Imported from libpng-1.0.4c.tar

ANNOUNCE

@@ -0,0 +1,85 @@
+
+Libpng 1.0.4c - October 1, 1999
+
+This is not intended to be a public release.  It will be replaced
+within a few weeks by a public version or by another test version.
+
+Changes since the last public release (1.0.3):
+
+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 free'ing 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
+  Changed "hptr += 16L" to "hptr = hptr + 16L" in pngmem.c for Turbo 3.0
+  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)
+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.
+
+Send comments/corrections/commendations to
+png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu
+
+Glenn R-P

CHANGES

@@ -0,0 +1,460 @@
+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
+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
+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 free'ing 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)
+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.

INSTALL

@@ -0,0 +1,99 @@
+
+Installing libpng version 1.0.4c - October 1, 1999
+
+Before installing libpng, you must first install zlib.  zlib
+can usually be found wherever you got libpng.  zlib can be
+placed in another directory, at the same level as libpng.
+Note that your system might already have a preinstalled
+zlib, but you will still need to have access to the
+zlib.h and zconf.h include files that correspond to the
+version of zlib that's installed.
+
+You can rename the directories that you downloaded (they
+might be called "libpng-1.0.4c" or "lpng103" and "zlib-1.1.3"
+or "zlib113") so that you have directories called "zlib" and "libpng".
+
+Your directory structure should look like this:
+
+   ..       (the parent directory)
+      libpng  (this directory)
+          INSTALL (this file)
+          README
+          *.h
+          *.c
+          scripts
+             makefile.*
+          pngtest.png
+          etc.
+      zlib
+          README
+          *.h
+          *.c
+          contrib
+          etc.
+
+First enter the zlib directory and follow the instructions
+in zlib/README.  Then come back here and choose the
+appropriate makefile.sys in the scripts directory.
+The files that are presently available in the scripts directory
+include
+
+ descrip.mms      =>  VMS makefile for MMS or MMK
+ makefile.std     =>  Generic UNIX makefile
+ makefile.knr     =>  Archaic UNIX Makefile that converts files with
+                      ansi2knr (Requires ansi2knr.c from
+                      ftp://ftp.cs.wisc.edu/ghost)
+ makefile.dec     =>  DEC Alpha UNIX makefile
+ makefile.hpux    =>  HPUX (10.20 and 11.00) makefile
+ makefile.sgi     =>  Silicon Graphics IRIX makefile
+ makefile.sunos   =>  Sun makefile
+ makefile.solaris =>  Solaris 2.X makefile (gcc, creates libpng.so.2.1.0.4c)
+ makefile.linux   =>  Linux/ELF makefile (gcc, creates libpng.so.2.1.0.4c)
+ 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.borland =>  Borland makefile
+ build.bat        =>  MS-DOS batch file for Borland compiler
+ makefile.dj2     =>  DJGPP 2 makefile
+ makefile.msc     =>  Microsoft C makefile
+ makefile.vcawin32 => makefile for Microsoft Visual C++ 5.0 and later (uses
+                      assembler code)
+ makefile.vcwin32 =>  makefile for Microsoft Visual C++ 4.0 and later (does not
+                      use assembler code)
+ makefile.turboc3 =>  Turbo C 3.0 makefile
+ 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
+ pngdll.mak       =>  To make a png32bd.dll with Borland C++ 4.5
+ pngdef.pas       =>  Defines for a png32bd.dll with Borland C++ 4.5
+ SCOPTIONS.ppc    =>  Used with smakefile.ppc
+
+Copy the file (or files) that you need from the
+scripts directory into this directory, for example
+
+   MSDOS example: copy scripts\makefile.msd makefile
+   UNIX example:    cp scripts/makefile.std makefile
+
+Read the makefile to see if you need to change any source or
+target directories to match your preferences.
+
+Then read pngconf.h to see if you want to make any configuration
+changes.
+
+Then just run "make test" which will create the libpng library in
+this directory and run a quick test that reads the "pngtest.png"
+file and writes a "pngout.png" file that should be identical to it.
+
+Most of the makefiles will allow you to run "make install" to
+put the library in its final resting place (if you want to
+do that, run "make install" in the zlib directory first if necessary).
+
+Further information can be found in the README and libpng.txt
+files, in the individual makefiles, and in png.h, and the manual
+pages libpng.3 and png.5.

KNOWNBUG

@@ -0,0 +1,40 @@
+
+Known bugs and suggested enhancements in libpng-1.0.4
+
+
+1. March 15, 1998 -- OPTIMIZATION -- Kevin Bracey
+
+   Loops need to be optimized everywhere
+
+   Make them count down instead of up -- Kevin Bracey
+
+   Optimizing compilers don't need this, and making
+   the change would be error prone -- Tom Lane, Glenn R-P
+
+   Question whether i-- or --i is better.
+
+   STATUS: Under investigation, postponed until after
+   libpng-1.0.5.  About 160 loops will be turned around
+   in libpng-1.0.Nn, for testing.
+
+2. July 4, 1998 -- ENHANCEMENT -- Glenn R-P
+
+   libpng-1.0.5 and earlier transform colors to gamma=1.0 space for
+   merging with background, and then back to the image's gamma.  The
+   bit_depth of the intermediate (gamma=1.0) representation is probably
+   not sufficient.  In the typical gamma=1/2.2 situation, the linear
+   pixels need about 4 more bits than the gamma-encoded ones, to avoid
+   loss of precision.  A similar situation exists with the rgb_to_gray
+   operation.
+
+   STATUS: under development.
+
+3. September 1999 -- ENHANCEMENT --
+
+   It should be possible to use libpng without floating-point aritmetic.
+
+   STATUS: Under investigation, implementation postponed until after
+   libpng-1.0.5.  The application interface will change because replacements
+   for the png_set_gAMA(), png_set_cHRM(), and corresponding png_get_()
+   functions will be needed.
+

LICENSE

@@ -0,0 +1,59 @@
+COPYRIGHT NOTICE:
+
+Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+(libpng versions 0.5, May 1995, through 0.89c, May 1996)
+Copyright (c) 1996, 1997 Andreas Dilger
+(libpng versions 0.90, December 1996, through 0.96, May 1997)
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+(libpng versions 0.97, January 1998, through 1.0.4c, October 1, 1999)
+
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+
+   John Bowler
+   Kevin Bracey
+   Sam Bushell
+   Andreas Dilger
+   Magnus Holmgren
+   Tom Lane
+   Dave Martindale
+   Glenn Randers-Pehrson
+   Greg Roelofs
+   Guy Eric Schalnat
+   Paul Schmidt
+   Tom Tanner
+   Willem van Schaik
+   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.
+
+Glenn Randers-Pehrson
+randeg@alum.rpi.edu
+October 1, 1999

README

@@ -0,0 +1,207 @@
+README for libpng 1.0.4c - October 1, 1999 (shared library 2.1)
+See the note about version numbers near the top of png.h
+
+See INSTALL for instructions on how to install libpng.
+
+This is 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 for about two and a half years.  However, it's
+finally gotten to the stage where there haven't been significant
+changes to the API in some time, and people have a bad feeling about
+libraries with versions < 1.0.
+
+****
+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 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 implementation mailing list <png-implement@ccrc.wustl.edu>
+and not on material submitted to Guy.
+
+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.
+If not, it should be at ftp.uu.net in /graphics/png
+Eventually, it will be at ftp.uu.net in /pub/archiving/zip/zlib
+
+You may also want a copy of the PNG specification.  It is available
+as an RFC and a W3C Recommendation.  Failing
+these resources you can try ftp.uu.net in the /graphics/png directory.
+
+This code is currently being archived at ftp.uu.net in the
+/graphics/png directory, 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.
+
+randeg@alum.rpi.edu
+png-implement@ccrc.wustl.edu
+
+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 address in the specification (png-group@w3.org).  At the same
+time, please do not send libpng questions to that address, send them to me
+or to png-implement@ccrc.wustl.edu.  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 three 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 for version
+1.0, it may be used later.
+
+Files in this distribution:
+
+      CHANGES       =>  Description of changes between libpng versions
+      README        =>  This file
+      TODO          =>  Things not implemented in the current library
+      build.bat     =>  MS-DOS batch file for Borland compiler
+      descrip.mms   =>  VMS project file
+      example.c     =>  Example code for using libpng functions
+      libpng.3      =>  manual page for libpng
+      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
+      pngerror.c    =>  Error/warning message I/O functions
+      pngget.c      =>  Functions for retrieving info from struct
+      pngmem.c      =>  Memory handling functions
+      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
+      scripts       =>  Directory containing scripts for building libpng:
+       descrip.mms      =>  VMS makefile for MMS or MMK
+       makefile.std     =>  Generic UNIX makefile
+       makefile.knr     =>  Archaic UNIX Makefile that converts files with
+                            ansi2knr (Requires ansi2knr.c from
+                            ftp://ftp.cs.wisc.edu/ghost)
+       makefile.dec     =>  DEC Alpha UNIX makefile
+       makefile.hpux    =>  HPUX (10.20 and 11.00) makefile
+       makefile.sgi     =>  Silicon Graphics IRIX makefile
+       makefile.sunos   =>  Sun makefile
+       makefile.solaris =>  Solaris 2.X makefile
+                            (gcc, creates libpng.so.2.1.0.4c)
+       makefile.linux   =>  Linux/ELF makefile
+                            (gcc, creates libpng.so.2.1.0.4c)
+       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.borland =>  Borland makefile
+       build.bat        =>  MS-DOS batch file for Borland compiler
+       makefile.dj2     =>  DJGPP 2 makefile
+       makefile.msc     =>  Microsoft C makefile
+       makefile.vcawin32 => makefile for Microsoft Visual C++ 5.0 and
+                            later (uses assembler code)
+       makefile.vcwin32 =>  makefile for Microsoft Visual C++ 4.0 and
+                            later (does not use assembler code)
+       makefile.turboc3 =>  Turbo C 3.0 makefile
+       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
+       pngdll.mak       =>  To make a png32bd.dll with Borland C++ 4.5
+       pngdef.pas       =>  Defines for a png32bd.dll with Borland C++ 4.5
+       SCOPTIONS.ppc    =>  Used with smakefile.ppc
+
+Good luck, and happy coding.
+
+-Glenn Randers-Pehrson
+ Internet: randeg@alum.rpi.edu
+ Web: http://www.rpi.edu/~randeg/index.html
+
+-Andreas Eric Dilger
+ Internet: adilger@enel.ucalgary.ca
+ Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
+
+-Guy Eric Schalnat
+ (formerly of Group 42, Inc)
+ Internet: gschal@infinet.com

TODO

@@ -0,0 +1,24 @@
+TODO - list of things to do for libpng:
+
+Final bug fixes.
+Fix problem with C++ and EXTERN "C".
+Better C++ wrapper/full C++ implementation?
+Keep up with public chunks.
+sPLT chunk handling.
+cHRM transformation.
+Support for application-defined chunk handlers.
+Improve setjmp/longjmp usage or remove it in favor of returning error codes.
+High-level API for reading images.
+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?).
+Optional palette (sPLT) creation.
+Histogram creation.
+Text conversion between different code pages (Latin-1 -> Mac and DOS).
+Improve API by hiding the info_ptr.
+Make a no-floating-point version.

Y2KINFO

@@ -0,0 +1,55 @@
+   Y2K compliance in libpng:
+   =========================
+      
+      October 1, 1999
+      
+      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 1.0.4c 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

example.c

@@ -1,237 +1,356 @@
+
 /* 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, and therefore
-   does not require a copyright notice.
+/* 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, 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.
+ */
 
-   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.
-   */
+#include "png.h"
 
-#include <png.h>
-
-/* check to see if a file is a png file using png_check_sig() */
-int check_png(char *file_name)
+/* 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)
 {
-   FILE *fp;
-   char buf[8];
-   int ret;
+   char buf[PNG_BYTES_TO_CHECK];
 
-   fp = fopen(file_name, "rb");
-   if (!fp)
-      return 0;
-   ret = fread(buf, 1, 8, fp);
-   fclose(fp);
-
-   if (ret != 8)
+   /* Open the prospective PNG file. */
+   if ((*fp = fopen(file_name, "rb")) != NULL);
       return 0;
 
-   ret = png_check_sig(buf, 8);
+   /* Read in some of the signature bytes */
+   if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK)
+      return 0;
 
-   return (ret);
+   /* 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). */
-void read_png(char *file_name)
+/* 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;
-   png_struct *png_ptr;
-   png_info *info_ptr;
 
-   /* open the file */
-   fp = fopen(file_name, "rb");
-   if (!fp)
+   if ((fp = fopen(file_name, "rb")) == NULL)
       return;
+#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! */
 
-   /* allocate the necessary structures */
-   png_ptr = malloc(sizeof (png_struct));
-   if (!png_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 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;
    }
 
-   info_ptr = malloc(sizeof (png_info));
-   if (!info_ptr)
+   /* Allocate/initialize the memory for image information.  REQUIRED. */
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
    {
       fclose(fp);
-      free(png_ptr);
+      png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
       return;
    }
 
-   /* set error handling */
+   /* 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_ptr->jmpbuf))
    {
-      png_read_destroy(png_ptr, info_ptr, (png_info *)0);
+      /* 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);
-      free(png_ptr);
-      free(info_ptr);
       /* If we get here, we had a problem reading the file */
       return;
    }
 
-   /* initialize the structures, info first for error handling */
-   png_info_init(info_ptr);
-   png_read_init(png_ptr);
-
-   /* set up the input control for the default input and message functions.
-    * If we were to replace both the input and message functions we don't
-    * need to call png_init_io first. */
+   /* 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);
 
-   /* if you are using replacement read functions, here you would call */
-   io_ptr = (user_io_struct *)malloc(sizeof(user_io_struct));
-   png_set_read_fn(png_ptr, (void *)io_ptr, user_read_fn);
+#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 you are using replacement message functions, here you would call */
-   msg_ptr = (user_msg_struct *)malloc(sizeof(user_msg_struct));
-   png_set_read_fn(png_ptr, (void *)msg_ptr, user_error_fn, user_warning_fn);
+   /* If we have already read some of the signature */
+   png_set_sig_bytes(png_ptr, sig_read);
 
-   /* read the file information */
+   /* 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);
 
-   /* set up the transformations you want.  Note that these are
-      all optional.  Only call them if you want them */
+   png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+       &interlace_type, NULL, NULL);
 
-   /* expand paletted colors into true rgb */
-   if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+/**** 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_expand(png_ptr);
 
-   /* expand grayscale images to the full 8 bits */
-   if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
-      info_ptr->bit_depth < 8)
+   /* 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_expand(png_ptr);
 
-   /* expand images with transparency to full alpha channels */
-   if (info_ptr->valid & PNG_INFO_tRNS)
+   /* 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_expand(png_ptr);
 
-   /* Set the background color to draw transparent and alpha
-      images over */
-   png_color_16 my_background;
+   /* 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.
+    */
 
-   if (info_ptr->valid & PNG_INFO_bKGD)
-      png_set_background(png_ptr, &(info_ptr->background),
-         PNG_GAMMA_FILE, 1, 1.0);
+   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_GAMMA_SCREEN, 0, 1.0);
+                         PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
 
-   /* tell libpng to handle the gamma conversion for you */
-   if (info_ptr->valid & PNG_INFO_gAMA)
-      png_set_gamma(png_ptr, screen_gamma, info_ptr->gamma);
-   else
-      png_set_gamma(png_ptr, screen_gamma, 0.45);
+   /* Some suggestions as to how to get a screen gamma value */
 
-   /* tell libpng to strip 16 bit depth files down to 8 bits */
-   if (info_ptr->bit_depth == 16)
-      png_set_strip_16(png_ptr);
-
-   /* dither rgb files down to 8 bit palettes & reduce palettes
-      to the number of colors available on your screen */
-   if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+   /* 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 */)
    {
-      if (info_ptr->valid & PNG_INFO_PLTE)
-         png_set_dither(png_ptr, info_ptr->palette,
-            info_ptr->num_palette, max_screen_colors,
-               info_ptr->histogram);
+      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 second 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_sRGB(png_ptr, intent, 0);
+   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)
+   {
+      png_uint_32 num_palette;
+      png_colorp palette;
+
+      /* This reduces the image to the application supplied palette */
+      if (/* we have our own palette */)
       {
-         png_color std_color_cube[MAX_SCREEN_COLORS] =
-            {/* ... colors ... */};
+         /* 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, NULL);
+            MAX_SCREEN_COLORS, 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_color16p histogram;
+
+         png_get_hIST(png_ptr, info_ptr, &histogram);
+
+         png_set_dither(png_ptr, palette, num_palette,
+                        max_screen_colors, histogram, 0);
       }
    }
 
-   /* invert monocrome files */
-   if (info_ptr->bit_depth == 1 &&
-      info_ptr->color_type == PNG_COLOR_GRAY)
-      png_set_invert(png_ptr);
+   /* invert monocrome files to have 0 as white and 1 as black */
+   png_set_invert_mono(png_ptr);
 
-   /* shift the pixels down to their true bit depth */
-   if (info_ptr->valid & PNG_INFO_sBIT)
-      png_set_shift(png_ptr, &(info_ptr->sig_bit));
+   /* 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_color8p sig_bit;
 
-   /* pack pixels into bytes */
-   if (info_ptr->bit_depth < 8)
-      png_set_packing(png_ptr);
+      png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+      png_set_shift(png_ptr, sig_bit);
+   }
 
-   /* flip the rgb pixels to bgr */
-   if (info_ptr->color_type == PNG_COLOR_TYPE_RGB ||
-      info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
-      png_set_bgr(png_ptr);
+   /* flip the RGB pixels to BGR (or RGBA to BGRA) */
+   png_set_bgr(png_ptr);
 
-   /* swap bytes of 16 bit files to least significant bit first */
-   if (info_ptr->bit_depth == 16)
-      png_set_swap(png_ptr);
+   /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+   png_set_swap_alpha(png_ptr);
 
-   /* add a filler byte to rgb files */
-   if (info_ptr->bit_depth == 8 &&
-      info_ptr->color_type == PNG_COLOR_TYPE_RGB)
-      png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
+   /* swap bytes of 16 bit files to least significant byte first */
+   png_set_swap(png_ptr);
 
-   /* turn on interlace handling if you are not using png_read_image() */
-   if (info_ptr->interlace_type)
-      number_passes = png_set_interlace_handling(png_ptr);
-   else
-      number_passes = 1;
+   /* Add filler (or alpha) byte (before/after each RGB triplet) */
+   png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
 
-   /* optional call to update palette with transformations */
-   png_start_read_image(png_ptr);
+   /* 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 update the info structure */
+   /* 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 png_info. */
+   /* Allocate the memory to hold the image using the fields of info_ptr. */
 
-   /* the easiest way to read the image */
-   png_bytef *row_pointers[height];
+   /* The easiest way to read the image: */
+   png_bytep row_pointers[height];
+
+   for (row = 0; row < height; row++)
+   {
+      row_pointers[row] = malloc(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);
 
-   /* the other way to read images - deal with interlacing */
+#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++)
    {
-      /* Read the image using the "sparkle" effect. */
-      png_read_rows(png_ptr, row_pointers, NULL, number_of_rows);
-
-      /* If you are only reading on row at a time, this works */
+#ifdef single /* Read the image a single row at a time */
       for (y = 0; y < height; y++)
       {
-         png_bytef *row_pointers = row[y];
-         png_read_rows(png_ptr, &row_pointers, NULL, 1);
+         png_read_rows(png_ptr, &row_pointers[y], NULL, 1);
       }
 
-      /* to get the rectangle effect, use the third parameter */
-      png_read_rows(png_ptr, NULL, row_pointers, number_of_rows);
+#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], NULL, number_of_rows);
+
+         png_read_rows(png_ptr, NULL, row_pointers[y], number_of_rows);
+#else no_sparkle /* Read the image using the "rectangle" effect */
+         png_read_rows(png_ptr, 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 the rest of the file, getting any additional chunks
-      in info_ptr */
+   /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
    png_read_end(png_ptr, info_ptr);
 
-   /* if you had allocated any memory structures for custom input or
-      messaging routines you need to free them before png_read_destroy */
-   free(png_get_io_ptr(png_ptr));
-   free(png_get_msg_ptr(png_ptr));
-
-   /* clean up after the read, and free any memory allocated */
-   png_read_destroy(png_ptr, info_ptr, (png_info *)0);
-
-   /* free the structures */
-   free(png_ptr);
-   free(info_ptr);
+   /* 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);
@@ -240,115 +359,286 @@ void read_png(char *file_name)
    return;
 }
 
+/* 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_ptr)->jmpbuf))
+   {
+      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_ptr)->jmpbuf))
+   {
+      /* 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 interlacing, 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 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, 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 ...)
+void write_png(char *file_name /* , ... other image information ... */)
 {
    FILE *fp;
-   png_struct *png_ptr;
-   png_info *info_ptr;
+   png_structp png_ptr;
+   png_infop info_ptr;
 
    /* open the file */
    fp = fopen(file_name, "wb");
-   if (!fp)
+   if (fp == NULL)
       return;
 
-   /* allocate the necessary structures */
-   png_ptr = malloc(sizeof (png_struct));
-   if (!png_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 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;
    }
 
-   info_ptr = malloc(sizeof (png_info));
-   if (!info_ptr)
+   /* Allocate/initialize the image information data.  REQUIRED */
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
    {
       fclose(fp);
-      free(png_ptr);
+      png_destroy_write_struct(&png_ptr,  (png_infopp)NULL);
       return;
    }
 
-   /* set error handling */
+   /* Set error handling.  REQUIRED if you aren't supplying your own
+    * error hadnling functions in the png_create_write_struct() call.
+    */
    if (setjmp(png_ptr->jmpbuf))
    {
-      png_write_destroy(png_ptr);
-      fclose(fp);
-      free(png_ptr);
-      free(info_ptr);
       /* If we get here, we had a problem reading the file */
+      fclose(fp);
+      png_destroy_write_struct(&png_ptr,  (png_infopp)NULL);
       return;
    }
 
-   /* initialize the structures */
-   png_info_init(info_ptr);
-   png_write_init(png_ptr);
-
-   /* set up the output control for the default output and message functions.
-    * If we were to replace both the output and message functions we don't
-    * need to call png_init_io first. */
+   /* 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 */
 
-   /* if you are using replacement write functions, here you would call */
-   io_ptr = (user_io_struct *)malloc(sizeof(user_io_struct));
-   png_set_write_fn(png_ptr, (void *)io_ptr, user_write_fn, user_flush_fn);
+   /* 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);
 
-   /* if you are using replacement message functions, here you would call */
-   msg_ptr = (user_msg_struct *)malloc(sizeof(user_msg_struct));
-   png_set_read_fn(png_ptr, (void *)msg_ptr, user_error_fn, user_warning_fn);
-
-   /* set the file information here */
-   info_ptr->width = ;
-   info_ptr->height = ;
-   etc.
-
-   /* set the palette if there is one */
-   info_ptr->valid |= PNG_INFO_PLTE;
-   info_ptr->palette = malloc(256 * sizeof (png_color));
-   info_ptr->num_palette = 256;
-   ... set palette colors ...
+   /* set the palette if there is one.  REQUIRED for indexed-color images */
+   palette = (png_colorp)png_malloc(png_ptr, 256 * sizeof (png_color));
+   /* ... set palette colors ... */
+   png_set_PLTE(png_ptr, info_ptr, palette, 256);
 
    /* optional significant bit chunk */
-   info_ptr->valid |= PNG_INFO_sBIT;
    /* if we are dealing with a grayscale image then */
-   info_ptr->sig_bit.gray = true_bit_depth;
+   sig_bit.gray = true_bit_depth;
    /* otherwise, if we are dealing with a color image then */
-   info_ptr->sig_bit.red = true_red_bit_depth;
-   info_ptr->sig_bit.green = true_green_bit_depth;
-   info_ptr->sig_bit.blue = true_blue_bit_depth;
+   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 */
-   info_ptr->sig_bit.alpha = true_alpha_bit_depth;
+   sig_bit.alpha = true_alpha_bit_depth;
+   png_set_sBIT(png_ptr, info_ptr, sig_bit);
 
-   /* optional gamma chunk is a good idea if you can write one */
-   info_ptr->valid |= PNG_INFO_gAMA;
-   info_ptr->gamma = gamma;
 
-   /* other optional chunks */
+   /* 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);
 
-   /* write the file information */
+   /* 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;
+   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 cHRM chunk 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);
 
+   /* 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 */
+    * all optional.  Only call them if you want them.
+    */
 
    /* invert monocrome pixels */
-   png_set_invert(png_ptr);
+   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, &(info_ptr->sig_bit));
+   /* 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);
 
-   /* flip bgr pixels to rgb */
+   /* 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 bit first */
+   /* swap bytes of 16-bit files to most significant byte first */
    png_set_swap(png_ptr);
 
-   /* get rid of filler bytes, pack rgb into 3 bytes.  The
-      filler number is not used. */
-   png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+   /* 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)
@@ -356,43 +646,53 @@ void write_png(char *file_name, ... other image information ...)
    else
       number_passes = 1;
 
-   /* the easiest way to write the image */
-   png_bytef *row_pointers[height];
+   /* 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];
+   png_bytep row_pointers[height];
+   for (k = 0; k < height; k++)
+     row_pointers[k] = image + k*width;
+
+   /* 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, number_of_rows);
+      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_bytef *row_pointers = row[y];
-         png_write_rows(png_ptr, &row_pointers, 1);
+         png_write_rows(png_ptr, &row_pointers[y], 1);
       }
    }
+#endif no_entire /* use only one output method */
 
-   /* write the rest of the file */
+   /* You can write optional chunks like tEXt, zTXt, and tIME at the end
+    * as well.
+    */
+
+   /* It is REQUIRED to call this to finish writing the rest of the file */
    png_write_end(png_ptr, info_ptr);
 
-   /* if you had allocated any memory structures for custom output or
-      messaging routines you need to free them before png_write_destroy */
-   free(png_get_io_ptr(png_ptr));
-   free(png_get_msg_ptr(png_ptr));
+   /* if you malloced the palette, free it here */
+   free(info_ptr->palette);
+
+   /* if you allocated any text comments, free them here */
 
    /* clean up after the write, and free any memory allocated */
-   png_write_destroy(png_ptr);
-
-   /* if you malloced the palette, free it here */
-   if (info_ptr->palette)
-      free(info_ptr->palette);
-
-   /* free the structures */
-   free(png_ptr);
-   free(info_ptr);
+   png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
 
    /* close the file */
    fclose(fp);

libpngpf.3

@@ -0,0 +1,505 @@
+.TH LIBPNGPF 3 October 1, 1999
+.SH NAME
+libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1, 1999
+(private functions)
+.SH SYNOPSIS
+\fB#include <png.h>\fP
+
+\fI\fB
+
+\fBvoid png_build_gamma_table (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_build_grayscale_palette (int \fP\fIbit_depth\fP\fB, png_colorp \fIpalette\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_calculate_crc (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIptr\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_check_chunk_name (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_size_t png_check_keyword (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIkey\fP\fB, png_charpp \fInew_key\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIrow\fP\fB, int \fImask\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_correct_palette (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fInum_palette\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_crc_error (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_crc_finish (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIskip\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_crc_read (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuf\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_create_struct (int \fP\fItype\fP\fB, png_malloc_ptr \fImalloc_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_voidp png_create_struct_2 (int \fItype\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_destroy_struct (png_voidp \fIstruct_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_destroy_struct_2 (png_voidp \fP\fIstruct_ptr\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_background (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_16p \fP\fItrans_values\fP\fB, png_color_16p \fP\fIbackground\fP\fB, png_color_16p \fP\fIbackground_1\fP\fB, png_bytep \fP\fIgamma_table\fP\fB, png_bytep \fP\fIgamma_from_1\fP\fB, png_bytep \fP\fIgamma_to_1\fP\fB, png_uint_16pp \fP\fIgamma_16\fP\fB, png_uint_16pp \fP\fIgamma_16_from_1\fP\fB, png_uint_16pp \fP\fIgamma_16_to_1\fP\fB, int \fIgamma_shift\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_bgr (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_chop (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_dither (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fP\fIpalette_lookup\fP\fB, png_bytep \fIdither_lookup\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_expand (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_16p \fItrans_value\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_expand_palette (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_colorp \fP\fIpalette\fP\fB, png_bytep \fP\fItrans\fP\fB, int \fInum_trans\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_gamma (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fP\fIgamma_table\fP\fB, png_uint_16pp \fP\fIgamma_16_table\fP\fB, int \fIgamma_shift\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_gray_to_rgb (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_invert (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_pack (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_uint_32 \fIbit_depth\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_packswap (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_read_filler (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, png_uint_32 \fIflags\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_read_interlace (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, int \fP\fIpass\fP\fB, png_uint_32 \fItransformations\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_read_invert_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_read_swap_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_read_transformations (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBint png_do_rgb_to_gray (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_shift (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_8p \fIbit_depth\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_strip_filler (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_uint_32 \fIflags\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_swap (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_unpack (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_unshift (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_8p \fIsig_bits\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_write_interlace (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, int \fIpass\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_write_invert_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_write_swap_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_do_write_transformations (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid *png_far_to_near (png_structp png_ptr,png_voidp \fP\fIptr\fP\fB, int \fIcheck\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_flush (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_int_32 png_get_int_32 (png_bytep \fIbuf\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_16 png_get_uint_16 (png_bytep \fIbuf\fP\fB);\fP
+
+\fI\fB
+
+\fBpng_uint_32 png_get_uint_32 (png_bytep \fIbuf\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_IEND (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_info_destroy (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_init_read_transformations (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_process_IDAT_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_length\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_process_some_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_check_crc (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_crc_finish (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_crc_skip (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_fill_buffer (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_handle_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_handle_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_handle_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_have_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_have_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_have_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_process_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_IDAT (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_sig (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_restore_buffer (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_length\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_save_buffer (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_filter_row (png_structp \fP\fIpng_ptr\fP\fB, png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fP\fIprev_row\fP\fB, int \fIfilter\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_finish_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_init (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_push_finish_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_start_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_transform_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_reset_crc (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_save_int_32 (png_bytep \fP\fIbuf\fP\fB, png_int_32 \fIi\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_save_uint_16 (png_bytep \fP\fIbuf\fP\fB, unsigned int \fIi\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_save_uint_32 (png_bytep \fP\fIbuf\fP\fB, png_uint_32 \fIi\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIvalues\fP\fB, int \fIcolor_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_cHRM (png_structp \fP\fIpng_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fBvoid png_write_filtered_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIfiltered_row\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_find_filter (png_structp \fP\fIpng_ptr\fP\fB, png_row_infop \fIrow_info\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_finish_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_gAMA (png_structp \fP\fIpng_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_uint_16p \fP\fIhist\fP\fB, int \fInum_hist\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_init (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_IDAT (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_IEND (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIwidth\fP\fB, png_uint_32 \fP\fIheight\fP\fB, int \fP\fIbit_depth\fP\fB, int \fP\fIcolor_type\fP\fB, int \fP\fIcompression_type\fP\fB, int \fP\fIfilter_type\fP\fB, int \fIinterlace_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIx_offset\fP\fB, png_uint_32 \fP\fIy_offset\fP\fB, int \fIunit_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIpurpose\fP\fB, png_int_32 \fP\fIX0\fP\fB, png_int_32 \fP\fIX1\fP\fB, int \fP\fItype\fP\fB, int \fP\fInparams\fP\fB, png_charp \fP\fIunits\fP\fB, png_charpp \fIparams\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIx_pixels_per_unit\fP\fB, png_uint_32 \fP\fIy_pixels_per_unit\fP\fB, int \fIunit_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, png_uint_32 \fInum_pal\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fP\fIsbit\fP\fB, int \fIcolor_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_sig (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_sRGB (png_structp \fP\fIpng_ptr\fP\fB, int \fIintent\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_start_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIkey\fP\fB, png_charp \fP\fItext\fP\fB, png_size_t \fItext_len\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fItrans\fP\fB, png_color_16p \fP\fIvalues\fP\fB, int \fP\fInumber\fP\fB, int \fIcolor_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIkey\fP\fB, png_charp \fP\fItext\fP\fB, png_size_t \fP\fItext_len\fP\fB, int \fIcompression\fP\fB);\fP
+
+\fI\fB
+
+\fBvoidpf png_zalloc (voidpf \fP\fIpng_ptr\fP\fB, uInt \fP\fIitems\fP\fB, uInt \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_zfree (voidpf \fP\fIpng_ptr\fP\fB, voidpf \fIptr\fP\fB);\fP
+
+\fI\fB
+
+.SH DESCRIPTION
+The functions listed above are used privately by libpng
+and are not recommended for use by applications.  They
+are listed alphabetically here as an aid to libpng maintainers.
+See png.h for more information on these functions.
+
+.SH SEE ALSO
+libpng(3), png(5)
+.SH AUTHOR
+Glenn Randers-Pehrson

lpfaq.txt

@@ -1,190 +0,0 @@
-libpng FAQ - August 20, 1995
-
-Maintainer:
-
-Guy Eric Schalnat: schalnat@group42.com  CompuServe: 75501,1625
-
-
-Contents:
-
-1) General Questions
-1.1) How official is this FAQ?
-1.2) How often is this FAQ posted?
-1.3) Where can I get this FAQ, libpng, zlib, the PNG
-     specification, test images, etc.?
-1.4) How ready is libpng?
-1.5) How portable is libpng?
-1.6) When will libpng be out of Beta?
-1.7) What remains to be done in libpng for the 1.0 release?
-1.8) Can I help?
-1.9) Why don't you answer your mail?
-
-2) Libpng questions
-2.1) Does the order of functions calls matter?
-2.2) When I try to read/write a png image, it doesn't work.
-2.3) Do I have to start with example.c?
-2.4) What things should I be careful of?
-2.5) Why doesn't example.c compile?
-
-3) Critical Patches
-No known bugs (for now :-).
-
-4) Non-critical patches
-No known bugs (for now :-).
-
-
-Questions:
-
-1) General Questions
-
-1.1) How official is this FAQ?
-
-As it was written by the author of libpng (that's me :), it's
-about offical as one can get.  However, it is not ready for
-prime time yet, as libpng is still in beta, and thus its
-users are of the sort that are willing to deal with beta
-software.  Thus, I assume all of you reading this have a
-basic familiarity with PNG, libpng, and C programming.  I'll
-write a basic section for libpng later, as well as some quick
-stuff on PNG itself (but this will not be the PNG FAQ.  I just
-don't have that kind of time).
-
-1.2) How often is this FAQ posted?
-
-As often as events warrant.  I doubt it'll get stale, and as
-it is not (and may never be) actually posted to a newsgroup,
-I feel no need to make monthy postings.
-
-1.3) Where can I get this FAQ, libpng, zlib, the PNG 
-specification, test images, etc.?
-
-Everything should be at ftp://ftp.uu.net/graphics/png and
-mirror sites.  On CompuServe, it should be at GO GRAPHSUPPORT
-in the Png Development library (lib 20).  Failing that, try
-my ftp site at ftp://ftp.group42.com/pub/png or web site at
-http://www.group42.com/  If you have trouble getting to these,
-the numerical address is 204.94.158.25
-
-1.4) How ready is libpng?
-
-In its current incarnation (0.8), it still may have a few bugs.
-I think I got all of the bugs this time, but one never knows.
-Also, the dithering currently in libpng is horrid, so that
-needs work.  Finally, I have yet to implement medium model
-support.
-
-1.5) How portable is libpng?
-
-As portable as I can make it.  It needs int's of at least
-16 bits, and longs of at least 32 bits.  It has not been
-tried for char's larger then 8 bits.  It should support
-any reasonable K&R C compiler, as well as any ANSI C
-compiler.  The most you should need to do is change the
-includes in pngconf.h.  So far, I know of no compiler in use
-that libpng will not compile on.
-
-1.6) When will libpng be out of Beta?
-
-That depends on my workload here.  I'm writing libpng for
-free, which generates tons of good will, but doesn't help
-put food on the table, so there are times I just can't do
-any real work on it.  There is still some work to be done
-(see question 1.7), so don't expect the official version
-before September (and that may be pushing it).  I'll try
-to get the next (last?) beta version out my early
-September.  Be warned, I always seem to take twice as
-long as I think I will.
-
-1.7) What remains to be done in libpng for the 1.0 release?
-
-Add Tim Wegner's medium memory model support. (Thanks, Tim).
-Improve the dithering.
-Rewrite libpng.txt, and comment the code better.
-Test with a final zlib.
-
-1.8) Can I help?
-
-Sweet words.  The most helpful thing you can do for the
-1.0 release is help testing on your compiler.  After this
-release, though, there is a large list of things that ought
-to be done to make libpng be more full featured.  We'll
-talk about this later, as I don't want to add tons of new
-code until after 1.0 gets out the door.  Please send me
-any makefile changes and/or other changes needed to support
-your compiler (with a #ifdef for the code changes).
-
-If any of you are good at technical writing, take a look at
-libpng.txt and correct it (or rewrite it) as necessary.  I
-am not a writer, I'm a programmer.  It shows.
-
-1.9) Why don't you answer your mail?
-
-I've been busy.  I'm sorry about that, and I've got to get
-into the habit of at least replying that I got the message.
-Also, some of you have sent me problems that I haven't gotten
-back to you yet.  If it is still a problem, you may want to
-give me a short message and remind me that I need to look into
-it.  Libpng is being tested by more people than I dared hope
-(which is a good thing), and I was unprepared to deal with so
-many problems so soon.
-
-
-2) Libpng questions
-
-2.1) Does the order of functions calls matter?
-
-In general, yes.  If you stick with the order I used in libpng.txt
-and example.c, you should be safe.  Be warned, however, that I
-messed up the order of png_set_interlace_handling().  It needs
-to be called *before* png_start_read_image(), not after.  Oops.
-The exceptions to this rule are all the png_set ... calls.
-They can be done in any order, but they all have to be done
-in the area indicated by libpng.txt/example.c.
-
-2.2) When I try to read/write a png image, it doesn't work.
-
-Does zlib's test program work (example.c)?  Does libpng's test
-program work (testpng.c)?  Have you installed the patches at
-the end of this FAQ?  After all that, if the problem continues,
-e-mail me, and we'll try to fix it.  If you don't have much 
-programming experience, be patient about the fix.  Code
-fragments help, as do *small* images (uuencoded please).  If
-I don't get back to you right away, give me some time.  Thanks.
-
-2.3) Do I have to start with example.c?
-
-No, but most people have had much better luck doing that.  Seems
-I didn't explain things well in libpng.txt, so things are not
-intuitive to people (which could be an api design problem also).
-Sometime in the future, we'll revisit the api design, and try
-to make it easier to use.  I'll rewrite libpng.txt before the
-1.0 release.
-
-2.4) What things should I be careful of?
-
-The main gotcha is calling png_read_init() before png_info_init().
-Also, always make sure you have a correct setjmp buffer.  That's
-all I can think of for now.
-
-2.5) Why doesn't example.c compile?
-
-I wrote example.c as a staring point for using libpng.  It doesn't
-compile because I don't know how you want to do things like allocating
-memory to hold the image, so I left that code out.  If you go in and
-finish it up, it should work fine.  The file pngtest.c gives a
-very simple example of reading and writing png files.
-
-
-3) Critical Patches
-
-No known bugs (for now :-).
-
-
-4) Non-critical patches
-
-No known bugs (for now :-).
-
-
-That's it so far as I know.  If I missed something, yell.
-
--Guy

png.5

@@ -0,0 +1,58 @@
+.TH PNG 5 "October 1, 1999"
+.SH NAME
+png \- Portable Network Graphics (PNG) format
+.SH DESCRIPTION
+PNG (Portable Network Graphics) is an extensible file format for the
+lossless, portable, well-compressed storage of raster images. PNG provides
+a patent-free replacement for GIF and can also replace many
+common uses of TIFF. Indexed-color, grayscale, and truecolor images are
+supported, plus an optional alpha channel. Sample depths range from
+1 to 16 bits.
+.br
+
+PNG is designed to work well in online viewing applications, such as the
+World Wide Web, so it is fully streamable with a progressive display
+option. PNG is robust, providing both full file integrity checking and
+fast, simple detection of common transmission errors. Also, PNG can store
+gamma and chromaticity data for improved color matching on heterogeneous
+platforms.
+
+.SH "SEE ALSO"
+.IR libpng(3), zlib(3), deflate(5), and zlib(5)
+.LP
+PNG 1.1 specification, January 1999:
+.IP
+.br
+http://www.cdrom.com/pub/png
+.LP
+PNG 1.0 specification, October 1996:
+.IP
+.br
+RFC 2083
+.IP
+.br
+ftp://ds.internic.net/rfc/rfc2083.txt
+.br
+or (as a W3C Recommendation) at
+.br
+http://www.w3.org/TR/REC-png.html
+.SH AUTHORS
+This man page: Glenn Randers-Pehrson
+.LP
+Portable Network Graphics (PNG) Specification Version 1.2 (July 8, 1999):
+Glenn Randers-Pehrson and others (png-list@ccrc.wustl.edu).
+.LP
+Portable Network Graphics (PNG) Specification Version 1.0 (October 1, 1996):
+Thomas Boutell and others (png-list@ccrc.wustl.edu).
+.LP
+
+
+.SH COPYRIGHT NOTICE
+The PNG-1.2 specification is copyright (c) 1999 Glenn Randers-Pehrson.
+See the specification for conditions of use and distribution.
+.LP
+The PNG-1.0 specification is copyright (c) 1996 Massachussets Institute of
+Technology.  See the specification for conditions of use and distribution.
+.LP
+.\" end of man page
+

png.c

@@ -1,203 +1,368 @@
 
-/* png.c - location for general purpose png functions
-
-   libpng 1.0 beta 2 - version 0.81
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
-   August 24, 1995
-   */
+/* png.c - location for general purpose libpng functions
+ *
+ * libpng version 1.0.4c - October 1, 1999
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ * 
+ */
 
 #define PNG_INTERNAL
 #define PNG_NO_EXTERN
 #include "png.h"
 
-/* version information for c files.  This better match the version
-   string defined in png.h */
-char png_libpng_ver[] = "0.81";
+/* Version information for C files.  This had better match the version
+ * string defined in png.h.
+ */
 
-/* place to hold the signiture string for a png file. */
-png_byte png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+char png_libpng_ver[12] = "1.0.4c";
 
-/* constant strings for known chunk types.  If you need to add a chunk,
-   add a string holding the name here.  If you want to make the code
-   portable to EBCDIC machines, use ASCII numbers, not characters. */
-png_byte png_IHDR[4] = { 73,  72,  68,  82};
-png_byte png_IDAT[4] = { 73,  68,  65,  84};
-png_byte png_IEND[4] = { 73,  69,  78,  68};
-png_byte png_PLTE[4] = { 80,  76,  84,  69};
-#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
-png_byte png_gAMA[4] = {103,  65,  77,  65};
-#endif
-#if defined(PNG_READ_sBIT_SUPPORTED) || defined(PNG_WRITE_sBIT_SUPPORTED)
-png_byte png_sBIT[4] = {115,  66,  73,  84};
-#endif
-#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED)
-png_byte png_cHRM[4] = { 99,  72,  82,  77};
-#endif
-#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED)
-png_byte png_tRNS[4] = {116,  82,  78,  83};
-#endif
-#if defined(PNG_READ_bKGD_SUPPORTED) || defined(PNG_WRITE_bKGD_SUPPORTED)
-png_byte png_bKGD[4] = { 98,  75,  71,  68};
-#endif
-#if defined(PNG_READ_hIST_SUPPORTED) || defined(PNG_WRITE_hIST_SUPPORTED)
-png_byte png_hIST[4] = {104,  73,  83,  84};
-#endif
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED)
-png_byte png_tEXt[4] = {116,  69,  88, 116};
-#endif
-#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
-png_byte png_zTXt[4] = {122,  84,  88, 116};
-#endif
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
-png_byte png_pHYs[4] = {112,  72,  89, 115};
-#endif
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
-png_byte png_oFFs[4] = {111,  70,  70, 115};
-#endif
-#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED)
-png_byte png_tIME[4] = {116,  73,  77,  69};
-#endif
+/* Place to hold the signature string for a PNG file. */
+png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+/* Constant strings for known chunk types.  If you need to add a chunk,
+ * add a string holding the name here.  If you want to make the code
+ * portable to EBCDIC machines, use ASCII numbers, not characters.
+ */
+png_byte FARDATA png_IHDR[5] = { 73,  72,  68,  82, '\0'};
+png_byte FARDATA png_IDAT[5] = { 73,  68,  65,  84, '\0'};
+png_byte FARDATA png_IEND[5] = { 73,  69,  78,  68, '\0'};
+png_byte FARDATA png_PLTE[5] = { 80,  76,  84,  69, '\0'};
+png_byte FARDATA png_bKGD[5] = { 98,  75,  71,  68, '\0'};
+png_byte FARDATA png_cHRM[5] = { 99,  72,  82,  77, '\0'};
+png_byte FARDATA png_gAMA[5] = {103,  65,  77,  65, '\0'};
+png_byte FARDATA png_hIST[5] = {104,  73,  83,  84, '\0'};
+png_byte FARDATA png_oFFs[5] = {111,  70,  70, 115, '\0'};
+png_byte FARDATA png_pCAL[5] = {112,  67,  65,  76, '\0'};
+png_byte FARDATA png_pHYs[5] = {112,  72,  89, 115, '\0'};
+png_byte FARDATA png_sBIT[5] = {115,  66,  73,  84, '\0'};
+png_byte FARDATA png_sRGB[5] = {115,  82,  71,  66, '\0'};
+png_byte FARDATA png_tEXt[5] = {116,  69,  88, 116, '\0'};
+png_byte FARDATA png_tIME[5] = {116,  73,  77,  69, '\0'};
+png_byte FARDATA png_tRNS[5] = {116,  82,  78,  83, '\0'};
+png_byte FARDATA png_zTXt[5] = {122,  84,  88, 116, '\0'};
 
 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
 /* start of interlace block */
-int png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
 
 /* offset to next interlace block */
-int png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
 
 /* start of interlace block in the y direction */
-int png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
 
 /* offset to next interlace block in the y direction */
-int png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
 
-/* width of interlace block */
-/* this is not currently used - if you need it, uncomment it here and
-   in png.h
-int png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
+/* Width of interlace block.  This is not currently used - if you need
+ * it, uncomment it here and in png.h
+int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
 */
 
-/* height of interlace block */
-/* this is not currently used - if you need it, uncomment it here and
-   in png.h
-int png_pass_height[] = {8, 8, 4, 4, 4, 2, 2, 1};
+/* Height of interlace block.  This is not currently used - if you need
+ * it, uncomment it here and in png.h
+int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
 */
 
-/* mask to determine which pixels are valid in a pass */
-int png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
+/* Mask to determine which pixels are valid in a pass */
+int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
 
-/* mask to determine which pixels to overwrite while displaying */
-int png_pass_dsp_mask[] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
+/* Mask to determine which pixels to overwrite while displaying */
+int FARDATA png_pass_dsp_mask[] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
 
+/* 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.
+ */
 
-int
-png_check_sig(png_byte *sig, int num)
+void
+png_set_sig_bytes(png_structp png_ptr, int num_bytes)
 {
-   if (num > 8)
-      num = 8;
-   if (num < 1)
-      return 0;
+   png_debug(1, "in png_set_sig_bytes\n");
+   if (num_bytes > 8)
+      png_error(png_ptr, "Too many bytes for PNG signature.");
 
-   return (!memcmp(sig, png_sig, num));
+   png_ptr->sig_bytes = 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
+png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
+{
+   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_sig[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
+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. */
 voidpf
 png_zalloc(voidpf png_ptr, uInt items, uInt size)
 {
-   return ((voidpf)png_large_malloc((png_struct FAR *)png_ptr,
-      (png_uint_32)items * (png_uint_32)size));
+   png_uint_32 num_bytes = (png_uint_32)items * size;
+   png_voidp ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
+
+   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);
+   }
+   return ((voidpf)ptr);
 }
 
 /* function to free memory for zlib */
 void
 png_zfree(voidpf png_ptr, voidpf ptr)
 {
-   png_large_free((png_struct FAR *)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 */
+/* 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
-png_reset_crc(png_struct *png_ptr)
+png_reset_crc(png_structp png_ptr)
 {
-   /* set crc to all 1's */
-   png_ptr->crc = 0xffffffffL;
+   png_ptr->crc = crc32(0, Z_NULL, 0);
 }
 
-/* Note: the crc code below was copied from the sample code in the
-   PNG spec, with appropriate modifications made to ensure the
-   variables are large enough */
-
-/* table of crc's of all 8-bit messages.  If you wish to png_malloc this
-   table, turn this into a pointer, and png_malloc it in make_crc_table().
-   You may then want to hook it into png_struct and free it with the
-   destroy functions. */
-static png_uint_32 crc_table[256];
-
-/* Flag: has the table been computed? Initially false. */
-static int crc_table_computed = 0;
-
-/* make the table for a fast crc */
-static void
-make_crc_table(void)
-{
-  png_uint_32 c;
-  int n, k;
-
-  for (n = 0; n < 256; n++)
-  {
-   c = (png_uint_32)n;
-   for (k = 0; k < 8; k++)
-     c = c & 1 ? 0xedb88320L ^ (c >> 1) : c >> 1;
-   crc_table[n] = c;
-  }
-  crc_table_computed = 1;
-}
-
-/* update a running crc with the bytes buf[0..len-1]--the crc should be
-   initialized to all 1's, and the transmitted value is the 1's complement
-   of the final running crc. */
-static png_uint_32
-update_crc(png_uint_32 crc, png_bytef *buf, png_uint_32 len)
-{
-  png_uint_32 c;
-  png_bytef *p;
-  png_uint_32 n;
-
-  c = crc;
-  p = buf;
-  n = len;
-
-  if (!crc_table_computed)
-  {
-   make_crc_table();
-  }
-
-  if (n > 0) do
-  {
-   c = crc_table[(png_byte)((c ^ (*p++)) & 0xff)] ^ (c >> 8);
-  } while (--n);
-
-  return c;
-}
-
-/* calculate the crc over a section of data.  Note that while we
-   are passing in a 32 bit value for length, on 16 bit machines, you
-   would need to use huge pointers to access all that data.  If you
-   need this, put huge here and above. */
+/* 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
-png_calculate_crc(png_struct *png_ptr, png_bytef *ptr,
-   png_uint_32 length)
+png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
 {
-   png_ptr->crc = update_crc(png_ptr->crc, ptr, 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);
 }
-void
-png_info_init(png_info *info)
+
+/* 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(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
+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
+   if ((info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
+      png_ptr->malloc_fn)) != NULL)
+#else
+   if ((info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO)) != NULL)
+#endif
+   {
+      png_info_init(info_ptr);
+   }
+
+   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
+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);
+#else
+      png_destroy_struct((png_voidp)info_ptr);
+#endif
+      *info_ptr_ptr = (png_infop)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.
+ */
+void
+png_info_init(png_infop info_ptr)
+{
+   png_debug(1, "in png_info_init\n");
    /* set everything to 0 */
-   memset(info, 0, sizeof (png_info));
+   png_memset(info_ptr, 0, sizeof (png_info));
 }
 
+/* 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
+png_info_destroy(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
+   png_debug(1, "in png_info_destroy\n");
+   if (info_ptr->text != NULL)
+   {
+      int i;
+      for (i = 0; i < info_ptr->num_text; i++)
+      {
+         png_free(png_ptr, info_ptr->text[i].key);
+      }
+      png_free(png_ptr, info_ptr->text);
+   }
+#endif
+#if defined(PNG_READ_pCAL_SUPPORTED)
+   png_free(png_ptr, info_ptr->pcal_purpose);
+   png_free(png_ptr, info_ptr->pcal_units);
+   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]);
+      }
+      png_free(png_ptr, info_ptr->pcal_params);
+   }
+#endif
+
+   png_info_init(info_ptr);
+}
+
+/* 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
+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().
+ */
+void
+png_init_io(png_structp png_ptr, FILE *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
+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*
+         sizeof(char)));
+   }
+
+#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*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
+   return ((png_charp)png_ptr->time_buffer);
+}
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+
+png_charp
+png_get_copyright(png_structp png_ptr)
+{
+   if(png_ptr == NULL)
+     /* silence compiler warning about unused png_ptr */ ;
+   return("\n libpng version 1.0.4c - October 1, 1999\n\
+   Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.\n\
+   Copyright (c) 1996, 1997 Andreas Dilger\n\
+   Copyright (c) 1998, 1999 Glenn Randers-Pehrson\n");
+}
+
+/* Generate a compiler error if there is an old png.h in the search path. */
+void
+png_check_version
+   (version_1_0_4c png_h_is_not_version_1_0_4c)
+{
+   if(png_h_is_not_version_1_0_4c == NULL)
+     /* silence compiler warning about unused parameter */ ;
+}

pngasmrd.h

@@ -0,0 +1,32 @@
+/* pngasmrd.h - assembler version of utilities to read a PNG file
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1999 Glenn Randers-Pehrson
+ *
+ */
+
+#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
+
+/* Set this in the makefile for VC++ on Pentium, not in pngconf.h */
+#ifdef PNG_USE_PNGVCRD
+/* Platform must be Pentium.  Makefile must assemble and load pngvcrd.c .
+ * MMX will be detected at run time and used if present.
+ */
+#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 on Pentium, not in pngconf.h */
+#ifdef PNG_USE_PNGGCCRD
+/* Platform must be Pentium.  Makefile must assemble and load pnggccrd.c
+ * (not available in libpng 1.0.4c).
+ * MMX will be detected at run time and used if present.
+ */
+#define PNG_HAVE_ASSEMBLER_COMBINE_ROW
+#define PNG_HAVE_ASSEMBLER_READ_INTERLACE
+#define PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
+#endif
+
+#endif

pngchang.txt

@@ -1,70 +0,0 @@
-pngchange.txt - 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
-   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
-   added support for medium memory model
-version 0.82
-   added ability to flush output stream automatically or manually
-   added ability to change I/O and error functions dynamically
-   moved pngerror.c into pngio.c to make all the default functions static
-   when freeing memory in png_read_destroy don't free memory we didn't allocate
-   added warnings when reading blocks of incorrect length
-   limit tEXt and zTXt keywords to 80 chars
-
-
-
-

pngconf.h

@@ -1,66 +1,93 @@
 
-/* pngconf.c - machine configurable file for libpng
-
-   libpng 1.0 beta 2 - version 0.81
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
-   August 24, 1995
-   */
+/* pngconf.h - machine configurable file for libpng
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ */
 
 /* 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 */
+ * 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
 
-/* 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 extreamly 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 then the size of a row (compressed),
-   it should not make much difference how big this is.  */
 
-#define PNG_ZBUF_SIZE 32768
+/* 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.
+ */
 
-/* While libpng currently uses zlib for it's compression, it has been designed
-   to stand on it's own.  Towards this end, there are two defines that are
-   used to help portability between machines.  To make it simpler to
-   setup libpng on a machine, this currently uses zlib's definitions, so
-   any changes should be made in zlib.  Libpng will check zlib's settings
-   and adjust it's own accordingly. */
-
-/* if you are running on a machine where you cannot allocate more then
-   64K of memory, 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_ALLOC_64K
-*/
-#ifdef MAXSEG_64K
-#define PNG_MAX_ALLOC_64K
+#ifndef PNG_ZBUF_SIZE
+#define PNG_ZBUF_SIZE 8192
 #endif
 
-/* this macro protects us against machines that don't have function
-   prototypes.  If your compiler does not handle function prototypes,
-   define this macro.  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. */
+/* 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
+
+/* 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
+ */
+
+#  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
+#    include <stdio.h>
+#  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
+#ifdef OF /* zlib prototype munger */
 #define PNGARG(arglist) OF(arglist)
 #else
 
 #ifdef _NO_PROTO
-#define PNGARG(arglist)
+#define PNGARG(arglist) ()
 #else
 #define PNGARG(arglist) arglist
 #endif /* _NO_PROTO */
@@ -69,39 +96,90 @@
 
 #endif /* PNGARG */
 
-/* enough people need this for various reasons to include it here */
+/* 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)
 #include <sys/types.h>
 #endif
-/* need the time information for reading tIME chunks */
-#include <time.h>
 
-/* for FILE.  If you are not using standard io, you don't need this */
-#include <stdio.h>
+/* 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
+__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__ */
+
 #ifdef BSD
 #include <strings.h>
 #else
 #include <string.h>
 #endif
 
-/* other defines for things like memory and the like can go here.  These
-   are the only files included in libpng, so if you need to change them,
-   change them here.  They are only included if PNG_INTERNAL is defined. */
+/* Other defines for things like memory and the like can go here.  */
 #ifdef PNG_INTERNAL
 #include <stdlib.h>
-#include <ctype.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(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
 
-/* other defines specific to compilers can go here.  Try to keep
-   them inside an appropriate ifdef/endif pair for portability */
+/* Codewarrior on NT has linking problems without this. */
+#if (defined(__MWERKS__) && defined(WIN32)) || defined(__STDC__)
+#define PNG_ALWAYS_EXTERN
+#endif
 
-/* for some reason, Borland C++ defines memcmp, etc. in mem.h, not
-   stdlib.h like it should (I think).  Or perhaps this is a C++
-   feature */
+/* For some reason, Borland C++ defines memcmp, etc. in mem.h, not
+ * stdlib.h like it should (I think).  Or perhaps this is a C++
+ * "feature"?
+ */
 #ifdef __TURBOC__
 #include <mem.h>
 #include "alloc.h"
@@ -111,98 +189,371 @@
 #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 */
+/* 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 get this
-   value less then 8, and even that may not work (I haven't tested
-   it). */
+/* 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 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.
-   */
+/* 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 transformations you will not be using can be undef'ed here */
 
-#define PNG_READ_INTERLACING_SUPPORTED
+/* 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)
+ */
+
+
+#if !defined(PNG_READ_TRANSFORMS_NOT_SUPPORTED) && \
+    !defined(PNG_NO_READ_TRANSFORMS)
+#define PNG_READ_TRANSFORMS_SUPPORTED
+#endif
+#if !defined(PNG_WRITE_TRANSFORMS_NOT_SUPPORTED) && \
+    !defined(PNG_NO_WRITE_TRANSFORMS)
+#define PNG_WRITE_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 */
 
-#define PNG_WRITE_INTERLACING_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_COMPOSITED_NODIV
+#define PNG_READ_COMPOSITE_NODIV_SUPPORTED    /* well tested on Intel and SGI */
+#endif
+
+#ifndef PNG_NO_READ_EMPTY_PLTE
+#define PNG_READ_EMPTY_PLTE_SUPPORTED  /* useful for MNG applications */
+#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
-#define PNG_WRITE_FILLER_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_FILLER
+#define PNG_WRITE_FILLER_SUPPORTED  /* This is the 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 */
+
+#ifndef PNG_NO_WRITE_WEIGHTED_FILTER
+#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+#endif
+
+#ifndef PNG_NO_WRITE_FLUSH
 #define PNG_WRITE_FLUSH_SUPPORTED
+#endif
 
-/* any chunks you are not interested in, you can undef here.  The
-   ones that allocate memory may be expecially important (hIST,
-   tEXt, zTXt, tRNS) Others will just save time and make png_info
-   smaller.  OPT_PLTE only disables the optional palette in RGB
-   and RGB Alpha images. */
+#ifndef PNG_NO_WRITE_EMPTY_PLTE
+#define PNG_WRITE_EMPTY_PLTE_SUPPORTED  /* useful for MNG applications */
+#endif
 
-#define PNG_READ_gAMA_SUPPORTED
-#define PNG_READ_sBIT_SUPPORTED
-#define PNG_READ_cHRM_SUPPORTED
-#define PNG_READ_tRNS_SUPPORTED
+#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()
+ */
+#ifndef PNG_NO_EASY_ACCESS
+#define PNG_EASY_ACCESS_SUPPORTED
+#endif
+
+#ifndef PNG_NO_ASSEMBLER_CODE
+#define PNG_ASSEMBLER_CODE_SUPPORTED
+#endif
+
+/* These are currently experimental features, define them if you want */
+
+/* very little testing */
+/*
+#define PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+#define PNG_USER_MEM_SUPPORTED
+*/
+
+/* This is only for PowerPC big-endian and 680x0 systems */
+/* some testing */
+/*
+#define PNG_READ_BIG_ENDIAN_SUPPORTED
+*/
+
+/* 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_ANCILLARY_CHUNKS_NOT_SUPPORTED) && \
+    !defined(PNG_NO_READ_ANCILLARY_CHUNKS)
+#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+#endif
+#if !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
+#ifndef PNG_NO_READ_bKGD
 #define PNG_READ_bKGD_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_cHRM
+#define PNG_READ_cHRM_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_gAMA
+#define PNG_READ_gAMA_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_hIST
 #define PNG_READ_hIST_SUPPORTED
-#define PNG_READ_pHYs_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_oFFs
 #define PNG_READ_oFFs_SUPPORTED
-#define PNG_READ_tIME_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_pCAL
+#define PNG_READ_pCAL_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_pHYs
+#define PNG_READ_pHYs_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sBIT
+#define PNG_READ_sBIT_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sRGB
+#define PNG_READ_sRGB_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_tEXt
 #define PNG_READ_tEXt_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_tIME
+#define PNG_READ_tIME_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_tRNS
+#define PNG_READ_tRNS_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_zTXt
 #define PNG_READ_zTXt_SUPPORTED
-#define PNG_READ_OPT_PLTE_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_OPT_PLTE
+#define PNG_READ_OPT_PLTE_SUPPORTED /* only affects support of the optional */
+#endif                              /* PLTE chunk in RGB and RGBA images */
+#endif /* PNG_READ_ANCILLARY_CHUNKS_SUPPORTED */
 
-#define PNG_WRITE_gAMA_SUPPORTED
-#define PNG_WRITE_sBIT_SUPPORTED
-#define PNG_WRITE_cHRM_SUPPORTED
-#define PNG_WRITE_tRNS_SUPPORTED
+#ifdef PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#ifndef PNG_NO_WRITE_bKGD
 #define PNG_WRITE_bKGD_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_cHRM
+#define PNG_WRITE_cHRM_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_gAMA
+#define PNG_WRITE_gAMA_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_hIST
 #define PNG_WRITE_hIST_SUPPORTED
-#define PNG_WRITE_pHYs_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_oFFs
 #define PNG_WRITE_oFFs_SUPPORTED
-#define PNG_WRITE_tIME_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_pCAL
+#define PNG_WRITE_pCAL_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_pHYs
+#define PNG_WRITE_pHYs_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_sBIT
+#define PNG_WRITE_sBIT_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_sRGB
+#define PNG_WRITE_sRGB_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_tEXt
 #define PNG_WRITE_tEXt_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_tIME
+#define PNG_WRITE_tIME_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_tRNS
+#define PNG_WRITE_tRNS_SUPPORTED
+#endif
+#ifndef PNG_NO_WRITE_zTXt
 #define PNG_WRITE_zTXt_SUPPORTED
+#endif
+#endif /* PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED */
 
-/* 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. */
+/* need the time information for reading tIME chunks */
+#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED)
+#include <time.h>
+#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;
@@ -210,48 +561,164 @@ 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
+/* 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) */
 typedef size_t png_size_t;
 
-/* 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 that might be very
-   large using the far keyword. The Zlib version used must also support
-   model independent data. As of version Zlib .95, the necessary changes 
-   have been made in Zlib. The USE_FAR_KEYWORD define triggers other
-   changes that are needed. Most of the far keyword changes are hidden
-   inside typedefs with suffix "f". Tim Wegner */
+/* 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)
+ */
 
-#if defined(FAR) && defined(M_I86MM)  /* MSC Medium model */
-#   define USE_FAR_KEYWORD
+/* 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
+
+#if !defined(__WIN32__) && !defined(__FLAT__)
+#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__ */
+
+#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
 
-typedef unsigned char FAR png_bytef;
+/* At this point FAR is always defined */
+#ifndef FARDATA
+#define FARDATA
+#endif
+
+/* 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 double          FAR * png_doublep;
+
+/* 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 double          FAR * FAR * png_doublepp;
+
+/* Pointers to pointers to pointers; i.e. pointer to array */
+typedef char            FAR * FAR * FAR * png_charppp;
+
+/* 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;
+
+
+#ifndef PNG_EXPORT
+   /* allow for compilation as dll under MS Windows */
+#  ifdef __WIN32DLL__
+#    define PNG_EXPORT(type,symbol) __declspec(dllexport) type symbol
+#  endif
+
+   /* this variant is used in Mozilla; may correspond to MSVC++ 6.0 changes */
+#  ifdef ALT_WIN32_DLL
+#    define PNG_EXPORT(type,symbol) type __attribute__((dllexport)) symbol
+#  endif
+
+   /* allow for compilation as dll with Borland C++ 5.0 */
+#  if defined(__BORLANDC__) && defined(_Windows) && defined(__DLL__)
+#    define PNG_EXPORT(type,symbol) type _export symbol
+#  endif
+
+   /* allow for compilation as shared lib under BeOS */
+#  ifdef __BEOSDLL__
+#    define PNG_EXPORT(type,symbol) __declspec(export) type symbol
+#  endif
+#endif
+
+#ifndef PNG_EXPORT
+#  define PNG_EXPORT(type,symbol) type symbol
+#endif
 
-/* End medium model changes to be in zconf.h */
 
 /* User may want to use these so not in PNG_INTERNAL. Any library functions
-   that are passed far data must be model independent. */
+ * that are passed far data must be model independent.
+ */
+
 #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_strcat _fstrcat
 #   define png_strlen _fstrlen
-#   define png_strcmp _fstrcmp
+#   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_strcat strcat
 #   define png_strlen strlen
-#   define png_strcmp strcmp
+#   define png_memcmp memcmp     /* SJT: added */
 #   define png_memcpy memcpy
 #   define png_memset memset
 #endif
 /* End of memory model independent support */
 
+/* Just a double check that someone hasn't tried to define something
+ * contradictory.
+ */
+#if (PNG_ZBUF_SIZE > 65536) && defined(PNG_MAX_MALLOC_64K)
+#undef PNG_ZBUF_SIZE
+#define PNG_ZBUF_SIZE 65536
+#endif
 
 #endif /* PNGCONF_H */
 

pngerror.c

@@ -0,0 +1,172 @@
+
+/* pngerror.c - stub functions for i/o and memory allocation
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ *
+ * 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 png_default_error PNGARG((png_structp png_ptr,
+                                      png_const_charp message));
+static void png_default_warning PNGARG((png_structp png_ptr,
+                                        png_const_charp 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
+png_error(png_structp png_ptr, png_const_charp message)
+{
+   if (png_ptr->error_fn != NULL)
+      (*(png_ptr->error_fn))(png_ptr, message);
+
+   /* if the following returns or doesn't exist, use the default function,
+      which will not return */
+   png_default_error(png_ptr, 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
+png_warning(png_structp png_ptr, png_const_charp message)
+{
+   if (png_ptr->warning_fn != NULL)
+      (*(png_ptr->warning_fn))(png_ptr, message);
+   else
+      png_default_warning(png_ptr, message);
+}
+
+/* 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) < 41 || (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
+png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp 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 & 0xf];
+         buffer[iout++] = ']';
+      } else {
+         buffer[iout++] = c;
+      }
+   }
+
+   if (message == NULL)
+      buffer[iout] = 0;
+   else {
+      buffer[iout++] = ':';
+      buffer[iout++] = ' ';
+      png_memcpy(buffer+iout, message, 64);
+      buffer[iout+63] = 0;
+   }
+}
+
+void
+png_chunk_error(png_structp png_ptr, png_const_charp message)
+{
+   char msg[16+64];
+   png_format_buffer(png_ptr, msg, message);
+   png_error(png_ptr, msg);
+}
+
+void
+png_chunk_warning(png_structp png_ptr, png_const_charp message)
+{
+   char msg[16+64];
+   png_format_buffer(png_ptr, msg, 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
+png_default_error(png_structp png_ptr, png_const_charp message)
+{
+#ifndef PNG_NO_CONSOLE_IO
+   fprintf(stderr, "libpng error: %s\n", message);
+#endif
+
+#ifdef USE_FAR_KEYWORD
+   {
+      jmp_buf jmpbuf;
+      png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
+      longjmp(jmpbuf, 1);
+   }
+#else
+   longjmp(png_ptr->jmpbuf, 1);
+#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
+png_default_warning(png_structp png_ptr, png_const_charp message)
+{
+#ifndef PNG_NO_CONSOLE_IO
+   fprintf(stderr, "libpng warning: %s\n", message);
+#endif
+   if (png_ptr == NULL)
+      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
+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
+png_get_error_ptr(png_structp png_ptr)
+{
+   return ((png_voidp)png_ptr->error_ptr);
+}
+
+
+

pngget.c

@@ -0,0 +1,650 @@
+
+/* pngget.c - retrieval of values from info struct
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+png_uint_32
+png_get_valid(png_structp png_ptr, png_infop info_ptr, png_uint_32 flag)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->valid & flag);
+   else
+      return(0);
+}
+
+png_uint_32
+png_get_rowbytes(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->rowbytes);
+   else
+      return(0);
+}
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* easy access to info, added in libpng-0.99 */
+png_uint_32
+png_get_image_width(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+   {
+      return info_ptr->width;
+   }
+   return (0);
+}
+
+png_uint_32
+png_get_image_height(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+   {
+      return info_ptr->height;
+   }
+   return (0);
+}
+
+png_byte
+png_get_bit_depth(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+   {
+      return info_ptr->bit_depth;
+   }
+   return (0);
+}
+
+png_byte
+png_get_color_type(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+   {
+      return info_ptr->color_type;
+   }
+   return (0);
+}
+
+png_byte
+png_get_filter_type(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+   {
+      return info_ptr->filter_type;
+   }
+   return (0);
+}
+
+png_byte
+png_get_interlace_type(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+   {
+      return info_ptr->interlace_type;
+   }
+   return (0);
+}
+
+png_byte
+png_get_compression_type(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+   {
+      return info_ptr->compression_type;
+   }
+   return (0);
+}
+
+png_uint_32
+png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      png_debug1(1, "in %s retrieval function\n", "png_get_x_pixels_per_meter");
+      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
+          return (0);
+      else return (info_ptr->x_pixels_per_unit);
+   }
+   else
+#endif
+   return (0);
+}
+
+png_uint_32
+png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      png_debug1(1, "in %s retrieval function\n", "png_get_y_pixels_per_meter");
+      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
+          return (0);
+      else return (info_ptr->y_pixels_per_unit);
+   }
+   else
+#endif
+   return (0);
+}
+
+png_uint_32
+png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      png_debug1(1, "in %s retrieval function\n", "png_get_pixels_per_meter");
+      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER ||
+         info_ptr->x_pixels_per_unit != info_ptr->y_pixels_per_unit)
+          return (0);
+      else return (info_ptr->x_pixels_per_unit);
+   }
+   else
+#endif
+   return (0);
+}
+
+float
+png_get_pixel_aspect_ratio(png_structp png_ptr, png_infop info_ptr)
+   {
+#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   {
+      png_debug1(1, "in %s retrieval function\n", "png_get_aspect_ratio");
+      if (info_ptr->x_pixels_per_unit == 0)
+         return ((float)0.0);
+      else
+         return ((float)info_ptr->y_pixels_per_unit
+            /(float)info_ptr->x_pixels_per_unit);
+   }
+   else
+#endif
+      return ((float)0.0);
+}
+
+png_uint_32
+png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   {
+      png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
+      if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
+          return (0);
+      else return (info_ptr->x_offset);
+   }
+   else
+#endif
+   return (0);
+}
+
+png_uint_32
+png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   {
+      png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
+      if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
+          return (0);
+      else return (info_ptr->y_offset);
+   }
+   else
+#endif
+   return (0);
+}
+
+png_uint_32
+png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   {
+      png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
+      if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
+          return (0);
+      else return (info_ptr->x_offset);
+   }
+   else
+#endif
+   return (0);
+}
+
+png_uint_32
+png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   {
+      png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
+      if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
+          return (0);
+      else return (info_ptr->y_offset);
+   }
+   else
+#endif
+   return (0);
+}
+
+#ifdef PNG_INCH_CONVERSIONS
+png_uint_32
+png_get_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
+{
+   return ((png_uint_32)((float)png_get_pixels_per_meter(png_ptr, info_ptr)
+     *.03937 +.5)
+}
+
+png_uint_32
+png_get_x_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
+{
+   return ((png_uint_32)((float)png_get_x_pixels_per_meter(png_ptr, info_ptr)
+     *.03937 +.5)
+}
+
+png_uint_32
+png_get_y_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
+{
+   return ((png_uint_32)((float)png_get_y_pixels_per_meter(png_ptr, info_ptr)
+     *.03937 +.5)
+}
+
+float
+png_get_x_offset_inches(png_structp png_ptr, png_infop info_ptr)
+{
+   return ((float)png_get_x_offset_microns(png_ptr, info_ptr)
+     *.03937/1000000. +.5)
+}
+
+float
+png_get_y_offset_inches(png_structp png_ptr, png_infop info_ptr)
+{
+   return ((float)png_get_y_offset_microns(png_ptr, info_ptr)
+     *.03937/1000000. +.5)
+}
+
+#if defined(PNG_READ_pHYs_SUPPORTED)
+png_uint_32
+png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+   png_uint_32 retval = 0;
+
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
+   {
+      png_debug1(1, "in %s retrieval function\n", "pHYs");
+      if (res_x != NULL)
+      {
+         *res_x = info_ptr->x_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+      if (res_y != NULL)
+      {
+         *res_y = info_ptr->y_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+      if (unit_type != NULL)
+      {
+         *unit_type = (int)info_ptr->phys_unit_type;
+         retval |= PNG_INFO_pHYs;
+         if(unit_type == 1)
+         {
+            if (res_x != NULL) *res_x = (png_uint_32)(*res_x * 39.37 + .50);
+            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * 39.37 + .50);
+         }
+      }
+   }
+   return (retval);
+}
+#endif /* PNG_READ_pHYs_SUPPORTED */
+#endif  /* PNG_INCH_CONVERSIONS */
+
+/* png_get_channels really belongs in here, too, but it's been around longer */
+
+#endif  /* PNG_EASY_ACCESS_SUPPORTED */
+
+png_byte
+png_get_channels(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->channels);
+   else
+      return (0);
+}
+
+png_bytep
+png_get_signature(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->signature);
+   else
+      return (NULL);
+}
+
+#if defined(PNG_READ_bKGD_SUPPORTED)
+png_uint_32
+png_get_bKGD(png_structp png_ptr, png_infop info_ptr,
+   png_color_16p *background)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
+      && background != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "bKGD");
+      *background = &(info_ptr->background);
+      return (PNG_INFO_bKGD);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_cHRM_SUPPORTED)
+png_uint_32
+png_get_cHRM(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)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   {
+      png_debug1(1, "in %s retrieval function\n", "cHRM");
+      if (white_x != NULL)
+         *white_x = (double)info_ptr->x_white;
+      if (white_y != NULL)
+         *white_y = (double)info_ptr->y_white;
+      if (red_x != NULL)
+         *red_x = (double)info_ptr->x_red;
+      if (red_y != NULL)
+         *red_y = (double)info_ptr->y_red;
+      if (green_x != NULL)
+         *green_x = (double)info_ptr->x_green;
+      if (green_y != NULL)
+         *green_y = (double)info_ptr->y_green;
+      if (blue_x != NULL)
+         *blue_x = (double)info_ptr->x_blue;
+      if (blue_y != NULL)
+         *blue_y = (double)info_ptr->y_blue;
+      return (PNG_INFO_cHRM);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_gAMA_SUPPORTED)
+png_uint_32
+png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+      && file_gamma != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "gAMA");
+      *file_gamma = (double)info_ptr->gamma;
+      return (PNG_INFO_gAMA);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_sRGB_SUPPORTED)
+png_uint_32
+png_get_sRGB(png_structp png_ptr, png_infop info_ptr, int *file_srgb_intent)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
+      && file_srgb_intent != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "sRGB");
+      *file_srgb_intent = (int)info_ptr->srgb_intent;
+      return (PNG_INFO_sRGB);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_hIST_SUPPORTED)
+png_uint_32
+png_get_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p *hist)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)
+      && hist != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "hIST");
+      *hist = info_ptr->hist;
+      return (PNG_INFO_hIST);
+   }
+   return (0);
+}
+#endif
+
+png_uint_32
+png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 *width, png_uint_32 *height, int *bit_depth,
+   int *color_type, int *interlace_type, int *compression_type,
+   int *filter_type)
+
+{
+   if (png_ptr != NULL && info_ptr != NULL && width != NULL && height != NULL &&
+      bit_depth != NULL && color_type != NULL)
+   {
+      int pixel_depth, channels;
+      png_uint_32 rowbytes_per_pixel;
+
+      png_debug1(1, "in %s retrieval function\n", "IHDR");
+      *width = info_ptr->width;
+      *height = info_ptr->height;
+      *bit_depth = info_ptr->bit_depth;
+      *color_type = info_ptr->color_type;
+      if (compression_type != NULL)
+         *compression_type = info_ptr->compression_type;
+      if (filter_type != NULL)
+         *filter_type = info_ptr->filter_type;
+      if (interlace_type != NULL)
+         *interlace_type = info_ptr->interlace_type;
+
+      /* check for potential overflow of rowbytes */
+      if (*color_type == PNG_COLOR_TYPE_PALETTE)
+         channels = 1;
+      else if (*color_type & PNG_COLOR_MASK_COLOR)
+         channels = 3;
+      else
+         channels = 1;
+      if (*color_type & PNG_COLOR_MASK_ALPHA)
+         channels++;
+      pixel_depth = *bit_depth * channels;
+      rowbytes_per_pixel = (pixel_depth + 7) >> 3;
+      if ((*width > PNG_MAX_UINT/rowbytes_per_pixel))
+      {
+         png_warning(png_ptr,
+            "Width too large for libpng to process image data.");
+      }
+      return (1);
+   }
+   return (0);
+}
+
+#if defined(PNG_READ_oFFs_SUPPORTED)
+png_uint_32
+png_get_oFFs(png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 *offset_x, png_uint_32 *offset_y, int *unit_type)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
+      && offset_x != NULL && offset_y != NULL && unit_type != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "oFFs");
+      *offset_x = info_ptr->x_offset;
+      *offset_y = info_ptr->y_offset;
+      *unit_type = (int)info_ptr->offset_unit_type;
+      return (PNG_INFO_oFFs);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_pCAL_SUPPORTED)
+png_uint_32
+png_get_pCAL(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)
+{
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL &&
+      purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+      nparams != NULL && units != NULL && params != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "pCAL");
+      *purpose = info_ptr->pcal_purpose;
+      *X0 = info_ptr->pcal_X0;
+      *X1 = info_ptr->pcal_X1;
+      *type = (int)info_ptr->pcal_type;
+      *nparams = (int)info_ptr->pcal_nparams;
+      *units = info_ptr->pcal_units;
+      *params = info_ptr->pcal_params;
+      return (PNG_INFO_pCAL);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_pHYs_SUPPORTED)
+png_uint_32
+png_get_pHYs(png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+   png_uint_32 retval = 0;
+
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
+   {
+      png_debug1(1, "in %s retrieval function\n", "pHYs");
+      if (res_x != NULL)
+      {
+         *res_x = info_ptr->x_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+      if (res_y != NULL)
+      {
+         *res_y = info_ptr->y_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+      if (unit_type != NULL)
+      {
+         *unit_type = (int)info_ptr->phys_unit_type;
+         retval |= PNG_INFO_pHYs;
+      }
+   }
+   return (retval);
+}
+#endif
+
+png_uint_32
+png_get_PLTE(png_structp png_ptr, png_infop info_ptr, png_colorp *palette,
+   int *num_palette)
+{
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_PLTE &&
+       palette != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "PLTE");
+      *palette = info_ptr->palette;
+      *num_palette = info_ptr->num_palette;
+      png_debug1(3, "num_palette = %d\n", *num_palette);
+      return (PNG_INFO_PLTE);
+   }
+   return (0);
+}
+
+#if defined(PNG_READ_sBIT_SUPPORTED)
+png_uint_32
+png_get_sBIT(png_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit)
+{
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT &&
+       sig_bit != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "sBIT");
+      *sig_bit = &(info_ptr->sig_bit);
+      return (PNG_INFO_sBIT);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
+png_uint_32
+png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr,
+   int *num_text)
+{
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
+   {
+      png_debug1(1, "in %s retrieval function\n",
+         (png_ptr->chunk_name[0] == '\0' ? "text"
+             : (png_const_charp)png_ptr->chunk_name));
+      if (text_ptr != NULL)
+         *text_ptr = info_ptr->text;
+      if (num_text != NULL)
+         *num_text = info_ptr->num_text;
+      return ((png_uint_32)info_ptr->num_text);
+   }
+   return(0);
+}
+#endif
+
+#if defined(PNG_READ_tIME_SUPPORTED)
+png_uint_32
+png_get_tIME(png_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
+{
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME &&
+       mod_time != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "tIME");
+      *mod_time = &(info_ptr->mod_time);
+      return (PNG_INFO_tIME);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_tRNS_SUPPORTED)
+png_uint_32
+png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
+   png_bytep *trans, int *num_trans, png_color_16p *trans_values)
+{
+   png_uint_32 retval = 0;
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
+   {
+      png_debug1(1, "in %s retrieval function\n", "tRNS");
+      if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+          if (trans != NULL)
+          {
+             *trans = info_ptr->trans;
+             retval |= PNG_INFO_tRNS;
+          }
+          if (trans_values != NULL)
+             *trans_values = &(info_ptr->trans_values);
+      }
+      else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
+      {
+          if (trans_values != NULL)
+          {
+             *trans_values = &(info_ptr->trans_values);
+             retval |= PNG_INFO_tRNS;
+          }
+          if(trans != NULL)
+             *trans = NULL;
+      }
+      if(num_trans != NULL)
+      {
+         *num_trans = info_ptr->num_trans;
+         retval |= PNG_INFO_tRNS;
+      }
+   }
+   return (retval);
+}
+#endif
+
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+png_byte
+png_get_rgb_to_gray_status (png_structp png_ptr)
+{
+   return png_ptr->rgb_to_gray_status;
+}
+#endif

pngio.c

@@ -1,411 +0,0 @@
-
-/* pngio.c - default functions for data I/O and error/warning messages
-
-   libpng 1.0 beta 3 - version 0.82
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
-   Some portions Copyright (C) 1995 Andreas Dilger
-   Sept 24, 1995
-
-   This file provides a location for all input/output.  Users which need
-   special handling are expected to write functions which have the same
-   arguments as these, and perform similar functions, but possibly have
-   different I/O methods.  Note that you shouldn't change these functions,
-   but rather write replacement functions and then change them at run
-   time with png_set_write_fn(...) or png_set_read_fn(...), etc */
-
-#include "png.h"
-
-
-/* Write the data to whatever output you are using.  The default
-   routine writes to a file pointer.  If you need to write to something
-   else, this is a good example of how to do it.  Note that this routine
-   sometimes gets called with very small lengths, so you should implement
-   some kind of simple buffering if you are using unbuffered writes.  This
-   should never be asked to write more then 64K on a 16 bit machine.  The
-   cast to png_size_t is there for insurance. */
-#ifndef USE_FAR_KEYWORD
-static void
-png_write_data(png_struct *png_ptr, png_bytef *data, png_uint_32 length)
-{
-   png_uint_32 check;
-
-   check = fwrite(data, 1, (png_size_t)length, png_ptr->fp);
-   if (check != length)
-   {
-      (*(png_ptr->error_fn))(png_ptr, "Write error");
-   }
-}
-#else 
-/* this is the model-independent version. Since the standard I/O library
-   can't handle far buffers in the medium and small models, we have to copy
-   the data.
-*/
-
-#define NEAR_BUF_SIZE 1024
-#define MIN(a,b) (a <= b ? a : b)
-
-#ifdef _MSC_VER
-/* for FP_OFF */
-#include <dos.h>
-#endif
-
-static void
-png_write_data(png_struct *png_ptr, png_bytef *data, png_uint_32 length)
-{
-   png_uint_32 check;
-   png_byte *n_data;
-    
-   /* Check if data really is near. If so, use usual code. */
-#ifdef _MSC_VER
-   /* do it this way just to quiet warning */
-   FP_OFF(n_data) = FP_OFF(data);  
-   if(FP_SEG(n_data) == FP_SEG(data))
-#else
-   /* this works in MSC also but with lost segment warning */
-   n_data = (png_byte *)data;  
-   if((png_bytef *)n_data == data) 
-#endif   
-   {
-      check = fwrite(n_data, 1, (png_size_t)length, png_ptr->fp);
-   }
-   else
-   {
-      png_byte buf[NEAR_BUF_SIZE];
-      png_size_t written, remaining, err;
-      check = 0;
-      remaining = (png_size_t)length;
-      do
-      {
-         written = MIN(NEAR_BUF_SIZE,remaining);
-         png_memcpy(buf,data,written); /* copy far buffer to near buffer */
-         err = fwrite(buf, 1, written, png_ptr->fp);
-         if(err != written)
-            break;
-         else
-            check += err;   
-         data += written;
-         remaining -= written;
-      }
-      while(remaining != 0);      
-   }
-   if (check != length)
-   {
-      (*(png_ptr->error_fn))(png_ptr, "Write error");
-   }
-}
-
-#endif
-
-
-/* Read the data from whatever input you are using.  The default
-   routine reads from a file pointer.  If you need to read from something
-   else, this is a good example of how to do it.  Note that this routine
-   sometimes gets called with very small lengths, so you should implement
-   some kind of simple buffering if you are using unbuffered reads.  This
-   should never be asked to read more then 64K on a 16 bit machine.  The
-   cast to png_size_t is there for insurance. */
-#ifndef USE_FAR_KEYWORD
-static void
-png_read_data(png_struct *png_ptr, png_bytef *data, png_uint_32 length)
-{
-   png_uint_32 check;
-
-   check = fread(data, 1, (size_t)length, png_ptr->fp);
-   if (check != length)
-   {
-      (*(png_ptr->error_fn))(png_ptr, "Read error");
-   }
-}
-#else
-static void
-png_read_data(png_struct *png_ptr, png_bytef *data, png_uint_32 length)
-{
-   png_uint_32 check;
-   png_byte *n_data;
-    
-   /* Check if data really is near. If so, use usual code. */
-#ifdef _MSC_VER
-   /* do it this way just to quiet warning */
-   FP_OFF(n_data) = FP_OFF(data);  
-   if(FP_SEG(n_data) == FP_SEG(data))
-#else
-   /* this works in MSC also but with lost segment warning */
-   n_data = (png_byte *)data;  
-   if((png_bytef *)n_data == data) 
-#endif   
-   {
-      check = fread(n_data, 1, (size_t)length, png_ptr->fp);
-   }
-   else
-   {
-      png_byte buf[NEAR_BUF_SIZE];
-      png_size_t read, remaining, err;
-      check = 0;
-      remaining = (png_size_t)length;
-      do
-      {
-         read = MIN(NEAR_BUF_SIZE,remaining);
-         err = fread(buf, 1, read, png_ptr->fp);
-         png_memcpy(data,buf,read); /* copy far buffer to near buffer */
-         if(err != read)
-            break;
-         else
-            check += err;   
-         data += read;
-         remaining -= read;
-      }
-      while(remaining != 0);      
-   }
-   if (check != length)
-   {
-      (*(png_ptr->error_fn))(png_ptr, "Read error");
-   }
-}
-#endif
-
-
-/* This function does nothing, and is used for the write function on
-   a read, and vice-versa.  It is an error if this function is
-   actually called. */
-static void
-png_empty_rw(png_struct *png_ptr, png_bytef *data, png_uint_32 length)
-{
-   if (png_ptr->read_data_fn == png_empty_rw)
-   {
-     (*(png_ptr->error_fn))(png_ptr, "Invalid read on a write device");
-   }
-   else /* if (png_ptr->write_data_fn == png_empty_rw) */
-   {
-     (*(png_ptr->error_fn))(png_ptr, "Invalid write on a read device");
-   }
-}
-
-
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
-/* This function does nothing, and is supplied for user I/O functions which
-   do not do any buffering.  This function is set when NULL is supplied for
-   the flush function pointer. */
-static void
-png_empty_flush(png_struct *png_ptr)
-{
-}
-
-
-/* Write out any remaining output that is stored in the output buffers.
-   If you supply a new write routine, you will probably need to supply a
-   replacement for this routine as well. */
-static void
-png_output_flush(png_struct *png_ptr)
-{
-   fflush(png_ptr->fp);
-}
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
-
-
-/* This function does nothing, and is called if the user supplies null
-   when setting the error function. */
-static void
-png_empty_error(png_structf *png_ptr, char *message)
-{
-#ifdef USE_FAR_KEYWORD
-   {
-      jmp_buf jmpbuf;
-      png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
-      longjmp(jmpbuf, 1);
-   }
-#else
-   longjmp(png_ptr->jmpbuf, 1);
-#endif
-}
-
-
-/* This function is called whenever there is an error.  Replace with a
-   function you wish to handle the error.  Note that this function
-   MUST NOT return, or the program will crash.  To be consistent with
-   the examples for the library and this function, you could call
-   longjmp(pnt_ptr->jmpbuf) to return to the program at the location of
-   the last setjmp(png_ptr->jmpbuf) after an error. */
-static void
-png_error(png_structf *png_ptr, char *message)
-{
-   fprintf(stderr, "libpng error: %s\n", message);
-
-   png_empty_error(png_ptr, message);
-}
-
-
-/* This function does nothing, and is called if the user supplies null
-   when setting the warning function. */
-static void
-png_empty_warning(png_struct *png_ptr, char *message)
-{
-}
-
-
-/* This function is called when there is a warning, but the library
-   thinks it can continue anyway.  You don't have to do anything here
-   if you don't want to.  In the default configuration, png_ptr is
-   not used, but it is passed in case it may be useful. */
-static void
-png_warning(png_struct *png_ptr, char *message)
-{
-   fprintf(stderr, "libpng warning: %s\n", message);
-}
-
-
-/* This function allows the application to supply new output functions for
-   libpng if standard C streams aren't being used.  The new write function
-   should call (*(png_ptr->error_fn))("Error message") to exit and output
-   any fatal error messages if it cannot output the correct number of bytes.
-   This function takes as its arguments:
-   png_ptr       - pointer to a png output data structure
-   io_ptr        - pointer to user supplied structure containing info about
-                   the output functions.  May be NULL.
-   write_data_fn - pointer to a new output function which takes as its
-                   arguments a pointer to a png_struct, a pointer to
-                   data to be written, and a 32-bit unsigned int which is
-                   the number of bytes to be written.  The new write
-                   function should call (*(png_ptr->error_fn))("Error msg")
-                   to exit and output any fatal error messages.
-   flush_data_fn - pointer to a new flush function which takes as its
-                   arguments a pointer to a png_struct.  After a call to
-                   the flush function, there should be no data in any buffers
-                   or pending transmission.  If the output method doesn't do
-                   any buffering of ouput, this parameter can be NULL.  If
-                   PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng
-                   compile time, output_flush_fn will be ignored, although
-                   it must be supplied for compatibility. */
-void
-png_set_write_fn(png_struct *png_ptr, void *io_ptr, png_rw_ptr write_data_fn,
-   png_flush_ptr output_flush_fn)
-{
-   png_ptr->io_ptr = io_ptr;
-
-   if (write_data_fn == NULL)
-   {
-      (*(png_ptr->error_fn))(png_ptr, "NULL write function pointer given");
-   }
-
-   png_ptr->write_data_fn = write_data_fn;
-
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
-   if (output_flush_fn == NULL)
-   {
-      png_ptr->output_flush_fn = png_empty_flush;
-   }
-   else
-   {
-      png_ptr->output_flush_fn = output_flush_fn;
-   }
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
-
-   /* It is an error to write to a read device */
-   png_ptr->read_data_fn = png_empty_rw;
-}
-
-
-/* This function allows the application to supply a new input function
-   for libpng if standard C streams aren't being used.  The new read function
-   should call  (*(png_ptr->error_fn))("Error message") to exit and output
-   any fatal error messages if the desired number of bytes is not available.
-   This function takes as its arguments:
-   png_ptr      - pointer to a png input data structure
-   io_ptr       - pointer to user supplied structure containing info about
-                  the input functions.  May be NULL.
-   read_data_fn - pointer to a new input function which takes as it's
-                  arguments a pointer to a png_struct, a pointer to
-                  a location where input data can be stored, and a 32-bit
-                  unsigned int which is the number of bytes to be read. */
-void
-png_set_read_fn(png_struct *png_ptr, void *io_ptr, png_rw_ptr read_data_fn)
-{
-   png_ptr->io_ptr = io_ptr;
-
-   if (read_data_fn == NULL)
-   {
-      (*(png_ptr->error_fn))(png_ptr, "NULL read function pointer given");
-   }
-   png_ptr->read_data_fn = read_data_fn;
-
-   /* It is an error to write to a read device */
-   png_ptr->write_data_fn = png_empty_rw;
-
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
-   png_ptr->output_flush_fn = png_empty_flush;
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
-}
-
-
-/* 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 and png_read_destroy are called. */
-void *
-png_get_io_ptr(png_struct *png_ptr)
-{
-   return png_ptr->io_ptr;
-}
-
-
-/* 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
-   error return method used in the default routine calls
-   longjmp(png_ptr->jmpbuf, 1), or exits if setjmp(png_ptr->jmpbuf) has never
-   been called. */
-void
-png_set_msg_fn(png_struct *png_ptr, void *msg_ptr, png_msg_ptr error_fn,
-   png_msg_ptr warning_fn)
-{
-   png_ptr->msg_ptr = msg_ptr;
-
-   if (error_fn == NULL)
-   {
-      png_ptr->error_fn = png_empty_error;
-   }
-   else
-   {
-      png_ptr->error_fn = error_fn;
-   }
-
-   if (warning_fn == NULL)
-   {
-      png_ptr->warning_fn = png_empty_warning;
-   }
-   else
-   {
-      png_ptr->warning_fn = warning_fn;
-   }
-}
-
-
-/* This function returns a pointer to the msg_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. */
-void *
-png_get_msg_ptr(png_struct *png_ptr)
-{
-   return png_ptr->msg_ptr;
-}
-
-
-/* Initialize the default input/output functions for the png file.
-   If you change the read, write or message routines, can call
-   either png_set_read_fn(...), png_set_write_fn(...), etc. to change
-   individual functions after a call to png_init_io(...).   You can also
-   call one of png_set_read_fn(...) or png_set_write_fn(...), AND
-   png_set_msg_fn(...) instead of png_init_io(...) if you aren't using
-   any of the default libpng functions. */
-void
-png_init_io(png_struct *png_ptr, FILE *fp)
-{
-   png_ptr->fp = fp;
-   png_ptr->error_fn = png_error;
-   png_ptr->warning_fn = png_warning;
-   png_ptr->write_data_fn = png_write_data;
-   png_ptr->read_data_fn = png_read_data;
-
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
-   png_ptr->output_flush_fn = png_output_flush;
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
-}

pngmem.c

@@ -1,313 +1,512 @@
 
 /* pngmem.c - stub functions for memory allocation
-
-   libpng 1.0 beta 2 - version 0.81
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
-   August 24, 1995
-
-   This file provides a location for all memory allocation.  Users which
-   need special memory handling are expected to modify the code in this file
-   to meet their needs.  See the instructions at each function. */
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ *
+ * This file provides a location for all memory allocation.  Users who
+ * need special memory handling are expected to supply replacement
+ * functions for png_malloc() and png_free(), and to use
+ * png_create_read_struct_2() and png_create_write_struct_2() to
+ * identify the replacement functions.
+ */
 
 #define PNG_INTERNAL
 #include "png.h"
 
+/* Borland DOS special memory handler */
+#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
+/* if you change this, be sure to change the one in png.h also */
+
+/* Allocate memory for a png_struct.  The malloc and memset can be replaced
+   by a single call to calloc() if this is thought to improve performance. */
+png_voidp
+png_create_struct(int type)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, NULL));
+}
+
+/* Alternate version of png_create_struct, for use with user-defined malloc. */
+png_voidp
+png_create_struct_2(int type, png_malloc_ptr malloc_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+   png_size_t size;
+   png_voidp struct_ptr;
+
+   if (type == PNG_STRUCT_INFO)
+     size = sizeof(png_info);
+   else if (type == PNG_STRUCT_PNG)
+     size = sizeof(png_struct);
+   else
+     return ((png_voidp)NULL);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(malloc_fn != NULL)
+   {
+      if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
+         png_memset(struct_ptr, 0, size);
+         return (struct_ptr);
+   }
+#endif /* PNG_USER_MEM_SUPPORTED */
+   if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
+   {
+      png_memset(struct_ptr, 0, size);
+   }
+   return (struct_ptr);
+}
+
+
+/* Free memory allocated by a png_create_struct() call */
+void
+png_destroy_struct(png_voidp struct_ptr)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
+}
+
+/* Free memory allocated by a png_create_struct() call */
+void
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
+{
+#endif
+   if (struct_ptr != NULL)
+   {
+#ifdef PNG_USER_MEM_SUPPORTED
+      if(free_fn != NULL)
+      {
+         png_struct dummy_struct;
+         png_structp png_ptr = &dummy_struct;
+         (*(free_fn))(png_ptr, struct_ptr);
+         struct_ptr = NULL;
+         return;
+      }
+#endif /* PNG_USER_MEM_SUPPORTED */
+      farfree (struct_ptr);
+      struct_ptr = NULL;
+   }
+}
+
 /* Allocate memory.  For reasonable files, size should never exceed
-   64K.  However, zlib may allocate more then 64K if you don't tell
-   it not to.  See zconf.h and png.h for more information. zlib does
-   need to allocate exactly 64K, so whatever you call here must
-   have the ability to do that. */
-
-/* Borland compilers have this habit of not giving you 64K chunks
-   that start on the segment in DOS mode.  This has not been observed
-   in Windows, and of course it doesn't matter in 32 bit mode, as there
-   are no segments.  Now libpng doesn't need that much memory normally,
-   but zlib does, so we have to normalize it, if necessary.  It would be
-   better if zlib worked in less then 64K, but it doesn't, so we
-   have to deal with it.  Truely, we are misusing farmalloc here,
-   as it is designed for use with huge pointers, which don't care
-   about segments.  So we allocate a large amount of memory, and
-   divvy off segments when needed.
-   */
-#ifdef __TURBOC__
-#ifndef __WIN32__
-#ifndef __FLAT__
-
-/* NUM_SEG is the number of segments allocated at once */
-#define NUM_SEG 4
-typedef struct borland_seg_struct
+ * 64K.  However, zlib may allocate more then 64K if you don't tell
+ * it not to.  See zconf.h and png.h for more information. zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ *
+ * Borland seems to have a problem in DOS mode for exactly 64K.
+ * It gives you a segment with an offset of 8 (perhaps to store its
+ * memory stuff).  zlib doesn't like this at all, so we have to
+ * detect and deal with it.  This code should not be needed in
+ * Windows or OS/2 modes, and only in 16 bit mode.  This code has
+ * been updated by Alexander Lehmann for version 0.89 to waste less
+ * memory.
+ *
+ * Note that we can't use png_size_t for the "size" declaration,
+ * since on some systems a png_size_t is a 16-bit quantity, and as a
+ * result, we would be truncating potentially larger memory requests
+ * (which should cause a fatal error) and introducing major problems.
+ */
+png_voidp
+png_malloc(png_structp png_ptr, png_uint_32 size)
 {
-   void *mem_ptr;
-   void *seg_ptr[NUM_SEG];
-   int seg_used[NUM_SEG];
-   int num_used;
-} borland_seg;
-
-borland_seg *save_array;
-int num_save_array;
-int max_save_array;
-
-#endif
-#endif
+#ifndef PNG_USER_MEM_SUPPORTED
+   png_voidp ret;
 #endif
+   if (png_ptr == NULL || size == 0)
+      return ((png_voidp)NULL);
 
-voidpf
-png_large_malloc(png_structf *png_ptr, png_uint_32 size)
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(png_ptr->malloc_fn != NULL)
+       return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
+   else
+       return png_malloc_default(png_ptr, size);
+}
+
+png_voidp
+png_malloc_default(png_structp png_ptr, png_uint_32 size)
 {
-   voidpf ret;
-   if (!png_ptr || !size)
-      return ((void *)0);
+   png_voidp ret;
+#endif /* PNG_USER_MEM_SUPPORTED */
 
 #ifdef PNG_MAX_MALLOC_64K
    if (size > (png_uint_32)65536L)
-      (*(png_ptr->error_fn))(png_ptr, "Cannot Allocate > 64K");
+      png_error(png_ptr, "Cannot Allocate > 64K");
 #endif
 
-#ifdef __TURBOC__
-#  if defined(__WIN32__) || defined(__FLAT__)
-   ret = malloc(size);
-#  else
-
-   if (size == 65536L)
+   if (size == (png_uint_32)65536L)
    {
-      unsigned long offset;
-      if (!save_array)
+      if (png_ptr->offset_table == NULL)
       {
+         /* try to see if we need to do any of this fancy stuff */
          ret = farmalloc(size);
-         offset = (unsigned long)(ret);
-         offset &= 0xffffL;
-      }
-      else
-      {
-         ret = (void *)0;
-      }
-      if (save_array || offset)
-      {
-         int i, j;
-
-         if (ret)
-            farfree(ret);
-         ret = (void *)0;
-
-         if (!save_array)
+         if (ret == NULL || ((png_size_t)ret & 0xffff))
          {
-            unsigned long offset;
-            png_byte huge *ptr;
+            int num_blocks;
+            png_uint_32 total_size;
+            png_bytep table;
             int i;
+            png_byte huge * hptr;
 
-            num_save_array = 1;
-            save_array = malloc(num_save_array * sizeof (borland_seg));
-            if (!save_array)
-               (*(png_ptr->error_fn))(png_ptr, "Out of Memory 1");
-            save_array->mem_ptr = farmalloc(
-               (unsigned long)(NUM_SEG) * 65536L + 65532L);
-            if (!save_array->mem_ptr)
-               (*(png_ptr->error_fn))(png_ptr, "Out of Memory 2");
-            offset = (unsigned long)(ret);
-            offset &= 0xffffL;
-            ptr = save_array->mem_ptr;
-            if (offset)
-               ptr += 65536L - offset;
-            for (i = 0; i < NUM_SEG; i++, ptr += 65536L)
+            if (ret != NULL)
             {
-               save_array->seg_ptr[i] = ptr;
-               save_array->seg_used[i] = 0;
+               farfree(ret);
+               ret = NULL;
             }
-            save_array->num_used = 0;
-         }
 
-         for (i = 0; i < num_save_array; i++)
-         {
-            for (j = 0; j < NUM_SEG; j++)
+            if(png_ptr->zlib_window_bits > 14)
+               num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
+            else
+               num_blocks = 1;
+            if (png_ptr->zlib_mem_level >= 7)
+               num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
+            else
+               num_blocks++;
+
+            total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;
+
+            table = farmalloc(total_size);
+
+            if (table == NULL)
             {
-               if (!save_array[i].seg_used[j])
-               {
-                  ret = save_array[i].seg_ptr[j];
-                  save_array[i].seg_used[j] = 1;
-                  save_array[i].num_used++;
-                  break;
-               }
+               png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */
             }
-            if (ret)
-               break;
-         }
 
-         if (!ret)
-         {
-            unsigned long offset;
-            png_byte huge *ptr;
-
-            save_array = realloc(save_array,
-               (num_save_array + 1) * sizeof (borland_seg));
-            if (!save_array)
-               (*(png_ptr->error_fn))(png_ptr, "Out of Memory 3");
-            save_array[num_save_array].mem_ptr = farmalloc(
-               (unsigned long)(NUM_SEG) * 65536L + 65532L);
-            if (!save_array[num_save_array].mem_ptr)
-               (*(png_ptr->error_fn))(png_ptr, "Out of Memory 4");
-            offset = (unsigned long)(ret);
-            offset &= 0xffffL;
-            ptr = save_array[num_save_array].mem_ptr;
-            if (offset)
-               ptr += 65536L - offset;
-            for (i = 0; i < NUM_SEG; i++, ptr += 65536L)
+            if ((png_size_t)table & 0xfff0)
             {
-               save_array[num_save_array].seg_ptr[i] = ptr;
-               save_array[num_save_array].seg_used[i] = 0;
+               png_error(png_ptr, "Farmalloc didn't return normalized pointer");
             }
-            ret = save_array[num_save_array].seg_ptr[0];
-            save_array[num_save_array].seg_used[0] = 1;
-            save_array[num_save_array].num_used = 1;
-            num_save_array++;
+
+            png_ptr->offset_table = table;
+            png_ptr->offset_table_ptr = farmalloc(num_blocks *
+               sizeof (png_bytep));
+
+            if (png_ptr->offset_table_ptr == NULL)
+            {
+               png_error(png_ptr, "Out Of memory.");
+            }
+
+            hptr = (png_byte huge *)table;
+            if ((png_size_t)hptr & 0xf)
+            {
+               hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+               hptr = hptr + 16L;  /* "hptr += 16L" fails on Turbo C++ 3.0 */
+            }
+            for (i = 0; i < num_blocks; i++)
+            {
+               png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+               hptr = hptr + (png_uint_32)65536L;  /* "+=" fails on TC++3.0 */
+            }
+
+            png_ptr->offset_table_number = num_blocks;
+            png_ptr->offset_table_count = 0;
+            png_ptr->offset_table_count_free = 0;
          }
       }
+
+      if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
+         png_error(png_ptr, "Out of Memory.");
+
+      ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
    }
    else
-   {
       ret = farmalloc(size);
+
+   if (ret == NULL)
+   {
+      png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */
    }
 
-#  endif /* __WIN32__ */
-#else /* __TURBOC__ */
-#  ifdef _MSC_VER
+   return (ret);
+}
+
+/* free a pointer allocated by png_malloc().  In the default
+   configuration, png_ptr is not used, but is passed in case it
+   is needed.  If ptr is NULL, return without taking any action. */
+void
+png_free(png_structp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
+   {
+      (*(png_ptr->free_fn))(png_ptr, ptr);
+      ptr = NULL;
+      return;
+   }
+   else png_free_default(png_ptr, ptr);
+}
+
+void
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+   if (png_ptr->offset_table != NULL)
+   {
+      int i;
+
+      for (i = 0; i < png_ptr->offset_table_count; i++)
+      {
+         if (ptr == png_ptr->offset_table_ptr[i])
+         {
+            ptr = NULL;
+            png_ptr->offset_table_count_free++;
+            break;
+         }
+      }
+      if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
+      {
+         farfree(png_ptr->offset_table);
+         farfree(png_ptr->offset_table_ptr);
+         png_ptr->offset_table = NULL;
+         png_ptr->offset_table_ptr = NULL;
+      }
+   }
+
+   if (ptr != NULL)
+   {
+      farfree(ptr);
+      ptr = NULL;
+   }
+}
+
+#else /* Not the Borland DOS special memory handler */
+
+/* Allocate memory for a png_struct or a png_info.  The malloc and
+   memset can be replaced by a single call to calloc() if this is thought
+   to improve performance noticably.*/
+png_voidp
+png_create_struct(int type)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, NULL));
+}
+
+/* Allocate memory for a png_struct or a png_info.  The malloc and
+   memset can be replaced by a single call to calloc() if this is thought
+   to improve performance noticably.*/
+png_voidp
+png_create_struct_2(int type, png_malloc_ptr malloc_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+   png_size_t size;
+   png_voidp struct_ptr;
+
+   if (type == PNG_STRUCT_INFO)
+      size = sizeof(png_info);
+   else if (type == PNG_STRUCT_PNG)
+      size = sizeof(png_struct);
+   else
+      return ((png_voidp)NULL);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(malloc_fn != NULL)
+   {
+      if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
+         png_memset(struct_ptr, 0, size);
+      return (struct_ptr);
+   }
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+#if defined(__TURBOC__) && !defined(__FLAT__)
+   if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
+#else
+# if defined(_MSC_VER) && defined(MAXSEG_64K)
+   if ((struct_ptr = (png_voidp)halloc(size,1)) != NULL)
+# else
+   if ((struct_ptr = (png_voidp)malloc(size)) != NULL)
+# endif
+#endif
+   {
+      png_memset(struct_ptr, 0, size);
+   }
+
+   return (struct_ptr);
+}
+
+
+/* Free memory allocated by a png_create_struct() call */
+void
+png_destroy_struct(png_voidp struct_ptr)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
+}
+
+/* Free memory allocated by a png_create_struct() call */
+void
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+   if (struct_ptr != NULL)
+   {
+#ifdef PNG_USER_MEM_SUPPORTED
+      if(free_fn != NULL)
+      {
+         png_struct dummy_struct;
+         png_structp png_ptr = &dummy_struct;
+         (*(free_fn))(png_ptr, struct_ptr);
+         struct_ptr = NULL;
+         return;
+      }
+#endif /* PNG_USER_MEM_SUPPORTED */
+#if defined(__TURBOC__) && !defined(__FLAT__)
+      farfree(struct_ptr);
+      struct_ptr = NULL;
+#else
+# if defined(_MSC_VER) && defined(MAXSEG_64K)
+      hfree(struct_ptr);
+      struct_ptr = NULL;
+# else
+      free(struct_ptr);
+      struct_ptr = NULL;
+# endif
+#endif
+   }
+}
+
+
+/* Allocate memory.  For reasonable files, size should never exceed
+   64K.  However, zlib may allocate more then 64K if you don't tell
+   it not to.  See zconf.h and png.h for more information.  zlib does
+   need to allocate exactly 64K, so whatever you call here must
+   have the ability to do that. */
+
+png_voidp
+png_malloc(png_structp png_ptr, png_uint_32 size)
+{
+#ifndef PNG_USER_MEM_SUPPORTED
+   png_voidp ret;
+#endif
+   if (png_ptr == NULL || size == 0)
+      return ((png_voidp)NULL);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(png_ptr->malloc_fn != NULL)
+       return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
+   else
+       return (png_malloc_default(png_ptr, size));
+}
+png_voidp
+png_malloc_default(png_structp png_ptr, png_uint_32 size)
+{
+   png_voidp ret;
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+#ifdef PNG_MAX_MALLOC_64K
+   if (size > (png_uint_32)65536L)
+      png_error(png_ptr, "Cannot Allocate > 64K");
+#endif
+
+#if defined(__TURBOC__) && !defined(__FLAT__)
+   ret = farmalloc(size);
+#else
+# if defined(_MSC_VER) && defined(MAXSEG_64K)
    ret = halloc(size, 1);
-#  else
-   /* everybody else, so normal malloc should do it. */
-   ret = malloc(size);
-#  endif
+# else
+   ret = malloc((size_t)size);
+# endif
 #endif
 
    if (ret == NULL)
    {
-      (*(png_ptr->error_fn))(png_ptr, "Out of Memory");
+      png_error(png_ptr, "Out of Memory");
    }
 
-   return ret;
+   return (ret);
 }
 
-/* free a pointer allocated by png_large_malloc().  In the default
-  configuration, png_ptr is not used, but is passed in case it
-  is needed.  If ptr is NULL, return without taking any action. */
+/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
+   without taking any action. */
 void
-png_large_free(png_structf *png_ptr, voidpf ptr)
+png_free(png_structp png_ptr, png_voidp ptr)
 {
-   if (!png_ptr)
+   if (png_ptr == NULL || ptr == NULL)
       return;
 
-   if (ptr != (void *)0)
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
    {
-#ifdef __TURBOC__
-#  if defined(__WIN32__) || defined(__FLAT__)
-      if (ptr)
-         free(ptr);
-#  else
-      int i, j;
+      (*(png_ptr->free_fn))(png_ptr, ptr);
+      ptr = NULL;
+      return;
+   }
+   else png_free_default(png_ptr, ptr);
+}
+void
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
 
-      for (i = 0; i < num_save_array; i++)
-      {
-         for (j = 0; j < NUM_SEG; j++)
-         {
-            if (ptr == save_array[i].seg_ptr[j])
-            {
-               save_array[i].seg_used[j] = 0;
-               ptr = 0;
-               save_array[i].num_used--;
-               if (!save_array[i].num_used)
-               {
-                  int k;
-
-                  num_save_array--;
-                  farfree(save_array[i].mem_ptr);
-                  for (k = i; k < num_save_array; k++)
-                     save_array[k] = save_array[k + 1];
-                  if (!num_save_array)
-                  {
-                     free(save_array);
-                     save_array = 0;
-                  }
-               }
-               break;
-            }
-         }
-         if (!ptr)
-            break;
-      }
-
-      if (ptr)
-         farfree(ptr);
-#  endif
+#if defined(__TURBOC__) && !defined(__FLAT__)
+   farfree(ptr);
+   ptr = NULL;
 #else
-#  ifdef _MSC_VER
-      hfree(ptr);
-#  else
-      free(ptr);
-#  endif
+# if defined(_MSC_VER) && defined(MAXSEG_64K)
+   hfree(ptr);
+   ptr = NULL;
+# else
+   free(ptr);
+   ptr = NULL;
+# endif
 #endif
-   }
 }
 
-/* Allocate memory.  This is called for smallish blocks only  It
-   should not get anywhere near 64K. */
-void *
-png_malloc(png_struct *png_ptr, png_uint_32 size)
+#endif /* Not Borland DOS special memory handler */
+
+png_voidp
+png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2,
+   png_uint_32 length)
 {
-   void *ret;
+   png_size_t size;
 
-   if (!png_ptr || !size)
-      return ((void *)0);
+   size = (png_size_t)length;
+   if ((png_uint_32)size != length)
+      png_error(png_ptr,"Overflow in png_memcpy_check.");
 
-#ifdef PNG_MAX_MALLOC_64K
-   if (size > (png_uint_32)65536L)
-      (*(png_ptr->error_fn))(png_ptr, "Cannot Allocate > 64K");
-#endif
-
-   ret = malloc((png_size_t)size);
-
-   if (!ret)
-   {
-      (*(png_ptr->error_fn))(png_ptr, "Out of Memory 6");
-   }
-
-   return ret;
+   return(png_memcpy (s1, s2, size));
 }
 
-/* Reallocate memory.  This will not get near 64K on a
-   even marginally reasonable file. */
-void *
-png_realloc(png_struct *png_ptr, void *ptr, png_uint_32 size,
-   png_uint_32 old_size)
+png_voidp
+png_memset_check (png_structp png_ptr, png_voidp s1, int value,
+   png_uint_32 length)
 {
-   void *ret;
+   png_size_t size;
 
-   if (!png_ptr || !old_size || !ptr || !size)
-      return ((void *)0);
+   size = (png_size_t)length;
+   if ((png_uint_32)size != length)
+      png_error(png_ptr,"Overflow in png_memset_check.");
 
-#ifdef PNG_MAX_MALLOC_64K
-   if (size > (png_uint_32)65536L)
-      (*(png_ptr->error_fn))(png_ptr, "Cannot Allocate > 64K");
-#endif
+   return (png_memset (s1, value, size));
 
-   ret = realloc(ptr, (png_size_t)size);
-
-   if (!ret)
-   {
-      (*(png_ptr->error_fn))(png_ptr, "Out of Memory 7");
-   }
-
-   return ret;
 }
 
-/* free a pointer allocated by png_malloc().  In the default
-  configuration, png_ptr is not used, but is passed incase it
-  is needed.  If ptr is NULL, return without taking any action. */
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
 void
-png_free(png_struct *png_ptr, void *ptr)
+png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+  malloc_fn, png_free_ptr free_fn)
 {
-   if (!png_ptr)
-      return;
-
-   if (ptr != (void *)0)
-      free(ptr);
+   png_ptr->mem_ptr = mem_ptr;
+   png_ptr->malloc_fn = malloc_fn;
+   png_ptr->free_fn = free_fn;
 }
 
+/* This function returns a pointer to the mem_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
+png_get_mem_ptr(png_structp png_ptr)
+{
+   return ((png_voidp)png_ptr->mem_ptr);
+}
+#endif /* PNG_USER_MEM_SUPPORTED */

pngrcb.c

@@ -1,237 +0,0 @@
-/* pngrcb.c - callbacks while reading a png file
-
-   libpng 1.0 beta 2 - version 0.81
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
-   August 24, 1995
-   */
-
-#define PNG_INTERNAL
-#include "png.h"
-
-void
-png_read_IHDR(png_struct *png_ptr, png_info *info,
-   png_uint_32 width, png_uint_32 height, int bit_depth,
-   int color_type, int compression_type, int filter_type,
-   int interlace_type)
-{
-   if (!png_ptr || !info)
-      return;
-
-   info->width = width;
-   info->height = height;
-   info->bit_depth = bit_depth;
-   info->color_type = color_type;
-   info->compression_type = compression_type;
-   info->filter_type = filter_type;
-   info->interlace_type = interlace_type;
-   if (info->color_type == PNG_COLOR_TYPE_PALETTE)
-      info->channels = 1;
-   else if (info->color_type & PNG_COLOR_MASK_COLOR)
-      info->channels = 3;
-   else
-      info->channels = 1;
-   if (info->color_type & PNG_COLOR_MASK_ALPHA)
-      info->channels++;
-   info->pixel_depth = info->channels * info->bit_depth;
-   info->rowbytes = ((info->width * info->pixel_depth + 7) >> 3);
-}
-
-void
-png_read_PLTE(png_struct *png_ptr, png_info *info,
-   png_color *palette, int num)
-{
-   if (!png_ptr || !info)
-      return;
-
-   info->palette = palette;
-   info->num_palette = num;
-   info->valid |= PNG_INFO_PLTE;
-}
-
-#if defined(PNG_READ_gAMA_SUPPORTED)
-void
-png_read_gAMA(png_struct *png_ptr, png_info *info, float gamma)
-{
-   if (!png_ptr || !info)
-      return;
-
-   info->gamma = gamma;
-   info->valid |= PNG_INFO_gAMA;
-}
-#endif
-
-#if defined(PNG_READ_sBIT_SUPPORTED)
-void
-png_read_sBIT(png_struct *png_ptr, png_info *info,
-   png_color_8 *sig_bit)
-{
-   if (!png_ptr || !info)
-      return;
-
-   memcpy(&(info->sig_bit), sig_bit, sizeof (png_color_8));
-   info->valid |= PNG_INFO_sBIT;
-}
-#endif
-
-#if defined(PNG_READ_cHRM_SUPPORTED)
-void
-png_read_cHRM(png_struct *png_ptr, png_info *info,
-   float white_x, float white_y, float red_x, float red_y,
-   float green_x, float green_y, float blue_x, float blue_y)
-{
-   if (!png_ptr || !info)
-      return;
-
-   info->x_white = white_x;
-   info->y_white = white_y;
-   info->x_red = red_x;
-   info->y_red = red_y;
-   info->x_green = green_x;
-   info->y_green = green_y;
-   info->x_blue = blue_x;
-   info->y_blue = blue_y;
-   info->valid |= PNG_INFO_cHRM;
-}
-#endif
-
-#if defined(PNG_READ_tRNS_SUPPORTED)
-void
-png_read_tRNS(png_struct *png_ptr, png_info *info,
-   png_byte *trans, int num_trans,   png_color_16 *trans_values)
-{
-   if (!png_ptr || !info)
-      return;
-
-   if (trans)
-   {
-      info->trans = trans;
-   }
-   else
-   {
-      memcpy(&(info->trans_values), trans_values,
-         sizeof(png_color_16));
-   }
-   info->num_trans = num_trans;
-   info->valid |= PNG_INFO_tRNS;
-}
-#endif
-
-#if defined(PNG_READ_bKGD_SUPPORTED)
-void
-png_read_bKGD(png_struct *png_ptr, png_info *info,
-   png_color_16 *background)
-{
-   if (!png_ptr || !info)
-      return;
-
-   memcpy(&(info->background), background, sizeof(png_color_16));
-   info->valid |= PNG_INFO_bKGD;
-}
-#endif
-
-#if defined(PNG_READ_hIST_SUPPORTED)
-void
-png_read_hIST(png_struct *png_ptr, png_info *info, png_uint_16 *hist)
-{
-   if (!png_ptr || !info)
-      return;
-
-   info->hist = hist;
-   info->valid |= PNG_INFO_hIST;
-}
-#endif
-
-#if defined(PNG_READ_pHYs_SUPPORTED)
-void
-png_read_pHYs(png_struct *png_ptr, png_info *info,
-   png_uint_32 res_x, png_uint_32 res_y, int unit_type)
-{
-   if (!png_ptr || !info)
-      return;
-
-   info->x_pixels_per_unit = res_x;
-   info->y_pixels_per_unit = res_y;
-   info->phys_unit_type = unit_type;
-   info->valid |= PNG_INFO_pHYs;
-}
-#endif
-
-#if defined(PNG_READ_oFFs_SUPPORTED)
-void
-png_read_oFFs(png_struct *png_ptr, png_info *info,
-   png_uint_32 offset_x, png_uint_32 offset_y, int unit_type)
-{
-   if (!png_ptr || !info)
-      return;
-
-   info->x_offset = offset_x;
-   info->y_offset = offset_y;
-   info->offset_unit_type = unit_type;
-   info->valid |= PNG_INFO_oFFs;
-}
-#endif
-
-#if defined(PNG_READ_tIME_SUPPORTED)
-void
-png_read_tIME(png_struct *png_ptr, png_info *info,
-   png_time *mod_time)
-{
-   if (!png_ptr || !info)
-      return;
-
-   memcpy(&(info->mod_time), mod_time, sizeof (png_time));
-   info->valid |= PNG_INFO_tIME;
-}
-#endif
-
-#if defined(PNG_READ_zTXt_SUPPORTED)
-void
-png_read_zTXt(png_struct *png_ptr, png_info *info,
-   charf *key, charf *text, png_uint_32 text_len, int compression)
-{
-   if (!png_ptr || !info)
-      return;
-
-   if (info->max_text <= info->num_text)
-   {
-      if (info->text)
-      {
-         png_uint_32 old_max;
-
-         old_max = info->max_text;
-         info->max_text = info->num_text + 16;
-         info->text = (png_text *)png_realloc(png_ptr,
-            info->text,
-            info->max_text * sizeof (png_text),
-            old_max * sizeof (png_text));
-      }
-      else
-      {
-         info->max_text = info->num_text + 16;
-         info->text = (png_text *)png_malloc(png_ptr,
-            info->max_text * sizeof (png_text));
-         info->num_text = 0;
-      }
-   }
-
-   info->text[info->num_text].key = key;
-   info->text[info->num_text].text = text;
-   info->text[info->num_text].text_length = text_len;
-   info->text[info->num_text].compression = compression;
-   info->num_text++;
-}
-#endif
-
-#if defined(PNG_READ_tEXt_SUPPORTED)
-void
-png_read_tEXt(png_struct *png_ptr, png_info *info,
-   charf *key, charf *text, png_uint_32 text_len)
-{
-   if (!png_ptr || !info)
-      return;
-
-   png_read_zTXt(png_ptr, info, key, text, text_len, -1);
-}
-#endif
-

pngrio.c

@@ -0,0 +1,151 @@
+
+/* pngrio.c - functions for data input
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ *
+ * This file provides a location for all input.  Users who need
+ * special handling are expected to write a function that has the same
+ * arguments as this and performs a similar function, but that possibly
+ * has a different input method.  Note that you shouldn't change this
+ * function, but rather write a replacement function and then make
+ * libpng use it at run time with png_set_read_fn(...).
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+/* Read the data from whatever input you are using.  The default routine
+   reads from a file pointer.  Note that this routine sometimes gets called
+   with very small lengths, so you should implement some kind of simple
+   buffering if you are using unbuffered reads.  This should never be asked
+   to read more then 64K on a 16 bit machine. */
+void
+png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_debug1(4,"reading %d bytes\n", length);
+   if (png_ptr->read_data_fn != NULL)
+      (*(png_ptr->read_data_fn))(png_ptr, data, length);
+   else
+      png_error(png_ptr, "Call to NULL read function");
+}
+
+#if !defined(PNG_NO_STDIO)
+/* This is the function that does the actual reading of data.  If you are
+   not reading from a standard C stream, you should create a replacement
+   read_data function and use it at run time with png_set_read_fn(), rather
+   than changing the library. */
+#ifndef USE_FAR_KEYWORD
+static void
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+
+   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+    * instead of an int, which is what fread() actually returns.
+    */
+   check = (png_size_t)fread(data, (png_size_t)1, length,
+      (FILE *)png_ptr->io_ptr);
+
+   if (check != length)
+   {
+      png_error(png_ptr, "Read Error");
+   }
+}
+#else
+/* this is the model-independent version. Since the standard I/O library
+   can't handle far buffers in the medium and small models, we have to copy
+   the data.
+*/
+
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+
+static void
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   int check;
+   png_byte *n_data;
+   FILE *io_ptr;
+
+   /* Check if data really is near. If so, use usual code. */
+   n_data = (png_byte *)CVT_PTR_NOCHECK(data);
+   io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr);
+   if ((png_bytep)n_data == data)
+   {
+      check = fread(n_data, 1, length, io_ptr);
+   }
+   else
+   {
+      png_byte buf[NEAR_BUF_SIZE];
+      png_size_t read, remaining, err;
+      check = 0;
+      remaining = length;
+      do
+      {
+         read = MIN(NEAR_BUF_SIZE, remaining);
+         err = fread(buf, (png_size_t)1, read, io_ptr);
+         png_memcpy(data, buf, read); /* copy far buffer to near buffer */
+         if(err != read)
+            break;
+         else
+            check += err;
+         data += read;
+         remaining -= read;
+      }
+      while (remaining != 0);
+   }
+   if ((png_uint_32)check != (png_uint_32)length)
+   {
+      png_error(png_ptr, "read Error");
+   }
+}
+#endif
+#endif
+
+/* This function allows the application to supply a new input function
+   for libpng if standard C streams aren't being used.
+
+   This function takes as its arguments:
+   png_ptr      - pointer to a png input data structure
+   io_ptr       - pointer to user supplied structure containing info about
+                  the input functions.  May be NULL.
+   read_data_fn - pointer to a new input function that takes as its
+                  arguments a pointer to a png_struct, a pointer to
+                  a location where input data can be stored, and a 32-bit
+                  unsigned int that is the number of bytes to be read.
+                  To exit and output any fatal error messages the new write
+                  function should call png_error(png_ptr, "Error msg"). */
+void
+png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
+   png_rw_ptr read_data_fn)
+{
+   png_ptr->io_ptr = io_ptr;
+
+#if !defined(PNG_NO_STDIO)
+   if (read_data_fn != NULL)
+      png_ptr->read_data_fn = read_data_fn;
+   else
+      png_ptr->read_data_fn = png_default_read_data;
+#else
+   png_ptr->read_data_fn = read_data_fn;
+#endif
+
+   /* It is an error to write to a read device */
+   if (png_ptr->write_data_fn != NULL)
+   {
+      png_ptr->write_data_fn = NULL;
+      png_warning(png_ptr,
+         "It's an error to set both read_data_fn and write_data_fn in the ");
+      png_warning(png_ptr,
+         "same structure.  Resetting write_data_fn to NULL.");
+   }
+
+#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+   png_ptr->output_flush_fn = NULL;
+#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+}
+

pngset.c

@@ -0,0 +1,391 @@
+
+/* pngset.c - storage of image information into info struct
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ *
+ * The functions here are used during reads to store data from the file
+ * into the info struct, and during writes to store application data
+ * into the info struct for writing into the file.  This abstracts the
+ * info struct and allows us to change the structure in the future.
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+#if defined(PNG_READ_bKGD_SUPPORTED) || defined(PNG_WRITE_bKGD_SUPPORTED)
+void
+png_set_bKGD(png_structp png_ptr, png_infop info_ptr, png_color_16p background)
+{
+   png_debug1(1, "in %s storage function\n", "bKGD");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   png_memcpy(&(info_ptr->background), background, sizeof(png_color_16));
+   info_ptr->valid |= PNG_INFO_bKGD;
+}
+#endif
+
+#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED)
+void
+png_set_cHRM(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)
+{
+   png_debug1(1, "in %s storage function\n", "cHRM");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->x_white = (float)white_x;
+   info_ptr->y_white = (float)white_y;
+   info_ptr->x_red   = (float)red_x;
+   info_ptr->y_red   = (float)red_y;
+   info_ptr->x_green = (float)green_x;
+   info_ptr->y_green = (float)green_y;
+   info_ptr->x_blue  = (float)blue_x;
+   info_ptr->y_blue  = (float)blue_y;
+   info_ptr->valid |= PNG_INFO_cHRM;
+}
+#endif
+
+#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
+void
+png_set_gAMA(png_structp png_ptr, png_infop info_ptr, double file_gamma)
+{
+   png_debug1(1, "in %s storage function\n", "gAMA");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->gamma = (float)file_gamma;
+   info_ptr->valid |= PNG_INFO_gAMA;
+}
+#endif
+
+#if defined(PNG_READ_hIST_SUPPORTED) || defined(PNG_WRITE_hIST_SUPPORTED)
+void
+png_set_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p hist)
+{
+   png_debug1(1, "in %s storage function\n", "hIST");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->hist = hist;
+   info_ptr->valid |= PNG_INFO_hIST;
+}
+#endif
+
+void
+png_set_IHDR(png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 width, png_uint_32 height, int bit_depth,
+   int color_type, int interlace_type, int compression_type,
+   int filter_type)
+{
+   int rowbytes_per_pixel;
+   png_debug1(1, "in %s storage function\n", "IHDR");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->width = width;
+   info_ptr->height = height;
+   info_ptr->bit_depth = (png_byte)bit_depth;
+   info_ptr->color_type =(png_byte) color_type;
+   info_ptr->compression_type = (png_byte)compression_type;
+   info_ptr->filter_type = (png_byte)filter_type;
+   info_ptr->interlace_type = (png_byte)interlace_type;
+   if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      info_ptr->channels = 1;
+   else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+      info_ptr->channels = 3;
+   else
+      info_ptr->channels = 1;
+   if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+      info_ptr->channels++;
+   info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
+
+   /* check for overflow */
+   rowbytes_per_pixel = (info_ptr->pixel_depth + 7) >> 3;
+   if (( width > PNG_MAX_UINT/rowbytes_per_pixel))
+   {
+      png_warning(png_ptr,
+         "Width too large to process image data; rowbytes will overflow.");
+      info_ptr->rowbytes = (png_size_t)0;
+   }
+   else
+      info_ptr->rowbytes = (info_ptr->width * info_ptr->pixel_depth + 7) >> 3;
+}
+
+#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+void
+png_set_oFFs(png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 offset_x, png_uint_32 offset_y, int unit_type)
+{
+   png_debug1(1, "in %s storage function\n", "oFFs");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->x_offset = offset_x;
+   info_ptr->y_offset = offset_y;
+   info_ptr->offset_unit_type = (png_byte)unit_type;
+   info_ptr->valid |= PNG_INFO_oFFs;
+}
+#endif
+
+#if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED)
+void
+png_set_pCAL(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)
+{
+   png_uint_32 length;
+   int i;
+
+   png_debug1(1, "in %s storage function\n", "pCAL");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   length = png_strlen(purpose) + 1;
+   png_debug1(3, "allocating purpose for info (%d bytes)\n", length);
+   info_ptr->pcal_purpose = (png_charp)png_malloc(png_ptr, length);
+   png_memcpy(info_ptr->pcal_purpose, purpose, (png_size_t)length);
+
+   png_debug(3, "storing X0, X1, type, and nparams in info\n");
+   info_ptr->pcal_X0 = X0;
+   info_ptr->pcal_X1 = X1;
+   info_ptr->pcal_type = (png_byte)type;
+   info_ptr->pcal_nparams = (png_byte)nparams;
+
+   length = png_strlen(units) + 1;
+   png_debug1(3, "allocating units for info (%d bytes)\n", length);
+   info_ptr->pcal_units = (png_charp)png_malloc(png_ptr, length);
+   png_memcpy(info_ptr->pcal_units, units, (png_size_t)length);
+
+   info_ptr->pcal_params = (png_charpp)png_malloc(png_ptr,
+      (png_uint_32)((nparams + 1) * sizeof(png_charp)));
+   info_ptr->pcal_params[nparams] = NULL;
+
+   for (i = 0; i < nparams; i++)
+   {
+      length = png_strlen(params[i]) + 1;
+      png_debug2(3, "allocating parameter %d for info (%d bytes)\n", i, length);
+      info_ptr->pcal_params[i] = (png_charp)png_malloc(png_ptr, length);
+      png_memcpy(info_ptr->pcal_params[i], params[i], (png_size_t)length);
+   }
+
+   info_ptr->valid |= PNG_INFO_pCAL;
+}
+#endif
+
+#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+void
+png_set_pHYs(png_structp png_ptr, png_infop info_ptr,
+   png_uint_32 res_x, png_uint_32 res_y, int unit_type)
+{
+   png_debug1(1, "in %s storage function\n", "pHYs");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->x_pixels_per_unit = res_x;
+   info_ptr->y_pixels_per_unit = res_y;
+   info_ptr->phys_unit_type = (png_byte)unit_type;
+   info_ptr->valid |= PNG_INFO_pHYs;
+}
+#endif
+
+void
+png_set_PLTE(png_structp png_ptr, png_infop info_ptr,
+   png_colorp palette, int num_palette)
+{
+   png_debug1(1, "in %s storage function\n", "PLTE");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->palette = palette;
+   info_ptr->num_palette = (png_uint_16)num_palette;
+   info_ptr->valid |= PNG_INFO_PLTE;
+}
+
+#if defined(PNG_READ_sBIT_SUPPORTED) || defined(PNG_WRITE_sBIT_SUPPORTED)
+void
+png_set_sBIT(png_structp png_ptr, png_infop info_ptr,
+   png_color_8p sig_bit)
+{
+   png_debug1(1, "in %s storage function\n", "sBIT");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   png_memcpy(&(info_ptr->sig_bit), sig_bit, sizeof (png_color_8));
+   info_ptr->valid |= PNG_INFO_sBIT;
+}
+#endif
+
+#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED)
+void
+png_set_sRGB(png_structp png_ptr, png_infop info_ptr, int intent)
+{
+   png_debug1(1, "in %s storage function\n", "sRGB");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->srgb_intent = (png_byte)intent;
+   info_ptr->valid |= PNG_INFO_sRGB;
+}
+void
+png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
+   int intent)
+{
+#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
+   float file_gamma;
+#endif
+#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED)
+   float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
+#endif
+   png_debug1(1, "in %s storage function\n", "sRGB_gAMA_and_cHRM");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   png_set_sRGB(png_ptr, info_ptr, intent);
+
+#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
+   file_gamma = (float).45;
+   png_set_gAMA(png_ptr, info_ptr, file_gamma);
+#endif
+
+#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED)
+   white_x = (float).3127;
+   white_y = (float).3290;
+   red_x   = (float).64;
+   red_y   = (float).33;
+   green_x = (float).30;
+   green_y = (float).60;
+   blue_x  = (float).15;
+   blue_y  = (float).06;
+
+   png_set_cHRM(png_ptr, info_ptr,
+      white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
+
+#endif
+}
+#endif
+
+#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \
+    defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
+void
+png_set_text(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
+   int num_text)
+{
+   int i;
+
+   png_debug1(1, "in %s storage function\n", (png_ptr->chunk_name[0] == '\0' ?
+      "text" : (png_const_charp)png_ptr->chunk_name));
+
+   if (png_ptr == NULL || info_ptr == NULL || num_text == 0)
+      return;
+
+   /* Make sure we have enough space in the "text" array in info_struct
+    * to hold all of the incoming text_ptr objects.
+    */
+   if (info_ptr->num_text + num_text > info_ptr->max_text)
+   {
+      if (info_ptr->text != NULL)
+      {
+         png_textp old_text;
+         int old_max;
+
+         old_max = info_ptr->max_text;
+         info_ptr->max_text = info_ptr->num_text + num_text + 8;
+         old_text = info_ptr->text;
+         info_ptr->text = (png_textp)png_malloc(png_ptr,
+            (png_uint_32)(info_ptr->max_text * sizeof (png_text)));
+         png_memcpy(info_ptr->text, old_text, (png_size_t)(old_max *
+            sizeof(png_text)));
+         png_free(png_ptr, old_text);
+      }
+      else
+      {
+         info_ptr->max_text = num_text + 8;
+         info_ptr->num_text = 0;
+         info_ptr->text = (png_textp)png_malloc(png_ptr,
+            (png_uint_32)(info_ptr->max_text * sizeof (png_text)));
+      }
+      png_debug1(3, "allocated %d entries for info_ptr->text\n",
+         info_ptr->max_text);
+   }
+
+   for (i = 0; i < num_text; i++)
+   {
+      png_textp textp = &(info_ptr->text[info_ptr->num_text]);
+
+      if (text_ptr[i].text == NULL)
+         text_ptr[i].text = (png_charp)"";
+
+      if (text_ptr[i].text[0] == '\0')
+      {
+         textp->text_length = 0;
+         textp->compression = PNG_TEXT_COMPRESSION_NONE;
+      }
+      else
+      {
+         textp->text_length = png_strlen(text_ptr[i].text);
+         textp->compression = text_ptr[i].compression;
+      }
+      textp->text = text_ptr[i].text;
+      textp->key = text_ptr[i].key;
+      info_ptr->num_text++;
+      png_debug1(3, "transferred text chunk %d\n", info_ptr->num_text);
+   }
+}
+#endif
+
+#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED)
+void
+png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_timep mod_time)
+{
+   png_debug1(1, "in %s storage function\n", "tIME");
+   if (png_ptr == NULL || info_ptr == NULL ||
+       (png_ptr->flags & PNG_FLAG_WROTE_tIME))
+      return;
+
+   png_memcpy(&(info_ptr->mod_time), mod_time, sizeof (png_time));
+   info_ptr->valid |= PNG_INFO_tIME;
+}
+#endif
+
+#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED)
+void
+png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
+   png_bytep trans, int num_trans, png_color_16p trans_values)
+{
+   png_debug1(1, "in %s storage function\n", "tRNS");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   if (trans != NULL)
+   {
+      info_ptr->trans = trans;
+   }
+
+   if (trans_values != NULL)
+   {
+      png_memcpy(&(info_ptr->trans_values), trans_values,
+         sizeof(png_color_16));
+      if (num_trans == 0)
+        num_trans = 1;
+   }
+   info_ptr->num_trans = (png_uint_16)num_trans;
+   info_ptr->valid |= PNG_INFO_tRNS;
+}
+#endif
+
+#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED)
+void
+png_permit_empty_plte (png_structp png_ptr, int empty_plte_permitted)
+{
+   png_debug1(1, "in png_permit_empty_plte\n", "");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->empty_plte_permitted=(png_byte)empty_plte_permitted;
+}
+#endif

pngtodo.txt

@@ -1,27 +0,0 @@
-pngtodo.txt - list of things to do for libpng
-
-for 0.9
-   medium memory model
-   improved dithering?
-
-for 1.1
-	push reader
-
-for 1.1 or later
-   overlaying one image on top of another
-	optional palette creation
-	histogram creation
-	text conversion between different code types
-   cHRM transformation
-   support for other chunks being defined (sCAl, the gIF series,
-      and others that people come up with).
-   pull writer
-   better dithering
-   keep up with public chunks
-   other compression libraries
-   more exotic interlace handling
-   better filtering (counting huffman bits?  filter type inertia?)
-   C++ wrapper
-   other languages (pascal, for one)
-   comments of > 64K
-

pngtrans.c

@@ -1,21 +1,22 @@
 
-/* pngtrans.c - transforms the data in a row
-   routines used by both readers and writers
-
-   libpng 1.0 beta 2 - version 0.81
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
-   August 24, 1995
-   */
+/* pngtrans.c - transforms the data in a row (used by both readers and writers)
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ */
 
 #define PNG_INTERNAL
 #include "png.h"
 
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
-/* turn on bgr to rgb mapping */
+/* turn on BGR-to-RGB mapping */
 void
-png_set_bgr(png_struct *png_ptr)
+png_set_bgr(png_structp png_ptr)
 {
+   png_debug(1, "in png_set_bgr\n");
    png_ptr->transformations |= PNG_BGR;
 }
 #endif
@@ -23,8 +24,9 @@ png_set_bgr(png_struct *png_ptr)
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
 /* turn on 16 bit byte swapping */
 void
-png_set_swap(png_struct *png_ptr)
+png_set_swap(png_structp png_ptr)
 {
+   png_debug(1, "in png_set_swap\n");
    if (png_ptr->bit_depth == 16)
       png_ptr->transformations |= PNG_SWAP_BYTES;
 }
@@ -33,8 +35,9 @@ png_set_swap(png_struct *png_ptr)
 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
 /* turn on pixel packing */
 void
-png_set_packing(png_struct *png_ptr)
+png_set_packing(png_structp png_ptr)
 {
+   png_debug(1, "in png_set_packing\n");
    if (png_ptr->bit_depth < 8)
    {
       png_ptr->transformations |= PNG_PACK;
@@ -43,77 +46,127 @@ png_set_packing(png_struct *png_ptr)
 }
 #endif
 
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* turn on packed pixel swapping */
+void
+png_set_packswap(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_packswap\n");
+   if (png_ptr->bit_depth < 8)
+      png_ptr->transformations |= PNG_PACKSWAP;
+}
+#endif
+
 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
 void
-png_set_shift(png_struct *png_ptr, png_color_8 *true_bits)
+png_set_shift(png_structp png_ptr, png_color_8p true_bits)
 {
+   png_debug(1, "in png_set_shift\n");
    png_ptr->transformations |= PNG_SHIFT;
    png_ptr->shift = *true_bits;
 }
 #endif
 
-#if defined(PNG_READ_INTERLACING_SUPPORTED) || defined(PNG_WRITE_INTERLACING_SUPPORTED)
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+    defined(PNG_WRITE_INTERLACING_SUPPORTED)
 int
-png_set_interlace_handling(png_struct *png_ptr)
+png_set_interlace_handling(png_structp png_ptr)
 {
+   png_debug(1, "in png_set_interlace handling\n");
    if (png_ptr->interlaced)
    {
       png_ptr->transformations |= PNG_INTERLACE;
-      return 7;
+      return (7);
    }
 
-   return 1;
+   return (1);
 }
 #endif
 
 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte on read, or remove a filler or alpha byte on write.
+ * The filler type has changed in v0.95 to allow future 2-byte fillers
+ * for 48-bit input data, as well as to avoid problems with some compilers
+ * that don't like bytes as parameters.
+ */
 void
-png_set_filler(png_struct *png_ptr, int filler, int filler_loc)
+png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 {
+   png_debug(1, "in png_set_filler\n");
    png_ptr->transformations |= PNG_FILLER;
    png_ptr->filler = (png_byte)filler;
-   png_ptr->filler_loc = (png_byte)filler_loc;
-   if (png_ptr->color_type == PNG_COLOR_TYPE_RGB &&
-      png_ptr->bit_depth == 8)
+   if (filler_loc == PNG_FILLER_AFTER)
+      png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
+   else
+      png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
+
+   /* This should probably go in the "do_filler" routine.
+    * I attempted to do that in libpng-1.0.1a but that caused problems
+    * so I restored it in libpng-1.0.2a
+   */
+
+   if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+   {
       png_ptr->usr_channels = 4;
-}
+   }
 
-/* old functions kept around for compatability purposes */
-void
-png_set_rgbx(png_struct *png_ptr)
-{
-   png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
-}
+   /* Also I added this in libpng-1.0.2a (what happens when we expand
+    * a less-than-8-bit grayscale to GA? */
 
+   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
+   {
+      png_ptr->usr_channels = 2;
+   }
+}
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
 void
-png_set_xrgb(png_struct *png_ptr)
+png_set_swap_alpha(png_structp png_ptr)
 {
-   png_set_filler(png_ptr, 0xff, PNG_FILLER_BEFORE);
+   png_debug(1, "in png_set_swap_alpha\n");
+   png_ptr->transformations |= PNG_SWAP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+void
+png_set_invert_alpha(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_invert_alpha\n");
+   png_ptr->transformations |= PNG_INVERT_ALPHA;
 }
 #endif
 
 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
 void
-png_set_invert_mono(png_struct *png_ptr)
+png_set_invert_mono(png_structp png_ptr)
 {
+   png_debug(1, "in png_set_invert_mono\n");
    png_ptr->transformations |= PNG_INVERT_MONO;
 }
 
-/* invert monocrome grayscale data */
+/* invert monochrome grayscale data */
 void
-png_do_invert(png_row_info *row_info, png_bytef *row)
+png_do_invert(png_row_infop row_info, png_bytep row)
 {
-   if (row && row_info && row_info->bit_depth == 1 &&
-      row_info->color_type == PNG_COLOR_TYPE_GRAY)
+   png_debug(1, "in png_do_invert\n");
+   if (row_info->bit_depth == 1 &&
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+       row != NULL && row_info != NULL &&
+#endif
+       row_info->color_type == PNG_COLOR_TYPE_GRAY)
    {
-      png_bytef *rp;
+      png_bytep rp = row;
       png_uint_32 i;
+      png_uint_32 istop = row_info->rowbytes;
 
-      for (i = 0, rp = row;
-         i < row_info->rowbytes;
-         i++, rp++)
+      for (i = 0; i < istop; i++)
       {
-         *rp = ~(*rp);
+         *rp = (png_byte)(~(*rp));
+         rp++;
       }
    }
 }
@@ -122,19 +175,22 @@ png_do_invert(png_row_info *row_info, png_bytef *row)
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
 /* swaps byte order on 16 bit depth images */
 void
-png_do_swap(png_row_info *row_info, png_bytef *row)
+png_do_swap(png_row_infop row_info, png_bytep row)
 {
-   if (row && row_info && row_info->bit_depth == 16)
+   png_debug(1, "in png_do_swap\n");
+   if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+       row != NULL && row_info != NULL &&
+#endif
+       row_info->bit_depth == 16)
    {
-      png_bytef *rp;
-      png_byte t;
+      png_bytep rp = row;
       png_uint_32 i;
+      png_uint_32 istop= row_info->width * row_info->channels;
 
-      for (i = 0, rp = row;
-         i < row_info->width * row_info->channels;
-         i++, rp += 2)
+      for (i = 0; i < istop; i++, rp += 2)
       {
-         t = *rp;
+         png_byte t = *rp;
          *rp = *(rp + 1);
          *(rp + 1) = t;
       }
@@ -142,80 +198,398 @@ png_do_swap(png_row_info *row_info, png_bytef *row)
 }
 #endif
 
-#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
-/* swaps red and blue */
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+static png_byte onebppswaptable[256] = {
+   0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
+   0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
+   0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
+   0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
+   0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
+   0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
+   0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
+   0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
+   0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
+   0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
+   0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
+   0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
+   0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
+   0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
+   0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
+   0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
+   0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
+   0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
+   0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
+   0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
+   0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
+   0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
+   0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
+   0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
+   0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
+   0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
+   0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
+   0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
+   0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
+   0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
+   0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
+   0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
+};
+
+static png_byte twobppswaptable[256] = {
+   0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
+   0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
+   0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
+   0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,
+   0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,
+   0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,
+   0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,
+   0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,
+   0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,
+   0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,
+   0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,
+   0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,
+   0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,
+   0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,
+   0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,
+   0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,
+   0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,
+   0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,
+   0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,
+   0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,
+   0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,
+   0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,
+   0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,
+   0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,
+   0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,
+   0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,
+   0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,
+   0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,
+   0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,
+   0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,
+   0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,
+   0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
+};
+
+static png_byte fourbppswaptable[256] = {
+   0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
+   0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
+   0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
+   0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,
+   0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,
+   0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,
+   0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,
+   0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,
+   0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,
+   0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,
+   0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,
+   0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,
+   0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,
+   0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,
+   0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,
+   0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,
+   0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,
+   0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,
+   0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,
+   0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,
+   0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,
+   0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,
+   0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,
+   0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,
+   0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,
+   0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,
+   0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,
+   0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,
+   0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,
+   0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,
+   0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,
+   0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
+};
+
+/* swaps pixel packing order within bytes */
 void
-png_do_bgr(png_row_info *row_info, png_bytef *row)
+png_do_packswap(png_row_infop row_info, png_bytep row)
 {
-   if (row && row_info && (row_info->color_type & 2))
+   png_debug(1, "in png_do_packswap\n");
+   if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+       row != NULL && row_info != NULL &&
+#endif
+       row_info->bit_depth < 8)
    {
-      if (row_info->color_type == 2 && row_info->bit_depth == 8)
-      {
-         png_bytef *rp;
-         png_byte t;
-         png_uint_32 i;
+      png_bytep rp, end, table;
 
-         for (i = 0, rp = row;
-            i < row_info->width;
-            i++, rp += 3)
+      end = row + row_info->rowbytes;
+
+      if (row_info->bit_depth == 1)
+         table = onebppswaptable;
+      else if (row_info->bit_depth == 2)
+         table = twobppswaptable;
+      else if (row_info->bit_depth == 4)
+         table = fourbppswaptable;
+      else
+         return;
+
+      for (rp = row; rp < end; rp++)
+         *rp = table[*rp];
+   }
+}
+#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+/* remove filler or alpha byte(s) */
+void
+png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags)
+{
+   png_debug(1, "in png_do_strip_filler\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+   if (row != NULL && row_info != NULL)
+#endif
+   {
+/*
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB ||
+          row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+*/
+      png_bytep sp=row;
+      png_bytep dp=row;
+      png_uint_32 row_width=row_info->width;
+      png_uint_32 i;
+
+      if (row_info->channels == 4)
+      {
+         if (row_info->bit_depth == 8)
          {
-            t = *rp;
-            *rp = *(rp + 2);
-            *(rp + 2) = t;
+            /* This converts from RGBX or RGBA to RGB */
+            if (flags & PNG_FLAG_FILLER_AFTER)
+            {
+               dp+=3; sp+=4;
+               for (i = 1; i < row_width; i++)
+               {
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  sp++;
+               }
+            }
+            /* This converts from XRGB or ARGB to RGB */
+            else
+            {
+               for (i = 0; i < row_width; i++)
+               {
+                  sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+               }
+            }
+            row_info->pixel_depth = 24;
+            row_info->rowbytes = row_width * 3;
          }
+         else /* if (row_info->bit_depth == 16) */
+         {
+            if (flags & PNG_FLAG_FILLER_AFTER)
+            {
+               /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */
+               sp += 8; dp += 6;
+               for (i = 1; i < row_width; i++)
+               {
+                  /* This could be (although memcpy is probably slower):
+                  png_memcpy(dp, sp, 6);
+                  sp += 8;
+                  dp += 6;
+                  */
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  sp += 2;
+               }
+            }
+            else
+            {
+               /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */
+               for (i = 0; i < row_width; i++)
+               {
+                  /* This could be (although memcpy is probably slower):
+                  png_memcpy(dp, sp, 6);
+                  sp += 8;
+                  dp += 6;
+                  */
+                  sp+=2;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+               }
+            }
+            row_info->pixel_depth = 48;
+            row_info->rowbytes = row_width * 6;
+         }
+         row_info->channels = 3;
+         row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
       }
-      else if (row_info->color_type == 6 && row_info->bit_depth == 8)
+/*
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY ||
+               row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+*/
+      else if (row_info->channels == 2)
       {
-         png_bytef *rp;
-         png_byte t;
-         png_uint_32 i;
-
-         for (i = 0, rp = row;
-            i < row_info->width;
-            i++, rp += 4)
+         if (row_info->bit_depth == 8)
          {
-            t = *rp;
-            *rp = *(rp + 2);
-            *(rp + 2) = t;
+            /* This converts from GX or GA to G */
+            if (flags & PNG_FLAG_FILLER_AFTER)
+            {
+               for (i = 0; i < row_width; i++)
+               {
+                  *dp++ = *sp++;
+                  sp++;
+               }
+            }
+            /* This converts from XG or AG to G */
+            else
+            {
+               for (i = 0; i < row_width; i++)
+               {
+                  sp++;
+                  *dp++ = *sp++;
+               }
+            }
+            row_info->pixel_depth = 8;
+            row_info->rowbytes = row_width;
          }
-      }
-      else if (row_info->color_type == 2 && row_info->bit_depth == 16)
-      {
-         png_bytef *rp;
-         png_byte t[2];
-         png_uint_32 i;
-
-         for (i = 0, rp = row;
-            i < row_info->width;
-            i++, rp += 6)
+         else /* if (row_info->bit_depth == 16) */
          {
-            t[0] = *rp;
-            t[1] = *(rp + 1);
-            *rp = *(rp + 4);
-            *(rp + 1) = *(rp + 5);
-            *(rp + 4) = t[0];
-            *(rp + 5) = t[1];
-         }
-      }
-      else if (row_info->color_type == 6 && row_info->bit_depth == 16)
-      {
-         png_bytef *rp;
-         png_byte t[2];
-         png_uint_32 i;
-
-         for (i = 0, rp = row;
-            i < row_info->width;
-            i++, rp += 8)
-         {
-            t[0] = *rp;
-            t[1] = *(rp + 1);
-            *rp = *(rp + 4);
-            *(rp + 1) = *(rp + 5);
-            *(rp + 4) = t[0];
-            *(rp + 5) = t[1];
+            if (flags & PNG_FLAG_FILLER_AFTER)
+            {
+               /* This converts from GGXX or GGAA to GG */
+               sp += 4; dp += 2;
+               for (i = 1; i < row_width; i++)
+               {
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+                  sp += 2;
+               }
+            }
+            else
+            {
+               /* This converts from XXGG or AAGG to GG */
+               for (i = 0; i < row_width; i++)
+               {
+                  sp += 2;
+                  *dp++ = *sp++;
+                  *dp++ = *sp++;
+               }
+            }
+            row_info->pixel_depth = 16;
+            row_info->rowbytes = row_width * 2;
          }
+         row_info->channels = 1;
+         row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
       }
    }
 }
 #endif
 
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* swaps red and blue bytes within a pixel */
+void
+png_do_bgr(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_bgr\n");
+   if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+       row != NULL && row_info != NULL &&
+#endif
+       (row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      png_uint_32 row_width = row_info->width;
+      if (row_info->bit_depth == 8)
+      {
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 3)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 2);
+               *(rp + 2) = save;
+            }
+         }
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 4)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 2);
+               *(rp + 2) = save;
+            }
+         }
+      }
+      else if (row_info->bit_depth == 16)
+      {
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 6)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 4);
+               *(rp + 4) = save;
+               save = *(rp + 1);
+               *(rp + 1) = *(rp + 5);
+               *(rp + 5) = save;
+            }
+         }
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 8)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 4);
+               *(rp + 4) = save;
+               save = *(rp + 1);
+               *(rp + 1) = *(rp + 5);
+               *(rp + 5) = save;
+            }
+         }
+      }
+   }
+}
+#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+void
+png_set_user_transform_info(png_structp png_ptr, png_voidp
+   user_transform_ptr, int user_transform_depth, int user_transform_channels)
+{
+   png_debug(1, "in png_set_user_transform_info\n");
+   png_ptr->user_transform_ptr = user_transform_ptr;
+   png_ptr->user_transform_depth = user_transform_depth;
+   png_ptr->user_transform_channels = user_transform_channels;
+}
+
+/* This function returns a pointer to the user_transform_ptr associated with
+ * the user transform functions.  The application should free any memory
+ * associated with this pointer before png_write_destroy and png_read_destroy
+ * are called.
+ */
+png_voidp
+png_get_user_transform_ptr(png_structp png_ptr)
+{
+   return ((png_voidp)png_ptr->user_transform_ptr);
+}
+#endif

pngwio.c

@@ -0,0 +1,213 @@
+
+/* pngwio.c - functions for data output
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ *
+ * This file provides a location for all output.  Users who need
+ * special handling are expected to write functions that have the same
+ * arguments as these and perform similar functions, but that possibly
+ * use different output methods.  Note that you shouldn't change these
+ * functions, but rather write replacement functions and then change
+ * them at run time with png_set_write_fn(...).
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+/* Write the data to whatever output you are using.  The default routine
+   writes to a file pointer.  Note that this routine sometimes gets called
+   with very small lengths, so you should implement some kind of simple
+   buffering if you are using unbuffered writes.  This should never be asked
+   to write more than 64K on a 16 bit machine.  */
+
+void
+png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   if (png_ptr->write_data_fn != NULL )
+      (*(png_ptr->write_data_fn))(png_ptr, data, length);
+   else
+      png_error(png_ptr, "Call to NULL write function");
+}
+
+#if !defined(PNG_NO_STDIO)
+/* This is the function that does the actual writing of data.  If you are
+   not writing to a standard C stream, you should create a replacement
+   write_data function and use it at run time with png_set_write_fn(), rather
+   than changing the library. */
+#ifndef USE_FAR_KEYWORD
+static void
+png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_uint_32 check;
+
+   check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr));
+   if (check != length)
+   {
+      png_error(png_ptr, "Write Error");
+   }
+}
+#else
+/* this is the model-independent version. Since the standard I/O library
+   can't handle far buffers in the medium and small models, we have to copy
+   the data.
+*/
+
+#define NEAR_BUF_SIZE 1024
+#define MIN(a,b) (a <= b ? a : b)
+
+static void
+png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_uint_32 check;
+   png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
+   FILE *io_ptr;
+
+   /* Check if data really is near. If so, use usual code. */
+   near_data = (png_byte *)CVT_PTR_NOCHECK(data);
+   io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr);
+   if ((png_bytep)near_data == data)
+   {
+      check = fwrite(near_data, 1, length, io_ptr);
+   }
+   else
+   {
+      png_byte buf[NEAR_BUF_SIZE];
+      png_size_t written, remaining, err;
+      check = 0;
+      remaining = length;
+      do
+      {
+         written = MIN(NEAR_BUF_SIZE, remaining);
+         png_memcpy(buf, data, written); /* copy far buffer to near buffer */
+         err = fwrite(buf, 1, written, io_ptr);
+         if (err != written)
+            break;
+         else
+            check += err;
+         data += written;
+         remaining -= written;
+      }
+      while (remaining != 0);
+   }
+   if (check != length)
+   {
+      png_error(png_ptr, "Write Error");
+   }
+}
+
+#endif
+#endif
+
+/* This function is called to output any data pending writing (normally
+   to disk).  After png_flush is called, there should be no data pending
+   writing in any buffers. */
+#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+void
+png_flush(png_structp png_ptr)
+{
+   if (png_ptr->output_flush_fn != NULL)
+      (*(png_ptr->output_flush_fn))(png_ptr);
+}
+
+#if !defined(PNG_NO_STDIO)
+static void
+png_default_flush(png_structp png_ptr)
+{
+   FILE *io_ptr;
+   io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr));
+   if (io_ptr != NULL)
+      fflush(io_ptr);
+}
+#endif
+#endif
+
+/* This function allows the application to supply new output functions for
+   libpng if standard C streams aren't being used.
+
+   This function takes as its arguments:
+   png_ptr       - pointer to a png output data structure
+   io_ptr        - pointer to user supplied structure containing info about
+                   the output functions.  May be NULL.
+   write_data_fn - pointer to a new output function that takes as its
+                   arguments a pointer to a png_struct, a pointer to
+                   data to be written, and a 32-bit unsigned int that is
+                   the number of bytes to be written.  The new write
+                   function should call png_error(png_ptr, "Error msg")
+                   to exit and output any fatal error messages.
+   flush_data_fn - pointer to a new flush function that takes as its
+                   arguments a pointer to a png_struct.  After a call to
+                   the flush function, there should be no data in any buffers
+                   or pending transmission.  If the output method doesn't do
+                   any buffering of ouput, a function prototype must still be
+                   supplied although it doesn't have to do anything.  If
+                   PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
+                   time, output_flush_fn will be ignored, although it must be
+                   supplied for compatibility. */
+void
+png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
+   png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
+{
+   png_ptr->io_ptr = io_ptr;
+
+#if !defined(PNG_NO_STDIO)
+   if (write_data_fn != NULL)
+      png_ptr->write_data_fn = write_data_fn;
+   else
+      png_ptr->write_data_fn = png_default_write_data;
+#else
+   png_ptr->write_data_fn = write_data_fn;
+#endif
+
+#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+#if !defined(PNG_NO_STDIO)
+   if (output_flush_fn != NULL)
+      png_ptr->output_flush_fn = output_flush_fn;
+   else
+      png_ptr->output_flush_fn = png_default_flush;
+#else
+   png_ptr->output_flush_fn = output_flush_fn;
+#endif
+#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+
+   /* It is an error to read while writing a png file */
+   if (png_ptr->read_data_fn != NULL)
+   {
+      png_ptr->read_data_fn = NULL;
+      png_warning(png_ptr,
+         "Attempted to set both read_data_fn and write_data_fn in");
+      png_warning(png_ptr,
+         "the same structure.  Resetting read_data_fn to NULL.");
+   }
+}
+
+#if defined(USE_FAR_KEYWORD)
+#if defined(_MSC_VER)
+void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
+{
+   void *near_ptr;
+   void FAR *far_ptr;
+   FP_OFF(near_ptr) = FP_OFF(ptr);
+   far_ptr = (void FAR *)near_ptr;
+   if(check != 0)
+      if(FP_SEG(ptr) != FP_SEG(far_ptr))
+         png_error(png_ptr,"segment lost in conversion");
+   return(near_ptr);
+}
+#  else
+void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
+{
+   void *near_ptr;
+   void FAR *far_ptr;
+   near_ptr = (void FAR *)ptr;
+   far_ptr = (void FAR *)near_ptr;
+   if(check != 0)
+      if(far_ptr != ptr)
+         png_error(png_ptr,"segment lost in conversion");
+   return(near_ptr);
+}
+#   endif
+#   endif

pngwtran.c

@@ -1,38 +1,68 @@
 
-/* pngwtran.c - transforms the data in a row for png writers
-
-   libpng 1.0 beta 2 - version 0.81
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
-   August 24, 1995
-   */
+/* pngwtran.c - transforms the data in a row for PNG writers
+ *
+ * libpng 1.0.4c - October 1, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ */
 
 #define PNG_INTERNAL
 #include "png.h"
 
-/* transform the data according to the users wishes.  The order of
-   transformations is significant. */
+/* Transform the data according to the user's wishes.  The order of
+ * transformations is significant.
+ */
 void
-png_do_write_transformations(png_struct *png_ptr)
+png_do_write_transformations(png_structp png_ptr)
 {
+   png_debug(1, "in png_do_write_transformations\n");
+
+#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+   if (png_ptr->transformations & PNG_USER_TRANSFORM)
+      if(png_ptr->write_user_transform_fn != NULL)
+        (*(png_ptr->write_user_transform_fn)) /* user write transform function */
+          (png_ptr,                    /* png_ptr */
+           &(png_ptr->row_info),       /* row_info:     */
+             /*  png_uint_32 width;          width of row */
+             /*  png_uint_32 rowbytes;       number of bytes in row */
+             /*  png_byte color_type;        color type of pixels */
+             /*  png_byte bit_depth;         bit depth of samples */
+             /*  png_byte channels;          number of channels (1-4) */
+             /*  png_byte pixel_depth;       bits per pixel (depth*channels) */
+           png_ptr->row_buf + 1);      /* start of pixel data for row */
+#endif
 #if defined(PNG_WRITE_FILLER_SUPPORTED)
-   if (png_ptr->transformations & PNG_RGBA)
-      png_do_write_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
-         png_ptr->filler_loc);
+   if (png_ptr->transformations & PNG_FILLER)
+      png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
+         png_ptr->flags);
+#endif
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+   if (png_ptr->transformations & PNG_PACKSWAP)
+      png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 #if defined(PNG_WRITE_PACK_SUPPORTED)
    if (png_ptr->transformations & PNG_PACK)
       png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1,
-         png_ptr->bit_depth);
+         (png_uint_32)png_ptr->bit_depth);
+#endif
+#if defined(PNG_WRITE_SWAP_SUPPORTED)
+   if (png_ptr->transformations & PNG_SWAP_BYTES)
+      png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
    if (png_ptr->transformations & PNG_SHIFT)
       png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1,
          &(png_ptr->shift));
 #endif
-#if defined(PNG_WRITE_SWAP_SUPPORTED)
-   if (png_ptr->transformations & PNG_SWAP_BYTES)
-      png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+   if (png_ptr->transformations & PNG_INVERT_ALPHA)
+      png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+   if (png_ptr->transformations & PNG_SWAP_ALPHA)
+      png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 #if defined(PNG_WRITE_BGR_SUPPORTED)
    if (png_ptr->transformations & PNG_BGR)
@@ -45,32 +75,37 @@ png_do_write_transformations(png_struct *png_ptr)
 }
 
 #if defined(PNG_WRITE_PACK_SUPPORTED)
-/* pack pixels into bytes.  Pass the true bit depth in bit_depth.  The
-   row_info bit depth should be 8 (one pixel per byte).  The channels
-   should be 1 (this only happens on grayscale and paletted images) */
+/* Pack pixels into bytes.  Pass the true bit depth in bit_depth.  The
+ * row_info bit depth should be 8 (one pixel per byte).  The channels
+ * should be 1 (this only happens on grayscale and paletted images).
+ */
 void
-png_do_pack(png_row_info *row_info, png_bytef *row, png_byte bit_depth)
+png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
 {
-   if (row_info && row && row_info->bit_depth == 8 &&
+   png_debug(1, "in png_do_pack\n");
+   if (row_info->bit_depth == 8 &&
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+       row != NULL && row_info != NULL &&
+#endif
       row_info->channels == 1)
    {
-      switch (bit_depth)
+      switch ((int)bit_depth)
       {
          case 1:
          {
-            png_bytef *sp;
-            png_bytef *dp;
-            int mask;
-            png_int_32 i;
-            int v;
+            png_bytep sp, dp;
+            int mask, v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
 
             sp = row;
             dp = row;
             mask = 0x80;
             v = 0;
-            for (i = 0; i < row_info->width; i++)
+
+            for (i = 0; i < row_width; i++)
             {
-               if (*sp)
+               if (*sp != 0)
                   v |= mask;
                sp++;
                if (mask > 1)
@@ -78,36 +113,36 @@ png_do_pack(png_row_info *row_info, png_bytef *row, png_byte bit_depth)
                else
                {
                   mask = 0x80;
-                  *dp = v;
+                  *dp = (png_byte)v;
                   dp++;
                   v = 0;
                }
             }
             if (mask != 0x80)
-               *dp = v;
+               *dp = (png_byte)v;
             break;
          }
          case 2:
          {
-            png_bytef *sp;
-            png_bytef *dp;
-            int shift;
-            png_int_32 i;
-            int v;
-            png_byte value;
+            png_bytep sp, dp;
+            int shift, v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
 
             sp = row;
             dp = row;
             shift = 6;
             v = 0;
-            for (i = 0; i < row_info->width; i++)
+            for (i = 0; i < row_width; i++)
             {
-               value = *sp & 0x3;
+               png_byte value;
+
+               value = (png_byte)(*sp & 0x3);
                v |= (value << shift);
                if (shift == 0)
                {
                   shift = 6;
-                  *dp = v;
+                  *dp = (png_byte)v;
                   dp++;
                   v = 0;
                }
@@ -116,31 +151,31 @@ png_do_pack(png_row_info *row_info, png_bytef *row, png_byte bit_depth)
                sp++;
             }
             if (shift != 6)
-                   *dp = v;
+               *dp = (png_byte)v;
             break;
          }
          case 4:
          {
-            png_bytef *sp;
-            png_bytef *dp;
-            int shift;
-            png_int_32 i;
-            int v;
-            png_byte value;
+            png_bytep sp, dp;
+            int shift, v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
 
             sp = row;
             dp = row;
             shift = 4;
             v = 0;
-            for (i = 0; i < row_info->width; i++)
+            for (i = 0; i < row_width; i++)
             {
-               value = *sp & 0xf;
+               png_byte value;
+
+               value = (png_byte)(*sp & 0xf);
                v |= (value << shift);
 
                if (shift == 0)
                {
                   shift = 4;
-                  *dp = v;
+                  *dp = (png_byte)v;
                   dp++;
                   v = 0;
                }
@@ -150,12 +185,12 @@ png_do_pack(png_row_info *row_info, png_bytef *row, png_byte bit_depth)
                sp++;
             }
             if (shift != 4)
-               *dp = v;
+               *dp = (png_byte)v;
             break;
          }
       }
-      row_info->bit_depth = bit_depth;
-      row_info->pixel_depth = bit_depth * row_info->channels;
+      row_info->bit_depth = (png_byte)bit_depth;
+      row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
       row_info->rowbytes =
          ((row_info->width * row_info->pixel_depth + 7) >> 3);
    }
@@ -163,22 +198,27 @@ png_do_pack(png_row_info *row_info, png_bytef *row, png_byte bit_depth)
 #endif
 
 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
-/* shift pixel values to take advantage of whole range.  Pass the
-   true number of bits in bit_depth.  The row should be packed
-   according to row_info->bit_depth.  Thus, if you had a row of
-   bit depth 4, but the pixels only had values from 0 to 7, you
-   would pass 3 as bit_depth, and this routine would translate the
-   data to 0 to 15. */
+/* Shift pixel values to take advantage of whole range.  Pass the
+ * true number of bits in bit_depth.  The row should be packed
+ * according to row_info->bit_depth.  Thus, if you had a row of
+ * bit depth 4, but the pixels only had values from 0 to 7, you
+ * would pass 3 as bit_depth, and this routine would translate the
+ * data to 0 to 15.
+ */
 void
-png_do_shift(png_row_info *row_info, png_bytef *row, png_color_8 *bit_depth)
+png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
 {
-   if (row && row_info &&
+   png_debug(1, "in png_do_shift\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+   if (row != NULL && row_info != NULL &&
+#else
+   if (
+#endif
       row_info->color_type != PNG_COLOR_TYPE_PALETTE)
    {
       int shift_start[4], shift_dec[4];
-      int channels;
+      int channels = 0;
 
-      channels = 0;
       if (row_info->color_type & PNG_COLOR_MASK_COLOR)
       {
          shift_start[channels] = row_info->bit_depth - bit_depth->red;
@@ -204,13 +244,13 @@ png_do_shift(png_row_info *row_info, png_bytef *row, png_color_8 *bit_depth)
          channels++;
       }
 
-      /* with low row dephts, could only be grayscale, so one channel */
+      /* with low row depths, could only be grayscale, so one channel */
       if (row_info->bit_depth < 8)
       {
-         png_bytef *bp;
+         png_bytep bp = row;
          png_uint_32 i;
-         int j;
          png_byte mask;
+         png_uint_32 row_bytes = row_info->rowbytes;
 
          if (bit_depth->gray == 1 && row_info->bit_depth == 2)
             mask = 0x55;
@@ -219,9 +259,10 @@ png_do_shift(png_row_info *row_info, png_bytef *row, png_color_8 *bit_depth)
          else
             mask = 0xff;
 
-         for (bp = row, i = 0; i < row_info->rowbytes; i++, bp++)
+         for (i = 0; i < row_bytes; i++, bp++)
          {
-            int v;
+            png_uint_16 v;
+            int j;
 
             v = *bp;
             *bp = 0;
@@ -236,110 +277,221 @@ png_do_shift(png_row_info *row_info, png_bytef *row, png_color_8 *bit_depth)
       }
       else if (row_info->bit_depth == 8)
       {
-         png_bytef *bp;
+         png_bytep bp = row;
          png_uint_32 i;
-         int j;
+         png_uint_32 istop = channels * row_info->width;
 
-         for (bp = row, i = 0; i < row_info->width; i++)
+         for (i = 0; i < istop; i++, bp++)
          {
-            int c;
 
-            for (c = 0; c < channels; c++, bp++)
+            png_uint_16 v;
+            int j;
+            int c = (int)(i%channels);
+
+            v = *bp;
+            *bp = 0;
+            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
             {
-               int v;
-
-               v = *bp;
-               *bp = 0;
-               for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
-               {
-                  if (j > 0)
-                     *bp |= (png_byte)((v << j) & 0xff);
-                  else
-                     *bp |= (png_byte)((v >> (-j)) & 0xff);
-               }
+               if (j > 0)
+                  *bp |= (png_byte)((v << j) & 0xff);
+               else
+                  *bp |= (png_byte)((v >> (-j)) & 0xff);
             }
          }
       }
       else
       {
-         png_bytef *bp;
+         png_bytep bp;
          png_uint_32 i;
-         int j;
+         png_uint_32 istop = channels * row_info->width;
 
-         for (bp = row, i = 0;
-            i < row_info->width * row_info->channels;
-            i++)
+         for (bp = row, i = 0; i < istop; i++)
          {
-            int c;
+            int c = (int)(i%channels);
+            png_uint_16 value, v;
+            int j;
 
-            for (c = 0; c < channels; c++, bp += 2)
+            v = ((png_uint_16)(*bp) << 8) + *(bp + 1);
+            value = 0;
+            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
             {
-               png_uint_16 value, v;
-
-               v = ((png_uint_16)(*bp) << 8) + (png_uint_16)(*(bp + 1));
-               value = 0;
-               for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
-               {
-                  if (j > 0)
-                     value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
-                  else
-                     value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
-               }
-               *bp = value >> 8;
-               *(bp + 1) = value & 0xff;
+               if (j > 0)
+                  value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
+               else
+                  value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
             }
+            *bp++ = (png_byte)(value >> 8);
+            *bp++ = (png_byte)(value & 0xff);
          }
       }
    }
 }
 #endif
 
-#ifdef PNG_WRITE_FILLER_SUPPORTED
-/* remove filler byte */
+#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
 void
-png_do_write_filler(png_row_info *row_info, png_bytef *row,
-   png_byte filler_loc)
+png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
 {
-   if (row && row_info && row_info->color_type == PNG_COLOR_TYPE_RGB &&
-      row_info->bit_depth == 8)
+   png_debug(1, "in png_do_write_swap_alpha\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+   if (row != NULL && row_info != NULL)
+#endif
    {
-      if (filler_loc == PNG_FILLER_AFTER)
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
       {
-      png_bytef *sp, *dp;
-         png_uint_32 i;
-
-         for (i = 1, sp = row + 4, dp = row + 3;
-            i < row_info->width;
-            i++)
+         /* This converts from ARGB to RGBA */
+         if (row_info->bit_depth == 8)
          {
-            *dp++ = *sp++;
-            *dp++ = *sp++;
-            *dp++ = *sp++;
-            sp++;
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save;
+            }
+         }
+         /* This converts from AARRGGBB to RRGGBBAA */
+         else
+         {
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save[2];
+               save[0] = *(sp++);
+               save[1] = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save[0];
+               *(dp++) = save[1];
+            }
          }
-         row_info->channels = 3;
-         row_info->pixel_depth = 24;
-         row_info->rowbytes = row_info->width * 3;
       }
-      else
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
       {
-      png_bytef *sp, *dp;
-         png_uint_32 i;
-
-         for (i = 1, sp = row + 4, dp = row + 3;
-            i < row_info->width;
-            i++)
+         /* This converts from AG to GA */
+         if (row_info->bit_depth == 8)
          {
-            sp++;
-            *dp++ = *sp++;
-            *dp++ = *sp++;
-            *dp++ = *sp++;
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save;
+            }
+         }
+         /* This converts from AAGG to GGAA */
+         else
+         {
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save[2];
+               save[0] = *(sp++);
+               save[1] = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save[0];
+               *(dp++) = save[1];
+            }
          }
-         row_info->channels = 3;
-         row_info->pixel_depth = 24;
-         row_info->rowbytes = row_info->width * 3;
       }
    }
 }
 #endif
 
+#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+void
+png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_invert_alpha\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+   if (row != NULL && row_info != NULL)
+#endif
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         /* This inverts the alpha channel in RGBA */
+         if (row_info->bit_depth == 8)
+         {
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = 255 - *(sp++);
+            }
+         }
+         /* This inverts the alpha channel in RRGGBBAA */
+         else
+         {
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = 255 - *(sp++);
+               *(dp++) = 255 - *(sp++);
+            }
+         }
+      }
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         /* This inverts the alpha channel in GA */
+         if (row_info->bit_depth == 8)
+         {
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               *(dp++) = *(sp++);
+               *(dp++) = 255 - *(sp++);
+            }
+         }
+         /* This inverts the alpha channel in GGAA */
+         else
+         {
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = 255 - *(sp++);
+               *(dp++) = 255 - *(sp++);
+            }
+         }
+      }
+   }
+}
+#endif

readme.txt

@@ -1,94 +0,0 @@
-readme.txt - for libpng 0.8
-
-This is the second beta version of libpng 1.0.  I've updated most
-of the stuff I want to before the final 1.0 version.  Remaining
-to do are the medium memory model support (which I'll put in
-as soon as we test this version), better dithering, and any bug
-fixes and makefile/include additions.  I expect a third (and
-perhaps final) beta after zlib is officially 1.0.
-
-I've tried to incorporate all the changes and makefiles everyone
-sent me.  However, I may of lost some in the flood.  If you sent
-me a change and I didn't put it in, send it again.  Sorry.
-
-Updates from libpng 0.71 include a new transformation,
-png_set_filler(), which replaces png_set_rgbx() and
-png_set_xrgb().  The old functions will be supported for
-awhile, but I'd suggest changing to the new function.  Also,
-I've added defines in png.h to remove unwanted code from the
-compiled library.  I've added a new field to png_realloc(), and
-fixed various bugs.  I've also split up pngstub.c into pngmem.c,
-pngio.c, and pngerror.c, in case you need to just change some of
-these.  I've pulled pngconf.h out of png.h, so you don't have to
-remake your changes every new release.  I've added a function to
-update the png_info structure after you're done setting up your
-transformations (png_read_update_info()).  The complete list of
-changes is in pngchang.txt.  Most of you won't be much affected
-by any of this.  Some of you will want to use the new features.
-
-For a detailed description on using libpng, read libpng.txt.  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, but you may have to modify it
-for your own needs.
-
-You will need zlib 0.95 or later to run this.  zlib is a compression
-library that is useful for more things then just png files.  If
-you need a compression library, check out zlib.h
-
-zlib should be available at the same place that libpng is.
-If not, it should be at ftp.uu.net in /graphics/png
-Eventually, it will be at ftp.uu.net in /pub/archiving/zip/zlib
-
-You will also want a copy of the PNG specification.  It should
-be available at the same place you picked up libpng.  If it is
-not there, try ftp.uu.net in the /graphics/png directory.
-
-This code is currently being archived at ftp.uu.net in the
-/graphics/png directory, and at ftp.group42.com (204.94.158.25)
-in the /pub/png directory, 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.
-
-You can reach me at:
-
-internet: schalnat@group42.com
-CompuServe: 75501,1625
-
-Please do not send me general questions about PNG.  Send them to
-the address in the specification.  At the same time, please do
-not send libpng questions to that address, send them to me.  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 9 months 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 for version
-1.0, it may be used later.
-
-Good luck, and happy coding.
-
--Guy Eric Schalnat
- Group 42, Inc.
- Internet: schalnat@group42.com
- CompuServe: 75501,1625
- Web: www.group42.com
- FTP: ftp.group42.com (204.94.158.25)
-

scripts/SCOPTIONS.ppc

@@ -0,0 +1,7 @@
+OPTIMIZE
+OPTPEEP
+OPTTIME
+OPTSCHED
+AUTOREGISTER
+PARMS=REGISTERS
+INCLUDEDIR=hlp:ppc/include

scripts/build.bat

@@ -0,0 +1,2 @@
+make -fmakefile.bor -B -DMODEL=m %1 %2 %3 libpng >buildm.out
+make -fmakefile.bor -B -DMODEL=l %1 %2 %3 libpng >buildl.out

scripts/descrip.mms

@@ -0,0 +1,52 @@
+
+cc_defs = /inc=$(ZLIBSRC)
+c_deb = 
+
+.ifdef __DECC__
+pref = /prefix=all
+.endif
+
+
+
+OBJS = png.obj, pngset.obj, pngget.obj, pngrutil.obj, pngtrans.obj,\
+	pngwutil.obj, pngread.obj, pngmem.obj, pngwrite.obj, pngrtran.obj,\
+	pngwtran.obj, pngrio.obj, pngwio.obj, pngerror.obj, pngpread.obj
+
+
+CFLAGS= $(C_DEB) $(CC_DEFS) $(PREF)
+
+all : pngtest.exe libpng.olb
+		@ write sys$output " pngtest available"
+
+libpng.olb : libpng.olb($(OBJS))
+	@ write sys$output " Libpng available"
+
+
+pngtest.exe : pngtest.obj libpng.olb
+              link pngtest,libpng.olb/lib,$(ZLIBSRC)libz.olb/lib
+
+test : pngtest.exe
+   run pngtest
+
+clean :
+	delete *.obj;*,*.exe;*
+
+
+# Other dependencies.
+png.obj : png.h, pngconf.h
+pngpread.obj : png.h, pngconf.h
+pngset.obj : png.h, pngconf.h
+pngget.obj : png.h, pngconf.h
+pngread.obj : png.h, pngconf.h
+pngrtran.obj : png.h, pngconf.h
+pngrutil.obj : png.h, pngconf.h
+pngerror.obj : png.h, pngconf.h
+pngmem.obj : png.h, pngconf.h
+pngrio.obj : png.h, pngconf.h
+pngwio.obj : png.h, pngconf.h
+pngtest.obj : png.h, pngconf.h
+pngtrans.obj : png.h, pngconf.h
+pngwrite.obj : png.h, pngconf.h
+pngwtran.obj : png.h, pngconf.h
+pngwutil.obj : png.h, pngconf.h
+

scripts/makefile.acorn

@@ -0,0 +1,51 @@
+# Project:   libpng
+
+
+# Toolflags:
+CCflags = -c -depend !Depend -IC:,Zlib: -g -throwback  -DRISCOS  -fnah 
+C++flags = -c -depend !Depend -IC: -throwback
+Linkflags = -aif -c++ -o $@
+ObjAsmflags = -throwback -NoCache -depend !Depend
+CMHGflags = 
+LibFileflags = -c -l -o $@ 
+Squeezeflags = -o $@
+
+
+# Final targets:
+@.libpng-lib:   @.o.png @.o.pngerror @.o.pngrio @.o.pngwio @.o.pngmem \
+	@.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngrtran \
+	@.o.pngrutil @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil 
+	LibFile $(LibFileflags) @.o.png @.o.pngerror @.o.pngrio @.o.pngrtran \
+	@.o.pngmem @.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngwio \
+	@.o.pngrutil @.o.pngtrans  @.o.pngwrite @.o.pngwtran @.o.pngwutil 
+@.mm-libpng-lib:   @.mm.png @.mm.pngerror @.mm.pngrio @.mm.pngwio @.mm.pngmem \
+	@.mm.pngpread @.mm.pngset @.mm.pngget @.mm.pngread @.mm.pngrtran \
+	@.mm.pngrutil @.mm.pngtrans @.mm.pngwrite @.mm.pngwtran @.mm.pngwutil 
+	LibFile $(LibFileflags) @.mm.png @.mm.pngerror @.mm.pngrio \
+	@.mm.pngwio @.mm.pngmem @.mm.pngpread @.mm.pngset @.mm.pngget \
+	@.mm.pngread @.mm.pngrtran @.mm.pngrutil @.mm.pngtrans @.mm.pngwrite \
+	@.mm.pngwtran @.mm.pngwutil 
+
+
+# User-editable dependencies:
+# (C) Copyright 1997 Tom Tanner
+Test: @.pngtest 
+	<Prefix$Dir>.pngtest
+	@remove <Prefix$Dir>.pngtest
+
+#It would be nice if you could stop "make" listing from here on!
+@.pngtest:   @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib 
+	Link $(Linkflags) @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib 
+
+.SUFFIXES: .o .mm .c
+
+.c.mm:
+	MemCheck.CC cc $(ccflags) -o $@ LibPng:$<
+.c.o:
+	cc $(ccflags) -o $@ $<
+
+
+# Static dependencies:
+
+
+# Dynamic dependencies:

scripts/makefile.amiga

@@ -0,0 +1,42 @@
+# Commodore Amiga Makefile
+# makefile for libpng and SAS C V6.55 compiler
+# Copyright (C) 1995 Wolf Faust
+
+#compiler
+CC=sc
+#compiler flags
+# WARNING: a bug in V6.51 causes bad code with OPTGO
+#          So use V6.55 or set NOOPTGO!!!!!!!!!
+CFLAGS= NOSTKCHK PARMS=REG OPTIMIZE OPTGO OPTPEEP OPTINLOCAL OPTINL\
+	OPTLOOP OPTRDEP=4 OPTDEP=4 OPTCOMP=4 DEFINE=PNG_INTERNAL
+#linker flags
+LDFLAGS= SD ND BATCH
+#link libs
+LDLIBS= libpng.lib libgz.lib LIB:scm.lib LIB:sc.lib Lib:amiga.lib
+# linker
+LN= slink
+# file deletion command
+RM= delete quiet
+# library (.lib) file creation command
+AR= oml
+# make directory command
+MKDIR= makedir
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o pngpread.o \
+pngread.o pngerror.o pngwrite.o pngrtran.o pngwtran.o pngrio.o pngwio.o pngmem.o
+
+all: libpng.lib pngtest
+
+libpng.lib: $(OBJS)
+-$(RM) libpng.lib
+$(AR) libpng.lib r $(OBJS)
+
+pngtest: pngtest.o libpng.lib
+$(LN) <WITH <
+$(LDFLAGS)
+TO pngtest
+FROM LIB:c.o pngtest.o
+LIB $(LDLIBS)
+<
+
+

scripts/makefile.atari

@@ -0,0 +1,33 @@
+# makefile for libpng
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# For conditions of distribution and use, see copyright notice in png.h
+# modified for LC56/ATARI assumes libz.lib is in same dir and uses default
+# rules for library management
+#
+CFLAGS=-I..\zlib -O
+LBR = png.lib
+LDFLAGS=-lpng -lz -lm
+
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
+OBJS = $(LBR)(png.o) $(LBR)(pngset.o) $(LBR)(pngget.o) $(LBR)(pngrutil.o)\
+	$(LBR)(pngtrans.o) $(LBR)(pngwutil.o)\
+	$(LBR)(pngread.o) $(LBR)(pngerror.o) $(LBR)(pngwrite.o)\
+	$(LBR)(pngrtran.o) $(LBR)(pngwtran.o)\
+	$(LBR)(pngmem.o) $(LBR)(pngrio.o) $(LBR)(pngwio.o) $(LBR)(pngpread.o)
+
+all: $(LBR) pngtest.ttp
+
+$(LBR): $(OBJS)
+
+pngtest.ttp: pngtest.o $(LBR)
+	$(CC) $(CFLAGS) $(LDFLAGS) -o$@ pngtest.o
+
+install: libpng.a
+	-@mkdir $(prefix)/include
+	-@mkdir $(prefix)/lib
+	cp png.h $(prefix)/include
+	cp pngconf.h $(prefix)/include
+	chmod 644 $(prefix)/include/png.h
+	chmod 644 $(prefix)/include/pngconf.h

scripts/makefile.beos

@@ -0,0 +1,104 @@
+# makefile for libpng on BeOS x86 ELF with gcc
+# modified from makefile.linux by Sander Stoks
+# Copyright (C) 1996, 1997 Andreas Dilger
+# Copyright (C) 1999 Greg Roelofs
+# For conditions of distribution and use, see copyright notice in png.h
+
+CC=gcc
+
+# Where the zlib library and include files are located
+ZLIBLIB=/usr/local/lib
+ZLIBINC=/usr/local/include
+
+ALIGN=
+# For i386:
+# ALIGN=-malign-loops=2 -malign-functions=2
+
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+
+# On BeOS, -O1 is actually better than -O3.  This is a known bug but it's
+# still here in R4.5
+CFLAGS=-I$(ZLIBINC) -Wall -O1 -funroll-loops \
+	$(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
+# LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng -lz -lm
+LDFLAGS=-L. -Wl,-soname=libpng.so.$(PNGMAJ) -L$(ZLIBLIB) -lz -lm
+
+RANLIB=ranlib
+#RANLIB=echo
+
+# read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
+# have to change it.
+PNGMAJ = 2
+PNGMIN = 1.0.4c
+PNGVER = $(PNGMAJ).$(PNGMIN)
+
+# where make install puts libpng.a, libpng.so*, and png.h
+prefix=/usr/local
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+OBJSDLL = $(OBJS)
+
+.SUFFIXES:      .c .o
+
+all: libpng.a libpng.so pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@ $(OBJS)
+	$(RANLIB) $@
+
+libpng.so: libpng.so.$(PNGMAJ)
+	ln -sf libpng.so.$(PNGMAJ) libpng.so
+	cp libpng.so* /boot/home/config/lib
+
+libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
+	ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+
+libpng.so.$(PNGVER): $(OBJSDLL)
+	$(CC) -L$(ZLIBLIB) -lz -nostart -Wl,-soname,libpng.so.$(PNGMAJ) -o
+libpng.so.$(PNGVER) \
+	 $(OBJSDLL)
+
+pngtest: pngtest.o libpng.so
+	$(CC) -L$(ZLIBLIB) -lz -lpng -o pngtest pngtest.o
+
+test: pngtest
+	./pngtest
+
+install: libpng.a libpng.so.$(PNGVER)
+	-@mkdir $(INCPATH) $(LIBPATH)
+	cp png.h pngconf.h $(INCPATH)
+	chmod 644 $(INCPATH)/png.h $(INCPATH)/pngconf.h
+	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
+	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
+	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
+	(cd $(LIBPATH); ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -sf libpng.so.$(PNGMAJ) libpng.so)
+
+clean:
+	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o png.pic.o: png.h pngconf.h
+pngerror.o pngerror.pic.o: png.h pngconf.h
+pngrio.o pngrio.pic.o: png.h pngconf.h
+pngwio.o pngwio.pic.o: png.h pngconf.h
+pngmem.o pngmem.pic.o: png.h pngconf.h
+pngset.o pngset.pic.o: png.h pngconf.h
+pngget.o pngget.pic.o: png.h pngconf.h
+pngread.o pngread.pic.o: png.h pngconf.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h
+pngpread.o pngpread.pic.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h

scripts/makefile.borland

@@ -0,0 +1,168 @@
+# Makefile for libpng
+# Borland C++ 4.5 (Note: All modules are compiled in C mode)
+# Will work with C++ 4.02 also
+# To build the library, do: 
+#       "make -fmakefile.borland -DMODEL=m"
+# or:   "make -fmakefile.borland -DMODEL=l"
+#
+# ------------- Borland C++ 4.5 -------------
+
+### Absolutely necessary for this makefile to work
+.AUTODEPEND
+
+## Useful user options
+
+# Usually defined in builtins.mak or the environment
+# Currently unused.
+!ifndef BCROOT
+BCROOT=N:\BC45
+!endif
+
+# Where zlib.h and zconf.h and zlib.lib are
+ZLIB_PATH=..\zlib
+
+!ifndef MODEL
+MODEL=l
+!endif
+
+#TARGET_CPU=3
+# 2 = 286, 3 = 386, etc.
+!ifndef TARGET_CPU
+TARGET_CPU=2
+!endif
+
+
+# Use this if you don't want Borland's fancy exception handling.
+NOEHLIB=noeh$(MODEL).lib
+
+!ifdef DEBUG
+CDEBUG=-v
+LDEBUG=-v
+!else
+CDEBUG=
+LDEBUG=
+!endif
+
+# STACKOFLOW=1
+!ifdef STACKOFLOW
+CDEBUG=$(CDEBUG) -N
+LDEBUG=$(LDEBUG) -N
+!endif
+
+
+## Compiler, linker, and lib stuff
+CC=bcc
+LD=bcc
+LIB=tlib
+
+MODELARG=-m$(MODEL)
+
+# -X- turns on dependency generation in the object file
+# -w  sets all warnings on
+# -O2 optimize for speed
+# -Z  global optimization
+CFLAGS=-O2 -Z -X- -w -I$(ZLIB_PATH) -$(TARGET_CPU) $(MODELARG) $(CDEBUG)
+
+# -M  generate map file
+LDFLAGS=-M $(LDEBUG)
+
+O=obj
+
+## variables
+OBJS = \
+	png.$(O) \
+	pngerror.$(O) \
+	pngmem.$(O) \
+	pngpread.$(O) \
+	pngset.$(O) \
+	pngget.$(O) \
+	pngread.$(O) \
+	pngrio.$(O) \
+	pngrtran.$(O) \
+	pngrutil.$(O) \
+	pngtrans.$(O) \
+	pngwrite.$(O) \
+	pngwtran.$(O) \
+	pngwio.$(O) \
+	pngwutil.$(O)
+
+LIBOBJS = \
+	+png.$(O) \
+	+pngerror.$(O) \
+	+pngmem.$(O) \
+	+pngpread.$(O) \
+	+pngread.$(O) \
+	+pngset.$(O) \
+	+pngget.$(O) \
+	+pngrio.$(O) \
+	+pngrtran.$(O) \
+	+pngrutil.$(O) \
+	+pngtrans.$(O) \
+	+pngwrite.$(O) \
+	+pngwtran.$(O) \
+	+pngwio.$(O) \
+	+pngwutil.$(O)
+
+LIBNAME=libpng$(MODEL).lib
+
+
+## Implicit rules
+# Braces let make "batch" calls to the compiler,
+# 2 calls instead of 12; space is important.
+.c.obj:
+	$(CC) $(CFLAGS) -c {$*.c }
+
+.c.exe:
+	$(CC) $(CFLAGS) $(LDFLAGS) $*.c
+
+
+## Major targets
+libpng: $(LIBNAME)
+
+pngtest: pngtest$(MODEL).exe
+
+test: pngtest$(MODEL).exe
+	pngtest$(MODEL)
+
+
+## Minor Targets
+
+png.obj: png.c
+pngset.obj: pngset.c
+pngget.obj: pngget.c
+pngread.obj: pngread.c
+pngpread.obj: pngpread.c
+pngrtran.obj: pngrtran.c
+pngrutil.obj: pngrutil.c
+pngerror.obj: pngerror.c
+pngmem.obj: pngmem.c
+pngrio.obj: pngrio.c
+pngwio.obj: pngwio.c
+pngtrans.obj: pngtrans.c
+pngwrite.obj: pngwrite.c
+pngwtran.obj: pngwtran.c
+pngwutil.obj: pngwutil.c
+
+
+$(LIBNAME): $(OBJS)
+	-del $(LIBNAME)
+	$(LIB) $(LIBNAME) @&&|
+$(LIBOBJS), libpng$(MODEL)
+|
+
+
+pngtest$(MODEL).obj: pngtest.c
+	$(CC) $(CFLAGS) -opngtest$(MODEL) -c pngtest.c
+
+pngtest$(MODEL).exe: pngtest$(MODEL).obj
+	$(CC) $(MODELARG) $(LDFLAGS) -L$(ZLIB_PATH) pngtest$(MODEL).obj $(LIBNAME) zlib$(MODEL).lib $(NOEHLIB)
+
+
+# Clean up anything else you want
+clean:
+	-del *.obj
+	-del *.lib
+	-del *.lst
+
+
+# End of makefile for libpng

scripts/makefile.dec

@@ -0,0 +1,89 @@
+# makefile for libpng on DEC Alpha Unix
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# For conditions of distribution and use, see copyright notice in png.h
+
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+
+# read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
+# have to change it.
+PNGMAJ = 2
+PNGMIN = 1.0.4c
+PNGVER = $(PNGMAJ).$(PNGMIN)
+
+CC=cc
+CFLAGS=-std -w1 -I$(ZLIBINC) -O # -g -DPNG_DEBUG=1
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+
+#RANLIB=echo
+RANLIB=ranlib
+
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+all: libpng.so libpng.a pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@  $(OBJS)
+	$(RANLIB) $@
+
+libpng.so: libpng.so.$(PNGMAJ)
+	ln -f -s libpng.so.$(PNGMAJ) libpng.so
+
+libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
+	ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+
+libpng.so.$(PNGVER): $(OBJS)
+	$(CC) -shared -o $@ $(OBJS) -L$(ZLIBLIB) -lz -lm
+
+pngtest: pngtest.o libpng.a
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a libpng.so.$(PNGVER)
+	-@mkdir $(prefix)/include
+	-@mkdir $(prefix)/lib
+	cp png.h $(prefix)/include
+	cp pngconf.h $(prefix)/include
+	chmod 644 $(prefix)/include/png.h
+	chmod 644 $(prefix)/include/pngconf.h
+	cp libpng.a $(prefix)/lib
+	cp libpng.so.$(PNGVER) $(prefix)/lib
+	chmod 644 $(prefix)/lib/libpng.a
+	chmod 644 $(prefix)/lib/libpng.so.$(PNGVER)
+	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
+	(cd $(LIBPATH); ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -f -s libpng.so.$(PNGMAJ) libpng.so)
+
+clean:
+	rm -f *.o libpng.a pngtest pngout.png libpng.so*
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
+pngmem.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
+pngread.o: png.h pngconf.h
+pngrtran.o: png.h pngconf.h
+pngrutil.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h
+pngtrans.o: png.h pngconf.h
+pngwrite.o: png.h pngconf.h
+pngwtran.o: png.h pngconf.h
+pngwutil.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h
+

scripts/makefile.dj2

@@ -0,0 +1,52 @@
+# DJGPP (DOS gcc) makefile for libpng
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# For conditions of distribution and use, see copyright notice in png.h
+
+# where make install puts libpng.a and png.h
+#prefix=/usr/local
+prefix=.
+
+CC=gcc
+CFLAGS=-I../zlib -O
+LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
+
+RANLIB=ranlib
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o pngwtran.o \
+	pngmem.o pngerror.o pngpread.o
+
+all: libpng.a pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@  $(OBJS)
+	$(RANLIB) $@
+
+pngtest: pngtest.o libpng.a
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+	coff2exe pngtest
+
+test: pngtest
+	./pngtest
+clean:
+	rm -f *.o libpng.a pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
+pngmem.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
+pngread.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h
+pngrtran.o: png.h pngconf.h
+pngrutil.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h
+pngtrans.o: png.h pngconf.h
+pngwrite.o: png.h pngconf.h
+pngwtran.o: png.h pngconf.h
+pngwutil.o: png.h pngconf.h
+

scripts/makefile.hpux

@@ -0,0 +1,67 @@
+# makefile for libpng, HPUX (10.20 and 11.00)
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42
+# Copyright (C) 1999 Glenn Randers-Pehrson
+# contributed by Jim Rice, Hewlett Packard
+# For conditions of distribution and use, see copyright notice in png.h
+
+# Where the zlib library and include files are located
+ZLIBLIB=/opt/zlib/lib
+ZLIBINC=/opt/zlib/include
+
+CC=cc
+CFLAGS=-I$(ZLIBINC) -O -Ae +DA1.1 +DS2.0
+CCFLAGS=-I$(ZLIBINC) -O -Ae +DA1.1 +DS2.0
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+
+RANLIB=ranlib
+
+# where make install puts libpng.a and png.h
+prefix=/opt/libpng
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+all: libpng.a pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@  $(OBJS)
+	$(RANLIB) $@
+
+pngtest: pngtest.o libpng.a
+	$(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a
+	-@mkdir $(prefix)/include
+	-@mkdir $(prefix)/lib
+	cp png.h $(prefix)/include
+	cp pngconf.h $(prefix)/include
+	chmod 644 $(prefix)/include/png.h
+	chmod 644 $(prefix)/include/pngconf.h
+	cp libpng.a $(prefix)/lib
+	chmod 644 $(prefix)/lib/libpng.a
+
+clean:
+	rm -f *.o libpng.a pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
+pngmem.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
+pngread.o: png.h pngconf.h
+pngrtran.o: png.h pngconf.h
+pngrutil.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h
+pngtrans.o: png.h pngconf.h
+pngwrite.o: png.h pngconf.h
+pngwtran.o: png.h pngconf.h
+pngwutil.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h

scripts/makefile.knr

@@ -0,0 +1,78 @@
+# makefile for libpng
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# For conditions of distribution and use, see copyright notice in png.h
+
+# This makefile requires file file ansi2knr.c, which you can get
+# from the Ghostscript ftp site at ftp://ftp.cs.wisc.edu/ghost/
+# If you have libjpeg, you probably already have ansi2knr.c in the jpeg
+# source distribution.
+
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
+CC=cc
+CFLAGS=-I../zlib -O
+LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
+# flags for ansi2knr
+ANSI2KNRFLAGS=
+
+RANLIB=ranlib
+#RANLIB=echo
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+all: ansi2knr libpng.a pngtest
+
+# general rule to allow ansi2knr to work
+.c.o:
+	./ansi2knr $*.c T$*.c
+	$(CC) $(CFLAGS) -c T$*.c
+	rm -f T$*.c $*.o
+	mv T$*.o $*.o
+
+ansi2knr: ansi2knr.c
+	$(CC) $(CFLAGS) $(ANSI2KNRFLAGS) -o ansi2knr ansi2knr.c
+
+libpng.a: ansi2knr $(OBJS)
+	ar rc $@  $(OBJS)
+	$(RANLIB) $@
+
+pngtest: pngtest.o libpng.a
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a
+	-@mkdir $(prefix)/include
+	-@mkdir $(prefix)/lib
+	cp png.h $(prefix)/include
+	cp pngconf.h $(prefix)/include
+	chmod 644 $(prefix)/include/png.h
+	chmod 644 $(prefix)/include/pngconf.h
+	cp libpng.a $(prefix)/lib
+	chmod 644 $(prefix)/lib/libpng.a
+
+clean:
+	rm -f *.o libpng.a pngtest pngout.png ansi2knr
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
+pngmem.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
+pngread.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h
+pngrtran.o: png.h pngconf.h
+pngrutil.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h
+pngtrans.o: png.h pngconf.h
+pngwrite.o: png.h pngconf.h
+pngwtran.o: png.h pngconf.h
+pngwutil.o: png.h pngconf.h

scripts/makefile.linux

@@ -0,0 +1,107 @@
+# makefile for libpng on Linux ELF with gcc
+# Copyright (C) 1996, 1997 Andreas Dilger
+# Copyright (C) 1998, 1999 Greg Roelofs
+# For conditions of distribution and use, see copyright notice in png.h
+
+CC=gcc
+
+# where "make install" puts libpng.a, libpng.so*, png.h and pngconf.h
+prefix=/usr/local
+
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+
+ALIGN=
+# for i386:
+#ALIGN=-malign-loops=2 -malign-functions=2
+
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+
+# for pgcc version 2.95.1, -O3 is buggy; don't us it.
+
+CFLAGS=-I$(ZLIBINC) -Wall -O3 -funroll-loops \
+	$(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng -lz -lm
+
+RANLIB=ranlib
+#RANLIB=echo
+
+# read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
+# have to change it.
+PNGMAJ = 2
+PNGMIN = 1.0.4c
+PNGVER = $(PNGMAJ).$(PNGMIN)
+
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+OBJSDLL = $(OBJS:.o=.pic.o)
+
+.SUFFIXES:      .c .o .pic.o
+
+.c.pic.o:
+	$(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+
+all: libpng.a libpng.so pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@ $(OBJS)
+	$(RANLIB) $@
+
+libpng.so: libpng.so.$(PNGMAJ)
+	ln -sf libpng.so.$(PNGMAJ) libpng.so
+
+libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
+	ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+
+libpng.so.$(PNGVER): $(OBJSDLL)
+	$(CC) -shared -Wl,-soname,libpng.so.$(PNGMAJ) -o libpng.so.$(PNGVER) \
+	 $(OBJSDLL) -L$(ZLIBLIB) -lz -lm -lc
+
+pngtest: pngtest.o libpng.so
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a libpng.so.$(PNGVER)
+	-@mkdir $(INCPATH) $(LIBPATH)
+	cp png.h pngconf.h $(INCPATH)
+	chmod 644 $(INCPATH)/png.h $(INCPATH)/pngconf.h
+	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
+	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
+	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
+	(cd $(LIBPATH); ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -sf libpng.so.$(PNGMAJ) libpng.so)
+
+clean:
+	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o png.pic.o: png.h pngconf.h
+pngerror.o pngerror.pic.o: png.h pngconf.h
+pngrio.o pngrio.pic.o: png.h pngconf.h
+pngwio.o pngwio.pic.o: png.h pngconf.h
+pngmem.o pngmem.pic.o: png.h pngconf.h
+pngset.o pngset.pic.o: png.h pngconf.h
+pngget.o pngget.pic.o: png.h pngconf.h
+pngread.o pngread.pic.o: png.h pngconf.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h
+pngpread.o pngpread.pic.o: png.h pngconf.h
+
+pngtest.o: png.h pngconf.h

scripts/makefile.mips

@@ -2,29 +2,29 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
-CC=gcc
-CFLAGS=-I../zlib -O2 -Wall -ansi -pedantic
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
+CC=cc
+CFLAGS=-I../zlib -O -systype sysv -DSYSV -w -Dmips
+#CFLAGS=-O
 LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
 
-RANLIB=ranlib
-#RANLIB=echo
+#RANLIB=ranlib
+RANLIB=echo
 
-# where make install puts libpng.a and png.h
-prefix=/home/munet-d2/sun/local
-
-OBJS = png.o pngrcb.o pngrutil.o pngtrans.o pngwutil.o \
-	pngread.o pngio.o pngwrite.o pngrtran.o pngwtran.o \
-   pngmem.o
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
 
 all: libpng.a pngtest
 
 libpng.a: $(OBJS)
 	ar rc $@  $(OBJS)
 	$(RANLIB) $@
-	rcp libpng.a vlsi:bin/lib/libpng.a
 
 pngtest: pngtest.o libpng.a
-	$(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS)
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
 
 test: pngtest
 	./pngtest
@@ -45,10 +45,14 @@ clean:
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
 png.o: png.h pngconf.h
-pngio.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
 pngmem.o: png.h pngconf.h
-pngrcb.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
 pngread.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h
 pngrtran.o: png.h pngconf.h
 pngrutil.o: png.h pngconf.h
 pngtest.o: png.h pngconf.h

scripts/makefile.msc

@@ -0,0 +1,86 @@
+# makefile for libpng
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# For conditions of distribution and use, see copyright notice in png.h
+# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
+
+# -------- Microsoft C 5.1 and later, does not use assembler code -----
+MODEL=-AL
+CFLAGS=-Oait -Gs -nologo -W3 $(MODEL) -I..\zlib
+#-Ox generates bad code with MSC 5.1
+CC=cl
+LD=link
+LDFLAGS=/e/st:0x1500/noe 
+O=.obj
+
+#uncomment next to put error messages in a file
+ERRFILE= >> pngerrs
+
+# variables
+OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
+OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
+OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
+
+all: libpng.lib
+
+png$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngset$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngget$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngread$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngpread$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrtran$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrutil$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngerror$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngmem$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtest$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtrans$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwrite$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwtran$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwutil$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
+	del libpng.lib
+	lib libpng $(OBJS1);
+	lib libpng $(OBJS2);
+	lib libpng $(OBJS3);
+
+pngtest.exe: pngtest.obj libpng.lib 
+	$(LD) $(LDFLAGS) pngtest.obj,,,libpng.lib ..\zlib\zlib.lib ;
+
+test: pngtest.exe
+	pngtest
+
+# End of makefile for libpng
+

scripts/makefile.os2

@@ -0,0 +1,69 @@
+# makefile for libpng on OS/2 with gcc
+# For conditions of distribution and use, see copyright notice in png.h
+
+# Related files: pngos2.def
+
+CC=gcc -Zomf -s
+
+# Where the zlib library and include files are located
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+CFLAGS=-I$(ZLIBINC) -Wall -O6 -funroll-loops -malign-loops=2 \
+	-malign-functions=2 #$(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lzdll -Zcrtdll
+AR=emxomfar
+
+PNGLIB=png.lib
+IMPLIB=emximp
+SHAREDLIB=png.dll
+SHAREDLIBIMP=pngdll.lib
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+.SUFFIXES:      .c .o
+
+all: $(PNGLIB) $(SHAREDLIB) $(SHAREDLIBIMP)
+
+$(PNGLIB): $(OBJS)
+	$(AR) rc $@ $(OBJS)
+
+$(SHAREDLIB): $(OBJS) pngos2.def
+	$(CC) $(LDFLAGS) -Zdll -o $@ $^
+
+$(SHAREDLIBIMP): pngos2.def
+	$(IMPLIB) -o $@ $^
+
+pngtest.exe: pngtest.o png.dll pngdll.lib
+	$(CC) -o $@ $(CFLAGS) $< $(LDFLAGS)
+
+test: pngtest.exe
+	./pngtest.exe
+
+clean:
+	rm -f *.o $(PNGLIB) png.dll pngdll.lib pngtest.exe pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o png.pic.o: png.h pngconf.h
+pngerror.o pngerror.pic.o: png.h pngconf.h
+pngrio.o pngrio.pic.o: png.h pngconf.h
+pngwio.o pngwio.pic.o: png.h pngconf.h
+pngmem.o pngmem.pic.o: png.h pngconf.h
+pngset.o pngset.pic.o: png.h pngconf.h
+pngget.o pngget.pic.o: png.h pngconf.h
+pngread.o pngread.pic.o: png.h pngconf.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h
+pngpread.o pngpread.pic.o: png.h pngconf.h
+
+pngtest.o: png.h pngconf.h

scripts/makefile.sco

@@ -0,0 +1,98 @@
+# makefile for SCO OSr5  ELF and Unixware 7 with Native cc
+# Contributed by Mike Hopkirk (hops@sco.com) modified from Makefile.lnx
+#   force ELF build dynamic linking, SONAME setting in lib and RPATH in app
+# Copyright (C) 1996, 1997 Andreas Dilger
+# Copyright (C) 1998 Greg Roelofs
+# For conditions of distribution and use, see copyright notice in png.h
+
+CC=cc
+
+# where make install puts libpng.a, libpng.so*, and png.h
+prefix=/usr/local
+
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+
+CFLAGS= -dy -belf -I$(ZLIBINC) -O3 
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+
+#RANLIB=ranlib
+RANLIB=echo
+
+# read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
+# have to change it.
+PNGMAJ = 2
+PNGMIN = 1.0.4c
+PNGVER = $(PNGMAJ).$(PNGMIN)
+
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+OBJSDLL = $(OBJS:.o=.pic.o)
+
+.SUFFIXES:      .c .o .pic.o
+
+.c.pic.o:
+	$(CC) -c $(CFLAGS) -KPIC -o $@ $*.c
+
+all: libpng.a libpng.so pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@ $(OBJS)
+	$(RANLIB) $@
+
+libpng.so: libpng.so.$(PNGMAJ)
+	ln -f -s libpng.so.$(PNGMAJ) libpng.so
+
+libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
+	ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+
+libpng.so.$(PNGVER): $(OBJSDLL)
+	$(CC) -G  -Wl,-h,libpng.so.$(PNGMAJ) -o libpng.so.$(PNGVER) \
+	 $(OBJSDLL)
+
+pngtest: pngtest.o libpng.so
+	LD_RUN_PATH=.:$(ZLIBLIB) $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a libpng.so.$(PNGVER)
+	-@mkdir $(INCPATH) $(LIBPATH)
+	cp png.h pngconf.h $(INCPATH)
+	chmod 644 $(INCPATH)/png.h $(INCPATH)/pngconf.h
+	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
+	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
+	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
+	(cd $(LIBPATH); ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -f -s libpng.so.$(PNGMAJ) libpng.so)
+
+clean:
+	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o png.pic.o: png.h pngconf.h
+pngerror.o pngerror.pic.o: png.h pngconf.h
+pngrio.o pngrio.pic.o: png.h pngconf.h
+pngwio.o pngwio.pic.o: png.h pngconf.h
+pngmem.o pngmem.pic.o: png.h pngconf.h
+pngset.o pngset.pic.o: png.h pngconf.h
+pngget.o pngget.pic.o: png.h pngconf.h
+pngread.o pngread.pic.o: png.h pngconf.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h
+pngpread.o pngpread.pic.o: png.h pngconf.h
+
+pngtest.o: png.h pngconf.h

scripts/makefile.sgi

@@ -0,0 +1,71 @@
+# makefile for libpng
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# For conditions of distribution and use, see copyright notice in png.h
+
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+
+CC=cc
+
+WARNMORE=-fullwarn
+# You can add the -n32 option; then zlib must also be compiled with -n32
+CFLAGS=-I$(ZLIBINC) -O $(WARNMORE) # -g -DPNG_DEBUG=5
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+
+RANLIB=echo
+#RANLIB=ranlib
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+all: libpng.a pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@  $(OBJS)
+	$(RANLIB) $@
+
+pngtest: pngtest.o libpng.a
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a
+	-@mkdir $(prefix)/include
+	-@mkdir $(prefix)/lib
+	cp png.h $(prefix)/include
+	cp pngconf.h $(prefix)/include
+	chmod 644 $(prefix)/include/png.h
+	chmod 644 $(prefix)/include/pngconf.h
+	cp libpng.a $(prefix)/lib
+	chmod 644 $(prefix)/lib/libpng.a
+
+clean:
+	rm -f *.o libpng.a pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
+pngmem.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
+pngread.o: png.h pngconf.h
+pngrtran.o: png.h pngconf.h
+pngrutil.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h
+pngtrans.o: png.h pngconf.h
+pngwrite.o: png.h pngconf.h
+pngwtran.o: png.h pngconf.h
+pngwutil.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h
+

scripts/makefile.solaris

@@ -0,0 +1,109 @@
+# makefile for libpng on Solaris 2.x with gcc
+# Contributed by William L. Sebok, based on makefile.linux
+# Copyright (C) 1996, 1997 Andreas Dilger
+# Copyright (C) 1998 Greg Roelofs
+# For conditions of distribution and use, see copyright notice in png.h
+
+CC=gcc
+
+# The commands "CC" and "LD" must NOT refer to /usr/ucb/cc and /usr/ucb/ld.
+# If they do, you need to adjust your PATH environment variable.
+# The environment variable LD_LIBRARY_PATH should not be set at all.  If
+# it is, things are likely to break.
+
+# Where make install puts libpng.a, libpng.so*, and png.h
+prefix=/usr/local
+
+# Where the zlib library and include files are located
+# Changing these to ../zlib poses a security risk.  If you want
+# to have zlib in an adjacent directory, specify the full path instead of "..".
+#ZLIBLIB=../zlib
+#ZLIBINC=../zlib
+
+ZLIBLIB=/usr/local/lib
+ZLIBINC=/usr/local/include
+
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+CFLAGS=-I$(ZLIBINC) -Wall -O3 \
+	# $(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=-L. -R. -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng -lz -lm
+
+#RANLIB=ranlib
+RANLIB=echo
+
+# read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
+# have to change it.
+PNGMAJ = 2
+PNGMIN = 1.0.4c
+PNGVER = $(PNGMAJ).$(PNGMIN)
+
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+OBJSDLL = $(OBJS:.o=.pic.o)
+
+.SUFFIXES:      .c .o .pic.o
+
+.c.pic.o:
+	$(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+
+all: libpng.a libpng.so pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@ $(OBJS)
+	$(RANLIB) $@
+
+libpng.so: libpng.so.$(PNGMAJ)
+	ln -f -s libpng.so.$(PNGMAJ) libpng.so
+
+libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
+	ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+
+libpng.so.$(PNGVER): $(OBJSDLL)
+	$(LD) -G -L$(ZLIBLIB) -R$(ZLIBLIB) -h libpng.so.$(PNGMAJ) \
+	 -o libpng.so.$(PNGVER) $(OBJSDLL) -lz
+
+pngtest: pngtest.o libpng.so
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a libpng.so.$(PNGVER)
+	-@mkdir $(INCPATH) $(LIBPATH)
+	cp png.h pngconf.h $(INCPATH)
+	chmod 644 $(INCPATH)/png.h $(INCPATH)/pngconf.h
+	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
+	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
+	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
+	(cd $(LIBPATH); ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -f -s libpng.so.$(PNGMAJ) libpng.so)
+
+clean:
+	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o png.pic.o: png.h pngconf.h
+pngerror.o pngerror.pic.o: png.h pngconf.h
+pngrio.o pngrio.pic.o: png.h pngconf.h
+pngwio.o pngwio.pic.o: png.h pngconf.h
+pngmem.o pngmem.pic.o: png.h pngconf.h
+pngset.o pngset.pic.o: png.h pngconf.h
+pngget.o pngget.pic.o: png.h pngconf.h
+pngread.o pngread.pic.o: png.h pngconf.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h
+pngpread.o pngpread.pic.o: png.h pngconf.h
+
+pngtest.o: png.h pngconf.h

scripts/makefile.std

@@ -0,0 +1,68 @@
+# makefile for libpng
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# For conditions of distribution and use, see copyright notice in png.h
+
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+
+CC=cc
+CFLAGS=-I$(ZLIBINC) -O # -g -DPNG_DEBUG=5
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+
+#RANLIB=echo
+RANLIB=ranlib
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+all: libpng.a pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@  $(OBJS)
+	$(RANLIB) $@
+
+pngtest: pngtest.o libpng.a
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a
+	-@mkdir $(prefix)/include
+	-@mkdir $(prefix)/lib
+	cp png.h $(prefix)/include
+	cp pngconf.h $(prefix)/include
+	chmod 644 $(prefix)/include/png.h
+	chmod 644 $(prefix)/include/pngconf.h
+	cp libpng.a $(prefix)/lib
+	chmod 644 $(prefix)/lib/libpng.a
+
+clean:
+	rm -f *.o libpng.a pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
+pngmem.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
+pngread.o: png.h pngconf.h
+pngrtran.o: png.h pngconf.h
+pngrutil.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h
+pngtrans.o: png.h pngconf.h
+pngwrite.o: png.h pngconf.h
+pngwtran.o: png.h pngconf.h
+pngwutil.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h
+

scripts/makefile.sunos

@@ -0,0 +1,72 @@
+# makefile for libpng
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# For conditions of distribution and use, see copyright notice in png.h
+
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
+# Where the zlib library and include files are located
+#ZLIBLIB=/usr/local/lib
+#ZLIBINC=/usr/local/include
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+
+
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow -Wconversion \
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes
+CC=gcc
+CFLAGS=-I$(ZLIBINC) -O # $(WARNMORE) -DPNG_DEBUG=5
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+
+RANLIB=ranlib
+#RANLIB=echo
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+all: libpng.a pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@  $(OBJS)
+	$(RANLIB) $@
+
+pngtest: pngtest.o libpng.a
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a
+	-@mkdir $(prefix)/include
+	-@mkdir $(prefix)/lib
+	cp png.h $(prefix)/include
+	cp pngconf.h $(prefix)/include
+	chmod 644 $(prefix)/include/png.h
+	chmod 644 $(prefix)/include/pngconf.h
+	cp libpng.a $(prefix)/lib
+	chmod 644 $(prefix)/lib/libpng.a
+
+clean:
+	rm -f *.o libpng.a pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
+pngmem.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
+pngread.o: png.h pngconf.h
+pngrtran.o: png.h pngconf.h
+pngrutil.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h
+pngtrans.o: png.h pngconf.h
+pngwrite.o: png.h pngconf.h
+pngwtran.o: png.h pngconf.h
+pngwutil.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h
+

scripts/makefile.turboc3

@@ -0,0 +1,82 @@
+# Makefile for libpng
+# TurboC++ 3.0 (Note: All modules are compiled in C mode)
+
+# To use, do "make -fmakefile.turboc3"
+
+# ------------- Turbo C++ 3.0 -------------
+MODEL=-ml
+CFLAGS=-O2 -Z $(MODEL) -I..\zlib
+CC=tcc
+LD=tcc
+LIB=tlib
+LDFLAGS=$(MODEL) -L..\zlib
+O=.obj
+E=.exe
+
+# variables
+OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
+OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
+OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
+OBJSL1 = +png$(O) +pngset$(O) +pngget$(O) +pngrutil$(O) +pngtrans$(O)
+OBJSL2 = +pngwutil$(O) +pngmem$(O) +pngpread$(O) +pngread$(O) +pngerror$(O)
+OBJSL3 = +pngwrite$(O) +pngrtran$(O) +pngwtran$(O) +pngrio$(O) +pngwio$(O)
+
+all: libpng.lib pngtest.exe
+
+png$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c
+
+pngset$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c
+
+pngget$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c
+
+pngread$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c
+
+pngpread$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c
+
+pngrtran$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c
+
+pngrutil$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c
+
+pngerror$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+pngmem$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+pngrio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+pngwio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+pngtest$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+pngtrans$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+pngwrite$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+pngwtran$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+pngwutil$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
+	$(LIB) libpng +$(OBJSL1)
+	$(LIB) libpng +$(OBJSL2)
+	$(LIB) libpng +$(OBJSL3)
+
+pngtest$(E): pngtest$(O) libpng.lib
+	$(CC) $(LDFLAGS) pngtest.obj libpng.lib zlib.lib
+
+# End of makefile for libpng

scripts/makefile.vcawin32

@@ -0,0 +1,94 @@
+# makefile for libpng
+# Copyright (C) 1998 Tim Wegner
+# For conditions of distribution and use, see copyright notice in png.h
+# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
+# To use, do "nmake /f scripts\makefile.vcawin32"
+
+# ---------- Microsoft Visual C++ 5.0 and later, uses assembler code------
+
+# Caution: the assembler code was introduced at libpng version 1.0.4 and has
+# not yet been thoroughly tested.
+
+# If you don't want to use assembler code, use makefile.vcwin32 instead.
+
+MODEL=- 
+CFLAGS=-DPNG_USE_PNGVCRD -Ox -GA3s -nologo -W3 -I..\zlib
+
+CC=cl
+LD=link
+LDFLAGS= 
+O=.obj
+
+#uncomment next to put error messages in a file
+#ERRFILE= >> pngerrs
+
+# variables
+OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
+OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
+OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O) pngvcrd$(O)
+
+all: libpng.lib
+
+png$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngset$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngget$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngread$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngpread$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrtran$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrutil$(O): png.h pngconf.h pngasmrd.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngvcrd$(O): png.h pngconf.h pngasmrd.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngerror$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngmem$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtest$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtrans$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwrite$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwtran$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwutil$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
+	del libpng.lib
+	lib /OUT:libpng.lib $(OBJS1) $(OBJS2) $(OBJS3)
+
+pngtest.exe: pngtest.obj libpng.lib 
+	$(LD) $(LDFLAGS) pngtest.obj libpng.lib ..\zlib\zlib.lib /OUT:pngtest.exe /SUBSYSTEM:CONSOLE
+
+test: pngtest.exe
+	pngtest
+
+# End of makefile for libpng
+

scripts/makefile.vcwin32

@@ -0,0 +1,87 @@
+# makefile for libpng
+# Copyright (C) 1998 Tim Wegner
+# For conditions of distribution and use, see copyright notice in png.h
+# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
+# To use, do "nmake /f scripts\makefile.vcwin32"
+
+# ---------- Microsoft Visual C++ 4.0 and later, no assembler code------
+# If you want to use assembler code, use makefile.vcawin32 instead.
+
+MODEL=- 
+CFLAGS= -Ox -GA3s -nologo -W3 -I..\zlib
+
+CC=cl
+LD=link
+LDFLAGS= 
+O=.obj
+
+#uncomment next to put error messages in a file
+#ERRFILE= >> pngerrs
+
+# variables
+OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
+OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
+OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
+
+all: libpng.lib
+
+png$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngset$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngget$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngread$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngpread$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrtran$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrutil$(O): png.h pngconf.h pngasmrd.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngerror$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngmem$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtest$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtrans$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwrite$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwtran$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwutil$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
+	del libpng.lib
+	lib /OUT:libpng.lib $(OBJS1) $(OBJS2) $(OBJS3)
+
+pngtest.exe: pngtest.obj libpng.lib 
+	$(LD) $(LDFLAGS) pngtest.obj libpng.lib ..\zlib\zlib.lib /OUT:pngtest.exe /SUBSYSTEM:CONSOLE
+
+test: pngtest.exe
+	pngtest
+
+# End of makefile for libpng
+

scripts/makefile.watcom

@@ -0,0 +1,88 @@
+# Makefile for libpng
+# Watcom 10.0 and later 32-bit protected mode flat memory model
+
+# Adapted by Pawel Mrochen, based on makefile.msc
+# For conditions of distribution and use, see copyright notice in png.h
+# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
+
+# To use, do "wmake /f scripts\makefile.watcom"
+
+# ------------- Watcom 10.0 and later -------------
+MODEL=-mf
+CFLAGS= $(MODEL) -5r -fp5 -fpi87 -oneatx -i=..\zlib
+CC=wcc386
+LD=wcl386
+LIB=wlib -b -c
+LDFLAGS=
+O=.obj
+
+#uncomment next to put error messages in a file
+#ERRFILE= >> pngerrs
+
+# variables
+OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
+OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
+OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
+
+all: test
+
+png$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngset$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngget$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngread$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngpread$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngrtran$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngrutil$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngerror$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngmem$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngrio$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngwio$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngtest$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngtrans$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngwrite$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngwtran$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+pngwutil$(O): png.h pngconf.h
+	$(CC) $(CFLAGS) $*.c $(ERRFILE)
+
+libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
+	$(LIB) -n libpng.lib $(OBJS1)
+	$(LIB) libpng.lib $(OBJS2)
+	$(LIB) libpng.lib $(OBJS3)
+
+pngtest.exe: pngtest.obj libpng.lib
+	$(LD) $(LDFLAGS) pngtest.obj libpng.lib ..\zlib\zlib.lib
+
+test: pngtest.exe .symbolic
+	pngtest
+
+# End of makefile for libpng

scripts/makevms.com

@@ -0,0 +1,125 @@
+$! make libpng under VMS
+$!
+$!
+$! Look for the compiler used
+$!
+$ zlibsrc = "[-.zlib]"
+$ ccopt="/include=''zlibsrc'"
+$ if f$getsyi("HW_MODEL").ge.1024
+$ then
+$  ccopt = "/prefix=all"+ccopt
+$  comp  = "__decc__=1"
+$  if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$ else
+$  if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs.""
+$   then
+$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$    if f$search("SYS$SYSTEM:VAXC.EXE").eqs.""
+$     then
+$      comp  = "__gcc__=1"
+$      CC :== GCC
+$     else
+$      comp = "__vaxc__=1"
+$     endif
+$   else
+$    if f$trnlnm("SYS").eqs."" then define sys decc$library_include:
+$    ccopt = "/decc/prefix=all"+ccopt
+$    comp  = "__decc__=1"
+$  endif
+$ endif
+$!
+$! Build the thing plain or with mms
+$!
+$ write sys$output "Compiling Libpng sources ..."
+$ if f$search("SYS$SYSTEM:MMS.EXE").eqs.""
+$  then
+$   dele pngtest.obj;*
+$   CALL MAKE png.OBJ "cc ''CCOPT' png" -
+	png.c png.h pngconf.h   
+$   CALL MAKE pngpread.OBJ "cc ''CCOPT' pngpread" -
+					 pngpread.c png.h pngconf.h
+$   CALL MAKE pngset.OBJ "cc ''CCOPT' pngset" -
+	pngset.c png.h pngconf.h
+$   CALL MAKE pngget.OBJ "cc ''CCOPT' pngget" -
+	pngget.c png.h pngconf.h
+$   CALL MAKE pngread.OBJ "cc ''CCOPT' pngread" -
+	pngread.c png.h pngconf.h
+$   CALL MAKE pngpread.OBJ "cc ''CCOPT' pngpread" -
+					 pngpread.c png.h pngconf.h
+$   CALL MAKE pngrtran.OBJ "cc ''CCOPT' pngrtran" -
+	pngrtran.c png.h pngconf.h
+$   CALL MAKE pngrutil.OBJ "cc ''CCOPT' pngrutil" -
+	pngrutil.c png.h pngconf.h
+$   CALL MAKE pngerror.OBJ "cc ''CCOPT' pngerror" -
+	pngerror.c png.h pngconf.h
+$   CALL MAKE pngmem.OBJ "cc ''CCOPT' pngmem" -
+	pngmem.c png.h pngconf.h
+$   CALL MAKE pngrio.OBJ "cc ''CCOPT' pngrio" -
+	pngrio.c png.h pngconf.h
+$   CALL MAKE pngwio.OBJ "cc ''CCOPT' pngwio" -
+	pngwio.c png.h pngconf.h
+$   CALL MAKE pngtrans.OBJ "cc ''CCOPT' pngtrans" -
+	pngtrans.c png.h pngconf.h
+$   CALL MAKE pngwrite.OBJ "cc ''CCOPT' pngwrite" -
+	pngwrite.c png.h pngconf.h
+$   CALL MAKE pngwtran.OBJ "cc ''CCOPT' pngwtran" -
+	pngwtran.c png.h pngconf.h
+$   CALL MAKE pngwutil.OBJ "cc ''CCOPT' pngwutil" -
+	pngwutil.c png.h pngconf.h
+$   write sys$output "Building Libpng ..."
+$   CALL MAKE libpng.OLB "lib/crea libpng.olb *.obj" *.OBJ
+$   write sys$output "Building pngtest..."
+$   CALL MAKE pngtest.OBJ "cc ''CCOPT' pngtest" -
+	pngtest.c png.h pngconf.h
+$   call make pngtest.exe - 
+	"LINK pngtest,libpng.olb/lib,''zlibsrc'libgz.olb/lib" - 
+	pngtest.obj libpng.olb
+$   write sys$output "Testing Libpng..."
+$   run pngtest
+$  else
+$   mms/macro=('comp',zlibsrc='zlibsrc')
+$  endif
+$ write sys$output "Libpng build completed"
+$ exit
+$!
+$!
+$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
+$ V = 'F$Verify(0)
+$! P1 = What we are trying to make
+$! P2 = Command to make it
+$! P3 - P8  What it depends on
+$
+$ If F$Search(P1) .Eqs. "" Then Goto Makeit
+$ Time = F$CvTime(F$File(P1,"RDT"))
+$arg=3
+$Loop:
+$       Argument = P'arg
+$       If Argument .Eqs. "" Then Goto Exit
+$       El=0
+$Loop2:
+$       File = F$Element(El," ",Argument)
+$       If File .Eqs. " " Then Goto Endl
+$       AFile = ""
+$Loop3:
+$       OFile = AFile
+$       AFile = F$Search(File)
+$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
+$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
+$       Goto Loop3
+$NextEL:
+$       El = El + 1
+$       Goto Loop2
+$EndL:
+$ arg=arg+1
+$ If arg .Le. 8 Then Goto Loop
+$ Goto Exit
+$
+$Makeit:
+$ VV=F$VERIFY(0)
+$ write sys$output P2
+$ 'P2
+$ VV='F$Verify(VV)
+$Exit:
+$ If V Then Set Verify
+$ENDSUBROUTINE
+

scripts/pngdef.pas

@@ -0,0 +1,722 @@
+unit pngdef;
+
+interface
+
+const
+  PNG_LIBPNG_VER_STRING = '1.0.4c';
+  PNG_LIBPNG_VER        =  10005;
+
+type
+  png_uint_32 = Cardinal;
+  png_int_32  = Longint;
+  png_uint_16 = Word;
+  png_int_16  = Smallint;
+  png_byte    = Byte;
+  png_size_t  = png_uint_32;
+  png_charpp  = ^png_charp;
+  png_charp   = PChar;
+  float       = single;
+  int         = Integer;
+  png_bytepp  = ^png_bytep;
+  png_bytep   = ^png_byte;
+  png_uint_16p = ^png_uint_16;
+  png_uint_16pp = ^png_uint_16p;
+  png_voidp    = pointer;
+  time_t       = Longint;
+  png_doublep  = ^png_double;
+  png_double   = double;
+
+  user_error_ptr  = Pointer;
+  png_error_ptrp = ^png_error_ptr;
+  png_error_ptr  = procedure(png_ptr: Pointer; msg: Pointer);
+             stdcall;
+  png_rw_ptrp = ^png_rw_ptr;
+  png_rw_ptr = procedure(png_ptr: Pointer; data: Pointer;
+                         length: png_size_t);
+             stdcall;
+  png_flush_ptrp = ^png_flush_ptr;
+  png_flush_ptr = procedure(png_ptr: Pointer);
+             stdcall;
+  png_progressive_info_ptrp = ^png_progressive_info_ptr;
+  png_progressive_info_ptr  = procedure(png_ptr: Pointer;
+                                        info_ptr: Pointer);
+             stdcall;
+  png_progressive_end_ptrp  = ^png_progressive_end_ptr;
+  png_progressive_end_ptr   = procedure(png_ptr: Pointer;
+                                        info_ptr: Pointer);
+             stdcall;
+  png_progressive_row_ptrp  = ^png_progressive_row_ptr;
+  png_progressive_row_ptr   = procedure(png_ptr: Pointer;
+                                data: Pointer; length: png_uint_32;
+                                count: int);
+             stdcall;
+  png_read_status_ptr = procedure(png_ptr: Pointer;
+                          row_number: png_uint_32; pass: int);
+             stdcall;
+  png_write_status_ptr = procedure(png_ptr: Pointer;
+                           row_number: png_uint_32; pass: int);
+             stdcall;
+  png_user_transform_ptr = procedure(png_ptr: Pointer;
+                             row_info: Pointer; data: png_bytep);
+             stdcall;
+
+  png_colorpp = ^png_colorp;
+  png_colorp = ^png_color;
+  png_color = packed record
+    red, green, blue: png_byte;
+    end;
+
+  png_color_16pp = ^png_color_16p;
+  png_color_16p = ^png_color_16;
+  png_color_16 = packed record
+    index: png_byte;                 //used for palette files
+    red, green, blue: png_uint_16;   //for use in red green blue files
+    gray: png_uint_16;               //for use in grayscale files
+    end;
+
+  png_color_8pp = ^png_color_8p;
+  png_color_8p = ^png_color_8;
+  png_color_8 = packed record
+    red, green, blue: png_byte;   //for use in red green blue files
+    gray: png_byte;               //for use in grayscale files
+    alpha: png_byte;              //for alpha channel files
+    end;
+
+  png_textpp = ^png_textp;
+  png_textp = ^png_text;
+  png_text = packed record
+    compression: int;            //compression value
+    key: png_charp;              //keyword, 1-79 character description of "text"
+    text: png_charp;             //comment, may be empty ("")
+    text_length: png_size_t;     //length of text field
+    end;
+
+  png_timepp = ^png_timep;
+  png_timep = ^png_time;
+  png_time = packed record
+    year: png_uint_16;           //yyyy
+    month: png_byte;             //1..12
+    day: png_byte;               //1..31
+    hour: png_byte;              //0..23
+    minute: png_byte;            //0..59
+    second: png_byte;            //0..60 (leap seconds)
+    end;
+
+  png_infopp = ^png_infop;
+  png_infop = Pointer;
+
+  png_row_infopp = ^png_row_infop;
+  png_row_infop = ^png_row_info;
+  png_row_info = packed record
+    width: png_uint_32;          //width of row
+    rowbytes: png_size_t;        //number of bytes in row
+    color_type: png_byte;        //color type of row
+    bit_depth: png_byte;         //bit depth of row
+    channels: png_byte;          //number of channels (1, 2, 3, or 4)
+    pixel_depth: png_byte;       //bits per pixel (depth * channels)
+    end;
+
+  png_structpp = ^png_structp;
+  png_structp = Pointer;
+
+const
+
+// Supported compression types for text in PNG files (tEXt, and zTXt).
+// The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed.
+
+  PNG_TEXT_COMPRESSION_NONE_WR = -3;
+  PNG_TEXT_COMPRESSION_zTXt_WR = -2;
+  PNG_TEXT_COMPRESSION_NONE    = -1;
+  PNG_TEXT_COMPRESSION_zTXt    = 0;
+
+// These describe the color_type field in png_info.
+// color type masks
+
+  PNG_COLOR_MASK_PALETTE   = 1;
+  PNG_COLOR_MASK_COLOR     = 2;
+  PNG_COLOR_MASK_ALPHA     = 4;
+
+// color types.  Note that not all combinations are legal
+
+  PNG_COLOR_TYPE_GRAY       = 0;
+  PNG_COLOR_TYPE_PALETTE    = PNG_COLOR_MASK_COLOR or
+                              PNG_COLOR_MASK_PALETTE;
+  PNG_COLOR_TYPE_RGB        = PNG_COLOR_MASK_COLOR;
+  PNG_COLOR_TYPE_RGB_ALPHA  = PNG_COLOR_MASK_COLOR or
+                              PNG_COLOR_MASK_ALPHA;
+  PNG_COLOR_TYPE_GRAY_ALPHA = PNG_COLOR_MASK_ALPHA;
+
+// This is for compression type. PNG 1.0 only defines the single type.
+
+  PNG_COMPRESSION_TYPE_BASE    = 0;   // Deflate method 8, 32K window
+  PNG_COMPRESSION_TYPE_DEFAULT = PNG_COMPRESSION_TYPE_BASE;
+
+// This is for filter type. PNG 1.0 only defines the single type.
+
+  PNG_FILTER_TYPE_BASE    = 0;       // Single row per-byte filtering
+  PNG_FILTER_TYPE_DEFAULT = PNG_FILTER_TYPE_BASE;
+
+// These are for the interlacing type.  These values should NOT be changed.
+
+  PNG_INTERLACE_NONE  = 0;      // Non-interlaced image
+  PNG_INTERLACE_ADAM7 = 1;      // Adam7 interlacing
+
+// These are for the oFFs chunk.  These values should NOT be changed.
+
+  PNG_OFFSET_PIXEL      = 0;    // Offset in pixels
+  PNG_OFFSET_MICROMETER = 1;    // Offset in micrometers (1/10^6 meter)
+
+// These are for the pCAL chunk.  These values should NOT be changed.
+
+  PNG_EQUATION_LINEAR     = 0;  // Linear transformation
+  PNG_EQUATION_BASE_E     = 1;  // Exponential base e transform
+  PNG_EQUATION_ARBITRARY  = 2;  // Arbitrary base exponential transform
+  PNG_EQUATION_HYPERBOLIC = 3;  // Hyperbolic sine transformation
+
+// These are for the pHYs chunk.  These values should NOT be changed.
+
+  PNG_RESOLUTION_UNKNOWN = 0;   // pixels/unknown unit (aspect ratio)
+  PNG_RESOLUTION_METER   = 1;   // pixels/meter
+
+// These are for the sRGB chunk.  These values should NOT be changed.
+  PNG_sRGB_INTENT_SATURATION = 0;
+  PNG_sRGB_INTENT_PERCEPTUAL = 1;
+  PNG_sRGB_INTENT_ABSOLUTE   = 2;
+  PNG_sRGB_INTENT_RELATIVE   = 3;
+
+// Handle alpha and tRNS by replacing with a background color.
+  PNG_BACKGROUND_GAMMA_UNKNOWN = 0;
+  PNG_BACKGROUND_GAMMA_SCREEN  = 1;
+  PNG_BACKGROUND_GAMMA_FILE    = 2;
+  PNG_BACKGROUND_GAMMA_UNIQUE  = 3;
+
+// 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
+
+  PNG_CRC_DEFAULT      = 0;  // error/quit          warn/discard data
+  PNG_CRC_ERROR_QUIT   = 1;  // error/quit          error/quit
+  PNG_CRC_WARN_DISCARD = 2;  // (INVALID)           warn/discard data
+  PNG_CRC_WARN_USE     = 3;  // warn/use data       warn/use data
+  PNG_CRC_QUIET_USE    = 4;  // quiet/use data      quiet/use data
+  PNG_CRC_NO_CHANGE    = 5;  // use current value   use current value 
+
+// 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.
+
+  PNG_NO_FILTERS   = $00;
+  PNG_FILTER_NONE  = $08;
+  PNG_FILTER_SUB   = $10;
+  PNG_FILTER_UP    = $20;
+  PNG_FILTER_AVG   = $40;
+  PNG_FILTER_PAETH = $80;
+  PNG_ALL_FILTERS  = PNG_FILTER_NONE or PNG_FILTER_SUB or
+                     PNG_FILTER_UP   or PNG_FILTER_AVG or
+                     PNG_FILTER_PAETH;
+
+// Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
+// These defines should NOT be changed.
+
+  PNG_FILTER_VALUE_NONE  = 0;
+  PNG_FILTER_VALUE_SUB   = 1;
+  PNG_FILTER_VALUE_UP    = 2;
+  PNG_FILTER_VALUE_AVG   = 3;
+  PNG_FILTER_VALUE_PAETH = 4;
+
+// Heuristic used for row filter selection.  These defines should NOT be
+// changed.
+
+  PNG_FILTER_HEURISTIC_DEFAULT    = 0;  // Currently "UNWEIGHTED"
+  PNG_FILTER_HEURISTIC_UNWEIGHTED = 1;  // Used by libpng < 0.95
+  PNG_FILTER_HEURISTIC_WEIGHTED   = 2;  // Experimental feature
+  PNG_FILTER_HEURISTIC_LAST       = 3;  // Not a valid value 
+
+procedure png_build_grayscale_palette(bit_depth: int; palette: png_colorp);
+             stdcall;
+function png_check_sig(sig: png_bytep; num: int): int;
+             stdcall;
+procedure png_chunk_error(png_ptr: png_structp;
+             const mess: png_charp);
+             stdcall;
+procedure png_chunk_warning(png_ptr: png_structp;
+             const mess: png_charp);
+             stdcall;
+procedure png_convert_from_time_t(ptime: png_timep; ttime: time_t);
+             stdcall;
+function png_convert_to_rfc1123(png_ptr: png_structp; ptime: png_timep):
+             png_charp;
+             stdcall;
+function png_create_info_struct(png_ptr: png_structp): png_infop;
+             stdcall;
+function png_create_read_struct(user_png_ver: png_charp;
+             error_ptr: user_error_ptr; error_fn: png_error_ptr;
+             warn_fn: png_error_ptr): png_structp;
+             stdcall;
+function png_get_copyright(png_ptr: png_structp): png_charp;
+             stdcall;
+function png_get_header_version(png_ptr: png_structp): png_charp;
+             stdcall;
+function png_create_write_struct(user_png_ver: png_charp;
+             error_ptr: user_error_ptr; error_fn: png_error_ptr;
+             warn_fn: png_error_ptr): png_structp;
+             stdcall;
+procedure png_destroy_info_struct(png_ptr: png_structp;
+             info_ptr_ptr: png_infopp);
+             stdcall;
+procedure png_destroy_read_struct(png_ptr_ptr: png_structpp;
+             info_ptr_ptr, end_info_ptr_ptr: png_infopp);
+             stdcall;
+procedure png_destroy_write_struct(png_ptr_ptr: png_structpp;
+             info_ptr_ptr: png_infopp);
+             stdcall;
+function png_get_IHDR(png_ptr: png_structp; info_ptr: png_infop;
+             var width, height: png_uint_32; var bit_depth,
+             color_type, interlace_type, compression_type,
+             filter_type: int): png_uint_32;
+             stdcall;
+function png_get_PLTE(png_ptr: png_structp; info_ptr: png_infop;
+             var palette: png_colorp; var num_palette: int):
+             png_uint_32;
+             stdcall;
+function png_get_bKGD(png_ptr: png_structp; info_ptr: png_infop;
+             var background: png_color_16p): png_uint_32;
+             stdcall;
+function png_get_bit_depth(png_ptr: png_structp; info_ptr: png_infop):
+             png_byte;
+             stdcall;
+function png_get_cHRM(png_ptr: png_structp; info_ptr: png_infop;
+             var white_x, white_y, red_x, red_y, green_x, green_y,
+             blue_x, blue_y: double): png_uint_32;
+             stdcall;
+function png_get_channels(png_ptr: png_structp; info_ptr: png_infop):
+             png_byte;
+             stdcall;
+function png_get_color_type(png_ptr: png_structp; info_ptr: png_infop):
+             png_byte;
+             stdcall;
+function png_get_compression_type(png_ptr: png_structp;
+             info_ptr: png_infop): png_byte;
+             stdcall;
+function png_get_error_ptr(png_ptr: png_structp): png_voidp;
+             stdcall;
+function png_get_filter_type(png_ptr: png_structp; info_ptr: png_infop):
+             png_byte;
+             stdcall;
+function png_get_gAMA(png_ptr: png_structp; info_ptr: png_infop;
+             var file_gamma: double): png_uint_32;
+             stdcall;
+function png_get_hIST(png_ptr: png_structp; info_ptr: png_infop;
+             var hist: png_uint_16p): png_uint_32;
+             stdcall;
+function png_get_image_height(png_ptr: png_structp; info_ptr: png_infop):
+             png_uint_32;
+             stdcall;
+function png_get_image_width(png_ptr: png_structp; info_ptr: png_infop):
+             png_uint_32;
+             stdcall;
+function png_get_interlace_type(png_ptr: png_structp;
+             info_ptr: png_infop): png_byte;
+             stdcall;
+function png_get_io_ptr(png_ptr: png_structp): png_voidp;
+             stdcall;
+function png_get_oFFs(png_ptr: png_structp; info_ptr: png_infop;
+             var offset_x, offset_y: png_uint_32;
+             var unit_type: int): png_uint_32;
+             stdcall;
+function png_get_pCAL(png_ptr: png_structp; info_ptr: png_infop;
+             var purpose: png_charp; var X0, X1: png_int_32;
+             var typ, nparams: int; var units: png_charp;
+             var params: png_charpp): png_uint_32;
+             stdcall;
+function png_get_pHYs(png_ptr: png_structp; info_ptr: png_infop;
+             var res_x, res_y: png_uint_32; var unit_type: int):
+             png_uint_32;
+             stdcall;
+function png_get_pixel_aspect_ratio(png_ptr: png_structp;
+             info_ptr: png_infop): float;
+             stdcall;
+function png_get_pixels_per_meter(png_ptr: png_structp;
+             info_ptr: png_infop): png_uint_32;
+             stdcall;
+function png_get_progressive_ptr(png_ptr: png_structp): png_voidp;
+             stdcall;
+function png_get_rgb_to_gray_status(png_ptr: png_structp);
+             stdcall;
+function png_get_rowbytes(png_ptr: png_structp; info_ptr: png_infop):
+             png_uint_32;
+             stdcall;
+function png_get_sBIT(png_ptr: png_structp; info_ptr: png_infop;
+             var sig_bits: png_color_8p): png_uint_32;
+             stdcall;
+function png_get_sRGB(png_ptr: png_structp; info_ptr: png_infop;
+             var file_srgb_intent: int): png_uint_32;
+             stdcall; 
+function png_get_signature(png_ptr: png_structp; info_ptr: png_infop):
+             png_bytep;
+             stdcall;
+function png_get_tIME(png_ptr: png_structp; info_ptr: png_infop;
+             var mod_time: png_timep): png_uint_32;
+             stdcall;
+function png_get_tRNS(png_ptr: png_structp; info_ptr: png_infop;
+             var trans: png_bytep; var num_trans: int;
+             var trans_values: png_color_16p): png_uint_32;
+             stdcall;
+function png_get_text(png_ptr: png_structp; info_ptr: png_infop;
+             var text_ptr: png_textp; var num_text: int):
+             png_uint_32;
+             stdcall;
+function png_get_valid(png_ptr: png_structp; info_ptr: png_infop;
+             flag: png_uint_32): png_uint_32;
+             stdcall;
+function png_get_x_offset_microns(png_ptr: png_structp;
+             info_ptr: png_infop): png_uint_32;
+             stdcall;
+function png_get_x_offset_pixels(png_ptr: png_structp;
+             info_ptr: png_infop): png_uint_32;
+             stdcall;
+function png_get_x_pixels_per_meter(png_ptr: png_structp;
+             info_ptr: png_infop): png_uint_32;
+             stdcall;
+function png_get_y_offset_microns(png_ptr: png_structp;
+             info_ptr: png_infop): png_uint_32;
+             stdcall;
+function png_get_y_offset_pixels(png_ptr: png_structp;
+             info_ptr: png_infop): png_uint_32;
+             stdcall;
+function png_get_y_pixels_per_meter(png_ptr: png_structp;
+             info_ptr: png_infop): png_uint_32;
+             stdcall;
+procedure png_process_data(png_ptr: png_structp; info_ptr: png_infop;
+             buffer: png_bytep; buffer_size: png_size_t);
+             stdcall;
+procedure png_progressive_combine_row(png_ptr: png_structp;
+             old_row, new_row: png_bytep);
+             stdcall;
+procedure png_read_end(png_ptr: png_structp; info_ptr: png_infop);
+              stdcall;
+procedure png_read_image(png_ptr: png_structp; image: png_bytepp);
+             stdcall;
+procedure png_read_info(png_ptr: png_structp; info_ptr: png_infop);
+             stdcall;
+procedure png_read_row(png_ptr: png_structp; row, dsp_row: png_bytep);
+             stdcall;
+procedure png_read_rows(png_ptr: png_structp; row, display_row:
+              png_bytepp; num_rows: png_uint_32);
+             stdcall;
+procedure png_read_update_info(png_ptr: png_structp; info_ptr: png_infop);
+             stdcall;
+procedure png_set_IHDR(png_ptr: png_structp; info_ptr: png_infop;
+             width, height: png_uint_32; bit_depth, color_type,
+             interlace_type, compression_type, filter_type: int);
+             stdcall;
+procedure png_set_PLTE(png_ptr: png_structp; info_ptr: png_infop;
+             palette: png_colorp; num_palette: int);
+             stdcall;
+procedure png_set_bKGD(png_ptr: png_structp; info_ptr: png_infop;
+             background: png_color_16p);
+             stdcall;
+procedure png_set_background(png_ptr: png_structp;
+             background_color: png_color_16p;
+             background_gamma_code, need_expand: int;
+             background_gamma: double);
+             stdcall;
+procedure png_set_bgr(png_ptr: png_structp);
+             stdcall;
+procedure png_set_cHRM(png_ptr: png_structp; info_ptr: png_infop;
+             white_x, white_y, red_x, red_y, green_x, green_y,
+             blue_x, blue_y: double);
+             stdcall;
+procedure png_set_compression_level(png_ptr: png_structp; level: int);
+             stdcall;
+procedure png_set_compression_mem_level(png_ptr: png_structp;
+             mem_level: int);
+             stdcall;
+procedure png_set_compression_method(png_ptr: png_structp; method: int);
+             stdcall;
+procedure png_set_compression_strategy(png_ptr: png_structp;
+             strategy: int);
+             stdcall;
+procedure png_set_compression_window_bits(png_ptr: png_structp;
+             window_bits: int);
+             stdcall;
+procedure png_set_crc_action(png_ptr: png_structp;
+             crit_action, ancil_action: int);
+             stdcall;
+procedure png_set_dither(png_ptr: png_structp; plaette: png_colorp;
+             num_palette, maximum_colors: int;
+             histogram: png_uint_16p; full_dither: int);
+             stdcall;
+procedure png_set_error_fn(png_ptr: png_structp; error_ptr: png_voidp;
+             error_fn, warning_fn: png_error_ptr);
+             stdcall;
+procedure png_set_expand(png_ptr: png_structp);
+             stdcall;
+procedure png_set_filler(png_ptr: png_structp; filler: png_uint_32;
+             filler_loc: int);
+             stdcall;
+procedure png_set_filter(png_ptr: png_structp; method, filters: int);
+             stdcall;
+procedure png_set_filter_heuristics(png_ptr: png_structp;
+             heuristic_method, num_weights: int;
+             filter_weights, filter_costs: png_doublep);
+             stdcall;
+procedure png_set_flush(png_ptr: png_structp; nrows: int);
+             stdcall;
+procedure png_set_gAMA(png_ptr: png_structp; info_ptr: png_infop;
+             file_gamma: double);
+             stdcall;
+procedure png_set_gamma(png_ptr: png_structp; screen_gamma,
+             default_file_gamma: double);
+             stdcall;
+procedure png_set_gray_1_2_4_to_8(png_ptr: png_structp);
+             stdcall;
+procedure png_set_gray_to_rgb(png_ptr: png_structp);
+             stdcall;
+procedure png_set_hIST(png_ptr: png_structp; info_ptr: png_infop;
+             hist: png_uint_16p);
+             stdcall;
+function png_set_interlace_handling(png_ptr: png_structp): int;
+             stdcall;
+procedure png_set_invert_alpha(png_ptr: png_structp);
+             stdcall;
+procedure png_set_invert_mono(png_ptr: png_structp);
+             stdcall;
+procedure png_set_oFFs(png_ptr: png_structp; info_ptr: png_infop;
+             offset_x, offset_y: png_uint_32; unit_type: int);
+             stdcall;
+procedure png_set_palette_to_rgb(png_ptr: png_structp);
+             stdcall;
+procedure png_set_pCAL(png_ptr: png_structp; info_ptr: png_infop;
+             purpose: png_charp; X0, X1: png_int_32;
+             typ, nparams: int; units: png_charp;
+             params: png_charpp);
+             stdcall;
+procedure png_set_pHYs(png_ptr: png_structp; info_ptr: png_infop;
+             res_x, res_y: png_uint_32; unit_type: int);
+             stdcall;
+procedure png_set_packing(png_ptr: png_structp);
+             stdcall;
+procedure png_set_packswap(png_ptr: png_structp);
+             stdcall;
+procedure png_set_progressive_read_fn(png_ptr: png_structp;
+             progressive_ptr: png_voidp;
+             info_fn: png_progressive_info_ptr;
+             row_fn: png_progressive_row_ptr;
+             end_fn: png_progressive_end_ptr);
+             stdcall;
+procedure png_set_read_fn(png_ptr: png_structp;
+             io_ptr: png_voidp; read_data_fn: png_rw_ptr);
+             stdcall;
+procedure png_set_read_status_fn(png_ptr: png_structp;
+             read_row_fn: png_read_status_ptr);
+             stdcall;
+procedure png_set_read_user_transform_fn(png_ptr: png_structp;
+             read_user_transform_fn: png_user_transform_ptr);
+             stdcall;
+procedure png_set_rgb_to_gray(png_ptr: png_structp; int: error_action);
+             stdcall;
+procedure png_set_sBIT(png_ptr: png_structp; info_ptr: png_infop;
+             sig_bits: png_color_8p);
+             stdcall;
+procedure png_set_sRGB(png_ptr: png_structp; info_ptr: png_infop;
+             intent: int);
+             stdcall;
+procedure png_set_sRGB_gAMA_and_cHRM(png_ptr: png_structp;
+             info_ptr: png_infop; intent: int);
+             stdcall;
+procedure png_set_shift(png_ptr: png_structp; true_bits: png_color_8p);
+             stdcall;
+procedure png_set_sig_bytes(png_ptr: png_structp; num_bytes: int);
+             stdcall;
+procedure png_set_strip_16(png_ptr: png_structp);
+             stdcall;
+procedure png_set_strip_alpha(png_ptr: png_structp);
+             stdcall;
+procedure png_set_swap(png_ptr: png_structp);
+             stdcall;
+procedure png_set_swap_alpha(png_ptr: png_structp);
+             stdcall;
+procedure png_set_tIME(png_ptr: png_structp; info_ptr: png_infop;
+             mod_time: png_timep);
+             stdcall;
+procedure png_set_tRNS(png_ptr: png_structp; info_ptr: png_infop;
+             trans: png_bytep; num_trans: int;
+             trans_values: png_color_16p);
+             stdcall;
+procedure png_set_tRNS_to_alpha(png_ptr: png_structp);
+             stdcall;
+procedure png_set_text(png_ptr: png_structp; info_ptr: png_infop;
+             text_ptr: png_textp; num_text: int);
+             stdcall;
+procedure png_set_write_fn(png_ptr: png_structp;
+             io_ptr: png_voidp; write_data_fn: png_rw_ptr;
+             output_flush_fn: png_flush_ptr);
+             stdcall;
+procedure png_set_write_status_fn(png_ptr: png_structp;
+             write_row_fn: png_write_status_ptr);
+             stdcall;
+procedure png_set_write_user_transform_fn(png_ptr: png_structp;
+             write_user_transform_fn: png_user_transform_ptr);
+             stdcall;
+function png_sig_cmp(sig: png_bytep; start, num_to_check: png_size_t):
+             int;
+             stdcall;
+procedure png_start_read_image(png_ptr: png_structp);
+             stdcall;
+procedure png_write_chunk(png_ptr: png_structp;
+             chunk_name, data: png_bytep; length: png_size_t);
+             stdcall;
+procedure png_write_chunk_data(png_ptr: png_structp;
+             data: png_bytep; length: png_size_t);
+             stdcall;
+procedure png_write_chunk_end(png_ptr: png_structp);
+             stdcall;
+procedure png_write_chunk_start(png_ptr: png_structp;
+             chunk_name: png_bytep; length: png_uint_32);
+             stdcall;
+procedure png_write_end(png_ptr: png_structp; info_ptr: png_infop);
+             stdcall;
+procedure png_write_flush(png_ptr: png_structp);
+             stdcall;
+procedure png_write_image(png_ptr: png_structp; image: png_bytepp);
+             stdcall;
+procedure png_write_info(png_ptr: png_structp; info_ptr: png_infop);
+             stdcall;
+procedure png_write_row(png_ptr: png_structp; row: png_bytep);
+             stdcall;
+procedure png_write_rows(png_ptr: png_structp; row: png_bytepp;
+             num_rows: png_uint_32);
+             stdcall;
+
+implementation
+
+const
+  pngDLL = 'png32bd.dll';
+
+procedure png_build_grayscale_palette; external pngDLL;
+function png_check_sig; external pngDLL;
+procedure png_chunk_error; external pngDLL;
+procedure png_chunk_warning; external pngDLL;
+procedure png_convert_from_time_t; external pngDLL;
+function png_convert_to_rfc1123; external pngDLL;
+function png_create_info_struct; external pngDLL;
+function png_create_read_struct; external pngDLL;
+function png_create_write_struct; external pngDLL;
+procedure png_destroy_info_struct; external pngDLL;
+procedure png_destroy_read_struct; external pngDLL;
+procedure png_destroy_write_struct; external pngDLL;
+function png_get_IHDR; external pngDLL;
+function png_get_PLTE; external pngDLL;
+function png_get_bKGD; external pngDLL;
+function png_get_bit_depth; external pngDLL;
+function png_get_cHRM; external pngDLL;
+function png_get_channels; external pngDLL;
+function png_get_color_type; external pngDLL;
+function png_get_compression_type; external pngDLL;
+function png_get_error_ptr; external pngDLL;
+function png_get_filter_type; external pngDLL;
+function png_get_gAMA; external pngDLL;
+function png_get_hIST; external pngDLL;
+function png_get_image_height; external pngDLL;
+function png_get_image_width; external pngDLL;
+function png_get_interlace_type; external pngDLL;
+function png_get_io_ptr; external pngDLL;
+function png_get_oFFs; external pngDLL;
+function png_get_pCAL; external pngDLL;
+function png_get_pHYs; external pngDLL;
+function png_get_pixel_aspect_ratio; external pngDLL;
+function png_get_pixels_per_meter; external pngDLL;
+function png_get_progressive_ptr; external pngDLL;
+function png_get_rowbytes; external pngDLL;
+function png_get_sBIT; external pngDLL;
+function png_get_sRGB; external pngDLL;
+function png_get_signature; external pngDLL;
+function png_get_tIME; external pngDLL;
+function png_get_tRNS; external pngDLL;
+function png_get_text; external pngDLL;
+function png_get_valid; external pngDLL;
+function png_get_x_offset_microns; external pngDLL;
+function png_get_x_offset_pixels; external pngDLL;
+function png_get_x_pixels_per_meter; external pngDLL;
+function png_get_y_offset_microns; external pngDLL;
+function png_get_y_offset_pixels; external pngDLL;
+function png_get_y_pixels_per_meter; external pngDLL;
+procedure png_process_data; external pngDLL;
+procedure png_progressive_combine_row; external pngDLL;
+procedure png_read_end; external pngDLL;
+procedure png_read_image; external pngDLL;
+procedure png_read_info; external pngDLL;
+procedure png_read_row; external pngDLL;
+procedure png_read_rows; external pngDLL;
+procedure png_read_update_info; external pngDLL;
+procedure png_set_IHDR; external pngDLL;
+procedure png_set_PLTE; external pngDLL;
+procedure png_set_bKGD; external pngDLL;
+procedure png_set_background; external pngDLL;
+procedure png_set_bgr; external pngDLL;
+procedure png_set_cHRM; external pngDLL;
+procedure png_set_compression_level; external pngDLL;
+procedure png_set_compression_mem_level; external pngDLL;
+procedure png_set_compression_method; external pngDLL;
+procedure png_set_compression_strategy; external pngDLL;
+procedure png_set_compression_window_bits; external pngDLL;
+procedure png_set_crc_action; external pngDLL;
+procedure png_set_dither; external pngDLL;
+procedure png_set_error_fn; external pngDLL;
+procedure png_set_expand; external pngDLL;
+procedure png_set_filler; external pngDLL;
+procedure png_set_filter; external pngDLL;
+procedure png_set_filter_heuristics; external pngDLL;
+procedure png_set_flush; external pngDLL;
+procedure png_set_gAMA; external pngDLL;
+procedure png_set_gamma; external pngDLL;
+procedure png_set_gray_to_rgb; external pngDLL;
+procedure png_set_hIST; external pngDLL;
+function png_set_interlace_handling; external pngDLL;
+procedure png_set_invert_alpha; external pngDLL;
+procedure png_set_invert_mono; external pngDLL;
+procedure png_set_oFFs; external pngDLL;
+procedure png_set_pCAL; external pngDLL;
+procedure png_set_pHYs; external pngDLL;
+procedure png_set_packing; external pngDLL;
+procedure png_set_packswap; external pngDLL;
+procedure png_set_progressive_read_fn; external pngDLL;
+procedure png_set_read_fn; external pngDLL;
+procedure png_set_read_status_fn; external pngDLL;
+procedure png_set_read_user_transform_fn; external pngDLL;
+procedure png_set_sBIT; external pngDLL;
+procedure png_set_sRGB; external pngDLL;
+procedure png_set_sRGB_gAMA_and_cHRM; external pngDLL;
+procedure png_set_shift; external pngDLL;
+procedure png_set_sig_bytes; external pngDLL;
+procedure png_set_strip_16; external pngDLL;
+procedure png_set_strip_alpha; external pngDLL;
+procedure png_set_swap; external pngDLL;
+procedure png_set_swap_alpha; external pngDLL;
+procedure png_set_tIME; external pngDLL;
+procedure png_set_tRNS; external pngDLL;
+procedure png_set_text; external pngDLL;
+procedure png_set_write_fn; external pngDLL;
+procedure png_set_write_status_fn; external pngDLL;
+procedure png_set_write_user_transform_fn; external pngDLL;
+function png_sig_cmp; external pngDLL;
+procedure png_start_read_image; external pngDLL;
+procedure png_write_chunk; external pngDLL;
+procedure png_write_chunk_data; external pngDLL;
+procedure png_write_chunk_end; external pngDLL;
+procedure png_write_chunk_start; external pngDLL;
+procedure png_write_end; external pngDLL;
+procedure png_write_flush; external pngDLL;
+procedure png_write_image; external pngDLL;
+procedure png_write_info; external pngDLL;
+procedure png_write_row; external pngDLL;
+procedure png_write_rows; external pngDLL;
+
+end.

scripts/pngdll.mak

@@ -0,0 +1,53 @@
+# Makefile for png32bd.dll
+# ------------- Borland C++ 4.5 -------------
+
+# This makefile expects to find zlib.h and zlib32bd.lib in the
+# $(ZLIBDIR) directory.
+
+# The object files here are compiled with the "stdcall" calling convention.
+# This DLL requires zlib32bd.lib to be compiled in the same way.
+
+# Note that png32bd.dll exports the zlib functions adler32, crc32 and
+# the deflate... and inflate... functions. It does not export the
+# compress and uncompress functions, nor any of the gz... functions,
+# since libpng does not call them.
+
+ZLIBDIR=..\zlib112
+ZLIB=zlib32bd.lib
+PNGDLL=png32bd.dll
+
+CFLAGS= -ps -O2 -C -K -N- -k- -d -3 -r- -w-par -w-aus -WDE -I$(ZLIBDIR)
+CC=f:\bc45\bin\bcc32
+LINKFLAGS= -Tpd -aa -c
+LINK=f:\bc45\bin\tlink32
+LIBDIR=f:\bc45\lib
+IMPLIB=f:\bc45\bin\implib
+
+.autodepend
+.c.obj:
+        $(CC) -c $(CFLAGS) $<
+ 
+OBJ1=png.obj pngerror.obj pngget.obj pngmem.obj pngpread.obj 
+OBJ2=pngread.obj pngrio.obj pngrtran.obj pngrutil.obj pngset.obj 
+OBJ3=pngtrans.obj pngwio.obj pngwrite.obj pngwtran.obj pngwutil.obj
+
+all: $(PNGDLL)
+
+$(PNGDLL): $(OBJ1) $(OBJ2) $(OBJ3) $(ZLIBDIR)\$(ZLIB)
+        $(LINK) @&&|
+$(LINKFLAGS) $(LIBDIR)\c0d32 +
+$(OBJ1) +
+$(OBJ2) +
+$(OBJ3)
+$@
+-x
+$(ZLIBDIR)\$(ZLIB) $(LIBDIR)\import32 $(LIBDIR)\cw32
+|,&&|
+LIBRARY $(@B)
+EXETYPE WINDOWS
+CODE PRELOAD MOVEABLE DISCARDABLE
+DATA PRELOAD MOVEABLE MULTIPLE
+|
+        $(IMPLIB) -c $(@R).lib $@
+
+# End of makefile for png32bd.dll

scripts/pngos2.def

@@ -0,0 +1,296 @@
+;----------------------------------------
+; PNGLIB module definition file for OS/2
+;----------------------------------------
+
+LIBRARY		PNG
+DESCRIPTION	"PNG image compression library for OS/2"
+CODE		PRELOAD MOVEABLE DISCARDABLE
+DATA		PRELOAD MOVEABLE MULTIPLE
+
+EXPORTS
+  png_set_sig_bytes
+  png_sig_cmp
+  png_check_sig
+  png_create_read_struct
+; png_create_read_struct_2
+  png_create_write_struct
+; png_create_write_struct_2
+  png_write_chunk
+  png_write_chunk_start
+  png_write_chunk_data
+  png_write_chunk_end
+  png_create_info_struct
+  png_info_init
+  png_write_info
+  png_read_info
+  png_convert_to_rfc1123
+  png_convert_from_struct_tm
+  png_convert_from_time_t
+  png_set_expand
+  png_set_bgr
+  png_set_gray_to_rgb
+  png_set_rgb_to_gray
+  png_build_grayscale_palette
+  png_set_strip_alpha
+  png_set_swap_alpha
+  png_set_invert_alpha
+  png_set_filler
+  png_set_swap
+  png_set_packing
+  png_set_packswap
+  png_set_shift
+  png_set_interlace_handling
+  png_set_invert_mono
+  png_set_background
+  png_set_strip_16
+  png_set_dither
+  png_set_gamma
+  png_set_flush
+  png_write_flush
+  png_start_read_image
+  png_read_update_info
+  png_read_rows
+  png_read_row
+  png_read_image
+  png_write_row
+  png_write_rows
+  png_write_image
+  png_write_end
+  png_read_end
+  png_destroy_info_struct
+  png_destroy_read_struct
+  png_read_destroy
+  png_destroy_write_struct
+; png_write_destroy_info
+  png_write_destroy
+  png_set_crc_action
+  png_set_filter
+  png_set_filter_heuristics
+  png_set_compression_level
+  png_set_compression_mem_level
+  png_set_compression_strategy
+  png_set_compression_window_bits
+  png_set_compression_method
+  png_init_io
+  png_get_copyright
+  png_set_error_fn
+  png_get_error_ptr
+  png_get_header_version
+; png_get_mem_fn
+; png_set_mem_fn
+  png_set_write_fn
+  png_set_read_fn
+  png_set_write_status_fn
+  png_set_read_status_fn
+  png_get_io_ptr
+  png_set_progressive_read_fn
+  png_set_read_status_fn
+  png_set_read_user_transform_fn
+  png_set_write_status_fn
+  png_set_write_user_transform_fn
+  png_get_progressive_ptr
+  png_process_data
+  png_progressive_combine_row
+  png_malloc
+  png_free
+  png_memcpy_check
+  png_memset_check
+; png_malloc_default
+; png_free_default
+; png_far_to_near
+  png_error
+  png_chunk_error
+  png_warning
+  png_chunk_warning
+  png_get_valid
+  png_get_rowbytes
+  png_get_channels
+  png_get_image_width
+  png_get_image_height
+  png_get_bit_depth
+  png_get_color_type
+  png_get_filter_type
+  png_get_interlace_type
+  png_get_compression_type
+  png_get_pixels_per_meter
+  png_get_pixel_aspect_ratio
+  png_get_rgb_to_gray_status
+  png_get_x_offset_pixels
+  png_get_y_offset_pixels
+  png_get_x_offset_microns
+  png_get_y_offset_microns
+  png_get_signature
+  png_get_bKGD
+  png_set_bKGD
+  png_get_cHRM
+  png_set_cHRM
+  png_get_gAMA
+  png_set_gAMA
+  png_get_hIST
+  png_set_hIST
+  png_get_IHDR
+  png_set_IHDR
+  png_get_oFFs
+  png_set_oFFs
+  png_get_pCAL
+  png_set_pCAL
+  png_get_pHYs
+  png_set_pHYs
+  png_get_PLTE
+  png_set_PLTE
+  png_get_sBIT
+  png_set_sBIT
+  png_get_sRGB
+  png_set_sRGB
+  png_set_sRGB_gAMA_and_cHRM
+  png_get_text
+  png_set_text
+  png_get_tIME
+  png_set_tIME
+  png_get_tRNS
+  png_set_tRNS
+  png_set_gray_1_2_4_to_8
+  png_set_tRNS_to_alpha
+  png_set_palette_to_rgb
+
+  png_create_struct
+  png_destroy_struct
+  png_info_destroy
+  png_zalloc
+  png_zfree
+  png_reset_crc
+  png_write_data
+  png_read_data
+  png_crc_read
+  png_crc_finish
+  png_crc_error
+  png_calculate_crc
+  png_flush
+  png_save_uint_32
+  png_save_int_32
+  png_save_uint_16
+  png_write_sig
+  png_write_IHDR
+  png_write_PLTE
+  png_write_IDAT
+  png_write_IEND
+  png_write_gAMA
+  png_write_sBIT
+  png_write_cHRM
+  png_write_sRGB
+  png_write_tRNS
+  png_write_bKGD
+  png_write_hIST
+  png_check_keyword
+  png_write_tEXt
+  png_write_zTXt
+  png_write_oFFs
+  png_write_pCAL
+  png_write_pHYs
+  png_write_tIME
+  png_write_finish_row
+  png_write_start_row
+  png_build_gamma_table
+  png_combine_row
+  png_do_read_interlace
+  png_do_write_interlace
+  png_read_filter_row
+  png_write_find_filter
+  png_write_filtered_row
+  png_read_finish_row
+  png_read_start_row
+  png_read_transform_info
+  png_do_read_filler
+  png_do_read_swap_alpha
+  png_do_write_swap_alpha
+  png_do_read_invert_alpha
+  png_do_write_invert_alpha
+  png_do_strip_filler
+  png_do_swap
+  png_do_packswap
+  png_do_rgb_to_gray
+  png_do_gray_to_rgb
+  png_do_unpack
+  png_do_unshift
+  png_do_invert
+  png_do_chop
+  png_do_dither
+; png_correct_palette
+  png_do_bgr
+  png_do_pack
+  png_do_shift
+  png_do_background
+  png_do_gamma
+  png_do_expand_palette
+  png_do_expand
+  png_handle_IHDR
+  png_handle_PLTE
+  png_handle_IEND
+  png_handle_gAMA
+  png_handle_sBIT
+  png_handle_cHRM
+  png_handle_sRGB
+  png_handle_tRNS
+  png_handle_bKGD
+  png_handle_hIST
+  png_handle_oFFs
+  png_handle_pCAL
+  png_handle_pHYs
+  png_handle_tIME
+  png_handle_tEXt
+  png_handle_zTXt
+  png_handle_unknown
+  png_check_chunk_name
+  png_do_read_transformations
+  png_do_write_transformations
+  png_init_read_transformations
+  png_push_read_chunk
+  png_push_read_sig
+; png_push_check_crc
+  png_push_crc_skip
+  png_push_crc_finish
+  png_push_fill_buffer
+  png_push_save_buffer
+  png_push_restore_buffer
+  png_push_read_IDAT
+  png_process_IDAT_data
+  png_push_process_row
+  png_push_handle_unknown
+  png_push_have_info
+  png_push_have_end
+  png_push_have_row
+; png_push_read_end
+  png_process_some_data
+  png_read_push_finish_row
+  png_push_handle_tEXt
+  png_push_read_tEXt
+  png_push_handle_zTXt
+  png_push_read_zTXt
+
+  png_libpng_ver
+  png_pass_start
+  png_pass_inc
+  png_pass_ystart
+  png_pass_yinc
+  png_pass_mask
+  png_pass_dsp_mask
+; png_pass_width
+; png_pass_height
+
+  png_IHDR
+  png_IDAT
+  png_IEND
+  png_PLTE
+  png_bKGD
+  png_cHRM
+  png_gAMA
+  png_hIST
+  png_oFFs
+  png_pCAL
+  png_pHYs
+  png_sBIT
+  png_sRGB
+  png_tEXt
+  png_tIME
+  png_tRNS
+  png_zTXt

scripts/smakefile.ppc

@@ -0,0 +1,29 @@
+# Amiga powerUP (TM) Makefile
+# makefile for libpng and SAS C V6.58/7.00 PPC compiler
+# Copyright (C) 1998 by Andreas R. Kleinert
+
+CC       = scppc
+CFLAGS   = NOSTKCHK NOSINT OPTIMIZE OPTGO OPTPEEP OPTINLOCAL OPTINL IDIR /zlib \
+           OPTLOOP OPTRDEP=8 OPTDEP=8 OPTCOMP=8
+LIBNAME  = libpng.a
+AR       = ppc-amigaos-ar
+AR_FLAGS = cr
+RANLIB   = ppc-amigaos-ranlib
+LDFLAGS  = -r -o
+LDLIBS   =  ../zlib/libzip.a LIB:scppc.a
+LN       = ppc-amigaos-ld
+RM       = delete quiet
+MKDIR    = makedir
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o pngread.o \
+pngerror.o pngpread.o pngwrite.o pngrtran.o pngwtran.o pngrio.o pngwio.o pngmem.o
+
+all: $(LIBNAME) pngtest
+
+$(LIBNAME): $(OBJS)
+            $(AR) $(AR_FLAGS) $@ $(OBJS)
+            $(RANLIB) $@
+
+pngtest: pngtest.o $(LIBNAME)
+        $(LN) $(LDFLAGS) pngtest LIB:c_ppc.o pngtest.o $(LIBNAME) $(LDLIBS) \
+LIB:end.o