/* png.h - header file for PNG reference library

 *

 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)

 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)

 *

 * This code is released under the libpng license (See LICENSE, below)

 *

 * Authors and maintainers:

 *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat

 *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger

 *  See also "Contributing Authors", below.

 *

 * Note about libpng version numbers:

 *

 *    Due to various miscommunications, unforeseen code incompatibilities

 *    and occasional factors outside the authors' control, version numbering

 *    on the library has not always been consistent and straightforward.

 *    The following table summarizes matters since version 0.89c, which was

 *    the first widely used release:

 *

 *    source                 png.h  png.h  shared-lib

 *    version                string   int  version

 *    -------                ------ -----  ----------

 *    0.89c "1.0 beta 3"     0.89      89  1.0.89

 *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]

 *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]

 *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]

 *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]

 *    0.97c                  0.97      97  2.0.97

 *    0.98                   0.98      98  2.0.98

 *    0.99                   0.99      98  2.0.99

 *    0.99a-m                0.99      99  2.0.99

 *    1.00                   1.00     100  2.1.0 [100 should be 10000]

 *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]

 *    1.0.1       png.h string is   10001  2.1.0

 *    1.0.1a-e    identical to the  10002  from here on, the shared library

 *    1.0.2       source version)   10002  is 2.V where V is the source code

 *    1.0.2a-b                      10003  version, except as noted.

 *    1.0.3                         10003

 *    1.0.3a-d                      10004

 *    1.0.4                         10004

 *    1.0.4a-f                      10005

 *    1.0.5 (+ 2 patches)           10005

 *    1.0.5a-d                      10006

 *    1.0.5e-r                      10100 (not source compatible)

 *    1.0.5s-v                      10006 (not binary compatible)

 *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)

 *    1.0.6d-f                      10007 (still binary incompatible)

 *    1.0.6g                        10007

 *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)

 *    1.0.6i                        10007  10.6i

 *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)

 *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)

 *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)

 *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)

 *    1.0.7                    1    10007  (still compatible)

 *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4

 *    1.0.8rc1                 1    10008  2.1.0.8rc1

 *    1.0.8                    1    10008  2.1.0.8

 *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6

 *    1.0.9rc1                 1    10009  2.1.0.9rc1

 *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10

 *    1.0.9rc2                 1    10009  2.1.0.9rc2

 *    1.0.9                    1    10009  2.1.0.9

 *    1.0.10beta1              1    10010  2.1.0.10beta1

 *    1.0.10rc1                1    10010  2.1.0.10rc1

 *    1.0.10                   1    10010  2.1.0.10

 *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3

 *    1.0.11rc1                1    10011  2.1.0.11rc1

 *    1.0.11                   1    10011  2.1.0.11

 *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2

 *    1.0.12rc1                2    10012  2.1.0.12rc1

 *    1.0.12                   2    10012  2.1.0.12

 *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)

 *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2

 *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5

 *    1.2.0rc1                 3    10200  3.1.2.0rc1

 *    1.2.0                    3    10200  3.1.2.0

 *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4

 *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2

 *    1.2.1                    3    10201  3.1.2.1

 *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6

 *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1

 *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1

 *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1

 *    1.0.13                  10    10013  10.so.0.1.0.13

 *    1.2.2                   12    10202  12.so.0.1.2.2

 *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6

 *    1.2.3                   12    10203  12.so.0.1.2.3

 *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3

 *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1

 *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1

 *    1.0.14                  10    10014  10.so.0.1.0.14

 *    1.2.4                   13    10204  12.so.0.1.2.4

 *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2

 *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3

 *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3

 *    1.0.15                  10    10015  10.so.0.1.0.15

 *    1.2.5                   13    10205  12.so.0.1.2.5

 *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4

 *    1.0.16                  10    10016  10.so.0.1.0.16

 *    1.2.6                   13    10206  12.so.0.1.2.6

 *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2

 *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1

 *    1.2.7                   13    10207  12.so.0.1.2.7

 *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5

 *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5

 *    1.2.8                   13    10208  12.so.0.1.2.8

 *    1.2.9beta1-3            13    10209  12.so.0.1.2.9beta1-3

 *    1.2.9beta4-11           13    10209  12.so.0.9[.0]

 *    1.2.9rc1                13    10209  12.so.0.9[.0]

 *    1.2.9                   13    10209  12.so.0.9[.0]

 *    1.2.10                  13    10210  12.so.0.10[.0]

 *    1.2.11beta1-4           13    10211  12.so.0.11[.0]

 *    1.2.11                  13    10211  12.so.0.11[.0]

 *    1.2.12                  13    10212  12.so.0.12[.0]

 *    1.2.13                  13    10213  12.so.0.13[.0]

 *

 *    Henceforth the source version will match the shared-library major

 *    and minor numbers; the shared-library major version number will be

 *    used for changes in backward compatibility, as it is intended.  The

 *    PNG_LIBPNG_VER macro, which is not used within libpng but is available

 *    for applications, is an unsigned integer of the form xyyzz corresponding

 *    to the source version x.y.z (leading zeros in y and z).  Beta versions

 *    were given the previous public release number plus a letter, until

 *    version 1.0.6j; from then on they were given the upcoming public

 *

 *    Binary incompatibility exists only when applications make direct access

 *    to the info_ptr or png_ptr members through png.h, and the compiled

 *    application is loaded with a different version of the library.

 *

 *    DLLNUM will change each time there are forward or backward changes

 *    in binary compatibility (e.g., when a new feature is added).

 *

 * See libpng.txt or libpng.3 for more information.  The PNG specification

 * is available as a W3C Recommendation and as an ISO Specification,

 * <http://www.w3.org/TR/2003/REC-PNG-20031110/

 */

/*

 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:

 *

 * If you modify libpng you may insert additional notices immediately following

 * this sentence.

 *

 * This code is released under the libpng license.

 *

 * distributed according to the same disclaimer and license as libpng-1.2.5

 * with the following individual added to the list of Contributing Authors:

 *

 *    Cosmin Truta

 *

 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are

 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are

 * distributed according to the same disclaimer and license as libpng-1.0.6

 * with the following individuals added to the list of Contributing Authors:

 *

 *    Simon-Pierre Cadieux

 *    Eric S. Raymond

 *    Gilles Vollant

 *

 * and with the following additions to the disclaimer:

 *

 *    There is no warranty against interference with your enjoyment of the

 *    library or against infringement.  There is no warranty that our

 *    efforts or the library will fulfill any of your particular purposes

 *    or needs.  This library is provided with all faults, and the entire

 *    risk of satisfactory quality, performance, accuracy, and effort is with

 *    the user.

 *

 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are

 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are

 * distributed according to the same disclaimer and license as libpng-0.96,

 * with the following individuals added to the list of Contributing Authors:

 *

 *    Tom Lane

 *    Glenn Randers-Pehrson

 *    Willem van Schaik

 *

 * libpng versions 0.89, June 1996, through 0.96, May 1997, are

 * Copyright (c) 1996, 1997 Andreas Dilger

 * Distributed according to the same disclaimer and license as libpng-0.88,

 * with the following individuals added to the list of Contributing Authors:

 *

 *    John Bowler

 *    Kevin Bracey

 *    Sam Bushell

 *    Magnus Holmgren

 *    Greg Roelofs

 *    Tom Tanner

 *

 * libpng versions 0.5, May 1995, through 0.88, January 1996, are

 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.

 *

 * For the purposes of this copyright and license, "Contributing Authors"

 * is defined as the following set of individuals:

 *

 *    Andreas Dilger

 *    Dave Martindale

 *    Guy Eric Schalnat

 *    Paul Schmidt

 *    Tim Wegner

 *

 * The PNG Reference Library is supplied "AS IS".  The Contributing Authors

 * and Group 42, Inc. disclaim all warranties, expressed or implied,

 * including, without limitation, the warranties of merchantability and of

 * fitness for any purpose.  The Contributing Authors and Group 42, Inc.

 * assume no liability for direct, indirect, incidental, special, exemplary,

 * or consequential damages, which may result from the use of the PNG

 * Reference Library, even if advised of the possibility of such damage.

 *

 * Permission is hereby granted to use, copy, modify, and distribute this

 * source code, or portions hereof, for any purpose, without fee, subject

 * to the following restrictions:

 *

 * 1. The origin of this source code must not be misrepresented.

 *

 * 2. Altered versions must be plainly marked as such and

 * must not be misrepresented as being the original source.

 *

 * 3. This Copyright notice may not be removed or altered from

 *    any source or altered source distribution.

 *

 * The Contributing Authors and Group 42, Inc. specifically permit, without

 * fee, and encourage the use of this source code as a component to

 * supporting the PNG file format in commercial products.  If you use this

 * source code in a product, acknowledgment is not required but would be

 * appreciated.

 */

/*

 * A "png_get_copyright" function is available, for convenient use in "about"

 * boxes and the like:

 *

 *

 * Also, the PNG logo (in PNG format, of course) is supplied in the

 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).

 */

/*

 * Libpng is OSI Certified Open Source Software.  OSI Certified is a

 * certification mark of the Open Source Initiative.

 */

/*

 * The contributing authors would like to thank all those who helped

 * with testing, bug fixes, and patience.  This wouldn't have been

 * possible without all of you.

 *

 * Thanks to Frank J. T. Wojcik for helping with the documentation.

 */

/*

 * Y2K compliance in libpng:

 * =========================

 *

 *

 *    Since the PNG Development group is an ad-hoc body, we can't make

 *    an official declaration.

 *

 *    This is your unofficial assurance that libpng from version 0.71 and

 *    versions were also Y2K compliant.

 *

 *    Libpng only has three year fields.  One is a 2-byte unsigned integer

 *    that will hold years up to 65535.  The other two hold the date in text

 *    format, and will hold years up to 9999.

 *

 *    The integer is

 *        "png_uint_16 year" in png_time_struct.

 *

 *    The strings are

 *        "png_charp time_buffer" in png_struct and

 *        "near_time_buffer", which is a local character string in png.c.

 *

 *    There are seven time-related functions:

 *        png.c: png_convert_to_rfc_1123() in png.c

 *          (formerly png_convert_to_rfc_1152() in error)

 *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c

 *        png_convert_from_time_t() in pngwrite.c

 *        png_get_tIME() in pngget.c

 *        png_handle_tIME() in pngrutil.c, called in pngread.c

 *        png_set_tIME() in pngset.c

 *        png_write_tIME() in pngwutil.c, called in pngwrite.c

 *

 *    All handle dates properly in a Y2K environment.  The

 *    png_convert_from_time_t() function calls gmtime() to convert from system

 *    clock time, which returns (year - 1900), which we properly convert to

 *    the full 4-digit year.  There is a possibility that applications using

 *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()

 *    function, or that they are incorrectly passing only a 2-digit year

 *    instead of "year - 1900" into the png_convert_from_struct_tm() function,

 *    but this is not under our control.  The libpng documentation has always

 *    stated that it works with 4-digit years, and the APIs have been

 *    documented as such.

 *

 *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned

 *    integer to hold the year, and can hold years as large as 65535.

 *

 *    zlib, upon which libpng depends, is also Y2K compliant.  It contains

 *    no date-related code.

 *

 *       Glenn Randers-Pehrson

 *       libpng maintainer

 *       PNG Development Group

 */

#ifndef PNG_H

#define PNG_H

/* This is not the place to learn how to use libpng.  The file libpng.txt

 * describes how to use libpng, and the file example.c summarizes it

 * with some code on which to build.  This file is useful for looking

 * at the actual function definitions and structure components.

 */

/* Version information for png.h - this should match the version in png.c */

#define PNG_HEADER_VERSION_STRING \

/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */

#define PNG_LIBPNG_VER_MAJOR   1

/* This should match the numeric part of the final component of

 * PNG_LIBPNG_VER_STRING, omitting any leading zero:

 */

#define PNG_LIBPNG_VER_BUILD  0

/* Release Status */

#define PNG_LIBPNG_BUILD_ALPHA    1

#define PNG_LIBPNG_BUILD_BETA     2

#define PNG_LIBPNG_BUILD_RC       3

#define PNG_LIBPNG_BUILD_STABLE   4

#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7

/* Release-Specific Flags */

#define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with

                                       PNG_LIBPNG_BUILD_STABLE only */

#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with

                                       PNG_LIBPNG_BUILD_SPECIAL */

#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with

                                       PNG_LIBPNG_BUILD_PRIVATE */

/* Careful here.  At one time, Guy wanted to use 082, but that would be octal.

 * We must not include leading zeros.

 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only

 * version 1.0.0 was mis-numbered 100 instead of 10000).  From

 * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release

 */

#ifndef PNG_VERSION_INFO_ONLY

/* Include the compression library's header */

#include "zlib.h"

#endif

/* Include all user configurable info, including optional assembler routines */

#include "pngconf.h"

/*

 * VS_FF_PRIVATEBUILD File *was not* built using standard release

 * procedures. If this value is given, the StringFileInfo block must

 * contain a PrivateBuild string.

 *

 * VS_FF_SPECIALBUILD File *was* built by the original company using

 * standard release procedures but is a variation of the standard

 * file of the same version number. If this value is given, the

 * StringFileInfo block must contain a SpecialBuild string.

 */

#  define PNG_LIBPNG_BUILD_TYPE \

          (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)

#else

#    define PNG_LIBPNG_BUILD_TYPE \

            (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)

#  else

#    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)

#  endif

#endif

#ifndef PNG_VERSION_INFO_ONLY

/* Inhibit C++ name-mangling for libpng functions but not for system calls. */

#ifdef __cplusplus

extern "C" {

#endif /* __cplusplus */

/* This file is arranged in several sections.  The first section contains

 * structure and type definitions.  The second section contains the external

 * library functions, while the third has the internal library functions,

 * which applications aren't expected to use directly.

 */

/* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */

#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)

/* Version information for C files, stored in png.c.  This had better match

 * the version above.

 */

#define png_libpng_ver png_get_header_ver(NULL)

#endif /* PNG_NO_EXTERN */

/* Three color definitions.  The order of the red, green, and blue, (and the

 * exact size) is not important, although the size of the fields need to

 * be png_byte or png_uint_16 (as defined below).

 */

typedef struct png_color_struct

{

   png_byte red;

   png_byte green;

   png_byte blue;

} png_color;

typedef png_color FAR * png_colorp;

typedef png_color FAR * FAR * png_colorpp;

typedef struct png_color_16_struct

{

   png_byte index;    /* used for palette files */

   png_uint_16 red;   /* for use in red green blue files */

   png_uint_16 green;

   png_uint_16 blue;

   png_uint_16 gray;  /* for use in grayscale files */

} png_color_16;

typedef png_color_16 FAR * png_color_16p;

typedef png_color_16 FAR * FAR * png_color_16pp;

typedef struct png_color_8_struct

{

   png_byte red;   /* for use in red green blue files */

   png_byte green;

   png_byte blue;

   png_byte gray;  /* for use in grayscale files */

   png_byte alpha; /* for alpha channel files */

} png_color_8;

typedef png_color_8 FAR * png_color_8p;

typedef png_color_8 FAR * FAR * png_color_8pp;

/*

 * The following two structures are used for the in-core representation

 * of sPLT chunks.

 */

typedef struct png_sPLT_entry_struct

{

   png_uint_16 red;

   png_uint_16 green;

   png_uint_16 blue;

   png_uint_16 alpha;

   png_uint_16 frequency;

} png_sPLT_entry;

typedef png_sPLT_entry FAR * png_sPLT_entryp;

typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;

/*  When the depth of the sPLT palette is 8 bits, the color and alpha samples

 *  occupy the LSB of their respective members, and the MSB of each member

 *  is zero-filled.  The frequency member always occupies the full 16 bits.

 */

typedef struct png_sPLT_struct

{

   png_charp name;           /* palette name */

   png_byte depth;           /* depth of palette samples */

   png_sPLT_entryp entries;  /* palette entries */

   png_int_32 nentries;      /* number of palette entries */

} png_sPLT_t;

typedef png_sPLT_t FAR * png_sPLT_tp;

typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;

#ifdef PNG_TEXT_SUPPORTED

/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,

 * and whether that contents is compressed or not.  The "key" field

 * points to a regular zero-terminated C string.  The "text", "lang", and

 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.

 * However, the * structure returned by png_get_text() will always contain

 * regular zero-terminated C strings (possibly empty), never NULL pointers,

 * so they can be safely used in printf() and other string-handling functions.

 */

typedef struct png_text_struct

{

   int  compression;       /* compression value:

                             -1: tEXt, none

                              0: zTXt, deflate