp -= (width_mmx*8 - 2); // sign fixed
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ sptr -= 2;
+ png_memcpy(v, sptr, 2);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ dp -= 2;
+ png_memcpy(dp, v, 2);
+ }
+ }
+ }
+ else if (width) // pass == 4 or 5
+ {
+ int width_mmx = ((width >> 1) << 1) ;
+ width -= width_mmx; // 0,1 pixels => 0,2 bytes
+ if (width_mmx)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $2, %%esi \n\t"
+ "subl $6, %%edi \n\t"
+
+ ".loop2_pass4: \n\t"
+ "movd (%%esi), %%mm0 \n\t" // x x x x 3 2 1 0
+ "punpcklwd %%mm0, %%mm0 \n\t" // 3 2 3 2 1 0 1 0
+ "subl $4, %%esi \n\t"
+ "movq %%mm0, (%%edi) \n\t"
+ "subl $8, %%edi \n\t"
+ "subl $2, %%ecx \n\t"
+ "jnz .loop2_pass4 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx) // ecx
+
+#if 0 /* %mm0 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0" // clobber list
+#endif
+ );
+ }
+
+ sptr -= (width_mmx*2 - 2); // sign fixed
+ dp -= (width_mmx*4 - 2); // sign fixed
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ sptr -= 2;
+ png_memcpy(v, sptr, 2);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ dp -= 2;
+ png_memcpy(dp, v, 2);
+ }
+ }
+ }
+ } /* end of pixel_bytes == 2 */
+
+ //--------------------------------------------------------------
+ else if (pixel_bytes == 4)
+ {
+ if (((pass == 0) || (pass == 1)) && width)
+ {
+ int width_mmx = ((width >> 1) << 1);
+ width -= width_mmx; // 0,1 pixels => 0,4 bytes
+ if (width_mmx)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $4, %%esi \n\t"
+ "subl $60, %%edi \n\t"
+
+ ".loop4_pass0: \n\t"
+ "movq (%%esi), %%mm0 \n\t" // 7 6 5 4 3 2 1 0
+ "movq %%mm0, %%mm1 \n\t" // 7 6 5 4 3 2 1 0
+ "punpckldq %%mm0, %%mm0 \n\t" // 3 2 1 0 3 2 1 0
+ "punpckhdq %%mm1, %%mm1 \n\t" // 7 6 5 4 7 6 5 4
+ "movq %%mm0, (%%edi) \n\t"
+ "movq %%mm0, 8(%%edi) \n\t"
+ "movq %%mm0, 16(%%edi) \n\t"
+ "movq %%mm0, 24(%%edi) \n\t"
+ "movq %%mm1, 32(%%edi) \n\t"
+ "movq %%mm1, 40(%%edi) \n\t"
+ "movq %%mm1, 48(%%edi) \n\t"
+ "subl $8, %%esi \n\t"
+ "movq %%mm1, 56(%%edi) \n\t"
+ "subl $64, %%edi \n\t"
+ "subl $2, %%ecx \n\t"
+ "jnz .loop4_pass0 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx) // ecx
+
+#if 0 /* %mm0, %mm1 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1" // clobber list
+#endif
+ );
+ }
+
+ sptr -= (width_mmx*4 - 4); // sign fixed
+ dp -= (width_mmx*32 - 4); // sign fixed
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ sptr -= 4;
+ png_memcpy(v, sptr, 4);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ dp -= 4;
+ png_memcpy(dp, v, 4);
+ }
+ }
+ }
+ else if (((pass == 2) || (pass == 3)) && width)
+ {
+ int width_mmx = ((width >> 1) << 1);
+ width -= width_mmx; // 0,1 pixels => 0,4 bytes
+ if (width_mmx)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $4, %%esi \n\t"
+ "subl $28, %%edi \n\t"
+
+ ".loop4_pass2: \n\t"
+ "movq (%%esi), %%mm0 \n\t" // 7 6 5 4 3 2 1 0
+ "movq %%mm0, %%mm1 \n\t" // 7 6 5 4 3 2 1 0
+ "punpckldq %%mm0, %%mm0 \n\t" // 3 2 1 0 3 2 1 0
+ "punpckhdq %%mm1, %%mm1 \n\t" // 7 6 5 4 7 6 5 4
+ "movq %%mm0, (%%edi) \n\t"
+ "movq %%mm0, 8(%%edi) \n\t"
+ "movq %%mm1, 16(%%edi) \n\t"
+ "movq %%mm1, 24(%%edi) \n\t"
+ "subl $8, %%esi \n\t"
+ "subl $32, %%edi \n\t"
+ "subl $2, %%ecx \n\t"
+ "jnz .loop4_pass2 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx) // ecx
+
+#if 0 /* %mm0, %mm1 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1" // clobber list
+#endif
+ );
+ }
+
+ sptr -= (width_mmx*4 - 4); // sign fixed
+ dp -= (width_mmx*16 - 4); // sign fixed
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ sptr -= 4;
+ png_memcpy(v, sptr, 4);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ dp -= 4;
+ png_memcpy(dp, v, 4);
+ }
+ }
+ }
+ else if (width) // pass == 4 or 5
+ {
+ int width_mmx = ((width >> 1) << 1) ;
+ width -= width_mmx; // 0,1 pixels => 0,4 bytes
+ if (width_mmx)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $4, %%esi \n\t"
+ "subl $12, %%edi \n\t"
+
+ ".loop4_pass4: \n\t"
+ "movq (%%esi), %%mm0 \n\t" // 7 6 5 4 3 2 1 0
+ "movq %%mm0, %%mm1 \n\t" // 7 6 5 4 3 2 1 0
+ "punpckldq %%mm0, %%mm0 \n\t" // 3 2 1 0 3 2 1 0
+ "punpckhdq %%mm1, %%mm1 \n\t" // 7 6 5 4 7 6 5 4
+ "movq %%mm0, (%%edi) \n\t"
+ "subl $8, %%esi \n\t"
+ "movq %%mm1, 8(%%edi) \n\t"
+ "subl $16, %%edi \n\t"
+ "subl $2, %%ecx \n\t"
+ "jnz .loop4_pass4 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width_mmx) // ecx
+
+#if 0 /* %mm0, %mm1 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0", "%mm1" // clobber list
+#endif
+ );
+ }
+
+ sptr -= (width_mmx*4 - 4); // sign fixed
+ dp -= (width_mmx*8 - 4); // sign fixed
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ sptr -= 4;
+ png_memcpy(v, sptr, 4);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ dp -= 4;
+ png_memcpy(dp, v, 4);
+ }
+ }
+ }
+ } /* end of pixel_bytes == 4 */
+
+ //--------------------------------------------------------------
+ else if (pixel_bytes == 8)
+ {
+// GRR TEST: should work, but needs testing (special 64-bit version of rpng2?)
+ // GRR NOTE: no need to combine passes here!
+ if (((pass == 0) || (pass == 1)) && width)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ // source is 8-byte RRGGBBAA
+ // dest is 64-byte RRGGBBAA RRGGBBAA RRGGBBAA RRGGBBAA ...
+ __asm__ __volatile__ (
+ "subl $56, %%edi \n\t" // start of last block
+
+ ".loop8_pass0: \n\t"
+ "movq (%%esi), %%mm0 \n\t" // 7 6 5 4 3 2 1 0
+ "movq %%mm0, (%%edi) \n\t"
+ "movq %%mm0, 8(%%edi) \n\t"
+ "movq %%mm0, 16(%%edi) \n\t"
+ "movq %%mm0, 24(%%edi) \n\t"
+ "movq %%mm0, 32(%%edi) \n\t"
+ "movq %%mm0, 40(%%edi) \n\t"
+ "movq %%mm0, 48(%%edi) \n\t"
+ "subl $8, %%esi \n\t"
+ "movq %%mm0, 56(%%edi) \n\t"
+ "subl $64, %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz .loop8_pass0 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width) // ecx
+
+#if 0 /* %mm0 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0" // clobber list
+#endif
+ );
+ }
+ else if (((pass == 2) || (pass == 3)) && width)
+ {
+ // source is 8-byte RRGGBBAA
+ // dest is 32-byte RRGGBBAA RRGGBBAA RRGGBBAA RRGGBBAA
+ // (recall that expansion is _in place_: sptr and dp
+ // both point at locations within same row buffer)
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $24, %%edi \n\t" // start of last block
+
+ ".loop8_pass2: \n\t"
+ "movq (%%esi), %%mm0 \n\t" // 7 6 5 4 3 2 1 0
+ "movq %%mm0, (%%edi) \n\t"
+ "movq %%mm0, 8(%%edi) \n\t"
+ "movq %%mm0, 16(%%edi) \n\t"
+ "subl $8, %%esi \n\t"
+ "movq %%mm0, 24(%%edi) \n\t"
+ "subl $32, %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz .loop8_pass2 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width) // ecx
+
+#if 0 /* %mm0 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0" // clobber list
+#endif
+ );
+ }
+ }
+ else if (width) // pass == 4 or 5
+ {
+ // source is 8-byte RRGGBBAA
+ // dest is 16-byte RRGGBBAA RRGGBBAA
+ {
+ int dummy_value_c; // fix 'forbidden register spilled'
+ int dummy_value_S;
+ int dummy_value_D;
+
+ __asm__ __volatile__ (
+ "subl $8, %%edi \n\t" // start of last block
+
+ ".loop8_pass4: \n\t"
+ "movq (%%esi), %%mm0 \n\t" // 7 6 5 4 3 2 1 0
+ "movq %%mm0, (%%edi) \n\t"
+ "subl $8, %%esi \n\t"
+ "movq %%mm0, 8(%%edi) \n\t"
+ "subl $16, %%edi \n\t"
+ "decl %%ecx \n\t"
+ "jnz .loop8_pass4 \n\t"
+ "EMMS \n\t" // DONE
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "1" (sptr), // esi // input regs
+ "2" (dp), // edi
+ "0" (width) // ecx
+
+#if 0 /* %mm0 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ : "%mm0" // clobber list
+#endif
+ );
+ }
+ }
+
+ } /* end of pixel_bytes == 8 */
+
+ //--------------------------------------------------------------
+ else if (pixel_bytes == 6)
+ {
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ png_memcpy(v, sptr, 6);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ png_memcpy(dp, v, 6);
+ dp -= 6;
+ }
+ sptr -= 6;
+ }
+ } /* end of pixel_bytes == 6 */
+
+ //--------------------------------------------------------------
+ else
+ {
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ png_memcpy(v, sptr, pixel_bytes);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ png_memcpy(dp, v, pixel_bytes);
+ dp -= pixel_bytes;
+ }
+ sptr-= pixel_bytes;
+ }
+ }
+ } // end of _mmx_supported ========================================
+
+ else /* MMX not supported: use modified C code - takes advantage
+ * of inlining of png_memcpy for a constant */
+ /* GRR 19991007: does it? or should pixel_bytes in each
+ * block be replaced with immediate value (e.g., 1)? */
+ /* GRR 19991017: replaced with constants in each case */
+#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
+ {
+ if (pixel_bytes == 1)
+ {
+ for (i = width; i; i--)
+ {
+ int j;
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ *dp-- = *sptr;
+ }
+ --sptr;
+ }
+ }
+ else if (pixel_bytes == 3)
+ {
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ png_memcpy(v, sptr, 3);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ png_memcpy(dp, v, 3);
+ dp -= 3;
+ }
+ sptr -= 3;
+ }
+ }
+ else if (pixel_bytes == 2)
+ {
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ png_memcpy(v, sptr, 2);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ png_memcpy(dp, v, 2);
+ dp -= 2;
+ }
+ sptr -= 2;
+ }
+ }
+ else if (pixel_bytes == 4)
+ {
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ png_memcpy(v, sptr, 4);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+#ifdef PNG_DEBUG
+ if (dp < row || dp+3 > row+png_ptr->row_buf_size)
+ {
+ printf("dp out of bounds: row=%d, dp=%d, rp=%d\n",
+ row, dp, row+png_ptr->row_buf_size);
+ printf("row_buf=%d\n",png_ptr->row_buf_size);
+ }
+#endif
+ png_memcpy(dp, v, 4);
+ dp -= 4;
+ }
+ sptr -= 4;
+ }
+ }
+ else if (pixel_bytes == 6)
+ {
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ png_memcpy(v, sptr, 6);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ png_memcpy(dp, v, 6);
+ dp -= 6;
+ }
+ sptr -= 6;
+ }
+ }
+ else if (pixel_bytes == 8)
+ {
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ png_memcpy(v, sptr, 8);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ png_memcpy(dp, v, 8);
+ dp -= 8;
+ }
+ sptr -= 8;
+ }
+ }
+ else /* GRR: should never be reached */
+ {
+ for (i = width; i; i--)
+ {
+ png_byte v[8];
+ int j;
+ png_memcpy(v, sptr, pixel_bytes);
+ for (j = 0; j < png_pass_inc[pass]; j++)
+ {
+ png_memcpy(dp, v, pixel_bytes);
+ dp -= pixel_bytes;
+ }
+ sptr -= pixel_bytes;
+ }
+ }
+
+ } /* end if (MMX not supported) */
+ break;
+ }
+ } /* end switch (row_info->pixel_depth) */
+
+ row_info->width = final_width;
+
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,final_width);
+ }
+
+} /* end png_do_read_interlace() */
+
+#endif /* PNG_HAVE_ASSEMBLER_READ_INTERLACE */
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+
+
+
+#if defined(PNG_HAVE_ASSEMBLER_READ_FILTER_ROW)
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+
+// These variables are utilized in the functions below. They are declared
+// globally here to ensure alignment on 8-byte boundaries.
+
+union uAll {
+ long long use;
+ double align;
+} _LBCarryMask = {0x0101010101010101LL},
+ _HBClearMask = {0x7f7f7f7f7f7f7f7fLL},
+ _ActiveMask, _ActiveMask2, _ActiveMaskEnd, _ShiftBpp, _ShiftRem;
+
+#ifdef PNG_THREAD_UNSAFE_OK
+//===========================================================================//
+// //
+// P N G _ R E A D _ F I L T E R _ R O W _ M M X _ A V G //
+// //
+//===========================================================================//
+
+// Optimized code for PNG Average filter decoder
+
+static void /* PRIVATE */
+png_read_filter_row_mmx_avg(png_row_infop row_info, png_bytep row,
+ png_bytep prev_row)
+{
+ int bpp;
+ int dummy_value_c; // fix 'forbidden register 2 (cx) was spilled' error
+ int dummy_value_S;
+ int dummy_value_D;
+
+ bpp = (row_info->pixel_depth + 7) >> 3; // get # bytes per pixel
+ _FullLength = row_info->rowbytes; // # of bytes to filter
+
+ __asm__ __volatile__ (
+ // initialize address pointers and offset
+#ifdef __PIC__
+ "pushl %%ebx \n\t" // save index to Global Offset Table
+#endif
+//pre "movl row, %%edi \n\t" // edi: Avg(x)
+ "xorl %%ebx, %%ebx \n\t" // ebx: x
+ "movl %%edi, %%edx \n\t"
+//pre "movl prev_row, %%esi \n\t" // esi: Prior(x)
+//pre "subl bpp, %%edx \n\t" // (bpp is preloaded into ecx)
+ "subl %%ecx, %%edx \n\t" // edx: Raw(x-bpp)
+
+ "xorl %%eax,%%eax \n\t"
+
+ // Compute the Raw value for the first bpp bytes
+ // Raw(x) = Avg(x) + (Prior(x)/2)
+ "avg_rlp: \n\t"
+ "movb (%%esi,%%ebx,),%%al \n\t" // load al with Prior(x)
+ "incl %%ebx \n\t"
+ "shrb %%al \n\t" // divide by 2
+ "addb -1(%%edi,%%ebx,),%%al \n\t" // add Avg(x); -1 to offset inc ebx
+//pre "cmpl bpp, %%ebx \n\t" // (bpp is preloaded into ecx)
+ "cmpl %%ecx, %%ebx \n\t"
+ "movb %%al,-1(%%edi,%%ebx,) \n\t" // write Raw(x); -1 to offset inc ebx
+ "jb avg_rlp \n\t" // mov does not affect flags
+
+ // get # of bytes to alignment
+ "movl %%edi, _dif \n\t" // take start of row
+ "addl %%ebx, _dif \n\t" // add bpp
+ "addl $0xf, _dif \n\t" // add 7+8 to incr past alignment bdry
+ "andl $0xfffffff8, _dif \n\t" // mask to alignment boundary
+ "subl %%edi, _dif \n\t" // subtract from start => value ebx at
+ "jz avg_go \n\t" // alignment
+
+ // fix alignment
+ // Compute the Raw value for the bytes up to the alignment boundary
+ // Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
+ "xorl %%ecx, %%ecx \n\t"
+
+ "avg_lp1: \n\t"
+ "xorl %%eax, %%eax \n\t"
+ "movb (%%esi,%%ebx,), %%cl \n\t" // load cl with Prior(x)
+ "movb (%%edx,%%ebx,), %%al \n\t" // load al with Raw(x-bpp)
+ "addw %%cx, %%ax \n\t"
+ "incl %%ebx \n\t"
+ "shrw %%ax \n\t" // divide by 2
+ "addb -1(%%edi,%%ebx,), %%al \n\t" // add Avg(x); -1 to offset inc ebx
+ "cmpl _dif, %%ebx \n\t" // check if at alignment boundary
+ "movb %%al, -1(%%edi,%%ebx,) \n\t" // write Raw(x); -1 to offset inc ebx
+ "jb avg_lp1 \n\t" // repeat until at alignment boundary
+
+ "avg_go: \n\t"
+ "movl _FullLength, %%eax \n\t"
+ "movl %%eax, %%ecx \n\t"
+ "subl %%ebx, %%eax \n\t" // subtract alignment fix
+ "andl $0x00000007, %%eax \n\t" // calc bytes over mult of 8
+ "subl %%eax, %%ecx \n\t" // drop over bytes from original length
+ "movl %%ecx, _MMXLength \n\t"
+#ifdef __PIC__
+ "popl %%ebx \n\t" // restore index to Global Offset Table
+#endif
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "0" (bpp), // ecx // input regs
+ "1" (prev_row), // esi
+ "2" (row) // edi
+
+ : "%eax", "%edx" // clobber list
+#ifndef __PIC__
+ , "%ebx"
+#endif
+ // GRR: INCLUDE "memory" as clobbered? (_dif, _MMXLength)
+ // (seems to work fine without...)
+ );
+
+ // now do the math for the rest of the row
+ switch (bpp)
+ {
+ case 3:
+ {
+ _ActiveMask.use = 0x0000000000ffffffLL;
+ _ShiftBpp.use = 24; // == 3 * 8
+ _ShiftRem.use = 40; // == 64 - 24
+
+ __asm__ __volatile__ (
+ // re-init address pointers and offset
+ "movq _ActiveMask, %%mm7 \n\t"
+ "movl _dif, %%ecx \n\t" // ecx: x = offset to
+ "movq _LBCarryMask, %%mm5 \n\t" // alignment boundary
+// preload "movl row, %%edi \n\t" // edi: Avg(x)
+ "movq _HBClearMask, %%mm4 \n\t"
+// preload "movl prev_row, %%esi \n\t" // esi: Prior(x)
+
+ // prime the pump: load the first Raw(x-bpp) data set
+ "movq -8(%%edi,%%ecx,), %%mm2 \n\t" // load previous aligned 8 bytes
+ // (correct pos. in loop below)
+ "avg_3lp: \n\t"
+ "movq (%%edi,%%ecx,), %%mm0 \n\t" // load mm0 with Avg(x)
+ "movq %%mm5, %%mm3 \n\t"
+ "psrlq _ShiftRem, %%mm2 \n\t" // correct position Raw(x-bpp)
+ // data
+ "movq (%%esi,%%ecx,), %%mm1 \n\t" // load mm1 with Prior(x)
+ "movq %%mm7, %%mm6 \n\t"
+ "pand %%mm1, %%mm3 \n\t" // get lsb for each prev_row byte
+ "psrlq $1, %%mm1 \n\t" // divide prev_row bytes by 2
+ "pand %%mm4, %%mm1 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm0 \n\t" // add (Prev_row/2) to Avg for
+ // each byte
+ // add 1st active group (Raw(x-bpp)/2) to average with LBCarry
+ "movq %%mm3, %%mm1 \n\t" // now use mm1 for getting
+ // LBCarrys
+ "pand %%mm2, %%mm1 \n\t" // get LBCarrys for each byte
+ // where both
+ // lsb's were == 1 (only valid for active group)
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm2 \n\t" // add LBCarrys to (Raw(x-bpp)/2)
+ // for each byte
+ "pand %%mm6, %%mm2 \n\t" // leave only Active Group 1
+ // bytes to add to Avg
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) + LBCarrys to
+ // Avg for each Active
+ // byte
+ // add 2nd active group (Raw(x-bpp)/2) to average with _LBCarry
+ "psllq _ShiftBpp, %%mm6 \n\t" // shift the mm6 mask to cover
+ // bytes 3-5
+ "movq %%mm0, %%mm2 \n\t" // mov updated Raws to mm2
+ "psllq _ShiftBpp, %%mm2 \n\t" // shift data to pos. correctly
+ "movq %%mm3, %%mm1 \n\t" // now use mm1 for getting
+ // LBCarrys
+ "pand %%mm2, %%mm1 \n\t" // get LBCarrys for each byte
+ // where both
+ // lsb's were == 1 (only valid for active group)
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm2 \n\t" // add LBCarrys to (Raw(x-bpp)/2)
+ // for each byte
+ "pand %%mm6, %%mm2 \n\t" // leave only Active Group 2
+ // bytes to add to Avg
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) + LBCarrys to
+ // Avg for each Active
+ // byte
+
+ // add 3rd active group (Raw(x-bpp)/2) to average with _LBCarry
+ "psllq _ShiftBpp, %%mm6 \n\t" // shift mm6 mask to cover last
+ // two
+ // bytes
+ "movq %%mm0, %%mm2 \n\t" // mov updated Raws to mm2
+ "psllq _ShiftBpp, %%mm2 \n\t" // shift data to pos. correctly
+ // Data only needs to be shifted once here to
+ // get the correct x-bpp offset.
+ "movq %%mm3, %%mm1 \n\t" // now use mm1 for getting
+ // LBCarrys
+ "pand %%mm2, %%mm1 \n\t" // get LBCarrys for each byte
+ // where both
+ // lsb's were == 1 (only valid for active group)
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm2 \n\t" // add LBCarrys to (Raw(x-bpp)/2)
+ // for each byte
+ "pand %%mm6, %%mm2 \n\t" // leave only Active Group 2
+ // bytes to add to Avg
+ "addl $8, %%ecx \n\t"
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) + LBCarrys to
+ // Avg for each Active
+ // byte
+ // now ready to write back to memory
+ "movq %%mm0, -8(%%edi,%%ecx,) \n\t"
+ // move updated Raw(x) to use as Raw(x-bpp) for next loop
+ "cmpl _MMXLength, %%ecx \n\t"
+ "movq %%mm0, %%mm2 \n\t" // mov updated Raw(x) to mm2
+ "jb avg_3lp \n\t"
+
+ : "=S" (dummy_value_S), // output regs (dummy)
+ "=D" (dummy_value_D)
+
+ : "0" (prev_row), // esi // input regs
+ "1" (row) // edi
+
+ : "%ecx" // clobber list
+#if 0 /* %mm0, ..., %mm7 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ , "%mm0", "%mm1", "%mm2", "%mm3"
+ , "%mm4", "%mm5", "%mm6", "%mm7"
+#endif
+ );
+ }
+ break; // end 3 bpp
+
+ case 6:
+ case 4:
+ //case 7: // who wrote this? PNG doesn't support 5 or 7 bytes/pixel
+ //case 5: // GRR BOGUS
+ {
+ _ActiveMask.use = 0xffffffffffffffffLL; // use shift below to clear
+ // appropriate inactive bytes
+ _ShiftBpp.use = bpp << 3;
+ _ShiftRem.use = 64 - _ShiftBpp.use;
+
+ __asm__ __volatile__ (
+ "movq _HBClearMask, %%mm4 \n\t"
+
+ // re-init address pointers and offset
+ "movl _dif, %%ecx \n\t" // ecx: x = offset to
+ // alignment boundary
+
+ // load _ActiveMask and clear all bytes except for 1st active group
+ "movq _ActiveMask, %%mm7 \n\t"
+// preload "movl row, %%edi \n\t" // edi: Avg(x)
+ "psrlq _ShiftRem, %%mm7 \n\t"
+// preload "movl prev_row, %%esi \n\t" // esi: Prior(x)
+ "movq %%mm7, %%mm6 \n\t"
+ "movq _LBCarryMask, %%mm5 \n\t"
+ "psllq _ShiftBpp, %%mm6 \n\t" // create mask for 2nd active
+ // group
+
+ // prime the pump: load the first Raw(x-bpp) data set
+ "movq -8(%%edi,%%ecx,), %%mm2 \n\t" // load previous aligned 8 bytes
+ // (we correct pos. in loop below)
+ "avg_4lp: \n\t"
+ "movq (%%edi,%%ecx,), %%mm0 \n\t"
+ "psrlq _ShiftRem, %%mm2 \n\t" // shift data to pos. correctly
+ "movq (%%esi,%%ecx,), %%mm1 \n\t"
+ // add (Prev_row/2) to average
+ "movq %%mm5, %%mm3 \n\t"
+ "pand %%mm1, %%mm3 \n\t" // get lsb for each prev_row byte
+ "psrlq $1, %%mm1 \n\t" // divide prev_row bytes by 2
+ "pand %%mm4, %%mm1 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm0 \n\t" // add (Prev_row/2) to Avg for
+ // each byte
+ // add 1st active group (Raw(x-bpp)/2) to average with _LBCarry
+ "movq %%mm3, %%mm1 \n\t" // now use mm1 for getting
+ // LBCarrys
+ "pand %%mm2, %%mm1 \n\t" // get LBCarrys for each byte
+ // where both
+ // lsb's were == 1 (only valid for active group)
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm2 \n\t" // add LBCarrys to (Raw(x-bpp)/2)
+ // for each byte
+ "pand %%mm7, %%mm2 \n\t" // leave only Active Group 1
+ // bytes to add to Avg
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) + LBCarrys to Avg
+ // for each Active
+ // byte
+ // add 2nd active group (Raw(x-bpp)/2) to average with _LBCarry
+ "movq %%mm0, %%mm2 \n\t" // mov updated Raws to mm2
+ "psllq _ShiftBpp, %%mm2 \n\t" // shift data to pos. correctly
+ "addl $8, %%ecx \n\t"
+ "movq %%mm3, %%mm1 \n\t" // now use mm1 for getting
+ // LBCarrys
+ "pand %%mm2, %%mm1 \n\t" // get LBCarrys for each byte
+ // where both
+ // lsb's were == 1 (only valid for active group)
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm2 \n\t" // add LBCarrys to (Raw(x-bpp)/2)
+ // for each byte
+ "pand %%mm6, %%mm2 \n\t" // leave only Active Group 2
+ // bytes to add to Avg
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) + LBCarrys to
+ // Avg for each Active
+ // byte
+ "cmpl _MMXLength, %%ecx \n\t"
+ // now ready to write back to memory
+ "movq %%mm0, -8(%%edi,%%ecx,) \n\t"
+ // prep Raw(x-bpp) for next loop
+ "movq %%mm0, %%mm2 \n\t" // mov updated Raws to mm2
+ "jb avg_4lp \n\t"
+
+ : "=S" (dummy_value_S), // output regs (dummy)
+ "=D" (dummy_value_D)
+
+ : "0" (prev_row), // esi // input regs
+ "1" (row) // edi
+
+ : "%ecx" // clobber list
+#if 0 /* %mm0, ..., %mm7 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ , "%mm0", "%mm1", "%mm2", "%mm3"
+ , "%mm4", "%mm5", "%mm6", "%mm7"
+#endif
+ );
+ }
+ break; // end 4,6 bpp
+
+ case 2:
+ {
+ _ActiveMask.use = 0x000000000000ffffLL;
+ _ShiftBpp.use = 16; // == 2 * 8
+ _ShiftRem.use = 48; // == 64 - 16
+
+ __asm__ __volatile__ (
+ // load _ActiveMask
+ "movq _ActiveMask, %%mm7 \n\t"
+ // re-init address pointers and offset
+ "movl _dif, %%ecx \n\t" // ecx: x = offset to alignment
+ // boundary
+ "movq _LBCarryMask, %%mm5 \n\t"
+// preload "movl row, %%edi \n\t" // edi: Avg(x)
+ "movq _HBClearMask, %%mm4 \n\t"
+// preload "movl prev_row, %%esi \n\t" // esi: Prior(x)
+
+ // prime the pump: load the first Raw(x-bpp) data set
+ "movq -8(%%edi,%%ecx,), %%mm2 \n\t" // load previous aligned 8 bytes
+ // (we correct pos. in loop below)
+ "avg_2lp: \n\t"
+ "movq (%%edi,%%ecx,), %%mm0 \n\t"
+ "psrlq _ShiftRem, %%mm2 \n\t" // shift data to pos. correctly
+ "movq (%%esi,%%ecx,), %%mm1 \n\t" // (GRR BUGFIX: was psllq)
+ // add (Prev_row/2) to average
+ "movq %%mm5, %%mm3 \n\t"
+ "pand %%mm1, %%mm3 \n\t" // get lsb for each prev_row byte
+ "psrlq $1, %%mm1 \n\t" // divide prev_row bytes by 2
+ "pand %%mm4, %%mm1 \n\t" // clear invalid bit 7 of each
+ // byte
+ "movq %%mm7, %%mm6 \n\t"
+ "paddb %%mm1, %%mm0 \n\t" // add (Prev_row/2) to Avg for
+ // each byte
+
+ // add 1st active group (Raw(x-bpp)/2) to average with _LBCarry
+ "movq %%mm3, %%mm1 \n\t" // now use mm1 for getting
+ // LBCarrys
+ "pand %%mm2, %%mm1 \n\t" // get LBCarrys for each byte
+ // where both
+ // lsb's were == 1 (only valid
+ // for active group)
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm2 \n\t" // add LBCarrys to (Raw(x-bpp)/2)
+ // for each byte
+ "pand %%mm6, %%mm2 \n\t" // leave only Active Group 1
+ // bytes to add to Avg
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) + LBCarrys to Avg
+ // for each Active byte
+
+ // add 2nd active group (Raw(x-bpp)/2) to average with _LBCarry
+ "psllq _ShiftBpp, %%mm6 \n\t" // shift the mm6 mask to cover
+ // bytes 2 & 3
+ "movq %%mm0, %%mm2 \n\t" // mov updated Raws to mm2
+ "psllq _ShiftBpp, %%mm2 \n\t" // shift data to pos. correctly
+ "movq %%mm3, %%mm1 \n\t" // now use mm1 for getting
+ // LBCarrys
+ "pand %%mm2, %%mm1 \n\t" // get LBCarrys for each byte
+ // where both
+ // lsb's were == 1 (only valid
+ // for active group)
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm2 \n\t" // add LBCarrys to (Raw(x-bpp)/2)
+ // for each byte
+ "pand %%mm6, %%mm2 \n\t" // leave only Active Group 2
+ // bytes to add to Avg
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) + LBCarrys to
+ // Avg for each Active byte
+
+ // add 3rd active group (Raw(x-bpp)/2) to average with _LBCarry
+ "psllq _ShiftBpp, %%mm6 \n\t" // shift the mm6 mask to cover
+ // bytes 4 & 5
+ "movq %%mm0, %%mm2 \n\t" // mov updated Raws to mm2
+ "psllq _ShiftBpp, %%mm2 \n\t" // shift data to pos. correctly
+ "movq %%mm3, %%mm1 \n\t" // now use mm1 for getting
+ // LBCarrys
+ "pand %%mm2, %%mm1 \n\t" // get LBCarrys for each byte
+ // where both lsb's were == 1
+ // (only valid for active group)
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm2 \n\t" // add LBCarrys to (Raw(x-bpp)/2)
+ // for each byte
+ "pand %%mm6, %%mm2 \n\t" // leave only Active Group 2
+ // bytes to add to Avg
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) + LBCarrys to
+ // Avg for each Active byte
+
+ // add 4th active group (Raw(x-bpp)/2) to average with _LBCarry
+ "psllq _ShiftBpp, %%mm6 \n\t" // shift the mm6 mask to cover
+ // bytes 6 & 7
+ "movq %%mm0, %%mm2 \n\t" // mov updated Raws to mm2
+ "psllq _ShiftBpp, %%mm2 \n\t" // shift data to pos. correctly
+ "addl $8, %%ecx \n\t"
+ "movq %%mm3, %%mm1 \n\t" // now use mm1 for getting
+ // LBCarrys
+ "pand %%mm2, %%mm1 \n\t" // get LBCarrys for each byte
+ // where both
+ // lsb's were == 1 (only valid
+ // for active group)
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm2 \n\t" // add LBCarrys to (Raw(x-bpp)/2)
+ // for each byte
+ "pand %%mm6, %%mm2 \n\t" // leave only Active Group 2
+ // bytes to add to Avg
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) + LBCarrys to
+ // Avg for each Active byte
+
+ "cmpl _MMXLength, %%ecx \n\t"
+ // now ready to write back to memory
+ "movq %%mm0, -8(%%edi,%%ecx,) \n\t"
+ // prep Raw(x-bpp) for next loop
+ "movq %%mm0, %%mm2 \n\t" // mov updated Raws to mm2
+ "jb avg_2lp \n\t"
+
+ : "=S" (dummy_value_S), // output regs (dummy)
+ "=D" (dummy_value_D)
+
+ : "0" (prev_row), // esi // input regs
+ "1" (row) // edi
+
+ : "%ecx" // clobber list
+#if 0 /* %mm0, ..., %mm7 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ , "%mm0", "%mm1", "%mm2", "%mm3"
+ , "%mm4", "%mm5", "%mm6", "%mm7"
+#endif
+ );
+ }
+ break; // end 2 bpp
+
+ case 1:
+ {
+ __asm__ __volatile__ (
+ // re-init address pointers and offset
+#ifdef __PIC__
+ "pushl %%ebx \n\t" // save Global Offset Table index
+#endif
+ "movl _dif, %%ebx \n\t" // ebx: x = offset to alignment
+ // boundary
+// preload "movl row, %%edi \n\t" // edi: Avg(x)
+ "cmpl _FullLength, %%ebx \n\t" // test if offset at end of array
+ "jnb avg_1end \n\t"
+ // do Paeth decode for remaining bytes
+// preload "movl prev_row, %%esi \n\t" // esi: Prior(x)
+ "movl %%edi, %%edx \n\t"
+// preload "subl bpp, %%edx \n\t" // (bpp is preloaded into ecx)
+ "subl %%ecx, %%edx \n\t" // edx: Raw(x-bpp)
+ "xorl %%ecx, %%ecx \n\t" // zero ecx before using cl & cx
+ // in loop below
+ "avg_1lp: \n\t"
+ // Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
+ "xorl %%eax, %%eax \n\t"
+ "movb (%%esi,%%ebx,), %%cl \n\t" // load cl with Prior(x)
+ "movb (%%edx,%%ebx,), %%al \n\t" // load al with Raw(x-bpp)
+ "addw %%cx, %%ax \n\t"
+ "incl %%ebx \n\t"
+ "shrw %%ax \n\t" // divide by 2
+ "addb -1(%%edi,%%ebx,), %%al \n\t" // add Avg(x); -1 to offset
+ // inc ebx
+ "cmpl _FullLength, %%ebx \n\t" // check if at end of array
+ "movb %%al, -1(%%edi,%%ebx,) \n\t" // write back Raw(x);
+ // mov does not affect flags; -1 to offset inc ebx
+ "jb avg_1lp \n\t"
+
+ "avg_1end: \n\t"
+#ifdef __PIC__
+ "popl %%ebx \n\t" // Global Offset Table index
+#endif
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "0" (bpp), // ecx // input regs
+ "1" (prev_row), // esi
+ "2" (row) // edi
+
+ : "%eax", "%edx" // clobber list
+#ifndef __PIC__
+ , "%ebx"
+#endif
+ );
+ }
+ return; // end 1 bpp
+
+ case 8:
+ {
+ __asm__ __volatile__ (
+ // re-init address pointers and offset
+ "movl _dif, %%ecx \n\t" // ecx: x == offset to alignment
+ "movq _LBCarryMask, %%mm5 \n\t" // boundary
+// preload "movl row, %%edi \n\t" // edi: Avg(x)
+ "movq _HBClearMask, %%mm4 \n\t"
+// preload "movl prev_row, %%esi \n\t" // esi: Prior(x)
+
+ // prime the pump: load the first Raw(x-bpp) data set
+ "movq -8(%%edi,%%ecx,), %%mm2 \n\t" // load previous aligned 8 bytes
+ // (NO NEED to correct pos. in loop below)
+
+ "avg_8lp: \n\t"
+ "movq (%%edi,%%ecx,), %%mm0 \n\t"
+ "movq %%mm5, %%mm3 \n\t"
+ "movq (%%esi,%%ecx,), %%mm1 \n\t"
+ "addl $8, %%ecx \n\t"
+ "pand %%mm1, %%mm3 \n\t" // get lsb for each prev_row byte
+ "psrlq $1, %%mm1 \n\t" // divide prev_row bytes by 2
+ "pand %%mm2, %%mm3 \n\t" // get LBCarrys for each byte
+ // where both lsb's were == 1
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm1 \n\t" // clear invalid bit 7, each byte
+ "paddb %%mm3, %%mm0 \n\t" // add LBCarrys to Avg, each byte
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7, each byte
+ "paddb %%mm1, %%mm0 \n\t" // add (Prev_row/2) to Avg, each
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) to Avg for each
+ "cmpl _MMXLength, %%ecx \n\t"
+ "movq %%mm0, -8(%%edi,%%ecx,) \n\t"
+ "movq %%mm0, %%mm2 \n\t" // reuse as Raw(x-bpp)
+ "jb avg_8lp \n\t"
+
+ : "=S" (dummy_value_S), // output regs (dummy)
+ "=D" (dummy_value_D)
+
+ : "0" (prev_row), // esi // input regs
+ "1" (row) // edi
+
+ : "%ecx" // clobber list
+#if 0 /* %mm0, ..., %mm5 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ , "%mm0", "%mm1", "%mm2"
+ , "%mm3", "%mm4", "%mm5"
+#endif
+ );
+ }
+ break; // end 8 bpp
+
+ default: // bpp greater than 8 (!= 1,2,3,4,[5],6,[7],8)
+ {
+
+#ifdef PNG_DEBUG
+ // GRR: PRINT ERROR HERE: SHOULD NEVER BE REACHED
+ png_debug(1,
+ "Internal logic error in pnggccrd (png_read_filter_row_mmx_avg())\n");
+#endif
+
+#if 0
+ __asm__ __volatile__ (
+ "movq _LBCarryMask, %%mm5 \n\t"
+ // re-init address pointers and offset
+ "movl _dif, %%ebx \n\t" // ebx: x = offset to
+ // alignment boundary
+ "movl row, %%edi \n\t" // edi: Avg(x)
+ "movq _HBClearMask, %%mm4 \n\t"
+ "movl %%edi, %%edx \n\t"
+ "movl prev_row, %%esi \n\t" // esi: Prior(x)
+ "subl bpp, %%edx \n\t" // edx: Raw(x-bpp)
+ "avg_Alp: \n\t"
+ "movq (%%edi,%%ebx,), %%mm0 \n\t"
+ "movq %%mm5, %%mm3 \n\t"
+ "movq (%%esi,%%ebx,), %%mm1 \n\t"
+ "pand %%mm1, %%mm3 \n\t" // get lsb for each prev_row byte
+ "movq (%%edx,%%ebx,), %%mm2 \n\t"
+ "psrlq $1, %%mm1 \n\t" // divide prev_row bytes by 2
+ "pand %%mm2, %%mm3 \n\t" // get LBCarrys for each byte
+ // where both lsb's were == 1
+ "psrlq $1, %%mm2 \n\t" // divide raw bytes by 2
+ "pand %%mm4, %%mm1 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm3, %%mm0 \n\t" // add LBCarrys to Avg for each
+ // byte
+ "pand %%mm4, %%mm2 \n\t" // clear invalid bit 7 of each
+ // byte
+ "paddb %%mm1, %%mm0 \n\t" // add (Prev_row/2) to Avg for
+ // each byte
+ "addl $8, %%ebx \n\t"
+ "paddb %%mm2, %%mm0 \n\t" // add (Raw/2) to Avg for each
+ // byte
+ "cmpl _MMXLength, %%ebx \n\t"
+ "movq %%mm0, -8(%%edi,%%ebx,) \n\t"
+ "jb avg_Alp \n\t"
+
+ : // FIXASM: output regs/vars go here, e.g.: "=m" (memory_var)
+
+ : // FIXASM: input regs, e.g.: "c" (count), "S" (src), "D" (dest)
+
+ : "%ebx", "%edx", "%edi", "%esi" // CHECKASM: clobber list
+ );
+#endif /* 0 - NEVER REACHED */
+ }
+ break;
+
+ } // end switch (bpp)
+
+ __asm__ __volatile__ (
+ // MMX acceleration complete; now do clean-up
+ // check if any remaining bytes left to decode
+#ifdef __PIC__
+ "pushl %%ebx \n\t" // save index to Global Offset Table
+#endif
+ "movl _MMXLength, %%ebx \n\t" // ebx: x == offset bytes after MMX
+//pre "movl row, %%edi \n\t" // edi: Avg(x)
+ "cmpl _FullLength, %%ebx \n\t" // test if offset at end of array
+ "jnb avg_end \n\t"
+
+ // do Avg decode for remaining bytes
+//pre "movl prev_row, %%esi \n\t" // esi: Prior(x)
+ "movl %%edi, %%edx \n\t"
+//pre "subl bpp, %%edx \n\t" // (bpp is preloaded into ecx)
+ "subl %%ecx, %%edx \n\t" // edx: Raw(x-bpp)
+ "xorl %%ecx, %%ecx \n\t" // zero ecx before using cl & cx below
+
+ "avg_lp2: \n\t"
+ // Raw(x) = Avg(x) + ((Raw(x-bpp) + Prior(x))/2)
+ "xorl %%eax, %%eax \n\t"
+ "movb (%%esi,%%ebx,), %%cl \n\t" // load cl with Prior(x)
+ "movb (%%edx,%%ebx,), %%al \n\t" // load al with Raw(x-bpp)
+ "addw %%cx, %%ax \n\t"
+ "incl %%ebx \n\t"
+ "shrw %%ax \n\t" // divide by 2
+ "addb -1(%%edi,%%ebx,), %%al \n\t" // add Avg(x); -1 to offset inc ebx
+ "cmpl _FullLength, %%ebx \n\t" // check if at end of array
+ "movb %%al, -1(%%edi,%%ebx,) \n\t" // write back Raw(x) [mov does not
+ "jb avg_lp2 \n\t" // affect flags; -1 to offset inc ebx]
+
+ "avg_end: \n\t"
+ "EMMS \n\t" // end MMX; prep for poss. FP instrs.
+#ifdef __PIC__
+ "popl %%ebx \n\t" // restore index to Global Offset Table
+#endif
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "0" (bpp), // ecx // input regs
+ "1" (prev_row), // esi
+ "2" (row) // edi
+
+ : "%eax", "%edx" // clobber list
+#ifndef __PIC__
+ , "%ebx"
+#endif
+ );
+
+} /* end png_read_filter_row_mmx_avg() */
+#endif
+
+
+
+#ifdef PNG_THREAD_UNSAFE_OK
+//===========================================================================//
+// //
+// P N G _ R E A D _ F I L T E R _ R O W _ M M X _ P A E T H //
+// //
+//===========================================================================//
+
+// Optimized code for PNG Paeth filter decoder
+
+static void /* PRIVATE */
+png_read_filter_row_mmx_paeth(png_row_infop row_info, png_bytep row,
+ png_bytep prev_row)
+{
+ int bpp;
+ int dummy_value_c; // fix 'forbidden register 2 (cx) was spilled' error
+ int dummy_value_S;
+ int dummy_value_D;
+
+ bpp = (row_info->pixel_depth + 7) >> 3; // Get # bytes per pixel
+ _FullLength = row_info->rowbytes; // # of bytes to filter
+
+ __asm__ __volatile__ (
+#ifdef __PIC__
+ "pushl %%ebx \n\t" // save index to Global Offset Table
+#endif
+ "xorl %%ebx, %%ebx \n\t" // ebx: x offset
+//pre "movl row, %%edi \n\t"
+ "xorl %%edx, %%edx \n\t" // edx: x-bpp offset
+//pre "movl prev_row, %%esi \n\t"
+ "xorl %%eax, %%eax \n\t"
+
+ // Compute the Raw value for the first bpp bytes
+ // Note: the formula works out to be always
+ // Paeth(x) = Raw(x) + Prior(x) where x < bpp
+ "paeth_rlp: \n\t"
+ "movb (%%edi,%%ebx,), %%al \n\t"
+ "addb (%%esi,%%ebx,), %%al \n\t"
+ "incl %%ebx \n\t"
+//pre "cmpl bpp, %%ebx \n\t" (bpp is preloaded into ecx)
+ "cmpl %%ecx, %%ebx \n\t"
+ "movb %%al, -1(%%edi,%%ebx,) \n\t"
+ "jb paeth_rlp \n\t"
+ // get # of bytes to alignment
+ "movl %%edi, _dif \n\t" // take start of row
+ "addl %%ebx, _dif \n\t" // add bpp
+ "xorl %%ecx, %%ecx \n\t"
+ "addl $0xf, _dif \n\t" // add 7 + 8 to incr past alignment
+ // boundary
+ "andl $0xfffffff8, _dif \n\t" // mask to alignment boundary
+ "subl %%edi, _dif \n\t" // subtract from start ==> value ebx
+ // at alignment
+ "jz paeth_go \n\t"
+ // fix alignment
+
+ "paeth_lp1: \n\t"
+ "xorl %%eax, %%eax \n\t"
+ // pav = p - a = (a + b - c) - a = b - c
+ "movb (%%esi,%%ebx,), %%al \n\t" // load Prior(x) into al
+ "movb (%%esi,%%edx,), %%cl \n\t" // load Prior(x-bpp) into cl
+ "subl %%ecx, %%eax \n\t" // subtract Prior(x-bpp)
+ "movl %%eax, _patemp \n\t" // Save pav for later use
+ "xorl %%eax, %%eax \n\t"
+ // pbv = p - b = (a + b - c) - b = a - c
+ "movb (%%edi,%%edx,), %%al \n\t" // load Raw(x-bpp) into al
+ "subl %%ecx, %%eax \n\t" // subtract Prior(x-bpp)
+ "movl %%eax, %%ecx \n\t"
+ // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+ "addl _patemp, %%eax \n\t" // pcv = pav + pbv
+ // pc = abs(pcv)
+ "testl $0x80000000, %%eax \n\t"
+ "jz paeth_pca \n\t"
+ "negl %%eax \n\t" // reverse sign of neg values
+
+ "paeth_pca: \n\t"
+ "movl %%eax, _pctemp \n\t" // save pc for later use
+ // pb = abs(pbv)
+ "testl $0x80000000, %%ecx \n\t"
+ "jz paeth_pba \n\t"
+ "negl %%ecx \n\t" // reverse sign of neg values
+
+ "paeth_pba: \n\t"
+ "movl %%ecx, _pbtemp \n\t" // save pb for later use
+ // pa = abs(pav)
+ "movl _patemp, %%eax \n\t"
+ "testl $0x80000000, %%eax \n\t"
+ "jz paeth_paa \n\t"
+ "negl %%eax \n\t" // reverse sign of neg values
+
+ "paeth_paa: \n\t"
+ "movl %%eax, _patemp \n\t" // save pa for later use
+ // test if pa <= pb
+ "cmpl %%ecx, %%eax \n\t"
+ "jna paeth_abb \n\t"
+ // pa > pb; now test if pb <= pc
+ "cmpl _pctemp, %%ecx \n\t"
+ "jna paeth_bbc \n\t"
+ // pb > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
+ "movb (%%esi,%%edx,), %%cl \n\t" // load Prior(x-bpp) into cl
+ "jmp paeth_paeth \n\t"
+
+ "paeth_bbc: \n\t"
+ // pb <= pc; Raw(x) = Paeth(x) + Prior(x)
+ "movb (%%esi,%%ebx,), %%cl \n\t" // load Prior(x) into cl
+ "jmp paeth_paeth \n\t"
+
+ "paeth_abb: \n\t"
+ // pa <= pb; now test if pa <= pc
+ "cmpl _pctemp, %%eax \n\t"
+ "jna paeth_abc \n\t"
+ // pa > pc; Raw(x) = Paeth(x) + Prior(x-bpp)
+ "movb (%%esi,%%edx,), %%cl \n\t" // load Prior(x-bpp) into cl
+ "jmp paeth_paeth \n\t"
+
+ "paeth_abc: \n\t"
+ // pa <= pc; Raw(x) = Paeth(x) + Raw(x-bpp)
+ "movb (%%edi,%%edx,), %%cl \n\t" // load Raw(x-bpp) into cl
+
+ "paeth_paeth: \n\t"
+ "incl %%ebx \n\t"
+ "incl %%edx \n\t"
+ // Raw(x) = (Paeth(x) + Paeth_Predictor( a, b, c )) mod 256
+ "addb %%cl, -1(%%edi,%%ebx,) \n\t"
+ "cmpl _dif, %%ebx \n\t"
+ "jb paeth_lp1 \n\t"
+
+ "paeth_go: \n\t"
+ "movl _FullLength, %%ecx \n\t"
+ "movl %%ecx, %%eax \n\t"
+ "subl %%ebx, %%eax \n\t" // subtract alignment fix
+ "andl $0x00000007, %%eax \n\t" // calc bytes over mult of 8
+ "subl %%eax, %%ecx \n\t" // drop over bytes from original length
+ "movl %%ecx, _MMXLength \n\t"
+#ifdef __PIC__
+ "popl %%ebx \n\t" // restore index to Global Offset Table
+#endif
+
+ : "=c" (dummy_value_c), // output regs (dummy)
+ "=S" (dummy_value_S),
+ "=D" (dummy_value_D)
+
+ : "0" (bpp), // ecx // input regs
+ "1" (prev_row), // esi
+ "2" (row) // edi
+
+ : "%eax", "%edx" // clobber list
+#ifndef __PIC__
+ , "%ebx"
+#endif
+ );
+
+ // now do the math for the rest of the row
+ switch (bpp)
+ {
+ case 3:
+ {
+ _ActiveMask.use = 0x0000000000ffffffLL;
+ _ActiveMaskEnd.use = 0xffff000000000000LL;
+ _ShiftBpp.use = 24; // == bpp(3) * 8
+ _ShiftRem.use = 40; // == 64 - 24
+
+ __asm__ __volatile__ (
+ "movl _dif, %%ecx \n\t"
+// preload "movl row, %%edi \n\t"
+// preload "movl prev_row, %%esi \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ // prime the pump: load the first Raw(x-bpp) data set
+ "movq -8(%%edi,%%ecx,), %%mm1 \n\t"
+ "paeth_3lp: \n\t"
+ "psrlq _ShiftRem, %%mm1 \n\t" // shift last 3 bytes to 1st
+ // 3 bytes
+ "movq (%%esi,%%ecx,), %%mm2 \n\t" // load b=Prior(x)
+ "punpcklbw %%mm0, %%mm1 \n\t" // unpack High bytes of a
+ "movq -8(%%esi,%%ecx,), %%mm3 \n\t" // prep c=Prior(x-bpp) bytes
+ "punpcklbw %%mm0, %%mm2 \n\t" // unpack High bytes of b
+ "psrlq _ShiftRem, %%mm3 \n\t" // shift last 3 bytes to 1st
+ // 3 bytes
+ // pav = p - a = (a + b - c) - a = b - c
+ "movq %%mm2, %%mm4 \n\t"
+ "punpcklbw %%mm0, %%mm3 \n\t" // unpack High bytes of c
+ // pbv = p - b = (a + b - c) - b = a - c
+ "movq %%mm1, %%mm5 \n\t"
+ "psubw %%mm3, %%mm4 \n\t"
+ "pxor %%mm7, %%mm7 \n\t"
+ // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+ "movq %%mm4, %%mm6 \n\t"
+ "psubw %%mm3, %%mm5 \n\t"
+
+ // pa = abs(p-a) = abs(pav)
+ // pb = abs(p-b) = abs(pbv)
+ // pc = abs(p-c) = abs(pcv)
+ "pcmpgtw %%mm4, %%mm0 \n\t" // create mask pav bytes < 0
+ "paddw %%mm5, %%mm6 \n\t"
+ "pand %%mm4, %%mm0 \n\t" // only pav bytes < 0 in mm7
+ "pcmpgtw %%mm5, %%mm7 \n\t" // create mask pbv bytes < 0
+ "psubw %%mm0, %%mm4 \n\t"
+ "pand %%mm5, %%mm7 \n\t" // only pbv bytes < 0 in mm0
+ "psubw %%mm0, %%mm4 \n\t"
+ "psubw %%mm7, %%mm5 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ "pcmpgtw %%mm6, %%mm0 \n\t" // create mask pcv bytes < 0
+ "pand %%mm6, %%mm0 \n\t" // only pav bytes < 0 in mm7
+ "psubw %%mm7, %%mm5 \n\t"
+ "psubw %%mm0, %%mm6 \n\t"
+ // test pa <= pb
+ "movq %%mm4, %%mm7 \n\t"
+ "psubw %%mm0, %%mm6 \n\t"
+ "pcmpgtw %%mm5, %%mm7 \n\t" // pa > pb?
+ "movq %%mm7, %%mm0 \n\t"
+ // use mm7 mask to merge pa & pb
+ "pand %%mm7, %%mm5 \n\t"
+ // use mm0 mask copy to merge a & b
+ "pand %%mm0, %%mm2 \n\t"
+ "pandn %%mm4, %%mm7 \n\t"
+ "pandn %%mm1, %%mm0 \n\t"
+ "paddw %%mm5, %%mm7 \n\t"
+ "paddw %%mm2, %%mm0 \n\t"
+ // test ((pa <= pb)? pa:pb) <= pc
+ "pcmpgtw %%mm6, %%mm7 \n\t" // pab > pc?
+ "pxor %%mm1, %%mm1 \n\t"
+ "pand %%mm7, %%mm3 \n\t"
+ "pandn %%mm0, %%mm7 \n\t"
+ "paddw %%mm3, %%mm7 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ "packuswb %%mm1, %%mm7 \n\t"
+ "movq (%%esi,%%ecx,), %%mm3 \n\t" // load c=Prior(x-bpp)
+ "pand _ActiveMask, %%mm7 \n\t"
+ "movq %%mm3, %%mm2 \n\t" // load b=Prior(x) step 1
+ "paddb (%%edi,%%ecx,), %%mm7 \n\t" // add Paeth predictor with Raw(x)
+ "punpcklbw %%mm0, %%mm3 \n\t" // unpack High bytes of c
+ "movq %%mm7, (%%edi,%%ecx,) \n\t" // write back updated value
+ "movq %%mm7, %%mm1 \n\t" // now mm1 will be used as
+ // Raw(x-bpp)
+ // now do Paeth for 2nd set of bytes (3-5)
+ "psrlq _ShiftBpp, %%mm2 \n\t" // load b=Prior(x) step 2
+ "punpcklbw %%mm0, %%mm1 \n\t" // unpack High bytes of a
+ "pxor %%mm7, %%mm7 \n\t"
+ "punpcklbw %%mm0, %%mm2 \n\t" // unpack High bytes of b
+ // pbv = p - b = (a + b - c) - b = a - c
+ "movq %%mm1, %%mm5 \n\t"
+ // pav = p - a = (a + b - c) - a = b - c
+ "movq %%mm2, %%mm4 \n\t"
+ "psubw %%mm3, %%mm5 \n\t"
+ "psubw %%mm3, %%mm4 \n\t"
+ // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) =
+ // pav + pbv = pbv + pav
+ "movq %%mm5, %%mm6 \n\t"
+ "paddw %%mm4, %%mm6 \n\t"
+
+ // pa = abs(p-a) = abs(pav)
+ // pb = abs(p-b) = abs(pbv)
+ // pc = abs(p-c) = abs(pcv)
+ "pcmpgtw %%mm5, %%mm0 \n\t" // create mask pbv bytes < 0
+ "pcmpgtw %%mm4, %%mm7 \n\t" // create mask pav bytes < 0
+ "pand %%mm5, %%mm0 \n\t" // only pbv bytes < 0 in mm0
+ "pand %%mm4, %%mm7 \n\t" // only pav bytes < 0 in mm7
+ "psubw %%mm0, %%mm5 \n\t"
+ "psubw %%mm7, %%mm4 \n\t"
+ "psubw %%mm0, %%mm5 \n\t"
+ "psubw %%mm7, %%mm4 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ "pcmpgtw %%mm6, %%mm0 \n\t" // create mask pcv bytes < 0
+ "pand %%mm6, %%mm0 \n\t" // only pav bytes < 0 in mm7
+ "psubw %%mm0, %%mm6 \n\t"
+ // test pa <= pb
+ "movq %%mm4, %%mm7 \n\t"
+ "psubw %%mm0, %%mm6 \n\t"
+ "pcmpgtw %%mm5, %%mm7 \n\t" // pa > pb?
+ "movq %%mm7, %%mm0 \n\t"
+ // use mm7 mask to merge pa & pb
+ "pand %%mm7, %%mm5 \n\t"
+ // use mm0 mask copy to merge a & b
+ "pand %%mm0, %%mm2 \n\t"
+ "pandn %%mm4, %%mm7 \n\t"
+ "pandn %%mm1, %%mm0 \n\t"
+ "paddw %%mm5, %%mm7 \n\t"
+ "paddw %%mm2, %%mm0 \n\t"
+ // test ((pa <= pb)? pa:pb) <= pc
+ "pcmpgtw %%mm6, %%mm7 \n\t" // pab > pc?
+ "movq (%%esi,%%ecx,), %%mm2 \n\t" // load b=Prior(x)
+ "pand %%mm7, %%mm3 \n\t"
+ "pandn %%mm0, %%mm7 \n\t"
+ "pxor %%mm1, %%mm1 \n\t"
+ "paddw %%mm3, %%mm7 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ "packuswb %%mm1, %%mm7 \n\t"
+ "movq %%mm2, %%mm3 \n\t" // load c=Prior(x-bpp) step 1
+ "pand _ActiveMask, %%mm7 \n\t"
+ "punpckhbw %%mm0, %%mm2 \n\t" // unpack High bytes of b
+ "psllq _ShiftBpp, %%mm7 \n\t" // shift bytes to 2nd group of
+ // 3 bytes
+ // pav = p - a = (a + b - c) - a = b - c
+ "movq %%mm2, %%mm4 \n\t"
+ "paddb (%%edi,%%ecx,), %%mm7 \n\t" // add Paeth predictor with Raw(x)
+ "psllq _ShiftBpp, %%mm3 \n\t" // load c=Prior(x-bpp) step 2
+ "movq %%mm7, (%%edi,%%ecx,) \n\t" // write back updated value
+ "movq %%mm7, %%mm1 \n\t"
+ "punpckhbw %%mm0, %%mm3 \n\t" // unpack High bytes of c
+ "psllq _ShiftBpp, %%mm1 \n\t" // shift bytes
+ // now mm1 will be used as Raw(x-bpp)
+ // now do Paeth for 3rd, and final, set of bytes (6-7)
+ "pxor %%mm7, %%mm7 \n\t"
+ "punpckhbw %%mm0, %%mm1 \n\t" // unpack High bytes of a
+ "psubw %%mm3, %%mm4 \n\t"
+ // pbv = p - b = (a + b - c) - b = a - c
+ "movq %%mm1, %%mm5 \n\t"
+ // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+ "movq %%mm4, %%mm6 \n\t"
+ "psubw %%mm3, %%mm5 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ "paddw %%mm5, %%mm6 \n\t"
+
+ // pa = abs(p-a) = abs(pav)
+ // pb = abs(p-b) = abs(pbv)
+ // pc = abs(p-c) = abs(pcv)
+ "pcmpgtw %%mm4, %%mm0 \n\t" // create mask pav bytes < 0
+ "pcmpgtw %%mm5, %%mm7 \n\t" // create mask pbv bytes < 0
+ "pand %%mm4, %%mm0 \n\t" // only pav bytes < 0 in mm7
+ "pand %%mm5, %%mm7 \n\t" // only pbv bytes < 0 in mm0
+ "psubw %%mm0, %%mm4 \n\t"
+ "psubw %%mm7, %%mm5 \n\t"
+ "psubw %%mm0, %%mm4 \n\t"
+ "psubw %%mm7, %%mm5 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ "pcmpgtw %%mm6, %%mm0 \n\t" // create mask pcv bytes < 0
+ "pand %%mm6, %%mm0 \n\t" // only pav bytes < 0 in mm7
+ "psubw %%mm0, %%mm6 \n\t"
+ // test pa <= pb
+ "movq %%mm4, %%mm7 \n\t"
+ "psubw %%mm0, %%mm6 \n\t"
+ "pcmpgtw %%mm5, %%mm7 \n\t" // pa > pb?
+ "movq %%mm7, %%mm0 \n\t"
+ // use mm0 mask copy to merge a & b
+ "pand %%mm0, %%mm2 \n\t"
+ // use mm7 mask to merge pa & pb
+ "pand %%mm7, %%mm5 \n\t"
+ "pandn %%mm1, %%mm0 \n\t"
+ "pandn %%mm4, %%mm7 \n\t"
+ "paddw %%mm2, %%mm0 \n\t"
+ "paddw %%mm5, %%mm7 \n\t"
+ // test ((pa <= pb)? pa:pb) <= pc
+ "pcmpgtw %%mm6, %%mm7 \n\t" // pab > pc?
+ "pand %%mm7, %%mm3 \n\t"
+ "pandn %%mm0, %%mm7 \n\t"
+ "paddw %%mm3, %%mm7 \n\t"
+ "pxor %%mm1, %%mm1 \n\t"
+ "packuswb %%mm7, %%mm1 \n\t"
+ // step ecx to next set of 8 bytes and repeat loop til done
+ "addl $8, %%ecx \n\t"
+ "pand _ActiveMaskEnd, %%mm1 \n\t"
+ "paddb -8(%%edi,%%ecx,), %%mm1 \n\t" // add Paeth predictor with
+ // Raw(x)
+
+ "cmpl _MMXLength, %%ecx \n\t"
+ "pxor %%mm0, %%mm0 \n\t" // pxor does not affect flags
+ "movq %%mm1, -8(%%edi,%%ecx,) \n\t" // write back updated value
+ // mm1 will be used as Raw(x-bpp) next loop
+ // mm3 ready to be used as Prior(x-bpp) next loop
+ "jb paeth_3lp \n\t"
+
+ : "=S" (dummy_value_S), // output regs (dummy)
+ "=D" (dummy_value_D)
+
+ : "0" (prev_row), // esi // input regs
+ "1" (row) // edi
+
+ : "%ecx" // clobber list
+#if 0 /* %mm0, ..., %mm7 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ , "%mm0", "%mm1", "%mm2", "%mm3"
+ , "%mm4", "%mm5", "%mm6", "%mm7"
+#endif
+ );
+ }
+ break; // end 3 bpp
+
+ case 6:
+ //case 7: // GRR BOGUS
+ //case 5: // GRR BOGUS
+ {
+ _ActiveMask.use = 0x00000000ffffffffLL;
+ _ActiveMask2.use = 0xffffffff00000000LL;
+ _ShiftBpp.use = bpp << 3; // == bpp * 8
+ _ShiftRem.use = 64 - _ShiftBpp.use;
+
+ __asm__ __volatile__ (
+ "movl _dif, %%ecx \n\t"
+// preload "movl row, %%edi \n\t"
+// preload "movl prev_row, %%esi \n\t"
+ // prime the pump: load the first Raw(x-bpp) data set
+ "movq -8(%%edi,%%ecx,), %%mm1 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+
+ "paeth_6lp: \n\t"
+ // must shift to position Raw(x-bpp) data
+ "psrlq _ShiftRem, %%mm1 \n\t"
+ // do first set of 4 bytes
+ "movq -8(%%esi,%%ecx,), %%mm3 \n\t" // read c=Prior(x-bpp) bytes
+ "punpcklbw %%mm0, %%mm1 \n\t" // unpack Low bytes of a
+ "movq (%%esi,%%ecx,), %%mm2 \n\t" // load b=Prior(x)
+ "punpcklbw %%mm0, %%mm2 \n\t" // unpack Low bytes of b
+ // must shift to position Prior(x-bpp) data
+ "psrlq _ShiftRem, %%mm3 \n\t"
+ // pav = p - a = (a + b - c) - a = b - c
+ "movq %%mm2, %%mm4 \n\t"
+ "punpcklbw %%mm0, %%mm3 \n\t" // unpack Low bytes of c
+ // pbv = p - b = (a + b - c) - b = a - c
+ "movq %%mm1, %%mm5 \n\t"
+ "psubw %%mm3, %%mm4 \n\t"
+ "pxor %%mm7, %%mm7 \n\t"
+ // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+ "movq %%mm4, %%mm6 \n\t"
+ "psubw %%mm3, %%mm5 \n\t"
+ // pa = abs(p-a) = abs(pav)
+ // pb = abs(p-b) = abs(pbv)
+ // pc = abs(p-c) = abs(pcv)
+ "pcmpgtw %%mm4, %%mm0 \n\t" // create mask pav bytes < 0
+ "paddw %%mm5, %%mm6 \n\t"
+ "pand %%mm4, %%mm0 \n\t" // only pav bytes < 0 in mm7
+ "pcmpgtw %%mm5, %%mm7 \n\t" // create mask pbv bytes < 0
+ "psubw %%mm0, %%mm4 \n\t"
+ "pand %%mm5, %%mm7 \n\t" // only pbv bytes < 0 in mm0
+ "psubw %%mm0, %%mm4 \n\t"
+ "psubw %%mm7, %%mm5 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ "pcmpgtw %%mm6, %%mm0 \n\t" // create mask pcv bytes < 0
+ "pand %%mm6, %%mm0 \n\t" // only pav bytes < 0 in mm7
+ "psubw %%mm7, %%mm5 \n\t"
+ "psubw %%mm0, %%mm6 \n\t"
+ // test pa <= pb
+ "movq %%mm4, %%mm7 \n\t"
+ "psubw %%mm0, %%mm6 \n\t"
+ "pcmpgtw %%mm5, %%mm7 \n\t" // pa > pb?
+ "movq %%mm7, %%mm0 \n\t"
+ // use mm7 mask to merge pa & pb
+ "pand %%mm7, %%mm5 \n\t"
+ // use mm0 mask copy to merge a & b
+ "pand %%mm0, %%mm2 \n\t"
+ "pandn %%mm4, %%mm7 \n\t"
+ "pandn %%mm1, %%mm0 \n\t"
+ "paddw %%mm5, %%mm7 \n\t"
+ "paddw %%mm2, %%mm0 \n\t"
+ // test ((pa <= pb)? pa:pb) <= pc
+ "pcmpgtw %%mm6, %%mm7 \n\t" // pab > pc?
+ "pxor %%mm1, %%mm1 \n\t"
+ "pand %%mm7, %%mm3 \n\t"
+ "pandn %%mm0, %%mm7 \n\t"
+ "paddw %%mm3, %%mm7 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ "packuswb %%mm1, %%mm7 \n\t"
+ "movq -8(%%esi,%%ecx,), %%mm3 \n\t" // load c=Prior(x-bpp)
+ "pand _ActiveMask, %%mm7 \n\t"
+ "psrlq _ShiftRem, %%mm3 \n\t"
+ "movq (%%esi,%%ecx,), %%mm2 \n\t" // load b=Prior(x) step 1
+ "paddb (%%edi,%%ecx,), %%mm7 \n\t" // add Paeth predictor and Raw(x)
+ "movq %%mm2, %%mm6 \n\t"
+ "movq %%mm7, (%%edi,%%ecx,) \n\t" // write back updated value
+ "movq -8(%%edi,%%ecx,), %%mm1 \n\t"
+ "psllq _ShiftBpp, %%mm6 \n\t"
+ "movq %%mm7, %%mm5 \n\t"
+ "psrlq _ShiftRem, %%mm1 \n\t"
+ "por %%mm6, %%mm3 \n\t"
+ "psllq _ShiftBpp, %%mm5 \n\t"
+ "punpckhbw %%mm0, %%mm3 \n\t" // unpack High bytes of c
+ "por %%mm5, %%mm1 \n\t"
+ // do second set of 4 bytes
+ "punpckhbw %%mm0, %%mm2 \n\t" // unpack High bytes of b
+ "punpckhbw %%mm0, %%mm1 \n\t" // unpack High bytes of a
+ // pav = p - a = (a + b - c) - a = b - c
+ "movq %%mm2, %%mm4 \n\t"
+ // pbv = p - b = (a + b - c) - b = a - c
+ "movq %%mm1, %%mm5 \n\t"
+ "psubw %%mm3, %%mm4 \n\t"
+ "pxor %%mm7, %%mm7 \n\t"
+ // pcv = p - c = (a + b - c) -c = (a - c) + (b - c) = pav + pbv
+ "movq %%mm4, %%mm6 \n\t"
+ "psubw %%mm3, %%mm5 \n\t"
+ // pa = abs(p-a) = abs(pav)
+ // pb = abs(p-b) = abs(pbv)
+ // pc = abs(p-c) = abs(pcv)
+ "pcmpgtw %%mm4, %%mm0 \n\t" // create mask pav bytes < 0
+ "paddw %%mm5, %%mm6 \n\t"
+ "pand %%mm4, %%mm0 \n\t" // only pav bytes < 0 in mm7
+ "pcmpgtw %%mm5, %%mm7 \n\t" // create mask pbv bytes < 0
+ "psubw %%mm0, %%mm4 \n\t"
+ "pand %%mm5, %%mm7 \n\t" // only pbv bytes < 0 in mm0
+ "psubw %%mm0, %%mm4 \n\t"
+ "psubw %%mm7, %%mm5 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ "pcmpgtw %%mm6, %%mm0 \n\t" // create mask pcv bytes < 0
+ "pand %%mm6, %%mm0 \n\t" // only pav bytes < 0 in mm7
+ "psubw %%mm7, %%mm5 \n\t"
+ "psubw %%mm0, %%mm6 \n\t"
+ // test pa <= pb
+ "movq %%mm4, %%mm7 \n\t"
+ "psubw %%mm0, %%mm6 \n\t"
+ "pcmpgtw %%mm5, %%mm7 \n\t" // pa > pb?
+ "movq %%mm7, %%mm0 \n\t"
+ // use mm7 mask to merge pa & pb
+ "pand %%mm7, %%mm5 \n\t"
+ // use mm0 mask copy to merge a & b
+ "pand %%mm0, %%mm2 \n\t"
+ "pandn %%mm4, %%mm7 \n\t"
+ "pandn %%mm1, %%mm0 \n\t"
+ "paddw %%mm5, %%mm7 \n\t"
+ "paddw %%mm2, %%mm0 \n\t"
+ // test ((pa <= pb)? pa:pb) <= pc
+ "pcmpgtw %%mm6, %%mm7 \n\t" // pab > pc?
+ "pxor %%mm1, %%mm1 \n\t"
+ "pand %%mm7, %%mm3 \n\t"
+ "pandn %%mm0, %%mm7 \n\t"
+ "pxor %%mm1, %%mm1 \n\t"
+ "paddw %%mm3, %%mm7 \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ // step ecx to next set of 8 bytes and repeat loop til done
+ "addl $8, %%ecx \n\t"
+ "packuswb %%mm7, %%mm1 \n\t"
+ "paddb -8(%%edi,%%ecx,), %%mm1 \n\t" // add Paeth predictor with Raw(x)
+ "cmpl _MMXLength, %%ecx \n\t"
+ "movq %%mm1, -8(%%edi,%%ecx,) \n\t" // write back updated value
+ // mm1 will be used as Raw(x-bpp) next loop
+ "jb paeth_6lp \n\t"
+
+ : "=S" (dummy_value_S), // output regs (dummy)
+ "=D" (dummy_value_D)
+
+ : "0" (prev_row), // esi // input regs
+ "1" (row) // edi
+
+ : "%ecx" // clobber list
+#if 0 /* %mm0, ..., %mm7 not supported by gcc 2.7.2.3 or egcs 1.1 */
+ , "%mm0", "%mm1", "%mm2", "%mm3"
+ , "%mm4", "%mm5", "%mm6", "%mm7"
+#endif
+ );
+ }
+ break; // end 6 bpp
+
+ case 4:
+ {
+ _ActiveMask.use = 0x00000000ffffffffLL;
+
+ __asm__ __volatile__ (
+ "movl _dif, %%ecx \n\t"
+// preload "movl row, %%edi \n\t"
+// preload "movl prev_row, %%esi \n\t"
+ "pxor %%mm0, %%mm0 \n\t"
+ // prime the pump: load the first Raw(x-bpp) data set
+ "movq -8(%%edi,%%ecx,), %%mm1 \n\t" // only time should need to read
+ // a=Raw(x-bpp) bytes
+ "paeth_4lp: \n\t"
+ // do first set of 4 bytes
+ "movq -8(%%esi,%%ecx,), %%mm3 \n\t" // read c=Prior(x-bpp) bytes