jpayne@69:
jpayne@69: /* png.h - header file for PNG reference library
jpayne@69: *
jpayne@69: * libpng version 1.6.43
jpayne@69: *
jpayne@69: * Copyright (c) 2018-2024 Cosmin Truta
jpayne@69: * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
jpayne@69: * Copyright (c) 1996-1997 Andreas Dilger
jpayne@69: * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
jpayne@69: *
jpayne@69: * This code is released under the libpng license. (See LICENSE, below.)
jpayne@69: *
jpayne@69: * Authors and maintainers:
jpayne@69: * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
jpayne@69: * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
jpayne@69: * libpng versions 0.97, January 1998, through 1.6.35, July 2018:
jpayne@69: * Glenn Randers-Pehrson
jpayne@69: * libpng versions 1.6.36, December 2018, through 1.6.43, February 2024:
jpayne@69: * Cosmin Truta
jpayne@69: * See also "Contributing Authors", below.
jpayne@69: */
jpayne@69:
jpayne@69: /*
jpayne@69: * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
jpayne@69: * =========================================
jpayne@69: *
jpayne@69: * PNG Reference Library License version 2
jpayne@69: * ---------------------------------------
jpayne@69: *
jpayne@69: * * Copyright (c) 1995-2024 The PNG Reference Library Authors.
jpayne@69: * * Copyright (c) 2018-2024 Cosmin Truta.
jpayne@69: * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
jpayne@69: * * Copyright (c) 1996-1997 Andreas Dilger.
jpayne@69: * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
jpayne@69: *
jpayne@69: * The software is supplied "as is", without warranty of any kind,
jpayne@69: * express or implied, including, without limitation, the warranties
jpayne@69: * of merchantability, fitness for a particular purpose, title, and
jpayne@69: * non-infringement. In no event shall the Copyright owners, or
jpayne@69: * anyone distributing the software, be liable for any damages or
jpayne@69: * other liability, whether in contract, tort or otherwise, arising
jpayne@69: * from, out of, or in connection with the software, or the use or
jpayne@69: * other dealings in the software, even if advised of the possibility
jpayne@69: * of such damage.
jpayne@69: *
jpayne@69: * Permission is hereby granted to use, copy, modify, and distribute
jpayne@69: * this software, or portions hereof, for any purpose, without fee,
jpayne@69: * subject to the following restrictions:
jpayne@69: *
jpayne@69: * 1. The origin of this software must not be misrepresented; you
jpayne@69: * must not claim that you wrote the original software. If you
jpayne@69: * use this software in a product, an acknowledgment in the product
jpayne@69: * documentation would be appreciated, but is not required.
jpayne@69: *
jpayne@69: * 2. Altered source versions must be plainly marked as such, and must
jpayne@69: * not be misrepresented as being the original software.
jpayne@69: *
jpayne@69: * 3. This Copyright notice may not be removed or altered from any
jpayne@69: * source or altered source distribution.
jpayne@69: *
jpayne@69: *
jpayne@69: * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
jpayne@69: * -----------------------------------------------------------------------
jpayne@69: *
jpayne@69: * libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are
jpayne@69: * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
jpayne@69: * derived from libpng-1.0.6, and are distributed according to the same
jpayne@69: * disclaimer and license as libpng-1.0.6 with the following individuals
jpayne@69: * added to the list of Contributing Authors:
jpayne@69: *
jpayne@69: * Simon-Pierre Cadieux
jpayne@69: * Eric S. Raymond
jpayne@69: * Mans Rullgard
jpayne@69: * Cosmin Truta
jpayne@69: * Gilles Vollant
jpayne@69: * James Yu
jpayne@69: * Mandar Sahastrabuddhe
jpayne@69: * Google Inc.
jpayne@69: * Vadim Barkov
jpayne@69: *
jpayne@69: * and with the following additions to the disclaimer:
jpayne@69: *
jpayne@69: * There is no warranty against interference with your enjoyment of
jpayne@69: * the library or against infringement. There is no warranty that our
jpayne@69: * efforts or the library will fulfill any of your particular purposes
jpayne@69: * or needs. This library is provided with all faults, and the entire
jpayne@69: * risk of satisfactory quality, performance, accuracy, and effort is
jpayne@69: * with the user.
jpayne@69: *
jpayne@69: * Some files in the "contrib" directory and some configure-generated
jpayne@69: * files that are distributed with libpng have other copyright owners, and
jpayne@69: * are released under other open source licenses.
jpayne@69: *
jpayne@69: * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
jpayne@69: * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
jpayne@69: * libpng-0.96, and are distributed according to the same disclaimer and
jpayne@69: * license as libpng-0.96, with the following individuals added to the
jpayne@69: * list of Contributing Authors:
jpayne@69: *
jpayne@69: * Tom Lane
jpayne@69: * Glenn Randers-Pehrson
jpayne@69: * Willem van Schaik
jpayne@69: *
jpayne@69: * libpng versions 0.89, June 1996, through 0.96, May 1997, are
jpayne@69: * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
jpayne@69: * and are distributed according to the same disclaimer and license as
jpayne@69: * libpng-0.88, with the following individuals added to the list of
jpayne@69: * Contributing Authors:
jpayne@69: *
jpayne@69: * John Bowler
jpayne@69: * Kevin Bracey
jpayne@69: * Sam Bushell
jpayne@69: * Magnus Holmgren
jpayne@69: * Greg Roelofs
jpayne@69: * Tom Tanner
jpayne@69: *
jpayne@69: * Some files in the "scripts" directory have other copyright owners,
jpayne@69: * but are released under this license.
jpayne@69: *
jpayne@69: * libpng versions 0.5, May 1995, through 0.88, January 1996, are
jpayne@69: * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
jpayne@69: *
jpayne@69: * For the purposes of this copyright and license, "Contributing Authors"
jpayne@69: * is defined as the following set of individuals:
jpayne@69: *
jpayne@69: * Andreas Dilger
jpayne@69: * Dave Martindale
jpayne@69: * Guy Eric Schalnat
jpayne@69: * Paul Schmidt
jpayne@69: * Tim Wegner
jpayne@69: *
jpayne@69: * The PNG Reference Library is supplied "AS IS". The Contributing
jpayne@69: * Authors and Group 42, Inc. disclaim all warranties, expressed or
jpayne@69: * implied, including, without limitation, the warranties of
jpayne@69: * merchantability and of fitness for any purpose. The Contributing
jpayne@69: * Authors and Group 42, Inc. assume no liability for direct, indirect,
jpayne@69: * incidental, special, exemplary, or consequential damages, which may
jpayne@69: * result from the use of the PNG Reference Library, even if advised of
jpayne@69: * the possibility of such damage.
jpayne@69: *
jpayne@69: * Permission is hereby granted to use, copy, modify, and distribute this
jpayne@69: * source code, or portions hereof, for any purpose, without fee, subject
jpayne@69: * to the following restrictions:
jpayne@69: *
jpayne@69: * 1. The origin of this source code must not be misrepresented.
jpayne@69: *
jpayne@69: * 2. Altered versions must be plainly marked as such and must not
jpayne@69: * be misrepresented as being the original source.
jpayne@69: *
jpayne@69: * 3. This Copyright notice may not be removed or altered from any
jpayne@69: * source or altered source distribution.
jpayne@69: *
jpayne@69: * The Contributing Authors and Group 42, Inc. specifically permit,
jpayne@69: * without fee, and encourage the use of this source code as a component
jpayne@69: * to supporting the PNG file format in commercial products. If you use
jpayne@69: * this source code in a product, acknowledgment is not required but would
jpayne@69: * be appreciated.
jpayne@69: *
jpayne@69: * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
jpayne@69: *
jpayne@69: * TRADEMARK
jpayne@69: * =========
jpayne@69: *
jpayne@69: * The name "libpng" has not been registered by the Copyright owners
jpayne@69: * as a trademark in any jurisdiction. However, because libpng has
jpayne@69: * been distributed and maintained world-wide, continually since 1995,
jpayne@69: * the Copyright owners claim "common-law trademark protection" in any
jpayne@69: * jurisdiction where common-law trademark is recognized.
jpayne@69: */
jpayne@69:
jpayne@69: /*
jpayne@69: * A "png_get_copyright" function is available, for convenient use in "about"
jpayne@69: * boxes and the like:
jpayne@69: *
jpayne@69: * printf("%s", png_get_copyright(NULL));
jpayne@69: *
jpayne@69: * Also, the PNG logo (in PNG format, of course) is supplied in the
jpayne@69: * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
jpayne@69: */
jpayne@69:
jpayne@69: /*
jpayne@69: * The contributing authors would like to thank all those who helped
jpayne@69: * with testing, bug fixes, and patience. This wouldn't have been
jpayne@69: * possible without all of you.
jpayne@69: *
jpayne@69: * Thanks to Frank J. T. Wojcik for helping with the documentation.
jpayne@69: */
jpayne@69:
jpayne@69: /* Note about libpng version numbers:
jpayne@69: *
jpayne@69: * Due to various miscommunications, unforeseen code incompatibilities
jpayne@69: * and occasional factors outside the authors' control, version numbering
jpayne@69: * on the library has not always been consistent and straightforward.
jpayne@69: * The following table summarizes matters since version 0.89c, which was
jpayne@69: * the first widely used release:
jpayne@69: *
jpayne@69: * source png.h png.h shared-lib
jpayne@69: * version string int version
jpayne@69: * ------- ------ ----- ----------
jpayne@69: * 0.89c "1.0 beta 3" 0.89 89 1.0.89
jpayne@69: * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
jpayne@69: * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
jpayne@69: * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
jpayne@69: * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
jpayne@69: * 0.97c 0.97 97 2.0.97
jpayne@69: * 0.98 0.98 98 2.0.98
jpayne@69: * 0.99 0.99 98 2.0.99
jpayne@69: * 0.99a-m 0.99 99 2.0.99
jpayne@69: * 1.00 1.00 100 2.1.0 [100 should be 10000]
jpayne@69: * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
jpayne@69: * 1.0.1 png.h string is 10001 2.1.0
jpayne@69: * 1.0.1a-e identical to the 10002 from here on, the shared library
jpayne@69: * 1.0.2 source version) 10002 is 2.V where V is the source code
jpayne@69: * 1.0.2a-b 10003 version, except as noted.
jpayne@69: * 1.0.3 10003
jpayne@69: * 1.0.3a-d 10004
jpayne@69: * 1.0.4 10004
jpayne@69: * 1.0.4a-f 10005
jpayne@69: * 1.0.5 (+ 2 patches) 10005
jpayne@69: * 1.0.5a-d 10006
jpayne@69: * 1.0.5e-r 10100 (not source compatible)
jpayne@69: * 1.0.5s-v 10006 (not binary compatible)
jpayne@69: * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
jpayne@69: * 1.0.6d-f 10007 (still binary incompatible)
jpayne@69: * 1.0.6g 10007
jpayne@69: * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
jpayne@69: * 1.0.6i 10007 10.6i
jpayne@69: * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
jpayne@69: * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
jpayne@69: * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
jpayne@69: * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
jpayne@69: * 1.0.7 1 10007 (still compatible)
jpayne@69: * ...
jpayne@69: * 1.0.69 10 10069 10.so.0.69[.0]
jpayne@69: * ...
jpayne@69: * 1.2.59 13 10259 12.so.0.59[.0]
jpayne@69: * ...
jpayne@69: * 1.4.20 14 10420 14.so.0.20[.0]
jpayne@69: * ...
jpayne@69: * 1.5.30 15 10530 15.so.15.30[.0]
jpayne@69: * ...
jpayne@69: * 1.6.43 16 10643 16.so.16.43[.0]
jpayne@69: *
jpayne@69: * Henceforth the source version will match the shared-library major and
jpayne@69: * minor numbers; the shared-library major version number will be used for
jpayne@69: * changes in backward compatibility, as it is intended.
jpayne@69: * The PNG_LIBPNG_VER macro, which is not used within libpng but is
jpayne@69: * available for applications, is an unsigned integer of the form XYYZZ
jpayne@69: * corresponding to the source version X.Y.Z (leading zeros in Y and Z).
jpayne@69: * Beta versions were given the previous public release number plus a
jpayne@69: * letter, until version 1.0.6j; from then on they were given the upcoming
jpayne@69: * public release number plus "betaNN" or "rcNN".
jpayne@69: *
jpayne@69: * Binary incompatibility exists only when applications make direct access
jpayne@69: * to the info_ptr or png_ptr members through png.h, and the compiled
jpayne@69: * application is loaded with a different version of the library.
jpayne@69: *
jpayne@69: * See libpng.txt or libpng.3 for more information. The PNG specification
jpayne@69: * is available as a W3C Recommendation and as an ISO/IEC Standard; see
jpayne@69: *
jpayne@69: */
jpayne@69:
jpayne@69: #ifndef PNG_H
jpayne@69: #define PNG_H
jpayne@69:
jpayne@69: /* This is not the place to learn how to use libpng. The file libpng-manual.txt
jpayne@69: * describes how to use libpng, and the file example.c summarizes it
jpayne@69: * with some code on which to build. This file is useful for looking
jpayne@69: * at the actual function definitions and structure components. If that
jpayne@69: * file has been stripped from your copy of libpng, you can find it at
jpayne@69: *
jpayne@69: *
jpayne@69: * If you just need to read a PNG file and don't want to read the documentation
jpayne@69: * skip to the end of this file and read the section entitled 'simplified API'.
jpayne@69: */
jpayne@69:
jpayne@69: /* Version information for png.h - this should match the version in png.c */
jpayne@69: #define PNG_LIBPNG_VER_STRING "1.6.43"
jpayne@69: #define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n"
jpayne@69:
jpayne@69: /* The versions of shared library builds should stay in sync, going forward */
jpayne@69: #define PNG_LIBPNG_VER_SHAREDLIB 16
jpayne@69: #define PNG_LIBPNG_VER_SONUM PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */
jpayne@69: #define PNG_LIBPNG_VER_DLLNUM PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */
jpayne@69:
jpayne@69: /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
jpayne@69: #define PNG_LIBPNG_VER_MAJOR 1
jpayne@69: #define PNG_LIBPNG_VER_MINOR 6
jpayne@69: #define PNG_LIBPNG_VER_RELEASE 43
jpayne@69:
jpayne@69: /* This should be zero for a public release, or non-zero for a
jpayne@69: * development version.
jpayne@69: */
jpayne@69: #define PNG_LIBPNG_VER_BUILD 0
jpayne@69:
jpayne@69: /* Release Status */
jpayne@69: #define PNG_LIBPNG_BUILD_ALPHA 1
jpayne@69: #define PNG_LIBPNG_BUILD_BETA 2
jpayne@69: #define PNG_LIBPNG_BUILD_RC 3
jpayne@69: #define PNG_LIBPNG_BUILD_STABLE 4
jpayne@69: #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
jpayne@69:
jpayne@69: /* Release-Specific Flags */
jpayne@69: #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
jpayne@69: PNG_LIBPNG_BUILD_STABLE only */
jpayne@69: #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
jpayne@69: PNG_LIBPNG_BUILD_SPECIAL */
jpayne@69: #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
jpayne@69: PNG_LIBPNG_BUILD_PRIVATE */
jpayne@69:
jpayne@69: #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
jpayne@69:
jpayne@69: /* Careful here. At one time, Guy wanted to use 082, but that
jpayne@69: * would be octal. We must not include leading zeros.
jpayne@69: * Versions 0.7 through 1.0.0 were in the range 0 to 100 here
jpayne@69: * (only version 1.0.0 was mis-numbered 100 instead of 10000).
jpayne@69: * From version 1.0.1 it is:
jpayne@69: * XXYYZZ, where XX=major, YY=minor, ZZ=release
jpayne@69: */
jpayne@69: #define PNG_LIBPNG_VER 10643 /* 1.6.43 */
jpayne@69:
jpayne@69: /* Library configuration: these options cannot be changed after
jpayne@69: * the library has been built.
jpayne@69: */
jpayne@69: #ifndef PNGLCONF_H
jpayne@69: /* If pnglibconf.h is missing, you can
jpayne@69: * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
jpayne@69: */
jpayne@69: # include "pnglibconf.h"
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifndef PNG_VERSION_INFO_ONLY
jpayne@69: /* Machine specific configuration. */
jpayne@69: # include "pngconf.h"
jpayne@69: #endif
jpayne@69:
jpayne@69: /*
jpayne@69: * Added at libpng-1.2.8
jpayne@69: *
jpayne@69: * Ref MSDN: Private as priority over Special
jpayne@69: * VS_FF_PRIVATEBUILD File *was not* built using standard release
jpayne@69: * procedures. If this value is given, the StringFileInfo block must
jpayne@69: * contain a PrivateBuild string.
jpayne@69: *
jpayne@69: * VS_FF_SPECIALBUILD File *was* built by the original company using
jpayne@69: * standard release procedures but is a variation of the standard
jpayne@69: * file of the same version number. If this value is given, the
jpayne@69: * StringFileInfo block must contain a SpecialBuild string.
jpayne@69: */
jpayne@69:
jpayne@69: #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
jpayne@69: # define PNG_LIBPNG_BUILD_TYPE \
jpayne@69: (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
jpayne@69: #else
jpayne@69: # ifdef PNG_LIBPNG_SPECIALBUILD
jpayne@69: # define PNG_LIBPNG_BUILD_TYPE \
jpayne@69: (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
jpayne@69: # else
jpayne@69: # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
jpayne@69: # endif
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifndef PNG_VERSION_INFO_ONLY
jpayne@69:
jpayne@69: /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
jpayne@69: #ifdef __cplusplus
jpayne@69: extern "C" {
jpayne@69: #endif /* __cplusplus */
jpayne@69:
jpayne@69: /* Version information for C files, stored in png.c. This had better match
jpayne@69: * the version above.
jpayne@69: */
jpayne@69: #define png_libpng_ver png_get_header_ver(NULL)
jpayne@69:
jpayne@69: /* This file is arranged in several sections:
jpayne@69: *
jpayne@69: * 1. [omitted]
jpayne@69: * 2. Any configuration options that can be specified by for the application
jpayne@69: * code when it is built. (Build time configuration is in pnglibconf.h)
jpayne@69: * 3. Type definitions (base types are defined in pngconf.h), structure
jpayne@69: * definitions.
jpayne@69: * 4. Exported library functions.
jpayne@69: * 5. Simplified API.
jpayne@69: * 6. Implementation options.
jpayne@69: *
jpayne@69: * The library source code has additional files (principally pngpriv.h) that
jpayne@69: * allow configuration of the library.
jpayne@69: */
jpayne@69:
jpayne@69: /* Section 1: [omitted] */
jpayne@69:
jpayne@69: /* Section 2: run time configuration
jpayne@69: * See pnglibconf.h for build time configuration
jpayne@69: *
jpayne@69: * Run time configuration allows the application to choose between
jpayne@69: * implementations of certain arithmetic APIs. The default is set
jpayne@69: * at build time and recorded in pnglibconf.h, but it is safe to
jpayne@69: * override these (and only these) settings. Note that this won't
jpayne@69: * change what the library does, only application code, and the
jpayne@69: * settings can (and probably should) be made on a per-file basis
jpayne@69: * by setting the #defines before including png.h
jpayne@69: *
jpayne@69: * Use macros to read integers from PNG data or use the exported
jpayne@69: * functions?
jpayne@69: * PNG_USE_READ_MACROS: use the macros (see below) Note that
jpayne@69: * the macros evaluate their argument multiple times.
jpayne@69: * PNG_NO_USE_READ_MACROS: call the relevant library function.
jpayne@69: *
jpayne@69: * Use the alternative algorithm for compositing alpha samples that
jpayne@69: * does not use division?
jpayne@69: * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
jpayne@69: * algorithm.
jpayne@69: * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
jpayne@69: *
jpayne@69: * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
jpayne@69: * false?
jpayne@69: * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
jpayne@69: * APIs to png_warning.
jpayne@69: * Otherwise the calls are mapped to png_error.
jpayne@69: */
jpayne@69:
jpayne@69: /* Section 3: type definitions, including structures and compile time
jpayne@69: * constants.
jpayne@69: * See pngconf.h for base types that vary by machine/system
jpayne@69: */
jpayne@69:
jpayne@69: /* This triggers a compiler error in png.c, if png.c and png.h
jpayne@69: * do not agree upon the version number.
jpayne@69: */
jpayne@69: typedef char* png_libpng_version_1_6_43;
jpayne@69:
jpayne@69: /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
jpayne@69: *
jpayne@69: * png_struct is the cache of information used while reading or writing a single
jpayne@69: * PNG file. One of these is always required, although the simplified API
jpayne@69: * (below) hides the creation and destruction of it.
jpayne@69: */
jpayne@69: typedef struct png_struct_def png_struct;
jpayne@69: typedef const png_struct * png_const_structp;
jpayne@69: typedef png_struct * png_structp;
jpayne@69: typedef png_struct * * png_structpp;
jpayne@69:
jpayne@69: /* png_info contains information read from or to be written to a PNG file. One
jpayne@69: * or more of these must exist while reading or creating a PNG file. The
jpayne@69: * information is not used by libpng during read but is used to control what
jpayne@69: * gets written when a PNG file is created. "png_get_" function calls read
jpayne@69: * information during read and "png_set_" functions calls write information
jpayne@69: * when creating a PNG.
jpayne@69: * been moved into a separate header file that is not accessible to
jpayne@69: * applications. Read libpng-manual.txt or libpng.3 for more info.
jpayne@69: */
jpayne@69: typedef struct png_info_def png_info;
jpayne@69: typedef png_info * png_infop;
jpayne@69: typedef const png_info * png_const_infop;
jpayne@69: typedef png_info * * png_infopp;
jpayne@69:
jpayne@69: /* Types with names ending 'p' are pointer types. The corresponding types with
jpayne@69: * names ending 'rp' are identical pointer types except that the pointer is
jpayne@69: * marked 'restrict', which means that it is the only pointer to the object
jpayne@69: * passed to the function. Applications should not use the 'restrict' types;
jpayne@69: * it is always valid to pass 'p' to a pointer with a function argument of the
jpayne@69: * corresponding 'rp' type. Different compilers have different rules with
jpayne@69: * regard to type matching in the presence of 'restrict'. For backward
jpayne@69: * compatibility libpng callbacks never have 'restrict' in their parameters and,
jpayne@69: * consequentially, writing portable application code is extremely difficult if
jpayne@69: * an attempt is made to use 'restrict'.
jpayne@69: */
jpayne@69: typedef png_struct * PNG_RESTRICT png_structrp;
jpayne@69: typedef const png_struct * PNG_RESTRICT png_const_structrp;
jpayne@69: typedef png_info * PNG_RESTRICT png_inforp;
jpayne@69: typedef const png_info * PNG_RESTRICT png_const_inforp;
jpayne@69:
jpayne@69: /* Three color definitions. The order of the red, green, and blue, (and the
jpayne@69: * exact size) is not important, although the size of the fields need to
jpayne@69: * be png_byte or png_uint_16 (as defined below).
jpayne@69: */
jpayne@69: typedef struct png_color_struct
jpayne@69: {
jpayne@69: png_byte red;
jpayne@69: png_byte green;
jpayne@69: png_byte blue;
jpayne@69: } png_color;
jpayne@69: typedef png_color * png_colorp;
jpayne@69: typedef const png_color * png_const_colorp;
jpayne@69: typedef png_color * * png_colorpp;
jpayne@69:
jpayne@69: typedef struct png_color_16_struct
jpayne@69: {
jpayne@69: png_byte index; /* used for palette files */
jpayne@69: png_uint_16 red; /* for use in red green blue files */
jpayne@69: png_uint_16 green;
jpayne@69: png_uint_16 blue;
jpayne@69: png_uint_16 gray; /* for use in grayscale files */
jpayne@69: } png_color_16;
jpayne@69: typedef png_color_16 * png_color_16p;
jpayne@69: typedef const png_color_16 * png_const_color_16p;
jpayne@69: typedef png_color_16 * * png_color_16pp;
jpayne@69:
jpayne@69: typedef struct png_color_8_struct
jpayne@69: {
jpayne@69: png_byte red; /* for use in red green blue files */
jpayne@69: png_byte green;
jpayne@69: png_byte blue;
jpayne@69: png_byte gray; /* for use in grayscale files */
jpayne@69: png_byte alpha; /* for alpha channel files */
jpayne@69: } png_color_8;
jpayne@69: typedef png_color_8 * png_color_8p;
jpayne@69: typedef const png_color_8 * png_const_color_8p;
jpayne@69: typedef png_color_8 * * png_color_8pp;
jpayne@69:
jpayne@69: /*
jpayne@69: * The following two structures are used for the in-core representation
jpayne@69: * of sPLT chunks.
jpayne@69: */
jpayne@69: typedef struct png_sPLT_entry_struct
jpayne@69: {
jpayne@69: png_uint_16 red;
jpayne@69: png_uint_16 green;
jpayne@69: png_uint_16 blue;
jpayne@69: png_uint_16 alpha;
jpayne@69: png_uint_16 frequency;
jpayne@69: } png_sPLT_entry;
jpayne@69: typedef png_sPLT_entry * png_sPLT_entryp;
jpayne@69: typedef const png_sPLT_entry * png_const_sPLT_entryp;
jpayne@69: typedef png_sPLT_entry * * png_sPLT_entrypp;
jpayne@69:
jpayne@69: /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
jpayne@69: * occupy the LSB of their respective members, and the MSB of each member
jpayne@69: * is zero-filled. The frequency member always occupies the full 16 bits.
jpayne@69: */
jpayne@69:
jpayne@69: typedef struct png_sPLT_struct
jpayne@69: {
jpayne@69: png_charp name; /* palette name */
jpayne@69: png_byte depth; /* depth of palette samples */
jpayne@69: png_sPLT_entryp entries; /* palette entries */
jpayne@69: png_int_32 nentries; /* number of palette entries */
jpayne@69: } png_sPLT_t;
jpayne@69: typedef png_sPLT_t * png_sPLT_tp;
jpayne@69: typedef const png_sPLT_t * png_const_sPLT_tp;
jpayne@69: typedef png_sPLT_t * * png_sPLT_tpp;
jpayne@69:
jpayne@69: #ifdef PNG_TEXT_SUPPORTED
jpayne@69: /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
jpayne@69: * and whether that contents is compressed or not. The "key" field
jpayne@69: * points to a regular zero-terminated C string. The "text" fields can be a
jpayne@69: * regular C string, an empty string, or a NULL pointer.
jpayne@69: * However, the structure returned by png_get_text() will always contain
jpayne@69: * the "text" field as a regular zero-terminated C string (possibly
jpayne@69: * empty), never a NULL pointer, so it can be safely used in printf() and
jpayne@69: * other string-handling functions. Note that the "itxt_length", "lang", and
jpayne@69: * "lang_key" members of the structure only exist when the library is built
jpayne@69: * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
jpayne@69: * default without iTXt support. Also note that when iTXt *is* supported,
jpayne@69: * the "lang" and "lang_key" fields contain NULL pointers when the
jpayne@69: * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
jpayne@69: * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
jpayne@69: * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
jpayne@69: * which is always 0 or 1, or its "compression method" which is always 0.
jpayne@69: */
jpayne@69: typedef struct png_text_struct
jpayne@69: {
jpayne@69: int compression; /* compression value:
jpayne@69: -1: tEXt, none
jpayne@69: 0: zTXt, deflate
jpayne@69: 1: iTXt, none
jpayne@69: 2: iTXt, deflate */
jpayne@69: png_charp key; /* keyword, 1-79 character description of "text" */
jpayne@69: png_charp text; /* comment, may be an empty string (ie "")
jpayne@69: or a NULL pointer */
jpayne@69: size_t text_length; /* length of the text string */
jpayne@69: size_t itxt_length; /* length of the itxt string */
jpayne@69: png_charp lang; /* language code, 0-79 characters
jpayne@69: or a NULL pointer */
jpayne@69: png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
jpayne@69: chars or a NULL pointer */
jpayne@69: } png_text;
jpayne@69: typedef png_text * png_textp;
jpayne@69: typedef const png_text * png_const_textp;
jpayne@69: typedef png_text * * png_textpp;
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Supported compression types for text in PNG files (tEXt, and zTXt).
jpayne@69: * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
jpayne@69: #define PNG_TEXT_COMPRESSION_NONE_WR -3
jpayne@69: #define PNG_TEXT_COMPRESSION_zTXt_WR -2
jpayne@69: #define PNG_TEXT_COMPRESSION_NONE -1
jpayne@69: #define PNG_TEXT_COMPRESSION_zTXt 0
jpayne@69: #define PNG_ITXT_COMPRESSION_NONE 1
jpayne@69: #define PNG_ITXT_COMPRESSION_zTXt 2
jpayne@69: #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
jpayne@69:
jpayne@69: /* png_time is a way to hold the time in an machine independent way.
jpayne@69: * Two conversions are provided, both from time_t and struct tm. There
jpayne@69: * is no portable way to convert to either of these structures, as far
jpayne@69: * as I know. If you know of a portable way, send it to me. As a side
jpayne@69: * note - PNG has always been Year 2000 compliant!
jpayne@69: */
jpayne@69: typedef struct png_time_struct
jpayne@69: {
jpayne@69: png_uint_16 year; /* full year, as in, 1995 */
jpayne@69: png_byte month; /* month of year, 1 - 12 */
jpayne@69: png_byte day; /* day of month, 1 - 31 */
jpayne@69: png_byte hour; /* hour of day, 0 - 23 */
jpayne@69: png_byte minute; /* minute of hour, 0 - 59 */
jpayne@69: png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
jpayne@69: } png_time;
jpayne@69: typedef png_time * png_timep;
jpayne@69: typedef const png_time * png_const_timep;
jpayne@69: typedef png_time * * png_timepp;
jpayne@69:
jpayne@69: #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
jpayne@69: defined(PNG_USER_CHUNKS_SUPPORTED)
jpayne@69: /* png_unknown_chunk is a structure to hold queued chunks for which there is
jpayne@69: * no specific support. The idea is that we can use this to queue
jpayne@69: * up private chunks for output even though the library doesn't actually
jpayne@69: * know about their semantics.
jpayne@69: *
jpayne@69: * The data in the structure is set by libpng on read and used on write.
jpayne@69: */
jpayne@69: typedef struct png_unknown_chunk_t
jpayne@69: {
jpayne@69: png_byte name[5]; /* Textual chunk name with '\0' terminator */
jpayne@69: png_byte *data; /* Data, should not be modified on read! */
jpayne@69: size_t size;
jpayne@69:
jpayne@69: /* On write 'location' must be set using the flag values listed below.
jpayne@69: * Notice that on read it is set by libpng however the values stored have
jpayne@69: * more bits set than are listed below. Always treat the value as a
jpayne@69: * bitmask. On write set only one bit - setting multiple bits may cause the
jpayne@69: * chunk to be written in multiple places.
jpayne@69: */
jpayne@69: png_byte location; /* mode of operation at read time */
jpayne@69: }
jpayne@69: png_unknown_chunk;
jpayne@69:
jpayne@69: typedef png_unknown_chunk * png_unknown_chunkp;
jpayne@69: typedef const png_unknown_chunk * png_const_unknown_chunkp;
jpayne@69: typedef png_unknown_chunk * * png_unknown_chunkpp;
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Flag values for the unknown chunk location byte. */
jpayne@69: #define PNG_HAVE_IHDR 0x01
jpayne@69: #define PNG_HAVE_PLTE 0x02
jpayne@69: #define PNG_AFTER_IDAT 0x08
jpayne@69:
jpayne@69: /* Maximum positive integer used in PNG is (2^31)-1 */
jpayne@69: #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
jpayne@69: #define PNG_UINT_32_MAX ((png_uint_32)(-1))
jpayne@69: #define PNG_SIZE_MAX ((size_t)(-1))
jpayne@69:
jpayne@69: /* These are constants for fixed point values encoded in the
jpayne@69: * PNG specification manner (x100000)
jpayne@69: */
jpayne@69: #define PNG_FP_1 100000
jpayne@69: #define PNG_FP_HALF 50000
jpayne@69: #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
jpayne@69: #define PNG_FP_MIN (-PNG_FP_MAX)
jpayne@69:
jpayne@69: /* These describe the color_type field in png_info. */
jpayne@69: /* color type masks */
jpayne@69: #define PNG_COLOR_MASK_PALETTE 1
jpayne@69: #define PNG_COLOR_MASK_COLOR 2
jpayne@69: #define PNG_COLOR_MASK_ALPHA 4
jpayne@69:
jpayne@69: /* color types. Note that not all combinations are legal */
jpayne@69: #define PNG_COLOR_TYPE_GRAY 0
jpayne@69: #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
jpayne@69: #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
jpayne@69: #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
jpayne@69: #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
jpayne@69: /* aliases */
jpayne@69: #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
jpayne@69: #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
jpayne@69:
jpayne@69: /* This is for compression type. PNG 1.0-1.2 only define the single type. */
jpayne@69: #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
jpayne@69: #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
jpayne@69:
jpayne@69: /* This is for filter type. PNG 1.0-1.2 only define the single type. */
jpayne@69: #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
jpayne@69: #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
jpayne@69: #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
jpayne@69:
jpayne@69: /* These are for the interlacing type. These values should NOT be changed. */
jpayne@69: #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
jpayne@69: #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
jpayne@69: #define PNG_INTERLACE_LAST 2 /* Not a valid value */
jpayne@69:
jpayne@69: /* These are for the oFFs chunk. These values should NOT be changed. */
jpayne@69: #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
jpayne@69: #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
jpayne@69: #define PNG_OFFSET_LAST 2 /* Not a valid value */
jpayne@69:
jpayne@69: /* These are for the pCAL chunk. These values should NOT be changed. */
jpayne@69: #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
jpayne@69: #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
jpayne@69: #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
jpayne@69: #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
jpayne@69: #define PNG_EQUATION_LAST 4 /* Not a valid value */
jpayne@69:
jpayne@69: /* These are for the sCAL chunk. These values should NOT be changed. */
jpayne@69: #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
jpayne@69: #define PNG_SCALE_METER 1 /* meters per pixel */
jpayne@69: #define PNG_SCALE_RADIAN 2 /* radians per pixel */
jpayne@69: #define PNG_SCALE_LAST 3 /* Not a valid value */
jpayne@69:
jpayne@69: /* These are for the pHYs chunk. These values should NOT be changed. */
jpayne@69: #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
jpayne@69: #define PNG_RESOLUTION_METER 1 /* pixels/meter */
jpayne@69: #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
jpayne@69:
jpayne@69: /* These are for the sRGB chunk. These values should NOT be changed. */
jpayne@69: #define PNG_sRGB_INTENT_PERCEPTUAL 0
jpayne@69: #define PNG_sRGB_INTENT_RELATIVE 1
jpayne@69: #define PNG_sRGB_INTENT_SATURATION 2
jpayne@69: #define PNG_sRGB_INTENT_ABSOLUTE 3
jpayne@69: #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
jpayne@69:
jpayne@69: /* This is for text chunks */
jpayne@69: #define PNG_KEYWORD_MAX_LENGTH 79
jpayne@69:
jpayne@69: /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
jpayne@69: #define PNG_MAX_PALETTE_LENGTH 256
jpayne@69:
jpayne@69: /* These determine if an ancillary chunk's data has been successfully read
jpayne@69: * from the PNG header, or if the application has filled in the corresponding
jpayne@69: * data in the info_struct to be written into the output file. The values
jpayne@69: * of the PNG_INFO_ defines should NOT be changed.
jpayne@69: */
jpayne@69: #define PNG_INFO_gAMA 0x0001U
jpayne@69: #define PNG_INFO_sBIT 0x0002U
jpayne@69: #define PNG_INFO_cHRM 0x0004U
jpayne@69: #define PNG_INFO_PLTE 0x0008U
jpayne@69: #define PNG_INFO_tRNS 0x0010U
jpayne@69: #define PNG_INFO_bKGD 0x0020U
jpayne@69: #define PNG_INFO_hIST 0x0040U
jpayne@69: #define PNG_INFO_pHYs 0x0080U
jpayne@69: #define PNG_INFO_oFFs 0x0100U
jpayne@69: #define PNG_INFO_tIME 0x0200U
jpayne@69: #define PNG_INFO_pCAL 0x0400U
jpayne@69: #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
jpayne@69: #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
jpayne@69: #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
jpayne@69: #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
jpayne@69: #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
jpayne@69: #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
jpayne@69:
jpayne@69: /* This is used for the transformation routines, as some of them
jpayne@69: * change these values for the row. It also should enable using
jpayne@69: * the routines for other purposes.
jpayne@69: */
jpayne@69: typedef struct png_row_info_struct
jpayne@69: {
jpayne@69: png_uint_32 width; /* width of row */
jpayne@69: size_t rowbytes; /* number of bytes in row */
jpayne@69: png_byte color_type; /* color type of row */
jpayne@69: png_byte bit_depth; /* bit depth of row */
jpayne@69: png_byte channels; /* number of channels (1, 2, 3, or 4) */
jpayne@69: png_byte pixel_depth; /* bits per pixel (depth * channels) */
jpayne@69: } png_row_info;
jpayne@69:
jpayne@69: typedef png_row_info * png_row_infop;
jpayne@69: typedef png_row_info * * png_row_infopp;
jpayne@69:
jpayne@69: /* These are the function types for the I/O functions and for the functions
jpayne@69: * that allow the user to override the default I/O functions with his or her
jpayne@69: * own. The png_error_ptr type should match that of user-supplied warning
jpayne@69: * and error functions, while the png_rw_ptr type should match that of the
jpayne@69: * user read/write data functions. Note that the 'write' function must not
jpayne@69: * modify the buffer it is passed. The 'read' function, on the other hand, is
jpayne@69: * expected to return the read data in the buffer.
jpayne@69: */
jpayne@69: typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
jpayne@69: typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t));
jpayne@69: typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
jpayne@69: typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
jpayne@69: int));
jpayne@69: typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
jpayne@69: int));
jpayne@69:
jpayne@69: #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
jpayne@69: typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
jpayne@69: typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
jpayne@69:
jpayne@69: /* The following callback receives png_uint_32 row_number, int pass for the
jpayne@69: * png_bytep data of the row. When transforming an interlaced image the
jpayne@69: * row number is the row number within the sub-image of the interlace pass, so
jpayne@69: * the value will increase to the height of the sub-image (not the full image)
jpayne@69: * then reset to 0 for the next pass.
jpayne@69: *
jpayne@69: * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
jpayne@69: * find the output pixel (x,y) given an interlaced sub-image pixel
jpayne@69: * (row,col,pass). (See below for these macros.)
jpayne@69: */
jpayne@69: typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
jpayne@69: png_uint_32, int));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
jpayne@69: defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
jpayne@69: typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
jpayne@69: png_bytep));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_USER_CHUNKS_SUPPORTED
jpayne@69: typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
jpayne@69: png_unknown_chunkp));
jpayne@69: #endif
jpayne@69: #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
jpayne@69: /* not used anywhere */
jpayne@69: /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_SETJMP_SUPPORTED
jpayne@69: /* This must match the function definition in , and the application
jpayne@69: * must include this before png.h to obtain the definition of jmp_buf. The
jpayne@69: * function is required to be PNG_NORETURN, but this is not checked. If the
jpayne@69: * function does return the application will crash via an abort() or similar
jpayne@69: * system level call.
jpayne@69: *
jpayne@69: * If you get a warning here while building the library you may need to make
jpayne@69: * changes to ensure that pnglibconf.h records the calling convention used by
jpayne@69: * your compiler. This may be very difficult - try using a different compiler
jpayne@69: * to build the library!
jpayne@69: */
jpayne@69: PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Transform masks for the high-level interface */
jpayne@69: #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
jpayne@69: #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
jpayne@69: #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
jpayne@69: #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
jpayne@69: #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
jpayne@69: #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
jpayne@69: #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
jpayne@69: #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
jpayne@69: #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
jpayne@69: #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
jpayne@69: #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
jpayne@69: #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
jpayne@69: #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
jpayne@69: /* Added to libpng-1.2.34 */
jpayne@69: #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
jpayne@69: #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
jpayne@69: /* Added to libpng-1.4.0 */
jpayne@69: #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
jpayne@69: /* Added to libpng-1.5.4 */
jpayne@69: #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
jpayne@69: #if ~0U > 0xffffU /* or else this might break on a 16-bit machine */
jpayne@69: #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Flags for MNG supported features */
jpayne@69: #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
jpayne@69: #define PNG_FLAG_MNG_FILTER_64 0x04
jpayne@69: #define PNG_ALL_MNG_FEATURES 0x05
jpayne@69:
jpayne@69: /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
jpayne@69: * this allowed the zlib default functions to be used on Windows
jpayne@69: * platforms. In 1.5 the zlib default malloc (which just calls malloc and
jpayne@69: * ignores the first argument) should be completely compatible with the
jpayne@69: * following.
jpayne@69: */
jpayne@69: typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
jpayne@69: png_alloc_size_t));
jpayne@69: typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
jpayne@69:
jpayne@69: /* Section 4: exported functions
jpayne@69: * Here are the function definitions most commonly used. This is not
jpayne@69: * the place to find out how to use libpng. See libpng-manual.txt for the
jpayne@69: * full explanation, see example.c for the summary. This just provides
jpayne@69: * a simple one line description of the use of each function.
jpayne@69: *
jpayne@69: * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
jpayne@69: * pngconf.h and in the *.dfn files in the scripts directory.
jpayne@69: *
jpayne@69: * PNG_EXPORT(ordinal, type, name, (args));
jpayne@69: *
jpayne@69: * ordinal: ordinal that is used while building
jpayne@69: * *.def files. The ordinal value is only
jpayne@69: * relevant when preprocessing png.h with
jpayne@69: * the *.dfn files for building symbol table
jpayne@69: * entries, and are removed by pngconf.h.
jpayne@69: * type: return type of the function
jpayne@69: * name: function name
jpayne@69: * args: function arguments, with types
jpayne@69: *
jpayne@69: * When we wish to append attributes to a function prototype we use
jpayne@69: * the PNG_EXPORTA() macro instead.
jpayne@69: *
jpayne@69: * PNG_EXPORTA(ordinal, type, name, (args), attributes);
jpayne@69: *
jpayne@69: * ordinal, type, name, and args: same as in PNG_EXPORT().
jpayne@69: * attributes: function attributes
jpayne@69: */
jpayne@69:
jpayne@69: /* Returns the version number of the library */
jpayne@69: PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
jpayne@69:
jpayne@69: /* Tell lib we have already handled the first magic bytes.
jpayne@69: * Handling more than 8 bytes from the beginning of the file is an error.
jpayne@69: */
jpayne@69: PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
jpayne@69:
jpayne@69: /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
jpayne@69: * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
jpayne@69: * signature, and non-zero otherwise. Having num_to_check == 0 or
jpayne@69: * start > 7 will always fail (i.e. return non-zero).
jpayne@69: */
jpayne@69: PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start,
jpayne@69: size_t num_to_check));
jpayne@69:
jpayne@69: /* Simple signature checking function. This is the same as calling
jpayne@69: * png_check_sig(sig, n) := (png_sig_cmp(sig, 0, n) == 0).
jpayne@69: */
jpayne@69: #define png_check_sig(sig, n) (png_sig_cmp((sig), 0, (n)) == 0) /* DEPRECATED */
jpayne@69:
jpayne@69: /* Allocate and initialize png_ptr struct for reading, and any other memory. */
jpayne@69: PNG_EXPORTA(4, png_structp, png_create_read_struct,
jpayne@69: (png_const_charp user_png_ver, png_voidp error_ptr,
jpayne@69: png_error_ptr error_fn, png_error_ptr warn_fn),
jpayne@69: PNG_ALLOCATED);
jpayne@69:
jpayne@69: /* Allocate and initialize png_ptr struct for writing, and any other memory */
jpayne@69: PNG_EXPORTA(5, png_structp, png_create_write_struct,
jpayne@69: (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
jpayne@69: png_error_ptr warn_fn),
jpayne@69: PNG_ALLOCATED);
jpayne@69:
jpayne@69: PNG_EXPORT(6, size_t, png_get_compression_buffer_size,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69:
jpayne@69: PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
jpayne@69: size_t size));
jpayne@69:
jpayne@69: /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
jpayne@69: * match up.
jpayne@69: */
jpayne@69: #ifdef PNG_SETJMP_SUPPORTED
jpayne@69: /* This function returns the jmp_buf built in to *png_ptr. It must be
jpayne@69: * supplied with an appropriate 'longjmp' function to use on that jmp_buf
jpayne@69: * unless the default error function is overridden in which case NULL is
jpayne@69: * acceptable. The size of the jmp_buf is checked against the actual size
jpayne@69: * allocated by the library - the call will return NULL on a mismatch
jpayne@69: * indicating an ABI mismatch.
jpayne@69: */
jpayne@69: PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
jpayne@69: png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
jpayne@69: # define png_jmpbuf(png_ptr) \
jpayne@69: (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
jpayne@69: #else
jpayne@69: # define png_jmpbuf(png_ptr) \
jpayne@69: (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
jpayne@69: #endif
jpayne@69: /* This function should be used by libpng applications in place of
jpayne@69: * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
jpayne@69: * will use it; otherwise it will call PNG_ABORT(). This function was
jpayne@69: * added in libpng-1.5.0.
jpayne@69: */
jpayne@69: PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
jpayne@69: PNG_NORETURN);
jpayne@69:
jpayne@69: #ifdef PNG_READ_SUPPORTED
jpayne@69: /* Reset the compression stream */
jpayne@69: PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
jpayne@69: #endif
jpayne@69:
jpayne@69: /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
jpayne@69: #ifdef PNG_USER_MEM_SUPPORTED
jpayne@69: PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
jpayne@69: (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
jpayne@69: png_error_ptr warn_fn,
jpayne@69: png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
jpayne@69: PNG_ALLOCATED);
jpayne@69: PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
jpayne@69: (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
jpayne@69: png_error_ptr warn_fn,
jpayne@69: png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
jpayne@69: PNG_ALLOCATED);
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Write the PNG file signature. */
jpayne@69: PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
jpayne@69:
jpayne@69: /* Write a PNG chunk - size, type, (optional) data, CRC. */
jpayne@69: PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
jpayne@69: chunk_name, png_const_bytep data, size_t length));
jpayne@69:
jpayne@69: /* Write the start of a PNG chunk - length and chunk name. */
jpayne@69: PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
jpayne@69: png_const_bytep chunk_name, png_uint_32 length));
jpayne@69:
jpayne@69: /* Write the data of a PNG chunk started with png_write_chunk_start(). */
jpayne@69: PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
jpayne@69: png_const_bytep data, size_t length));
jpayne@69:
jpayne@69: /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
jpayne@69: PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
jpayne@69:
jpayne@69: /* Allocate and initialize the info structure */
jpayne@69: PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
jpayne@69: PNG_ALLOCATED);
jpayne@69:
jpayne@69: /* DEPRECATED: this function allowed init structures to be created using the
jpayne@69: * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
jpayne@69: * the API will be removed in the future.
jpayne@69: */
jpayne@69: PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
jpayne@69: size_t png_info_struct_size), PNG_DEPRECATED);
jpayne@69:
jpayne@69: /* Writes all the PNG information before the image. */
jpayne@69: PNG_EXPORT(20, void, png_write_info_before_PLTE,
jpayne@69: (png_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69: PNG_EXPORT(21, void, png_write_info,
jpayne@69: (png_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69:
jpayne@69: #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
jpayne@69: /* Read the information before the actual image data. */
jpayne@69: PNG_EXPORT(22, void, png_read_info,
jpayne@69: (png_structrp png_ptr, png_inforp info_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_TIME_RFC1123_SUPPORTED
jpayne@69: /* Convert to a US string format: there is no localization support in this
jpayne@69: * routine. The original implementation used a 29 character buffer in
jpayne@69: * png_struct, this will be removed in future versions.
jpayne@69: */
jpayne@69: #if PNG_LIBPNG_VER < 10700
jpayne@69: /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
jpayne@69: PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
jpayne@69: png_const_timep ptime),PNG_DEPRECATED);
jpayne@69: #endif
jpayne@69: PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
jpayne@69: png_const_timep ptime));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_CONVERT_tIME_SUPPORTED
jpayne@69: /* Convert from a struct tm to png_time */
jpayne@69: PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
jpayne@69: const struct tm * ttime));
jpayne@69:
jpayne@69: /* Convert from time_t to png_time. Uses gmtime() */
jpayne@69: PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
jpayne@69: #endif /* CONVERT_tIME */
jpayne@69:
jpayne@69: #ifdef PNG_READ_EXPAND_SUPPORTED
jpayne@69: /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
jpayne@69: PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
jpayne@69: PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
jpayne@69: PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
jpayne@69: PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_EXPAND_16_SUPPORTED
jpayne@69: /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
jpayne@69: * of a tRNS chunk if present.
jpayne@69: */
jpayne@69: PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
jpayne@69: /* Use blue, green, red order for pixels. */
jpayne@69: PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
jpayne@69: /* Expand the grayscale to 24-bit RGB if necessary. */
jpayne@69: PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
jpayne@69: /* Reduce RGB to grayscale. */
jpayne@69: #define PNG_ERROR_ACTION_NONE 1
jpayne@69: #define PNG_ERROR_ACTION_WARN 2
jpayne@69: #define PNG_ERROR_ACTION_ERROR 3
jpayne@69: #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
jpayne@69:
jpayne@69: PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
jpayne@69: int error_action, double red, double green))
jpayne@69: PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
jpayne@69: int error_action, png_fixed_point red, png_fixed_point green))
jpayne@69:
jpayne@69: PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
jpayne@69: png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
jpayne@69: PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
jpayne@69: png_colorp palette));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
jpayne@69: /* How the alpha channel is interpreted - this affects how the color channels
jpayne@69: * of a PNG file are returned to the calling application when an alpha channel,
jpayne@69: * or a tRNS chunk in a palette file, is present.
jpayne@69: *
jpayne@69: * This has no effect on the way pixels are written into a PNG output
jpayne@69: * datastream. The color samples in a PNG datastream are never premultiplied
jpayne@69: * with the alpha samples.
jpayne@69: *
jpayne@69: * The default is to return data according to the PNG specification: the alpha
jpayne@69: * channel is a linear measure of the contribution of the pixel to the
jpayne@69: * corresponding composited pixel, and the color channels are unassociated
jpayne@69: * (not premultiplied). The gamma encoded color channels must be scaled
jpayne@69: * according to the contribution and to do this it is necessary to undo
jpayne@69: * the encoding, scale the color values, perform the composition and re-encode
jpayne@69: * the values. This is the 'PNG' mode.
jpayne@69: *
jpayne@69: * The alternative is to 'associate' the alpha with the color information by
jpayne@69: * storing color channel values that have been scaled by the alpha.
jpayne@69: * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
jpayne@69: * (the latter being the two common names for associated alpha color channels).
jpayne@69: *
jpayne@69: * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
jpayne@69: * value is equal to the maximum value.
jpayne@69: *
jpayne@69: * The final choice is to gamma encode the alpha channel as well. This is
jpayne@69: * broken because, in practice, no implementation that uses this choice
jpayne@69: * correctly undoes the encoding before handling alpha composition. Use this
jpayne@69: * choice only if other serious errors in the software or hardware you use
jpayne@69: * mandate it; the typical serious error is for dark halos to appear around
jpayne@69: * opaque areas of the composited PNG image because of arithmetic overflow.
jpayne@69: *
jpayne@69: * The API function png_set_alpha_mode specifies which of these choices to use
jpayne@69: * with an enumerated 'mode' value and the gamma of the required output:
jpayne@69: */
jpayne@69: #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
jpayne@69: #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
jpayne@69: #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
jpayne@69: #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
jpayne@69: #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
jpayne@69: #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
jpayne@69:
jpayne@69: PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
jpayne@69: double output_gamma))
jpayne@69: PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
jpayne@69: int mode, png_fixed_point output_gamma))
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
jpayne@69: /* The output_gamma value is a screen gamma in libpng terminology: it expresses
jpayne@69: * how to decode the output values, not how they are encoded.
jpayne@69: */
jpayne@69: #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
jpayne@69: #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
jpayne@69: #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
jpayne@69: #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
jpayne@69: #endif
jpayne@69:
jpayne@69: /* The following are examples of calls to png_set_alpha_mode to achieve the
jpayne@69: * required overall gamma correction and, where necessary, alpha
jpayne@69: * premultiplication.
jpayne@69: *
jpayne@69: * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
jpayne@69: * This is the default libpng handling of the alpha channel - it is not
jpayne@69: * pre-multiplied into the color components. In addition the call states
jpayne@69: * that the output is for a sRGB system and causes all PNG files without gAMA
jpayne@69: * chunks to be assumed to be encoded using sRGB.
jpayne@69: *
jpayne@69: * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
jpayne@69: * In this case the output is assumed to be something like an sRGB conformant
jpayne@69: * display preceded by a power-law lookup table of power 1.45. This is how
jpayne@69: * early Mac systems behaved.
jpayne@69: *
jpayne@69: * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
jpayne@69: * This is the classic Jim Blinn approach and will work in academic
jpayne@69: * environments where everything is done by the book. It has the shortcoming
jpayne@69: * of assuming that input PNG data with no gamma information is linear - this
jpayne@69: * is unlikely to be correct unless the PNG files where generated locally.
jpayne@69: * Most of the time the output precision will be so low as to show
jpayne@69: * significant banding in dark areas of the image.
jpayne@69: *
jpayne@69: * png_set_expand_16(pp);
jpayne@69: * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
jpayne@69: * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
jpayne@69: * are assumed to have the sRGB encoding if not marked with a gamma value and
jpayne@69: * the output is always 16 bits per component. This permits accurate scaling
jpayne@69: * and processing of the data. If you know that your input PNG files were
jpayne@69: * generated locally you might need to replace PNG_DEFAULT_sRGB with the
jpayne@69: * correct value for your system.
jpayne@69: *
jpayne@69: * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
jpayne@69: * If you just need to composite the PNG image onto an existing background
jpayne@69: * and if you control the code that does this you can use the optimization
jpayne@69: * setting. In this case you just copy completely opaque pixels to the
jpayne@69: * output. For pixels that are not completely transparent (you just skip
jpayne@69: * those) you do the composition math using png_composite or png_composite_16
jpayne@69: * below then encode the resultant 8-bit or 16-bit values to match the output
jpayne@69: * encoding.
jpayne@69: *
jpayne@69: * Other cases
jpayne@69: * If neither the PNG nor the standard linear encoding work for you because
jpayne@69: * of the software or hardware you use then you have a big problem. The PNG
jpayne@69: * case will probably result in halos around the image. The linear encoding
jpayne@69: * will probably result in a washed out, too bright, image (it's actually too
jpayne@69: * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
jpayne@69: * substantially reduce the halos. Alternatively try:
jpayne@69: *
jpayne@69: * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
jpayne@69: * This option will also reduce the halos, but there will be slight dark
jpayne@69: * halos round the opaque parts of the image where the background is light.
jpayne@69: * In the OPTIMIZED mode the halos will be light halos where the background
jpayne@69: * is dark. Take your pick - the halos are unavoidable unless you can get
jpayne@69: * your hardware/software fixed! (The OPTIMIZED approach is slightly
jpayne@69: * faster.)
jpayne@69: *
jpayne@69: * When the default gamma of PNG files doesn't match the output gamma.
jpayne@69: * If you have PNG files with no gamma information png_set_alpha_mode allows
jpayne@69: * you to provide a default gamma, but it also sets the output gamma to the
jpayne@69: * matching value. If you know your PNG files have a gamma that doesn't
jpayne@69: * match the output you can take advantage of the fact that
jpayne@69: * png_set_alpha_mode always sets the output gamma but only sets the PNG
jpayne@69: * default if it is not already set:
jpayne@69: *
jpayne@69: * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
jpayne@69: * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
jpayne@69: * The first call sets both the default and the output gamma values, the
jpayne@69: * second call overrides the output gamma without changing the default. This
jpayne@69: * is easier than achieving the same effect with png_set_gamma. You must use
jpayne@69: * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
jpayne@69: * fire if more than one call to png_set_alpha_mode and png_set_background is
jpayne@69: * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
jpayne@69: * are ignored.
jpayne@69: */
jpayne@69:
jpayne@69: #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
jpayne@69: PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
jpayne@69: defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
jpayne@69: PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
jpayne@69: defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
jpayne@69: PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
jpayne@69: /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
jpayne@69: PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
jpayne@69: int flags));
jpayne@69: /* The values of the PNG_FILLER_ defines should NOT be changed */
jpayne@69: # define PNG_FILLER_BEFORE 0
jpayne@69: # define PNG_FILLER_AFTER 1
jpayne@69: /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
jpayne@69: PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
jpayne@69: png_uint_32 filler, int flags));
jpayne@69: #endif /* READ_FILLER || WRITE_FILLER */
jpayne@69:
jpayne@69: #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
jpayne@69: /* Swap bytes in 16-bit depth files. */
jpayne@69: PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
jpayne@69: /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
jpayne@69: PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
jpayne@69: defined(PNG_WRITE_PACKSWAP_SUPPORTED)
jpayne@69: /* Swap packing order of pixels in bytes. */
jpayne@69: PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
jpayne@69: /* Converts files to legal bit depths. */
jpayne@69: PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
jpayne@69: true_bits));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
jpayne@69: defined(PNG_WRITE_INTERLACING_SUPPORTED)
jpayne@69: /* Have the code handle the interlacing. Returns the number of passes.
jpayne@69: * MUST be called before png_read_update_info or png_start_read_image,
jpayne@69: * otherwise it will not have the desired effect. Note that it is still
jpayne@69: * necessary to call png_read_row or png_read_rows png_get_image_height
jpayne@69: * times for each pass.
jpayne@69: */
jpayne@69: PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
jpayne@69: /* Invert monochrome files */
jpayne@69: PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_BACKGROUND_SUPPORTED
jpayne@69: /* Handle alpha and tRNS by replacing with a background color. Prior to
jpayne@69: * libpng-1.5.4 this API must not be called before the PNG file header has been
jpayne@69: * read. Doing so will result in unexpected behavior and possible warnings or
jpayne@69: * errors if the PNG file contains a bKGD chunk.
jpayne@69: */
jpayne@69: PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
jpayne@69: png_const_color_16p background_color, int background_gamma_code,
jpayne@69: int need_expand, double background_gamma))
jpayne@69: PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
jpayne@69: png_const_color_16p background_color, int background_gamma_code,
jpayne@69: int need_expand, png_fixed_point background_gamma))
jpayne@69: #endif
jpayne@69: #ifdef PNG_READ_BACKGROUND_SUPPORTED
jpayne@69: # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
jpayne@69: # define PNG_BACKGROUND_GAMMA_SCREEN 1
jpayne@69: # define PNG_BACKGROUND_GAMMA_FILE 2
jpayne@69: # define PNG_BACKGROUND_GAMMA_UNIQUE 3
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
jpayne@69: /* Scale a 16-bit depth file down to 8-bit, accurately. */
jpayne@69: PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
jpayne@69: #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
jpayne@69: /* Strip the second byte of information from a 16-bit depth file. */
jpayne@69: PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_QUANTIZE_SUPPORTED
jpayne@69: /* Turn on quantizing, and reduce the palette to the number of colors
jpayne@69: * available.
jpayne@69: */
jpayne@69: PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
jpayne@69: png_colorp palette, int num_palette, int maximum_colors,
jpayne@69: png_const_uint_16p histogram, int full_quantize));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_GAMMA_SUPPORTED
jpayne@69: /* The threshold on gamma processing is configurable but hard-wired into the
jpayne@69: * library. The following is the floating point variant.
jpayne@69: */
jpayne@69: #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
jpayne@69:
jpayne@69: /* Handle gamma correction. Screen_gamma=(display_exponent).
jpayne@69: * NOTE: this API simply sets the screen and file gamma values. It will
jpayne@69: * therefore override the value for gamma in a PNG file if it is called after
jpayne@69: * the file header has been read - use with care - call before reading the PNG
jpayne@69: * file for best results!
jpayne@69: *
jpayne@69: * These routines accept the same gamma values as png_set_alpha_mode (described
jpayne@69: * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
jpayne@69: * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
jpayne@69: * is the inverse of a 'screen gamma' value.
jpayne@69: */
jpayne@69: PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
jpayne@69: double screen_gamma, double override_file_gamma))
jpayne@69: PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
jpayne@69: png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_WRITE_FLUSH_SUPPORTED
jpayne@69: /* Set how many lines between output flushes - 0 for no flushing */
jpayne@69: PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
jpayne@69: /* Flush the current PNG output buffer */
jpayne@69: PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Optional update palette with requested transformations */
jpayne@69: PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
jpayne@69:
jpayne@69: /* Optional call to update the users info structure */
jpayne@69: PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
jpayne@69: png_inforp info_ptr));
jpayne@69:
jpayne@69: #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
jpayne@69: /* Read one or more rows of image data. */
jpayne@69: PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
jpayne@69: png_bytepp display_row, png_uint_32 num_rows));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
jpayne@69: /* Read a row of data. */
jpayne@69: PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
jpayne@69: png_bytep display_row));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
jpayne@69: /* Read the whole image into memory at once. */
jpayne@69: PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Write a row of image data */
jpayne@69: PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
jpayne@69: png_const_bytep row));
jpayne@69:
jpayne@69: /* Write a few rows of image data: (*row) is not written; however, the type
jpayne@69: * is declared as writeable to maintain compatibility with previous versions
jpayne@69: * of libpng and to allow the 'display_row' array from read_rows to be passed
jpayne@69: * unchanged to write_rows.
jpayne@69: */
jpayne@69: PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
jpayne@69: png_uint_32 num_rows));
jpayne@69:
jpayne@69: /* Write the image data */
jpayne@69: PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
jpayne@69:
jpayne@69: /* Write the end of the PNG file. */
jpayne@69: PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
jpayne@69: png_inforp info_ptr));
jpayne@69:
jpayne@69: #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
jpayne@69: /* Read the end of the PNG file. */
jpayne@69: PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Free any memory associated with the png_info_struct */
jpayne@69: PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
jpayne@69: png_infopp info_ptr_ptr));
jpayne@69:
jpayne@69: /* Free any memory associated with the png_struct and the png_info_structs */
jpayne@69: PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
jpayne@69: png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
jpayne@69:
jpayne@69: /* Free any memory associated with the png_struct and the png_info_structs */
jpayne@69: PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
jpayne@69: png_infopp info_ptr_ptr));
jpayne@69:
jpayne@69: /* Set the libpng method of handling chunk CRC errors */
jpayne@69: PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
jpayne@69: int ancil_action));
jpayne@69:
jpayne@69: /* Values for png_set_crc_action() say how to handle CRC errors in
jpayne@69: * ancillary and critical chunks, and whether to use the data contained
jpayne@69: * therein. Note that it is impossible to "discard" data in a critical
jpayne@69: * chunk. For versions prior to 0.90, the action was always error/quit,
jpayne@69: * whereas in version 0.90 and later, the action for CRC errors in ancillary
jpayne@69: * chunks is warn/discard. These values should NOT be changed.
jpayne@69: *
jpayne@69: * value action:critical action:ancillary
jpayne@69: */
jpayne@69: #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
jpayne@69: #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
jpayne@69: #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
jpayne@69: #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
jpayne@69: #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
jpayne@69: #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
jpayne@69:
jpayne@69: #ifdef PNG_WRITE_SUPPORTED
jpayne@69: /* These functions give the user control over the scan-line filtering in
jpayne@69: * libpng and the compression methods used by zlib. These functions are
jpayne@69: * mainly useful for testing, as the defaults should work with most users.
jpayne@69: * Those users who are tight on memory or want faster performance at the
jpayne@69: * expense of compression can modify them. See the compression library
jpayne@69: * header file (zlib.h) for an explanation of the compression functions.
jpayne@69: */
jpayne@69:
jpayne@69: /* Set the filtering method(s) used by libpng. Currently, the only valid
jpayne@69: * value for "method" is 0.
jpayne@69: */
jpayne@69: PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
jpayne@69: int filters));
jpayne@69: #endif /* WRITE */
jpayne@69:
jpayne@69: /* Flags for png_set_filter() to say which filters to use. The flags
jpayne@69: * are chosen so that they don't conflict with real filter types
jpayne@69: * below, in case they are supplied instead of the #defined constants.
jpayne@69: * These values should NOT be changed.
jpayne@69: */
jpayne@69: #define PNG_NO_FILTERS 0x00
jpayne@69: #define PNG_FILTER_NONE 0x08
jpayne@69: #define PNG_FILTER_SUB 0x10
jpayne@69: #define PNG_FILTER_UP 0x20
jpayne@69: #define PNG_FILTER_AVG 0x40
jpayne@69: #define PNG_FILTER_PAETH 0x80
jpayne@69: #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
jpayne@69: #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
jpayne@69:
jpayne@69: /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
jpayne@69: * These defines should NOT be changed.
jpayne@69: */
jpayne@69: #define PNG_FILTER_VALUE_NONE 0
jpayne@69: #define PNG_FILTER_VALUE_SUB 1
jpayne@69: #define PNG_FILTER_VALUE_UP 2
jpayne@69: #define PNG_FILTER_VALUE_AVG 3
jpayne@69: #define PNG_FILTER_VALUE_PAETH 4
jpayne@69: #define PNG_FILTER_VALUE_LAST 5
jpayne@69:
jpayne@69: #ifdef PNG_WRITE_SUPPORTED
jpayne@69: #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
jpayne@69: PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
jpayne@69: int heuristic_method, int num_weights, png_const_doublep filter_weights,
jpayne@69: png_const_doublep filter_costs))
jpayne@69: PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
jpayne@69: (png_structrp png_ptr, int heuristic_method, int num_weights,
jpayne@69: png_const_fixed_point_p filter_weights,
jpayne@69: png_const_fixed_point_p filter_costs))
jpayne@69: #endif /* WRITE_WEIGHTED_FILTER */
jpayne@69:
jpayne@69: /* The following are no longer used and will be removed from libpng-1.7: */
jpayne@69: #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
jpayne@69: #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
jpayne@69: #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
jpayne@69: #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
jpayne@69:
jpayne@69: /* Set the library compression level. Currently, valid values range from
jpayne@69: * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
jpayne@69: * (0 - no compression, 9 - "maximal" compression). Note that tests have
jpayne@69: * shown that zlib compression levels 3-6 usually perform as well as level 9
jpayne@69: * for PNG images, and do considerably fewer calculations. In the future,
jpayne@69: * these values may not correspond directly to the zlib compression levels.
jpayne@69: */
jpayne@69: #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
jpayne@69: PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
jpayne@69: int level));
jpayne@69:
jpayne@69: PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
jpayne@69: int mem_level));
jpayne@69:
jpayne@69: PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
jpayne@69: int strategy));
jpayne@69:
jpayne@69: /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
jpayne@69: * smaller value of window_bits if it can do so safely.
jpayne@69: */
jpayne@69: PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
jpayne@69: int window_bits));
jpayne@69:
jpayne@69: PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
jpayne@69: int method));
jpayne@69: #endif /* WRITE_CUSTOMIZE_COMPRESSION */
jpayne@69:
jpayne@69: #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
jpayne@69: /* Also set zlib parameters for compressing non-IDAT chunks */
jpayne@69: PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
jpayne@69: int level));
jpayne@69:
jpayne@69: PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
jpayne@69: int mem_level));
jpayne@69:
jpayne@69: PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
jpayne@69: int strategy));
jpayne@69:
jpayne@69: /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
jpayne@69: * smaller value of window_bits if it can do so safely.
jpayne@69: */
jpayne@69: PNG_EXPORT(225, void, png_set_text_compression_window_bits,
jpayne@69: (png_structrp png_ptr, int window_bits));
jpayne@69:
jpayne@69: PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
jpayne@69: int method));
jpayne@69: #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
jpayne@69: #endif /* WRITE */
jpayne@69:
jpayne@69: /* These next functions are called for input/output, memory, and error
jpayne@69: * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
jpayne@69: * and call standard C I/O routines such as fread(), fwrite(), and
jpayne@69: * fprintf(). These functions can be made to use other I/O routines
jpayne@69: * at run time for those applications that need to handle I/O in a
jpayne@69: * different manner by calling png_set_???_fn(). See libpng-manual.txt for
jpayne@69: * more information.
jpayne@69: */
jpayne@69:
jpayne@69: #ifdef PNG_STDIO_SUPPORTED
jpayne@69: /* Initialize the input/output for the PNG file to the default functions. */
jpayne@69: PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Replace the (error and abort), and warning functions with user
jpayne@69: * supplied functions. If no messages are to be printed you must still
jpayne@69: * write and use replacement functions. The replacement error_fn should
jpayne@69: * still do a longjmp to the last setjmp location if you are using this
jpayne@69: * method of error handling. If error_fn or warning_fn is NULL, the
jpayne@69: * default function will be used.
jpayne@69: */
jpayne@69:
jpayne@69: PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
jpayne@69: png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
jpayne@69:
jpayne@69: /* Return the user pointer associated with the error functions */
jpayne@69: PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
jpayne@69:
jpayne@69: /* Replace the default data output functions with a user supplied one(s).
jpayne@69: * If buffered output is not used, then output_flush_fn can be set to NULL.
jpayne@69: * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
jpayne@69: * output_flush_fn will be ignored (and thus can be NULL).
jpayne@69: * It is probably a mistake to use NULL for output_flush_fn if
jpayne@69: * write_data_fn is not also NULL unless you have built libpng with
jpayne@69: * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
jpayne@69: * default flush function, which uses the standard *FILE structure, will
jpayne@69: * be used.
jpayne@69: */
jpayne@69: PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
jpayne@69: png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
jpayne@69:
jpayne@69: /* Replace the default data input function with a user supplied one. */
jpayne@69: PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
jpayne@69: png_rw_ptr read_data_fn));
jpayne@69:
jpayne@69: /* Return the user pointer associated with the I/O functions */
jpayne@69: PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
jpayne@69:
jpayne@69: PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
jpayne@69: png_read_status_ptr read_row_fn));
jpayne@69:
jpayne@69: PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
jpayne@69: png_write_status_ptr write_row_fn));
jpayne@69:
jpayne@69: #ifdef PNG_USER_MEM_SUPPORTED
jpayne@69: /* Replace the default memory allocation functions with user supplied one(s). */
jpayne@69: PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
jpayne@69: png_malloc_ptr malloc_fn, png_free_ptr free_fn));
jpayne@69: /* Return the user pointer associated with the memory functions */
jpayne@69: PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
jpayne@69: PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
jpayne@69: png_user_transform_ptr read_user_transform_fn));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
jpayne@69: PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
jpayne@69: png_user_transform_ptr write_user_transform_fn));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
jpayne@69: PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
jpayne@69: png_voidp user_transform_ptr, int user_transform_depth,
jpayne@69: int user_transform_channels));
jpayne@69: /* Return the user pointer associated with the user transform functions */
jpayne@69: PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
jpayne@69: /* Return information about the row currently being processed. Note that these
jpayne@69: * APIs do not fail but will return unexpected results if called outside a user
jpayne@69: * transform callback. Also note that when transforming an interlaced image the
jpayne@69: * row number is the row number within the sub-image of the interlace pass, so
jpayne@69: * the value will increase to the height of the sub-image (not the full image)
jpayne@69: * then reset to 0 for the next pass.
jpayne@69: *
jpayne@69: * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
jpayne@69: * find the output pixel (x,y) given an interlaced sub-image pixel
jpayne@69: * (row,col,pass). (See below for these macros.)
jpayne@69: */
jpayne@69: PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
jpayne@69: PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
jpayne@69: /* This callback is called only for *unknown* chunks. If
jpayne@69: * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
jpayne@69: * chunks to be treated as unknown, however in this case the callback must do
jpayne@69: * any processing required by the chunk (e.g. by calling the appropriate
jpayne@69: * png_set_ APIs.)
jpayne@69: *
jpayne@69: * There is no write support - on write, by default, all the chunks in the
jpayne@69: * 'unknown' list are written in the specified position.
jpayne@69: *
jpayne@69: * The integer return from the callback function is interpreted thus:
jpayne@69: *
jpayne@69: * negative: An error occurred; png_chunk_error will be called.
jpayne@69: * zero: The chunk was not handled, the chunk will be saved. A critical
jpayne@69: * chunk will cause an error at this point unless it is to be saved.
jpayne@69: * positive: The chunk was handled, libpng will ignore/discard it.
jpayne@69: *
jpayne@69: * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about
jpayne@69: * how this behavior will change in libpng 1.7
jpayne@69: */
jpayne@69: PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
jpayne@69: png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_USER_CHUNKS_SUPPORTED
jpayne@69: PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
jpayne@69: /* Sets the function callbacks for the push reader, and a pointer to a
jpayne@69: * user-defined structure available to the callback functions.
jpayne@69: */
jpayne@69: PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
jpayne@69: png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
jpayne@69: png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
jpayne@69:
jpayne@69: /* Returns the user pointer associated with the push read functions */
jpayne@69: PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69:
jpayne@69: /* Function to be called when data becomes available */
jpayne@69: PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_bytep buffer, size_t buffer_size));
jpayne@69:
jpayne@69: /* A function which may be called *only* within png_process_data to stop the
jpayne@69: * processing of any more data. The function returns the number of bytes
jpayne@69: * remaining, excluding any that libpng has cached internally. A subsequent
jpayne@69: * call to png_process_data must supply these bytes again. If the argument
jpayne@69: * 'save' is set to true the routine will first save all the pending data and
jpayne@69: * will always return 0.
jpayne@69: */
jpayne@69: PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save));
jpayne@69:
jpayne@69: /* A function which may be called *only* outside (after) a call to
jpayne@69: * png_process_data. It returns the number of bytes of data to skip in the
jpayne@69: * input. Normally it will return 0, but if it returns a non-zero value the
jpayne@69: * application must skip than number of bytes of input data and pass the
jpayne@69: * following data to the next call to png_process_data.
jpayne@69: */
jpayne@69: PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
jpayne@69:
jpayne@69: /* Function that combines rows. 'new_row' is a flag that should come from
jpayne@69: * the callback and be non-NULL if anything needs to be done; the library
jpayne@69: * stores its own version of the new data internally and ignores the passed
jpayne@69: * in value.
jpayne@69: */
jpayne@69: PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
jpayne@69: png_bytep old_row, png_const_bytep new_row));
jpayne@69: #endif /* PROGRESSIVE_READ */
jpayne@69:
jpayne@69: PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
jpayne@69: png_alloc_size_t size), PNG_ALLOCATED);
jpayne@69: /* Added at libpng version 1.4.0 */
jpayne@69: PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
jpayne@69: png_alloc_size_t size), PNG_ALLOCATED);
jpayne@69:
jpayne@69: /* Added at libpng version 1.2.4 */
jpayne@69: PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
jpayne@69: png_alloc_size_t size), PNG_ALLOCATED);
jpayne@69:
jpayne@69: /* Frees a pointer allocated by png_malloc() */
jpayne@69: PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
jpayne@69:
jpayne@69: /* Free data that was allocated internally */
jpayne@69: PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_uint_32 free_me, int num));
jpayne@69:
jpayne@69: /* Reassign the responsibility for freeing existing data, whether allocated
jpayne@69: * by libpng or by the application; this works on the png_info structure passed
jpayne@69: * in, without changing the state for other png_info structures.
jpayne@69: */
jpayne@69: PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, int freer, png_uint_32 mask));
jpayne@69:
jpayne@69: /* Assignments for png_data_freer */
jpayne@69: #define PNG_DESTROY_WILL_FREE_DATA 1
jpayne@69: #define PNG_SET_WILL_FREE_DATA 1
jpayne@69: #define PNG_USER_WILL_FREE_DATA 2
jpayne@69: /* Flags for png_ptr->free_me and info_ptr->free_me */
jpayne@69: #define PNG_FREE_HIST 0x0008U
jpayne@69: #define PNG_FREE_ICCP 0x0010U
jpayne@69: #define PNG_FREE_SPLT 0x0020U
jpayne@69: #define PNG_FREE_ROWS 0x0040U
jpayne@69: #define PNG_FREE_PCAL 0x0080U
jpayne@69: #define PNG_FREE_SCAL 0x0100U
jpayne@69: #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
jpayne@69: # define PNG_FREE_UNKN 0x0200U
jpayne@69: #endif
jpayne@69: /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
jpayne@69: #define PNG_FREE_PLTE 0x1000U
jpayne@69: #define PNG_FREE_TRNS 0x2000U
jpayne@69: #define PNG_FREE_TEXT 0x4000U
jpayne@69: #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
jpayne@69: #define PNG_FREE_ALL 0xffffU
jpayne@69: #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
jpayne@69:
jpayne@69: #ifdef PNG_USER_MEM_SUPPORTED
jpayne@69: PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
jpayne@69: png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
jpayne@69: PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
jpayne@69: png_voidp ptr), PNG_DEPRECATED);
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_ERROR_TEXT_SUPPORTED
jpayne@69: /* Fatal error in PNG image of libpng - can't continue */
jpayne@69: PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
jpayne@69: png_const_charp error_message), PNG_NORETURN);
jpayne@69:
jpayne@69: /* The same, but the chunk name is prepended to the error string. */
jpayne@69: PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
jpayne@69: png_const_charp error_message), PNG_NORETURN);
jpayne@69:
jpayne@69: #else
jpayne@69: /* Fatal error in PNG image of libpng - can't continue */
jpayne@69: PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
jpayne@69: # define png_error(s1,s2) png_err(s1)
jpayne@69: # define png_chunk_error(s1,s2) png_err(s1)
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_WARNINGS_SUPPORTED
jpayne@69: /* Non-fatal error in libpng. Can continue, but may have a problem. */
jpayne@69: PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
jpayne@69: png_const_charp warning_message));
jpayne@69:
jpayne@69: /* Non-fatal error in libpng, chunk name is prepended to message. */
jpayne@69: PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
jpayne@69: png_const_charp warning_message));
jpayne@69: #else
jpayne@69: # define png_warning(s1,s2) ((void)(s1))
jpayne@69: # define png_chunk_warning(s1,s2) ((void)(s1))
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_BENIGN_ERRORS_SUPPORTED
jpayne@69: /* Benign error in libpng. Can continue, but may have a problem.
jpayne@69: * User can choose whether to handle as a fatal error or as a warning. */
jpayne@69: PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
jpayne@69: png_const_charp warning_message));
jpayne@69:
jpayne@69: #ifdef PNG_READ_SUPPORTED
jpayne@69: /* Same, chunk name is prepended to message (only during read) */
jpayne@69: PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
jpayne@69: png_const_charp warning_message));
jpayne@69: #endif
jpayne@69:
jpayne@69: PNG_EXPORT(109, void, png_set_benign_errors,
jpayne@69: (png_structrp png_ptr, int allowed));
jpayne@69: #else
jpayne@69: # ifdef PNG_ALLOW_BENIGN_ERRORS
jpayne@69: # define png_benign_error png_warning
jpayne@69: # define png_chunk_benign_error png_chunk_warning
jpayne@69: # else
jpayne@69: # define png_benign_error png_error
jpayne@69: # define png_chunk_benign_error png_chunk_error
jpayne@69: # endif
jpayne@69: #endif
jpayne@69:
jpayne@69: /* The png_set_ functions are for storing values in the png_info_struct.
jpayne@69: * Similarly, the png_get_ calls are used to read values from the
jpayne@69: * png_info_struct, either storing the parameters in the passed variables, or
jpayne@69: * setting pointers into the png_info_struct where the data is stored. The
jpayne@69: * png_get_ functions return a non-zero value if the data was available
jpayne@69: * in info_ptr, or return zero and do not change any of the parameters if the
jpayne@69: * data was not available.
jpayne@69: *
jpayne@69: * These functions should be used instead of directly accessing png_info
jpayne@69: * to avoid problems with future changes in the size and internal layout of
jpayne@69: * png_info_struct.
jpayne@69: */
jpayne@69: /* Returns "flag" if chunk data is valid in info_ptr. */
jpayne@69: PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, png_uint_32 flag));
jpayne@69:
jpayne@69: /* Returns number of bytes needed to hold a transformed row. */
jpayne@69: PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: #ifdef PNG_INFO_IMAGE_SUPPORTED
jpayne@69: /* Returns row_pointers, which is an array of pointers to scanlines that was
jpayne@69: * returned from png_read_png().
jpayne@69: */
jpayne@69: PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: /* Set row_pointers, which is an array of pointers to scanlines for use
jpayne@69: * by png_write_png().
jpayne@69: */
jpayne@69: PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_bytepp row_pointers));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Returns number of color channels in image. */
jpayne@69: PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: #ifdef PNG_EASY_ACCESS_SUPPORTED
jpayne@69: /* Returns image width in pixels. */
jpayne@69: PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: /* Returns image height in pixels. */
jpayne@69: PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: /* Returns image bit_depth. */
jpayne@69: PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: /* Returns image color_type. */
jpayne@69: PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: /* Returns image filter_type. */
jpayne@69: PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: /* Returns image interlace_type. */
jpayne@69: PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: /* Returns image compression_type. */
jpayne@69: PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69:
jpayne@69: /* Returns image resolution in pixels per meter, from pHYs chunk data. */
jpayne@69: PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69: PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69: PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69:
jpayne@69: /* Returns pixel aspect ratio, computed from pHYs chunk data. */
jpayne@69: PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr))
jpayne@69: PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr))
jpayne@69:
jpayne@69: /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
jpayne@69: PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69: PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69: PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69: PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69:
jpayne@69: #endif /* EASY_ACCESS */
jpayne@69:
jpayne@69: #ifdef PNG_READ_SUPPORTED
jpayne@69: /* Returns pointer to signature string read from PNG header */
jpayne@69: PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_bKGD_SUPPORTED
jpayne@69: PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_color_16p *background));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_bKGD_SUPPORTED
jpayne@69: PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_color_16p background));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_cHRM_SUPPORTED
jpayne@69: PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
jpayne@69: double *red_y, double *green_x, double *green_y, double *blue_x,
jpayne@69: double *blue_y))
jpayne@69: PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
jpayne@69: double *green_X, double *green_Y, double *green_Z, double *blue_X,
jpayne@69: double *blue_Y, double *blue_Z))
jpayne@69: PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr,
jpayne@69: png_fixed_point *int_white_x, png_fixed_point *int_white_y,
jpayne@69: png_fixed_point *int_red_x, png_fixed_point *int_red_y,
jpayne@69: png_fixed_point *int_green_x, png_fixed_point *int_green_y,
jpayne@69: png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
jpayne@69: PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr,
jpayne@69: png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
jpayne@69: png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
jpayne@69: png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
jpayne@69: png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
jpayne@69: png_fixed_point *int_blue_Z))
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_cHRM_SUPPORTED
jpayne@69: PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr,
jpayne@69: double white_x, double white_y, double red_x, double red_y, double green_x,
jpayne@69: double green_y, double blue_x, double blue_y))
jpayne@69: PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, double red_X, double red_Y, double red_Z,
jpayne@69: double green_X, double green_Y, double green_Z, double blue_X,
jpayne@69: double blue_Y, double blue_Z))
jpayne@69: PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_fixed_point int_white_x,
jpayne@69: png_fixed_point int_white_y, png_fixed_point int_red_x,
jpayne@69: png_fixed_point int_red_y, png_fixed_point int_green_x,
jpayne@69: png_fixed_point int_green_y, png_fixed_point int_blue_x,
jpayne@69: png_fixed_point int_blue_y))
jpayne@69: PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
jpayne@69: png_fixed_point int_red_Z, png_fixed_point int_green_X,
jpayne@69: png_fixed_point int_green_Y, png_fixed_point int_green_Z,
jpayne@69: png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
jpayne@69: png_fixed_point int_blue_Z))
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_eXIf_SUPPORTED
jpayne@69: PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_bytep *exif));
jpayne@69: PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_bytep exif));
jpayne@69:
jpayne@69: PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
jpayne@69: PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_gAMA_SUPPORTED
jpayne@69: PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, double *file_gamma))
jpayne@69: PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr,
jpayne@69: png_fixed_point *int_file_gamma))
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_gAMA_SUPPORTED
jpayne@69: PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, double file_gamma))
jpayne@69: PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_fixed_point int_file_gamma))
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_hIST_SUPPORTED
jpayne@69: PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_uint_16p *hist));
jpayne@69: PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_uint_16p hist));
jpayne@69: #endif
jpayne@69:
jpayne@69: PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
jpayne@69: int *bit_depth, int *color_type, int *interlace_method,
jpayne@69: int *compression_method, int *filter_method));
jpayne@69:
jpayne@69: PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
jpayne@69: int color_type, int interlace_method, int compression_method,
jpayne@69: int filter_method));
jpayne@69:
jpayne@69: #ifdef PNG_oFFs_SUPPORTED
jpayne@69: PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
jpayne@69: int *unit_type));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_oFFs_SUPPORTED
jpayne@69: PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
jpayne@69: int unit_type));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_pCAL_SUPPORTED
jpayne@69: PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
jpayne@69: png_int_32 *X1, int *type, int *nparams, png_charp *units,
jpayne@69: png_charpp *params));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_pCAL_SUPPORTED
jpayne@69: PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
jpayne@69: int type, int nparams, png_const_charp units, png_charpp params));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_pHYs_SUPPORTED
jpayne@69: PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
jpayne@69: int *unit_type));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_pHYs_SUPPORTED
jpayne@69: PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
jpayne@69: #endif
jpayne@69:
jpayne@69: PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_colorp *palette, int *num_palette));
jpayne@69:
jpayne@69: PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_colorp palette, int num_palette));
jpayne@69:
jpayne@69: #ifdef PNG_sBIT_SUPPORTED
jpayne@69: PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_color_8p *sig_bit));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_sBIT_SUPPORTED
jpayne@69: PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_color_8p sig_bit));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_sRGB_SUPPORTED
jpayne@69: PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, int *file_srgb_intent));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_sRGB_SUPPORTED
jpayne@69: PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, int srgb_intent));
jpayne@69: PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, int srgb_intent));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_iCCP_SUPPORTED
jpayne@69: PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_charpp name, int *compression_type,
jpayne@69: png_bytepp profile, png_uint_32 *proflen));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_iCCP_SUPPORTED
jpayne@69: PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_charp name, int compression_type,
jpayne@69: png_const_bytep profile, png_uint_32 proflen));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_sPLT_SUPPORTED
jpayne@69: PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_sPLT_tpp entries));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_sPLT_SUPPORTED
jpayne@69: PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_TEXT_SUPPORTED
jpayne@69: /* png_get_text also returns the number of text chunks in *num_text */
jpayne@69: PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_textp *text_ptr, int *num_text));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Note while png_set_text() will accept a structure whose text,
jpayne@69: * language, and translated keywords are NULL pointers, the structure
jpayne@69: * returned by png_get_text will always contain regular
jpayne@69: * zero-terminated C strings. They might be empty strings but
jpayne@69: * they will never be NULL pointers.
jpayne@69: */
jpayne@69:
jpayne@69: #ifdef PNG_TEXT_SUPPORTED
jpayne@69: PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_textp text_ptr, int num_text));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_tIME_SUPPORTED
jpayne@69: PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_timep *mod_time));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_tIME_SUPPORTED
jpayne@69: PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_timep mod_time));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_tRNS_SUPPORTED
jpayne@69: PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
jpayne@69: png_color_16p *trans_color));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_tRNS_SUPPORTED
jpayne@69: PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
jpayne@69: png_const_color_16p trans_color));
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_sCAL_SUPPORTED
jpayne@69: PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, int *unit, double *width, double *height))
jpayne@69: #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
jpayne@69: defined(PNG_FLOATING_POINT_SUPPORTED)
jpayne@69: /* NOTE: this API is currently implemented using floating point arithmetic,
jpayne@69: * consequently it can only be used on systems with floating point support.
jpayne@69: * In any case the range of values supported by png_fixed_point is small and it
jpayne@69: * is highly recommended that png_get_sCAL_s be used instead.
jpayne@69: */
jpayne@69: PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
jpayne@69: png_fixed_point *width, png_fixed_point *height))
jpayne@69: #endif
jpayne@69: PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
jpayne@69: png_charpp swidth, png_charpp sheight));
jpayne@69:
jpayne@69: PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, int unit, double width, double height))
jpayne@69: PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, int unit, png_fixed_point width,
jpayne@69: png_fixed_point height))
jpayne@69: PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, int unit,
jpayne@69: png_const_charp swidth, png_const_charp sheight));
jpayne@69: #endif /* sCAL */
jpayne@69:
jpayne@69: #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
jpayne@69: /* Provide the default handling for all unknown chunks or, optionally, for
jpayne@69: * specific unknown chunks.
jpayne@69: *
jpayne@69: * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
jpayne@69: * ignored and the default was used, the per-chunk setting only had an effect on
jpayne@69: * write. If you wish to have chunk-specific handling on read in code that must
jpayne@69: * work on earlier versions you must use a user chunk callback to specify the
jpayne@69: * desired handling (keep or discard.)
jpayne@69: *
jpayne@69: * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
jpayne@69: * parameter is interpreted as follows:
jpayne@69: *
jpayne@69: * READ:
jpayne@69: * PNG_HANDLE_CHUNK_AS_DEFAULT:
jpayne@69: * Known chunks: do normal libpng processing, do not keep the chunk (but
jpayne@69: * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
jpayne@69: * Unknown chunks: for a specific chunk use the global default, when used
jpayne@69: * as the default discard the chunk data.
jpayne@69: * PNG_HANDLE_CHUNK_NEVER:
jpayne@69: * Discard the chunk data.
jpayne@69: * PNG_HANDLE_CHUNK_IF_SAFE:
jpayne@69: * Keep the chunk data if the chunk is not critical else raise a chunk
jpayne@69: * error.
jpayne@69: * PNG_HANDLE_CHUNK_ALWAYS:
jpayne@69: * Keep the chunk data.
jpayne@69: *
jpayne@69: * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
jpayne@69: * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
jpayne@69: * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
jpayne@69: * it simply resets the behavior to the libpng default.
jpayne@69: *
jpayne@69: * INTERACTION WITH USER CHUNK CALLBACKS:
jpayne@69: * The per-chunk handling is always used when there is a png_user_chunk_ptr
jpayne@69: * callback and the callback returns 0; the chunk is then always stored *unless*
jpayne@69: * it is critical and the per-chunk setting is other than ALWAYS. Notice that
jpayne@69: * the global default is *not* used in this case. (In effect the per-chunk
jpayne@69: * value is incremented to at least IF_SAFE.)
jpayne@69: *
jpayne@69: * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
jpayne@69: * per-chunk defaults will be honored. If you want to preserve the current
jpayne@69: * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
jpayne@69: * as the default - if you don't do this libpng 1.6 will issue a warning.
jpayne@69: *
jpayne@69: * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
jpayne@69: * earlier simply return '1' (handled).
jpayne@69: *
jpayne@69: * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
jpayne@69: * If this is *not* set known chunks will always be handled by libpng and
jpayne@69: * will never be stored in the unknown chunk list. Known chunks listed to
jpayne@69: * png_set_keep_unknown_chunks will have no effect. If it is set then known
jpayne@69: * chunks listed with a keep other than AS_DEFAULT will *never* be processed
jpayne@69: * by libpng, in addition critical chunks must either be processed by the
jpayne@69: * callback or saved.
jpayne@69: *
jpayne@69: * The IHDR and IEND chunks must not be listed. Because this turns off the
jpayne@69: * default handling for chunks that would otherwise be recognized the
jpayne@69: * behavior of libpng transformations may well become incorrect!
jpayne@69: *
jpayne@69: * WRITE:
jpayne@69: * When writing chunks the options only apply to the chunks specified by
jpayne@69: * png_set_unknown_chunks (below), libpng will *always* write known chunks
jpayne@69: * required by png_set_ calls and will always write the core critical chunks
jpayne@69: * (as required for PLTE).
jpayne@69: *
jpayne@69: * Each chunk in the png_set_unknown_chunks list is looked up in the
jpayne@69: * png_set_keep_unknown_chunks list to find the keep setting, this is then
jpayne@69: * interpreted as follows:
jpayne@69: *
jpayne@69: * PNG_HANDLE_CHUNK_AS_DEFAULT:
jpayne@69: * Write safe-to-copy chunks and write other chunks if the global
jpayne@69: * default is set to _ALWAYS, otherwise don't write this chunk.
jpayne@69: * PNG_HANDLE_CHUNK_NEVER:
jpayne@69: * Do not write the chunk.
jpayne@69: * PNG_HANDLE_CHUNK_IF_SAFE:
jpayne@69: * Write the chunk if it is safe-to-copy, otherwise do not write it.
jpayne@69: * PNG_HANDLE_CHUNK_ALWAYS:
jpayne@69: * Write the chunk.
jpayne@69: *
jpayne@69: * Note that the default behavior is effectively the opposite of the read case -
jpayne@69: * in read unknown chunks are not stored by default, in write they are written
jpayne@69: * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
jpayne@69: * - on write the safe-to-copy bit is checked, on read the critical bit is
jpayne@69: * checked and on read if the chunk is critical an error will be raised.
jpayne@69: *
jpayne@69: * num_chunks:
jpayne@69: * ===========
jpayne@69: * If num_chunks is positive, then the "keep" parameter specifies the manner
jpayne@69: * for handling only those chunks appearing in the chunk_list array,
jpayne@69: * otherwise the chunk list array is ignored.
jpayne@69: *
jpayne@69: * If num_chunks is 0 the "keep" parameter specifies the default behavior for
jpayne@69: * unknown chunks, as described above.
jpayne@69: *
jpayne@69: * If num_chunks is negative, then the "keep" parameter specifies the manner
jpayne@69: * for handling all unknown chunks plus all chunks recognized by libpng
jpayne@69: * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
jpayne@69: * be processed by libpng.
jpayne@69: */
jpayne@69: #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
jpayne@69: PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
jpayne@69: int keep, png_const_bytep chunk_list, int num_chunks));
jpayne@69: #endif /* HANDLE_AS_UNKNOWN */
jpayne@69:
jpayne@69: /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
jpayne@69: * the result is therefore true (non-zero) if special handling is required,
jpayne@69: * false for the default handling.
jpayne@69: */
jpayne@69: PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
jpayne@69: png_const_bytep chunk_name));
jpayne@69: #endif /* SET_UNKNOWN_CHUNKS */
jpayne@69:
jpayne@69: #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
jpayne@69: PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_const_unknown_chunkp unknowns,
jpayne@69: int num_unknowns));
jpayne@69: /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
jpayne@69: * unknowns to the location currently stored in the png_struct. This is
jpayne@69: * invariably the wrong value on write. To fix this call the following API
jpayne@69: * for each chunk in the list with the correct location. If you know your
jpayne@69: * code won't be compiled on earlier versions you can rely on
jpayne@69: * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
jpayne@69: * the correct thing.
jpayne@69: */
jpayne@69:
jpayne@69: PNG_EXPORT(175, void, png_set_unknown_chunk_location,
jpayne@69: (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
jpayne@69:
jpayne@69: PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, png_unknown_chunkpp entries));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Png_free_data() will turn off the "valid" flag for anything it frees.
jpayne@69: * If you need to turn it off for a chunk that your application has freed,
jpayne@69: * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
jpayne@69: */
jpayne@69: PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
jpayne@69: png_inforp info_ptr, int mask));
jpayne@69:
jpayne@69: #ifdef PNG_INFO_IMAGE_SUPPORTED
jpayne@69: /* The "params" pointer is currently not used and is for future expansion. */
jpayne@69: #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
jpayne@69: PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
jpayne@69: int transforms, png_voidp params));
jpayne@69: #endif
jpayne@69: #ifdef PNG_WRITE_SUPPORTED
jpayne@69: PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
jpayne@69: int transforms, png_voidp params));
jpayne@69: #endif
jpayne@69: #endif
jpayne@69:
jpayne@69: PNG_EXPORT(180, png_const_charp, png_get_copyright,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69: PNG_EXPORT(181, png_const_charp, png_get_header_ver,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69: PNG_EXPORT(182, png_const_charp, png_get_header_version,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69: PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69:
jpayne@69: #ifdef PNG_MNG_FEATURES_SUPPORTED
jpayne@69: PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
jpayne@69: png_uint_32 mng_features_permitted));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* For use in png_set_keep_unknown, added to version 1.2.6 */
jpayne@69: #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
jpayne@69: #define PNG_HANDLE_CHUNK_NEVER 1
jpayne@69: #define PNG_HANDLE_CHUNK_IF_SAFE 2
jpayne@69: #define PNG_HANDLE_CHUNK_ALWAYS 3
jpayne@69: #define PNG_HANDLE_CHUNK_LAST 4
jpayne@69:
jpayne@69: /* Strip the prepended error numbers ("#nnn ") from error and warning
jpayne@69: * messages before passing them to the error or warning handler.
jpayne@69: */
jpayne@69: #ifdef PNG_ERROR_NUMBERS_SUPPORTED
jpayne@69: PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
jpayne@69: png_uint_32 strip_mode));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Added in libpng-1.2.6 */
jpayne@69: #ifdef PNG_SET_USER_LIMITS_SUPPORTED
jpayne@69: PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
jpayne@69: png_uint_32 user_width_max, png_uint_32 user_height_max));
jpayne@69: PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69: PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69: /* Added in libpng-1.4.0 */
jpayne@69: PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
jpayne@69: png_uint_32 user_chunk_cache_max));
jpayne@69: PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69: /* Added in libpng-1.4.1 */
jpayne@69: PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
jpayne@69: png_alloc_size_t user_chunk_cache_max));
jpayne@69: PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69: #endif
jpayne@69:
jpayne@69: #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
jpayne@69: PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69:
jpayne@69: PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69:
jpayne@69: PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr));
jpayne@69:
jpayne@69: PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr))
jpayne@69: #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
jpayne@69: PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr))
jpayne@69: #endif
jpayne@69:
jpayne@69: PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr))
jpayne@69: #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
jpayne@69: PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
jpayne@69: (png_const_structrp png_ptr, png_const_inforp info_ptr))
jpayne@69: #endif
jpayne@69:
jpayne@69: # ifdef PNG_pHYs_SUPPORTED
jpayne@69: PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
jpayne@69: png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
jpayne@69: int *unit_type));
jpayne@69: # endif /* pHYs */
jpayne@69: #endif /* INCH_CONVERSIONS */
jpayne@69:
jpayne@69: /* Added in libpng-1.4.0 */
jpayne@69: #ifdef PNG_IO_STATE_SUPPORTED
jpayne@69: PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
jpayne@69:
jpayne@69: /* Removed from libpng 1.6; use png_get_io_chunk_type. */
jpayne@69: PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
jpayne@69: PNG_DEPRECATED)
jpayne@69:
jpayne@69: PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
jpayne@69: (png_const_structrp png_ptr));
jpayne@69:
jpayne@69: /* The flags returned by png_get_io_state() are the following: */
jpayne@69: # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
jpayne@69: # define PNG_IO_READING 0x0001 /* currently reading */
jpayne@69: # define PNG_IO_WRITING 0x0002 /* currently writing */
jpayne@69: # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
jpayne@69: # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
jpayne@69: # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
jpayne@69: # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
jpayne@69: # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
jpayne@69: # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
jpayne@69: #endif /* IO_STATE */
jpayne@69:
jpayne@69: /* Interlace support. The following macros are always defined so that if
jpayne@69: * libpng interlace handling is turned off the macros may be used to handle
jpayne@69: * interlaced images within the application.
jpayne@69: */
jpayne@69: #define PNG_INTERLACE_ADAM7_PASSES 7
jpayne@69:
jpayne@69: /* Two macros to return the first row and first column of the original,
jpayne@69: * full, image which appears in a given pass. 'pass' is in the range 0
jpayne@69: * to 6 and the result is in the range 0 to 7.
jpayne@69: */
jpayne@69: #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
jpayne@69: #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
jpayne@69:
jpayne@69: /* A macro to return the offset between pixels in the output row for a pair of
jpayne@69: * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
jpayne@69: * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
jpayne@69: * COL_OFFSET is from one column to the next, within a row.
jpayne@69: */
jpayne@69: #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
jpayne@69: #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
jpayne@69:
jpayne@69: /* Two macros to help evaluate the number of rows or columns in each
jpayne@69: * pass. This is expressed as a shift - effectively log2 of the number or
jpayne@69: * rows or columns in each 8x8 tile of the original image.
jpayne@69: */
jpayne@69: #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
jpayne@69: #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
jpayne@69:
jpayne@69: /* Hence two macros to determine the number of rows or columns in a given
jpayne@69: * pass of an image given its height or width. In fact these macros may
jpayne@69: * return non-zero even though the sub-image is empty, because the other
jpayne@69: * dimension may be empty for a small image.
jpayne@69: */
jpayne@69: #define PNG_PASS_ROWS(height, pass) (((height)+(((1<>PNG_PASS_ROW_SHIFT(pass))
jpayne@69: #define PNG_PASS_COLS(width, pass) (((width)+(((1<>PNG_PASS_COL_SHIFT(pass))
jpayne@69:
jpayne@69: /* For the reader row callbacks (both progressive and sequential) it is
jpayne@69: * necessary to find the row in the output image given a row in an interlaced
jpayne@69: * image, so two more macros:
jpayne@69: */
jpayne@69: #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
jpayne@69: (((y_in)<>(((7-(off))-(pass))<<2)) & 0xF) | \
jpayne@69: ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
jpayne@69:
jpayne@69: #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
jpayne@69: ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
jpayne@69: #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
jpayne@69: ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
jpayne@69:
jpayne@69: #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
jpayne@69: /* With these routines we avoid an integer divide, which will be slower on
jpayne@69: * most machines. However, it does take more operations than the corresponding
jpayne@69: * divide method, so it may be slower on a few RISC systems. There are two
jpayne@69: * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
jpayne@69: *
jpayne@69: * Note that the rounding factors are NOT supposed to be the same! 128 and
jpayne@69: * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
jpayne@69: * standard method.
jpayne@69: *
jpayne@69: * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
jpayne@69: */
jpayne@69:
jpayne@69: /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
jpayne@69:
jpayne@69: # define png_composite(composite, fg, alpha, bg) \
jpayne@69: { \
jpayne@69: png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
jpayne@69: * (png_uint_16)(alpha) \
jpayne@69: + (png_uint_16)(bg)*(png_uint_16)(255 \
jpayne@69: - (png_uint_16)(alpha)) + 128); \
jpayne@69: (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
jpayne@69: }
jpayne@69:
jpayne@69: # define png_composite_16(composite, fg, alpha, bg) \
jpayne@69: { \
jpayne@69: png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
jpayne@69: * (png_uint_32)(alpha) \
jpayne@69: + (png_uint_32)(bg)*(65535 \
jpayne@69: - (png_uint_32)(alpha)) + 32768); \
jpayne@69: (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
jpayne@69: }
jpayne@69:
jpayne@69: #else /* Standard method using integer division */
jpayne@69:
jpayne@69: # define png_composite(composite, fg, alpha, bg) \
jpayne@69: (composite) = \
jpayne@69: (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
jpayne@69: (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
jpayne@69: 127) / 255))
jpayne@69:
jpayne@69: # define png_composite_16(composite, fg, alpha, bg) \
jpayne@69: (composite) = \
jpayne@69: (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
jpayne@69: (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
jpayne@69: 32767) / 65535))
jpayne@69: #endif /* READ_COMPOSITE_NODIV */
jpayne@69:
jpayne@69: #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
jpayne@69: PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
jpayne@69: PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
jpayne@69: PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
jpayne@69: #endif
jpayne@69:
jpayne@69: PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
jpayne@69: png_const_bytep buf));
jpayne@69: /* No png_get_int_16 -- may be added if there's a real need for it. */
jpayne@69:
jpayne@69: /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
jpayne@69: #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
jpayne@69: PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
jpayne@69: #endif
jpayne@69: #ifdef PNG_SAVE_INT_32_SUPPORTED
jpayne@69: PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
jpayne@69: #endif
jpayne@69:
jpayne@69: /* Place a 16-bit number into a buffer in PNG byte order.
jpayne@69: * The parameter is declared unsigned int, not png_uint_16,
jpayne@69: * just to avoid potential problems on pre-ANSI C compilers.
jpayne@69: */
jpayne@69: #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
jpayne@69: PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
jpayne@69: /* No png_save_int_16 -- may be added if there's a real need for it. */
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_USE_READ_MACROS
jpayne@69: /* Inline macros to do direct reads of bytes from the input buffer.
jpayne@69: * The png_get_int_32() routine assumes we are using two's complement
jpayne@69: * format for negative values, which is almost certainly true.
jpayne@69: */
jpayne@69: # define PNG_get_uint_32(buf) \
jpayne@69: (((png_uint_32)(*(buf)) << 24) + \
jpayne@69: ((png_uint_32)(*((buf) + 1)) << 16) + \
jpayne@69: ((png_uint_32)(*((buf) + 2)) << 8) + \
jpayne@69: ((png_uint_32)(*((buf) + 3))))
jpayne@69:
jpayne@69: /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
jpayne@69: * function) incorrectly returned a value of type png_uint_32.
jpayne@69: */
jpayne@69: # define PNG_get_uint_16(buf) \
jpayne@69: ((png_uint_16) \
jpayne@69: (((unsigned int)(*(buf)) << 8) + \
jpayne@69: ((unsigned int)(*((buf) + 1)))))
jpayne@69:
jpayne@69: # define PNG_get_int_32(buf) \
jpayne@69: ((png_int_32)((*(buf) & 0x80) \
jpayne@69: ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
jpayne@69: : (png_int_32)png_get_uint_32(buf)))
jpayne@69:
jpayne@69: /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
jpayne@69: * but defining a macro name prefixed with PNG_PREFIX.
jpayne@69: */
jpayne@69: # ifndef PNG_PREFIX
jpayne@69: # define png_get_uint_32(buf) PNG_get_uint_32(buf)
jpayne@69: # define png_get_uint_16(buf) PNG_get_uint_16(buf)
jpayne@69: # define png_get_int_32(buf) PNG_get_int_32(buf)
jpayne@69: # endif
jpayne@69: #else
jpayne@69: # ifdef PNG_PREFIX
jpayne@69: /* No macros; revert to the (redefined) function */
jpayne@69: # define PNG_get_uint_32 (png_get_uint_32)
jpayne@69: # define PNG_get_uint_16 (png_get_uint_16)
jpayne@69: # define PNG_get_int_32 (png_get_int_32)
jpayne@69: # endif
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
jpayne@69: PNG_EXPORT(242, void, png_set_check_for_invalid_index,
jpayne@69: (png_structrp png_ptr, int allowed));
jpayne@69: # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
jpayne@69: PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
jpayne@69: png_const_infop info_ptr));
jpayne@69: # endif
jpayne@69: #endif /* CHECK_FOR_INVALID_INDEX */
jpayne@69:
jpayne@69: /*******************************************************************************
jpayne@69: * Section 5: SIMPLIFIED API
jpayne@69: *******************************************************************************
jpayne@69: *
jpayne@69: * Please read the documentation in libpng-manual.txt (TODO: write said
jpayne@69: * documentation) if you don't understand what follows.
jpayne@69: *
jpayne@69: * The simplified API hides the details of both libpng and the PNG file format
jpayne@69: * itself. It allows PNG files to be read into a very limited number of
jpayne@69: * in-memory bitmap formats or to be written from the same formats. If these
jpayne@69: * formats do not accommodate your needs then you can, and should, use the more
jpayne@69: * sophisticated APIs above - these support a wide variety of in-memory formats
jpayne@69: * and a wide variety of sophisticated transformations to those formats as well
jpayne@69: * as a wide variety of APIs to manipulate ancillary information.
jpayne@69: *
jpayne@69: * To read a PNG file using the simplified API:
jpayne@69: *
jpayne@69: * 1) Declare a 'png_image' structure (see below) on the stack, set the
jpayne@69: * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
jpayne@69: * (this is REQUIRED, your program may crash if you don't do it.)
jpayne@69: * 2) Call the appropriate png_image_begin_read... function.
jpayne@69: * 3) Set the png_image 'format' member to the required sample format.
jpayne@69: * 4) Allocate a buffer for the image and, if required, the color-map.
jpayne@69: * 5) Call png_image_finish_read to read the image and, if required, the
jpayne@69: * color-map into your buffers.
jpayne@69: *
jpayne@69: * There are no restrictions on the format of the PNG input itself; all valid
jpayne@69: * color types, bit depths, and interlace methods are acceptable, and the
jpayne@69: * input image is transformed as necessary to the requested in-memory format
jpayne@69: * during the png_image_finish_read() step. The only caveat is that if you
jpayne@69: * request a color-mapped image from a PNG that is full-color or makes
jpayne@69: * complex use of an alpha channel the transformation is extremely lossy and the
jpayne@69: * result may look terrible.
jpayne@69: *
jpayne@69: * To write a PNG file using the simplified API:
jpayne@69: *
jpayne@69: * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
jpayne@69: * 2) Initialize the members of the structure that describe the image, setting
jpayne@69: * the 'format' member to the format of the image samples.
jpayne@69: * 3) Call the appropriate png_image_write... function with a pointer to the
jpayne@69: * image and, if necessary, the color-map to write the PNG data.
jpayne@69: *
jpayne@69: * png_image is a structure that describes the in-memory format of an image
jpayne@69: * when it is being read or defines the in-memory format of an image that you
jpayne@69: * need to write:
jpayne@69: */
jpayne@69: #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
jpayne@69: defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
jpayne@69:
jpayne@69: #define PNG_IMAGE_VERSION 1
jpayne@69:
jpayne@69: typedef struct png_control *png_controlp;
jpayne@69: typedef struct
jpayne@69: {
jpayne@69: png_controlp opaque; /* Initialize to NULL, free with png_image_free */
jpayne@69: png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
jpayne@69: png_uint_32 width; /* Image width in pixels (columns) */
jpayne@69: png_uint_32 height; /* Image height in pixels (rows) */
jpayne@69: png_uint_32 format; /* Image format as defined below */
jpayne@69: png_uint_32 flags; /* A bit mask containing informational flags */
jpayne@69: png_uint_32 colormap_entries;
jpayne@69: /* Number of entries in the color-map */
jpayne@69:
jpayne@69: /* In the event of an error or warning the following field will be set to a
jpayne@69: * non-zero value and the 'message' field will contain a '\0' terminated
jpayne@69: * string with the libpng error or warning message. If both warnings and
jpayne@69: * an error were encountered, only the error is recorded. If there
jpayne@69: * are multiple warnings, only the first one is recorded.
jpayne@69: *
jpayne@69: * The upper 30 bits of this value are reserved, the low two bits contain
jpayne@69: * a value as follows:
jpayne@69: */
jpayne@69: # define PNG_IMAGE_WARNING 1
jpayne@69: # define PNG_IMAGE_ERROR 2
jpayne@69: /*
jpayne@69: * The result is a two-bit code such that a value more than 1 indicates
jpayne@69: * a failure in the API just called:
jpayne@69: *
jpayne@69: * 0 - no warning or error
jpayne@69: * 1 - warning
jpayne@69: * 2 - error
jpayne@69: * 3 - error preceded by warning
jpayne@69: */
jpayne@69: # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
jpayne@69:
jpayne@69: png_uint_32 warning_or_error;
jpayne@69:
jpayne@69: char message[64];
jpayne@69: } png_image, *png_imagep;
jpayne@69:
jpayne@69: /* The samples of the image have one to four channels whose components have
jpayne@69: * original values in the range 0 to 1.0:
jpayne@69: *
jpayne@69: * 1: A single gray or luminance channel (G).
jpayne@69: * 2: A gray/luminance channel and an alpha channel (GA).
jpayne@69: * 3: Three red, green, blue color channels (RGB).
jpayne@69: * 4: Three color channels and an alpha channel (RGBA).
jpayne@69: *
jpayne@69: * The components are encoded in one of two ways:
jpayne@69: *
jpayne@69: * a) As a small integer, value 0..255, contained in a single byte. For the
jpayne@69: * alpha channel the original value is simply value/255. For the color or
jpayne@69: * luminance channels the value is encoded according to the sRGB specification
jpayne@69: * and matches the 8-bit format expected by typical display devices.
jpayne@69: *
jpayne@69: * The color/gray channels are not scaled (pre-multiplied) by the alpha
jpayne@69: * channel and are suitable for passing to color management software.
jpayne@69: *
jpayne@69: * b) As a value in the range 0..65535, contained in a 2-byte integer. All
jpayne@69: * channels can be converted to the original value by dividing by 65535; all
jpayne@69: * channels are linear. Color channels use the RGB encoding (RGB end-points) of
jpayne@69: * the sRGB specification. This encoding is identified by the
jpayne@69: * PNG_FORMAT_FLAG_LINEAR flag below.
jpayne@69: *
jpayne@69: * When the simplified API needs to convert between sRGB and linear colorspaces,
jpayne@69: * the actual sRGB transfer curve defined in the sRGB specification (see the
jpayne@69: * article at ) is used, not the gamma=1/2.2
jpayne@69: * approximation used elsewhere in libpng.
jpayne@69: *
jpayne@69: * When an alpha channel is present it is expected to denote pixel coverage
jpayne@69: * of the color or luminance channels and is returned as an associated alpha
jpayne@69: * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
jpayne@69: * value.
jpayne@69: *
jpayne@69: * The samples are either contained directly in the image data, between 1 and 8
jpayne@69: * bytes per pixel according to the encoding, or are held in a color-map indexed
jpayne@69: * by bytes in the image data. In the case of a color-map the color-map entries
jpayne@69: * are individual samples, encoded as above, and the image data has one byte per
jpayne@69: * pixel to select the relevant sample from the color-map.
jpayne@69: */
jpayne@69:
jpayne@69: /* PNG_FORMAT_*
jpayne@69: *
jpayne@69: * #defines to be used in png_image::format. Each #define identifies a
jpayne@69: * particular layout of sample data and, if present, alpha values. There are
jpayne@69: * separate defines for each of the two component encodings.
jpayne@69: *
jpayne@69: * A format is built up using single bit flag values. All combinations are
jpayne@69: * valid. Formats can be built up from the flag values or you can use one of
jpayne@69: * the predefined values below. When testing formats always use the FORMAT_FLAG
jpayne@69: * macros to test for individual features - future versions of the library may
jpayne@69: * add new flags.
jpayne@69: *
jpayne@69: * When reading or writing color-mapped images the format should be set to the
jpayne@69: * format of the entries in the color-map then png_image_{read,write}_colormap
jpayne@69: * called to read or write the color-map and set the format correctly for the
jpayne@69: * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
jpayne@69: *
jpayne@69: * NOTE: libpng can be built with particular features disabled. If you see
jpayne@69: * compiler errors because the definition of one of the following flags has been
jpayne@69: * compiled out it is because libpng does not have the required support. It is
jpayne@69: * possible, however, for the libpng configuration to enable the format on just
jpayne@69: * read or just write; in that case you may see an error at run time. You can
jpayne@69: * guard against this by checking for the definition of the appropriate
jpayne@69: * "_SUPPORTED" macro, one of:
jpayne@69: *
jpayne@69: * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
jpayne@69: */
jpayne@69: #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
jpayne@69: #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
jpayne@69: #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
jpayne@69: #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
jpayne@69:
jpayne@69: #ifdef PNG_FORMAT_BGR_SUPPORTED
jpayne@69: # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef PNG_FORMAT_AFIRST_SUPPORTED
jpayne@69: # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
jpayne@69: #endif
jpayne@69:
jpayne@69: #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
jpayne@69:
jpayne@69: /* Commonly used formats have predefined macros.
jpayne@69: *
jpayne@69: * First the single byte (sRGB) formats:
jpayne@69: */
jpayne@69: #define PNG_FORMAT_GRAY 0
jpayne@69: #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
jpayne@69: #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
jpayne@69: #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
jpayne@69: #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
jpayne@69: #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
jpayne@69: #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
jpayne@69: #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
jpayne@69: #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
jpayne@69:
jpayne@69: /* Then the linear 2-byte formats. When naming these "Y" is used to
jpayne@69: * indicate a luminance (gray) channel.
jpayne@69: */
jpayne@69: #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
jpayne@69: #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
jpayne@69: #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
jpayne@69: #define PNG_FORMAT_LINEAR_RGB_ALPHA \
jpayne@69: (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
jpayne@69:
jpayne@69: /* With color-mapped formats the image data is one byte for each pixel, the byte
jpayne@69: * is an index into the color-map which is formatted as above. To obtain a
jpayne@69: * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
jpayne@69: * to one of the above definitions, or you can use one of the definitions below.
jpayne@69: */
jpayne@69: #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
jpayne@69: #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
jpayne@69: #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
jpayne@69: #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
jpayne@69: #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
jpayne@69: #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
jpayne@69:
jpayne@69: /* PNG_IMAGE macros
jpayne@69: *
jpayne@69: * These are convenience macros to derive information from a png_image
jpayne@69: * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
jpayne@69: * actual image sample values - either the entries in the color-map or the
jpayne@69: * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
jpayne@69: * for the pixels and will always return 1 for color-mapped formats. The
jpayne@69: * remaining macros return information about the rows in the image and the
jpayne@69: * complete image.
jpayne@69: *
jpayne@69: * NOTE: All the macros that take a png_image::format parameter are compile time
jpayne@69: * constants if the format parameter is, itself, a constant. Therefore these
jpayne@69: * macros can be used in array declarations and case labels where required.
jpayne@69: * Similarly the macros are also pre-processor constants (sizeof is not used) so
jpayne@69: * they can be used in #if tests.
jpayne@69: *
jpayne@69: * First the information about the samples.
jpayne@69: */
jpayne@69: #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
jpayne@69: (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
jpayne@69: /* Return the total number of channels in a given format: 1..4 */
jpayne@69:
jpayne@69: #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
jpayne@69: ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
jpayne@69: /* Return the size in bytes of a single component of a pixel or color-map
jpayne@69: * entry (as appropriate) in the image: 1 or 2.
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
jpayne@69: (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
jpayne@69: /* This is the size of the sample data for one sample. If the image is
jpayne@69: * color-mapped it is the size of one color-map entry (and image pixels are
jpayne@69: * one byte in size), otherwise it is the size of one image pixel.
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
jpayne@69: (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
jpayne@69: /* The maximum size of the color-map required by the format expressed in a
jpayne@69: * count of components. This can be used to compile-time allocate a
jpayne@69: * color-map:
jpayne@69: *
jpayne@69: * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
jpayne@69: *
jpayne@69: * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
jpayne@69: *
jpayne@69: * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
jpayne@69: * information from one of the png_image_begin_read_ APIs and dynamically
jpayne@69: * allocate the required memory.
jpayne@69: */
jpayne@69:
jpayne@69: /* Corresponding information about the pixels */
jpayne@69: #define PNG_IMAGE_PIXEL_(test,fmt)\
jpayne@69: (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
jpayne@69:
jpayne@69: #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
jpayne@69: PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
jpayne@69: /* The number of separate channels (components) in a pixel; 1 for a
jpayne@69: * color-mapped image.
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
jpayne@69: PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
jpayne@69: /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
jpayne@69: * image.
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
jpayne@69: /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
jpayne@69:
jpayne@69: /* Information about the whole row, or whole image */
jpayne@69: #define PNG_IMAGE_ROW_STRIDE(image)\
jpayne@69: (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
jpayne@69: /* Return the total number of components in a single row of the image; this
jpayne@69: * is the minimum 'row stride', the minimum count of components between each
jpayne@69: * row. For a color-mapped image this is the minimum number of bytes in a
jpayne@69: * row.
jpayne@69: *
jpayne@69: * WARNING: this macro overflows for some images with more than one component
jpayne@69: * and very large image widths. libpng will refuse to process an image where
jpayne@69: * this macro would overflow.
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
jpayne@69: (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
jpayne@69: /* Return the size, in bytes, of an image buffer given a png_image and a row
jpayne@69: * stride - the number of components to leave space for in each row.
jpayne@69: *
jpayne@69: * WARNING: this macro overflows a 32-bit integer for some large PNG images,
jpayne@69: * libpng will refuse to process an image where such an overflow would occur.
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_SIZE(image)\
jpayne@69: PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
jpayne@69: /* Return the size, in bytes, of the image in memory given just a png_image;
jpayne@69: * the row stride is the minimum stride required for the image.
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_COLORMAP_SIZE(image)\
jpayne@69: (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
jpayne@69: /* Return the size, in bytes, of the color-map of this image. If the image
jpayne@69: * format is not a color-map format this will return a size sufficient for
jpayne@69: * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
jpayne@69: * you don't want to allocate a color-map in this case.
jpayne@69: */
jpayne@69:
jpayne@69: /* PNG_IMAGE_FLAG_*
jpayne@69: *
jpayne@69: * Flags containing additional information about the image are held in the
jpayne@69: * 'flags' field of png_image.
jpayne@69: */
jpayne@69: #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
jpayne@69: /* This indicates that the RGB values of the in-memory bitmap do not
jpayne@69: * correspond to the red, green and blue end-points defined by sRGB.
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_FLAG_FAST 0x02
jpayne@69: /* On write emphasise speed over compression; the resultant PNG file will be
jpayne@69: * larger but will be produced significantly faster, particular for large
jpayne@69: * images. Do not use this option for images which will be distributed, only
jpayne@69: * used it when producing intermediate files that will be read back in
jpayne@69: * repeatedly. For a typical 24-bit image the option will double the read
jpayne@69: * speed at the cost of increasing the image size by 25%, however for many
jpayne@69: * more compressible images the PNG file can be 10 times larger with only a
jpayne@69: * slight speed gain.
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
jpayne@69: /* On read if the image is a 16-bit per component image and there is no gAMA
jpayne@69: * or sRGB chunk assume that the components are sRGB encoded. Notice that
jpayne@69: * images output by the simplified API always have gamma information; setting
jpayne@69: * this flag only affects the interpretation of 16-bit images from an
jpayne@69: * external source. It is recommended that the application expose this flag
jpayne@69: * to the user; the user can normally easily recognize the difference between
jpayne@69: * linear and sRGB encoding. This flag has no effect on write - the data
jpayne@69: * passed to the write APIs must have the correct encoding (as defined
jpayne@69: * above.)
jpayne@69: *
jpayne@69: * If the flag is not set (the default) input 16-bit per component data is
jpayne@69: * assumed to be linear.
jpayne@69: *
jpayne@69: * NOTE: the flag can only be set after the png_image_begin_read_ call,
jpayne@69: * because that call initializes the 'flags' field.
jpayne@69: */
jpayne@69:
jpayne@69: #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
jpayne@69: /* READ APIs
jpayne@69: * ---------
jpayne@69: *
jpayne@69: * The png_image passed to the read APIs must have been initialized by setting
jpayne@69: * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
jpayne@69: */
jpayne@69: #ifdef PNG_STDIO_SUPPORTED
jpayne@69: PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
jpayne@69: const char *file_name));
jpayne@69: /* The named file is opened for read and the image header is filled in
jpayne@69: * from the PNG header in the file.
jpayne@69: */
jpayne@69:
jpayne@69: PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
jpayne@69: FILE* file));
jpayne@69: /* The PNG header is read from the stdio FILE object. */
jpayne@69: #endif /* STDIO */
jpayne@69:
jpayne@69: PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
jpayne@69: png_const_voidp memory, size_t size));
jpayne@69: /* The PNG header is read from the given memory buffer. */
jpayne@69:
jpayne@69: PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
jpayne@69: png_const_colorp background, void *buffer, png_int_32 row_stride,
jpayne@69: void *colormap));
jpayne@69: /* Finish reading the image into the supplied buffer and clean up the
jpayne@69: * png_image structure.
jpayne@69: *
jpayne@69: * row_stride is the step, in byte or 2-byte units as appropriate,
jpayne@69: * between adjacent rows. A positive stride indicates that the top-most row
jpayne@69: * is first in the buffer - the normal top-down arrangement. A negative
jpayne@69: * stride indicates that the bottom-most row is first in the buffer.
jpayne@69: *
jpayne@69: * background need only be supplied if an alpha channel must be removed from
jpayne@69: * a png_byte format and the removal is to be done by compositing on a solid
jpayne@69: * color; otherwise it may be NULL and any composition will be done directly
jpayne@69: * onto the buffer. The value is an sRGB color to use for the background,
jpayne@69: * for grayscale output the green channel is used.
jpayne@69: *
jpayne@69: * background must be supplied when an alpha channel must be removed from a
jpayne@69: * single byte color-mapped output format, in other words if:
jpayne@69: *
jpayne@69: * 1) The original format from png_image_begin_read_from_* had
jpayne@69: * PNG_FORMAT_FLAG_ALPHA set.
jpayne@69: * 2) The format set by the application does not.
jpayne@69: * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
jpayne@69: * PNG_FORMAT_FLAG_LINEAR *not* set.
jpayne@69: *
jpayne@69: * For linear output removing the alpha channel is always done by compositing
jpayne@69: * on black and background is ignored.
jpayne@69: *
jpayne@69: * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
jpayne@69: * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
jpayne@69: * image->colormap_entries will be updated to the actual number of entries
jpayne@69: * written to the colormap; this may be less than the original value.
jpayne@69: */
jpayne@69:
jpayne@69: PNG_EXPORT(238, void, png_image_free, (png_imagep image));
jpayne@69: /* Free any data allocated by libpng in image->opaque, setting the pointer to
jpayne@69: * NULL. May be called at any time after the structure is initialized.
jpayne@69: */
jpayne@69: #endif /* SIMPLIFIED_READ */
jpayne@69:
jpayne@69: #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
jpayne@69: /* WRITE APIS
jpayne@69: * ----------
jpayne@69: * For write you must initialize a png_image structure to describe the image to
jpayne@69: * be written. To do this use memset to set the whole structure to 0 then
jpayne@69: * initialize fields describing your image.
jpayne@69: *
jpayne@69: * version: must be set to PNG_IMAGE_VERSION
jpayne@69: * opaque: must be initialized to NULL
jpayne@69: * width: image width in pixels
jpayne@69: * height: image height in rows
jpayne@69: * format: the format of the data (image and color-map) you wish to write
jpayne@69: * flags: set to 0 unless one of the defined flags applies; set
jpayne@69: * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
jpayne@69: * values do not correspond to the colors in sRGB.
jpayne@69: * colormap_entries: set to the number of entries in the color-map (0 to 256)
jpayne@69: */
jpayne@69: #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
jpayne@69: PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
jpayne@69: const char *file, int convert_to_8bit, const void *buffer,
jpayne@69: png_int_32 row_stride, const void *colormap));
jpayne@69: /* Write the image to the named file. */
jpayne@69:
jpayne@69: PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
jpayne@69: int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
jpayne@69: const void *colormap));
jpayne@69: /* Write the image to the given (FILE*). */
jpayne@69: #endif /* SIMPLIFIED_WRITE_STDIO */
jpayne@69:
jpayne@69: /* With all write APIs if image is in one of the linear formats with 16-bit
jpayne@69: * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
jpayne@69: * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
jpayne@69: * encoded PNG file is written.
jpayne@69: *
jpayne@69: * With color-mapped data formats the colormap parameter point to a color-map
jpayne@69: * with at least image->colormap_entries encoded in the specified format. If
jpayne@69: * the format is linear the written PNG color-map will be converted to sRGB
jpayne@69: * regardless of the convert_to_8_bit flag.
jpayne@69: *
jpayne@69: * With all APIs row_stride is handled as in the read APIs - it is the spacing
jpayne@69: * from one row to the next in component sized units (1 or 2 bytes) and if
jpayne@69: * negative indicates a bottom-up row layout in the buffer. If row_stride is
jpayne@69: * zero, libpng will calculate it for you from the image width and number of
jpayne@69: * channels.
jpayne@69: *
jpayne@69: * Note that the write API does not support interlacing, sub-8-bit pixels or
jpayne@69: * most ancillary chunks. If you need to write text chunks (e.g. for copyright
jpayne@69: * notices) you need to use one of the other APIs.
jpayne@69: */
jpayne@69:
jpayne@69: PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
jpayne@69: png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
jpayne@69: const void *buffer, png_int_32 row_stride, const void *colormap));
jpayne@69: /* Write the image to the given memory buffer. The function both writes the
jpayne@69: * whole PNG data stream to *memory and updates *memory_bytes with the count
jpayne@69: * of bytes written.
jpayne@69: *
jpayne@69: * 'memory' may be NULL. In this case *memory_bytes is not read however on
jpayne@69: * success the number of bytes which would have been written will still be
jpayne@69: * stored in *memory_bytes. On failure *memory_bytes will contain 0.
jpayne@69: *
jpayne@69: * If 'memory' is not NULL it must point to memory[*memory_bytes] of
jpayne@69: * writeable memory.
jpayne@69: *
jpayne@69: * If the function returns success memory[*memory_bytes] (if 'memory' is not
jpayne@69: * NULL) contains the written PNG data. *memory_bytes will always be less
jpayne@69: * than or equal to the original value.
jpayne@69: *
jpayne@69: * If the function returns false and *memory_bytes was not changed an error
jpayne@69: * occurred during write. If *memory_bytes was changed, or is not 0 if
jpayne@69: * 'memory' was NULL, the write would have succeeded but for the memory
jpayne@69: * buffer being too small. *memory_bytes contains the required number of
jpayne@69: * bytes and will be bigger that the original value.
jpayne@69: */
jpayne@69:
jpayne@69: #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
jpayne@69: row_stride, colormap)\
jpayne@69: png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
jpayne@69: row_stride, colormap)
jpayne@69: /* Return the amount of memory in 'size' required to compress this image.
jpayne@69: * The png_image structure 'image' must be filled in as in the above
jpayne@69: * function and must not be changed before the actual write call, the buffer
jpayne@69: * and all other parameters must also be identical to that in the final
jpayne@69: * write call. The 'size' variable need not be initialized.
jpayne@69: *
jpayne@69: * NOTE: the macro returns true/false, if false is returned 'size' will be
jpayne@69: * set to zero and the write failed and probably will fail if tried again.
jpayne@69: */
jpayne@69:
jpayne@69: /* You can pre-allocate the buffer by making sure it is of sufficient size
jpayne@69: * regardless of the amount of compression achieved. The buffer size will
jpayne@69: * always be bigger than the original image and it will never be filled. The
jpayne@69: * following macros are provided to assist in allocating the buffer.
jpayne@69: */
jpayne@69: #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
jpayne@69: /* The number of uncompressed bytes in the PNG byte encoding of the image;
jpayne@69: * uncompressing the PNG IDAT data will give this number of bytes.
jpayne@69: *
jpayne@69: * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
jpayne@69: * macro can because of the extra bytes used in the PNG byte encoding. You
jpayne@69: * need to avoid this macro if your image size approaches 2^30 in width or
jpayne@69: * height. The same goes for the remainder of these macros; they all produce
jpayne@69: * bigger numbers than the actual in-memory image size.
jpayne@69: */
jpayne@69: #ifndef PNG_ZLIB_MAX_SIZE
jpayne@69: # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
jpayne@69: /* An upper bound on the number of compressed bytes given 'b' uncompressed
jpayne@69: * bytes. This is based on deflateBounds() in zlib; different
jpayne@69: * implementations of zlib compression may conceivably produce more data so
jpayne@69: * if your zlib implementation is not zlib itself redefine this macro
jpayne@69: * appropriately.
jpayne@69: */
jpayne@69: #endif
jpayne@69:
jpayne@69: #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
jpayne@69: PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
jpayne@69: /* An upper bound on the size of the data in the PNG IDAT chunks. */
jpayne@69:
jpayne@69: #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
jpayne@69: ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
jpayne@69: (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
jpayne@69: 12U+3U*(image).colormap_entries/*PLTE data*/+\
jpayne@69: (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
jpayne@69: 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
jpayne@69: 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
jpayne@69: /* A helper for the following macro; if your compiler cannot handle the
jpayne@69: * following macro use this one with the result of
jpayne@69: * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
jpayne@69: * compilers should handle this just fine.)
jpayne@69: */
jpayne@69:
jpayne@69: #define PNG_IMAGE_PNG_SIZE_MAX(image)\
jpayne@69: PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
jpayne@69: /* An upper bound on the total length of the PNG data stream for 'image'.
jpayne@69: * The result is of type png_alloc_size_t, on 32-bit systems this may
jpayne@69: * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
jpayne@69: * run out of buffer space but return a corrected size which should work.
jpayne@69: */
jpayne@69: #endif /* SIMPLIFIED_WRITE */
jpayne@69: /*******************************************************************************
jpayne@69: * END OF SIMPLIFIED API
jpayne@69: ******************************************************************************/
jpayne@69: #endif /* SIMPLIFIED_{READ|WRITE} */
jpayne@69:
jpayne@69: /*******************************************************************************
jpayne@69: * Section 6: IMPLEMENTATION OPTIONS
jpayne@69: *******************************************************************************
jpayne@69: *
jpayne@69: * Support for arbitrary implementation-specific optimizations. The API allows
jpayne@69: * particular options to be turned on or off. 'Option' is the number of the
jpayne@69: * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
jpayne@69: * by the PNG_OPTION_ defines below.
jpayne@69: *
jpayne@69: * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
jpayne@69: * are detected at run time, however sometimes it may be impossible
jpayne@69: * to do this in user mode, in which case it is necessary to discover
jpayne@69: * the capabilities in an OS specific way. Such capabilities are
jpayne@69: * listed here when libpng has support for them and must be turned
jpayne@69: * ON by the application if present.
jpayne@69: *
jpayne@69: * SOFTWARE: sometimes software optimizations actually result in performance
jpayne@69: * decrease on some architectures or systems, or with some sets of
jpayne@69: * PNG images. 'Software' options allow such optimizations to be
jpayne@69: * selected at run time.
jpayne@69: */
jpayne@69: #ifdef PNG_SET_OPTION_SUPPORTED
jpayne@69: #ifdef PNG_ARM_NEON_API_SUPPORTED
jpayne@69: # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
jpayne@69: #endif
jpayne@69: #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
jpayne@69: #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
jpayne@69: #ifdef PNG_MIPS_MSA_API_SUPPORTED
jpayne@69: # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
jpayne@69: #endif
jpayne@69: #ifdef PNG_DISABLE_ADLER32_CHECK_SUPPORTED
jpayne@69: # define PNG_IGNORE_ADLER32 8 /* SOFTWARE: disable Adler32 check on IDAT */
jpayne@69: #endif
jpayne@69: #ifdef PNG_POWERPC_VSX_API_SUPPORTED
jpayne@69: # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions
jpayne@69: * supported */
jpayne@69: #endif
jpayne@69: #ifdef PNG_MIPS_MMI_API_SUPPORTED
jpayne@69: # define PNG_MIPS_MMI 12 /* HARDWARE: MIPS MMI SIMD instructions supported */
jpayne@69: #endif
jpayne@69:
jpayne@69: #define PNG_OPTION_NEXT 14 /* Next option - numbers must be even */
jpayne@69:
jpayne@69: /* Return values: NOTE: there are four values and 'off' is *not* zero */
jpayne@69: #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
jpayne@69: #define PNG_OPTION_INVALID 1 /* Option number out of range */
jpayne@69: #define PNG_OPTION_OFF 2
jpayne@69: #define PNG_OPTION_ON 3
jpayne@69:
jpayne@69: PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
jpayne@69: int onoff));
jpayne@69: #endif /* SET_OPTION */
jpayne@69:
jpayne@69: /*******************************************************************************
jpayne@69: * END OF HARDWARE AND SOFTWARE OPTIONS
jpayne@69: ******************************************************************************/
jpayne@69:
jpayne@69: /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
jpayne@69: * defs, and in scripts/symbols.def.
jpayne@69: */
jpayne@69:
jpayne@69: /* The last ordinal number (this is the *last* one already used; the next
jpayne@69: * one to use is one more than this.)
jpayne@69: */
jpayne@69: #ifdef PNG_EXPORT_LAST_ORDINAL
jpayne@69: PNG_EXPORT_LAST_ORDINAL(249);
jpayne@69: #endif
jpayne@69:
jpayne@69: #ifdef __cplusplus
jpayne@69: }
jpayne@69: #endif
jpayne@69:
jpayne@69: #endif /* PNG_VERSION_INFO_ONLY */
jpayne@69: /* Do not put anything past this line */
jpayne@69: #endif /* PNG_H */