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  1.  
  2. /* png.h - header file for PNG reference library
  3.  *
  4.  * libpng version 1.5.1 - February 3, 2011
  5.  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  6.  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  7.  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  8.  *
  9.  * This code is released under the libpng license (See LICENSE, below)
  10.  *
  11.  * Authors and maintainers:
  12.  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  13.  *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
  14.  *   libpng versions 0.97, January 1998, through 1.5.1 - February 3, 2011: Glenn
  15.  *   See also "Contributing Authors", below.
  16.  *
  17.  * Note about libpng version numbers:
  18.  *
  19.  *   Due to various miscommunications, unforeseen code incompatibilities
  20.  *   and occasional factors outside the authors' control, version numbering
  21.  *   on the library has not always been consistent and straightforward.
  22.  *   The following table summarizes matters since version 0.89c, which was
  23.  *   the first widely used release:
  24.  *
  25.  *    source                 png.h  png.h  shared-lib
  26.  *    version                string   int  version
  27.  *    -------                ------ -----  ----------
  28.  *    0.89c "1.0 beta 3"     0.89      89  1.0.89
  29.  *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
  30.  *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
  31.  *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
  32.  *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
  33.  *    0.97c                  0.97      97  2.0.97
  34.  *    0.98                   0.98      98  2.0.98
  35.  *    0.99                   0.99      98  2.0.99
  36.  *    0.99a-m                0.99      99  2.0.99
  37.  *    1.00                   1.00     100  2.1.0 [100 should be 10000]
  38.  *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
  39.  *    1.0.1       png.h string is   10001  2.1.0
  40.  *    1.0.1a-e    identical to the  10002  from here on, the shared library
  41.  *    1.0.2       source version)   10002  is 2.V where V is the source code
  42.  *    1.0.2a-b                      10003  version, except as noted.
  43.  *    1.0.3                         10003
  44.  *    1.0.3a-d                      10004
  45.  *    1.0.4                         10004
  46.  *    1.0.4a-f                      10005
  47.  *    1.0.5 (+ 2 patches)           10005
  48.  *    1.0.5a-d                      10006
  49.  *    1.0.5e-r                      10100 (not source compatible)
  50.  *    1.0.5s-v                      10006 (not binary compatible)
  51.  *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
  52.  *    1.0.6d-f                      10007 (still binary incompatible)
  53.  *    1.0.6g                        10007
  54.  *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
  55.  *    1.0.6i                        10007  10.6i
  56.  *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
  57.  *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
  58.  *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
  59.  *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
  60.  *    1.0.7                    1    10007  (still compatible)
  61.  *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4
  62.  *    1.0.8rc1                 1    10008  2.1.0.8rc1
  63.  *    1.0.8                    1    10008  2.1.0.8
  64.  *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6
  65.  *    1.0.9rc1                 1    10009  2.1.0.9rc1
  66.  *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10
  67.  *    1.0.9rc2                 1    10009  2.1.0.9rc2
  68.  *    1.0.9                    1    10009  2.1.0.9
  69.  *    1.0.10beta1              1    10010  2.1.0.10beta1
  70.  *    1.0.10rc1                1    10010  2.1.0.10rc1
  71.  *    1.0.10                   1    10010  2.1.0.10
  72.  *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3
  73.  *    1.0.11rc1                1    10011  2.1.0.11rc1
  74.  *    1.0.11                   1    10011  2.1.0.11
  75.  *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2
  76.  *    1.0.12rc1                2    10012  2.1.0.12rc1
  77.  *    1.0.12                   2    10012  2.1.0.12
  78.  *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)
  79.  *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2
  80.  *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5
  81.  *    1.2.0rc1                 3    10200  3.1.2.0rc1
  82.  *    1.2.0                    3    10200  3.1.2.0
  83.  *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4
  84.  *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2
  85.  *    1.2.1                    3    10201  3.1.2.1
  86.  *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6
  87.  *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1
  88.  *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1
  89.  *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1
  90.  *    1.0.13                  10    10013  10.so.0.1.0.13
  91.  *    1.2.2                   12    10202  12.so.0.1.2.2
  92.  *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6
  93.  *    1.2.3                   12    10203  12.so.0.1.2.3
  94.  *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3
  95.  *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1
  96.  *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1
  97.  *    1.0.14                  10    10014  10.so.0.1.0.14
  98.  *    1.2.4                   13    10204  12.so.0.1.2.4
  99.  *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2
  100.  *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3
  101.  *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3
  102.  *    1.0.15                  10    10015  10.so.0.1.0.15
  103.  *    1.2.5                   13    10205  12.so.0.1.2.5
  104.  *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4
  105.  *    1.0.16                  10    10016  10.so.0.1.0.16
  106.  *    1.2.6                   13    10206  12.so.0.1.2.6
  107.  *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2
  108.  *    1.0.17rc1               10    10017  12.so.0.1.0.17rc1
  109.  *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
  110.  *    1.0.17                  10    10017  12.so.0.1.0.17
  111.  *    1.2.7                   13    10207  12.so.0.1.2.7
  112.  *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5
  113.  *    1.0.18rc1-5             10    10018  12.so.0.1.0.18rc1-5
  114.  *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
  115.  *    1.0.18                  10    10018  12.so.0.1.0.18
  116.  *    1.2.8                   13    10208  12.so.0.1.2.8
  117.  *    1.2.9beta1-3            13    10209  12.so.0.1.2.9beta1-3
  118.  *    1.2.9beta4-11           13    10209  12.so.0.9[.0]
  119.  *    1.2.9rc1                13    10209  12.so.0.9[.0]
  120.  *    1.2.9                   13    10209  12.so.0.9[.0]
  121.  *    1.2.10beta1-7           13    10210  12.so.0.10[.0]
  122.  *    1.2.10rc1-2             13    10210  12.so.0.10[.0]
  123.  *    1.2.10                  13    10210  12.so.0.10[.0]
  124.  *    1.4.0beta1-5            14    10400  14.so.0.0[.0]
  125.  *    1.2.11beta1-4           13    10211  12.so.0.11[.0]
  126.  *    1.4.0beta7-8            14    10400  14.so.0.0[.0]
  127.  *    1.2.11                  13    10211  12.so.0.11[.0]
  128.  *    1.2.12                  13    10212  12.so.0.12[.0]
  129.  *    1.4.0beta9-14           14    10400  14.so.0.0[.0]
  130.  *    1.2.13                  13    10213  12.so.0.13[.0]
  131.  *    1.4.0beta15-36          14    10400  14.so.0.0[.0]
  132.  *    1.4.0beta37-87          14    10400  14.so.14.0[.0]
  133.  *    1.4.0rc01               14    10400  14.so.14.0[.0]
  134.  *    1.4.0beta88-109         14    10400  14.so.14.0[.0]
  135.  *    1.4.0rc02-08            14    10400  14.so.14.0[.0]
  136.  *    1.4.0                   14    10400  14.so.14.0[.0]
  137.  *    1.4.1beta01-03          14    10401  14.so.14.1[.0]
  138.  *    1.4.1rc01               14    10401  14.so.14.1[.0]
  139.  *    1.4.1beta04-12          14    10401  14.so.14.1[.0]
  140.  *    1.4.1                   14    10401  14.so.14.1[.0]
  141.  *    1.4.2                   14    10402  14.so.14.2[.0]
  142.  *    1.4.3                   14    10403  14.so.14.3[.0]
  143.  *    1.4.4                   14    10404  14.so.14.4[.0]
  144.  *    1.5.0beta01-58          15    10500  15.so.15.0[.0]
  145.  *    1.5.0rc01-07            15    10500  15.so.15.0[.0]
  146.  *    1.5.0                   15    10500  15.so.15.0[.0]
  147.  *    1.5.1beta01-11          15    10501  15.so.15.1[.0]
  148.  *    1.5.1rc01-02            15    10501  15.so.15.1[.0]
  149.  *    1.5.1                   15    10501  15.so.15.1[.0]
  150.  *
  151.  *   Henceforth the source version will match the shared-library major
  152.  *   and minor numbers; the shared-library major version number will be
  153.  *   used for changes in backward compatibility, as it is intended.  The
  154.  *   PNG_LIBPNG_VER macro, which is not used within libpng but is available
  155.  *   for applications, is an unsigned integer of the form xyyzz corresponding
  156.  *   to the source version x.y.z (leading zeros in y and z).  Beta versions
  157.  *   were given the previous public release number plus a letter, until
  158.  *   version 1.0.6j; from then on they were given the upcoming public
  159.  *   release number plus "betaNN" or "rcN".
  160.  *
  161.  *   Binary incompatibility exists only when applications make direct access
  162.  *   to the info_ptr or png_ptr members through png.h, and the compiled
  163.  *   application is loaded with a different version of the library.
  164.  *
  165.  *   DLLNUM will change each time there are forward or backward changes
  166.  *   in binary compatibility (e.g., when a new feature is added).
  167.  *
  168.  * See libpng-manual.txt or libpng.3 for more information.  The PNG
  169.  * specification is available as a W3C Recommendation and as an ISO
  170.  * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/
  171.  */
  172.  
  173. /*
  174.  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
  175.  *
  176.  * If you modify libpng you may insert additional notices immediately following
  177.  * this sentence.
  178.  *
  179.  * This code is released under the libpng license.
  180.  *
  181.  * libpng versions 1.2.6, August 15, 2004, through 1.5.1, February 3, 2011, are
  182.  * Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
  183.  * distributed according to the same disclaimer and license as libpng-1.2.5
  184.  * with the following individual added to the list of Contributing Authors:
  185.  *
  186.  *    Cosmin Truta
  187.  *
  188.  * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
  189.  * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
  190.  * distributed according to the same disclaimer and license as libpng-1.0.6
  191.  * with the following individuals added to the list of Contributing Authors:
  192.  *
  193.  *    Simon-Pierre Cadieux
  194.  *    Eric S. Raymond
  195.  *    Gilles Vollant
  196.  *
  197.  * and with the following additions to the disclaimer:
  198.  *
  199.  *    There is no warranty against interference with your enjoyment of the
  200.  *    library or against infringement.  There is no warranty that our
  201.  *    efforts or the library will fulfill any of your particular purposes
  202.  *    or needs.  This library is provided with all faults, and the entire
  203.  *    risk of satisfactory quality, performance, accuracy, and effort is with
  204.  *    the user.
  205.  *
  206.  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
  207.  * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
  208.  * distributed according to the same disclaimer and license as libpng-0.96,
  209.  * with the following individuals added to the list of Contributing Authors:
  210.  *
  211.  *    Tom Lane
  212.  *    Glenn Randers-Pehrson
  213.  *    Willem van Schaik
  214.  *
  215.  * libpng versions 0.89, June 1996, through 0.96, May 1997, are
  216.  * Copyright (c) 1996, 1997 Andreas Dilger
  217.  * Distributed according to the same disclaimer and license as libpng-0.88,
  218.  * with the following individuals added to the list of Contributing Authors:
  219.  *
  220.  *    John Bowler
  221.  *    Kevin Bracey
  222.  *    Sam Bushell
  223.  *    Magnus Holmgren
  224.  *    Greg Roelofs
  225.  *    Tom Tanner
  226.  *
  227.  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
  228.  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  229.  *
  230.  * For the purposes of this copyright and license, "Contributing Authors"
  231.  * is defined as the following set of individuals:
  232.  *
  233.  *    Andreas Dilger
  234.  *    Dave Martindale
  235.  *    Guy Eric Schalnat
  236.  *    Paul Schmidt
  237.  *    Tim Wegner
  238.  *
  239.  * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
  240.  * and Group 42, Inc. disclaim all warranties, expressed or implied,
  241.  * including, without limitation, the warranties of merchantability and of
  242.  * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
  243.  * assume no liability for direct, indirect, incidental, special, exemplary,
  244.  * or consequential damages, which may result from the use of the PNG
  245.  * Reference Library, even if advised of the possibility of such damage.
  246.  *
  247.  * Permission is hereby granted to use, copy, modify, and distribute this
  248.  * source code, or portions hereof, for any purpose, without fee, subject
  249.  * to the following restrictions:
  250.  *
  251.  *   1. The origin of this source code must not be misrepresented.
  252.  *
  253.  *   2. Altered versions must be plainly marked as such and must not
  254.  *      be misrepresented as being the original source.
  255.  *
  256.  *   3. This Copyright notice may not be removed or altered from
  257.  *      any source or altered source distribution.
  258.  *
  259.  * The Contributing Authors and Group 42, Inc. specifically permit, without
  260.  * fee, and encourage the use of this source code as a component to
  261.  * supporting the PNG file format in commercial products.  If you use this
  262.  * source code in a product, acknowledgment is not required but would be
  263.  * appreciated.
  264.  */
  265.  
  266. /*
  267.  * A "png_get_copyright" function is available, for convenient use in "about"
  268.  * boxes and the like:
  269.  *
  270.  *     printf("%s", png_get_copyright(NULL));
  271.  *
  272.  * Also, the PNG logo (in PNG format, of course) is supplied in the
  273.  * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
  274.  */
  275.  
  276. /*
  277.  * Libpng is OSI Certified Open Source Software.  OSI Certified is a
  278.  * certification mark of the Open Source Initiative.
  279.  */
  280.  
  281. /*
  282.  * The contributing authors would like to thank all those who helped
  283.  * with testing, bug fixes, and patience.  This wouldn't have been
  284.  * possible without all of you.
  285.  *
  286.  * Thanks to Frank J. T. Wojcik for helping with the documentation.
  287.  */
  288.  
  289. /*
  290.  * Y2K compliance in libpng:
  291.  * =========================
  292.  *
  293.  *    February 3, 2011
  294.  *
  295.  *    Since the PNG Development group is an ad-hoc body, we can't make
  296.  *    an official declaration.
  297.  *
  298.  *    This is your unofficial assurance that libpng from version 0.71 and
  299.  *    upward through 1.5.1 are Y2K compliant.  It is my belief that
  300.  *    earlier versions were also Y2K compliant.
  301.  *
  302.  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
  303.  *    that will hold years up to 65535.  The other two hold the date in text
  304.  *    format, and will hold years up to 9999.
  305.  *
  306.  *    The integer is
  307.  *        "png_uint_16 year" in png_time_struct.
  308.  *
  309.  *    The strings are
  310.  *        "png_charp time_buffer" in png_struct and
  311.  *        "near_time_buffer", which is a local character string in png.c.
  312.  *
  313.  *    There are seven time-related functions:
  314.  *        png.c: png_convert_to_rfc_1123() in png.c
  315.  *          (formerly png_convert_to_rfc_1152() in error)
  316.  *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
  317.  *        png_convert_from_time_t() in pngwrite.c
  318.  *        png_get_tIME() in pngget.c
  319.  *        png_handle_tIME() in pngrutil.c, called in pngread.c
  320.  *        png_set_tIME() in pngset.c
  321.  *        png_write_tIME() in pngwutil.c, called in pngwrite.c
  322.  *
  323.  *    All handle dates properly in a Y2K environment.  The
  324.  *    png_convert_from_time_t() function calls gmtime() to convert from system
  325.  *    clock time, which returns (year - 1900), which we properly convert to
  326.  *    the full 4-digit year.  There is a possibility that applications using
  327.  *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
  328.  *    function, or that they are incorrectly passing only a 2-digit year
  329.  *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
  330.  *    but this is not under our control.  The libpng documentation has always
  331.  *    stated that it works with 4-digit years, and the APIs have been
  332.  *    documented as such.
  333.  *
  334.  *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
  335.  *    integer to hold the year, and can hold years as large as 65535.
  336.  *
  337.  *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
  338.  *    no date-related code.
  339.  *
  340.  *       Glenn Randers-Pehrson
  341.  *       libpng maintainer
  342.  *       PNG Development Group
  343.  */
  344.  
  345. #ifndef PNG_H
  346. #define PNG_H
  347.  
  348. /* This is not the place to learn how to use libpng. The file libpng-manual.txt
  349.  * describes how to use libpng, and the file example.c summarizes it
  350.  * with some code on which to build.  This file is useful for looking
  351.  * at the actual function definitions and structure components.
  352.  */
  353.  
  354. /* Version information for png.h - this should match the version in png.c */
  355. #define PNG_LIBPNG_VER_STRING "1.5.1"
  356. #define PNG_HEADER_VERSION_STRING \
  357.      " libpng version 1.5.1 - February 3, 2011\n"
  358.  
  359. #define PNG_LIBPNG_VER_SONUM   15
  360. #define PNG_LIBPNG_VER_DLLNUM  15
  361.  
  362. /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
  363. #define PNG_LIBPNG_VER_MAJOR   1
  364. #define PNG_LIBPNG_VER_MINOR   5
  365. #define PNG_LIBPNG_VER_RELEASE 1
  366. /* This should match the numeric part of the final component of
  367.  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  368.  */
  369.  
  370. #define PNG_LIBPNG_VER_BUILD  0
  371.  
  372. /* Release Status */
  373. #define PNG_LIBPNG_BUILD_ALPHA    1
  374. #define PNG_LIBPNG_BUILD_BETA     2
  375. #define PNG_LIBPNG_BUILD_RC       3
  376. #define PNG_LIBPNG_BUILD_STABLE   4
  377. #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
  378.  
  379. /* Release-Specific Flags */
  380. #define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
  381.                                        PNG_LIBPNG_BUILD_STABLE only */
  382. #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
  383.                                        PNG_LIBPNG_BUILD_SPECIAL */
  384. #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
  385.                                        PNG_LIBPNG_BUILD_PRIVATE */
  386.  
  387. #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
  388.  
  389. /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  390.  * We must not include leading zeros.
  391.  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
  392.  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  393.  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  394.  */
  395. #define PNG_LIBPNG_VER 10501 /* 1.5.1 */
  396.  
  397. /* Library configuration: these options cannot be changed after
  398.  * the library has been built.
  399.  */
  400. #ifndef PNGLCONF_H
  401.     /* If pnglibconf.h is missing, you can
  402.      * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
  403.      */
  404. #   include "pnglibconf.h"
  405. #endif
  406.  
  407. #ifndef PNG_VERSION_INFO_ONLY
  408. /* Standard header files (not needed for the version info) */
  409. #  ifdef PNG_SETJMP_SUPPORTED
  410. #    include <setjmp.h>
  411. #  endif
  412.  
  413. /* Need the time information for converting tIME chunks, it
  414.  * defines struct tm:
  415.  */
  416. #ifdef PNG_CONVERT_tIME_SUPPORTED
  417.    /* "time.h" functions are not supported on all operating systems */
  418. #  include <time.h>
  419. #endif
  420.  
  421. /* Machine specific configuration. */
  422. #  include "pngconf.h"
  423. #endif
  424.  
  425. /*
  426.  * Added at libpng-1.2.8
  427.  *
  428.  * Ref MSDN: Private as priority over Special
  429.  * VS_FF_PRIVATEBUILD File *was not* built using standard release
  430.  * procedures. If this value is given, the StringFileInfo block must
  431.  * contain a PrivateBuild string.
  432.  *
  433.  * VS_FF_SPECIALBUILD File *was* built by the original company using
  434.  * standard release procedures but is a variation of the standard
  435.  * file of the same version number. If this value is given, the
  436.  * StringFileInfo block must contain a SpecialBuild string.
  437.  */
  438.  
  439. #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
  440. #  define PNG_LIBPNG_BUILD_TYPE \
  441.        (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
  442. #else
  443. #  ifdef PNG_LIBPNG_SPECIALBUILD
  444. #    define PNG_LIBPNG_BUILD_TYPE \
  445.          (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
  446. #  else
  447. #    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
  448. #  endif
  449. #endif
  450.  
  451. #ifndef PNG_VERSION_INFO_ONLY
  452.  
  453. /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
  454. #ifdef __cplusplus
  455. extern "C" {
  456. #endif /* __cplusplus */
  457.  
  458. /* Version information for C files, stored in png.c.  This had better match
  459.  * the version above.
  460.  */
  461. #define png_libpng_ver png_get_header_ver(NULL)
  462.  
  463. /* This file is arranged in several sections:
  464.  *
  465.  * 1. Any configuration options that can be specified by for the application
  466.  *    code when it is built.  (Build time configuration is in pnglibconf.h)
  467.  * 2. Type definitions (base types are defined in pngconf.h), structure
  468.  *    definitions.
  469.  * 3. Exported library functions.
  470.  *
  471.  * The library source code has additional files (principally pngpriv.h) that
  472.  * allow configuration of the library.
  473.  */
  474. /* Section 1: run time configuration
  475.  * See pnglibconf.h for build time configuration
  476.  *
  477.  * Run time configuration allows the application to choose between
  478.  * implementations of certain arithmetic APIs.  The default is set
  479.  * at build time and recorded in pnglibconf.h, but it is safe to
  480.  * override these (and only these) settings.  Note that this won't
  481.  * change what the library does, only application code, and the
  482.  * settings can (and probably should) be made on a per-file basis
  483.  * by setting the #defines before including png.h
  484.  *
  485.  * Use macros to read integers from PNG data or use the exported
  486.  * functions?
  487.  *   PNG_USE_READ_MACROS: use the macros (see below)  Note that
  488.  *     the macros evaluate their argument multiple times.
  489.  *   PNG_NO_USE_READ_MACROS: call the relevant library function.
  490.  *
  491.  * Use the alternative algorithm for compositing alpha samples that
  492.  * does not use division?
  493.  *   PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
  494.  *      algorithm.
  495.  *   PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
  496.  *
  497.  * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
  498.  * false?
  499.  *   PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
  500.  *      APIs to png_warning.
  501.  * Otherwise the calls are mapped to png_error.
  502.  */
  503.  
  504. /* Section 2: type definitions, including structures and compile time
  505.  * constants.
  506.  * See pngconf.h for base types that vary by machine/system
  507.  */
  508.  
  509. /* This triggers a compiler error in png.c, if png.c and png.h
  510.  * do not agree upon the version number.
  511.  */
  512. typedef char* png_libpng_version_1_5_1;
  513.  
  514. /* Three color definitions.  The order of the red, green, and blue, (and the
  515.  * exact size) is not important, although the size of the fields need to
  516.  * be png_byte or png_uint_16 (as defined below).
  517.  */
  518. typedef struct png_color_struct
  519. {
  520.    png_byte red;
  521.    png_byte green;
  522.    png_byte blue;
  523. } png_color;
  524. typedef png_color FAR * png_colorp;
  525. typedef PNG_CONST png_color FAR * png_const_colorp;
  526. typedef png_color FAR * FAR * png_colorpp;
  527.  
  528. typedef struct png_color_16_struct
  529. {
  530.    png_byte index;    /* used for palette files */
  531.    png_uint_16 red;   /* for use in red green blue files */
  532.    png_uint_16 green;
  533.    png_uint_16 blue;
  534.    png_uint_16 gray;  /* for use in grayscale files */
  535. } png_color_16;
  536. typedef png_color_16 FAR * png_color_16p;
  537. typedef PNG_CONST png_color_16 FAR * png_const_color_16p;
  538. typedef png_color_16 FAR * FAR * png_color_16pp;
  539.  
  540. typedef struct png_color_8_struct
  541. {
  542.    png_byte red;   /* for use in red green blue files */
  543.    png_byte green;
  544.    png_byte blue;
  545.    png_byte gray;  /* for use in grayscale files */
  546.    png_byte alpha; /* for alpha channel files */
  547. } png_color_8;
  548. typedef png_color_8 FAR * png_color_8p;
  549. typedef PNG_CONST png_color_8 FAR * png_const_color_8p;
  550. typedef png_color_8 FAR * FAR * png_color_8pp;
  551.  
  552. /*
  553.  * The following two structures are used for the in-core representation
  554.  * of sPLT chunks.
  555.  */
  556. typedef struct png_sPLT_entry_struct
  557. {
  558.    png_uint_16 red;
  559.    png_uint_16 green;
  560.    png_uint_16 blue;
  561.    png_uint_16 alpha;
  562.    png_uint_16 frequency;
  563. } png_sPLT_entry;
  564. typedef png_sPLT_entry FAR * png_sPLT_entryp;
  565. typedef PNG_CONST png_sPLT_entry FAR * png_const_sPLT_entryp;
  566. typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
  567.  
  568. /*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
  569.  *  occupy the LSB of their respective members, and the MSB of each member
  570.  *  is zero-filled.  The frequency member always occupies the full 16 bits.
  571.  */
  572.  
  573. typedef struct png_sPLT_struct
  574. {
  575.    png_charp name;           /* palette name */
  576.    png_byte depth;           /* depth of palette samples */
  577.    png_sPLT_entryp entries;  /* palette entries */
  578.    png_int_32 nentries;      /* number of palette entries */
  579. } png_sPLT_t;
  580. typedef png_sPLT_t FAR * png_sPLT_tp;
  581. typedef PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp;
  582. typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
  583.  
  584. #ifdef PNG_TEXT_SUPPORTED
  585. /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
  586.  * and whether that contents is compressed or not.  The "key" field
  587.  * points to a regular zero-terminated C string.  The "text", "lang", and
  588.  * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
  589.  * However, the * structure returned by png_get_text() will always contain
  590.  * regular zero-terminated C strings (possibly empty), never NULL pointers,
  591.  * so they can be safely used in printf() and other string-handling functions.
  592.  */
  593. typedef struct png_text_struct
  594. {
  595.    int  compression;       /* compression value:
  596.                              -1: tEXt, none
  597.                               0: zTXt, deflate
  598.                               1: iTXt, none
  599.                               2: iTXt, deflate  */
  600.    png_charp key;          /* keyword, 1-79 character description of "text" */
  601.    png_charp text;         /* comment, may be an empty string (ie "")
  602.                               or a NULL pointer */
  603.    png_size_t text_length; /* length of the text string */
  604.    png_size_t itxt_length; /* length of the itxt string */
  605.    png_charp lang;         /* language code, 0-79 characters
  606.                               or a NULL pointer */
  607.    png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
  608.                               chars or a NULL pointer */
  609. } png_text;
  610. typedef png_text FAR * png_textp;
  611. typedef PNG_CONST png_text FAR * png_const_textp;
  612. typedef png_text FAR * FAR * png_textpp;
  613. #endif
  614.  
  615. /* Supported compression types for text in PNG files (tEXt, and zTXt).
  616.  * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
  617. #define PNG_TEXT_COMPRESSION_NONE_WR -3
  618. #define PNG_TEXT_COMPRESSION_zTXt_WR -2
  619. #define PNG_TEXT_COMPRESSION_NONE    -1
  620. #define PNG_TEXT_COMPRESSION_zTXt     0
  621. #define PNG_ITXT_COMPRESSION_NONE     1
  622. #define PNG_ITXT_COMPRESSION_zTXt     2
  623. #define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
  624.  
  625. /* png_time is a way to hold the time in an machine independent way.
  626.  * Two conversions are provided, both from time_t and struct tm.  There
  627.  * is no portable way to convert to either of these structures, as far
  628.  * as I know.  If you know of a portable way, send it to me.  As a side
  629.  * note - PNG has always been Year 2000 compliant!
  630.  */
  631. typedef struct png_time_struct
  632. {
  633.    png_uint_16 year; /* full year, as in, 1995 */
  634.    png_byte month;   /* month of year, 1 - 12 */
  635.    png_byte day;     /* day of month, 1 - 31 */
  636.    png_byte hour;    /* hour of day, 0 - 23 */
  637.    png_byte minute;  /* minute of hour, 0 - 59 */
  638.    png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
  639. } png_time;
  640. typedef png_time FAR * png_timep;
  641. typedef PNG_CONST png_time FAR * png_const_timep;
  642. typedef png_time FAR * FAR * png_timepp;
  643.  
  644. #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
  645.     defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
  646. /* png_unknown_chunk is a structure to hold queued chunks for which there is
  647.  * no specific support.  The idea is that we can use this to queue
  648.  * up private chunks for output even though the library doesn't actually
  649.  * know about their semantics.
  650.  */
  651. typedef struct png_unknown_chunk_t
  652. {
  653.     png_byte name[5];
  654.     png_byte *data;
  655.     png_size_t size;
  656.  
  657.     /* libpng-using applications should NOT directly modify this byte. */
  658.     png_byte location; /* mode of operation at read time */
  659. }
  660. png_unknown_chunk;
  661. typedef png_unknown_chunk FAR * png_unknown_chunkp;
  662. typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp;
  663. typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
  664. #endif
  665.  
  666. typedef struct png_info_def png_info;
  667. typedef png_info FAR * png_infop;
  668. typedef PNG_CONST png_info FAR * png_const_infop;
  669. typedef png_info FAR * FAR * png_infopp;
  670.  
  671. /* Maximum positive integer used in PNG is (2^31)-1 */
  672. #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
  673. #define PNG_UINT_32_MAX ((png_uint_32)(-1))
  674. #define PNG_SIZE_MAX ((png_size_t)(-1))
  675.  
  676. /* These are constants for fixed point values encoded in the
  677.  * PNG specification manner (x100000)
  678.  */
  679. #define PNG_FP_1    100000
  680. #define PNG_FP_HALF  50000
  681.  
  682. /* These describe the color_type field in png_info. */
  683. /* color type masks */
  684. #define PNG_COLOR_MASK_PALETTE    1
  685. #define PNG_COLOR_MASK_COLOR      2
  686. #define PNG_COLOR_MASK_ALPHA      4
  687.  
  688. /* color types.  Note that not all combinations are legal */
  689. #define PNG_COLOR_TYPE_GRAY 0
  690. #define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
  691. #define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
  692. #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
  693. #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
  694. /* aliases */
  695. #define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
  696. #define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
  697.  
  698. /* This is for compression type. PNG 1.0-1.2 only define the single type. */
  699. #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
  700. #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
  701.  
  702. /* This is for filter type. PNG 1.0-1.2 only define the single type. */
  703. #define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
  704. #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
  705. #define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
  706.  
  707. /* These are for the interlacing type.  These values should NOT be changed. */
  708. #define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
  709. #define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
  710. #define PNG_INTERLACE_LAST        2 /* Not a valid value */
  711.  
  712. /* These are for the oFFs chunk.  These values should NOT be changed. */
  713. #define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
  714. #define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
  715. #define PNG_OFFSET_LAST           2 /* Not a valid value */
  716.  
  717. /* These are for the pCAL chunk.  These values should NOT be changed. */
  718. #define PNG_EQUATION_LINEAR       0 /* Linear transformation */
  719. #define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
  720. #define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
  721. #define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
  722. #define PNG_EQUATION_LAST         4 /* Not a valid value */
  723.  
  724. /* These are for the sCAL chunk.  These values should NOT be changed. */
  725. #define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
  726. #define PNG_SCALE_METER           1 /* meters per pixel */
  727. #define PNG_SCALE_RADIAN          2 /* radians per pixel */
  728. #define PNG_SCALE_LAST            3 /* Not a valid value */
  729.  
  730. /* These are for the pHYs chunk.  These values should NOT be changed. */
  731. #define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
  732. #define PNG_RESOLUTION_METER      1 /* pixels/meter */
  733. #define PNG_RESOLUTION_LAST       2 /* Not a valid value */
  734.  
  735. /* These are for the sRGB chunk.  These values should NOT be changed. */
  736. #define PNG_sRGB_INTENT_PERCEPTUAL 0
  737. #define PNG_sRGB_INTENT_RELATIVE   1
  738. #define PNG_sRGB_INTENT_SATURATION 2
  739. #define PNG_sRGB_INTENT_ABSOLUTE   3
  740. #define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
  741.  
  742. /* This is for text chunks */
  743. #define PNG_KEYWORD_MAX_LENGTH     79
  744.  
  745. /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
  746. #define PNG_MAX_PALETTE_LENGTH    256
  747.  
  748. /* These determine if an ancillary chunk's data has been successfully read
  749.  * from the PNG header, or if the application has filled in the corresponding
  750.  * data in the info_struct to be written into the output file.  The values
  751.  * of the PNG_INFO_<chunk> defines should NOT be changed.
  752.  */
  753. #define PNG_INFO_gAMA 0x0001
  754. #define PNG_INFO_sBIT 0x0002
  755. #define PNG_INFO_cHRM 0x0004
  756. #define PNG_INFO_PLTE 0x0008
  757. #define PNG_INFO_tRNS 0x0010
  758. #define PNG_INFO_bKGD 0x0020
  759. #define PNG_INFO_hIST 0x0040
  760. #define PNG_INFO_pHYs 0x0080
  761. #define PNG_INFO_oFFs 0x0100
  762. #define PNG_INFO_tIME 0x0200
  763. #define PNG_INFO_pCAL 0x0400
  764. #define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
  765. #define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
  766. #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
  767. #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
  768. #define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
  769.  
  770. /* This is used for the transformation routines, as some of them
  771.  * change these values for the row.  It also should enable using
  772.  * the routines for other purposes.
  773.  */
  774. typedef struct png_row_info_struct
  775. {
  776.    png_uint_32 width;    /* width of row */
  777.    png_size_t rowbytes;  /* number of bytes in row */
  778.    png_byte color_type;  /* color type of row */
  779.    png_byte bit_depth;   /* bit depth of row */
  780.    png_byte channels;    /* number of channels (1, 2, 3, or 4) */
  781.    png_byte pixel_depth; /* bits per pixel (depth * channels) */
  782. } png_row_info;
  783.  
  784. typedef png_row_info FAR * png_row_infop;
  785. typedef png_row_info FAR * FAR * png_row_infopp;
  786.  
  787. /* These are the function types for the I/O functions and for the functions
  788.  * that allow the user to override the default I/O functions with his or her
  789.  * own.  The png_error_ptr type should match that of user-supplied warning
  790.  * and error functions, while the png_rw_ptr type should match that of the
  791.  * user read/write data functions.  Note that the 'write' function must not
  792.  * modify the buffer it is passed. The 'read' function, on the other hand, is
  793.  * expected to return the read data in the buffer.
  794.  */
  795. typedef struct png_struct_def png_struct;
  796. typedef PNG_CONST png_struct FAR * png_const_structp;
  797. typedef png_struct FAR * png_structp;
  798.  
  799. typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp), );
  800. typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t), );
  801. typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp), );
  802. typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
  803.     int), );
  804. typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
  805.     int), );
  806.  
  807. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  808. typedef PNG_CALLBACK(void, *png_progressive_info_ptr,
  809.     (png_structp, png_infop), );
  810. typedef PNG_CALLBACK(void, *png_progressive_end_ptr,
  811.     (png_structp, png_infop), );
  812. typedef PNG_CALLBACK(void, *png_progressive_row_ptr,
  813.     (png_structp, png_bytep, png_uint_32, int), );
  814. #endif
  815.  
  816. #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
  817.     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
  818. typedef PNG_CALLBACK(void, *png_user_transform_ptr,
  819.     (png_structp, png_row_infop, png_bytep), );
  820. #endif
  821.  
  822. #ifdef PNG_USER_CHUNKS_SUPPORTED
  823. typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
  824.     png_unknown_chunkp), );
  825. #endif
  826. #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
  827. typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp), );
  828. #endif
  829.  
  830. #ifdef PNG_SETJMP_SUPPORTED
  831. /* This must match the function definition in <setjmp.h>, and the
  832.  * application must include this before png.h to obtain the definition
  833.  * of jmp_buf.  The function is required to be PNG_NORETURN.  (Note that
  834.  * PNG_PTR_NORETURN is used here because current versions of the Microsoft
  835.  * C compiler do not support the PNG_NORETURN attribute on a pointer.)
  836.  *
  837.  * If you get a type warning from the compiler when linking against this line
  838.  * then your compiler has 'longjmp' that does not match the requirements of the
  839.  * compiler that built libpng.  You will have to write a wrapper function for
  840.  * your compiler's longjmp and call png_set_longjmp_fn directly (not via the
  841.  * png_jmpbuf macro.)
  842.  *
  843.  * If you get a warning here while building the library you will need to make
  844.  * changes to ensure that pnglibconf.h records the calling convention used by
  845.  * your compiler.  This may be very difficult - try using a different compiler
  846.  * to build the library!
  847.  */
  848. typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)),
  849.    PNG_PTR_NORETURN);
  850. #endif
  851.  
  852. /* Transform masks for the high-level interface */
  853. #define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
  854. #define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
  855. #define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
  856. #define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
  857. #define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
  858. #define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
  859. #define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
  860. #define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
  861. #define PNG_TRANSFORM_BGR            0x0080    /* read and write */
  862. #define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
  863. #define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
  864. #define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
  865. #define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* write only */
  866. /* Added to libpng-1.2.34 */
  867. #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
  868. #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
  869. /* Added to libpng-1.4.0 */
  870. #define PNG_TRANSFORM_GRAY_TO_RGB   0x2000      /* read only */
  871.  
  872. /* Flags for MNG supported features */
  873. #define PNG_FLAG_MNG_EMPTY_PLTE     0x01
  874. #define PNG_FLAG_MNG_FILTER_64      0x04
  875. #define PNG_ALL_MNG_FEATURES        0x05
  876.  
  877. /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
  878.  * this allowed the zlib default functions to be used on Windows
  879.  * platforms.  In 1.5 the zlib default malloc (which just calls malloc and
  880.  * ignores the first argument) should be completely compatible with the
  881.  * following.
  882.  */
  883. typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
  884.     png_alloc_size_t), );
  885. typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp), );
  886.  
  887. typedef png_struct FAR * FAR * png_structpp;
  888.  
  889. /* Section 3: exported functions
  890.  * Here are the function definitions most commonly used.  This is not
  891.  * the place to find out how to use libpng.  See libpng-manual.txt for the
  892.  * full explanation, see example.c for the summary.  This just provides
  893.  * a simple one line description of the use of each function.
  894.  *
  895.  * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
  896.  * pngconf.h and in the *.dfn files in the scripts directory.
  897.  *
  898.  *   PNG_EXPORT(ordinal, type, name, (args));
  899.  *
  900.  *       ordinal:    ordinal that is used while building
  901.  *                   *.def files. The ordinal value is only
  902.  *                   relevant when preprocessing png.h with
  903.  *                   the *.dfn files for building symbol table
  904.  *                   entries, and are removed by pngconf.h.
  905.  *       type:       return type of the function
  906.  *       name:       function name
  907.  *       args:       function arguments, with types
  908.  *
  909.  * When we wish to append attributes to a function prototype we use
  910.  * the PNG_EXPORTA() macro instead.
  911.  *
  912.  *   PNG_EXPORTA(ordinal, type, name, (args), attributes);
  913.  *
  914.  *       ordinal, type, name, and args: same as in PNG_EXPORT().
  915.  *       attributes: function attributes
  916.  */
  917.  
  918. /* Returns the version number of the library */
  919. PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
  920.  
  921. /* Tell lib we have already handled the first <num_bytes> magic bytes.
  922.  * Handling more than 8 bytes from the beginning of the file is an error.
  923.  */
  924. PNG_EXPORT(2, void, png_set_sig_bytes, (png_structp png_ptr, int num_bytes));
  925.  
  926. /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
  927.  * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
  928.  * signature, and non-zero otherwise.  Having num_to_check == 0 or
  929.  * start > 7 will always fail (ie return non-zero).
  930.  */
  931. PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
  932.     png_size_t num_to_check));
  933.  
  934. /* Simple signature checking function.  This is the same as calling
  935.  * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
  936.  */
  937. #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
  938.  
  939. /* Allocate and initialize png_ptr struct for reading, and any other memory. */
  940. PNG_EXPORTA(4, png_structp, png_create_read_struct,
  941.     (png_const_charp user_png_ver, png_voidp error_ptr,
  942.     png_error_ptr error_fn, png_error_ptr warn_fn),
  943.     PNG_ALLOCATED);
  944.  
  945. /* Allocate and initialize png_ptr struct for writing, and any other memory */
  946. PNG_EXPORTA(5, png_structp, png_create_write_struct,
  947.     (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
  948.     png_error_ptr warn_fn),
  949.     PNG_ALLOCATED);
  950.  
  951. PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
  952.     (png_const_structp png_ptr));
  953.  
  954. PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr,
  955.     png_size_t size));
  956.  
  957. /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
  958.  * match up.
  959.  */
  960. #ifdef PNG_SETJMP_SUPPORTED
  961. /* This function returns the jmp_buf built in to *png_ptr.  It must be
  962.  * supplied with an appropriate 'longjmp' function to use on that jmp_buf
  963.  * unless the default error function is overridden in which case NULL is
  964.  * acceptable.  The size of the jmp_buf is checked against the actual size
  965.  * allocated by the library - the call will return NULL on a mismatch
  966.  * indicating an ABI mismatch.
  967.  */
  968. PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr,
  969.     png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
  970. #  define png_jmpbuf(png_ptr) \
  971.       (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
  972. #else
  973. #  define png_jmpbuf(png_ptr) \
  974.       (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
  975. #endif
  976. /* This function should be used by libpng applications in place of
  977.  * longjmp(png_ptr->jmpbuf, val).  If longjmp_fn() has been set, it
  978.  * will use it; otherwise it will call PNG_ABORT().  This function was
  979.  * added in libpng-1.5.0.
  980.  */
  981. PNG_EXPORTA(9, void, png_longjmp, (png_structp png_ptr, int val),
  982.     PNG_NORETURN);
  983.  
  984. #ifdef PNG_READ_SUPPORTED
  985. /* Reset the compression stream */
  986. PNG_EXPORT(10, int, png_reset_zstream, (png_structp png_ptr));
  987. #endif
  988.  
  989. /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
  990. #ifdef PNG_USER_MEM_SUPPORTED
  991. PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
  992.     (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
  993.     png_error_ptr warn_fn,
  994.     png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
  995.     PNG_ALLOCATED);
  996. PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
  997.     (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
  998.     png_error_ptr warn_fn,
  999.     png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
  1000.     PNG_ALLOCATED);
  1001. #endif
  1002.  
  1003. /* Write the PNG file signature. */
  1004. PNG_EXPORT(13, void, png_write_sig, (png_structp png_ptr));
  1005.  
  1006. /* Write a PNG chunk - size, type, (optional) data, CRC. */
  1007. PNG_EXPORT(14, void, png_write_chunk, (png_structp png_ptr, png_const_bytep
  1008.     chunk_name, png_const_bytep data, png_size_t length));
  1009.  
  1010. /* Write the start of a PNG chunk - length and chunk name. */
  1011. PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr,
  1012.     png_const_bytep chunk_name, png_uint_32 length));
  1013.  
  1014. /* Write the data of a PNG chunk started with png_write_chunk_start(). */
  1015. PNG_EXPORT(16, void, png_write_chunk_data, (png_structp png_ptr,
  1016.     png_const_bytep data, png_size_t length));
  1017.  
  1018. /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
  1019. PNG_EXPORT(17, void, png_write_chunk_end, (png_structp png_ptr));
  1020.  
  1021. /* Allocate and initialize the info structure */
  1022. PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr),
  1023.     PNG_ALLOCATED);
  1024.  
  1025. PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr,
  1026.     png_size_t png_info_struct_size));
  1027.  
  1028. /* Writes all the PNG information before the image. */
  1029. PNG_EXPORT(20, void, png_write_info_before_PLTE,
  1030.     (png_structp png_ptr, png_infop info_ptr));
  1031. PNG_EXPORT(21, void, png_write_info,
  1032.     (png_structp png_ptr, png_infop info_ptr));
  1033.  
  1034. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1035. /* Read the information before the actual image data. */
  1036. PNG_EXPORT(22, void, png_read_info,
  1037.     (png_structp png_ptr, png_infop info_ptr));
  1038. #endif
  1039.  
  1040. #ifdef PNG_TIME_RFC1123_SUPPORTED
  1041. PNG_EXPORT(23, png_const_charp, png_convert_to_rfc1123,
  1042.     (png_structp png_ptr,
  1043.     png_const_timep ptime));
  1044. #endif
  1045.  
  1046. #ifdef PNG_CONVERT_tIME_SUPPORTED
  1047. /* Convert from a struct tm to png_time */
  1048. PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
  1049.     PNG_CONST struct tm FAR * ttime));
  1050.  
  1051. /* Convert from time_t to png_time.  Uses gmtime() */
  1052. PNG_EXPORT(25, void, png_convert_from_time_t,
  1053.     (png_timep ptime, time_t ttime));
  1054. #endif /* PNG_CONVERT_tIME_SUPPORTED */
  1055.  
  1056. #ifdef PNG_READ_EXPAND_SUPPORTED
  1057. /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
  1058. PNG_EXPORT(26, void, png_set_expand, (png_structp png_ptr));
  1059. PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structp png_ptr));
  1060. PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structp png_ptr));
  1061. PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr));
  1062. #endif
  1063.  
  1064. #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
  1065. /* Use blue, green, red order for pixels. */
  1066. PNG_EXPORT(30, void, png_set_bgr, (png_structp png_ptr));
  1067. #endif
  1068.  
  1069. #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
  1070. /* Expand the grayscale to 24-bit RGB if necessary. */
  1071. PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structp png_ptr));
  1072. #endif
  1073.  
  1074. #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
  1075. /* Reduce RGB to grayscale. */
  1076. PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr,
  1077.     int error_action, double red, double green));
  1078. PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr,
  1079.     int error_action, png_fixed_point red, png_fixed_point green));
  1080.  
  1081. PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp
  1082.     png_ptr));
  1083. #endif
  1084.  
  1085. PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
  1086.     png_colorp palette));
  1087.  
  1088. #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
  1089. PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr));
  1090. #endif
  1091.  
  1092. #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
  1093.     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
  1094. PNG_EXPORT(37, void, png_set_swap_alpha, (png_structp png_ptr));
  1095. #endif
  1096.  
  1097. #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
  1098.     defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
  1099. PNG_EXPORT(38, void, png_set_invert_alpha, (png_structp png_ptr));
  1100. #endif
  1101.  
  1102. #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
  1103. /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
  1104. PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler,
  1105.     int flags));
  1106. /* The values of the PNG_FILLER_ defines should NOT be changed */
  1107. #  define PNG_FILLER_BEFORE 0
  1108. #  define PNG_FILLER_AFTER 1
  1109. /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
  1110. PNG_EXPORT(40, void, png_set_add_alpha,
  1111.     (png_structp png_ptr, png_uint_32 filler,
  1112.     int flags));
  1113. #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
  1114.  
  1115. #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
  1116. /* Swap bytes in 16-bit depth files. */
  1117. PNG_EXPORT(41, void, png_set_swap, (png_structp png_ptr));
  1118. #endif
  1119.  
  1120. #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
  1121. /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
  1122. PNG_EXPORT(42, void, png_set_packing, (png_structp png_ptr));
  1123. #endif
  1124.  
  1125. #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
  1126.     defined(PNG_WRITE_PACKSWAP_SUPPORTED)
  1127. /* Swap packing order of pixels in bytes. */
  1128. PNG_EXPORT(43, void, png_set_packswap, (png_structp png_ptr));
  1129. #endif
  1130.  
  1131. #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
  1132. /* Converts files to legal bit depths. */
  1133. PNG_EXPORT(44, void, png_set_shift, (png_structp png_ptr, png_const_color_8p
  1134.     true_bits));
  1135. #endif
  1136.  
  1137. #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
  1138.     defined(PNG_WRITE_INTERLACING_SUPPORTED)
  1139. /* Have the code handle the interlacing.  Returns the number of passes.
  1140.  * MUST be called before png_read_update_info or png_start_read_image,
  1141.  * otherwise it will not have the desired effect.  Note that it is still
  1142.  * necessary to call png_read_row or png_read_rows png_get_image_height
  1143.  * times for each pass.
  1144. */
  1145. PNG_EXPORT(45, int, png_set_interlace_handling, (png_structp png_ptr));
  1146. #endif
  1147.  
  1148. #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
  1149. /* Invert monochrome files */
  1150. PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr));
  1151. #endif
  1152.  
  1153. #ifdef PNG_READ_BACKGROUND_SUPPORTED
  1154. /* Handle alpha and tRNS by replacing with a background color. */
  1155. PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr,
  1156.     png_const_color_16p background_color, int background_gamma_code,
  1157.     int need_expand, double background_gamma));
  1158. PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr,
  1159.     png_const_color_16p background_color, int background_gamma_code,
  1160.     int need_expand, png_fixed_point background_gamma));
  1161. #endif
  1162. #ifdef PNG_READ_BACKGROUND_SUPPORTED
  1163. #  define PNG_BACKGROUND_GAMMA_UNKNOWN 0
  1164. #  define PNG_BACKGROUND_GAMMA_SCREEN  1
  1165. #  define PNG_BACKGROUND_GAMMA_FILE    2
  1166. #  define PNG_BACKGROUND_GAMMA_UNIQUE  3
  1167. #endif
  1168.  
  1169. #ifdef PNG_READ_16_TO_8_SUPPORTED
  1170. /* Strip the second byte of information from a 16-bit depth file. */
  1171. PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr));
  1172. #endif
  1173.  
  1174. #ifdef PNG_READ_QUANTIZE_SUPPORTED
  1175. /* Turn on quantizing, and reduce the palette to the number of colors
  1176.  * available.
  1177.  */
  1178. PNG_EXPORT(49, void, png_set_quantize,
  1179.     (png_structp png_ptr, png_colorp palette,
  1180.     int num_palette, int maximum_colors, png_const_uint_16p histogram,
  1181.     int full_quantize));
  1182. #endif
  1183.  
  1184. #ifdef PNG_READ_GAMMA_SUPPORTED
  1185. /* The threshold on gamma processing is configurable but hard-wired into the
  1186.  * library.  The following is the floating point variant.
  1187.  */
  1188. #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
  1189.  
  1190. /* Handle gamma correction. Screen_gamma=(display_exponent) */
  1191. PNG_FP_EXPORT(50, void, png_set_gamma,
  1192.     (png_structp png_ptr, double screen_gamma,
  1193.     double default_file_gamma));
  1194. PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr,
  1195.     png_fixed_point screen_gamma, png_fixed_point default_file_gamma));
  1196. #endif
  1197.  
  1198. #ifdef PNG_WRITE_FLUSH_SUPPORTED
  1199. /* Set how many lines between output flushes - 0 for no flushing */
  1200. PNG_EXPORT(51, void, png_set_flush, (png_structp png_ptr, int nrows));
  1201. /* Flush the current PNG output buffer */
  1202. PNG_EXPORT(52, void, png_write_flush, (png_structp png_ptr));
  1203. #endif
  1204.  
  1205. /* Optional update palette with requested transformations */
  1206. PNG_EXPORT(53, void, png_start_read_image, (png_structp png_ptr));
  1207.  
  1208. /* Optional call to update the users info structure */
  1209. PNG_EXPORT(54, void, png_read_update_info,
  1210.     (png_structp png_ptr, png_infop info_ptr));
  1211.  
  1212. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1213. /* Read one or more rows of image data. */
  1214. PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row,
  1215.     png_bytepp display_row, png_uint_32 num_rows));
  1216. #endif
  1217.  
  1218. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1219. /* Read a row of data. */
  1220. PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row,
  1221.     png_bytep display_row));
  1222. #endif
  1223.  
  1224. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1225. /* Read the whole image into memory at once. */
  1226. PNG_EXPORT(57, void, png_read_image, (png_structp png_ptr, png_bytepp image));
  1227. #endif
  1228.  
  1229. /* Write a row of image data */
  1230. PNG_EXPORT(58, void, png_write_row,
  1231.     (png_structp png_ptr, png_const_bytep row));
  1232.  
  1233. /* Write a few rows of image data: (*row) is not written; however, the type
  1234.  * is declared as writeable to maintain compatibility with previous versions
  1235.  * of libpng and to allow the 'display_row' array from read_rows to be passed
  1236.  * unchanged to write_rows.
  1237.  */
  1238. PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row,
  1239.     png_uint_32 num_rows));
  1240.  
  1241. /* Write the image data */
  1242. PNG_EXPORT(60, void, png_write_image,
  1243.     (png_structp png_ptr, png_bytepp image));
  1244.  
  1245. /* Write the end of the PNG file. */
  1246. PNG_EXPORT(61, void, png_write_end,
  1247.     (png_structp png_ptr, png_infop info_ptr));
  1248.  
  1249. #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
  1250. /* Read the end of the PNG file. */
  1251. PNG_EXPORT(62, void, png_read_end, (png_structp png_ptr, png_infop info_ptr));
  1252. #endif
  1253.  
  1254. /* Free any memory associated with the png_info_struct */
  1255. PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr,
  1256.     png_infopp info_ptr_ptr));
  1257.  
  1258. /* Free any memory associated with the png_struct and the png_info_structs */
  1259. PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
  1260.     png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
  1261.  
  1262. /* Free any memory associated with the png_struct and the png_info_structs */
  1263. PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
  1264.     png_infopp info_ptr_ptr));
  1265.  
  1266. /* Set the libpng method of handling chunk CRC errors */
  1267. PNG_EXPORT(66, void, png_set_crc_action,
  1268.     (png_structp png_ptr, int crit_action, int ancil_action));
  1269.  
  1270. /* Values for png_set_crc_action() say how to handle CRC errors in
  1271.  * ancillary and critical chunks, and whether to use the data contained
  1272.  * therein.  Note that it is impossible to "discard" data in a critical
  1273.  * chunk.  For versions prior to 0.90, the action was always error/quit,
  1274.  * whereas in version 0.90 and later, the action for CRC errors in ancillary
  1275.  * chunks is warn/discard.  These values should NOT be changed.
  1276.  *
  1277.  *      value                       action:critical     action:ancillary
  1278.  */
  1279. #define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
  1280. #define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
  1281. #define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
  1282. #define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
  1283. #define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
  1284. #define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
  1285.  
  1286. /* These functions give the user control over the scan-line filtering in
  1287.  * libpng and the compression methods used by zlib.  These functions are
  1288.  * mainly useful for testing, as the defaults should work with most users.
  1289.  * Those users who are tight on memory or want faster performance at the
  1290.  * expense of compression can modify them.  See the compression library
  1291.  * header file (zlib.h) for an explination of the compression functions.
  1292.  */
  1293.  
  1294. /* Set the filtering method(s) used by libpng.  Currently, the only valid
  1295.  * value for "method" is 0.
  1296.  */
  1297. PNG_EXPORT(67, void, png_set_filter,
  1298.     (png_structp png_ptr, int method, int filters));
  1299.  
  1300. /* Flags for png_set_filter() to say which filters to use.  The flags
  1301.  * are chosen so that they don't conflict with real filter types
  1302.  * below, in case they are supplied instead of the #defined constants.
  1303.  * These values should NOT be changed.
  1304.  */
  1305. #define PNG_NO_FILTERS     0x00
  1306. #define PNG_FILTER_NONE    0x08
  1307. #define PNG_FILTER_SUB     0x10
  1308. #define PNG_FILTER_UP      0x20
  1309. #define PNG_FILTER_AVG     0x40
  1310. #define PNG_FILTER_PAETH   0x80
  1311. #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
  1312.                          PNG_FILTER_AVG | PNG_FILTER_PAETH)
  1313.  
  1314. /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
  1315.  * These defines should NOT be changed.
  1316.  */
  1317. #define PNG_FILTER_VALUE_NONE  0
  1318. #define PNG_FILTER_VALUE_SUB   1
  1319. #define PNG_FILTER_VALUE_UP    2
  1320. #define PNG_FILTER_VALUE_AVG   3
  1321. #define PNG_FILTER_VALUE_PAETH 4
  1322. #define PNG_FILTER_VALUE_LAST  5
  1323.  
  1324. #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
  1325. /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
  1326.  * defines, either the default (minimum-sum-of-absolute-differences), or
  1327.  * the experimental method (weighted-minimum-sum-of-absolute-differences).
  1328.  *
  1329.  * Weights are factors >= 1.0, indicating how important it is to keep the
  1330.  * filter type consistent between rows.  Larger numbers mean the current
  1331.  * filter is that many times as likely to be the same as the "num_weights"
  1332.  * previous filters.  This is cumulative for each previous row with a weight.
  1333.  * There needs to be "num_weights" values in "filter_weights", or it can be
  1334.  * NULL if the weights aren't being specified.  Weights have no influence on
  1335.  * the selection of the first row filter.  Well chosen weights can (in theory)
  1336.  * improve the compression for a given image.
  1337.  *
  1338.  * Costs are factors >= 1.0 indicating the relative decoding costs of a
  1339.  * filter type.  Higher costs indicate more decoding expense, and are
  1340.  * therefore less likely to be selected over a filter with lower computational
  1341.  * costs.  There needs to be a value in "filter_costs" for each valid filter
  1342.  * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
  1343.  * setting the costs.  Costs try to improve the speed of decompression without
  1344.  * unduly increasing the compressed image size.
  1345.  *
  1346.  * A negative weight or cost indicates the default value is to be used, and
  1347.  * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
  1348.  * The default values for both weights and costs are currently 1.0, but may
  1349.  * change if good general weighting/cost heuristics can be found.  If both
  1350.  * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
  1351.  * to the UNWEIGHTED method, but with added encoding time/computation.
  1352.  */
  1353. PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr,
  1354.     int heuristic_method, int num_weights, png_const_doublep filter_weights,
  1355.     png_const_doublep filter_costs));
  1356. PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
  1357.     (png_structp png_ptr,
  1358.     int heuristic_method, int num_weights, png_const_fixed_point_p
  1359.     filter_weights, png_const_fixed_point_p filter_costs));
  1360. #endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
  1361.  
  1362. /* Heuristic used for row filter selection.  These defines should NOT be
  1363.  * changed.
  1364.  */
  1365. #define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
  1366. #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
  1367. #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
  1368. #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
  1369.  
  1370. /* Set the library compression level.  Currently, valid values range from
  1371.  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
  1372.  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
  1373.  * shown that zlib compression levels 3-6 usually perform as well as level 9
  1374.  * for PNG images, and do considerably fewer caclulations.  In the future,
  1375.  * these values may not correspond directly to the zlib compression levels.
  1376.  */
  1377. PNG_EXPORT(69, void, png_set_compression_level,
  1378.     (png_structp png_ptr, int level));
  1379.  
  1380. PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr,
  1381.     int mem_level));
  1382.  
  1383. PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr,
  1384.     int strategy));
  1385.  
  1386. PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr,
  1387.     int window_bits));
  1388.  
  1389. PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr,
  1390.     int method));
  1391.  
  1392. /* These next functions are called for input/output, memory, and error
  1393.  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
  1394.  * and call standard C I/O routines such as fread(), fwrite(), and
  1395.  * fprintf().  These functions can be made to use other I/O routines
  1396.  * at run time for those applications that need to handle I/O in a
  1397.  * different manner by calling png_set_???_fn().  See libpng-manual.txt for
  1398.  * more information.
  1399.  */
  1400.  
  1401. #ifdef PNG_STDIO_SUPPORTED
  1402. /* Initialize the input/output for the PNG file to the default functions. */
  1403. PNG_EXPORT(74, void, png_init_io, (png_structp png_ptr, png_FILE_p fp));
  1404. #endif
  1405.  
  1406. /* Replace the (error and abort), and warning functions with user
  1407.  * supplied functions.  If no messages are to be printed you must still
  1408.  * write and use replacement functions. The replacement error_fn should
  1409.  * still do a longjmp to the last setjmp location if you are using this
  1410.  * method of error handling.  If error_fn or warning_fn is NULL, the
  1411.  * default function will be used.
  1412.  */
  1413.  
  1414. PNG_EXPORT(75, void, png_set_error_fn,
  1415.     (png_structp png_ptr, png_voidp error_ptr,
  1416.     png_error_ptr error_fn, png_error_ptr warning_fn));
  1417.  
  1418. /* Return the user pointer associated with the error functions */
  1419. PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structp png_ptr));
  1420.  
  1421. /* Replace the default data output functions with a user supplied one(s).
  1422.  * If buffered output is not used, then output_flush_fn can be set to NULL.
  1423.  * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
  1424.  * output_flush_fn will be ignored (and thus can be NULL).
  1425.  * It is probably a mistake to use NULL for output_flush_fn if
  1426.  * write_data_fn is not also NULL unless you have built libpng with
  1427.  * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
  1428.  * default flush function, which uses the standard *FILE structure, will
  1429.  * be used.
  1430.  */
  1431. PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr,
  1432.     png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
  1433.  
  1434. /* Replace the default data input function with a user supplied one. */
  1435. PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr,
  1436.     png_rw_ptr read_data_fn));
  1437.  
  1438. /* Return the user pointer associated with the I/O functions */
  1439. PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_structp png_ptr));
  1440.  
  1441. PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr,
  1442.     png_read_status_ptr read_row_fn));
  1443.  
  1444. PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr,
  1445.     png_write_status_ptr write_row_fn));
  1446.  
  1447. #ifdef PNG_USER_MEM_SUPPORTED
  1448. /* Replace the default memory allocation functions with user supplied one(s). */
  1449. PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr,
  1450.     png_malloc_ptr malloc_fn, png_free_ptr free_fn));
  1451. /* Return the user pointer associated with the memory functions */
  1452. PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structp png_ptr));
  1453. #endif
  1454.  
  1455. #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
  1456. PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr,
  1457.     png_user_transform_ptr read_user_transform_fn));
  1458. #endif
  1459.  
  1460. #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
  1461. PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr,
  1462.     png_user_transform_ptr write_user_transform_fn));
  1463. #endif
  1464.  
  1465. #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
  1466. PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr,
  1467.     png_voidp user_transform_ptr, int user_transform_depth,
  1468.     int user_transform_channels));
  1469. /* Return the user pointer associated with the user transform functions */
  1470. PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
  1471.     (png_const_structp png_ptr));
  1472. #endif
  1473.  
  1474. #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
  1475. /* Return information about the row currently being processed.  Note that these
  1476.  * APIs do not fail but will return unexpected results if called outside a user
  1477.  * transform callback.  Also note that when transforming an interlaced image the
  1478.  * row number is still the row in the final, de-interlaced, image but the row
  1479.  * only contains the data of the current pass - consult png_row_info for the
  1480.  * actual width of the row!
  1481.  */
  1482. PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp));
  1483. PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp));
  1484. #endif
  1485.  
  1486. #ifdef PNG_USER_CHUNKS_SUPPORTED
  1487. PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr,
  1488.     png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
  1489. PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr));
  1490. #endif
  1491.  
  1492. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  1493. /* Sets the function callbacks for the push reader, and a pointer to a
  1494.  * user-defined structure available to the callback functions.
  1495.  */
  1496. PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr,
  1497.     png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
  1498.     png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
  1499.  
  1500. /* Returns the user pointer associated with the push read functions */
  1501. PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structp png_ptr));
  1502.  
  1503. /* Function to be called when data becomes available */
  1504. PNG_EXPORT(92, void, png_process_data,
  1505.     (png_structp png_ptr, png_infop info_ptr,
  1506.     png_bytep buffer, png_size_t buffer_size));
  1507.  
  1508. /* A function which may be called *only* within png_process_data to stop the
  1509.  * processing of any more data.  The function returns the number of bytes
  1510.  * remaining, excluding any that libpng has cached internally.  A subsequent
  1511.  * call to png_process_data must supply these bytes again.  If the argument
  1512.  * 'save' is set to true the routine will first save all the pending data and
  1513.  * will always return 0.
  1514.  */
  1515. PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structp, int save));
  1516.  
  1517. /* A function which may be called *only* outside (after) a call to
  1518.  * png_process_data.  It returns the number of bytes of data to skip in the
  1519.  * input.  Normally it will return 0, but if it returns a non-zero value the
  1520.  * application must skip than number of bytes of input data and pass the
  1521.  * following data to the next call to png_process_data.
  1522.  */
  1523. PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp));
  1524.  
  1525. /* Function that combines rows.  'new_row' is a flag that should come from
  1526.  * the callback and be non-NULL if anything needs to be done; the library
  1527.  * stores its own version of the new data internally and ignores the passed
  1528.  * in value.
  1529.  */
  1530. PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr,
  1531.     png_bytep old_row, png_const_bytep new_row));
  1532. #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
  1533.  
  1534. PNG_EXPORTA(94, png_voidp, png_malloc,
  1535.     (png_structp png_ptr, png_alloc_size_t size),
  1536.     PNG_ALLOCATED);
  1537. /* Added at libpng version 1.4.0 */
  1538. PNG_EXPORTA(95, png_voidp, png_calloc,
  1539.     (png_structp png_ptr, png_alloc_size_t size),
  1540.     PNG_ALLOCATED);
  1541.  
  1542. /* Added at libpng version 1.2.4 */
  1543. PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr,
  1544.     png_alloc_size_t size), PNG_ALLOCATED);
  1545.  
  1546. /* Frees a pointer allocated by png_malloc() */
  1547. PNG_EXPORT(97, void, png_free, (png_structp png_ptr, png_voidp ptr));
  1548.  
  1549. /* Free data that was allocated internally */
  1550. PNG_EXPORT(98, void, png_free_data,
  1551.     (png_structp png_ptr, png_infop info_ptr, png_uint_32 free_me, int num));
  1552.  
  1553. /* Reassign responsibility for freeing existing data, whether allocated
  1554.  * by libpng or by the application */
  1555. PNG_EXPORT(99, void, png_data_freer,
  1556.     (png_structp png_ptr, png_infop info_ptr, int freer, png_uint_32 mask));
  1557.  
  1558. /* Assignments for png_data_freer */
  1559. #define PNG_DESTROY_WILL_FREE_DATA 1
  1560. #define PNG_SET_WILL_FREE_DATA 1
  1561. #define PNG_USER_WILL_FREE_DATA 2
  1562. /* Flags for png_ptr->free_me and info_ptr->free_me */
  1563. #define PNG_FREE_HIST 0x0008
  1564. #define PNG_FREE_ICCP 0x0010
  1565. #define PNG_FREE_SPLT 0x0020
  1566. #define PNG_FREE_ROWS 0x0040
  1567. #define PNG_FREE_PCAL 0x0080
  1568. #define PNG_FREE_SCAL 0x0100
  1569. #define PNG_FREE_UNKN 0x0200
  1570. #define PNG_FREE_LIST 0x0400
  1571. #define PNG_FREE_PLTE 0x1000
  1572. #define PNG_FREE_TRNS 0x2000
  1573. #define PNG_FREE_TEXT 0x4000
  1574. #define PNG_FREE_ALL  0x7fff
  1575. #define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
  1576.  
  1577. #ifdef PNG_USER_MEM_SUPPORTED
  1578. PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr,
  1579.     png_alloc_size_t size), PNG_ALLOCATED);
  1580. PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr));
  1581. #endif
  1582.  
  1583. #ifdef PNG_ERROR_TEXT_SUPPORTED
  1584. /* Fatal error in PNG image of libpng - can't continue */
  1585. PNG_EXPORTA(102, void, png_error,
  1586.     (png_structp png_ptr, png_const_charp error_message),
  1587.     PNG_NORETURN);
  1588.  
  1589. /* The same, but the chunk name is prepended to the error string. */
  1590. PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr,
  1591.     png_const_charp error_message), PNG_NORETURN);
  1592.  
  1593. #else
  1594. /* Fatal error in PNG image of libpng - can't continue */
  1595. PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN);
  1596. #endif
  1597.  
  1598. /* Non-fatal error in libpng.  Can continue, but may have a problem. */
  1599. PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
  1600.     png_const_charp warning_message));
  1601.  
  1602. /* Non-fatal error in libpng, chunk name is prepended to message. */
  1603. PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr,
  1604.     png_const_charp warning_message));
  1605.  
  1606. #ifdef PNG_BENIGN_ERRORS_SUPPORTED
  1607. /* Benign error in libpng.  Can continue, but may have a problem.
  1608.  * User can choose whether to handle as a fatal error or as a warning. */
  1609. #  undef png_benign_error
  1610. PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr,
  1611.     png_const_charp warning_message));
  1612.  
  1613. /* Same, chunk name is prepended to message. */
  1614. #  undef png_chunk_benign_error
  1615. PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr,
  1616.     png_const_charp warning_message));
  1617.  
  1618. PNG_EXPORT(109, void, png_set_benign_errors,
  1619.     (png_structp png_ptr, int allowed));
  1620. #else
  1621. #  ifdef PNG_ALLOW_BENIGN_ERRORS
  1622. #    define png_benign_error png_warning
  1623. #    define png_chunk_benign_error png_chunk_warning
  1624. #  else
  1625. #    define png_benign_error png_error
  1626. #    define png_chunk_benign_error png_chunk_error
  1627. #  endif
  1628. #endif
  1629.  
  1630. /* The png_set_<chunk> functions are for storing values in the png_info_struct.
  1631.  * Similarly, the png_get_<chunk> calls are used to read values from the
  1632.  * png_info_struct, either storing the parameters in the passed variables, or
  1633.  * setting pointers into the png_info_struct where the data is stored.  The
  1634.  * png_get_<chunk> functions return a non-zero value if the data was available
  1635.  * in info_ptr, or return zero and do not change any of the parameters if the
  1636.  * data was not available.
  1637.  *
  1638.  * These functions should be used instead of directly accessing png_info
  1639.  * to avoid problems with future changes in the size and internal layout of
  1640.  * png_info_struct.
  1641.  */
  1642. /* Returns "flag" if chunk data is valid in info_ptr. */
  1643. PNG_EXPORT(110, png_uint_32, png_get_valid,
  1644.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1645.     png_uint_32 flag));
  1646.  
  1647. /* Returns number of bytes needed to hold a transformed row. */
  1648. PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr,
  1649.     png_const_infop info_ptr));
  1650.  
  1651. #ifdef PNG_INFO_IMAGE_SUPPORTED
  1652. /* Returns row_pointers, which is an array of pointers to scanlines that was
  1653.  * returned from png_read_png().
  1654.  */
  1655. PNG_EXPORT(112, png_bytepp, png_get_rows,
  1656.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1657. /* Set row_pointers, which is an array of pointers to scanlines for use
  1658.  * by png_write_png().
  1659.  */
  1660. PNG_EXPORT(113, void, png_set_rows, (png_structp png_ptr,
  1661.     png_infop info_ptr, png_bytepp row_pointers));
  1662. #endif
  1663.  
  1664. /* Returns number of color channels in image. */
  1665. PNG_EXPORT(114, png_byte, png_get_channels,
  1666.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1667.  
  1668. #ifdef PNG_EASY_ACCESS_SUPPORTED
  1669. /* Returns image width in pixels. */
  1670. PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr,
  1671.     png_const_infop info_ptr));
  1672.  
  1673. /* Returns image height in pixels. */
  1674. PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr,
  1675.     png_const_infop info_ptr));
  1676.  
  1677. /* Returns image bit_depth. */
  1678. PNG_EXPORT(117, png_byte, png_get_bit_depth,
  1679.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1680.  
  1681. /* Returns image color_type. */
  1682. PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr,
  1683.     png_const_infop info_ptr));
  1684.  
  1685. /* Returns image filter_type. */
  1686. PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr,
  1687.     png_const_infop info_ptr));
  1688.  
  1689. /* Returns image interlace_type. */
  1690. PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr,
  1691.     png_const_infop info_ptr));
  1692.  
  1693. /* Returns image compression_type. */
  1694. PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr,
  1695.     png_const_infop info_ptr));
  1696.  
  1697. /* Returns image resolution in pixels per meter, from pHYs chunk data. */
  1698. PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
  1699.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1700. PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
  1701.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1702. PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
  1703.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1704.  
  1705. /* Returns pixel aspect ratio, computed from pHYs chunk data.  */
  1706. PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
  1707.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1708. PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
  1709.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1710.  
  1711. /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
  1712. PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
  1713.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1714. PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
  1715.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1716. PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
  1717.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1718. PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
  1719.     (png_const_structp png_ptr, png_const_infop info_ptr));
  1720.  
  1721. #endif /* PNG_EASY_ACCESS_SUPPORTED */
  1722.  
  1723. /* Returns pointer to signature string read from PNG header */
  1724. PNG_EXPORT(130, png_const_bytep, png_get_signature,
  1725.     (png_const_structp png_ptr, png_infop info_ptr));
  1726.  
  1727. #ifdef PNG_bKGD_SUPPORTED
  1728. PNG_EXPORT(131, png_uint_32, png_get_bKGD,
  1729.     (png_const_structp png_ptr, png_infop info_ptr,
  1730.     png_color_16p *background));
  1731. #endif
  1732.  
  1733. #ifdef PNG_bKGD_SUPPORTED
  1734. PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr,
  1735.     png_const_color_16p background));
  1736. #endif
  1737.  
  1738. #ifdef PNG_cHRM_SUPPORTED
  1739. PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr,
  1740.    png_const_infop info_ptr, double *white_x, double *white_y, double *red_x,
  1741.     double *red_y, double *green_x, double *green_y, double *blue_x,
  1742.     double *blue_y));
  1743. #ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */
  1744. PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
  1745.     (png_const_structp png_ptr,
  1746.     png_const_infop info_ptr, png_fixed_point *int_white_x,
  1747.     png_fixed_point *int_white_y, png_fixed_point *int_red_x,
  1748.     png_fixed_point *int_red_y, png_fixed_point *int_green_x,
  1749.     png_fixed_point *int_green_y, png_fixed_point *int_blue_x,
  1750.     png_fixed_point *int_blue_y));
  1751. #endif
  1752. #endif
  1753.  
  1754. #ifdef PNG_cHRM_SUPPORTED
  1755. PNG_FP_EXPORT(135, void, png_set_cHRM,
  1756.     (png_structp png_ptr, png_infop info_ptr,
  1757.     double white_x, double white_y, double red_x, double red_y, double green_x,
  1758.     double green_y, double blue_x, double blue_y));
  1759. PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr,
  1760.     png_infop info_ptr, png_fixed_point int_white_x,
  1761.     png_fixed_point int_white_y, png_fixed_point int_red_x,
  1762.     png_fixed_point int_red_y, png_fixed_point int_green_x,
  1763.     png_fixed_point int_green_y, png_fixed_point int_blue_x,
  1764.     png_fixed_point int_blue_y));
  1765. #endif
  1766.  
  1767. #ifdef PNG_gAMA_SUPPORTED
  1768. PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA,
  1769.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1770.     double *file_gamma));
  1771. PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
  1772.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1773.     png_fixed_point *int_file_gamma));
  1774. #endif
  1775.  
  1776. #ifdef PNG_gAMA_SUPPORTED
  1777. PNG_FP_EXPORT(139, void, png_set_gAMA, (png_structp png_ptr,
  1778.     png_infop info_ptr, double file_gamma));
  1779. PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr,
  1780.     png_infop info_ptr, png_fixed_point int_file_gamma));
  1781. #endif
  1782.  
  1783. #ifdef PNG_hIST_SUPPORTED
  1784. PNG_EXPORT(141, png_uint_32, png_get_hIST,
  1785.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1786.     png_uint_16p *hist));
  1787. #endif
  1788.  
  1789. #ifdef PNG_hIST_SUPPORTED
  1790. PNG_EXPORT(142, void, png_set_hIST, (png_structp png_ptr,
  1791.     png_infop info_ptr, png_const_uint_16p hist));
  1792. #endif
  1793.  
  1794. PNG_EXPORT(143, png_uint_32, png_get_IHDR,
  1795.     (png_structp png_ptr, png_infop info_ptr,
  1796.     png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type,
  1797.     int *interlace_method, int *compression_method, int *filter_method));
  1798.  
  1799. PNG_EXPORT(144, void, png_set_IHDR,
  1800.     (png_structp png_ptr, png_infop info_ptr,
  1801.     png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
  1802.     int interlace_method, int compression_method, int filter_method));
  1803.  
  1804. #ifdef PNG_oFFs_SUPPORTED
  1805. PNG_EXPORT(145, png_uint_32, png_get_oFFs,
  1806.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1807.     png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type));
  1808. #endif
  1809.  
  1810. #ifdef PNG_oFFs_SUPPORTED
  1811. PNG_EXPORT(146, void, png_set_oFFs,
  1812.     (png_structp png_ptr, png_infop info_ptr,
  1813.     png_int_32 offset_x, png_int_32 offset_y, int unit_type));
  1814. #endif
  1815.  
  1816. #ifdef PNG_pCAL_SUPPORTED
  1817. PNG_EXPORT(147, png_uint_32, png_get_pCAL,
  1818.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1819.     png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type,
  1820.     int *nparams,
  1821.     png_charp *units, png_charpp *params));
  1822. #endif
  1823.  
  1824. #ifdef PNG_pCAL_SUPPORTED
  1825. PNG_EXPORT(148, void, png_set_pCAL, (png_structp png_ptr,
  1826.     png_infop info_ptr,
  1827.     png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
  1828.     int nparams, png_const_charp units, png_charpp params));
  1829. #endif
  1830.  
  1831. #ifdef PNG_pHYs_SUPPORTED
  1832. PNG_EXPORT(149, png_uint_32, png_get_pHYs,
  1833.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1834.     png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
  1835. #endif
  1836.  
  1837. #ifdef PNG_pHYs_SUPPORTED
  1838. PNG_EXPORT(150, void, png_set_pHYs,
  1839.     (png_structp png_ptr, png_infop info_ptr,
  1840.     png_uint_32 res_x, png_uint_32 res_y, int unit_type));
  1841. #endif
  1842.  
  1843. PNG_EXPORT(151, png_uint_32, png_get_PLTE,
  1844.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1845.     png_colorp *palette, int *num_palette));
  1846.  
  1847. PNG_EXPORT(152, void, png_set_PLTE,
  1848.     (png_structp png_ptr, png_infop info_ptr,
  1849.     png_const_colorp palette, int num_palette));
  1850.  
  1851. #ifdef PNG_sBIT_SUPPORTED
  1852. PNG_EXPORT(153, png_uint_32, png_get_sBIT,
  1853.     (png_const_structp png_ptr, png_infop info_ptr,
  1854.     png_color_8p *sig_bit));
  1855. #endif
  1856.  
  1857. #ifdef PNG_sBIT_SUPPORTED
  1858. PNG_EXPORT(154, void, png_set_sBIT,
  1859.     (png_structp png_ptr, png_infop info_ptr, png_const_color_8p sig_bit));
  1860. #endif
  1861.  
  1862. #ifdef PNG_sRGB_SUPPORTED
  1863. PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structp png_ptr,
  1864.     png_const_infop info_ptr, int *file_srgb_intent));
  1865. #endif
  1866.  
  1867. #ifdef PNG_sRGB_SUPPORTED
  1868. PNG_EXPORT(156, void, png_set_sRGB,
  1869.     (png_structp png_ptr, png_infop info_ptr, int srgb_intent));
  1870. PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr,
  1871.     png_infop info_ptr, int srgb_intent));
  1872. #endif
  1873.  
  1874. #ifdef PNG_iCCP_SUPPORTED
  1875. PNG_EXPORT(158, png_uint_32, png_get_iCCP,
  1876.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1877.     png_charpp name, int *compression_type, png_bytepp profile,
  1878.     png_uint_32 *proflen));
  1879. #endif
  1880.  
  1881. #ifdef PNG_iCCP_SUPPORTED
  1882. PNG_EXPORT(159, void, png_set_iCCP,
  1883.     (png_structp png_ptr, png_infop info_ptr,
  1884.     png_const_charp name, int compression_type, png_const_bytep profile,
  1885.     png_uint_32 proflen));
  1886. #endif
  1887.  
  1888. #ifdef PNG_sPLT_SUPPORTED
  1889. PNG_EXPORT(160, png_uint_32, png_get_sPLT,
  1890.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1891.     png_sPLT_tpp entries));
  1892. #endif
  1893.  
  1894. #ifdef PNG_sPLT_SUPPORTED
  1895. PNG_EXPORT(161, void, png_set_sPLT,
  1896.     (png_structp png_ptr, png_infop info_ptr,
  1897.     png_const_sPLT_tp entries, int nentries));
  1898. #endif
  1899.  
  1900. #ifdef PNG_TEXT_SUPPORTED
  1901. /* png_get_text also returns the number of text chunks in *num_text */
  1902. PNG_EXPORT(162, png_uint_32, png_get_text,
  1903.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1904.     png_textp *text_ptr, int *num_text));
  1905. #endif
  1906.  
  1907. /* Note while png_set_text() will accept a structure whose text,
  1908.  * language, and  translated keywords are NULL pointers, the structure
  1909.  * returned by png_get_text will always contain regular
  1910.  * zero-terminated C strings.  They might be empty strings but
  1911.  * they will never be NULL pointers.
  1912.  */
  1913.  
  1914. #ifdef PNG_TEXT_SUPPORTED
  1915. PNG_EXPORT(163, void, png_set_text,
  1916.     (png_structp png_ptr, png_infop info_ptr,
  1917.     png_const_textp text_ptr, int num_text));
  1918. #endif
  1919.  
  1920. #ifdef PNG_tIME_SUPPORTED
  1921. PNG_EXPORT(164, png_uint_32, png_get_tIME,
  1922.     (png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time));
  1923. #endif
  1924.  
  1925. #ifdef PNG_tIME_SUPPORTED
  1926. PNG_EXPORT(165, void, png_set_tIME,
  1927.     (png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time));
  1928. #endif
  1929.  
  1930. #ifdef PNG_tRNS_SUPPORTED
  1931. PNG_EXPORT(166, png_uint_32, png_get_tRNS,
  1932.     (png_const_structp png_ptr, png_infop info_ptr,
  1933.     png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color));
  1934. #endif
  1935.  
  1936. #ifdef PNG_tRNS_SUPPORTED
  1937. PNG_EXPORT(167, void, png_set_tRNS,
  1938.     (png_structp png_ptr, png_infop info_ptr,
  1939.     png_const_bytep trans_alpha, int num_trans,
  1940.     png_const_color_16p trans_color));
  1941. #endif
  1942.  
  1943. #ifdef PNG_sCAL_SUPPORTED
  1944. PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL,
  1945.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1946.     int *unit, double *width, double *height));
  1947. #ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
  1948. /* NOTE: this API is currently implemented using floating point arithmetic,
  1949.  * consequently it can only be used on systems with floating point support.
  1950.  * In any case the range of values supported by png_fixed_point is small and it
  1951.  * is highly recommended that png_get_sCAL_s be used instead.
  1952.  */
  1953. PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
  1954.     (png_structp png_ptr, png_const_infop info_ptr, int *unit,
  1955.     png_fixed_point *width,
  1956.     png_fixed_point *height));
  1957. #endif
  1958. PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
  1959.     (png_const_structp png_ptr, png_const_infop info_ptr,
  1960.     int *unit, png_charpp swidth, png_charpp sheight));
  1961.  
  1962. PNG_FP_EXPORT(170, void, png_set_sCAL,
  1963.     (png_structp png_ptr, png_infop info_ptr,
  1964.     int unit, double width, double height));
  1965. PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr,
  1966.    png_infop info_ptr, int unit, png_fixed_point width,
  1967.    png_fixed_point height));
  1968. PNG_EXPORT(171, void, png_set_sCAL_s,
  1969.     (png_structp png_ptr, png_infop info_ptr,
  1970.     int unit, png_const_charp swidth, png_const_charp sheight));
  1971. #endif /* PNG_sCAL_SUPPORTED */
  1972.  
  1973. #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
  1974. /* Provide a list of chunks and how they are to be handled, if the built-in
  1975.    handling or default unknown chunk handling is not desired.  Any chunks not
  1976.    listed will be handled in the default manner.  The IHDR and IEND chunks
  1977.    must not be listed.
  1978.       keep = 0: follow default behaviour
  1979.            = 1: do not keep
  1980.            = 2: keep only if safe-to-copy
  1981.            = 3: keep even if unsafe-to-copy
  1982. */
  1983. PNG_EXPORT(172, void, png_set_keep_unknown_chunks,
  1984.     (png_structp png_ptr, int keep,
  1985.     png_const_bytep chunk_list, int num_chunks));
  1986. PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr,
  1987.     png_const_bytep chunk_name));
  1988. #endif
  1989. #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
  1990. PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr,
  1991.     png_infop info_ptr, png_const_unknown_chunkp unknowns,
  1992.     int num_unknowns));
  1993. PNG_EXPORT(175, void, png_set_unknown_chunk_location,
  1994.     (png_structp png_ptr, png_infop info_ptr, int chunk, int location));
  1995. PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr,
  1996.     png_const_infop info_ptr, png_unknown_chunkpp entries));
  1997. #endif
  1998.  
  1999. /* Png_free_data() will turn off the "valid" flag for anything it frees.
  2000.  * If you need to turn it off for a chunk that your application has freed,
  2001.  * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
  2002.  */
  2003. PNG_EXPORT(177, void, png_set_invalid,
  2004.     (png_structp png_ptr, png_infop info_ptr, int mask));
  2005.  
  2006. #ifdef PNG_INFO_IMAGE_SUPPORTED
  2007. /* The "params" pointer is currently not used and is for future expansion. */
  2008. PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr,
  2009.     int transforms, png_voidp params));
  2010. PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr,
  2011.     int transforms, png_voidp params));
  2012. #endif
  2013.  
  2014. PNG_EXPORT(180, png_const_charp, png_get_copyright,
  2015.     (png_const_structp png_ptr));
  2016. PNG_EXPORT(181, png_const_charp, png_get_header_ver,
  2017.     (png_const_structp png_ptr));
  2018. PNG_EXPORT(182, png_const_charp, png_get_header_version,
  2019.     (png_const_structp png_ptr));
  2020. PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
  2021.     (png_const_structp png_ptr));
  2022.  
  2023. #ifdef PNG_MNG_FEATURES_SUPPORTED
  2024. PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr,
  2025.     png_uint_32 mng_features_permitted));
  2026. #endif
  2027.  
  2028. /* For use in png_set_keep_unknown, added to version 1.2.6 */
  2029. #define PNG_HANDLE_CHUNK_AS_DEFAULT   0
  2030. #define PNG_HANDLE_CHUNK_NEVER        1
  2031. #define PNG_HANDLE_CHUNK_IF_SAFE      2
  2032. #define PNG_HANDLE_CHUNK_ALWAYS       3
  2033.  
  2034. /* Strip the prepended error numbers ("#nnn ") from error and warning
  2035.  * messages before passing them to the error or warning handler.
  2036.  */
  2037. #ifdef PNG_ERROR_NUMBERS_SUPPORTED
  2038. PNG_EXPORT(185, void, png_set_strip_error_numbers,
  2039.     (png_structp png_ptr,
  2040.     png_uint_32 strip_mode));
  2041. #endif
  2042.  
  2043. /* Added in libpng-1.2.6 */
  2044. #ifdef PNG_SET_USER_LIMITS_SUPPORTED
  2045. PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr,
  2046.     png_uint_32 user_width_max, png_uint_32 user_height_max));
  2047. PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
  2048.     (png_const_structp png_ptr));
  2049. PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
  2050.     (png_const_structp png_ptr));
  2051. /* Added in libpng-1.4.0 */
  2052. PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr,
  2053.     png_uint_32 user_chunk_cache_max));
  2054. PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
  2055.     (png_const_structp png_ptr));
  2056. /* Added in libpng-1.4.1 */
  2057. PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr,
  2058.     png_alloc_size_t user_chunk_cache_max));
  2059. PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
  2060.     (png_const_structp png_ptr));
  2061. #endif
  2062.  
  2063. #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
  2064. PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
  2065.     (png_const_structp png_ptr, png_const_infop info_ptr));
  2066.  
  2067. PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
  2068.     (png_const_structp png_ptr, png_const_infop info_ptr));
  2069.  
  2070. PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
  2071.     (png_const_structp png_ptr, png_const_infop info_ptr));
  2072.  
  2073. PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
  2074.     (png_const_structp png_ptr, png_const_infop info_ptr));
  2075. #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
  2076. PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
  2077.     (png_structp png_ptr, png_const_infop info_ptr));
  2078. #endif
  2079.  
  2080. PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr,
  2081.     png_const_infop info_ptr));
  2082. #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
  2083. PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
  2084.     (png_structp png_ptr, png_const_infop info_ptr));
  2085. #endif
  2086.  
  2087. #  ifdef PNG_pHYs_SUPPORTED
  2088. PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr,
  2089.     png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
  2090.     int *unit_type));
  2091. #  endif /* PNG_pHYs_SUPPORTED */
  2092. #endif  /* PNG_INCH_CONVERSIONS_SUPPORTED */
  2093.  
  2094. /* Added in libpng-1.4.0 */
  2095. #ifdef PNG_IO_STATE_SUPPORTED
  2096. PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_structp png_ptr));
  2097.  
  2098. PNG_EXPORTA(200, png_const_bytep, png_get_io_chunk_name,
  2099.     (png_structp png_ptr), PNG_DEPRECATED);
  2100. PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
  2101.     (png_const_structp png_ptr));
  2102.  
  2103. /* The flags returned by png_get_io_state() are the following: */
  2104. #  define PNG_IO_NONE        0x0000   /* no I/O at this moment */
  2105. #  define PNG_IO_READING     0x0001   /* currently reading */
  2106. #  define PNG_IO_WRITING     0x0002   /* currently writing */
  2107. #  define PNG_IO_SIGNATURE   0x0010   /* currently at the file signature */
  2108. #  define PNG_IO_CHUNK_HDR   0x0020   /* currently at the chunk header */
  2109. #  define PNG_IO_CHUNK_DATA  0x0040   /* currently at the chunk data */
  2110. #  define PNG_IO_CHUNK_CRC   0x0080   /* currently at the chunk crc */
  2111. #  define PNG_IO_MASK_OP     0x000f   /* current operation: reading/writing */
  2112. #  define PNG_IO_MASK_LOC    0x00f0   /* current location: sig/hdr/data/crc */
  2113. #endif /* ?PNG_IO_STATE_SUPPORTED */
  2114.  
  2115. /* Interlace support.  The following macros are always defined so that if
  2116.  * libpng interlace handling is turned off the macros may be used to handle
  2117.  * interlaced images within the application.
  2118.  */
  2119. #define PNG_INTERLACE_ADAM7_PASSES 7
  2120.  
  2121. /* Two macros to return the first row and first column of the original,
  2122.  * full, image which appears in a given pass.  'pass' is in the range 0
  2123.  * to 6 and the result is in the range 0 to 7.
  2124.  */
  2125. #define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7)
  2126. #define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7)
  2127.  
  2128. /* Two macros to help evaluate the number of rows or columns in each
  2129.  * pass.  This is expressed as a shift - effectively log2 of the number or
  2130.  * rows or columns in each 8x8 tile of the original image.
  2131.  */
  2132. #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
  2133. #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
  2134.  
  2135. /* Hence two macros to determine the number of rows or columns in a given
  2136.  * pass of an image given its height or width.  In fact these macros may
  2137.  * return non-zero even though the sub-image is empty, because the other
  2138.  * dimension may be empty for a small image.
  2139.  */
  2140. #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
  2141.    -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
  2142. #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
  2143.    -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
  2144.  
  2145. /* For the progressive reader it is necessary to find the row in the output
  2146.  * image given a row in an interlaced image, so two more macros:
  2147.  */
  2148. #define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
  2149.    (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
  2150. #define PNG_COL_FROM_PASS_COL(xIn, pass) \
  2151.    (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
  2152.  
  2153. /* Two macros which return a boolean (0 or 1) saying whether the given row
  2154.  * or column is in a particular pass.  These use a common utility macro that
  2155.  * returns a mask for a given pass - the offset 'off' selects the row or
  2156.  * column version.  The mask has the appropriate bit set for each column in
  2157.  * the tile.
  2158.  */
  2159. #define PNG_PASS_MASK(pass,off) ( \
  2160.    ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \
  2161.    ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U))
  2162.  
  2163. #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
  2164.    ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
  2165. #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
  2166.    ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
  2167.  
  2168. #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
  2169. /* With these routines we avoid an integer divide, which will be slower on
  2170.  * most machines.  However, it does take more operations than the corresponding
  2171.  * divide method, so it may be slower on a few RISC systems.  There are two
  2172.  * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
  2173.  *
  2174.  * Note that the rounding factors are NOT supposed to be the same!  128 and
  2175.  * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
  2176.  * standard method.
  2177.  *
  2178.  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
  2179.  */
  2180.  
  2181.  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
  2182.  
  2183. #  define png_composite(composite, fg, alpha, bg)         \
  2184.      { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
  2185.            * (png_uint_16)(alpha)                         \
  2186.            + (png_uint_16)(bg)*(png_uint_16)(255          \
  2187.            - (png_uint_16)(alpha)) + (png_uint_16)128);   \
  2188.        (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
  2189.  
  2190. #  define png_composite_16(composite, fg, alpha, bg)       \
  2191.      { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg)  \
  2192.            * (png_uint_32)(alpha)                          \
  2193.            + (png_uint_32)(bg)*(png_uint_32)(65535L        \
  2194.            - (png_uint_32)(alpha)) + (png_uint_32)32768L); \
  2195.        (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
  2196.  
  2197. #else  /* Standard method using integer division */
  2198.  
  2199. #  define png_composite(composite, fg, alpha, bg)                          \
  2200.      (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +  \
  2201.      (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
  2202.      (png_uint_16)127) / 255)
  2203.  
  2204. #  define png_composite_16(composite, fg, alpha, bg)                         \
  2205.      (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
  2206.      (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +        \
  2207.      (png_uint_32)32767) / (png_uint_32)65535L)
  2208. #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
  2209.  
  2210. #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
  2211. PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
  2212. PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
  2213. PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
  2214. #endif
  2215.  
  2216. PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr,
  2217.     png_const_bytep buf));
  2218. /* No png_get_int_16 -- may be added if there's a real need for it. */
  2219.  
  2220. /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
  2221. #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
  2222. PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
  2223. #endif
  2224. #ifdef PNG_SAVE_INT_32_SUPPORTED
  2225. PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
  2226. #endif
  2227.  
  2228. /* Place a 16-bit number into a buffer in PNG byte order.
  2229.  * The parameter is declared unsigned int, not png_uint_16,
  2230.  * just to avoid potential problems on pre-ANSI C compilers.
  2231.  */
  2232. #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
  2233. PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
  2234. /* No png_save_int_16 -- may be added if there's a real need for it. */
  2235. #endif
  2236.  
  2237. #ifdef PNG_USE_READ_MACROS
  2238. /* Inline macros to do direct reads of bytes from the input buffer.
  2239.  * The png_get_int_32() routine assumes we are using two's complement
  2240.  * format for negative values, which is almost certainly true.
  2241.  */
  2242. #  define png_get_uint_32(buf) \
  2243.      (((png_uint_32)(*(buf)) << 24) + \
  2244.       ((png_uint_32)(*((buf) + 1)) << 16) + \
  2245.       ((png_uint_32)(*((buf) + 2)) << 8) + \
  2246.       ((png_uint_32)(*((buf) + 3))))
  2247.  
  2248.    /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
  2249.     * function) incorrectly returned a value of type png_uint_32.
  2250.     */
  2251. #  define png_get_uint_16(buf) \
  2252.      ((png_uint_16) \
  2253.       (((unsigned int)(*(buf)) << 8) + \
  2254.        ((unsigned int)(*((buf) + 1)))))
  2255.  
  2256. #  define png_get_int_32(buf) \
  2257.      ((png_int_32)((*(buf) & 0x80) \
  2258.       ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
  2259.       : (png_int_32)png_get_uint_32(buf)))
  2260. #endif
  2261.  
  2262. /* Maintainer: Put new public prototypes here ^, in libpng.3, and project
  2263.  * defs
  2264.  */
  2265.  
  2266. /* The last ordinal number (this is the *last* one already used; the next
  2267.  * one to use is one more than this.)  Maintainer, remember to add an entry to
  2268.  * scripts/symbols.def as well.
  2269.  */
  2270. #ifdef PNG_EXPORT_LAST_ORDINAL
  2271.   PNG_EXPORT_LAST_ORDINAL(220);
  2272. #endif
  2273.  
  2274. #ifdef __cplusplus
  2275. }
  2276. #endif
  2277.  
  2278. #endif /* PNG_VERSION_INFO_ONLY */
  2279. /* Do not put anything past this line */
  2280. #endif /* PNG_H */
  2281.