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Diffstat (limited to 'media/libpng/png.h')
| -rw-r--r-- | media/libpng/png.h | 3375 |
1 files changed, 3375 insertions, 0 deletions
diff --git a/media/libpng/png.h b/media/libpng/png.h new file mode 100644 index 000000000..7c9c0f1fb --- /dev/null +++ b/media/libpng/png.h @@ -0,0 +1,3375 @@ + +/* png.h - header file for PNG reference library + * + * libpng version 1.6.26, October 20, 2016 + * + * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license (See LICENSE, below) + * + * Authors and maintainers: + * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat + * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger + * libpng versions 0.97, January 1998, through 1.6.26, October 20, 2016: + * Glenn Randers-Pehrson. + * See also "Contributing Authors", below. + */ + +/* + * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: + * + * If you modify libpng you may insert additional notices immediately following + * this sentence. + * + * This modified version of libpng code adds animated PNG support and is + * released under the libpng license described below. The modifications are + * Copyright (c) 2006-2007 Andrew Smith, Copyright (c) 2008-2016 Max Stepin, + * and are delimited by "#ifdef PNG_APNG_SUPPORTED / #endif" directives + * surrounding them in the modified libpng source files. + * + * This modified version of libpng code adds Intel-SSE support and is + * released under the libpng license described below. The modifications are + * Copyright (c) 2016 Google, Inc., and consist of the source files in the + * "sse2" subdirectory and added code in pngpriv.h delimited by + * #ifndef PNG_INTEL_SSE_OPT / #endif directives. + * + * This code is released under the libpng license. + * + * Some files in the "contrib" directory and some configure-generated + * files that are distributed with libpng have other copyright owners and + * are released under other open source licenses. + * + * libpng versions 1.0.7, July 1, 2000 through 1.6.26, October 20, 2016 are + * Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are + * derived from libpng-1.0.6, and are distributed according to the same + * disclaimer and license as libpng-1.0.6 with the following individuals + * added to the list of Contributing Authors: + * + * Simon-Pierre Cadieux + * Eric S. Raymond + * Mans Rullgard + * Cosmin Truta + * Gilles Vollant + * James Yu + * Mandar Sahastrabuddhe + * + * and with the following additions to the disclaimer: + * + * There is no warranty against interference with your enjoyment of the + * library or against infringement. There is no warranty that our + * efforts or the library will fulfill any of your particular purposes + * or needs. This library is provided with all faults, and the entire + * risk of satisfactory quality, performance, accuracy, and effort is with + * the user. + * + * Some files in the "contrib" directory have other copyright owners and + * are released under other open source licenses. + * + * + * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are + * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from + * libpng-0.96, and are distributed according to the same disclaimer and + * license as libpng-0.96, with the following individuals added to the list + * of Contributing Authors: + * + * Tom Lane + * Glenn Randers-Pehrson + * Willem van Schaik + * + * Some files in the "scripts" directory have different copyright owners + * but are also released under this license. + * + * libpng versions 0.89, June 1996, through 0.96, May 1997, are + * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, + * and are distributed according to the same disclaimer and license as + * libpng-0.88, with the following individuals added to the list of + * Contributing Authors: + * + * John Bowler + * Kevin Bracey + * Sam Bushell + * Magnus Holmgren + * Greg Roelofs + * Tom Tanner + * + * Some files in the "scripts" directory have other copyright owners + * but are released under this license. + * + * libpng versions 0.5, May 1995, through 0.88, January 1996, are + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * For the purposes of this copyright and license, "Contributing Authors" + * is defined as the following set of individuals: + * + * Andreas Dilger + * Dave Martindale + * Guy Eric Schalnat + * Paul Schmidt + * Tim Wegner + * + * The PNG Reference Library is supplied "AS IS". The Contributing Authors + * and Group 42, Inc. disclaim all warranties, expressed or implied, + * including, without limitation, the warranties of merchantability and of + * fitness for any purpose. The Contributing Authors and Group 42, Inc. + * assume no liability for direct, indirect, incidental, special, exemplary, + * or consequential damages, which may result from the use of the PNG + * Reference Library, even if advised of the possibility of such damage. + * + * Permission is hereby granted to use, copy, modify, and distribute this + * source code, or portions hereof, for any purpose, without fee, subject + * to the following restrictions: + * + * 1. The origin of this source code must not be misrepresented. + * + * 2. Altered versions must be plainly marked as such and must not + * be misrepresented as being the original source. + * + * 3. This Copyright notice may not be removed or altered from any + * source or altered source distribution. + * + * The Contributing Authors and Group 42, Inc. specifically permit, without + * fee, and encourage the use of this source code as a component to + * supporting the PNG file format in commercial products. If you use this + * source code in a product, acknowledgment is not required but would be + * appreciated. + * + * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. + * + * TRADEMARK: + * + * The name "libpng" has not been registered by the Copyright owner + * as a trademark in any jurisdiction. However, because libpng has + * been distributed and maintained world-wide, continually since 1995, + * the Copyright owner claims "common-law trademark protection" in any + * jurisdiction where common-law trademark is recognized. + * + * OSI CERTIFICATION: + * + * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is + * a certification mark of the Open Source Initiative. OSI has not addressed + * the additional disclaimers inserted at version 1.0.7. + * + * EXPORT CONTROL: + * + * The Copyright owner believes that the Export Control Classification + * Number (ECCN) for libpng is EAR99, which means not subject to export + * controls or International Traffic in Arms Regulations (ITAR) because + * it is open source, publicly available software, that does not contain + * any encryption software. See the EAR, paragraphs 734.3(b)(3) and + * 734.7(b). + */ + +/* + * A "png_get_copyright" function is available, for convenient use in "about" + * boxes and the like: + * + * printf("%s", png_get_copyright(NULL)); + * + * Also, the PNG logo (in PNG format, of course) is supplied in the + * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). + */ + +/* + * The contributing authors would like to thank all those who helped + * with testing, bug fixes, and patience. This wouldn't have been + * possible without all of you. + * + * Thanks to Frank J. T. Wojcik for helping with the documentation. + */ + +/* Note about libpng version numbers: + * + * Due to various miscommunications, unforeseen code incompatibilities + * and occasional factors outside the authors' control, version numbering + * on the library has not always been consistent and straightforward. + * The following table summarizes matters since version 0.89c, which was + * the first widely used release: + * + * source png.h png.h shared-lib + * version string int version + * ------- ------ ----- ---------- + * 0.89c "1.0 beta 3" 0.89 89 1.0.89 + * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] + * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] + * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] + * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] + * 0.97c 0.97 97 2.0.97 + * 0.98 0.98 98 2.0.98 + * 0.99 0.99 98 2.0.99 + * 0.99a-m 0.99 99 2.0.99 + * 1.00 1.00 100 2.1.0 [100 should be 10000] + * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] + * 1.0.1 png.h string is 10001 2.1.0 + * 1.0.1a-e identical to the 10002 from here on, the shared library + * 1.0.2 source version) 10002 is 2.V where V is the source code + * 1.0.2a-b 10003 version, except as noted. + * 1.0.3 10003 + * 1.0.3a-d 10004 + * 1.0.4 10004 + * 1.0.4a-f 10005 + * 1.0.5 (+ 2 patches) 10005 + * 1.0.5a-d 10006 + * 1.0.5e-r 10100 (not source compatible) + * 1.0.5s-v 10006 (not binary compatible) + * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) + * 1.0.6d-f 10007 (still binary incompatible) + * 1.0.6g 10007 + * 1.0.6h 10007 10.6h (testing xy.z so-numbering) + * 1.0.6i 10007 10.6i + * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) + * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) + * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) + * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) + * 1.0.7 1 10007 (still compatible) + * ... + * 1.0.19 10 10019 10.so.0.19[.0] + * ... + * 1.2.56 13 10256 12.so.0.56[.0] + * ... + * 1.5.27 15 10527 15.so.15.27[.0] + * ... + * 1.6.26 16 10626 16.so.16.26[.0] + * + * Henceforth the source version will match the shared-library major + * and minor numbers; the shared-library major version number will be + * used for changes in backward compatibility, as it is intended. The + * PNG_LIBPNG_VER macro, which is not used within libpng but is available + * for applications, is an unsigned integer of the form xyyzz corresponding + * to the source version x.y.z (leading zeros in y and z). Beta versions + * were given the previous public release number plus a letter, until + * version 1.0.6j; from then on they were given the upcoming public + * release number plus "betaNN" or "rcNN". + * + * Binary incompatibility exists only when applications make direct access + * to the info_ptr or png_ptr members through png.h, and the compiled + * application is loaded with a different version of the library. + * + * DLLNUM will change each time there are forward or backward changes + * in binary compatibility (e.g., when a new feature is added). + * + * See libpng.txt or libpng.3 for more information. The PNG specification + * is available as a W3C Recommendation and as an ISO Specification, + * <http://www.w3.org/TR/2003/REC-PNG-20031110/ + */ + +/* + * Y2K compliance in libpng: + * ========================= + * + * October 20, 2016 + * + * Since the PNG Development group is an ad-hoc body, we can't make + * an official declaration. + * + * This is your unofficial assurance that libpng from version 0.71 and + * upward through 1.6.26 are Y2K compliant. It is my belief that + * earlier versions were also Y2K compliant. + * + * Libpng only has two year fields. One is a 2-byte unsigned integer + * that will hold years up to 65535. The other, which is deprecated, + * holds the date in text format, and will hold years up to 9999. + * + * The integer is + * "png_uint_16 year" in png_time_struct. + * + * The string is + * "char time_buffer[29]" in png_struct. This is no longer used + * in libpng-1.6.x and will be removed from libpng-1.7.0. + * + * There are seven time-related functions: + * png.c: png_convert_to_rfc_1123_buffer() in png.c + * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and + * png_convert_to_rfc_1152() in error prior to libpng-0.98) + * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c + * png_convert_from_time_t() in pngwrite.c + * png_get_tIME() in pngget.c + * png_handle_tIME() in pngrutil.c, called in pngread.c + * png_set_tIME() in pngset.c + * png_write_tIME() in pngwutil.c, called in pngwrite.c + * + * All handle dates properly in a Y2K environment. The + * png_convert_from_time_t() function calls gmtime() to convert from system + * clock time, which returns (year - 1900), which we properly convert to + * the full 4-digit year. There is a possibility that libpng applications + * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer() + * function, or that they are incorrectly passing only a 2-digit year + * instead of "year - 1900" into the png_convert_from_struct_tm() function, + * but this is not under our control. The libpng documentation has always + * stated that it works with 4-digit years, and the APIs have been + * documented as such. + * + * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned + * integer to hold the year, and can hold years as large as 65535. + * + * zlib, upon which libpng depends, is also Y2K compliant. It contains + * no date-related code. + * + * Glenn Randers-Pehrson + * libpng maintainer + * PNG Development Group + */ + +#ifndef PNG_H +#define PNG_H + +/* This is not the place to learn how to use libpng. The file libpng-manual.txt + * describes how to use libpng, and the file example.c summarizes it + * with some code on which to build. This file is useful for looking + * at the actual function definitions and structure components. If that + * file has been stripped from your copy of libpng, you can find it at + * <http://www.libpng.org/pub/png/libpng-manual.txt> + * + * If you just need to read a PNG file and don't want to read the documentation + * skip to the end of this file and read the section entitled 'simplified API'. + */ + +/* Version information for png.h - this should match the version in png.c */ +#define PNG_LIBPNG_VER_STRING "1.6.26+apng" +#define PNG_HEADER_VERSION_STRING \ + " libpng version 1.6.26+apng - October 20, 2016\n" + +#define PNG_LIBPNG_VER_SONUM 16 +#define PNG_LIBPNG_VER_DLLNUM 16 + +/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ +#define PNG_LIBPNG_VER_MAJOR 1 +#define PNG_LIBPNG_VER_MINOR 6 +#define PNG_LIBPNG_VER_RELEASE 26 + +/* This should match the numeric part of the final component of + * PNG_LIBPNG_VER_STRING, omitting any leading zero: + */ + +#define PNG_LIBPNG_VER_BUILD 0 + +/* Release Status */ +#define PNG_LIBPNG_BUILD_ALPHA 1 +#define PNG_LIBPNG_BUILD_BETA 2 +#define PNG_LIBPNG_BUILD_RC 3 +#define PNG_LIBPNG_BUILD_STABLE 4 +#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 + +/* Release-Specific Flags */ +#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with + PNG_LIBPNG_BUILD_STABLE only */ +#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with + PNG_LIBPNG_BUILD_SPECIAL */ +#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with + PNG_LIBPNG_BUILD_PRIVATE */ + +#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE + +/* Careful here. At one time, Guy wanted to use 082, but that would be octal. + * We must not include leading zeros. + * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only + * version 1.0.0 was mis-numbered 100 instead of 10000). From + * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release + */ +#define PNG_LIBPNG_VER 10626 /* 1.6.26 */ + +/* Library configuration: these options cannot be changed after + * the library has been built. + */ +#ifndef PNGLCONF_H +/* If pnglibconf.h is missing, you can + * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h + */ +# include "pnglibconf.h" +#endif + +#define PNG_APNG_SUPPORTED +#define PNG_READ_APNG_SUPPORTED +#define PNG_WRITE_APNG_SUPPORTED + +#ifndef PNG_VERSION_INFO_ONLY +/* Machine specific configuration. */ +# include "pngconf.h" +#endif + +/* + * Added at libpng-1.2.8 + * + * Ref MSDN: Private as priority over Special + * VS_FF_PRIVATEBUILD File *was not* built using standard release + * procedures. If this value is given, the StringFileInfo block must + * contain a PrivateBuild string. + * + * VS_FF_SPECIALBUILD File *was* built by the original company using + * standard release procedures but is a variation of the standard + * file of the same version number. If this value is given, the + * StringFileInfo block must contain a SpecialBuild string. + */ + +#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ +# define PNG_LIBPNG_BUILD_TYPE \ + (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) +#else +# ifdef PNG_LIBPNG_SPECIALBUILD +# define PNG_LIBPNG_BUILD_TYPE \ + (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) +# else +# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) +# endif +#endif + +#ifndef PNG_VERSION_INFO_ONLY + +/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Version information for C files, stored in png.c. This had better match + * the version above. + */ +#define png_libpng_ver png_get_header_ver(NULL) + +/* This file is arranged in several sections: + * + * 1. [omitted] + * 2. Any configuration options that can be specified by for the application + * code when it is built. (Build time configuration is in pnglibconf.h) + * 3. Type definitions (base types are defined in pngconf.h), structure + * definitions. + * 4. Exported library functions. + * 5. Simplified API. + * 6. Implementation options. + * + * The library source code has additional files (principally pngpriv.h) that + * allow configuration of the library. + */ + +/* Section 1: [omitted] */ + +/* Section 2: run time configuration + * See pnglibconf.h for build time configuration + * + * Run time configuration allows the application to choose between + * implementations of certain arithmetic APIs. The default is set + * at build time and recorded in pnglibconf.h, but it is safe to + * override these (and only these) settings. Note that this won't + * change what the library does, only application code, and the + * settings can (and probably should) be made on a per-file basis + * by setting the #defines before including png.h + * + * Use macros to read integers from PNG data or use the exported + * functions? + * PNG_USE_READ_MACROS: use the macros (see below) Note that + * the macros evaluate their argument multiple times. + * PNG_NO_USE_READ_MACROS: call the relevant library function. + * + * Use the alternative algorithm for compositing alpha samples that + * does not use division? + * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' + * algorithm. + * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. + * + * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is + * false? + * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error + * APIs to png_warning. + * Otherwise the calls are mapped to png_error. + */ + +/* Section 3: type definitions, including structures and compile time + * constants. + * See pngconf.h for base types that vary by machine/system + */ + +#ifdef PNG_APNG_SUPPORTED +/* dispose_op flags from inside fcTL */ +#define PNG_DISPOSE_OP_NONE 0x00 +#define PNG_DISPOSE_OP_BACKGROUND 0x01 +#define PNG_DISPOSE_OP_PREVIOUS 0x02 + +/* blend_op flags from inside fcTL */ +#define PNG_BLEND_OP_SOURCE 0x00 +#define PNG_BLEND_OP_OVER 0x01 +#endif /* APNG */ + +/* This triggers a compiler error in png.c, if png.c and png.h + * do not agree upon the version number. + */ +typedef char* png_libpng_version_1_6_26; + +/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. + * + * png_struct is the cache of information used while reading or writing a single + * PNG file. One of these is always required, although the simplified API + * (below) hides the creation and destruction of it. + */ +typedef struct png_struct_def png_struct; +typedef const png_struct * png_const_structp; +typedef png_struct * png_structp; +typedef png_struct * * png_structpp; + +/* png_info contains information read from or to be written to a PNG file. One + * or more of these must exist while reading or creating a PNG file. The + * information is not used by libpng during read but is used to control what + * gets written when a PNG file is created. "png_get_" function calls read + * information during read and "png_set_" functions calls write information + * when creating a PNG. + * been moved into a separate header file that is not accessible to + * applications. Read libpng-manual.txt or libpng.3 for more info. + */ +typedef struct png_info_def png_info; +typedef png_info * png_infop; +typedef const png_info * png_const_infop; +typedef png_info * * png_infopp; + +/* Types with names ending 'p' are pointer types. The corresponding types with + * names ending 'rp' are identical pointer types except that the pointer is + * marked 'restrict', which means that it is the only pointer to the object + * passed to the function. Applications should not use the 'restrict' types; + * it is always valid to pass 'p' to a pointer with a function argument of the + * corresponding 'rp' type. Different compilers have different rules with + * regard to type matching in the presence of 'restrict'. For backward + * compatibility libpng callbacks never have 'restrict' in their parameters and, + * consequentially, writing portable application code is extremely difficult if + * an attempt is made to use 'restrict'. + */ +typedef png_struct * PNG_RESTRICT png_structrp; +typedef const png_struct * PNG_RESTRICT png_const_structrp; +typedef png_info * PNG_RESTRICT png_inforp; +typedef const png_info * PNG_RESTRICT png_const_inforp; + +/* Three color definitions. The order of the red, green, and blue, (and the + * exact size) is not important, although the size of the fields need to + * be png_byte or png_uint_16 (as defined below). + */ +typedef struct png_color_struct +{ + png_byte red; + png_byte green; + png_byte blue; +} png_color; +typedef png_color * png_colorp; +typedef const png_color * png_const_colorp; +typedef png_color * * png_colorpp; + +typedef struct png_color_16_struct +{ + png_byte index; /* used for palette files */ + png_uint_16 red; /* for use in red green blue files */ + png_uint_16 green; + png_uint_16 blue; + png_uint_16 gray; /* for use in grayscale files */ +} png_color_16; +typedef png_color_16 * png_color_16p; +typedef const png_color_16 * png_const_color_16p; +typedef png_color_16 * * png_color_16pp; + +typedef struct png_color_8_struct +{ + png_byte red; /* for use in red green blue files */ + png_byte green; + png_byte blue; + png_byte gray; /* for use in grayscale files */ + png_byte alpha; /* for alpha channel files */ +} png_color_8; +typedef png_color_8 * png_color_8p; +typedef const png_color_8 * png_const_color_8p; +typedef png_color_8 * * png_color_8pp; + +/* + * The following two structures are used for the in-core representation + * of sPLT chunks. + */ +typedef struct png_sPLT_entry_struct +{ + png_uint_16 red; + png_uint_16 green; + png_uint_16 blue; + png_uint_16 alpha; + png_uint_16 frequency; +} png_sPLT_entry; +typedef png_sPLT_entry * png_sPLT_entryp; +typedef const png_sPLT_entry * png_const_sPLT_entryp; +typedef png_sPLT_entry * * png_sPLT_entrypp; + +/* When the depth of the sPLT palette is 8 bits, the color and alpha samples + * occupy the LSB of their respective members, and the MSB of each member + * is zero-filled. The frequency member always occupies the full 16 bits. + */ + +typedef struct png_sPLT_struct +{ + png_charp name; /* palette name */ + png_byte depth; /* depth of palette samples */ + png_sPLT_entryp entries; /* palette entries */ + png_int_32 nentries; /* number of palette entries */ +} png_sPLT_t; +typedef png_sPLT_t * png_sPLT_tp; +typedef const png_sPLT_t * png_const_sPLT_tp; +typedef png_sPLT_t * * png_sPLT_tpp; + +#ifdef PNG_TEXT_SUPPORTED +/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, + * and whether that contents is compressed or not. The "key" field + * points to a regular zero-terminated C string. The "text" fields can be a + * regular C string, an empty string, or a NULL pointer. + * However, the structure returned by png_get_text() will always contain + * the "text" field as a regular zero-terminated C string (possibly + * empty), never a NULL pointer, so it can be safely used in printf() and + * other string-handling functions. Note that the "itxt_length", "lang", and + * "lang_key" members of the structure only exist when the library is built + * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by + * default without iTXt support. Also note that when iTXt *is* supported, + * the "lang" and "lang_key" fields contain NULL pointers when the + * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or + * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the + * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" + * which is always 0 or 1, or its "compression method" which is always 0. + */ +typedef struct png_text_struct +{ + int compression; /* compression value: + -1: tEXt, none + 0: zTXt, deflate + 1: iTXt, none + 2: iTXt, deflate */ + png_charp key; /* keyword, 1-79 character description of "text" */ + png_charp text; /* comment, may be an empty string (ie "") + or a NULL pointer */ + png_size_t text_length; /* length of the text string */ + png_size_t itxt_length; /* length of the itxt string */ + png_charp lang; /* language code, 0-79 characters + or a NULL pointer */ + png_charp lang_key; /* keyword translated UTF-8 string, 0 or more + chars or a NULL pointer */ +} png_text; +typedef png_text * png_textp; +typedef const png_text * png_const_textp; +typedef png_text * * png_textpp; +#endif + +/* Supported compression types for text in PNG files (tEXt, and zTXt). + * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ +#define PNG_TEXT_COMPRESSION_NONE_WR -3 +#define PNG_TEXT_COMPRESSION_zTXt_WR -2 +#define PNG_TEXT_COMPRESSION_NONE -1 +#define PNG_TEXT_COMPRESSION_zTXt 0 +#define PNG_ITXT_COMPRESSION_NONE 1 +#define PNG_ITXT_COMPRESSION_zTXt 2 +#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ + +/* png_time is a way to hold the time in an machine independent way. + * Two conversions are provided, both from time_t and struct tm. There + * is no portable way to convert to either of these structures, as far + * as I know. If you know of a portable way, send it to me. As a side + * note - PNG has always been Year 2000 compliant! + */ +typedef struct png_time_struct +{ + png_uint_16 year; /* full year, as in, 1995 */ + png_byte month; /* month of year, 1 - 12 */ + png_byte day; /* day of month, 1 - 31 */ + png_byte hour; /* hour of day, 0 - 23 */ + png_byte minute; /* minute of hour, 0 - 59 */ + png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ +} png_time; +typedef png_time * png_timep; +typedef const png_time * png_const_timep; +typedef png_time * * png_timepp; + +#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ + defined(PNG_USER_CHUNKS_SUPPORTED) +/* png_unknown_chunk is a structure to hold queued chunks for which there is + * no specific support. The idea is that we can use this to queue + * up private chunks for output even though the library doesn't actually + * know about their semantics. + * + * The data in the structure is set by libpng on read and used on write. + */ +typedef struct png_unknown_chunk_t +{ + png_byte name[5]; /* Textual chunk name with '\0' terminator */ + png_byte *data; /* Data, should not be modified on read! */ + png_size_t size; + + /* On write 'location' must be set using the flag values listed below. + * Notice that on read it is set by libpng however the values stored have + * more bits set than are listed below. Always treat the value as a + * bitmask. On write set only one bit - setting multiple bits may cause the + * chunk to be written in multiple places. + */ + png_byte location; /* mode of operation at read time */ +} +png_unknown_chunk; + +typedef png_unknown_chunk * png_unknown_chunkp; +typedef const png_unknown_chunk * png_const_unknown_chunkp; +typedef png_unknown_chunk * * png_unknown_chunkpp; +#endif + +/* Flag values for the unknown chunk location byte. */ +#define PNG_HAVE_IHDR 0x01 +#define PNG_HAVE_PLTE 0x02 +#define PNG_AFTER_IDAT 0x08 + +/* Maximum positive integer used in PNG is (2^31)-1 */ +#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) +#define PNG_UINT_32_MAX ((png_uint_32)(-1)) +#define PNG_SIZE_MAX ((png_size_t)(-1)) + +/* These are constants for fixed point values encoded in the + * PNG specification manner (x100000) + */ +#define PNG_FP_1 100000 +#define PNG_FP_HALF 50000 +#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) +#define PNG_FP_MIN (-PNG_FP_MAX) + +/* These describe the color_type field in png_info. */ +/* color type masks */ +#define PNG_COLOR_MASK_PALETTE 1 +#define PNG_COLOR_MASK_COLOR 2 +#define PNG_COLOR_MASK_ALPHA 4 + +/* color types. Note that not all combinations are legal */ +#define PNG_COLOR_TYPE_GRAY 0 +#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) +#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) +#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) +#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) +/* aliases */ +#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA +#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA + +/* This is for compression type. PNG 1.0-1.2 only define the single type. */ +#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ +#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE + +/* This is for filter type. PNG 1.0-1.2 only define the single type. */ +#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ +#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ +#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE + +/* These are for the interlacing type. These values should NOT be changed. */ +#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ +#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ +#define PNG_INTERLACE_LAST 2 /* Not a valid value */ + +/* These are for the oFFs chunk. These values should NOT be changed. */ +#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ +#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ +#define PNG_OFFSET_LAST 2 /* Not a valid value */ + +/* These are for the pCAL chunk. These values should NOT be changed. */ +#define PNG_EQUATION_LINEAR 0 /* Linear transformation */ +#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ +#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ +#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ +#define PNG_EQUATION_LAST 4 /* Not a valid value */ + +/* These are for the sCAL chunk. These values should NOT be changed. */ +#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ +#define PNG_SCALE_METER 1 /* meters per pixel */ +#define PNG_SCALE_RADIAN 2 /* radians per pixel */ +#define PNG_SCALE_LAST 3 /* Not a valid value */ + +/* These are for the pHYs chunk. These values should NOT be changed. */ +#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ +#define PNG_RESOLUTION_METER 1 /* pixels/meter */ +#define PNG_RESOLUTION_LAST 2 /* Not a valid value */ + +/* These are for the sRGB chunk. These values should NOT be changed. */ +#define PNG_sRGB_INTENT_PERCEPTUAL 0 +#define PNG_sRGB_INTENT_RELATIVE 1 +#define PNG_sRGB_INTENT_SATURATION 2 +#define PNG_sRGB_INTENT_ABSOLUTE 3 +#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ + +/* This is for text chunks */ +#define PNG_KEYWORD_MAX_LENGTH 79 + +/* Maximum number of entries in PLTE/sPLT/tRNS arrays */ +#define PNG_MAX_PALETTE_LENGTH 256 + +/* These determine if an ancillary chunk's data has been successfully read + * from the PNG header, or if the application has filled in the corresponding + * data in the info_struct to be written into the output file. The values + * of the PNG_INFO_<chunk> defines should NOT be changed. + */ +#define PNG_INFO_gAMA 0x0001U +#define PNG_INFO_sBIT 0x0002U +#define PNG_INFO_cHRM 0x0004U +#define PNG_INFO_PLTE 0x0008U +#define PNG_INFO_tRNS 0x0010U +#define PNG_INFO_bKGD 0x0020U +#define PNG_INFO_hIST 0x0040U +#define PNG_INFO_pHYs 0x0080U +#define PNG_INFO_oFFs 0x0100U +#define PNG_INFO_tIME 0x0200U +#define PNG_INFO_pCAL 0x0400U +#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */ +#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */ +#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ +#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ +#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ +#ifdef PNG_APNG_SUPPORTED +#define PNG_INFO_acTL 0x10000U +#define PNG_INFO_fcTL 0x20000U +#endif + +/* This is used for the transformation routines, as some of them + * change these values for the row. It also should enable using + * the routines for other purposes. + */ +typedef struct png_row_info_struct +{ + png_uint_32 width; /* width of row */ + png_size_t rowbytes; /* number of bytes in row */ + png_byte color_type; /* color type of row */ + png_byte bit_depth; /* bit depth of row */ + png_byte channels; /* number of channels (1, 2, 3, or 4) */ + png_byte pixel_depth; /* bits per pixel (depth * channels) */ +} png_row_info; + +typedef png_row_info * png_row_infop; +typedef png_row_info * * png_row_infopp; + +/* These are the function types for the I/O functions and for the functions + * that allow the user to override the default I/O functions with his or her + * own. The png_error_ptr type should match that of user-supplied warning + * and error functions, while the png_rw_ptr type should match that of the + * user read/write data functions. Note that the 'write' function must not + * modify the buffer it is passed. The 'read' function, on the other hand, is + * expected to return the read data in the buffer. + */ +typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); +typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); +typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); +typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, + int)); +typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, + int)); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); +typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); +#ifdef PNG_APNG_SUPPORTED +typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp, + png_uint_32)); +#endif + +/* The following callback receives png_uint_32 row_number, int pass for the + * png_bytep data of the row. When transforming an interlaced image the + * row number is the row number within the sub-image of the interlace pass, so + * the value will increase to the height of the sub-image (not the full image) + * then reset to 0 for the next pass. + * + * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to + * find the output pixel (x,y) given an interlaced sub-image pixel + * (row,col,pass). (See below for these macros.) + */ +typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, + png_uint_32, int)); +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, + png_bytep)); +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, + png_unknown_chunkp)); +#endif +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED +/* not used anywhere */ +/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ +#endif + +#ifdef PNG_SETJMP_SUPPORTED +/* This must match the function definition in <setjmp.h>, and the application + * must include this before png.h to obtain the definition of jmp_buf. The + * function is required to be PNG_NORETURN, but this is not checked. If the + * function does return the application will crash via an abort() or similar + * system level call. + * + * If you get a warning here while building the library you may need to make + * changes to ensure that pnglibconf.h records the calling convention used by + * your compiler. This may be very difficult - try using a different compiler + * to build the library! + */ +PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); +#endif + +/* Transform masks for the high-level interface */ +#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ +#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ +#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ +#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ +#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ +#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ +#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ +#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ +#define PNG_TRANSFORM_BGR 0x0080 /* read and write */ +#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ +#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ +#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ +#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ +/* Added to libpng-1.2.34 */ +#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER +#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ +/* Added to libpng-1.4.0 */ +#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ +/* Added to libpng-1.5.4 */ +#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ +#if INT_MAX >= 0x8000 /* else this might break */ +#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ +#endif + +/* Flags for MNG supported features */ +#define PNG_FLAG_MNG_EMPTY_PLTE 0x01 +#define PNG_FLAG_MNG_FILTER_64 0x04 +#define PNG_ALL_MNG_FEATURES 0x05 + +/* NOTE: prior to 1.5 these functions had no 'API' style declaration, + * this allowed the zlib default functions to be used on Windows + * platforms. In 1.5 the zlib default malloc (which just calls malloc and + * ignores the first argument) should be completely compatible with the + * following. + */ +typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, + png_alloc_size_t)); +typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); + +/* Section 4: exported functions + * Here are the function definitions most commonly used. This is not + * the place to find out how to use libpng. See libpng-manual.txt for the + * full explanation, see example.c for the summary. This just provides + * a simple one line description of the use of each function. + * + * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in + * pngconf.h and in the *.dfn files in the scripts directory. + * + * PNG_EXPORT(ordinal, type, name, (args)); + * + * ordinal: ordinal that is used while building + * *.def files. The ordinal value is only + * relevant when preprocessing png.h with + * the *.dfn files for building symbol table + * entries, and are removed by pngconf.h. + * type: return type of the function + * name: function name + * args: function arguments, with types + * + * When we wish to append attributes to a function prototype we use + * the PNG_EXPORTA() macro instead. + * + * PNG_EXPORTA(ordinal, type, name, (args), attributes); + * + * ordinal, type, name, and args: same as in PNG_EXPORT(). + * attributes: function attributes + */ + +/* Returns the version number of the library */ +PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); + +/* Tell lib we have already handled the first <num_bytes> magic bytes. + * Handling more than 8 bytes from the beginning of the file is an error. + */ +PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); + +/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a + * PNG file. Returns zero if the supplied bytes match the 8-byte PNG + * signature, and non-zero otherwise. Having num_to_check == 0 or + * start > 7 will always fail (ie return non-zero). + */ +PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, + png_size_t num_to_check)); + +/* Simple signature checking function. This is the same as calling + * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). + */ +#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) + +/* Allocate and initialize png_ptr struct for reading, and any other memory. */ +PNG_EXPORTA(4, png_structp, png_create_read_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn), + PNG_ALLOCATED); + +/* Allocate and initialize png_ptr struct for writing, and any other memory */ +PNG_EXPORTA(5, png_structp, png_create_write_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn), + PNG_ALLOCATED); + +PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, + (png_const_structrp png_ptr)); + +PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, + png_size_t size)); + +/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp + * match up. + */ +#ifdef PNG_SETJMP_SUPPORTED +/* This function returns the jmp_buf built in to *png_ptr. It must be + * supplied with an appropriate 'longjmp' function to use on that jmp_buf + * unless the default error function is overridden in which case NULL is + * acceptable. The size of the jmp_buf is checked against the actual size + * allocated by the library - the call will return NULL on a mismatch + * indicating an ABI mismatch. + */ +PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, + png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); +# define png_jmpbuf(png_ptr) \ + (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) +#else +# define png_jmpbuf(png_ptr) \ + (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) +#endif +/* This function should be used by libpng applications in place of + * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it + * will use it; otherwise it will call PNG_ABORT(). This function was + * added in libpng-1.5.0. + */ +PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), + PNG_NORETURN); + +#ifdef PNG_READ_SUPPORTED +/* Reset the compression stream */ +PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); +#endif + +/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ +#ifdef PNG_USER_MEM_SUPPORTED +PNG_EXPORTA(11, png_structp, png_create_read_struct_2, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + PNG_ALLOCATED); +PNG_EXPORTA(12, png_structp, png_create_write_struct_2, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + PNG_ALLOCATED); +#endif + +/* Write the PNG file signature. */ +PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); + +/* Write a PNG chunk - size, type, (optional) data, CRC. */ +PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep + chunk_name, png_const_bytep data, png_size_t length)); + +/* Write the start of a PNG chunk - length and chunk name. */ +PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, + png_const_bytep chunk_name, png_uint_32 length)); + +/* Write the data of a PNG chunk started with png_write_chunk_start(). */ +PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, + png_const_bytep data, png_size_t length)); + +/* Finish a chunk started with png_write_chunk_start() (includes CRC). */ +PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); + +/* Allocate and initialize the info structure */ +PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), + PNG_ALLOCATED); + +/* DEPRECATED: this function allowed init structures to be created using the + * default allocation method (typically malloc). Use is deprecated in 1.6.0 and + * the API will be removed in the future. + */ +PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, + png_size_t png_info_struct_size), PNG_DEPRECATED); + +/* Writes all the PNG information before the image. */ +PNG_EXPORT(20, void, png_write_info_before_PLTE, + (png_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(21, void, png_write_info, + (png_structrp png_ptr, png_const_inforp info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the information before the actual image data. */ +PNG_EXPORT(22, void, png_read_info, + (png_structrp png_ptr, png_inforp info_ptr)); +#endif + +#ifdef PNG_TIME_RFC1123_SUPPORTED + /* Convert to a US string format: there is no localization support in this + * routine. The original implementation used a 29 character buffer in + * png_struct, this will be removed in future versions. + */ +#if PNG_LIBPNG_VER < 10700 +/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ +PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, + png_const_timep ptime),PNG_DEPRECATED); +#endif +PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], + png_const_timep ptime)); +#endif + +#ifdef PNG_CONVERT_tIME_SUPPORTED +/* Convert from a struct tm to png_time */ +PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, + const struct tm * ttime)); + +/* Convert from time_t to png_time. Uses gmtime() */ +PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); +#endif /* CONVERT_tIME */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ +PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); +PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); +PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); +PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion + * of a tRNS chunk if present. + */ +PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Use blue, green, red order for pixels. */ +PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +/* Expand the grayscale to 24-bit RGB if necessary. */ +PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +/* Reduce RGB to grayscale. */ +#define PNG_ERROR_ACTION_NONE 1 +#define PNG_ERROR_ACTION_WARN 2 +#define PNG_ERROR_ACTION_ERROR 3 +#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ + +PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, + int error_action, double red, double green)) +PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, + int error_action, png_fixed_point red, png_fixed_point green)) + +PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp + png_ptr)); +#endif + +#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED +PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, + png_colorp palette)); +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +/* How the alpha channel is interpreted - this affects how the color channels + * of a PNG file are returned to the calling application when an alpha channel, + * or a tRNS chunk in a palette file, is present. + * + * This has no effect on the way pixels are written into a PNG output + * datastream. The color samples in a PNG datastream are never premultiplied + * with the alpha samples. + * + * The default is to return data according to the PNG specification: the alpha + * channel is a linear measure of the contribution of the pixel to the + * corresponding composited pixel, and the color channels are unassociated + * (not premultiplied). The gamma encoded color channels must be scaled + * according to the contribution and to do this it is necessary to undo + * the encoding, scale the color values, perform the composition and reencode + * the values. This is the 'PNG' mode. + * + * The alternative is to 'associate' the alpha with the color information by + * storing color channel values that have been scaled by the alpha. + * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes + * (the latter being the two common names for associated alpha color channels). + * + * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha + * value is equal to the maximum value. + * + * The final choice is to gamma encode the alpha channel as well. This is + * broken because, in practice, no implementation that uses this choice + * correctly undoes the encoding before handling alpha composition. Use this + * choice only if other serious errors in the software or hardware you use + * mandate it; the typical serious error is for dark halos to appear around + * opaque areas of the composited PNG image because of arithmetic overflow. + * + * The API function png_set_alpha_mode specifies which of these choices to use + * with an enumerated 'mode' value and the gamma of the required output: + */ +#define PNG_ALPHA_PNG 0 /* according to the PNG standard */ +#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ +#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ +#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ +#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ +#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ + +PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, + double output_gamma)) +PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, + int mode, png_fixed_point output_gamma)) +#endif + +#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) +/* The output_gamma value is a screen gamma in libpng terminology: it expresses + * how to decode the output values, not how they are encoded. + */ +#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ +#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ +#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ +#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ +#endif + +/* The following are examples of calls to png_set_alpha_mode to achieve the + * required overall gamma correction and, where necessary, alpha + * premultiplication. + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + * This is the default libpng handling of the alpha channel - it is not + * pre-multiplied into the color components. In addition the call states + * that the output is for a sRGB system and causes all PNG files without gAMA + * chunks to be assumed to be encoded using sRGB. + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + * In this case the output is assumed to be something like an sRGB conformant + * display preceeded by a power-law lookup table of power 1.45. This is how + * early Mac systems behaved. + * + * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); + * This is the classic Jim Blinn approach and will work in academic + * environments where everything is done by the book. It has the shortcoming + * of assuming that input PNG data with no gamma information is linear - this + * is unlikely to be correct unless the PNG files where generated locally. + * Most of the time the output precision will be so low as to show + * significant banding in dark areas of the image. + * + * png_set_expand_16(pp); + * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); + * This is a somewhat more realistic Jim Blinn inspired approach. PNG files + * are assumed to have the sRGB encoding if not marked with a gamma value and + * the output is always 16 bits per component. This permits accurate scaling + * and processing of the data. If you know that your input PNG files were + * generated locally you might need to replace PNG_DEFAULT_sRGB with the + * correct value for your system. + * + * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); + * If you just need to composite the PNG image onto an existing background + * and if you control the code that does this you can use the optimization + * setting. In this case you just copy completely opaque pixels to the + * output. For pixels that are not completely transparent (you just skip + * those) you do the composition math using png_composite or png_composite_16 + * below then encode the resultant 8-bit or 16-bit values to match the output + * encoding. + * + * Other cases + * If neither the PNG nor the standard linear encoding work for you because + * of the software or hardware you use then you have a big problem. The PNG + * case will probably result in halos around the image. The linear encoding + * will probably result in a washed out, too bright, image (it's actually too + * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably + * substantially reduce the halos. Alternatively try: + * + * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); + * This option will also reduce the halos, but there will be slight dark + * halos round the opaque parts of the image where the background is light. + * In the OPTIMIZED mode the halos will be light halos where the background + * is dark. Take your pick - the halos are unavoidable unless you can get + * your hardware/software fixed! (The OPTIMIZED approach is slightly + * faster.) + * + * When the default gamma of PNG files doesn't match the output gamma. + * If you have PNG files with no gamma information png_set_alpha_mode allows + * you to provide a default gamma, but it also sets the ouput gamma to the + * matching value. If you know your PNG files have a gamma that doesn't + * match the output you can take advantage of the fact that + * png_set_alpha_mode always sets the output gamma but only sets the PNG + * default if it is not already set: + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + * The first call sets both the default and the output gamma values, the + * second call overrides the output gamma without changing the default. This + * is easier than achieving the same effect with png_set_gamma. You must use + * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will + * fire if more than one call to png_set_alpha_mode and png_set_background is + * made in the same read operation, however multiple calls with PNG_ALPHA_PNG + * are ignored. + */ + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED +PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) +/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ +PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, + int flags)); +/* The values of the PNG_FILLER_ defines should NOT be changed */ +# define PNG_FILLER_BEFORE 0 +# define PNG_FILLER_AFTER 1 +/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ +PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, + png_uint_32 filler, int flags)); +#endif /* READ_FILLER || WRITE_FILLER */ + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Swap bytes in 16-bit depth files. */ +PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ +PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ + defined(PNG_WRITE_PACKSWAP_SUPPORTED) +/* Swap packing order of pixels in bytes. */ +PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) +/* Converts files to legal bit depths. */ +PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p + true_bits)); +#endif + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) +/* Have the code handle the interlacing. Returns the number of passes. + * MUST be called before png_read_update_info or png_start_read_image, + * otherwise it will not have the desired effect. Note that it is still + * necessary to call png_read_row or png_read_rows png_get_image_height + * times for each pass. +*/ +PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +/* Invert monochrome files */ +PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* Handle alpha and tRNS by replacing with a background color. Prior to + * libpng-1.5.4 this API must not be called before the PNG file header has been + * read. Doing so will result in unexpected behavior and possible warnings or + * errors if the PNG file contains a bKGD chunk. + */ +PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, double background_gamma)) +PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, png_fixed_point background_gamma)) +#endif +#ifdef PNG_READ_BACKGROUND_SUPPORTED +# define PNG_BACKGROUND_GAMMA_UNKNOWN 0 +# define PNG_BACKGROUND_GAMMA_SCREEN 1 +# define PNG_BACKGROUND_GAMMA_FILE 2 +# define PNG_BACKGROUND_GAMMA_UNIQUE 3 +#endif + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +/* Scale a 16-bit depth file down to 8-bit, accurately. */ +PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */ +/* Strip the second byte of information from a 16-bit depth file. */ +PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* Turn on quantizing, and reduce the palette to the number of colors + * available. + */ +PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, + png_colorp palette, int num_palette, int maximum_colors, + png_const_uint_16p histogram, int full_quantize)); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* The threshold on gamma processing is configurable but hard-wired into the + * library. The following is the floating point variant. + */ +#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) + +/* Handle gamma correction. Screen_gamma=(display_exponent). + * NOTE: this API simply sets the screen and file gamma values. It will + * therefore override the value for gamma in a PNG file if it is called after + * the file header has been read - use with care - call before reading the PNG + * file for best results! + * + * These routines accept the same gamma values as png_set_alpha_mode (described + * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either + * API (floating point or fixed.) Notice, however, that the 'file_gamma' value + * is the inverse of a 'screen gamma' value. + */ +PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, + double screen_gamma, double override_file_gamma)) +PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, + png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +/* Set how many lines between output flushes - 0 for no flushing */ +PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); +/* Flush the current PNG output buffer */ +PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); +#endif + +/* Optional update palette with requested transformations */ +PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); + +/* Optional call to update the users info structure */ +PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, + png_inforp info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read one or more rows of image data. */ +PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, + png_bytepp display_row, png_uint_32 num_rows)); +#endif + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read a row of data. */ +PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, + png_bytep display_row)); +#endif + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the whole image into memory at once. */ +PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); +#endif + +/* Write a row of image data */ +PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, + png_const_bytep row)); + +/* Write a few rows of image data: (*row) is not written; however, the type + * is declared as writeable to maintain compatibility with previous versions + * of libpng and to allow the 'display_row' array from read_rows to be passed + * unchanged to write_rows. + */ +PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, + png_uint_32 num_rows)); + +/* Write the image data */ +PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); + +/* Write the end of the PNG file. */ +PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, + png_inforp info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the end of the PNG file. */ +PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); +#endif + +/* Free any memory associated with the png_info_struct */ +PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, + png_infopp info_ptr_ptr)); + +/* Free any memory associated with the png_struct and the png_info_structs */ +PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, + png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); + +/* Free any memory associated with the png_struct and the png_info_structs */ +PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, + png_infopp info_ptr_ptr)); + +/* Set the libpng method of handling chunk CRC errors */ +PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, + int ancil_action)); + +/* Values for png_set_crc_action() say how to handle CRC errors in + * ancillary and critical chunks, and whether to use the data contained + * therein. Note that it is impossible to "discard" data in a critical + * chunk. For versions prior to 0.90, the action was always error/quit, + * whereas in version 0.90 and later, the action for CRC errors in ancillary + * chunks is warn/discard. These values should NOT be changed. + * + * value action:critical action:ancillary + */ +#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ +#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ +#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ +#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ +#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ +#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ + +#ifdef PNG_WRITE_SUPPORTED +/* These functions give the user control over the scan-line filtering in + * libpng and the compression methods used by zlib. These functions are + * mainly useful for testing, as the defaults should work with most users. + * Those users who are tight on memory or want faster performance at the + * expense of compression can modify them. See the compression library + * header file (zlib.h) for an explination of the compression functions. + */ + +/* Set the filtering method(s) used by libpng. Currently, the only valid + * value for "method" is 0. + */ +PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, + int filters)); +#endif /* WRITE */ + +/* Flags for png_set_filter() to say which filters to use. The flags + * are chosen so that they don't conflict with real filter types + * below, in case they are supplied instead of the #defined constants. + * These values should NOT be changed. + */ +#define PNG_NO_FILTERS 0x00 +#define PNG_FILTER_NONE 0x08 +#define PNG_FILTER_SUB 0x10 +#define PNG_FILTER_UP 0x20 +#define PNG_FILTER_AVG 0x40 +#define PNG_FILTER_PAETH 0x80 +#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP) +#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH) + +/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. + * These defines should NOT be changed. + */ +#define PNG_FILTER_VALUE_NONE 0 +#define PNG_FILTER_VALUE_SUB 1 +#define PNG_FILTER_VALUE_UP 2 +#define PNG_FILTER_VALUE_AVG 3 +#define PNG_FILTER_VALUE_PAETH 4 +#define PNG_FILTER_VALUE_LAST 5 + +#ifdef PNG_WRITE_SUPPORTED +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ +PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, + int heuristic_method, int num_weights, png_const_doublep filter_weights, + png_const_doublep filter_costs)) +PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, + (png_structrp png_ptr, int heuristic_method, int num_weights, + png_const_fixed_point_p filter_weights, + png_const_fixed_point_p filter_costs)) +#endif /* WRITE_WEIGHTED_FILTER */ + +/* The following are no longer used and will be removed from libpng-1.7: */ +#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ +#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ +#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ +#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ + +/* Set the library compression level. Currently, valid values range from + * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 + * (0 - no compression, 9 - "maximal" compression). Note that tests have + * shown that zlib compression levels 3-6 usually perform as well as level 9 + * for PNG images, and do considerably fewer caclulations. In the future, + * these values may not correspond directly to the zlib compression levels. + */ +#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED +PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, + int level)); + +PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, + int mem_level)); + +PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, + int strategy)); + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, + int window_bits)); + +PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, + int method)); +#endif /* WRITE_CUSTOMIZE_COMPRESSION */ + +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED +/* Also set zlib parameters for compressing non-IDAT chunks */ +PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, + int level)); + +PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, + int mem_level)); + +PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, + int strategy)); + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +PNG_EXPORT(225, void, png_set_text_compression_window_bits, + (png_structrp png_ptr, int window_bits)); + +PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, + int method)); +#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ +#endif /* WRITE */ + +/* These next functions are called for input/output, memory, and error + * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, + * and call standard C I/O routines such as fread(), fwrite(), and + * fprintf(). These functions can be made to use other I/O routines + * at run time for those applications that need to handle I/O in a + * different manner by calling png_set_???_fn(). See libpng-manual.txt for + * more information. + */ + +#ifdef PNG_STDIO_SUPPORTED +/* Initialize the input/output for the PNG file to the default functions. */ +PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); +#endif + +/* Replace the (error and abort), and warning functions with user + * supplied functions. If no messages are to be printed you must still + * write and use replacement functions. The replacement error_fn should + * still do a longjmp to the last setjmp location if you are using this + * method of error handling. If error_fn or warning_fn is NULL, the + * default function will be used. + */ + +PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, + png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); + +/* Return the user pointer associated with the error functions */ +PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); + +/* Replace the default data output functions with a user supplied one(s). + * If buffered output is not used, then output_flush_fn can be set to NULL. + * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time + * output_flush_fn will be ignored (and thus can be NULL). + * It is probably a mistake to use NULL for output_flush_fn if + * write_data_fn is not also NULL unless you have built libpng with + * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's + * default flush function, which uses the standard *FILE structure, will + * be used. + */ +PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); + +/* Replace the default data input function with a user supplied one. */ +PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr read_data_fn)); + +/* Return the user pointer associated with the I/O functions */ +PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); + +PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, + png_read_status_ptr read_row_fn)); + +PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, + png_write_status_ptr write_row_fn)); + +#ifdef PNG_USER_MEM_SUPPORTED +/* Replace the default memory allocation functions with user supplied one(s). */ +PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn)); +/* Return the user pointer associated with the memory functions */ +PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); +#endif + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED +PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, + png_user_transform_ptr read_user_transform_fn)); +#endif + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED +PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, + png_user_transform_ptr write_user_transform_fn)); +#endif + +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, + png_voidp user_transform_ptr, int user_transform_depth, + int user_transform_channels)); +/* Return the user pointer associated with the user transform functions */ +PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, + (png_const_structrp png_ptr)); +#endif + +#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED +/* Return information about the row currently being processed. Note that these + * APIs do not fail but will return unexpected results if called outside a user + * transform callback. Also note that when transforming an interlaced image the + * row number is the row number within the sub-image of the interlace pass, so + * the value will increase to the height of the sub-image (not the full image) + * then reset to 0 for the next pass. + * + * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to + * find the output pixel (x,y) given an interlaced sub-image pixel + * (row,col,pass). (See below for these macros.) + */ +PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); +PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); +#endif + +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED +/* This callback is called only for *unknown* chunks. If + * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known + * chunks to be treated as unknown, however in this case the callback must do + * any processing required by the chunk (e.g. by calling the appropriate + * png_set_ APIs.) + * + * There is no write support - on write, by default, all the chunks in the + * 'unknown' list are written in the specified position. + * + * The integer return from the callback function is interpreted thus: + * + * negative: An error occurred; png_chunk_error will be called. + * zero: The chunk was not handled, the chunk will be saved. A critical + * chunk will cause an error at this point unless it is to be saved. + * positive: The chunk was handled, libpng will ignore/discard it. + * + * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about + * how this behavior will change in libpng 1.7 + */ +PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, + png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); +#endif + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +/* Sets the function callbacks for the push reader, and a pointer to a + * user-defined structure available to the callback functions. + */ +PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, + png_voidp progressive_ptr, png_progressive_info_ptr info_fn, + png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); + +/* Returns the user pointer associated with the push read functions */ +PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, + (png_const_structrp png_ptr)); + +/* Function to be called when data becomes available */ +PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, + png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)); + +/* A function which may be called *only* within png_process_data to stop the + * processing of any more data. The function returns the number of bytes + * remaining, excluding any that libpng has cached internally. A subsequent + * call to png_process_data must supply these bytes again. If the argument + * 'save' is set to true the routine will first save all the pending data and + * will always return 0. + */ +PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save)); + +/* A function which may be called *only* outside (after) a call to + * png_process_data. It returns the number of bytes of data to skip in the + * input. Normally it will return 0, but if it returns a non-zero value the + * application must skip than number of bytes of input data and pass the + * following data to the next call to png_process_data. + */ +PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); + +/* Function that combines rows. 'new_row' is a flag that should come from + * the callback and be non-NULL if anything needs to be done; the library + * stores its own version of the new data internally and ignores the passed + * in value. + */ +PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, + png_bytep old_row, png_const_bytep new_row)); +#endif /* PROGRESSIVE_READ */ + +PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); +/* Added at libpng version 1.4.0 */ +PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); + +/* Added at libpng version 1.2.4 */ +PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); + +/* Frees a pointer allocated by png_malloc() */ +PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); + +/* Free data that was allocated internally */ +PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 free_me, int num)); + +/* Reassign responsibility for freeing existing data, whether allocated + * by libpng or by the application; this works on the png_info structure passed + * in, it does not change the state for other png_info structures. + * + * It is unlikely that this function works correctly as of 1.6.0 and using it + * may result either in memory leaks or double free of allocated data. + */ +PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, + png_inforp info_ptr, int freer, png_uint_32 mask)); + +/* Assignments for png_data_freer */ +#define PNG_DESTROY_WILL_FREE_DATA 1 +#define PNG_SET_WILL_FREE_DATA 1 +#define PNG_USER_WILL_FREE_DATA 2 +/* Flags for png_ptr->free_me and info_ptr->free_me */ +#define PNG_FREE_HIST 0x0008U +#define PNG_FREE_ICCP 0x0010U +#define PNG_FREE_SPLT 0x0020U +#define PNG_FREE_ROWS 0x0040U +#define PNG_FREE_PCAL 0x0080U +#define PNG_FREE_SCAL 0x0100U +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +# define PNG_FREE_UNKN 0x0200U +#endif +/* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */ +#define PNG_FREE_PLTE 0x1000U +#define PNG_FREE_TRNS 0x2000U +#define PNG_FREE_TEXT 0x4000U +#define PNG_FREE_ALL 0x7fffU +#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ + +#ifdef PNG_USER_MEM_SUPPORTED +PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); +PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, + png_voidp ptr), PNG_DEPRECATED); +#endif + +#ifdef PNG_ERROR_TEXT_SUPPORTED +/* Fatal error in PNG image of libpng - can't continue */ +PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, + png_const_charp error_message), PNG_NORETURN); + +/* The same, but the chunk name is prepended to the error string. */ +PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, + png_const_charp error_message), PNG_NORETURN); + +#else +/* Fatal error in PNG image of libpng - can't continue */ +PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); +# define png_error(s1,s2) png_err(s1) +# define png_chunk_error(s1,s2) png_err(s1) +#endif + +#ifdef PNG_WARNINGS_SUPPORTED +/* Non-fatal error in libpng. Can continue, but may have a problem. */ +PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, + png_const_charp warning_message)); + +/* Non-fatal error in libpng, chunk name is prepended to message. */ +PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, + png_const_charp warning_message)); +#else +# define png_warning(s1,s2) ((void)(s1)) +# define png_chunk_warning(s1,s2) ((void)(s1)) +#endif + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +/* Benign error in libpng. Can continue, but may have a problem. + * User can choose whether to handle as a fatal error or as a warning. */ +PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, + png_const_charp warning_message)); + +#ifdef PNG_READ_SUPPORTED +/* Same, chunk name is prepended to message (only during read) */ +PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, + png_const_charp warning_message)); +#endif + +PNG_EXPORT(109, void, png_set_benign_errors, + (png_structrp png_ptr, int allowed)); +#else +# ifdef PNG_ALLOW_BENIGN_ERRORS +# define png_benign_error png_warning +# define png_chunk_benign_error png_chunk_warning +# else +# define png_benign_error png_error +# define png_chunk_benign_error png_chunk_error +# endif +#endif + +/* The png_set_<chunk> functions are for storing values in the png_info_struct. + * Similarly, the png_get_<chunk> calls are used to read values from the + * png_info_struct, either storing the parameters in the passed variables, or + * setting pointers into the png_info_struct where the data is stored. The + * png_get_<chunk> functions return a non-zero value if the data was available + * in info_ptr, or return zero and do not change any of the parameters if the + * data was not available. + * + * These functions should be used instead of directly accessing png_info + * to avoid problems with future changes in the size and internal layout of + * png_info_struct. + */ +/* Returns "flag" if chunk data is valid in info_ptr. */ +PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 flag)); + +/* Returns number of bytes needed to hold a transformed row. */ +PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +#ifdef PNG_INFO_IMAGE_SUPPORTED +/* Returns row_pointers, which is an array of pointers to scanlines that was + * returned from png_read_png(). + */ +PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Set row_pointers, which is an array of pointers to scanlines for use + * by png_write_png(). + */ +PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, + png_inforp info_ptr, png_bytepp row_pointers)); +#endif + +/* Returns number of color channels in image. */ +PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +#ifdef PNG_EASY_ACCESS_SUPPORTED +/* Returns image width in pixels. */ +PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image height in pixels. */ +PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image bit_depth. */ +PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image color_type. */ +PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image filter_type. */ +PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image interlace_type. */ +PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image compression_type. */ +PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image resolution in pixels per meter, from pHYs chunk data. */ +PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +/* Returns pixel aspect ratio, computed from pHYs chunk data. */ +PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) + +/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ +PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +#endif /* EASY_ACCESS */ + +#ifdef PNG_READ_SUPPORTED +/* Returns pointer to signature string read from PNG header */ +PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); +#endif + +#ifdef PNG_bKGD_SUPPORTED +PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, + png_inforp info_ptr, png_color_16p *background)); +#endif + +#ifdef PNG_bKGD_SUPPORTED +PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_color_16p background)); +#endif + +#ifdef PNG_cHRM_SUPPORTED +PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, + png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, + double *red_y, double *green_x, double *green_y, double *blue_x, + double *blue_y)) +PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, + png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, + double *green_X, double *green_Y, double *green_Z, double *blue_X, + double *blue_Y, double *blue_Z)) +PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_white_x, png_fixed_point *int_white_y, + png_fixed_point *int_red_x, png_fixed_point *int_red_y, + png_fixed_point *int_green_x, png_fixed_point *int_green_y, + png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) +PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_red_X, png_fixed_point *int_red_Y, + png_fixed_point *int_red_Z, png_fixed_point *int_green_X, + png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, + png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, + png_fixed_point *int_blue_Z)) +#endif + +#ifdef PNG_cHRM_SUPPORTED +PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, + png_inforp info_ptr, + double white_x, double white_y, double red_x, double red_y, double green_x, + double green_y, double blue_x, double blue_y)) +PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, + png_inforp info_ptr, double red_X, double red_Y, double red_Z, + double green_X, double green_Y, double green_Z, double blue_X, + double blue_Y, double blue_Z)) +PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, png_fixed_point int_white_x, + png_fixed_point int_white_y, png_fixed_point int_red_x, + png_fixed_point int_red_y, png_fixed_point int_green_x, + png_fixed_point int_green_y, png_fixed_point int_blue_x, + png_fixed_point int_blue_y)) +PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, + png_fixed_point int_red_Z, png_fixed_point int_green_X, + png_fixed_point int_green_Y, png_fixed_point int_green_Z, + png_fixed_point int_blue_X, png_fixed_point int_blue_Y, + png_fixed_point int_blue_Z)) +#endif + +#ifdef PNG_gAMA_SUPPORTED +PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, + png_const_inforp info_ptr, double *file_gamma)) +PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_file_gamma)) +#endif + +#ifdef PNG_gAMA_SUPPORTED +PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, + png_inforp info_ptr, double file_gamma)) +PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, png_fixed_point int_file_gamma)) +#endif + +#ifdef PNG_hIST_SUPPORTED +PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_16p *hist)); +#endif + +#ifdef PNG_hIST_SUPPORTED +PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_uint_16p hist)); +#endif + +PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, + int *bit_depth, int *color_type, int *interlace_method, + int *compression_method, int *filter_method)); + +PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_method, int compression_method, + int filter_method)); + +#ifdef PNG_oFFs_SUPPORTED +PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, + int *unit_type)); +#endif + +#ifdef PNG_oFFs_SUPPORTED +PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, + png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, + int unit_type)); +#endif + +#ifdef PNG_pCAL_SUPPORTED +PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, + png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, + png_int_32 *X1, int *type, int *nparams, png_charp *units, + png_charpp *params)); +#endif + +#ifdef PNG_pCAL_SUPPORTED +PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, + int type, int nparams, png_const_charp units, png_charpp params)); +#endif + +#ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, + int *unit_type)); +#endif + +#ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); +#endif + +PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, + png_inforp info_ptr, png_colorp *palette, int *num_palette)); + +PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, + png_inforp info_ptr, png_const_colorp palette, int num_palette)); + +#ifdef PNG_sBIT_SUPPORTED +PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_color_8p *sig_bit)); +#endif + +#ifdef PNG_sBIT_SUPPORTED +PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_color_8p sig_bit)); +#endif + +#ifdef PNG_sRGB_SUPPORTED +PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, + png_const_inforp info_ptr, int *file_srgb_intent)); +#endif + +#ifdef PNG_sRGB_SUPPORTED +PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, + png_inforp info_ptr, int srgb_intent)); +PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, + png_inforp info_ptr, int srgb_intent)); +#endif + +#ifdef PNG_iCCP_SUPPORTED +PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, + png_inforp info_ptr, png_charpp name, int *compression_type, + png_bytepp profile, png_uint_32 *proflen)); +#endif + +#ifdef PNG_iCCP_SUPPORTED +PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_charp name, int compression_type, + png_const_bytep profile, png_uint_32 proflen)); +#endif + +#ifdef PNG_sPLT_SUPPORTED +PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_sPLT_tpp entries)); +#endif + +#ifdef PNG_sPLT_SUPPORTED +PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); +#endif + +#ifdef PNG_TEXT_SUPPORTED +/* png_get_text also returns the number of text chunks in *num_text */ +PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, + png_inforp info_ptr, png_textp *text_ptr, int *num_text)); +#endif + +/* Note while png_set_text() will accept a structure whose text, + * language, and translated keywords are NULL pointers, the structure + * returned by png_get_text will always contain regular + * zero-terminated C strings. They might be empty strings but + * they will never be NULL pointers. + */ + +#ifdef PNG_TEXT_SUPPORTED +PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_textp text_ptr, int num_text)); +#endif + +#ifdef PNG_tIME_SUPPORTED +PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, + png_inforp info_ptr, png_timep *mod_time)); +#endif + +#ifdef PNG_tIME_SUPPORTED +PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_timep mod_time)); +#endif + +#ifdef PNG_tRNS_SUPPORTED +PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, + png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, + png_color_16p *trans_color)); +#endif + +#ifdef PNG_tRNS_SUPPORTED +PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, + png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, + png_const_color_16p trans_color)); +#endif + +#ifdef PNG_sCAL_SUPPORTED +PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, + png_const_inforp info_ptr, int *unit, double *width, double *height)) +#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ + defined(PNG_FLOATING_POINT_SUPPORTED) +/* NOTE: this API is currently implemented using floating point arithmetic, + * consequently it can only be used on systems with floating point support. + * In any case the range of values supported by png_fixed_point is small and it + * is highly recommended that png_get_sCAL_s be used instead. + */ +PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, + png_fixed_point *width, png_fixed_point *height)) +#endif +PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, + (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, + png_charpp swidth, png_charpp sheight)); + +PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, + png_inforp info_ptr, int unit, double width, double height)) +PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, int unit, png_fixed_point width, + png_fixed_point height)) +PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, + png_inforp info_ptr, int unit, + png_const_charp swidth, png_const_charp sheight)); +#endif /* sCAL */ + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED +/* Provide the default handling for all unknown chunks or, optionally, for + * specific unknown chunks. + * + * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was + * ignored and the default was used, the per-chunk setting only had an effect on + * write. If you wish to have chunk-specific handling on read in code that must + * work on earlier versions you must use a user chunk callback to specify the + * desired handling (keep or discard.) + * + * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The + * parameter is interpreted as follows: + * + * READ: + * PNG_HANDLE_CHUNK_AS_DEFAULT: + * Known chunks: do normal libpng processing, do not keep the chunk (but + * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) + * Unknown chunks: for a specific chunk use the global default, when used + * as the default discard the chunk data. + * PNG_HANDLE_CHUNK_NEVER: + * Discard the chunk data. + * PNG_HANDLE_CHUNK_IF_SAFE: + * Keep the chunk data if the chunk is not critical else raise a chunk + * error. + * PNG_HANDLE_CHUNK_ALWAYS: + * Keep the chunk data. + * + * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, + * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent + * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks + * it simply resets the behavior to the libpng default. + * + * INTERACTION WTIH USER CHUNK CALLBACKS: + * The per-chunk handling is always used when there is a png_user_chunk_ptr + * callback and the callback returns 0; the chunk is then always stored *unless* + * it is critical and the per-chunk setting is other than ALWAYS. Notice that + * the global default is *not* used in this case. (In effect the per-chunk + * value is incremented to at least IF_SAFE.) + * + * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and + * per-chunk defaults will be honored. If you want to preserve the current + * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE + * as the default - if you don't do this libpng 1.6 will issue a warning. + * + * If you want unhandled unknown chunks to be discarded in libpng 1.6 and + * earlier simply return '1' (handled). + * + * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: + * If this is *not* set known chunks will always be handled by libpng and + * will never be stored in the unknown chunk list. Known chunks listed to + * png_set_keep_unknown_chunks will have no effect. If it is set then known + * chunks listed with a keep other than AS_DEFAULT will *never* be processed + * by libpng, in addition critical chunks must either be processed by the + * callback or saved. + * + * The IHDR and IEND chunks must not be listed. Because this turns off the + * default handling for chunks that would otherwise be recognized the + * behavior of libpng transformations may well become incorrect! + * + * WRITE: + * When writing chunks the options only apply to the chunks specified by + * png_set_unknown_chunks (below), libpng will *always* write known chunks + * required by png_set_ calls and will always write the core critical chunks + * (as required for PLTE). + * + * Each chunk in the png_set_unknown_chunks list is looked up in the + * png_set_keep_unknown_chunks list to find the keep setting, this is then + * interpreted as follows: + * + * PNG_HANDLE_CHUNK_AS_DEFAULT: + * Write safe-to-copy chunks and write other chunks if the global + * default is set to _ALWAYS, otherwise don't write this chunk. + * PNG_HANDLE_CHUNK_NEVER: + * Do not write the chunk. + * PNG_HANDLE_CHUNK_IF_SAFE: + * Write the chunk if it is safe-to-copy, otherwise do not write it. + * PNG_HANDLE_CHUNK_ALWAYS: + * Write the chunk. + * + * Note that the default behavior is effectively the opposite of the read case - + * in read unknown chunks are not stored by default, in write they are written + * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different + * - on write the safe-to-copy bit is checked, on read the critical bit is + * checked and on read if the chunk is critical an error will be raised. + * + * num_chunks: + * =========== + * If num_chunks is positive, then the "keep" parameter specifies the manner + * for handling only those chunks appearing in the chunk_list array, + * otherwise the chunk list array is ignored. + * + * If num_chunks is 0 the "keep" parameter specifies the default behavior for + * unknown chunks, as described above. + * + * If num_chunks is negative, then the "keep" parameter specifies the manner + * for handling all unknown chunks plus all chunks recognized by libpng + * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to + * be processed by libpng. + */ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, + int keep, png_const_bytep chunk_list, int num_chunks)); +#endif /* HANDLE_AS_UNKNOWN */ + +/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; + * the result is therefore true (non-zero) if special handling is required, + * false for the default handling. + */ +PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, + png_const_bytep chunk_name)); +#endif /* SET_UNKNOWN_CHUNKS */ + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_unknown_chunkp unknowns, + int num_unknowns)); + /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added + * unknowns to the location currently stored in the png_struct. This is + * invariably the wrong value on write. To fix this call the following API + * for each chunk in the list with the correct location. If you know your + * code won't be compiled on earlier versions you can rely on + * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing + * the correct thing. + */ + +PNG_EXPORT(175, void, png_set_unknown_chunk_location, + (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); + +PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, + png_inforp info_ptr, png_unknown_chunkpp entries)); +#endif + +/* Png_free_data() will turn off the "valid" flag for anything it frees. + * If you need to turn it off for a chunk that your application has freed, + * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); + */ +PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, + png_inforp info_ptr, int mask)); + +#ifdef PNG_INFO_IMAGE_SUPPORTED +/* The "params" pointer is currently not used and is for future expansion. */ +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, + int transforms, png_voidp params)); +#endif +#ifdef PNG_WRITE_SUPPORTED +PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, + int transforms, png_voidp params)); +#endif +#endif + +PNG_EXPORT(180, png_const_charp, png_get_copyright, + (png_const_structrp png_ptr)); +PNG_EXPORT(181, png_const_charp, png_get_header_ver, + (png_const_structrp png_ptr)); +PNG_EXPORT(182, png_const_charp, png_get_header_version, + (png_const_structrp png_ptr)); +PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, + (png_const_structrp png_ptr)); + +#ifdef PNG_MNG_FEATURES_SUPPORTED +PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, + png_uint_32 mng_features_permitted)); +#endif + +/* For use in png_set_keep_unknown, added to version 1.2.6 */ +#define PNG_HANDLE_CHUNK_AS_DEFAULT 0 +#define PNG_HANDLE_CHUNK_NEVER 1 +#define PNG_HANDLE_CHUNK_IF_SAFE 2 +#define PNG_HANDLE_CHUNK_ALWAYS 3 +#define PNG_HANDLE_CHUNK_LAST 4 + +/* Strip the prepended error numbers ("#nnn ") from error and warning + * messages before passing them to the error or warning handler. + */ +#ifdef PNG_ERROR_NUMBERS_SUPPORTED +PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, + png_uint_32 strip_mode)); +#endif + +/* Added in libpng-1.2.6 */ +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, + png_uint_32 user_width_max, png_uint_32 user_height_max)); +PNG_EXPORT(187, png_uint_32, png_get_user_width_max, + (png_const_structrp png_ptr)); +PNG_EXPORT(188, png_uint_32, png_get_user_height_max, + (png_const_structrp png_ptr)); +/* Added in libpng-1.4.0 */ +PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, + png_uint_32 user_chunk_cache_max)); +PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, + (png_const_structrp png_ptr)); +/* Added in libpng-1.4.1 */ +PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, + png_alloc_size_t user_chunk_cache_max)); +PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, + (png_const_structrp png_ptr)); +#endif + +#if defined(PNG_INCH_CONVERSIONS_SUPPORTED) +PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +PNG_FP_EXPORT(196, float, png_get_x_offset_inches, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ +PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +#endif + +PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, + png_const_inforp info_ptr)) +#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ +PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +#endif + +# ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, + int *unit_type)); +# endif /* pHYs */ +#endif /* INCH_CONVERSIONS */ + +/* Added in libpng-1.4.0 */ +#ifdef PNG_IO_STATE_SUPPORTED +PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); + +/* Removed from libpng 1.6; use png_get_io_chunk_type. */ +PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), + PNG_DEPRECATED) + +PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, + (png_const_structrp png_ptr)); + +/* The flags returned by png_get_io_state() are the following: */ +# define PNG_IO_NONE 0x0000 /* no I/O at this moment */ +# define PNG_IO_READING 0x0001 /* currently reading */ +# define PNG_IO_WRITING 0x0002 /* currently writing */ +# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ +# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ +# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ +# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ +# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ +# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ +#endif /* IO_STATE */ + +/* Interlace support. The following macros are always defined so that if + * libpng interlace handling is turned off the macros may be used to handle + * interlaced images within the application. + */ +#define PNG_INTERLACE_ADAM7_PASSES 7 + +/* Two macros to return the first row and first column of the original, + * full, image which appears in a given pass. 'pass' is in the range 0 + * to 6 and the result is in the range 0 to 7. + */ +#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) +#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) + +/* A macro to return the offset between pixels in the output row for a pair of + * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that + * follows. Note that ROW_OFFSET is the offset from one row to the next whereas + * COL_OFFSET is from one column to the next, within a row. + */ +#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) +#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) + +/* Two macros to help evaluate the number of rows or columns in each + * pass. This is expressed as a shift - effectively log2 of the number or + * rows or columns in each 8x8 tile of the original image. + */ +#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) +#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) + +/* Hence two macros to determine the number of rows or columns in a given + * pass of an image given its height or width. In fact these macros may + * return non-zero even though the sub-image is empty, because the other + * dimension may be empty for a small image. + */ +#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ + -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) +#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ + -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) + +/* For the reader row callbacks (both progressive and sequential) it is + * necessary to find the row in the output image given a row in an interlaced + * image, so two more macros: + */ +#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ + (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) +#define PNG_COL_FROM_PASS_COL(x_in, pass) \ + (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) + +/* Two macros which return a boolean (0 or 1) saying whether the given row + * or column is in a particular pass. These use a common utility macro that + * returns a mask for a given pass - the offset 'off' selects the row or + * column version. The mask has the appropriate bit set for each column in + * the tile. + */ +#define PNG_PASS_MASK(pass,off) ( \ + ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ + ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) + +#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ + ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) +#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ + ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) + +#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED +/* With these routines we avoid an integer divide, which will be slower on + * most machines. However, it does take more operations than the corresponding + * divide method, so it may be slower on a few RISC systems. There are two + * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. + * + * Note that the rounding factors are NOT supposed to be the same! 128 and + * 32768 are correct for the NODIV code; 127 and 32767 are correct for the + * standard method. + * + * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] + */ + + /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ + +# define png_composite(composite, fg, alpha, bg) \ + { \ + png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ + * (png_uint_16)(alpha) \ + + (png_uint_16)(bg)*(png_uint_16)(255 \ + - (png_uint_16)(alpha)) + 128); \ + (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \ + } + +# define png_composite_16(composite, fg, alpha, bg) \ + { \ + png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ + * (png_uint_32)(alpha) \ + + (png_uint_32)(bg)*(65535 \ + - (png_uint_32)(alpha)) + 32768); \ + (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \ + } + +#else /* Standard method using integer division */ + +# define png_composite(composite, fg, alpha, bg) \ + (composite) = \ + (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ + (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ + 127) / 255)) + +# define png_composite_16(composite, fg, alpha, bg) \ + (composite) = \ + (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ + (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ + 32767) / 65535)) +#endif /* READ_COMPOSITE_NODIV */ + +#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); +PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); +PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); +#endif + +PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, + png_const_bytep buf)); +/* No png_get_int_16 -- may be added if there's a real need for it. */ + +/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); +#endif +#ifdef PNG_SAVE_INT_32_SUPPORTED +PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); +#endif + +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); +/* No png_save_int_16 -- may be added if there's a real need for it. */ +#endif + +#ifdef PNG_USE_READ_MACROS +/* Inline macros to do direct reads of bytes from the input buffer. + * The png_get_int_32() routine assumes we are using two's complement + * format for negative values, which is almost certainly true. + */ +# define PNG_get_uint_32(buf) \ + (((png_uint_32)(*(buf)) << 24) + \ + ((png_uint_32)(*((buf) + 1)) << 16) + \ + ((png_uint_32)(*((buf) + 2)) << 8) + \ + ((png_uint_32)(*((buf) + 3)))) + + /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the + * function) incorrectly returned a value of type png_uint_32. + */ +# define PNG_get_uint_16(buf) \ + ((png_uint_16) \ + (((unsigned int)(*(buf)) << 8) + \ + ((unsigned int)(*((buf) + 1))))) + +# define PNG_get_int_32(buf) \ + ((png_int_32)((*(buf) & 0x80) \ + ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ + : (png_int_32)png_get_uint_32(buf))) + +/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, + * but defining a macro name prefixed with PNG_PREFIX. + */ +# ifndef PNG_PREFIX +# define png_get_uint_32(buf) PNG_get_uint_32(buf) +# define png_get_uint_16(buf) PNG_get_uint_16(buf) +# define png_get_int_32(buf) PNG_get_int_32(buf) +# endif +#else +# ifdef PNG_PREFIX + /* No macros; revert to the (redefined) function */ +# define PNG_get_uint_32 (png_get_uint_32) +# define PNG_get_uint_16 (png_get_uint_16) +# define PNG_get_int_32 (png_get_int_32) +# endif +#endif + +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED +PNG_EXPORT(242, void, png_set_check_for_invalid_index, + (png_structrp png_ptr, int allowed)); +# ifdef PNG_GET_PALETTE_MAX_SUPPORTED +PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, + png_const_infop info_ptr)); +# endif +#endif /* CHECK_FOR_INVALID_INDEX */ + +/******************************************************************************* + * Section 5: SIMPLIFIED API + ******************************************************************************* + * + * Please read the documentation in libpng-manual.txt (TODO: write said + * documentation) if you don't understand what follows. + * + * The simplified API hides the details of both libpng and the PNG file format + * itself. It allows PNG files to be read into a very limited number of + * in-memory bitmap formats or to be written from the same formats. If these + * formats do not accomodate your needs then you can, and should, use the more + * sophisticated APIs above - these support a wide variety of in-memory formats + * and a wide variety of sophisticated transformations to those formats as well + * as a wide variety of APIs to manipulate ancillary information. + * + * To read a PNG file using the simplified API: + * + * 1) Declare a 'png_image' structure (see below) on the stack, set the + * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL + * (this is REQUIRED, your program may crash if you don't do it.) + * 2) Call the appropriate png_image_begin_read... function. + * 3) Set the png_image 'format' member to the required sample format. + * 4) Allocate a buffer for the image and, if required, the color-map. + * 5) Call png_image_finish_read to read the image and, if required, the + * color-map into your buffers. + * + * There are no restrictions on the format of the PNG input itself; all valid + * color types, bit depths, and interlace methods are acceptable, and the + * input image is transformed as necessary to the requested in-memory format + * during the png_image_finish_read() step. The only caveat is that if you + * request a color-mapped image from a PNG that is full-color or makes + * complex use of an alpha channel the transformation is extremely lossy and the + * result may look terrible. + * + * To write a PNG file using the simplified API: + * + * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. + * 2) Initialize the members of the structure that describe the image, setting + * the 'format' member to the format of the image samples. + * 3) Call the appropriate png_image_write... function with a pointer to the + * image and, if necessary, the color-map to write the PNG data. + * + * png_image is a structure that describes the in-memory format of an image + * when it is being read or defines the in-memory format of an image that you + * need to write: + */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) + +#define PNG_IMAGE_VERSION 1 + +typedef struct png_control *png_controlp; +typedef struct +{ + png_controlp opaque; /* Initialize to NULL, free with png_image_free */ + png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ + png_uint_32 width; /* Image width in pixels (columns) */ + png_uint_32 height; /* Image height in pixels (rows) */ + png_uint_32 format; /* Image format as defined below */ + png_uint_32 flags; /* A bit mask containing informational flags */ + png_uint_32 colormap_entries; + /* Number of entries in the color-map */ + + /* In the event of an error or warning the following field will be set to a + * non-zero value and the 'message' field will contain a '\0' terminated + * string with the libpng error or warning message. If both warnings and + * an error were encountered, only the error is recorded. If there + * are multiple warnings, only the first one is recorded. + * + * The upper 30 bits of this value are reserved, the low two bits contain + * a value as follows: + */ +# define PNG_IMAGE_WARNING 1 +# define PNG_IMAGE_ERROR 2 + /* + * The result is a two-bit code such that a value more than 1 indicates + * a failure in the API just called: + * + * 0 - no warning or error + * 1 - warning + * 2 - error + * 3 - error preceded by warning + */ +# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) + + png_uint_32 warning_or_error; + + char message[64]; +} png_image, *png_imagep; + +/* The samples of the image have one to four channels whose components have + * original values in the range 0 to 1.0: + * + * 1: A single gray or luminance channel (G). + * 2: A gray/luminance channel and an alpha channel (GA). + * 3: Three red, green, blue color channels (RGB). + * 4: Three color channels and an alpha channel (RGBA). + * + * The components are encoded in one of two ways: + * + * a) As a small integer, value 0..255, contained in a single byte. For the + * alpha channel the original value is simply value/255. For the color or + * luminance channels the value is encoded according to the sRGB specification + * and matches the 8-bit format expected by typical display devices. + * + * The color/gray channels are not scaled (pre-multiplied) by the alpha + * channel and are suitable for passing to color management software. + * + * b) As a value in the range 0..65535, contained in a 2-byte integer. All + * channels can be converted to the original value by dividing by 65535; all + * channels are linear. Color channels use the RGB encoding (RGB end-points) of + * the sRGB specification. This encoding is identified by the + * PNG_FORMAT_FLAG_LINEAR flag below. + * + * When the simplified API needs to convert between sRGB and linear colorspaces, + * the actual sRGB transfer curve defined in the sRGB specification (see the + * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 + * approximation used elsewhere in libpng. + * + * When an alpha channel is present it is expected to denote pixel coverage + * of the color or luminance channels and is returned as an associated alpha + * channel: the color/gray channels are scaled (pre-multiplied) by the alpha + * value. + * + * The samples are either contained directly in the image data, between 1 and 8 + * bytes per pixel according to the encoding, or are held in a color-map indexed + * by bytes in the image data. In the case of a color-map the color-map entries + * are individual samples, encoded as above, and the image data has one byte per + * pixel to select the relevant sample from the color-map. + */ + +/* PNG_FORMAT_* + * + * #defines to be used in png_image::format. Each #define identifies a + * particular layout of sample data and, if present, alpha values. There are + * separate defines for each of the two component encodings. + * + * A format is built up using single bit flag values. All combinations are + * valid. Formats can be built up from the flag values or you can use one of + * the predefined values below. When testing formats always use the FORMAT_FLAG + * macros to test for individual features - future versions of the library may + * add new flags. + * + * When reading or writing color-mapped images the format should be set to the + * format of the entries in the color-map then png_image_{read,write}_colormap + * called to read or write the color-map and set the format correctly for the + * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! + * + * NOTE: libpng can be built with particular features disabled. If you see + * compiler errors because the definition of one of the following flags has been + * compiled out it is because libpng does not have the required support. It is + * possible, however, for the libpng configuration to enable the format on just + * read or just write; in that case you may see an error at run time. You can + * guard against this by checking for the definition of the appropriate + * "_SUPPORTED" macro, one of: + * + * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED + */ +#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ +#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ +#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ +#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ + +#ifdef PNG_FORMAT_BGR_SUPPORTED +# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ +#endif + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED +# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ +#endif + +/* Commonly used formats have predefined macros. + * + * First the single byte (sRGB) formats: + */ +#define PNG_FORMAT_GRAY 0 +#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA +#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) +#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR +#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) +#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) +#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) +#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) +#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) + +/* Then the linear 2-byte formats. When naming these "Y" is used to + * indicate a luminance (gray) channel. + */ +#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR +#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) +#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) +#define PNG_FORMAT_LINEAR_RGB_ALPHA \ + (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) + +/* With color-mapped formats the image data is one byte for each pixel, the byte + * is an index into the color-map which is formatted as above. To obtain a + * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP + * to one of the above definitions, or you can use one of the definitions below. + */ +#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) + +/* PNG_IMAGE macros + * + * These are convenience macros to derive information from a png_image + * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the + * actual image sample values - either the entries in the color-map or the + * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values + * for the pixels and will always return 1 for color-mapped formats. The + * remaining macros return information about the rows in the image and the + * complete image. + * + * NOTE: All the macros that take a png_image::format parameter are compile time + * constants if the format parameter is, itself, a constant. Therefore these + * macros can be used in array declarations and case labels where required. + * Similarly the macros are also pre-processor constants (sizeof is not used) so + * they can be used in #if tests. + * + * First the information about the samples. + */ +#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ + (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) + /* Return the total number of channels in a given format: 1..4 */ + +#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ + ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) + /* Return the size in bytes of a single component of a pixel or color-map + * entry (as appropriate) in the image: 1 or 2. + */ + +#define PNG_IMAGE_SAMPLE_SIZE(fmt)\ + (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) + /* This is the size of the sample data for one sample. If the image is + * color-mapped it is the size of one color-map entry (and image pixels are + * one byte in size), otherwise it is the size of one image pixel. + */ + +#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ + (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) + /* The maximum size of the color-map required by the format expressed in a + * count of components. This can be used to compile-time allocate a + * color-map: + * + * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; + * + * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; + * + * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the + * information from one of the png_image_begin_read_ APIs and dynamically + * allocate the required memory. + */ + +/* Corresponding information about the pixels */ +#define PNG_IMAGE_PIXEL_(test,fmt)\ + (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) + +#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ + PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) + /* The number of separate channels (components) in a pixel; 1 for a + * color-mapped image. + */ + +#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ + PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) + /* The size, in bytes, of each component in a pixel; 1 for a color-mapped + * image. + */ + +#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) + /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ + +/* Information about the whole row, or whole image */ +#define PNG_IMAGE_ROW_STRIDE(image)\ + (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) + /* Return the total number of components in a single row of the image; this + * is the minimum 'row stride', the minimum count of components between each + * row. For a color-mapped image this is the minimum number of bytes in a + * row. + * + * WARNING: this macro overflows for some images with more than one component + * and very large image widths. libpng will refuse to process an image where + * this macro would overflow. + */ + +#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ + (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) + /* Return the size, in bytes, of an image buffer given a png_image and a row + * stride - the number of components to leave space for in each row. + * + * WARNING: this macro overflows a 32-bit integer for some large PNG images, + * libpng will refuse to process an image where such an overflow would occur. + */ + +#define PNG_IMAGE_SIZE(image)\ + PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) + /* Return the size, in bytes, of the image in memory given just a png_image; + * the row stride is the minimum stride required for the image. + */ + +#define PNG_IMAGE_COLORMAP_SIZE(image)\ + (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) + /* Return the size, in bytes, of the color-map of this image. If the image + * format is not a color-map format this will return a size sufficient for + * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if + * you don't want to allocate a color-map in this case. + */ + +/* PNG_IMAGE_FLAG_* + * + * Flags containing additional information about the image are held in the + * 'flags' field of png_image. + */ +#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 + /* This indicates the the RGB values of the in-memory bitmap do not + * correspond to the red, green and blue end-points defined by sRGB. + */ + +#define PNG_IMAGE_FLAG_FAST 0x02 + /* On write emphasise speed over compression; the resultant PNG file will be + * larger but will be produced significantly faster, particular for large + * images. Do not use this option for images which will be distributed, only + * used it when producing intermediate files that will be read back in + * repeatedly. For a typical 24-bit image the option will double the read + * speed at the cost of increasing the image size by 25%, however for many + * more compressible images the PNG file can be 10 times larger with only a + * slight speed gain. + */ + +#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 + /* On read if the image is a 16-bit per component image and there is no gAMA + * or sRGB chunk assume that the components are sRGB encoded. Notice that + * images output by the simplified API always have gamma information; setting + * this flag only affects the interpretation of 16-bit images from an + * external source. It is recommended that the application expose this flag + * to the user; the user can normally easily recognize the difference between + * linear and sRGB encoding. This flag has no effect on write - the data + * passed to the write APIs must have the correct encoding (as defined + * above.) + * + * If the flag is not set (the default) input 16-bit per component data is + * assumed to be linear. + * + * NOTE: the flag can only be set after the png_image_begin_read_ call, + * because that call initializes the 'flags' field. + */ + +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED +/* READ APIs + * --------- + * + * The png_image passed to the read APIs must have been initialized by setting + * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) + */ +#ifdef PNG_STDIO_SUPPORTED +PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, + const char *file_name)); + /* The named file is opened for read and the image header is filled in + * from the PNG header in the file. + */ + +PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, + FILE* file)); + /* The PNG header is read from the stdio FILE object. */ +#endif /* STDIO */ + +PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, + png_const_voidp memory, png_size_t size)); + /* The PNG header is read from the given memory buffer. */ + +PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, + png_const_colorp background, void *buffer, png_int_32 row_stride, + void *colormap)); + /* Finish reading the image into the supplied buffer and clean up the + * png_image structure. + * + * row_stride is the step, in byte or 2-byte units as appropriate, + * between adjacent rows. A positive stride indicates that the top-most row + * is first in the buffer - the normal top-down arrangement. A negative + * stride indicates that the bottom-most row is first in the buffer. + * + * background need only be supplied if an alpha channel must be removed from + * a png_byte format and the removal is to be done by compositing on a solid + * color; otherwise it may be NULL and any composition will be done directly + * onto the buffer. The value is an sRGB color to use for the background, + * for grayscale output the green channel is used. + * + * background must be supplied when an alpha channel must be removed from a + * single byte color-mapped output format, in other words if: + * + * 1) The original format from png_image_begin_read_from_* had + * PNG_FORMAT_FLAG_ALPHA set. + * 2) The format set by the application does not. + * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and + * PNG_FORMAT_FLAG_LINEAR *not* set. + * + * For linear output removing the alpha channel is always done by compositing + * on black and background is ignored. + * + * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must + * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. + * image->colormap_entries will be updated to the actual number of entries + * written to the colormap; this may be less than the original value. + */ + +PNG_EXPORT(238, void, png_image_free, (png_imagep image)); + /* Free any data allocated by libpng in image->opaque, setting the pointer to + * NULL. May be called at any time after the structure is initialized. + */ +#endif /* SIMPLIFIED_READ */ + +#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED +/* WRITE APIS + * ---------- + * For write you must initialize a png_image structure to describe the image to + * be written. To do this use memset to set the whole structure to 0 then + * initialize fields describing your image. + * + * version: must be set to PNG_IMAGE_VERSION + * opaque: must be initialized to NULL + * width: image width in pixels + * height: image height in rows + * format: the format of the data (image and color-map) you wish to write + * flags: set to 0 unless one of the defined flags applies; set + * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB + * values do not correspond to the colors in sRGB. + * colormap_entries: set to the number of entries in the color-map (0 to 256) + */ +#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, + const char *file, int convert_to_8bit, const void *buffer, + png_int_32 row_stride, const void *colormap)); + /* Write the image to the named file. */ + +PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, + int convert_to_8_bit, const void *buffer, png_int_32 row_stride, + const void *colormap)); + /* Write the image to the given (FILE*). */ +#endif /* SIMPLIFIED_WRITE_STDIO */ + +/* With all write APIs if image is in one of the linear formats with 16-bit + * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG + * gamma encoded according to the sRGB specification, otherwise a 16-bit linear + * encoded PNG file is written. + * + * With color-mapped data formats the colormap parameter point to a color-map + * with at least image->colormap_entries encoded in the specified format. If + * the format is linear the written PNG color-map will be converted to sRGB + * regardless of the convert_to_8_bit flag. + * + * With all APIs row_stride is handled as in the read APIs - it is the spacing + * from one row to the next in component sized units (1 or 2 bytes) and if + * negative indicates a bottom-up row layout in the buffer. If row_stride is + * zero, libpng will calculate it for you from the image width and number of + * channels. + * + * Note that the write API does not support interlacing, sub-8-bit pixels or + * most ancillary chunks. If you need to write text chunks (e.g. for copyright + * notices) you need to use one of the other APIs. + */ + +PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory, + png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit, + const void *buffer, png_int_32 row_stride, const void *colormap)); + /* Write the image to the given memory buffer. The function both writes the + * whole PNG data stream to *memory and updates *memory_bytes with the count + * of bytes written. + * + * 'memory' may be NULL. In this case *memory_bytes is not read however on + * success the number of bytes which would have been written will still be + * stored in *memory_bytes. On failure *memory_bytes will contain 0. + * + * If 'memory' is not NULL it must point to memory[*memory_bytes] of + * writeable memory. + * + * If the function returns success memory[*memory_bytes] (if 'memory' is not + * NULL) contains the written PNG data. *memory_bytes will always be less + * than or equal to the original value. + * + * If the function returns false and *memory_bytes was not changed an error + * occured during write. If *memory_bytes was changed, or is not 0 if + * 'memory' was NULL, the write would have succeeded but for the memory + * buffer being too small. *memory_bytes contains the required number of + * bytes and will be bigger that the original value. + */ + +#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\ + row_stride, colormap)\ + png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\ + row_stride, colormap) + /* Return the amount of memory in 'size' required to compress this image. + * The png_image structure 'image' must be filled in as in the above + * function and must not be changed before the actual write call, the buffer + * and all other parameters must also be identical to that in the final + * write call. The 'size' variable need not be initialized. + * + * NOTE: the macro returns true/false, if false is returned 'size' will be + * set to zero and the write failed and probably will fail if tried again. + */ + +/* You can pre-allocate the buffer by making sure it is of sufficient size + * regardless of the amount of compression achieved. The buffer size will + * always be bigger than the original image and it will never be filled. The + * following macros are provided to assist in allocating the buffer. + */ +#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height) + /* The number of uncompressed bytes in the PNG byte encoding of the image; + * uncompressing the PNG IDAT data will give this number of bytes. + * + * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this + * macro can because of the extra bytes used in the PNG byte encoding. You + * need to avoid this macro if your image size approaches 2^30 in width or + * height. The same goes for the remainder of these macros; they all produce + * bigger numbers than the actual in-memory image size. + */ +#ifndef PNG_ZLIB_MAX_SIZE +# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U) + /* An upper bound on the number of compressed bytes given 'b' uncompressed + * bytes. This is based on deflateBounds() in zlib; different + * implementations of zlib compression may conceivably produce more data so + * if your zlib implementation is not zlib itself redefine this macro + * appropriately. + */ +#endif + +#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\ + PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image)) + /* An upper bound on the size of the data in the PNG IDAT chunks. */ + +#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\ + ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\ + (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\ + 12U+3U*(image).colormap_entries/*PLTE data*/+\ + (((image).format&PNG_FORMAT_FLAG_ALPHA)?\ + 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\ + 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size)) + /* A helper for the following macro; if your compiler cannot handle the + * following macro use this one with the result of + * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most + * compilers should handle this just fine.) + */ + +#define PNG_IMAGE_PNG_SIZE_MAX(image)\ + PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image)) + /* An upper bound on the total length of the PNG data stream for 'image'. + * The result is of type png_alloc_size_t, on 32-bit systems this may + * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will + * run out of buffer space but return a corrected size which should work. + */ +#endif /* SIMPLIFIED_WRITE */ +/******************************************************************************* + * END OF SIMPLIFIED API + ******************************************************************************/ +#endif /* SIMPLIFIED_{READ|WRITE} */ + +/******************************************************************************* + * Section 6: IMPLEMENTATION OPTIONS + ******************************************************************************* + * + * Support for arbitrary implementation-specific optimizations. The API allows + * particular options to be turned on or off. 'Option' is the number of the + * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given + * by the PNG_OPTION_ defines below. + * + * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions, + * are detected at run time, however sometimes it may be impossible + * to do this in user mode, in which case it is necessary to discover + * the capabilities in an OS specific way. Such capabilities are + * listed here when libpng has support for them and must be turned + * ON by the application if present. + * + * SOFTWARE: sometimes software optimizations actually result in performance + * decrease on some architectures or systems, or with some sets of + * PNG images. 'Software' options allow such optimizations to be + * selected at run time. + */ +#ifdef PNG_SET_OPTION_SUPPORTED +#ifdef PNG_ARM_NEON_API_SUPPORTED +# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ +#endif +#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ +#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ +#ifdef PNG_MIPS_MSA_API_SUPPORTED +# define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */ +#endif +#define PNG_OPTION_NEXT 8 /* Next option - numbers must be even */ + +/* Return values: NOTE: there are four values and 'off' is *not* zero */ +#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ +#define PNG_OPTION_INVALID 1 /* Option number out of range */ +#define PNG_OPTION_OFF 2 +#define PNG_OPTION_ON 3 + +PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, + int onoff)); +#endif /* SET_OPTION */ + +/******************************************************************************* + * END OF HARDWARE AND SOFTWARE OPTIONS + ******************************************************************************/ + +#ifdef PNG_APNG_SUPPORTED +PNG_EXPORT(246, png_uint_32, png_get_acTL, (png_structp png_ptr, + png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays)); + +PNG_EXPORT(247, png_uint_32, png_set_acTL, (png_structp png_ptr, + png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays)); + +PNG_EXPORT(248, png_uint_32, png_get_num_frames, (png_structp png_ptr, + png_infop info_ptr)); + +PNG_EXPORT(249, png_uint_32, png_get_num_plays, (png_structp png_ptr, + png_infop info_ptr)); + +PNG_EXPORT(250, png_uint_32, png_get_next_frame_fcTL, + (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width, + png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset, + png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op, + png_byte *blend_op)); + +PNG_EXPORT(251, png_uint_32, png_set_next_frame_fcTL, + (png_structp png_ptr, png_infop info_ptr, png_uint_32 width, + png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, + png_byte blend_op)); + +PNG_EXPORT(252, png_uint_32, png_get_next_frame_width, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(253, png_uint_32, png_get_next_frame_height, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(254, png_uint_32, png_get_next_frame_x_offset, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(255, png_uint_32, png_get_next_frame_y_offset, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(256, png_uint_16, png_get_next_frame_delay_num, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(257, png_uint_16, png_get_next_frame_delay_den, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(258, png_byte, png_get_next_frame_dispose_op, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(259, png_byte, png_get_next_frame_blend_op, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(260, png_byte, png_get_first_frame_is_hidden, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(261, png_uint_32, png_set_first_frame_is_hidden, + (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden)); + +#ifdef PNG_READ_APNG_SUPPORTED +PNG_EXPORT(262, void, png_read_frame_head, (png_structp png_ptr, + png_infop info_ptr)); +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_EXPORT(263, void, png_set_progressive_frame_fn, (png_structp png_ptr, + png_progressive_frame_ptr frame_info_fn, + png_progressive_frame_ptr frame_end_fn)); +#endif /* PROGRESSIVE_READ */ +#endif /* READ_APNG */ + +#ifdef PNG_WRITE_APNG_SUPPORTED +PNG_EXPORT(264, void, png_write_frame_head, (png_structp png_ptr, + png_infop info_ptr, png_bytepp row_pointers, + png_uint_32 width, png_uint_32 height, + png_uint_32 x_offset, png_uint_32 y_offset, + png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, + png_byte blend_op)); + +PNG_EXPORT(265, void, png_write_frame_tail, (png_structp png_ptr, + png_infop info_ptr)); +#endif /* WRITE_APNG */ +#endif /* APNG */ + +/* Maintainer: Put new public prototypes here ^, in libpng.3, in project + * defs, and in scripts/symbols.def. + */ + +/* The last ordinal number (this is the *last* one already used; the next + * one to use is one more than this.) + */ +#ifdef PNG_EXPORT_LAST_ORDINAL +#ifdef PNG_APNG_SUPPORTED + PNG_EXPORT_LAST_ORDINAL(265); +#else + PNG_EXPORT_LAST_ORDINAL(245); +#endif /* APNG */ +#endif + +#ifdef __cplusplus +} +#endif + +#endif /* PNG_VERSION_INFO_ONLY */ +/* Do not put anything past this line */ +#endif /* PNG_H */ |