0,0 → 1,3314 |
|
/* png.h - header file for PNG reference library |
* |
* libpng version 1.6.5 - September 14, 2013 |
* Copyright (c) 1998-2013 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 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger |
* libpng versions 0.97, January 1998, through 1.6.5 - September 14, 2013: Glenn |
* See also "Contributing Authors", below. |
* |
* Note about libpng version numbers: |
* |
* Due to various miscommunications, unforeseen code incompatibilities |
* and occasional factors outside the authors' control, version numbering |
* on the library has not always been consistent and straightforward. |
* The following table summarizes matters since version 0.89c, which was |
* the first widely used release: |
* |
* source png.h png.h shared-lib |
* version string int version |
* ------- ------ ----- ---------- |
* 0.89c "1.0 beta 3" 0.89 89 1.0.89 |
* 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] |
* 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] |
* 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] |
* 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] |
* 0.97c 0.97 97 2.0.97 |
* 0.98 0.98 98 2.0.98 |
* 0.99 0.99 98 2.0.99 |
* 0.99a-m 0.99 99 2.0.99 |
* 1.00 1.00 100 2.1.0 [100 should be 10000] |
* 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] |
* 1.0.1 png.h string is 10001 2.1.0 |
* 1.0.1a-e identical to the 10002 from here on, the shared library |
* 1.0.2 source version) 10002 is 2.V where V is the source code |
* 1.0.2a-b 10003 version, except as noted. |
* 1.0.3 10003 |
* 1.0.3a-d 10004 |
* 1.0.4 10004 |
* 1.0.4a-f 10005 |
* 1.0.5 (+ 2 patches) 10005 |
* 1.0.5a-d 10006 |
* 1.0.5e-r 10100 (not source compatible) |
* 1.0.5s-v 10006 (not binary compatible) |
* 1.0.6 (+ 3 patches) 10006 (still binary incompatible) |
* 1.0.6d-f 10007 (still binary incompatible) |
* 1.0.6g 10007 |
* 1.0.6h 10007 10.6h (testing xy.z so-numbering) |
* 1.0.6i 10007 10.6i |
* 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) |
* 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) |
* 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) |
* 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) |
* 1.0.7 1 10007 (still compatible) |
* 1.0.8beta1-4 1 10008 2.1.0.8beta1-4 |
* 1.0.8rc1 1 10008 2.1.0.8rc1 |
* 1.0.8 1 10008 2.1.0.8 |
* 1.0.9beta1-6 1 10009 2.1.0.9beta1-6 |
* 1.0.9rc1 1 10009 2.1.0.9rc1 |
* 1.0.9beta7-10 1 10009 2.1.0.9beta7-10 |
* 1.0.9rc2 1 10009 2.1.0.9rc2 |
* 1.0.9 1 10009 2.1.0.9 |
* 1.0.10beta1 1 10010 2.1.0.10beta1 |
* 1.0.10rc1 1 10010 2.1.0.10rc1 |
* 1.0.10 1 10010 2.1.0.10 |
* 1.0.11beta1-3 1 10011 2.1.0.11beta1-3 |
* 1.0.11rc1 1 10011 2.1.0.11rc1 |
* 1.0.11 1 10011 2.1.0.11 |
* 1.0.12beta1-2 2 10012 2.1.0.12beta1-2 |
* 1.0.12rc1 2 10012 2.1.0.12rc1 |
* 1.0.12 2 10012 2.1.0.12 |
* 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned) |
* 1.2.0beta1-2 2 10200 2.1.2.0beta1-2 |
* 1.2.0beta3-5 3 10200 3.1.2.0beta3-5 |
* 1.2.0rc1 3 10200 3.1.2.0rc1 |
* 1.2.0 3 10200 3.1.2.0 |
* 1.2.1beta1-4 3 10201 3.1.2.1beta1-4 |
* 1.2.1rc1-2 3 10201 3.1.2.1rc1-2 |
* 1.2.1 3 10201 3.1.2.1 |
* 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6 |
* 1.0.13beta1 10 10013 10.so.0.1.0.13beta1 |
* 1.0.13rc1 10 10013 10.so.0.1.0.13rc1 |
* 1.2.2rc1 12 10202 12.so.0.1.2.2rc1 |
* 1.0.13 10 10013 10.so.0.1.0.13 |
* 1.2.2 12 10202 12.so.0.1.2.2 |
* 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6 |
* 1.2.3 12 10203 12.so.0.1.2.3 |
* 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3 |
* 1.0.14rc1 13 10014 10.so.0.1.0.14rc1 |
* 1.2.4rc1 13 10204 12.so.0.1.2.4rc1 |
* 1.0.14 10 10014 10.so.0.1.0.14 |
* 1.2.4 13 10204 12.so.0.1.2.4 |
* 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2 |
* 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3 |
* 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3 |
* 1.0.15 10 10015 10.so.0.1.0.15 |
* 1.2.5 13 10205 12.so.0.1.2.5 |
* 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4 |
* 1.0.16 10 10016 10.so.0.1.0.16 |
* 1.2.6 13 10206 12.so.0.1.2.6 |
* 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2 |
* 1.0.17rc1 10 10017 12.so.0.1.0.17rc1 |
* 1.2.7rc1 13 10207 12.so.0.1.2.7rc1 |
* 1.0.17 10 10017 12.so.0.1.0.17 |
* 1.2.7 13 10207 12.so.0.1.2.7 |
* 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5 |
* 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5 |
* 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5 |
* 1.0.18 10 10018 12.so.0.1.0.18 |
* 1.2.8 13 10208 12.so.0.1.2.8 |
* 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3 |
* 1.2.9beta4-11 13 10209 12.so.0.9[.0] |
* 1.2.9rc1 13 10209 12.so.0.9[.0] |
* 1.2.9 13 10209 12.so.0.9[.0] |
* 1.2.10beta1-7 13 10210 12.so.0.10[.0] |
* 1.2.10rc1-2 13 10210 12.so.0.10[.0] |
* 1.2.10 13 10210 12.so.0.10[.0] |
* 1.4.0beta1-5 14 10400 14.so.0.0[.0] |
* 1.2.11beta1-4 13 10211 12.so.0.11[.0] |
* 1.4.0beta7-8 14 10400 14.so.0.0[.0] |
* 1.2.11 13 10211 12.so.0.11[.0] |
* 1.2.12 13 10212 12.so.0.12[.0] |
* 1.4.0beta9-14 14 10400 14.so.0.0[.0] |
* 1.2.13 13 10213 12.so.0.13[.0] |
* 1.4.0beta15-36 14 10400 14.so.0.0[.0] |
* 1.4.0beta37-87 14 10400 14.so.14.0[.0] |
* 1.4.0rc01 14 10400 14.so.14.0[.0] |
* 1.4.0beta88-109 14 10400 14.so.14.0[.0] |
* 1.4.0rc02-08 14 10400 14.so.14.0[.0] |
* 1.4.0 14 10400 14.so.14.0[.0] |
* 1.4.1beta01-03 14 10401 14.so.14.1[.0] |
* 1.4.1rc01 14 10401 14.so.14.1[.0] |
* 1.4.1beta04-12 14 10401 14.so.14.1[.0] |
* 1.4.1 14 10401 14.so.14.1[.0] |
* 1.4.2 14 10402 14.so.14.2[.0] |
* 1.4.3 14 10403 14.so.14.3[.0] |
* 1.4.4 14 10404 14.so.14.4[.0] |
* 1.5.0beta01-58 15 10500 15.so.15.0[.0] |
* 1.5.0rc01-07 15 10500 15.so.15.0[.0] |
* 1.5.0 15 10500 15.so.15.0[.0] |
* 1.5.1beta01-11 15 10501 15.so.15.1[.0] |
* 1.5.1rc01-02 15 10501 15.so.15.1[.0] |
* 1.5.1 15 10501 15.so.15.1[.0] |
* 1.5.2beta01-03 15 10502 15.so.15.2[.0] |
* 1.5.2rc01-03 15 10502 15.so.15.2[.0] |
* 1.5.2 15 10502 15.so.15.2[.0] |
* 1.5.3beta01-10 15 10503 15.so.15.3[.0] |
* 1.5.3rc01-02 15 10503 15.so.15.3[.0] |
* 1.5.3beta11 15 10503 15.so.15.3[.0] |
* 1.5.3 [omitted] |
* 1.5.4beta01-08 15 10504 15.so.15.4[.0] |
* 1.5.4rc01 15 10504 15.so.15.4[.0] |
* 1.5.4 15 10504 15.so.15.4[.0] |
* 1.5.5beta01-08 15 10505 15.so.15.5[.0] |
* 1.5.5rc01 15 10505 15.so.15.5[.0] |
* 1.5.5 15 10505 15.so.15.5[.0] |
* 1.5.6beta01-07 15 10506 15.so.15.6[.0] |
* 1.5.6rc01-03 15 10506 15.so.15.6[.0] |
* 1.5.6 15 10506 15.so.15.6[.0] |
* 1.5.7beta01-05 15 10507 15.so.15.7[.0] |
* 1.5.7rc01-03 15 10507 15.so.15.7[.0] |
* 1.5.7 15 10507 15.so.15.7[.0] |
* 1.6.0beta01-40 16 10600 16.so.16.0[.0] |
* 1.6.0rc01-08 16 10600 16.so.16.0[.0] |
* 1.6.0 16 10600 16.so.16.0[.0] |
* 1.6.1beta01-09 16 10601 16.so.16.1[.0] |
* 1.6.1rc01 16 10601 16.so.16.1[.0] |
* 1.6.1 16 10601 16.so.16.1[.0] |
* 1.6.2beta01 16 10602 16.so.16.2[.0] |
* 1.6.2rc01-06 16 10602 16.so.16.2[.0] |
* 1.6.2 16 10602 16.so.16.2[.0] |
* 1.6.3beta01-11 16 10603 16.so.16.3[.0] |
* 1.6.3rc01 16 10603 16.so.16.3[.0] |
* 1.6.3 16 10603 16.so.16.3[.0] |
* 1.6.4beta01-02 16 10604 16.so.16.4[.0] |
* 1.6.4rc01 16 10604 16.so.16.4[.0] |
* 1.6.4 16 10604 16.so.16.4[.0] |
* 1.6.5 16 10605 16.so.16.5[.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-manual.txt or libpng.3 for more information. The PNG |
* specification is available as a W3C Recommendation and as an ISO |
* Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/ |
*/ |
|
/* |
* COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: |
* |
* If you modify libpng you may insert additional notices immediately following |
* this sentence. |
* |
* This code is released under the libpng license. |
* |
* libpng versions 1.2.6, August 15, 2004, through 1.6.5, September 14, 2013, are |
* Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are |
* distributed according to the same disclaimer and license as libpng-1.2.5 |
* with the following individual added to the list of Contributing Authors: |
* |
* Cosmin Truta |
* |
* libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are |
* Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are |
* distributed according to the same disclaimer and license as libpng-1.0.6 |
* with the following individuals added to the list of Contributing Authors: |
* |
* Simon-Pierre Cadieux |
* Eric S. Raymond |
* Gilles Vollant |
* |
* and with the following additions to the disclaimer: |
* |
* There is no warranty against interference with your enjoyment of the |
* library or against infringement. There is no warranty that our |
* efforts or the library will fulfill any of your particular purposes |
* or needs. This library is provided with all faults, and the entire |
* risk of satisfactory quality, performance, accuracy, and effort is with |
* the user. |
* |
* libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are |
* Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are |
* distributed according to the same disclaimer and license as libpng-0.96, |
* with the following individuals added to the list of Contributing Authors: |
* |
* Tom Lane |
* Glenn Randers-Pehrson |
* Willem van Schaik |
* |
* libpng versions 0.89, June 1996, through 0.96, May 1997, are |
* Copyright (c) 1996, 1997 Andreas Dilger |
* Distributed according to the same disclaimer and license as libpng-0.88, |
* with the following individuals added to the list of Contributing Authors: |
* |
* John Bowler |
* Kevin Bracey |
* Sam Bushell |
* Magnus Holmgren |
* Greg Roelofs |
* Tom Tanner |
* |
* libpng versions 0.5, May 1995, through 0.88, January 1996, are |
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
* |
* For the purposes of this copyright and license, "Contributing Authors" |
* is defined as the following set of individuals: |
* |
* Andreas Dilger |
* Dave Martindale |
* Guy Eric Schalnat |
* Paul Schmidt |
* Tim Wegner |
* |
* The PNG Reference Library is supplied "AS IS". The Contributing Authors |
* and Group 42, Inc. disclaim all warranties, expressed or implied, |
* including, without limitation, the warranties of merchantability and of |
* fitness for any purpose. The Contributing Authors and Group 42, Inc. |
* assume no liability for direct, indirect, incidental, special, exemplary, |
* or consequential damages, which may result from the use of the PNG |
* Reference Library, even if advised of the possibility of such damage. |
* |
* Permission is hereby granted to use, copy, modify, and distribute this |
* source code, or portions hereof, for any purpose, without fee, subject |
* to the following restrictions: |
* |
* 1. The origin of this source code must not be misrepresented. |
* |
* 2. Altered versions must be plainly marked as such and must not |
* be misrepresented as being the original source. |
* |
* 3. This Copyright notice may not be removed or altered from |
* any source or altered source distribution. |
* |
* The Contributing Authors and Group 42, Inc. specifically permit, without |
* fee, and encourage the use of this source code as a component to |
* supporting the PNG file format in commercial products. If you use this |
* source code in a product, acknowledgment is not required but would be |
* appreciated. |
*/ |
|
/* |
* A "png_get_copyright" function is available, for convenient use in "about" |
* boxes and the like: |
* |
* 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). |
*/ |
|
/* |
* Libpng is OSI Certified Open Source Software. OSI Certified is a |
* certification mark of the Open Source Initiative. |
*/ |
|
/* |
* The contributing authors would like to thank all those who helped |
* with testing, bug fixes, and patience. This wouldn't have been |
* possible without all of you. |
* |
* Thanks to Frank J. T. Wojcik for helping with the documentation. |
*/ |
|
/* |
* Y2K compliance in libpng: |
* ========================= |
* |
* September 14, 2013 |
* |
* 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 1.6.5 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 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 "1.6.5" |
#define PNG_HEADER_VERSION_STRING \ |
" libpng version 1.6.5 - September 14, 2013\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 5 |
|
/* 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 10605 /* 1.6.5 */ |
|
/* Library configuration: these options cannot be changed after |
* the library has been built. |
*/ |
#ifndef PNGLCONF_H |
/* If pnglibconf.h is missing, you can |
* copy scripts/pnglibconf.h.prebuilt to pnglibconf.h |
*/ |
# include "pnglibconf.h" |
#endif |
|
#ifndef PNG_VERSION_INFO_ONLY |
/* Machine specific configuration. */ |
# include "pngconf.h" |
#endif |
|
/* |
* Added at libpng-1.2.8 |
* |
* Ref MSDN: Private as priority over Special |
* VS_FF_PRIVATEBUILD File *was not* built using standard release |
* procedures. If this value is given, the StringFileInfo block must |
* contain a PrivateBuild string. |
* |
* VS_FF_SPECIALBUILD File *was* built by the original company using |
* standard release procedures but is a variation of the standard |
* file of the same version number. If this value is given, the |
* StringFileInfo block must contain a SpecialBuild string. |
*/ |
|
#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ |
# define PNG_LIBPNG_BUILD_TYPE \ |
(PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) |
#else |
# ifdef PNG_LIBPNG_SPECIALBUILD |
# define PNG_LIBPNG_BUILD_TYPE \ |
(PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) |
# else |
# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) |
# endif |
#endif |
|
#ifndef PNG_VERSION_INFO_ONLY |
|
/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ |
#ifdef __cplusplus |
extern "C" { |
#endif /* __cplusplus */ |
|
/* Version information for C files, stored in png.c. This had better match |
* the version above. |
*/ |
#define png_libpng_ver png_get_header_ver(NULL) |
|
/* This file is arranged in several sections: |
* |
* 1. Any configuration options that can be specified by for the application |
* code when it is built. (Build time configuration is in pnglibconf.h) |
* 2. Type definitions (base types are defined in pngconf.h), structure |
* definitions. |
* 3. Exported library functions. |
* 4. Simplified API. |
* |
* The library source code has additional files (principally pngpriv.h) that |
* allow configuration of the library. |
*/ |
/* Section 1: 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 2: type definitions, including structures and compile time |
* constants. |
* See pngconf.h for base types that vary by machine/system |
*/ |
|
/* This triggers a compiler error in png.c, if png.c and png.h |
* do not agree upon the version number. |
*/ |
typedef char* png_libpng_version_1_6_5; |
|
/* 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; |
|
#ifdef PNG_STORE_UNKNOWN_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 0x0001 |
#define PNG_INFO_sBIT 0x0002 |
#define PNG_INFO_cHRM 0x0004 |
#define PNG_INFO_PLTE 0x0008 |
#define PNG_INFO_tRNS 0x0010 |
#define PNG_INFO_bKGD 0x0020 |
#define PNG_INFO_hIST 0x0040 |
#define PNG_INFO_pHYs 0x0080 |
#define PNG_INFO_oFFs 0x0100 |
#define PNG_INFO_tIME 0x0200 |
#define PNG_INFO_pCAL 0x0400 |
#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ |
#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */ |
#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */ |
#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */ |
#define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */ |
|
/* 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)); |
|
/* 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 */ |
#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ |
|
/* 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 3: 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 /* PNG_CONVERT_tIME_SUPPORTED */ |
|
#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 when an alpha channel, or 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. 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. The |
* advantage is that the color channels can be resampled (the image can be |
* scaled) in this form. The disadvantage is that normal practice is to store |
* linear, not (gamma) encoded, values and this requires 16-bit channels for |
* still images rather than the 8-bit channels that are just about sufficient if |
* gamma encoding is used. In addition all non-transparent pixel values, |
* including completely opaque ones, must be gamma encoded to produce the final |
* image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the |
* latter being the two common names for associated alpha color channels.) |
* |
* Since it is not necessary to perform arithmetic on opaque color values so |
* long as they are not to be resampled and are in the final color space it is |
* possible to optimize the handling of alpha by storing the opaque pixels in |
* the PNG format (adjusted for the output color space) while storing partially |
* opaque pixels in the standard, linear, format. The accuracy required for |
* standard alpha composition is relatively low, because the pixels are |
* isolated, therefore typically the accuracy loss in storing 8-bit linear |
* values is acceptable. (This is not true if the alpha channel is used to |
* simulate transparency over large areas - use 16 bits or the PNG mode in |
* this case!) This is the 'OPTIMIZED' mode. For this 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. The values used |
* correspond to the normal numbers used to describe the overall gamma of a |
* computer display system; for example 2.2 for an sRGB conformant system. The |
* values are scaled by 100000 in the _fixed version of the API (so 220000 for |
* sRGB.) |
* |
* The inverse of the value is always used to provide a default for the PNG file |
* encoding if it has no gAMA chunk and if png_set_gamma() has not been called |
* to override the PNG gamma information. |
* |
* When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode |
* opaque pixels however pixels with lower alpha values are not encoded, |
* regardless of the output gamma setting. |
* |
* When the standard Porter Duff handling is requested with mode 1 the output |
* encoding is set to be linear and the output_gamma value is only relevant |
* as a default for input data that has no gamma information. The linear output |
* encoding will be overridden if png_set_gamma() is called - the results may be |
* highly unexpected! |
* |
* The following numbers are derived from the sRGB standard and the research |
* behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of |
* 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing |
* correction required to take account of any differences in the color |
* environment of the original scene and the intended display environment; the |
* value expresses how to *decode* the image for display, not how the original |
* data was *encoded*. |
* |
* sRGB provides a peg for the PNG standard by defining a viewing environment. |
* sRGB itself, and earlier TV standards, actually use a more complex transform |
* (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is |
* limited to simple power laws.) By saying that an image for direct display on |
* an sRGB conformant system should be stored with a gAMA chunk value of 45455 |
* (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification |
* makes it possible to derive values for other display systems and |
* environments. |
* |
* The Mac value is deduced from the sRGB based on an assumption that the actual |
* extra viewing correction used in early Mac display systems was implemented as |
* a power 1.45 lookup table. |
* |
* Any system where a programmable lookup table is used or where the behavior of |
* the final display device characteristics can be changed requires system |
* specific code to obtain the current characteristic. However this can be |
* difficult and most PNG gamma correction only requires an approximate value. |
* |
* By default, if png_set_alpha_mode() is not called, libpng assumes that all |
* values are unencoded, linear, values and that the output device also has a |
* linear characteristic. This is only very rarely correct - it is invariably |
* better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the |
* default if you don't know what the right answer is! |
* |
* The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS |
* 10.6) which used a correction table to implement a somewhat lower gamma on an |
* otherwise sRGB system. |
* |
* Both these values are reserved (not simple gamma values) in order to allow |
* more precise correction internally in the future. |
* |
* NOTE: the following values can be passed to either the fixed or floating |
* point APIs, but the floating point API will also accept floating point |
* values. |
*/ |
#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 Gray or 24-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 Gray or 24-bit RGB images. */ |
PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, |
png_uint_32 filler, int flags)); |
#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */ |
|
#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 */ |
|
/* 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)); |
|
/* 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_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ |
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_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */ |
/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_ |
* defines, either the default (minimum-sum-of-absolute-differences), or |
* the experimental method (weighted-minimum-sum-of-absolute-differences). |
* |
* Weights are factors >= 1.0, indicating how important it is to keep the |
* filter type consistent between rows. Larger numbers mean the current |
* filter is that many times as likely to be the same as the "num_weights" |
* previous filters. This is cumulative for each previous row with a weight. |
* There needs to be "num_weights" values in "filter_weights", or it can be |
* NULL if the weights aren't being specified. Weights have no influence on |
* the selection of the first row filter. Well chosen weights can (in theory) |
* improve the compression for a given image. |
* |
* Costs are factors >= 1.0 indicating the relative decoding costs of a |
* filter type. Higher costs indicate more decoding expense, and are |
* therefore less likely to be selected over a filter with lower computational |
* costs. There needs to be a value in "filter_costs" for each valid filter |
* type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't |
* setting the costs. Costs try to improve the speed of decompression without |
* unduly increasing the compressed image size. |
* |
* A negative weight or cost indicates the default value is to be used, and |
* values in the range [0.0, 1.0) indicate the value is to remain unchanged. |
* The default values for both weights and costs are currently 1.0, but may |
* change if good general weighting/cost heuristics can be found. If both |
* the weights and costs are set to 1.0, this degenerates the WEIGHTED method |
* to the UNWEIGHTED method, but with added encoding time/computation. |
*/ |
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 /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ |
|
/* Heuristic used for row filter selection. These defines should NOT be |
* changed. |
*/ |
#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 */ |
|
#ifdef PNG_WRITE_SUPPORTED |
/* 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. |
*/ |
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 |
|
#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 /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ |
|
/* 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 occured, 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)); |
|
#ifdef PNG_READ_INTERLACING_SUPPORTED |
/* 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 /* PNG_READ_INTERLACING_SUPPORTED */ |
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ |
|
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_EXPORTA(99, void, png_data_freer, (png_const_structrp png_ptr, |
png_inforp info_ptr, int freer, png_uint_32 mask), PNG_DEPRECATED); |
|
/* 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 0x0008 |
#define PNG_FREE_ICCP 0x0010 |
#define PNG_FREE_SPLT 0x0020 |
#define PNG_FREE_ROWS 0x0040 |
#define PNG_FREE_PCAL 0x0080 |
#define PNG_FREE_SCAL 0x0100 |
#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED |
# define PNG_FREE_UNKN 0x0200 |
#endif |
/* PNG_FREE_LIST 0x0400 removed in 1.6.0 because it is ignored */ |
#define PNG_FREE_PLTE 0x1000 |
#define PNG_FREE_TRNS 0x2000 |
#define PNG_FREE_TEXT 0x4000 |
#define PNG_FREE_ALL 0x7fff |
#define PNG_FREE_MUL 0x4220 /* 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); |
#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)); |
#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 /* PNG_EASY_ACCESS_SUPPORTED */ |
|
#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 /* PNG_sCAL_SUPPORTED */ |
|
#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. |
*/ |
PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, |
int keep, png_const_bytep chunk_list, int num_chunks)); |
|
/* 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 |
|
#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. */ |
PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, |
int transforms, png_voidp params)); |
PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, |
int transforms, png_voidp params)); |
#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 /* PNG_pHYs_SUPPORTED */ |
#endif /* PNG_INCH_CONVERSIONS_SUPPORTED */ |
|
/* 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 /* ?PNG_IO_STATE_SUPPORTED */ |
|
/* 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); } |
|
# 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)((temp + (temp >> 16)) >> 16); } |
|
#else /* Standard method using integer division */ |
|
# define png_composite(composite, fg, alpha, bg) \ |
(composite) = (png_byte)(((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)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ |
(png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ |
32767) / 65535) |
#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */ |
|
#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) ^ 0xffffffffL) + 1)) \ |
: (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 |
|
/******************************************************************************* |
* 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 and set the |
* version field to PNG_IMAGE_VERSION. |
* 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: |
*/ |
#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. |
*/ |
|
#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. |
*/ |
|
#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 /* PNG_STDIO_SUPPORTED */ |
|
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 /* PNG_SIMPLIFIED_READ_SUPPORTED */ |
|
#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED |
#ifdef PNG_STDIO_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) |
*/ |
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*). */ |
|
/* With both 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. |
* |
* Note that the write API does not support interlacing or sub-8-bit pixels. |
*/ |
#endif /* PNG_STDIO_SUPPORTED */ |
#endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */ |
/******************************************************************************* |
* END OF SIMPLIFIED API |
******************************************************************************/ |
|
#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 */ |
|
/******************************************************************************* |
* 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_OPTION_NEXT 4 /* 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 |
|
/******************************************************************************* |
* END OF HARDWARE OPTIONS |
******************************************************************************/ |
|
/* Maintainer: Put new public prototypes here ^, in libpng.3, and project |
* defs, scripts/pnglibconf.h, and scripts/pnglibconf.h.prebuilt |
*/ |
|
/* The last ordinal number (this is the *last* one already used; the next |
* one to use is one more than this.) Maintainer, remember to add an entry to |
* scripts/symbols.def as well. |
*/ |
#ifdef PNG_EXPORT_LAST_ORDINAL |
PNG_EXPORT_LAST_ORDINAL(244); |
#endif |
|
#ifdef __cplusplus |
} |
#endif |
|
#endif /* PNG_VERSION_INFO_ONLY */ |
/* Do not put anything past this line */ |
#endif /* PNG_H */ |