Attachment 42708 Details for Bug 33710 – the requested /mnt/sdb8/sergei/AFSWD_debug/install/libpng-1.4.5/include/libpng14/png.h

the requested /mnt/sdb8/sergei/AFSWD_debug/install/libpng-1.4.5/include/libpng14/png.h

png.h (text/x-chdr), 115.67 KB, created by Sergei Steshenko on 2011-01-30 02:46:24 UTC

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Creator: Sergei Steshenko

Created: 2011-01-30 02:46:24 UTC

Size: 115.67 KB

patch

obsolete

>
>/* png.h - header file for PNG reference library
> *
> * libpng version 1.4.5 - December 9, 2010
> * Copyright (c) 1998-2010 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 code is released under the libpng license (See LICENSE, below)
> *
> * Authors and maintainers:
> *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
> *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
> *  libpng versions 0.97, January 1998, through 1.4.5 - December 9, 2010: Glenn
> *  See also "Contributing Authors", below.
> *
> * Note about libpng version numbers:
> *
> *    Due to various miscommunications, unforeseen code incompatibilities
> *    and occasional factors outside the authors' control, version numbering
> *    on the library has not always been consistent and straightforward.
> *    The following table summarizes matters since version 0.89c, which was
> *    the first widely used release:
> *
> *    source                 png.h  png.h  shared-lib
> *    version                string   int  version
> *    -------                ------ -----  ----------
> *    0.89c "1.0 beta 3"     0.89      89  1.0.89
> *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
> *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
> *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
> *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
> *    0.97c                  0.97      97  2.0.97
> *    0.98                   0.98      98  2.0.98
> *    0.99                   0.99      98  2.0.99
> *    0.99a-m                0.99      99  2.0.99
> *    1.00                   1.00     100  2.1.0 [100 should be 10000]
> *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
> *    1.0.1       png.h string is   10001  2.1.0
> *    1.0.1a-e    identical to the  10002  from here on, the shared library
> *    1.0.2       source version)   10002  is 2.V where V is the source code
> *    1.0.2a-b                      10003  version, except as noted.
> *    1.0.3                         10003
> *    1.0.3a-d                      10004
> *    1.0.4                         10004
> *    1.0.4a-f                      10005
> *    1.0.5 (+ 2 patches)           10005
> *    1.0.5a-d                      10006
> *    1.0.5e-r                      10100 (not source compatible)
> *    1.0.5s-v                      10006 (not binary compatible)
> *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
> *    1.0.6d-f                      10007 (still binary incompatible)
> *    1.0.6g                        10007
> *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
> *    1.0.6i                        10007  10.6i
> *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
> *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
> *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
> *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
> *    1.0.7                    1    10007  (still compatible)
> *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4
> *    1.0.8rc1                 1    10008  2.1.0.8rc1
> *    1.0.8                    1    10008  2.1.0.8
> *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6
> *    1.0.9rc1                 1    10009  2.1.0.9rc1
> *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10
> *    1.0.9rc2                 1    10009  2.1.0.9rc2
> *    1.0.9                    1    10009  2.1.0.9
> *    1.0.10beta1              1    10010  2.1.0.10beta1
> *    1.0.10rc1                1    10010  2.1.0.10rc1
> *    1.0.10                   1    10010  2.1.0.10
> *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3
> *    1.0.11rc1                1    10011  2.1.0.11rc1
> *    1.0.11                   1    10011  2.1.0.11
> *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2
> *    1.0.12rc1                2    10012  2.1.0.12rc1
> *    1.0.12                   2    10012  2.1.0.12
> *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)
> *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2
> *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5
> *    1.2.0rc1                 3    10200  3.1.2.0rc1
> *    1.2.0                    3    10200  3.1.2.0
> *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4
> *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2
> *    1.2.1                    3    10201  3.1.2.1
> *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6
> *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1
> *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1
> *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1
> *    1.0.13                  10    10013  10.so.0.1.0.13
> *    1.2.2                   12    10202  12.so.0.1.2.2
> *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6
> *    1.2.3                   12    10203  12.so.0.1.2.3
> *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3
> *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1
> *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1
> *    1.0.14                  10    10014  10.so.0.1.0.14
> *    1.2.4                   13    10204  12.so.0.1.2.4
> *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2
> *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3
> *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3
> *    1.0.15                  10    10015  10.so.0.1.0.15
> *    1.2.5                   13    10205  12.so.0.1.2.5
> *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4
> *    1.0.16                  10    10016  10.so.0.1.0.16
> *    1.2.6                   13    10206  12.so.0.1.2.6
> *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2
> *    1.0.17rc1               10    10017  12.so.0.1.0.17rc1
> *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
> *    1.0.17                  10    10017  12.so.0.1.0.17
> *    1.2.7                   13    10207  12.so.0.1.2.7
> *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5
> *    1.0.18rc1-5             10    10018  12.so.0.1.0.18rc1-5
> *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
> *    1.0.18                  10    10018  12.so.0.1.0.18
> *    1.2.8                   13    10208  12.so.0.1.2.8
> *    1.2.9beta1-3            13    10209  12.so.0.1.2.9beta1-3
> *    1.2.9beta4-11           13    10209  12.so.0.9[.0]
> *    1.2.9rc1                13    10209  12.so.0.9[.0]
> *    1.2.9                   13    10209  12.so.0.9[.0]
> *    1.2.10beta1-7           13    10210  12.so.0.10[.0]
> *    1.2.10rc1-2             13    10210  12.so.0.10[.0]
> *    1.2.10                  13    10210  12.so.0.10[.0]
> *    1.4.0beta1-5            14    10400  14.so.0.0[.0]
> *    1.2.11beta1-4           13    10211  12.so.0.11[.0]
> *    1.4.0beta7-8            14    10400  14.so.0.0[.0]
> *    1.2.11                  13    10211  12.so.0.11[.0]
> *    1.2.12                  13    10212  12.so.0.12[.0]
> *    1.4.0beta9-14           14    10400  14.so.0.0[.0]
> *    1.2.13                  13    10213  12.so.0.13[.0]
> *    1.4.0beta15-36          14    10400  14.so.0.0[.0]
> *    1.4.0beta37-87          14    10400  14.so.14.0[.0]
> *    1.4.0rc01               14    10400  14.so.14.0[.0]
> *    1.4.0beta88-109         14    10400  14.so.14.0[.0]
> *    1.4.0rc02-08            14    10400  14.so.14.0[.0]
> *    1.4.0                   14    10400  14.so.14.0[.0]
> *    1.4.1beta01-03          14    10401  14.so.14.1[.0]
> *    1.4.1rc01               14    10401  14.so.14.1[.0]
> *    1.4.1beta04-12          14    10401  14.so.14.1[.0]
> *    1.4.1rc02-04            14    10401  14.so.14.1[.0]
> *    1.4.1                   14    10401  14.so.14.1[.0]
> *    1.4.2beta01             14    10402  14.so.14.2[.0]
> *    1.4.2rc02-06            14    10402  14.so.14.2[.0]
> *    1.4.2                   14    10402  14.so.14.2[.0]
> *    1.4.3beta01-05          14    10403  14.so.14.3[.0]
> *    1.4.3rc01-03            14    10403  14.so.14.3[.0]
> *    1.4.3                   14    10403  14.so.14.3[.0]
> *    1.4.4beta01-08          14    10404  14.so.14.4[.0]
> *    1.4.4rc01-05            14    10404  14.so.14.4[.0]
> *    1.4.4                   14    10404  14.so.14.4[.0]
> *    1.4.5beta01-04          14    10405  14.so.14.5[.0]
> *    1.4.5rc01               14    10405  14.so.14.5[.0]
> *    1.4.5beta05-07          14    10405  14.so.14.5[.0]
> *    1.4.5rc02-03            14    10405  14.so.14.5[.0]
> *    1.4.5                   14    10405  14.so.14.5[.0]
> *
> *    Henceforth the source version will match the shared-library major
> *    and minor numbers; the shared-library major version number will be
> *    used for changes in backward compatibility, as it is intended.  The
> *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
> *    for applications, is an unsigned integer of the form xyyzz corresponding
> *    to the source version x.y.z (leading zeros in y and z).  Beta versions
> *    were given the previous public release number plus a letter, until
> *    version 1.0.6j; from then on they were given the upcoming public
> *    release number plus "betaNN" or "rcN".
> *
> *    Binary incompatibility exists only when applications make direct access
> *    to the info_ptr or png_ptr members through png.h, and the compiled
> *    application is loaded with a different version of the library.
> *
> *    DLLNUM will change each time there are forward or backward changes
> *    in binary compatibility (e.g., when a new feature is added).
> *
> * See libpng.txt or libpng.3 for more information.  The PNG specification
> * is available as a W3C Recommendation and as an ISO Specification,
> * <http://www.w3.org/TR/2003/REC-PNG-20031110/
> */
>
>/*
> * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
> *
> * If you modify libpng you may insert additional notices immediately following
> * this sentence.
> *
> * This code is released under the libpng license.
> *
> * libpng versions 1.2.6, August 15, 2004, through 1.4.5, December 9, 2010, are
> * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
> * distributed according to the same disclaimer and license as libpng-1.2.5
> * with the following individual added to the list of Contributing Authors:
> *
> *    Cosmin Truta
> *
> * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
> * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
> * distributed according to the same disclaimer and license as libpng-1.0.6
> * with the following individuals added to the list of Contributing Authors:
> *
> *    Simon-Pierre Cadieux
> *    Eric S. Raymond
> *    Gilles Vollant
> *
> * and with the following additions to the disclaimer:
> *
> *    There is no warranty against interference with your enjoyment of the
> *    library or against infringement.  There is no warranty that our
> *    efforts or the library will fulfill any of your particular purposes
> *    or needs.  This library is provided with all faults, and the entire
> *    risk of satisfactory quality, performance, accuracy, and effort is with
> *    the user.
> *
> * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
> * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
> * distributed according to the same disclaimer and license as libpng-0.96,
> * with the following individuals added to the list of Contributing Authors:
> *
> *    Tom Lane
> *    Glenn Randers-Pehrson
> *    Willem van Schaik
> *
> * libpng versions 0.89, June 1996, through 0.96, May 1997, are
> * Copyright (c) 1996, 1997 Andreas Dilger
> * Distributed according to the same disclaimer and license as libpng-0.88,
> * with the following individuals added to the list of Contributing Authors:
> *
> *    John Bowler
> *    Kevin Bracey
> *    Sam Bushell
> *    Magnus Holmgren
> *    Greg Roelofs
> *    Tom Tanner
> *
> * libpng versions 0.5, May 1995, through 0.88, January 1996, are
> * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
> *
> * For the purposes of this copyright and license, "Contributing Authors"
> * is defined as the following set of individuals:
> *
> *    Andreas Dilger
> *    Dave Martindale
> *    Guy Eric Schalnat
> *    Paul Schmidt
> *    Tim Wegner
> *
> * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
> * and Group 42, Inc. disclaim all warranties, expressed or implied,
> * including, without limitation, the warranties of merchantability and of
> * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
> * assume no liability for direct, indirect, incidental, special, exemplary,
> * or consequential damages, which may result from the use of the PNG
> * Reference Library, even if advised of the possibility of such damage.
> *
> * Permission is hereby granted to use, copy, modify, and distribute this
> * source code, or portions hereof, for any purpose, without fee, subject
> * to the following restrictions:
> *
> * 1. The origin of this source code must not be misrepresented.
> *
> * 2. Altered versions must be plainly marked as such and
> * must not be misrepresented as being the original source.
> *
> * 3. This Copyright notice may not be removed or altered from
> *    any source or altered source distribution.
> *
> * The Contributing Authors and Group 42, Inc. specifically permit, without
> * fee, and encourage the use of this source code as a component to
> * supporting the PNG file format in commercial products.  If you use this
> * source code in a product, acknowledgment is not required but would be
> * appreciated.
> */
>
>/*
> * A "png_get_copyright" function is available, for convenient use in "about"
> * boxes and the like:
> *
> *     printf("%s",png_get_copyright(NULL));
> *
> * Also, the PNG logo (in PNG format, of course) is supplied in the
> * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
> */
>
>/*
> * Libpng is OSI Certified Open Source Software.  OSI Certified is a
> * certification mark of the Open Source Initiative.
> */
>
>/*
> * The contributing authors would like to thank all those who helped
> * with testing, bug fixes, and patience.  This wouldn't have been
> * possible without all of you.
> *
> * Thanks to Frank J. T. Wojcik for helping with the documentation.
> */
>
>/*
> * Y2K compliance in libpng:
> * =========================
> *
> *    December 9, 2010
> *
> *    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 1.4.5 are Y2K compliant.  It is my belief that earlier
> *    versions were also Y2K compliant.
> *
> *    Libpng only has three year fields.  One is a 2-byte unsigned integer
> *    that will hold years up to 65535.  The other two hold the date in text
> *    format, and will hold years up to 9999.
> *
> *    The integer is
> *        "png_uint_16 year" in png_time_struct.
> *
> *    The strings are
> *        "png_charp time_buffer" in png_struct and
> *        "near_time_buffer", which is a local character string in png.c.
> *
> *    There are seven time-related functions:
> *        png.c: png_convert_to_rfc_1123() in png.c
> *          (formerly png_convert_to_rfc_1152() in error)
> *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
> *        png_convert_from_time_t() in pngwrite.c
> *        png_get_tIME() in pngget.c
> *        png_handle_tIME() in pngrutil.c, called in pngread.c
> *        png_set_tIME() in pngset.c
> *        png_write_tIME() in pngwutil.c, called in pngwrite.c
> *
> *    All handle dates properly in a Y2K environment.  The
> *    png_convert_from_time_t() function calls gmtime() to convert from system
> *    clock time, which returns (year - 1900), which we properly convert to
> *    the full 4-digit year.  There is a possibility that applications using
> *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
> *    function, or that they are incorrectly passing only a 2-digit year
> *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
> *    but this is not under our control.  The libpng documentation has always
> *    stated that it works with 4-digit years, and the APIs have been
> *    documented as such.
> *
> *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
> *    integer to hold the year, and can hold years as large as 65535.
> *
> *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
> *    no date-related code.
> *
> *       Glenn Randers-Pehrson
> *       libpng maintainer
> *       PNG Development Group
> */
>
>#ifndef PNG_H
>#define PNG_H
>
>/* This is not the place to learn how to use libpng.  The file libpng.txt
> * describes how to use libpng, and the file example.c summarizes it
> * with some code on which to build.  This file is useful for looking
> * at the actual function definitions and structure components.
> */
>
>/* Version information for png.h - this should match the version in png.c */
>#define PNG_LIBPNG_VER_STRING "1.4.5"
>#define PNG_HEADER_VERSION_STRING \
>   " libpng version 1.4.5 - December 9, 2010\n"
>
>#define PNG_LIBPNG_VER_SONUM   14
>#define PNG_LIBPNG_VER_DLLNUM  14
>
>/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
>#define PNG_LIBPNG_VER_MAJOR   1
>#define PNG_LIBPNG_VER_MINOR   4
>#define PNG_LIBPNG_VER_RELEASE 5
>/* This should match the numeric part of the final component of
> * PNG_LIBPNG_VER_STRING, omitting any leading zero:
> */
>
>#define PNG_LIBPNG_VER_BUILD  0
>
>/* Release Status */
>#define PNG_LIBPNG_BUILD_ALPHA    1
>#define PNG_LIBPNG_BUILD_BETA     2
>#define PNG_LIBPNG_BUILD_RC       3
>#define PNG_LIBPNG_BUILD_STABLE   4
>#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
>
>/* Release-Specific Flags */
>#define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
>                                       PNG_LIBPNG_BUILD_STABLE only */
>#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
>                                       PNG_LIBPNG_BUILD_SPECIAL */
>#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
>                                       PNG_LIBPNG_BUILD_PRIVATE */
>
>#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
>
>/* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
> * We must not include leading zeros.
> * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
> * version 1.0.0 was mis-numbered 100 instead of 10000).  From
> * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
> */
>#define PNG_LIBPNG_VER 10405 /* 1.4.5 */
>
>#ifndef PNG_VERSION_INFO_ONLY
>/* Include the compression library's header */
>#include "zlib.h"
>#endif
>
>/* Include all user configurable info, including optional assembler routines */
>#include "pngconf.h"
>
>/*
> * Added at libpng-1.2.8
> *
> * Ref MSDN: Private as priority over Special
> * VS_FF_PRIVATEBUILD File *was not* built using standard release
> * procedures. If this value is given, the StringFileInfo block must
> * contain a PrivateBuild string.
> *
> * VS_FF_SPECIALBUILD File *was* built by the original company using
> * standard release procedures but is a variation of the standard
> * file of the same version number. If this value is given, the
> * StringFileInfo block must contain a SpecialBuild string.
> */
>
>#ifdef PNG_USER_PRIVATEBUILD
>#  define PNG_LIBPNG_BUILD_TYPE \
>          (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
>#else
>#  ifdef PNG_LIBPNG_SPECIALBUILD
>#    define PNG_LIBPNG_BUILD_TYPE \
>            (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
>#  else
>#    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
>#  endif
>#endif
>
>#ifndef PNG_VERSION_INFO_ONLY
>
>/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
>#ifdef __cplusplus
>extern "C" {
>#endif /* __cplusplus */
>
>/* This file is arranged in several sections.  The first section contains
> * structure and type definitions.  The second section contains the external
> * library functions, while the third has the internal library functions,
> * which applications aren't expected to use directly.
> */
>
>/* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
>#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
>/* Version information for C files, stored in png.c.  This had better match
> * the version above.
> */
>#define png_libpng_ver png_get_header_ver(NULL)
>
>#endif /* PNG_NO_EXTERN */
>
>/* Three color definitions.  The order of the red, green, and blue, (and the
> * exact size) is not important, although the size of the fields need to
> * be png_byte or png_uint_16 (as defined below).
> */
>typedef struct png_color_struct
>{
>   png_byte red;
>   png_byte green;
>   png_byte blue;
>} png_color;
>typedef png_color FAR * png_colorp;
>typedef png_color FAR * FAR * png_colorpp;
>
>typedef struct png_color_16_struct
>{
>   png_byte index;    /* used for palette files */
>   png_uint_16 red;   /* for use in red green blue files */
>   png_uint_16 green;
>   png_uint_16 blue;
>   png_uint_16 gray;  /* for use in grayscale files */
>} png_color_16;
>typedef png_color_16 FAR * png_color_16p;
>typedef png_color_16 FAR * FAR * png_color_16pp;
>
>typedef struct png_color_8_struct
>{
>   png_byte red;   /* for use in red green blue files */
>   png_byte green;
>   png_byte blue;
>   png_byte gray;  /* for use in grayscale files */
>   png_byte alpha; /* for alpha channel files */
>} png_color_8;
>typedef png_color_8 FAR * png_color_8p;
>typedef png_color_8 FAR * FAR * png_color_8pp;
>
>/*
> * The following two structures are used for the in-core representation
> * of sPLT chunks.
> */
>typedef struct png_sPLT_entry_struct
>{
>   png_uint_16 red;
>   png_uint_16 green;
>   png_uint_16 blue;
>   png_uint_16 alpha;
>   png_uint_16 frequency;
>} png_sPLT_entry;
>typedef png_sPLT_entry FAR * png_sPLT_entryp;
>typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
>
>/*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
> *  occupy the LSB of their respective members, and the MSB of each member
> *  is zero-filled.  The frequency member always occupies the full 16 bits.
> */
>
>typedef struct png_sPLT_struct
>{
>   png_charp name;           /* palette name */
>   png_byte depth;           /* depth of palette samples */
>   png_sPLT_entryp entries;  /* palette entries */
>   png_int_32 nentries;      /* number of palette entries */
>} png_sPLT_t;
>typedef png_sPLT_t FAR * png_sPLT_tp;
>typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
>
>#ifdef PNG_TEXT_SUPPORTED
>/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
> * and whether that contents is compressed or not.  The "key" field
> * points to a regular zero-terminated C string.  The "text", "lang", and
> * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
> * However, the * structure returned by png_get_text() will always contain
> * regular zero-terminated C strings (possibly empty), never NULL pointers,
> * so they can be safely used in printf() and other string-handling functions.
> */
>typedef struct png_text_struct
>{
>   int  compression;       /* compression value:
>                             -1: tEXt, none
>                              0: zTXt, deflate
>                              1: iTXt, none
>                              2: iTXt, deflate  */
>   png_charp key;          /* keyword, 1-79 character description of "text" */
>   png_charp text;         /* comment, may be an empty string (ie "")
>                              or a NULL pointer */
>   png_size_t text_length; /* length of the text string */
>#ifdef PNG_iTXt_SUPPORTED
>   png_size_t itxt_length; /* length of the itxt string */
>   png_charp lang;         /* language code, 0-79 characters
>                              or a NULL pointer */
>   png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
>                              chars or a NULL pointer */
>#endif
>} png_text;
>typedef png_text FAR * png_textp;
>typedef png_text FAR * FAR * png_textpp;
>#endif
>
>/* Supported compression types for text in PNG files (tEXt, and zTXt).
> * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
>#define PNG_TEXT_COMPRESSION_NONE_WR -3
>#define PNG_TEXT_COMPRESSION_zTXt_WR -2
>#define PNG_TEXT_COMPRESSION_NONE    -1
>#define PNG_TEXT_COMPRESSION_zTXt     0
>#define PNG_ITXT_COMPRESSION_NONE     1
>#define PNG_ITXT_COMPRESSION_zTXt     2
>#define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
>
>/* png_time is a way to hold the time in an machine independent way.
> * Two conversions are provided, both from time_t and struct tm.  There
> * is no portable way to convert to either of these structures, as far
> * as I know.  If you know of a portable way, send it to me.  As a side
> * note - PNG has always been Year 2000 compliant!
> */
>typedef struct png_time_struct
>{
>   png_uint_16 year; /* full year, as in, 1995 */
>   png_byte month;   /* month of year, 1 - 12 */
>   png_byte day;     /* day of month, 1 - 31 */
>   png_byte hour;    /* hour of day, 0 - 23 */
>   png_byte minute;  /* minute of hour, 0 - 59 */
>   png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
>} png_time;
>typedef png_time FAR * png_timep;
>typedef png_time FAR * FAR * png_timepp;
>
>#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
> defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
>/* png_unknown_chunk is a structure to hold queued chunks for which there is
> * no specific support.  The idea is that we can use this to queue
> * up private chunks for output even though the library doesn't actually
> * know about their semantics.
> */
>typedef struct png_unknown_chunk_t
>{
>    png_byte name[5];
>    png_byte *data;
>    png_size_t size;
>
>    /* libpng-using applications should NOT directly modify this byte. */
>    png_byte location; /* mode of operation at read time */
>}
>png_unknown_chunk;
>typedef png_unknown_chunk FAR * png_unknown_chunkp;
>typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
>#endif
>
>/* png_info is a structure that holds the information in a PNG file so
> * that the application can find out the characteristics of the image.
> * If you are reading the file, this structure will tell you what is
> * in the PNG file.  If you are writing the file, fill in the information
> * you want to put into the PNG file, then call png_write_info().
> * The names chosen should be very close to the PNG specification, so
> * consult that document for information about the meaning of each field.
> *
> * With libpng < 0.95, it was only possible to directly set and read the
> * the values in the png_info_struct, which meant that the contents and
> * order of the values had to remain fixed.  With libpng 0.95 and later,
> * however, there are now functions that abstract the contents of
> * png_info_struct from the application, so this makes it easier to use
> * libpng with dynamic libraries, and even makes it possible to use
> * libraries that don't have all of the libpng ancillary chunk-handing
> * functionality.
> *
> * In any case, the order of the parameters in png_info_struct should NOT
> * be changed for as long as possible to keep compatibility with applications
> * that use the old direct-access method with png_info_struct.
> *
> * The following members may have allocated storage attached that should be
> * cleaned up before the structure is discarded: palette, trans, text,
> * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
> * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
> * are automatically freed when the info structure is deallocated, if they were
> * allocated internally by libpng.  This behavior can be changed by means
> * of the png_data_freer() function.
> *
> * More allocation details: all the chunk-reading functions that
> * change these members go through the corresponding png_set_*
> * functions.  A function to clear these members is available: see
> * png_free_data().  The png_set_* functions do not depend on being
> * able to point info structure members to any of the storage they are
> * passed (they make their own copies), EXCEPT that the png_set_text
> * functions use the same storage passed to them in the text_ptr or
> * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
> * functions do not make their own copies.
> */
>typedef struct png_info_struct
>{
>   /* the following are necessary for every PNG file */
>   png_uint_32 width PNG_DEPSTRUCT;  /* width of image in pixels (from IHDR) */
>   png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels (from IHDR) */
>   png_uint_32 valid PNG_DEPSTRUCT;  /* valid chunk data (see PNG_INFO_
>                                        below) */
>   png_size_t rowbytes PNG_DEPSTRUCT; /* bytes needed to hold an untransformed
>                                         row */
>   png_colorp palette PNG_DEPSTRUCT;      /* array of color values
>                                             (valid & PNG_INFO_PLTE) */
>   png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in
>                                             "palette" (PLTE) */
>   png_uint_16 num_trans PNG_DEPSTRUCT;   /* number of transparent palette
>                                             color (tRNS) */
>   png_byte bit_depth PNG_DEPSTRUCT;      /* 1, 2, 4, 8, or 16 bits/channel
>                                             (from IHDR) */
>   png_byte color_type PNG_DEPSTRUCT;     /* see PNG_COLOR_TYPE_ below
>                                             (from IHDR) */
>   /* The following three should have been named *_method not *_type */
>   png_byte compression_type PNG_DEPSTRUCT; /* must be
>                                             PNG_COMPRESSION_TYPE_BASE (IHDR) */
>   png_byte filter_type PNG_DEPSTRUCT;    /* must be PNG_FILTER_TYPE_BASE
>                                             (from IHDR) */
>   png_byte interlace_type PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE,
>                                             PNG_INTERLACE_ADAM7 */
>
>   /* The following is informational only on read, and not used on writes. */
>   png_byte channels PNG_DEPSTRUCT;       /* number of data channels per
>                                             pixel (1, 2, 3, 4) */
>   png_byte pixel_depth PNG_DEPSTRUCT;    /* number of bits per pixel */
>   png_byte spare_byte PNG_DEPSTRUCT;     /* to align the data, and for
>                                             future use */
>   png_byte signature[8] PNG_DEPSTRUCT;   /* magic bytes read by libpng
>                                             from start of file */
>
>   /* The rest of the data is optional.  If you are reading, check the
>    * valid field to see if the information in these are valid.  If you
>    * are writing, set the valid field to those chunks you want written,
>    * and initialize the appropriate fields below.
>    */
>
>#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
>   /* The gAMA chunk describes the gamma characteristics of the system
>    * on which the image was created, normally in the range [1.0, 2.5].
>    * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
>    */
>   float gamma PNG_DEPSTRUCT; /* gamma value of image,
>                                 if (valid & PNG_INFO_gAMA) */
>#endif
>
>#ifdef PNG_sRGB_SUPPORTED
>    /* GR-P, 0.96a */
>    /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
>   png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent
>                                          [0, 1, 2, or 3] */
>#endif
>
>#ifdef PNG_TEXT_SUPPORTED
>   /* The tEXt, and zTXt chunks contain human-readable textual data in
>    * uncompressed, compressed, and optionally compressed forms, respectively.
>    * The data in "text" is an array of pointers to uncompressed,
>    * null-terminated C strings. Each chunk has a keyword that describes the
>    * textual data contained in that chunk.  Keywords are not required to be
>    * unique, and the text string may be empty.  Any number of text chunks may
>    * be in an image.
>    */
>   int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
>   int max_text PNG_DEPSTRUCT; /* current size of text array */
>   png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
>#endif /* PNG_TEXT_SUPPORTED */
>
>#ifdef PNG_tIME_SUPPORTED
>   /* The tIME chunk holds the last time the displayed image data was
>    * modified.  See the png_time struct for the contents of this struct.
>    */
>   png_time mod_time PNG_DEPSTRUCT;
>#endif
>
>#ifdef PNG_sBIT_SUPPORTED
>   /* The sBIT chunk specifies the number of significant high-order bits
>    * in the pixel data.  Values are in the range [1, bit_depth], and are
>    * only specified for the channels in the pixel data.  The contents of
>    * the low-order bits is not specified.  Data is valid if
>    * (valid & PNG_INFO_sBIT) is non-zero.
>    */
>   png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
>#endif
>
>#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
>defined(PNG_READ_BACKGROUND_SUPPORTED)
>   /* The tRNS chunk supplies transparency data for paletted images and
>    * other image types that don't need a full alpha channel.  There are
>    * "num_trans" transparency values for a paletted image, stored in the
>    * same order as the palette colors, starting from index 0.  Values
>    * for the data are in the range [0, 255], ranging from fully transparent
>    * to fully opaque, respectively.  For non-paletted images, there is a
>    * single color specified that should be treated as fully transparent.
>    * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
>    */
>   png_bytep trans_alpha PNG_DEPSTRUCT;    /* alpha values for paletted
>                                              image */
>   png_color_16 trans_color PNG_DEPSTRUCT; /* transparent color for
>                                              non-palette image */
>#endif
>
>#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
>   /* The bKGD chunk gives the suggested image background color if the
>    * display program does not have its own background color and the image
>    * is needs to composited onto a background before display.  The colors
>    * in "background" are normally in the same color space/depth as the
>    * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
>    */
>   png_color_16 background PNG_DEPSTRUCT;
>#endif
>
>#ifdef PNG_oFFs_SUPPORTED
>   /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
>    * and downwards from the top-left corner of the display, page, or other
>    * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
>    * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
>    */
>   png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
>   png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
>   png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
>#endif
>
>#ifdef PNG_pHYs_SUPPORTED
>   /* The pHYs chunk gives the physical pixel density of the image for
>    * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
>    * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
>    */
>   png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
>   png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
>   png_byte phys_unit_type PNG_DEPSTRUCT; /* resolution type (see
>                                             PNG_RESOLUTION_ below) */
>#endif
>
>#ifdef PNG_hIST_SUPPORTED
>   /* The hIST chunk contains the relative frequency or importance of the
>    * various palette entries, so that a viewer can intelligently select a
>    * reduced-color palette, if required.  Data is an array of "num_palette"
>    * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
>    * is non-zero.
>    */
>   png_uint_16p hist PNG_DEPSTRUCT;
>#endif
>
>#ifdef PNG_cHRM_SUPPORTED
>   /* The cHRM chunk describes the CIE color characteristics of the monitor
>    * on which the PNG was created.  This data allows the viewer to do gamut
>    * mapping of the input image to ensure that the viewer sees the same
>    * colors in the image as the creator.  Values are in the range
>    * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
>    */
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>   float x_white PNG_DEPSTRUCT;
>   float y_white PNG_DEPSTRUCT;
>   float x_red PNG_DEPSTRUCT;
>   float y_red PNG_DEPSTRUCT;
>   float x_green PNG_DEPSTRUCT;
>   float y_green PNG_DEPSTRUCT;
>   float x_blue PNG_DEPSTRUCT;
>   float y_blue PNG_DEPSTRUCT;
>#endif
>#endif
>
>#ifdef PNG_pCAL_SUPPORTED
>   /* The pCAL chunk describes a transformation between the stored pixel
>    * values and original physical data values used to create the image.
>    * The integer range [0, 2^bit_depth - 1] maps to the floating-point
>    * range given by [pcal_X0, pcal_X1], and are further transformed by a
>    * (possibly non-linear) transformation function given by "pcal_type"
>    * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
>    * defines below, and the PNG-Group's PNG extensions document for a
>    * complete description of the transformations and how they should be
>    * implemented, and for a description of the ASCII parameter strings.
>    * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
>    */
>   png_charp pcal_purpose PNG_DEPSTRUCT;  /* pCAL chunk description string */
>   png_int_32 pcal_X0 PNG_DEPSTRUCT;      /* minimum value */
>   png_int_32 pcal_X1 PNG_DEPSTRUCT;      /* maximum value */
>   png_charp pcal_units PNG_DEPSTRUCT;    /* Latin-1 string giving physical
>                                             units */
>   png_charpp pcal_params PNG_DEPSTRUCT;  /* ASCII strings containing
>                                             parameter values */
>   png_byte pcal_type PNG_DEPSTRUCT;      /* equation type
>                                             (see PNG_EQUATION_ below) */
>   png_byte pcal_nparams PNG_DEPSTRUCT;   /* number of parameters given
>                                             in pcal_params */
>#endif
>
>/* New members added in libpng-1.0.6 */
>   png_uint_32 free_me PNG_DEPSTRUCT;     /* flags items libpng is
>                                             responsible for freeing */
>
>#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
> defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
>   /* Storage for unknown chunks that the library doesn't recognize. */
>   png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
>   png_size_t unknown_chunks_num PNG_DEPSTRUCT;
>#endif
>
>#ifdef PNG_iCCP_SUPPORTED
>   /* iCCP chunk data. */
>   png_charp iccp_name PNG_DEPSTRUCT;     /* profile name */
>   png_charp iccp_profile PNG_DEPSTRUCT;  /* International Color Consortium
>                                             profile data */
>                            /* Note to maintainer: should be png_bytep */
>   png_uint_32 iccp_proflen PNG_DEPSTRUCT;  /* ICC profile data length */
>   png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
>#endif
>
>#ifdef PNG_sPLT_SUPPORTED
>   /* Data on sPLT chunks (there may be more than one). */
>   png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
>   png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
>#endif
>
>#ifdef PNG_sCAL_SUPPORTED
>   /* The sCAL chunk describes the actual physical dimensions of the
>    * subject matter of the graphic.  The chunk contains a unit specification
>    * a byte value, and two ASCII strings representing floating-point
>    * values.  The values are width and height corresponsing to one pixel
>    * in the image.  This external representation is converted to double
>    * here.  Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
>    */
>   png_byte scal_unit PNG_DEPSTRUCT;         /* unit of physical scale */
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>   double scal_pixel_width PNG_DEPSTRUCT;    /* width of one pixel */
>   double scal_pixel_height PNG_DEPSTRUCT;   /* height of one pixel */
>#endif
>#ifdef PNG_FIXED_POINT_SUPPORTED
>   png_charp scal_s_width PNG_DEPSTRUCT;     /* string containing height */
>   png_charp scal_s_height PNG_DEPSTRUCT;    /* string containing width */
>#endif
>#endif
>
>#ifdef PNG_INFO_IMAGE_SUPPORTED
>   /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
>      non-zero */
>   /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
>   png_bytepp row_pointers PNG_DEPSTRUCT;        /* the image bits */
>#endif
>
>#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
>   png_fixed_point int_gamma PNG_DEPSTRUCT; /* gamma of image,
>                                               if (valid & PNG_INFO_gAMA) */
>#endif
>
>#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
>   png_fixed_point int_x_white PNG_DEPSTRUCT;
>   png_fixed_point int_y_white PNG_DEPSTRUCT;
>   png_fixed_point int_x_red PNG_DEPSTRUCT;
>   png_fixed_point int_y_red PNG_DEPSTRUCT;
>   png_fixed_point int_x_green PNG_DEPSTRUCT;
>   png_fixed_point int_y_green PNG_DEPSTRUCT;
>   png_fixed_point int_x_blue PNG_DEPSTRUCT;
>   png_fixed_point int_y_blue PNG_DEPSTRUCT;
>#endif
>
>} png_info;
>
>typedef png_info FAR * png_infop;
>typedef png_info FAR * FAR * png_infopp;
>
>/* Maximum positive integer used in PNG is (2^31)-1 */
>#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
>#define PNG_UINT_32_MAX ((png_uint_32)(-1))
>#define PNG_SIZE_MAX ((png_size_t)(-1))
>
>/* These describe the color_type field in png_info. */
>/* color type masks */
>#define PNG_COLOR_MASK_PALETTE    1
>#define PNG_COLOR_MASK_COLOR      2
>#define PNG_COLOR_MASK_ALPHA      4
>
>/* color types.  Note that not all combinations are legal */
>#define PNG_COLOR_TYPE_GRAY 0
>#define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
>#define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
>#define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
>#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
>/* aliases */
>#define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
>#define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
>
>/* This is for compression type. PNG 1.0-1.2 only define the single type. */
>#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
>#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
>
>/* This is for filter type. PNG 1.0-1.2 only define the single type. */
>#define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
>#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
>#define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
>
>/* These are for the interlacing type.  These values should NOT be changed. */
>#define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
>#define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
>#define PNG_INTERLACE_LAST        2 /* Not a valid value */
>
>/* These are for the oFFs chunk.  These values should NOT be changed. */
>#define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
>#define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
>#define PNG_OFFSET_LAST           2 /* Not a valid value */
>
>/* These are for the pCAL chunk.  These values should NOT be changed. */
>#define PNG_EQUATION_LINEAR       0 /* Linear transformation */
>#define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
>#define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
>#define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
>#define PNG_EQUATION_LAST         4 /* Not a valid value */
>
>/* These are for the sCAL chunk.  These values should NOT be changed. */
>#define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
>#define PNG_SCALE_METER           1 /* meters per pixel */
>#define PNG_SCALE_RADIAN          2 /* radians per pixel */
>#define PNG_SCALE_LAST            3 /* Not a valid value */
>
>/* These are for the pHYs chunk.  These values should NOT be changed. */
>#define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
>#define PNG_RESOLUTION_METER      1 /* pixels/meter */
>#define PNG_RESOLUTION_LAST       2 /* Not a valid value */
>
>/* These are for the sRGB chunk.  These values should NOT be changed. */
>#define PNG_sRGB_INTENT_PERCEPTUAL 0
>#define PNG_sRGB_INTENT_RELATIVE   1
>#define PNG_sRGB_INTENT_SATURATION 2
>#define PNG_sRGB_INTENT_ABSOLUTE   3
>#define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
>
>/* This is for text chunks */
>#define PNG_KEYWORD_MAX_LENGTH     79
>
>/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
>#define PNG_MAX_PALETTE_LENGTH    256
>
>/* These determine if an ancillary chunk's data has been successfully read
> * from the PNG header, or if the application has filled in the corresponding
> * data in the info_struct to be written into the output file.  The values
> * of the PNG_INFO_<chunk> defines should NOT be changed.
> */
>#define PNG_INFO_gAMA 0x0001
>#define PNG_INFO_sBIT 0x0002
>#define PNG_INFO_cHRM 0x0004
>#define PNG_INFO_PLTE 0x0008
>#define PNG_INFO_tRNS 0x0010
>#define PNG_INFO_bKGD 0x0020
>#define PNG_INFO_hIST 0x0040
>#define PNG_INFO_pHYs 0x0080
>#define PNG_INFO_oFFs 0x0100
>#define PNG_INFO_tIME 0x0200
>#define PNG_INFO_pCAL 0x0400
>#define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
>#define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
>#define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
>#define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
>#define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
>
>/* This is used for the transformation routines, as some of them
> * change these values for the row.  It also should enable using
> * the routines for other purposes.
> */
>typedef struct png_row_info_struct
>{
>   png_uint_32 width; /* width of row */
>   png_size_t rowbytes; /* number of bytes in row */
>   png_byte color_type; /* color type of row */
>   png_byte bit_depth; /* bit depth of row */
>   png_byte channels; /* number of channels (1, 2, 3, or 4) */
>   png_byte pixel_depth; /* bits per pixel (depth * channels) */
>} png_row_info;
>
>typedef png_row_info FAR * png_row_infop;
>typedef png_row_info FAR * FAR * png_row_infopp;
>
>/* These are the function types for the I/O functions and for the functions
> * that allow the user to override the default I/O functions with his or her
> * own.  The png_error_ptr type should match that of user-supplied warning
> * and error functions, while the png_rw_ptr type should match that of the
> * user read/write data functions.
> */
>typedef struct png_struct_def png_struct;
>typedef png_struct FAR * png_structp;
>
>typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
>typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
>typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
>typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
>   int));
>typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
>   int));
>
>#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
>typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp,
>   png_infop));
>typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
>typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
>   png_uint_32, int));
>#endif
>
>#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
>    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
>typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
>    png_row_infop, png_bytep));
>#endif
>
>#ifdef PNG_USER_CHUNKS_SUPPORTED
>typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp,
>   png_unknown_chunkp));
>#endif
>#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
>typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
>#endif
>#ifdef PNG_SETJMP_SUPPORTED
>/* This must match the function definition in <setjmp.h>, and the
> * application must include this before png.h to obtain the definition
> * of jmp_buf.
> */
>typedef void (PNGAPI *png_longjmp_ptr) PNGARG((jmp_buf, int));
>#endif
>
>/* Transform masks for the high-level interface */
>#define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
>#define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
>#define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
>#define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
>#define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
>#define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
>#define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
>#define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
>#define PNG_TRANSFORM_BGR            0x0080    /* read and write */
>#define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
>#define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
>#define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
>#define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* write only */
>/* Added to libpng-1.2.34 */
>#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
>#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
>/* Added to libpng-1.4.0 */
>#define PNG_TRANSFORM_GRAY_TO_RGB   0x2000      /* read only */
>
>/* Flags for MNG supported features */
>#define PNG_FLAG_MNG_EMPTY_PLTE     0x01
>#define PNG_FLAG_MNG_FILTER_64      0x04
>#define PNG_ALL_MNG_FEATURES        0x05
>
>typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_alloc_size_t));
>typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
>
>/* The structure that holds the information to read and write PNG files.
> * The only people who need to care about what is inside of this are the
> * people who will be modifying the library for their own special needs.
> * It should NOT be accessed directly by an application, except to store
> * the jmp_buf.
> */
>
>struct png_struct_def
>{
>#ifdef PNG_SETJMP_SUPPORTED
>   jmp_buf jmpbuf PNG_DEPSTRUCT;            /* used in png_error */
>   png_longjmp_ptr longjmp_fn PNG_DEPSTRUCT;/* setjmp non-local goto
>                                               function. */
>#endif
>   png_error_ptr error_fn PNG_DEPSTRUCT;    /* function for printing
>                                               errors and aborting */
>   png_error_ptr warning_fn PNG_DEPSTRUCT;  /* function for printing
>                                               warnings */
>   png_voidp error_ptr PNG_DEPSTRUCT;       /* user supplied struct for
>                                               error functions */
>   png_rw_ptr write_data_fn PNG_DEPSTRUCT;  /* function for writing
>                                               output data */
>   png_rw_ptr read_data_fn PNG_DEPSTRUCT;   /* function for reading
>                                               input data */
>   png_voidp io_ptr PNG_DEPSTRUCT;          /* ptr to application struct
>                                               for I/O functions */
>
>#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
>   png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT; /* user read
>                                                                 transform */
>#endif
>
>#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
>   png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT; /* user write
>                                                                  transform */
>#endif
>
>/* These were added in libpng-1.0.2 */
>#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
>#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
>    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
>   png_voidp user_transform_ptr PNG_DEPSTRUCT; /* user supplied struct
>                                                  for user transform */
>   png_byte user_transform_depth PNG_DEPSTRUCT;    /* bit depth of user
>                                                      transformed pixels */
>   png_byte user_transform_channels PNG_DEPSTRUCT; /* channels in user
>                                                      transformed pixels */
>#endif
>#endif
>
>   png_uint_32 mode PNG_DEPSTRUCT;          /* tells us where we are in
>                                               the PNG file */
>   png_uint_32 flags PNG_DEPSTRUCT;         /* flags indicating various
>                                               things to libpng */
>   png_uint_32 transformations PNG_DEPSTRUCT; /* which transformations
>                                                 to perform */
>
>   z_stream zstream PNG_DEPSTRUCT;          /* pointer to decompression
>                                               structure (below) */
>   png_bytep zbuf PNG_DEPSTRUCT;            /* buffer for zlib */
>   png_size_t zbuf_size PNG_DEPSTRUCT;      /* size of zbuf */
>   int zlib_level PNG_DEPSTRUCT;            /* holds zlib compression level */
>   int zlib_method PNG_DEPSTRUCT;           /* holds zlib compression method */
>   int zlib_window_bits PNG_DEPSTRUCT;      /* holds zlib compression window
>                                               bits */
>   int zlib_mem_level PNG_DEPSTRUCT;        /* holds zlib compression memory
>                                               level */
>   int zlib_strategy PNG_DEPSTRUCT;         /* holds zlib compression
>                                               strategy */
>
>   png_uint_32 width PNG_DEPSTRUCT;         /* width of image in pixels */
>   png_uint_32 height PNG_DEPSTRUCT;        /* height of image in pixels */
>   png_uint_32 num_rows PNG_DEPSTRUCT;      /* number of rows in current pass */
>   png_uint_32 usr_width PNG_DEPSTRUCT;     /* width of row at start of write */
>   png_size_t rowbytes PNG_DEPSTRUCT;       /* size of row in bytes */
>#if 0 /* Replaced with the following in libpng-1.4.1 */
>   png_size_t irowbytes PNG_DEPSTRUCT;
>#endif
>/* Added in libpng-1.4.1 */
>#ifdef PNG_USER_LIMITS_SUPPORTED
>   /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
>    * can occupy when decompressed.  0 means unlimited.
>    * We will change the typedef from png_size_t to png_alloc_size_t
>    * in libpng-1.6.0
>    */
>   png_alloc_size_t user_chunk_malloc_max PNG_DEPSTRUCT;
>#endif
>   png_uint_32 iwidth PNG_DEPSTRUCT;        /* width of current interlaced
>                                               row in pixels */
>   png_uint_32 row_number PNG_DEPSTRUCT;    /* current row in interlace pass */
>   png_bytep prev_row PNG_DEPSTRUCT;        /* buffer to save previous
>                                               (unfiltered) row */
>   png_bytep row_buf PNG_DEPSTRUCT;         /* buffer to save current
>                                               (unfiltered) row */
>   png_bytep sub_row PNG_DEPSTRUCT;         /* buffer to save "sub" row
>                                               when filtering */
>   png_bytep up_row PNG_DEPSTRUCT;          /* buffer to save "up" row
>                                               when filtering */
>   png_bytep avg_row PNG_DEPSTRUCT;         /* buffer to save "avg" row
>                                               when filtering */
>   png_bytep paeth_row PNG_DEPSTRUCT;       /* buffer to save "Paeth" row
>                                               when filtering */
>   png_row_info row_info PNG_DEPSTRUCT;     /* used for transformation
>                                               routines */
>
>   png_uint_32 idat_size PNG_DEPSTRUCT;     /* current IDAT size for read */
>   png_uint_32 crc PNG_DEPSTRUCT;           /* current chunk CRC value */
>   png_colorp palette PNG_DEPSTRUCT;        /* palette from the input file */
>   png_uint_16 num_palette PNG_DEPSTRUCT;   /* number of color entries in
>                                               palette */
>   png_uint_16 num_trans PNG_DEPSTRUCT;     /* number of transparency values */
>   png_byte chunk_name[5] PNG_DEPSTRUCT;    /* null-terminated name of current
>                                               chunk */
>   png_byte compression PNG_DEPSTRUCT;      /* file compression type
>                                               (always 0) */
>   png_byte filter PNG_DEPSTRUCT;           /* file filter type (always 0) */
>   png_byte interlaced PNG_DEPSTRUCT;       /* PNG_INTERLACE_NONE,
>                                               PNG_INTERLACE_ADAM7 */
>   png_byte pass PNG_DEPSTRUCT;             /* current interlace pass (0 - 6) */
>   png_byte do_filter PNG_DEPSTRUCT;        /* row filter flags (see
>                                               PNG_FILTER_ below ) */
>   png_byte color_type PNG_DEPSTRUCT;       /* color type of file */
>   png_byte bit_depth PNG_DEPSTRUCT;        /* bit depth of file */
>   png_byte usr_bit_depth PNG_DEPSTRUCT;    /* bit depth of users row */
>   png_byte pixel_depth PNG_DEPSTRUCT;      /* number of bits per pixel */
>   png_byte channels PNG_DEPSTRUCT;         /* number of channels in file */
>   png_byte usr_channels PNG_DEPSTRUCT;     /* channels at start of write */
>   png_byte sig_bytes PNG_DEPSTRUCT;        /* magic bytes read/written from
>                                               start of file */
>
>#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
>   png_uint_16 filler PNG_DEPSTRUCT;           /* filler bytes for pixel
>                                                  expansion */
>#endif
>
>#ifdef PNG_bKGD_SUPPORTED
>   png_byte background_gamma_type PNG_DEPSTRUCT;
>#  ifdef PNG_FLOATING_POINT_SUPPORTED
>   float background_gamma PNG_DEPSTRUCT;
>#  endif
>   png_color_16 background PNG_DEPSTRUCT;   /* background color in
>                                               screen gamma space */
>#ifdef PNG_READ_GAMMA_SUPPORTED
>   png_color_16 background_1 PNG_DEPSTRUCT; /* background normalized
>                                               to gamma 1.0 */
>#endif
>#endif /* PNG_bKGD_SUPPORTED */
>
>#ifdef PNG_WRITE_FLUSH_SUPPORTED
>   png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing
>                                               output */
>   png_uint_32 flush_dist PNG_DEPSTRUCT;    /* how many rows apart to flush,
>                                               0 - no flush */
>   png_uint_32 flush_rows PNG_DEPSTRUCT;    /* number of rows written since
>                                               last flush */
>#endif
>
>#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
>   int gamma_shift PNG_DEPSTRUCT;      /* number of "insignificant" bits
>                                          16-bit gamma */
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>   float gamma PNG_DEPSTRUCT;          /* file gamma value */
>   float screen_gamma PNG_DEPSTRUCT;   /* screen gamma value
>                                          (display_exponent) */
>#endif
>#endif
>
>#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
>   png_bytep gamma_table PNG_DEPSTRUCT;     /* gamma table for 8-bit
>                                               depth files */
>   png_bytep gamma_from_1 PNG_DEPSTRUCT;    /* converts from 1.0 to screen */
>   png_bytep gamma_to_1 PNG_DEPSTRUCT;      /* converts from file to 1.0 */
>   png_uint_16pp gamma_16_table PNG_DEPSTRUCT; /* gamma table for 16-bit
>                                                  depth files */
>   png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to
>                                                   screen */
>   png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
>#endif
>
>#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
>   png_color_8 sig_bit PNG_DEPSTRUCT;       /* significant bits in each
>                                               available channel */
>#endif
>
>#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
>   png_color_8 shift PNG_DEPSTRUCT;         /* shift for significant bit
>                                               tranformation */
>#endif
>
>#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
> || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
>   png_bytep trans_alpha PNG_DEPSTRUCT;           /* alpha values for
>                                                     paletted files */
>   png_color_16 trans_color PNG_DEPSTRUCT;  /* transparent color for
>                                               non-paletted files */
>#endif
>
>   png_read_status_ptr read_row_fn PNG_DEPSTRUCT;   /* called after each
>                                                       row is decoded */
>   png_write_status_ptr write_row_fn PNG_DEPSTRUCT; /* called after each
>                                                       row is encoded */
>#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
>   png_progressive_info_ptr info_fn PNG_DEPSTRUCT; /* called after header
>                                                      data fully read */
>   png_progressive_row_ptr row_fn PNG_DEPSTRUCT;   /* called after each
>                                                      prog. row is decoded */
>   png_progressive_end_ptr end_fn PNG_DEPSTRUCT;   /* called after image
>                                                      is complete */
>   png_bytep save_buffer_ptr PNG_DEPSTRUCT;        /* current location in
>                                                      save_buffer */
>   png_bytep save_buffer PNG_DEPSTRUCT;            /* buffer for previously
>                                                      read data */
>   png_bytep current_buffer_ptr PNG_DEPSTRUCT;     /* current location in
>                                                      current_buffer */
>   png_bytep current_buffer PNG_DEPSTRUCT;         /* buffer for recently
>                                                      used data */
>   png_uint_32 push_length PNG_DEPSTRUCT;          /* size of current input
>                                                      chunk */
>   png_uint_32 skip_length PNG_DEPSTRUCT;          /* bytes to skip in
>                                                      input data */
>   png_size_t save_buffer_size PNG_DEPSTRUCT;      /* amount of data now
>                                                      in save_buffer */
>   png_size_t save_buffer_max PNG_DEPSTRUCT;       /* total size of
>                                                      save_buffer */
>   png_size_t buffer_size PNG_DEPSTRUCT;           /* total amount of
>                                                      available input data */
>   png_size_t current_buffer_size PNG_DEPSTRUCT;   /* amount of data now
>                                                      in current_buffer */
>   int process_mode PNG_DEPSTRUCT;                 /* what push library
>                                                      is currently doing */
>   int cur_palette PNG_DEPSTRUCT;                  /* current push library
>                                                      palette index */
>
>#  ifdef PNG_TEXT_SUPPORTED
>     png_size_t current_text_size PNG_DEPSTRUCT;   /* current size of
>                                                      text input data */
>     png_size_t current_text_left PNG_DEPSTRUCT;   /* how much text left
>                                                      to read in input */
>     png_charp current_text PNG_DEPSTRUCT;         /* current text chunk
>                                                      buffer */
>     png_charp current_text_ptr PNG_DEPSTRUCT;     /* current location
>                                                      in current_text */
>#  endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
>
>#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
>
>#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
>/* For the Borland special 64K segment handler */
>   png_bytepp offset_table_ptr PNG_DEPSTRUCT;
>   png_bytep offset_table PNG_DEPSTRUCT;
>   png_uint_16 offset_table_number PNG_DEPSTRUCT;
>   png_uint_16 offset_table_count PNG_DEPSTRUCT;
>   png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
>#endif
>
>#ifdef PNG_READ_QUANTIZE_SUPPORTED
>   png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for quantizing */
>   png_bytep quantize_index PNG_DEPSTRUCT; /* index translation for palette
>                                              files */
>#endif
>
>#if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
>   png_uint_16p hist PNG_DEPSTRUCT;                /* histogram */
>#endif
>
>#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
>   png_byte heuristic_method PNG_DEPSTRUCT;        /* heuristic for row
>                                                      filter selection */
>   png_byte num_prev_filters PNG_DEPSTRUCT;        /* number of weights
>                                                      for previous rows */
>   png_bytep prev_filters PNG_DEPSTRUCT;           /* filter type(s) of
>                                                      previous row(s) */
>   png_uint_16p filter_weights PNG_DEPSTRUCT;      /* weight(s) for previous
>                                                      line(s) */
>   png_uint_16p inv_filter_weights PNG_DEPSTRUCT;  /* 1/weight(s) for
>                                                      previous line(s) */
>   png_uint_16p filter_costs PNG_DEPSTRUCT;        /* relative filter
>                                                      calculation cost */
>   png_uint_16p inv_filter_costs PNG_DEPSTRUCT;    /* 1/relative filter
>                                                      calculation cost */
>#endif
>
>#ifdef PNG_TIME_RFC1123_SUPPORTED
>   png_charp time_buffer PNG_DEPSTRUCT; /* String to hold RFC 1123 time text */
>#endif
>
>/* New members added in libpng-1.0.6 */
>
>   png_uint_32 free_me PNG_DEPSTRUCT;    /* flags items libpng is
>                                            responsible for freeing */
>
>#ifdef PNG_USER_CHUNKS_SUPPORTED
>   png_voidp user_chunk_ptr PNG_DEPSTRUCT;
>   png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT; /* user read
>                                                           chunk handler */
>#endif
>
>#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
>   int num_chunk_list PNG_DEPSTRUCT;
>   png_bytep chunk_list PNG_DEPSTRUCT;
>#endif
>
>/* New members added in libpng-1.0.3 */
>#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
>   png_byte rgb_to_gray_status PNG_DEPSTRUCT;
>   /* These were changed from png_byte in libpng-1.0.6 */
>   png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
>   png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
>   png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
>#endif
>
>/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
>#if defined(PNG_MNG_FEATURES_SUPPORTED) || \
>    defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
>    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
>/* Changed from png_byte to png_uint_32 at version 1.2.0 */
>   png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
>#endif
>
>/* New member added in libpng-1.0.7 */
>#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
>   png_fixed_point int_gamma PNG_DEPSTRUCT;
>#endif
>
>/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
>#ifdef PNG_MNG_FEATURES_SUPPORTED
>   png_byte filter_type PNG_DEPSTRUCT;
>#endif
>
>/* New members added in libpng-1.2.0 */
>
>/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
>#ifdef PNG_USER_MEM_SUPPORTED
>   png_voidp mem_ptr PNG_DEPSTRUCT;             /* user supplied struct for
>                                                   mem functions */
>   png_malloc_ptr malloc_fn PNG_DEPSTRUCT;      /* function for
>                                                   allocating memory */
>   png_free_ptr free_fn PNG_DEPSTRUCT;          /* function for
>                                                   freeing memory */
>#endif
>
>/* New member added in libpng-1.0.13 and 1.2.0 */
>   png_bytep big_row_buf PNG_DEPSTRUCT;         /* buffer to save current
>                                                   (unfiltered) row */
>
>#ifdef PNG_READ_QUANTIZE_SUPPORTED
>/* The following three members were added at version 1.0.14 and 1.2.4 */
>   png_bytep quantize_sort PNG_DEPSTRUCT;          /* working sort array */
>   png_bytep index_to_palette PNG_DEPSTRUCT;       /* where the original
>                                                     index currently is
>                                                     in the palette */
>   png_bytep palette_to_index PNG_DEPSTRUCT;       /* which original index
>                                                      points to this
>                                                      palette color */
>#endif
>
>/* New members added in libpng-1.0.16 and 1.2.6 */
>   png_byte compression_type PNG_DEPSTRUCT;
>
>#ifdef PNG_USER_LIMITS_SUPPORTED
>   png_uint_32 user_width_max PNG_DEPSTRUCT;
>   png_uint_32 user_height_max PNG_DEPSTRUCT;
>   /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
>    * chunks that can be stored (0 means unlimited).
>    */
>   png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
>#endif
>
>/* New member added in libpng-1.0.25 and 1.2.17 */
>#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
>   /* Storage for unknown chunk that the library doesn't recognize. */
>   png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
>#endif
>
>/* New members added in libpng-1.2.26 */
>  png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
>  png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
>
>/* New member added in libpng-1.2.30 */
>  png_charp chunkdata PNG_DEPSTRUCT;  /* buffer for reading chunk data */
>
>#ifdef PNG_IO_STATE_SUPPORTED
>/* New member added in libpng-1.4.0 */
>   png_uint_32 io_state PNG_DEPSTRUCT;
>#endif
>};
>
>
>/* This triggers a compiler error in png.c, if png.c and png.h
> * do not agree upon the version number.
> */
>typedef png_structp version_1_4_5;
>
>typedef png_struct FAR * FAR * png_structpp;
>
>/* Here are the function definitions most commonly used.  This is not
> * the place to find out how to use libpng.  See libpng.txt for the
> * full explanation, see example.c for the summary.  This just provides
> * a simple one line description of the use of each function.
> */
>
>/* Returns the version number of the library */
>PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
>
>/* Tell lib we have already handled the first <num_bytes> magic bytes.
> * Handling more than 8 bytes from the beginning of the file is an error.
> */
>PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
>   int num_bytes));
>
>/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
> * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
> * signature, and non-zero otherwise.  Having num_to_check == 0 or
> * start > 7 will always fail (ie return non-zero).
> */
>PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
>   png_size_t num_to_check));
>
>/* Simple signature checking function.  This is the same as calling
> * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
> */
>#define png_check_sig(sig,n) !png_sig_cmp((sig), 0, (n))
>
>/* Allocate and initialize png_ptr struct for reading, and any other memory. */
>PNG_EXPORT(png_structp,png_create_read_struct)
>   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
>   png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
>
>/* Allocate and initialize png_ptr struct for writing, and any other memory */
>PNG_EXPORT(png_structp,png_create_write_struct)
>   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
>   png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
>
>PNG_EXPORT(png_size_t,png_get_compression_buffer_size)
>   PNGARG((png_structp png_ptr));
>
>PNG_EXPORT(void,png_set_compression_buffer_size)
>   PNGARG((png_structp png_ptr, png_size_t size));
>
>/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
> * match up.
> */
>#ifdef PNG_SETJMP_SUPPORTED
>/* This function returns the jmp_buf built in to *png_ptr.  It must be
> * supplied with an appropriate 'longjmp' function to use on that jmp_buf
> * unless the default error function is overridden in which case NULL is
> * acceptable.  The size of the jmp_buf is checked against the actual size
> * allocated by the library - the call will return NULL on a mismatch
> * indicating an ABI mismatch.
> */
>PNG_EXPORT(jmp_buf*, png_set_longjmp_fn)
>   PNGARG((png_structp png_ptr, png_longjmp_ptr longjmp_fn, size_t
>       jmp_buf_size));
>#  define png_jmpbuf(png_ptr) \
>   (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
>#else
>#  define png_jmpbuf(png_ptr) \
>   (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
>#endif
>
>#ifdef PNG_READ_SUPPORTED
>/* Reset the compression stream */
>PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
>#endif
>
>/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
>#ifdef PNG_USER_MEM_SUPPORTED
>PNG_EXPORT(png_structp,png_create_read_struct_2)
>   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
>   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
>   png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
>PNG_EXPORT(png_structp,png_create_write_struct_2)
>   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
>   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
>   png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
>#endif
>
>/* Write the PNG file signature. */
>PNG_EXPORT(void,png_write_sig) PNGARG((png_structp png_ptr));
>
>/* Write a PNG chunk - size, type, (optional) data, CRC. */
>PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
>   png_bytep chunk_name, png_bytep data, png_size_t length));
>
>/* Write the start of a PNG chunk - length and chunk name. */
>PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
>   png_bytep chunk_name, png_uint_32 length));
>
>/* Write the data of a PNG chunk started with png_write_chunk_start(). */
>PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
>   png_bytep data, png_size_t length));
>
>/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
>PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
>
>/* Allocate and initialize the info structure */
>PNG_EXPORT(png_infop,png_create_info_struct)
>   PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
>
>PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
>    png_size_t png_info_struct_size));
>
>/* Writes all the PNG information before the image. */
>PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
>   png_infop info_ptr));
>PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
>   png_infop info_ptr));
>
>#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
>/* Read the information before the actual image data. */
>PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
>   png_infop info_ptr));
>#endif
>
>#ifdef PNG_TIME_RFC1123_SUPPORTED
>PNG_EXPORT(png_charp,png_convert_to_rfc1123)
>   PNGARG((png_structp png_ptr, png_timep ptime));
>#endif
>
>#ifdef PNG_CONVERT_tIME_SUPPORTED
>/* Convert from a struct tm to png_time */
>PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
>   struct tm FAR * ttime));
>
>/* Convert from time_t to png_time.  Uses gmtime() */
>PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
>   time_t ttime));
>#endif /* PNG_CONVERT_tIME_SUPPORTED */
>
>#ifdef PNG_READ_EXPAND_SUPPORTED
>/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
>PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
>PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
>  png_ptr));
>PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
>PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
>#endif
>
>#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
>/* Use blue, green, red order for pixels. */
>PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
>#endif
>
>#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
>/* Expand the grayscale to 24-bit RGB if necessary. */
>PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
>#endif
>
>#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
>/* Reduce RGB to grayscale. */
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
>   int error_action, double red, double green ));
>#endif
>PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
>   int error_action, png_fixed_point red, png_fixed_point green ));
>PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
>   png_ptr));
>#endif
>
>PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
>   png_colorp palette));
>
>#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
>PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
>#endif
>
>#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
>    defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
>PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
>#endif
>
>#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
>    defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
>PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
>#endif
>
>#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
>/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
>PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
>   png_uint_32 filler, int flags));
>/* The values of the PNG_FILLER_ defines should NOT be changed */
>#define PNG_FILLER_BEFORE 0
>#define PNG_FILLER_AFTER 1
>/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
>PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
>   png_uint_32 filler, int flags));
>#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
>
>#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
>/* Swap bytes in 16-bit depth files. */
>PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
>#endif
>
>#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
>/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
>PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
>#endif
>
>#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
>    defined(PNG_WRITE_PACKSWAP_SUPPORTED)
>/* Swap packing order of pixels in bytes. */
>PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
>#endif
>
>#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
>/* Converts files to legal bit depths. */
>PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
>   png_color_8p true_bits));
>#endif
>
>#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
>    defined(PNG_WRITE_INTERLACING_SUPPORTED)
>/* Have the code handle the interlacing.  Returns the number of passes. */
>PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
>#endif
>
>#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
>/* Invert monochrome files */
>PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
>#endif
>
>#ifdef PNG_READ_BACKGROUND_SUPPORTED
>/* Handle alpha and tRNS by replacing with a background color. */
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
>   png_color_16p background_color, int background_gamma_code,
>   int need_expand, double background_gamma));
>#endif
>#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
>#define PNG_BACKGROUND_GAMMA_SCREEN  1
>#define PNG_BACKGROUND_GAMMA_FILE    2
>#define PNG_BACKGROUND_GAMMA_UNIQUE  3
>#endif
>
>#ifdef PNG_READ_16_TO_8_SUPPORTED
>/* Strip the second byte of information from a 16-bit depth file. */
>PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
>#endif
>
>#ifdef PNG_READ_QUANTIZE_SUPPORTED
>/* Turn on quantizing, and reduce the palette to the number of colors
> * available.  Prior to libpng-1.4.2, this was png_set_dither().
> */
>PNG_EXPORT(void,png_set_quantize) PNGARG((png_structp png_ptr,
>   png_colorp palette, int num_palette, int maximum_colors,
>   png_uint_16p histogram, int full_quantize));
>#endif
>/* This migration aid will be removed from libpng-1.5.0 */
>#define png_set_dither png_set_quantize
>
>#ifdef PNG_READ_GAMMA_SUPPORTED
>/* Handle gamma correction. Screen_gamma=(display_exponent) */
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
>   double screen_gamma, double default_file_gamma));
>#endif
>#endif
>
>
>#ifdef PNG_WRITE_FLUSH_SUPPORTED
>/* Set how many lines between output flushes - 0 for no flushing */
>PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
>/* Flush the current PNG output buffer */
>PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
>#endif
>
>/* Optional update palette with requested transformations */
>PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
>
>/* Optional call to update the users info structure */
>PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
>   png_infop info_ptr));
>
>#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
>/* Read one or more rows of image data. */
>PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
>   png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
>#endif
>
>#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
>/* Read a row of data. */
>PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
>   png_bytep row,
>   png_bytep display_row));
>#endif
>
>#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
>/* Read the whole image into memory at once. */
>PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
>   png_bytepp image));
>#endif
>
>/* Write a row of image data */
>PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
>   png_bytep row));
>
>/* Write a few rows of image data */
>PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
>   png_bytepp row, png_uint_32 num_rows));
>
>/* Write the image data */
>PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
>   png_bytepp image));
>
>/* Write the end of the PNG file. */
>PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
>   png_infop info_ptr));
>
>#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
>/* Read the end of the PNG file. */
>PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
>   png_infop info_ptr));
>#endif
>
>/* Free any memory associated with the png_info_struct */
>PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
>   png_infopp info_ptr_ptr));
>
>/* Free any memory associated with the png_struct and the png_info_structs */
>PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
>   png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
>
>/* Free any memory associated with the png_struct and the png_info_structs */
>PNG_EXPORT(void,png_destroy_write_struct)
>   PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
>
>/* Set the libpng method of handling chunk CRC errors */
>PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
>   int crit_action, int ancil_action));
>
>/* Values for png_set_crc_action() to say how to handle CRC errors in
> * ancillary and critical chunks, and whether to use the data contained
> * therein.  Note that it is impossible to "discard" data in a critical
> * chunk.  For versions prior to 0.90, the action was always error/quit,
> * whereas in version 0.90 and later, the action for CRC errors in ancillary
> * chunks is warn/discard.  These values should NOT be changed.
> *
> *      value                       action:critical     action:ancillary
> */
>#define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
>#define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
>#define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
>#define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
>#define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
>#define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
>
>/* These functions give the user control over the scan-line filtering in
> * libpng and the compression methods used by zlib.  These functions are
> * mainly useful for testing, as the defaults should work with most users.
> * Those users who are tight on memory or want faster performance at the
> * expense of compression can modify them.  See the compression library
> * header file (zlib.h) for an explination of the compression functions.
> */
>
>/* Set the filtering method(s) used by libpng.  Currently, the only valid
> * value for "method" is 0.
> */
>PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
>   int filters));
>
>/* Flags for png_set_filter() to say which filters to use.  The flags
> * are chosen so that they don't conflict with real filter types
> * below, in case they are supplied instead of the #defined constants.
> * These values should NOT be changed.
> */
>#define PNG_NO_FILTERS     0x00
>#define PNG_FILTER_NONE    0x08
>#define PNG_FILTER_SUB     0x10
>#define PNG_FILTER_UP      0x20
>#define PNG_FILTER_AVG     0x40
>#define PNG_FILTER_PAETH   0x80
>#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
>                         PNG_FILTER_AVG | PNG_FILTER_PAETH)
>
>/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
> * These defines should NOT be changed.
> */
>#define PNG_FILTER_VALUE_NONE  0
>#define PNG_FILTER_VALUE_SUB   1
>#define PNG_FILTER_VALUE_UP    2
>#define PNG_FILTER_VALUE_AVG   3
>#define PNG_FILTER_VALUE_PAETH 4
>#define PNG_FILTER_VALUE_LAST  5
>
>#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
>/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
> * defines, either the default (minimum-sum-of-absolute-differences), or
> * the experimental method (weighted-minimum-sum-of-absolute-differences).
> *
> * Weights are factors >= 1.0, indicating how important it is to keep the
> * filter type consistent between rows.  Larger numbers mean the current
> * filter is that many times as likely to be the same as the "num_weights"
> * previous filters.  This is cumulative for each previous row with a weight.
> * There needs to be "num_weights" values in "filter_weights", or it can be
> * NULL if the weights aren't being specified.  Weights have no influence on
> * the selection of the first row filter.  Well chosen weights can (in theory)
> * improve the compression for a given image.
> *
> * Costs are factors >= 1.0 indicating the relative decoding costs of a
> * filter type.  Higher costs indicate more decoding expense, and are
> * therefore less likely to be selected over a filter with lower computational
> * costs.  There needs to be a value in "filter_costs" for each valid filter
> * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
> * setting the costs.  Costs try to improve the speed of decompression without
> * unduly increasing the compressed image size.
> *
> * A negative weight or cost indicates the default value is to be used, and
> * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
> * The default values for both weights and costs are currently 1.0, but may
> * change if good general weighting/cost heuristics can be found.  If both
> * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
> * to the UNWEIGHTED method, but with added encoding time/computation.
> */
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
>   int heuristic_method, int num_weights, png_doublep filter_weights,
>   png_doublep filter_costs));
>#endif
>#endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
>
>/* Heuristic used for row filter selection.  These defines should NOT be
> * changed.
> */
>#define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
>#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
>#define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
>#define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
>
>/* Set the library compression level.  Currently, valid values range from
> * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
> * (0 - no compression, 9 - "maximal" compression).  Note that tests have
> * shown that zlib compression levels 3-6 usually perform as well as level 9
> * for PNG images, and do considerably fewer caclulations.  In the future,
> * these values may not correspond directly to the zlib compression levels.
> */
>PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
>   int level));
>
>PNG_EXPORT(void,png_set_compression_mem_level)
>   PNGARG((png_structp png_ptr, int mem_level));
>
>PNG_EXPORT(void,png_set_compression_strategy)
>   PNGARG((png_structp png_ptr, int strategy));
>
>PNG_EXPORT(void,png_set_compression_window_bits)
>   PNGARG((png_structp png_ptr, int window_bits));
>
>PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
>   int method));
>
>/* These next functions are called for input/output, memory, and error
> * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
> * and call standard C I/O routines such as fread(), fwrite(), and
> * fprintf().  These functions can be made to use other I/O routines
> * at run time for those applications that need to handle I/O in a
> * different manner by calling png_set_???_fn().  See libpng.txt for
> * more information.
> */
>
>#ifdef PNG_STDIO_SUPPORTED
>/* Initialize the input/output for the PNG file to the default functions. */
>PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr,
>    png_FILE_p fp));
>#endif
>
>/* Replace the (error and abort), and warning functions with user
> * supplied functions.  If no messages are to be printed you must still
> * write and use replacement functions. The replacement error_fn should
> * still do a longjmp to the last setjmp location if you are using this
> * method of error handling.  If error_fn or warning_fn is NULL, the
> * default function will be used.
> */
>
>PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
>   png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
>
>/* Return the user pointer associated with the error functions */
>PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
>
>/* Replace the default data output functions with a user supplied one(s).
> * If buffered output is not used, then output_flush_fn can be set to NULL.
> * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
> * output_flush_fn will be ignored (and thus can be NULL).
> * It is probably a mistake to use NULL for output_flush_fn if
> * write_data_fn is not also NULL unless you have built libpng with
> * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
> * default flush function, which uses the standard *FILE structure, will
> * be used.
> */
>PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
>   png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
>
>/* Replace the default data input function with a user supplied one. */
>PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
>   png_voidp io_ptr, png_rw_ptr read_data_fn));
>
>/* Return the user pointer associated with the I/O functions */
>PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
>
>PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
>   png_read_status_ptr read_row_fn));
>
>PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
>   png_write_status_ptr write_row_fn));
>
>#ifdef PNG_USER_MEM_SUPPORTED
>/* Replace the default memory allocation functions with user supplied one(s). */
>PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
>   png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
>/* Return the user pointer associated with the memory functions */
>PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
>#endif
>
>#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
>PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
>   png_ptr, png_user_transform_ptr read_user_transform_fn));
>#endif
>
>#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
>PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
>   png_ptr, png_user_transform_ptr write_user_transform_fn));
>#endif
>
>#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
>    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
>PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
>   png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
>   int user_transform_channels));
>/* Return the user pointer associated with the user transform functions */
>PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
>   PNGARG((png_structp png_ptr));
>#endif
>
>#ifdef PNG_USER_CHUNKS_SUPPORTED
>PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
>   png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
>PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
>   png_ptr));
>#endif
>
>#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
>/* Sets the function callbacks for the push reader, and a pointer to a
> * user-defined structure available to the callback functions.
> */
>PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
>   png_voidp progressive_ptr,
>   png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
>   png_progressive_end_ptr end_fn));
>
>/* Returns the user pointer associated with the push read functions */
>PNG_EXPORT(png_voidp,png_get_progressive_ptr)
>   PNGARG((png_structp png_ptr));
>
>/* Function to be called when data becomes available */
>PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
>
>/* Function that combines rows.  Not very much different than the
> * png_combine_row() call.  Is this even used?????
> */
>PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
>   png_bytep old_row, png_bytep new_row));
>#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
>
>PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
>   png_alloc_size_t size)) PNG_ALLOCATED;
>/* Added at libpng version 1.4.0 */
>PNG_EXPORT(png_voidp,png_calloc) PNGARG((png_structp png_ptr,
>   png_alloc_size_t size)) PNG_ALLOCATED;
>
>/* Added at libpng version 1.2.4 */
>PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
>   png_alloc_size_t size)) PNG_ALLOCATED;
>
>/* Frees a pointer allocated by png_malloc() */
>PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
>
>/* Free data that was allocated internally */
>PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_uint_32 free_me, int num));
>/* Reassign responsibility for freeing existing data, whether allocated
> * by libpng or by the application */
>PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, int freer, png_uint_32 mask));
>/* Assignments for png_data_freer */
>#define PNG_DESTROY_WILL_FREE_DATA 1
>#define PNG_SET_WILL_FREE_DATA 1
>#define PNG_USER_WILL_FREE_DATA 2
>/* Flags for png_ptr->free_me and info_ptr->free_me */
>#define PNG_FREE_HIST 0x0008
>#define PNG_FREE_ICCP 0x0010
>#define PNG_FREE_SPLT 0x0020
>#define PNG_FREE_ROWS 0x0040
>#define PNG_FREE_PCAL 0x0080
>#define PNG_FREE_SCAL 0x0100
>#define PNG_FREE_UNKN 0x0200
>#define PNG_FREE_LIST 0x0400
>#define PNG_FREE_PLTE 0x1000
>#define PNG_FREE_TRNS 0x2000
>#define PNG_FREE_TEXT 0x4000
>#define PNG_FREE_ALL  0x7fff
>#define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
>
>#ifdef PNG_USER_MEM_SUPPORTED
>PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
>   png_alloc_size_t size)) PNG_ALLOCATED;
>PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
>   png_voidp ptr));
>#endif
>
>#ifndef PNG_NO_ERROR_TEXT
>/* Fatal error in PNG image of libpng - can't continue */
>PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
>   png_const_charp error_message)) PNG_NORETURN;
>
>/* The same, but the chunk name is prepended to the error string. */
>PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
>   png_const_charp error_message)) PNG_NORETURN;
>
>#else
>/* Fatal error in PNG image of libpng - can't continue */
>PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
>#endif
>
>/* Non-fatal error in libpng.  Can continue, but may have a problem. */
>PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
>   png_const_charp warning_message));
>
>/* Non-fatal error in libpng, chunk name is prepended to message. */
>PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
>   png_const_charp warning_message));
>
>#ifdef PNG_BENIGN_ERRORS_SUPPORTED
>/* Benign error in libpng.  Can continue, but may have a problem.
> * User can choose whether to handle as a fatal error or as a warning. */
>PNG_EXPORT(void,png_benign_error) PNGARG((png_structp png_ptr,
>   png_const_charp warning_message));
>
>/* Same, chunk name is prepended to message. */
>PNG_EXPORT(void,png_chunk_benign_error) PNGARG((png_structp png_ptr,
>   png_const_charp warning_message));
>
>PNG_EXPORT(void,png_set_benign_errors) PNGARG((png_structp
>   png_ptr, int allowed));
>#endif
>
>/* The png_set_<chunk> functions are for storing values in the png_info_struct.
> * Similarly, the png_get_<chunk> calls are used to read values from the
> * png_info_struct, either storing the parameters in the passed variables, or
> * setting pointers into the png_info_struct where the data is stored.  The
> * png_get_<chunk> functions return a non-zero value if the data was available
> * in info_ptr, or return zero and do not change any of the parameters if the
> * data was not available.
> *
> * These functions should be used instead of directly accessing png_info
> * to avoid problems with future changes in the size and internal layout of
> * png_info_struct.
> */
>/* Returns "flag" if chunk data is valid in info_ptr. */
>PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
>png_infop info_ptr, png_uint_32 flag));
>
>/* Returns number of bytes needed to hold a transformed row. */
>PNG_EXPORT(png_size_t,png_get_rowbytes) PNGARG((png_structp png_ptr,
>png_infop info_ptr));
>
>#ifdef PNG_INFO_IMAGE_SUPPORTED
>/* Returns row_pointers, which is an array of pointers to scanlines that was
> * returned from png_read_png().
> */
>PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
>png_infop info_ptr));
>/* Set row_pointers, which is an array of pointers to scanlines for use
> * by png_write_png().
> */
>PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_bytepp row_pointers));
>#endif
>
>/* Returns number of color channels in image. */
>PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
>png_infop info_ptr));
>
>#ifdef PNG_EASY_ACCESS_SUPPORTED
>/* Returns image width in pixels. */
>PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>
>/* Returns image height in pixels. */
>PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>
>/* Returns image bit_depth. */
>PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>
>/* Returns image color_type. */
>PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>
>/* Returns image filter_type. */
>PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>
>/* Returns image interlace_type. */
>PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>
>/* Returns image compression_type. */
>PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>
>/* Returns image resolution in pixels per meter, from pHYs chunk data. */
>PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>
>/* Returns pixel aspect ratio, computed from pHYs chunk data.  */
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>#endif
>
>/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
>PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
>png_ptr, png_infop info_ptr));
>
>#endif /* PNG_EASY_ACCESS_SUPPORTED */
>
>/* Returns pointer to signature string read from PNG header */
>PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
>png_infop info_ptr));
>
>#ifdef PNG_bKGD_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_color_16p *background));
>#endif
>
>#ifdef PNG_bKGD_SUPPORTED
>PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_color_16p background));
>#endif
>
>#ifdef PNG_cHRM_SUPPORTED
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, double *white_x, double *white_y, double *red_x,
>   double *red_y, double *green_x, double *green_y, double *blue_x,
>   double *blue_y));
>#endif
>#ifdef PNG_FIXED_POINT_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
>   *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
>   png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
>   *int_blue_x, png_fixed_point *int_blue_y));
>#endif
>#endif
>
>#ifdef PNG_cHRM_SUPPORTED
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, double white_x, double white_y, double red_x,
>   double red_y, double green_x, double green_y, double blue_x, double blue_y));
>#endif
>#ifdef PNG_FIXED_POINT_SUPPORTED
>PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
>   png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
>   int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
>   png_fixed_point int_blue_y));
>#endif
>#endif
>
>#ifdef PNG_gAMA_SUPPORTED
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, double *file_gamma));
>#endif
>PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_fixed_point *int_file_gamma));
>#endif
>
>#ifdef PNG_gAMA_SUPPORTED
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, double file_gamma));
>#endif
>PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_fixed_point int_file_gamma));
>#endif
>
>#ifdef PNG_hIST_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_uint_16p *hist));
>#endif
>
>#ifdef PNG_hIST_SUPPORTED
>PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_uint_16p hist));
>#endif
>
>PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
>   int *bit_depth, int *color_type, int *interlace_method,
>   int *compression_method, int *filter_method));
>
>PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
>   int color_type, int interlace_method, int compression_method,
>   int filter_method));
>
>#ifdef PNG_oFFs_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
>   int *unit_type));
>#endif
>
>#ifdef PNG_oFFs_SUPPORTED
>PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
>   int unit_type));
>#endif
>
>#ifdef PNG_pCAL_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
>   int *type, int *nparams, png_charp *units, png_charpp *params));
>#endif
>
>#ifdef PNG_pCAL_SUPPORTED
>PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
>   int type, int nparams, png_charp units, png_charpp params));
>#endif
>
>#ifdef PNG_pHYs_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
>#endif
>
>#ifdef PNG_pHYs_SUPPORTED
>PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
>#endif
>
>PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_colorp *palette, int *num_palette));
>
>PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_colorp palette, int num_palette));
>
>#ifdef PNG_sBIT_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_color_8p *sig_bit));
>#endif
>
>#ifdef PNG_sBIT_SUPPORTED
>PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_color_8p sig_bit));
>#endif
>
>#ifdef PNG_sRGB_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, int *intent));
>#endif
>
>#ifdef PNG_sRGB_SUPPORTED
>PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, int intent));
>PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, int intent));
>#endif
>
>#ifdef PNG_iCCP_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_charpp name, int *compression_type,
>   png_charpp profile, png_uint_32 *proflen));
>   /* Note to maintainer: profile should be png_bytepp */
>#endif
>
>#ifdef PNG_iCCP_SUPPORTED
>PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_charp name, int compression_type,
>   png_charp profile, png_uint_32 proflen));
>   /* Note to maintainer: profile should be png_bytep */
>#endif
>
>#ifdef PNG_sPLT_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_sPLT_tpp entries));
>#endif
>
>#ifdef PNG_sPLT_SUPPORTED
>PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_sPLT_tp entries, int nentries));
>#endif
>
>#ifdef PNG_TEXT_SUPPORTED
>/* png_get_text also returns the number of text chunks in *num_text */
>PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_textp *text_ptr, int *num_text));
>#endif
>
>/* Note while png_set_text() will accept a structure whose text,
> * language, and  translated keywords are NULL pointers, the structure
> * returned by png_get_text will always contain regular
> * zero-terminated C strings.  They might be empty strings but
> * they will never be NULL pointers.
> */
>
>#ifdef PNG_TEXT_SUPPORTED
>PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_textp text_ptr, int num_text));
>#endif
>
>#ifdef PNG_tIME_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_timep *mod_time));
>#endif
>
>#ifdef PNG_tIME_SUPPORTED
>PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_timep mod_time));
>#endif
>
>#ifdef PNG_tRNS_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_bytep *trans_alpha, int *num_trans,
>   png_color_16p *trans_color));
>#endif
>
>#ifdef PNG_tRNS_SUPPORTED
>PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_bytep trans_alpha, int num_trans,
>   png_color_16p trans_color));
>#endif
>
>#ifdef PNG_tRNS_SUPPORTED
>#endif
>
>#ifdef PNG_sCAL_SUPPORTED
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, int *unit, double *width, double *height));
>#else
>#ifdef PNG_FIXED_POINT_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
>#endif
>#endif
>#endif /* PNG_sCAL_SUPPORTED */
>
>#ifdef PNG_sCAL_SUPPORTED
>#ifdef PNG_FLOATING_POINT_SUPPORTED
>PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, int unit, double width, double height));
>#else
>#ifdef PNG_FIXED_POINT_SUPPORTED
>PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
>#endif
>#endif
>#endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
>
>#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
>/* Provide a list of chunks and how they are to be handled, if the built-in
>   handling or default unknown chunk handling is not desired.  Any chunks not
>   listed will be handled in the default manner.  The IHDR and IEND chunks
>   must not be listed.
>      keep = 0: follow default behaviour
>           = 1: do not keep
>           = 2: keep only if safe-to-copy
>           = 3: keep even if unsafe-to-copy
>*/
>PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
>   png_ptr, int keep, png_bytep chunk_list, int num_chunks));
>PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
>   chunk_name));
>#endif
>#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
>PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
>PNG_EXPORT(void, png_set_unknown_chunk_location)
>   PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
>PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
>   png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
>#endif
>
>/* Png_free_data() will turn off the "valid" flag for anything it frees.
> * If you need to turn it off for a chunk that your application has freed,
> * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
> */
>PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
>   png_infop info_ptr, int mask));
>
>#ifdef PNG_INFO_IMAGE_SUPPORTED
>/* The "params" pointer is currently not used and is for future expansion. */
>PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
>                        png_infop info_ptr,
>                        int transforms,
>                        png_voidp params));
>PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
>                        png_infop info_ptr,
>                        int transforms,
>                        png_voidp params));
>#endif
>
>PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
>PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
>PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp
>    png_ptr));
>PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
>
>#ifdef PNG_MNG_FEATURES_SUPPORTED
>PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
>   png_ptr, png_uint_32 mng_features_permitted));
>#endif
>
>/* For use in png_set_keep_unknown, added to version 1.2.6 */
>#define PNG_HANDLE_CHUNK_AS_DEFAULT   0
>#define PNG_HANDLE_CHUNK_NEVER        1
>#define PNG_HANDLE_CHUNK_IF_SAFE      2
>#define PNG_HANDLE_CHUNK_ALWAYS       3
>
>/* Strip the prepended error numbers ("#nnn ") from error and warning
> * messages before passing them to the error or warning handler.
> */
>#ifdef PNG_ERROR_NUMBERS_SUPPORTED
>PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
>   png_ptr, png_uint_32 strip_mode));
>#endif
>
>/* Added in libpng-1.2.6 */
>#ifdef PNG_SET_USER_LIMITS_SUPPORTED
>PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
>   png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
>PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
>   png_ptr));
>PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
>   png_ptr));
>/* Added in libpng-1.4.0 */
>PNG_EXPORT(void,png_set_chunk_cache_max) PNGARG((png_structp
>   png_ptr, png_uint_32 user_chunk_cache_max));
>PNG_EXPORT(png_uint_32,png_get_chunk_cache_max)
>   PNGARG((png_structp png_ptr));
>/* Added in libpng-1.4.1 */
>PNG_EXPORT(void,png_set_chunk_malloc_max) PNGARG((png_structp
>   png_ptr, png_alloc_size_t user_chunk_cache_max));
>PNG_EXPORT(png_alloc_size_t,png_get_chunk_malloc_max)
>   PNGARG((png_structp png_ptr));
>#endif
>
>#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
>PNG_EXPORT(png_uint_32,png_get_pixels_per_inch) PNGARG((png_structp png_ptr,
>png_infop info_ptr));
>
>PNG_EXPORT(png_uint_32,png_get_x_pixels_per_inch) PNGARG((png_structp png_ptr,
>png_infop info_ptr));
>
>PNG_EXPORT(png_uint_32,png_get_y_pixels_per_inch) PNGARG((png_structp png_ptr,
>png_infop info_ptr));
>
>PNG_EXPORT(float,png_get_x_offset_inches) PNGARG((png_structp png_ptr,
>png_infop info_ptr));
>
>PNG_EXPORT(float,png_get_y_offset_inches) PNGARG((png_structp png_ptr,
>png_infop info_ptr));
>
>#ifdef PNG_pHYs_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_pHYs_dpi) PNGARG((png_structp png_ptr,
>png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
>#endif /* PNG_pHYs_SUPPORTED */
>#endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
>
>/* Added in libpng-1.4.0 */
>#ifdef PNG_IO_STATE_SUPPORTED
>PNG_EXPORT(png_uint_32,png_get_io_state) PNGARG((png_structp png_ptr));
>
>PNG_EXPORT(png_bytep,png_get_io_chunk_name)
>   PNGARG((png_structp png_ptr));
>
>/* The flags returned by png_get_io_state() are the following: */
>#define PNG_IO_NONE        0x0000   /* no I/O at this moment */
>#define PNG_IO_READING     0x0001   /* currently reading */
>#define PNG_IO_WRITING     0x0002   /* currently writing */
>#define PNG_IO_SIGNATURE   0x0010   /* currently at the file signature */
>#define PNG_IO_CHUNK_HDR   0x0020   /* currently at the chunk header */
>#define PNG_IO_CHUNK_DATA  0x0040   /* currently at the chunk data */
>#define PNG_IO_CHUNK_CRC   0x0080   /* currently at the chunk crc */
>#define PNG_IO_MASK_OP     0x000f   /* current operation: reading/writing */
>#define PNG_IO_MASK_LOC    0x00f0   /* current location: sig/hdr/data/crc */
>#endif /* ?PNG_IO_STATE_SUPPORTED */
>
>/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
> * defs
> */
>
>#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
>/* With these routines we avoid an integer divide, which will be slower on
> * most machines.  However, it does take more operations than the corresponding
> * divide method, so it may be slower on a few RISC systems.  There are two
> * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
> *
> * Note that the rounding factors are NOT supposed to be the same!  128 and
> * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
> * standard method.
> *
> * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
> */
>
> /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
>
>#  define png_composite(composite, fg, alpha, bg)         \
>     { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
>           * (png_uint_16)(alpha)                         \
>           + (png_uint_16)(bg)*(png_uint_16)(255          \
>           - (png_uint_16)(alpha)) + (png_uint_16)128);   \
>       (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
>
>#  define png_composite_16(composite, fg, alpha, bg)       \
>     { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg)  \
>           * (png_uint_32)(alpha)                          \
>           + (png_uint_32)(bg)*(png_uint_32)(65535L        \
>           - (png_uint_32)(alpha)) + (png_uint_32)32768L); \
>       (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
>
>#else  /* Standard method using integer division */
>
>#  define png_composite(composite, fg, alpha, bg)                            \
>     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
>       (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
>       (png_uint_16)127) / 255)
>
>#  define png_composite_16(composite, fg, alpha, bg)                         \
>     (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
>       (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
>       (png_uint_32)32767) / (png_uint_32)65535L)
>#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
>
>#ifdef PNG_USE_READ_MACROS
>/* Inline macros to do direct reads of bytes from the input buffer.
> * The png_get_int_32() routine assumes we are using two's complement
> * format for negative values, which is almost certainly true.
> */
>#  define png_get_uint_32(buf) \
>     (((png_uint_32)(*(buf)) << 24) + \
>      ((png_uint_32)(*((buf) + 1)) << 16) + \
>      ((png_uint_32)(*((buf) + 2)) << 8) + \
>      ((png_uint_32)(*((buf) + 3))))
>
>  /* The following definition introduces an API incompatibility (but not
>   * an ABI incompatibility) with libpng-1.4.0 through 1.4.4.  Prior to
>   * libpng-1.4.5 the macro, which is used by default, returned (incorrectly)
>   * a (png_uint_32), while the function, if used instead, correctly returned
>   * a (png_uint_16).
>   *
>   * Libpng versions 1.0.x and 1.2.x only used a function so are not affected
>   * by this potential API incompatibility between macros.
>   */
>#  define png_get_uint_16(buf) \
>     ((png_uint_16) \
>       (((unsigned int)(*(buf)) << 8) + \
>        ((unsigned int)(*((buf) + 1)))))
>
>#  define png_get_int_32(buf) \
>     ((png_int_32)((*(buf) & 0x80) \
>      ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
>      : (png_int_32)png_get_uint_32(buf)))
>#else
>PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
>PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
>#ifdef PNG_GET_INT_32_SUPPORTED
>PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
>#endif
>#endif
>PNG_EXPORT(png_uint_32,png_get_uint_31)
>  PNGARG((png_structp png_ptr, png_bytep buf));
>/* No png_get_int_16 -- may be added if there's a real need for it. */
>
>/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
>PNG_EXPORT(void,png_save_uint_32)
>   PNGARG((png_bytep buf, png_uint_32 i));
>PNG_EXPORT(void,png_save_int_32)
>   PNGARG((png_bytep buf, png_int_32 i));
>
>/* Place a 16-bit number into a buffer in PNG byte order.
> * The parameter is declared unsigned int, not png_uint_16,
> * just to avoid potential problems on pre-ANSI C compilers.
> */
>PNG_EXPORT(void,png_save_uint_16)
>   PNGARG((png_bytep buf, unsigned int i));
>/* No png_save_int_16 -- may be added if there's a real need for it. */
>
>/* ************************************************************************* */
>
>/* Various modes of operation.  Note that after an init, mode is set to
> * zero automatically when the structure is created.
> */
>#define PNG_HAVE_IHDR               0x01
>#define PNG_HAVE_PLTE               0x02
>#define PNG_HAVE_IDAT               0x04
>#define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
>#define PNG_HAVE_IEND               0x10
>#define PNG_HAVE_gAMA               0x20
>#define PNG_HAVE_cHRM               0x40
>
>#ifdef __cplusplus
>}
>#endif
>
>#endif /* PNG_VERSION_INFO_ONLY */
>/* Do not put anything past this line */
>#endif /* PNG_H */

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Attachments on bug 33710: 42706 | 42708 | 42709

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