2
/* png.h - header file for PNG reference library
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* libpng version 1.0.8 - July 24, 2000
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* Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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* Authors and maintainers:
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* libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
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* libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
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* libpng versions 0.97, January 1998, through 1.0.8 - July 24, 2000: Glenn
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* See also "Contributing Authors", below.
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* Note about libpng version numbers:
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* Due to various miscommunications, unforeseen code incompatibilities
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* and occasional factors outside the authors' control, version numbering
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* on the library has not always been consistent and straightforward.
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* The following table summarizes matters since version 0.89c, which was
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* the first widely used release:
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* source png.h png.h shared-lib
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* version string int version
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* ------- ------ ----- ----------
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* 0.89c "1.0 beta 3" 0.89 89 1.0.89
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* 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
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* 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
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* 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
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* 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
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* 0.97c 0.97 97 2.0.97
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* 0.99a-m 0.99 99 2.0.99
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* 1.00 1.00 100 2.1.0 [100 should be 10000]
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* 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
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* 1.0.1 png.h string is 10001 2.1.0
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* 1.0.1a-e identical to the 10002 from here on, the shared library
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* 1.0.2 source version) 10002 is 2.V where V is the source code
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* 1.0.2a-b 10003 version, except as noted.
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* 1.0.5 (+ 2 patches) 10005
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* 1.0.5e-r 10100 (not source compatible)
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* 1.0.5s-v 10006 (not binary compatible)
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* 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
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* 1.0.6d-f 10007 (still binary incompatible)
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* 1.0.6h 10007 10.6h (testing xy.z so-numbering)
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* 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
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* 1.0.7beta11-18 10007 2.1.0.7beta11-18 (binary compatible)
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* 1.0.7rc1-2 10007 2.1.0.7rc1-2 (binary compatible)
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* 1.0.7 10007 (still compatible)
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* 1.0.8beta1-4 10008 2.1.0.8beta1-4
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* 1.0.8rc1 10008 2.1.0.8rc1
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* Henceforth the source version will match the shared-library major
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* and minor numbers; the shared-library major version number will be
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* used for changes in backward compatibility, as it is intended. The
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* PNG_PNGLIB_VER macro, which is not used within libpng but is available
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* for applications, is an unsigned integer of the form xyyzz corresponding
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* to the source version x.y.z (leading zeros in y and z). Beta versions
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* were given the previous public release number plus a letter, until
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* version 1.0.6j; from then on they were given the upcoming public
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* release number plus "betaNN" or "rcN".
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* Binary incompatibility exists only when applications make direct access
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* to the info_ptr or png_ptr members through png.h, and the compiled
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* application is loaded with a different version of the library.
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* See libpng.txt or libpng.3 for more information. The PNG specification
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* is available as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/>
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* and as a W3C Recommendation <http://www.w3.org/TR/REC.png.html>
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* COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
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* If you modify libpng you may insert additional notices immediately following
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* libpng versions 1.0.7, July 1, 2000, through 1.0.8, July 24, 2000, are
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* Copyright (c) 2000 Glenn Randers-Pehrson, and are
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* distributed according to the same disclaimer and license as libpng-1.0.6
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* with the following individuals added to the list of Contributing Authors
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* Simon-Pierre Cadieux
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* and with the following additions to the disclaimer:
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* There is no warranty against interference with your enjoyment of the
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* library or against infringement. There is no warranty that our
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* efforts or the library will fulfill any of your particular purposes
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* or needs. This library is provided with all faults, and the entire
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* risk of satisfactory quality, performance, accuracy, and effort is with
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* libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
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* Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
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* Distributed according to the same disclaimer and license as libpng-0.96,
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* with the following individuals added to the list of Contributing Authors:
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* Glenn Randers-Pehrson
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* libpng versions 0.89, June 1996, through 0.96, May 1997, are
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* Copyright (c) 1996, 1997 Andreas Dilger
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* Distributed according to the same disclaimer and license as libpng-0.88,
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* with the following individuals added to the list of Contributing Authors:
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* libpng versions 0.5, May 1995, through 0.88, January 1996, are
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* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
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* For the purposes of this copyright and license, "Contributing Authors"
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* is defined as the following set of individuals:
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* The PNG Reference Library is supplied "AS IS". The Contributing Authors
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* and Group 42, Inc. disclaim all warranties, expressed or implied,
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* including, without limitation, the warranties of merchantability and of
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* fitness for any purpose. The Contributing Authors and Group 42, Inc.
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* assume no liability for direct, indirect, incidental, special, exemplary,
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* or consequential damages, which may result from the use of the PNG
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* Reference Library, even if advised of the possibility of such damage.
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* Permission is hereby granted to use, copy, modify, and distribute this
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* source code, or portions hereof, for any purpose, without fee, subject
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* to the following restrictions:
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* 1. The origin of this source code must not be misrepresented.
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* 2. Altered versions must be plainly marked as such and must not
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* be misrepresented as being the original source.
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* 3. This Copyright notice may not be removed or altered from any
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* source or altered source distribution.
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* The Contributing Authors and Group 42, Inc. specifically permit, without
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* fee, and encourage the use of this source code as a component to
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* supporting the PNG file format in commercial products. If you use this
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* source code in a product, acknowledgment is not required but would be
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* A "png_get_copyright" function is available, for convenient use in "about"
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* boxes and the like:
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* printf("%s",png_get_copyright(NULL));
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* Also, the PNG logo (in PNG format, of course) is supplied in the
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* files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
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* Libpng is OSI Certified Open Source Software. OSI Certified is a
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* certification mark of the Open Source Initiative.
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* The contributing authors would like to thank all those who helped
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* with testing, bug fixes, and patience. This wouldn't have been
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* possible without all of you.
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* Thanks to Frank J. T. Wojcik for helping with the documentation.
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* Y2K compliance in libpng:
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* =========================
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* Since the PNG Development group is an ad-hoc body, we can't make
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* an official declaration.
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* This is your unofficial assurance that libpng from version 0.71 and
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* upward through 1.0.8 are Y2K compliant. It is my belief that earlier
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* versions were also Y2K compliant.
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* Libpng only has three year fields. One is a 2-byte unsigned integer
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* that will hold years up to 65535. The other two hold the date in text
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* format, and will hold years up to 9999.
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* "png_uint_16 year" in png_time_struct.
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* "png_charp time_buffer" in png_struct and
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* "near_time_buffer", which is a local character string in png.c.
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* There are seven time-related functions:
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* png.c: png_convert_to_rfc_1123() in png.c
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* (formerly png_convert_to_rfc_1152() in error)
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* png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
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* png_convert_from_time_t() in pngwrite.c
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* png_get_tIME() in pngget.c
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* png_handle_tIME() in pngrutil.c, called in pngread.c
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* png_set_tIME() in pngset.c
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* png_write_tIME() in pngwutil.c, called in pngwrite.c
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* All handle dates properly in a Y2K environment. The
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* png_convert_from_time_t() function calls gmtime() to convert from system
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* clock time, which returns (year - 1900), which we properly convert to
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* the full 4-digit year. There is a possibility that applications using
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* libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
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* function, or that they are incorrectly passing only a 2-digit year
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* instead of "year - 1900" into the png_convert_from_struct_tm() function,
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* but this is not under our control. The libpng documentation has always
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* stated that it works with 4-digit years, and the APIs have been
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* documented as such.
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* The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
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* integer to hold the year, and can hold years as large as 65535.
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* zlib, upon which libpng depends, is also Y2K compliant. It contains
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* no date-related code.
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* Glenn Randers-Pehrson
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* PNG Development Group
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/* This is not the place to learn how to use libpng. The file libpng.txt
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* describes how to use libpng, and the file example.c summarizes it
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* with some code on which to build. This file is useful for looking
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* at the actual function definitions and structure components.
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/* Version information for png.h - this should match the version in png.c */
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#define PNG_LIBPNG_VER_STRING "1.0.8"
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#define PNG_LIBPNG_VER_SONUM 2
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/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
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#define PNG_LIBPNG_VER_MAJOR 1
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#define PNG_LIBPNG_VER_MINOR 0
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#define PNG_LIBPNG_VER_RELEASE 8
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/* This should match the numeric part of the final component of
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* PNG_LIBPNG_VER_STRING, omitting any leading zero: */
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#define PNG_LIBPNG_VER_BUILD 0
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/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
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* We must not include leading zeros.
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* Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
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* version 1.0.0 was mis-numbered 100 instead of 10000). From
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* version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release */
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#define PNG_LIBPNG_VER 10008 /* 1.0.8 */
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/* Note to maintainer: update this number in scripts/pngdef.pas as well */
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#ifndef PNG_VERSION_INFO_ONLY
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/* include the compression library's header */
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/* include all user configurable info */
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/* macros for optional assembler routines */
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#if defined(PNG_INTERNAL) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
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# include "pngasmrd.h"
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/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
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#endif /* __cplusplus */
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/* This file is arranged in several sections. The first section contains
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* structure and type definitions. The second section contains the external
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* library functions, while the third has the internal library functions,
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* which applications aren't expected to use directly.
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/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
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#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
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/* Version information for C files, stored in png.c. This had better match
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#ifdef PNG_USE_GLOBAL_ARRAYS
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PNG_EXPORT_VAR (char) png_libpng_ver[12]; /* need room for 99.99.99-patch-aa0*/
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/* Note to maintainer: increase to 18 at the next opportunity */
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#define png_libpng_ver png_get_header_ver(NULL)
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#ifdef PNG_USE_GLOBAL_ARRAYS
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/* This was removed in version 1.0.5c */
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/* Structures to facilitate easy interlacing. See png.c for more details */
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PNG_EXPORT_VAR (int FARDATA) png_pass_start[7];
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PNG_EXPORT_VAR (int FARDATA) png_pass_inc[7];
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PNG_EXPORT_VAR (int FARDATA) png_pass_ystart[7];
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PNG_EXPORT_VAR (int FARDATA) png_pass_yinc[7];
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PNG_EXPORT_VAR (int FARDATA) png_pass_mask[7];
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PNG_EXPORT_VAR (int FARDATA) png_pass_dsp_mask[7];
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#ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
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extern int FARDATA png_pass_width[7]; /* now used in pngvcrd.c, pnggccrd.c */
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/* This isn't currently used. If you need it, see png.c for more details.
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extern int FARDATA png_pass_height[7];
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#endif /* PNG_NO_EXTERN */
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/* Three color definitions. The order of the red, green, and blue, (and the
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* exact size) is not important, although the size of the fields need to
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* be png_byte or png_uint_16 (as defined below).
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typedef struct png_color_struct
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typedef png_color FAR * png_colorp;
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typedef png_color FAR * FAR * png_colorpp;
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typedef struct png_color_16_struct
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png_byte index; /* used for palette files */
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png_uint_16 red; /* for use in red green blue files */
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png_uint_16 gray; /* for use in grayscale files */
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typedef png_color_16 FAR * png_color_16p;
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typedef png_color_16 FAR * FAR * png_color_16pp;
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typedef struct png_color_8_struct
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png_byte red; /* for use in red green blue files */
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png_byte gray; /* for use in grayscale files */
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png_byte alpha; /* for alpha channel files */
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typedef png_color_8 FAR * png_color_8p;
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typedef png_color_8 FAR * FAR * png_color_8pp;
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* The following two structures are used for the in-core representation
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typedef struct png_sPLT_entry_struct
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png_uint_16 frequency;
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typedef png_sPLT_entry FAR * png_sPLT_entryp;
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typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
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/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
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* occupy the LSB of their respective members, and the MSB of each member
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* is zero-filled. The frequency member always occupies the full 16 bits.
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typedef struct png_sPLT_struct
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png_charp name; /* palette name */
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png_byte depth; /* depth of palette samples */
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png_sPLT_entryp entries; /* palette entries */
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png_int_32 nentries; /* number of palette entries */
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typedef png_sPLT_t FAR * png_sPLT_tp;
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typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
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#ifdef PNG_TEXT_SUPPORTED
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/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
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* and whether that contents is compressed or not. The "key" field
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* points to a regular zero-terminated C string. The "text", "lang", and
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* "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
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* However, the * structure returned by png_get_text() will always contain
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* regular zero-terminated C strings (possibly empty), never NULL pointers,
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* so they can be safely used in printf() and other string-handling functions.
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typedef struct png_text_struct
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int compression; /* compression value:
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png_charp key; /* keyword, 1-79 character description of "text" */
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png_charp text; /* comment, may be an empty string (ie "")
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png_size_t text_length; /* length of the text string */
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#ifdef PNG_iTXt_SUPPORTED
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png_size_t itxt_length; /* length of the itxt string */
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png_charp lang; /* language code, 0-79 characters
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png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
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chars or a NULL pointer */
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typedef png_text FAR * png_textp;
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typedef png_text FAR * FAR * png_textpp;
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/* Supported compression types for text in PNG files (tEXt, and zTXt).
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* The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
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#define PNG_TEXT_COMPRESSION_NONE_WR -3
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#define PNG_TEXT_COMPRESSION_zTXt_WR -2
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#define PNG_TEXT_COMPRESSION_NONE -1
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#define PNG_TEXT_COMPRESSION_zTXt 0
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#define PNG_ITXT_COMPRESSION_NONE 1
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#define PNG_ITXT_COMPRESSION_zTXt 2
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#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
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/* png_time is a way to hold the time in an machine independent way.
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* Two conversions are provided, both from time_t and struct tm. There
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* is no portable way to convert to either of these structures, as far
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* as I know. If you know of a portable way, send it to me. As a side
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* note - PNG is Year 2000 compliant!
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typedef struct png_time_struct
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png_uint_16 year; /* full year, as in, 1995 */
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png_byte month; /* month of year, 1 - 12 */
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png_byte day; /* day of month, 1 - 31 */
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png_byte hour; /* hour of day, 0 - 23 */
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png_byte minute; /* minute of hour, 0 - 59 */
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png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
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typedef png_time FAR * png_timep;
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typedef png_time FAR * FAR * png_timepp;
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#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
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/* png_unknown_chunk is a structure to hold queued chunks for which there is
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* no specific support. The idea is that we can use this to queue
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* up private chunks for output even though the library doesn't actually
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* know about their semantics.
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typedef struct png_unknown_chunk_t
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/* libpng-using applications should NOT directly modify this byte. */
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png_byte location; /* mode of operation at read time */
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typedef png_unknown_chunk FAR * png_unknown_chunkp;
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typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
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/* png_info is a structure that holds the information in a PNG file so
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* that the application can find out the characteristics of the image.
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* If you are reading the file, this structure will tell you what is
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* in the PNG file. If you are writing the file, fill in the information
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* you want to put into the PNG file, then call png_write_info().
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* The names chosen should be very close to the PNG specification, so
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* consult that document for information about the meaning of each field.
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* With libpng < 0.95, it was only possible to directly set and read the
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* the values in the png_info_struct, which meant that the contents and
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* order of the values had to remain fixed. With libpng 0.95 and later,
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* however, there are now functions that abstract the contents of
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* png_info_struct from the application, so this makes it easier to use
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* libpng with dynamic libraries, and even makes it possible to use
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* libraries that don't have all of the libpng ancillary chunk-handing
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* In any case, the order of the parameters in png_info_struct should NOT
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* be changed for as long as possible to keep compatibility with applications
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* that use the old direct-access method with png_info_struct.
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* The following members may have allocated storage attached that should be
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* cleaned up before the structure is discarded: palette, trans, text,
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* pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
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* splt_palettes, scal_unit, row_pointers, and unknowns. By default, these are
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* automatically freed when the info structure is deallocated, if they were
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* allocated internally by libpng. This behavior can be changed by means
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* of the png_data_freer() function.
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* More allocation details: all the chunk-reading functions that change these
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* members go through the corresponding png_set_* functions. A function to
506
* clear these members is available: see png_free_data(). Some of the
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* png_set_* functions do not depend on being able to point info structure
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* members to any of the storage they are passed (they make their own copies),
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* EXCEPT that the png_set_text functions use the same storage passed to them
510
* in the text_ptr or itxt_ptr structure argument, and the png_set_tRNS,
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* png_set_PLTE, png_set_hIST, png_set_iCCP, png_set_rows, png_set_sPLT,
512
* and png_set_unknowns do not make their own copies.
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typedef struct png_info_struct
516
/* the following are necessary for every PNG file */
517
png_uint_32 width; /* width of image in pixels (from IHDR) */
518
png_uint_32 height; /* height of image in pixels (from IHDR) */
519
png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
520
png_uint_32 rowbytes; /* bytes needed to hold an untransformed row */
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png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
522
png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
523
png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
524
png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
525
png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
526
png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
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png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
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png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
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/* The following is informational only on read, and not used on writes. */
531
png_byte channels; /* number of data channels per pixel (1, 2, 3, 4)*/
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png_byte pixel_depth; /* number of bits per pixel */
533
png_byte spare_byte; /* to align the data, and for future use */
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png_byte signature[8]; /* magic bytes read by libpng from start of file */
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/* The rest of the data is optional. If you are reading, check the
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* valid field to see if the information in these are valid. If you
538
* are writing, set the valid field to those chunks you want written,
539
* and initialize the appropriate fields below.
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#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
543
/* The gAMA chunk describes the gamma characteristics of the system
544
* on which the image was created, normally in the range [1.0, 2.5].
545
* Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
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float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
550
#if defined(PNG_sRGB_SUPPORTED)
552
/* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
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png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
556
#if defined(PNG_TEXT_SUPPORTED)
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/* The tEXt, and zTXt chunks contain human-readable textual data in
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* uncompressed, compressed, and optionally compressed forms, respectively.
559
* The data in "text" is an array of pointers to uncompressed,
560
* null-terminated C strings. Each chunk has a keyword that describes the
561
* textual data contained in that chunk. Keywords are not required to be
562
* unique, and the text string may be empty. Any number of text chunks may
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int num_text; /* number of comments read/to write */
566
int max_text; /* current size of text array */
567
png_textp text; /* array of comments read/to write */
568
#endif /* PNG_TEXT_SUPPORTED */
570
#if defined(PNG_tIME_SUPPORTED)
571
/* The tIME chunk holds the last time the displayed image data was
572
* modified. See the png_time struct for the contents of this struct.
577
#if defined(PNG_sBIT_SUPPORTED)
578
/* The sBIT chunk specifies the number of significant high-order bits
579
* in the pixel data. Values are in the range [1, bit_depth], and are
580
* only specified for the channels in the pixel data. The contents of
581
* the low-order bits is not specified. Data is valid if
582
* (valid & PNG_INFO_sBIT) is non-zero.
584
png_color_8 sig_bit; /* significant bits in color channels */
587
#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
588
defined(PNG_READ_BACKGROUND_SUPPORTED)
589
/* The tRNS chunk supplies transparency data for paletted images and
590
* other image types that don't need a full alpha channel. There are
591
* "num_trans" transparency values for a paletted image, stored in the
592
* same order as the palette colors, starting from index 0. Values
593
* for the data are in the range [0, 255], ranging from fully transparent
594
* to fully opaque, respectively. For non-paletted images, there is a
595
* single color specified that should be treated as fully transparent.
596
* Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
598
png_bytep trans; /* transparent values for paletted image */
599
png_color_16 trans_values; /* transparent color for non-palette image */
602
#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
603
/* The bKGD chunk gives the suggested image background color if the
604
* display program does not have its own background color and the image
605
* is needs to composited onto a background before display. The colors
606
* in "background" are normally in the same color space/depth as the
607
* pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
609
png_color_16 background;
612
#if defined(PNG_oFFs_SUPPORTED)
613
/* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
614
* and downwards from the top-left corner of the display, page, or other
615
* application-specific co-ordinate space. See the PNG_OFFSET_ defines
616
* below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
618
png_int_32 x_offset; /* x offset on page */
619
png_int_32 y_offset; /* y offset on page */
620
png_byte offset_unit_type; /* offset units type */
623
#if defined(PNG_pHYs_SUPPORTED)
624
/* The pHYs chunk gives the physical pixel density of the image for
625
* display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
626
* defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
628
png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
629
png_uint_32 y_pixels_per_unit; /* vertical pixel density */
630
png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
633
#if defined(PNG_hIST_SUPPORTED)
634
/* The hIST chunk contains the relative frequency or importance of the
635
* various palette entries, so that a viewer can intelligently select a
636
* reduced-color palette, if required. Data is an array of "num_palette"
637
* values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
643
#ifdef PNG_cHRM_SUPPORTED
644
/* The cHRM chunk describes the CIE color characteristics of the monitor
645
* on which the PNG was created. This data allows the viewer to do gamut
646
* mapping of the input image to ensure that the viewer sees the same
647
* colors in the image as the creator. Values are in the range
648
* [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
650
#ifdef PNG_FLOATING_POINT_SUPPORTED
662
#if defined(PNG_pCAL_SUPPORTED)
663
/* The pCAL chunk describes a transformation between the stored pixel
664
* values and original physical data values used to create the image.
665
* The integer range [0, 2^bit_depth - 1] maps to the floating-point
666
* range given by [pcal_X0, pcal_X1], and are further transformed by a
667
* (possibly non-linear) transformation function given by "pcal_type"
668
* and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
669
* defines below, and the PNG-Group's PNG extensions document for a
670
* complete description of the transformations and how they should be
671
* implemented, and for a description of the ASCII parameter strings.
672
* Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
674
png_charp pcal_purpose; /* pCAL chunk description string */
675
png_int_32 pcal_X0; /* minimum value */
676
png_int_32 pcal_X1; /* maximum value */
677
png_charp pcal_units; /* Latin-1 string giving physical units */
678
png_charpp pcal_params; /* ASCII strings containing parameter values */
679
png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
680
png_byte pcal_nparams; /* number of parameters given in pcal_params */
683
#ifdef PNG_FREE_ME_SUPPORTED
684
png_uint_32 free_me; /* flags items libpng is responsible for freeing */
687
#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
688
/* storage for unknown chunks that the library doesn't recognize. */
689
png_unknown_chunkp unknown_chunks;
690
png_size_t unknown_chunks_num;
693
#if defined(PNG_iCCP_SUPPORTED)
694
/* iCCP chunk data. */
695
png_charp iccp_name; /* profile name */
696
png_charp iccp_profile; /* International Color Consortium profile data */
697
png_uint_32 iccp_proflen; /* ICC profile data length */
698
png_byte iccp_compression; /* Always zero */
701
#if defined(PNG_sPLT_SUPPORTED)
702
/* data on sPLT chunks (there may be more than one). */
703
png_sPLT_tp splt_palettes;
704
png_uint_32 splt_palettes_num;
707
#if defined(PNG_sCAL_SUPPORTED)
708
/* The sCAL chunk describes the actual physical dimensions of the
709
* subject matter of the graphic. The chunk contains a unit specification
710
* a byte value, and two ASCII strings representing floating-point
711
* values. The values are width and height corresponsing to one pixel
712
* in the image. This external representation is converted to double
713
* here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
715
png_byte scal_unit; /* unit of physical scale */
716
#ifdef PNG_FLOATING_POINT_SUPPORTED
717
double scal_pixel_width; /* width of one pixel */
718
double scal_pixel_height; /* height of one pixel */
720
#ifdef PNG_FIXED_POINT_SUPPORTED
721
png_charp scal_s_width; /* string containing height */
722
png_charp scal_s_height; /* string containing width */
726
#if defined(PNG_INFO_IMAGE_SUPPORTED)
727
/* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
728
/* Data valid if (valid & PNG_INFO_IDAT) non-zero */
729
png_bytepp row_pointers; /* the image bits */
732
#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
733
png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
736
#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
737
png_fixed_point int_x_white;
738
png_fixed_point int_y_white;
739
png_fixed_point int_x_red;
740
png_fixed_point int_y_red;
741
png_fixed_point int_x_green;
742
png_fixed_point int_y_green;
743
png_fixed_point int_x_blue;
744
png_fixed_point int_y_blue;
749
typedef png_info FAR * png_infop;
750
typedef png_info FAR * FAR * png_infopp;
752
/* Maximum positive integer used in PNG is (2^31)-1 */
753
#define PNG_MAX_UINT ((png_uint_32)0x7fffffffL)
755
/* These describe the color_type field in png_info. */
756
/* color type masks */
757
#define PNG_COLOR_MASK_PALETTE 1
758
#define PNG_COLOR_MASK_COLOR 2
759
#define PNG_COLOR_MASK_ALPHA 4
761
/* color types. Note that not all combinations are legal */
762
#define PNG_COLOR_TYPE_GRAY 0
763
#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
764
#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
765
#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
766
#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
768
/* This is for compression type. PNG 1.0-1.2 only define the single type. */
769
#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
770
#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
772
/* This is for filter type. PNG 1.0-1.2 only define the single type. */
773
#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
774
#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
776
/* These are for the interlacing type. These values should NOT be changed. */
777
#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
778
#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
779
#define PNG_INTERLACE_LAST 2 /* Not a valid value */
781
/* These are for the oFFs chunk. These values should NOT be changed. */
782
#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
783
#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
784
#define PNG_OFFSET_LAST 2 /* Not a valid value */
786
/* These are for the pCAL chunk. These values should NOT be changed. */
787
#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
788
#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
789
#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
790
#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
791
#define PNG_EQUATION_LAST 4 /* Not a valid value */
793
/* These are for the sCAL chunk. These values should NOT be changed. */
794
#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
795
#define PNG_SCALE_METER 1 /* meters per pixel */
796
#define PNG_SCALE_RADIAN 2 /* radians per pixel */
797
#define PNG_SCALE_LAST 3 /* Not a valid value */
799
/* These are for the pHYs chunk. These values should NOT be changed. */
800
#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
801
#define PNG_RESOLUTION_METER 1 /* pixels/meter */
802
#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
804
/* These are for the sRGB chunk. These values should NOT be changed. */
805
#define PNG_sRGB_INTENT_PERCEPTUAL 0
806
#define PNG_sRGB_INTENT_RELATIVE 1
807
#define PNG_sRGB_INTENT_SATURATION 2
808
#define PNG_sRGB_INTENT_ABSOLUTE 3
809
#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
811
/* This is for text chunks */
812
#define PNG_KEYWORD_MAX_LENGTH 79
815
/* These determine if an ancillary chunk's data has been successfully read
816
* from the PNG header, or if the application has filled in the corresponding
817
* data in the info_struct to be written into the output file. The values
818
* of the PNG_INFO_<chunk> defines should NOT be changed.
820
#define PNG_INFO_gAMA 0x0001
821
#define PNG_INFO_sBIT 0x0002
822
#define PNG_INFO_cHRM 0x0004
823
#define PNG_INFO_PLTE 0x0008
824
#define PNG_INFO_tRNS 0x0010
825
#define PNG_INFO_bKGD 0x0020
826
#define PNG_INFO_hIST 0x0040
827
#define PNG_INFO_pHYs 0x0080
828
#define PNG_INFO_oFFs 0x0100
829
#define PNG_INFO_tIME 0x0200
830
#define PNG_INFO_pCAL 0x0400
831
#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
832
#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
833
#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
834
#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
835
#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
837
/* This is used for the transformation routines, as some of them
838
* change these values for the row. It also should enable using
839
* the routines for other purposes.
841
typedef struct png_row_info_struct
843
png_uint_32 width; /* width of row */
844
png_uint_32 rowbytes; /* number of bytes in row */
845
png_byte color_type; /* color type of row */
846
png_byte bit_depth; /* bit depth of row */
847
png_byte channels; /* number of channels (1, 2, 3, or 4) */
848
png_byte pixel_depth; /* bits per pixel (depth * channels) */
851
typedef png_row_info FAR * png_row_infop;
852
typedef png_row_info FAR * FAR * png_row_infopp;
854
/* These are the function types for the I/O functions and for the functions
855
* that allow the user to override the default I/O functions with his or her
856
* own. The png_error_ptr type should match that of user-supplied warning
857
* and error functions, while the png_rw_ptr type should match that of the
858
* user read/write data functions.
860
typedef struct png_struct_def png_struct;
861
typedef png_struct FAR * png_structp;
863
typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
864
typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
865
typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
866
typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
868
typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
871
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
872
typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
873
typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
874
typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
878
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
879
defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
880
defined(PNG_LEGACY_SUPPORTED)
881
typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
882
png_row_infop, png_bytep));
885
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
886
typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
888
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
889
typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
892
/* Transform masks for the high-level interface */
893
#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
894
#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
895
#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
896
#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
897
#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
898
#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
899
#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
900
#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
901
#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
902
#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
903
#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
904
#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
905
#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* WRITE only */
907
typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
908
typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
910
/* The structure that holds the information to read and write PNG files.
911
* The only people who need to care about what is inside of this are the
912
* people who will be modifying the library for their own special needs.
913
* It should NOT be accessed directly by an application, except to store
917
struct png_struct_def
919
#ifdef PNG_SETJMP_SUPPORTED
920
jmp_buf jmpbuf; /* used in png_error */
922
png_error_ptr error_fn; /* function for printing errors and aborting */
923
png_error_ptr warning_fn; /* function for printing warnings */
924
png_voidp error_ptr; /* user supplied struct for error functions */
925
png_rw_ptr write_data_fn; /* function for writing output data */
926
png_rw_ptr read_data_fn; /* function for reading input data */
927
png_voidp io_ptr; /* ptr to application struct for I/O functions*/
929
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
930
png_user_transform_ptr read_user_transform_fn; /* user read transform */
933
#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
934
png_user_transform_ptr write_user_transform_fn; /* user write transform */
937
/* These were added in libpng-1.0.2 */
938
#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
939
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
940
defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
941
png_voidp user_transform_ptr; /* user supplied struct for user transform */
942
png_byte user_transform_depth; /* bit depth of user transformed pixels */
943
png_byte user_transform_channels; /* channels in user transformed pixels */
947
png_uint_32 mode; /* tells us where we are in the PNG file */
948
png_uint_32 flags; /* flags indicating various things to libpng */
949
png_uint_32 transformations; /* which transformations to perform */
951
z_stream zstream; /* pointer to decompression structure (below) */
952
png_bytep zbuf; /* buffer for zlib */
953
png_size_t zbuf_size; /* size of zbuf */
954
int zlib_level; /* holds zlib compression level */
955
int zlib_method; /* holds zlib compression method */
956
int zlib_window_bits; /* holds zlib compression window bits */
957
int zlib_mem_level; /* holds zlib compression memory level */
958
int zlib_strategy; /* holds zlib compression strategy */
960
png_uint_32 width; /* width of image in pixels */
961
png_uint_32 height; /* height of image in pixels */
962
png_uint_32 num_rows; /* number of rows in current pass */
963
png_uint_32 usr_width; /* width of row at start of write */
964
png_uint_32 rowbytes; /* size of row in bytes */
965
png_uint_32 irowbytes; /* size of current interlaced row in bytes */
966
png_uint_32 iwidth; /* width of current interlaced row in pixels */
967
png_uint_32 row_number; /* current row in interlace pass */
968
png_bytep prev_row; /* buffer to save previous (unfiltered) row */
969
png_bytep row_buf; /* buffer to save current (unfiltered) row */
970
png_bytep sub_row; /* buffer to save "sub" row when filtering */
971
png_bytep up_row; /* buffer to save "up" row when filtering */
972
png_bytep avg_row; /* buffer to save "avg" row when filtering */
973
png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
974
png_row_info row_info; /* used for transformation routines */
976
png_uint_32 idat_size; /* current IDAT size for read */
977
png_uint_32 crc; /* current chunk CRC value */
978
png_colorp palette; /* palette from the input file */
979
png_uint_16 num_palette; /* number of color entries in palette */
980
png_uint_16 num_trans; /* number of transparency values */
981
png_byte chunk_name[5]; /* null-terminated name of current chunk */
982
png_byte compression; /* file compression type (always 0) */
983
png_byte filter; /* file filter type (always 0) */
984
png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
985
png_byte pass; /* current interlace pass (0 - 6) */
986
png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
987
png_byte color_type; /* color type of file */
988
png_byte bit_depth; /* bit depth of file */
989
png_byte usr_bit_depth; /* bit depth of users row */
990
png_byte pixel_depth; /* number of bits per pixel */
991
png_byte channels; /* number of channels in file */
992
png_byte usr_channels; /* channels at start of write */
993
png_byte sig_bytes; /* magic bytes read/written from start of file */
995
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
996
#ifdef PNG_LEGACY_SUPPORTED
997
png_byte filler; /* filler byte for pixel expansion */
999
png_uint_16 filler; /* filler bytes for pixel expansion */
1003
#if defined(PNG_READ_bKGD_SUPPORTED)
1004
png_byte background_gamma_type;
1005
# ifdef PNG_FLOATING_POINT_SUPPORTED
1006
float background_gamma;
1008
png_color_16 background; /* background color in screen gamma space */
1009
# if defined(PNG_READ_GAMMA_SUPPORTED)
1010
png_color_16 background_1; /* background normalized to gamma 1.0 */
1011
# endif /* PNG_READ_GAMMA && PNG_READ_bKGD_SUPPORTED */
1012
#endif /* PNG_READ_bKGD_SUPPORTED */
1014
#if defined(PNG_WRITE_FLUSH_SUPPORTED)
1015
png_flush_ptr output_flush_fn;/* Function for flushing output */
1016
png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
1017
png_uint_32 flush_rows; /* number of rows written since last flush */
1020
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1021
int gamma_shift; /* number of "insignificant" bits 16-bit gamma */
1022
#ifdef PNG_FLOATING_POINT_SUPPORTED
1023
float gamma; /* file gamma value */
1024
float screen_gamma; /* screen gamma value (display_exponent) */
1028
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1029
png_bytep gamma_table; /* gamma table for 8-bit depth files */
1030
png_bytep gamma_from_1; /* converts from 1.0 to screen */
1031
png_bytep gamma_to_1; /* converts from file to 1.0 */
1032
png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
1033
png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
1034
png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
1037
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_sBIT_SUPPORTED)
1038
png_color_8 sig_bit; /* significant bits in each available channel */
1041
#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1042
png_color_8 shift; /* shift for significant bit tranformation */
1045
#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1046
|| defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1047
png_bytep trans; /* transparency values for paletted files */
1048
png_color_16 trans_values; /* transparency values for non-paletted files */
1051
png_read_status_ptr read_row_fn; /* called after each row is decoded */
1052
png_write_status_ptr write_row_fn; /* called after each row is encoded */
1053
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1054
png_progressive_info_ptr info_fn; /* called after header data fully read */
1055
png_progressive_row_ptr row_fn; /* called after each prog. row is decoded */
1056
png_progressive_end_ptr end_fn; /* called after image is complete */
1057
png_bytep save_buffer_ptr; /* current location in save_buffer */
1058
png_bytep save_buffer; /* buffer for previously read data */
1059
png_bytep current_buffer_ptr; /* current location in current_buffer */
1060
png_bytep current_buffer; /* buffer for recently used data */
1061
png_uint_32 push_length; /* size of current input chunk */
1062
png_uint_32 skip_length; /* bytes to skip in input data */
1063
png_size_t save_buffer_size; /* amount of data now in save_buffer */
1064
png_size_t save_buffer_max; /* total size of save_buffer */
1065
png_size_t buffer_size; /* total amount of available input data */
1066
png_size_t current_buffer_size; /* amount of data now in current_buffer */
1067
int process_mode; /* what push library is currently doing */
1068
int cur_palette; /* current push library palette index */
1070
# if defined(PNG_READ_TEXT_SUPPORTED)
1071
png_size_t current_text_size; /* current size of text input data */
1072
png_size_t current_text_left; /* how much text left to read in input */
1073
png_charp current_text; /* current text chunk buffer */
1074
png_charp current_text_ptr; /* current location in current_text */
1075
# endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_READ_TEXT_SUPPORTED */
1077
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1079
#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1080
/* for the Borland special 64K segment handler */
1081
png_bytepp offset_table_ptr;
1082
png_bytep offset_table;
1083
png_uint_16 offset_table_number;
1084
png_uint_16 offset_table_count;
1085
png_uint_16 offset_table_count_free;
1088
#if defined(PNG_READ_DITHER_SUPPORTED)
1089
png_bytep palette_lookup; /* lookup table for dithering */
1090
png_bytep dither_index; /* index translation for palette files */
1093
#if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_READ_hIST_SUPPORTED)
1094
png_uint_16p hist; /* histogram */
1097
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1098
png_byte heuristic_method; /* heuristic for row filter selection */
1099
png_byte num_prev_filters; /* number of weights for previous rows */
1100
png_bytep prev_filters; /* filter type(s) of previous row(s) */
1101
png_uint_16p filter_weights; /* weight(s) for previous line(s) */
1102
png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
1103
png_uint_16p filter_costs; /* relative filter calculation cost */
1104
png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
1107
#if defined(PNG_TIME_RFC1123_SUPPORTED)
1108
png_charp time_buffer; /* String to hold RFC 1123 time text */
1111
#ifdef PNG_USER_MEM_SUPPORTED
1112
png_voidp mem_ptr; /* user supplied struct for mem functions */
1113
png_malloc_ptr malloc_fn; /* function for allocating memory */
1114
png_free_ptr free_fn; /* function for freeing memory */
1117
/* New members added in libpng-1.0.6 */
1119
#ifdef PNG_FREE_ME_SUPPORTED
1120
png_uint_32 free_me; /* flags items libpng is responsible for freeing */
1123
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1124
png_voidp user_chunk_ptr;
1125
png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
1128
#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1130
png_bytep chunk_list;
1133
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1134
png_byte rgb_to_gray_status;
1135
png_uint_16 rgb_to_gray_red_coeff;
1136
png_uint_16 rgb_to_gray_green_coeff;
1137
png_uint_16 rgb_to_gray_blue_coeff;
1140
#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1141
defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1142
png_byte empty_plte_permitted;
1145
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1146
png_fixed_point int_gamma;
1151
/* This prevents a compiler error in png_get_copyright() in png.c if png.c
1152
and png.h are both at * version 1.0.8
1154
typedef png_structp version_1_0_8;
1156
typedef png_struct FAR * FAR * png_structpp;
1158
/* Here are the function definitions most commonly used. This is not
1159
* the place to find out how to use libpng. See libpng.txt for the
1160
* full explanation, see example.c for the summary. This just provides
1161
* a simple one line description of the use of each function.
1164
/* Returns the version number of the library */
1165
extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1167
/* Tell lib we have already handled the first <num_bytes> magic bytes.
1168
* Handling more than 8 bytes from the beginning of the file is an error.
1170
extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1173
/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1174
* PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1175
* signature, and non-zero otherwise. Having num_to_check == 0 or
1176
* start > 7 will always fail (ie return non-zero).
1178
extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1179
png_size_t num_to_check));
1181
/* Simple signature checking function. This is the same as calling
1182
* png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1184
extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
1186
/* Allocate and initialize png_ptr struct for reading, and any other memory. */
1187
extern PNG_EXPORT(png_structp,png_create_read_struct)
1188
PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1189
png_error_ptr error_fn, png_error_ptr warn_fn));
1191
/* Allocate and initialize png_ptr struct for writing, and any other memory */
1192
extern PNG_EXPORT(png_structp,png_create_write_struct)
1193
PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1194
png_error_ptr error_fn, png_error_ptr warn_fn));
1196
extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1197
PNGARG((png_structp png_ptr));
1199
extern PNG_EXPORT(void,png_set_compression_buffer_size)
1200
PNGARG((png_structp png_ptr, png_uint_32 size));
1202
/* Reset the compression stream */
1203
extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1205
#ifdef PNG_USER_MEM_SUPPORTED
1206
extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1207
PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1208
png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1209
png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1210
extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1211
PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1212
png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1213
png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1216
/* Write a PNG chunk - size, type, (optional) data, CRC. */
1217
extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1218
png_bytep chunk_name, png_bytep data, png_size_t length));
1220
/* Write the start of a PNG chunk - length and chunk name. */
1221
extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1222
png_bytep chunk_name, png_uint_32 length));
1224
/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1225
extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1226
png_bytep data, png_size_t length));
1228
/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1229
extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1231
/* Allocate and initialize the info structure */
1232
extern PNG_EXPORT(png_infop,png_create_info_struct)
1233
PNGARG((png_structp png_ptr));
1235
/* Initialize the info structure (old interface - NOT DLL EXPORTED) */
1236
extern void png_info_init PNGARG((png_infop info_ptr));
1238
/* Writes all the PNG information before the image. */
1239
extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1240
png_infop info_ptr));
1241
extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1242
png_infop info_ptr));
1244
/* read the information before the actual image data. */
1245
extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1246
png_infop info_ptr));
1248
#if defined(PNG_TIME_RFC1123_SUPPORTED)
1249
extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1250
PNGARG((png_structp png_ptr, png_timep ptime));
1253
#if !defined(_WIN32_WCE)
1254
/* "time.h" functions are not supported on WindowsCE */
1255
#if defined(PNG_WRITE_tIME_SUPPORTED)
1256
/* convert from a struct tm to png_time */
1257
extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1258
struct tm FAR * ttime));
1260
/* convert from time_t to png_time. Uses gmtime() */
1261
extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1263
#endif /* PNG_WRITE_tIME_SUPPORTED */
1264
#endif /* _WIN32_WCE */
1266
#if defined(PNG_READ_EXPAND_SUPPORTED)
1267
/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1268
extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1269
extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
1270
extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1271
extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1274
#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1275
/* Use blue, green, red order for pixels. */
1276
extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1279
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
1280
/* Expand the grayscale to 24-bit RGB if necessary. */
1281
extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1284
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1285
/* Reduce RGB to grayscale. */
1286
#ifdef PNG_FLOATING_POINT_SUPPORTED
1287
extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1288
int error_action, double red, double green ));
1290
extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1291
int error_action, png_fixed_point red, png_fixed_point green ));
1292
extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1296
extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1297
png_colorp palette));
1299
#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1300
extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1303
#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1304
defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1305
extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1308
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1309
defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1310
extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1313
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1314
/* Add a filler byte to 24-bit RGB images. */
1315
extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1316
png_uint_32 filler, int flags));
1317
/* The values of the PNG_FILLER_ defines should NOT be changed */
1318
#define PNG_FILLER_BEFORE 0
1319
#define PNG_FILLER_AFTER 1
1320
#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1322
#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1323
/* Swap bytes in 16-bit depth files. */
1324
extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1327
#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1328
/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1329
extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1332
#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1333
/* Swap packing order of pixels in bytes. */
1334
extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1337
#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1338
/* Converts files to legal bit depths. */
1339
extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1340
png_color_8p true_bits));
1343
#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1344
defined(PNG_WRITE_INTERLACING_SUPPORTED)
1345
/* Have the code handle the interlacing. Returns the number of passes. */
1346
extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1349
#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1350
/* Invert monochrome files */
1351
extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1354
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
1355
/* Handle alpha and tRNS by replacing with a background color. */
1356
#ifdef PNG_FLOATING_POINT_SUPPORTED
1357
extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1358
png_color_16p background_color, int background_gamma_code,
1359
int need_expand, double background_gamma));
1361
#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1362
#define PNG_BACKGROUND_GAMMA_SCREEN 1
1363
#define PNG_BACKGROUND_GAMMA_FILE 2
1364
#define PNG_BACKGROUND_GAMMA_UNIQUE 3
1367
#if defined(PNG_READ_16_TO_8_SUPPORTED)
1368
/* strip the second byte of information from a 16-bit depth file. */
1369
extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1372
#if defined(PNG_READ_DITHER_SUPPORTED)
1373
/* Turn on dithering, and reduce the palette to the number of colors available. */
1374
extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1375
png_colorp palette, int num_palette, int maximum_colors,
1376
png_uint_16p histogram, int full_dither));
1379
#if defined(PNG_READ_GAMMA_SUPPORTED)
1380
/* Handle gamma correction. Screen_gamma=(display_exponent) */
1381
#ifdef PNG_FLOATING_POINT_SUPPORTED
1382
extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1383
double screen_gamma, double default_file_gamma));
1387
#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1388
defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1389
/* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1390
extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1391
int empty_plte_permitted));
1394
#if defined(PNG_WRITE_FLUSH_SUPPORTED)
1395
/* Set how many lines between output flushes - 0 for no flushing */
1396
extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1397
/* Flush the current PNG output buffer */
1398
extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1401
/* optional update palette with requested transformations */
1402
extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1404
/* optional call to update the users info structure */
1405
extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1406
png_infop info_ptr));
1408
/* read a one or more rows of image data.*/
1409
extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1410
png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1412
/* read a row of data.*/
1413
extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1415
png_bytep display_row));
1417
/* read the whole image into memory at once. */
1418
extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1421
/* write a row of image data */
1422
extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1425
/* write a few rows of image data */
1426
extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1427
png_bytepp row, png_uint_32 num_rows));
1429
/* write the image data */
1430
extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1433
/* writes the end of the PNG file. */
1434
extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1435
png_infop info_ptr));
1437
/* read the end of the PNG file. */
1438
extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1439
png_infop info_ptr));
1441
/* free any memory associated with the png_info_struct */
1442
extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1443
png_infopp info_ptr_ptr));
1445
/* free any memory associated with the png_struct and the png_info_structs */
1446
extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1447
png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1449
/* free all memory used by the read (old method - NOT DLL EXPORTED) */
1450
extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1451
png_infop end_info_ptr));
1453
/* free any memory associated with the png_struct and the png_info_structs */
1454
extern PNG_EXPORT(void,png_destroy_write_struct)
1455
PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1457
/* free any memory used in info_ptr struct (old method - NOT DLL EXPORTED) */
1458
extern void png_write_destroy_info PNGARG((png_infop info_ptr));
1460
/* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1461
extern void png_write_destroy PNGARG((png_structp png_ptr));
1463
/* set the libpng method of handling chunk CRC errors */
1464
extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1465
int crit_action, int ancil_action));
1467
/* Values for png_set_crc_action() to say how to handle CRC errors in
1468
* ancillary and critical chunks, and whether to use the data contained
1469
* therein. Note that it is impossible to "discard" data in a critical
1470
* chunk. For versions prior to 0.90, the action was always error/quit,
1471
* whereas in version 0.90 and later, the action for CRC errors in ancillary
1472
* chunks is warn/discard. These values should NOT be changed.
1474
* value action:critical action:ancillary
1476
#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1477
#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1478
#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1479
#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1480
#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1481
#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1483
/* These functions give the user control over the scan-line filtering in
1484
* libpng and the compression methods used by zlib. These functions are
1485
* mainly useful for testing, as the defaults should work with most users.
1486
* Those users who are tight on memory or want faster performance at the
1487
* expense of compression can modify them. See the compression library
1488
* header file (zlib.h) for an explination of the compression functions.
1491
/* set the filtering method(s) used by libpng. Currently, the only valid
1492
* value for "method" is 0.
1494
extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1497
/* Flags for png_set_filter() to say which filters to use. The flags
1498
* are chosen so that they don't conflict with real filter types
1499
* below, in case they are supplied instead of the #defined constants.
1500
* These values should NOT be changed.
1502
#define PNG_NO_FILTERS 0x00
1503
#define PNG_FILTER_NONE 0x08
1504
#define PNG_FILTER_SUB 0x10
1505
#define PNG_FILTER_UP 0x20
1506
#define PNG_FILTER_AVG 0x40
1507
#define PNG_FILTER_PAETH 0x80
1508
#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1509
PNG_FILTER_AVG | PNG_FILTER_PAETH)
1511
/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1512
* These defines should NOT be changed.
1514
#define PNG_FILTER_VALUE_NONE 0
1515
#define PNG_FILTER_VALUE_SUB 1
1516
#define PNG_FILTER_VALUE_UP 2
1517
#define PNG_FILTER_VALUE_AVG 3
1518
#define PNG_FILTER_VALUE_PAETH 4
1519
#define PNG_FILTER_VALUE_LAST 5
1521
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1522
/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1523
* defines, either the default (minimum-sum-of-absolute-differences), or
1524
* the experimental method (weighted-minimum-sum-of-absolute-differences).
1526
* Weights are factors >= 1.0, indicating how important it is to keep the
1527
* filter type consistent between rows. Larger numbers mean the current
1528
* filter is that many times as likely to be the same as the "num_weights"
1529
* previous filters. This is cumulative for each previous row with a weight.
1530
* There needs to be "num_weights" values in "filter_weights", or it can be
1531
* NULL if the weights aren't being specified. Weights have no influence on
1532
* the selection of the first row filter. Well chosen weights can (in theory)
1533
* improve the compression for a given image.
1535
* Costs are factors >= 1.0 indicating the relative decoding costs of a
1536
* filter type. Higher costs indicate more decoding expense, and are
1537
* therefore less likely to be selected over a filter with lower computational
1538
* costs. There needs to be a value in "filter_costs" for each valid filter
1539
* type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1540
* setting the costs. Costs try to improve the speed of decompression without
1541
* unduly increasing the compressed image size.
1543
* A negative weight or cost indicates the default value is to be used, and
1544
* values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1545
* The default values for both weights and costs are currently 1.0, but may
1546
* change if good general weighting/cost heuristics can be found. If both
1547
* the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1548
* to the UNWEIGHTED method, but with added encoding time/computation.
1550
#ifdef PNG_FLOATING_POINT_SUPPORTED
1551
extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1552
int heuristic_method, int num_weights, png_doublep filter_weights,
1553
png_doublep filter_costs));
1555
#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1557
/* Heuristic used for row filter selection. These defines should NOT be
1560
#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1561
#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1562
#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1563
#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1565
/* Set the library compression level. Currently, valid values range from
1566
* 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1567
* (0 - no compression, 9 - "maximal" compression). Note that tests have
1568
* shown that zlib compression levels 3-6 usually perform as well as level 9
1569
* for PNG images, and do considerably fewer caclulations. In the future,
1570
* these values may not correspond directly to the zlib compression levels.
1572
extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1575
extern PNG_EXPORT(void,png_set_compression_mem_level)
1576
PNGARG((png_structp png_ptr, int mem_level));
1578
extern PNG_EXPORT(void,png_set_compression_strategy)
1579
PNGARG((png_structp png_ptr, int strategy));
1581
extern PNG_EXPORT(void,png_set_compression_window_bits)
1582
PNGARG((png_structp png_ptr, int window_bits));
1584
extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1587
/* These next functions are called for input/output, memory, and error
1588
* handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1589
* and call standard C I/O routines such as fread(), fwrite(), and
1590
* fprintf(). These functions can be made to use other I/O routines
1591
* at run time for those applications that need to handle I/O in a
1592
* different manner by calling png_set_???_fn(). See libpng.txt for
1596
#if !defined(PNG_NO_STDIO)
1597
/* Initialize the input/output for the PNG file to the default functions. */
1598
extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1601
/* Replace the (error and abort), and warning functions with user
1602
* supplied functions. If no messages are to be printed you must still
1603
* write and use replacement functions. The replacement error_fn should
1604
* still do a longjmp to the last setjmp location if you are using this
1605
* method of error handling. If error_fn or warning_fn is NULL, the
1606
* default function will be used.
1609
extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1610
png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1612
/* Return the user pointer associated with the error functions */
1613
extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1615
/* Replace the default data output functions with a user supplied one(s).
1616
* If buffered output is not used, then output_flush_fn can be set to NULL.
1617
* If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1618
* output_flush_fn will be ignored (and thus can be NULL).
1620
extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1621
png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1623
/* Replace the default data input function with a user supplied one. */
1624
extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1625
png_voidp io_ptr, png_rw_ptr read_data_fn));
1627
/* Return the user pointer associated with the I/O functions */
1628
extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1630
extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1631
png_read_status_ptr read_row_fn));
1633
extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1634
png_write_status_ptr write_row_fn));
1636
#ifdef PNG_USER_MEM_SUPPORTED
1637
/* Replace the default memory allocation functions with user supplied one(s). */
1638
extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1639
png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1640
/* Return the user pointer associated with the memory functions */
1641
extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
1644
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1645
defined(PNG_LEGACY_SUPPORTED)
1646
extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
1647
png_ptr, png_user_transform_ptr read_user_transform_fn));
1650
#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1651
defined(PNG_LEGACY_SUPPORTED)
1652
extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
1653
png_ptr, png_user_transform_ptr write_user_transform_fn));
1656
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1657
defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1658
defined(PNG_LEGACY_SUPPORTED)
1659
extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
1660
png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
1661
int user_transform_channels));
1662
/* Return the user pointer associated with the user transform functions */
1663
extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
1664
PNGARG((png_structp png_ptr));
1667
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1668
extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
1669
png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1670
extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
1674
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1675
/* Sets the function callbacks for the push reader, and a pointer to a
1676
* user-defined structure available to the callback functions.
1678
extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
1679
png_voidp progressive_ptr,
1680
png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1681
png_progressive_end_ptr end_fn));
1683
/* returns the user pointer associated with the push read functions */
1684
extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
1685
PNGARG((png_structp png_ptr));
1687
/* function to be called when data becomes available */
1688
extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
1689
png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
1691
/* function that combines rows. Not very much different than the
1692
* png_combine_row() call. Is this even used?????
1694
extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
1695
png_bytep old_row, png_bytep new_row));
1696
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1698
extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
1701
/* frees a pointer allocated by png_malloc() */
1702
extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
1704
/* Free data that was allocated internally */
1705
extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
1706
png_infop info_ptr, png_uint_32 free_me, int num));
1707
#ifdef PNG_FREE_ME_SUPPORTED
1708
/* Reassign responsibility for freeing existing data, whether allocated
1709
* by libpng or by the application */
1710
extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
1711
png_infop info_ptr, int freer, png_uint_32 mask));
1713
/* assignments for png_data_freer */
1714
#define PNG_DESTROY_WILL_FREE_DATA 1
1715
#define PNG_SET_WILL_FREE_DATA 1
1716
#define PNG_USER_WILL_FREE_DATA 2
1717
/* Flags for png_ptr->free_me and info_ptr->free_me */
1718
#define PNG_FREE_HIST 0x0008
1719
#define PNG_FREE_ICCP 0x0010
1720
#define PNG_FREE_SPLT 0x0020
1721
#define PNG_FREE_ROWS 0x0040
1722
#define PNG_FREE_PCAL 0x0080
1723
#define PNG_FREE_SCAL 0x0100
1724
#define PNG_FREE_UNKN 0x0200
1725
#define PNG_FREE_LIST 0x0400
1726
#define PNG_FREE_PLTE 0x1000
1727
#define PNG_FREE_TRNS 0x2000
1728
#define PNG_FREE_TEXT 0x4000
1729
#define PNG_FREE_ALL 0x7fff
1730
#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1732
#ifdef PNG_USER_MEM_SUPPORTED
1733
extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
1735
extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
1739
extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
1740
png_voidp s1, png_voidp s2, png_uint_32 size));
1742
extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
1743
png_voidp s1, int value, png_uint_32 size));
1745
#if defined(USE_FAR_KEYWORD) /* memory model conversion function */
1746
extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
1748
#endif /* USE_FAR_KEYWORD */
1750
/* Fatal error in PNG image of libpng - can't continue */
1751
extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
1752
png_const_charp error));
1754
/* The same, but the chunk name is prepended to the error string. */
1755
extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
1756
png_const_charp error));
1758
/* Non-fatal error in libpng. Can continue, but may have a problem. */
1759
extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
1760
png_const_charp message));
1762
/* Non-fatal error in libpng, chunk name is prepended to message. */
1763
extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
1764
png_const_charp message));
1766
/* The png_set_<chunk> functions are for storing values in the png_info_struct.
1767
* Similarly, the png_get_<chunk> calls are used to read values from the
1768
* png_info_struct, either storing the parameters in the passed variables, or
1769
* setting pointers into the png_info_struct where the data is stored. The
1770
* png_get_<chunk> functions return a non-zero value if the data was available
1771
* in info_ptr, or return zero and do not change any of the parameters if the
1772
* data was not available.
1774
* These functions should be used instead of directly accessing png_info
1775
* to avoid problems with future changes in the size and internal layout of
1778
/* Returns "flag" if chunk data is valid in info_ptr. */
1779
extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
1780
png_infop info_ptr, png_uint_32 flag));
1782
/* Returns number of bytes needed to hold a transformed row. */
1783
extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
1784
png_infop info_ptr));
1786
#if defined(PNG_INFO_IMAGE_SUPPORTED)
1787
/* Returns row_pointers, which is an array of pointers to scanlines that was
1788
returned from png_read_png(). */
1789
extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
1790
png_infop info_ptr));
1791
/* Set row_pointers, which is an array of pointers to scanlines for use
1792
by png_write_png(). */
1793
extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
1794
png_infop info_ptr, png_bytepp row_pointers));
1797
/* Returns number of color channels in image. */
1798
extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
1799
png_infop info_ptr));
1801
#ifdef PNG_EASY_ACCESS_SUPPORTED
1802
/* Returns image width in pixels. */
1803
extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
1804
png_ptr, png_infop info_ptr));
1806
/* Returns image height in pixels. */
1807
extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
1808
png_ptr, png_infop info_ptr));
1810
/* Returns image bit_depth. */
1811
extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
1812
png_ptr, png_infop info_ptr));
1814
/* Returns image color_type. */
1815
extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
1816
png_ptr, png_infop info_ptr));
1818
/* Returns image filter_type. */
1819
extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
1820
png_ptr, png_infop info_ptr));
1822
/* Returns image interlace_type. */
1823
extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
1824
png_ptr, png_infop info_ptr));
1826
/* Returns image compression_type. */
1827
extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
1828
png_ptr, png_infop info_ptr));
1830
/* Returns image resolution in pixels per meter, from pHYs chunk data. */
1831
extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
1832
png_ptr, png_infop info_ptr));
1833
extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
1834
png_ptr, png_infop info_ptr));
1835
extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
1836
png_ptr, png_infop info_ptr));
1838
/* Returns pixel aspect ratio, computed from pHYs chunk data. */
1839
#ifdef PNG_FLOATING_POINT_SUPPORTED
1840
extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
1841
png_ptr, png_infop info_ptr));
1844
/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1845
extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
1846
png_ptr, png_infop info_ptr));
1847
extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
1848
png_ptr, png_infop info_ptr));
1849
extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
1850
png_ptr, png_infop info_ptr));
1851
extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
1852
png_ptr, png_infop info_ptr));
1854
#endif /* PNG_EASY_ACCESS_SUPPORTED */
1856
/* Returns pointer to signature string read from PNG header */
1857
extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
1858
png_infop info_ptr));
1860
#if defined(PNG_READ_bKGD_SUPPORTED)
1861
extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
1862
png_infop info_ptr, png_color_16p *background));
1865
#if defined(PNG_bKGD_SUPPORTED)
1866
extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
1867
png_infop info_ptr, png_color_16p background));
1870
#if defined(PNG_READ_cHRM_SUPPORTED)
1871
#ifdef PNG_FLOATING_POINT_SUPPORTED
1872
extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
1873
png_infop info_ptr, double *white_x, double *white_y, double *red_x,
1874
double *red_y, double *green_x, double *green_y, double *blue_x,
1877
#ifdef PNG_FIXED_POINT_SUPPORTED
1878
extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
1879
png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
1880
*int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
1881
png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
1882
*int_blue_x, png_fixed_point *int_blue_y));
1886
#if defined(PNG_cHRM_SUPPORTED)
1887
#ifdef PNG_FLOATING_POINT_SUPPORTED
1888
extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
1889
png_infop info_ptr, double white_x, double white_y, double red_x,
1890
double red_y, double green_x, double green_y, double blue_x, double blue_y));
1892
#ifdef PNG_FIXED_POINT_SUPPORTED
1893
extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
1894
png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
1895
png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
1896
int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
1897
png_fixed_point int_blue_y));
1901
#if defined(PNG_READ_gAMA_SUPPORTED)
1902
#ifdef PNG_FLOATING_POINT_SUPPORTED
1903
extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
1904
png_infop info_ptr, double *file_gamma));
1906
extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
1907
png_infop info_ptr, png_fixed_point *int_file_gamma));
1910
#if defined(PNG_gAMA_SUPPORTED)
1911
#ifdef PNG_FLOATING_POINT_SUPPORTED
1912
extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
1913
png_infop info_ptr, double file_gamma));
1915
extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
1916
png_infop info_ptr, png_fixed_point int_file_gamma));
1919
#if defined(PNG_READ_hIST_SUPPORTED)
1920
extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
1921
png_infop info_ptr, png_uint_16p *hist));
1924
#if defined(PNG_hIST_SUPPORTED)
1925
extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
1926
png_infop info_ptr, png_uint_16p hist));
1929
extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
1930
png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
1931
int *bit_depth, int *color_type, int *interlace_type,
1932
int *compression_type, int *filter_type));
1934
extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
1935
png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
1936
int color_type, int interlace_type, int compression_type, int filter_type));
1938
#if defined(PNG_READ_oFFs_SUPPORTED)
1939
extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
1940
png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
1944
#if defined(PNG_oFFs_SUPPORTED)
1945
extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
1946
png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
1950
#if defined(PNG_READ_pCAL_SUPPORTED)
1951
extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
1952
png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
1953
int *type, int *nparams, png_charp *units, png_charpp *params));
1956
#if defined(PNG_pCAL_SUPPORTED)
1957
extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
1958
png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
1959
int type, int nparams, png_charp units, png_charpp params));
1962
#if defined(PNG_READ_pHYs_SUPPORTED)
1963
extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
1964
png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
1967
#if defined(PNG_pHYs_SUPPORTED)
1968
extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
1969
png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
1972
extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
1973
png_infop info_ptr, png_colorp *palette, int *num_palette));
1975
extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
1976
png_infop info_ptr, png_colorp palette, int num_palette));
1978
#if defined(PNG_READ_sBIT_SUPPORTED)
1979
extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
1980
png_infop info_ptr, png_color_8p *sig_bit));
1983
#if defined(PNG_sBIT_SUPPORTED)
1984
extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
1985
png_infop info_ptr, png_color_8p sig_bit));
1988
#if defined(PNG_READ_sRGB_SUPPORTED)
1989
extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
1990
png_infop info_ptr, int *intent));
1993
#if defined(PNG_sRGB_SUPPORTED)
1994
extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
1995
png_infop info_ptr, int intent));
1996
extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
1997
png_infop info_ptr, int intent));
2000
#if defined(PNG_READ_iCCP_SUPPORTED)
2001
extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2002
png_infop info_ptr, png_charpp name, int *compression_type,
2003
png_charpp profile, png_uint_32 *proflen));
2006
#if defined(PNG_iCCP_SUPPORTED)
2007
extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2008
png_infop info_ptr, png_charp name, int compression_type,
2009
png_charp profile, png_uint_32 proflen));
2012
#if defined(PNG_READ_sPLT_SUPPORTED)
2013
extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2014
png_infop info_ptr, png_sPLT_tpp entries));
2017
#if defined(PNG_sPLT_SUPPORTED)
2018
extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2019
png_infop info_ptr, png_sPLT_tp entries, int nentries));
2022
#if defined(PNG_READ_TEXT_SUPPORTED)
2023
/* png_get_text also returns the number of text chunks in *num_text */
2024
extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2025
png_infop info_ptr, png_textp *text_ptr, int *num_text));
2029
* Note while png_set_text() will accept a structure whose text,
2030
* language, and translated keywords are NULL pointers, the structure
2031
* returned by png_get_text will always contain regular
2032
* zero-terminated C strings. They might be empty strings but
2033
* they will never be NULL pointers.
2036
#if defined(PNG_TEXT_SUPPORTED)
2037
extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2038
png_infop info_ptr, png_textp text_ptr, int num_text));
2041
#if defined(PNG_READ_tIME_SUPPORTED)
2042
extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2043
png_infop info_ptr, png_timep *mod_time));
2046
#if defined(PNG_tIME_SUPPORTED)
2047
extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2048
png_infop info_ptr, png_timep mod_time));
2051
#if defined(PNG_READ_tRNS_SUPPORTED)
2052
extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2053
png_infop info_ptr, png_bytep *trans, int *num_trans,
2054
png_color_16p *trans_values));
2057
#if defined(PNG_tRNS_SUPPORTED)
2058
extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2059
png_infop info_ptr, png_bytep trans, int num_trans,
2060
png_color_16p trans_values));
2063
#if defined(PNG_tRNS_SUPPORTED)
2066
#if defined(PNG_READ_sCAL_SUPPORTED)
2067
#ifdef PNG_FLOATING_POINT_SUPPORTED
2068
extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2069
png_infop info_ptr, int *unit, double *width, double *height));
2071
#ifdef PNG_FIXED_POINT_SUPPORTED
2072
extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2073
png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2076
#endif /* PNG_READ_sCAL_SUPPORTED */
2078
#if defined(PNG_sCAL_SUPPORTED)
2079
#ifdef PNG_FLOATING_POINT_SUPPORTED
2080
extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2081
png_infop info_ptr, int unit, double width, double height));
2083
#ifdef PNG_FIXED_POINT_SUPPORTED
2084
extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2085
png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2087
#endif /* PNG_READ_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2089
#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
2090
/* provide a list of chunks and how they are to be handled, if the built-in
2091
handling or default unknown chunk handling is not desired. Any chunks not
2092
listed will be handled in the default manner. The IHDR and IEND chunks
2094
keep = 0: follow default behavour
2096
= 2: keep only if safe-to-copy
2097
= 3: keep even if unsafe-to-copy
2099
extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2100
png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2101
extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2102
png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2103
extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2104
PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2105
extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2106
png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2109
/* Png_free_data() will turn off the "valid" flag for anything it frees.
2110
If you need to turn it off for a chunk that your application has freed,
2111
you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
2112
extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2113
png_infop info_ptr, int mask));
2115
#if defined(PNG_INFO_IMAGE_SUPPORTED)
2116
/* The "params" pointer is currently not used and is for future expansion. */
2117
extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2121
extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2127
/* Define PNG_DEBUG at compile time for debugging information. Higher
2128
* numbers for PNG_DEBUG mean more debugging information. This has
2129
* only been added since version 0.95 so it is not implemented throughout
2130
* libpng yet, but more support will be added as needed.
2134
#if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2137
#define png_debug(l,m) _RPT0(_CRT_WARN,m)
2138
#define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m,p1)
2139
#define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m,p1,p2)
2141
#else /* PNG_DEBUG_FILE || !_MSC_VER */
2142
#ifndef PNG_DEBUG_FILE
2143
#define PNG_DEBUG_FILE stderr
2144
#endif /* PNG_DEBUG_FILE */
2146
#define png_debug(l,m) \
2149
fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2150
(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2152
#define png_debug1(l,m,p1) \
2155
fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2156
(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2158
#define png_debug2(l,m,p1,p2) \
2161
fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2162
(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2164
#endif /* (PNG_DEBUG > 1) */
2165
#endif /* _MSC_VER */
2166
#endif /* (PNG_DEBUG > 0) */
2167
#endif /* PNG_DEBUG */
2169
#define png_debug(l, m)
2172
#define png_debug1(l, m, p1)
2175
#define png_debug2(l, m, p1, p2)
2178
extern PNG_EXPORT(png_bytep,png_sig_bytes) PNGARG((void));
2180
extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2181
extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2182
extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2183
extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2185
#define PNG_HEADER_VERSION_STRING \
2186
" libpng version 1.0.8 - July 24, 2000 (header)\n"
2188
#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2189
/* With these routines we avoid an integer divide, which will be slower on
2190
* most machines. However, it does take more operations than the corresponding
2191
* divide method, so it may be slower on a few RISC systems. There are two
2192
* shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2194
* Note that the rounding factors are NOT supposed to be the same! 128 and
2195
* 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2198
* [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2201
/* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2203
# define png_composite(composite, fg, alpha, bg) \
2204
{ png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2205
+ (png_uint_16)(bg)*(png_uint_16)(255 - \
2206
(png_uint_16)(alpha)) + (png_uint_16)128); \
2207
(composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2209
# define png_composite_16(composite, fg, alpha, bg) \
2210
{ png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2211
+ (png_uint_32)(bg)*(png_uint_32)(65535L - \
2212
(png_uint_32)(alpha)) + (png_uint_32)32768L); \
2213
(composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2215
#else /* standard method using integer division */
2217
# define png_composite(composite, fg, alpha, bg) \
2218
(composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2219
(png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2220
(png_uint_16)127) / 255)
2222
# define png_composite_16(composite, fg, alpha, bg) \
2223
(composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2224
(png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2225
(png_uint_32)32767) / (png_uint_32)65535L)
2227
#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2229
/* These next functions are used internally in the code. They generally
2230
* shouldn't be used unless you are writing code to add or replace some
2231
* functionality in libpng. More information about most functions can
2232
* be found in the files where the functions are located.
2235
#if defined(PNG_INTERNAL)
2237
/* Various modes of operation. Note that after an init, mode is set to
2238
* zero automatically when the structure is created.
2240
#define PNG_HAVE_IHDR 0x01
2241
#define PNG_HAVE_PLTE 0x02
2242
#define PNG_HAVE_IDAT 0x04
2243
#define PNG_AFTER_IDAT 0x08
2244
#define PNG_HAVE_IEND 0x10
2245
#define PNG_HAVE_gAMA 0x20
2246
#define PNG_HAVE_cHRM 0x40
2247
#define PNG_HAVE_sRGB 0x80
2248
#define PNG_HAVE_CHUNK_HEADER 0x100
2249
#define PNG_WROTE_tIME 0x200
2250
#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2251
#define PNG_BACKGROUND_IS_GRAY 0x800
2253
/* flags for the transformations the PNG library does on the image data */
2254
#define PNG_BGR 0x0001
2255
#define PNG_INTERLACE 0x0002
2256
#define PNG_PACK 0x0004
2257
#define PNG_SHIFT 0x0008
2258
#define PNG_SWAP_BYTES 0x0010
2259
#define PNG_INVERT_MONO 0x0020
2260
#define PNG_DITHER 0x0040
2261
#define PNG_BACKGROUND 0x0080
2262
#define PNG_BACKGROUND_EXPAND 0x0100
2264
#define PNG_16_TO_8 0x0400
2265
#define PNG_RGBA 0x0800
2266
#define PNG_EXPAND 0x1000
2267
#define PNG_GAMMA 0x2000
2268
#define PNG_GRAY_TO_RGB 0x4000
2269
#define PNG_FILLER 0x8000L
2270
#define PNG_PACKSWAP 0x10000L
2271
#define PNG_SWAP_ALPHA 0x20000L
2272
#define PNG_STRIP_ALPHA 0x40000L
2273
#define PNG_INVERT_ALPHA 0x80000L
2274
#define PNG_USER_TRANSFORM 0x100000L
2275
#define PNG_RGB_TO_GRAY_ERR 0x200000L
2276
#define PNG_RGB_TO_GRAY_WARN 0x400000L
2277
#define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
2279
/* flags for png_create_struct */
2280
#define PNG_STRUCT_PNG 0x0001
2281
#define PNG_STRUCT_INFO 0x0002
2283
/* Scaling factor for filter heuristic weighting calculations */
2284
#define PNG_WEIGHT_SHIFT 8
2285
#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2286
#define PNG_COST_SHIFT 3
2287
#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2289
/* flags for the png_ptr->flags rather than declaring a byte for each one */
2290
#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
2291
#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
2292
#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
2293
#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
2294
#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
2295
#define PNG_FLAG_ZLIB_FINISHED 0x0020
2296
#define PNG_FLAG_ROW_INIT 0x0040
2297
#define PNG_FLAG_FILLER_AFTER 0x0080
2298
#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
2299
#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
2300
#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
2301
#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
2302
#define PNG_FLAG_FREE_PLTE 0x1000
2303
#define PNG_FLAG_FREE_TRNS 0x2000
2304
#define PNG_FLAG_FREE_HIST 0x4000
2305
#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
2306
#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
2307
#define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
2309
/* For use in png_set_keep_unknown, png_handle_as_unknown */
2310
#define HANDLE_CHUNK_AS_DEFAULT 0
2311
#define HANDLE_CHUNK_NEVER 1
2312
#define HANDLE_CHUNK_IF_SAFE 2
2313
#define HANDLE_CHUNK_ALWAYS 3
2315
#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
2316
PNG_FLAG_CRC_ANCILLARY_NOWARN)
2318
#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
2319
PNG_FLAG_CRC_CRITICAL_IGNORE)
2321
#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
2322
PNG_FLAG_CRC_CRITICAL_MASK)
2324
/* save typing and make code easier to understand */
2325
#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
2326
abs((int)((c1).green) - (int)((c2).green)) + \
2327
abs((int)((c1).blue) - (int)((c2).blue)))
2329
/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
2330
#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
2331
/* place to hold the signature string for a PNG file. */
2332
#ifdef PNG_USE_GLOBAL_ARRAYS
2333
PNG_EXPORT_VAR (png_byte FARDATA) png_sig[8];
2335
#define png_sig png_sig_bytes(NULL)
2337
#endif /* PNG_NO_EXTERN */
2339
/* Constant strings for known chunk types. If you need to add a chunk,
2340
* define the name here, and add an invocation of the macro in png.c and
2341
* wherever it's needed.
2343
#define PNG_IHDR const png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
2344
#define PNG_IDAT const png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
2345
#define PNG_IEND const png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
2346
#define PNG_PLTE const png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
2347
#define PNG_bKGD const png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
2348
#define PNG_cHRM const png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
2349
#define PNG_gAMA const png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
2350
#define PNG_hIST const png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
2351
#define PNG_iCCP const png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
2352
#define PNG_iTXt const png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
2353
#define PNG_oFFs const png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
2354
#define PNG_pCAL const png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
2355
#define PNG_sCAL const png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
2356
#define PNG_pHYs const png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
2357
#define PNG_sBIT const png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
2358
#define PNG_sPLT const png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
2359
#define PNG_sRGB const png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
2360
#define PNG_tEXt const png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
2361
#define PNG_tIME const png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
2362
#define PNG_tRNS const png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
2363
#define PNG_zTXt const png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
2365
#ifdef PNG_USE_GLOBAL_ARRAYS
2366
PNG_EXPORT_VAR (const png_byte FARDATA) png_IHDR[5];
2367
PNG_EXPORT_VAR (const png_byte FARDATA) png_IDAT[5];
2368
PNG_EXPORT_VAR (const png_byte FARDATA) png_IEND[5];
2369
PNG_EXPORT_VAR (const png_byte FARDATA) png_PLTE[5];
2370
PNG_EXPORT_VAR (const png_byte FARDATA) png_bKGD[5];
2371
PNG_EXPORT_VAR (const png_byte FARDATA) png_cHRM[5];
2372
PNG_EXPORT_VAR (const png_byte FARDATA) png_gAMA[5];
2373
PNG_EXPORT_VAR (const png_byte FARDATA) png_hIST[5];
2374
PNG_EXPORT_VAR (const png_byte FARDATA) png_iCCP[5];
2375
PNG_EXPORT_VAR (const png_byte FARDATA) png_iTXt[5];
2376
PNG_EXPORT_VAR (const png_byte FARDATA) png_oFFs[5];
2377
PNG_EXPORT_VAR (const png_byte FARDATA) png_pCAL[5];
2378
PNG_EXPORT_VAR (const png_byte FARDATA) png_sCAL[5];
2379
PNG_EXPORT_VAR (const png_byte FARDATA) png_pHYs[5];
2380
PNG_EXPORT_VAR (const png_byte FARDATA) png_sBIT[5];
2381
PNG_EXPORT_VAR (const png_byte FARDATA) png_sPLT[5];
2382
PNG_EXPORT_VAR (const png_byte FARDATA) png_sRGB[5];
2383
PNG_EXPORT_VAR (const png_byte FARDATA) png_tEXt[5];
2384
PNG_EXPORT_VAR (const png_byte FARDATA) png_tIME[5];
2385
PNG_EXPORT_VAR (const png_byte FARDATA) png_tRNS[5];
2386
PNG_EXPORT_VAR (const png_byte FARDATA) png_zTXt[5];
2387
#endif /* PNG_USE_GLOBAL_ARRAYS */
2390
/* Inline macros to do direct reads of bytes from the input buffer. These
2391
* require that you are using an architecture that uses PNG byte ordering
2392
* (MSB first) and supports unaligned data storage. I think that PowerPC
2393
* in big-endian mode and 680x0 are the only ones that will support this.
2394
* The x86 line of processors definitely do not. The png_get_int_32()
2395
* routine also assumes we are using two's complement format for negative
2396
* values, which is almost certainly true.
2398
#if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
2399
# if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_oFFs_SUPPORTED)
2400
# define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2402
# define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2403
# define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2405
# if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_oFFs_SUPPORTED)
2406
PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf));
2408
PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf));
2409
PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf));
2410
#endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2412
/* Initialize png_ptr struct for reading, and allocate any other memory.
2413
* (old interface - DEPRECATED).
2415
extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
2416
#define png_read_init(png_ptr) png_read_init_2(png_ptr, \
2417
PNG_LIBPNG_VER_STRING, sizeof(png_struct), sizeof(png_info));
2418
extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
2419
png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2422
/* Initialize png_ptr struct for writing, and allocate any other memory.
2423
* (old interface - DEPRECATED).
2425
extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
2426
#define png_write_init(png_ptr) png_write_init_2(png_ptr, \
2427
PNG_LIBPNG_VER_STRING, sizeof(png_struct), sizeof(png_info));
2428
extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
2429
png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2432
/* Allocate memory for an internal libpng struct */
2433
PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
2435
/* Free memory from internal libpng struct */
2436
PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
2438
PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
2440
PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
2441
png_free_ptr free_fn));
2443
/* Free any memory that info_ptr points to and reset struct. */
2444
PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
2445
png_infop info_ptr));
2447
/* Function to allocate memory for zlib. */
2448
PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
2450
/* Function to free memory for zlib */
2451
PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
2453
/* Reset the CRC variable */
2454
PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
2456
/* Write the "data" buffer to whatever output you are using. */
2457
PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
2458
png_size_t length));
2460
/* Read data from whatever input you are using into the "data" buffer */
2461
PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
2462
png_size_t length));
2464
/* Read bytes into buf, and update png_ptr->crc */
2465
PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
2466
png_size_t length));
2468
/* Decompress data in a chunk that uses compression */
2469
#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
2470
defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_sPLT_SUPPORTED)
2471
PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
2472
int comp_type, png_charp chunkdata, png_size_t chunklength,
2473
png_size_t prefix_length, png_size_t *data_length));
2476
/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
2477
PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
2479
/* Read the CRC from the file and compare it to the libpng calculated CRC */
2480
PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
2482
/* Calculate the CRC over a section of data. Note that we are only
2483
* passing a maximum of 64K on systems that have this as a memory limit,
2484
* since this is the maximum buffer size we can specify.
2486
PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
2487
png_size_t length));
2489
#if defined(PNG_WRITE_FLUSH_SUPPORTED)
2490
PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
2493
/* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2494
* The only currently known PNG chunks that use signed numbers are
2495
* the ancillary extension chunks, oFFs and pCAL.
2497
PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
2499
#if defined(PNG_WRITE_pCAL_SUPPORTED)
2500
PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i));
2503
/* Place a 16-bit number into a buffer in PNG byte order.
2504
* The parameter is declared unsigned int, not png_uint_16,
2505
* just to avoid potential problems on pre-ANSI C compilers.
2507
PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, unsigned int i));
2509
/* simple function to write the signature */
2510
PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
2512
/* write various chunks */
2514
/* Write the IHDR chunk, and update the png_struct with the necessary
2517
PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
2519
int bit_depth, int color_type, int compression_type, int filter_type,
2520
int interlace_type));
2522
PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
2523
png_uint_32 num_pal));
2525
PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
2526
png_size_t length));
2528
PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
2530
#if defined(PNG_WRITE_gAMA_SUPPORTED)
2531
#ifdef PNG_FLOATING_POINT_SUPPORTED
2532
PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
2534
#ifdef PNG_FIXED_POINT_SUPPORTED
2535
PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
2540
#if defined(PNG_WRITE_sBIT_SUPPORTED)
2541
PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
2545
#if defined(PNG_WRITE_cHRM_SUPPORTED)
2546
#ifdef PNG_FLOATING_POINT_SUPPORTED
2547
PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
2548
double white_x, double white_y,
2549
double red_x, double red_y, double green_x, double green_y,
2550
double blue_x, double blue_y));
2552
#ifdef PNG_FIXED_POINT_SUPPORTED
2553
PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
2554
png_fixed_point int_white_x, png_fixed_point int_white_y,
2555
png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2556
int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2557
png_fixed_point int_blue_y));
2561
#if defined(PNG_WRITE_sRGB_SUPPORTED)
2562
PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
2566
#if defined(PNG_WRITE_iCCP_SUPPORTED)
2567
PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
2568
png_charp name, int compression_type,
2569
png_charp profile, int proflen));
2572
#if defined(PNG_WRITE_sPLT_SUPPORTED)
2573
PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
2574
png_sPLT_tp palette));
2577
#if defined(PNG_WRITE_tRNS_SUPPORTED)
2578
PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
2579
png_color_16p values, int number, int color_type));
2582
#if defined(PNG_WRITE_bKGD_SUPPORTED)
2583
PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
2584
png_color_16p values, int color_type));
2587
#if defined(PNG_WRITE_hIST_SUPPORTED)
2588
PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
2592
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
2593
defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
2594
PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
2595
png_charp key, png_charpp new_key));
2598
#if defined(PNG_WRITE_tEXt_SUPPORTED)
2599
PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
2600
png_charp text, png_size_t text_len));
2603
#if defined(PNG_WRITE_zTXt_SUPPORTED)
2604
PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
2605
png_charp text, png_size_t text_len, int compression));
2608
#if defined(PNG_WRITE_iTXt_SUPPORTED)
2609
PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
2610
int compression, png_charp key, png_charp lang, png_charp lang_key,
2614
#if defined(PNG_WRITE_oFFs_SUPPORTED)
2615
PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
2616
png_uint_32 x_offset, png_uint_32 y_offset, int unit_type));
2619
#if defined(PNG_WRITE_pCAL_SUPPORTED)
2620
PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
2621
png_int_32 X0, png_int_32 X1, int type, int nparams,
2622
png_charp units, png_charpp params));
2625
#if defined(PNG_WRITE_pHYs_SUPPORTED)
2626
PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
2627
png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
2631
#if defined(PNG_WRITE_tIME_SUPPORTED)
2632
PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
2633
png_timep mod_time));
2636
#if defined(PNG_WRITE_sCAL_SUPPORTED)
2637
#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
2638
PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
2639
int unit, double width, double height));
2641
#ifdef PNG_FIXED_POINT_SUPPORTED
2642
PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
2643
int unit, png_charp width, png_charp height));
2648
/* Called when finished processing a row of data */
2649
PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
2651
/* Internal use only. Called before first row of data */
2652
PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
2654
#if defined(PNG_READ_GAMMA_SUPPORTED)
2655
PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
2658
/* combine a row of data, dealing with alpha, etc. if requested */
2659
PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
2662
#if defined(PNG_READ_INTERLACING_SUPPORTED)
2663
/* expand an interlaced row */
2664
PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
2665
png_bytep row, int pass, png_uint_32 transformations));
2668
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
2669
/* grab pixels out of a row for an interlaced pass */
2670
PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
2671
png_bytep row, int pass));
2674
/* unfilter a row */
2675
PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
2676
png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
2678
/* Choose the best filter to use and filter the row data */
2679
PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
2680
png_row_infop row_info));
2682
/* Write out the filtered row. */
2683
PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
2684
png_bytep filtered_row));
2685
/* finish a row while reading, dealing with interlacing passes, etc. */
2686
PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
2688
/* initialize the row buffers, etc. */
2689
PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
2690
/* optional call to update the users info structure */
2691
PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
2692
png_infop info_ptr));
2694
/* these are the functions that do the transformations */
2695
#if defined(PNG_READ_FILLER_SUPPORTED)
2696
PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
2697
png_bytep row, png_uint_32 filler, png_uint_32 flags));
2700
#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
2701
PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
2705
#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
2706
PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
2710
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
2711
PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
2715
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
2716
PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
2720
#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
2721
defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
2722
PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
2723
png_bytep row, png_uint_32 flags));
2726
#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
2727
PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
2730
#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
2731
PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
2734
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
2735
PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
2736
row_info, png_bytep row));
2739
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
2740
PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
2744
#if defined(PNG_READ_PACK_SUPPORTED)
2745
PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
2748
#if defined(PNG_READ_SHIFT_SUPPORTED)
2749
PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
2750
png_color_8p sig_bits));
2753
#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
2754
PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
2757
#if defined(PNG_READ_16_TO_8_SUPPORTED)
2758
PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
2761
#if defined(PNG_READ_DITHER_SUPPORTED)
2762
PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
2763
png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
2765
# if defined(PNG_CORRECT_PALETTE_SUPPORTED)
2766
PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
2767
png_colorp palette, int num_palette));
2771
#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
2772
PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
2775
#if defined(PNG_WRITE_PACK_SUPPORTED)
2776
PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
2777
png_bytep row, png_uint_32 bit_depth));
2780
#if defined(PNG_WRITE_SHIFT_SUPPORTED)
2781
PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
2782
png_color_8p bit_depth));
2785
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
2786
PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
2787
png_color_16p trans_values, png_color_16p background,
2788
png_color_16p background_1,
2789
png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
2790
png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
2791
png_uint_16pp gamma_16_to_1, int gamma_shift));
2794
#if defined(PNG_READ_GAMMA_SUPPORTED)
2795
PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
2796
png_bytep gamma_table, png_uint_16pp gamma_16_table,
2800
#if defined(PNG_READ_EXPAND_SUPPORTED)
2801
PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
2802
png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
2803
PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
2804
png_bytep row, png_color_16p trans_value));
2807
/* The following decodes the appropriate chunks, and does error correction,
2808
* then calls the appropriate callback for the chunk if it is valid.
2811
/* decode the IHDR chunk */
2812
PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
2813
png_uint_32 length));
2814
PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
2815
png_uint_32 length));
2816
PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
2817
png_uint_32 length));
2819
#if defined(PNG_READ_bKGD_SUPPORTED)
2820
PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
2821
png_uint_32 length));
2824
#if defined(PNG_READ_cHRM_SUPPORTED)
2825
PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
2826
png_uint_32 length));
2829
#if defined(PNG_READ_gAMA_SUPPORTED)
2830
PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
2831
png_uint_32 length));
2834
#if defined(PNG_READ_hIST_SUPPORTED)
2835
PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
2836
png_uint_32 length));
2839
#if defined(PNG_READ_iCCP_SUPPORTED)
2840
extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
2841
png_uint_32 length));
2842
#endif /* PNG_READ_iCCP_SUPPORTED */
2844
#if defined(PNG_READ_iTXt_SUPPORTED)
2845
PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
2846
png_uint_32 length));
2849
#if defined(PNG_READ_oFFs_SUPPORTED)
2850
PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
2851
png_uint_32 length));
2854
#if defined(PNG_READ_pCAL_SUPPORTED)
2855
PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
2856
png_uint_32 length));
2859
#if defined(PNG_READ_pHYs_SUPPORTED)
2860
PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
2861
png_uint_32 length));
2864
#if defined(PNG_READ_sBIT_SUPPORTED)
2865
PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
2866
png_uint_32 length));
2869
#if defined(PNG_READ_sCAL_SUPPORTED)
2870
PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
2871
png_uint_32 length));
2874
#if defined(PNG_READ_sPLT_SUPPORTED)
2875
extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
2876
png_uint_32 length));
2877
#endif /* PNG_READ_sPLT_SUPPORTED */
2879
#if defined(PNG_READ_sRGB_SUPPORTED)
2880
PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
2881
png_uint_32 length));
2884
#if defined(PNG_READ_tEXt_SUPPORTED)
2885
PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
2886
png_uint_32 length));
2889
#if defined(PNG_READ_tIME_SUPPORTED)
2890
PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
2891
png_uint_32 length));
2894
#if defined(PNG_READ_tRNS_SUPPORTED)
2895
PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
2896
png_uint_32 length));
2899
#if defined(PNG_READ_zTXt_SUPPORTED)
2900
PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
2901
png_uint_32 length));
2904
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2905
PNG_EXTERN int png_handle_as_unknown PNGARG((png_structp png_ptr, png_bytep
2909
PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
2910
png_infop info_ptr, png_uint_32 length));
2912
PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
2913
png_bytep chunk_name));
2915
/* handle the transformations for reading and writing */
2916
PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
2917
PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
2919
PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
2921
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2922
PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
2923
png_infop info_ptr));
2924
PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
2925
png_infop info_ptr));
2926
PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
2927
PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
2928
png_uint_32 length));
2929
PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
2930
PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
2931
png_bytep buffer, png_size_t length));
2932
PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
2933
PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
2934
png_bytep buffer, png_size_t buffer_length));
2935
PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
2936
PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
2937
png_bytep buffer, png_size_t buffer_length));
2938
PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
2939
PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
2940
png_infop info_ptr, png_uint_32 length));
2941
PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
2942
png_infop info_ptr));
2943
PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
2944
png_infop info_ptr));
2945
PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
2946
PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
2947
png_infop info_ptr));
2948
PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
2949
png_infop info_ptr));
2950
PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
2951
#if defined(PNG_READ_tEXt_SUPPORTED)
2952
PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
2953
png_infop info_ptr, png_uint_32 length));
2954
PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
2955
png_infop info_ptr));
2957
#if defined(PNG_READ_zTXt_SUPPORTED)
2958
PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
2959
png_infop info_ptr, png_uint_32 length));
2960
PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
2961
png_infop info_ptr));
2963
#if defined(PNG_READ_iTXt_SUPPORTED)
2964
PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
2965
png_infop info_ptr, png_uint_32 length));
2966
PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
2967
png_infop info_ptr));
2970
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2972
#endif /* PNG_INTERNAL */
2978
#endif /* PNG_VERSION_INFO_ONLY */
2979
/* do not put anything past this line */
added
removed
gdchart0.94c/gd-1.8.3/libpng-1.0.8/png.h
