/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

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

 *

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file and, per its terms, should not be removed:

 *

 *

 * (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 0.89, June 1996, through 0.96, May 1997: Andreas Dilger

 *     Glenn Randers-Pehrson.

 *   See also "Contributing Authors", below.

 */

/*

 * 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.

 *

 * derived from libpng-1.0.6, 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

 *    Mans Rullgard

 *    Cosmin Truta

 *    Gilles Vollant

 *    James Yu

 *

 * 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) 1998-2000 Glenn Randers-Pehrson, are derived from

 * libpng-0.96, 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, are derived from libpng-0.88,

 * and are 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.

 *

 * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.

 */

/*

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

 * boxes and the like:

 *

 *    printf("%s", png_get_copyright(NULL));

 *

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

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

 */

/*

 * 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.

 */

/* 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)

 *    ...

 *    1.0.19                  10    10019  10.so.0.19[.0]

 *    ...

 *    ...

 *    ...

 *

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

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

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

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

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

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

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

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

 *    release number plus "betaNN" or "rcNN".

 *

 *    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/

 */

/*

 * 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

 *    earlier versions were also Y2K compliant.

 *

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

 *    that will hold years up to 65535.  The other, which is deprecated,

 *    holds the date in text format, and will hold years up to 9999.

 *

 *    The integer is

 *        "png_uint_16 year" in png_time_struct.

 *

 *    The string is

 *        "char time_buffer[29]" in png_struct.  This is no longer used

 *    in libpng-1.6.x and will be removed from libpng-1.7.0.

 *

 *    There are seven time-related functions:

 *        png.c: png_convert_to_rfc_1123_buffer() in png.c

 *          (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and

 *          png_convert_to_rfc_1152() in error prior to libpng-0.98)

 *        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 libpng applications

 *    are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()

 *    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-manual.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.  If that

 * file has been stripped from your copy of libpng, you can find it at

 * <http://www.libpng.org/pub/png/libpng-manual.txt>

 *

 * If you just need to read a PNG file and don't want to read the documentation

 * skip to the end of this file and read the section entitled 'simplified API'.

 */

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

#define PNG_HEADER_VERSION_STRING \

#define PNG_LIBPNG_VER_SONUM   16

#define PNG_LIBPNG_VER_DLLNUM  16

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

#define PNG_LIBPNG_VER_MAJOR   1

#define PNG_LIBPNG_VER_MINOR   6

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

 * PNG_LIBPNG_VER_STRING, omitting any leading zero:

 */

#define PNG_LIBPNG_VER_BUILD  0

/* Release Status */

#define PNG_LIBPNG_BUILD_ALPHA    1

#define PNG_LIBPNG_BUILD_BETA     2

#define PNG_LIBPNG_BUILD_RC       3

#define PNG_LIBPNG_BUILD_STABLE   4

#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7

/* Release-Specific Flags */

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

                                       PNG_LIBPNG_BUILD_STABLE only */

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

                                       PNG_LIBPNG_BUILD_SPECIAL */

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

                                       PNG_LIBPNG_BUILD_PRIVATE */

#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE

/* 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

 */

/* Library configuration: these options cannot be changed after

 * the library has been built.

 */

#ifndef PNGLCONF_H

    /* If pnglibconf.h is missing, you can

     * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h

     */

#   include "pnglibconf.h"

#endif

#ifndef PNG_VERSION_INFO_ONLY

   /* Machine specific configuration. */

#  include "pngconf.h"

#endif

/*

 * Added at libpng-1.2.8

 *

 * Ref MSDN: Private as priority over Special

 * VS_FF_PRIVATEBUILD File *was not* built using standard release

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

 * contain a PrivateBuild string.

 *

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

 * standard release procedures but is a variation of the standard

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

 * StringFileInfo block must contain a SpecialBuild string.

 */

#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */

#  define PNG_LIBPNG_BUILD_TYPE \

       (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)

#else

#  ifdef PNG_LIBPNG_SPECIALBUILD

#    define PNG_LIBPNG_BUILD_TYPE \

         (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)

#  else

#    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)

#  endif

#endif

#ifndef PNG_VERSION_INFO_ONLY

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

#ifdef __cplusplus

extern "C" {

#endif /* __cplusplus */

/* 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)

/* This file is arranged in several sections:

 *

 * 1. [omitted]

 * 2. Any configuration options that can be specified by for the application

 *    code when it is built.  (Build time configuration is in pnglibconf.h)

 * 3. Type definitions (base types are defined in pngconf.h), structure

 *    definitions.

 * 4. Exported library functions.

 * 5. Simplified API.

 * 6. Implementation options.

 *

 * The library source code has additional files (principally pngpriv.h) that

 * allow configuration of the library.

 */

/* Section 1: [omitted] */

/* Section 2: run time configuration

 * See pnglibconf.h for build time configuration

 *

 * Run time configuration allows the application to choose between

 * implementations of certain arithmetic APIs.  The default is set

 * at build time and recorded in pnglibconf.h, but it is safe to

 * override these (and only these) settings.  Note that this won't

 * change what the library does, only application code, and the

 * settings can (and probably should) be made on a per-file basis

 * by setting the #defines before including png.h

 *

 * Use macros to read integers from PNG data or use the exported

 * functions?

 *   PNG_USE_READ_MACROS: use the macros (see below)  Note that

 *     the macros evaluate their argument multiple times.

 *   PNG_NO_USE_READ_MACROS: call the relevant library function.

 *

 * Use the alternative algorithm for compositing alpha samples that

 * does not use division?

 *   PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'

 *      algorithm.

 *   PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.

 *

 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is

 * false?

 *   PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error

 *      APIs to png_warning.

 * Otherwise the calls are mapped to png_error.

 */

/* Section 3: type definitions, including structures and compile time

 * constants.

 * See pngconf.h for base types that vary by machine/system

 */

/* This triggers a compiler error in png.c, if png.c and png.h

 * do not agree upon the version number.

 */

/* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.

 *

 * png_struct is the cache of information used while reading or writing a single

 * PNG file.  One of these is always required, although the simplified API