Imported from libpng-1.0.11.tar

ANNOUNCE

@@ -0,0 +1,20 @@
+
+Libpng 1.0.11 - April 27, 2001
+
+This is a public release of libpng, intended for use in production codes.
+
+Changes since the last public release (1.0.10):
+
+  Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
+  Removed a no-longer needed AIX work-around from pngconf.h
+  Changed several "//" single-line comments to C-style in pnggccrd.c
+  Removed PNGAPI from private functions whose prototypes did not have PNGAPI.
+  Updated scripts/pngos2.def
+  Added a check for NULL return from user's malloc_fn().
+  Removed some useless type casts of the NULL pointer.
+  Added makefile.netbsd
+
+Send comments/corrections/commendations to
+png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu
+
+Glenn R-P

CHANGES

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+CHANGES - changes for libpng
+
+version 0.2
+  added reader into png.h
+  fixed small problems in stub file
+version 0.3
+  added pull reader
+  split up pngwrite.c to several files
+  added pnglib.txt
+  added example.c
+  cleaned up writer, adding a few new tranformations
+  fixed some bugs in writer
+  interfaced with zlib 0.5
+  added K&R support
+  added check for 64 KB blocks for 16 bit machines
+version 0.4
+  cleaned up code and commented code
+  simplified time handling into png_time
+  created png_color_16 and png_color_8 to handle color needs
+  cleaned up color type defines
+  fixed various bugs
+  made various names more consistant
+  interfaced with zlib 0.71
+  cleaned up zTXt reader and writer (using zlib's Reset functions)
+  split transformations into pngrtran.c and pngwtran.c
+version 0.5
+  interfaced with zlib 0.8
+  fixed many reading and writing bugs
+  saved using 3 spaces instead of tabs
+version 0.6
+  added png_large_malloc() and png_large_free()
+  added png_size_t
+  cleaned up some compiler warnings
+  added png_start_read_image()
+version 0.7
+  cleaned up lots of bugs
+  finished dithering and other stuff
+  added test program
+  changed name from pnglib to libpng
+version 0.71 [June, 1995]
+  changed pngtest.png for zlib 0.93
+  fixed error in libpng.txt and example.c
+version 0.8
+  cleaned up some bugs
+  added png_set_filler()
+  split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
+  added #define's to remove unwanted code
+  moved png_info_init() to png.c
+  added old_size into png_realloc()
+  added functions to manually set filtering and compression info
+  changed compression parameters based on image type
+  optimized filter selection code
+  added version info
+  changed external functions passing floats to doubles (k&r problems?)
+  put all the configurable stuff in pngconf.h
+  enabled png_set_shift to work with paletted images on read
+  added png_read_update_info() - updates info structure with
+     transformations
+version 0.81 [August, 1995]
+  incorporated Tim Wegner's medium model code (thanks, Tim)
+version 0.82 [September, 1995]
+  [unspecified changes]
+version 0.85 [December, 1995]
+  added more medium model code (almost everything's a far)
+  added i/o, error, and memory callback functions
+  fixed some bugs (16 bit, 4 bit interlaced, etc.)
+  added first run progressive reader (barely tested)
+version 0.86 [January, 1996]
+  fixed bugs
+  improved documentation
+version 0.87 [January, 1996]
+  fixed medium model bugs
+  fixed other bugs introduced in 0.85 and 0.86
+  added some minor documentation
+version 0.88 [January, 1996]
+  fixed progressive bugs
+  replaced tabs with spaces
+  cleaned up documentation
+  added callbacks for read/write and warning/error functions
+version 0.89 [July, 1996]
+  added new initialization API to make libpng work better with shared libs
+     we now have png_create_read_struct(), png_create_write_struct(),
+     png_create_info_struct(), png_destroy_read_struct(), and
+     png_destroy_write_struct() instead of the separate calls to
+     malloc and png_read_init(), png_info_init(), and png_write_init()
+  changed warning/error callback functions to fix bug - this means you
+     should use the new initialization API if you were using the old
+     png_set_message_fn() calls, and that the old API no longer exists
+     so that people are aware that they need to change their code
+  changed filter selection API to allow selection of multiple filters
+     since it didn't work in previous versions of libpng anyways
+  optimized filter selection code
+  fixed png_set_background() to allow using an arbitrary RGB color for
+     paletted images
+  fixed gamma and background correction for paletted images, so
+     png_correct_palette is not needed unless you are correcting an
+     external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
+     in pngconf.h) - if nobody uses this, it may disappear in the future.
+  fixed bug with Borland 64K memory allocation (Alexander Lehmann)
+  fixed bug in interlace handling (Smarasderagd, I think)
+  added more error checking for writing and image to reduce invalid files
+  separated read and write functions so that they won't both be linked
+     into a binary when only reading or writing functionality is used
+  new pngtest image also has interlacing and zTXt
+  updated documentation to reflect new API
+version 0.90 [January, 1997]
+  made CRC errors/warnings on critical and ancillary chunks configurable
+  libpng will use the zlib CRC routines by (compile-time) default
+  changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
+  added external C++ wrapper statements to png.h (Gilles Dauphin)
+  allow PNG file to be read when some or all of file signature has already
+     been read from the beginning of the stream.  ****This affects the size
+     of info_struct and invalidates all programs that use a shared libpng****
+  fixed png_filler() declarations
+  fixed? background color conversions
+  fixed order of error function pointers to match documentation
+  current chunk name is now available in png_struct to reduce the number
+     of nearly identical error messages (will simplify multi-lingual
+     support when available)
+  try to get ready for unknown-chunk callback functions:
+     - previously read critical chunks are flagged, so the chunk handling
+       routines can determine if the chunk is in the right place
+     - all chunk handling routines have the same prototypes, so we will
+       be able to handle all chunks via a callback mechanism
+  try to fix Linux "setjmp" buffer size problems
+  removed png_large_malloc, png_large_free, and png_realloc functions.
+version 0.95 [March, 1997]
+  fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
+  fixed bug in PNG file signature compares when start != 0
+  changed parameter type of png_set_filler(...filler...) from png_byte
+     to png_uint_32
+  added test for MACOS to ensure that both math.h and fp.h are not #included
+  added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
+  added "packswap" transformation, which changes the endianness of
+     packed-pixel bytes (Kevin Bracey)
+  added "strip_alpha" transformation, which removes the alpha channel of
+     input images without using it (not neccesarily a good idea)
+  added "swap_alpha" transformation, which puts the alpha channel in front
+     of the color bytes instead of after
+  removed all implicit variable tests which assume NULL == 0 (I think)
+  changed several variables to "png_size_t" to show 16/32-bit limitations
+  added new pCAL chunk read/write support
+  added experimental filter selection weighting (Greg Roelofs)
+  removed old png_set_rgbx() and png_set_xrgb() functions that have been
+     obsolete for about 2 years now (use png_set_filler() instead)
+  added macros to read 16- and 32-bit ints directly from buffer, to be
+     used only on those systems that support it (namely PowerPC and 680x0)
+     With some testing, this may become the default for MACOS/PPC systems.
+  only calculate CRC on data if we are going to use it
+  added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
+  added macros for simple libpng debugging output selectable at compile time
+  removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
+  more description of info_struct in libpng.txt and png.h
+  more instructions in example.c
+  more chunk types tested in pngtest.c
+  renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
+     png_set_<chunk>.  We now have corresponding png_get_<chunk>
+     functions in pngget.c to get infomation in info_ptr.  This isolates
+     the application from the internal organization of png_info_struct
+     (good for shared library implementations).
+version 0.96 [May, 1997]
+  fixed serious bug with < 8bpp images introduced in 0.95
+  fixed 256-color transparency bug (Greg Roelofs)
+  fixed up documentation (Greg Roelofs, Laszlo Nyul)
+  fixed "error" in pngconf.h for Linux setjmp() behaviour
+  fixed DOS medium model support (Tim Wegner)
+  fixed png_check_keyword() for case with error in static string text
+  added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
+  added typecasts to quiet compiler errors
+  added more debugging info
+version 0.97 [January, 1998]
+  removed PNG_USE_OWN_CRC capability
+  relocated png_set_crc_action from pngrutil.c to pngrtran.c
+  fixed typecasts of "new_key", etc. (Andreas Dilger)
+  added RFC 1152 [sic] date support
+  fixed bug in gamma handling of 4-bit grayscale
+  added 2-bit grayscale gamma handling (Glenn R-P)
+  added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
+  minor corrections in libpng.txt
+  added simple sRGB support (Glenn R-P)
+  easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
+     all configurable options can be selected from command-line instead
+     of having to edit pngconf.h (Glenn R-P)
+  fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
+  added more conditions for png_do_background, to avoid changing
+     black pixels to background when a background is supplied and
+     no pixels are transparent
+  repaired PNG_NO_STDIO behaviour
+  tested NODIV support and made it default behaviour (Greg Roelofs)
+  added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
+  regularized version numbering scheme and bumped shared-library major
+     version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)
+version 0.98 [January, 1998]
+  cleaned up some typos in libpng.txt and in code documentation
+  fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
+  cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
+  changed recommendation about file_gamma for PC images to .51 from .45,
+     in example.c and libpng.txt, added comments to distinguish between
+     screen_gamma, viewing_gamma, and display_gamma.
+  changed all references to RFC1152 to read RFC1123 and changed the
+     PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
+  added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
+  changed srgb_intent from png_byte to int to avoid compiler bugs
+version 0.99 [January 30, 1998]
+  free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
+  fixed a longstanding "packswap" bug in pngtrans.c
+  fixed some inconsistencies in pngconf.h that prevented compiling with
+     PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
+  fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
+  changed recommendation about file_gamma for PC images to .50 from .51 in
+     example.c and libpng.txt, and changed file_gamma for sRGB images to .45
+  added a number of functions to access information from the png structure
+     png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
+  added TARGET_MACOS similar to zlib-1.0.8
+  define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
+  added type casting to all png_malloc() function calls
+version 0.99a [January 31, 1998]
+  Added type casts and parentheses to all returns that return a value.(Tim W.)
+version 0.99b [February 4, 1998]
+  Added type cast png_uint_32 on malloc function calls where needed.
+  Changed type of num_hist from png_uint_32 to int (same as num_palette).
+  Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
+  Renamed makefile.elf to makefile.lnx.
+version 0.99c [February 7, 1998]
+  More type casting.  Removed erroneous overflow test in pngmem.c.
+  Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
+  Added UNIX manual pages libpng.3 (incorporating libpng.txt) and  png.5.
+version 0.99d [February 11, 1998]
+  Renamed "far_to_near()" "png_far_to_near()"
+  Revised libpng.3
+  Version 99c "buffered" operations didn't work as intended.  Replaced them
+    with png_memcpy_check() and png_memset_check().
+  Added many "if (png_ptr == NULL) return" to quell compiler warnings about
+    unused png_ptr, mostly in pngget.c and pngset.c.
+  Check for overlength tRNS chunk present when indexed-color PLTE is read.
+  Cleaned up spelling errors in libpng.3/libpng.txt
+  Corrected a problem with png_get_tRNS() which returned undefined trans array
+version 0.99e [February 28, 1998]
+  Corrected png_get_tRNS() again.
+  Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
+  Touched up example.c to make more of it compileable, although the entire
+    file still can't be compiled (Willem van Schaik)
+  Fixed a bug in png_do_shift() (Bryan Tsai)
+  Added a space in png.h prototype for png_write_chunk_start()
+  Replaced pngtest.png with one created with zlib 1.1.1
+  Changed pngtest to report PASS even when file size is different (Jean-loup G.)
+  Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
+version 0.99f [March 5, 1998]
+  Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
+  Moved makefiles into a "scripts" directory, and added INSTALL instruction file
+  Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
+  Added pointers to "note on libpng versions" in makefile.lnx and README
+  Added row callback feature when reading and writing nonprogressive rows
+     and added a test of this feature in pngtest.c
+  Added user transform callbacks, with test of the feature in pngtest.c
+version 0.99g [March 6, 1998, morning]
+  Minor changes to pngtest.c to suppress compiler warnings.
+  Removed "beta" language from documentation.
+version 0.99h [March 6, 1998, evening]
+  Minor changes to previous minor changes to pngtest.c
+  Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
+  and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
+  Added user transform capability
+version 1.00 [March 7, 1998]
+  Changed several typedefs in pngrutil.c
+  Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
+  replaced "while(1)" with "for(;;)"
+  added PNGARG() to prototypes in pngtest.c and removed some prototypes
+  updated some of the makefiles (Tom Lane)
+  changed some typedefs (s_start, etc.) in pngrutil.c
+  fixed dimensions of "short_months" array in pngwrite.c
+  Replaced ansi2knr.c with the one from jpeg-v6
+version 1.0.0 [March 8, 1998]
+  Changed name from 1.00 to 1.0.0 (Adam Costello)
+  Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
+version 1.0.0a [March 9, 1998]
+  Fixed three bugs in pngrtran.c to make gamma+background handling consistent
+  (Greg Roelofs)
+  Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
+  for major, minor, and bugfix releases.  This is 10001. (Adam Costello,
+  Tom Lane)
+  Make months range from 1-12 in png_convert_to_rfc1123
+version 1.0.0b [March 13, 1998]
+  Quieted compiler complaints about two empty "for" loops in pngrutil.c
+  Minor changes to makefile.s2x
+  Removed #ifdef/#endif around a png_free() in pngread.c
+version 1.0.1 [March 14, 1998]
+  Changed makefile.s2x to reduce security risk of using a relative pathname
+  Fixed some typos in the documentation (Greg).
+  Fixed a problem with value of "channels" returned by png_read_update_info()
+version 1.0.1a [April 21, 1998]
+  Optimized Paeth calculations by replacing abs() function calls with intrinsics
+  plus other loop optimizations. Improves avg decoding speed by about 20%.
+  Commented out i386istic "align" compiler flags in makefile.lnx.
+  Reduced the default warning level in some makefiles, to make them consistent.
+  Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
+  Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
+  Added grayscale and 16-bit capability to png_do_read_filler().
+  Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
+    too large when writing an image with bit_depth < 8 (Bob Dellaca).
+  Corrected some bugs in the experimental weighted filtering heuristics.
+  Moved a misplaced pngrutil code block that truncates tRNS if it has more
+    than num_palette entries -- test was done before num_palette was defined.
+  Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
+  Changed compiler flags in makefile.wat for better optimization (Pawel Mrochen).
+version 1.0.1b [May 2, 1998]
+  Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
+  Relocated the png_composite macros from pngrtran.c to png.h (Greg).
+  Added makefile.sco (contributed by Mike Hopkirk).
+  Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
+  Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
+  More work on the Paeth-filtering, achieving imperceptible speedup (A Kleinert).
+  More work on loop optimization which may help when compiled with C++ compilers.
+  Added warnings when people try to use transforms they've defined out.
+  Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
+  Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
+version 1.0.1c [May 11, 1998]
+  Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
+    filler bytes should have been 0xff instead of 0xf.
+  Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
+  Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
+    out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
+  Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
+    for consistency, in pngconf.h
+  Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
+    to remove unwanted capabilities via the compile line
+  Made some corrections to grammar (which, it's) in documentation (Greg).
+  Corrected example.c, use of row_pointers in png_write_image().
+version 1.0.1d [May 24, 1998]
+  Corrected several statements that used side effects illegally in pngrutil.c
+    and pngtrans.c, that were introduced in version 1.0.1b
+  Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
+  More corrections to example.c, use of row_pointers in png_write_image()
+    and png_read_rows().
+  Added pngdll.mak and pngdef.pas to scripts directory, contributed by
+    Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
+  Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
+  Changed several loops from count-down to count-up, for consistency.
+version 1.0.1e [June 6, 1998]
+  Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
+    added warnings when people try to set png_read_fn and png_write_fn in
+    the same structure.
+  Added a test such that png_do_gamma will be done when num_trans==0
+    for truecolor images that have defined a background.  This corrects an
+    error that was introduced in libpng-0.90 that can cause gamma processing
+    to be skipped.
+  Added tests in png.h to include "trans" and "trans_values" in structures
+    when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
+  Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
+  Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
+  Added capability for user-provided malloc_fn() and free_fn() functions,
+    and revised pngtest.c to demonstrate their use, replacing the
+    PNGTEST_DEBUG_MEM feature.
+  Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
+version 1.0.2 [June 14, 1998]
+  Fixed two bugs in makefile.bor .
+version 1.0.2a [December 30, 1998]
+  Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
+  Fixed a bug in png_do_filler() that made it fail to write filler bytes in
+    the left-most pixel of each row (Kevin Bracey).
+  Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
+    in pngtest.c (Duncan Simpson).
+  Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
+    even when no tIME chunk was present in the source file.
+  Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
+  Fixed a problem in png_read_push_finish_row(), which would not skip some
+    passes that it should skip, for images that are less than 3 pixels high.
+  Interchanged the order of calls to png_do_swap() and png_do_shift()
+    in pngwtran.c (John Cromer).
+  Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
+  Changed "bad adaptive filter type" from error to warning in pngrutil.c .
+  Fixed a documentation error about default filtering with 8-bit indexed-color.
+  Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
+    (L. Peter Deutsch).
+  Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
+  Added png_get_copyright() and png_get_header_version() functions.
+  Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
+  Added information about debugging in libpng.txt and libpng.3 .
+  Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and makefile.sco.
+  Removed lines after Dynamic Dependencies" in makefile.aco .
+  Revised makefile.dec to make a shared library (Jeremie Petit).
+  Removed trailing blanks from all files.
+version 1.0.2a [January 6, 1999]
+  Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
+  Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
+  Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
+  Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
+    which is obsolete.
+version 1.0.3 [January 14, 1999]
+  Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
+  Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.
+version 1.0.3a [August 12, 1999]
+  Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
+     if an attempt is made to read an interlaced image when it's not supported.
+  Added check if png_ptr->trans is defined before freeing it in pngread.c
+  Modified the Y2K statement to include versions back to version 0.71
+  Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
+  Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
+  Replaced leading blanks with tab characters in makefile.hux
+  Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
+  Changed (float)red and (float)green to (double)red, (double)green
+     in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
+  Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
+  Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
+  Updated documentation to refer to the PNG-1.2 specification.
+  Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
+    in makefile.knr, INSTALL, and README (L. Peter Deutsch)
+  Fixed bugs in calculation of the length of rowbytes when adding alpha
+    channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
+  Added function png_set_user_transform_info() to store user_transform_ptr,
+    user_depth, and user_channels into the png_struct, and a function
+    png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
+  Added function png_set_empty_plte_permitted() to make libpng useable
+    in MNG applications.
+  Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
+  Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
+    consistent with PNG-1.2, and allow variance of 500 before complaining.
+  Added assembler code contributed by Intel in file pngvcrd.c and modified
+    makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation, Gilles Vollant)
+  Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
+  Added some aliases for png_set_expand() in pngrtran.c, namely
+    png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
+    (Greg Roelofs, in "PNG: The Definitive Guide").
+  Added makefile.beo for BEOS on X86, contributed by Sander Stok.
+version 1.0.3b [August 26, 1999]
+  Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
+  Changed leading blanks to tabs in all makefiles.
+  Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
+  Made alternate versions of  png_set_expand() in pngrtran.c, namely
+    png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
+    (Greg Roelofs, in "PNG: The Definitive Guide").  Deleted the 1.0.3a aliases.
+  Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
+  Revised calculation of num_blocks in pngmem.c to avoid a potentially
+    negative shift distance, whose results are undefined in the C language.
+  Added a check in pngset.c to prevent writing multiple tIME chunks.
+  Added a check in pngwrite.c to detect invalid small window_bits sizes.
+version 1.0.3d [September 4, 1999]
+  Fixed type casting of igamma in pngrutil.c
+  Added new png_expand functions to scripts/pngdef.pas and pngos2.def
+  Added a demo read_user_transform_fn that examines the row filters in pngtest.c
+version 1.0.4 [September 24, 1999]
+  Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
+  Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
+  Made several minor corrections to pngtest.c
+  Renamed the makefiles with longer but more user friendly extensions.
+  Copied the PNG copyright and license to a separate LICENSE file.
+  Revised documentation, png.h, and example.c to remove reference to
+    "viewing_gamma" which no longer appears in the PNG specification.
+  Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
+  Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
+  Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
+    assembler code) and makefile.vcwin32 (doesn't).
+  Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
+  Added a copy of pngnow.png to the distribution.
+version 1.0.4a [September 25, 1999]
+  Increase max_pixel_depth in pngrutil.c if a user transform needs it.
+  Changed several division operations to right-shifts in pngvcrd.c
+version 1.0.4b [September 30, 1999]
+  Added parentheses in line 3732 of pngvcrd.c
+  Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
+version 1.0.4c [October 1, 1999]
+  Added a "png_check_version" function in png.c and pngtest.c that will generate
+    a helpful compiler error if an old png.h is found in the search path.
+  Changed type of png_user_transform_depth|channels from int to png_byte.
+version 1.0.4d [October 6, 1999]
+  Changed 0.45 to 0.45455 in png_set_sRGB()
+  Removed unused PLTE entries from pngnow.png
+  Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
+version 1.0.4e [October 10, 1999]
+  Fixed sign error in pngvcrd.c (Greg Roelofs)
+  Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
+version 1.0.4f [October 15, 1999]
+  Surrounded example.c code with #if 0 .. #endif to prevent people from
+    inadvertently trying to compile it.
+  Changed png_get_header_version() from a function to a macro in png.h
+  Added type casting mostly in pngrtran.c and pngwtran.c
+  Removed some pointless "ptr = NULL" in pngmem.c
+  Added a "contrib" directory containing the source code from Greg's book.
+version 1.0.5 [October 15, 1999]
+  Minor editing of the INSTALL and README files.
+version 1.0.5a [October 23, 1999]
+  Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
+  Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
+  Further optimization and bugfix of pngvcrd.c
+  Revised pngset.c so that it does not allocate or free memory in the user's
+    text_ptr structure.  Instead, it makes its own copy.
+  Created separate write_end_info_struct in pngtest.c for a more severe test.
+  Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
+version 1.0.5b [November 23, 1999]
+  Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
+    PNG_FLAG_WROTE_tIME from flags to mode.
+  Added png_write_info_before_PLTE() function.
+  Fixed some typecasting in contrib/gregbook/*.c
+  Updated scripts/makevms.com and added makevms.com to contrib/gregbook
+    and contrib/pngminus (Martin Zinser)
+version 1.0.5c [November 26, 1999]
+  Moved png_get_header_version from png.h to png.c, to accomodate ansi2knr.
+  Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
+    accomodate making DLL's: Moved usr_png_ver from global variable to function
+    png_get_header_ver() in png.c.  Moved png_sig to png_sig_bytes in png.c and
+    eliminated use of png_sig in pngwutil.c.  Moved the various png_CHNK arrays
+    into pngtypes.h.  Eliminated use of global png_pass arrays.  Declared the
+    png_CHNK and png_pass arrays to be "const".  Made the global arrays
+    available to applications (although none are used in libpng itself) when
+    PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
+  Removed some extraneous "-I" from contrib/pngminus/makefile.std
+  Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
+  Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
+version 1.0.5d [November 29, 1999]
+  Add type cast (png_const_charp) two places in png.c
+  Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
+  Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
+    to applications a macro "PNG_USE_LOCAL_ARRAYS".
+  #ifdef out all the new declarations when PNG_USE_GLOBAL_ARRAYS is defined.
+  Added PNG_EXPORT_VAR macro to accommodate making DLL's.
+version 1.0.5e [November 30, 1999]
+  Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
+    structure; refactored the inflate/deflate support to make adding new chunks
+    with trailing compressed parts easier in the future, and added new functions
+    png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
+    png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
+  NOTE: Applications that write text chunks MUST define png_text->lang
+    before calling png_set_text(). It must be set to NULL if you want to
+    write tEXt or zTXt chunks.  If you want your application to be able to
+    run with older versions of libpng, use
+
+      #ifdef PNG_iTXt_SUPPORTED
+         png_text[i].lang = NULL;
+      #endif
+
+  Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
+    offsets (Eric S. Raymond).
+  Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
+    PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
+    macros, leaving the separate macros also available.
+  Removed comments on #endifs at the end of many short, non-nested #if-blocks.
+version 1.0.5f [December 6, 1999]
+  Changed makefile.solaris to issue a warning about potential problems when
+    the ucb "ld" is in the path ahead of the ccs "ld".
+  Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
+  Added sCAL chunk support (Eric S. Raymond).
+version 1.0.5g [December 7, 1999]
+  Fixed "png_free_spallettes" typo in png.h
+  Added code to handle new chunks in pngpread.c
+  Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
+  Added "translated_key" to png_text structure and png_write_iTXt().
+  Added code in pngwrite.c to work around a newly discovered zlib bug.
+version 1.0.5h [December 10, 1999]
+  NOTE: regarding the note for version 1.0.5e, the following must also
+    be included in your code:
+        png_text[i].translated_key = NULL;
+  Unknown chunk handling is now supported.
+  Option to eliminate all floating point support was added.  Some new
+    fixed-point functions such as png_set_gAMA_fixed() were added.
+  Expanded tabs and removed trailing blanks in source files.
+version 1.0.5i [December 13, 1999]
+  Added some type casts to silence compiler warnings.
+  Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
+  Removed leading blanks from a #define in pngvcrd.c
+  Added some parameters to the new png_set_keep_unknown_chunks() function.
+  Added a test for up->location != 0 in the first instance of writing
+    unknown chunks in pngwrite.c
+  Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
+    prevent recursion.
+  Added png_free_hIST() function.
+  Various patches to fix bugs in the sCAL and integer cHRM processing,
+    and to add some convenience macros for use with sCAL.
+version 1.0.5j [December 21, 1999]
+  Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
+    around buggy compilers.
+  Added new type "png_fixed_point" for integers that hold float*100000 values
+  Restored backward compatibility of tEXt/zTXt chunk processing:
+    Restored the first four members of png_text to the same order as v.1.0.5d.
+    Added members "lang_key" and "itxt_length" to png_text struct.  Set
+    text_length=0 when "text" contains iTXt data.  Use the "compression"
+    member to distinguish among tEXt/zTXt/iTXt types.  Added
+    PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
+    The "Note" above, about backward incompatibility of libpng-1.0.5e, no
+    longer applies.
+  Fixed png_read|write_iTXt() to read|write parameters in the right order,
+    and to write the iTXt chunk after IDAT if it appears in the end_ptr.
+  Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
+  Reversed the order of trying to write floating-point and fixed-point gAMA.
+version 1.0.5k [December 27, 1999]
+  Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
+  Added png_handle_as_unknown() function (Glenn)
+  Added png_free_chunk_list() function and chunk_list and num_chunk_list members
+    of png_ptr.
+  Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
+  Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
+    about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
+  Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
+  Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
+  Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
+version 1.0.5l [January 1, 2000]
+  Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
+    for setting a callback function to handle unknown chunks and for
+    retrieving the associated user pointer (Glenn).
+version 1.0.5m [January 7, 2000]
+  Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
+version 1.0.5n [January 9, 2000]
+  Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
+    own memory for info_ptr->palette.  This makes it safe for the calling
+    application to free its copy of the palette any time after it calls
+    png_set_PLTE().
+version 1.0.5o [January 20, 2000]
+  Cosmetic changes only (removed some trailing blanks and TABs)
+version 1.0.5p [January 31, 2000]
+  Renamed pngdll.mak to makefile.bd32
+  Cosmetic changes in pngtest.c
+version 1.0.5q [February 5, 2000]
+  Relocated the makefile.solaris warning about PATH problems.
+  Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
+  Revised makefile.gcmmx
+  Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
+version 1.0.5r [February 7, 2000]
+  Removed superfluous prototype for png_get_itxt from png.h
+  Fixed a bug in pngrtran.c that improperly expanded the background color.
+  Return *num_text=0 from png_get_text() when appropriate, and fix documentation
+    of png_get_text() in libpng.txt/libpng.3.
+version 1.0.5s [February 18, 2000]
+  Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
+    new error handler that's planned for the next libpng release, and changed
+    example.c, pngtest.c, and contrib programs to use this macro.
+  Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
+  Fixed a bug in png_read_png() that caused it to fail to expand some images
+    that it should have expanded.
+  Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
+    in pngget.c
+  Changed the allocation of palette, history, and trans arrays back to
+    the version 1.0.5 method (linking instead of copying) which restores
+    backward compatibility with version 1.0.5.  Added some remarks about
+    that in example.c.  Added "free_me" member to info_ptr and png_ptr
+    and added png_free_data() function.
+  Updated makefile.linux and makefile.gccmmx to make directories conditionally.
+  Made cosmetic changes to pngasmrd.h
+  Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
+  Modified png_read_png() to allocate info_ptr->row_pointers only if it
+    hasn't already been allocated.
+version 1.0.5t [March 4, 2000]
+  Changed png_jmp_env() migration aiding macro to png_jmpbuf().
+  Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
+  Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
+    PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
+  Files in contrib/gregbook were revised to use png_jmpbuf() and to select
+    a 24-bit visual if one is available, and to allow abbreviated options.
+  Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
+  Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
+version 1.0.5u [March 5, 2000]
+  Simplified the code that detects old png.h in png.c and pngtest.c
+  Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
+  Increased precision of rgb_to_gray calculations from 8 to 15 bits and
+    added png_set_rgb_to_gray_fixed() function.
+  Added makefile.bc32 (32-bit Borland C++, C mode)
+version 1.0.5v [March 11, 2000]
+  Added some parentheses to the png_jmpbuf macro definition.
+  Updated references to the zlib home page, which has moved to freesoftware.com.
+  Corrected bugs in documentation regarding png_read_row() and png_write_row().
+  Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
+  Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
+    revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
+version 1.0.6 [March 20, 2000]
+  Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
+  Added makefile.sggcc (SGI IRIX with gcc)
+version 1.0.6d [April 7, 2000]
+  Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
+  Added data_length parameter to png_decompress_chunk() function
+  Revised documentation to remove reference to abandoned png_free_chnk functions
+  Fixed an error in png_rgb_to_gray_fixed()
+  Revised example.c, usage of png_destroy_write_struct().
+  Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
+  Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c
+  Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
+version 1.0.6e [April 9, 2000]
+  Added png_data_freer() function.
+  In the code that checks for over-length tRNS chunks, added check of
+    info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
+  Minor revisions of libpng.txt/libpng.3.
+  Check for existing data and free it if the free_me flag is set, in png_set_*()
+    and png_handle_*().
+  Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED
+    is defined.
+  Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
+    and mentioned the purposes of the two macros in libpng.txt/libpng.3.
+version 1.0.6f [April 14, 2000]
+  Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data.
+  Add checks in png_set_text() for NULL members of the input text structure.
+  Revised libpng.txt/libpng.3.
+  Removed superfluous prototype for png_set_itxt from png.h
+  Removed "else" from pngread.c, after png_error(), and changed "0" to "length".
+  Changed several png_errors about malformed ancillary chunks to png_warnings.
+version 1.0.6g [April 24, 2000]
+  Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined.
+  Relocated paragraph about png_set_background() in libpng.3/libpng.txt
+    and other revisions (Matthias Benckmann)
+  Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and
+    png_ptr members to restore binary compatibility with libpng-1.0.5
+    (breaks compatibility with libpng-1.0.6).
+version 1.0.6h [April 24, 2000]
+  Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds
+    libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h)
+    This is a temporary change for test purposes.
+version 1.0.6i [May 2, 2000]
+  Rearranged some members at the end of png_info and png_struct, to put
+    unknown_chunks_num and free_me within the original size of the png_structs
+    and free_me, png_read_user_fn, and png_free_fn within the original png_info,
+    because some old applications allocate the structs directly instead of
+    using png_create_*().
+  Added documentation of user memory functions in libpng.txt/libpng.3
+  Modified png_read_png so that it will use user_allocated row_pointers
+    if present, unless free_me directs that it be freed, and added description
+    of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3.
+  Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version
+    1.00) members of png_struct and png_info, to regain binary compatibility
+    when you define this macro.  Capabilities lost in this event
+    are user transforms (new in version 1.0.0),the user transform pointer
+    (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT,
+    the high-level interface, and unknown chunks support (all new in 1.0.6).
+    This was necessary because of old applications that allocate the structs
+    directly as authors were instructed to do in libpng-0.88 and earlier,
+    instead of using png_create_*().
+  Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which
+    can be used to detect codes that directly allocate the structs, and
+    code to check these modes in png_read_init() and png_write_init() and
+    generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED
+    was not defined.
+  Added makefile.intel and updated makefile.watcom (Pawel Mrochen)
+version 1.0.6j [May 3, 2000]
+  Overloaded png_read_init() and png_write_init() with macros that convert
+    calls to png_read_init_2() or png_write_init_2() that check the version
+    and structure sizes.
+version 1.0.7beta11 [May 7, 2000]
+  Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
+    which are no longer used.
+  Eliminated the three new members of png_text when PNG_NO_iTXt_SUPPORTED
+    or PNG_LEGACY_SUPPORTED is defined.
+  Made PNG_NO_ITXT_SUPPORTED the default setting, to avoid memory overrun
+    when old applications fill the info_ptr->text structure directly.
+  Added PNGAPI macro, and added it to the definitions of all exported functions.
+  Relocated version macro definitions ahead of the includes of zlib.h and
+    pngconf.h in png.h.
+version 1.0.7beta12 [May 12, 2000]
+  Revised pngset.c to avoid a problem with expanding the png_debug macro.
+  Deleted some extraneous defines from pngconf.h
+  Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
+  Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined.
+  Added png_access_version_number() function.
+  Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
+  Expanded libpng.3/libpng.txt information about png_data_freer().
+version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
+  Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
+    warnings instead of errors, as pngrutil.c does.
+  Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png()
+    will actually write IDATs.
+  Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32.
+  Make png_free_data() ignore its final parameter except when freeing data
+    that can have multiple instances (text, sPLT, unknowns).
+  Fixed a new bug in png_set_rows().
+  Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5.
+  Added png_set_invalid() function.
+  Fixed incorrect illustrations of png_destroy_write_struct() in example.c.
+version 1.0.7beta15 [May 30, 2000]
+  Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce
+    fewer error messages.
+  Rearranged checks for Z_OK to check the most likely path first in pngpread.c
+    and pngwutil.c.
+  Added checks in pngtest.c for png_create_*() returning NULL, and mentioned
+    in libpng.txt/libpng.3 the need for applications to check this.
+  Changed names of png_default_*() functions in pngtest to pngtest_*().
+  Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32.
+  Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c
+  Set each pointer to NULL after freeing it in png_free_data().
+  Worked around a problem in pngconf.h; AIX's strings.h defines an "index"
+    macro that conflicts with libpng's png_color_16.index. (Dimitri Papadapoulos)
+  Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux).
+version 1.0.7beta16 [June 4, 2000]
+  Revised the workaround of AIX string.h "index" bug.
+  Added a check for overlength PLTE chunk in pngrutil.c.
+  Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer
+    indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler.
+  Added a warning in png_decompress_chunk() when it runs out of data, e.g.
+    when it tries to read an erroneous PhotoShop iCCP chunk.
+  Added PNG_USE_DLL macro.
+  Revised the copyright/disclaimer/license notice.
+  Added contrib/msvctest directory
+version 1.0.7rc1 [June 9, 2000]
+  Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA  (0x0400 not 0x0200)
+  Added contrib/visupng directory (Willem van Schaik)
+version 1.0.7beta18 [June 23, 2000]
+  Revised PNGAPI definition, and pngvcrd.c to work with __GCC__
+    and do not redefine PNGAPI if it is passed in via a compiler directive.
+  Revised visupng/PngFile.c to remove returns from within the Try block.
+  Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros.
+  Updated contrib/visupng/cexcept.h to version 1.0.0.
+  Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks.
+version 1.0.7rc2 [June 28, 2000]
+  Updated license to include disclaimers required by UCITA.
+  Fixed "DJBPP" typo in pnggccrd.c introduced in beta18.
+version 1.0.7 [July 1, 2000]
+  Revised the definition of "trans_values" in libpng.3/libpng.txt
+version 1.0.8beta1 [July 8, 2000]
+  Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
+  Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
+     pngwutil.c.
+  Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
+  Removed unused "#include <assert.h>" from png.c
+  Added WindowsCE support.
+  Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment.
+version 1.0.8beta2 [July 10, 2000]
+  Added project files to the wince directory and made further revisions
+     of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
+version 1.0.8beta3 [July 11, 2000]
+  Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
+     for indexed-color input files to avoid potential double-freeing trans array
+     under some unusual conditions; problem was introduced in version 1.0.6f.
+  Further revisions to pngtest.c and files in the wince subdirectory.
+version 1.0.8beta4 [July 14, 2000]
+  Added the files pngbar.png and pngbar.jpg to the distribution.
+  Added makefile.cygwin, and cygwin support in pngconf.h
+  Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)
+version 1.0.8rc1 [July 16, 2000]
+  Revised png_debug() macros and statements to eliminate compiler warnings.
+version 1.0.8 [July 24, 2000]
+  Added png_flush() in pngwrite.c, after png_write_IEND().
+  Updated makefile.hpux to build a shared library.
+version 1.0.9beta1 [November 10, 2000]
+  Fixed typo in scripts/makefile.hpux
+  Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
+  Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
+  Changed "cdrom.com" in documentation to "libpng.org"
+  Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
+  Changed type of "params" from voidp to png_voidp in png_read|write_png().
+  Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h.
+  Revised the 3 instances of WRITEFILE in pngtest.c.
+  Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory.
+  Updated png.rc in dll/msvc project
+  Revised makefile.dec to define and use LIBPATH and INCPATH
+  Increased size of global png_libpng_ver[] array from 12 to 18 chars.
+  Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const.
+  Removed duplicate png_crc_finish() from png_handle_bKGD() function.
+  Added a warning when application calls png_read_update_info() multiple times.
+  Revised makefile.cygwin
+  Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
+  Replaced png_set_empty_plte_permitted() with png_permit_mng_features().
+version 1.0.9beta2 [November 19, 2000]
+  Renamed the "dll" subdirectory "projects".
+  Added borland project files to "projects" subdirectory.
+  Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
+  Add error message in png_set_compression_buffer_size() when malloc fails.
+version 1.0.9beta3 [November 23, 2000]
+  Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
+  Removed the png_flush() in pngwrite.c that crashes some applications
+    that don't set png_output_flush_fn.
+  Added makefile.macosx and makefile.aix to scripts directory.
+version 1.0.9beta4 [December 1, 2000]
+  Change png_chunk_warning to png_warning in png_check_keyword().
+  Increased the first part of msg buffer from 16 to 18 in png_chunk_error().
+version 1.0.9beta5 [December 15, 2000]
+  Added support for filter method 64 (for PNG datastreams embedded in MNG).
+version 1.0.9beta6 [December 18, 2000]
+  Revised png_set_filter() to accept filter method 64 when appropriate.
+  Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
+    help prevent applications from using MNG features in PNG datastreams.
+  Added png_permit_mng_features() function.
+  Revised libpng.3/libpng.txt.  Changed "filter type" to "filter method".
+version 1.0.9rc1 [December 23, 2000]
+  Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c
+  Fixed error handling of unknown compression type in png_decompress_chunk().
+  In pngconf.h, define __cdecl when _MSC_VER is defined.
+version 1.0.9beta7 [December 28, 2000]
+  Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
+  Revised memory management in png_set_hIST and png_handle_hIST in a backward
+    compatible manner.  PLTE and tRNS were revised similarly.
+  Revised the iCCP chunk reader to ignore trailing garbage.
+version 1.0.9beta8 [January 12, 2001]
+  Moved pngasmrd.h into pngconf.h.
+  Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.
+version 1.0.9beta9 [January 15, 2001]
+  Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to
+    wince and msvc project module definition files.
+  Minor revision of makefile.cygwin.
+  Fixed bug with progressive reading of narrow interlaced images in pngpread.c
+version 1.0.9beta10 [January 16, 2001]
+  Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined.
+  Fixed "png_mmx_supported" typo in project definition files.
+version 1.0.9beta11 [January 19, 2001]
+  Updated makefile.sgi to make shared library.
+  Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED
+    by default, for the benefit of DLL forward compatibility.  These will
+    be re-enabled in version 1.2.0.
+version 1.0.9rc2 [January 22, 2001]
+  Revised cygwin support.
+version 1.0.9 [January 31, 2001]
+  Added check of cygwin's ALL_STATIC in pngconf.h
+  Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
+version 1.0.10beta1 [March 14, 2001]
+  Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
+  Reformatted libpng.3 to eliminate bad line breaks.
+  Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
+  Added prototype for png_mmx_support() near the top of pnggccrd.c
+  Moved some error checking from png_handle_IHDR to png_set_IHDR.
+  Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
+  Revised png_mmx_support() function in pnggccrd.c
+  Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
+  Fixed memory leak in contrib/visupng/PngFile.c
+  Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
+  Added warnings when retrieving or setting gamma=0.
+  Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().
+version 1.0.10rc1 [March 23, 2001]
+  Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy,
+    and png_strlen.
+  Revised png_mmx_supported() function in pnggccrd.c to return proper value.
+  Fixed bug in progressive reading (pngpread.c) with small images (height < 8).
+version 1.0.10 [March 30, 2001]
+  Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
+  Added beos project files (Chris Herborth)
+version 1.0.11beta1 [April 3, 2001]
+  Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
+  Removed a no-longer needed AIX work-around from pngconf.h
+  Changed several "//" single-line comments to C-style in pnggccrd.c
+version 1.0.11beta2 [April 11, 2001]
+  Removed PNGAPI from several functions whose prototypes did not have PNGAPI.
+  Updated scripts/pngos2.def
+version 1.0.11beta3 [April 14, 2001]
+  Added checking the results of many instances of png_malloc() for NULL
+version 1.0.11beta4 [April 20, 2001]
+  Undid the changes from version 1.0.11beta3.  Added a check for NULL return
+    from user's malloc_fn().
+  Removed some useless type casts of the NULL pointer.
+  Added makefile.netbsd
+version 1.0.11 [April 27, 2001]
+  Revised makefile.netbsd
+
+Send comments/corrections/commendations to
+png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu
+
+Glenn R-P

INSTALL

@@ -0,0 +1,137 @@
+
+Installing libpng version 1.0.11 - April 27, 2001
+
+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-1.0.11" or "lpng109" 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
+          contrib
+             gregbook
+             msvctest
+             pngminus
+             pngsuite
+             visupng
+          projects
+             beos
+             borland
+             msvc
+             wince
+          scripts
+             makefile.*
+          pngtest.png
+          etc.
+      zlib
+          README
+          *.h
+          *.c
+          contrib
+          etc.
+
+If the line endings in the files look funny, you may wish to get the other
+distribution of libpng.  It is available in both tar.gz (UNIX style line
+endings) and zip (DOS style line endings) formats.
+
+If you are building libpng with MSVC, you can enter the libpng\msvc directory
+and follow the instructions in msvc\README.txt.  You can build libpng for
+WindowsCE by entering the libpng\wince directory and following the
+instructions in the README* files.
+
+Else 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
+
+ makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
+ makefile.linux    =>  Linux/ELF makefile (gcc, creates libpng.so.2.1.0.11)
+ makefile.gcmmx    =>  Linux/ELF makefile (gcc, creates libpng.so.2.1.0.11,
+                       uses assembler code tuned for Intel MMX platform)
+ makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
+ makefile.knr      =>  Archaic UNIX Makefile that converts files with
+                       ansi2knr (Requires ansi2knr.c from
+                       ftp://ftp.cs.wisc.edu/ghost)
+ makefile.aix      =>  AIX makefile
+ makefile.cygwin   =>  Cygwin/gcc makefile
+ makefile.dec      =>  DEC Alpha UNIX makefile
+ makefile.hpgcc    =>  HPUX makefile using gcc
+ makefile.hpux     =>  HPUX (10.20 and 11.00) makefile
+ makefile.ibmc     =>  IBM C/C++ version 3.x for Win32 and OS/2 (static)
+ makefile.intel    =>  Intel C/C++ version 4.0 and later
+ libpng.icc        =>  Project file for IBM VisualAge/C++ version 4.0 or later
+ makefile.macosx   =>  MACOS X Makefile
+ makefile.netbsd   =>  NetBSD/cc makefile, uses PNGGCCRD
+ makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
+ makefile.sggcc    =>  Silicon Graphics (gcc, creates libpng.so.2.1.0.11)
+ makefile.sunos    =>  Sun makefile
+ makefile.solaris  =>  Solaris 2.X makefile (gcc, creates libpng.so.2.1.0.11)
+ makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
+ makefile.mips     =>  MIPS makefile
+ makefile.acorn    =>  Acorn makefile
+ makefile.amiga    =>  Amiga makefile
+ smakefile.ppc     =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
+                       (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
+ makefile.atari    =>  Atari makefile
+ makefile.beos     =>  BEOS makefile for X86
+ makefile.bor      =>  Borland makefile (uses bcc)
+ makefile.bc32     =>  32-bit Borland C++ (all modules compiled in C mode)
+ makefile.bd32     =>  To make a png32bd.dll with Borland C++ 4.5
+ makefile.tc3      =>  Turbo C 3.0 makefile
+ makefile.dj2      =>  DJGPP 2 makefile
+ makefile.msc      =>  Microsoft C makefile
+ makefile.vcawin32 =>  makefile for Microsoft Visual C++ 5.0 and later (uses
+                       assembler code tuned for Intel MMX platform)
+ makefile.vcwin32  =>  makefile for Microsoft Visual C++ 4.0 and later (does
+                       not use assembler code)
+ makefile.os2      =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
+ pngos2.def        =>  OS/2 module definition file used by makefile.os2
+ makefile.watcom   =>  Watcom 10a+ Makefile, 32-bit flat memory model
+ makevms.com       =>  VMS build script
+ descrip.mms       =>  VMS makefile for MMS or MMK
+ 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.msc 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.
+Look for "9782 zero samples" in the output of the test.  For more
+confidence, you can run another test by typing "pngtest pngnow.png"
+and looking for "289 zero samples" in the output.  Also, you can
+run "pngtest -m *.png" in the "contrib/pngsuite" directory and compare
+your output with the result shown in contrib/pngsuite/README.
+
+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, in png.h, in the README files in
+subdirectories of the LIB directory, and the manual pages libpng.3 and png.5.

KNOWNBUG

@@ -0,0 +1,7 @@
+
+Known bugs in libpng-1.0.11
+
+1. April 22, 2001: pnggccrd.c has been reported to crash on NetBSD when
+   reading interlaced PNG files, when assembler code is enabled.
+
+   STATUS: Under investigation.

LICENSE

@@ -0,0 +1,102 @@
+
+This copy of the libpng notices is provided for your convenience.  In case of
+any discrepancy between this copy and the notices in the file png.h that is
+included in the libpng distribution, the latter shall prevail.
+
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+
+If you modify libpng you may insert additional notices immediately following
+this sentence.
+
+libpng versions 1.0.7, July 1, 2000, through 1.0.11, April 27, 2001, are
+Copyright (c) 2000, 2001 Glenn Randers-Pehrson
+and are distributed according to the same disclaimer and license as libpng-1.0.6
+with the following individuals added to the list of Contributing Authors
+
+   Simon-Pierre Cadieux
+   Eric S. Raymond
+   Gilles Vollant
+
+and with the following additions to the disclaimer:
+
+   There is no warranty against interference with your enjoyment of the
+   library or against infringement.  There is no warranty that our
+   efforts or the library will fulfill any of your particular purposes
+   or needs.  This library is provided with all faults, and the entire
+   risk of satisfactory quality, performance, accuracy, and effort is with
+   the user.
+
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-0.96,
+with the following individuals added to the list of Contributing Authors:
+
+   Tom Lane
+   Glenn Randers-Pehrson
+   Willem van Schaik
+
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996, 1997 Andreas Dilger
+Distributed according to the same disclaimer and license as libpng-0.88,
+with the following individuals added to the list of Contributing Authors:
+
+   John Bowler
+   Kevin Bracey
+   Sam Bushell
+   Magnus Holmgren
+   Greg Roelofs
+   Tom Tanner
+
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+
+   Andreas Dilger
+   Dave Martindale
+   Guy Eric Schalnat
+   Paul Schmidt
+   Tim Wegner
+
+The PNG Reference Library is supplied "AS IS".  The Contributing Authors
+and Group 42, Inc. disclaim all warranties, expressed or implied,
+including, without limitation, the warranties of merchantability and of
+fitness for any purpose.  The Contributing Authors and Group 42, Inc.
+assume no liability for direct, indirect, incidental, special, exemplary,
+or consequential damages, which may result from the use of the PNG
+Reference Library, even if advised of the possibility of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+
+1. The origin of this source code must not be misrepresented.
+
+2. Altered versions must be plainly marked as such and
+   must not be misrepresented as being the original source.
+
+3. This Copyright notice may not be removed or altered from
+   any source or altered source distribution.
+
+The Contributing Authors and Group 42, Inc. specifically permit, without
+fee, and encourage the use of this source code as a component to
+supporting the PNG file format in commercial products.  If you use this
+source code in a product, acknowledgment is not required but would be
+appreciated.
+
+
+A "png_get_copyright" function is available, for convenient use in "about"
+boxes and the like:
+
+   printf("%s",png_get_copyright(NULL));
+
+Also, the PNG logo (in PNG format, of course) is supplied in the
+files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is a
+certification mark of the Open Source Initiative.
+
+Glenn Randers-Pehrson
+randeg@alum.rpi.edu
+April 27, 2001

README

@@ -0,0 +1,247 @@
+README for libpng 1.0.11 - April 27, 2001 (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.
+
+Libpng comes in two distribution formats.  Get libpng-*.tar.gz if you
+want UNIX-style line endings in the text files, or lpng*.zip if you want
+DOS-style line endings.
+
+Version 0.89 was the first official release of libpng.  Don't let the
+fact that it's the first release fool you.  The libpng library has been in
+extensive use and testing since mid-1995.  By late 1997 it had
+finally gotten to the stage where there hadn't been significant
+changes to the API in some time, and people have a bad feeling about
+libraries with versions < 1.0.  Version 1.0.0 was released in
+March 1998.
+
+****
+Note that some of the changes to the png_info structure render this
+version of the library binary incompatible with libpng-0.89 or
+earlier versions if you are using a shared library.  The type of the
+"filler" parameter for png_set_filler() has changed from png_byte to
+png_uint_32, which will affect shared-library applications that use
+this function.
+
+To avoid problems with changes to the internals of png_info_struct,
+new APIs have been made available in 0.95 to avoid direct application
+access to info_ptr.  These functions are the png_set_<chunk> and
+png_get_<chunk> functions.  These functions should be used when
+accessing/storing the info_struct data, rather than manipulating it
+directly, to avoid such problems in the future.
+
+It is important to note that the APIs do not make current programs
+that access the info struct directly incompatible with the new
+library.  However, it is strongly suggested that new programs use
+the new APIs (as shown in example.c and pngtest.c), and older programs
+be converted to the new format, to facilitate upgrades in the future.
+****
+
+Additions since 0.90 include the ability to compile libpng as a
+Windows DLL, and new APIs for accessing data in the info struct.
+Experimental functions include the ability to set weighting and cost
+factors for row filter selection, direct reads of integers from buffers
+on big-endian processors that support misaligned data access, faster
+methods of doing alpha composition, and more accurate 16->8 bit color
+conversion.
+
+The additions since 0.89 include the ability to read from a PNG stream
+which has had some (or all) of the signature bytes read by the calling
+application.  This also allows the reading of embedded PNG streams that
+do not have the PNG file signature.  As well, it is now possible to set
+the library action on the detection of chunk CRC errors.  It is possible
+to set different actions based on whether the CRC error occurred in a
+critical or an ancillary chunk.
+
+The changes made to the library, and bugs fixed are based on discussions
+on the PNG implementation mailing list <png-implement@ccrc.wustl.edu>
+and not on material submitted privately to Guy, Andreas, or Glenn.  They will
+forward any good suggestions to the list.
+
+For a detailed description on using libpng, read libpng.txt.  For
+examples of libpng in a program, see example.c and pngtest.c.  For usage
+information and restrictions (what little they are) on libpng, see
+png.h.  For a description on using zlib (the compression library used by
+libpng) and zlib's restrictions, see zlib.h
+
+I have included a general makefile, as well as several machine and
+compiler specific ones, but you may have to modify one for your own needs.
+
+You should use zlib 1.0.4 or later to run this, but it MAY work with
+versions as old as zlib 0.95.  Even so, there are bugs in older zlib
+versions which can cause the output of invalid compression streams for
+some images.  You will definitely need zlib 1.0.4 or later if you are
+taking advantage of the MS-DOS "far" structure allocation for the small
+and medium memory models.  You should also note that zlib is a
+compression library that is useful for more things than just PNG files.
+You can use zlib as a drop-in replacement for fread() and fwrite() if
+you are so inclined.
+
+zlib should be available at the same place that libpng is.
+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:
+
+      ANNOUNCE      =>  Announcement of this version, with recent changes
+      CHANGES       =>  Description of changes between libpng versions
+      KNOWNBUG      =>  List of known bugs and deficiencies
+      LICENSE       =>  License to use and redistribute libpng
+      README        =>  This file
+      TODO          =>  Things not implemented in the current library
+      Y2KINFO       =>  Statement of Y2K compliance
+      example.c     =>  Example code for using libpng functions
+      libpng.3      =>  manual page for libpng (includes libpng.txt)
+      libpng.txt    =>  Description of libpng and its functions
+      libpngpf.3    =>  manual page for libpng's private functions
+      png.5         =>  manual page for the PNG format
+      png.c         =>  Basic interface functions common to library
+      png.h         =>  Library function and interface declarations
+      pngconf.h     =>  System specific library configuration
+      pngasmrd.h    =>  Header file for assembler-coded functions
+      pngerror.c    =>  Error/warning message I/O functions
+      pngget.c      =>  Functions for retrieving info from struct
+      pngmem.c      =>  Memory handling functions
+      pngbar.png    =>  PNG logo, 88x31
+      pngnow.png    =>  PNG logo, 98x31
+      pngpread.c    =>  Progressive reading functions
+      pngread.c     =>  Read data/helper high-level functions
+      pngrio.c      =>  Lowest-level data read I/O functions
+      pngrtran.c    =>  Read data transformation functions
+      pngrutil.c    =>  Read data utility functions
+      pngset.c      =>  Functions for storing data into the info_struct
+      pngtest.c     =>  Library test program
+      pngtest.png   =>  Library test sample image
+      pngtrans.c    =>  Common data transformation functions
+      pngwio.c      =>  Lowest-level write I/O functions
+      pngwrite.c    =>  High-level write functions
+      pngwtran.c    =>  Write data transformations
+      pngwutil.c    =>  Write utility functions
+      contrib       =>  Contributions
+       gregbook         =>  source code for PNG reading and writing, from
+                            Greg Roelofs' "PNG: The Definitive Guide",
+                            O'Reilly, 1999
+       msvctest     =>  Builds and runs pngtest using a MSVC workspace
+       pngminus     =>  Simple pnm2png and png2pnm programs
+       pngsuite     =>  Test images
+       visupng      =>  Contains a MSVC workspace for VisualPng
+      projects      =>  Contains project files and workspaces for building DLL
+       beos             =>  Contains a Beos workspace for building libpng
+       borland          =>  Contains a Borland workspace for building libpng
+                            and zlib
+       msvc             =>  Contains a Microsoft Visual C++ (MSVC) workspace
+                            for building libpng and zlib
+       wince            =>  Contains a Microsoft Visual C++ (Windows CD Toolkit)
+                            workspace for building libpng and zlib on WindowsCE
+      scripts       =>  Directory containing scripts for building libpng:
+       descrip.mms      =>  VMS makefile for MMS or MMK
+       makefile.std     =>  Generic UNIX makefile (cc, creates static libpng.a)
+       makefile.linux   =>  Linux/ELF makefile
+                            (gcc, creates libpng.so.2.1.0.11)
+       makefile.gcmmx   =>  Linux/ELF makefile (gcc, creates
+                            libpng.so.2.1.0.11, uses assembler code
+                            tuned for Intel MMX platform)
+       makefile.gcc     =>  Generic makefile (gcc, creates static libpng.a)
+       makefile.knr     =>  Archaic UNIX Makefile that converts files with
+                            ansi2knr (Requires ansi2knr.c from
+                            ftp://ftp.cs.wisc.edu/ghost)
+       makefile.aix     =>  AIX makefile
+       makefile.cygwin  =>  Cygwin/gcc makefile
+       makefile.dec     =>  DEC Alpha UNIX makefile
+       makefile.hpgcc   =>  HPUX makefile using gcc
+       makefile.hpux    =>  HPUX (10.20 and 11.00) makefile
+       makefile.ibmc    =>  IBM C/C++ version 3.x for Win32 and OS/2 (static)
+       makefile.intel   =>  Intel C/C++ version 4.0 and later
+       libpng.icc       =>  Project file, IBM VisualAge/C++ 4.0 or later
+       makefile.macosx  =>  MACOS X Makefile
+       makefile.netbsd  =>  NetBSD/cc makefile, uses PNGGCCRD
+       makefile.sgi     =>  Silicon Graphics IRIX (cc, creates static lib)
+       makefile.sggcc   =>  Silicon Graphics (gcc, creates libpng.so.2.1.0.11)
+       makefile.sunos   =>  Sun makefile
+       makefile.solaris =>  Solaris 2.X makefile
+                            (gcc, creates libpng.so.2.1.0.11)
+       makefile.sco     =>  For SCO OSr5  ELF and Unixware 7 with Native cc
+       makefile.mips    =>  MIPS makefile
+       makefile.acorn   =>  Acorn makefile
+       makefile.amiga   =>  Amiga makefile
+       smakefile.ppc    =>  AMIGA smakefile for SAS C V6.58/7.00 PPC
+                            compiler (Requires SCOPTIONS, copied from
+                            scripts/SCOPTIONS.ppc)
+       makefile.atari   =>  Atari makefile
+       makefile.beos    =>  BEOS makefile for X86
+       makefile.bor     =>  Borland makefile (uses bcc)
+       makefile.bc32    =>  32-bit Borland C++ (all modules compiled in C mode)
+       makefile.bd32    =>  To make a png32bd.dll with Borland C++ 4.5
+       makefile.tc3     =>  Turbo C 3.0 makefile
+       makefile.dj2     =>  DJGPP 2 makefile
+       makefile.msc     =>  Microsoft C makefile
+       makefile.vcawin32 => makefile for Microsoft Visual C++ 5.0 and
+                            later (uses assembler code tuned for Intel MMX
+                            platform)
+       makefile.vcwin32 =>  makefile for Microsoft Visual C++ 4.0 and
+                            later (does not use assembler code)
+       makefile.os2     =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
+       pngos2.def       =>  OS/2 module definition file used by makefile.os2
+       makefile.watcom  =>  Watcom 10a+ Makefile, 32-bit flat memory model
+       makevms.com      =>  VMS build script
+       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
+
+-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.
+Improve API by hiding the png_struct and png_info structs.
+Finish work on the no-floating-point version (including gamma compensation)
+Better C++ wrapper/full C++ implementation?
+Fix problem with C++ and EXTERN "C".
+cHRM transformation.
+Improve setjmp/longjmp usage or remove it in favor of returning error codes.
+Add "grayscale->palette" transformation and "palette->grayscale" detection.
+Improved dithering.
+Multi-lingual error and warning message support.
+Complete sRGB transformation (presently it simply uses gamma=0.45455).
+Man pages for function calls.
+Better documentation.
+Better filter selection
+   (counting huffman bits/precompression?  filter inertia?  filter costs?).
+Histogram creation.
+Text conversion between different code pages (Latin-1 -> Mac and DOS).
+Should we always malloc 2^bit_depth PLTE/tRNS/hIST entries for safety?
+Build gamma tables using fixed point (and do away with floating point entirely).
+Use greater precision when changing to linear gamma for compositing against
+  background and doing rgb-to-gray transformation.
+Investigate pre-incremented loop counters and other loop constructions.

Y2KINFO

@@ -0,0 +1,55 @@
+   Y2K compliance in libpng:
+   =========================
+
+      April 27, 2001
+
+      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 1.0.11 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

ansi2knr.c

@@ -1,488 +0,0 @@
-/* Copyright (C) 1989, 1991, 1993 Aladdin Enterprises. All rights reserved. */
-
-/* ansi2knr.c */
-/* Convert ANSI function declarations to K&R syntax */
-
-/*
-ansi2knr is distributed in the hope that it will be useful, but
-WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
-to anyone for the consequences of using it or for whether it serves any
-particular purpose or works at all, unless he says so in writing.  Refer
-to the GNU General Public License for full details.
-
-Everyone is granted permission to copy, modify and redistribute
-ansi2knr, but only under the conditions described in the GNU
-General Public License.  A copy of this license is supposed to have been
-given to you along with ansi2knr so you can know your rights and
-responsibilities.  It should be in a file named COPYING.  Among other
-things, the copyright notice and this notice must be preserved on all
-copies.
-*/
-
-/*
----------- Here is the GNU GPL file COPYING, referred to above ----------
------ These terms do NOT apply to the JPEG software itself; see README ------
-
-		    GHOSTSCRIPT GENERAL PUBLIC LICENSE
-		    (Clarified 11 Feb 1988)
-
- Copyright (C) 1988 Richard M. Stallman
- Everyone is permitted to copy and distribute verbatim copies of this
- license, but changing it is not allowed.  You can also use this wording
- to make the terms for other programs.
-
-  The license agreements of most software companies keep you at the
-mercy of those companies.  By contrast, our general public license is
-intended to give everyone the right to share Ghostscript.  To make sure
-that you get the rights we want you to have, we need to make
-restrictions that forbid anyone to deny you these rights or to ask you
-to surrender the rights.  Hence this license agreement.
-
-  Specifically, we want to make sure that you have the right to give
-away copies of Ghostscript, that you receive source code or else can get
-it if you want it, that you can change Ghostscript or use pieces of it
-in new free programs, and that you know you can do these things.
-
-  To make sure that everyone has such rights, we have to forbid you to
-deprive anyone else of these rights.  For example, if you distribute
-copies of Ghostscript, you must give the recipients all the rights that
-you have.  You must make sure that they, too, receive or can get the
-source code.  And you must tell them their rights.
-
-  Also, for our own protection, we must make certain that everyone finds
-out that there is no warranty for Ghostscript.  If Ghostscript is
-modified by someone else and passed on, we want its recipients to know
-that what they have is not what we distributed, so that any problems
-introduced by others will not reflect on our reputation.
-
-  Therefore we (Richard M. Stallman and the Free Software Foundation,
-Inc.) make the following terms which say what you must do to be allowed
-to distribute or change Ghostscript.
-
-
-			COPYING POLICIES
-
-  1. You may copy and distribute verbatim copies of Ghostscript source
-code as you receive it, in any medium, provided that you conspicuously
-and appropriately publish on each copy a valid copyright and license
-notice "Copyright (C) 1989 Aladdin Enterprises.  All rights reserved.
-Distributed by Free Software Foundation, Inc." (or with whatever year is
-appropriate); keep intact the notices on all files that refer to this
-License Agreement and to the absence of any warranty; and give any other
-recipients of the Ghostscript program a copy of this License Agreement
-along with the program.  You may charge a distribution fee for the
-physical act of transferring a copy.
-
-  2. You may modify your copy or copies of Ghostscript or any portion of
-it, and copy and distribute such modifications under the terms of
-Paragraph 1 above, provided that you also do the following:
-
-    a) cause the modified files to carry prominent notices stating
-    that you changed the files and the date of any change; and
-
-    b) cause the whole of any work that you distribute or publish,
-    that in whole or in part contains or is a derivative of Ghostscript
-    or any part thereof, to be licensed at no charge to all third
-    parties on terms identical to those contained in this License
-    Agreement (except that you may choose to grant more extensive
-    warranty protection to some or all third parties, at your option).
-
-    c) You may charge a distribution fee for the physical act of
-    transferring a copy, and you may at your option offer warranty
-    protection in exchange for a fee.
-
-Mere aggregation of another unrelated program with this program (or its
-derivative) on a volume of a storage or distribution medium does not bring
-the other program under the scope of these terms.
-
-  3. You may copy and distribute Ghostscript (or a portion or derivative
-of it, under Paragraph 2) in object code or executable form under the
-terms of Paragraphs 1 and 2 above provided that you also do one of the
-following:
-
-    a) accompany it with the complete corresponding machine-readable
-    source code, which must be distributed under the terms of
-    Paragraphs 1 and 2 above; or,
-
-    b) accompany it with a written offer, valid for at least three
-    years, to give any third party free (except for a nominal
-    shipping charge) a complete machine-readable copy of the
-    corresponding source code, to be distributed under the terms of
-    Paragraphs 1 and 2 above; or,
-
-    c) accompany it with the information you received as to where the
-    corresponding source code may be obtained.  (This alternative is
-    allowed only for noncommercial distribution and only if you
-    received the program in object code or executable form alone.)
-
-For an executable file, complete source code means all the source code for
-all modules it contains; but, as a special exception, it need not include
-source code for modules which are standard libraries that accompany the
-operating system on which the executable file runs.
-
-  4. You may not copy, sublicense, distribute or transfer Ghostscript
-except as expressly provided under this License Agreement.  Any attempt
-otherwise to copy, sublicense, distribute or transfer Ghostscript is
-void and your rights to use the program under this License agreement
-shall be automatically terminated.  However, parties who have received
-computer software programs from you with this License Agreement will not
-have their licenses terminated so long as such parties remain in full
-compliance.
-
-  5. If you wish to incorporate parts of Ghostscript into other free
-programs whose distribution conditions are different, write to the Free
-Software Foundation at 675 Mass Ave, Cambridge, MA 02139.  We have not
-yet worked out a simple rule that can be stated here, but we will often
-permit this.  We will be guided by the two goals of preserving the free
-status of all derivatives of our free software and of promoting the
-sharing and reuse of software.
-
-Your comments and suggestions about our licensing policies and our
-software are welcome!  Please contact the Free Software Foundation,
-Inc., 675 Mass Ave, Cambridge, MA 02139, or call (617) 876-3296.
-
-		       NO WARRANTY
-
-  BECAUSE GHOSTSCRIPT IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY
-NO WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW.  EXCEPT
-WHEN OTHERWISE STATED IN WRITING, FREE SOFTWARE FOUNDATION, INC, RICHARD
-M. STALLMAN, ALADDIN ENTERPRISES, L. PETER DEUTSCH, AND/OR OTHER PARTIES
-PROVIDE GHOSTSCRIPT "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
-EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE
-ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF GHOSTSCRIPT IS WITH
-YOU.  SHOULD GHOSTSCRIPT PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
-NECESSARY SERVICING, REPAIR OR CORRECTION.
-
-  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL RICHARD M.
-STALLMAN, THE FREE SOFTWARE FOUNDATION, INC., L. PETER DEUTSCH, ALADDIN
-ENTERPRISES, AND/OR ANY OTHER PARTY WHO MAY MODIFY AND REDISTRIBUTE
-GHOSTSCRIPT AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING
-ANY LOST PROFITS, LOST MONIES, OR OTHER SPECIAL, INCIDENTAL OR
-CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
-(INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED
-INACCURATE OR LOSSES SUSTAINED BY THIRD PARTIES OR A FAILURE OF THE
-PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS) GHOSTSCRIPT, EVEN IF YOU
-HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM
-BY ANY OTHER PARTY.
-
--------------------- End of file COPYING ------------------------------
-*/
-
-
-#include <stdio.h>
-#include <ctype.h>
-
-#ifdef BSD
-#include <strings.h>
-#else
-#ifdef VMS
-	extern int strlen(), strncmp();
-#else
-#include <string.h>
-#endif
-#endif
-
-/* malloc and free should be declared in stdlib.h, */
-/* but if you've got a K&R compiler, they probably aren't. */
-#ifdef MSDOS
-#include <malloc.h>
-#else
-#ifdef VMS
-     extern char *malloc();
-     extern void free();
-#else
-     extern char *malloc();
-     extern int free();
-#endif
-#endif
-
-/* Usage:
-	ansi2knr input_file [output_file]
- * If no output_file is supplied, output goes to stdout.
- * There are no error messages.
- *
- * ansi2knr recognizes functions by seeing a non-keyword identifier
- * at the left margin, followed by a left parenthesis,
- * with a right parenthesis as the last character on the line.
- * It will recognize a multi-line header provided that the last character
- * of the last line of the header is a right parenthesis,
- * and no intervening line ends with a left brace or a semicolon.
- * These algorithms ignore whitespace and comments, except that
- * the function name must be the first thing on the line.
- * The following constructs will confuse it:
- *	- Any other construct that starts at the left margin and
- *	    follows the above syntax (such as a macro or function call).
- *	- Macros that tinker with the syntax of the function header.
- */
-
-/* Scanning macros */
-#define isidchar(ch) (isalnum(ch) || (ch) == '_')
-#define isidfirstchar(ch) (isalpha(ch) || (ch) == '_')
-
-/* Forward references */
-char *skipspace();
-int writeblanks();
-int test1();
-int convert1();
-
-/* The main program */
-main(argc, argv)
-    int argc;
-    char *argv[];
-{	FILE *in, *out;
-#define bufsize 5000			/* arbitrary size */
-	char *buf;
-	char *line;
-	switch ( argc )
-	   {
-	default:
-		printf("Usage: ansi2knr input_file [output_file]\n");
-		exit(0);
-	case 2:
-		out = stdout; break;
-	case 3:
-		out = fopen(argv[2], "w");
-		if ( out == NULL )
-		   {	fprintf(stderr, "Cannot open %s\n", argv[2]);
-			exit(1);
-		   }
-	   }
-	in = fopen(argv[1], "r");
-	if ( in == NULL )
-	   {	fprintf(stderr, "Cannot open %s\n", argv[1]);
-		exit(1);
-	   }
-	fprintf(out, "#line 1 \"%s\"\n", argv[1]);
-	buf = malloc(bufsize);
-	line = buf;
-	while ( fgets(line, (unsigned)(buf + bufsize - line), in) != NULL )
-	   {	switch ( test1(buf) )
-		   {
-		case 1:			/* a function */
-			convert1(buf, out);
-			break;
-		case -1:		/* maybe the start of a function */
-			line = buf + strlen(buf);
-			if ( line != buf + (bufsize - 1) ) /* overflow check */
-				continue;
-			/* falls through */
-		default:		/* not a function */
-			fputs(buf, out);
-			break;
-		   }
-		line = buf;
-	   }
-	if ( line != buf ) fputs(buf, out);
-	free(buf);
-	fclose(out);
-	fclose(in);
-	return 0;
-}
-
-/* Skip over space and comments, in either direction. */
-char *
-skipspace(p, dir)
-    register char *p;
-    register int dir;			/* 1 for forward, -1 for backward */
-{	for ( ; ; )
-	   {	while ( isspace(*p) ) p += dir;
-		if ( !(*p == '/' && p[dir] == '*') ) break;
-		p += dir;  p += dir;
-		while ( !(*p == '*' && p[dir] == '/') )
-		   {	if ( *p == 0 ) return p;	/* multi-line comment?? */
-			p += dir;
-		   }
-		p += dir;  p += dir;
-	   }
-	return p;
-}
-
-/*
- * Write blanks over part of a string.
- */
-int
-writeblanks(start, end)
-    char *start;
-    char *end;
-{	char *p;
-	for ( p = start; p < end; p++ ) *p = ' ';
-	return 0;
-}
-
-/*
- * Test whether the string in buf is a function definition.
- * The string may contain and/or end with a newline.
- * Return as follows:
- *	0 - definitely not a function definition;
- *	1 - definitely a function definition;
- *	-1 - may be the beginning of a function definition,
- *		append another line and look again.
- */
-int
-test1(buf)
-    char *buf;
-{	register char *p = buf;
-	char *bend;
-	char *endfn;
-	int contin;
-	if ( !isidfirstchar(*p) )
-		return 0;		/* no name at left margin */
-	bend = skipspace(buf + strlen(buf) - 1, -1);
-	switch ( *bend )
-	   {
-	case ')': contin = 1; break;
-	case '{':
-	case ';': return 0;		/* not a function */
-	default: contin = -1;
-	   }
-	while ( isidchar(*p) ) p++;
-	endfn = p;
-	p = skipspace(p, 1);
-	if ( *p++ != '(' )
-		return 0;		/* not a function */
-	p = skipspace(p, 1);
-	if ( *p == ')' )
-		return 0;		/* no parameters */
-	/* Check that the apparent function name isn't a keyword. */
-	/* We only need to check for keywords that could be followed */
-	/* by a left parenthesis (which, unfortunately, is most of them). */
-	   {	static char *words[] =
-		   {	"asm", "auto", "case", "char", "const", "double",
-			"extern", "float", "for", "if", "int", "long",
-			"register", "return", "short", "signed", "sizeof",
-			"static", "switch", "typedef", "unsigned",
-			"void", "volatile", "while", 0
-		   };
-		char **key = words;
-		char *kp;
-		int len = endfn - buf;
-		while ( (kp = *key) != 0 )
-		   {	if ( strlen(kp) == len && !strncmp(kp, buf, len) )
-				return 0;	/* name is a keyword */
-			key++;
-		   }
-	   }
-	return contin;
-}
-
-int
-convert1(buf, out)
-    char *buf;
-    FILE *out;
-{	char *endfn;
-	register char *p;
-	char **breaks;
-	unsigned num_breaks = 2;	/* for testing */
-	char **btop;
-	char **bp;
-	char **ap;
-	/* Pre-ANSI implementations don't agree on whether strchr */
-	/* is called strchr or index, so we open-code it here. */
-	for ( endfn = buf; *(endfn++) != '('; ) ;
-top:	p = endfn;
-	breaks = (char **)malloc(sizeof(char *) * num_breaks * 2);
-	if ( breaks == 0 )
-	   {	/* Couldn't allocate break table, give up */
-		fprintf(stderr, "Unable to allocate break table!\n");
-		fputs(buf, out);
-		return -1;
-	   }
-	btop = breaks + num_breaks * 2 - 2;
-	bp = breaks;
-	/* Parse the argument list */
-	do
-	   {	int level = 0;
-		char *end = NULL;
-		if ( bp >= btop )
-		   {	/* Filled up break table. */
-			/* Allocate a bigger one and start over. */
-			free((char *)breaks);
-			num_breaks <<= 1;
-			goto top;
-		   }
-		*bp++ = p;
-		/* Find the end of the argument */
-		for ( ; end == NULL; p++ )
-		   {	switch(*p)
-			   {
-			case ',': if ( !level ) end = p; break;
-			case '(': level++; break;
-			case ')': if ( --level < 0 ) end = p; break;
-			case '/': p = skipspace(p, 1) - 1; break;
-			default: ;
-			   }
-		   }
-		p--;			/* back up over terminator */
-		/* Find the name being declared. */
-		/* This is complicated because of procedure and */
-		/* array modifiers. */
-		for ( ; ; )
-		   {	p = skipspace(p - 1, -1);
-			switch ( *p )
-			   {
-			case ']':	/* skip array dimension(s) */
-			case ')':	/* skip procedure args OR name */
-			   {	int level = 1;
-				while ( level )
-				 switch ( *--p )
-				   {
-				case ']': case ')': level++; break;
-				case '[': case '(': level--; break;
-				case '/': p = skipspace(p, -1) + 1; break;
-				default: ;
-				   }
-			   }
-				if ( *p == '(' && *skipspace(p + 1, 1) == '*' )
-				   {	/* We found the name being declared */
-					while ( !isidfirstchar(*p) )
-						p = skipspace(p, 1) + 1;
-					goto found;
-				   }
-				break;
-			default: goto found;
-			   }
-		   }
-found:		if ( *p == '.' && p[-1] == '.' && p[-2] == '.' )
-		   {	p++;
-			if ( bp == breaks + 1 )	/* sole argument */
-				writeblanks(breaks[0], p);
-			else
-				writeblanks(bp[-1] - 1, p);
-			bp--;
-		   }
-		else
-		   {	while ( isidchar(*p) ) p--;
-			*bp++ = p+1;
-		   }
-		p = end;
-	   }
-	while ( *p++ == ',' );
-	*bp = p;
-	/* Make a special check for 'void' arglist */
-	if ( bp == breaks+2 )
-	   {	p = skipspace(breaks[0], 1);
-		if ( !strncmp(p, "void", 4) )
-		   {	p = skipspace(p+4, 1);
-			if ( p == breaks[2] - 1 )
-			   {	bp = breaks;	/* yup, pretend arglist is empty */
-				writeblanks(breaks[0], p + 1);
-			   }
-		   }
-	   }
-	/* Put out the function name */
-	p = buf;
-	while ( p != endfn ) putc(*p, out), p++;
-	/* Put out the declaration */
-	for ( ap = breaks+1; ap < bp; ap += 2 )
-	   {	p = *ap;
-		while ( isidchar(*p) ) putc(*p, out), p++;
-		if ( ap < bp - 1 ) fputs(", ", out);
-	   }
-	fputs(")  ", out);
-	/* Put out the argument declarations */
-	for ( ap = breaks+2; ap <= bp; ap += 2 ) (*ap)[-1] = ';';
-	fputs(breaks[0], out);
-	free((char *)breaks);
-	return 0;
-}

build.bat

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

configure

@@ -0,0 +1,6 @@
+echo "
+  There is no \"configure\" script for Libpng-1.0.11.  Instead, please
+  copy the appropriate makefile for your system from the \"scripts\"
+  directory.  Read the INSTALL file for more details.
+"
+

contrib/gregbook/LICENSE

@@ -0,0 +1,26 @@
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------

contrib/gregbook/Makefile.sgi

@@ -0,0 +1,102 @@
+# Sample makefile for rpng-x / rpng2-x / wpng for SGI using cc and make.
+# Greg Roelofs
+# Last modified:  16 January 1000
+#
+#	The programs built by this makefile are described in the book,
+#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#	Associates, 1999).  Go buy a copy, eh?  Buy some for friends
+#	and family, too.  (Not that this is a blatant plug or anything.)
+#
+# Invoke this makefile from a shell prompt in the usual way; for example:
+#
+#	make -f Makefile.sgi
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are both installed in /usr/local/{include,lib} (as indicated by the
+# PNG* and Z* macros below).  Edit as appropriate--choose only ONE each of
+# the PNGINC, PNGLIB, ZINC and ZLIB lines.
+#
+# This makefile builds dynamically linked executables (against libpng and zlib,
+# that is), but that can be changed by uncommenting the appropriate PNGLIB and
+# ZLIB lines.
+
+
+# macros --------------------------------------------------------------------
+
+PNGINC = -I/usr/local/include
+PNGLIB = -L/usr/local/lib -lpng	# dynamically linked against libpng
+#PNGLIB = /usr/local/lib/libpng.a	# statically linked against libpng
+# or:
+#PNGINC = -I../..
+#PNGLIB = -L../.. -lpng
+#PNGLIB = ../../libpng.a
+
+ZINC = -I/usr/local/include
+ZLIB = -L/usr/local/lib -lz		# dynamically linked against zlib
+#ZLIB = /usr/local/lib/libz.a		# statically linked against zlib
+#ZINC = -I../zlib
+#ZLIB = -L../zlib -lz
+#ZLIB = ../../../zlib/libz.a
+
+XINC = -I/usr/include/X11		# old-style, stock X distributions
+XLIB = -L/usr/lib/X11 -lX11
+#XINC = -I/usr/openwin/include    	# Sun workstations (OpenWindows)
+#XLIB = -L/usr/openwin/lib -lX11
+#XINC = -I/usr/X11R6/include		# new X distributions (XFree86, etc.)
+#XLIB = -L/usr/X11R6/lib -lX11
+
+INCS = $(PNGINC) $(ZINC) $(XINC)
+RLIBS = $(PNGLIB) $(ZLIB) $(XLIB) -lm
+WLIBS = $(PNGLIB) $(ZLIB)
+
+CC = cc
+LD = cc
+RM = rm -f
+CFLAGS = -O -fullwarn $(INCS)
+LDFLAGS =
+O = .o
+E =
+
+RPNG  = rpng-x
+RPNG2 = rpng2-x
+WPNG  = wpng
+
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+
+EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CFLAGS) $<
+
+
+# dependencies --------------------------------------------------------------
+
+all:  $(EXES)
+
+$(RPNG)$(E): $(ROBJS)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBS)
+
+$(RPNG2)$(E): $(ROBJS2)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBS)
+
+$(WPNG)$(E): $(WOBJS)
+	$(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBS)
+
+$(RPNG)$(O):	$(RPNG).c readpng.h
+$(RPNG2)$(O):	$(RPNG2).c readpng2.h
+$(WPNG)$(O):	$(WPNG).c writepng.h
+
+readpng$(O):	readpng.c readpng.h
+readpng2$(O):	readpng2.c readpng2.h
+writepng$(O):	writepng.c writepng.h
+
+
+# maintenance ---------------------------------------------------------------
+
+clean:
+	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)

contrib/gregbook/Makefile.unx

@@ -0,0 +1,104 @@
+# Sample makefile for rpng-x / rpng2-x / wpng using gcc and make.
+# Greg Roelofs
+# Last modified:  28 February 2000
+#
+#	The programs built by this makefile are described in the book,
+#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#	Associates, 1999).  Go buy a copy, eh?  Buy some for friends
+#	and family, too.  (Not that this is a blatant plug or anything.)
+#
+# Invoke this makefile from a shell prompt in the usual way; for example:
+#
+#	make -f Makefile.unx
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are both installed in /usr/local/{include,lib} (as indicated by the
+# PNG* and Z* macros below).  Edit as appropriate--choose only ONE each of
+# the PNGINC, PNGLIB, ZINC and ZLIB lines.
+#
+# This makefile builds statically linked executables (against libpng and zlib,
+# that is), but that can be changed by uncommenting the appropriate PNGLIB and
+# ZLIB lines.
+
+
+# macros --------------------------------------------------------------------
+
+PNGINC = -I/usr/local/include
+#PNGLIB = -L/usr/local/lib -lpng	# dynamically linked against libpng
+PNGLIB = /usr/local/lib/libpng.a	# statically linked against libpng
+# or:
+#PNGINC = -I../..
+#PNGLIB = -L../.. -lpng
+#PNGLIB = ../../libpng.a
+
+ZINC = -I/usr/local/include
+#ZLIB = -L/usr/local/lib -lz		# dynamically linked against zlib
+ZLIB = /usr/local/lib/libz.a		# statically linked against zlib
+#ZINC = -I../zlib
+#ZLIB = -L../zlib -lz
+#ZLIB = ../../../zlib/libz.a
+
+#XINC = -I/usr/include/X11		# old-style, stock X distributions
+#XLIB = -L/usr/lib/X11 -lX11
+#XINC = -I/usr/openwin/include    	# Sun workstations (OpenWindows)
+#XLIB = -L/usr/openwin/lib -lX11
+XINC = -I/usr/X11R6/include		# new X distributions (XFree86, etc.)
+XLIB = -L/usr/X11R6/lib -lX11
+
+INCS = $(PNGINC) $(ZINC) $(XINC)
+RLIBS = $(PNGLIB) $(ZLIB) $(XLIB) -lm
+WLIBS = $(PNGLIB) $(ZLIB)
+
+CC = gcc
+LD = gcc
+RM = rm -f
+CFLAGS = -O -Wall $(INCS)
+# [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
+# [-ansi, -pedantic and -W can also be used]
+LDFLAGS =
+O = .o
+E =
+
+RPNG  = rpng-x
+RPNG2 = rpng2-x
+WPNG  = wpng
+
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+
+EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CFLAGS) $<
+
+
+# dependencies --------------------------------------------------------------
+
+all:  $(EXES)
+
+$(RPNG)$(E): $(ROBJS)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBS)
+
+$(RPNG2)$(E): $(ROBJS2)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBS)
+
+$(WPNG)$(E): $(WOBJS)
+	$(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBS)
+
+$(RPNG)$(O):	$(RPNG).c readpng.h
+$(RPNG2)$(O):	$(RPNG2).c readpng2.h
+$(WPNG)$(O):	$(WPNG).c writepng.h
+
+readpng$(O):	readpng.c readpng.h
+readpng2$(O):	readpng2.c readpng2.h
+writepng$(O):	writepng.c writepng.h
+
+
+# maintenance ---------------------------------------------------------------
+
+clean:
+	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)

contrib/gregbook/Makefile.w32

@@ -0,0 +1,112 @@
+# Sample makefile for rpng-win / rpng2-win / wpng using MSVC and NMAKE.
+# Greg Roelofs
+# Last modified:  16 February 1999
+#
+#	The programs built by this makefile are described in the book,
+#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#	Associates, 1999).  Go buy a copy, eh?  Buy some for friends
+#	and family, too.  (Not that this is a blatant plug or anything.)
+#
+# Invoke this makefile from a DOS prompt window via:
+#
+#	%devstudio%\vc\bin\vcvars32.bat
+#	nmake -nologo -f Makefile.w32
+#
+# where %devstudio% is the installation directory for MSVC / DevStudio.  If
+# you get "environment out of space" errors, create a desktop shortcut with
+# "c:\windows\command.com /e:4096" as the program command line and set the
+# working directory to this directory.  Then double-click to open the new
+# DOS-prompt window with a bigger environment and retry the commands above.
+# 
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are in subdirectories at the same level as the current subdirectory
+# (as indicated by the PNGPATH and ZPATH macros below).  Edit as appropriate.
+#
+# Note that the names of the dynamic and static libpng and zlib libraries
+# used below may change in later releases of the libraries.  This makefile
+# builds statically linked executables, but that can be changed by uncom-
+# menting the appropriate PNGLIB and ZLIB lines.
+
+!include <ntwin32.mak>
+
+
+# macros --------------------------------------------------------------------
+
+PNGPATH = ../..
+PNGINC = -I$(PNGPATH)
+#PNGLIB = $(PNGPATH)/pngdll.lib
+PNGLIB = $(PNGPATH)/libpng.lib
+
+ZPATH = ../../../zlib
+ZINC = -I$(ZPATH)
+#ZLIB = $(ZPATH)/zlibdll.lib
+ZLIB = $(ZPATH)/zlibstat.lib
+
+WINLIBS = -defaultlib:user32.lib gdi32.lib
+# ["real" apps may also need comctl32.lib, comdlg32.lib, winmm.lib, etc.]
+
+INCS = $(PNGINC) $(ZINC)
+RLIBS = $(PNGLIB) $(ZLIB) $(WINLIBS)
+WLIBS = $(PNGLIB) $(ZLIB)
+
+CC = cl
+LD = link
+RM = del
+CFLAGS = -nologo -O -W3 $(INCS) $(cvars)
+# [note that -Wall is an MSVC-specific compilation flag ("all warnings on")]
+# [see %devstudio%\vc\include\win32.mak for cvars macro definition]
+O = .obj
+E = .exe
+
+RLDFLAGS = -nologo -subsystem:windows
+WLDFLAGS = -nologo
+
+RPNG  = rpng-win
+RPNG2 = rpng2-win
+WPNG  = wpng
+
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+
+EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CFLAGS) $<
+
+
+# dependencies --------------------------------------------------------------
+
+all:  $(EXES)
+
+$(RPNG)$(E): $(ROBJS)
+	$(LD) $(RLDFLAGS) -out:$@ $(ROBJS) $(RLIBS)
+
+$(RPNG2)$(E): $(ROBJS2)
+	$(LD) $(RLDFLAGS) -out:$@ $(ROBJS2) $(RLIBS)
+
+$(WPNG)$(E): $(WOBJS)
+	$(LD) $(WLDFLAGS) -out:$@ $(WOBJS) $(WLIBS)
+
+$(RPNG)$(O):	$(RPNG).c readpng.h
+$(RPNG2)$(O):	$(RPNG2).c readpng2.h
+$(WPNG)$(O):	$(WPNG).c writepng.h
+
+readpng$(O):	readpng.c readpng.h
+readpng2$(O):	readpng2.c readpng2.h
+writepng$(O):	writepng.c writepng.h
+
+
+# maintenance ---------------------------------------------------------------
+
+clean:
+#	ideally we could just do this:
+#	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)
+#	...but the Windows "DEL" command is none too bright, so:
+	$(RM) r*$(E)
+	$(RM) w*$(E)
+	$(RM) r*$(O)
+	$(RM) w*$(O)

contrib/gregbook/README

@@ -0,0 +1,183 @@
+                     ===========================
+                      PNG: The Definitive Guide
+                     ===========================
+
+                             Source Code
+
+Chapters 13, 14 and 15 of "PNG: The Definitive Guide" discuss three free,
+cross-platform demo programs that show how to use the libpng reference
+library:  rpng, rpng2 and wpng.  rpng and rpng2 are viewers; the first is
+a very simple example that that shows how a standard file-viewer might use
+libpng, while the second is designed to process streaming data and shows
+how a web browser might be written.  wpng is a simple command-line program
+that reads binary PGM and PPM files (the ``raw'' grayscale and RGB subsets
+of PBMPLUS/NetPBM) and converts them to PNG.
+
+The source code for all three demo programs currently compiles under
+Unix, OpenVMS, and 32-bit Windows.  (Special thanks to Martin Zinser,
+zinser@decus.de, for making the necessary changes for OpenVMS and for
+providing an appropriate build script.)  Build instructions can be
+found below.
+
+Files:
+
+   README             this file
+   README.w32         additional Windows-specific information
+   LICENSE            terms of distribution and reuse (BSD-like)
+
+   Makefile.unx       Unix makefile
+   Makefile.w32       Windows (MSVC) makefile
+   makevms.com        OpenVMS build script
+
+   rpng-win.c         Windows front end for the basic viewer
+   rpng-x.c           X Window System (Unix, OpenVMS) front end
+   readpng.c          generic back end for the basic viewer
+   readpng.h          header file for the basic viewer
+
+   rpng2-win.c        Windows front end for the progressive viewer
+   rpng2-x.c          X front end for the progressive viewer
+   readpng2.c         generic back end for the progressive viewer
+   readpng2.h         header file for the progressive viewer
+
+   wpng.c             generic (text) front end for the converter
+   writepng.c         generic back end for the converter
+   writepng.h         header file for the converter
+
+   toucan.png         transparent PNG for testing (by Stefan Schneider)
+
+Note that the programs are designed to be functional, but their primary
+purpose is to demonstrate how to use libpng to add PNG support to other
+programs.  As such, their user interfaces are crude and definitely not
+intended for everyday use.
+
+Please see http://www.cdrom.com/pub/png/pngbook.html for further infor-
+mation and links to the latest version of the source code, and Chapters
+13-15 of the book for detailed discussion of the three programs.
+
+Greg Roelofs
+19 March 2000
+
+
+BUILD INSTRUCTIONS
+
+ - Prerequisites:
+
+      - zlib		ftp://ftp.cdrom.com/pub/infozip/zlib/zlib.html
+      - libpng		http://www.cdrom.com/pub/png/pngcode.html
+      - pngbook		http://www.cdrom.com/pub/png/book/sources.html
+
+     The pngbook demo programs are explicitly designed to demonstrate proper
+     coding techniques for using the libpng reference library.  As a result,
+     you need to download and build both zlib (on which libpng depends) and
+     libpng.  A common build setup is to place the zlib, libpng and pngbook
+     subdirectory trees ("folders") in the same parent directory.  Then the
+     libpng build can refer to files in ../zlib (or ..\zlib or [-.zlib]),
+     and similarly for the pngbook build.
+
+     Note that all three packages are designed to be built from a command
+     line by default; those who wish to use a graphical or other integrated
+     development environments are on their own.
+
+
+ - Unix:
+
+     Unpack the latest pngbook sources (which should correspond to this
+     README file) into a directory and change into that directory.
+
+     Copy Makefile.unx to Makefile and edit the PNG* and Z* variables
+     appropriately (possibly also the X* variables if necessary).
+
+     make
+
+     There is no "install" target, so copy the three executables somewhere
+     in your path or run them from the current directory.  All three will
+     print a basic usage screen when run without any command-line arguments;
+     see the book for more details.
+
+
+ - Windows:
+
+     Unpack the latest pngbook sources (which should correspond to this
+     README file) into a folder, open a "DOS shell" or "command prompt"
+     or equivalent command-line window, and cd into the folder where you
+     unpacked the source code.
+
+     For MSVC, set up the necessary environment variables by invoking
+ 
+        %devstudio%\vc\bin\vcvars32.bat
+
+     where where %devstudio% is the installation directory for MSVC /
+     DevStudio.  If you get "environment out of space" errors under 95/98,
+     create a desktop shortcut with "c:\windows\command.com /e:4096" as
+     the program command line and set the working directory to the pngbook
+     directory.  Then double-click to open the new DOS-prompt window with
+     a bigger environment and retry the commands above.
+
+     Copy Makefile.w32 to Makefile and edit the PNGPATH and ZPATH variables
+     appropriately (possibly also the "INC" and "LIB" variables if needed).
+     Note that the names of the dynamic and static libpng and zlib libraries
+     used in the makefile may change in later releases of the libraries.
+     Also note that, as of libpng version 1.0.5, MSVC DLL builds do not work.
+     This makefile therefore builds statically linked executables, but if
+     the DLL problems ever get fixed, uncommenting the appropriate PNGLIB
+     and ZLIB lines will build dynamically linked executables instead.
+
+     Do the build by typing
+
+        nmake
+
+     The result should be three executables:  rpng-win.exe, rpng2-win.exe,
+     and wpng.exe.  Copy them somewhere in your PATH or run them from the
+     current folder.  Unlike the Unix versions, the two windowed programs
+     (rpng and rpng2) do not display a usage screen when invoked without
+     command-line arguments; see README.w32 for brief help or the book for
+     details.  Note that the programs use the Unix-style "-" character to
+     specify options, instead of the more common DOS/Windows "/" character.
+
+
+ - OpenVMS:
+
+     Unpack the pngbook sources into a subdirectory and change into that
+     subdirectory.
+
+     Edit makevms.com appropriately, specifically the zpath and pngpath
+     variables.
+
+     @makevms
+
+     To run the programs, they probably first need to be set up as "foreign
+     symbols," with "disk" and "dir" set appropriately:
+
+     $ rpng == "$disk:[dir]rpng-x.exe"
+     $ rpng2 == "$disk:[dir]rpng2-x.exe"
+     $ wpng == "$disk:[dir]wpng.exe"
+
+     All three will print a basic usage screen when run without any command-
+     line arguments; see the book for more details.  Note that the options
+     style is Unix-like, i.e., preceded by "-" rather than "/".
+
+
+RUNNING THE PROGRAMS:  (VERY) BRIEF INTRO
+
+     rpng is a simple PNG viewer that can display transparent PNGs with a
+     specified background color; for example,
+
+	rpng -bgcolor #ff0000 toucan.png
+
+     would display the image with a red background.  rpng2 is a progressive
+     viewer that simulates a web browser in some respects; it can display
+     images against either a background color or a dynamically generated
+     background image.  For example:
+
+	rpng2 -bgpat 16 toucan.png
+
+     wpng is a purely command-line image converter from binary PBMPLUS/NetPBM
+     format (.pgm or .ppm) to PNG; for example,
+
+	wpng -time < toucan.ppm > toucan.png
+
+     would convert the specified PPM file (using redirection) to PNG, auto-
+     matically setting the PNG modification-time chunk.
+
+     All options can be abbreviated to the shortest unique value; for example,
+     "-bgc" for -bgcolor (versus "-bgp" for -bgpat), or "-g" for -gamma.

contrib/gregbook/README.w32

@@ -0,0 +1,53 @@
+See the main README file for basic instructions on compiling and running
+the programs.  See http://www.cdrom.com/pub/png/pngbook.html for further
+information and links to the source code, and Chapters 13-15 of the book
+for detailed discussion of the three programs.
+
+Since the two viewers, rpng and rpng2, are both designed to write infor-
+mation to the console (i.e., a DOS-window command line) while displaying
+the image in a graphical window--and since I haven't yet figured out how
+to do that under Windows--here are the usage screens for the two programs:
+
+
+rpng-win 1.02 of 19 March 2000:  Simple PNG Viewer for Windows
+   Compiled with libpng 1.0.5; using libpng 1.0.5.
+   Compiled with zlib 1.1.3; using zlib 1.1.3.
+
+Usage:  rpng-win [-gamma exp] [-bgcolor bg] file.png
+    exp 	transfer-function exponent (``gamma'') of the display
+		  system in floating-point format (e.g., ``2.2''); equal
+		  to the product of the lookup-table exponent (varies)
+		  and the CRT exponent (usually 2.2); must be positive
+    bg  	desired background color in 7-character hex RGB format
+		  (e.g., ``#ff7f00'' for orange:  same as HTML colors);
+		  used with transparent images
+
+Press Q, Esc or mouse button 1 after image is displayed to quit.
+
+
+rpng2-win 1.04 of 19 March 2000:  Progressive PNG Viewer for Windows
+   Compiled with libpng 1.0.5; using libpng 1.0.5.
+   Compiled with zlib 1.1.3; using zlib 1.1.3.
+
+Usage:  rpng2-win [-gamma exp] [-bgcolor bg | -bgpat pat] [-timing] file.png
+
+    exp 	transfer-function exponent (``gamma'') of the display
+		  system in floating-point format (e.g., ``2.2''); equal
+		  to the product of the lookup-table exponent (varies)
+		  and the CRT exponent (usually 2.2); must be positive
+    bg  	desired background color in 7-character hex RGB format
+		  (e.g., ``#ff7f00'' for orange:  same as HTML colors);
+		  used with transparent images; overrides -bgpat
+    pat 	desired background pattern number (1-16); used with
+		  transparent images; overrides -bgcolor
+    -timing	enables delay for every block read, to simulate modem
+		  download of image (~36 Kbps)
+
+Press Q, Esc or mouse button 1 after image is displayed to quit.
+
+
+The usage screen for the third (non-windowed) program, wpng, can be seen
+simply by invoking it without any parameters (``wpng'').
+
+Greg Roelofs
+19 March 2000

contrib/gregbook/makevms.com

@@ -0,0 +1,131 @@
+$!------------------------------------------------------------------------------
+$! make "PNG: The Definitive Guide" demo programs (for X) under OpenVMS
+$!
+$! Script created by Martin Zinser for libpng; modified by Greg Roelofs
+$! for standalone pngbook source distribution.
+$!
+$!
+$!    Set locations where zlib and libpng sources live.
+$!
+$ zpath   = ""
+$ pngpath = ""
+$ if f$search("[-.zlib]zlib.h").nes."" then zpath = "[-.zlib]"
+$ if f$search("[-.libpng]png.h").nes."" then pngpath = "[-.libpng]"
+$!
+$ if f$search("[---.zlib]zlib.h").nes."" then zpath = "[---.zlib]"
+$ if f$search("[--]png.h").nes."" then pngpath = "[--]"
+$!
+$ if zpath .eqs. ""
+$ then
+$   write sys$output "Zlib include not found. Exiting..."
+$   exit 2
+$ endif 
+$!
+$ if pngpath .eqs. ""
+$ then
+$   write sys$output "Libpng include not found. Exiting..."
+$   exit 2
+$ endif 
+$!
+$!    Look for the compiler used.
+$!
+$ ccopt="/include=(''zpath',''pngpath')"
+$ 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
+$ open/write lopt lib.opt
+$ write lopt "''pngpath'libpng.olb/lib"
+$ write lopt "''zpath'libz.olb/lib"
+$ close lopt
+$ open/write xopt x11.opt
+$ write xopt "sys$library:decw$xlibshr.exe/share"
+$ close xopt
+$!
+$!    Build 'em.
+$!
+$ write sys$output "Compiling PNG book programs ..."
+$   CALL MAKE readpng.OBJ "cc ''CCOPT' readpng" -
+	readpng.c readpng.h
+$   CALL MAKE readpng2.OBJ "cc ''CCOPT' readpng2" -
+	readpng2.c readpng2.h
+$   CALL MAKE writepng.OBJ "cc ''CCOPT' writepng" -
+	writepng.c writepng.h
+$   write sys$output "Building rpng-x..."
+$   CALL MAKE rpng-x.OBJ "cc ''CCOPT' rpng-x" -
+	rpng-x.c readpng.h
+$   call make rpng-x.exe -
+	"LINK rpng-x,readpng,lib.opt/opt,x11.opt/opt" -
+	rpng-x.obj readpng.obj
+$   write sys$output "Building rpng2-x..."
+$   CALL MAKE rpng2-x.OBJ "cc ''CCOPT' rpng2-x" -
+	rpng2-x.c readpng2.h
+$   call make rpng2-x.exe -
+	"LINK rpng2-x,readpng2,lib.opt/opt,x11.opt/opt" -
+	rpng2-x.obj readpng2.obj
+$   write sys$output "Building wpng..."
+$   CALL MAKE wpng.OBJ "cc ''CCOPT' wpng" -
+	wpng.c writepng.h
+$   call make wpng.exe -
+	"LINK wpng,writepng,lib.opt/opt" -
+	wpng.obj writepng.obj
+$ 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

contrib/gregbook/readpng.c

@@ -0,0 +1,280 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                              readpng.c
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "png.h"        /* libpng header; includes zlib.h */
+#include "readpng.h"    /* typedefs, common macros, public prototypes */
+
+/* future versions of libpng will provide this macro: */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr)   ((png_ptr)->jmpbuf)
+#endif
+
+
+static png_structp png_ptr = NULL;
+static png_infop info_ptr = NULL;
+
+png_uint_32  width, height;
+int  bit_depth, color_type;
+uch  *image_data = NULL;
+
+
+void readpng_version_info(void)
+{
+    fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+      PNG_LIBPNG_VER_STRING, png_libpng_ver);
+    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+      ZLIB_VERSION, zlib_version);
+}
+
+
+/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
+
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
+{
+    uch sig[8];
+
+
+    /* first do a quick check that the file really is a PNG image; could
+     * have used slightly more general png_sig_cmp() function instead */
+
+    fread(sig, 1, 8, infile);
+    if (!png_check_sig(sig, 8))
+        return 1;   /* bad signature */
+
+
+    /* could pass pointers to user-defined error handlers instead of NULLs: */
+
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        return 4;   /* out of memory */
+    }
+
+
+    /* we could create a second info struct here (end_info), but it's only
+     * useful if we want to keep pre- and post-IDAT chunk info separated
+     * (mainly for PNG-aware image editors and converters) */
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+
+
+    png_init_io(png_ptr, infile);
+    png_set_sig_bytes(png_ptr, 8);  /* we already read the 8 signature bytes */
+
+    png_read_info(png_ptr, info_ptr);  /* read all PNG info up to image data */
+
+
+    /* alternatively, could make separate calls to png_get_image_width(),
+     * etc., but want bit_depth and color_type for later [don't care about
+     * compression_type and filter_type => NULLs] */
+
+    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+      NULL, NULL, NULL);
+    *pWidth = width;
+    *pHeight = height;
+
+
+    /* OK, that's all we need for now; return happy */
+
+    return 0;
+}
+
+
+
+
+/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error;
+ * scales values to 8-bit if necessary */
+
+int readpng_get_bgcolor(uch *red, uch *green, uch *blue)
+{
+    png_color_16p pBackground;
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+
+
+    if (!png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+        return 1;
+
+    /* it is not obvious from the libpng documentation, but this function
+     * takes a pointer to a pointer, and it always returns valid red, green
+     * and blue values, regardless of color_type: */
+
+    png_get_bKGD(png_ptr, info_ptr, &pBackground);
+
+
+    /* however, it always returns the raw bKGD data, regardless of any
+     * bit-depth transformations, so check depth and adjust if necessary */
+
+    if (bit_depth == 16) {
+        *red   = pBackground->red   >> 8;
+        *green = pBackground->green >> 8;
+        *blue  = pBackground->blue  >> 8;
+    } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+        if (bit_depth == 1)
+            *red = *green = *blue = pBackground->gray? 255 : 0;
+        else if (bit_depth == 2)
+            *red = *green = *blue = (255/3) * pBackground->gray;
+        else /* bit_depth == 4 */
+            *red = *green = *blue = (255/15) * pBackground->gray;
+    } else {
+        *red   = (uch)pBackground->red;
+        *green = (uch)pBackground->green;
+        *blue  = (uch)pBackground->blue;
+    }
+
+    return 0;
+}
+
+
+
+
+/* display_exponent == LUT_exponent * CRT_exponent */
+
+uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
+{
+    double  gamma;
+    png_uint_32  i, rowbytes;
+    png_bytepp  row_pointers = NULL;
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return NULL;
+    }
+
+
+    /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
+     * transparency chunks to full alpha channel; strip 16-bit-per-sample
+     * images to 8 bits per sample; and convert grayscale to RGB[A] */
+
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_expand(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+        png_set_expand(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+        png_set_expand(png_ptr);
+    if (bit_depth == 16)
+        png_set_strip_16(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+        png_set_gray_to_rgb(png_ptr);
+
+
+    /* unlike the example in the libpng documentation, we have *no* idea where
+     * this file may have come from--so if it doesn't have a file gamma, don't
+     * do any correction ("do no harm") */
+
+    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+        png_set_gamma(png_ptr, display_exponent, gamma);
+
+
+    /* all transformations have been registered; now update info_ptr data,
+     * get rowbytes and channels, and allocate image memory */
+
+    png_read_update_info(png_ptr, info_ptr);
+
+    *pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+    *pChannels = (int)png_get_channels(png_ptr, info_ptr);
+
+    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return NULL;
+    }
+    if ((row_pointers = (png_bytepp)malloc(height*sizeof(png_bytep))) == NULL) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        free(image_data);
+        image_data = NULL;
+        return NULL;
+    }
+
+    Trace((stderr, "readpng_get_image:  rowbytes = %ld, height = %ld\n", rowbytes, height));
+
+
+    /* set the individual row_pointers to point at the correct offsets */
+
+    for (i = 0;  i < height;  ++i)
+        row_pointers[i] = image_data + i*rowbytes;
+
+
+    /* now we can go ahead and just read the whole image */
+
+    png_read_image(png_ptr, row_pointers);
+
+
+    /* and we're done!  (png_read_end() can be omitted if no processing of
+     * post-IDAT text/time/etc. is desired) */
+
+    free(row_pointers);
+    row_pointers = NULL;
+
+    png_read_end(png_ptr, NULL);
+
+    return image_data;
+}
+
+
+void readpng_cleanup(int free_image_data)
+{
+    if (free_image_data && image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+
+    if (png_ptr && info_ptr) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        png_ptr = NULL;
+        info_ptr = NULL;
+    }
+}

contrib/gregbook/readpng.h

@@ -0,0 +1,64 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                              readpng.h
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+
+/* prototypes for public functions in readpng.c */
+
+void readpng_version_info(void);
+
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight);
+
+int readpng_get_bgcolor(uch *bg_red, uch *bg_green, uch *bg_blue);
+
+uch *readpng_get_image(double display_exponent, int *pChannels,
+                       ulg *pRowbytes);
+
+void readpng_cleanup(int free_image_data);

contrib/gregbook/readpng2.c

@@ -0,0 +1,424 @@
+/*---------------------------------------------------------------------------
+
+   rpng2 - progressive-model PNG display program                 readpng2.c
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2001 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+
+#include <stdlib.h>     /* for exit() prototype */
+
+#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
+#include "readpng2.h"   /* typedefs, common macros, public prototypes */
+
+
+/* local prototypes */
+
+static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr);
+static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
+                                 png_uint_32 row_num, int pass);
+static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr);
+static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg);
+
+
+
+
+void readpng2_version_info(void)
+{
+    fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+      PNG_LIBPNG_VER_STRING, png_libpng_ver);
+
+    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+      ZLIB_VERSION, zlib_version);
+}
+
+
+
+
+int readpng2_check_sig(uch *sig, int num)
+{
+    return png_check_sig(sig, num);
+}
+
+
+
+
+/* returns 0 for success, 2 for libpng problem, 4 for out of memory */
+
+int readpng2_init(mainprog_info *mainprog_ptr)
+{
+    png_structp  png_ptr;       /* note:  temporary variables! */
+    png_infop  info_ptr;
+
+
+    /* could also replace libpng warning-handler (final NULL), but no need: */
+
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+      readpng2_error_handler, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        return 4;   /* out of memory */
+    }
+
+
+    /* we could create a second info struct here (end_info), but it's only
+     * useful if we want to keep pre- and post-IDAT chunk info separated
+     * (mainly for PNG-aware image editors and converters) */
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function, unless an alternate error handler was installed--
+     * but compatible error handlers must either use longjmp() themselves
+     * (as in this program) or exit immediately, so here we are: */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+
+
+    /* instead of doing png_init_io() here, now we set up our callback
+     * functions for progressive decoding */
+
+    png_set_progressive_read_fn(png_ptr, mainprog_ptr,
+      readpng2_info_callback, readpng2_row_callback, readpng2_end_callback);
+
+    /* make sure we save our pointers for use in readpng2_decode_data() */
+
+    mainprog_ptr->png_ptr = png_ptr;
+    mainprog_ptr->info_ptr = info_ptr;
+
+
+    /* and that's all there is to initialization */
+
+    return 0;
+}
+
+
+
+
+/* returns 0 for success, 2 for libpng (longjmp) problem */
+
+int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* hand off the next chunk of input data to libpng for decoding */
+
+    png_process_data(png_ptr, info_ptr, rawbuf, length);
+
+    return 0;
+}
+
+
+
+
+static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
+{
+    mainprog_info  *mainprog_ptr;
+    int  color_type, bit_depth;
+    double  gamma;
+
+
+    /* setjmp() doesn't make sense here, because we'd either have to exit(),
+     * longjmp() ourselves, or return control to libpng, which doesn't want
+     * to see us again.  By not doing anything here, libpng will instead jump
+     * to readpng2_decode_data(), which can return an error value to the main
+     * program. */
+
+
+    /* retrieve the pointer to our special-purpose struct, using the png_ptr
+     * that libpng passed back to us (i.e., not a global this time--there's
+     * no real difference for a single image, but for a multithreaded browser
+     * decoding several PNG images at the same time, one needs to avoid mixing
+     * up different images' structs) */
+
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+
+    if (mainprog_ptr == NULL) {         /* we be hosed */
+        fprintf(stderr,
+          "readpng2 error:  main struct not recoverable in info_callback.\n");
+        fflush(stderr);
+        return;
+        /*
+         * Alternatively, we could call our error-handler just like libpng
+         * does, which would effectively terminate the program.  Since this
+         * can only happen if png_ptr gets redirected somewhere odd or the
+         * main PNG struct gets wiped, we're probably toast anyway.  (If
+         * png_ptr itself is NULL, we would not have been called.)
+         */
+    }
+
+
+    /* this is just like in the non-progressive case */
+
+    png_get_IHDR(png_ptr, info_ptr, &mainprog_ptr->width,
+      &mainprog_ptr->height, &bit_depth, &color_type, NULL, NULL, NULL);
+
+
+    /* since we know we've read all of the PNG file's "header" (i.e., up
+     * to IDAT), we can check for a background color here */
+
+    if (mainprog_ptr->need_bgcolor &&
+        png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+    {
+        png_color_16p pBackground;
+
+        /* it is not obvious from the libpng documentation, but this function
+         * takes a pointer to a pointer, and it always returns valid red,
+         * green and blue values, regardless of color_type: */
+        png_get_bKGD(png_ptr, info_ptr, &pBackground);
+
+        /* however, it always returns the raw bKGD data, regardless of any
+         * bit-depth transformations, so check depth and adjust if necessary */
+        if (bit_depth == 16) {
+            mainprog_ptr->bg_red   = pBackground->red   >> 8;
+            mainprog_ptr->bg_green = pBackground->green >> 8;
+            mainprog_ptr->bg_blue  = pBackground->blue  >> 8;
+        } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+            if (bit_depth == 1)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
+            else if (bit_depth == 2)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
+            else /* bit_depth == 4 */
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
+        } else {
+            mainprog_ptr->bg_red   = (uch)pBackground->red;
+            mainprog_ptr->bg_green = (uch)pBackground->green;
+            mainprog_ptr->bg_blue  = (uch)pBackground->blue;
+        }
+    }
+
+
+    /* as before, let libpng expand palette images to RGB, low-bit-depth
+     * grayscale images to 8 bits, transparency chunks to full alpha channel;
+     * strip 16-bit-per-sample images to 8 bits per sample; and convert
+     * grayscale to RGB[A] */
+
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_expand(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+        png_set_expand(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+        png_set_expand(png_ptr);
+    if (bit_depth == 16)
+        png_set_strip_16(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+        png_set_gray_to_rgb(png_ptr);
+
+
+    /* Unlike the basic viewer, which was designed to operate on local files,
+     * this program is intended to simulate a web browser--even though we
+     * actually read from a local file, too.  But because we are pretending
+     * that most of the images originate on the Internet, we follow the recom-
+     * mendation of the sRGB proposal and treat unlabelled images (no gAMA
+     * chunk) as existing in the sRGB color space.  That is, we assume that
+     * such images have a file gamma of 0.45455, which corresponds to a PC-like
+     * display system.  This change in assumptions will have no effect on a
+     * PC-like system, but on a Mac, SGI, NeXT or other system with a non-
+     * identity lookup table, it will darken unlabelled images, which effec-
+     * tively favors images from PC-like systems over those originating on
+     * the local platform.  Note that mainprog_ptr->display_exponent is the
+     * "gamma" value for the entire display system, i.e., the product of
+     * LUT_exponent and CRT_exponent. */
+
+    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, gamma);
+    else
+        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, 0.45455);
+
+
+    /* we'll let libpng expand interlaced images, too */
+
+    mainprog_ptr->passes = png_set_interlace_handling(png_ptr);
+
+
+    /* all transformations have been registered; now update info_ptr data and
+     * then get rowbytes and channels */
+
+    png_read_update_info(png_ptr, info_ptr);
+
+    mainprog_ptr->rowbytes = (int)png_get_rowbytes(png_ptr, info_ptr);
+    mainprog_ptr->channels = png_get_channels(png_ptr, info_ptr);
+
+
+    /* Call the main program to allocate memory for the image buffer and
+     * initialize windows and whatnot.  (The old-style function-pointer
+     * invocation is used for compatibility with a few supposedly ANSI
+     * compilers that nevertheless barf on "fn_ptr()"-style syntax.) */
+
+    (*mainprog_ptr->mainprog_init)();
+
+
+    /* and that takes care of initialization */
+
+    return;
+}
+
+
+
+
+
+static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
+                                  png_uint_32 row_num, int pass)
+{
+    mainprog_info  *mainprog_ptr;
+
+
+    /* first check whether the row differs from the previous pass; if not,
+     * nothing to combine or display */
+
+    if (!new_row)
+        return;
+
+
+    /* retrieve the pointer to our special-purpose struct so we can access
+     * the old rows and image-display callback function */
+
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+
+
+    /* save the pass number for optional use by the front end */
+
+    mainprog_ptr->pass = pass;
+
+
+    /* have libpng either combine the new row data with the existing row data
+     * from previous passes (if interlaced) or else just copy the new row
+     * into the main program's image buffer */
+
+    png_progressive_combine_row(png_ptr, mainprog_ptr->row_pointers[row_num],
+      new_row);
+
+
+    /* finally, call the display routine in the main program with the number
+     * of the row we just updated */
+
+    (*mainprog_ptr->mainprog_display_row)(row_num);
+
+
+    /* and we're ready for more */
+
+    return;
+}
+
+
+
+
+
+static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr)
+{
+    mainprog_info  *mainprog_ptr;
+
+
+    /* retrieve the pointer to our special-purpose struct */
+
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+
+
+    /* let the main program know that it should flush any buffered image
+     * data to the display now and set a "done" flag or whatever, but note
+     * that it SHOULD NOT DESTROY THE PNG STRUCTS YET--in other words, do
+     * NOT call readpng2_cleanup() either here or in the finish_display()
+     * routine; wait until control returns to the main program via
+     * readpng2_decode_data() */
+
+    (*mainprog_ptr->mainprog_finish_display)();
+
+
+    /* all done */
+
+    return;
+}
+
+
+
+
+
+void readpng2_cleanup(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+    if (png_ptr && info_ptr)
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+
+    mainprog_ptr->png_ptr = NULL;
+    mainprog_ptr->info_ptr = NULL;
+}
+
+
+
+
+
+static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg)
+{
+    mainprog_info  *mainprog_ptr;
+
+    /* This function, aside from the extra step of retrieving the "error
+     * pointer" (below) and the fact that it exists within the application
+     * rather than within libpng, is essentially identical to libpng's
+     * default error handler.  The second point is critical:  since both
+     * setjmp() and longjmp() are called from the same code, they are
+     * guaranteed to have compatible notions of how big a jmp_buf is,
+     * regardless of whether _BSD_SOURCE or anything else has (or has not)
+     * been defined. */
+
+    fprintf(stderr, "readpng2 libpng error: %s\n", msg);
+    fflush(stderr);
+
+    mainprog_ptr = png_get_error_ptr(png_ptr);
+    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
+        fprintf(stderr,
+          "readpng2 severe error:  jmpbuf not recoverable; terminating.\n");
+        fflush(stderr);
+        exit(99);
+    }
+
+    longjmp(mainprog_ptr->jmpbuf, 1);
+}

contrib/gregbook/readpng2.h

@@ -0,0 +1,91 @@
+/*---------------------------------------------------------------------------
+
+   rpng2 - progressive-model PNG display program                 readpng2.h
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2001 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+typedef struct _mainprog_info {
+    double display_exponent;
+    ulg width;
+    ulg height;
+    void *png_ptr;
+    void *info_ptr;
+    void (*mainprog_init)(void);
+    void (*mainprog_display_row)(ulg row_num);
+    void (*mainprog_finish_display)(void);
+    uch *image_data;
+    uch **row_pointers;
+    jmp_buf jmpbuf;
+    int passes;              /* not used */
+    int pass;
+    int rowbytes;
+    int channels;
+    int need_bgcolor;
+#if (defined(__i386__) || defined(_M_IX86))
+    int nommxfilters;
+    int nommxcombine;
+    int nommxinterlace;
+#endif
+    int done;
+    uch bg_red;
+    uch bg_green;
+    uch bg_blue;
+} mainprog_info;
+
+
+/* prototypes for public functions in readpng2.c */
+
+void readpng2_version_info(void);
+
+int readpng2_check_sig(uch *sig, int num);
+
+int readpng2_init(mainprog_info *mainprog_ptr);
+
+int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length);
+
+void readpng2_cleanup(mainprog_info *mainprog_ptr);

contrib/gregbook/rpng-win.c

@@ -0,0 +1,620 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                             rpng-win.c
+
+   This program decodes and displays PNG images, with gamma correction and
+   optionally with a user-specified background color (in case the image has
+   transparency).  It is very nearly the most basic PNG viewer possible.
+   This version is for 32-bit Windows; it may compile under 16-bit Windows
+   with a little tweaking (or maybe not).
+
+   to do:
+    - stdout/stderr don't work!  need message window (maybe scrollable?)
+    - handle quoted command-line args (especially filenames with spaces)
+    - have minimum window width:  oh well
+    - use %.1023s to simplify truncation of title-bar string?
+
+  ---------------------------------------------------------------------------
+
+   Changelog:
+    - 1.00:  initial public release
+    - 1.01:  modified to allow abbreviated options; fixed long/ulong mis-
+              match; switched to png_jmpbuf() macro
+    - 1.02:  added extra set of parentheses to png_jmpbuf() macro; fixed
+              command-line parsing bug
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#define PROGNAME  "rpng-win"
+#define LONGNAME  "Simple PNG Viewer for Windows"
+#define VERSION   "1.02 of 19 March 2000"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <windows.h>
+
+/* #define DEBUG  :  this enables the Trace() macros */
+
+#include "readpng.h"    /* typedefs, common macros, readpng prototypes */
+
+
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+
+
+/* local prototypes */
+static int        rpng_win_create_window(HINSTANCE hInst, int showmode);
+static int        rpng_win_display_image(void);
+static void       rpng_win_cleanup(void);
+LRESULT CALLBACK  rpng_win_wndproc(HWND, UINT, WPARAM, LPARAM);
+
+
+static char titlebar[1024], *window_name = titlebar;
+static char *progname = PROGNAME;
+static char *appname = LONGNAME;
+static char *icon_name = PROGNAME;     /* GRR:  not (yet) used */
+static char *filename;
+static FILE *infile;
+
+static char *bgstr;
+static uch bg_red=0, bg_green=0, bg_blue=0;
+
+static double display_exponent;
+
+static ulg image_width, image_height, image_rowbytes;
+static int image_channels;
+static uch *image_data;
+
+/* Windows-specific variables */
+static ulg wimage_rowbytes;
+static uch *dib;
+static uch *wimage_data;
+static BITMAPINFOHEADER *bmih;
+
+static HWND global_hwnd;
+
+
+
+
+int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
+{
+    char *args[1024];                 /* arbitrary limit, but should suffice */
+    char *p, *q, **argv = args;
+    int argc = 0;
+    int rc, alen, flen;
+    int error = 0;
+    int have_bg = FALSE;
+    double LUT_exponent;              /* just the lookup table */
+    double CRT_exponent = 2.2;        /* just the monitor */
+    double default_display_exponent;  /* whole display system */
+    MSG msg;
+
+
+    filename = (char *)NULL;
+
+
+    /* First set the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities.  And
+     * yes, these ifdefs are completely wasted in a Windows program... */
+
+#if defined(NeXT)
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to get the
+     * "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+
+
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        display_exponent = atof(p);
+    else
+        display_exponent = default_display_exponent;
+
+
+    /* Windows really hates command lines, so we have to set up our own argv.
+     * Note that we do NOT bother with quoted arguments here, so don't use
+     * filenames with spaces in 'em! */
+
+    argv[argc++] = PROGNAME;
+    p = cmd;
+    for (;;) {
+        if (*p == ' ')
+            while (*++p == ' ')
+                ;
+        /* now p points at the first non-space after some spaces */
+        if (*p == '\0')
+            break;    /* nothing after the spaces:  done */
+        argv[argc++] = q = p;
+        while (*q && *q != ' ')
+            ++q;
+        /* now q points at a space or the end of the string */
+        if (*q == '\0')
+            break;    /* last argv already terminated; quit */
+        *q = '\0';    /* change space to terminator */
+        p = q + 1;
+    }
+    argv[argc] = NULL;   /* terminate the argv array itself */
+
+
+    /* Now parse the command line for options and the PNG filename. */
+
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                display_exponent = atof(*argv);
+                if (display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else
+                    have_bg = TRUE;
+            }
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+
+    if (!filename) {
+        ++error;
+    } else if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
+            switch (rc) {
+                case 1:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] is not a PNG file: incorrect signature\n",
+                      filename);
+                    break;
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n",
+                      filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng_init() error\n");
+                    break;
+            }
+            ++error;
+        }
+        if (error)
+            fclose(infile);
+    }
+
+
+    /* usage screen */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+         "Usage:  %s [-gamma exp] [-bgcolor bg] file.png\n"
+         "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+         "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+         "\t\t  to the product of the lookup-table exponent (varies)\n"
+         "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+         "    bg  \tdesired background color in 7-character hex RGB format\n"
+         "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+         "\t\t  used with transparent images\n"
+         "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
+         "\n", PROGNAME, default_display_exponent);
+        exit(1);
+    }
+
+
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+
+
+    /* if the user didn't specify a background color on the command line,
+     * check for one in the PNG file--if not, the initialized values of 0
+     * (black) will be used */
+
+    if (have_bg)
+        sscanf(bgstr+1, "%2x%2x%2x", &bg_red, &bg_green, &bg_blue);
+    else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
+        readpng_cleanup(TRUE);
+        fprintf(stderr, PROGNAME
+          ":  libpng error while checking for background color\n");
+        exit(2);
+    }
+
+
+    /* do the basic Windows initialization stuff, make the window and fill it
+     * with the background color */
+
+    if (rpng_win_create_window(hInst, showmode))
+        exit(2);
+
+
+    /* decode the image, all at once */
+
+    Trace((stderr, "calling readpng_get_image()\n"))
+    image_data = readpng_get_image(display_exponent, &image_channels,
+      &image_rowbytes);
+    Trace((stderr, "done with readpng_get_image()\n"))
+
+
+    /* done with PNG file, so clean up to minimize memory usage (but do NOT
+     * nuke image_data!) */
+
+    readpng_cleanup(FALSE);
+    fclose(infile);
+
+    if (!image_data) {
+        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
+        exit(3);
+    }
+
+
+    /* display image (composite with background if requested) */
+
+    Trace((stderr, "calling rpng_win_display_image()\n"))
+    if (rpng_win_display_image()) {
+        free(image_data);
+        exit(4);
+    }
+    Trace((stderr, "done with rpng_win_display_image()\n"))
+
+
+    /* wait for the user to tell us when to quit */
+
+    printf(
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+    fflush(stdout);
+
+    while (GetMessage(&msg, NULL, 0, 0)) {
+        TranslateMessage(&msg);
+        DispatchMessage(&msg);
+    }
+
+
+    /* OK, we're done:  clean up all image and Windows resources and go away */
+
+    rpng_win_cleanup();
+
+    return msg.wParam;
+}
+
+
+
+
+
+static int rpng_win_create_window(HINSTANCE hInst, int showmode)
+{
+    uch *dest;
+    int extra_width, extra_height;
+    ulg i, j;
+    WNDCLASSEX wndclass;
+
+
+/*---------------------------------------------------------------------------
+    Allocate memory for the display-specific version of the image (round up
+    to multiple of 4 for Windows DIB).
+  ---------------------------------------------------------------------------*/
+
+    wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2;
+
+    if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
+                              wimage_rowbytes*image_height)))
+    {
+        return 4;   /* fail */
+    }
+
+/*---------------------------------------------------------------------------
+    Initialize the DIB.  Negative height means to use top-down BMP ordering
+    (must be uncompressed, but that's what we want).  Bit count of 1, 4 or 8
+    implies a colormap of RGBX quads, but 24-bit BMPs just use B,G,R values
+    directly => wimage_data begins immediately after BMP header.
+  ---------------------------------------------------------------------------*/
+
+    memset(dib, 0, sizeof(BITMAPINFOHEADER));
+    bmih = (BITMAPINFOHEADER *)dib;
+    bmih->biSize = sizeof(BITMAPINFOHEADER);
+    bmih->biWidth = image_width;
+    bmih->biHeight = -((long)image_height);
+    bmih->biPlanes = 1;
+    bmih->biBitCount = 24;
+    bmih->biCompression = 0;
+    wimage_data = dib + sizeof(BITMAPINFOHEADER);
+
+/*---------------------------------------------------------------------------
+    Fill in background color (black by default); data are in BGR order.
+  ---------------------------------------------------------------------------*/
+
+    for (j = 0;  j < image_height;  ++j) {
+        dest = wimage_data + j*wimage_rowbytes;
+        for (i = image_width;  i > 0;  --i) {
+            *dest++ = bg_blue;
+            *dest++ = bg_green;
+            *dest++ = bg_red;
+        }
+    }
+
+/*---------------------------------------------------------------------------
+    Set the window parameters.
+  ---------------------------------------------------------------------------*/
+
+    memset(&wndclass, 0, sizeof(wndclass));
+
+    wndclass.cbSize = sizeof(wndclass);
+    wndclass.style = CS_HREDRAW | CS_VREDRAW;
+    wndclass.lpfnWndProc = rpng_win_wndproc;
+    wndclass.hInstance = hInst;
+    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
+    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
+    wndclass.hbrBackground = (HBRUSH)GetStockObject(DKGRAY_BRUSH);
+    wndclass.lpszMenuName = NULL;
+    wndclass.lpszClassName = progname;
+    wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
+
+    RegisterClassEx(&wndclass);
+
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+
+    extra_width  = 2*(GetSystemMetrics(SM_CXBORDER) +
+                      GetSystemMetrics(SM_CXDLGFRAME));
+    extra_height = 2*(GetSystemMetrics(SM_CYBORDER) +
+                      GetSystemMetrics(SM_CYDLGFRAME)) +
+                      GetSystemMetrics(SM_CYCAPTION);
+
+    global_hwnd = CreateWindow(progname, titlebar, WS_OVERLAPPEDWINDOW,
+      CW_USEDEFAULT, CW_USEDEFAULT, image_width+extra_width,
+      image_height+extra_height, NULL, NULL, hInst, NULL);
+
+    ShowWindow(global_hwnd, showmode);
+    UpdateWindow(global_hwnd);
+
+    return 0;
+
+} /* end function rpng_win_create_window() */
+
+
+
+
+
+static int rpng_win_display_image()
+{
+    uch *src, *dest;
+    uch r, g, b, a;
+    ulg i, row, lastrow;
+    RECT rect;
+
+
+    Trace((stderr, "beginning display loop (image_channels == %d)\n",
+      image_channels))
+    Trace((stderr, "(width = %ld, rowbytes = %ld, wimage_rowbytes = %d)\n",
+      image_width, image_rowbytes, wimage_rowbytes))
+
+
+/*---------------------------------------------------------------------------
+    Blast image data to buffer.  This whole routine takes place before the
+    message loop begins, so there's no real point in any pseudo-progressive
+    display...
+  ---------------------------------------------------------------------------*/
+
+    for (lastrow = row = 0;  row < image_height;  ++row) {
+        src = image_data + row*image_rowbytes;
+        dest = wimage_data + row*wimage_rowbytes;
+        if (image_channels == 3) {
+            for (i = image_width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dest++ = b;
+                *dest++ = g;   /* note reverse order */
+                *dest++ = r;
+            }
+        } else /* if (image_channels == 4) */ {
+            for (i = image_width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                a = *src++;
+                if (a == 255) {
+                    *dest++ = b;
+                    *dest++ = g;
+                    *dest++ = r;
+                } else if (a == 0) {
+                    *dest++ = bg_blue;
+                    *dest++ = bg_green;
+                    *dest++ = bg_red;
+                } else {
+                    /* this macro (copied from png.h) composites the
+                     * foreground and background values and puts the
+                     * result into the first argument; there are no
+                     * side effects with the first argument */
+                    alpha_composite(*dest++, b, a, bg_blue);
+                    alpha_composite(*dest++, g, a, bg_green);
+                    alpha_composite(*dest++, r, a, bg_red);
+                }
+            }
+        }
+        /* display after every 16 lines */
+        if (((row+1) & 0xf) == 0) {
+            rect.left = 0L;
+            rect.top = (LONG)lastrow;
+            rect.right = (LONG)image_width;      /* possibly off by one? */
+            rect.bottom = (LONG)lastrow + 16L;   /* possibly off by one? */
+            InvalidateRect(global_hwnd, &rect, FALSE);
+            UpdateWindow(global_hwnd);     /* similar to XFlush() */
+            lastrow = row + 1;
+        }
+    }
+
+    Trace((stderr, "calling final image-flush routine\n"))
+    if (lastrow < image_height) {
+        rect.left = 0L;
+        rect.top = (LONG)lastrow;
+        rect.right = (LONG)image_width;      /* possibly off by one? */
+        rect.bottom = (LONG)image_height;    /* possibly off by one? */
+        InvalidateRect(global_hwnd, &rect, FALSE);
+        UpdateWindow(global_hwnd);     /* similar to XFlush() */
+    }
+
+/*
+    last param determines whether or not background is wiped before paint
+    InvalidateRect(global_hwnd, NULL, TRUE);
+    UpdateWindow(global_hwnd);
+ */
+
+    return 0;
+}
+
+
+
+
+
+static void rpng_win_cleanup()
+{
+    if (image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+
+    if (dib) {
+        free(dib);
+        dib = NULL;
+    }
+}
+
+
+
+
+
+LRESULT CALLBACK rpng_win_wndproc(HWND hwnd, UINT iMsg, WPARAM wP, LPARAM lP)
+{
+    HDC         hdc;
+    PAINTSTRUCT ps;
+    int rc;
+
+    switch (iMsg) {
+        case WM_CREATE:
+            /* one-time processing here, if any */
+            return 0;
+
+        case WM_PAINT:
+            hdc = BeginPaint(hwnd, &ps);
+                    /*                    dest                          */
+            rc = StretchDIBits(hdc, 0, 0, image_width, image_height,
+                    /*                    source                        */
+                                    0, 0, image_width, image_height,
+                                    wimage_data, (BITMAPINFO *)bmih,
+                    /*              iUsage: no clue                     */
+                                    0, SRCCOPY);
+            EndPaint(hwnd, &ps);
+            return 0;
+
+        /* wait for the user to tell us when to quit */
+        case WM_CHAR:
+            switch (wP) {      /* only need one, so ignore repeat count */
+                case 'q':
+                case 'Q':
+                case 0x1B:     /* Esc key */
+                    PostQuitMessage(0);
+            }
+            return 0;
+
+        case WM_LBUTTONDOWN:   /* another way of quitting */
+        case WM_DESTROY:
+            PostQuitMessage(0);
+            return 0;
+    }
+
+    return DefWindowProc(hwnd, iMsg, wP, lP);
+}

contrib/gregbook/rpng-x.c

@@ -0,0 +1,843 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                               rpng-x.c
+
+   This program decodes and displays PNG images, with gamma correction and
+   optionally with a user-specified background color (in case the image has
+   transparency).  It is very nearly the most basic PNG viewer possible.
+   This version is for the X Window System (tested by author under Unix and
+   by Martin Zinser under OpenVMS; may work under OS/2 with some tweaking).
+
+   to do:
+    - 8-bit support
+    - use %.1023s to simplify truncation of title-bar string?
+
+  ---------------------------------------------------------------------------
+
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  modified to allow abbreviated options; fixed long/ulong mis-
+              match; switched to png_jmpbuf() macro
+    - 1.10:  added support for non-default visuals; fixed X pixel-conversion
+    - 1.11:  added extra set of parentheses to png_jmpbuf() macro; fixed
+              command-line parsing bug
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#define PROGNAME  "rpng-x"
+#define LONGNAME  "Simple PNG Viewer for X"
+#define VERSION   "1.11 of 19 March 2000"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xos.h>
+#include <X11/keysym.h>
+
+/* #define DEBUG  :  this enables the Trace() macros */
+
+#include "readpng.h"   /* typedefs, common macros, readpng prototypes */
+
+
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+
+
+/* local prototypes */
+static int  rpng_x_create_window(void);
+static int  rpng_x_display_image(void);
+static void rpng_x_cleanup(void);
+static int  rpng_x_msb(ulg u32val);
+
+
+static char titlebar[1024], *window_name = titlebar;
+static char *appname = LONGNAME;
+static char *icon_name = PROGNAME;
+static char *filename;
+static FILE *infile;
+
+static char *bgstr;
+static uch bg_red=0, bg_green=0, bg_blue=0;
+
+static double display_exponent;
+
+static ulg image_width, image_height, image_rowbytes;
+static int image_channels;
+static uch *image_data;
+
+/* X-specific variables */
+static char *displayname;
+static XImage *ximage;
+static Display *display;
+static int depth;
+static Visual *visual;
+static XVisualInfo *visual_list;
+static int RShift, GShift, BShift;
+static ulg RMask, GMask, BMask;
+static Window window;
+static GC gc;
+static Colormap colormap;
+
+static int have_nondefault_visual = FALSE;
+static int have_colormap = FALSE;
+static int have_window = FALSE;
+/*
+ulg numcolors=0, pixels[256];
+ush reds[256], greens[256], blues[256];
+ */
+
+
+
+
+int main(int argc, char **argv)
+{
+#ifdef sgi
+    char tmpline[80];
+#endif
+    char *p;
+    int rc, alen, flen;
+    int error = 0;
+    int have_bg = FALSE;
+    double LUT_exponent;               /* just the lookup table */
+    double CRT_exponent = 2.2;         /* just the monitor */
+    double default_display_exponent;   /* whole display system */
+    XEvent e;
+    KeySym k;
+
+
+    displayname = (char *)NULL;
+    filename = (char *)NULL;
+
+
+    /* First set the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities. */
+
+#if defined(NeXT)
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to get the
+     * "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+
+
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        display_exponent = atof(p);
+    else
+        display_exponent = default_display_exponent;
+
+
+    /* Now parse the command line for options and the PNG filename. */
+
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-display", 2)) {
+            if (!*++argv)
+                ++error;
+            else
+                displayname = *argv;
+        } else if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                display_exponent = atof(*argv);
+                if (display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error; 
+                else 
+                    have_bg = TRUE;
+            }
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+
+    if (!filename) {
+        ++error;
+    } else if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
+            switch (rc) {
+                case 1:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] is not a PNG file: incorrect signature\n",
+                      filename);
+                    break;
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n",
+                      filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng_init() error\n");
+                    break;
+            }
+            ++error;
+        } else {
+            display = XOpenDisplay(displayname);
+            if (!display) {
+                readpng_cleanup(TRUE);
+                fprintf(stderr, PROGNAME ":  can't open X display [%s]\n",
+                  displayname? displayname : "default");
+                ++error;
+            }
+        }
+        if (error)
+            fclose(infile);
+    }
+
+
+    /* usage screen */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
+          "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
+          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+          "\t\t  to the product of the lookup-table exponent (varies)\n"
+          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+          "    bg  \tdesired background color in 7-character hex RGB format\n"
+          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+          "\t\t  used with transparent images\n"
+          "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
+          "is displayed) to quit.\n"
+          "\n", PROGNAME, default_display_exponent);
+        exit(1);
+    }
+
+
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+
+
+    /* if the user didn't specify a background color on the command line,
+     * check for one in the PNG file--if not, the initialized values of 0
+     * (black) will be used */
+
+    if (have_bg) {
+        unsigned r, g, b;   /* this approach quiets compiler warnings */
+
+        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+        bg_red   = (uch)r;
+        bg_green = (uch)g;
+        bg_blue  = (uch)b;
+    } else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
+        readpng_cleanup(TRUE);
+        fprintf(stderr, PROGNAME
+          ":  libpng error while checking for background color\n");
+        exit(2);
+    }
+
+
+    /* do the basic X initialization stuff, make the window and fill it
+     * with the background color */
+
+    if (rpng_x_create_window())
+        exit(2);
+
+
+    /* decode the image, all at once */
+
+    Trace((stderr, "calling readpng_get_image()\n"))
+    image_data = readpng_get_image(display_exponent, &image_channels,
+      &image_rowbytes);
+    Trace((stderr, "done with readpng_get_image()\n"))
+
+
+    /* done with PNG file, so clean up to minimize memory usage (but do NOT
+     * nuke image_data!) */
+
+    readpng_cleanup(FALSE);
+    fclose(infile);
+
+    if (!image_data) {
+        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
+        exit(3);
+    }
+
+
+    /* display image (composite with background if requested) */
+
+    Trace((stderr, "calling rpng_x_display_image()\n"))
+    if (rpng_x_display_image()) {
+        free(image_data);
+        exit(4);
+    }
+    Trace((stderr, "done with rpng_x_display_image()\n"))
+
+
+    /* wait for the user to tell us when to quit */
+
+    printf(
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+    fflush(stdout);
+
+    do
+        XNextEvent(display, &e);
+    while (!(e.type == ButtonPress && e.xbutton.button == Button1) &&
+           !(e.type == KeyPress &&    /*  v--- or 1 for shifted keys */
+             ((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape) ));
+
+
+    /* OK, we're done:  clean up all image and X resources and go away */
+
+    rpng_x_cleanup();
+
+    return 0;
+}
+
+
+
+
+
+static int rpng_x_create_window(void)
+{
+    uch *xdata;
+    int need_colormap = FALSE;
+    int screen, pad;
+    ulg bg_pixel = 0L;
+    ulg attrmask;
+    Window root;
+    XEvent e;
+    XGCValues gcvalues;
+    XSetWindowAttributes attr;
+    XSizeHints *size_hints;
+    XTextProperty windowName, *pWindowName = &windowName;
+    XTextProperty iconName, *pIconName = &iconName;
+    XVisualInfo visual_info;
+    XWMHints *wm_hints;
+
+
+    screen = DefaultScreen(display);
+    depth = DisplayPlanes(display, screen);
+    root = RootWindow(display, screen);
+
+#ifdef DEBUG
+    XSynchronize(display, True);
+#endif
+
+#if 0
+/* GRR:  add 8-bit support */
+    if (/* depth != 8 && */ depth != 16 && depth != 24 && depth != 32) {
+        fprintf(stderr,
+          "screen depth %d not supported (only 16-, 24- or 32-bit TrueColor)\n",
+          depth);
+        return 2;
+    }
+
+    XMatchVisualInfo(display, screen, depth,
+      (depth == 8)? PseudoColor : TrueColor, &visual_info);
+    visual = visual_info.visual;
+#else
+    if (depth != 16 && depth != 24 && depth != 32) {
+        int visuals_matched = 0;
+
+        Trace((stderr, "default depth is %d:  checking other visuals\n",
+          depth))
+
+        /* 24-bit first */
+        visual_info.screen = screen;
+        visual_info.depth = 24;
+        visual_list = XGetVisualInfo(display,
+          VisualScreenMask | VisualDepthMask, &visual_info, &visuals_matched);
+        if (visuals_matched == 0) {
+/* GRR:  add 15-, 16- and 32-bit TrueColor visuals (also DirectColor?) */
+            fprintf(stderr, "default screen depth %d not supported, and no"
+              " 24-bit visuals found\n", depth);
+            return 2;
+        }
+        Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
+          visuals_matched))
+        visual = visual_list[0].visual;
+        depth = visual_list[0].depth;
+/*
+        colormap_size = visual_list[0].colormap_size;
+        visual_class = visual->class;
+        visualID = XVisualIDFromVisual(visual);
+ */
+        have_nondefault_visual = TRUE;
+        need_colormap = TRUE;
+    } else {
+        XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
+        visual = visual_info.visual;
+    }
+#endif
+
+    RMask = visual->red_mask;
+    GMask = visual->green_mask;
+    BMask = visual->blue_mask;
+
+/* GRR:  add/check 8-bit support */
+    if (depth == 8 || need_colormap) {
+        colormap = XCreateColormap(display, root, visual, AllocNone);
+        if (!colormap) {
+            fprintf(stderr, "XCreateColormap() failed\n");
+            return 2;
+        }
+        have_colormap = TRUE;
+    }
+    if (depth == 15 || depth == 16) {
+        RShift = 15 - rpng_x_msb(RMask);    /* these are right-shifts */
+        GShift = 15 - rpng_x_msb(GMask);
+        BShift = 15 - rpng_x_msb(BMask);
+    } else if (depth > 16) {
+#define NO_24BIT_MASKS
+#ifdef NO_24BIT_MASKS
+        RShift = rpng_x_msb(RMask) - 7;     /* these are left-shifts */
+        GShift = rpng_x_msb(GMask) - 7;
+        BShift = rpng_x_msb(BMask) - 7;
+#else
+        RShift = 7 - rpng_x_msb(RMask);     /* these are right-shifts, too */
+        GShift = 7 - rpng_x_msb(GMask);
+        BShift = 7 - rpng_x_msb(BMask);
+#endif
+    }
+    if (depth >= 15 && (RShift < 0 || GShift < 0 || BShift < 0)) {
+        fprintf(stderr, "rpng internal logic error:  negative X shift(s)!\n");
+        return 2;
+    }
+
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+
+    attr.backing_store = Always;
+    attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask;
+    attrmask = CWBackingStore | CWEventMask;
+    if (have_nondefault_visual) {
+        attr.colormap = colormap;
+        attr.background_pixel = 0;
+        attr.border_pixel = 1;
+        attrmask |= CWColormap | CWBackPixel | CWBorderPixel;
+    }
+
+    window = XCreateWindow(display, root, 0, 0, image_width, image_height, 0,
+      depth, InputOutput, visual, attrmask, &attr);
+
+    if (window == None) {
+        fprintf(stderr, "XCreateWindow() failed\n");
+        return 2;
+    } else
+        have_window = TRUE;
+
+    if (depth == 8)
+        XSetWindowColormap(display, window, colormap);
+
+    if (!XStringListToTextProperty(&window_name, 1, pWindowName))
+        pWindowName = NULL;
+    if (!XStringListToTextProperty(&icon_name, 1, pIconName))
+        pIconName = NULL;
+
+    /* OK if either hints allocation fails; XSetWMProperties() allows NULLs */
+
+    if ((size_hints = XAllocSizeHints()) != NULL) {
+        /* window will not be resizable */
+        size_hints->flags = PMinSize | PMaxSize;
+        size_hints->min_width = size_hints->max_width = (int)image_width;
+        size_hints->min_height = size_hints->max_height = (int)image_height;
+    }
+
+    if ((wm_hints = XAllocWMHints()) != NULL) {
+        wm_hints->initial_state = NormalState;
+        wm_hints->input = True;
+     /* wm_hints->icon_pixmap = icon_pixmap; */
+        wm_hints->flags = StateHint | InputHint  /* | IconPixmapHint */ ;
+    }
+
+    XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
+      size_hints, wm_hints, NULL);
+
+    XMapWindow(display, window);
+
+    gc = XCreateGC(display, window, 0, &gcvalues);
+
+/*---------------------------------------------------------------------------
+    Fill window with the specified background color.
+  ---------------------------------------------------------------------------*/
+
+    if (depth == 24 || depth == 32) {
+        bg_pixel = ((ulg)bg_red   << RShift) |
+                   ((ulg)bg_green << GShift) |
+                   ((ulg)bg_blue  << BShift);
+    } else if (depth == 16) {
+        bg_pixel = ((((ulg)bg_red   << 8) >> RShift) & RMask) |
+                   ((((ulg)bg_green << 8) >> GShift) & GMask) |
+                   ((((ulg)bg_blue  << 8) >> BShift) & BMask);
+    } else /* depth == 8 */ {
+
+        /* GRR:  add 8-bit support */
+
+    }
+
+    XSetForeground(display, gc, bg_pixel);
+    XFillRectangle(display, window, gc, 0, 0, image_width, image_height);
+
+/*---------------------------------------------------------------------------
+    Wait for first Expose event to do any drawing, then flush.
+  ---------------------------------------------------------------------------*/
+
+    do
+        XNextEvent(display, &e);
+    while (e.type != Expose || e.xexpose.count);
+
+    XFlush(display);
+
+/*---------------------------------------------------------------------------
+    Allocate memory for the X- and display-specific version of the image.
+  ---------------------------------------------------------------------------*/
+
+    if (depth == 24 || depth == 32) {
+        xdata = (uch *)malloc(4*image_width*image_height);
+        pad = 32;
+    } else if (depth == 16) {
+        xdata = (uch *)malloc(2*image_width*image_height);
+        pad = 16;
+    } else /* depth == 8 */ {
+        xdata = (uch *)malloc(image_width*image_height);
+        pad = 8;
+    }
+
+    if (!xdata) {
+        fprintf(stderr, PROGNAME ":  unable to allocate image memory\n");
+        return 4;
+    }
+
+    ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
+      (char *)xdata, image_width, image_height, pad, 0);
+
+    if (!ximage) {
+        fprintf(stderr, PROGNAME ":  XCreateImage() failed\n");
+        free(xdata);
+        return 3;
+    }
+
+    /* to avoid testing the byte order every pixel (or doubling the size of
+     * the drawing routine with a giant if-test), we arbitrarily set the byte
+     * order to MSBFirst and let Xlib worry about inverting things on little-
+     * endian machines (like Linux/x86, old VAXen, etc.)--this is not the most
+     * efficient approach (the giant if-test would be better), but in the
+     * interest of clarity, we take the easy way out... */
+
+    ximage->byte_order = MSBFirst;
+
+    return 0;
+
+} /* end function rpng_x_create_window() */
+
+
+
+
+
+static int rpng_x_display_image(void)
+{
+    uch *src;
+    char *dest;
+    uch r, g, b, a;
+    ulg i, row, lastrow = 0;
+    ulg pixel;
+    int ximage_rowbytes = ximage->bytes_per_line;
+/*  int bpp = ximage->bits_per_pixel;  */
+
+
+    Trace((stderr, "beginning display loop (image_channels == %d)\n",
+      image_channels))
+    Trace((stderr, "   (width = %ld, rowbytes = %ld, ximage_rowbytes = %d)\n",
+      image_width, image_rowbytes, ximage_rowbytes))
+    Trace((stderr, "   (bpp = %d)\n", ximage->bits_per_pixel))
+    Trace((stderr, "   (byte_order = %s)\n", ximage->byte_order == MSBFirst?
+      "MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
+
+    if (depth == 24 || depth == 32) {
+        ulg red, green, blue;
+
+        for (lastrow = row = 0;  row < image_height;  ++row) {
+            src = image_data + row*image_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (image_channels == 3) {
+                for (i = image_width;  i > 0;  --i) {
+                    red   = *src++;
+                    green = *src++;
+                    blue  = *src++;
+#ifdef NO_24BIT_MASKS
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    /* GRR BUG:  this assumes bpp == 32, but may be 24: */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+#else
+                    red   = (RShift < 0)? red   << (-RShift) : red   >> RShift;
+                    green = (GShift < 0)? green << (-GShift) : green >> GShift;
+                    blue  = (BShift < 0)? blue  << (-BShift) : blue  >> BShift;
+                    pixel = (red & RMask) | (green & GMask) | (blue & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+#endif
+                }
+            } else /* if (image_channels == 4) */ {
+                for (i = image_width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (a == 255) {
+                        red   = r;
+                        green = g;
+                        blue  = b;
+                    } else if (a == 0) {
+                        red   = bg_red;
+                        green = bg_green;
+                        blue  = bg_blue;
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result into the
+                         * first argument */
+                        alpha_composite(red,   r, a, bg_red);
+                        alpha_composite(green, g, a, bg_green);
+                        alpha_composite(blue,  b, a, bg_blue);
+                    }
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, image_width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+
+    } else if (depth == 16) {
+        ush red, green, blue;
+
+        for (lastrow = row = 0;  row < image_height;  ++row) {
+            src = image_data + row*image_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (image_channels == 3) {
+                for (i = image_width;  i > 0;  --i) {
+                    red   = ((ush)(*src) << 8);
+                    ++src;
+                    green = ((ush)(*src) << 8);
+                    ++src;
+                    blue  = ((ush)(*src) << 8);
+                    ++src;
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            } else /* if (image_channels == 4) */ {
+                for (i = image_width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (a == 255) {
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    } else if (a == 0) {
+                        red   = ((ush)bg_red   << 8);
+                        green = ((ush)bg_green << 8);
+                        blue  = ((ush)bg_blue  << 8);
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result back into
+                         * the first argument (== fg byte here:  safe) */
+                        alpha_composite(r, r, a, bg_red);
+                        alpha_composite(g, g, a, bg_green);
+                        alpha_composite(b, b, a, bg_blue);
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    }
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, image_width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+
+    } else /* depth == 8 */ {
+
+        /* GRR:  add 8-bit support */
+
+    }
+
+    Trace((stderr, "calling final XPutImage()\n"))
+    if (lastrow < image_height) {
+        XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+          (int)lastrow, image_width, image_height-lastrow);
+        XFlush(display);
+    }
+
+    return 0;
+}
+
+
+
+
+static void rpng_x_cleanup(void)
+{
+    if (image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+
+    if (ximage) {
+        if (ximage->data) {
+            free(ximage->data);           /* we allocated it, so we free it */
+            ximage->data = (char *)NULL;  /*  instead of XDestroyImage() */
+        }
+        XDestroyImage(ximage);
+        ximage = NULL;
+    }
+
+    XFreeGC(display, gc);
+
+    if (have_window)
+        XDestroyWindow(display, window);
+
+    if (have_colormap)
+        XFreeColormap(display, colormap);
+
+    if (have_nondefault_visual)
+        XFree(visual_list);
+}
+
+
+
+
+
+static int rpng_x_msb(ulg u32val)
+{
+    int i;
+
+    for (i = 31;  i >= 0;  --i) {
+        if (u32val & 0x80000000L)
+            break;
+        u32val <<= 1;
+    }
+    return i;
+}

contrib/gregbook/wpng.c

@@ -0,0 +1,816 @@
+/*---------------------------------------------------------------------------
+
+   wpng - simple PNG-writing program                                 wpng.c
+
+   This program converts certain NetPBM binary files (grayscale and RGB,
+   maxval = 255) to PNG.  Non-interlaced PNGs are written progressively;
+   interlaced PNGs are read and written in one memory-intensive blast.
+   Thanks to Jean-loup Gailly for providing the necessary trick to read
+   interactive text from the keyboard while stdin is redirected.
+
+   NOTE:  includes provisional support for PNM type "8" (portable alphamap)
+          images, presumed to be a 32-bit interleaved RGBA format; no pro-
+          vision for possible interleaved grayscale+alpha (16-bit) format.
+          THIS IS UNLIKELY TO BECOME AN OFFICIAL NETPBM ALPHA FORMAT!
+
+   to do:
+    - delete output file if quit before calling any writepng routines
+    - process backspace with -text option under DOS/Win? (currently get ^H)
+
+  ---------------------------------------------------------------------------
+
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  modified to allow abbreviated options
+    - 1.03:  removed extraneous character from usage screen; fixed bug in
+              command-line parsing
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#define PROGNAME  "wpng"
+#define VERSION   "1.03 of 19 March 2000"
+#define APPNAME   "Simple PGM/PPM/PAM to PNG Converter"
+
+#if defined(__MSDOS__) || defined(__OS2__)
+#  define DOS_OS2_W32
+#elif defined(_WIN32) || defined(__WIN32__)
+#  define DOS_OS2_W32
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <setjmp.h>     /* for jmpbuf declaration in writepng.h */
+#include <time.h>
+
+#ifdef DOS_OS2_W32
+#  include <io.h>       /* for isatty(), setmode() prototypes */
+#  include <fcntl.h>    /* O_BINARY for fdopen() without text translation */
+#  ifdef __EMX__
+#    ifndef getch
+#      define getch() _read_kbd(0, 1, 0)    /* need getche() */
+#    endif
+#  else /* !__EMX__ */
+#    ifdef __GO32__
+#      include <pc.h>
+#      define getch() getkey()  /* GRR:  need getche() */
+#    else
+#      include <conio.h>        /* for getche() console input */
+#    endif
+#  endif /* ?__EMX__ */
+#  define FGETS(buf,len,stream)  dos_kbd_gets(buf,len)
+#else
+#  include <unistd.h>           /* for isatty() prototype */
+#  define FGETS fgets
+#endif
+
+/* #define DEBUG  :  this enables the Trace() macros */
+
+/* #define FORBID_LATIN1_CTRL  :  this requires the user to re-enter any
+   text that includes control characters discouraged by the PNG spec; text
+   that includes an escape character (27) must be re-entered regardless */
+
+#include "writepng.h"   /* typedefs, common macros, writepng prototypes */
+
+
+
+/* local prototypes */
+
+static int  wpng_isvalid_latin1(uch *p, int len);
+static void wpng_cleanup(void);
+
+#ifdef DOS_OS2_W32
+   static char *dos_kbd_gets(char *buf, int len);
+#endif
+
+
+
+static mainprog_info wpng_info;   /* lone global */
+
+
+
+int main(int argc, char **argv)
+{
+#ifndef DOS_OS2_W32
+    FILE *keybd;
+#endif
+#ifdef sgi
+    FILE *tmpfile;      /* or we could just use keybd, since no overlap */
+    char tmpline[80];
+#endif
+    char *inname = NULL, outname[256];
+    char *p, pnmchar, pnmline[256];
+    char *bgstr, *textbuf = NULL;
+    ulg rowbytes;
+    int rc, len = 0;
+    int error = 0;
+    int text = FALSE;
+    int maxval;
+    double LUT_exponent;                /* just the lookup table */
+    double CRT_exponent = 2.2;          /* just the monitor */
+    double default_display_exponent;    /* whole display system */
+    double default_gamma = 0.0;
+
+
+    wpng_info.infile = NULL;
+    wpng_info.outfile = NULL;
+    wpng_info.image_data = NULL;
+    wpng_info.row_pointers = NULL;
+    wpng_info.filter = FALSE;
+    wpng_info.interlaced = FALSE;
+    wpng_info.have_bg = FALSE;
+    wpng_info.have_time = FALSE;
+    wpng_info.have_text = 0;
+    wpng_info.gamma = 0.0;
+
+
+    /* First get the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  If the PNM image
+     * looks correct on the user's display system, its file gamma is the
+     * inverse of this value.  (Note that this is not an exhaustive list
+     * of LUT values--e.g., OpenStep has a lot of weird ones--but it should
+     * cover 99% of the current possibilities.  This section must ensure
+     * that default_display_exponent is positive.) */
+
+#if defined(NeXT)
+    /* third-party utilities can modify the default LUT exponent */
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to
+     * get the "gamma" value, so we do it the hard way */
+    tmpfile = fopen("/etc/config/system.glGammaVal", "r");
+    if (tmpfile) {
+        double sgi_gamma;
+
+        fgets(tmpline, 80, tmpfile);
+        fclose(tmpfile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+
+
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+
+    if ((p = getenv("SCREEN_GAMMA")) != NULL) {
+        double exponent = atof(p);
+
+        if (exponent > 0.0)
+            default_gamma = 1.0 / exponent;
+    }
+
+    if (default_gamma == 0.0)
+        default_gamma = 1.0 / default_display_exponent;
+
+
+    /* Now parse the command line for options and the PNM filename. */
+
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-i", 2)) {
+            wpng_info.interlaced = TRUE;
+        } else if (!strncmp(*argv, "-time", 3)) {
+            wpng_info.modtime = time(NULL);
+            wpng_info.have_time = TRUE;
+        } else if (!strncmp(*argv, "-text", 3)) {
+            text = TRUE;
+        } else if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                wpng_info.gamma = atof(*argv);
+                if (wpng_info.gamma <= 0.0)
+                    ++error;
+                else if (wpng_info.gamma > 1.01)
+                    fprintf(stderr, PROGNAME
+                      " warning:  file gammas are usually less than 1.0\n");
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 4)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else {
+                    unsigned r, g, b;  /* this way quiets compiler warnings */
+
+                    sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+                    wpng_info.bg_red   = (uch)r;
+                    wpng_info.bg_green = (uch)g;
+                    wpng_info.bg_blue  = (uch)b;
+                    wpng_info.have_bg = TRUE;
+                }
+            }
+        } else {
+            if (**argv != '-') {
+                inname = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+
+
+    /* open the input and output files, or register an error and abort */
+
+    if (!inname) {
+        if (isatty(0)) {
+            fprintf(stderr, PROGNAME
+              ":  must give input filename or provide image data via stdin\n");
+            ++error;
+        } else {
+#ifdef DOS_OS2_W32
+            /* some buggy C libraries require BOTH setmode() and fdopen(bin) */
+            setmode(fileno(stdin), O_BINARY);
+            setmode(fileno(stdout), O_BINARY);
+#endif
+            if ((wpng_info.infile = fdopen(fileno(stdin), "rb")) == NULL) {
+                fprintf(stderr, PROGNAME
+                  ":  unable to reopen stdin in binary mode\n");
+                ++error;
+            } else
+            if ((wpng_info.outfile = fdopen(fileno(stdout), "wb")) == NULL) {
+                fprintf(stderr, PROGNAME
+                  ":  unable to reopen stdout in binary mode\n");
+                fclose(wpng_info.infile);
+                ++error;
+            } else
+                wpng_info.filter = TRUE;
+        }
+    } else if ((len = strlen(inname)) > 250) {
+        fprintf(stderr, PROGNAME ":  input filename is too long [%d chars]\n",
+          len);
+        ++error;
+    } else if (!(wpng_info.infile = fopen(inname, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open input file [%s]\n", inname);
+        ++error;
+    }
+
+    if (!error) {
+        fgets(pnmline, 256, wpng_info.infile);
+        if (pnmline[0] != 'P' || ((pnmchar = pnmline[1]) != '5' &&
+            pnmchar != '6' && pnmchar != '8'))
+        {
+            fprintf(stderr, PROGNAME
+              ":  input file [%s] is not a binary PGM, PPM or PAM file\n",
+              inname);
+            ++error;
+        } else {
+            wpng_info.pnmtype = (int)(pnmchar - '0');
+            if (wpng_info.pnmtype != 8)
+                wpng_info.have_bg = FALSE;  /* no need for bg if opaque */
+            do {
+                fgets(pnmline, 256, wpng_info.infile);  /* lose any comments */
+            } while (pnmline[0] == '#');
+            sscanf(pnmline, "%ld %ld", &wpng_info.width, &wpng_info.height);
+            do {
+                fgets(pnmline, 256, wpng_info.infile);  /* more comment lines */
+            } while (pnmline[0] == '#');
+            sscanf(pnmline, "%d", &maxval);
+            if (wpng_info.width <= 0L || wpng_info.height <= 0L ||
+                maxval != 255)
+            {
+                fprintf(stderr, PROGNAME
+                  ":  only positive width/height, maxval == 255 allowed \n");
+                ++error;
+            }
+            wpng_info.sample_depth = 8;  /* <==> maxval 255 */
+
+            if (!wpng_info.filter) {
+                /* make outname from inname */
+                if ((p = strrchr(inname, '.')) == NULL ||
+                    (p - inname) != (len - 4))
+                {
+                    strcpy(outname, inname);
+                    strcpy(outname+len, ".png");
+                } else {
+                    len -= 4;
+                    strncpy(outname, inname, len);
+                    strcpy(outname+len, ".png");
+                }
+                /* check if outname already exists; if not, open */
+                if ((wpng_info.outfile = fopen(outname, "rb")) != NULL) {
+                    fprintf(stderr, PROGNAME ":  output file exists [%s]\n",
+                      outname);
+                    fclose(wpng_info.outfile);
+                    ++error;
+                } else if (!(wpng_info.outfile = fopen(outname, "wb"))) {
+                    fprintf(stderr, PROGNAME ":  can't open output file [%s]\n",
+                      outname);
+                    ++error;
+                }
+            }
+        }
+        if (error) {
+            fclose(wpng_info.infile);
+            wpng_info.infile = NULL;
+            if (wpng_info.filter) {
+                fclose(wpng_info.outfile);
+                wpng_info.outfile = NULL;
+            }
+        }
+    }
+
+
+    /* if we had any errors, print usage and die horrible death...arrr! */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, APPNAME);
+        writepng_version_info();
+        fprintf(stderr, "\n"
+"Usage:  %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] pnmfile\n"
+"or: ... | %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] | ...\n"
+         "    exp \ttransfer-function exponent (``gamma'') of the image in\n"
+         "\t\t  floating-point format (e.g., ``%.5f''); if image looks\n"
+         "\t\t  correct on given display system, image gamma is equal to\n"
+         "\t\t  inverse of display-system exponent, i.e., 1 / (LUT * CRT)\n"
+         "\t\t  (where LUT = lookup-table exponent and CRT = CRT exponent;\n"
+         "\t\t  first varies, second is usually 2.2, all are positive)\n"
+         "    bg  \tdesired background color for alpha-channel images, in\n"
+         "\t\t  7-character hex RGB format (e.g., ``#ff7700'' for orange:\n"
+         "\t\t  same as HTML colors)\n"
+         "    -text\tprompt interactively for text info (tEXt chunks)\n"
+         "    -time\tinclude a tIME chunk (last modification time)\n"
+         "    -interlace\twrite interlaced PNG image\n"
+         "\n"
+"pnmfile or stdin must be a binary PGM (`P5'), PPM (`P6') or (extremely\n"
+"unofficial and unsupported!) PAM (`P8') file.  Currently it is required\n"
+"to have maxval == 255 (i.e., no scaling).  If pnmfile is specified, it\n"
+"is converted to the corresponding PNG file with the same base name but a\n"
+"``.png'' extension; files read from stdin are converted and sent to stdout.\n"
+"The conversion is progressive (low memory usage) unless interlacing is\n"
+"requested; in that case the whole image will be buffered in memory and\n"
+"written in one call.\n"
+         "\n", PROGNAME, PROGNAME, default_gamma);
+        exit(1);
+    }
+
+
+    /* prepare the text buffers for libpng's use; note that even though
+     * PNG's png_text struct includes a length field, we don't have to fill
+     * it out */
+
+    if (text &&
+#ifndef DOS_OS2_W32
+        (keybd = fdopen(fileno(stderr), "r")) != NULL &&
+#endif
+        (textbuf = (char *)malloc((5 + 9)*75)) != NULL)
+    {
+        int i, valid, result;
+
+        fprintf(stderr,
+          "Enter text info (no more than 72 characters per line);\n");
+        fprintf(stderr, "to skip a field, hit the <Enter> key.\n");
+        /* note:  just <Enter> leaves len == 1 */
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_TITLE_OFFSET;
+            fprintf(stderr, "  Title: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.title = p;
+                wpng_info.have_text |= TEXT_TITLE;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_TITLE;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_TITLE;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_AUTHOR_OFFSET;
+            fprintf(stderr, "  Author: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.author = p;
+                wpng_info.have_text |= TEXT_AUTHOR;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_AUTHOR;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_AUTHOR;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_DESC_OFFSET;
+            fprintf(stderr, "  Description (up to 9 lines):\n");
+            for (i = 1;  i < 10;  ++i) {
+                fprintf(stderr, "    [%d] ", i);
+                fflush(stderr);
+                if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1)
+                    p += len;   /* now points at NULL; char before is newline */
+                else
+                    break;
+            }
+            if ((len = p - (textbuf + TEXT_DESC_OFFSET)) > 1) {
+                if (p[-1] == '\n') {
+                    p[-1] = '\0';
+                    --len;
+                }
+                wpng_info.desc = textbuf + TEXT_DESC_OFFSET;
+                wpng_info.have_text |= TEXT_DESC;
+                p = textbuf + TEXT_DESC_OFFSET;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_DESC;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_DESC;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_COPY_OFFSET;
+            fprintf(stderr, "  Copyright: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.copyright = p;
+                wpng_info.have_text |= TEXT_COPY;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_COPY;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_COPY;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_EMAIL_OFFSET;
+            fprintf(stderr, "  E-mail: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.email = p;
+                wpng_info.have_text |= TEXT_EMAIL;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_EMAIL;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_EMAIL;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_URL_OFFSET;
+            fprintf(stderr, "  URL: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.url = p;
+                wpng_info.have_text |= TEXT_URL;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_URL;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_URL;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+#ifndef DOS_OS2_W32
+        fclose(keybd);
+#endif
+
+    } else if (text) {
+        fprintf(stderr, PROGNAME ":  unable to allocate memory for text\n");
+        text = FALSE;
+        wpng_info.have_text = 0;
+    }
+
+
+    /* allocate libpng stuff, initialize transformations, write pre-IDAT data */
+
+    if ((rc = writepng_init(&wpng_info)) != 0) {
+        switch (rc) {
+            case 2:
+                fprintf(stderr, PROGNAME
+                  ":  libpng initialization problem (longjmp)\n");
+                break;
+            case 4:
+                fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                break;
+            case 11:
+                fprintf(stderr, PROGNAME
+                  ":  internal logic error (unexpected PNM type)\n");
+                break;
+            default:
+                fprintf(stderr, PROGNAME
+                  ":  unknown writepng_init() error\n");
+                break;
+        }
+        exit(rc);
+    }
+
+
+    /* free textbuf, since it's a completely local variable and all text info
+     * has just been written to the PNG file */
+
+    if (text && textbuf) {
+        free(textbuf);
+        textbuf = NULL;
+    }
+
+
+    /* calculate rowbytes on basis of image type; note that this becomes much
+     * more complicated if we choose to support PBM type, ASCII PNM types, or
+     * 16-bit-per-sample binary data [currently not an official NetPBM type] */
+
+    if (wpng_info.pnmtype == 5)
+        rowbytes = wpng_info.width;
+    else if (wpng_info.pnmtype == 6)
+        rowbytes = wpng_info.width * 3;
+    else /* if (wpng_info.pnmtype == 8) */
+        rowbytes = wpng_info.width * 4;
+
+
+    /* read and write the image, either in its entirety (if writing interlaced
+     * PNG) or row by row (if non-interlaced) */
+
+    fprintf(stderr, "Encoding image data...\n");
+    fflush(stderr);
+
+    if (wpng_info.interlaced) {
+        long i;
+        ulg bytes;
+        ulg image_bytes = rowbytes * wpng_info.height;   /* overflow? */
+
+        wpng_info.image_data = (uch *)malloc(image_bytes);
+        wpng_info.row_pointers = (uch **)malloc(wpng_info.height*sizeof(uch *));
+        if (wpng_info.image_data == NULL || wpng_info.row_pointers == NULL) {
+            fprintf(stderr, PROGNAME ":  insufficient memory for image data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(5);
+        }
+        for (i = 0;  i < wpng_info.height;  ++i)
+            wpng_info.row_pointers[i] = wpng_info.image_data + i*rowbytes;
+        bytes = fread(wpng_info.image_data, 1, image_bytes, wpng_info.infile);
+        if (bytes != image_bytes) {
+            fprintf(stderr, PROGNAME ":  expected %lu bytes, got %lu bytes\n",
+              image_bytes, bytes);
+            fprintf(stderr, "  (continuing anyway)\n");
+        }
+        if (writepng_encode_image(&wpng_info) != 0) {
+            fprintf(stderr, PROGNAME
+              ":  libpng problem (longjmp) while writing image data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+
+    } else /* not interlaced:  write progressively (row by row) */ {
+        long j;
+        ulg bytes;
+
+        wpng_info.image_data = (uch *)malloc(rowbytes);
+        if (wpng_info.image_data == NULL) {
+            fprintf(stderr, PROGNAME ":  insufficient memory for row data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(5);
+        }
+        error = 0;
+        for (j = wpng_info.height;  j > 0L;  --j) {
+            bytes = fread(wpng_info.image_data, 1, rowbytes, wpng_info.infile);
+            if (bytes != rowbytes) {
+                fprintf(stderr, PROGNAME
+                  ":  expected %lu bytes, got %lu bytes (row %ld)\n", rowbytes,
+                  bytes, wpng_info.height-j);
+                ++error;
+                break;
+            }
+            if (writepng_encode_row(&wpng_info) != 0) {
+                fprintf(stderr, PROGNAME
+                  ":  libpng problem (longjmp) while writing row %ld\n",
+                  wpng_info.height-j);
+                ++error;
+                break;
+            }
+        }
+        if (error) {
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+        if (writepng_encode_finish(&wpng_info) != 0) {
+            fprintf(stderr, PROGNAME ":  error on final libpng call\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+    }
+
+
+    /* OK, we're done (successfully):  clean up all resources and quit */
+
+    fprintf(stderr, "Done.\n");
+    fflush(stderr);
+
+    writepng_cleanup(&wpng_info);
+    wpng_cleanup();
+
+    return 0;
+}
+
+
+
+
+
+static int wpng_isvalid_latin1(uch *p, int len)
+{
+    int i, result = -1;
+
+    for (i = 0;  i < len;  ++i) {
+        if (p[i] == 10 || (p[i] > 31 && p[i] < 127) || p[i] > 160)
+            continue;           /* character is completely OK */
+        if (result < 0 || (p[result] != 27 && p[i] == 27))
+            result = i;         /* mark location of first questionable one */
+    }                           /*  or of first escape character (bad) */
+
+    return result;
+}
+
+
+
+
+
+static void wpng_cleanup(void)
+{
+    if (wpng_info.outfile) {
+        fclose(wpng_info.outfile);
+        wpng_info.outfile = NULL;
+    }
+
+    if (wpng_info.infile) {
+        fclose(wpng_info.infile);
+        wpng_info.infile = NULL;
+    }
+
+    if (wpng_info.image_data) {
+        free(wpng_info.image_data);
+        wpng_info.image_data = NULL;
+    }
+
+    if (wpng_info.row_pointers) {
+        free(wpng_info.row_pointers);
+        wpng_info.row_pointers = NULL;
+    }
+}
+
+
+
+
+#ifdef DOS_OS2_W32
+
+static char *dos_kbd_gets(char *buf, int len)
+{
+    int ch, count=0;
+
+    do {
+        buf[count++] = ch = getche();
+    } while (ch != '\r' && count < len-1);
+
+    buf[count--] = '\0';        /* terminate string */
+    if (buf[count] == '\r')     /* Enter key makes CR, so change to newline */
+        buf[count] = '\n';
+
+    fprintf(stderr, "\n");      /* Enter key does *not* cause a newline */
+    fflush(stderr);
+
+    return buf;
+}
+
+#endif /* DOS_OS2_W32 */

contrib/gregbook/writepng.c

@@ -0,0 +1,368 @@
+/*---------------------------------------------------------------------------
+
+   wpng - simple PNG-writing program                             writepng.c
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+
+#include <stdlib.h>     /* for exit() prototype */
+
+#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
+#include "writepng.h"   /* typedefs, common macros, public prototypes */
+
+
+/* local prototype */
+
+static void writepng_error_handler(png_structp png_ptr, png_const_charp msg);
+
+
+
+void writepng_version_info(void)
+{
+  fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+    PNG_LIBPNG_VER_STRING, png_libpng_ver);
+  fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+    ZLIB_VERSION, zlib_version);
+}
+
+
+
+
+/* returns 0 for success, 2 for libpng problem, 4 for out of memory, 11 for
+ *  unexpected pnmtype; note that outfile might be stdout */
+
+int writepng_init(mainprog_info *mainprog_ptr)
+{
+    png_structp  png_ptr;       /* note:  temporary variables! */
+    png_infop  info_ptr;
+    int color_type, interlace_type;
+
+
+    /* could also replace libpng warning-handler (final NULL), but no need: */
+
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+      writepng_error_handler, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_write_struct(&png_ptr, NULL);
+        return 4;   /* out of memory */
+    }
+
+
+    /* setjmp() must be called in every function that calls a PNG-writing
+     * libpng function, unless an alternate error handler was installed--
+     * but compatible error handlers must either use longjmp() themselves
+     * (as in this program) or exit immediately, so here we go: */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        return 2;
+    }
+
+
+    /* make sure outfile is (re)opened in BINARY mode */
+
+    png_init_io(png_ptr, mainprog_ptr->outfile);
+
+
+    /* set the compression levels--in general, always want to leave filtering
+     * turned on (except for palette images) and allow all of the filters,
+     * which is the default; want 32K zlib window, unless entire image buffer
+     * is 16K or smaller (unknown here)--also the default; usually want max
+     * compression (NOT the default); and remaining compression flags should
+     * be left alone */
+
+    png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
+/*
+    >> this is default for no filtering; Z_FILTERED is default otherwise:
+    png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
+    >> these are all defaults:
+    png_set_compression_mem_level(png_ptr, 8);
+    png_set_compression_window_bits(png_ptr, 15);
+    png_set_compression_method(png_ptr, 8);
+ */
+
+
+    /* set the image parameters appropriately */
+
+    if (mainprog_ptr->pnmtype == 5)
+        color_type = PNG_COLOR_TYPE_GRAY;
+    else if (mainprog_ptr->pnmtype == 6)
+        color_type = PNG_COLOR_TYPE_RGB;
+    else if (mainprog_ptr->pnmtype == 8)
+        color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+    else {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        return 11;
+    }
+
+    interlace_type = mainprog_ptr->interlaced? PNG_INTERLACE_ADAM7 :
+                                               PNG_INTERLACE_NONE;
+
+    png_set_IHDR(png_ptr, info_ptr, mainprog_ptr->width, mainprog_ptr->height,
+      mainprog_ptr->sample_depth, color_type, interlace_type,
+      PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+    if (mainprog_ptr->gamma > 0.0)
+        png_set_gAMA(png_ptr, info_ptr, mainprog_ptr->gamma);
+
+    if (mainprog_ptr->have_bg) {   /* we know it's RGBA, not gray+alpha */
+        png_color_16  background;
+
+        background.red = mainprog_ptr->bg_red;
+        background.green = mainprog_ptr->bg_green;
+        background.blue = mainprog_ptr->bg_blue;
+        png_set_bKGD(png_ptr, info_ptr, &background);
+    }
+
+    if (mainprog_ptr->have_time) {
+        png_time  modtime;
+
+        png_convert_from_time_t(&modtime, mainprog_ptr->modtime);
+        png_set_tIME(png_ptr, info_ptr, &modtime);
+    }
+
+    if (mainprog_ptr->have_text) {
+        png_text  text[6];
+        int  num_text = 0;
+
+        if (mainprog_ptr->have_text & TEXT_TITLE) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Title";
+            text[num_text].text = mainprog_ptr->title;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_AUTHOR) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Author";
+            text[num_text].text = mainprog_ptr->author;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_DESC) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Description";
+            text[num_text].text = mainprog_ptr->desc;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_COPY) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Copyright";
+            text[num_text].text = mainprog_ptr->copyright;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_EMAIL) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "E-mail";
+            text[num_text].text = mainprog_ptr->email;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_URL) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "URL";
+            text[num_text].text = mainprog_ptr->url;
+            ++num_text;
+        }
+        png_set_text(png_ptr, info_ptr, text, num_text);
+    }
+
+
+    /* write all chunks up to (but not including) first IDAT */
+
+    png_write_info(png_ptr, info_ptr);
+
+
+    /* if we wanted to write any more text info *after* the image data, we
+     * would set up text struct(s) here and call png_set_text() again, with
+     * just the new data; png_set_tIME() could also go here, but it would
+     * have no effect since we already called it above (only one tIME chunk
+     * allowed) */
+
+
+    /* set up the transformations:  for now, just pack low-bit-depth pixels
+     * into bytes (one, two or four pixels per byte) */
+
+    png_set_packing(png_ptr);
+/*  png_set_shift(png_ptr, &sig_bit);  to scale low-bit-depth values */
+
+
+    /* make sure we save our pointers for use in writepng_encode_image() */
+
+    mainprog_ptr->png_ptr = png_ptr;
+    mainprog_ptr->info_ptr = info_ptr;
+
+
+    /* OK, that's all we need to do for now; return happy */
+
+    return 0;
+}
+
+
+
+
+
+/* returns 0 for success, 2 for libpng (longjmp) problem */
+
+int writepng_encode_image(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* and now we just write the whole image; libpng takes care of interlacing
+     * for us */
+
+    png_write_image(png_ptr, mainprog_ptr->row_pointers);
+
+
+    /* since that's it, we also close out the end of the PNG file now--if we
+     * had any text or time info to write after the IDATs, second argument
+     * would be info_ptr, but we optimize slightly by sending NULL pointer: */
+
+    png_write_end(png_ptr, NULL);
+
+    return 0;
+}
+
+
+
+
+
+/* returns 0 if succeeds, 2 if libpng problem */
+
+int writepng_encode_row(mainprog_info *mainprog_ptr)  /* NON-interlaced only! */
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* image_data points at our one row of image data */
+
+    png_write_row(png_ptr, mainprog_ptr->image_data);
+
+    return 0;
+}
+
+
+
+
+
+/* returns 0 if succeeds, 2 if libpng problem */
+
+int writepng_encode_finish(mainprog_info *mainprog_ptr)   /* NON-interlaced! */
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* close out PNG file; if we had any text or time info to write after
+     * the IDATs, second argument would be info_ptr: */
+
+    png_write_end(png_ptr, NULL);
+
+    return 0;
+}
+
+
+
+
+
+void writepng_cleanup(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+    if (png_ptr && info_ptr)
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+}
+
+
+
+
+
+static void writepng_error_handler(png_structp png_ptr, png_const_charp msg)
+{
+    mainprog_info  *mainprog_ptr;
+
+    /* This function, aside from the extra step of retrieving the "error
+     * pointer" (below) and the fact that it exists within the application
+     * rather than within libpng, is essentially identical to libpng's
+     * default error handler.  The second point is critical:  since both
+     * setjmp() and longjmp() are called from the same code, they are
+     * guaranteed to have compatible notions of how big a jmp_buf is,
+     * regardless of whether _BSD_SOURCE or anything else has (or has not)
+     * been defined. */
+
+    fprintf(stderr, "writepng libpng error: %s\n", msg);
+    fflush(stderr);
+
+    mainprog_ptr = png_get_error_ptr(png_ptr);
+    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
+        fprintf(stderr,
+          "writepng severe error:  jmpbuf not recoverable; terminating.\n");
+        fflush(stderr);
+        exit(99);
+    }
+
+    longjmp(mainprog_ptr->jmpbuf, 1);
+}

contrib/gregbook/writepng.h

@@ -0,0 +1,109 @@
+/*---------------------------------------------------------------------------
+
+   wpng - simple PNG-writing program                             writepng.h
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+
+#define TEXT_TITLE    0x01
+#define TEXT_AUTHOR   0x02
+#define TEXT_DESC     0x04
+#define TEXT_COPY     0x08
+#define TEXT_EMAIL    0x10
+#define TEXT_URL      0x20
+
+#define TEXT_TITLE_OFFSET        0
+#define TEXT_AUTHOR_OFFSET      72
+#define TEXT_COPY_OFFSET     (2*72)
+#define TEXT_EMAIL_OFFSET    (3*72)
+#define TEXT_URL_OFFSET      (4*72)
+#define TEXT_DESC_OFFSET     (5*72)
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+typedef struct _mainprog_info {
+    double gamma;
+    long width;
+    long height;
+    time_t modtime;
+    FILE *infile;
+    FILE *outfile;
+    void *png_ptr;
+    void *info_ptr;
+    uch *image_data;
+    uch **row_pointers;
+    char *title;
+    char *author;
+    char *desc;
+    char *copyright;
+    char *email;
+    char *url;
+    int filter;    /* command-line-filter flag, not PNG row filter! */
+    int pnmtype;
+    int sample_depth;
+    int interlaced;
+    int have_bg;
+    int have_time;
+    int have_text;
+    jmp_buf jmpbuf;
+    uch bg_red;
+    uch bg_green;
+    uch bg_blue;
+} mainprog_info;
+
+
+/* prototypes for public functions in writepng.c */
+
+void writepng_version_info(void);
+
+int writepng_init(mainprog_info *mainprog_ptr);
+
+int writepng_encode_image(mainprog_info *mainprog_ptr);
+
+int writepng_encode_row(mainprog_info *mainprog_ptr);
+
+int writepng_encode_finish(mainprog_info *mainprog_ptr);
+
+void writepng_cleanup(mainprog_info *mainprog_ptr);

contrib/msvctest/README.txt

@@ -0,0 +1,22 @@
+Microsoft Developer Studio Build File, Format Version 6.00 for
+msvctest
+
+Assumes that libpng DLLs and LIBs are in ..\..\projects\msvc\win32\libpng
+Assumes that zlib DLLs and LIBs are in ..\..\projects\msvc\win32\zlib
+
+To build:
+
+1) On the main menu Select "Build|Set Active configuration".
+   Choose the configuration that corresponds to the library you want to test.
+   This library must have been built using the libpng MS project located in
+   the "mscv" subdirectory.
+
+2) Select "Build|Clean"
+
+3) Select "Build|Rebuild All"
+
+4) The test results should appear in the "Build" pane of the Output Window.
+
+
+Simon-Pierre Cadieux
+Methodex Computer Systems Inc.

contrib/msvctest/msvctest.dsp

@@ -0,0 +1,247 @@
+# Microsoft Developer Studio Project File - Name="msvctest" - Package Owner=<4>
+# Microsoft Developer Studio Generated Build File, Format Version 6.00
+# ** DO NOT EDIT **
+
+# TARGTYPE "Win32 (x86) Console Application" 0x0103
+
+CFG=msvctest - Win32 Debug DLL
+!MESSAGE This is not a valid makefile. To build this project using NMAKE,
+!MESSAGE use the Export Makefile command and run
+!MESSAGE 
+!MESSAGE NMAKE /f "msvctest.mak".
+!MESSAGE 
+!MESSAGE You can specify a configuration when running NMAKE
+!MESSAGE by defining the macro CFG on the command line. For example:
+!MESSAGE 
+!MESSAGE NMAKE /f "msvctest.mak" CFG="msvctest - Win32 Debug DLL"
+!MESSAGE 
+!MESSAGE Possible choices for configuration are:
+!MESSAGE 
+!MESSAGE "msvctest - Win32 DLL" (based on "Win32 (x86) Console Application")
+!MESSAGE "msvctest - Win32 Debug DLL" (based on "Win32 (x86) Console Application")
+!MESSAGE "msvctest - Win32 ASM DLL" (based on "Win32 (x86) Console Application")
+!MESSAGE "msvctest - Win32 Debug ASM DLL" (based on "Win32 (x86) Console Application")
+!MESSAGE "msvctest - Win32 LIB" (based on "Win32 (x86) Console Application")
+!MESSAGE "msvctest - Win32 Debug LIB" (based on "Win32 (x86) Console Application")
+!MESSAGE 
+
+# Begin Project
+# PROP AllowPerConfigDependencies 0
+# PROP Scc_ProjName ""
+# PROP Scc_LocalPath ""
+CPP=cl.exe
+RSC=rc.exe
+
+!IF  "$(CFG)" == "msvctest - Win32 DLL"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 0
+# PROP BASE Output_Dir "dll"
+# PROP BASE Intermediate_Dir "dll"
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 0
+# PROP Output_Dir "dll"
+# PROP Intermediate_Dir "dll"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /O1 /D "NDEBUG" /D "WIN32" /D "_CONSOLE" /FD /c
+# ADD CPP /nologo /MD /W3 /O1 /I "..\..\..\zlib" /D "NDEBUG" /D "WIN32" /D "_CONSOLE" /D "PNG_DLL" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /c
+# ADD BASE RSC /l 0x409 /d "NDEBUG"
+# ADD RSC /l 0x409 /d "NDEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 /nologo /subsystem:console /machine:I386
+# ADD LINK32 ..\..\projects\msvc\win32\libpng\dll\libpng1.lib /nologo /subsystem:console /machine:I386
+# Begin Special Build Tool
+OutDir=.\dll
+SOURCE="$(InputPath)"
+PostBuild_Desc=[Run Test]
+PostBuild_Cmds=set path=..\..\projects\msvc\win32\libpng\dll;..\..\projects\msvc\win32\zlib\dll;	$(outdir)\msvctest.exe ..\..\pngtest.png
+# End Special Build Tool
+
+!ELSEIF  "$(CFG)" == "msvctest - Win32 Debug DLL"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 1
+# PROP BASE Output_Dir "dll_dbg"
+# PROP BASE Intermediate_Dir "dll_dbg"
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 1
+# PROP Output_Dir "dll_dbg"
+# PROP Intermediate_Dir "dll_dbg"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /Zi /Od /D "_DEBUG" /D "WIN32" /D "_CONSOLE" /D "_MBCS" /YX /FD /GZ /c
+# ADD CPP /nologo /MDd /W3 /Zi /Od /I "..\..\..\zlib" /D "_DEBUG" /D "WIN32" /D "_CONSOLE" /D "_MBCS" /D "PNG_DLL" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /GZ /c
+# ADD BASE RSC /l 0x409 /d "_DEBUG"
+# ADD RSC /l 0x409 /d "_DEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept
+# ADD LINK32 ..\..\projects\msvc\win32\libpng\dll_dbg\libpng1d.lib /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept
+# Begin Special Build Tool
+OutDir=.\dll_dbg
+SOURCE="$(InputPath)"
+PostBuild_Desc=[Run Test]
+PostBuild_Cmds=set path=..\..\projects\msvc\win32\libpng\dll_dbg;..\..\projects\msvc\win32\zlib\dll_dbg;	$(outdir)\msvctest.exe ..\..\pngtest.png
+# End Special Build Tool
+
+!ELSEIF  "$(CFG)" == "msvctest - Win32 ASM DLL"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 0
+# PROP BASE Output_Dir "dll_asm"
+# PROP BASE Intermediate_Dir "dll_asm"
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 0
+# PROP Output_Dir "dll_asm"
+# PROP Intermediate_Dir "dll_asm"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /O1 /D "NDEBUG" /D "WIN32" /D "_CONSOLE" /FD /c
+# ADD CPP /nologo /MD /W3 /O1 /I "..\..\..\zlib" /D "NDEBUG" /D "WIN32" /D "_CONSOLE" /D "PNG_DLL" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /c
+# ADD BASE RSC /l 0x409 /d "NDEBUG"
+# ADD RSC /l 0x409 /d "NDEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 /nologo /subsystem:console /machine:I386
+# ADD LINK32 ..\..\projects\msvc\win32\libpng\dll_asm\libpng1a.lib /nologo /subsystem:console /machine:I386
+# Begin Special Build Tool
+OutDir=.\dll_asm
+SOURCE="$(InputPath)"
+PostBuild_Desc=[Run Test]
+PostBuild_Cmds=set path=..\..\projects\msvc\win32\libpng\dll_asm;..\..\projects\msvc\win32\zlib\dll_asm;	$(outdir)\msvctest.exe ..\..\pngtest.png
+# End Special Build Tool
+
+!ELSEIF  "$(CFG)" == "msvctest - Win32 Debug ASM DLL"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 1
+# PROP BASE Output_Dir "dll_dbga"
+# PROP BASE Intermediate_Dir "dll_dbga"
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 1
+# PROP Output_Dir "dll_dbga"
+# PROP Intermediate_Dir "dll_dbga"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /Zi /Od /D "_DEBUG" /D "WIN32" /D "_CONSOLE" /D "_MBCS" /YX /FD /GZ /c
+# ADD CPP /nologo /MDd /W3 /Zi /Od /I "..\..\..\zlib" /D "_DEBUG" /D "WIN32" /D "_CONSOLE" /D "_MBCS" /D "PNG_DLL" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /GZ /c
+# ADD BASE RSC /l 0x409 /d "_DEBUG"
+# ADD RSC /l 0x409 /d "_DEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept
+# ADD LINK32 ..\..\projects\msvc\win32\libpng\dll_dbga\libpng1b.lib /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept
+# Begin Special Build Tool
+OutDir=.\dll_dbga
+SOURCE="$(InputPath)"
+PostBuild_Desc=[Run Test]
+PostBuild_Cmds=set path=..\..\projects\msvc\win32\libpng\dll_dbga;..\..\projects\msvc\win32\zlib\dll_dbga;	$(outdir)\msvctest.exe ..\..\pngtest.png
+# End Special Build Tool
+
+!ELSEIF  "$(CFG)" == "msvctest - Win32 LIB"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 0
+# PROP BASE Output_Dir "lib"
+# PROP BASE Intermediate_Dir "lib"
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 0
+# PROP Output_Dir "lib"
+# PROP Intermediate_Dir "lib"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /O1 /D "NDEBUG" /D "WIN32" /D "_CONSOLE" /FD /c
+# ADD CPP /nologo /W3 /O1 /I "..\..\..\zlib" /D "NDEBUG" /D "WIN32" /D "_CONSOLE" /FD /c
+# ADD BASE RSC /l 0x409 /d "NDEBUG"
+# ADD RSC /l 0x409 /d "NDEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 /nologo /subsystem:console /machine:I386
+# ADD LINK32 ..\..\projects\msvc\win32\libpng\lib\libpng.lib /nologo /subsystem:console /machine:I386
+# Begin Special Build Tool
+OutDir=.\lib
+SOURCE="$(InputPath)"
+PostBuild_Desc=[Run Test]
+PostBuild_Cmds=$(outdir)\msvctest.exe ..\..\pngtest.png
+# End Special Build Tool
+
+!ELSEIF  "$(CFG)" == "msvctest - Win32 Debug LIB"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 1
+# PROP BASE Output_Dir "lib_dbg"
+# PROP BASE Intermediate_Dir "lib_dbg"
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 1
+# PROP Output_Dir "lib_dbg"
+# PROP Intermediate_Dir "lib_dbg"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /Zi /Od /D "_DEBUG" /D "WIN32" /D "_CONSOLE" /D "_MBCS" /YX /FD /GZ /c
+# ADD CPP /nologo /W3 /Zi /Od /I "..\..\..\zlib" /D "_DEBUG" /D "WIN32" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
+# ADD BASE RSC /l 0x409 /d "_DEBUG"
+# ADD RSC /l 0x409 /d "_DEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept
+# ADD LINK32 ..\..\projects\msvc\win32\libpng\lib_dbg\libpng.lib /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept
+# Begin Special Build Tool
+OutDir=.\lib_dbg
+SOURCE="$(InputPath)"
+PostBuild_Desc=[Run Test]
+PostBuild_Cmds=$(outdir)\msvctest.exe ..\..\pngtest.png
+# End Special Build Tool
+
+!ENDIF 
+
+# Begin Target
+
+# Name "msvctest - Win32 DLL"
+# Name "msvctest - Win32 Debug DLL"
+# Name "msvctest - Win32 ASM DLL"
+# Name "msvctest - Win32 Debug ASM DLL"
+# Name "msvctest - Win32 LIB"
+# Name "msvctest - Win32 Debug LIB"
+# Begin Group "Source Files"
+
+# PROP Default_Filter "cpp;c;cxx;rc;def;r;odl;idl;hpj;bat"
+# Begin Source File
+
+SOURCE=..\..\pngtest.c
+# End Source File
+# Begin Source File
+
+SOURCE=.\README.txt
+# PROP Exclude_From_Build 1
+# End Source File
+# End Group
+# Begin Group "Header Files"
+
+# PROP Default_Filter "h;hpp;hxx;hm;inl"
+# End Group
+# Begin Group "Resource Files"
+
+# PROP Default_Filter "ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
+# End Group
+# End Target
+# End Project

contrib/msvctest/msvctest.dsw

@@ -0,0 +1,29 @@
+Microsoft Developer Studio Workspace File, Format Version 6.00
+# WARNING: DO NOT EDIT OR DELETE THIS WORKSPACE FILE!
+
+###############################################################################
+
+Project: "msvctest"=.\msvctest.dsp - Package Owner=<4>
+
+Package=<5>
+{{{
+}}}
+
+Package=<4>
+{{{
+}}}
+
+###############################################################################
+
+Global:
+
+Package=<5>
+{{{
+}}}
+
+Package=<3>
+{{{
+}}}
+
+###############################################################################
+

contrib/pngminus/README

@@ -0,0 +1,153 @@
+PngMinus
+--------
+(copyright Willem van Schaik, 1999)
+
+
+License
+-------
+
+Permission to use, copy, modify, and distribute this software and
+its documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and
+that both that copyright notice and this permission notice appear in
+supporting documentation. This software is provided "as is" without
+express or implied warranty.
+
+
+Some history
+------------
+Soon after the creation of PNG in 1995, the need was felt for a set of
+pnmtopng / pngtopnm utilities. Independantly Alexander Lehmann and I
+(Willem van Schaik) started such a project. Luckily we discovered this
+and merged the two together into pnmtopng.tar.gz, which is available
+from a/o ftp://swrinde.nde.swri.edu/pub/png/.
+
+These two utilities have many, many options and make use of most of the
+features of PNG, like gamma, alpha, sbit, text-chunks, etc. This makes
+the utilities quite complex and by now not anymore very maintainable.
+When we wrote these programs, libpng was still in an early stage.
+Therefore, lots of the functionality that we put in our software can now
+be done using transform-functions in libpng.
+
+Finally, to compile these programs, you need to have installed and
+compiled three libraries: libpng, zlib and netpbm. Especially the latter
+makes the whole setup a bit bulky. But that's unavoidable given the many
+features of pnmtopng.
+
+
+What now
+--------
+At this moment libpng is in a very stable state and can do much of the
+work done in pnmtopng. Also, pnmtopng needs to be upgraded to the new
+interface of libpng. Hence, it is time for a rewrite from the ground up
+of pnmtopng and pngtopnm. This will happen in the near future (stay
+tuned). The new package will get a different name to distinguish it from
+the old one: PngPlus.
+
+To experiment a bit with the new interface of libpng, I started off with
+a small prototype that contains only the basic functionality. It doesn't
+have any of the options to read or write special chunks and it will do
+no gamma correction. But this makes it also a simple program that is
+quite easy to understand and can serve well as a template for other
+software developments. (By now there are of course a couple of programs,
+like Greg Roelofs' rpng/wpng, that can be used just as good.)
+
+
+Can and can not
+---------------
+As this is the small brother of the future PngPlus, I called this fellow
+PngMinus. Because I started this development in good-old Turbo-C, I
+avoided the use the netpbm library, which requires DOS extenders. Again,
+another reason to call it PngMinus (minus netpbm :-). So, part of the
+program are some elementary routines to read / write pgm- and ppm-files.
+It does not read b&w pbm-files.
+
+The downside of this approach is that you can not use them on images
+that require blocks of memory bigger than 64k (the DOS version). For
+larger images you will get an out-of-memory error.
+
+As said before, PngMinus doesn't correct for gamma. When reading
+png-files you can do this just as well by piping the output of png2pnm
+to pnmgamma, one of the standard PbmPlus tools. This same scenario will
+most probably also be followed in the full-blown future PngPlus, with
+the addition of course of the possibility to create gamma-chunks when
+writing png-files.
+
+On the other hand it supports alpha-channels. When reading a png-image
+you can write the alpha-channel into a pgm-file. And when creating an
+RGB+A png-image, you just combine a ppm-file with a corresponding
+pgm-file containing the alpha-channel. When reading, transparency chunks
+are converted into an alpha-channel and from there on treated the same
+way.
+
+Finally you can opt for writing ascii or binary pgm- and ppm-files. When
+the bit-depth is 16, the format will always be ascii.
+
+
+Using it
+--------
+To distinguish them from pnmtopng and PngPlus, the utilities are named
+png2pnm and pnm2png (2 instead of to). The input- and output-files can
+be given as parameters or through redirection. Therefore the programs
+can be part of a pipe.
+
+To list the options type "png2pnm -h" or "pnm2png -h".
+
+
+Just like Scandinavian furniture
+--------------------------------
+You have to put it together yourself. I did test the software under
+MS-DOS with Turbo-C 3.0 and under RedHat Linux 4.2 with gcc. In both
+cases I used libpng-1.0.4 and zlib-1.1.3. Later versions should be OK,
+however some older libpng versions have a bug in pngmem.c when using
+Turbo-C 3.0 (see below).
+
+You can build it using one of the two makefiles (make -f makefile.###)
+or use the batch/script files pngminus.bat / pngminus.sh. This assumes
+that you have built the libraries in ../libpng and ../zlib. Using Linux,
+make sure that you have built libpng with makefile.std and not
+makefile.linux (also called .lnx in earlier versions of libpng). The
+latter creates a .so shared-library, while the PngMinus makefile assumes
+a normal .a static library.
+
+If you create a ../pngsuite directory and then store the basn####.png
+files from PngSuite (http://www.schaik.com/pngsuite/) in there, you can
+test in one go the proper functioning of PngMinus, see png2pnm.bat and
+pnm2png.bat (or the .sh versions).
+
+
+Warranty
+-------
+Please, remember that this was just a small experiment to learn a few
+things. It will have many unforeseen features <vbg>. Who said bugs? Use
+it when you are in need for something simple or when you want to start
+developing your own stuff.
+
+
+The Turbo bug
+-------------
+** pngmem.old
+          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+          hptr += 16L;
+** pngmem.c
+          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+          hptr = hptr + 16L;
+**
+
+** pngmem.old
+          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+          hptr += (png_uint_32)65536L;
+** pngmem.c
+          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+          hptr = hptr + 65536L;
+**
+
+
+The end
+-------
+Willem van Schaik
+mailto:willem@schaik.com
+http://www.schaik.com/png/
+-------
+Oct 1999
+

contrib/pngminus/makefile.std

@@ -0,0 +1,52 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# Linux / Unix
+
+CC=cc -O
+LD=cc -O
+#CC=gcc -O
+#LD=gcc -O
+LB=ar
+RM=rm
+CP=cp
+
+PNGPATH = /usr/local
+PNGINC = $(PNGPATH)/include
+#PNGLIB = $(PNGPATH)/lib -lpng
+PNGLIB = $(PNGPATH)/lib/libpng.a
+
+ZPATH = /usr/local
+ZINC = $(ZPATH)/include
+#ZLIB = $(ZPATH)/lib -lz
+ZLIB = $(ZPATH)/lib/libz.a
+
+CCFLAGS=-I$(PNGINC) -I$(ZINC)
+LDFLAGS=-L$(PNGLIB) -L$(ZLIB)
+C=.c
+O=.o
+L=.a
+E=
+
+# dependencies
+
+all: png2pnm$(E) pnm2png$(E)
+
+png2pnm$(O): png2pnm$(C)
+	$(CC) -c $(CCFLAGS) png2pnm$(C)
+
+png2pnm$(E): png2pnm$(O)
+	$(LD) -o png2pnm$(E) png2pnm$(O) $(LDFLAGS) -lpng -lz -lm
+
+pnm2png$(O): pnm2png$(C)
+	$(CC) -c $(CCFLAGS) pnm2png$(C)
+
+pnm2png$(E): pnm2png$(O)
+	$(LD) -o pnm2png$(E) pnm2png$(O) $(LDFLAGS) -lpng -lz -lm
+
+clean:
+	$(RM) png2pnm$(O)
+	$(RM) pnm2png$(O)
+	$(RM) png2pnm$(E)
+	$(RM) pnm2png$(E)
+
+# End of makefile for png2pnm / pnm2png
+

contrib/pngminus/makefile.tc3

@@ -0,0 +1,38 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# TurboC++ 3.0
+
+CC=tcc -Ic:\tc3\inc
+LD=tcc -Lc:\tc3\lib
+LB=tlib
+RM=del
+CP=copy
+MODEL=l
+CCFLAGS=-O -m$(MODEL) -I..\libpng -I..\zlib
+LDFLAGS=-m$(MODEL) -L..\libpng -L..\zlib
+C=.c
+O=.obj
+L=.lib
+E=.exe
+
+# dependencies
+
+all: png2pnm$(E) pnm2png$(E)
+
+png2pnm$(O): png2pnm$(C)
+        $(CC) -c $(CCFLAGS) png2pnm$(C)
+
+png2pnm$(E): png2pnm$(O)
+        $(LD) $(LDFLAGS) png2pnm$(O) libpng$(L) zlib$(L)
+
+pnm2png$(O): pnm2png$(C)
+        $(CC) -c $(CCFLAGS) pnm2png$(C)
+
+pnm2png$(E): pnm2png$(O)
+        $(LD) $(LDFLAGS) pnm2png$(O) libpng$(L) zlib$(L)
+
+clean:
+        $(RM) *$(O)
+        $(RM) *$(E)
+
+# End of makefile for png2pnm / pnm2png
+

contrib/pngminus/makevms.com

@@ -0,0 +1,92 @@
+$!------------------------------------------------------------------------------
+$! make Contrib programs of libpng under OpenVMS
+$!
+$!
+$! Look for the compiler used
+$!
+$ 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
+$ open/write lopt lib.opt
+$ write lopt "[--]libpng.olb/lib"
+$ write lopt "''zlibsrc'libz.olb/lib"
+$ close lopt
+$ open/write xopt x11.opt
+$ write xopt "sys$library:decw$xlibshr.exe/share"
+$ close xopt
+$ write sys$output "Compiling PNG contrib programs ..."
+$   write sys$output "Building pnm2png..."
+$   CALL MAKE pnm2png.OBJ "cc ''CCOPT' pnm2png" -
+	pnm2png.c
+$   call make pnm2png.exe -
+	"LINK pnm2png,lib.opt/opt" -
+	pnm2png.obj
+$   write sys$output "Building png2pnm..."
+$   CALL MAKE png2pnm.OBJ "cc ''CCOPT' png2pnm" -
+	png2pnm.c
+$   call make png2pnm.exe -
+	"LINK png2pnm,lib.opt/opt" -
+	png2pnm.obj
+$ 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

contrib/pngminus/png2pnm.bat

@@ -0,0 +1,41 @@
+REM -- grayscale
+png2pnm.exe -noraw ..\pngsuite\basn0g01.png basn0g01.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g02.png basn0g02.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g04.png basn0g04.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g08.png basn0g08.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g16.png basn0g16.pgm
+REM -- full-color
+png2pnm.exe -noraw ..\pngsuite\basn2c08.png basn2c08.ppm
+png2pnm.exe -noraw ..\pngsuite\basn2c16.png basn2c16.ppm
+REM -- palletted
+png2pnm.exe -noraw ..\pngsuite\basn3p01.png basn3p01.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p02.png basn3p02.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p04.png basn3p04.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p08.png basn3p08.ppm
+REM -- gray with alpha-channel
+png2pnm.exe -noraw ..\pngsuite\basn4a08.png basn4a08.pgm
+png2pnm.exe -noraw ..\pngsuite\basn4a16.png basn4a16.pgm
+REM -- color with alpha-channel
+png2pnm.exe -noraw -alpha basn6a08.pgm ..\pngsuite\basn6a08.png basn6a08.ppm
+png2pnm.exe -noraw -alpha basn6a16.pgm ..\pngsuite\basn6a16.png basn6a16.ppm
+REM -- grayscale
+png2pnm.exe -raw ..\pngsuite\basn0g01.png rawn0g01.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g02.png rawn0g02.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g04.png rawn0g04.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g08.png rawn0g08.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g16.png rawn0g16.pgm
+REM -- full-color
+png2pnm.exe -raw ..\pngsuite\basn2c08.png rawn2c08.ppm
+png2pnm.exe -raw ..\pngsuite\basn2c16.png rawn2c16.ppm
+REM -- palletted
+png2pnm.exe -raw ..\pngsuite\basn3p01.png rawn3p01.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p02.png rawn3p02.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p04.png rawn3p04.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p08.png rawn3p08.ppm
+REM -- gray with alpha-channel
+png2pnm.exe -raw ..\pngsuite\basn4a08.png rawn4a08.pgm
+png2pnm.exe -raw ..\pngsuite\basn4a16.png rawn4a16.pgm
+REM -- color with alpha-channel
+png2pnm.exe -noraw -alpha rawn6a08.pgm ..\pngsuite\basn6a08.png rawn6a08.ppm
+png2pnm.exe -noraw -alpha rawn6a16.pgm ..\pngsuite\basn6a16.png rawn6a16.ppm
+

contrib/pngminus/png2pnm.c

@@ -0,0 +1,430 @@
+/*
+ *  png2pnm.c --- conversion from PNG-file to PGM/PPM-file
+ *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
+ *
+ *  version 1.0 - 1999.10.15 - First version.
+ *
+ *  Permission to use, copy, modify, and distribute this software and
+ *  its documentation for any purpose and without fee is hereby granted,
+ *  provided that the above copyright notice appear in all copies and
+ *  that both that copyright notice and this permission notice appear in
+ *  supporting documentation. This software is provided "as is" without
+ *  express or implied warranty.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef __TURBOC__
+#include <mem.h>
+#include <fcntl.h>
+#endif
+
+#ifndef BOOL
+#define BOOL unsigned char
+#endif
+#ifndef TRUE
+#define TRUE (BOOL) 1
+#endif
+#ifndef FALSE
+#define FALSE (BOOL) 0
+#endif
+
+#ifdef __TURBOC__
+#define STDIN  0
+#define STDOUT 1
+#define STDERR 2
+#endif
+
+/* to make png2pnm verbose so we can find problems (needs to be before png.h) */
+#ifndef PNG_DEBUG
+#define PNG_DEBUG 0
+#endif
+
+#include "png.h"
+
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+
+/* function prototypes */
+
+int  main (int argc, char *argv[]);
+void usage ();
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha);
+
+/*
+ *  main
+ */
+
+int main(int argc, char *argv[])
+{
+  FILE *fp_rd = stdin;
+  FILE *fp_wr = stdout;
+  FILE *fp_al = NULL;
+  BOOL raw = TRUE;
+  BOOL alpha = FALSE;
+  int argi;
+
+  for (argi = 1; argi < argc; argi++)
+  {
+    if (argv[argi][0] == '-')
+    {
+      switch (argv[argi][1])
+      {
+        case 'n':
+          raw = FALSE;
+          break;
+        case 'r':
+          raw = TRUE;
+          break;
+        case 'a':
+          alpha = TRUE;
+          argi++;
+          if ((fp_al = fopen (argv[argi], "wb")) == NULL)
+          {
+            fprintf (stderr, "PNM2PNG\n");
+            fprintf (stderr, "Error:  can not create alpha-channel file %s\n", argv[argi]);
+            exit (1);
+          }
+          break;
+        case 'h':
+        case '?':
+          usage();
+          exit(0);
+          break;
+        default:
+          fprintf (stderr, "PNG2PNM\n");
+          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
+          usage();
+          exit(1);
+          break;
+      } /* end switch */
+    }
+    else if (fp_rd == stdin)
+    {
+      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
+      {
+             fprintf (stderr, "PNG2PNM\n");
+            fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
+            exit (1);
+      }
+    }
+    else if (fp_wr == stdout)
+    {
+      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
+      {
+        fprintf (stderr, "PNG2PNM\n");
+        fprintf (stderr, "Error:  can not create file %s\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else
+    {
+      fprintf (stderr, "PNG2PNM\n");
+      fprintf (stderr, "Error:  too many parameters\n");
+      usage();
+      exit(1);
+    }
+  } /* end for */
+
+#ifdef __TURBOC__
+  /* set stdin/stdout if required to binary */
+  if (fp_rd == stdin)
+  {
+    setmode (STDIN, O_BINARY);
+  }
+  if ((raw) && (fp_wr == stdout))
+  {
+    setmode (STDOUT, O_BINARY);
+  }
+#endif
+
+  /* call the conversion program itself */
+  if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
+  {
+    fprintf (stderr, "PNG2PNM\n");
+    fprintf (stderr, "Error:  unsuccessful convertion of PNG-image\n");
+    exit(1);
+  }
+
+  /* close input file */
+  fclose (fp_rd);
+  /* close output file */
+  fclose (fp_wr);
+  /* close alpha file */
+  if (alpha)
+    fclose (fp_al);
+
+  return 0;
+}
+
+/*
+ *  usage
+ */
+
+void usage()
+{
+  fprintf (stderr, "PNG2PNM\n");
+  fprintf (stderr, "   by Willem van Schaik, 1999\n");
+#ifdef __TURBOC__
+  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
+#else
+  fprintf (stderr, "   for Linux (and Unix) compilers\n");
+#endif
+  fprintf (stderr, "Usage:  png2pnm [options] <file>.png [<file>.pnm]\n");
+  fprintf (stderr, "   or:  ... | png2pnm [options]\n");
+  fprintf (stderr, "Options:\n");
+  fprintf (stderr, "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
+  fprintf (stderr, "   -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
+  fprintf (stderr, "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
+  fprintf (stderr, "   -h | -?  print this help-information\n");
+}
+
+/*
+ *  png2pnm
+ */
+
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha)
+{
+  png_struct    *png_ptr = NULL;
+  png_info	*info_ptr = NULL;
+  png_byte      buf[8];
+  png_byte      *png_pixels = NULL;
+  png_byte      **row_pointers = NULL;
+  png_byte      *pix_ptr = NULL;
+  png_uint_32   row_bytes;
+
+  png_uint_32   width;
+  png_uint_32   height;
+  int           bit_depth;
+  int           channels;
+  int           color_type;
+  int           alpha_present;
+  int           row, col;
+  int           ret;
+  int           i;
+  long          dep_16;
+
+  /* read and check signature in PNG file */
+  ret = fread (buf, 1, 8, png_file);
+  if (ret != 8)
+    return FALSE;
+
+  ret = png_check_sig (buf, 8);
+  if (!ret)
+    return FALSE;
+
+  /* create png and info structures */
+
+  png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING,
+    NULL, NULL, NULL);
+  if (!png_ptr)
+    return FALSE;   /* out of memory */
+
+  info_ptr = png_create_info_struct (png_ptr);
+  if (!info_ptr)
+  {
+    png_destroy_read_struct (&png_ptr, NULL, NULL);
+    return FALSE;   /* out of memory */
+  }
+
+  if (setjmp (png_jmpbuf(png_ptr)))
+  {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
+
+  /* set up the input control for C streams */
+  png_init_io (png_ptr, png_file);
+  png_set_sig_bytes (png_ptr, 8);  /* we already read the 8 signature bytes */
+
+  /* read the file information */
+  png_read_info (png_ptr, info_ptr);
+
+  /* get size and bit-depth of the PNG-image */
+  png_get_IHDR (png_ptr, info_ptr,
+    &width, &height, &bit_depth, &color_type,
+    NULL, NULL, NULL);
+
+  /* set-up the transformations */
+
+  /* transform paletted images into full-color rgb */
+  if (color_type == PNG_COLOR_TYPE_PALETTE)
+    png_set_expand (png_ptr);
+  /* expand images to bit-depth 8 (only applicable for grayscale images) */
+  if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+    png_set_expand (png_ptr);
+  /* transform transparency maps into full alpha-channel */
+  if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
+    png_set_expand (png_ptr);
+
+#ifdef NJET
+  /* downgrade 16-bit images to 8 bit */
+  if (bit_depth == 16)
+    png_set_strip_16 (png_ptr);
+  /* transform grayscale images into full-color */
+  if (color_type == PNG_COLOR_TYPE_GRAY ||
+    color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    png_set_gray_to_rgb (png_ptr);
+  /* only if file has a file gamma, we do a correction */
+  if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
+    png_set_gamma (png_ptr, (double) 2.2, file_gamma);
+#endif
+
+  /* all transformations have been registered; now update info_ptr data,
+   * get rowbytes and channels, and allocate image memory */
+
+  png_read_update_info (png_ptr, info_ptr);
+
+  /* get the new color-type and bit-depth (after expansion/stripping) */
+  png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+    NULL, NULL, NULL);
+
+  /* check for 16-bit files */
+  if (bit_depth == 16)
+  {
+    raw = FALSE;
+#ifdef __TURBOC__
+    pnm_file->flags &= ~((unsigned) _F_BIN);
+#endif
+  }
+
+  /* calculate new number of channels and store alpha-presence */
+  if (color_type == PNG_COLOR_TYPE_GRAY)
+    channels = 1;
+  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    channels = 2;
+  else if (color_type == PNG_COLOR_TYPE_RGB)
+    channels = 3;
+  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+    channels = 4;
+  else
+    channels = 0; /* should never happen */
+  alpha_present = (channels - 1) % 2;
+
+  /* check if alpha is expected to be present in file */
+  if (alpha && !alpha_present)
+  {
+    fprintf (stderr, "PNG2PNM\n");
+    fprintf (stderr, "Error:  PNG-file doesn't contain alpha channel\n");
+    exit (1);
+  }
+
+  /* row_bytes is the width x number of channels x (bit-depth / 8) */
+  row_bytes = png_get_rowbytes (png_ptr, info_ptr);
+
+  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
+
+  if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+  {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    free (png_pixels);
+    png_pixels = NULL;
+    return FALSE;
+  }
+
+  /* set the individual row_pointers to point at the correct offsets */
+  for (i = 0; i < (height); i++)
+    row_pointers[i] = png_pixels + i * row_bytes;
+
+  /* now we can go ahead and just read the whole image */
+  png_read_image (png_ptr, row_pointers);
+
+  /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
+  png_read_end (png_ptr, info_ptr);
+
+  /* clean up after the read, and free any memory allocated - REQUIRED */
+  png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL);
+
+  /* write header of PNM file */
+
+  if ((color_type == PNG_COLOR_TYPE_GRAY) ||
+      (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+  {
+    fprintf (pnm_file, "%s\n", (raw) ? "P5" : "P2");
+    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
+    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+  else if ((color_type == PNG_COLOR_TYPE_RGB) ||
+           (color_type == PNG_COLOR_TYPE_RGB_ALPHA))
+  {
+    fprintf (pnm_file, "%s\n", (raw) ? "P6" : "P3");
+    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
+    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+
+  /* write header of PGM file with alpha channel */
+
+  if ((alpha) &&
+      ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
+       (color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+  {
+    fprintf (alpha_file, "%s\n", (raw) ? "P5" : "P2");
+    fprintf (alpha_file, "%d %d\n", (int) width, (int) height);
+    fprintf (alpha_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+
+  /* write data to PNM file */
+  pix_ptr = png_pixels;
+
+  for (row = 0; row < height; row++)
+  {
+    for (col = 0; col < width; col++)
+    {
+      for (i = 0; i < (channels - alpha_present); i++)
+      {
+        if (raw)
+          fputc ((int) *pix_ptr++ , pnm_file);
+        else
+          if (bit_depth == 16){
+	    dep_16 = (long) *pix_ptr++;
+            fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++));
+          }
+          else
+            fprintf (pnm_file, "%ld ", (long) *pix_ptr++);
+      }
+      if (alpha_present)
+      {
+        if (!alpha)
+        {
+          pix_ptr++; /* alpha */
+          if (bit_depth == 16)
+            pix_ptr++;
+        }
+        else /* output alpha-channel as pgm file */
+        {
+          if (raw)
+            fputc ((int) *pix_ptr++ , alpha_file);
+          else
+            if (bit_depth == 16){
+	      dep_16 = (long) *pix_ptr++;
+              fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
+	    }  
+            else
+              fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
+        }
+      } /* if alpha_present */
+
+      if (!raw)
+        if (col % 4 == 3)
+          fprintf (pnm_file, "\n");
+    } /* end for col */
+
+    if (!raw)
+      if (col % 4 != 0)
+        fprintf (pnm_file, "\n");
+  } /* end for row */
+
+  if (row_pointers != (unsigned char**) NULL)
+    free (row_pointers);
+  if (png_pixels != (unsigned char*) NULL)
+    free (png_pixels);
+
+  return TRUE;
+
+} /* end of source */
+

contrib/pngminus/png2pnm.sh

@@ -0,0 +1,41 @@
+# -- grayscale
+./png2pnm -noraw ../pngsuite/basn0g01.png basn0g01.pgm
+./png2pnm -noraw ../pngsuite/basn0g02.png basn0g02.pgm
+./png2pnm -noraw ../pngsuite/basn0g04.png basn0g04.pgm
+./png2pnm -noraw ../pngsuite/basn0g08.png basn0g08.pgm
+./png2pnm -noraw ../pngsuite/basn0g16.png basn0g16.pgm
+# -- full-color
+./png2pnm -noraw ../pngsuite/basn2c08.png basn2c08.ppm
+./png2pnm -noraw ../pngsuite/basn2c16.png basn2c16.ppm
+# -- palletted
+./png2pnm -noraw ../pngsuite/basn3p01.png basn3p01.ppm
+./png2pnm -noraw ../pngsuite/basn3p02.png basn3p02.ppm
+./png2pnm -noraw ../pngsuite/basn3p04.png basn3p04.ppm
+./png2pnm -noraw ../pngsuite/basn3p08.png basn3p08.ppm
+# -- gray with alpha-channel
+./png2pnm -noraw ../pngsuite/basn4a08.png basn4a08.pgm
+./png2pnm -noraw ../pngsuite/basn4a16.png basn4a16.pgm
+# -- color with alpha-channel
+./png2pnm -noraw -alpha basn6a08.pgm ../pngsuite/basn6a08.png basn6a08.ppm
+./png2pnm -noraw -alpha basn6a16.pgm ../pngsuite/basn6a16.png basn6a16.ppm
+# -- grayscale
+./png2pnm -raw ../pngsuite/basn0g01.png rawn0g01.pgm
+./png2pnm -raw ../pngsuite/basn0g02.png rawn0g02.pgm
+./png2pnm -raw ../pngsuite/basn0g04.png rawn0g04.pgm
+./png2pnm -raw ../pngsuite/basn0g08.png rawn0g08.pgm
+./png2pnm -raw ../pngsuite/basn0g16.png rawn0g16.pgm
+# -- full-color
+./png2pnm -raw ../pngsuite/basn2c08.png rawn2c08.ppm
+./png2pnm -raw ../pngsuite/basn2c16.png rawn2c16.ppm
+# -- palletted
+./png2pnm -raw ../pngsuite/basn3p01.png rawn3p01.ppm
+./png2pnm -raw ../pngsuite/basn3p02.png rawn3p02.ppm
+./png2pnm -raw ../pngsuite/basn3p04.png rawn3p04.ppm
+./png2pnm -raw ../pngsuite/basn3p08.png rawn3p08.ppm
+# -- gray with alpha-channel
+./png2pnm -raw ../pngsuite/basn4a08.png rawn4a08.pgm
+./png2pnm -raw ../pngsuite/basn4a16.png rawn4a16.pgm
+# -- color with alpha-channel
+./png2pnm -noraw -alpha rawn6a08.pgm ../pngsuite/basn6a08.png rawn6a08.ppm
+./png2pnm -noraw -alpha rawn6a16.pgm ../pngsuite/basn6a16.png rawn6a16.ppm
+

contrib/pngminus/pngminus.bat

@@ -0,0 +1,4 @@
+make -f makefile.tc3
+call png2pnm.bat
+call pnm2png.bat
+

contrib/pngminus/pngminus.sh

@@ -0,0 +1,4 @@
+make -f makefile.std
+sh png2pnm.sh
+sh pnm2png.sh
+

contrib/pngminus/pnm2png.bat

@@ -0,0 +1,41 @@
+REM -- grayscale
+pnm2png.exe basn0g01.pgm basn0g01.png
+pnm2png.exe basn0g02.pgm basn0g02.png
+pnm2png.exe basn0g04.pgm basn0g04.png
+pnm2png.exe basn0g08.pgm basn0g08.png
+pnm2png.exe basn0g16.pgm basn0g16.png
+REM -- full-color
+pnm2png.exe basn2c08.ppm basn2c08.png
+pnm2png.exe basn2c16.ppm basn2c16.png
+REM -- palletted
+pnm2png.exe basn3p01.ppm basn3p01.png
+pnm2png.exe basn3p02.ppm basn3p02.png
+pnm2png.exe basn3p04.ppm basn3p04.png
+pnm2png.exe basn3p08.ppm basn3p08.png
+REM -- gray with alpha-channel
+pnm2png.exe -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
+pnm2png.exe -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
+REM -- color with alpha-channel
+pnm2png.exe -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
+pnm2png.exe -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
+REM -- grayscale
+pnm2png.exe rawn0g01.pgm rawn0g01.png
+pnm2png.exe rawn0g02.pgm rawn0g02.png
+pnm2png.exe rawn0g04.pgm rawn0g04.png
+pnm2png.exe rawn0g08.pgm rawn0g08.png
+pnm2png.exe rawn0g16.pgm rawn0g16.png
+REM -- full-color
+pnm2png.exe rawn2c08.ppm rawn2c08.png
+pnm2png.exe rawn2c16.ppm rawn2c16.png
+REM -- palletted
+pnm2png.exe rawn3p01.ppm rawn3p01.png
+pnm2png.exe rawn3p02.ppm rawn3p02.png
+pnm2png.exe rawn3p04.ppm rawn3p04.png
+pnm2png.exe rawn3p08.ppm rawn3p08.png
+REM -- gray with alpha-channel
+pnm2png.exe -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
+pnm2png.exe -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
+REM -- color with alpha-channel
+pnm2png.exe -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
+pnm2png.exe -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
+

contrib/pngminus/pnm2png.c

@@ -0,0 +1,533 @@
+/*
+ *  pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file
+ *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
+ *
+ *  version 1.0 - 1999.10.15 - First version.
+ *
+ *  Permission to use, copy, modify, and distribute this software and
+ *  its documentation for any purpose and without fee is hereby granted,
+ *  provided that the above copyright notice appear in all copies and
+ *  that both that copyright notice and this permission notice appear in
+ *  supporting documentation. This software is provided "as is" without
+ *  express or implied warranty.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef __TURBOC__
+#include <mem.h>
+#include <fcntl.h>
+#endif
+
+#ifndef BOOL
+#define BOOL unsigned char
+#endif
+#ifndef TRUE
+#define TRUE (BOOL) 1
+#endif
+#ifndef FALSE
+#define FALSE (BOOL) 0
+#endif
+
+#define STDIN  0
+#define STDOUT 1
+#define STDERR 2
+
+/* to make pnm2png verbose so we can find problems (needs to be before png.h) */
+#ifndef PNG_DEBUG
+#define PNG_DEBUG 0
+#endif
+
+#include "png.h"
+
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+
+/* function prototypes */
+
+int  main (int argc, char *argv[]);
+void usage ();
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha);
+void get_token(FILE *pnm_file, char *token);
+png_uint_32 get_data (FILE *pnm_file, int depth);
+png_uint_32 get_value (FILE *pnm_file, int depth);
+
+/*
+ *  main
+ */
+
+int main(int argc, char *argv[])
+{
+  FILE *fp_rd = stdin;
+  FILE *fp_al = NULL;
+  FILE *fp_wr = stdout;
+  BOOL interlace = FALSE;
+  BOOL alpha = FALSE;
+  int argi;
+
+  for (argi = 1; argi < argc; argi++)
+  {
+    if (argv[argi][0] == '-')
+    {
+      switch (argv[argi][1])
+      {
+        case 'i':
+          interlace = TRUE;
+          break;
+        case 'a':
+          alpha = TRUE;
+          argi++;
+          if ((fp_al = fopen (argv[argi], "rb")) == NULL)
+          {
+            fprintf (stderr, "PNM2PNG\n");
+            fprintf (stderr, "Error:  alpha-channel file %s does not exist\n",
+               argv[argi]);
+            exit (1);
+          }
+          break;
+        case 'h':
+        case '?':
+          usage();
+          exit(0);
+          break;
+        default:
+          fprintf (stderr, "PNM2PNG\n");
+          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
+          usage();
+          exit(1);
+          break;
+      } /* end switch */
+    }
+    else if (fp_rd == stdin)
+    {
+      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
+      {
+        fprintf (stderr, "PNM2PNG\n");
+        fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else if (fp_wr == stdout)
+    {
+      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
+      {
+        fprintf (stderr, "PNM2PNG\n");
+        fprintf (stderr, "Error:  can not create PNG-file %s\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else
+    {
+      fprintf (stderr, "PNM2PNG\n");
+      fprintf (stderr, "Error:  too many parameters\n");
+      usage();
+      exit (1);
+    }
+  } /* end for */
+
+#ifdef __TURBOC__
+  /* set stdin/stdout to binary, we're reading the PNM always! in binary format */
+  if (fp_rd == stdin)
+  {
+    setmode (STDIN, O_BINARY);
+  }
+  if (fp_wr == stdout)
+  {
+    setmode (STDOUT, O_BINARY);
+  }
+#endif
+
+  /* call the conversion program itself */
+  if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
+  {
+    fprintf (stderr, "PNM2PNG\n");
+    fprintf (stderr, "Error:  unsuccessful converting to PNG-image\n");
+    exit (1);
+  }
+
+  /* close input file */
+  fclose (fp_rd);
+  /* close output file */
+  fclose (fp_wr);
+  /* close alpha file */
+  if (alpha)
+    fclose (fp_al);
+
+  return 0;
+}
+
+/*
+ *  usage
+ */
+
+void usage()
+{
+  fprintf (stderr, "PNM2PNG\n");
+  fprintf (stderr, "   by Willem van Schaik, 1999\n");
+#ifdef __TURBOC__
+  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
+#else
+  fprintf (stderr, "   for Linux (and Unix) compilers\n");
+#endif
+  fprintf (stderr, "Usage:  pnm2png [options] <file>.<pnm> [<file>.png]\n");
+  fprintf (stderr, "   or:  ... | pnm2png [options]\n");
+  fprintf (stderr, "Options:\n");
+  fprintf (stderr, "   -i[nterlace]   write png-file with interlacing on\n");
+  fprintf (stderr, "   -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
+  fprintf (stderr, "   -h | -?  print this help-information\n");
+}
+
+/*
+ *  pnm2png
+ */
+
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha)
+{
+  png_struct    *png_ptr = NULL;
+  png_info      *info_ptr = NULL;
+  png_byte      *png_pixels = NULL;
+  png_byte      **row_pointers = NULL;
+  png_byte      *pix_ptr = NULL;
+  png_uint_32   row_bytes;
+
+  char          type_token[16];
+  char          width_token[16];
+  char          height_token[16];
+  char          maxval_token[16];
+  int           color_type;
+  png_uint_32   width, alpha_width;
+  png_uint_32   height, alpha_height;
+  png_uint_32   maxval;
+  int           bit_depth = 0;
+  int           channels;
+  int           alpha_depth = 0;
+  int           alpha_present;
+  int           row, col;
+  BOOL          raw, alpha_raw = FALSE;
+  png_uint_32   tmp16;
+  int           i;
+
+  /* read header of PNM file */
+
+  get_token(pnm_file, type_token);
+  if (type_token[0] != 'P')
+  {
+    return FALSE;
+  }
+  else if ((type_token[1] == '1') || (type_token[1] == '4'))
+  {
+    raw = (type_token[1] == '4');
+    color_type = PNG_COLOR_TYPE_GRAY;
+    bit_depth = 1;
+  }
+  else if ((type_token[1] == '2') || (type_token[1] == '5'))
+  {
+    raw = (type_token[1] == '5');
+    color_type = PNG_COLOR_TYPE_GRAY;
+    get_token(pnm_file, width_token);
+    sscanf (width_token, "%lu", &width);
+    get_token(pnm_file, height_token);
+    sscanf (height_token, "%lu", &height);
+    get_token(pnm_file, maxval_token);
+    sscanf (maxval_token, "%lu", &maxval);
+    if (maxval <= 1)
+      bit_depth = 1;
+    else if (maxval <= 3)
+      bit_depth = 2;
+    else if (maxval <= 15)
+      bit_depth = 4;
+    else if (maxval <= 255)
+      bit_depth = 8;
+    else /* if (maxval <= 65535) */
+      bit_depth = 16;
+  }
+  else if ((type_token[1] == '3') || (type_token[1] == '6'))
+  {
+    raw = (type_token[1] == '6');
+    color_type = PNG_COLOR_TYPE_RGB;
+    get_token(pnm_file, width_token);
+    sscanf (width_token, "%lu", &width);
+    get_token(pnm_file, height_token);
+    sscanf (height_token, "%lu", &height);
+    get_token(pnm_file, maxval_token);
+    sscanf (maxval_token, "%lu", &maxval);
+    if (maxval <= 1)
+      bit_depth = 1;
+    else if (maxval <= 3)
+      bit_depth = 2;
+    else if (maxval <= 15)
+      bit_depth = 4;
+    else if (maxval <= 255)
+      bit_depth = 8;
+    else /* if (maxval <= 65535) */
+      bit_depth = 16;
+  }
+  else
+  {
+    return FALSE;
+  }
+
+  /* read header of PGM file with alpha channel */
+
+  if (alpha)
+  {
+    if (color_type == PNG_COLOR_TYPE_GRAY)
+      color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+    if (color_type == PNG_COLOR_TYPE_RGB)
+      color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+
+    get_token(alpha_file, type_token);
+    if (type_token[0] != 'P')
+    {
+      return FALSE;
+    }
+    else if ((type_token[1] == '2') || (type_token[1] == '5'))
+    {
+      alpha_raw = (type_token[1] == '5');
+      get_token(alpha_file, width_token);
+      sscanf (width_token, "%lu", &alpha_width);
+      if (alpha_width != width)
+        return FALSE;
+      get_token(alpha_file, height_token);
+      sscanf (height_token, "%lu", &alpha_height);
+      if (alpha_height != height)
+        return FALSE;
+      get_token(alpha_file, maxval_token);
+      sscanf (maxval_token, "%lu", &maxval);
+      if (maxval <= 1)
+        alpha_depth = 1;
+      else if (maxval <= 3)
+        alpha_depth = 2;
+      else if (maxval <= 15)
+        alpha_depth = 4;
+      else if (maxval <= 255)
+        alpha_depth = 8;
+      else /* if (maxval <= 65535) */
+        alpha_depth = 16;
+      if (alpha_depth != bit_depth)
+        return FALSE;
+    }
+    else
+    {
+      return FALSE;
+    }
+  } /* end if alpha */
+
+  /* calculate the number of channels and store alpha-presence */
+  if (color_type == PNG_COLOR_TYPE_GRAY)
+    channels = 1;
+  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    channels = 2;
+  else if (color_type == PNG_COLOR_TYPE_RGB)
+    channels = 3;
+  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+    channels = 4;
+  else
+    channels = 0; /* should not happen */
+
+  alpha_present = (channels - 1) % 2;
+
+  /* row_bytes is the width x number of channels x (bit-depth / 8) */
+  row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
+
+  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)
+    return FALSE;
+
+  /* read data from PNM file */
+  pix_ptr = png_pixels;
+
+  for (row = 0; row < height; row++)
+  {
+    for (col = 0; col < width; col++)
+    {
+      for (i = 0; i < (channels - alpha_present); i++)
+      {
+        if (raw)
+          *pix_ptr++ = get_data (pnm_file, bit_depth);
+        else
+          if (bit_depth <= 8)
+            *pix_ptr++ = get_value (pnm_file, bit_depth);
+          else
+          {
+            tmp16 = get_value (pnm_file, bit_depth);
+            *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
+            pix_ptr++;
+            *pix_ptr = (png_byte) (tmp16 & 0xFF);
+            pix_ptr++;
+          }
+      }
+
+      if (alpha) /* read alpha-channel from pgm file */
+      {
+        if (alpha_raw)
+          *pix_ptr++ = get_data (alpha_file, alpha_depth);
+        else
+          if (alpha_depth <= 8)
+            *pix_ptr++ = get_value (alpha_file, bit_depth);
+          else
+          {
+            tmp16 = get_value (alpha_file, bit_depth);
+            *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
+            *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
+          }
+      } /* if alpha */
+
+    } /* end for col */
+  } /* end for row */
+
+  /* prepare the standard PNG structures */
+  png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+  if (!png_ptr)
+  {
+    return FALSE;
+  }
+  info_ptr = png_create_info_struct (png_ptr);
+  if (!info_ptr)
+  {
+    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+    return FALSE;
+  }
+
+  /* setjmp() must be called in every function that calls a PNG-reading libpng function */
+  if (setjmp (png_jmpbuf(png_ptr)))
+  {
+    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+    return FALSE;
+  }
+
+  /* initialize the png structure */
+  png_init_io (png_ptr, png_file);
+
+  /* we're going to write more or less the same PNG as the input file */
+  png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
+    (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
+    PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+  /* write the file header information */
+  png_write_info (png_ptr, info_ptr);
+
+  /* if needed we will allocate memory for an new array of row-pointers */
+  if (row_pointers == (unsigned char**) NULL)
+  {
+    if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+    {
+      png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+      return FALSE;
+    }
+  }
+
+  /* set the individual row_pointers to point at the correct offsets */
+  for (i = 0; i < (height); i++)
+    row_pointers[i] = png_pixels + i * row_bytes;
+
+  /* write out the entire image data in one call */
+  png_write_image (png_ptr, row_pointers);
+
+  /* write the additional chuncks to the PNG file (not really needed) */
+  png_write_end (png_ptr, info_ptr);
+
+  /* clean up after the write, and free any memory allocated */
+  png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+
+  if (row_pointers != (unsigned char**) NULL)
+    free (row_pointers);
+  if (png_pixels != (unsigned char*) NULL)
+    free (png_pixels);
+
+  return TRUE;
+} /* end of pnm2png */
+
+/*
+ * get_token() - gets the first string after whitespace
+ */
+
+void get_token(FILE *pnm_file, char *token)
+{
+  int i = 0;
+
+  /* remove white-space */
+  do
+  {
+    token[i] = (unsigned char) fgetc (pnm_file);
+  }
+  while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
+
+  /* read string */
+  do
+  {
+    i++;
+    token[i] = (unsigned char) fgetc (pnm_file);
+  }
+  while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
+
+  token[i] = '\0';
+
+  return;
+}
+
+/*
+ * get_data() - takes first byte and converts into next pixel value,
+ *        taking as much bits as defined by bit-depth and
+ *        using the bit-depth to fill up a byte (0Ah -> AAh)
+ */
+
+png_uint_32 get_data (FILE *pnm_file, int depth)
+{
+  static int bits_left = 0;
+  static int old_value = 0;
+  static int mask = 0;
+  int i;
+  png_uint_32 ret_value;
+
+  if (mask == 0)
+    for (i = 0; i < depth; i++)
+      mask = (mask >> 1) | 0x80;
+
+  if (bits_left <= 0)
+  {
+    old_value = fgetc (pnm_file);
+    bits_left = 8;
+  }
+
+  ret_value = old_value & mask;
+  for (i = 1; i < (8 / depth); i++)
+    ret_value = ret_value || (ret_value >> depth);
+
+  old_value = (old_value << depth) & 0xFF;
+  bits_left -= depth;
+
+  return ret_value;
+}
+
+/*
+ * get_value() - takes first (numeric) string and converts into number,
+ *         using the bit-depth to fill up a byte (0Ah -> AAh)
+ */
+
+png_uint_32 get_value (FILE *pnm_file, int depth)
+{
+  static png_uint_32 mask = 0;
+  png_byte token[16];
+  png_uint_32 ret_value;
+  int i = 0;
+
+  if (mask == 0)
+    for (i = 0; i < depth; i++)
+      mask = (mask << 1) | 0x01;
+
+  get_token (pnm_file, (char *) token);
+  sscanf ((const char *) token, "%lu", &ret_value);
+
+  ret_value &= mask;
+
+  if (depth < 8)
+    for (i = 0; i < (8 / depth); i++)
+      ret_value = (ret_value << depth) || ret_value;
+
+  return ret_value;
+}
+
+/* end of source */
+

contrib/pngminus/pnm2png.sh

@@ -0,0 +1,41 @@
+# -- grayscale
+./pnm2png basn0g01.pgm basn0g01.png
+./pnm2png basn0g02.pgm basn0g02.png
+./pnm2png basn0g04.pgm basn0g04.png
+./pnm2png basn0g08.pgm basn0g08.png
+./pnm2png basn0g16.pgm basn0g16.png
+# -- full-color
+./pnm2png basn2c08.ppm basn2c08.png
+./pnm2png basn2c16.ppm basn2c16.png
+# -- palletted
+./pnm2png basn3p01.ppm basn3p01.png
+./pnm2png basn3p02.ppm basn3p02.png
+./pnm2png basn3p04.ppm basn3p04.png
+./pnm2png basn3p08.ppm basn3p08.png
+# -- gray with alpha-channel
+./pnm2png -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
+./pnm2png -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
+# -- color with alpha-channel
+./pnm2png -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
+./pnm2png -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
+# -- grayscale
+./pnm2png rawn0g01.pgm rawn0g01.png
+./pnm2png rawn0g02.pgm rawn0g02.png
+./pnm2png rawn0g04.pgm rawn0g04.png
+./pnm2png rawn0g08.pgm rawn0g08.png
+./pnm2png rawn0g16.pgm rawn0g16.png
+# -- full-color
+./pnm2png rawn2c08.ppm rawn2c08.png
+./pnm2png rawn2c16.ppm rawn2c16.png
+# -- palletted
+./pnm2png rawn3p01.ppm rawn3p01.png
+./pnm2png rawn3p02.ppm rawn3p02.png
+./pnm2png rawn3p04.ppm rawn3p04.png
+./pnm2png rawn3p08.ppm rawn3p08.png
+# -- gray with alpha-channel
+./pnm2png -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
+./pnm2png -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
+# -- color with alpha-channel
+./pnm2png -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
+./pnm2png -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
+

contrib/pngsuite/README

@@ -0,0 +1,85 @@
+
+pngsuite
+--------
+(c) Willem van Schaik, 1999
+
+Permission to use, copy, and distribute these images for any purpose and
+without fee is hereby granted.
+
+These 15 images are part of the much larger PngSuite test-set of 
+images, available for developers of PNG supporting software. The 
+complete set, available at http:/www.schaik.com/pngsuite/, contains 
+a variety of images to test interlacing, gamma settings, ancillary
+chunks, etc.
+
+The images in this directory represent the basic PNG color-types:
+grayscale (1-16 bit deep), full color (8 or 16 bit), paletted
+(1-8 bit) and grayscale or color images with alpha channel. You
+can use them to test the proper functioning of PNG software.
+
+    filename      depth type
+    ------------ ------ --------------
+    basn0g01.png  1-bit grayscale
+    basn0g02.png  2-bit grayscale
+    basn0g04.png  4-bit grayscale
+    basn0g08.png  8-bit grayscale
+    basn0g16.png 16-bit grayscale
+    basn2c08.png  8-bit truecolor
+    basn2c16.png 16-bit truecolor
+    basn3p01.png  1-bit paletted
+    basn3p02.png  2-bit paletted
+    basn3p04.png  4-bit paletted
+    basn3p08.png  8-bit paletted
+    basn4a08.png  8-bit gray with alpha
+    basn4a16.png 16-bit gray with alpha
+    basn6a08.png  8-bit RGBA
+    basn6a16.png 16-bit RGBA
+
+Here is the correct result of typing "pngtest -m *.png" in
+this directory:
+
+Testing basn0g01.png: PASS (524 zero samples)
+ Filter 0 was used 32 times
+Testing basn0g02.png: PASS (448 zero samples)
+ Filter 0 was used 32 times
+Testing basn0g04.png: PASS (520 zero samples)
+ Filter 0 was used 32 times
+Testing basn0g08.png: PASS (3 zero samples)
+ Filter 1 was used 9 times
+ Filter 4 was used 23 times
+Testing basn0g16.png: PASS (1 zero samples)
+ Filter 1 was used 1 times
+ Filter 2 was used 31 times
+Testing basn2c08.png: PASS (6 zero samples)
+ Filter 1 was used 5 times
+ Filter 4 was used 27 times
+Testing basn2c16.png: PASS (592 zero samples)
+ Filter 1 was used 1 times
+ Filter 4 was used 31 times
+Testing basn3p01.png: PASS (512 zero samples)
+ Filter 0 was used 32 times
+Testing basn3p02.png: PASS (448 zero samples)
+ Filter 0 was used 32 times
+Testing basn3p04.png: PASS (544 zero samples)
+ Filter 0 was used 32 times
+Testing basn3p08.png: PASS (4 zero samples)
+ Filter 0 was used 32 times
+Testing basn4a08.png: PASS (32 zero samples)
+ Filter 1 was used 1 times
+ Filter 4 was used 31 times
+Testing basn4a16.png: PASS (64 zero samples)
+ Filter 0 was used 1 times
+ Filter 1 was used 2 times
+ Filter 2 was used 1 times
+ Filter 4 was used 28 times
+Testing basn6a08.png: PASS (160 zero samples)
+ Filter 1 was used 1 times
+ Filter 4 was used 31 times
+Testing basn6a16.png: PASS (1072 zero samples)
+ Filter 1 was used 4 times
+ Filter 4 was used 28 times
+libpng passes test
+
+Willem van Schaik
+<willem@schaik.com>
+October 1999

contrib/visupng/PngFile.c

@@ -0,0 +1,439 @@
+//-------------------------------------
+//  PNGFILE.C -- Image File Functions
+//-------------------------------------
+
+// Copyright 2000, Willem van Schaik.  For conditions of distribution and
+// use, see the copyright/license/disclaimer notice in png.h
+
+#include <windows.h>
+#include <commdlg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "png.h"
+#include "pngfile.h"
+#include "cexcept.h"
+
+define_exception_type(const char *);
+extern struct exception_context the_exception_context[1];
+struct exception_context the_exception_context[1];
+png_const_charp msg;
+
+static OPENFILENAME ofn;
+
+static png_structp png_ptr = NULL;
+static png_infop info_ptr = NULL;
+
+
+// cexcept interface
+
+static void
+png_cexcept_error(png_structp png_ptr, png_const_charp msg)
+{
+   if(png_ptr)
+     ;
+#ifndef PNG_NO_CONSOLE_IO
+   fprintf(stderr, "libpng error: %s\n", msg);
+#endif
+   {
+      Throw msg;
+   }
+}
+
+// Windows open-file functions
+
+void PngFileInitialize (HWND hwnd)
+{
+    static TCHAR szFilter[] = TEXT ("PNG Files (*.PNG)\0*.png\0")
+        TEXT ("All Files (*.*)\0*.*\0\0");
+
+    ofn.lStructSize       = sizeof (OPENFILENAME);
+    ofn.hwndOwner         = hwnd;
+    ofn.hInstance         = NULL;
+    ofn.lpstrFilter       = szFilter;
+    ofn.lpstrCustomFilter = NULL;
+    ofn.nMaxCustFilter    = 0;
+    ofn.nFilterIndex      = 0;
+    ofn.lpstrFile         = NULL;          // Set in Open and Close functions
+    ofn.nMaxFile          = MAX_PATH;
+    ofn.lpstrFileTitle    = NULL;          // Set in Open and Close functions
+    ofn.nMaxFileTitle     = MAX_PATH;
+    ofn.lpstrInitialDir   = NULL;
+    ofn.lpstrTitle        = NULL;
+    ofn.Flags             = 0;             // Set in Open and Close functions
+    ofn.nFileOffset       = 0;
+    ofn.nFileExtension    = 0;
+    ofn.lpstrDefExt       = TEXT ("png");
+    ofn.lCustData         = 0;
+    ofn.lpfnHook          = NULL;
+    ofn.lpTemplateName    = NULL;
+}
+
+BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
+{
+    ofn.hwndOwner         = hwnd;
+    ofn.lpstrFile         = pstrFileName;
+    ofn.lpstrFileTitle    = pstrTitleName;
+    ofn.Flags             = OFN_HIDEREADONLY;
+
+    return GetOpenFileName (&ofn);
+}
+
+BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
+{
+    ofn.hwndOwner         = hwnd;
+    ofn.lpstrFile         = pstrFileName;
+    ofn.lpstrFileTitle    = pstrTitleName;
+    ofn.Flags             = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT;
+
+    return GetSaveFileName (&ofn);
+}
+
+// PNG image handler functions
+
+BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
+                   int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor)
+{
+    static FILE        *pfFile;
+    png_byte            pbSig[8];
+    int                 iBitDepth;
+    int                 iColorType;
+    double              dGamma;
+    png_color_16       *pBackground;
+    png_uint_32         ulChannels;
+    png_uint_32         ulRowBytes;
+    png_byte           *pbImageData = *ppbImageData;
+    static png_byte   **ppbRowPointers = NULL;
+    int                 i;
+
+    // open the PNG input file
+
+    if (!pstrFileName)
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    if (!(pfFile = fopen(pstrFileName, "rb")))
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    // first check the eight byte PNG signature
+
+    fread(pbSig, 1, 8, pfFile);
+    if (!png_check_sig(pbSig, 8))
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    // create the two png(-info) structures
+
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL,
+      (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
+    if (!png_ptr)
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    Try
+    {
+        
+        // initialize the png structure
+        
+#if !defined(PNG_NO_STDIO)
+        png_init_io(png_ptr, pfFile);
+#else
+        png_set_read_fn(png_ptr, (png_voidp)pfFile, png_read_data);
+#endif
+        
+        png_set_sig_bytes(png_ptr, 8);
+        
+        // read all PNG info up to image data
+        
+        png_read_info(png_ptr, info_ptr);
+        
+        // get width, height, bit-depth and color-type
+        
+        png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
+            &iColorType, NULL, NULL, NULL);
+        
+        // expand images of all color-type and bit-depth to 3x8 bit RGB images
+        // let the library process things like alpha, transparency, background
+        
+        if (iBitDepth == 16)
+            png_set_strip_16(png_ptr);
+        if (iColorType == PNG_COLOR_TYPE_PALETTE)
+            png_set_expand(png_ptr);
+        if (iBitDepth < 8)
+            png_set_expand(png_ptr);
+        if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+            png_set_expand(png_ptr);
+        if (iColorType == PNG_COLOR_TYPE_GRAY ||
+            iColorType == PNG_COLOR_TYPE_GRAY_ALPHA)
+            png_set_gray_to_rgb(png_ptr);
+        
+        // set the background color to draw transparent and alpha images over.
+        if (png_get_bKGD(png_ptr, info_ptr, &pBackground))
+        {
+            png_set_background(png_ptr, pBackground, PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+            pBkgColor->red   = (byte) pBackground->red;
+            pBkgColor->green = (byte) pBackground->green;
+            pBkgColor->blue  = (byte) pBackground->blue;
+        }
+        else
+        {
+            pBkgColor = NULL;
+        }
+        
+        // if required set gamma conversion
+        if (png_get_gAMA(png_ptr, info_ptr, &dGamma))
+            png_set_gamma(png_ptr, (double) 2.2, dGamma);
+        
+        // after the transformations have been registered update info_ptr data
+        
+        png_read_update_info(png_ptr, info_ptr);
+        
+        // get again width, height and the new bit-depth and color-type
+        
+        png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
+            &iColorType, NULL, NULL, NULL);
+        
+        
+        // row_bytes is the width x number of channels
+        
+        ulRowBytes = png_get_rowbytes(png_ptr, info_ptr);
+        ulChannels = png_get_channels(png_ptr, info_ptr);
+        
+        *piChannels = ulChannels;
+        
+        // now we can allocate memory to store the image
+        
+        if (pbImageData)
+        {
+            free (pbImageData);
+            pbImageData = NULL;
+        }
+        if ((pbImageData = (png_byte *) malloc(ulRowBytes * (*piHeight)
+                            * sizeof(png_byte))) == NULL)
+        {
+            png_error(png_ptr, "Visual PNG: out of memory");
+        }
+        *ppbImageData = pbImageData;
+        
+        // and allocate memory for an array of row-pointers
+        
+        if ((ppbRowPointers = (png_bytepp) malloc((*piHeight)
+                            * sizeof(png_bytep))) == NULL)
+        {
+            png_error(png_ptr, "Visual PNG: out of memory");
+        }
+        
+        // set the individual row-pointers to point at the correct offsets
+        
+        for (i = 0; i < (*piHeight); i++)
+            ppbRowPointers[i] = pbImageData + i * ulRowBytes;
+        
+        // now we can go ahead and just read the whole image
+        
+        png_read_image(png_ptr, ppbRowPointers);
+        
+        // read the additional chunks in the PNG file (not really needed)
+        
+        png_read_end(png_ptr, NULL);
+        
+        // and we're done
+        
+        free (ppbRowPointers);
+        ppbRowPointers = NULL;
+        
+        // yepp, done
+    }
+
+    Catch (msg)
+    {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+
+        *ppbImageData = pbImageData = NULL;
+        
+        if(ppbRowPointers)
+            free (ppbRowPointers);
+
+        fclose(pfFile);
+
+        return FALSE;
+    }
+
+    fclose (pfFile);
+
+    return TRUE;
+}
+
+
+BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
+                   int iWidth, int iHeight, png_color bkgColor)
+{
+    const int           ciBitDepth = 8;
+    const int           ciChannels = 3;
+
+    static FILE        *pfFile;
+    png_uint_32         ulRowBytes;
+    static png_byte   **ppbRowPointers = NULL;
+    int                 i;
+
+    // open the PNG output file
+
+    if (!pstrFileName)
+        return FALSE;
+
+    if (!(pfFile = fopen(pstrFileName, "wb")))
+        return FALSE;
+
+    // prepare the standard PNG structures
+
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
+      (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
+    if (!png_ptr)
+    {
+        fclose(pfFile);
+        return FALSE;
+    }
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        fclose(pfFile);
+        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
+        return FALSE;
+    }
+
+    Try
+    {
+        // initialize the png structure
+        
+#if !defined(PNG_NO_STDIO)
+        png_init_io(png_ptr, pfFile);
+#else
+        png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush);
+#endif
+        
+        // we're going to write a very simple 3x8 bit RGB image
+        
+        png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight, ciBitDepth,
+            PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
+            PNG_FILTER_TYPE_BASE);
+        
+        // write the file header information
+        
+        png_write_info(png_ptr, info_ptr);
+        
+        // swap the BGR pixels in the DiData structure to RGB
+        
+        png_set_bgr(png_ptr);
+        
+        // row_bytes is the width x number of channels
+        
+        ulRowBytes = iWidth * ciChannels;
+        
+        // we can allocate memory for an array of row-pointers
+        
+        if ((ppbRowPointers = (png_bytepp) malloc(iHeight * sizeof(png_bytep))) == NULL)
+            Throw "Visualpng: Out of memory";
+        
+        // set the individual row-pointers to point at the correct offsets
+        
+        for (i = 0; i < iHeight; i++)
+            ppbRowPointers[i] = pDiData + i * (((ulRowBytes + 3) >> 2) << 2);
+        
+        // write out the entire image data in one call
+        
+        png_write_image (png_ptr, ppbRowPointers);
+        
+        // write the additional chunks to the PNG file (not really needed)
+        
+        png_write_end(png_ptr, info_ptr);
+        
+        // and we're done
+        
+        free (ppbRowPointers);
+        ppbRowPointers = NULL;
+        
+        // clean up after the write, and free any memory allocated
+        
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        
+        // yepp, done
+    }
+
+    Catch (msg)
+    {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+
+        if(ppbRowPointers)
+            free (ppbRowPointers);
+
+        fclose(pfFile);
+
+        return FALSE;
+    }
+    
+    fclose (pfFile);
+    
+    return TRUE;
+}
+
+#ifdef PNG_NO_STDIO
+
+static void
+png_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");
+   }
+}
+
+static void
+png_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");
+   }
+}
+
+static void
+png_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
+
+//-----------------
+//  end of source
+//-----------------

contrib/visupng/PngFile.h

@@ -0,0 +1,27 @@
+//------------------------------------------
+//  PNGFILE.H -- Header File for pngfile.c
+//------------------------------------------
+
+// Copyright 2000, Willem van Schaik.  For conditions of distribution and
+// use, see the copyright/license/disclaimer notice in png.h
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <windows.h>
+
+void PngFileInitialize (HWND hwnd) ;
+BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
+BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
+
+BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData, 
+                   int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor);
+BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
+                   int iWidth, int iHeight, png_color BkgColor);
+
+#if defined(PNG_NO_STDIO)
+static void png_read_data(png_structp png_ptr, png_bytep data, png_size_t length);
+static void png_write_data(png_structp png_ptr, png_bytep data, png_size_t length);
+static void png_flush(png_structp png_ptr);
+#endif
+

contrib/visupng/README.txt

@@ -0,0 +1,58 @@
+Microsoft Developer Studio Build File, Format Version 6.00 for VisualPng
+------------------------------------------------------------------------
+
+Copyright 2000, Willem van Schaik.  For conditions of distribution and
+use, see the copyright/license/disclaimer notice in png.h
+
+As a PNG .dll demo VisualPng is finished. More features would only hinder
+the program's objective. However, further extensions (like support for other 
+graphics formats) are in development. To get these, or for pre-compiled 
+binaries, go to "http://www.schaik.com/png/visualpng.html".
+
+------------------------------------------------------------------------
+
+Assumes that
+
+   libpng DLLs and LIBs are in ..\..\projects\msvc\win32\libpng
+   zlib DLLs and LIBs are in   ..\..\projects\msvc\win32\zlib
+   libpng header files are in  ..\..\..\libpng
+   zlib header files are in    ..\..\..\zlib
+   the pngsuite images are in  ..\pngsuite
+
+To build:
+
+1) On the main menu Select "Build|Set Active configuration".
+   Choose the configuration that corresponds to the library you want to test.
+   This library must have been built using the libpng MS project located in
+   the "..\..\mscv" subdirectory.
+
+2) Select "Build|Clean"
+
+3) Select "Build|Rebuild All"
+
+4) After compiling and linking VisualPng will be started to view an image
+   from the PngSuite directory.  Press Ctrl-N (and Ctrl-V) for other images.
+
+
+To install:
+
+When distributing VisualPng (or a further development) the following options
+are available:
+
+1) Build the program with the configuration "Win32 LIB" and you only need to
+   include the executable from the ./lib directory in your distribution.
+
+2) Build the program with the configuration "Win32 DLL" and you need to put
+   in your distribution the executable from the ./dll directory and the dll's
+   libpng1.dll, zlib.dll and msvcrt.dll.  These need to be in the user's PATH.
+
+
+Willem van Schaik
+Calgary, June 6th 2000
+
+P.S. VisualPng was written based on preliminary work of:
+
+    - Simon-Pierre Cadieux
+    - Glenn Randers-Pehrson
+    - Greg Roelofs
+

contrib/visupng/VisualPng.c

@@ -0,0 +1,961 @@
+//------------------------------------
+//  VisualPng.C -- Shows a PNG image
+//------------------------------------
+
+// Copyright 2000, Willem van Schaik.  For conditions of distribution and
+// use, see the copyright/license/disclaimer notice in png.h
+
+// switches
+
+// defines
+
+#define PROGNAME  "VisualPng"
+#define LONGNAME  "Win32 Viewer for PNG-files"
+#define VERSION   "1.0 of 2000 June 07"
+
+// constants
+
+#define MARGIN 8
+
+// standard includes
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <windows.h>
+
+// application includes
+
+#include "png.h"
+#include "pngfile.h"
+#include "resource.h"
+
+// macros
+
+// function prototypes
+
+LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);
+BOOL    CALLBACK AboutDlgProc (HWND, UINT, WPARAM, LPARAM) ;
+
+BOOL CenterAbout (HWND hwndChild, HWND hwndParent);
+
+BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
+        int *pFileIndex);
+
+BOOL SearchPngList (TCHAR *pFileList, int FileCount, int *pFileIndex,
+        PTSTR pstrPrevName, PTSTR pstrNextName);
+
+BOOL LoadImageFile(HWND hwnd, PTSTR pstrPathName,
+        png_byte **ppbImage, int *pxImgSize, int *pyImgSize, int *piChannels,
+        png_color *pBkgColor);
+
+BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
+        BYTE **ppDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched);
+
+BOOL InitBitmap (
+        BYTE *pDiData, int cxWinSize, int cyWinSize);
+
+BOOL FillBitmap (
+        BYTE *pDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched);
+
+// a few global variables
+
+static char *szProgName = PROGNAME;
+static char *szAppName = LONGNAME;
+static char *szIconName = PROGNAME;
+static char szCmdFileName [MAX_PATH];
+
+// MAIN routine
+
+int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
+                    PSTR szCmdLine, int iCmdShow)
+{
+    HACCEL   hAccel;
+    HWND     hwnd;
+    MSG      msg;
+    WNDCLASS wndclass;
+    int ixBorders, iyBorders;
+
+    wndclass.style         = CS_HREDRAW | CS_VREDRAW;
+    wndclass.lpfnWndProc   = WndProc;
+    wndclass.cbClsExtra    = 0;
+    wndclass.cbWndExtra    = 0;
+    wndclass.hInstance     = hInstance;
+    wndclass.hIcon         = LoadIcon (hInstance, szIconName) ;
+    wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW);
+    wndclass.hbrBackground = NULL; // (HBRUSH) GetStockObject (GRAY_BRUSH);
+    wndclass.lpszMenuName  = szProgName;
+    wndclass.lpszClassName = szProgName;
+
+    if (!RegisterClass (&wndclass))
+    {
+        MessageBox (NULL, TEXT ("Error: this program requires Windows NT!"),
+            szProgName, MB_ICONERROR);
+        return 0;
+    }
+
+    // if filename given on commandline, store it
+    if ((szCmdLine != NULL) && (*szCmdLine != '\0'))
+        if (szCmdLine[0] == '"')
+            strncpy (szCmdFileName, szCmdLine + 1, strlen(szCmdLine) - 2);
+        else
+            strcpy (szCmdFileName, szCmdLine);
+    else
+        strcpy (szCmdFileName, "");
+
+    // calculate size of window-borders
+    ixBorders = 2 * (GetSystemMetrics (SM_CXBORDER) +
+                     GetSystemMetrics (SM_CXDLGFRAME));
+    iyBorders = 2 * (GetSystemMetrics (SM_CYBORDER) +
+                     GetSystemMetrics (SM_CYDLGFRAME)) +
+                     GetSystemMetrics (SM_CYCAPTION) +
+                     GetSystemMetrics (SM_CYMENUSIZE) +
+                     1; /* WvS: don't ask me why? */
+
+    hwnd = CreateWindow (szProgName, szAppName,
+        WS_OVERLAPPEDWINDOW,
+        CW_USEDEFAULT, CW_USEDEFAULT,
+        512 + 2 * MARGIN + ixBorders, 384 + 2 * MARGIN + iyBorders,
+//      CW_USEDEFAULT, CW_USEDEFAULT,
+        NULL, NULL, hInstance, NULL);
+
+    ShowWindow (hwnd, iCmdShow);
+    UpdateWindow (hwnd);
+
+    hAccel = LoadAccelerators (hInstance, szProgName);
+
+    while (GetMessage (&msg, NULL, 0, 0))
+    {
+        if (!TranslateAccelerator (hwnd, hAccel, &msg))
+        {
+            TranslateMessage (&msg);
+            DispatchMessage (&msg);
+        }
+    }
+    return msg.wParam;
+}
+
+LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
+        LPARAM lParam)
+{
+    static HINSTANCE          hInstance ;
+    static HDC                hdc;
+    static PAINTSTRUCT        ps;
+    static HMENU              hMenu;
+
+    static BITMAPFILEHEADER  *pbmfh;
+    static BITMAPINFOHEADER  *pbmih;
+    static BYTE              *pbImage;
+    static int                cxWinSize, cyWinSize;
+    static int                cxImgSize, cyImgSize;
+    static int                cImgChannels;
+    static png_color          bkgColor = {127, 127, 127};
+
+    static BOOL               bStretched = TRUE;
+
+    static BYTE              *pDib = NULL;
+    static BYTE              *pDiData = NULL;
+
+    static TCHAR              szImgPathName [MAX_PATH];
+    static TCHAR              szTitleName [MAX_PATH];
+
+    static TCHAR             *pPngFileList = NULL;
+    static int                iPngFileCount;
+    static int                iPngFileIndex;
+
+    BOOL                      bOk;
+
+    switch (message)
+    {
+    case WM_CREATE:
+        hInstance = ((LPCREATESTRUCT) lParam)->hInstance ;
+        PngFileInitialize (hwnd);
+
+        strcpy (szImgPathName, "");
+
+        // in case we process file given on command-line
+
+        if (szCmdFileName[0] != '\0')
+        {
+            strcpy (szImgPathName, szCmdFileName);
+
+            // read the other png-files in the directory for later
+            // next/previous commands
+
+            BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
+                          &iPngFileIndex);
+
+            // load the image from file
+
+            if (!LoadImageFile (hwnd, szImgPathName,
+                &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
+                return 0;
+
+            // invalidate the client area for later update
+
+            InvalidateRect (hwnd, NULL, TRUE);
+
+            // display the PNG into the DIBitmap
+
+            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+        }
+
+        return 0;
+
+    case WM_SIZE:
+        cxWinSize = LOWORD (lParam);
+        cyWinSize = HIWORD (lParam);
+
+        // invalidate the client area for later update
+
+        InvalidateRect (hwnd, NULL, TRUE);
+
+        // display the PNG into the DIBitmap
+
+        DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+            pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+
+        return 0;
+
+    case WM_INITMENUPOPUP:
+        hMenu = GetMenu (hwnd);
+
+        if (pbImage)
+            EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_ENABLED);
+        else
+            EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_GRAYED);
+
+        return 0;
+
+    case WM_COMMAND:
+        hMenu = GetMenu (hwnd);
+
+        switch (LOWORD (wParam))
+        {
+        case IDM_FILE_OPEN:
+
+            // show the File Open dialog box
+
+            if (!PngFileOpenDlg (hwnd, szImgPathName, szTitleName))
+                return 0;
+
+            // read the other png-files in the directory for later
+            // next/previous commands
+
+            BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
+                          &iPngFileIndex);
+
+            // load the image from file
+
+            if (!LoadImageFile (hwnd, szImgPathName,
+                &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
+                return 0;
+
+            // invalidate the client area for later update
+
+            InvalidateRect (hwnd, NULL, TRUE);
+
+            // display the PNG into the DIBitmap
+
+            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+
+            return 0;
+
+        case IDM_FILE_SAVE:
+
+            // show the File Save dialog box
+
+            if (!PngFileSaveDlg (hwnd, szImgPathName, szTitleName))
+                return 0;
+
+            // save the PNG to a disk file
+
+            SetCursor (LoadCursor (NULL, IDC_WAIT));
+            ShowCursor (TRUE);
+
+            bOk = PngSaveImage (szImgPathName, pDiData, cxWinSize, cyWinSize,
+                  bkgColor);
+
+            ShowCursor (FALSE);
+            SetCursor (LoadCursor (NULL, IDC_ARROW));
+
+            if (!bOk)
+                MessageBox (hwnd, TEXT ("Error in saving the PNG image"),
+                szProgName, MB_ICONEXCLAMATION | MB_OK);
+            return 0;
+
+        case IDM_FILE_NEXT:
+
+            // read next entry in the directory
+
+            if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
+                NULL, szImgPathName))
+            {
+                if (strcmp (szImgPathName, "") == 0)
+                    return 0;
+                
+                // load the image from file
+                
+                if (!LoadImageFile (hwnd, szImgPathName, &pbImage,
+                        &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
+                    return 0;
+                
+                // invalidate the client area for later update
+                
+                InvalidateRect (hwnd, NULL, TRUE);
+                
+                // display the PNG into the DIBitmap
+                
+                DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                    pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+            }
+            
+            return 0;
+
+        case IDM_FILE_PREVIOUS:
+
+            // read previous entry in the directory
+
+            if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
+                szImgPathName, NULL))
+            {
+                
+                if (strcmp (szImgPathName, "") == 0)
+                    return 0;
+                
+                // load the image from file
+                
+                if (!LoadImageFile (hwnd, szImgPathName, &pbImage, &cxImgSize,
+                    &cyImgSize, &cImgChannels, &bkgColor))
+                    return 0;
+                
+                // invalidate the client area for later update
+                
+                InvalidateRect (hwnd, NULL, TRUE);
+                
+                // display the PNG into the DIBitmap
+                
+                DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                    pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+            }
+
+            return 0;
+
+        case IDM_FILE_EXIT:
+
+            // more cleanup needed...
+
+            // free image buffer
+
+            if (pDib != NULL)
+            {
+                free (pDib);
+                pDib = NULL;
+            }
+
+            // free file-list
+
+            if (pPngFileList != NULL)
+            {
+                free (pPngFileList);
+                pPngFileList = NULL;
+            }
+
+            // let's go ...
+
+            exit (0);
+
+            return 0;
+
+        case IDM_OPTIONS_STRETCH:
+            bStretched = !bStretched;
+            if (bStretched)
+                CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_CHECKED);
+            else
+                CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_UNCHECKED);
+
+            // invalidate the client area for later update
+
+            InvalidateRect (hwnd, NULL, TRUE);
+
+            // display the PNG into the DIBitmap
+
+            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+
+            return 0;
+
+        case IDM_HELP_ABOUT:
+            DialogBox (hInstance, TEXT ("AboutBox"), hwnd, AboutDlgProc) ;
+            return 0;
+
+        } // end switch
+
+        break;
+
+    case WM_PAINT:
+        hdc = BeginPaint (hwnd, &ps);
+
+        if (pDib)
+            SetDIBitsToDevice (hdc, 0, 0, cxWinSize, cyWinSize, 0, 0,
+                0, cyWinSize, pDiData, (BITMAPINFO *) pDib, DIB_RGB_COLORS);
+
+        EndPaint (hwnd, &ps);
+        return 0;
+
+    case WM_DESTROY:
+        if (pbmfh)
+        {
+            free (pbmfh);
+            pbmfh = NULL;
+        }
+
+        PostQuitMessage (0);
+        return 0;
+    }
+
+    return DefWindowProc (hwnd, message, wParam, lParam);
+}
+
+BOOL CALLBACK AboutDlgProc (HWND hDlg, UINT message,
+                            WPARAM wParam, LPARAM lParam)
+{
+     switch (message)
+     {
+     case WM_INITDIALOG :
+          ShowWindow (hDlg, SW_HIDE);
+          CenterAbout (hDlg, GetWindow (hDlg, GW_OWNER));
+          ShowWindow (hDlg, SW_SHOW);
+          return TRUE ;
+
+     case WM_COMMAND :
+          switch (LOWORD (wParam))
+          {
+          case IDOK :
+          case IDCANCEL :
+               EndDialog (hDlg, 0) ;
+               return TRUE ;
+          }
+          break ;
+     }
+     return FALSE ;
+}
+
+//---------------
+//  CenterAbout
+//---------------
+
+BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
+{
+   RECT    rChild, rParent, rWorkArea;
+   int     wChild, hChild, wParent, hParent;
+   int     xNew, yNew;
+   BOOL  bResult;
+
+   // Get the Height and Width of the child window
+   GetWindowRect (hwndChild, &rChild);
+   wChild = rChild.right - rChild.left;
+   hChild = rChild.bottom - rChild.top;
+
+   // Get the Height and Width of the parent window
+   GetWindowRect (hwndParent, &rParent);
+   wParent = rParent.right - rParent.left;
+   hParent = rParent.bottom - rParent.top;
+
+   // Get the limits of the 'workarea'
+   bResult = SystemParametersInfo(
+      SPI_GETWORKAREA,  // system parameter to query or set
+      sizeof(RECT),
+      &rWorkArea,
+      0);
+   if (!bResult) {
+      rWorkArea.left = rWorkArea.top = 0;
+      rWorkArea.right = GetSystemMetrics(SM_CXSCREEN);
+      rWorkArea.bottom = GetSystemMetrics(SM_CYSCREEN);
+   }
+
+   // Calculate new X position, then adjust for workarea
+   xNew = rParent.left + ((wParent - wChild) /2);
+   if (xNew < rWorkArea.left) {
+      xNew = rWorkArea.left;
+   } else if ((xNew+wChild) > rWorkArea.right) {
+      xNew = rWorkArea.right - wChild;
+   }
+
+   // Calculate new Y position, then adjust for workarea
+   yNew = rParent.top  + ((hParent - hChild) /2);
+   if (yNew < rWorkArea.top) {
+      yNew = rWorkArea.top;
+   } else if ((yNew+hChild) > rWorkArea.bottom) {
+      yNew = rWorkArea.bottom - hChild;
+   }
+
+   // Set it, and return
+   return SetWindowPos (hwndChild, NULL, xNew, yNew, 0, 0, SWP_NOSIZE |
+          SWP_NOZORDER);
+}
+
+//----------------
+//  BuildPngList
+//----------------
+
+BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
+     int *pFileIndex)
+{
+    static TCHAR              szImgPathName [MAX_PATH];
+    static TCHAR              szImgFileName [MAX_PATH];
+    static TCHAR              szImgFindName [MAX_PATH];
+
+    WIN32_FIND_DATA           finddata;
+    HANDLE                    hFind;
+
+    static TCHAR              szTmp [MAX_PATH];
+    BOOL                      bOk;
+    int                       i, ii;
+    int                       j, jj;
+
+    // free previous file-list
+
+    if (*ppFileList != NULL)
+    {
+        free (*ppFileList);
+        *ppFileList = NULL;
+    }
+
+    // extract foldername, filename and search-name
+
+    strcpy (szImgPathName, pstrPathName);
+    strcpy (szImgFileName, strrchr (pstrPathName, '\\') + 1);
+
+    strcpy (szImgFindName, szImgPathName);
+    *(strrchr (szImgFindName, '\\') + 1) = '\0';
+    strcat (szImgFindName, "*.png");
+
+    // first cycle: count number of files in directory for memory allocation
+
+    *pFileCount = 0;
+
+    hFind = FindFirstFile(szImgFindName, &finddata);
+    bOk = (hFind != (HANDLE) -1);
+
+    while (bOk)
+    {
+        *pFileCount += 1;
+        bOk = FindNextFile(hFind, &finddata);
+    }
+    FindClose(hFind);
+
+    // allocation memory for file-list
+
+    *ppFileList = (TCHAR *) malloc (*pFileCount * MAX_PATH);
+
+    // second cycle: read directory and store filenames in file-list
+
+    hFind = FindFirstFile(szImgFindName, &finddata);
+    bOk = (hFind != (HANDLE) -1);
+
+    i = 0;
+    ii = 0;
+    while (bOk)
+    {
+        strcpy (*ppFileList + ii, szImgPathName);
+        strcpy (strrchr(*ppFileList + ii, '\\') + 1, finddata.cFileName);
+
+        if (strcmp(pstrPathName, *ppFileList + ii) == 0)
+            *pFileIndex = i;
+
+        ii += MAX_PATH;
+        i++;
+
+        bOk = FindNextFile(hFind, &finddata);
+    }
+    FindClose(hFind);
+
+    // finally we must sort the file-list
+
+    for (i = 0; i < *pFileCount - 1; i++)
+    {
+        ii = i * MAX_PATH;
+        for (j = i+1; j < *pFileCount; j++)
+        {
+            jj = j * MAX_PATH;
+            if (strcmp (*ppFileList + ii, *ppFileList + jj) > 0)
+            {
+                strcpy (szTmp, *ppFileList + jj);
+                strcpy (*ppFileList + jj, *ppFileList + ii);
+                strcpy (*ppFileList + ii, szTmp);
+
+                // check if this was the current image that we moved
+
+                if (*pFileIndex == i)
+                    *pFileIndex = j;
+                else
+                    if (*pFileIndex == j)
+                        *pFileIndex = i;
+            }
+        }
+    }
+
+    return TRUE;
+}
+
+//----------------
+//  SearchPngList
+//----------------
+
+BOOL SearchPngList (
+        TCHAR *pFileList, int FileCount, int *pFileIndex,
+        PTSTR pstrPrevName, PTSTR pstrNextName)
+{
+    if (FileCount > 0)
+    {
+        // get previous entry
+        
+        if (pstrPrevName != NULL)
+        {
+            if (*pFileIndex > 0)
+                *pFileIndex -= 1;
+            else
+                *pFileIndex = FileCount - 1;
+            
+            strcpy (pstrPrevName, pFileList + (*pFileIndex * MAX_PATH));
+        }
+        
+        // get next entry
+        
+        if (pstrNextName != NULL)
+        {
+            if (*pFileIndex < FileCount - 1)
+                *pFileIndex += 1;
+            else
+                *pFileIndex = 0;
+            
+            strcpy (pstrNextName, pFileList + (*pFileIndex * MAX_PATH));
+        }
+        
+        return TRUE;
+    }
+    else
+    {
+        return FALSE;
+    }
+}
+
+//-----------------
+//  LoadImageFile
+//-----------------
+
+BOOL LoadImageFile (HWND hwnd, PTSTR pstrPathName,
+                png_byte **ppbImage, int *pxImgSize, int *pyImgSize,
+                int *piChannels, png_color *pBkgColor)
+{
+    static TCHAR szTmp [MAX_PATH];
+
+    // if there's an existing PNG, free the memory
+
+    if (*ppbImage)
+    {
+        free (*ppbImage);
+        *ppbImage = NULL;
+    }
+
+    // Load the entire PNG into memory
+
+    SetCursor (LoadCursor (NULL, IDC_WAIT));
+    ShowCursor (TRUE);
+
+    PngLoadImage (pstrPathName, ppbImage, pxImgSize, pyImgSize, piChannels,
+                  pBkgColor);
+
+    ShowCursor (FALSE);
+    SetCursor (LoadCursor (NULL, IDC_ARROW));
+
+    if (*ppbImage != NULL)
+    {
+        sprintf (szTmp, "VisualPng - %s", strrchr(pstrPathName, '\\') + 1);
+        SetWindowText (hwnd, szTmp);
+    }
+    else
+    {
+        MessageBox (hwnd, TEXT ("Error in loading the PNG image"),
+            szProgName, MB_ICONEXCLAMATION | MB_OK);
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+//----------------
+//  DisplayImage
+//----------------
+
+BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
+        BYTE **ppDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched)
+{
+    BYTE                       *pDib = *ppDib;
+    BYTE                       *pDiData = *ppDiData;
+    // BITMAPFILEHEADER        *pbmfh;
+    BITMAPINFOHEADER           *pbmih;
+    WORD                        wDIRowBytes;
+    png_color                   bkgBlack = {0, 0, 0};
+    png_color                   bkgGray  = {127, 127, 127};
+    png_color                   bkgWhite = {255, 255, 255};
+
+    // allocate memory for the Device Independant bitmap
+
+    wDIRowBytes = (WORD) ((3 * cxWinSize + 3L) >> 2) << 2;
+
+    if (pDib)
+    {
+        free (pDib);
+        pDib = NULL;
+    }
+
+    if (!(pDib = (BYTE *) malloc (sizeof(BITMAPINFOHEADER) +
+        wDIRowBytes * cyWinSize)))
+    {
+        MessageBox (hwnd, TEXT ("Error in displaying the PNG image"),
+            szProgName, MB_ICONEXCLAMATION | MB_OK);
+        *ppDib = pDib = NULL;
+        return FALSE;
+    }
+    *ppDib = pDib;
+    memset (pDib, 0, sizeof(BITMAPINFOHEADER));
+
+    // initialize the dib-structure
+
+    pbmih = (BITMAPINFOHEADER *) pDib;
+    pbmih->biSize = sizeof(BITMAPINFOHEADER);
+    pbmih->biWidth = cxWinSize;
+    pbmih->biHeight = -((long) cyWinSize);
+    pbmih->biPlanes = 1;
+    pbmih->biBitCount = 24;
+    pbmih->biCompression = 0;
+    pDiData = pDib + sizeof(BITMAPINFOHEADER);
+    *ppDiData = pDiData;
+
+    // first fill bitmap with gray and image border
+
+    InitBitmap (pDiData, cxWinSize, cyWinSize);
+
+    // then fill bitmap with image
+
+    if (pbImage)
+    {
+        FillBitmap (
+            pDiData, cxWinSize, cyWinSize,
+            pbImage, cxImgSize, cyImgSize, cImgChannels,
+            bStretched);
+    }
+
+    return TRUE;
+}
+
+//--------------
+//  InitBitmap
+//--------------
+
+BOOL InitBitmap (BYTE *pDiData, int cxWinSize, int cyWinSize)
+{
+    BYTE *dst;
+    int x, y, col;
+
+    // initialize the background with gray
+
+    dst = pDiData;
+    for (y = 0; y < cyWinSize; y++)
+    {
+        col = 0;
+        for (x = 0; x < cxWinSize; x++)
+        {
+            // fill with GRAY
+            *dst++ = 127;
+            *dst++ = 127;
+            *dst++ = 127;
+            col += 3;
+        }
+        // rows start on 4 byte boundaries
+        while ((col % 4) != 0)
+        {
+            dst++;
+            col++;
+        }
+    }
+
+    return TRUE;
+}
+
+//--------------
+//  FillBitmap
+//--------------
+
+BOOL FillBitmap (
+        BYTE *pDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched)
+{
+    BYTE *pStretchedImage;
+    BYTE *pImg;
+    BYTE *src, *dst;
+    BYTE r, g, b, a;
+    const int cDIChannels = 3;
+    WORD wImgRowBytes;
+    WORD wDIRowBytes;
+    int cxNewSize, cyNewSize;
+    int cxImgPos, cyImgPos;
+    int xImg, yImg;
+    int xWin, yWin;
+    int xOld, yOld;
+    int xNew, yNew;
+
+    if (bStretched)
+    {
+        cxNewSize = cxWinSize - 2 * MARGIN;
+        cyNewSize = cyWinSize - 2 * MARGIN;
+
+        // stretch the image to it's window determined size
+
+        // the following two are the same, but the first has side-effects
+        // because of rounding
+//      if ((cyNewSize / cxNewSize) > (cyImgSize / cxImgSize))
+        if ((cyNewSize * cxImgSize) > (cyImgSize * cxNewSize))
+        {
+            cyNewSize = cxNewSize * cyImgSize / cxImgSize;
+            cxImgPos = MARGIN;
+            cyImgPos = (cyWinSize - cyNewSize) / 2;
+        }
+        else
+        {
+            cxNewSize = cyNewSize * cxImgSize / cyImgSize;
+            cyImgPos = MARGIN;
+            cxImgPos = (cxWinSize - cxNewSize) / 2;
+        }
+
+        pStretchedImage = malloc (cImgChannels * cxNewSize * cyNewSize);
+        pImg = pStretchedImage;
+
+        for (yNew = 0; yNew < cyNewSize; yNew++)
+        {
+            yOld = yNew * cyImgSize / cyNewSize;
+            for (xNew = 0; xNew < cxNewSize; xNew++)
+            {
+                xOld = xNew * cxImgSize / cxNewSize;
+
+                r = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 0);
+                g = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 1);
+                b = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 2);
+                *pImg++ = r;
+                *pImg++ = g;
+                *pImg++ = b;
+                if (cImgChannels == 4)
+                {
+                    a = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld)
+                        + 3);
+                    *pImg++ = a;
+                }
+            }
+        }
+
+        // calculate row-bytes
+
+        wImgRowBytes = cImgChannels * cxNewSize;
+        wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
+
+        // copy image to screen
+
+        for (yImg = 0, yWin = cyImgPos; yImg < cyNewSize; yImg++, yWin++)
+        {
+            if (yWin >= cyWinSize - cyImgPos)
+                break;
+            src = pStretchedImage + yImg * wImgRowBytes;
+            dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
+
+            for (xImg = 0, xWin = cxImgPos; xImg < cxNewSize; xImg++, xWin++)
+            {
+                if (xWin >= cxWinSize - cxImgPos)
+                    break;
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dst++ = b; /* note the reverse order */
+                *dst++ = g;
+                *dst++ = r;
+                if (cImgChannels == 4)
+                {
+                    a = *src++;
+                }
+            }
+        }
+
+        // free memory
+
+        if (pStretchedImage != NULL)
+        {
+            free (pStretchedImage);
+            pStretchedImage = NULL;
+        }
+
+    }
+
+    // process the image not-stretched
+
+    else
+    {
+        // calculate the central position
+
+        cxImgPos = (cxWinSize - cxImgSize) / 2;
+        cyImgPos = (cyWinSize - cyImgSize) / 2;
+
+        // check for image larger than window
+
+        if (cxImgPos < MARGIN)
+            cxImgPos = MARGIN;
+        if (cyImgPos < MARGIN)
+            cyImgPos = MARGIN;
+
+        // calculate both row-bytes
+
+        wImgRowBytes = cImgChannels * cxImgSize;
+        wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
+
+        // copy image to screen
+
+        for (yImg = 0, yWin = cyImgPos; yImg < cyImgSize; yImg++, yWin++)
+        {
+            if (yWin >= cyWinSize - MARGIN)
+                break;
+            src = pbImage + yImg * wImgRowBytes;
+            dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
+
+            for (xImg = 0, xWin = cxImgPos; xImg < cxImgSize; xImg++, xWin++)
+            {
+                if (xWin >= cxWinSize - MARGIN)
+                    break;
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dst++ = b; /* note the reverse order */
+                *dst++ = g;
+                *dst++ = r;
+                if (cImgChannels == 4)
+                {
+                    a = *src++;
+                }
+            }
+        }
+    }
+
+    return TRUE;
+}
+
+//-----------------
+//  end of source
+//-----------------

contrib/visupng/VisualPng.dsp

@@ -0,0 +1,223 @@
+# Microsoft Developer Studio Project File - Name="VisualPng" - Package Owner=<4>
+# Microsoft Developer Studio Generated Build File, Format Version 6.00
+
+# Copyright 2000, Willem van Schaik.  For conditions of distribution and
+# use, see the copyright/license/disclaimer notice in png.h
+
+# ** DO NOT EDIT **
+
+# TARGTYPE "Win32 (x86) Application" 0x0101
+
+CFG=VisualPng - Win32 Debug LIB
+!MESSAGE This is not a valid makefile. To build this project using NMAKE,
+!MESSAGE use the Export Makefile command and run
+!MESSAGE 
+!MESSAGE NMAKE /f "VisualPng.mak".
+!MESSAGE 
+!MESSAGE You can specify a configuration when running NMAKE
+!MESSAGE by defining the macro CFG on the command line. For example:
+!MESSAGE 
+!MESSAGE NMAKE /f "VisualPng.mak" CFG="VisualPng - Win32 Debug LIB"
+!MESSAGE 
+!MESSAGE Possible choices for configuration are:
+!MESSAGE 
+!MESSAGE "VisualPng - Win32 DLL" (based on "Win32 (x86) Application")
+!MESSAGE "VisualPng - Win32 Debug DLL" (based on "Win32 (x86) Application")
+!MESSAGE "VisualPng - Win32 LIB" (based on "Win32 (x86) Application")
+!MESSAGE "VisualPng - Win32 Debug LIB" (based on "Win32 (x86) Application")
+!MESSAGE 
+
+# Begin Project
+# PROP AllowPerConfigDependencies 0
+# PROP Scc_ProjName ""
+# PROP Scc_LocalPath ""
+CPP=cl.exe
+MTL=midl.exe
+RSC=rc.exe
+
+!IF  "$(CFG)" == "VisualPng - Win32 DLL"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 0
+# PROP BASE Output_Dir "VisualPng___Win32_DLL"
+# PROP BASE Intermediate_Dir "VisualPng___Win32_DLL"
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 0
+# PROP Output_Dir "dll"
+# PROP Intermediate_Dir "dll"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /GX /O2 /I "libpng" /I "zlib" /D "PNG_USE_DLL" /D "WIN32" /D "NDEBUG" /D "_WINDOWS" /D "_MBCS" /YX /FD /c
+# ADD CPP /nologo /W3 /GX /O2 /I "..\..\..\libpng" /I "..\..\..\zlib" /D "WIN32" /D "NDEBUG" /D "_WINDOWS" /D "_MBCS" /D "PNG_USE_DLL" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /c
+# SUBTRACT CPP /YX
+# ADD BASE MTL /nologo /D "NDEBUG" /mktyplib203 /win32
+# ADD MTL /nologo /D "NDEBUG" /mktyplib203 /win32
+# ADD BASE RSC /l 0x409 /d "NDEBUG"
+# ADD RSC /l 0x409 /d "NDEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 libpng1.lib zlibd.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /machine:I386 /libpath:"libpng" /libpath:"zlib"
+# ADD LINK32 libpng1.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /machine:I386 /libpath:"..\..\projects\msvc\win32\libpng\dll"
+# Begin Special Build Tool
+OutDir=.\dll
+SOURCE="$(InputPath)"
+PostBuild_Cmds=set path=..\..\projects\msvc\win32\libpng\dll;..\..\projects\msvc\win32\zlib\dll;	$(outdir)\VisualPng.exe ..\..\contrib\pngsuite\basn6a16.png
+# End Special Build Tool
+
+!ELSEIF  "$(CFG)" == "VisualPng - Win32 Debug DLL"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 1
+# PROP BASE Output_Dir "VisualPng___Win32_Debug_DLL"
+# PROP BASE Intermediate_Dir "VisualPng___Win32_Debug_DLL"
+# PROP BASE Ignore_Export_Lib 0
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 1
+# PROP Output_Dir "dll_dbg"
+# PROP Intermediate_Dir "dll_dbg"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /Gm /GX /ZI /Od /I "libpng" /I "zlib" /D "PNG_USE_DLL" /D "WIN32" /D "_DEBUG" /D "_WINDOWS" /D "_MBCS" /YX /FD /GZ /c
+# ADD CPP /nologo /W3 /Gm /GX /ZI /Od /I "..\..\..\libpng" /I "..\..\..\zlib" /D "WIN32" /D "_DEBUG" /D "_WINDOWS" /D "_MBCS" /D "PNG_USE_DLL" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /GZ /c
+# SUBTRACT CPP /YX
+# ADD BASE MTL /nologo /D "_DEBUG" /mktyplib203 /win32
+# ADD MTL /nologo /D "_DEBUG" /mktyplib203 /win32
+# ADD BASE RSC /l 0x409 /d "_DEBUG"
+# ADD RSC /l 0x409 /d "_DEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 libpng1.lib zlibd.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /debug /machine:I386 /nodefaultlib:"libc" /pdbtype:sept /libpath:"libpng" /libpath:"zlib"
+# SUBTRACT BASE LINK32 /nodefaultlib
+# ADD LINK32 libpng1d.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /debug /machine:I386 /nodefaultlib:"libc" /pdbtype:sept /libpath:"..\..\projects\msvc\win32\libpng\dll_dbg"
+# SUBTRACT LINK32 /nodefaultlib
+# Begin Special Build Tool
+OutDir=.\dll_dbg
+SOURCE="$(InputPath)"
+PostBuild_Cmds=set path=..\..\projects\msvc\win32\libpng\dll_dbg;..\..\projects\msvc\win32\zlib\dll_dbg;	$(outdir)\VisualPng.exe ..\..\contrib\pngsuite\basn6a16.png
+# End Special Build Tool
+
+!ELSEIF  "$(CFG)" == "VisualPng - Win32 LIB"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 0
+# PROP BASE Output_Dir "VisualPng___Win32_LIB"
+# PROP BASE Intermediate_Dir "VisualPng___Win32_LIB"
+# PROP BASE Ignore_Export_Lib 0
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 0
+# PROP Output_Dir "lib"
+# PROP Intermediate_Dir "lib"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /GX /O2 /I "..\..\..\libpng" /I "..\..\..\zlib" /D "WIN32" /D "NDEBUG" /D "_WINDOWS" /D "_MBCS" /D "PNG_USE_DLL" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /c
+# SUBTRACT BASE CPP /YX
+# ADD CPP /nologo /W3 /GX /O2 /I "..\..\..\libpng" /I "..\..\..\zlib" /D "WIN32" /D "NDEBUG" /D "_WINDOWS" /D "_MBCS" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /c
+# SUBTRACT CPP /YX
+# ADD BASE MTL /nologo /D "NDEBUG" /mktyplib203 /win32
+# ADD MTL /nologo /D "NDEBUG" /mktyplib203 /win32
+# ADD BASE RSC /l 0x409 /d "NDEBUG"
+# ADD RSC /l 0x409 /d "NDEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 libpng1.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /machine:I386 /libpath:"..\..\projects\msvc\win32\libpng\dll"
+# ADD LINK32 libpng.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /machine:I386 /libpath:"..\..\projects\msvc\win32\libpng\lib"
+# Begin Special Build Tool
+OutDir=.\lib
+SOURCE="$(InputPath)"
+PostBuild_Cmds=$(outdir)\VisualPng.exe ..\..\contrib\pngsuite\basn6a16.png
+# End Special Build Tool
+
+!ELSEIF  "$(CFG)" == "VisualPng - Win32 Debug LIB"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 1
+# PROP BASE Output_Dir "VisualPng___Win32_Debug_LIB"
+# PROP BASE Intermediate_Dir "VisualPng___Win32_Debug_LIB"
+# PROP BASE Ignore_Export_Lib 0
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 1
+# PROP Output_Dir "lib_dbg"
+# PROP Intermediate_Dir "lib_dbg"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /Gm /GX /ZI /Od /I "..\..\..\libpng" /I "..\..\..\zlib" /D "WIN32" /D "_DEBUG" /D "_WINDOWS" /D "_MBCS" /D "PNG_USE_DLL" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /YX /FD /GZ /c
+# ADD CPP /nologo /W3 /Gm /GX /ZI /Od /I "..\..\..\libpng" /I "..\..\..\zlib" /D "WIN32" /D "_DEBUG" /D "_WINDOWS" /D "_MBCS" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /GZ /c
+# SUBTRACT CPP /YX
+# ADD BASE MTL /nologo /D "_DEBUG" /mktyplib203 /win32
+# ADD MTL /nologo /D "_DEBUG" /mktyplib203 /win32
+# ADD BASE RSC /l 0x409 /d "_DEBUG"
+# ADD RSC /l 0x409 /d "_DEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 libpng1d.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /debug /machine:I386 /nodefaultlib:"libc" /pdbtype:sept /libpath:"..\..\projects\msvc\win32\libpng\dll_dbg"
+# SUBTRACT BASE LINK32 /nodefaultlib
+# ADD LINK32 libpng.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /debug /machine:I386 /nodefaultlib:"libc" /pdbtype:sept /libpath:"..\..\projects\msvc\win32\libpng\lib_dbg"
+# SUBTRACT LINK32 /nodefaultlib
+# Begin Special Build Tool
+OutDir=.\lib_dbg
+SOURCE="$(InputPath)"
+PostBuild_Cmds=$(outdir)\VisualPng.exe ..\..\contrib\pngsuite\basn6a16.png
+# End Special Build Tool
+
+!ENDIF 
+
+# Begin Target
+
+# Name "VisualPng - Win32 DLL"
+# Name "VisualPng - Win32 Debug DLL"
+# Name "VisualPng - Win32 LIB"
+# Name "VisualPng - Win32 Debug LIB"
+# Begin Group "Source Files"
+
+# PROP Default_Filter "cpp;c;cxx;rc;def;r;odl;idl;hpj;bat"
+# Begin Source File
+
+SOURCE=.\PngFile.c
+# End Source File
+# Begin Source File
+
+SOURCE=.\VisualPng.c
+# End Source File
+# End Group
+# Begin Group "Header Files"
+
+# PROP Default_Filter "h;hpp;hxx;hm;inl"
+# Begin Source File
+
+SOURCE=.\cexcept.h
+# End Source File
+# Begin Source File
+
+SOURCE=.\PngFile.h
+# End Source File
+# Begin Source File
+
+SOURCE=.\resource.h
+# End Source File
+# End Group
+# Begin Group "Resource Files"
+
+# PROP Default_Filter "ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
+# Begin Source File
+
+SOURCE=.\VisualPng.ico
+# End Source File
+# Begin Source File
+
+SOURCE=.\VisualPng.rc
+# End Source File
+# End Group
+# End Target
+# End Project

contrib/visupng/VisualPng.dsw

@@ -0,0 +1,29 @@
+Microsoft Developer Studio Workspace File, Format Version 6.00
+# WARNING: DO NOT EDIT OR DELETE THIS WORKSPACE FILE!
+
+###############################################################################
+
+Project: "VisualPng"=.\VisualPng.dsp - Package Owner=<4>
+
+Package=<5>
+{{{
+}}}
+
+Package=<4>
+{{{
+}}}
+
+###############################################################################
+
+Global:
+
+Package=<5>
+{{{
+}}}
+
+Package=<3>
+{{{
+}}}
+
+###############################################################################
+

contrib/visupng/VisualPng.rc

@@ -0,0 +1,152 @@
+//Microsoft Developer Studio generated resource script.
+//
+#include "resource.h"
+
+#define APSTUDIO_READONLY_SYMBOLS
+/////////////////////////////////////////////////////////////////////////////
+//
+// Generated from the TEXTINCLUDE 2 resource.
+//
+#include "afxres.h"
+
+/////////////////////////////////////////////////////////////////////////////
+#undef APSTUDIO_READONLY_SYMBOLS
+
+/////////////////////////////////////////////////////////////////////////////
+// English (U.S.) resources
+
+#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
+#ifdef _WIN32
+LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
+#pragma code_page(1252)
+#endif //_WIN32
+
+#ifdef APSTUDIO_INVOKED
+/////////////////////////////////////////////////////////////////////////////
+//
+// TEXTINCLUDE
+//
+
+1 TEXTINCLUDE DISCARDABLE 
+BEGIN
+    "resource.h\0"
+END
+
+2 TEXTINCLUDE DISCARDABLE 
+BEGIN
+    "#include ""afxres.h""\r\n"
+    "\0"
+END
+
+3 TEXTINCLUDE DISCARDABLE 
+BEGIN
+    "\r\n"
+    "\0"
+END
+
+#endif    // APSTUDIO_INVOKED
+
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// Menu
+//
+
+VISUALPNG MENU DISCARDABLE 
+BEGIN
+    POPUP "&File"
+    BEGIN
+        MENUITEM "&Open Image...\tCtrl+O",      IDM_FILE_OPEN
+        MENUITEM "Save &As...",                 IDM_FILE_SAVE
+        MENUITEM SEPARATOR
+        MENUITEM "&Next Image\tCtrl+N",         IDM_FILE_NEXT
+        MENUITEM "Pre&vious Image\tCtrl+V",     IDM_FILE_PREVIOUS
+        MENUITEM SEPARATOR
+        MENUITEM "E&xit\tAlt+X",                IDM_FILE_EXIT
+    END
+    POPUP "&Options"
+    BEGIN
+        MENUITEM "&Stretch",                    IDM_OPTIONS_STRETCH, CHECKED
+    END
+    POPUP "&Help"
+    BEGIN
+        MENUITEM "&About",                      IDM_HELP_ABOUT
+    END
+END
+
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// Accelerator
+//
+
+VISUALPNG ACCELERATORS DISCARDABLE 
+BEGIN
+    "N",            IDM_FILE_NEXT,          VIRTKEY, CONTROL, NOINVERT
+    "O",            IDM_FILE_OPEN,          VIRTKEY, CONTROL, NOINVERT
+    "P",            IDM_FILE_PREVIOUS,      VIRTKEY, CONTROL, NOINVERT
+    "V",            IDM_FILE_PREVIOUS,      VIRTKEY, CONTROL, NOINVERT
+    "X",            IDM_FILE_EXIT,          VIRTKEY, ALT, NOINVERT
+END
+
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// Icon
+//
+
+// Icon with lowest ID value placed first to ensure application icon
+// remains consistent on all systems.
+VISUALPNG               ICON    DISCARDABLE     "VisualPng.ico"
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// Dialog
+//
+
+ABOUTBOX DIALOG DISCARDABLE  0, 0, 186, 94
+STYLE DS_MODALFRAME | WS_POPUP
+FONT 8, "MS Sans Serif"
+BEGIN
+    DEFPUSHBUTTON   "OK",IDOK,68,67,50,14
+    CTEXT           "VisualPng 1.0  -  June 2000",IDC_STATIC,49,14,88,8
+    LTEXT           "a PNG image viewer",IDC_STATIC,60,30,66,8
+    LTEXT           "(c) Willem van Schaik, 2000",IDC_STATIC,48,52,90,8
+    LTEXT           "to demonstrate the use of libpng in Visual C",
+                    IDC_STATIC,25,38,136,8
+END
+
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// DESIGNINFO
+//
+
+#ifdef APSTUDIO_INVOKED
+GUIDELINES DESIGNINFO DISCARDABLE 
+BEGIN
+    "ABOUTBOX", DIALOG
+    BEGIN
+        LEFTMARGIN, 7
+        RIGHTMARGIN, 179
+        TOPMARGIN, 7
+        BOTTOMMARGIN, 87
+    END
+END
+#endif    // APSTUDIO_INVOKED
+
+#endif    // English (U.S.) resources
+/////////////////////////////////////////////////////////////////////////////
+
+
+
+#ifndef APSTUDIO_INVOKED
+/////////////////////////////////////////////////////////////////////////////
+//
+// Generated from the TEXTINCLUDE 3 resource.
+//
+
+
+/////////////////////////////////////////////////////////////////////////////
+#endif    // not APSTUDIO_INVOKED
+

contrib/visupng/cexcept.h

@@ -0,0 +1,244 @@
+/*===
+cexcept.h 1.0.0 (2000-Jun-21-Wed)
+Adam M. Costello <amc@cs.berkeley.edu>
+
+An interface for exception-handling in ANSI C, developed jointly with
+Cosmin Truta <cosmin@cs.toronto.edu>.
+
+    Copyright (c) 2000 Adam M. Costello and Cosmin Truta.  Everyone
+    is hereby granted permission to do whatever they like with this
+    file, provided that if they modify it they take reasonable steps to
+    avoid confusing or misleading people about the authors, version,
+    and terms of use of the derived file.  The copyright holders make
+    no guarantees about the correctness of this file, and are not
+    responsible for any damage resulting from its use.
+
+If this interface is used by multiple .c files, they shouldn't include
+this header file directly.  Instead, create a wrapper header file that
+includes this header file and then invokes the define_exception_type
+macro (see below), and let your .c files include that header file.
+
+The interface consists of one type, one well-known name, and six macros.
+
+
+define_exception_type(type_name);
+
+    This macro is used like an external declaration.  It specifies
+    the type of object that gets copied from the exception thrower to
+    the exception catcher.  The type_name can be any type that can be
+    assigned to, that is, a non-constant arithmetic type, struct, union,
+    or pointer.  Examples:
+
+        define_exception_type(int);
+
+        enum exception { out_of_memory, bad_arguments, disk_full };
+        define_exception_type(enum exception);
+
+        struct exception { int code; const char *msg; };
+        define_exception_type(struct exception);
+
+
+struct exception_context;
+
+    This type may be used after the define_exception_type() macro has
+    been invoked.  A struct exception_context must be known to both
+    the thrower and the catcher.  It is expected that there be one
+    context for each thread that uses exceptions.  It would certainly
+    be dangerous for multiple threads to access the same context.
+    One thread can use multiple contexts, but that is likely to be
+    confusing and not typically useful.  The application can allocate
+    this structure in any way it pleases--automatic, static, or dynamic.
+    The application programmer should pretend not to know the structure
+    members, which are subject to change.
+
+
+struct exception_context *the_exception_context;
+
+    The Try/Catch and Throw statements (described below) implicitly
+    refer to a context, using the name the_exception_context.  It is
+    the application's responsibility to make sure that this name yields
+    the address of a mutable (non-constant) struct exception_context
+    wherever those statements are used.  Subject to that constraint, the
+    application may declare a variable of this name anywhere it likes
+    (inside a function, in a parameter list, or externally), and may
+    use whatever storage class specifiers (static, extern, etc) or type
+    qualifiers (const, volatile) it likes.  Examples:
+
+        static struct exception_context
+          * const the_exception_context = &foo;
+
+        { struct exception_context *the_exception_context = bar; ... }
+
+        int blah(struct exception_context *the_exception_context, ...);
+
+        extern struct exception_context the_exception_context[1];
+
+    The last example illustrates a trick that avoids creating a pointer
+    object separate from the structure object.
+
+    The name could even be a macro, for example:
+
+        struct exception_context ec_array[numthreads];
+        #define the_exception_context (ec_array + thread_id)
+
+    Be aware that the_exception_context is used several times by the
+    Try/Catch/Throw macros, so it shouldn't be expensive or have side
+    effects.  The expansion must be a drop-in replacement for an
+    identifier, so it's safest to put parentheses around it.
+
+
+void init_exception_context(struct exception_context *ec);
+
+    For context structures allocated statically (by an external
+    definition or using the "static" keyword), the implicit
+    initialization to all zeros is sufficient, but contexts allocated
+    by other means must be initialized using this macro before they
+    are used by a Try/Catch statement.  It does no harm to initialize
+    a context more than once (by using this macro on a statically
+    allocated context, or using this macro twice on the same context),
+    but a context must not be re-initialized after it has been used by a
+    Try/Catch statement.
+
+
+Try statement
+Catch (expression) statement
+
+    The Try/Catch/Throw macros are capitalized in order to avoid
+    confusion with the C++ keywords, which have subtly different
+    semantics.
+
+    A Try/Catch statement has a syntax similar to an if/else
+    statement, except that the parenthesized expression goes after
+    the second keyword rather than the first.  As with if/else,
+    there are two clauses, each of which may be a simple statement
+    ending with a semicolon or a brace-enclosed compound statement.
+    But whereas the else clause is optional, the Catch clause is
+    required.  The expression must be a modifiable lvalue (something
+    capable of being assigned to) of the exact same type passed to
+    define_exception_type().
+
+    If a Throw that uses the same exception context as the Try/Catch is
+    executed within the Try clause (typically within a function called
+    by the Try clause), and the exception is not caught by a nested
+    Try/Catch statement, then a copy of the exception will be assigned
+    to the expression, and control will jump to the Catch clause.  If no
+    such Throw is executed, then the assignment is not performed, and
+    the Catch clause is not executed.
+
+    Regardless of whether an exception is caught, the expression is
+    always evaluated exactly once, which is significant if it has side
+    effects, for example:
+
+        Try foo();
+        Catch (p[++i].e) { ... }
+
+    IMPORTANT: Jumping into or out of a Try clause (for example via
+    return, break, continue, goto, longjmp) is forbidden--the compiler
+    will not complain, but bad things will happen at run-time.  Jumping
+    into or out of a Catch clause is okay, and so is jumping around
+    inside a Try clause.  In many cases where one is tempted to return
+    from a Try clause, it will suffice to use Throw, and then return
+    from the Catch clause.  Another option is to set a flag variable and
+    use goto to jump to the end of the Try clause, then check the flag
+    after the Try/Catch statement.
+
+    IMPORTANT: The values of any non-volatile automatic variables
+    changed within the Try clause are undefined after an exception is
+    caught.  Therefore, variables modified inside the Try block whose
+    values are needed later outside the Try block must either use static
+    storage or be declared with the "volatile" type qualifier.
+
+
+Throw expression;
+
+    A Throw statement is very much like a return statement, except that
+    the expression is required.  Whereas return jumps back to the place
+    where the current function was called, Throw jumps back to the Catch
+    clause of the innermost enclosing Try clause.  The expression must
+    be compatible with the type passed to define_exception_type().  The
+    exception must be caught, otherwise the program may crash.
+
+    Slight limitation:  If the expression is a comma-expression it must
+    be enclosed in parentheses.
+
+
+Try statement
+Catch_anonymous statement
+
+    When the value of the exception is not needed, a Try/Catch statement
+    can use Catch_anonymous instead of Catch (expression).
+
+
+Everything below this point is for the benefit of the compiler.  The
+application programmer should pretend not to know any of it, because it
+is subject to change.
+
+===*/
+
+
+#ifndef CEXCEPT_H
+#define CEXCEPT_H
+
+
+#include <setjmp.h>
+
+#define define_exception_type(etype) \
+struct exception__state { \
+  etype *exception; \
+  jmp_buf env; \
+}
+
+struct exception_context { \
+  struct exception__state *last; \
+  int caught; \
+};
+
+#define init_exception_context(ec) ((void)((ec)->last = 0))
+
+#define Catch(e) exception__catch(&(e))
+#define Catch_anonymous exception__catch(0)
+
+#define Try \
+  { \
+    struct exception__state *exception__p, exception__s; \
+    int exception__i; \
+    exception__p = the_exception_context->last; \
+    the_exception_context->last = &exception__s; \
+    for (exception__i = 0; ; exception__i = 1) \
+      if (exception__i) { \
+        if (setjmp(exception__s.env) == 0) { \
+          if (&exception__s)
+
+#define exception__catch(e_addr) \
+          else { } \
+          the_exception_context->caught = 0; \
+        } \
+        else the_exception_context->caught = 1; \
+        the_exception_context->last = exception__p; \
+        break; \
+      } \
+      else exception__s.exception = e_addr; \
+  } \
+  if (!the_exception_context->caught) { } \
+  else
+
+/* Try ends with if(), and Catch begins and ends with else.  This     */
+/* ensures that the Try/Catch syntax is really the same as the        */
+/* if/else syntax.                                                    */
+/*                                                                    */
+/* We use &exception__s instead of 1 to appease compilers that        */
+/* warn about constant expressions inside if().  Most compilers       */
+/* should still recognize that &exception__s is never zero and avoid  */
+/* generating test code.                                              */
+/*                                                                    */
+/* We use the variable exception__i to start the loop at the bottom,  */
+/* rather than jump into the loop using a switch statement, to        */
+/* appease compilers that warn about jumping into loops.              */
+
+#define Throw \
+  for (;; longjmp(the_exception_context->last->env, 1)) \
+    if (the_exception_context->last->exception) \
+      *the_exception_context->last->exception =
+
+
+#endif /* CEXCEPT_H */

contrib/visupng/resource.h

@@ -0,0 +1,23 @@
+//{{NO_DEPENDENCIES}}
+// Microsoft Developer Studio generated include file.
+// Used by VisualPng.rc
+//
+#define IDM_FILE_OPEN                   40001
+#define IDM_FILE_SAVE                   40002
+#define IDM_FILE_NEXT                   40003
+#define IDM_FILE_PREVIOUS               40004
+#define IDM_FILE_EXIT                   40005
+#define IDM_OPTIONS_BACKGROUND          40006
+#define IDM_OPTIONS_STRETCH             40007
+#define IDM_HELP_ABOUT                  40008
+
+// Next default values for new objects
+// 
+#ifdef APSTUDIO_INVOKED
+#ifndef APSTUDIO_READONLY_SYMBOLS
+#define _APS_NEXT_RESOURCE_VALUE        113
+#define _APS_NEXT_COMMAND_VALUE         40009
+#define _APS_NEXT_CONTROL_VALUE         1001
+#define _APS_NEXT_SYMED_VALUE           101
+#endif
+#endif

libpngpf.3

@@ -0,0 +1,549 @@
+.TH LIBPNGPF 3 "April 27, 2001"
+.SH NAME
+libpng \- Portable Network Graphics (PNG) Reference Library 1.0.11
+(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
+
+\fBpng_charp png_decompress_chunk (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcomp_type\fP\fB, png_charp \fP\fIchunkdata\fP\fB, png_size_t \fP\fIchunklength\fP\fB, png_size_t \fP\fIprefix_length\fP\fB, png_size_t \fI*data_length\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
+
+\fBint png_handle_as_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\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_iCCP (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_iTXt (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_sCAL (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_sPLT (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_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_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIwhite_x\fP\fB, png_uint_32 \fP\fIwhite_y\fP\fB, png_uint_32 \fP\fIred_x\fP\fB, png_uint_32 \fP\fIred_y\fP\fB, png_uint_32 \fP\fIgreen_x\fP\fB, png_uint_32 \fP\fIgreen_y\fP\fB, png_uint_32 \fP\fIblue_x\fP\fB, png_uint_32 \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_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIint_file_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_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_charp \fP\fIprofile\fP\fB, int \fIproflen\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_iTXt (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcompression\fP\fB, png_charp \fP\fIkey\fP\fB, png_charp \fP\fIlang\fP\fB, png_charp \fP\fItranslated_key\fP\fB, png_charp \fItext)\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_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_sCAL_s (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIunit\fP\fB, png_charp \fP\fIwidth\fP\fB, png_charp \fIheight\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_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_spalette_p \fIpalette\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

makefile.aco

@@ -1,115 +0,0 @@
-# makefile for libpng on Acorn RISCOS
-# 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 -o $@ 
-Squeezeflags = -o $@
-
-
-# Final targets:
-@.libpng-lib:   @.o.png @.o.pngerror @.o.pngrio @.o.pngwio @.o.pngmem \
-        @.o.pngpread @.o.pngrcb @.o.pngread @.o.pngrtran @.o.pngrutil \
-        @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil
-        LibFile $(LibFileflags) @.o.png @.o.pngerror @.o.pngrio @.o.pngwio \
-        @.o.pngmem @.o.pngpread @.o.pngrcb @.o.pngread @.o.pngrtran \
-        @.o.pngrutil @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil 
-@.test:   @.tests.pngtest 
-        echo Please run "Test" in directory tests 
-@.tests.pngtest:   @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib 
-        Link $(Linkflags) @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib 
-
-
-# User-editable dependencies:
-.c.o:
-        cc $(ccflags) -o $@ $<
-
-
-# Static dependencies:
-@.o.example:   @.tests.c.example
-        cc $(ccflags) -o @.o.example @.tests.c.example 
-@.o.pngtest:   @.tests.c.pngtest
-        cc $(ccflags) -o @.o.pngtest @.tests.c.pngtest 
-
-
-# Dynamic dependencies:
-o.png:	c.png
-o.png:	h.png
-o.png:	Zlib:h.zlib
-o.png:	Zlib:h.zconf
-o.png:	h.pngconf
-o.pngerror:	c.pngerror
-o.pngerror:	h.png
-o.pngerror:	Zlib:h.zlib
-o.pngerror:	Zlib:h.zconf
-o.pngerror:	h.pngconf
-o.pngrio:	c.pngrio
-o.pngrio:	h.png
-o.pngrio:	Zlib:h.zlib
-o.pngrio:	Zlib:h.zconf
-o.pngrio:	h.pngconf
-o.pngwio:	c.pngwio
-o.pngwio:	h.png
-o.pngwio:	Zlib:h.zlib
-o.pngwio:	Zlib:h.zconf
-o.pngwio:	h.pngconf
-o.pngmem:	c.pngmem
-o.pngmem:	h.png
-o.pngmem:	Zlib:h.zlib
-o.pngmem:	Zlib:h.zconf
-o.pngmem:	h.pngconf
-o.pngpread:	c.pngpread
-o.pngpread:	h.png
-o.pngpread:	Zlib:h.zlib
-o.pngpread:	Zlib:h.zconf
-o.pngpread:	h.pngconf
-o.pngrcb:	c.pngrcb
-o.pngrcb:	h.png
-o.pngrcb:	Zlib:h.zlib
-o.pngrcb:	Zlib:h.zconf
-o.pngrcb:	h.pngconf
-o.pngread:	c.pngread
-o.pngread:	h.png
-o.pngread:	Zlib:h.zlib
-o.pngread:	Zlib:h.zconf
-o.pngread:	h.pngconf
-o.pngrtran:	c.pngrtran
-o.pngrtran:	h.png
-o.pngrtran:	Zlib:h.zlib
-o.pngrtran:	Zlib:h.zconf
-o.pngrtran:	h.pngconf
-o.pngrutil:	c.pngrutil
-o.pngrutil:	h.png
-o.pngrutil:	Zlib:h.zlib
-o.pngrutil:	Zlib:h.zconf
-o.pngrutil:	h.pngconf
-o.pngtrans:	c.pngtrans
-o.pngtrans:	h.png
-o.pngtrans:	Zlib:h.zlib
-o.pngtrans:	Zlib:h.zconf
-o.pngtrans:	h.pngconf
-o.pngwrite:	c.pngwrite
-o.pngwrite:	h.png
-o.pngwrite:	Zlib:h.zlib
-o.pngwrite:	Zlib:h.zconf
-o.pngwrite:	h.pngconf
-o.pngwtran:	c.pngwtran
-o.pngwtran:	h.png
-o.pngwtran:	Zlib:h.zlib
-o.pngwtran:	Zlib:h.zconf
-o.pngwtran:	h.pngconf
-o.pngwutil:	c.pngwutil
-o.pngwutil:	h.png
-o.pngwutil:	Zlib:h.zlib
-o.pngwutil:	Zlib:h.zconf
-o.pngwutil:	h.pngconf
-o.pngtest:	tests.c.pngtest
-o.pngtest:	h.png
-o.pngtest:	Zlib:h.zlib
-o.pngtest:	Zlib:h.zconf
-o.pngtest:	h.pngconf

makefile.elf

@@ -1,74 +0,0 @@
-# makefile for libpng on (linux) ELF
-# 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 -fPIC
-LDFLAGS=-L. -Wl,-rpath,. -L../zlib/ -Wl,-rpath,../zlib/ -lpng -lz -lm
-
-RANLIB=ranlib
-#RANLIB=echo
-
-PNGVER = 0.89
-
-# where make install puts libpng.a, libpng.so*, and png.h
-prefix=/usr/local
-
-OBJS = png.o pngrcb.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 pngtest
-
-libpng.a: $(OBJS)
-	ar rc $@  $(OBJS)
-	$(RANLIB) $@
-
-libpng.so: libpng.so.1
-	ln -sf libpng.so.1 libpng.so
-
-libpng.so.1: libpng.so.1.$(PNGVER)
-	ln -sf libpng.so.1.$(PNGVER) libpng.so.1
-
-libpng.so.1.$(PNGVER): $(OBJS)
-	gcc -shared -Wl,-soname,libpng.so.1 -o libpng.so.1.$(PNGVER) $(OBJS)
-
-pngtest: pngtest.o libpng.so
-	$(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS)
-
-test: pngtest
-	./pngtest
-
-install: libpng.so.1.$(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 $(prefix)/include/pngconf.h
-	cp libpng.so.1.$(PNGVER) $(prefix)/lib
-	chmod 755 $(prefix)/lib/libpng.so.1.$(PNGVER)
-	-@/bin/rm $(prefix)/lib/libpng.so.1 $(prefix)/lib/libpng.so
-	(cd $(prefix)/lib; ln -sf libpng.so.1.$(PNGVER) libpng.so.1; \
-	 ln -sf libpng.so.1 libpng.so)
-
-clean:
-	rm -f *.o libpng.so.1.$(PNGVER) libpng.so.1 libpng.so 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
-pngrcb.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

makefile.tc

@@ -1,72 +0,0 @@
-# Makefile for libpng
-# TurboC++ 3.0 (Note: All modules are compiled in C mode)
-
-# To use, do "make -fmakefile.tc"
-
-# ------------- Turbo C++ 3.0 -------------
-MODEL=-ml
-CFLAGS=-O2 -Z $(MODEL) -I..\zlib
-CC=tcc
-LD=tcc
-LIB=tlib
-LDFLAGS=$(MODEL)
-O=.obj
-
-# variables
-OBJS1 = png$(O) pngrcb$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O) pngmem$(O) pngpread$(O)
-OBJS2 = pngread$(O) pngerror$(O) pngwrite$(O) pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
-OBJSL1 = +png$(O) +pngrcb$(O) +pngrutil$(O) +pngtrans$(O) +pngwutil$(O) +pngmem$(O) +pngpread$(O)
-OBJSL2 = +pngread$(O) +pngerror$(O) +pngwrite$(O) +pngrtran$(O) +pngwtran$(O) +pngrio$(O) +pngwio$(O)
-
-all: libpng.lib
-
-png$(O): png.h pngconf.h
-		  $(CC) -c $(CFLAGS) $*.c
-
-pngrcb$(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)
-        $(LIB) libpng +$(OBJSL1)
-        $(LIB) libpng +$(OBJSL2)
-
-# End of makefile for libpng

png.5

@@ -0,0 +1,60 @@
+.TH PNG 5 "April 27, 2001"
+.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 1.2 specification, July 1999:
+.IP
+.br
+http://www.libpng.org/pub/png
+.br
+or ftp://ftp.uu.net/graphics/png/documents
+.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

@@ -1,97 +1,148 @@
 
-/* png.c - location for general purpose png functions
-
-   libpng 1.0 beta 3 - version 0.89
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
-   May 25, 1996
-   */
+/* png.c - location for general purpose libpng functions
+ *
+ * libpng version 1.0.11 - April 27, 2001
+ * Copyright (c) 1998-2001 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ */
 
 #define PNG_INTERNAL
 #define PNG_NO_EXTERN
 #include "png.h"
 
-/* version information for c files.  This better match the version
-   string defined in png.h */
-char png_libpng_ver[] = "0.89";
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef version_1_0_11 Your_png_h_is_not_version_1_0_11;
 
-/* place to hold the signiture string for a png file. */
-png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+/* Version information for C files.  This had better match the version
+ * string defined in png.h.  */
 
-/* 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[4] = { 73,  72,  68,  82};
-png_byte FARDATA png_IDAT[4] = { 73,  68,  65,  84};
-png_byte FARDATA png_IEND[4] = { 73,  69,  78,  68};
-png_byte FARDATA png_PLTE[4] = { 80,  76,  84,  69};
-png_byte FARDATA png_gAMA[4] = {103,  65,  77,  65};
-png_byte FARDATA png_sBIT[4] = {115,  66,  73,  84};
-png_byte FARDATA png_cHRM[4] = { 99,  72,  82,  77};
-png_byte FARDATA png_tRNS[4] = {116,  82,  78,  83};
-png_byte FARDATA png_bKGD[4] = { 98,  75,  71,  68};
-png_byte FARDATA png_hIST[4] = {104,  73,  83,  84};
-png_byte FARDATA png_tEXt[4] = {116,  69,  88, 116};
-png_byte FARDATA png_zTXt[4] = {122,  84,  88, 116};
-png_byte FARDATA png_pHYs[4] = {112,  72,  89, 115};
-png_byte FARDATA png_oFFs[4] = {111,  70,  70, 115};
-png_byte FARDATA png_tIME[4] = {116,  73,  77,  69};
+#ifdef PNG_USE_GLOBAL_ARRAYS
+/* png_libpng_ver was changed to a function in version 1.0.5c */
+const char png_libpng_ver[18] = "1.0.11";
+
+/* png_sig was changed to a function in version 1.0.5c */
+/* Place to hold the signature string for a PNG file. */
+const png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+/* Invoke global declarations for constant strings for known chunk types */
+PNG_IHDR;
+PNG_IDAT;
+PNG_IEND;
+PNG_PLTE;
+PNG_bKGD;
+PNG_cHRM;
+PNG_gAMA;
+PNG_hIST;
+PNG_iCCP;
+PNG_iTXt;
+PNG_oFFs;
+PNG_pCAL;
+PNG_sCAL;
+PNG_pHYs;
+PNG_sBIT;
+PNG_sPLT;
+PNG_sRGB;
+PNG_tEXt;
+PNG_tIME;
+PNG_tRNS;
+PNG_zTXt;
 
 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
 /* start of interlace block */
-int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
 
 /* offset to next interlace block */
-int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
 
 /* start of interlace block in the y direction */
-int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
 
 /* offset to next interlace block in the y direction */
-int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+const 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 FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
+/* width of interlace block (used in assembler routines only) */
+#ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
+const int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
+#endif
+
+/* Height of interlace block.  This is not currently used - if you need
+ * it, uncomment it here and in png.h
+const int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
 */
 
-/* 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 */
+const int FARDATA 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 */
+const int FARDATA 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};
+#endif
 
+/* 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_bytep sig, int num)
+void PNGAPI
+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 (!png_memcmp(sig, png_sig, num));
+   png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
 }
 
-/* Function to allocate memory for zlib. */
-voidpf
+/* Checks whether the supplied bytes match the PNG signature.  We allow
+ * checking less than the full 8-byte signature so that those apps that
+ * already read the first few bytes of a file to determine the file type
+ * can simply check the remaining bytes for extra assurance.  Returns
+ * an integer less than, equal to, or greater than zero if sig is found,
+ * respectively, to be less than, to match, or be greater than the correct
+ * PNG signature (this is the same behaviour as strcmp, memcmp, etc).
+ */
+int PNGAPI
+png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
+{
+   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+   if (num_to_check > 8)
+      num_to_check = 8;
+   else if (num_to_check < 1)
+      return (0);
+
+   if (start > 7)
+      return (0);
+
+   if (start + num_to_check > 8)
+      num_to_check = 8 - start;
+
+   return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
+}
+
+/* (Obsolete) function to check signature bytes.  It does not allow one
+ * to check a partial signature.  This function might be removed in the
+ * future - use png_sig_cmp().  Returns true (nonzero) if the file is a PNG.
+ */
+int PNGAPI
+png_check_sig(png_bytep sig, int num)
+{
+  return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
+}
+
+/* Function to allocate memory for zlib and clear it to 0. */
+voidpf /* PRIVATE */
 png_zalloc(voidpf png_ptr, uInt items, uInt size)
 {
-   png_voidp ptr;
-   png_uint_32 num_bytes;
+   png_uint_32 num_bytes = (png_uint_32)items * size;
+   png_voidp ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
 
-   ptr = png_large_malloc((png_structp)png_ptr,
-      (png_uint_32)items * (png_uint_32)size);
-   num_bytes = (png_uint_32)items * (png_uint_32)size;
-   if (num_bytes > (png_uint_32)0x7fff)
+#ifndef PNG_NO_ZALLOC_ZERO
+   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,
@@ -101,128 +152,561 @@ png_zalloc(voidpf png_ptr, uInt items, uInt size)
    {
       png_memset(ptr, 0, (png_size_t)num_bytes);
    }
-   return (voidpf)(ptr);
+#endif
+   return ((voidpf)ptr);
 }
 
 /* function to free memory for zlib */
-void
+void /* PRIVATE */
 png_zfree(voidpf png_ptr, voidpf ptr)
 {
-   png_large_free((png_structp)png_ptr, (png_voidp)ptr);
+   png_free((png_structp)png_ptr, (png_voidp)ptr);
 }
 
-/* reset the crc variable to 32 bits of 1's.  Care must be taken
-   in case crc is > 32 bits to leave the top bits 0 */
-void
+/* Reset the CRC variable to 32 bits of 1's.  Care must be taken
+ * in case CRC is > 32 bits to leave the top bits 0.
+ */
+void /* PRIVATE */
 png_reset_crc(png_structp png_ptr)
 {
-   /* 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)
+/* Calculate the CRC over a section of data.  We can only pass as
+ * much data to this routine as the largest single buffer size.  We
+ * also check that this data will actually be used before going to the
+ * trouble of calculating it.
+ */
+void /* PRIVATE */
+png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
 {
-  png_uint_32 c;
-  int n, k;
+   int need_crc = 1;
 
-  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;
+   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);
 }
 
-/* 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_bytep buf, png_uint_32 len)
-{
-  png_uint_32 c;
-  png_bytep 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. */
-void
-png_calculate_crc(png_structp png_ptr, png_bytep ptr,
-   png_uint_32 length)
-{
-   png_ptr->crc = update_crc(png_ptr->crc, ptr, length);
-}
-
-png_infop
+/* 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 PNGAPI
 png_create_info_struct(png_structp png_ptr)
 {
    png_infop info_ptr;
 
+   png_debug(1, "in png_create_info_struct\n");
+   if(png_ptr == NULL) return (NULL);
+#ifdef PNG_USER_MEM_SUPPORTED
+   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_memset(info_ptr, 0, sizeof(png_info));
-      png_ptr->do_free |= PNG_FREE_INFO;
+      png_info_init(info_ptr);
    }
 
-   return info_ptr;
+   return (info_ptr);
 }
 
-void
-png_info_init(png_infop info)
+/* This function frees the memory associated with a single info struct.
+ * Normally, one would use either png_destroy_read_struct() or
+ * png_destroy_write_struct() to free an info struct, but this may be
+ * useful for some applications.
+ */
+void PNGAPI
+png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
 {
+   png_infop info_ptr = NULL;
+
+   png_debug(1, "in png_destroy_info_struct\n");
+   if (info_ptr_ptr != NULL)
+      info_ptr = *info_ptr_ptr;
+
+   if (info_ptr != NULL)
+   {
+      png_info_destroy(png_ptr, info_ptr);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn);
+#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 /* PRIVATE */
+png_info_init(png_infop info_ptr)
+{
+   png_debug(1, "in png_info_init\n");
    /* set everything to 0 */
-   png_memset(info, 0, sizeof (png_info));
+   png_memset(info_ptr, 0, sizeof (png_info));
+}
+
+#ifdef PNG_FREE_ME_SUPPORTED
+void PNGAPI
+png_data_freer(png_structp png_ptr, png_infop info_ptr,
+   int freer, png_uint_32 mask)
+{
+   png_debug(1, "in png_data_freer\n");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   if(freer == PNG_DESTROY_WILL_FREE_DATA)
+      info_ptr->free_me |= mask;
+   else if(freer == PNG_USER_WILL_FREE_DATA)
+      info_ptr->free_me &= ~mask;
+   else
+      png_warning(png_ptr,
+         "Unknown freer parameter in png_data_freer.");
+}
+#endif
+
+void PNGAPI
+png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
+   int num)
+{
+   png_debug(1, "in png_free_data\n");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+#if defined(PNG_TEXT_SUPPORTED)
+/* free text item num or (if num == -1) all text items */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_TEXT)
+#endif
+{
+   if (num != -1)
+   {
+     if (info_ptr->text && info_ptr->text[num].key)
+     {
+         png_free(png_ptr, info_ptr->text[num].key);
+         info_ptr->text[num].key = NULL;
+     }
+   }
+   else
+   {
+       int i;
+       for (i = 0; i < info_ptr->num_text; i++)
+           png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
+       png_free(png_ptr, info_ptr->text);
+       info_ptr->text = NULL;
+       info_ptr->num_text=0;
+   }
+}
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED)
+/* free any tRNS entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
+#else
+if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
+#endif
+{
+    png_free(png_ptr, info_ptr->trans);
+    info_ptr->valid &= ~PNG_INFO_tRNS;
+    info_ptr->trans = NULL;
+}
+#endif
+
+#if defined(PNG_sCAL_SUPPORTED)
+/* free any sCAL entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_SCAL)
+#endif
+{
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+    png_free(png_ptr, info_ptr->scal_s_width);
+    png_free(png_ptr, info_ptr->scal_s_height);
+    info_ptr->scal_s_width = NULL;
+    info_ptr->scal_s_height = NULL;
+#endif
+    info_ptr->valid &= ~PNG_INFO_sCAL;
+}
+#endif
+
+#if defined(PNG_pCAL_SUPPORTED)
+/* free any pCAL entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_PCAL)
+#endif
+{
+    png_free(png_ptr, info_ptr->pcal_purpose);
+    png_free(png_ptr, info_ptr->pcal_units);
+    info_ptr->pcal_purpose = NULL;
+    info_ptr->pcal_units = NULL;
+    if (info_ptr->pcal_params != NULL)
+    {
+        int i;
+        for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
+        {
+          png_free(png_ptr, info_ptr->pcal_params[i]);
+          info_ptr->pcal_params[i]=NULL;
+        }
+        png_free(png_ptr, info_ptr->pcal_params);
+        info_ptr->pcal_params = NULL;
+    }
+    info_ptr->valid &= ~PNG_INFO_pCAL;
+}
+#endif
+
+#if defined(PNG_iCCP_SUPPORTED)
+/* free any iCCP entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_ICCP)
+#endif
+{
+    png_free(png_ptr, info_ptr->iccp_name);
+    png_free(png_ptr, info_ptr->iccp_profile);
+    info_ptr->iccp_name = NULL;
+    info_ptr->iccp_profile = NULL;
+    info_ptr->valid &= ~PNG_INFO_iCCP;
+}
+#endif
+
+#if defined(PNG_sPLT_SUPPORTED)
+/* free a given sPLT entry, or (if num == -1) all sPLT entries */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_SPLT)
+#endif
+{
+   if (num != -1)
+   {
+      if(info_ptr->splt_palettes)
+      {
+          png_free(png_ptr, info_ptr->splt_palettes[num].name);
+          png_free(png_ptr, info_ptr->splt_palettes[num].entries);
+          info_ptr->splt_palettes[num].name = NULL;
+          info_ptr->splt_palettes[num].entries = NULL;
+      }
+   }
+   else
+   {
+       if(info_ptr->splt_palettes_num)
+       {
+         int i;
+         for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+            png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
+
+         png_free(png_ptr, info_ptr->splt_palettes);
+         info_ptr->splt_palettes = NULL;
+         info_ptr->splt_palettes_num = 0;
+       }
+       info_ptr->valid &= ~PNG_INFO_sPLT;
+   }
+}
+#endif
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_UNKN)
+#endif
+{
+   if (num != -1)
+   {
+       if(info_ptr->unknown_chunks)
+       {
+          png_free(png_ptr, info_ptr->unknown_chunks[num].data);
+          info_ptr->unknown_chunks[num].data = NULL;
+       }
+   }
+   else
+   {
+       int i;
+
+       if(info_ptr->unknown_chunks_num)
+       {
+         for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
+            png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
+
+         png_free(png_ptr, info_ptr->unknown_chunks);
+         info_ptr->unknown_chunks = NULL;
+         info_ptr->unknown_chunks_num = 0;
+       }
+   }
+}
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+/* free any hIST entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_HIST)  & info_ptr->free_me)
+#else
+if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
+#endif
+{
+    png_free(png_ptr, info_ptr->hist);
+    info_ptr->hist = NULL;
+    info_ptr->valid &= ~PNG_INFO_hIST;
+}
+#endif
+
+/* free any PLTE entry that was internally allocated */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
+#else
+if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
+#endif
+{
+    png_zfree(png_ptr, info_ptr->palette);
+    info_ptr->palette = NULL;
+    info_ptr->valid &= ~PNG_INFO_PLTE;
+    info_ptr->num_palette = 0;
+}
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+/* free any image bits attached to the info structure */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_ROWS)
+#endif
+{
+    if(info_ptr->row_pointers)
+    {
+       int row;
+       for (row = 0; row < (int)info_ptr->height; row++)
+       {
+          png_free(png_ptr, info_ptr->row_pointers[row]);
+          info_ptr->row_pointers[row]=NULL;
+       }
+       png_free(png_ptr, info_ptr->row_pointers);
+       info_ptr->row_pointers=NULL;
+    }
+    info_ptr->valid &= ~PNG_INFO_IDAT;
+}
+#endif
+
+#ifdef PNG_FREE_ME_SUPPORTED
+   if(num == -1)
+     info_ptr->free_me &= ~mask;
+   else
+     info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
+#endif
+}
+
+/* This is an internal routine to free any memory that the info struct is
+ * pointing to before re-using it or freeing the struct itself.  Recall
+ * that png_free() checks for NULL pointers for us.
+ */
+void /* PRIVATE */
+png_info_destroy(png_structp png_ptr, png_infop info_ptr)
+{
+   png_debug(1, "in png_info_destroy\n");
+
+   png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+   if (png_ptr->num_chunk_list)
+   {
+       png_free(png_ptr, png_ptr->chunk_list);
+       png_ptr->chunk_list=NULL;
+       png_ptr->num_chunk_list=0;
+   }
+#endif
+
+   png_info_init(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 and png_read_destroy are called. */
-png_voidp
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy() or png_read_destroy() are called.
+ */
+png_voidp PNGAPI
 png_get_io_ptr(png_structp png_ptr)
 {
-   return png_ptr->io_ptr;
+   return (png_ptr->io_ptr);
 }
- 
-/* Initialize the default input/output functions for the png file.  If you
-   change the 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)
+
+#if !defined(PNG_NO_STDIO)
+/* Initialize the default input/output functions for the PNG file.  If you
+ * use your own read or write routines, you can call either png_set_read_fn()
+ * or png_set_write_fn() instead of png_init_io().  If you have defined
+ * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
+ * necessarily available.
+ */
+void PNGAPI
+png_init_io(png_structp png_ptr, png_FILE_p fp)
 {
+   png_debug(1, "in png_init_io\n");
    png_ptr->io_ptr = (png_voidp)fp;
 }
+#endif
+
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Convert the supplied time into an RFC 1123 string suitable for use in
+ * a "Creation Time" or other text-based time string.
+ */
+png_charp PNGAPI
+png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
+{
+   static PNG_CONST char short_months[12][4] =
+        {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+
+   if (png_ptr->time_buffer == NULL)
+   {
+      png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
+         sizeof(char)));
+   }
+
+#if defined(_WIN32_WCE)
+   {
+      wchar_t time_buf[29];
+      wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
+          ptime->day % 32, short_months[(ptime->month - 1) % 12],
+        ptime->year, ptime->hour % 24, ptime->minute % 60,
+          ptime->second % 61);
+      WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
+          NULL, NULL);
+   }
+#else
+#ifdef USE_FAR_KEYWORD
+   {
+      char near_time_buf[29];
+      sprintf(near_time_buf, "%d %s %d %02d:%02d:%02d +0000",
+          ptime->day % 32, short_months[(ptime->month - 1) % 12],
+          ptime->year, ptime->hour % 24, ptime->minute % 60,
+          ptime->second % 61);
+      png_memcpy(png_ptr->time_buffer, near_time_buf,
+          29*sizeof(char));
+   }
+#else
+   sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000",
+       ptime->day % 32, short_months[(ptime->month - 1) % 12],
+       ptime->year, ptime->hour % 24, ptime->minute % 60,
+       ptime->second % 61);
+#endif
+#endif /* _WIN32_WCE */
+   return ((png_charp)png_ptr->time_buffer);
+}
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+
+#if 0
+/* Signature string for a PNG file. */
+png_bytep PNGAPI
+png_sig_bytes(void)
+{
+   return ((png_bytep)"\211\120\116\107\015\012\032\012");
+}
+#endif
+
+png_charp PNGAPI
+png_get_copyright(png_structp png_ptr)
+{
+   if (png_ptr != NULL || png_ptr == NULL)  /* silence compiler warning */
+   return ((png_charp) "\n libpng version 1.0.11 - April 27, 2001\n\
+   Copyright (c) 1998-2001 Glenn Randers-Pehrson\n\
+   Copyright (c) 1996, 1997 Andreas Dilger\n\
+   Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.\n");
+   return ((png_charp) "");
+}
+
+/* The following return the library version as a short string in the
+ * format 1.0.0 through 99.99.99zz.  To get the version of *.h files used
+ * with your application, print out PNG_LIBPNG_VER_STRING, which is defined
+ * in png.h.
+ */
+
+png_charp PNGAPI
+png_get_libpng_ver(png_structp png_ptr)
+{
+   /* Version of *.c files used when building libpng */
+   if(png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+      return((png_charp) "1.0.11");
+   return((png_charp) "1.0.11");
+}
+
+png_charp PNGAPI
+png_get_header_ver(png_structp png_ptr)
+{
+   /* Version of *.h files used when building libpng */
+   if(png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+      return((png_charp) PNG_LIBPNG_VER_STRING);
+   return((png_charp) PNG_LIBPNG_VER_STRING);
+}
+
+png_charp PNGAPI
+png_get_header_version(png_structp png_ptr)
+{
+   /* Returns longer string containing both version and date */
+   if(png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+      return((png_charp) PNG_HEADER_VERSION_STRING);
+   return((png_charp) PNG_HEADER_VERSION_STRING);
+}
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+int /* PRIVATE */
+png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
+{
+   /* check chunk_name and return "keep" value if it's on the list, else 0 */
+   int i;
+   png_bytep p;
+   if((png_ptr == NULL && chunk_name == NULL) || png_ptr->num_chunk_list<=0)
+      return 0;
+   p=png_ptr->chunk_list+png_ptr->num_chunk_list*5-5;
+   for (i = png_ptr->num_chunk_list; i; i--, p-=5)
+      if (!png_memcmp(chunk_name, p, 4))
+        return ((int)*(p+4));
+   return 0;
+}
+#endif
+
+/* This function, added to libpng-1.0.6g, is untested. */
+int PNGAPI
+png_reset_zstream(png_structp png_ptr)
+{
+   return (inflateReset(&png_ptr->zstream));
+}
+
+/* This function was added to libpng-1.0.7 */
+png_uint_32 PNGAPI
+png_access_version_number(void)
+{
+   /* Version of *.c files used when building libpng */
+   return((png_uint_32) 10011L);
+}
+
+
+#if 0 /* delay this until version 1.2.0 */
+/* this function was added to libpng 1.0.9 (porting aid to libpng-1.2.0) */
+#ifndef PNG_ASSEMBLER_CODE_SUPPORTED
+int PNGAPI
+png_mmx_support(void)
+{
+    return -1;
+}
+#endif
+#endif /* 0 */

pngasmrd.h

@@ -0,0 +1,11 @@
+/* pngasmrd.h - assembler version of utilities to read a PNG file
+ *
+ * libpng 1.0.11 - April 27, 2001
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 2001 Glenn Randers-Pehrson
+ *
+ */
+
+/* This file is obsolete in libpng-1.0.9 and later; its contents now appear
+ * at the end of pngconf.h.
+ */

pngchang.txt

@@ -1,103 +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
-   incorporated Tim Wegner's medium model code (thanks, Tim)
-version 0.85
-   added more medium model code (almost everythings 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
-   fixed bugs
-   improved documentation
-version 0.87
-   fixed medium model bugs
-   fixed other bugs introduced in 0.85 and 0.86
-   added some minor documentation
-version 0.88
-   fixed progressive bugs
-   replaced tabs with spaces
-   cleaned up documentation
-   added callbacks for read/write and warning/error functions
-version 0.89 
-   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)
-   fixed bug with Borland 64K memory allocation (Alexander Lehmann)
-   fixed bug in interlace handling (Smaraderagd, 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 dcumentation to reflect new API

pngerror.c

@@ -1,32 +1,37 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
-
-   libpng 1.0 beta 3 - version 0.89
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
-   May 25, 1996
-
-   This file provides a location for all error handling.  Users which
-   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. */
+ *
+ * libpng 1.0.11 - April 27, 2001
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2001 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This file provides a location for all error handling.  Users who
+ * need special error handling are expected to write replacement functions
+ * and use png_set_error_fn() to use those functions.  See the instructions
+ * at each function.
+ */
 
 #define PNG_INTERNAL
 #include "png.h"
 
-static void png_default_error PNGARG((png_structp png_ptr,
+static void /* PRIVATE */
+png_default_error PNGARG((png_structp png_ptr,
                                       png_const_charp message));
-static void png_default_warning PNGARG((png_structp png_ptr,
+static void /* PRIVATE */
+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
+ * should not be changed.  If there is a need to handle errors differently,
+ * you should supply a replacement error function and use png_set_error_fn()
+ * to replace the error function at run-time.
+ */
+void PNGAPI
 png_error(png_structp png_ptr, png_const_charp message)
 {
-   if (png_ptr->error_fn)
+   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,
@@ -35,60 +40,135 @@ png_error(png_structp png_ptr, png_const_charp 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
+ * should not be changed.  If there is a need to handle warnings differently,
+ * you should supply a replacement warning function and use
+ * png_set_error_fn() to replace the warning function at run-time.
+ */
+void PNGAPI
 png_warning(png_structp png_ptr, png_const_charp message)
 {
-   if (png_ptr->warning_fn)
+   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 /* PRIVATE */
+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 & 0x0f];
+         buffer[iout++] = ']';
+      }
+      else
+      {
+         buffer[iout++] = (png_byte)c;
+      }
+   }
+
+   if (message == NULL)
+      buffer[iout] = 0;
+   else
+   {
+      buffer[iout++] = ':';
+      buffer[iout++] = ' ';
+      png_memcpy(buffer+iout, message, 64);
+      buffer[iout+63] = 0;
+   }
+}
+
+void PNGAPI
+png_chunk_error(png_structp png_ptr, png_const_charp message)
+{
+   char msg[18+64];
+   png_format_buffer(png_ptr, msg, message);
+   png_error(png_ptr, msg);
+}
+
+void PNGAPI
+png_chunk_warning(png_structp png_ptr, png_const_charp message)
+{
+   char msg[18+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
+ * this function MUST NOT RETURN, or the program will likely crash.  This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static void /* PRIVATE */
 png_default_error(png_structp png_ptr, png_const_charp message)
 {
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
    fprintf(stderr, "libpng error: %s\n", message);
+#else
+   if (message)
+     /* make compiler happy */ ;
 #endif
 
-#ifdef USE_FAR_KEYWORD
+#ifdef PNG_SETJMP_SUPPORTED
+#  ifdef USE_FAR_KEYWORD
    {
       jmp_buf jmpbuf;
       png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
       longjmp(jmpbuf, 1);
    }
-#else
+#  else
    longjmp(png_ptr->jmpbuf, 1);
+# endif
+#else
+   if (png_ptr)
+     /* make compiler happy */ ;
+   PNG_ABORT();
 #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 to.  In the default configuration, png_ptr is
-   not used, but it is passed in case it may be useful. */
-static void
+ * it can continue anyway.  Replacement functions don't have to do anything
+ * here if you don't want them to.  In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void /* PRIVATE */
 png_default_warning(png_structp png_ptr, png_const_charp message)
 {
-   if (!png_ptr)
-      return;
-
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
    fprintf(stderr, "libpng warning: %s\n", message);
+#else
+   if (message)
+     /* appease compiler */ ;
 #endif
+   if (png_ptr)
+      return;
 }
 
 /* This function is called when the application wants to use another method
-   of handling errors and warnings.  Note that the error function MUST NOT
-   return to the calling routine or serious problems will occur.  The return
-   method used in the default routine calls longjmp(png_ptr->jmpbuf, 1) */
-void
+ * of handling errors and warnings.  Note that the error function MUST NOT
+ * return to the calling routine or serious problems will occur.  The return
+ * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
+ */
+void PNGAPI
 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
    png_error_ptr error_fn, png_error_ptr warning_fn)
 {
@@ -99,12 +179,13 @@ png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 
 
 /* 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
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
 png_get_error_ptr(png_structp png_ptr)
 {
-   return png_ptr->error_ptr;
+   return ((png_voidp)png_ptr->error_ptr);
 }
 
 

pngget.c

@@ -0,0 +1,828 @@
+
+/* pngget.c - retrieval of values from info struct
+ *
+ * libpng 1.0.11 - April 27, 2001
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2001 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+png_uint_32 PNGAPI
+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 PNGAPI
+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);
+}
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+png_bytepp PNGAPI
+png_get_rows(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->row_pointers);
+   else
+      return(0);
+}
+#endif
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* easy access to info, added in libpng-0.99 */
+png_uint_32 PNGAPI
+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 PNGAPI
+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 PNGAPI
+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 PNGAPI
+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 PNGAPI
+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 PNGAPI
+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 PNGAPI
+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 PNGAPI
+png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_pHYs_SUPPORTED)
+   if (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
+   return (0);
+#endif
+   return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_pHYs_SUPPORTED)
+   if (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
+   return (0);
+#endif
+   return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_pHYs_SUPPORTED)
+   if (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
+   return (0);
+#endif
+   return (0);
+}
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_pixel_aspect_ratio(png_structp png_ptr, png_infop info_ptr)
+   {
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_pHYs_SUPPORTED)
+   if (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)((float)info_ptr->y_pixels_per_unit
+            /(float)info_ptr->x_pixels_per_unit));
+   }
+#else
+   return (0.0);
+#endif
+   return ((float)0.0);
+}
+#endif
+
+png_int_32 PNGAPI
+png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_oFFs_SUPPORTED)
+   if (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
+   return (0);
+#endif
+   return (0);
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_oFFs_SUPPORTED)
+   if (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
+   return (0);
+#endif
+   return (0);
+}
+
+png_int_32 PNGAPI
+png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_oFFs_SUPPORTED)
+   if (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
+   return (0);
+#endif
+   return (0);
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_oFFs_SUPPORTED)
+   if (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
+   return (0);
+#endif
+   return (0);
+}
+
+#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
+png_uint_32 PNGAPI
+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)
+     *.0254 +.5));
+}
+
+png_uint_32 PNGAPI
+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)
+     *.0254 +.5));
+}
+
+png_uint_32 PNGAPI
+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)
+     *.0254 +.5));
+}
+
+float PNGAPI
+png_get_x_offset_inches(png_structp png_ptr, png_infop info_ptr)
+{
+   return ((float)png_get_x_offset_microns(png_ptr, info_ptr)
+     *.00003937);
+}
+
+float PNGAPI
+png_get_y_offset_inches(png_structp png_ptr, png_infop info_ptr)
+{
+   return ((float)png_get_y_offset_microns(png_ptr, info_ptr)
+     *.00003937);
+}
+
+#if defined(PNG_pHYs_SUPPORTED)
+png_uint_32 PNGAPI
+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 * .0254 + .50);
+            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
+         }
+      }
+   }
+   return (retval);
+}
+#endif /* PNG_pHYs_SUPPORTED */
+#endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
+
+/* png_get_channels really belongs in here, too, but it's been around longer */
+
+#endif  /* PNG_EASY_ACCESS_SUPPORTED */
+
+png_byte PNGAPI
+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 PNGAPI
+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_bKGD_SUPPORTED)
+png_uint_32 PNGAPI
+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_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+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
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
+   png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
+   png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
+   png_fixed_point *blue_x, png_fixed_point *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 = info_ptr->int_x_white;
+      if (white_y != NULL)
+         *white_y = info_ptr->int_y_white;
+      if (red_x != NULL)
+         *red_x = info_ptr->int_x_red;
+      if (red_y != NULL)
+         *red_y = info_ptr->int_y_red;
+      if (green_x != NULL)
+         *green_x = info_ptr->int_x_green;
+      if (green_y != NULL)
+         *green_y = info_ptr->int_y_green;
+      if (blue_x != NULL)
+         *blue_x = info_ptr->int_x_blue;
+      if (blue_y != NULL)
+         *blue_y = info_ptr->int_y_blue;
+      return (PNG_INFO_cHRM);
+   }
+   return (0);
+}
+#endif
+#endif
+
+#if defined(PNG_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+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
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA_fixed(png_structp png_ptr, png_infop info_ptr,
+    png_fixed_point *int_file_gamma)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+      && int_file_gamma != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "gAMA");
+      *int_file_gamma = info_ptr->int_gamma;
+      return (PNG_INFO_gAMA);
+   }
+   return (0);
+}
+#endif
+#endif
+
+#if defined(PNG_sRGB_SUPPORTED)
+png_uint_32 PNGAPI
+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_iCCP_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_iCCP(png_structp png_ptr, png_infop info_ptr,
+             png_charpp name, int *compression_type,
+             png_charpp profile, png_uint_32 *proflen)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
+      && name != NULL && profile != NULL && proflen != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "iCCP");
+      *name = info_ptr->iccp_name;
+      *profile = info_ptr->iccp_profile;
+      /* compression_type is a dummy so the API won't have to change
+         if we introduce multiple compression types later. */
+      *proflen = (int)info_ptr->iccp_proflen;
+      *compression_type = (int)info_ptr->iccp_compression;
+      return (PNG_INFO_iCCP);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_sPLT_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_sPLT(png_structp png_ptr, png_infop info_ptr,
+             png_sPLT_tpp spalettes)
+{
+   if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
+     *spalettes = info_ptr->splt_palettes;
+   return ((png_uint_32)info_ptr->splt_palettes_num);
+}
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+png_uint_32 PNGAPI
+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 PNGAPI
+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_oFFs_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_oFFs(png_structp png_ptr, png_infop info_ptr,
+   png_int_32 *offset_x, png_int_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_pCAL_SUPPORTED)
+png_uint_32 PNGAPI
+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_sCAL_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL(png_structp png_ptr, png_infop info_ptr,
+             int *unit, double *width, double *height)
+{
+    if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL))
+    {
+        *unit = info_ptr->scal_unit;
+        *width = info_ptr->scal_pixel_width;
+        *height = info_ptr->scal_pixel_height;
+        return (PNG_INFO_sCAL);
+    }
+    return(0);
+}
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL_s(png_structp png_ptr, png_infop info_ptr,
+             int *unit, png_charpp width, png_charpp height)
+{
+    if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL))
+    {
+        *unit = info_ptr->scal_unit;
+        *width = info_ptr->scal_s_width;
+        *height = info_ptr->scal_s_height;
+        return (PNG_INFO_sCAL);
+    }
+    return(0);
+}
+#endif
+#endif
+#endif
+
+#if defined(PNG_pHYs_SUPPORTED)
+png_uint_32 PNGAPI
+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 PNGAPI
+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_sBIT_SUPPORTED)
+png_uint_32 PNGAPI
+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_TEXT_SUPPORTED)
+png_uint_32 PNGAPI
+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);
+   }
+   if (num_text != NULL)
+     *num_text = 0;
+   return(0);
+}
+#endif
+
+#if defined(PNG_tIME_SUPPORTED)
+png_uint_32 PNGAPI
+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_tRNS_SUPPORTED)
+png_uint_32 PNGAPI
+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_UNKNOWN_CHUNKS_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_unknown_chunks(png_structp png_ptr, png_infop info_ptr,
+             png_unknown_chunkpp unknowns)
+{
+   if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
+     *unknowns = info_ptr->unknown_chunks;
+   return ((png_uint_32)info_ptr->unknown_chunks_num);
+}
+#endif
+
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+png_byte PNGAPI
+png_get_rgb_to_gray_status (png_structp png_ptr)
+{
+   return (png_byte)(png_ptr? png_ptr->rgb_to_gray_status : 0);
+}
+#endif
+
+#if defined(PNG_USER_CHUNKS_SUPPORTED)
+png_voidp PNGAPI
+png_get_user_chunk_ptr(png_structp png_ptr)
+{
+   return (png_ptr? png_ptr->user_chunk_ptr : NULL);
+}
+#endif
+
+
+png_uint_32 PNGAPI
+png_get_compression_buffer_size(png_structp png_ptr)
+{
+   return (png_uint_32)(png_ptr? png_ptr->zbuf_size : 0L);
+}
+

pngmem.c

@@ -1,14 +1,18 @@
 
 /* pngmem.c - stub functions for memory allocation
-
-   libpng 1.0 beta 3 - version 0.89
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
-   May 25, 1996
-
-   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 1.0.11 - April 27, 2001
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2001 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This file provides a location for all 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"
@@ -18,12 +22,20 @@
 /* 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(uInt type)
+   by a single call to calloc() if this is thought to improve performance. */
+png_voidp /* PRIVATE */
+png_create_struct(int type)
 {
-   png_size_t 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 /* PRIVATE */
+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)
@@ -31,59 +43,110 @@ png_create_struct(uInt type)
    else if (type == PNG_STRUCT_PNG)
      size = sizeof(png_struct);
    else
-     return (png_voidp)NULL;
+     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
+void /* PRIVATE */
 png_destroy_struct(png_voidp struct_ptr)
 {
-   if (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 /* PRIVATE */
+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);
+         return;
+      }
+#endif /* PNG_USER_MEM_SUPPORTED */
       farfree (struct_ptr);
+   }
 }
 
 /* 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. */
+ * 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 PNGAPI
+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);
 
-/* 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 it's
-   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.
-*/
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(png_ptr->malloc_fn != NULL)
+   {
+       ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
+       if (ret == NULL)
+          png_error(png_ptr, "Out of memory!");
+       return (ret);
+   }
+   else
+       return png_malloc_default(png_ptr, size);
+}
 
-png_voidp
-png_large_malloc(png_structp png_ptr, png_uint_32 size)
+png_voidp PNGAPI
+png_malloc_default(png_structp png_ptr, png_uint_32 size)
 {
    png_voidp ret;
-   if (!png_ptr || !size)
-      return ((voidp)NULL);
+#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 (size == (png_uint_32)(65536L))
+   if (size == (png_uint_32)65536L)
    {
-      if (!png_ptr->offset_table)
+      if (png_ptr->offset_table == NULL)
       {
          /* try to see if we need to do any of this fancy stuff */
          ret = farmalloc(size);
-         if (!ret || ((long)ret & 0xffff))
+         if (ret == NULL || ((png_size_t)ret & 0xffff))
          {
             int num_blocks;
             png_uint_32 total_size;
@@ -91,12 +154,15 @@ png_large_malloc(png_structp png_ptr, png_uint_32 size)
             int i;
             png_byte huge * hptr;
 
-            if (ret)
+            if (ret != NULL)
+            {
                farfree(ret);
-            ret = NULL;
+               ret = NULL;
+            }
 
-            num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
-            if (num_blocks < 1)
+            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));
@@ -107,35 +173,35 @@ png_large_malloc(png_structp png_ptr, png_uint_32 size)
 
             table = farmalloc(total_size);
 
-            if (!table)
+            if (table == NULL)
             {
-               png_error(png_ptr, "Out of Memory");
+               png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */
             }
 
-            if ((long)table & 0xfff0)
+            if ((png_size_t)table & 0xfff0)
             {
                png_error(png_ptr, "Farmalloc didn't return normalized pointer");
             }
 
             png_ptr->offset_table = table;
-            png_ptr->offset_table_ptr = farmalloc(
-               num_blocks * sizeof (png_bytep));
+            png_ptr->offset_table_ptr = farmalloc(num_blocks *
+               sizeof (png_bytep));
 
-            if (!png_ptr->offset_table_ptr)
+            if (png_ptr->offset_table_ptr == NULL)
             {
-               png_error(png_ptr, "Out of memory");
+               png_error(png_ptr, "Out Of memory.");
             }
 
             hptr = (png_byte huge *)table;
-            if ((long)hptr & 0xf)
+            if ((png_size_t)hptr & 0xf)
             {
                hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
-               hptr += 16L;
+               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 += 65536L;
+               hptr = hptr + (png_uint_32)65536L;  /* "+=" fails on TC++3.0 */
             }
 
             png_ptr->offset_table_number = num_blocks;
@@ -145,7 +211,7 @@ png_large_malloc(png_structp png_ptr, png_uint_32 size)
       }
 
       if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
-         png_error(png_ptr, "Out of Memory");
+         png_error(png_ptr, "Out of Memory.");
 
       ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
    }
@@ -154,68 +220,100 @@ png_large_malloc(png_structp png_ptr, png_uint_32 size)
 
    if (ret == NULL)
    {
-      png_error(png_ptr, "Out of Memory");
+      png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */
    }
 
-   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. */
-void
-png_large_free(png_structp png_ptr, png_voidp ptr)
+/* 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 PNGAPI
+png_free(png_structp png_ptr, png_voidp ptr)
 {
-   if (!png_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);
+      return;
+   }
+   else png_free_default(png_ptr, ptr);
+}
+
+void PNGAPI
+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)
    {
-      if (png_ptr->offset_table)
-      {
-         int i;
-
-         for (i = 0; i < png_ptr->offset_table_count; i++)
-         {
-            if (ptr == png_ptr->offset_table_ptr[i])
-            {
-               ptr = 0;
-               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 = 0;
-            png_ptr->offset_table_ptr = 0;
-         }
-      }
-
-      if (ptr)
-         farfree(ptr);
+      farfree(ptr);
    }
 }
 
 #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(uInt type)
+   memset can be replaced by a single call to calloc() if this is thought
+   to improve performance noticably.*/
+png_voidp /* PRIVATE */
+png_create_struct(int type)
 {
-   size_t size;
+#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 /* PRIVATE */
+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);
+      size = sizeof(png_info);
    else if (type == PNG_STRUCT_PNG)
-     size = sizeof(png_struct);
+      size = sizeof(png_struct);
    else
-     return (png_voidp)NULL;
+      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)
@@ -235,10 +333,29 @@ png_create_struct(uInt type)
 
 
 /* Free memory allocated by a png_create_struct() call */
-void
+void /* PRIVATE */
 png_destroy_struct(png_voidp struct_ptr)
 {
-   if (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 /* PRIVATE */
+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);
+         return;
+      }
+#endif /* PNG_USER_MEM_SUPPORTED */
 #if defined(__TURBOC__) && !defined(__FLAT__)
       farfree(struct_ptr);
 #else
@@ -248,21 +365,39 @@ png_destroy_struct(png_voidp struct_ptr)
       free(struct_ptr);
 # 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
+   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_large_malloc(png_structp png_ptr, png_uint_32 size)
+png_voidp PNGAPI
+png_malloc(png_structp png_ptr, png_uint_32 size)
 {
    png_voidp ret;
-   if (!png_ptr || !size)
-      return ((voidp)0);
+   if (png_ptr == NULL || size == 0)
+      return ((png_voidp)NULL);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(png_ptr->malloc_fn != NULL)
+   {
+       ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
+       if (ret == NULL)
+          png_error(png_ptr, "Out of Memory!");
+       return (ret);
+   }
+   else
+       return (png_malloc_default(png_ptr, size));
+}
+png_voidp /* PRIVATE */
+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)
@@ -275,111 +410,100 @@ png_large_malloc(png_structp png_ptr, png_uint_32 size)
 # if defined(_MSC_VER) && defined(MAXSEG_64K)
    ret = halloc(size, 1);
 # else
-   ret = malloc(size);
+   ret = malloc((size_t)size);
 # endif
 #endif
 
    if (ret == NULL)
-   {
       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. */
-void
-png_large_free(png_structp png_ptr, png_voidp ptr)
+/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
+   without taking any action. */
+void PNGAPI
+png_free(png_structp png_ptr, png_voidp ptr)
 {
-   if (!png_ptr)
+   if (png_ptr == NULL || ptr == NULL)
       return;
 
-   if (ptr != NULL)
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
    {
+      (*(png_ptr->free_fn))(png_ptr, ptr);
+      return;
+   }
+   else png_free_default(png_ptr, ptr);
+}
+void /* PRIVATE */
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+
+#endif /* PNG_USER_MEM_SUPPORTED */
+
 #if defined(__TURBOC__) && !defined(__FLAT__)
-      farfree(ptr);
+   farfree(ptr);
 #else
 # if defined(_MSC_VER) && defined(MAXSEG_64K)
-      hfree(ptr);
+   hfree(ptr);
 # else
-      free(ptr);
+   free(ptr);
 # endif
 #endif
-   }
 }
 
 #endif /* Not Borland DOS special memory handler */
 
-/* Allocate memory.  This is called for smallish blocks only  It
-   should not get anywhere near 64K.  On segmented machines, this
-   must come from the local heap (for zlib).  Currently, zlib is
-   the only one that uses this, so you should only get one call
-   to this, and that a small block. */
-void *
-png_malloc(png_structp png_ptr, png_uint_32 size)
+png_voidp /* PRIVATE */
+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_error(png_ptr, "Cannot Allocate > 64K");
-#endif
-
-
-   ret = malloc((png_size_t)size);
-
-   if (!ret)
-   {
-      png_error(png_ptr, "Out of Memory");
-   }
-
-   return ret;
+   return(png_memcpy (s1, s2, size));
 }
 
-/* Reallocate memory.  This will not get near 64K on a
-   even marginally reasonable file.  This is not used in
-   the current version of the library. */
-void *
-png_realloc(png_structp png_ptr, void * ptr, png_uint_32 size,
-   png_uint_32 old_size)
+png_voidp /* PRIVATE */
+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_error(png_ptr, "Cannot Allocate > 64K");
-#endif
+   return (png_memset (s1, value, size));
 
-   ret = realloc(ptr, (png_size_t)size);
-
-   if (!ret)
-   {
-      png_error(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. */
-void
-png_free(png_structp png_ptr, void * ptr)
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
+void PNGAPI
+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 PNGAPI
+png_get_mem_ptr(png_structp png_ptr)
+{
+   return ((png_voidp)png_ptr->mem_ptr);
+}
+#endif /* PNG_USER_MEM_SUPPORTED */

pngrcb.c

@@ -1,243 +0,0 @@
-/* pngrcb.c - callbacks while reading a png file
-
-   libpng 1.0 beta 3 - version 0.89
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
-   May 25, 1996
-   */
-
-#define PNG_INTERNAL
-#include "png.h"
-
-void
-png_read_IHDR(png_structp png_ptr, png_infop 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 = (png_byte)bit_depth;
-   info->color_type =(png_byte) color_type;
-   info->compression_type = (png_byte)compression_type;
-   info->filter_type = (png_byte)filter_type;
-   info->interlace_type = (png_byte)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 = (png_byte)(info->channels * info->bit_depth);
-   info->rowbytes = ((info->width * info->pixel_depth + 7) >> 3);
-}
-
-void
-png_read_PLTE(png_structp png_ptr, png_infop info,
-   png_colorp palette, int num)
-{
-   if (!png_ptr || !info)
-      return;
-
-   info->palette = palette;
-   info->num_palette = (png_uint_16)num;
-   info->valid |= PNG_INFO_PLTE;
-}
-
-#if defined(PNG_READ_gAMA_SUPPORTED)
-void
-png_read_gAMA(png_structp png_ptr, png_infop info, double 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_structp png_ptr, png_infop info,
-   png_color_8p sig_bit)
-{
-   if (!png_ptr || !info)
-      return;
-
-   png_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_structp png_ptr, png_infop info,
-   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 || !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_structp png_ptr, png_infop info,
-   png_bytep trans, int num_trans,   png_color_16p trans_values)
-{
-   if (!png_ptr || !info)
-      return;
-
-   if (trans)
-   {
-      info->trans = trans;
-   }
-   else
-   {
-      png_memcpy(&(info->trans_values), trans_values,
-         sizeof(png_color_16));
-   }
-   info->num_trans = (png_uint_16)num_trans;
-   info->valid |= PNG_INFO_tRNS;
-}
-#endif
-
-#if defined(PNG_READ_bKGD_SUPPORTED)
-void
-png_read_bKGD(png_structp png_ptr, png_infop info,
-   png_color_16p background)
-{
-   if (!png_ptr || !info)
-      return;
-
-   png_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_structp png_ptr, png_infop info, png_uint_16p 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_structp png_ptr, png_infop 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 = (png_byte)unit_type;
-   info->valid |= PNG_INFO_pHYs;
-}
-#endif
-
-#if defined(PNG_READ_oFFs_SUPPORTED)
-void
-png_read_oFFs(png_structp png_ptr, png_infop 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 = (png_byte)unit_type;
-   info->valid |= PNG_INFO_oFFs;
-}
-#endif
-
-#if defined(PNG_READ_tIME_SUPPORTED)
-void
-png_read_tIME(png_structp png_ptr, png_infop info,
-   png_timep mod_time)
-{
-   if (!png_ptr || !info)
-      return;
-
-   png_memcpy(&(info->mod_time), mod_time, sizeof (png_time));
-   info->valid |= PNG_INFO_tIME;
-}
-#endif
-
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
-void
-png_read_zTXt(png_structp png_ptr, png_infop info,
-   png_charp key, png_charp 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;
-         {
-            png_textp old_text;
-
-            old_text = info->text;
-            info->text = (png_textp)png_large_malloc(png_ptr,
-               info->max_text * sizeof (png_text));
-            png_memcpy(info->text, old_text,
-               (png_size_t)(old_max * sizeof (png_text)));
-            png_large_free(png_ptr, old_text);
-         }
-      }
-      else
-      {
-         info->max_text = 16;
-         info->num_text = 0;
-         info->text = (png_textp)png_large_malloc(png_ptr,
-            info->max_text * sizeof (png_text));
-      }
-   }
-
-   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_structp png_ptr, png_infop info,
-   png_charp key, png_charp 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

@@ -1,17 +1,19 @@
 
 /* pngrio.c - functions for data input
-
-   libpng 1.0 beta 3 - version 0.89
-   For conditions of distribution and use, see copyright notice in png.h
-   Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
-   May 25, 1996
-
-   This file provides a location for all input.  Users which need
-   special handling are expected to write a function which has the same
-   arguments as this, and perform a similar function, but 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(...) */
+ *
+ * libpng 1.0.11 - April 27, 2001
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2001 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This file provides a location for all 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"
@@ -20,76 +22,85 @@
    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.  The cast to png_size_t is
-   there to quiet some compilers */
-void
-png_read_data(png_structp png_ptr, png_bytep data, png_uint_32 length)
+   to read more then 64K on a 16 bit machine. */
+void /* PRIVATE */
+png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
-   if (png_ptr->read_data_fn)
+   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");
 }
 
-/* This is the function which does the actual reading of data.  If you are
+#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_uint_32 length)
+static void /* PRIVATE */
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
-   png_uint_32 check;
+   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.
+    */
+#if defined(_WIN32_WCE)
+   if ( !ReadFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
+      check = 0;
+#else
+   check = (png_size_t)fread(data, (png_size_t)1, length,
+      (png_FILE_p)png_ptr->io_ptr);
+#endif
 
-   check = fread(data, 1, (size_t)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)
- 
-#ifdef _MSC_VER
-/* for FP_OFF */
-#include <dos.h>
-#endif
- 
-static void
-png_default_read_data(png_structp png_ptr, png_bytep data, png_uint_32 length)
+
+static void /* PRIVATE */
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
-   png_uint_32 check;
+   int check;
    png_byte *n_data;
+   png_FILE_p io_ptr;
 
    /* 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;
+   n_data = (png_byte *)CVT_PTR_NOCHECK(data);
+   io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
    if ((png_bytep)n_data == data)
-#endif
    {
-      check = fread(n_data, 1, (size_t)length, (FILE *)png_ptr->io_ptr);
+#if defined(_WIN32_WCE)
+      if ( !ReadFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
+         check = 0;
+#else
+      check = fread(n_data, 1, length, io_ptr);
+#endif
    }
    else
    {
       png_byte buf[NEAR_BUF_SIZE];
       png_size_t read, remaining, err;
       check = 0;
-      remaining = (png_size_t)length;
+      remaining = length;
       do
       {
          read = MIN(NEAR_BUF_SIZE, remaining);
-         err = fread(buf, 1, read, (FILE *)png_ptr->io_ptr);
+#if defined(_WIN32_WCE)
+         if ( !ReadFile((HANDLE)(io_ptr), buf, read, &err, NULL) )
+            err = 0;
+#else
+         err = fread(buf, (png_size_t)1, read, io_ptr);
+#endif
          png_memcpy(data, buf, read); /* copy far buffer to near buffer */
          if(err != read)
             break;
@@ -100,12 +111,11 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_uint_32 length)
       }
       while (remaining != 0);
    }
-   if (check != length)
-   {
+   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.
@@ -114,28 +124,39 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_uint_32 length)
    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
+   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 which is the number of bytes to be read.
+                  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
+void PNGAPI
 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 (read_data_fn)
+#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 */
-   png_ptr->write_data_fn = NULL;
+   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 */
+#endif
 }
 

pngset.c

@@ -0,0 +1,970 @@
+
+/* pngset.c - storage of image information into info struct
+ *
+ * libpng 1.0.11 - April 27, 2001
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2001 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * 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_bKGD_SUPPORTED)
+void PNGAPI
+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_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+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;
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   info_ptr->int_x_white = (png_fixed_point)(white_x*100000.+0.5);
+   info_ptr->int_y_white = (png_fixed_point)(white_y*100000.+0.5);
+   info_ptr->int_x_red   = (png_fixed_point)(red_x*100000.+0.5);
+   info_ptr->int_y_red   = (png_fixed_point)(red_y*100000.+0.5);
+   info_ptr->int_x_green = (png_fixed_point)(green_x*100000.+0.5);
+   info_ptr->int_y_green = (png_fixed_point)(green_y*100000.+0.5);
+   info_ptr->int_x_blue  = (png_fixed_point)(blue_x*100000.+0.5);
+   info_ptr->int_y_blue  = (png_fixed_point)(blue_y*100000.+0.5);
+#endif
+   info_ptr->valid |= PNG_INFO_cHRM;
+}
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
+   png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+   png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+   png_fixed_point blue_x, png_fixed_point blue_y)
+{
+   png_debug1(1, "in %s storage function\n", "cHRM");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->int_x_white = white_x;
+   info_ptr->int_y_white = white_y;
+   info_ptr->int_x_red   = red_x;
+   info_ptr->int_y_red   = red_y;
+   info_ptr->int_x_green = green_x;
+   info_ptr->int_y_green = green_y;
+   info_ptr->int_x_blue  = blue_x;
+   info_ptr->int_y_blue  = blue_y;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   info_ptr->x_white = (float)(white_x/100000.);
+   info_ptr->y_white = (float)(white_y/100000.);
+   info_ptr->x_red   = (float)(red_x/100000.);
+   info_ptr->y_red   = (float)(red_y/100000.);
+   info_ptr->x_green = (float)(green_x/100000.);
+   info_ptr->y_green = (float)(green_y/100000.);
+   info_ptr->x_blue  = (float)(blue_x/100000.);
+   info_ptr->y_blue  = (float)(blue_y/100000.);
+#endif
+   info_ptr->valid |= PNG_INFO_cHRM;
+}
+#endif
+#endif
+
+#if defined(PNG_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+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;
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   info_ptr->int_gamma = (int)(file_gamma*100000.+.5);
+#endif
+   info_ptr->valid |= PNG_INFO_gAMA;
+   if(file_gamma == 0.0)
+      png_warning(png_ptr, "Setting gamma=0");
+}
+#endif
+void PNGAPI
+png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
+   int_gamma)
+{
+   png_debug1(1, "in %s storage function\n", "gAMA");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   info_ptr->gamma = (float)(int_gamma/100000.);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   info_ptr->int_gamma = int_gamma;
+#endif
+   info_ptr->valid |= PNG_INFO_gAMA;
+   if(int_gamma == 0)
+      png_warning(png_ptr, "Setting gamma=0");
+}
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+void PNGAPI
+png_set_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p hist)
+{
+   int	i;
+
+   png_debug1(1, "in %s storage function\n", "hIST");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   if (info_ptr->num_palette == 0)
+   {
+       png_warning(png_ptr,
+          "Palette size 0, hIST allocation skipped.");
+       return;
+   }
+
+#ifdef PNG_FREE_ME_SUPPORTED
+   png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);
+#endif
+   png_ptr->hist = (png_uint_16p)png_malloc(png_ptr,
+      (png_uint_32)(info_ptr->num_palette * sizeof (png_uint_16)));
+
+   for (i = 0; i < info_ptr->num_palette; i++)
+       png_ptr->hist[i] = hist[i];
+   info_ptr->hist = png_ptr->hist;
+   info_ptr->valid |= PNG_INFO_hIST;
+
+#ifdef PNG_FREE_ME_SUPPORTED
+   info_ptr->free_me |= PNG_FREE_HIST;
+#else
+   png_ptr->flags |= PNG_FLAG_FREE_HIST;
+#endif
+}
+#endif
+
+void PNGAPI
+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;
+
+   /* check for width and height valid values */
+   if (width == 0 || height == 0)
+      png_error(png_ptr, "Image width or height is zero in IHDR");
+   if (width > PNG_MAX_UINT || height > PNG_MAX_UINT)
+      png_error(png_ptr, "Invalid image size in IHDR");
+
+   /* check other values */
+   if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
+      bit_depth != 8 && bit_depth != 16)
+      png_error(png_ptr, "Invalid bit depth in IHDR");
+
+   if (color_type < 0 || color_type == 1 ||
+      color_type == 5 || color_type > 6)
+      png_error(png_ptr, "Invalid color type in IHDR");
+
+   if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
+       ((color_type == PNG_COLOR_TYPE_RGB ||
+         color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
+         color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
+      png_error(png_ptr, "Invalid color type/bit depth combination in IHDR");
+
+   if (interlace_type >= PNG_INTERLACE_LAST)
+      png_error(png_ptr, "Unknown interlace method in IHDR");
+
+   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+      png_error(png_ptr, "Unknown compression method in IHDR");
+
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+   /* Accept filter_method 64 (intrapixel differencing) only if
+    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+    * 2. Libpng did not read a PNG signature (this filter_method is only
+    *    used in PNG datastreams that are embedded in MNG datastreams) and
+    * 3. The application called png_permit_mng_features with a mask that
+    *    included PNG_FLAG_MNG_FILTER_64 and
+    * 4. The filter_method is 64 and
+    * 5. The color_type is RGB or RGBA
+    */
+   if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&png_ptr->mng_features_permitted)
+      png_warning(png_ptr,"MNG features are not allowed in a PNG datastream\n");
+   if(filter_type != PNG_FILTER_TYPE_BASE)
+   {
+     if(!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+        (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
+        ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
+        (color_type == PNG_COLOR_TYPE_RGB || 
+         color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+        png_error(png_ptr, "Unknown filter method in IHDR");
+     if(png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)
+        png_warning(png_ptr, "Invalid filter method in IHDR");
+   }
+#else
+   if(filter_type != PNG_FILTER_TYPE_BASE)
+      png_error(png_ptr, "Unknown filter method in IHDR");
+#endif
+
+   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_oFFs_SUPPORTED)
+void PNGAPI
+png_set_oFFs(png_structp png_ptr, png_infop info_ptr,
+   png_int_32 offset_x, png_int_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_pCAL_SUPPORTED)
+void PNGAPI
+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 (%lu 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 (%lu 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 (%lu 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;
+#ifdef PNG_FREE_ME_SUPPORTED
+   info_ptr->free_me |= PNG_FREE_PCAL;
+#endif
+}
+#endif
+
+#if defined(PNG_READ_sCAL_SUPPORTED) || defined(PNG_WRITE_sCAL_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL(png_structp png_ptr, png_infop info_ptr,
+             int unit, double width, double height)
+{
+   png_debug1(1, "in %s storage function\n", "sCAL");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->scal_unit = (png_byte)unit;
+   info_ptr->scal_pixel_width = width;
+   info_ptr->scal_pixel_height = height;
+
+   info_ptr->valid |= PNG_INFO_sCAL;
+}
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
+             int unit, png_charp swidth, png_charp sheight)
+{
+   png_uint_32 length;
+
+   png_debug1(1, "in %s storage function\n", "sCAL");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->scal_unit = (png_byte)unit;
+
+   length = png_strlen(swidth) + 1;
+   png_debug1(3, "allocating unit for info (%d bytes)\n", length);
+   info_ptr->scal_s_width = (png_charp)png_malloc(png_ptr, length);
+   png_memcpy(info_ptr->scal_s_width, swidth, (png_size_t)length);
+
+   length = png_strlen(sheight) + 1;
+   png_debug1(3, "allocating unit for info (%d bytes)\n", length);
+   info_ptr->scal_s_height = (png_charp)png_malloc(png_ptr, length);
+   png_memcpy(info_ptr->scal_s_height, sheight, (png_size_t)length);
+
+   info_ptr->valid |= PNG_INFO_sCAL;
+#ifdef PNG_FREE_ME_SUPPORTED
+   info_ptr->free_me |= PNG_FREE_SCAL;
+#endif
+}
+#endif
+#endif
+#endif
+
+#if defined(PNG_pHYs_SUPPORTED)
+void PNGAPI
+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 PNGAPI
+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;
+
+   /*
+    * It may not actually be necessary to set png_ptr->palette here;
+    * we do it for backward compatibility with the way the png_handle_tRNS
+    * function used to do the allocation.
+    */
+#ifdef PNG_FREE_ME_SUPPORTED
+   png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
+#endif
+   png_ptr->palette = (png_colorp)png_zalloc(png_ptr, (uInt)num_palette,
+      sizeof (png_color));
+   png_memcpy(png_ptr->palette, palette, num_palette * sizeof (png_color));
+   info_ptr->palette = png_ptr->palette;
+   info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
+
+#ifdef PNG_FREE_ME_SUPPORTED
+   info_ptr->free_me |= PNG_FREE_PLTE;
+#else
+   png_ptr->flags |= PNG_FLAG_FREE_PLTE;
+#endif
+
+   info_ptr->valid |= PNG_INFO_PLTE;
+}
+
+#if defined(PNG_sBIT_SUPPORTED)
+void PNGAPI
+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_sRGB_SUPPORTED)
+void PNGAPI
+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 PNGAPI
+png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
+   int intent)
+{
+#if defined(PNG_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   float file_gamma;
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   png_fixed_point int_file_gamma;
+#endif
+#endif
+#if defined(PNG_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y, int_green_x,
+      int_green_y, int_blue_x, int_blue_y;
+#endif
+#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_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   file_gamma = (float).45455;
+   png_set_gAMA(png_ptr, info_ptr, file_gamma);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   int_file_gamma = 45455L;
+   png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma);
+#endif
+#endif
+
+#if defined(PNG_cHRM_SUPPORTED)
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   int_white_x = 31270L;
+   int_white_y = 32900L;
+   int_red_x   = 64000L;
+   int_red_y   = 33000L;
+   int_green_x = 30000L;
+   int_green_y = 60000L;
+   int_blue_x  = 15000L;
+   int_blue_y  =  6000L;
+
+   png_set_cHRM_fixed(png_ptr, info_ptr,
+      int_white_x, int_white_y, int_red_x, int_red_y, int_green_x, int_green_y,
+      int_blue_x, int_blue_y);
+#endif
+#ifdef PNG_FLOATING_POINT_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
+}
+#endif
+
+
+#if defined(PNG_iCCP_SUPPORTED)
+void PNGAPI
+png_set_iCCP(png_structp png_ptr, png_infop info_ptr,
+             png_charp name, int compression_type,
+             png_charp profile, png_uint_32 proflen)
+{
+   png_charp new_iccp_name;
+   png_charp new_iccp_profile;
+
+   png_debug1(1, "in %s storage function\n", "iCCP");
+   if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
+      return;
+
+   new_iccp_name = (png_charp)png_malloc(png_ptr, png_strlen(name)+1);
+   png_strcpy(new_iccp_name, name);
+   new_iccp_profile = (png_charp)png_malloc(png_ptr, proflen);
+   png_memcpy(new_iccp_profile, profile, (png_size_t)proflen);
+
+   png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
+
+   info_ptr->iccp_proflen = proflen;
+   info_ptr->iccp_name = new_iccp_name;
+   info_ptr->iccp_profile = new_iccp_profile;
+   /* Compression is always zero but is here so the API and info structure
+    * does not have to change if we introduce multiple compression types */
+   info_ptr->iccp_compression = (png_byte)compression_type;
+#ifdef PNG_FREE_ME_SUPPORTED
+   info_ptr->free_me |= PNG_FREE_ICCP;
+#endif
+   info_ptr->valid |= PNG_INFO_iCCP;
+}
+#endif
+
+#if defined(PNG_TEXT_SUPPORTED)
+void PNGAPI
+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)));
+#ifdef PNG_FREE_ME_SUPPORTED
+         info_ptr->free_me |= PNG_FREE_TEXT;
+#endif
+      }
+      png_debug1(3, "allocated %d entries for info_ptr->text\n",
+         info_ptr->max_text);
+   }
+   for (i = 0; i < num_text; i++)
+   {
+      png_size_t text_length,key_len;
+      png_size_t lang_len,lang_key_len;
+      png_textp textp = &(info_ptr->text[info_ptr->num_text]);
+
+      if (text_ptr[i].key == NULL)
+          continue;
+
+      key_len = png_strlen(text_ptr[i].key);
+
+      if(text_ptr[i].compression <= 0)
+      {
+        lang_len = 0;
+        lang_key_len = 0;
+      }
+      else
+#ifdef PNG_iTXt_SUPPORTED
+      {
+        /* set iTXt data */
+        if (text_ptr[i].key != NULL)
+          lang_len = png_strlen(text_ptr[i].lang);
+        else
+          lang_len = 0;
+        if (text_ptr[i].lang_key != NULL)
+          lang_key_len = png_strlen(text_ptr[i].lang_key);
+        else
+          lang_key_len = 0;
+      }
+#else
+      {
+        png_warning(png_ptr, "iTXt chunk not supported.");
+        continue;
+      }
+#endif
+
+      if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
+      {
+         text_length = 0;
+#ifdef PNG_iTXt_SUPPORTED
+         if(text_ptr[i].compression > 0)
+            textp->compression = PNG_ITXT_COMPRESSION_NONE;
+         else
+#endif
+            textp->compression = PNG_TEXT_COMPRESSION_NONE;
+      }
+      else
+      {
+         text_length = png_strlen(text_ptr[i].text);
+         textp->compression = text_ptr[i].compression;
+      }
+
+      textp->key = (png_charp)png_malloc(png_ptr,
+         (png_uint_32)(key_len + text_length + lang_len + lang_key_len + 4));
+      png_debug2(2, "Allocated %d bytes at %x in png_set_text\n",
+         key_len + lang_len + lang_key_len + text_length + 4, (int)textp->key);
+
+      png_memcpy(textp->key, text_ptr[i].key,
+         (png_size_t)(key_len));
+      *(textp->key+key_len) = '\0';
+#ifdef PNG_iTXt_SUPPORTED
+      if (text_ptr[i].compression > 0)
+      {
+         textp->lang=textp->key + key_len + 1;
+         png_memcpy(textp->lang, text_ptr[i].lang, lang_len);
+         *(textp->lang+lang_len) = '\0';
+         textp->lang_key=textp->lang + lang_len + 1;
+         png_memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
+         *(textp->lang_key+lang_key_len) = '\0';
+         textp->text=textp->lang_key + lang_key_len + 1;
+      }
+      else
+#endif
+      {
+#ifdef PNG_iTXt_SUPPORTED
+         textp->lang=(png_charp)NULL;
+         textp->lang_key=(png_charp)NULL;
+#endif
+         textp->text=textp->key + key_len + 1;
+      }
+      if(text_length)
+         png_memcpy(textp->text, text_ptr[i].text,
+            (png_size_t)(text_length));
+      *(textp->text+text_length) = '\0';
+
+#ifdef PNG_iTXt_SUPPORTED
+      if(textp->compression > 0)
+      {
+         textp->text_length = 0;
+         textp->itxt_length = text_length;
+      }
+      else
+#endif
+      {
+         textp->text_length = text_length;
+#ifdef PNG_iTXt_SUPPORTED
+         textp->itxt_length = 0;
+#endif
+      }
+      info_ptr->text[info_ptr->num_text]= *textp;
+      info_ptr->num_text++;
+      png_debug1(3, "transferred text chunk %d\n", info_ptr->num_text);
+   }
+}
+#endif
+
+#if defined(PNG_tIME_SUPPORTED)
+void PNGAPI
+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->mode & PNG_WROTE_tIME))
+      return;
+
+   png_memcpy(&(info_ptr->mod_time), mod_time, sizeof (png_time));
+   info_ptr->valid |= PNG_INFO_tIME;
+}
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED)
+void PNGAPI
+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)
+   {
+       /*
+	* It may not actually be necessary to set png_ptr->trans here;
+	* we do it for backward compatibility with the way the png_handle_tRNS
+	* function used to do the allocation.
+	*/
+#ifdef PNG_FREE_ME_SUPPORTED
+       png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+#endif
+       png_ptr->trans = info_ptr->trans = (png_bytep)png_malloc(png_ptr,
+           num_trans);
+       png_memcpy(info_ptr->trans, trans, num_trans);
+#ifdef PNG_FREE_ME_SUPPORTED
+       info_ptr->free_me |= PNG_FREE_TRNS;
+#else
+       png_ptr->flags |= PNG_FLAG_FREE_TRNS;
+#endif
+   }
+
+   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_sPLT_SUPPORTED)
+void PNGAPI
+png_set_sPLT(png_structp png_ptr,
+             png_infop info_ptr, png_sPLT_tp entries, int nentries)
+{
+    png_sPLT_tp np;
+    int i;
+
+    np = (png_sPLT_tp)png_malloc(png_ptr,
+        (info_ptr->splt_palettes_num + nentries) * sizeof(png_sPLT_t));
+
+    png_memcpy(np, info_ptr->splt_palettes,
+           info_ptr->splt_palettes_num * sizeof(png_sPLT_t));
+    png_free(png_ptr, info_ptr->splt_palettes);
+    info_ptr->splt_palettes=NULL;
+
+    for (i = 0; i < nentries; i++)
+    {
+        png_sPLT_tp to = np + info_ptr->splt_palettes_num + i;
+        png_sPLT_tp from = entries + i;
+
+        to->name = (png_charp)png_malloc(png_ptr,
+            png_strlen(from->name) + 1);
+        png_strcpy(to->name, from->name);
+        to->entries = (png_sPLT_entryp)png_malloc(png_ptr,
+            from->nentries * sizeof(png_sPLT_t));
+        png_memcpy(to->entries, from->entries,
+            from->nentries * sizeof(png_sPLT_t));
+        to->nentries = from->nentries;
+        to->depth = from->depth;
+    }
+
+    info_ptr->splt_palettes = np;
+    info_ptr->splt_palettes_num += nentries;
+    info_ptr->valid |= PNG_INFO_sPLT;
+#ifdef PNG_FREE_ME_SUPPORTED
+    info_ptr->free_me |= PNG_FREE_SPLT;
+#endif
+}
+#endif /* PNG_sPLT_SUPPORTED */
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+void PNGAPI
+png_set_unknown_chunks(png_structp png_ptr,
+   png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns)
+{
+    png_unknown_chunkp np;
+    int i;
+
+    if (png_ptr == NULL || info_ptr == NULL || num_unknowns == 0)
+        return;
+
+    np = (png_unknown_chunkp)png_malloc(png_ptr,
+        (info_ptr->unknown_chunks_num + num_unknowns) *
+        sizeof(png_unknown_chunk));
+
+    png_memcpy(np, info_ptr->unknown_chunks,
+           info_ptr->unknown_chunks_num * sizeof(png_unknown_chunk));
+    png_free(png_ptr, info_ptr->unknown_chunks);
+    info_ptr->unknown_chunks=NULL;
+
+    for (i = 0; i < num_unknowns; i++)
+    {
+        png_unknown_chunkp to = np + info_ptr->unknown_chunks_num + i;
+        png_unknown_chunkp from = unknowns + i;
+
+        png_strcpy((png_charp)to->name, (png_charp)from->name);
+        to->data = (png_bytep)png_malloc(png_ptr, from->size);
+        png_memcpy(to->data, from->data, from->size);
+        to->size = from->size;
+
+        /* note our location in the read or write sequence */
+        to->location = (png_byte)(png_ptr->mode & 0xff);
+    }
+
+    info_ptr->unknown_chunks = np;
+    info_ptr->unknown_chunks_num += num_unknowns;
+#ifdef PNG_FREE_ME_SUPPORTED
+    info_ptr->free_me |= PNG_FREE_UNKN;
+#endif
+}
+void PNGAPI
+png_set_unknown_chunk_location(png_structp png_ptr, png_infop info_ptr,
+   int chunk, int location)
+{
+   if(png_ptr != NULL && info_ptr != NULL && chunk >= 0 && chunk <
+         (int)info_ptr->unknown_chunks_num)
+      info_ptr->unknown_chunks[chunk].location = (png_byte)location;
+}
+#endif
+
+#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
+    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
+void PNGAPI
+png_permit_empty_plte (png_structp png_ptr, int empty_plte_permitted)
+{
+   /* This function is deprecated in favor of png_permit_mng_features()
+      and will be removed from libpng-2.0.0 */
+   png_debug(1, "in png_permit_empty_plte, DEPRECATED.\n");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->mng_features_permitted = (png_byte)
+     ((png_ptr->mng_features_permitted & (~(PNG_FLAG_MNG_EMPTY_PLTE))) |
+     ((empty_plte_permitted & PNG_FLAG_MNG_EMPTY_PLTE)));
+}
+#endif
+
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+png_uint_32 PNGAPI
+png_permit_mng_features (png_structp png_ptr, png_uint_32 mng_features)
+{
+   png_debug(1, "in png_permit_mng_features\n");
+   if (png_ptr == NULL)
+      return (png_uint_32)0;
+   png_ptr->mng_features_permitted =
+     (png_byte)(mng_features & PNG_ALL_MNG_FEATURES);
+   return (png_uint_32)png_ptr->mng_features_permitted;
+}
+#endif
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+void PNGAPI
+png_set_keep_unknown_chunks(png_structp png_ptr, int keep, png_bytep
+   chunk_list, int num_chunks)
+{
+    png_bytep new_list, p;
+    int i, old_num_chunks;
+    if (num_chunks == 0)
+    {
+      if(keep == HANDLE_CHUNK_ALWAYS || keep == HANDLE_CHUNK_IF_SAFE)
+        png_ptr->flags |= PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+      else
+        png_ptr->flags &= ~PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+
+      if(keep == HANDLE_CHUNK_ALWAYS)
+        png_ptr->flags |= PNG_FLAG_KEEP_UNSAFE_CHUNKS;
+      else
+        png_ptr->flags &= ~PNG_FLAG_KEEP_UNSAFE_CHUNKS;
+      return;
+    }
+    if (chunk_list == NULL)
+      return;
+    old_num_chunks=png_ptr->num_chunk_list;
+    new_list=(png_bytep)png_malloc(png_ptr,5*(num_chunks+old_num_chunks));
+    if(png_ptr->chunk_list != NULL)
+    {
+       png_memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
+       png_free(png_ptr, png_ptr->chunk_list);
+       png_ptr->chunk_list=NULL;
+    }
+    png_memcpy(new_list+5*old_num_chunks, chunk_list, 5*num_chunks);
+    for (p=new_list+5*old_num_chunks+4, i=0; i<num_chunks; i++, p+=5)
+       *p=(png_byte)keep;
+    png_ptr->num_chunk_list=old_num_chunks+num_chunks;
+    png_ptr->chunk_list=new_list;
+#ifdef PNG_FREE_ME_SUPPORTED
+    png_ptr->free_me |= PNG_FREE_LIST;
+#endif
+}
+#endif
+
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+void PNGAPI
+png_set_read_user_chunk_fn(png_structp png_ptr, png_voidp user_chunk_ptr,
+   png_user_chunk_ptr read_user_chunk_fn)
+{
+   png_debug(1, "in png_set_read_user_chunk_fn\n");
+   png_ptr->read_user_chunk_fn = read_user_chunk_fn;
+   png_ptr->user_chunk_ptr = user_chunk_ptr;
+}
+#endif
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+void PNGAPI
+png_set_rows(png_structp png_ptr, png_infop info_ptr, png_bytepp row_pointers)
+{
+   png_debug1(1, "in %s storage function\n", "rows");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   if(info_ptr->row_pointers && (info_ptr->row_pointers != row_pointers))
+      png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+   info_ptr->row_pointers = row_pointers;
+   if(row_pointers)
+      info_ptr->valid |= PNG_INFO_IDAT;
+}
+#endif
+
+void PNGAPI
+png_set_compression_buffer_size(png_structp png_ptr, png_uint_32 size)
+{
+    if(png_ptr->zbuf)
+       png_free(png_ptr, png_ptr->zbuf);
+    png_ptr->zbuf_size = (png_size_t)size;
+    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, size);
+    png_ptr->zstream.next_out = png_ptr->zbuf;
+    png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+}
+
+void PNGAPI
+png_set_invalid(png_structp png_ptr, png_infop info_ptr, int mask)
+{
+   if (png_ptr && info_ptr)
+      info_ptr->valid &= ~(mask);
+}
+