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3248 lines
140 KiB
C
3248 lines
140 KiB
C
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/* png.h - header file for PNG reference library
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*
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* libpng version 1.6.37 - April 14, 2019
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*
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* Copyright (c) 2018-2019 Cosmin Truta
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* Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
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* Copyright (c) 1996-1997 Andreas Dilger
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* Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
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*
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* This code is released under the libpng license. (See LICENSE, below.)
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*
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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 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
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* libpng versions 0.97, January 1998, through 1.6.35, July 2018:
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* Glenn Randers-Pehrson
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* libpng versions 1.6.36, December 2018, through 1.6.37, April 2019:
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* Cosmin Truta
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* See also "Contributing Authors", below.
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*/
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/*
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* COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
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* =========================================
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*
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* PNG Reference Library License version 2
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* ---------------------------------------
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*
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* * Copyright (c) 1995-2019 The PNG Reference Library Authors.
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* * Copyright (c) 2018-2019 Cosmin Truta.
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* * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
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* * Copyright (c) 1996-1997 Andreas Dilger.
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* * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
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*
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* The software is supplied "as is", without warranty of any kind,
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* express or implied, including, without limitation, the warranties
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* of merchantability, fitness for a particular purpose, title, and
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* non-infringement. In no event shall the Copyright owners, or
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* anyone distributing the software, be liable for any damages or
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* other liability, whether in contract, tort or otherwise, arising
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* from, out of, or in connection with the software, or the use or
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* other dealings in the software, even if advised of the possibility
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* of such damage.
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*
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* Permission is hereby granted to use, copy, modify, and distribute
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* this software, or portions hereof, for any purpose, without fee,
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* subject to the following restrictions:
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*
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* 1. The origin of this software must not be misrepresented; you
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* must not claim that you wrote the original software. If you
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* use this software in a product, an acknowledgment in the product
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* documentation would be appreciated, but is not required.
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*
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* 2. Altered source versions must be plainly marked as such, and must
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* not be misrepresented as being the original software.
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*
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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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*
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*
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* PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
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* -----------------------------------------------------------------------
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*
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* libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are
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* Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
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* derived from libpng-1.0.6, and are distributed according to the same
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* disclaimer and license as libpng-1.0.6 with the following individuals
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* added to the list of Contributing Authors:
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*
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* Simon-Pierre Cadieux
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* Eric S. Raymond
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* Mans Rullgard
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* Cosmin Truta
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* Gilles Vollant
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* James Yu
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* Mandar Sahastrabuddhe
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* Google Inc.
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* Vadim Barkov
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*
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* and with the following additions to the disclaimer:
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*
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* There is no warranty against interference with your enjoyment of
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* the 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
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* with the user.
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*
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* Some files in the "contrib" directory and some configure-generated
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* files that are distributed with libpng have other copyright owners, and
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* are released under other open source licenses.
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*
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* libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
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* Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
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* libpng-0.96, and are distributed according to the same disclaimer and
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* license as libpng-0.96, with the following individuals added to the
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* list of Contributing Authors:
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*
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* Tom Lane
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* Glenn Randers-Pehrson
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* Willem van Schaik
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*
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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, are derived from libpng-0.88,
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* and are distributed according to the same disclaimer and license as
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* libpng-0.88, with the following individuals added to the list of
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* Contributing Authors:
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*
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* John Bowler
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* Kevin Bracey
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* Sam Bushell
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* Magnus Holmgren
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* Greg Roelofs
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* Tom Tanner
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*
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* Some files in the "scripts" directory have other copyright owners,
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* but are released under this license.
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*
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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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*
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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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*
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* Andreas Dilger
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* Dave Martindale
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* Guy Eric Schalnat
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* Paul Schmidt
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* Tim Wegner
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*
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* The PNG Reference Library is supplied "AS IS". The Contributing
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* Authors and Group 42, Inc. disclaim all warranties, expressed or
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* implied, including, without limitation, the warranties of
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* merchantability and of fitness for any purpose. The Contributing
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* Authors and Group 42, Inc. assume no liability for direct, indirect,
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* incidental, special, exemplary, or consequential damages, which may
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* result from the use of the PNG Reference Library, even if advised of
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* the possibility of such damage.
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*
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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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*
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* 1. The origin of this source code must not be misrepresented.
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*
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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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*
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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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*
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* The Contributing Authors and Group 42, Inc. specifically permit,
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* without fee, and encourage the use of this source code as a component
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* to supporting the PNG file format in commercial products. If you use
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* this source code in a product, acknowledgment is not required but would
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* be appreciated.
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*
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* END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
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*
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* TRADEMARK
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* =========
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*
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* The name "libpng" has not been registered by the Copyright owners
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* as a trademark in any jurisdiction. However, because libpng has
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* been distributed and maintained world-wide, continually since 1995,
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* the Copyright owners claim "common-law trademark protection" in any
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* jurisdiction where common-law trademark is recognized.
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*/
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/*
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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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*
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* printf("%s", png_get_copyright(NULL));
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*
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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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*/
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/*
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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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*
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* Thanks to Frank J. T. Wojcik for helping with the documentation.
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*/
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/* Note about libpng version numbers:
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*
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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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*
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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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* 0.98 0.98 98 2.0.98
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* 0.99 0.99 98 2.0.99
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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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* 1.0.3 10003
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* 1.0.3a-d 10004
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* 1.0.4 10004
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* 1.0.4a-f 10005
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* 1.0.5 (+ 2 patches) 10005
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* 1.0.5a-d 10006
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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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* 1.0.6g 10007
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* 1.0.6h 10007 10.6h (testing xy.z so-numbering)
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* 1.0.6i 10007 10.6i
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* 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
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* 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
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* 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
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* 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
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* 1.0.7 1 10007 (still compatible)
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* ...
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* 1.0.69 10 10069 10.so.0.69[.0]
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* ...
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* 1.2.59 13 10259 12.so.0.59[.0]
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* ...
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* 1.4.20 14 10420 14.so.0.20[.0]
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* ...
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* 1.5.30 15 10530 15.so.15.30[.0]
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* ...
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* 1.6.37 16 10637 16.so.16.37[.0]
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*
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* Henceforth the source version will match the shared-library major and
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* minor numbers; the shared-library major version number will be used for
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* changes in backward compatibility, as it is intended.
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* The PNG_LIBPNG_VER macro, which is not used within libpng but is
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* available for applications, is an unsigned integer of the form XYYZZ
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* corresponding to the source version X.Y.Z (leading zeros in Y and Z).
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* Beta versions were given the previous public release number plus a
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* letter, until version 1.0.6j; from then on they were given the upcoming
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* public release number plus "betaNN" or "rcNN".
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*
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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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*
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* DLLNUM will change each time there are forward or backward changes
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* in binary compatibility (e.g., when a new feature is added).
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*
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* See libpng.txt or libpng.3 for more information. The PNG specification
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* is available as a W3C Recommendation and as an ISO/IEC Standard; see
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* <https://www.w3.org/TR/2003/REC-PNG-20031110/>
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*/
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#ifndef PNG_H
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#define PNG_H
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/* This is not the place to learn how to use libpng. The file libpng-manual.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. If that
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* file has been stripped from your copy of libpng, you can find it at
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* <http://www.libpng.org/pub/png/libpng-manual.txt>
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*
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* If you just need to read a PNG file and don't want to read the documentation
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* skip to the end of this file and read the section entitled 'simplified API'.
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*/
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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 "1.6.37"
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#define PNG_HEADER_VERSION_STRING " libpng version 1.6.37 - April 14, 2019\n"
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#define PNG_LIBPNG_VER_SONUM 16
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#define PNG_LIBPNG_VER_DLLNUM 16
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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 6
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#define PNG_LIBPNG_VER_RELEASE 37
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/* This should be zero for a public release, or non-zero for a
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* development version. [Deprecated]
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*/
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#define PNG_LIBPNG_VER_BUILD 0
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/* Release Status */
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#define PNG_LIBPNG_BUILD_ALPHA 1
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#define PNG_LIBPNG_BUILD_BETA 2
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#define PNG_LIBPNG_BUILD_RC 3
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#define PNG_LIBPNG_BUILD_STABLE 4
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#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
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/* Release-Specific Flags */
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#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
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PNG_LIBPNG_BUILD_STABLE only */
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#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
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PNG_LIBPNG_BUILD_SPECIAL */
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#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
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PNG_LIBPNG_BUILD_PRIVATE */
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#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
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/* Careful here. At one time, Guy wanted to use 082, but that
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* would be octal. 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
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* (only version 1.0.0 was mis-numbered 100 instead of 10000).
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* From version 1.0.1 it is:
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* XXYYZZ, where XX=major, YY=minor, ZZ=release
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*/
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#define PNG_LIBPNG_VER 10637 /* 1.6.37 */
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/* Library configuration: these options cannot be changed after
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* the library has been built.
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*/
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#ifndef PNGLCONF_H
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/* If pnglibconf.h is missing, you can
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* copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
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*/
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# include "pnglibconf.h"
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#endif
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#ifndef PNG_VERSION_INFO_ONLY
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/* Machine specific configuration. */
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# include "pngconf.h"
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#endif
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/*
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* Added at libpng-1.2.8
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*
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* Ref MSDN: Private as priority over Special
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* VS_FF_PRIVATEBUILD File *was not* built using standard release
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* procedures. If this value is given, the StringFileInfo block must
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* contain a PrivateBuild string.
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*
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* VS_FF_SPECIALBUILD File *was* built by the original company using
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* standard release procedures but is a variation of the standard
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* file of the same version number. If this value is given, the
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* StringFileInfo block must contain a SpecialBuild string.
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*/
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#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
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# define PNG_LIBPNG_BUILD_TYPE \
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(PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
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#else
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# ifdef PNG_LIBPNG_SPECIALBUILD
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# define PNG_LIBPNG_BUILD_TYPE \
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(PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
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# else
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# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
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# endif
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#endif
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#ifndef PNG_VERSION_INFO_ONLY
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/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
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#ifdef __cplusplus
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extern "C" {
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#endif /* __cplusplus */
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/* Version information for C files, stored in png.c. This had better match
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* the version above.
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*/
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#define png_libpng_ver png_get_header_ver(NULL)
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/* This file is arranged in several sections:
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*
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* 1. [omitted]
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* 2. Any configuration options that can be specified by for the application
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* code when it is built. (Build time configuration is in pnglibconf.h)
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* 3. Type definitions (base types are defined in pngconf.h), structure
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* definitions.
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* 4. Exported library functions.
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* 5. Simplified API.
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* 6. Implementation options.
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*
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* The library source code has additional files (principally pngpriv.h) that
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* allow configuration of the library.
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*/
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/* Section 1: [omitted] */
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/* Section 2: run time configuration
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* See pnglibconf.h for build time configuration
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*
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* Run time configuration allows the application to choose between
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* implementations of certain arithmetic APIs. The default is set
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* at build time and recorded in pnglibconf.h, but it is safe to
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* override these (and only these) settings. Note that this won't
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* change what the library does, only application code, and the
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* settings can (and probably should) be made on a per-file basis
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* by setting the #defines before including png.h
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*
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* Use macros to read integers from PNG data or use the exported
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* functions?
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* PNG_USE_READ_MACROS: use the macros (see below) Note that
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* the macros evaluate their argument multiple times.
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* PNG_NO_USE_READ_MACROS: call the relevant library function.
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*
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* Use the alternative algorithm for compositing alpha samples that
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* does not use division?
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* PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
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* algorithm.
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* PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
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*
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* How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
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* false?
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* PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
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* APIs to png_warning.
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* Otherwise the calls are mapped to png_error.
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*/
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/* Section 3: type definitions, including structures and compile time
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* constants.
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* See pngconf.h for base types that vary by machine/system
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*/
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/* This triggers a compiler error in png.c, if png.c and png.h
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* do not agree upon the version number.
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*/
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typedef char* png_libpng_version_1_6_37;
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|
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/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
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*
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* png_struct is the cache of information used while reading or writing a single
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* PNG file. One of these is always required, although the simplified API
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* (below) hides the creation and destruction of it.
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*/
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typedef struct png_struct_def png_struct;
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typedef const png_struct * png_const_structp;
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typedef png_struct * png_structp;
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typedef png_struct * * png_structpp;
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/* png_info contains information read from or to be written to a PNG file. One
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* or more of these must exist while reading or creating a PNG file. The
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* information is not used by libpng during read but is used to control what
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* gets written when a PNG file is created. "png_get_" function calls read
|
|
* information during read and "png_set_" functions calls write information
|
|
* when creating a PNG.
|
|
* been moved into a separate header file that is not accessible to
|
|
* applications. Read libpng-manual.txt or libpng.3 for more info.
|
|
*/
|
|
typedef struct png_info_def png_info;
|
|
typedef png_info * png_infop;
|
|
typedef const png_info * png_const_infop;
|
|
typedef png_info * * png_infopp;
|
|
|
|
/* Types with names ending 'p' are pointer types. The corresponding types with
|
|
* names ending 'rp' are identical pointer types except that the pointer is
|
|
* marked 'restrict', which means that it is the only pointer to the object
|
|
* passed to the function. Applications should not use the 'restrict' types;
|
|
* it is always valid to pass 'p' to a pointer with a function argument of the
|
|
* corresponding 'rp' type. Different compilers have different rules with
|
|
* regard to type matching in the presence of 'restrict'. For backward
|
|
* compatibility libpng callbacks never have 'restrict' in their parameters and,
|
|
* consequentially, writing portable application code is extremely difficult if
|
|
* an attempt is made to use 'restrict'.
|
|
*/
|
|
typedef png_struct * PNG_RESTRICT png_structrp;
|
|
typedef const png_struct * PNG_RESTRICT png_const_structrp;
|
|
typedef png_info * PNG_RESTRICT png_inforp;
|
|
typedef const png_info * PNG_RESTRICT png_const_inforp;
|
|
|
|
/* Three color definitions. The order of the red, green, and blue, (and the
|
|
* exact size) is not important, although the size of the fields need to
|
|
* be png_byte or png_uint_16 (as defined below).
|
|
*/
|
|
typedef struct png_color_struct
|
|
{
|
|
png_byte red;
|
|
png_byte green;
|
|
png_byte blue;
|
|
} png_color;
|
|
typedef png_color * png_colorp;
|
|
typedef const png_color * png_const_colorp;
|
|
typedef png_color * * png_colorpp;
|
|
|
|
typedef struct png_color_16_struct
|
|
{
|
|
png_byte index; /* used for palette files */
|
|
png_uint_16 red; /* for use in red green blue files */
|
|
png_uint_16 green;
|
|
png_uint_16 blue;
|
|
png_uint_16 gray; /* for use in grayscale files */
|
|
} png_color_16;
|
|
typedef png_color_16 * png_color_16p;
|
|
typedef const png_color_16 * png_const_color_16p;
|
|
typedef png_color_16 * * png_color_16pp;
|
|
|
|
typedef struct png_color_8_struct
|
|
{
|
|
png_byte red; /* for use in red green blue files */
|
|
png_byte green;
|
|
png_byte blue;
|
|
png_byte gray; /* for use in grayscale files */
|
|
png_byte alpha; /* for alpha channel files */
|
|
} png_color_8;
|
|
typedef png_color_8 * png_color_8p;
|
|
typedef const png_color_8 * png_const_color_8p;
|
|
typedef png_color_8 * * png_color_8pp;
|
|
|
|
/*
|
|
* The following two structures are used for the in-core representation
|
|
* of sPLT chunks.
|
|
*/
|
|
typedef struct png_sPLT_entry_struct
|
|
{
|
|
png_uint_16 red;
|
|
png_uint_16 green;
|
|
png_uint_16 blue;
|
|
png_uint_16 alpha;
|
|
png_uint_16 frequency;
|
|
} png_sPLT_entry;
|
|
typedef png_sPLT_entry * png_sPLT_entryp;
|
|
typedef const png_sPLT_entry * png_const_sPLT_entryp;
|
|
typedef png_sPLT_entry * * png_sPLT_entrypp;
|
|
|
|
/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
|
|
* occupy the LSB of their respective members, and the MSB of each member
|
|
* is zero-filled. The frequency member always occupies the full 16 bits.
|
|
*/
|
|
|
|
typedef struct png_sPLT_struct
|
|
{
|
|
png_charp name; /* palette name */
|
|
png_byte depth; /* depth of palette samples */
|
|
png_sPLT_entryp entries; /* palette entries */
|
|
png_int_32 nentries; /* number of palette entries */
|
|
} png_sPLT_t;
|
|
typedef png_sPLT_t * png_sPLT_tp;
|
|
typedef const png_sPLT_t * png_const_sPLT_tp;
|
|
typedef png_sPLT_t * * png_sPLT_tpp;
|
|
|
|
#ifdef PNG_TEXT_SUPPORTED
|
|
/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
|
|
* and whether that contents is compressed or not. The "key" field
|
|
* points to a regular zero-terminated C string. The "text" fields can be a
|
|
* regular C string, an empty string, or a NULL pointer.
|
|
* However, the structure returned by png_get_text() will always contain
|
|
* the "text" field as a regular zero-terminated C string (possibly
|
|
* empty), never a NULL pointer, so it can be safely used in printf() and
|
|
* other string-handling functions. Note that the "itxt_length", "lang", and
|
|
* "lang_key" members of the structure only exist when the library is built
|
|
* with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
|
|
* default without iTXt support. Also note that when iTXt *is* supported,
|
|
* the "lang" and "lang_key" fields contain NULL pointers when the
|
|
* "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
|
|
* PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
|
|
* same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
|
|
* which is always 0 or 1, or its "compression method" which is always 0.
|
|
*/
|
|
typedef struct png_text_struct
|
|
{
|
|
int compression; /* compression value:
|
|
-1: tEXt, none
|
|
0: zTXt, deflate
|
|
1: iTXt, none
|
|
2: iTXt, deflate */
|
|
png_charp key; /* keyword, 1-79 character description of "text" */
|
|
png_charp text; /* comment, may be an empty string (ie "")
|
|
or a NULL pointer */
|
|
size_t text_length; /* length of the text string */
|
|
size_t itxt_length; /* length of the itxt string */
|
|
png_charp lang; /* language code, 0-79 characters
|
|
or a NULL pointer */
|
|
png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
|
|
chars or a NULL pointer */
|
|
} png_text;
|
|
typedef png_text * png_textp;
|
|
typedef const png_text * png_const_textp;
|
|
typedef png_text * * png_textpp;
|
|
#endif
|
|
|
|
/* Supported compression types for text in PNG files (tEXt, and zTXt).
|
|
* The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
|
|
#define PNG_TEXT_COMPRESSION_NONE_WR -3
|
|
#define PNG_TEXT_COMPRESSION_zTXt_WR -2
|
|
#define PNG_TEXT_COMPRESSION_NONE -1
|
|
#define PNG_TEXT_COMPRESSION_zTXt 0
|
|
#define PNG_ITXT_COMPRESSION_NONE 1
|
|
#define PNG_ITXT_COMPRESSION_zTXt 2
|
|
#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
|
|
|
|
/* png_time is a way to hold the time in an machine independent way.
|
|
* Two conversions are provided, both from time_t and struct tm. There
|
|
* is no portable way to convert to either of these structures, as far
|
|
* as I know. If you know of a portable way, send it to me. As a side
|
|
* note - PNG has always been Year 2000 compliant!
|
|
*/
|
|
typedef struct png_time_struct
|
|
{
|
|
png_uint_16 year; /* full year, as in, 1995 */
|
|
png_byte month; /* month of year, 1 - 12 */
|
|
png_byte day; /* day of month, 1 - 31 */
|
|
png_byte hour; /* hour of day, 0 - 23 */
|
|
png_byte minute; /* minute of hour, 0 - 59 */
|
|
png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
|
|
} png_time;
|
|
typedef png_time * png_timep;
|
|
typedef const png_time * png_const_timep;
|
|
typedef png_time * * png_timepp;
|
|
|
|
#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
|
|
defined(PNG_USER_CHUNKS_SUPPORTED)
|
|
/* png_unknown_chunk is a structure to hold queued chunks for which there is
|
|
* no specific support. The idea is that we can use this to queue
|
|
* up private chunks for output even though the library doesn't actually
|
|
* know about their semantics.
|
|
*
|
|
* The data in the structure is set by libpng on read and used on write.
|
|
*/
|
|
typedef struct png_unknown_chunk_t
|
|
{
|
|
png_byte name[5]; /* Textual chunk name with '\0' terminator */
|
|
png_byte *data; /* Data, should not be modified on read! */
|
|
size_t size;
|
|
|
|
/* On write 'location' must be set using the flag values listed below.
|
|
* Notice that on read it is set by libpng however the values stored have
|
|
* more bits set than are listed below. Always treat the value as a
|
|
* bitmask. On write set only one bit - setting multiple bits may cause the
|
|
* chunk to be written in multiple places.
|
|
*/
|
|
png_byte location; /* mode of operation at read time */
|
|
}
|
|
png_unknown_chunk;
|
|
|
|
typedef png_unknown_chunk * png_unknown_chunkp;
|
|
typedef const png_unknown_chunk * png_const_unknown_chunkp;
|
|
typedef png_unknown_chunk * * png_unknown_chunkpp;
|
|
#endif
|
|
|
|
/* Flag values for the unknown chunk location byte. */
|
|
#define PNG_HAVE_IHDR 0x01
|
|
#define PNG_HAVE_PLTE 0x02
|
|
#define PNG_AFTER_IDAT 0x08
|
|
|
|
/* Maximum positive integer used in PNG is (2^31)-1 */
|
|
#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
|
|
#define PNG_UINT_32_MAX ((png_uint_32)(-1))
|
|
#define PNG_SIZE_MAX ((size_t)(-1))
|
|
|
|
/* These are constants for fixed point values encoded in the
|
|
* PNG specification manner (x100000)
|
|
*/
|
|
#define PNG_FP_1 100000
|
|
#define PNG_FP_HALF 50000
|
|
#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
|
|
#define PNG_FP_MIN (-PNG_FP_MAX)
|
|
|
|
/* These describe the color_type field in png_info. */
|
|
/* color type masks */
|
|
#define PNG_COLOR_MASK_PALETTE 1
|
|
#define PNG_COLOR_MASK_COLOR 2
|
|
#define PNG_COLOR_MASK_ALPHA 4
|
|
|
|
/* color types. Note that not all combinations are legal */
|
|
#define PNG_COLOR_TYPE_GRAY 0
|
|
#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
|
|
#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
|
|
#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
|
|
#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
|
|
/* aliases */
|
|
#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
|
|
#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
|
|
|
|
/* This is for compression type. PNG 1.0-1.2 only define the single type. */
|
|
#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
|
|
#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
|
|
|
|
/* This is for filter type. PNG 1.0-1.2 only define the single type. */
|
|
#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
|
|
#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
|
|
#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
|
|
|
|
/* These are for the interlacing type. These values should NOT be changed. */
|
|
#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
|
|
#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
|
|
#define PNG_INTERLACE_LAST 2 /* Not a valid value */
|
|
|
|
/* These are for the oFFs chunk. These values should NOT be changed. */
|
|
#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
|
|
#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
|
|
#define PNG_OFFSET_LAST 2 /* Not a valid value */
|
|
|
|
/* These are for the pCAL chunk. These values should NOT be changed. */
|
|
#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
|
|
#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
|
|
#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
|
|
#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
|
|
#define PNG_EQUATION_LAST 4 /* Not a valid value */
|
|
|
|
/* These are for the sCAL chunk. These values should NOT be changed. */
|
|
#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
|
|
#define PNG_SCALE_METER 1 /* meters per pixel */
|
|
#define PNG_SCALE_RADIAN 2 /* radians per pixel */
|
|
#define PNG_SCALE_LAST 3 /* Not a valid value */
|
|
|
|
/* These are for the pHYs chunk. These values should NOT be changed. */
|
|
#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
|
|
#define PNG_RESOLUTION_METER 1 /* pixels/meter */
|
|
#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
|
|
|
|
/* These are for the sRGB chunk. These values should NOT be changed. */
|
|
#define PNG_sRGB_INTENT_PERCEPTUAL 0
|
|
#define PNG_sRGB_INTENT_RELATIVE 1
|
|
#define PNG_sRGB_INTENT_SATURATION 2
|
|
#define PNG_sRGB_INTENT_ABSOLUTE 3
|
|
#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
|
|
|
|
/* This is for text chunks */
|
|
#define PNG_KEYWORD_MAX_LENGTH 79
|
|
|
|
/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
|
|
#define PNG_MAX_PALETTE_LENGTH 256
|
|
|
|
/* These determine if an ancillary chunk's data has been successfully read
|
|
* from the PNG header, or if the application has filled in the corresponding
|
|
* data in the info_struct to be written into the output file. The values
|
|
* of the PNG_INFO_<chunk> defines should NOT be changed.
|
|
*/
|
|
#define PNG_INFO_gAMA 0x0001U
|
|
#define PNG_INFO_sBIT 0x0002U
|
|
#define PNG_INFO_cHRM 0x0004U
|
|
#define PNG_INFO_PLTE 0x0008U
|
|
#define PNG_INFO_tRNS 0x0010U
|
|
#define PNG_INFO_bKGD 0x0020U
|
|
#define PNG_INFO_hIST 0x0040U
|
|
#define PNG_INFO_pHYs 0x0080U
|
|
#define PNG_INFO_oFFs 0x0100U
|
|
#define PNG_INFO_tIME 0x0200U
|
|
#define PNG_INFO_pCAL 0x0400U
|
|
#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
|
|
#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
|
|
#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
|
|
#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
|
|
#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
|
|
#define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
|
|
|
|
/* This is used for the transformation routines, as some of them
|
|
* change these values for the row. It also should enable using
|
|
* the routines for other purposes.
|
|
*/
|
|
typedef struct png_row_info_struct
|
|
{
|
|
png_uint_32 width; /* width of row */
|
|
size_t rowbytes; /* number of bytes in row */
|
|
png_byte color_type; /* color type of row */
|
|
png_byte bit_depth; /* bit depth of row */
|
|
png_byte channels; /* number of channels (1, 2, 3, or 4) */
|
|
png_byte pixel_depth; /* bits per pixel (depth * channels) */
|
|
} png_row_info;
|
|
|
|
typedef png_row_info * png_row_infop;
|
|
typedef png_row_info * * png_row_infopp;
|
|
|
|
/* These are the function types for the I/O functions and for the functions
|
|
* that allow the user to override the default I/O functions with his or her
|
|
* own. The png_error_ptr type should match that of user-supplied warning
|
|
* and error functions, while the png_rw_ptr type should match that of the
|
|
* user read/write data functions. Note that the 'write' function must not
|
|
* modify the buffer it is passed. The 'read' function, on the other hand, is
|
|
* expected to return the read data in the buffer.
|
|
*/
|
|
typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
|
|
typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t));
|
|
typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
|
|
typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
|
|
int));
|
|
typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
|
|
int));
|
|
|
|
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
|
|
typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
|
|
typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
|
|
|
|
/* The following callback receives png_uint_32 row_number, int pass for the
|
|
* png_bytep data of the row. When transforming an interlaced image the
|
|
* row number is the row number within the sub-image of the interlace pass, so
|
|
* the value will increase to the height of the sub-image (not the full image)
|
|
* then reset to 0 for the next pass.
|
|
*
|
|
* Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
|
|
* find the output pixel (x,y) given an interlaced sub-image pixel
|
|
* (row,col,pass). (See below for these macros.)
|
|
*/
|
|
typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
|
|
png_uint_32, int));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
|
|
defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
|
|
typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
|
|
png_bytep));
|
|
#endif
|
|
|
|
#ifdef PNG_USER_CHUNKS_SUPPORTED
|
|
typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
|
|
png_unknown_chunkp));
|
|
#endif
|
|
#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
|
|
/* not used anywhere */
|
|
/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
|
|
#endif
|
|
|
|
#ifdef PNG_SETJMP_SUPPORTED
|
|
/* This must match the function definition in <setjmp.h>, and the application
|
|
* must include this before png.h to obtain the definition of jmp_buf. The
|
|
* function is required to be PNG_NORETURN, but this is not checked. If the
|
|
* function does return the application will crash via an abort() or similar
|
|
* system level call.
|
|
*
|
|
* If you get a warning here while building the library you may need to make
|
|
* changes to ensure that pnglibconf.h records the calling convention used by
|
|
* your compiler. This may be very difficult - try using a different compiler
|
|
* to build the library!
|
|
*/
|
|
PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
|
|
#endif
|
|
|
|
/* Transform masks for the high-level interface */
|
|
#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
|
|
#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
|
|
#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
|
|
#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
|
|
#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
|
|
#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
|
|
#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
|
|
#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
|
|
#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
|
|
#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
|
|
#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
|
|
#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
|
|
#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
|
|
/* Added to libpng-1.2.34 */
|
|
#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
|
|
#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
|
|
/* Added to libpng-1.4.0 */
|
|
#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
|
|
/* Added to libpng-1.5.4 */
|
|
#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
|
|
#if INT_MAX >= 0x8000 /* else this might break */
|
|
#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
|
|
#endif
|
|
|
|
/* Flags for MNG supported features */
|
|
#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
|
|
#define PNG_FLAG_MNG_FILTER_64 0x04
|
|
#define PNG_ALL_MNG_FEATURES 0x05
|
|
|
|
/* NOTE: prior to 1.5 these functions had no 'API' style declaration,
|
|
* this allowed the zlib default functions to be used on Windows
|
|
* platforms. In 1.5 the zlib default malloc (which just calls malloc and
|
|
* ignores the first argument) should be completely compatible with the
|
|
* following.
|
|
*/
|
|
typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
|
|
png_alloc_size_t));
|
|
typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
|
|
|
|
/* Section 4: exported functions
|
|
* Here are the function definitions most commonly used. This is not
|
|
* the place to find out how to use libpng. See libpng-manual.txt for the
|
|
* full explanation, see example.c for the summary. This just provides
|
|
* a simple one line description of the use of each function.
|
|
*
|
|
* The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
|
|
* pngconf.h and in the *.dfn files in the scripts directory.
|
|
*
|
|
* PNG_EXPORT(ordinal, type, name, (args));
|
|
*
|
|
* ordinal: ordinal that is used while building
|
|
* *.def files. The ordinal value is only
|
|
* relevant when preprocessing png.h with
|
|
* the *.dfn files for building symbol table
|
|
* entries, and are removed by pngconf.h.
|
|
* type: return type of the function
|
|
* name: function name
|
|
* args: function arguments, with types
|
|
*
|
|
* When we wish to append attributes to a function prototype we use
|
|
* the PNG_EXPORTA() macro instead.
|
|
*
|
|
* PNG_EXPORTA(ordinal, type, name, (args), attributes);
|
|
*
|
|
* ordinal, type, name, and args: same as in PNG_EXPORT().
|
|
* attributes: function attributes
|
|
*/
|
|
|
|
/* Returns the version number of the library */
|
|
PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
|
|
|
|
/* Tell lib we have already handled the first <num_bytes> magic bytes.
|
|
* Handling more than 8 bytes from the beginning of the file is an error.
|
|
*/
|
|
PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
|
|
|
|
/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
|
|
* PNG file. Returns zero if the supplied bytes match the 8-byte PNG
|
|
* signature, and non-zero otherwise. Having num_to_check == 0 or
|
|
* start > 7 will always fail (ie return non-zero).
|
|
*/
|
|
PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start,
|
|
size_t num_to_check));
|
|
|
|
/* Simple signature checking function. This is the same as calling
|
|
* png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
|
|
*/
|
|
#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
|
|
|
|
/* Allocate and initialize png_ptr struct for reading, and any other memory. */
|
|
PNG_EXPORTA(4, png_structp, png_create_read_struct,
|
|
(png_const_charp user_png_ver, png_voidp error_ptr,
|
|
png_error_ptr error_fn, png_error_ptr warn_fn),
|
|
PNG_ALLOCATED);
|
|
|
|
/* Allocate and initialize png_ptr struct for writing, and any other memory */
|
|
PNG_EXPORTA(5, png_structp, png_create_write_struct,
|
|
(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
|
|
png_error_ptr warn_fn),
|
|
PNG_ALLOCATED);
|
|
|
|
PNG_EXPORT(6, size_t, png_get_compression_buffer_size,
|
|
(png_const_structrp png_ptr));
|
|
|
|
PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
|
|
size_t size));
|
|
|
|
/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
|
|
* match up.
|
|
*/
|
|
#ifdef PNG_SETJMP_SUPPORTED
|
|
/* This function returns the jmp_buf built in to *png_ptr. It must be
|
|
* supplied with an appropriate 'longjmp' function to use on that jmp_buf
|
|
* unless the default error function is overridden in which case NULL is
|
|
* acceptable. The size of the jmp_buf is checked against the actual size
|
|
* allocated by the library - the call will return NULL on a mismatch
|
|
* indicating an ABI mismatch.
|
|
*/
|
|
PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
|
|
png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
|
|
# define png_jmpbuf(png_ptr) \
|
|
(*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
|
|
#else
|
|
# define png_jmpbuf(png_ptr) \
|
|
(LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
|
|
#endif
|
|
/* This function should be used by libpng applications in place of
|
|
* longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
|
|
* will use it; otherwise it will call PNG_ABORT(). This function was
|
|
* added in libpng-1.5.0.
|
|
*/
|
|
PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
|
|
PNG_NORETURN);
|
|
|
|
#ifdef PNG_READ_SUPPORTED
|
|
/* Reset the compression stream */
|
|
PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
|
|
#endif
|
|
|
|
/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
|
|
#ifdef PNG_USER_MEM_SUPPORTED
|
|
PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
|
|
(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
|
|
png_error_ptr warn_fn,
|
|
png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
|
|
PNG_ALLOCATED);
|
|
PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
|
|
(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
|
|
png_error_ptr warn_fn,
|
|
png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
|
|
PNG_ALLOCATED);
|
|
#endif
|
|
|
|
/* Write the PNG file signature. */
|
|
PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
|
|
|
|
/* Write a PNG chunk - size, type, (optional) data, CRC. */
|
|
PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
|
|
chunk_name, png_const_bytep data, size_t length));
|
|
|
|
/* Write the start of a PNG chunk - length and chunk name. */
|
|
PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
|
|
png_const_bytep chunk_name, png_uint_32 length));
|
|
|
|
/* Write the data of a PNG chunk started with png_write_chunk_start(). */
|
|
PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
|
|
png_const_bytep data, size_t length));
|
|
|
|
/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
|
|
PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
|
|
|
|
/* Allocate and initialize the info structure */
|
|
PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
|
|
PNG_ALLOCATED);
|
|
|
|
/* DEPRECATED: this function allowed init structures to be created using the
|
|
* default allocation method (typically malloc). Use is deprecated in 1.6.0 and
|
|
* the API will be removed in the future.
|
|
*/
|
|
PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
|
|
size_t png_info_struct_size), PNG_DEPRECATED);
|
|
|
|
/* Writes all the PNG information before the image. */
|
|
PNG_EXPORT(20, void, png_write_info_before_PLTE,
|
|
(png_structrp png_ptr, png_const_inforp info_ptr));
|
|
PNG_EXPORT(21, void, png_write_info,
|
|
(png_structrp png_ptr, png_const_inforp info_ptr));
|
|
|
|
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
|
|
/* Read the information before the actual image data. */
|
|
PNG_EXPORT(22, void, png_read_info,
|
|
(png_structrp png_ptr, png_inforp info_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_TIME_RFC1123_SUPPORTED
|
|
/* Convert to a US string format: there is no localization support in this
|
|
* routine. The original implementation used a 29 character buffer in
|
|
* png_struct, this will be removed in future versions.
|
|
*/
|
|
#if PNG_LIBPNG_VER < 10700
|
|
/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
|
|
PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
|
|
png_const_timep ptime),PNG_DEPRECATED);
|
|
#endif
|
|
PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
|
|
png_const_timep ptime));
|
|
#endif
|
|
|
|
#ifdef PNG_CONVERT_tIME_SUPPORTED
|
|
/* Convert from a struct tm to png_time */
|
|
PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
|
|
const struct tm * ttime));
|
|
|
|
/* Convert from time_t to png_time. Uses gmtime() */
|
|
PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
|
|
#endif /* CONVERT_tIME */
|
|
|
|
#ifdef PNG_READ_EXPAND_SUPPORTED
|
|
/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
|
|
PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
|
|
PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
|
|
PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
|
|
PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
|
/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
|
|
* of a tRNS chunk if present.
|
|
*/
|
|
PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
|
|
/* Use blue, green, red order for pixels. */
|
|
PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
|
/* Expand the grayscale to 24-bit RGB if necessary. */
|
|
PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
|
/* Reduce RGB to grayscale. */
|
|
#define PNG_ERROR_ACTION_NONE 1
|
|
#define PNG_ERROR_ACTION_WARN 2
|
|
#define PNG_ERROR_ACTION_ERROR 3
|
|
#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
|
|
|
|
PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
|
|
int error_action, double red, double green))
|
|
PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
|
|
int error_action, png_fixed_point red, png_fixed_point green))
|
|
|
|
PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
|
|
png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
|
|
PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
|
|
png_colorp palette));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
|
/* How the alpha channel is interpreted - this affects how the color channels
|
|
* of a PNG file are returned to the calling application when an alpha channel,
|
|
* or a tRNS chunk in a palette file, is present.
|
|
*
|
|
* This has no effect on the way pixels are written into a PNG output
|
|
* datastream. The color samples in a PNG datastream are never premultiplied
|
|
* with the alpha samples.
|
|
*
|
|
* The default is to return data according to the PNG specification: the alpha
|
|
* channel is a linear measure of the contribution of the pixel to the
|
|
* corresponding composited pixel, and the color channels are unassociated
|
|
* (not premultiplied). The gamma encoded color channels must be scaled
|
|
* according to the contribution and to do this it is necessary to undo
|
|
* the encoding, scale the color values, perform the composition and re-encode
|
|
* the values. This is the 'PNG' mode.
|
|
*
|
|
* The alternative is to 'associate' the alpha with the color information by
|
|
* storing color channel values that have been scaled by the alpha.
|
|
* image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
|
|
* (the latter being the two common names for associated alpha color channels).
|
|
*
|
|
* For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
|
|
* value is equal to the maximum value.
|
|
*
|
|
* The final choice is to gamma encode the alpha channel as well. This is
|
|
* broken because, in practice, no implementation that uses this choice
|
|
* correctly undoes the encoding before handling alpha composition. Use this
|
|
* choice only if other serious errors in the software or hardware you use
|
|
* mandate it; the typical serious error is for dark halos to appear around
|
|
* opaque areas of the composited PNG image because of arithmetic overflow.
|
|
*
|
|
* The API function png_set_alpha_mode specifies which of these choices to use
|
|
* with an enumerated 'mode' value and the gamma of the required output:
|
|
*/
|
|
#define PNG_ALPHA_PNG 0 /* according to the PNG standard */
|
|
#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
|
|
#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
|
|
#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
|
|
#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
|
|
#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
|
|
|
|
PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
|
|
double output_gamma))
|
|
PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
|
|
int mode, png_fixed_point output_gamma))
|
|
#endif
|
|
|
|
#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
|
|
/* The output_gamma value is a screen gamma in libpng terminology: it expresses
|
|
* how to decode the output values, not how they are encoded.
|
|
*/
|
|
#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
|
|
#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
|
|
#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
|
|
#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
|
|
#endif
|
|
|
|
/* The following are examples of calls to png_set_alpha_mode to achieve the
|
|
* required overall gamma correction and, where necessary, alpha
|
|
* premultiplication.
|
|
*
|
|
* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
|
|
* This is the default libpng handling of the alpha channel - it is not
|
|
* pre-multiplied into the color components. In addition the call states
|
|
* that the output is for a sRGB system and causes all PNG files without gAMA
|
|
* chunks to be assumed to be encoded using sRGB.
|
|
*
|
|
* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
|
|
* In this case the output is assumed to be something like an sRGB conformant
|
|
* display preceded by a power-law lookup table of power 1.45. This is how
|
|
* early Mac systems behaved.
|
|
*
|
|
* png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
|
|
* This is the classic Jim Blinn approach and will work in academic
|
|
* environments where everything is done by the book. It has the shortcoming
|
|
* of assuming that input PNG data with no gamma information is linear - this
|
|
* is unlikely to be correct unless the PNG files where generated locally.
|
|
* Most of the time the output precision will be so low as to show
|
|
* significant banding in dark areas of the image.
|
|
*
|
|
* png_set_expand_16(pp);
|
|
* png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
|
|
* This is a somewhat more realistic Jim Blinn inspired approach. PNG files
|
|
* are assumed to have the sRGB encoding if not marked with a gamma value and
|
|
* the output is always 16 bits per component. This permits accurate scaling
|
|
* and processing of the data. If you know that your input PNG files were
|
|
* generated locally you might need to replace PNG_DEFAULT_sRGB with the
|
|
* correct value for your system.
|
|
*
|
|
* png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
|
|
* If you just need to composite the PNG image onto an existing background
|
|
* and if you control the code that does this you can use the optimization
|
|
* setting. In this case you just copy completely opaque pixels to the
|
|
* output. For pixels that are not completely transparent (you just skip
|
|
* those) you do the composition math using png_composite or png_composite_16
|
|
* below then encode the resultant 8-bit or 16-bit values to match the output
|
|
* encoding.
|
|
*
|
|
* Other cases
|
|
* If neither the PNG nor the standard linear encoding work for you because
|
|
* of the software or hardware you use then you have a big problem. The PNG
|
|
* case will probably result in halos around the image. The linear encoding
|
|
* will probably result in a washed out, too bright, image (it's actually too
|
|
* contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
|
|
* substantially reduce the halos. Alternatively try:
|
|
*
|
|
* png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
|
|
* This option will also reduce the halos, but there will be slight dark
|
|
* halos round the opaque parts of the image where the background is light.
|
|
* In the OPTIMIZED mode the halos will be light halos where the background
|
|
* is dark. Take your pick - the halos are unavoidable unless you can get
|
|
* your hardware/software fixed! (The OPTIMIZED approach is slightly
|
|
* faster.)
|
|
*
|
|
* When the default gamma of PNG files doesn't match the output gamma.
|
|
* If you have PNG files with no gamma information png_set_alpha_mode allows
|
|
* you to provide a default gamma, but it also sets the output gamma to the
|
|
* matching value. If you know your PNG files have a gamma that doesn't
|
|
* match the output you can take advantage of the fact that
|
|
* png_set_alpha_mode always sets the output gamma but only sets the PNG
|
|
* default if it is not already set:
|
|
*
|
|
* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
|
|
* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
|
|
* The first call sets both the default and the output gamma values, the
|
|
* second call overrides the output gamma without changing the default. This
|
|
* is easier than achieving the same effect with png_set_gamma. You must use
|
|
* PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
|
|
* fire if more than one call to png_set_alpha_mode and png_set_background is
|
|
* made in the same read operation, however multiple calls with PNG_ALPHA_PNG
|
|
* are ignored.
|
|
*/
|
|
|
|
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
|
PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
|
|
defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
|
|
PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
|
|
defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
|
|
PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
|
|
/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
|
|
PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
|
|
int flags));
|
|
/* The values of the PNG_FILLER_ defines should NOT be changed */
|
|
# define PNG_FILLER_BEFORE 0
|
|
# define PNG_FILLER_AFTER 1
|
|
/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
|
|
PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
|
|
png_uint_32 filler, int flags));
|
|
#endif /* READ_FILLER || WRITE_FILLER */
|
|
|
|
#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
|
|
/* Swap bytes in 16-bit depth files. */
|
|
PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
|
|
/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
|
|
PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
|
|
defined(PNG_WRITE_PACKSWAP_SUPPORTED)
|
|
/* Swap packing order of pixels in bytes. */
|
|
PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
|
|
/* Converts files to legal bit depths. */
|
|
PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
|
|
true_bits));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
|
|
defined(PNG_WRITE_INTERLACING_SUPPORTED)
|
|
/* Have the code handle the interlacing. Returns the number of passes.
|
|
* MUST be called before png_read_update_info or png_start_read_image,
|
|
* otherwise it will not have the desired effect. Note that it is still
|
|
* necessary to call png_read_row or png_read_rows png_get_image_height
|
|
* times for each pass.
|
|
*/
|
|
PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
|
|
/* Invert monochrome files */
|
|
PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_BACKGROUND_SUPPORTED
|
|
/* Handle alpha and tRNS by replacing with a background color. Prior to
|
|
* libpng-1.5.4 this API must not be called before the PNG file header has been
|
|
* read. Doing so will result in unexpected behavior and possible warnings or
|
|
* errors if the PNG file contains a bKGD chunk.
|
|
*/
|
|
PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
|
|
png_const_color_16p background_color, int background_gamma_code,
|
|
int need_expand, double background_gamma))
|
|
PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
|
|
png_const_color_16p background_color, int background_gamma_code,
|
|
int need_expand, png_fixed_point background_gamma))
|
|
#endif
|
|
#ifdef PNG_READ_BACKGROUND_SUPPORTED
|
|
# define PNG_BACKGROUND_GAMMA_UNKNOWN 0
|
|
# define PNG_BACKGROUND_GAMMA_SCREEN 1
|
|
# define PNG_BACKGROUND_GAMMA_FILE 2
|
|
# define PNG_BACKGROUND_GAMMA_UNIQUE 3
|
|
#endif
|
|
|
|
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
|
/* Scale a 16-bit depth file down to 8-bit, accurately. */
|
|
PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
|
#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
|
|
/* Strip the second byte of information from a 16-bit depth file. */
|
|
PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_QUANTIZE_SUPPORTED
|
|
/* Turn on quantizing, and reduce the palette to the number of colors
|
|
* available.
|
|
*/
|
|
PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
|
|
png_colorp palette, int num_palette, int maximum_colors,
|
|
png_const_uint_16p histogram, int full_quantize));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
/* The threshold on gamma processing is configurable but hard-wired into the
|
|
* library. The following is the floating point variant.
|
|
*/
|
|
#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
|
|
|
|
/* Handle gamma correction. Screen_gamma=(display_exponent).
|
|
* NOTE: this API simply sets the screen and file gamma values. It will
|
|
* therefore override the value for gamma in a PNG file if it is called after
|
|
* the file header has been read - use with care - call before reading the PNG
|
|
* file for best results!
|
|
*
|
|
* These routines accept the same gamma values as png_set_alpha_mode (described
|
|
* above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
|
|
* API (floating point or fixed.) Notice, however, that the 'file_gamma' value
|
|
* is the inverse of a 'screen gamma' value.
|
|
*/
|
|
PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
|
|
double screen_gamma, double override_file_gamma))
|
|
PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
|
|
png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
|
|
#endif
|
|
|
|
#ifdef PNG_WRITE_FLUSH_SUPPORTED
|
|
/* Set how many lines between output flushes - 0 for no flushing */
|
|
PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
|
|
/* Flush the current PNG output buffer */
|
|
PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
|
|
#endif
|
|
|
|
/* Optional update palette with requested transformations */
|
|
PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
|
|
|
|
/* Optional call to update the users info structure */
|
|
PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
|
|
png_inforp info_ptr));
|
|
|
|
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
|
|
/* Read one or more rows of image data. */
|
|
PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
|
|
png_bytepp display_row, png_uint_32 num_rows));
|
|
#endif
|
|
|
|
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
|
|
/* Read a row of data. */
|
|
PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
|
|
png_bytep display_row));
|
|
#endif
|
|
|
|
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
|
|
/* Read the whole image into memory at once. */
|
|
PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
|
|
#endif
|
|
|
|
/* Write a row of image data */
|
|
PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
|
|
png_const_bytep row));
|
|
|
|
/* Write a few rows of image data: (*row) is not written; however, the type
|
|
* is declared as writeable to maintain compatibility with previous versions
|
|
* of libpng and to allow the 'display_row' array from read_rows to be passed
|
|
* unchanged to write_rows.
|
|
*/
|
|
PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
|
|
png_uint_32 num_rows));
|
|
|
|
/* Write the image data */
|
|
PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
|
|
|
|
/* Write the end of the PNG file. */
|
|
PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
|
|
png_inforp info_ptr));
|
|
|
|
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
|
|
/* Read the end of the PNG file. */
|
|
PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
|
|
#endif
|
|
|
|
/* Free any memory associated with the png_info_struct */
|
|
PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
|
|
png_infopp info_ptr_ptr));
|
|
|
|
/* Free any memory associated with the png_struct and the png_info_structs */
|
|
PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
|
|
png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
|
|
|
|
/* Free any memory associated with the png_struct and the png_info_structs */
|
|
PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
|
|
png_infopp info_ptr_ptr));
|
|
|
|
/* Set the libpng method of handling chunk CRC errors */
|
|
PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
|
|
int ancil_action));
|
|
|
|
/* Values for png_set_crc_action() say how to handle CRC errors in
|
|
* ancillary and critical chunks, and whether to use the data contained
|
|
* therein. Note that it is impossible to "discard" data in a critical
|
|
* chunk. For versions prior to 0.90, the action was always error/quit,
|
|
* whereas in version 0.90 and later, the action for CRC errors in ancillary
|
|
* chunks is warn/discard. These values should NOT be changed.
|
|
*
|
|
* value action:critical action:ancillary
|
|
*/
|
|
#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
|
|
#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
|
|
#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
|
|
#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
|
|
#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
|
|
#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
|
|
|
|
#ifdef PNG_WRITE_SUPPORTED
|
|
/* These functions give the user control over the scan-line filtering in
|
|
* libpng and the compression methods used by zlib. These functions are
|
|
* mainly useful for testing, as the defaults should work with most users.
|
|
* Those users who are tight on memory or want faster performance at the
|
|
* expense of compression can modify them. See the compression library
|
|
* header file (zlib.h) for an explination of the compression functions.
|
|
*/
|
|
|
|
/* Set the filtering method(s) used by libpng. Currently, the only valid
|
|
* value for "method" is 0.
|
|
*/
|
|
PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
|
|
int filters));
|
|
#endif /* WRITE */
|
|
|
|
/* Flags for png_set_filter() to say which filters to use. The flags
|
|
* are chosen so that they don't conflict with real filter types
|
|
* below, in case they are supplied instead of the #defined constants.
|
|
* These values should NOT be changed.
|
|
*/
|
|
#define PNG_NO_FILTERS 0x00
|
|
#define PNG_FILTER_NONE 0x08
|
|
#define PNG_FILTER_SUB 0x10
|
|
#define PNG_FILTER_UP 0x20
|
|
#define PNG_FILTER_AVG 0x40
|
|
#define PNG_FILTER_PAETH 0x80
|
|
#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
|
|
#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
|
|
|
|
/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
|
|
* These defines should NOT be changed.
|
|
*/
|
|
#define PNG_FILTER_VALUE_NONE 0
|
|
#define PNG_FILTER_VALUE_SUB 1
|
|
#define PNG_FILTER_VALUE_UP 2
|
|
#define PNG_FILTER_VALUE_AVG 3
|
|
#define PNG_FILTER_VALUE_PAETH 4
|
|
#define PNG_FILTER_VALUE_LAST 5
|
|
|
|
#ifdef PNG_WRITE_SUPPORTED
|
|
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
|
|
PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
|
|
int heuristic_method, int num_weights, png_const_doublep filter_weights,
|
|
png_const_doublep filter_costs))
|
|
PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
|
|
(png_structrp png_ptr, int heuristic_method, int num_weights,
|
|
png_const_fixed_point_p filter_weights,
|
|
png_const_fixed_point_p filter_costs))
|
|
#endif /* WRITE_WEIGHTED_FILTER */
|
|
|
|
/* The following are no longer used and will be removed from libpng-1.7: */
|
|
#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
|
|
#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
|
|
#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
|
|
#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
|
|
|
|
/* Set the library compression level. Currently, valid values range from
|
|
* 0 - 9, corresponding directly to the zlib compression levels 0 - 9
|
|
* (0 - no compression, 9 - "maximal" compression). Note that tests have
|
|
* shown that zlib compression levels 3-6 usually perform as well as level 9
|
|
* for PNG images, and do considerably fewer caclulations. In the future,
|
|
* these values may not correspond directly to the zlib compression levels.
|
|
*/
|
|
#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
|
|
PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
|
|
int level));
|
|
|
|
PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
|
|
int mem_level));
|
|
|
|
PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
|
|
int strategy));
|
|
|
|
/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
|
|
* smaller value of window_bits if it can do so safely.
|
|
*/
|
|
PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
|
|
int window_bits));
|
|
|
|
PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
|
|
int method));
|
|
#endif /* WRITE_CUSTOMIZE_COMPRESSION */
|
|
|
|
#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
|
|
/* Also set zlib parameters for compressing non-IDAT chunks */
|
|
PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
|
|
int level));
|
|
|
|
PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
|
|
int mem_level));
|
|
|
|
PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
|
|
int strategy));
|
|
|
|
/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
|
|
* smaller value of window_bits if it can do so safely.
|
|
*/
|
|
PNG_EXPORT(225, void, png_set_text_compression_window_bits,
|
|
(png_structrp png_ptr, int window_bits));
|
|
|
|
PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
|
|
int method));
|
|
#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
|
|
#endif /* WRITE */
|
|
|
|
/* These next functions are called for input/output, memory, and error
|
|
* handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
|
|
* and call standard C I/O routines such as fread(), fwrite(), and
|
|
* fprintf(). These functions can be made to use other I/O routines
|
|
* at run time for those applications that need to handle I/O in a
|
|
* different manner by calling png_set_???_fn(). See libpng-manual.txt for
|
|
* more information.
|
|
*/
|
|
|
|
#ifdef PNG_STDIO_SUPPORTED
|
|
/* Initialize the input/output for the PNG file to the default functions. */
|
|
PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
|
|
#endif
|
|
|
|
/* Replace the (error and abort), and warning functions with user
|
|
* supplied functions. If no messages are to be printed you must still
|
|
* write and use replacement functions. The replacement error_fn should
|
|
* still do a longjmp to the last setjmp location if you are using this
|
|
* method of error handling. If error_fn or warning_fn is NULL, the
|
|
* default function will be used.
|
|
*/
|
|
|
|
PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
|
|
png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
|
|
|
|
/* Return the user pointer associated with the error functions */
|
|
PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
|
|
|
|
/* Replace the default data output functions with a user supplied one(s).
|
|
* If buffered output is not used, then output_flush_fn can be set to NULL.
|
|
* If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
|
|
* output_flush_fn will be ignored (and thus can be NULL).
|
|
* It is probably a mistake to use NULL for output_flush_fn if
|
|
* write_data_fn is not also NULL unless you have built libpng with
|
|
* PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
|
|
* default flush function, which uses the standard *FILE structure, will
|
|
* be used.
|
|
*/
|
|
PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
|
|
png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
|
|
|
|
/* Replace the default data input function with a user supplied one. */
|
|
PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
|
|
png_rw_ptr read_data_fn));
|
|
|
|
/* Return the user pointer associated with the I/O functions */
|
|
PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
|
|
|
|
PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
|
|
png_read_status_ptr read_row_fn));
|
|
|
|
PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
|
|
png_write_status_ptr write_row_fn));
|
|
|
|
#ifdef PNG_USER_MEM_SUPPORTED
|
|
/* Replace the default memory allocation functions with user supplied one(s). */
|
|
PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
|
|
png_malloc_ptr malloc_fn, png_free_ptr free_fn));
|
|
/* Return the user pointer associated with the memory functions */
|
|
PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
|
|
PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
|
|
png_user_transform_ptr read_user_transform_fn));
|
|
#endif
|
|
|
|
#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
|
|
PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
|
|
png_user_transform_ptr write_user_transform_fn));
|
|
#endif
|
|
|
|
#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
|
|
PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
|
|
png_voidp user_transform_ptr, int user_transform_depth,
|
|
int user_transform_channels));
|
|
/* Return the user pointer associated with the user transform functions */
|
|
PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
|
|
(png_const_structrp png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
|
|
/* Return information about the row currently being processed. Note that these
|
|
* APIs do not fail but will return unexpected results if called outside a user
|
|
* transform callback. Also note that when transforming an interlaced image the
|
|
* row number is the row number within the sub-image of the interlace pass, so
|
|
* the value will increase to the height of the sub-image (not the full image)
|
|
* then reset to 0 for the next pass.
|
|
*
|
|
* Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
|
|
* find the output pixel (x,y) given an interlaced sub-image pixel
|
|
* (row,col,pass). (See below for these macros.)
|
|
*/
|
|
PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
|
|
PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
|
|
#endif
|
|
|
|
#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
|
|
/* This callback is called only for *unknown* chunks. If
|
|
* PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
|
|
* chunks to be treated as unknown, however in this case the callback must do
|
|
* any processing required by the chunk (e.g. by calling the appropriate
|
|
* png_set_ APIs.)
|
|
*
|
|
* There is no write support - on write, by default, all the chunks in the
|
|
* 'unknown' list are written in the specified position.
|
|
*
|
|
* The integer return from the callback function is interpreted thus:
|
|
*
|
|
* negative: An error occurred; png_chunk_error will be called.
|
|
* zero: The chunk was not handled, the chunk will be saved. A critical
|
|
* chunk will cause an error at this point unless it is to be saved.
|
|
* positive: The chunk was handled, libpng will ignore/discard it.
|
|
*
|
|
* See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about
|
|
* how this behavior will change in libpng 1.7
|
|
*/
|
|
PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
|
|
png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
|
|
#endif
|
|
|
|
#ifdef PNG_USER_CHUNKS_SUPPORTED
|
|
PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
|
|
/* Sets the function callbacks for the push reader, and a pointer to a
|
|
* user-defined structure available to the callback functions.
|
|
*/
|
|
PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
|
|
png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
|
|
png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
|
|
|
|
/* Returns the user pointer associated with the push read functions */
|
|
PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
|
|
(png_const_structrp png_ptr));
|
|
|
|
/* Function to be called when data becomes available */
|
|
PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
|
|
png_inforp info_ptr, png_bytep buffer, size_t buffer_size));
|
|
|
|
/* A function which may be called *only* within png_process_data to stop the
|
|
* processing of any more data. The function returns the number of bytes
|
|
* remaining, excluding any that libpng has cached internally. A subsequent
|
|
* call to png_process_data must supply these bytes again. If the argument
|
|
* 'save' is set to true the routine will first save all the pending data and
|
|
* will always return 0.
|
|
*/
|
|
PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save));
|
|
|
|
/* A function which may be called *only* outside (after) a call to
|
|
* png_process_data. It returns the number of bytes of data to skip in the
|
|
* input. Normally it will return 0, but if it returns a non-zero value the
|
|
* application must skip than number of bytes of input data and pass the
|
|
* following data to the next call to png_process_data.
|
|
*/
|
|
PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
|
|
|
|
/* Function that combines rows. 'new_row' is a flag that should come from
|
|
* the callback and be non-NULL if anything needs to be done; the library
|
|
* stores its own version of the new data internally and ignores the passed
|
|
* in value.
|
|
*/
|
|
PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
|
|
png_bytep old_row, png_const_bytep new_row));
|
|
#endif /* PROGRESSIVE_READ */
|
|
|
|
PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
|
|
png_alloc_size_t size), PNG_ALLOCATED);
|
|
/* Added at libpng version 1.4.0 */
|
|
PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
|
|
png_alloc_size_t size), PNG_ALLOCATED);
|
|
|
|
/* Added at libpng version 1.2.4 */
|
|
PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
|
|
png_alloc_size_t size), PNG_ALLOCATED);
|
|
|
|
/* Frees a pointer allocated by png_malloc() */
|
|
PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
|
|
|
|
/* Free data that was allocated internally */
|
|
PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_uint_32 free_me, int num));
|
|
|
|
/* Reassign responsibility for freeing existing data, whether allocated
|
|
* by libpng or by the application; this works on the png_info structure passed
|
|
* in, it does not change the state for other png_info structures.
|
|
*
|
|
* It is unlikely that this function works correctly as of 1.6.0 and using it
|
|
* may result either in memory leaks or double free of allocated data.
|
|
*/
|
|
PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, int freer, png_uint_32 mask));
|
|
|
|
/* Assignments for png_data_freer */
|
|
#define PNG_DESTROY_WILL_FREE_DATA 1
|
|
#define PNG_SET_WILL_FREE_DATA 1
|
|
#define PNG_USER_WILL_FREE_DATA 2
|
|
/* Flags for png_ptr->free_me and info_ptr->free_me */
|
|
#define PNG_FREE_HIST 0x0008U
|
|
#define PNG_FREE_ICCP 0x0010U
|
|
#define PNG_FREE_SPLT 0x0020U
|
|
#define PNG_FREE_ROWS 0x0040U
|
|
#define PNG_FREE_PCAL 0x0080U
|
|
#define PNG_FREE_SCAL 0x0100U
|
|
#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
|
|
# define PNG_FREE_UNKN 0x0200U
|
|
#endif
|
|
/* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
|
|
#define PNG_FREE_PLTE 0x1000U
|
|
#define PNG_FREE_TRNS 0x2000U
|
|
#define PNG_FREE_TEXT 0x4000U
|
|
#define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
|
|
#define PNG_FREE_ALL 0xffffU
|
|
#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
|
|
|
|
#ifdef PNG_USER_MEM_SUPPORTED
|
|
PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
|
|
png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
|
|
PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
|
|
png_voidp ptr), PNG_DEPRECATED);
|
|
#endif
|
|
|
|
#ifdef PNG_ERROR_TEXT_SUPPORTED
|
|
/* Fatal error in PNG image of libpng - can't continue */
|
|
PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
|
|
png_const_charp error_message), PNG_NORETURN);
|
|
|
|
/* The same, but the chunk name is prepended to the error string. */
|
|
PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
|
|
png_const_charp error_message), PNG_NORETURN);
|
|
|
|
#else
|
|
/* Fatal error in PNG image of libpng - can't continue */
|
|
PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
|
|
# define png_error(s1,s2) png_err(s1)
|
|
# define png_chunk_error(s1,s2) png_err(s1)
|
|
#endif
|
|
|
|
#ifdef PNG_WARNINGS_SUPPORTED
|
|
/* Non-fatal error in libpng. Can continue, but may have a problem. */
|
|
PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
|
|
png_const_charp warning_message));
|
|
|
|
/* Non-fatal error in libpng, chunk name is prepended to message. */
|
|
PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
|
|
png_const_charp warning_message));
|
|
#else
|
|
# define png_warning(s1,s2) ((void)(s1))
|
|
# define png_chunk_warning(s1,s2) ((void)(s1))
|
|
#endif
|
|
|
|
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
|
|
/* Benign error in libpng. Can continue, but may have a problem.
|
|
* User can choose whether to handle as a fatal error or as a warning. */
|
|
PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
|
|
png_const_charp warning_message));
|
|
|
|
#ifdef PNG_READ_SUPPORTED
|
|
/* Same, chunk name is prepended to message (only during read) */
|
|
PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
|
|
png_const_charp warning_message));
|
|
#endif
|
|
|
|
PNG_EXPORT(109, void, png_set_benign_errors,
|
|
(png_structrp png_ptr, int allowed));
|
|
#else
|
|
# ifdef PNG_ALLOW_BENIGN_ERRORS
|
|
# define png_benign_error png_warning
|
|
# define png_chunk_benign_error png_chunk_warning
|
|
# else
|
|
# define png_benign_error png_error
|
|
# define png_chunk_benign_error png_chunk_error
|
|
# endif
|
|
#endif
|
|
|
|
/* The png_set_<chunk> functions are for storing values in the png_info_struct.
|
|
* Similarly, the png_get_<chunk> calls are used to read values from the
|
|
* png_info_struct, either storing the parameters in the passed variables, or
|
|
* setting pointers into the png_info_struct where the data is stored. The
|
|
* png_get_<chunk> functions return a non-zero value if the data was available
|
|
* in info_ptr, or return zero and do not change any of the parameters if the
|
|
* data was not available.
|
|
*
|
|
* These functions should be used instead of directly accessing png_info
|
|
* to avoid problems with future changes in the size and internal layout of
|
|
* png_info_struct.
|
|
*/
|
|
/* Returns "flag" if chunk data is valid in info_ptr. */
|
|
PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, png_uint_32 flag));
|
|
|
|
/* Returns number of bytes needed to hold a transformed row. */
|
|
PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
#ifdef PNG_INFO_IMAGE_SUPPORTED
|
|
/* Returns row_pointers, which is an array of pointers to scanlines that was
|
|
* returned from png_read_png().
|
|
*/
|
|
PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
/* Set row_pointers, which is an array of pointers to scanlines for use
|
|
* by png_write_png().
|
|
*/
|
|
PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_bytepp row_pointers));
|
|
#endif
|
|
|
|
/* Returns number of color channels in image. */
|
|
PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
#ifdef PNG_EASY_ACCESS_SUPPORTED
|
|
/* Returns image width in pixels. */
|
|
PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
/* Returns image height in pixels. */
|
|
PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
/* Returns image bit_depth. */
|
|
PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
/* Returns image color_type. */
|
|
PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
/* Returns image filter_type. */
|
|
PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
/* Returns image interlace_type. */
|
|
PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
/* Returns image compression_type. */
|
|
PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
|
|
/* Returns image resolution in pixels per meter, from pHYs chunk data. */
|
|
PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
|
|
/* Returns pixel aspect ratio, computed from pHYs chunk data. */
|
|
PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr))
|
|
PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr))
|
|
|
|
/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
|
|
PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
|
|
#endif /* EASY_ACCESS */
|
|
|
|
#ifdef PNG_READ_SUPPORTED
|
|
/* Returns pointer to signature string read from PNG header */
|
|
PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr));
|
|
#endif
|
|
|
|
#ifdef PNG_bKGD_SUPPORTED
|
|
PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_color_16p *background));
|
|
#endif
|
|
|
|
#ifdef PNG_bKGD_SUPPORTED
|
|
PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_color_16p background));
|
|
#endif
|
|
|
|
#ifdef PNG_cHRM_SUPPORTED
|
|
PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
|
|
double *red_y, double *green_x, double *green_y, double *blue_x,
|
|
double *blue_y))
|
|
PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
|
|
double *green_X, double *green_Y, double *green_Z, double *blue_X,
|
|
double *blue_Y, double *blue_Z))
|
|
PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr,
|
|
png_fixed_point *int_white_x, png_fixed_point *int_white_y,
|
|
png_fixed_point *int_red_x, png_fixed_point *int_red_y,
|
|
png_fixed_point *int_green_x, png_fixed_point *int_green_y,
|
|
png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
|
|
PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr,
|
|
png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
|
|
png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
|
|
png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
|
|
png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
|
|
png_fixed_point *int_blue_Z))
|
|
#endif
|
|
|
|
#ifdef PNG_cHRM_SUPPORTED
|
|
PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr,
|
|
double white_x, double white_y, double red_x, double red_y, double green_x,
|
|
double green_y, double blue_x, double blue_y))
|
|
PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, double red_X, double red_Y, double red_Z,
|
|
double green_X, double green_Y, double green_Z, double blue_X,
|
|
double blue_Y, double blue_Z))
|
|
PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_fixed_point int_white_x,
|
|
png_fixed_point int_white_y, png_fixed_point int_red_x,
|
|
png_fixed_point int_red_y, png_fixed_point int_green_x,
|
|
png_fixed_point int_green_y, png_fixed_point int_blue_x,
|
|
png_fixed_point int_blue_y))
|
|
PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
|
|
png_fixed_point int_red_Z, png_fixed_point int_green_X,
|
|
png_fixed_point int_green_Y, png_fixed_point int_green_Z,
|
|
png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
|
|
png_fixed_point int_blue_Z))
|
|
#endif
|
|
|
|
#ifdef PNG_eXIf_SUPPORTED
|
|
PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_bytep *exif));
|
|
PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_bytep exif));
|
|
|
|
PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
|
|
PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif));
|
|
#endif
|
|
|
|
#ifdef PNG_gAMA_SUPPORTED
|
|
PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, double *file_gamma))
|
|
PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr,
|
|
png_fixed_point *int_file_gamma))
|
|
#endif
|
|
|
|
#ifdef PNG_gAMA_SUPPORTED
|
|
PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, double file_gamma))
|
|
PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_fixed_point int_file_gamma))
|
|
#endif
|
|
|
|
#ifdef PNG_hIST_SUPPORTED
|
|
PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_uint_16p *hist));
|
|
PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_uint_16p hist));
|
|
#endif
|
|
|
|
PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
|
|
int *bit_depth, int *color_type, int *interlace_method,
|
|
int *compression_method, int *filter_method));
|
|
|
|
PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
|
|
int color_type, int interlace_method, int compression_method,
|
|
int filter_method));
|
|
|
|
#ifdef PNG_oFFs_SUPPORTED
|
|
PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
|
|
int *unit_type));
|
|
#endif
|
|
|
|
#ifdef PNG_oFFs_SUPPORTED
|
|
PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
|
|
int unit_type));
|
|
#endif
|
|
|
|
#ifdef PNG_pCAL_SUPPORTED
|
|
PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
|
|
png_int_32 *X1, int *type, int *nparams, png_charp *units,
|
|
png_charpp *params));
|
|
#endif
|
|
|
|
#ifdef PNG_pCAL_SUPPORTED
|
|
PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
|
|
int type, int nparams, png_const_charp units, png_charpp params));
|
|
#endif
|
|
|
|
#ifdef PNG_pHYs_SUPPORTED
|
|
PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
|
|
int *unit_type));
|
|
#endif
|
|
|
|
#ifdef PNG_pHYs_SUPPORTED
|
|
PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
|
|
#endif
|
|
|
|
PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_colorp *palette, int *num_palette));
|
|
|
|
PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_colorp palette, int num_palette));
|
|
|
|
#ifdef PNG_sBIT_SUPPORTED
|
|
PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_color_8p *sig_bit));
|
|
#endif
|
|
|
|
#ifdef PNG_sBIT_SUPPORTED
|
|
PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_color_8p sig_bit));
|
|
#endif
|
|
|
|
#ifdef PNG_sRGB_SUPPORTED
|
|
PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, int *file_srgb_intent));
|
|
#endif
|
|
|
|
#ifdef PNG_sRGB_SUPPORTED
|
|
PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, int srgb_intent));
|
|
PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, int srgb_intent));
|
|
#endif
|
|
|
|
#ifdef PNG_iCCP_SUPPORTED
|
|
PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_charpp name, int *compression_type,
|
|
png_bytepp profile, png_uint_32 *proflen));
|
|
#endif
|
|
|
|
#ifdef PNG_iCCP_SUPPORTED
|
|
PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_charp name, int compression_type,
|
|
png_const_bytep profile, png_uint_32 proflen));
|
|
#endif
|
|
|
|
#ifdef PNG_sPLT_SUPPORTED
|
|
PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_sPLT_tpp entries));
|
|
#endif
|
|
|
|
#ifdef PNG_sPLT_SUPPORTED
|
|
PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
|
|
#endif
|
|
|
|
#ifdef PNG_TEXT_SUPPORTED
|
|
/* png_get_text also returns the number of text chunks in *num_text */
|
|
PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_textp *text_ptr, int *num_text));
|
|
#endif
|
|
|
|
/* Note while png_set_text() will accept a structure whose text,
|
|
* language, and translated keywords are NULL pointers, the structure
|
|
* returned by png_get_text will always contain regular
|
|
* zero-terminated C strings. They might be empty strings but
|
|
* they will never be NULL pointers.
|
|
*/
|
|
|
|
#ifdef PNG_TEXT_SUPPORTED
|
|
PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_textp text_ptr, int num_text));
|
|
#endif
|
|
|
|
#ifdef PNG_tIME_SUPPORTED
|
|
PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_timep *mod_time));
|
|
#endif
|
|
|
|
#ifdef PNG_tIME_SUPPORTED
|
|
PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_timep mod_time));
|
|
#endif
|
|
|
|
#ifdef PNG_tRNS_SUPPORTED
|
|
PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
|
|
png_color_16p *trans_color));
|
|
#endif
|
|
|
|
#ifdef PNG_tRNS_SUPPORTED
|
|
PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
|
|
png_const_color_16p trans_color));
|
|
#endif
|
|
|
|
#ifdef PNG_sCAL_SUPPORTED
|
|
PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, int *unit, double *width, double *height))
|
|
#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
|
|
defined(PNG_FLOATING_POINT_SUPPORTED)
|
|
/* NOTE: this API is currently implemented using floating point arithmetic,
|
|
* consequently it can only be used on systems with floating point support.
|
|
* In any case the range of values supported by png_fixed_point is small and it
|
|
* is highly recommended that png_get_sCAL_s be used instead.
|
|
*/
|
|
PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
|
|
png_fixed_point *width, png_fixed_point *height))
|
|
#endif
|
|
PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
|
|
png_charpp swidth, png_charpp sheight));
|
|
|
|
PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, int unit, double width, double height))
|
|
PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, int unit, png_fixed_point width,
|
|
png_fixed_point height))
|
|
PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, int unit,
|
|
png_const_charp swidth, png_const_charp sheight));
|
|
#endif /* sCAL */
|
|
|
|
#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
|
|
/* Provide the default handling for all unknown chunks or, optionally, for
|
|
* specific unknown chunks.
|
|
*
|
|
* NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
|
|
* ignored and the default was used, the per-chunk setting only had an effect on
|
|
* write. If you wish to have chunk-specific handling on read in code that must
|
|
* work on earlier versions you must use a user chunk callback to specify the
|
|
* desired handling (keep or discard.)
|
|
*
|
|
* The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
|
|
* parameter is interpreted as follows:
|
|
*
|
|
* READ:
|
|
* PNG_HANDLE_CHUNK_AS_DEFAULT:
|
|
* Known chunks: do normal libpng processing, do not keep the chunk (but
|
|
* see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
|
|
* Unknown chunks: for a specific chunk use the global default, when used
|
|
* as the default discard the chunk data.
|
|
* PNG_HANDLE_CHUNK_NEVER:
|
|
* Discard the chunk data.
|
|
* PNG_HANDLE_CHUNK_IF_SAFE:
|
|
* Keep the chunk data if the chunk is not critical else raise a chunk
|
|
* error.
|
|
* PNG_HANDLE_CHUNK_ALWAYS:
|
|
* Keep the chunk data.
|
|
*
|
|
* If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
|
|
* below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
|
|
* to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
|
|
* it simply resets the behavior to the libpng default.
|
|
*
|
|
* INTERACTION WITH USER CHUNK CALLBACKS:
|
|
* The per-chunk handling is always used when there is a png_user_chunk_ptr
|
|
* callback and the callback returns 0; the chunk is then always stored *unless*
|
|
* it is critical and the per-chunk setting is other than ALWAYS. Notice that
|
|
* the global default is *not* used in this case. (In effect the per-chunk
|
|
* value is incremented to at least IF_SAFE.)
|
|
*
|
|
* IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
|
|
* per-chunk defaults will be honored. If you want to preserve the current
|
|
* behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
|
|
* as the default - if you don't do this libpng 1.6 will issue a warning.
|
|
*
|
|
* If you want unhandled unknown chunks to be discarded in libpng 1.6 and
|
|
* earlier simply return '1' (handled).
|
|
*
|
|
* PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
|
|
* If this is *not* set known chunks will always be handled by libpng and
|
|
* will never be stored in the unknown chunk list. Known chunks listed to
|
|
* png_set_keep_unknown_chunks will have no effect. If it is set then known
|
|
* chunks listed with a keep other than AS_DEFAULT will *never* be processed
|
|
* by libpng, in addition critical chunks must either be processed by the
|
|
* callback or saved.
|
|
*
|
|
* The IHDR and IEND chunks must not be listed. Because this turns off the
|
|
* default handling for chunks that would otherwise be recognized the
|
|
* behavior of libpng transformations may well become incorrect!
|
|
*
|
|
* WRITE:
|
|
* When writing chunks the options only apply to the chunks specified by
|
|
* png_set_unknown_chunks (below), libpng will *always* write known chunks
|
|
* required by png_set_ calls and will always write the core critical chunks
|
|
* (as required for PLTE).
|
|
*
|
|
* Each chunk in the png_set_unknown_chunks list is looked up in the
|
|
* png_set_keep_unknown_chunks list to find the keep setting, this is then
|
|
* interpreted as follows:
|
|
*
|
|
* PNG_HANDLE_CHUNK_AS_DEFAULT:
|
|
* Write safe-to-copy chunks and write other chunks if the global
|
|
* default is set to _ALWAYS, otherwise don't write this chunk.
|
|
* PNG_HANDLE_CHUNK_NEVER:
|
|
* Do not write the chunk.
|
|
* PNG_HANDLE_CHUNK_IF_SAFE:
|
|
* Write the chunk if it is safe-to-copy, otherwise do not write it.
|
|
* PNG_HANDLE_CHUNK_ALWAYS:
|
|
* Write the chunk.
|
|
*
|
|
* Note that the default behavior is effectively the opposite of the read case -
|
|
* in read unknown chunks are not stored by default, in write they are written
|
|
* by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
|
|
* - on write the safe-to-copy bit is checked, on read the critical bit is
|
|
* checked and on read if the chunk is critical an error will be raised.
|
|
*
|
|
* num_chunks:
|
|
* ===========
|
|
* If num_chunks is positive, then the "keep" parameter specifies the manner
|
|
* for handling only those chunks appearing in the chunk_list array,
|
|
* otherwise the chunk list array is ignored.
|
|
*
|
|
* If num_chunks is 0 the "keep" parameter specifies the default behavior for
|
|
* unknown chunks, as described above.
|
|
*
|
|
* If num_chunks is negative, then the "keep" parameter specifies the manner
|
|
* for handling all unknown chunks plus all chunks recognized by libpng
|
|
* except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
|
|
* be processed by libpng.
|
|
*/
|
|
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
|
|
PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
|
|
int keep, png_const_bytep chunk_list, int num_chunks));
|
|
#endif /* HANDLE_AS_UNKNOWN */
|
|
|
|
/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
|
|
* the result is therefore true (non-zero) if special handling is required,
|
|
* false for the default handling.
|
|
*/
|
|
PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
|
|
png_const_bytep chunk_name));
|
|
#endif /* SET_UNKNOWN_CHUNKS */
|
|
|
|
#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
|
|
PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_const_unknown_chunkp unknowns,
|
|
int num_unknowns));
|
|
/* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
|
|
* unknowns to the location currently stored in the png_struct. This is
|
|
* invariably the wrong value on write. To fix this call the following API
|
|
* for each chunk in the list with the correct location. If you know your
|
|
* code won't be compiled on earlier versions you can rely on
|
|
* png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
|
|
* the correct thing.
|
|
*/
|
|
|
|
PNG_EXPORT(175, void, png_set_unknown_chunk_location,
|
|
(png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
|
|
|
|
PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, png_unknown_chunkpp entries));
|
|
#endif
|
|
|
|
/* Png_free_data() will turn off the "valid" flag for anything it frees.
|
|
* If you need to turn it off for a chunk that your application has freed,
|
|
* you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
|
|
*/
|
|
PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
|
|
png_inforp info_ptr, int mask));
|
|
|
|
#ifdef PNG_INFO_IMAGE_SUPPORTED
|
|
/* The "params" pointer is currently not used and is for future expansion. */
|
|
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
|
|
PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
|
|
int transforms, png_voidp params));
|
|
#endif
|
|
#ifdef PNG_WRITE_SUPPORTED
|
|
PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
|
|
int transforms, png_voidp params));
|
|
#endif
|
|
#endif
|
|
|
|
PNG_EXPORT(180, png_const_charp, png_get_copyright,
|
|
(png_const_structrp png_ptr));
|
|
PNG_EXPORT(181, png_const_charp, png_get_header_ver,
|
|
(png_const_structrp png_ptr));
|
|
PNG_EXPORT(182, png_const_charp, png_get_header_version,
|
|
(png_const_structrp png_ptr));
|
|
PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
|
|
(png_const_structrp png_ptr));
|
|
|
|
#ifdef PNG_MNG_FEATURES_SUPPORTED
|
|
PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
|
|
png_uint_32 mng_features_permitted));
|
|
#endif
|
|
|
|
/* For use in png_set_keep_unknown, added to version 1.2.6 */
|
|
#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
|
|
#define PNG_HANDLE_CHUNK_NEVER 1
|
|
#define PNG_HANDLE_CHUNK_IF_SAFE 2
|
|
#define PNG_HANDLE_CHUNK_ALWAYS 3
|
|
#define PNG_HANDLE_CHUNK_LAST 4
|
|
|
|
/* Strip the prepended error numbers ("#nnn ") from error and warning
|
|
* messages before passing them to the error or warning handler.
|
|
*/
|
|
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
|
|
PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
|
|
png_uint_32 strip_mode));
|
|
#endif
|
|
|
|
/* Added in libpng-1.2.6 */
|
|
#ifdef PNG_SET_USER_LIMITS_SUPPORTED
|
|
PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
|
|
png_uint_32 user_width_max, png_uint_32 user_height_max));
|
|
PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
|
|
(png_const_structrp png_ptr));
|
|
PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
|
|
(png_const_structrp png_ptr));
|
|
/* Added in libpng-1.4.0 */
|
|
PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
|
|
png_uint_32 user_chunk_cache_max));
|
|
PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
|
|
(png_const_structrp png_ptr));
|
|
/* Added in libpng-1.4.1 */
|
|
PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
|
|
png_alloc_size_t user_chunk_cache_max));
|
|
PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
|
|
(png_const_structrp png_ptr));
|
|
#endif
|
|
|
|
#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
|
|
PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
|
|
PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
|
|
PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr));
|
|
|
|
PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr))
|
|
#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
|
|
PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr))
|
|
#endif
|
|
|
|
PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr))
|
|
#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
|
|
PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
|
|
(png_const_structrp png_ptr, png_const_inforp info_ptr))
|
|
#endif
|
|
|
|
# ifdef PNG_pHYs_SUPPORTED
|
|
PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
|
|
png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
|
|
int *unit_type));
|
|
# endif /* pHYs */
|
|
#endif /* INCH_CONVERSIONS */
|
|
|
|
/* Added in libpng-1.4.0 */
|
|
#ifdef PNG_IO_STATE_SUPPORTED
|
|
PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
|
|
|
|
/* Removed from libpng 1.6; use png_get_io_chunk_type. */
|
|
PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
|
|
PNG_DEPRECATED)
|
|
|
|
PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
|
|
(png_const_structrp png_ptr));
|
|
|
|
/* The flags returned by png_get_io_state() are the following: */
|
|
# define PNG_IO_NONE 0x0000 /* no I/O at this moment */
|
|
# define PNG_IO_READING 0x0001 /* currently reading */
|
|
# define PNG_IO_WRITING 0x0002 /* currently writing */
|
|
# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
|
|
# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
|
|
# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
|
|
# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
|
|
# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
|
|
# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
|
|
#endif /* IO_STATE */
|
|
|
|
/* Interlace support. The following macros are always defined so that if
|
|
* libpng interlace handling is turned off the macros may be used to handle
|
|
* interlaced images within the application.
|
|
*/
|
|
#define PNG_INTERLACE_ADAM7_PASSES 7
|
|
|
|
/* Two macros to return the first row and first column of the original,
|
|
* full, image which appears in a given pass. 'pass' is in the range 0
|
|
* to 6 and the result is in the range 0 to 7.
|
|
*/
|
|
#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
|
|
#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
|
|
|
|
/* A macro to return the offset between pixels in the output row for a pair of
|
|
* pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
|
|
* follows. Note that ROW_OFFSET is the offset from one row to the next whereas
|
|
* COL_OFFSET is from one column to the next, within a row.
|
|
*/
|
|
#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
|
|
#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
|
|
|
|
/* Two macros to help evaluate the number of rows or columns in each
|
|
* pass. This is expressed as a shift - effectively log2 of the number or
|
|
* rows or columns in each 8x8 tile of the original image.
|
|
*/
|
|
#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
|
|
#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
|
|
|
|
/* Hence two macros to determine the number of rows or columns in a given
|
|
* pass of an image given its height or width. In fact these macros may
|
|
* return non-zero even though the sub-image is empty, because the other
|
|
* dimension may be empty for a small image.
|
|
*/
|
|
#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
|
|
-1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
|
|
#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
|
|
-1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
|
|
|
|
/* For the reader row callbacks (both progressive and sequential) it is
|
|
* necessary to find the row in the output image given a row in an interlaced
|
|
* image, so two more macros:
|
|
*/
|
|
#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
|
|
(((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
|
|
#define PNG_COL_FROM_PASS_COL(x_in, pass) \
|
|
(((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
|
|
|
|
/* Two macros which return a boolean (0 or 1) saying whether the given row
|
|
* or column is in a particular pass. These use a common utility macro that
|
|
* returns a mask for a given pass - the offset 'off' selects the row or
|
|
* column version. The mask has the appropriate bit set for each column in
|
|
* the tile.
|
|
*/
|
|
#define PNG_PASS_MASK(pass,off) ( \
|
|
((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
|
|
((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
|
|
|
|
#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
|
|
((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
|
|
#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
|
|
((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
|
|
|
|
#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
|
|
/* With these routines we avoid an integer divide, which will be slower on
|
|
* most machines. However, it does take more operations than the corresponding
|
|
* divide method, so it may be slower on a few RISC systems. There are two
|
|
* shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
|
|
*
|
|
* Note that the rounding factors are NOT supposed to be the same! 128 and
|
|
* 32768 are correct for the NODIV code; 127 and 32767 are correct for the
|
|
* standard method.
|
|
*
|
|
* [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
|
|
*/
|
|
|
|
/* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
|
|
|
|
# define png_composite(composite, fg, alpha, bg) \
|
|
{ \
|
|
png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
|
|
* (png_uint_16)(alpha) \
|
|
+ (png_uint_16)(bg)*(png_uint_16)(255 \
|
|
- (png_uint_16)(alpha)) + 128); \
|
|
(composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
|
|
}
|
|
|
|
# define png_composite_16(composite, fg, alpha, bg) \
|
|
{ \
|
|
png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
|
|
* (png_uint_32)(alpha) \
|
|
+ (png_uint_32)(bg)*(65535 \
|
|
- (png_uint_32)(alpha)) + 32768); \
|
|
(composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
|
|
}
|
|
|
|
#else /* Standard method using integer division */
|
|
|
|
# define png_composite(composite, fg, alpha, bg) \
|
|
(composite) = \
|
|
(png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
|
|
(png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
|
|
127) / 255))
|
|
|
|
# define png_composite_16(composite, fg, alpha, bg) \
|
|
(composite) = \
|
|
(png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
|
|
(png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
|
|
32767) / 65535))
|
|
#endif /* READ_COMPOSITE_NODIV */
|
|
|
|
#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
|
|
PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
|
|
PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
|
|
PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
|
|
#endif
|
|
|
|
PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
|
|
png_const_bytep buf));
|
|
/* No png_get_int_16 -- may be added if there's a real need for it. */
|
|
|
|
/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
|
|
#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
|
|
PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
|
|
#endif
|
|
#ifdef PNG_SAVE_INT_32_SUPPORTED
|
|
PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
|
|
#endif
|
|
|
|
/* Place a 16-bit number into a buffer in PNG byte order.
|
|
* The parameter is declared unsigned int, not png_uint_16,
|
|
* just to avoid potential problems on pre-ANSI C compilers.
|
|
*/
|
|
#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
|
|
PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
|
|
/* No png_save_int_16 -- may be added if there's a real need for it. */
|
|
#endif
|
|
|
|
#ifdef PNG_USE_READ_MACROS
|
|
/* Inline macros to do direct reads of bytes from the input buffer.
|
|
* The png_get_int_32() routine assumes we are using two's complement
|
|
* format for negative values, which is almost certainly true.
|
|
*/
|
|
# define PNG_get_uint_32(buf) \
|
|
(((png_uint_32)(*(buf)) << 24) + \
|
|
((png_uint_32)(*((buf) + 1)) << 16) + \
|
|
((png_uint_32)(*((buf) + 2)) << 8) + \
|
|
((png_uint_32)(*((buf) + 3))))
|
|
|
|
/* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
|
|
* function) incorrectly returned a value of type png_uint_32.
|
|
*/
|
|
# define PNG_get_uint_16(buf) \
|
|
((png_uint_16) \
|
|
(((unsigned int)(*(buf)) << 8) + \
|
|
((unsigned int)(*((buf) + 1)))))
|
|
|
|
# define PNG_get_int_32(buf) \
|
|
((png_int_32)((*(buf) & 0x80) \
|
|
? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
|
|
: (png_int_32)png_get_uint_32(buf)))
|
|
|
|
/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
|
|
* but defining a macro name prefixed with PNG_PREFIX.
|
|
*/
|
|
# ifndef PNG_PREFIX
|
|
# define png_get_uint_32(buf) PNG_get_uint_32(buf)
|
|
# define png_get_uint_16(buf) PNG_get_uint_16(buf)
|
|
# define png_get_int_32(buf) PNG_get_int_32(buf)
|
|
# endif
|
|
#else
|
|
# ifdef PNG_PREFIX
|
|
/* No macros; revert to the (redefined) function */
|
|
# define PNG_get_uint_32 (png_get_uint_32)
|
|
# define PNG_get_uint_16 (png_get_uint_16)
|
|
# define PNG_get_int_32 (png_get_int_32)
|
|
# endif
|
|
#endif
|
|
|
|
#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
|
|
PNG_EXPORT(242, void, png_set_check_for_invalid_index,
|
|
(png_structrp png_ptr, int allowed));
|
|
# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
|
|
PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
|
|
png_const_infop info_ptr));
|
|
# endif
|
|
#endif /* CHECK_FOR_INVALID_INDEX */
|
|
|
|
/*******************************************************************************
|
|
* Section 5: SIMPLIFIED API
|
|
*******************************************************************************
|
|
*
|
|
* Please read the documentation in libpng-manual.txt (TODO: write said
|
|
* documentation) if you don't understand what follows.
|
|
*
|
|
* The simplified API hides the details of both libpng and the PNG file format
|
|
* itself. It allows PNG files to be read into a very limited number of
|
|
* in-memory bitmap formats or to be written from the same formats. If these
|
|
* formats do not accommodate your needs then you can, and should, use the more
|
|
* sophisticated APIs above - these support a wide variety of in-memory formats
|
|
* and a wide variety of sophisticated transformations to those formats as well
|
|
* as a wide variety of APIs to manipulate ancillary information.
|
|
*
|
|
* To read a PNG file using the simplified API:
|
|
*
|
|
* 1) Declare a 'png_image' structure (see below) on the stack, set the
|
|
* version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
|
|
* (this is REQUIRED, your program may crash if you don't do it.)
|
|
* 2) Call the appropriate png_image_begin_read... function.
|
|
* 3) Set the png_image 'format' member to the required sample format.
|
|
* 4) Allocate a buffer for the image and, if required, the color-map.
|
|
* 5) Call png_image_finish_read to read the image and, if required, the
|
|
* color-map into your buffers.
|
|
*
|
|
* There are no restrictions on the format of the PNG input itself; all valid
|
|
* color types, bit depths, and interlace methods are acceptable, and the
|
|
* input image is transformed as necessary to the requested in-memory format
|
|
* during the png_image_finish_read() step. The only caveat is that if you
|
|
* request a color-mapped image from a PNG that is full-color or makes
|
|
* complex use of an alpha channel the transformation is extremely lossy and the
|
|
* result may look terrible.
|
|
*
|
|
* To write a PNG file using the simplified API:
|
|
*
|
|
* 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
|
|
* 2) Initialize the members of the structure that describe the image, setting
|
|
* the 'format' member to the format of the image samples.
|
|
* 3) Call the appropriate png_image_write... function with a pointer to the
|
|
* image and, if necessary, the color-map to write the PNG data.
|
|
*
|
|
* png_image is a structure that describes the in-memory format of an image
|
|
* when it is being read or defines the in-memory format of an image that you
|
|
* need to write:
|
|
*/
|
|
#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
|
|
defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
|
|
|
|
#define PNG_IMAGE_VERSION 1
|
|
|
|
typedef struct png_control *png_controlp;
|
|
typedef struct
|
|
{
|
|
png_controlp opaque; /* Initialize to NULL, free with png_image_free */
|
|
png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
|
|
png_uint_32 width; /* Image width in pixels (columns) */
|
|
png_uint_32 height; /* Image height in pixels (rows) */
|
|
png_uint_32 format; /* Image format as defined below */
|
|
png_uint_32 flags; /* A bit mask containing informational flags */
|
|
png_uint_32 colormap_entries;
|
|
/* Number of entries in the color-map */
|
|
|
|
/* In the event of an error or warning the following field will be set to a
|
|
* non-zero value and the 'message' field will contain a '\0' terminated
|
|
* string with the libpng error or warning message. If both warnings and
|
|
* an error were encountered, only the error is recorded. If there
|
|
* are multiple warnings, only the first one is recorded.
|
|
*
|
|
* The upper 30 bits of this value are reserved, the low two bits contain
|
|
* a value as follows:
|
|
*/
|
|
# define PNG_IMAGE_WARNING 1
|
|
# define PNG_IMAGE_ERROR 2
|
|
/*
|
|
* The result is a two-bit code such that a value more than 1 indicates
|
|
* a failure in the API just called:
|
|
*
|
|
* 0 - no warning or error
|
|
* 1 - warning
|
|
* 2 - error
|
|
* 3 - error preceded by warning
|
|
*/
|
|
# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
|
|
|
|
png_uint_32 warning_or_error;
|
|
|
|
char message[64];
|
|
} png_image, *png_imagep;
|
|
|
|
/* The samples of the image have one to four channels whose components have
|
|
* original values in the range 0 to 1.0:
|
|
*
|
|
* 1: A single gray or luminance channel (G).
|
|
* 2: A gray/luminance channel and an alpha channel (GA).
|
|
* 3: Three red, green, blue color channels (RGB).
|
|
* 4: Three color channels and an alpha channel (RGBA).
|
|
*
|
|
* The components are encoded in one of two ways:
|
|
*
|
|
* a) As a small integer, value 0..255, contained in a single byte. For the
|
|
* alpha channel the original value is simply value/255. For the color or
|
|
* luminance channels the value is encoded according to the sRGB specification
|
|
* and matches the 8-bit format expected by typical display devices.
|
|
*
|
|
* The color/gray channels are not scaled (pre-multiplied) by the alpha
|
|
* channel and are suitable for passing to color management software.
|
|
*
|
|
* b) As a value in the range 0..65535, contained in a 2-byte integer. All
|
|
* channels can be converted to the original value by dividing by 65535; all
|
|
* channels are linear. Color channels use the RGB encoding (RGB end-points) of
|
|
* the sRGB specification. This encoding is identified by the
|
|
* PNG_FORMAT_FLAG_LINEAR flag below.
|
|
*
|
|
* When the simplified API needs to convert between sRGB and linear colorspaces,
|
|
* the actual sRGB transfer curve defined in the sRGB specification (see the
|
|
* article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2
|
|
* approximation used elsewhere in libpng.
|
|
*
|
|
* When an alpha channel is present it is expected to denote pixel coverage
|
|
* of the color or luminance channels and is returned as an associated alpha
|
|
* channel: the color/gray channels are scaled (pre-multiplied) by the alpha
|
|
* value.
|
|
*
|
|
* The samples are either contained directly in the image data, between 1 and 8
|
|
* bytes per pixel according to the encoding, or are held in a color-map indexed
|
|
* by bytes in the image data. In the case of a color-map the color-map entries
|
|
* are individual samples, encoded as above, and the image data has one byte per
|
|
* pixel to select the relevant sample from the color-map.
|
|
*/
|
|
|
|
/* PNG_FORMAT_*
|
|
*
|
|
* #defines to be used in png_image::format. Each #define identifies a
|
|
* particular layout of sample data and, if present, alpha values. There are
|
|
* separate defines for each of the two component encodings.
|
|
*
|
|
* A format is built up using single bit flag values. All combinations are
|
|
* valid. Formats can be built up from the flag values or you can use one of
|
|
* the predefined values below. When testing formats always use the FORMAT_FLAG
|
|
* macros to test for individual features - future versions of the library may
|
|
* add new flags.
|
|
*
|
|
* When reading or writing color-mapped images the format should be set to the
|
|
* format of the entries in the color-map then png_image_{read,write}_colormap
|
|
* called to read or write the color-map and set the format correctly for the
|
|
* image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
|
|
*
|
|
* NOTE: libpng can be built with particular features disabled. If you see
|
|
* compiler errors because the definition of one of the following flags has been
|
|
* compiled out it is because libpng does not have the required support. It is
|
|
* possible, however, for the libpng configuration to enable the format on just
|
|
* read or just write; in that case you may see an error at run time. You can
|
|
* guard against this by checking for the definition of the appropriate
|
|
* "_SUPPORTED" macro, one of:
|
|
*
|
|
* PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
|
|
*/
|
|
#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
|
|
#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
|
|
#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
|
|
#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
|
|
|
|
#ifdef PNG_FORMAT_BGR_SUPPORTED
|
|
# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
|
|
#endif
|
|
|
|
#ifdef PNG_FORMAT_AFIRST_SUPPORTED
|
|
# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
|
|
#endif
|
|
|
|
#define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
|
|
|
|
/* Commonly used formats have predefined macros.
|
|
*
|
|
* First the single byte (sRGB) formats:
|
|
*/
|
|
#define PNG_FORMAT_GRAY 0
|
|
#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
|
|
#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
|
|
#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
|
|
#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
|
|
#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
|
|
#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
|
|
#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
|
|
#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
|
|
|
|
/* Then the linear 2-byte formats. When naming these "Y" is used to
|
|
* indicate a luminance (gray) channel.
|
|
*/
|
|
#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
|
|
#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
|
|
#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
|
|
#define PNG_FORMAT_LINEAR_RGB_ALPHA \
|
|
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
|
|
|
|
/* With color-mapped formats the image data is one byte for each pixel, the byte
|
|
* is an index into the color-map which is formatted as above. To obtain a
|
|
* color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
|
|
* to one of the above definitions, or you can use one of the definitions below.
|
|
*/
|
|
#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
|
|
#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
|
|
#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
|
|
#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
|
|
#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
|
|
#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
|
|
|
|
/* PNG_IMAGE macros
|
|
*
|
|
* These are convenience macros to derive information from a png_image
|
|
* structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
|
|
* actual image sample values - either the entries in the color-map or the
|
|
* pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
|
|
* for the pixels and will always return 1 for color-mapped formats. The
|
|
* remaining macros return information about the rows in the image and the
|
|
* complete image.
|
|
*
|
|
* NOTE: All the macros that take a png_image::format parameter are compile time
|
|
* constants if the format parameter is, itself, a constant. Therefore these
|
|
* macros can be used in array declarations and case labels where required.
|
|
* Similarly the macros are also pre-processor constants (sizeof is not used) so
|
|
* they can be used in #if tests.
|
|
*
|
|
* First the information about the samples.
|
|
*/
|
|
#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
|
|
(((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
|
|
/* Return the total number of channels in a given format: 1..4 */
|
|
|
|
#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
|
|
((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
|
|
/* Return the size in bytes of a single component of a pixel or color-map
|
|
* entry (as appropriate) in the image: 1 or 2.
|
|
*/
|
|
|
|
#define PNG_IMAGE_SAMPLE_SIZE(fmt)\
|
|
(PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
|
|
/* This is the size of the sample data for one sample. If the image is
|
|
* color-mapped it is the size of one color-map entry (and image pixels are
|
|
* one byte in size), otherwise it is the size of one image pixel.
|
|
*/
|
|
|
|
#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
|
|
(PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
|
|
/* The maximum size of the color-map required by the format expressed in a
|
|
* count of components. This can be used to compile-time allocate a
|
|
* color-map:
|
|
*
|
|
* png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
|
|
*
|
|
* png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
|
|
*
|
|
* Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
|
|
* information from one of the png_image_begin_read_ APIs and dynamically
|
|
* allocate the required memory.
|
|
*/
|
|
|
|
/* Corresponding information about the pixels */
|
|
#define PNG_IMAGE_PIXEL_(test,fmt)\
|
|
(((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
|
|
|
|
#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
|
|
PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
|
|
/* The number of separate channels (components) in a pixel; 1 for a
|
|
* color-mapped image.
|
|
*/
|
|
|
|
#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
|
|
PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
|
|
/* The size, in bytes, of each component in a pixel; 1 for a color-mapped
|
|
* image.
|
|
*/
|
|
|
|
#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
|
|
/* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
|
|
|
|
/* Information about the whole row, or whole image */
|
|
#define PNG_IMAGE_ROW_STRIDE(image)\
|
|
(PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
|
|
/* Return the total number of components in a single row of the image; this
|
|
* is the minimum 'row stride', the minimum count of components between each
|
|
* row. For a color-mapped image this is the minimum number of bytes in a
|
|
* row.
|
|
*
|
|
* WARNING: this macro overflows for some images with more than one component
|
|
* and very large image widths. libpng will refuse to process an image where
|
|
* this macro would overflow.
|
|
*/
|
|
|
|
#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
|
|
(PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
|
|
/* Return the size, in bytes, of an image buffer given a png_image and a row
|
|
* stride - the number of components to leave space for in each row.
|
|
*
|
|
* WARNING: this macro overflows a 32-bit integer for some large PNG images,
|
|
* libpng will refuse to process an image where such an overflow would occur.
|
|
*/
|
|
|
|
#define PNG_IMAGE_SIZE(image)\
|
|
PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
|
|
/* Return the size, in bytes, of the image in memory given just a png_image;
|
|
* the row stride is the minimum stride required for the image.
|
|
*/
|
|
|
|
#define PNG_IMAGE_COLORMAP_SIZE(image)\
|
|
(PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
|
|
/* Return the size, in bytes, of the color-map of this image. If the image
|
|
* format is not a color-map format this will return a size sufficient for
|
|
* 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
|
|
* you don't want to allocate a color-map in this case.
|
|
*/
|
|
|
|
/* PNG_IMAGE_FLAG_*
|
|
*
|
|
* Flags containing additional information about the image are held in the
|
|
* 'flags' field of png_image.
|
|
*/
|
|
#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
|
|
/* This indicates that the RGB values of the in-memory bitmap do not
|
|
* correspond to the red, green and blue end-points defined by sRGB.
|
|
*/
|
|
|
|
#define PNG_IMAGE_FLAG_FAST 0x02
|
|
/* On write emphasise speed over compression; the resultant PNG file will be
|
|
* larger but will be produced significantly faster, particular for large
|
|
* images. Do not use this option for images which will be distributed, only
|
|
* used it when producing intermediate files that will be read back in
|
|
* repeatedly. For a typical 24-bit image the option will double the read
|
|
* speed at the cost of increasing the image size by 25%, however for many
|
|
* more compressible images the PNG file can be 10 times larger with only a
|
|
* slight speed gain.
|
|
*/
|
|
|
|
#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
|
|
/* On read if the image is a 16-bit per component image and there is no gAMA
|
|
* or sRGB chunk assume that the components are sRGB encoded. Notice that
|
|
* images output by the simplified API always have gamma information; setting
|
|
* this flag only affects the interpretation of 16-bit images from an
|
|
* external source. It is recommended that the application expose this flag
|
|
* to the user; the user can normally easily recognize the difference between
|
|
* linear and sRGB encoding. This flag has no effect on write - the data
|
|
* passed to the write APIs must have the correct encoding (as defined
|
|
* above.)
|
|
*
|
|
* If the flag is not set (the default) input 16-bit per component data is
|
|
* assumed to be linear.
|
|
*
|
|
* NOTE: the flag can only be set after the png_image_begin_read_ call,
|
|
* because that call initializes the 'flags' field.
|
|
*/
|
|
|
|
#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
|
|
/* READ APIs
|
|
* ---------
|
|
*
|
|
* The png_image passed to the read APIs must have been initialized by setting
|
|
* the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
|
|
*/
|
|
#ifdef PNG_STDIO_SUPPORTED
|
|
PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
|
|
const char *file_name));
|
|
/* The named file is opened for read and the image header is filled in
|
|
* from the PNG header in the file.
|
|
*/
|
|
|
|
PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
|
|
FILE* file));
|
|
/* The PNG header is read from the stdio FILE object. */
|
|
#endif /* STDIO */
|
|
|
|
PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
|
|
png_const_voidp memory, size_t size));
|
|
/* The PNG header is read from the given memory buffer. */
|
|
|
|
PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
|
|
png_const_colorp background, void *buffer, png_int_32 row_stride,
|
|
void *colormap));
|
|
/* Finish reading the image into the supplied buffer and clean up the
|
|
* png_image structure.
|
|
*
|
|
* row_stride is the step, in byte or 2-byte units as appropriate,
|
|
* between adjacent rows. A positive stride indicates that the top-most row
|
|
* is first in the buffer - the normal top-down arrangement. A negative
|
|
* stride indicates that the bottom-most row is first in the buffer.
|
|
*
|
|
* background need only be supplied if an alpha channel must be removed from
|
|
* a png_byte format and the removal is to be done by compositing on a solid
|
|
* color; otherwise it may be NULL and any composition will be done directly
|
|
* onto the buffer. The value is an sRGB color to use for the background,
|
|
* for grayscale output the green channel is used.
|
|
*
|
|
* background must be supplied when an alpha channel must be removed from a
|
|
* single byte color-mapped output format, in other words if:
|
|
*
|
|
* 1) The original format from png_image_begin_read_from_* had
|
|
* PNG_FORMAT_FLAG_ALPHA set.
|
|
* 2) The format set by the application does not.
|
|
* 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
|
|
* PNG_FORMAT_FLAG_LINEAR *not* set.
|
|
*
|
|
* For linear output removing the alpha channel is always done by compositing
|
|
* on black and background is ignored.
|
|
*
|
|
* colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
|
|
* be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
|
|
* image->colormap_entries will be updated to the actual number of entries
|
|
* written to the colormap; this may be less than the original value.
|
|
*/
|
|
|
|
PNG_EXPORT(238, void, png_image_free, (png_imagep image));
|
|
/* Free any data allocated by libpng in image->opaque, setting the pointer to
|
|
* NULL. May be called at any time after the structure is initialized.
|
|
*/
|
|
#endif /* SIMPLIFIED_READ */
|
|
|
|
#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
|
|
/* WRITE APIS
|
|
* ----------
|
|
* For write you must initialize a png_image structure to describe the image to
|
|
* be written. To do this use memset to set the whole structure to 0 then
|
|
* initialize fields describing your image.
|
|
*
|
|
* version: must be set to PNG_IMAGE_VERSION
|
|
* opaque: must be initialized to NULL
|
|
* width: image width in pixels
|
|
* height: image height in rows
|
|
* format: the format of the data (image and color-map) you wish to write
|
|
* flags: set to 0 unless one of the defined flags applies; set
|
|
* PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
|
|
* values do not correspond to the colors in sRGB.
|
|
* colormap_entries: set to the number of entries in the color-map (0 to 256)
|
|
*/
|
|
#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
|
|
PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
|
|
const char *file, int convert_to_8bit, const void *buffer,
|
|
png_int_32 row_stride, const void *colormap));
|
|
/* Write the image to the named file. */
|
|
|
|
PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
|
|
int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
|
|
const void *colormap));
|
|
/* Write the image to the given (FILE*). */
|
|
#endif /* SIMPLIFIED_WRITE_STDIO */
|
|
|
|
/* With all write APIs if image is in one of the linear formats with 16-bit
|
|
* data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
|
|
* gamma encoded according to the sRGB specification, otherwise a 16-bit linear
|
|
* encoded PNG file is written.
|
|
*
|
|
* With color-mapped data formats the colormap parameter point to a color-map
|
|
* with at least image->colormap_entries encoded in the specified format. If
|
|
* the format is linear the written PNG color-map will be converted to sRGB
|
|
* regardless of the convert_to_8_bit flag.
|
|
*
|
|
* With all APIs row_stride is handled as in the read APIs - it is the spacing
|
|
* from one row to the next in component sized units (1 or 2 bytes) and if
|
|
* negative indicates a bottom-up row layout in the buffer. If row_stride is
|
|
* zero, libpng will calculate it for you from the image width and number of
|
|
* channels.
|
|
*
|
|
* Note that the write API does not support interlacing, sub-8-bit pixels or
|
|
* most ancillary chunks. If you need to write text chunks (e.g. for copyright
|
|
* notices) you need to use one of the other APIs.
|
|
*/
|
|
|
|
PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
|
|
png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
|
|
const void *buffer, png_int_32 row_stride, const void *colormap));
|
|
/* Write the image to the given memory buffer. The function both writes the
|
|
* whole PNG data stream to *memory and updates *memory_bytes with the count
|
|
* of bytes written.
|
|
*
|
|
* 'memory' may be NULL. In this case *memory_bytes is not read however on
|
|
* success the number of bytes which would have been written will still be
|
|
* stored in *memory_bytes. On failure *memory_bytes will contain 0.
|
|
*
|
|
* If 'memory' is not NULL it must point to memory[*memory_bytes] of
|
|
* writeable memory.
|
|
*
|
|
* If the function returns success memory[*memory_bytes] (if 'memory' is not
|
|
* NULL) contains the written PNG data. *memory_bytes will always be less
|
|
* than or equal to the original value.
|
|
*
|
|
* If the function returns false and *memory_bytes was not changed an error
|
|
* occurred during write. If *memory_bytes was changed, or is not 0 if
|
|
* 'memory' was NULL, the write would have succeeded but for the memory
|
|
* buffer being too small. *memory_bytes contains the required number of
|
|
* bytes and will be bigger that the original value.
|
|
*/
|
|
|
|
#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
|
|
row_stride, colormap)\
|
|
png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
|
|
row_stride, colormap)
|
|
/* Return the amount of memory in 'size' required to compress this image.
|
|
* The png_image structure 'image' must be filled in as in the above
|
|
* function and must not be changed before the actual write call, the buffer
|
|
* and all other parameters must also be identical to that in the final
|
|
* write call. The 'size' variable need not be initialized.
|
|
*
|
|
* NOTE: the macro returns true/false, if false is returned 'size' will be
|
|
* set to zero and the write failed and probably will fail if tried again.
|
|
*/
|
|
|
|
/* You can pre-allocate the buffer by making sure it is of sufficient size
|
|
* regardless of the amount of compression achieved. The buffer size will
|
|
* always be bigger than the original image and it will never be filled. The
|
|
* following macros are provided to assist in allocating the buffer.
|
|
*/
|
|
#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
|
|
/* The number of uncompressed bytes in the PNG byte encoding of the image;
|
|
* uncompressing the PNG IDAT data will give this number of bytes.
|
|
*
|
|
* NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
|
|
* macro can because of the extra bytes used in the PNG byte encoding. You
|
|
* need to avoid this macro if your image size approaches 2^30 in width or
|
|
* height. The same goes for the remainder of these macros; they all produce
|
|
* bigger numbers than the actual in-memory image size.
|
|
*/
|
|
#ifndef PNG_ZLIB_MAX_SIZE
|
|
# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
|
|
/* An upper bound on the number of compressed bytes given 'b' uncompressed
|
|
* bytes. This is based on deflateBounds() in zlib; different
|
|
* implementations of zlib compression may conceivably produce more data so
|
|
* if your zlib implementation is not zlib itself redefine this macro
|
|
* appropriately.
|
|
*/
|
|
#endif
|
|
|
|
#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
|
|
PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
|
|
/* An upper bound on the size of the data in the PNG IDAT chunks. */
|
|
|
|
#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
|
|
((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
|
|
(((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
|
|
12U+3U*(image).colormap_entries/*PLTE data*/+\
|
|
(((image).format&PNG_FORMAT_FLAG_ALPHA)?\
|
|
12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
|
|
12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
|
|
/* A helper for the following macro; if your compiler cannot handle the
|
|
* following macro use this one with the result of
|
|
* PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
|
|
* compilers should handle this just fine.)
|
|
*/
|
|
|
|
#define PNG_IMAGE_PNG_SIZE_MAX(image)\
|
|
PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
|
|
/* An upper bound on the total length of the PNG data stream for 'image'.
|
|
* The result is of type png_alloc_size_t, on 32-bit systems this may
|
|
* overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
|
|
* run out of buffer space but return a corrected size which should work.
|
|
*/
|
|
#endif /* SIMPLIFIED_WRITE */
|
|
/*******************************************************************************
|
|
* END OF SIMPLIFIED API
|
|
******************************************************************************/
|
|
#endif /* SIMPLIFIED_{READ|WRITE} */
|
|
|
|
/*******************************************************************************
|
|
* Section 6: IMPLEMENTATION OPTIONS
|
|
*******************************************************************************
|
|
*
|
|
* Support for arbitrary implementation-specific optimizations. The API allows
|
|
* particular options to be turned on or off. 'Option' is the number of the
|
|
* option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
|
|
* by the PNG_OPTION_ defines below.
|
|
*
|
|
* HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
|
|
* are detected at run time, however sometimes it may be impossible
|
|
* to do this in user mode, in which case it is necessary to discover
|
|
* the capabilities in an OS specific way. Such capabilities are
|
|
* listed here when libpng has support for them and must be turned
|
|
* ON by the application if present.
|
|
*
|
|
* SOFTWARE: sometimes software optimizations actually result in performance
|
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* decrease on some architectures or systems, or with some sets of
|
|
* PNG images. 'Software' options allow such optimizations to be
|
|
* selected at run time.
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|
*/
|
|
#ifdef PNG_SET_OPTION_SUPPORTED
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|
#ifdef PNG_ARM_NEON_API_SUPPORTED
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|
# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
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|
#endif
|
|
#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
|
|
#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
|
|
#ifdef PNG_MIPS_MSA_API_SUPPORTED
|
|
# define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
|
|
#endif
|
|
#define PNG_IGNORE_ADLER32 8
|
|
#ifdef PNG_POWERPC_VSX_API_SUPPORTED
|
|
# define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */
|
|
#endif
|
|
#define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */
|
|
|
|
/* Return values: NOTE: there are four values and 'off' is *not* zero */
|
|
#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
|
|
#define PNG_OPTION_INVALID 1 /* Option number out of range */
|
|
#define PNG_OPTION_OFF 2
|
|
#define PNG_OPTION_ON 3
|
|
|
|
PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
|
|
int onoff));
|
|
#endif /* SET_OPTION */
|
|
|
|
/*******************************************************************************
|
|
* END OF HARDWARE AND SOFTWARE OPTIONS
|
|
******************************************************************************/
|
|
|
|
/* Maintainer: Put new public prototypes here ^, in libpng.3, in project
|
|
* defs, and in scripts/symbols.def.
|
|
*/
|
|
|
|
/* The last ordinal number (this is the *last* one already used; the next
|
|
* one to use is one more than this.)
|
|
*/
|
|
#ifdef PNG_EXPORT_LAST_ORDINAL
|
|
PNG_EXPORT_LAST_ORDINAL(249);
|
|
#endif
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* PNG_VERSION_INFO_ONLY */
|
|
/* Do not put anything past this line */
|
|
#endif /* PNG_H */
|