CoCalc -- pngpriv.h

GitHub Repository: Tetragramm/opencv
Path: blob/master/3rdparty/libpng/pngpriv.h
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/* pngpriv.h - private declarations for use inside libpng
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 *
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 * Last changed in libpng 1.6.32 [August 24, 2017]
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 * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
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 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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 *
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 * This code is released under the libpng license.
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 * For conditions of distribution and use, see the disclaimer
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 * and license in png.h
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 */
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/* The symbols declared in this file (including the functions declared
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 * as extern) are PRIVATE.  They are not part of the libpng public
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 * interface, and are not recommended for use by regular applications.
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 * Some of them may become public in the future; others may stay private,
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 * change in an incompatible way, or even disappear.
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 * Although the libpng users are not forbidden to include this header,
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 * they should be well aware of the issues that may arise from doing so.
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 */
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#ifndef PNGPRIV_H
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#define PNGPRIV_H
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/* Feature Test Macros.  The following are defined here to ensure that correctly
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 * implemented libraries reveal the APIs libpng needs to build and hide those
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 * that are not needed and potentially damaging to the compilation.
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 *
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 * Feature Test Macros must be defined before any system header is included (see
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 * POSIX 1003.1 2.8.2 "POSIX Symbols."
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 *
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 * These macros only have an effect if the operating system supports either
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 * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
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 * Windows/Visual Studio) there is no effect; the OS specific tests below are
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 * still required (as of 2011-05-02.)
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 */
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#ifndef _POSIX_SOURCE
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# define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
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#endif
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#ifndef PNG_VERSION_INFO_ONLY
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/* Standard library headers not required by png.h: */
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#  include <stdlib.h>
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#  include <string.h>
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#endif
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#define PNGLIB_BUILD /*libpng is being built, not used*/
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/* If HAVE_CONFIG_H is defined during the build then the build system must
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 * provide an appropriate "config.h" file on the include path.  The header file
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 * must provide definitions as required below (search for "HAVE_CONFIG_H");
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 * see configure.ac for more details of the requirements.  The macro
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 * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
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 * 'configure'; define this macro to prevent the configure build including the
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 * configure generated config.h.  Libpng is expected to compile without *any*
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 * special build system support on a reasonably ANSI-C compliant system.
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 */
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#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
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#  include <config.h>
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   /* Pick up the definition of 'restrict' from config.h if it was read: */
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#  define PNG_RESTRICT restrict
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#endif
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/* To support symbol prefixing it is necessary to know *before* including png.h
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 * whether the fixed point (and maybe other) APIs are exported, because if they
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 * are not internal definitions may be required.  This is handled below just
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 * before png.h is included, but load the configuration now if it is available.
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 */
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#ifndef PNGLCONF_H
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#  include "pnglibconf.h"
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#endif
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/* Local renames may change non-exported API functions from png.h */
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#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
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#  include "pngprefix.h"
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#endif
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#ifdef PNG_USER_CONFIG
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#  include "pngusr.h"
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   /* These should have been defined in pngusr.h */
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#  ifndef PNG_USER_PRIVATEBUILD
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#    define PNG_USER_PRIVATEBUILD "Custom libpng build"
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#  endif
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#  ifndef PNG_USER_DLLFNAME_POSTFIX
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#    define PNG_USER_DLLFNAME_POSTFIX "Cb"
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#  endif
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#endif
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/* Compile time options.
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 * =====================
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 * In a multi-arch build the compiler may compile the code several times for the
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 * same object module, producing different binaries for different architectures.
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 * When this happens configure-time setting of the target host options cannot be
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 * done and this interferes with the handling of the ARM NEON optimizations, and
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 * possibly other similar optimizations.  Put additional tests here; in general
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 * this is needed when the same option can be changed at both compile time and
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 * run time depending on the target OS (i.e. iOS vs Android.)
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 *
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 * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
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 * this is not possible with certain compilers (Oracle SUN OS CC), as a result
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 * it is necessary to ensure that all extern functions that *might* be used
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 * regardless of $(CFLAGS) get declared in this file.  The test on __ARM_NEON__
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 * below is one example of this behavior because it is controlled by the
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 * presence or not of -mfpu=neon on the GCC command line, it is possible to do
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 * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
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 * do this.
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 */
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#ifndef PNG_ARM_NEON_OPT
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   /* ARM NEON optimizations are being controlled by the compiler settings,
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    * typically the target FPU.  If the FPU has been set to NEON (-mfpu=neon
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    * with GCC) then the compiler will define __ARM_NEON__ and we can rely
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    * unconditionally on NEON instructions not crashing, otherwise we must
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    * disable use of NEON instructions.
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    *
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    * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
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    * can only be turned on automatically if that is supported too.  If
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    * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
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    * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
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    * off.
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    *
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    * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated
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    * __ARM_NEON__, so we check both variants.
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    *
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    * To disable ARM_NEON optimizations entirely, and skip compiling the
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    * associated assembler code, pass --enable-arm-neon=no to configure
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    * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS.
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    */
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#  if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
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   defined(PNG_ALIGNED_MEMORY_SUPPORTED)
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#     define PNG_ARM_NEON_OPT 2
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#  else
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#     define PNG_ARM_NEON_OPT 0
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#  endif
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#endif
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#if PNG_ARM_NEON_OPT > 0
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   /* NEON optimizations are to be at least considered by libpng, so enable the
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    * callbacks to do this.
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    */
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#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
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   /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
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    * if possible - if __ARM_NEON__ is set and the compiler version is not known
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    * to be broken.  This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
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    * be:
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    *
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    *    1  The intrinsics code (the default with __ARM_NEON__)
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    *    2  The hand coded assembler (the default without __ARM_NEON__)
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    *
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    * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
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    * this is *NOT* supported and may cease to work even after a minor revision
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    * to libpng.  It *is* valid to do this for testing purposes, e.g. speed
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    * testing or a new compiler, but the results should be communicated to the
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    * libpng implementation list for incorporation in the next minor release.
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    */
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#  ifndef PNG_ARM_NEON_IMPLEMENTATION
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#     if defined(__ARM_NEON__) || defined(__ARM_NEON)
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#        if defined(__clang__)
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            /* At present it is unknown by the libpng developers which versions
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             * of clang support the intrinsics, however some or perhaps all
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             * versions do not work with the assembler so this may be
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             * irrelevant, so just use the default (do nothing here.)
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             */
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#        elif defined(__GNUC__)
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            /* GCC 4.5.4 NEON support is known to be broken.  4.6.3 is known to
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             * work, so if this *is* GCC, or G++, look for a version >4.5
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             */
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#           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
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#              define PNG_ARM_NEON_IMPLEMENTATION 2
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#           endif /* no GNUC support */
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#        endif /* __GNUC__ */
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#     else /* !defined __ARM_NEON__ */
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         /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
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          */
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#        define PNG_ARM_NEON_IMPLEMENTATION 2
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#     endif /* __ARM_NEON__ */
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#  endif /* !PNG_ARM_NEON_IMPLEMENTATION */
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#  ifndef PNG_ARM_NEON_IMPLEMENTATION
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      /* Use the intrinsics code by default. */
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#     define PNG_ARM_NEON_IMPLEMENTATION 1
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#  endif
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#endif /* PNG_ARM_NEON_OPT > 0 */
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#ifndef PNG_MIPS_MSA_OPT
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#  if defined(__mips_msa) && (__mips_isa_rev >= 5) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
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#     define PNG_MIPS_MSA_OPT 2
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#  else
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#     define PNG_MIPS_MSA_OPT 0
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#  endif
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#endif
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#ifndef PNG_POWERPC_VSX_OPT
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#  if defined(__PPC64__) && defined(__ALTIVEC__) && defined(__VSX__)
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#     define PNG_POWERPC_VSX_OPT 2
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#  else
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#     define PNG_POWERPC_VSX_OPT 0
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#  endif
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#endif
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#ifndef PNG_INTEL_SSE_OPT
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#   ifdef PNG_INTEL_SSE
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      /* Only check for SSE if the build configuration has been modified to
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       * enable SSE optimizations.  This means that these optimizations will
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       * be off by default.  See contrib/intel for more details.
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       */
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#     if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
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       defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
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       (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
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#         define PNG_INTEL_SSE_OPT 1
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#      endif
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#   endif
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#endif
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#if defined(PNG_INTEL_SSE_OPT) && PNG_INTEL_SSE_OPT > 0
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#   ifndef PNG_INTEL_SSE_IMPLEMENTATION
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#      if defined(__SSE4_1__) || defined(__AVX__)
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          /* We are not actually using AVX, but checking for AVX is the best
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             way we can detect SSE4.1 and SSSE3 on MSVC.
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          */
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#         define PNG_INTEL_SSE_IMPLEMENTATION 3
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#      elif defined(__SSSE3__)
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#         define PNG_INTEL_SSE_IMPLEMENTATION 2
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#      elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
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       (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
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#         define PNG_INTEL_SSE_IMPLEMENTATION 1
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#      else
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#         define PNG_INTEL_SSE_IMPLEMENTATION 0
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#      endif
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#   endif
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#   if PNG_INTEL_SSE_IMPLEMENTATION > 0
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#      define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
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#   endif
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#endif
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#if PNG_MIPS_MSA_OPT > 0
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#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_msa
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#  ifndef PNG_MIPS_MSA_IMPLEMENTATION
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#     if defined(__mips_msa)
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#        if defined(__clang__)
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#        elif defined(__GNUC__)
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#           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
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#              define PNG_MIPS_MSA_IMPLEMENTATION 2
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#           endif /* no GNUC support */
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#        endif /* __GNUC__ */
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#     else /* !defined __mips_msa */
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#        define PNG_MIPS_MSA_IMPLEMENTATION 2
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#     endif /* __mips_msa */
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#  endif /* !PNG_MIPS_MSA_IMPLEMENTATION */
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#  ifndef PNG_MIPS_MSA_IMPLEMENTATION
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#     define PNG_MIPS_MSA_IMPLEMENTATION 1
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#  endif
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#endif /* PNG_MIPS_MSA_OPT > 0 */
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#if PNG_POWERPC_VSX_OPT > 0
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#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx
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#  define PNG_POWERPC_VSX_IMPLEMENTATION 1
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#endif
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/* Is this a build of a DLL where compilation of the object modules requires
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 * different preprocessor settings to those required for a simple library?  If
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 * so PNG_BUILD_DLL must be set.
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 *
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 * If libpng is used inside a DLL but that DLL does not export the libpng APIs
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 * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
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 * static library of libpng then link the DLL against that.
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 */
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#ifndef PNG_BUILD_DLL
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#  ifdef DLL_EXPORT
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      /* This is set by libtool when files are compiled for a DLL; libtool
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       * always compiles twice, even on systems where it isn't necessary.  Set
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       * PNG_BUILD_DLL in case it is necessary:
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       */
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#     define PNG_BUILD_DLL
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#  else
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#     ifdef _WINDLL
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         /* This is set by the Microsoft Visual Studio IDE in projects that
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          * build a DLL.  It can't easily be removed from those projects (it
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          * isn't visible in the Visual Studio UI) so it is a fairly reliable
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          * indication that PNG_IMPEXP needs to be set to the DLL export
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          * attributes.
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          */
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#        define PNG_BUILD_DLL
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#     else
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#        ifdef __DLL__
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            /* This is set by the Borland C system when compiling for a DLL
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             * (as above.)
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             */
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#           define PNG_BUILD_DLL
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#        else
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            /* Add additional compiler cases here. */
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#        endif
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#     endif
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#  endif
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#endif /* Setting PNG_BUILD_DLL if required */
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/* See pngconf.h for more details: the builder of the library may set this on
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 * the command line to the right thing for the specific compilation system or it
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 * may be automagically set above (at present we know of no system where it does
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 * need to be set on the command line.)
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 *
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 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
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 * setting it to the "import" setting for a DLL build.
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 */
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#ifndef PNG_IMPEXP
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#  ifdef PNG_BUILD_DLL
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#     define PNG_IMPEXP PNG_DLL_EXPORT
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#  else
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      /* Not building a DLL, or the DLL doesn't require specific export
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       * definitions.
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       */
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#     define PNG_IMPEXP
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#  endif
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#endif
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/* No warnings for private or deprecated functions in the build: */
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#ifndef PNG_DEPRECATED
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#  define PNG_DEPRECATED
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#endif
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#ifndef PNG_PRIVATE
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#  define PNG_PRIVATE
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#endif
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/* Symbol preprocessing support.
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 *
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 * To enable listing global, but internal, symbols the following macros should
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 * always be used to declare an extern data or function object in this file.
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 */
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#ifndef PNG_INTERNAL_DATA
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#  define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array
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#endif
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#ifndef PNG_INTERNAL_FUNCTION
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#  define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
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      PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
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#endif
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#ifndef PNG_INTERNAL_CALLBACK
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#  define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
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      PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\
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         PNG_EMPTY attributes)
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#endif
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/* If floating or fixed point APIs are disabled they may still be compiled
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 * internally.  To handle this make sure they are declared as the appropriate
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 * internal extern function (otherwise the symbol prefixing stuff won't work and
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 * the functions will be used without definitions.)
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 *
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 * NOTE: although all the API functions are declared here they are not all
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 * actually built!  Because the declarations are still made it is necessary to
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 * fake out types that they depend on.
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 */
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#ifndef PNG_FP_EXPORT
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#  ifndef PNG_FLOATING_POINT_SUPPORTED
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#     define PNG_FP_EXPORT(ordinal, type, name, args)\
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         PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
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#     ifndef PNG_VERSION_INFO_ONLY
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         typedef struct png_incomplete png_double;
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         typedef png_double*           png_doublep;
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         typedef const png_double*     png_const_doublep;
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         typedef png_double**          png_doublepp;
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#     endif
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#  endif
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#endif
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#ifndef PNG_FIXED_EXPORT
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#  ifndef PNG_FIXED_POINT_SUPPORTED
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#     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
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         PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
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#  endif
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#endif
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#include "png.h"
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/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
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#ifndef PNG_DLL_EXPORT
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#  define PNG_DLL_EXPORT
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#endif
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/* This is a global switch to set the compilation for an installed system
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 * (a release build).  It can be set for testing debug builds to ensure that
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 * they will compile when the build type is switched to RC or STABLE, the
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 * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE.  Set this in CPPFLAGS
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 * with either:
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 *
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 *   -DPNG_RELEASE_BUILD Turns on the release compile path
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 *   -DPNG_RELEASE_BUILD=0 Turns it off
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 * or in your pngusr.h with
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 *   #define PNG_RELEASE_BUILD=1 Turns on the release compile path
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 *   #define PNG_RELEASE_BUILD=0 Turns it off
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 */
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#ifndef PNG_RELEASE_BUILD
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#  define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
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#endif
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/* SECURITY and SAFETY:
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 *
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 * libpng is built with support for internal limits on image dimensions and
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 * memory usage.  These are documented in scripts/pnglibconf.dfa of the
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 * source and recorded in the machine generated header file pnglibconf.h.
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 */
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/* If you are running on a machine where you cannot allocate more
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 * than 64K of memory at once, uncomment this.  While libpng will not
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 * normally need that much memory in a chunk (unless you load up a very
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 * large file), zlib needs to know how big of a chunk it can use, and
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 * libpng thus makes sure to check any memory allocation to verify it
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 * will fit into memory.
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 *
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 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
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 * same limit and pngconf.h (already included) sets the limit
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 * if certain operating systems are detected.
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 */
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#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
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#  define PNG_MAX_MALLOC_64K
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#endif
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#ifndef PNG_UNUSED
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/* Unused formal parameter warnings are silenced using the following macro
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 * which is expected to have no bad effects on performance (optimizing
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 * compilers will probably remove it entirely).  Note that if you replace
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 * it with something other than whitespace, you must include the terminating
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 * semicolon.
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 */
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#  define PNG_UNUSED(param) (void)param;
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#endif
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/* Just a little check that someone hasn't tried to define something
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 * contradictory.
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 */
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#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
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#  undef PNG_ZBUF_SIZE
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#  define PNG_ZBUF_SIZE 65536L
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#endif
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/* If warnings or errors are turned off the code is disabled or redirected here.
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 * From 1.5.4 functions have been added to allow very limited formatting of
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 * error and warning messages - this code will also be disabled here.
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 */
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#ifdef PNG_WARNINGS_SUPPORTED
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#  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
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#else
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#  define png_warning_parameter(p,number,string) ((void)0)
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#  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
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#  define png_warning_parameter_signed(p,number,format,value) ((void)0)
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#  define png_formatted_warning(pp,p,message) ((void)(pp))
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#  define PNG_WARNING_PARAMETERS(p)
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#endif
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#ifndef PNG_ERROR_TEXT_SUPPORTED
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#  define png_fixed_error(s1,s2) png_err(s1)
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#endif
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/* Some fixed point APIs are still required even if not exported because
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 * they get used by the corresponding floating point APIs.  This magic
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 * deals with this:
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 */
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#ifdef PNG_FIXED_POINT_SUPPORTED
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#  define PNGFAPI PNGAPI
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#else
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#  define PNGFAPI /* PRIVATE */
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#endif
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#ifndef PNG_VERSION_INFO_ONLY
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/* Other defines specific to compilers can go here.  Try to keep
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 * them inside an appropriate ifdef/endif pair for portability.
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 */
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/* C allows up-casts from (void*) to any pointer and (const void*) to any
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 * pointer to a const object.  C++ regards this as a type error and requires an
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 * explicit, static, cast and provides the static_cast<> rune to ensure that
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 * const is not cast away.
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 */
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#ifdef __cplusplus
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#  define png_voidcast(type, value) static_cast<type>(value)
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#  define png_constcast(type, value) const_cast<type>(value)
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#  define png_aligncast(type, value) \
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   static_cast<type>(static_cast<void*>(value))
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#  define png_aligncastconst(type, value) \
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   static_cast<type>(static_cast<const void*>(value))
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#else
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#  define png_voidcast(type, value) (value)
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#  ifdef _WIN64
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#     ifdef __GNUC__
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         typedef unsigned long long png_ptruint;
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#     else
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         typedef unsigned __int64 png_ptruint;
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#     endif
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#  else
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      typedef unsigned long png_ptruint;
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#  endif
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#  define png_constcast(type, value) ((type)(png_ptruint)(const void*)(value))
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#  define png_aligncast(type, value) ((void*)(value))
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#  define png_aligncastconst(type, value) ((const void*)(value))
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#endif /* __cplusplus */
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#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
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    defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
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   /* png.c requires the following ANSI-C constants if the conversion of
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    * floating point to ASCII is implemented therein:
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    *
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    *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
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    *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
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    *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
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    */
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#  include <float.h>
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#  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
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    defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
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   /* We need to check that <math.h> hasn't already been included earlier
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    * as it seems it doesn't agree with <fp.h>, yet we should really use
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    * <fp.h> if possible.
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    */
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#    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
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#      include <fp.h>
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#    endif
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#  else
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#    include <math.h>
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#  endif
523
#  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
524
   /* Amiga SAS/C: We must include builtin FPU functions when compiling using
525
    * MATH=68881
526
    */
527
#    include <m68881.h>
528
#  endif
529
#endif
530

531
/* This provides the non-ANSI (far) memory allocation routines. */
532
#if defined(__TURBOC__) && defined(__MSDOS__)
533
#  include <mem.h>
534
#  include <alloc.h>
535
#endif
536

537
#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
538
    defined(_WIN32) || defined(__WIN32__)
539
#  include <windows.h>  /* defines _WINDOWS_ macro */
540
#endif
541
#endif /* PNG_VERSION_INFO_ONLY */
542

543
/* Moved here around 1.5.0beta36 from pngconf.h */
544
/* Users may want to use these so they are not private.  Any library
545
 * functions that are passed far data must be model-independent.
546
 */
547

548
/* Memory model/platform independent fns */
549
#ifndef PNG_ABORT
550
#  if defined(_WINDOWS_) && !defined(WINRT)
551
#    define PNG_ABORT() ExitProcess(0)
552
#  else
553
#    define PNG_ABORT() abort()
554
#  endif
555
#endif
556

557
/* These macros may need to be architecture dependent. */
558
#define PNG_ALIGN_NONE   0 /* do not use data alignment */
559
#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
560
#ifdef offsetof
561
#  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
562
#else
563
#  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
564
#endif
565
#define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
566

567
#ifndef PNG_ALIGN_TYPE
568
   /* Default to using aligned access optimizations and requiring alignment to a
569
    * multiple of the data type size.  Override in a compiler specific fashion
570
    * if necessary by inserting tests here:
571
    */
572
#  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
573
#endif
574

575
#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
576
   /* This is used because in some compiler implementations non-aligned
577
    * structure members are supported, so the offsetof approach below fails.
578
    * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
579
    * is good for performance.  Do not do this unless you have tested the result
580
    * and understand it.
581
    */
582
#  define png_alignof(type) (sizeof (type))
583
#else
584
#  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
585
#     define png_alignof(type) offsetof(struct{char c; type t;}, t)
586
#  else
587
#     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
588
#        define png_alignof(type) (1)
589
#     endif
590
      /* Else leave png_alignof undefined to prevent use thereof */
591
#  endif
592
#endif
593

594
/* This implicitly assumes alignment is always to a power of 2. */
595
#ifdef png_alignof
596
#  define png_isaligned(ptr, type)\
597
   (((type)((const char*)ptr-(const char*)0) & \
598
   (type)(png_alignof(type)-1)) == 0)
599
#else
600
#  define png_isaligned(ptr, type) 0
601
#endif
602

603
/* End of memory model/platform independent support */
604
/* End of 1.5.0beta36 move from pngconf.h */
605

606
/* CONSTANTS and UTILITY MACROS
607
 * These are used internally by libpng and not exposed in the API
608
 */
609

610
/* Various modes of operation.  Note that after an init, mode is set to
611
 * zero automatically when the structure is created.  Three of these
612
 * are defined in png.h because they need to be visible to applications
613
 * that call png_set_unknown_chunk().
614
 */
615
/* #define PNG_HAVE_IHDR            0x01U (defined in png.h) */
616
/* #define PNG_HAVE_PLTE            0x02U (defined in png.h) */
617
#define PNG_HAVE_IDAT               0x04U
618
/* #define PNG_AFTER_IDAT           0x08U (defined in png.h) */
619
#define PNG_HAVE_IEND               0x10U
620
                   /*               0x20U (unused) */
621
                   /*               0x40U (unused) */
622
                   /*               0x80U (unused) */
623
#define PNG_HAVE_CHUNK_HEADER      0x100U
624
#define PNG_WROTE_tIME             0x200U
625
#define PNG_WROTE_INFO_BEFORE_PLTE 0x400U
626
#define PNG_BACKGROUND_IS_GRAY     0x800U
627
#define PNG_HAVE_PNG_SIGNATURE    0x1000U
628
#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
629
                   /*             0x4000U (unused) */
630
#define PNG_IS_READ_STRUCT        0x8000U /* Else is a write struct */
631

632
/* Flags for the transformations the PNG library does on the image data */
633
#define PNG_BGR                 0x0001U
634
#define PNG_INTERLACE           0x0002U
635
#define PNG_PACK                0x0004U
636
#define PNG_SHIFT               0x0008U
637
#define PNG_SWAP_BYTES          0x0010U
638
#define PNG_INVERT_MONO         0x0020U
639
#define PNG_QUANTIZE            0x0040U
640
#define PNG_COMPOSE             0x0080U    /* Was PNG_BACKGROUND */
641
#define PNG_BACKGROUND_EXPAND   0x0100U
642
#define PNG_EXPAND_16           0x0200U    /* Added to libpng 1.5.2 */
643
#define PNG_16_TO_8             0x0400U    /* Becomes 'chop' in 1.5.4 */
644
#define PNG_RGBA                0x0800U
645
#define PNG_EXPAND              0x1000U
646
#define PNG_GAMMA               0x2000U
647
#define PNG_GRAY_TO_RGB         0x4000U
648
#define PNG_FILLER              0x8000U
649
#define PNG_PACKSWAP           0x10000U
650
#define PNG_SWAP_ALPHA         0x20000U
651
#define PNG_STRIP_ALPHA        0x40000U
652
#define PNG_INVERT_ALPHA       0x80000U
653
#define PNG_USER_TRANSFORM    0x100000U
654
#define PNG_RGB_TO_GRAY_ERR   0x200000U
655
#define PNG_RGB_TO_GRAY_WARN  0x400000U
656
#define PNG_RGB_TO_GRAY       0x600000U /* two bits, RGB_TO_GRAY_ERR|WARN */
657
#define PNG_ENCODE_ALPHA      0x800000U /* Added to libpng-1.5.4 */
658
#define PNG_ADD_ALPHA        0x1000000U /* Added to libpng-1.2.7 */
659
#define PNG_EXPAND_tRNS      0x2000000U /* Added to libpng-1.2.9 */
660
#define PNG_SCALE_16_TO_8    0x4000000U /* Added to libpng-1.5.4 */
661
                       /*    0x8000000U unused */
662
                       /*   0x10000000U unused */
663
                       /*   0x20000000U unused */
664
                       /*   0x40000000U unused */
665
/* Flags for png_create_struct */
666
#define PNG_STRUCT_PNG   0x0001U
667
#define PNG_STRUCT_INFO  0x0002U
668

669
/* Flags for the png_ptr->flags rather than declaring a byte for each one */
670
#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001U
671
#define PNG_FLAG_ZSTREAM_INITIALIZED      0x0002U /* Added to libpng-1.6.0 */
672
                                  /*      0x0004U    unused */
673
#define PNG_FLAG_ZSTREAM_ENDED            0x0008U /* Added to libpng-1.6.0 */
674
                                  /*      0x0010U    unused */
675
                                  /*      0x0020U    unused */
676
#define PNG_FLAG_ROW_INIT                 0x0040U
677
#define PNG_FLAG_FILLER_AFTER             0x0080U
678
#define PNG_FLAG_CRC_ANCILLARY_USE        0x0100U
679
#define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200U
680
#define PNG_FLAG_CRC_CRITICAL_USE         0x0400U
681
#define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800U
682
#define PNG_FLAG_ASSUME_sRGB              0x1000U /* Added to libpng-1.5.4 */
683
#define PNG_FLAG_OPTIMIZE_ALPHA           0x2000U /* Added to libpng-1.5.4 */
684
#define PNG_FLAG_DETECT_UNINITIALIZED     0x4000U /* Added to libpng-1.5.4 */
685
/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000U */
686
/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS      0x10000U */
687
#define PNG_FLAG_LIBRARY_MISMATCH        0x20000U
688
#define PNG_FLAG_STRIP_ERROR_NUMBERS     0x40000U
689
#define PNG_FLAG_STRIP_ERROR_TEXT        0x80000U
690
#define PNG_FLAG_BENIGN_ERRORS_WARN     0x100000U /* Added to libpng-1.4.0 */
691
#define PNG_FLAG_APP_WARNINGS_WARN      0x200000U /* Added to libpng-1.6.0 */
692
#define PNG_FLAG_APP_ERRORS_WARN        0x400000U /* Added to libpng-1.6.0 */
693
                                  /*    0x800000U    unused */
694
                                  /*   0x1000000U    unused */
695
                                  /*   0x2000000U    unused */
696
                                  /*   0x4000000U    unused */
697
                                  /*   0x8000000U    unused */
698
                                  /*  0x10000000U    unused */
699
                                  /*  0x20000000U    unused */
700
                                  /*  0x40000000U    unused */
701

702
#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
703
                                     PNG_FLAG_CRC_ANCILLARY_NOWARN)
704

705
#define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
706
                                     PNG_FLAG_CRC_CRITICAL_IGNORE)
707

708
#define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
709
                                     PNG_FLAG_CRC_CRITICAL_MASK)
710

711
/* Save typing and make code easier to understand */
712

713
#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
714
   abs((int)((c1).green) - (int)((c2).green)) + \
715
   abs((int)((c1).blue) - (int)((c2).blue)))
716

717
/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
718
 * by dividing by 257 *with rounding*.  This macro is exact for the given range.
719
 * See the discourse in pngrtran.c png_do_scale_16_to_8.  The values in the
720
 * macro were established by experiment (modifying the added value).  The macro
721
 * has a second variant that takes a value already scaled by 255 and divides by
722
 * 65535 - this has a maximum error of .502.  Over the range 0..65535*65535 it
723
 * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
724
 */
725
#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
726
#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
727

728
/* Added to libpng-1.2.6 JB */
729
#define PNG_ROWBYTES(pixel_bits, width) \
730
    ((pixel_bits) >= 8 ? \
731
    ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
732
    (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
733

734
/* This returns the number of trailing bits in the last byte of a row, 0 if the
735
 * last byte is completely full of pixels.  It is, in principle, (pixel_bits x
736
 * width) % 8, but that would overflow for large 'width'.  The second macro is
737
 * the same except that it returns the number of unused bits in the last byte;
738
 * (8-TRAILBITS), but 0 when TRAILBITS is 0.
739
 *
740
 * NOTE: these macros are intended to be self-evidently correct and never
741
 * overflow on the assumption that pixel_bits is in the range 0..255.  The
742
 * arguments are evaluated only once and they can be signed (e.g. as a result of
743
 * the integral promotions).  The result of the expression always has type
744
 * (png_uint_32), however the compiler always knows it is in the range 0..7.
745
 */
746
#define PNG_TRAILBITS(pixel_bits, width) \
747
    (((pixel_bits) * ((width) % (png_uint_32)8)) % 8)
748

749
#define PNG_PADBITS(pixel_bits, width) \
750
    ((8 - PNG_TRAILBITS(pixel_bits, width)) % 8)
751

752
/* PNG_OUT_OF_RANGE returns true if value is outside the range
753
 * ideal-delta..ideal+delta.  Each argument is evaluated twice.
754
 * "ideal" and "delta" should be constants, normally simple
755
 * integers, "value" a variable. Added to libpng-1.2.6 JB
756
 */
757
#define PNG_OUT_OF_RANGE(value, ideal, delta) \
758
   ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
759

760
/* Conversions between fixed and floating point, only defined if
761
 * required (to make sure the code doesn't accidentally use float
762
 * when it is supposedly disabled.)
763
 */
764
#ifdef PNG_FLOATING_POINT_SUPPORTED
765
/* The floating point conversion can't overflow, though it can and
766
 * does lose accuracy relative to the original fixed point value.
767
 * In practice this doesn't matter because png_fixed_point only
768
 * stores numbers with very low precision.  The png_ptr and s
769
 * arguments are unused by default but are there in case error
770
 * checking becomes a requirement.
771
 */
772
#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
773

774
/* The fixed point conversion performs range checking and evaluates
775
 * its argument multiple times, so must be used with care.  The
776
 * range checking uses the PNG specification values for a signed
777
 * 32-bit fixed point value except that the values are deliberately
778
 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
779
 * (2^31-1) * 100000). 's' is a string that describes the value being
780
 * converted.
781
 *
782
 * NOTE: this macro will raise a png_error if the range check fails,
783
 * therefore it is normally only appropriate to use this on values
784
 * that come from API calls or other sources where an out of range
785
 * error indicates a programming error, not a data error!
786
 *
787
 * NOTE: by default this is off - the macro is not used - because the
788
 * function call saves a lot of code.
789
 */
790
#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
791
#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
792
    ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
793
#endif
794
/* else the corresponding function is defined below, inside the scope of the
795
 * cplusplus test.
796
 */
797
#endif
798

799
/* Constants for known chunk types.  If you need to add a chunk, define the name
800
 * here.  For historical reasons these constants have the form png_<name>; i.e.
801
 * the prefix is lower case.  Please use decimal values as the parameters to
802
 * match the ISO PNG specification and to avoid relying on the C locale
803
 * interpretation of character values.
804
 *
805
 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
806
 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
807
 * to be generated if required.
808
 *
809
 * PNG_32b correctly produces a value shifted by up to 24 bits, even on
810
 * architectures where (int) is only 16 bits.
811
 */
812
#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
813
#define PNG_U32(b1,b2,b3,b4) \
814
   (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
815

816
/* Constants for known chunk types.
817
 *
818
 * MAINTAINERS: If you need to add a chunk, define the name here.
819
 * For historical reasons these constants have the form png_<name>; i.e.
820
 * the prefix is lower case.  Please use decimal values as the parameters to
821
 * match the ISO PNG specification and to avoid relying on the C locale
822
 * interpretation of character values.  Please keep the list sorted.
823
 *
824
 * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
825
 * type.  In fact the specification does not express chunk types this way,
826
 * however using a 32-bit value means that the chunk type can be read from the
827
 * stream using exactly the same code as used for a 32-bit unsigned value and
828
 * can be examined far more efficiently (using one arithmetic compare).
829
 *
830
 * Prior to 1.5.6 the chunk type constants were expressed as C strings.  The
831
 * libpng API still uses strings for 'unknown' chunks and a macro,
832
 * PNG_STRING_FROM_CHUNK, allows a string to be generated if required.  Notice
833
 * that for portable code numeric values must still be used; the string "IHDR"
834
 * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
835
 *
836
 * In 1.7.0 the definitions will be made public in png.h to avoid having to
837
 * duplicate the same definitions in application code.
838
 */
839
#define png_IDAT PNG_U32( 73,  68,  65,  84)
840
#define png_IEND PNG_U32( 73,  69,  78,  68)
841
#define png_IHDR PNG_U32( 73,  72,  68,  82)
842
#define png_PLTE PNG_U32( 80,  76,  84,  69)
843
#define png_bKGD PNG_U32( 98,  75,  71,  68)
844
#define png_cHRM PNG_U32( 99,  72,  82,  77)
845
#define png_eXIf PNG_U32(101,  88,  73, 102) /* registered July 2017 */
846
#define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
847
#define png_gAMA PNG_U32(103,  65,  77,  65)
848
#define png_gIFg PNG_U32(103,  73,  70, 103)
849
#define png_gIFt PNG_U32(103,  73,  70, 116) /* deprecated */
850
#define png_gIFx PNG_U32(103,  73,  70, 120)
851
#define png_hIST PNG_U32(104,  73,  83,  84)
852
#define png_iCCP PNG_U32(105,  67,  67,  80)
853
#define png_iTXt PNG_U32(105,  84,  88, 116)
854
#define png_oFFs PNG_U32(111,  70,  70, 115)
855
#define png_pCAL PNG_U32(112,  67,  65,  76)
856
#define png_pHYs PNG_U32(112,  72,  89, 115)
857
#define png_sBIT PNG_U32(115,  66,  73,  84)
858
#define png_sCAL PNG_U32(115,  67,  65,  76)
859
#define png_sPLT PNG_U32(115,  80,  76,  84)
860
#define png_sRGB PNG_U32(115,  82,  71,  66)
861
#define png_sTER PNG_U32(115,  84,  69,  82)
862
#define png_tEXt PNG_U32(116,  69,  88, 116)
863
#define png_tIME PNG_U32(116,  73,  77,  69)
864
#define png_tRNS PNG_U32(116,  82,  78,  83)
865
#define png_zTXt PNG_U32(122,  84,  88, 116)
866

867
/* The following will work on (signed char*) strings, whereas the get_uint_32
868
 * macro will fail on top-bit-set values because of the sign extension.
869
 */
870
#define PNG_CHUNK_FROM_STRING(s)\
871
   PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
872

873
/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
874
 * signed and the argument is a (char[])  This macro will fail miserably on
875
 * systems where (char) is more than 8 bits.
876
 */
877
#define PNG_STRING_FROM_CHUNK(s,c)\
878
   (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
879
   ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
880
   ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
881
   ((char*)(s))[3]=(char)((c & 0xff)))
882

883
/* Do the same but terminate with a null character. */
884
#define PNG_CSTRING_FROM_CHUNK(s,c)\
885
   (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
886

887
/* Test on flag values as defined in the spec (section 5.4): */
888
#define PNG_CHUNK_ANCILLARY(c)   (1 & ((c) >> 29))
889
#define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLARY(c))
890
#define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
891
#define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
892
#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
893

894
/* Gamma values (new at libpng-1.5.4): */
895
#define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
896
#define PNG_GAMMA_MAC_INVERSE 65909
897
#define PNG_GAMMA_sRGB_INVERSE 45455
898

899
/* Almost everything below is C specific; the #defines above can be used in
900
 * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
901
 */
902
#ifndef PNG_VERSION_INFO_ONLY
903

904
#include "pngstruct.h"
905
#include "pnginfo.h"
906

907
/* Validate the include paths - the include path used to generate pnglibconf.h
908
 * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
909
 */
910
#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
911
#  error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
912
      "-I (include path) error: see the notes in pngpriv.h"
913
   /* This means that when pnglibconf.h was built the copy of zlib.h that it
914
    * used is not the same as the one being used here.  Because the build of
915
    * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
916
    * zlib version number and because this affects handling of certain broken
917
    * PNG files the -I directives must match.
918
    *
919
    * The most likely explanation is that you passed a -I in CFLAGS. This will
920
    * not work; all the preprocessor directories and in particular all the -I
921
    * directives must be in CPPFLAGS.
922
    */
923
#endif
924

925
/* This is used for 16-bit gamma tables -- only the top level pointers are
926
 * const; this could be changed:
927
 */
928
typedef const png_uint_16p * png_const_uint_16pp;
929

930
/* Added to libpng-1.5.7: sRGB conversion tables */
931
#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
932
   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
933
#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
934
PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
935
   /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
936
    * 0..65535.  This table gives the closest 16-bit answers (no errors).
937
    */
938
#endif
939

940
PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
941
PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
942

943
#define PNG_sRGB_FROM_LINEAR(linear) \
944
  ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
945
   + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
946
   /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
947
    * encoded value with maximum error 0.646365.  Note that the input is not a
948
    * 16-bit value; it has been multiplied by 255! */
949
#endif /* SIMPLIFIED_READ/WRITE */
950

951

952
/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
953
#ifdef __cplusplus
954
extern "C" {
955
#endif /* __cplusplus */
956

957
/* Internal functions; these are not exported from a DLL however because they
958
 * are used within several of the C source files they have to be C extern.
959
 *
960
 * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
961
 */
962

963
/* Zlib support */
964
#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
965
PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
966
   PNG_EMPTY);
967
   /* Used by the zlib handling functions to ensure that z_stream::msg is always
968
    * set before they return.
969
    */
970

971
#ifdef PNG_WRITE_SUPPORTED
972
PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
973
   png_compression_bufferp *list),PNG_EMPTY);
974
   /* Free the buffer list used by the compressed write code. */
975
#endif
976

977
#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
978
   !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
979
   (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
980
   defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
981
   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
982
   (defined(PNG_sCAL_SUPPORTED) && \
983
   defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
984
PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
985
   double fp, png_const_charp text),PNG_EMPTY);
986
#endif
987

988
/* Check the user version string for compatibility, returns false if the version
989
 * numbers aren't compatible.
990
 */
991
PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
992
   png_const_charp user_png_ver),PNG_EMPTY);
993

994
/* Internal base allocator - no messages, NULL on failure to allocate.  This
995
 * does, however, call the application provided allocator and that could call
996
 * png_error (although that would be a bug in the application implementation.)
997
 */
998
PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
999
   png_alloc_size_t size),PNG_ALLOCATED);
1000

1001
#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
1002
   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
1003
/* Internal array allocator, outputs no error or warning messages on failure,
1004
 * just returns NULL.
1005
 */
1006
PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
1007
   int nelements, size_t element_size),PNG_ALLOCATED);
1008

1009
/* The same but an existing array is extended by add_elements.  This function
1010
 * also memsets the new elements to 0 and copies the old elements.  The old
1011
 * array is not freed or altered.
1012
 */
1013
PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
1014
   png_const_voidp array, int old_elements, int add_elements,
1015
   size_t element_size),PNG_ALLOCATED);
1016
#endif /* text, sPLT or unknown chunks */
1017

1018
/* Magic to create a struct when there is no struct to call the user supplied
1019
 * memory allocators.  Because error handling has not been set up the memory
1020
 * handlers can't safely call png_error, but this is an obscure and undocumented
1021
 * restriction so libpng has to assume that the 'free' handler, at least, might
1022
 * call png_error.
1023
 */
1024
PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
1025
   (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1026
    png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
1027
    png_free_ptr free_fn),PNG_ALLOCATED);
1028

1029
/* Free memory from internal libpng struct */
1030
PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
1031
   PNG_EMPTY);
1032

1033
/* Free an allocated jmp_buf (always succeeds) */
1034
PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
1035

1036
/* Function to allocate memory for zlib.  PNGAPI is disallowed. */
1037
PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
1038
   PNG_ALLOCATED);
1039

1040
/* Function to free memory for zlib.  PNGAPI is disallowed. */
1041
PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
1042

1043
/* Next four functions are used internally as callbacks.  PNGCBAPI is required
1044
 * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
1045
 * PNGCBAPI at 1.5.0
1046
 */
1047

1048
PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
1049
    png_bytep data, png_size_t length),PNG_EMPTY);
1050

1051
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1052
PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
1053
    png_bytep buffer, png_size_t length),PNG_EMPTY);
1054
#endif
1055

1056
PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
1057
    png_bytep data, png_size_t length),PNG_EMPTY);
1058

1059
#ifdef PNG_WRITE_FLUSH_SUPPORTED
1060
#  ifdef PNG_STDIO_SUPPORTED
1061
PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
1062
   PNG_EMPTY);
1063
#  endif
1064
#endif
1065

1066
/* Reset the CRC variable */
1067
PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
1068

1069
/* Write the "data" buffer to whatever output you are using */
1070
PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
1071
    png_const_bytep data, png_size_t length),PNG_EMPTY);
1072

1073
/* Read and check the PNG file signature */
1074
PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
1075
   png_inforp info_ptr),PNG_EMPTY);
1076

1077
/* Read the chunk header (length + type name) */
1078
PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
1079
   PNG_EMPTY);
1080

1081
/* Read data from whatever input you are using into the "data" buffer */
1082
PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
1083
    png_size_t length),PNG_EMPTY);
1084

1085
/* Read bytes into buf, and update png_ptr->crc */
1086
PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
1087
    png_uint_32 length),PNG_EMPTY);
1088

1089
/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
1090
PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
1091
   png_uint_32 skip),PNG_EMPTY);
1092

1093
/* Read the CRC from the file and compare it to the libpng calculated CRC */
1094
PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
1095

1096
/* Calculate the CRC over a section of data.  Note that we are only
1097
 * passing a maximum of 64K on systems that have this as a memory limit,
1098
 * since this is the maximum buffer size we can specify.
1099
 */
1100
PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
1101
   png_const_bytep ptr, png_size_t length),PNG_EMPTY);
1102

1103
#ifdef PNG_WRITE_FLUSH_SUPPORTED
1104
PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
1105
#endif
1106

1107
/* Write various chunks */
1108

1109
/* Write the IHDR chunk, and update the png_struct with the necessary
1110
 * information.
1111
 */
1112
PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
1113
   png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1114
   int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
1115

1116
PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
1117
   png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
1118

1119
PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
1120
   png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
1121
   PNG_EMPTY);
1122

1123
PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
1124

1125
#ifdef PNG_WRITE_gAMA_SUPPORTED
1126
PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
1127
    png_fixed_point file_gamma),PNG_EMPTY);
1128
#endif
1129

1130
#ifdef PNG_WRITE_sBIT_SUPPORTED
1131
PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
1132
    png_const_color_8p sbit, int color_type),PNG_EMPTY);
1133
#endif
1134

1135
#ifdef PNG_WRITE_cHRM_SUPPORTED
1136
PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
1137
    const png_xy *xy), PNG_EMPTY);
1138
   /* The xy value must have been previously validated */
1139
#endif
1140

1141
#ifdef PNG_WRITE_sRGB_SUPPORTED
1142
PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1143
    int intent),PNG_EMPTY);
1144
#endif
1145

1146
#ifdef PNG_WRITE_eXIf_SUPPORTED
1147
PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr,
1148
    png_bytep exif, int num_exif),PNG_EMPTY);
1149
#endif
1150

1151
#ifdef PNG_WRITE_iCCP_SUPPORTED
1152
PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1153
   png_const_charp name, png_const_bytep profile), PNG_EMPTY);
1154
   /* The profile must have been previously validated for correctness, the
1155
    * length comes from the first four bytes.  Only the base, deflate,
1156
    * compression is supported.
1157
    */
1158
#endif
1159

1160
#ifdef PNG_WRITE_sPLT_SUPPORTED
1161
PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1162
    png_const_sPLT_tp palette),PNG_EMPTY);
1163
#endif
1164

1165
#ifdef PNG_WRITE_tRNS_SUPPORTED
1166
PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1167
    png_const_bytep trans, png_const_color_16p values, int number,
1168
    int color_type),PNG_EMPTY);
1169
#endif
1170

1171
#ifdef PNG_WRITE_bKGD_SUPPORTED
1172
PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1173
    png_const_color_16p values, int color_type),PNG_EMPTY);
1174
#endif
1175

1176
#ifdef PNG_WRITE_hIST_SUPPORTED
1177
PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1178
    png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1179
#endif
1180

1181
/* Chunks that have keywords */
1182
#ifdef PNG_WRITE_tEXt_SUPPORTED
1183
PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1184
   png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
1185
#endif
1186

1187
#ifdef PNG_WRITE_zTXt_SUPPORTED
1188
PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1189
    key, png_const_charp text, int compression),PNG_EMPTY);
1190
#endif
1191

1192
#ifdef PNG_WRITE_iTXt_SUPPORTED
1193
PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1194
    int compression, png_const_charp key, png_const_charp lang,
1195
    png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1196
#endif
1197

1198
#ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
1199
PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1200
    png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1201
#endif
1202

1203
#ifdef PNG_WRITE_oFFs_SUPPORTED
1204
PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1205
    png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1206
#endif
1207

1208
#ifdef PNG_WRITE_pCAL_SUPPORTED
1209
PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1210
    png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1211
    png_const_charp units, png_charpp params),PNG_EMPTY);
1212
#endif
1213

1214
#ifdef PNG_WRITE_pHYs_SUPPORTED
1215
PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1216
    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1217
    int unit_type),PNG_EMPTY);
1218
#endif
1219

1220
#ifdef PNG_WRITE_tIME_SUPPORTED
1221
PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1222
    png_const_timep mod_time),PNG_EMPTY);
1223
#endif
1224

1225
#ifdef PNG_WRITE_sCAL_SUPPORTED
1226
PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1227
    int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1228
#endif
1229

1230
/* Called when finished processing a row of data */
1231
PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1232
    PNG_EMPTY);
1233

1234
/* Internal use only.   Called before first row of data */
1235
PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1236
    PNG_EMPTY);
1237

1238
/* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
1239
 * array of png_ptr->width pixels.  If the image is not interlaced or this
1240
 * is the final pass this just does a memcpy, otherwise the "display" flag
1241
 * is used to determine whether to copy pixels that are not in the current pass.
1242
 *
1243
 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1244
 * function to achieve the documented 'blocky' appearance during interlaced read
1245
 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1246
 * are not changed if they are not in the current pass, when display is 0.
1247
 *
1248
 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1249
 *
1250
 * The API always reads from the png_struct row buffer and always assumes that
1251
 * it is full width (png_do_read_interlace has already been called.)
1252
 *
1253
 * This function is only ever used to write to row buffers provided by the
1254
 * caller of the relevant libpng API and the row must have already been
1255
 * transformed by the read transformations.
1256
 *
1257
 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1258
 * bitmasks for use within the code, otherwise runtime generated masks are used.
1259
 * The default is compile time masks.
1260
 */
1261
#ifndef PNG_USE_COMPILE_TIME_MASKS
1262
#  define PNG_USE_COMPILE_TIME_MASKS 1
1263
#endif
1264
PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1265
    png_bytep row, int display),PNG_EMPTY);
1266

1267
#ifdef PNG_READ_INTERLACING_SUPPORTED
1268
/* Expand an interlaced row: the 'row_info' describes the pass data that has
1269
 * been read in and must correspond to the pixels in 'row', the pixels are
1270
 * expanded (moved apart) in 'row' to match the final layout, when doing this
1271
 * the pixels are *replicated* to the intervening space.  This is essential for
1272
 * the correct operation of png_combine_row, above.
1273
 */
1274
PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1275
    png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1276
#endif
1277

1278
/* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
1279

1280
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1281
/* Grab pixels out of a row for an interlaced pass */
1282
PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1283
    png_bytep row, int pass),PNG_EMPTY);
1284
#endif
1285

1286
/* Unfilter a row: check the filter value before calling this, there is no point
1287
 * calling it for PNG_FILTER_VALUE_NONE.
1288
 */
1289
PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1290
    row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1291

1292
#if PNG_ARM_NEON_OPT > 0
1293
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1294
    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1295
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1296
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1297
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1298
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1299
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1300
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1301
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1302
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1303
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1304
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1305
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1306
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1307
#endif
1308

1309
#if PNG_MIPS_MSA_OPT > 0
1310
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_msa,(png_row_infop row_info,
1311
    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1312
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_msa,(png_row_infop
1313
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1314
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_msa,(png_row_infop
1315
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1316
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_msa,(png_row_infop
1317
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1318
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop
1319
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1320
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop
1321
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1322
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop
1323
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1324
#endif
1325

1326
#if PNG_POWERPC_VSX_OPT > 0
1327
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_vsx,(png_row_infop row_info,
1328
    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1329
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_vsx,(png_row_infop
1330
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1331
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_vsx,(png_row_infop
1332
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1333
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_vsx,(png_row_infop
1334
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1335
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_vsx,(png_row_infop
1336
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1337
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_vsx,(png_row_infop
1338
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1339
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_vsx,(png_row_infop
1340
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1341
#endif
1342

1343
#if defined(PNG_INTEL_SSE_IMPLEMENTATION) && PNG_INTEL_SSE_IMPLEMENTATION > 0
1344
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
1345
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1346
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
1347
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1348
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
1349
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1350
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
1351
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1352
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
1353
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1354
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
1355
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1356
#endif
1357

1358
/* Choose the best filter to use and filter the row data */
1359
PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1360
    png_row_infop row_info),PNG_EMPTY);
1361

1362
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1363
PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1364
   png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1365
   /* Read 'avail_out' bytes of data from the IDAT stream.  If the output buffer
1366
    * is NULL the function checks, instead, for the end of the stream.  In this
1367
    * case a benign error will be issued if the stream end is not found or if
1368
    * extra data has to be consumed.
1369
    */
1370
PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1371
   PNG_EMPTY);
1372
   /* This cleans up when the IDAT LZ stream does not end when the last image
1373
    * byte is read; there is still some pending input.
1374
    */
1375

1376
PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1377
   PNG_EMPTY);
1378
   /* Finish a row while reading, dealing with interlacing passes, etc. */
1379
#endif /* SEQUENTIAL_READ */
1380

1381
/* Initialize the row buffers, etc. */
1382
PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1383

1384
#if ZLIB_VERNUM >= 0x1240
1385
PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
1386
      PNG_EMPTY);
1387
#  define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
1388
#else /* Zlib < 1.2.4 */
1389
#  define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
1390
#endif /* Zlib < 1.2.4 */
1391

1392
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1393
/* Optional call to update the users info structure */
1394
PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1395
    png_inforp info_ptr),PNG_EMPTY);
1396
#endif
1397

1398
/* Shared transform functions, defined in pngtran.c */
1399
#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1400
    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1401
PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1402
    png_bytep row, int at_start),PNG_EMPTY);
1403
#endif
1404

1405
#ifdef PNG_16BIT_SUPPORTED
1406
#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1407
PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1408
    png_bytep row),PNG_EMPTY);
1409
#endif
1410
#endif
1411

1412
#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1413
    defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1414
PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1415
    png_bytep row),PNG_EMPTY);
1416
#endif
1417

1418
#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1419
PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1420
    png_bytep row),PNG_EMPTY);
1421
#endif
1422

1423
#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1424
PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1425
    png_bytep row),PNG_EMPTY);
1426
#endif
1427

1428
/* The following decodes the appropriate chunks, and does error correction,
1429
 * then calls the appropriate callback for the chunk if it is valid.
1430
 */
1431

1432
/* Decode the IHDR chunk */
1433
PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1434
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1435
PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1436
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1437
PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1438
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1439

1440
#ifdef PNG_READ_bKGD_SUPPORTED
1441
PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1442
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1443
#endif
1444

1445
#ifdef PNG_READ_cHRM_SUPPORTED
1446
PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1447
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1448
#endif
1449

1450
#ifdef PNG_READ_eXIf_SUPPORTED
1451
PNG_INTERNAL_FUNCTION(void,png_handle_eXIf,(png_structrp png_ptr,
1452
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1453
#endif
1454

1455
#ifdef PNG_READ_gAMA_SUPPORTED
1456
PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1457
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1458
#endif
1459

1460
#ifdef PNG_READ_hIST_SUPPORTED
1461
PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1462
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1463
#endif
1464

1465
#ifdef PNG_READ_iCCP_SUPPORTED
1466
PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1467
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1468
#endif /* READ_iCCP */
1469

1470
#ifdef PNG_READ_iTXt_SUPPORTED
1471
PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1472
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1473
#endif
1474

1475
#ifdef PNG_READ_oFFs_SUPPORTED
1476
PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1477
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1478
#endif
1479

1480
#ifdef PNG_READ_pCAL_SUPPORTED
1481
PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1482
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1483
#endif
1484

1485
#ifdef PNG_READ_pHYs_SUPPORTED
1486
PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1487
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1488
#endif
1489

1490
#ifdef PNG_READ_sBIT_SUPPORTED
1491
PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1492
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1493
#endif
1494

1495
#ifdef PNG_READ_sCAL_SUPPORTED
1496
PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1497
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1498
#endif
1499

1500
#ifdef PNG_READ_sPLT_SUPPORTED
1501
PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1502
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1503
#endif /* READ_sPLT */
1504

1505
#ifdef PNG_READ_sRGB_SUPPORTED
1506
PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1507
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1508
#endif
1509

1510
#ifdef PNG_READ_tEXt_SUPPORTED
1511
PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1512
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1513
#endif
1514

1515
#ifdef PNG_READ_tIME_SUPPORTED
1516
PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1517
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1518
#endif
1519

1520
#ifdef PNG_READ_tRNS_SUPPORTED
1521
PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1522
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1523
#endif
1524

1525
#ifdef PNG_READ_zTXt_SUPPORTED
1526
PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1527
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1528
#endif
1529

1530
PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_const_structrp png_ptr,
1531
    const png_uint_32 chunk_name),PNG_EMPTY);
1532

1533
PNG_INTERNAL_FUNCTION(void,png_check_chunk_length,(png_const_structrp png_ptr,
1534
    const png_uint_32 chunk_length),PNG_EMPTY);
1535

1536
PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1537
    png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1538
   /* This is the function that gets called for unknown chunks.  The 'keep'
1539
    * argument is either non-zero for a known chunk that has been set to be
1540
    * handled as unknown or zero for an unknown chunk.  By default the function
1541
    * just skips the chunk or errors out if it is critical.
1542
    */
1543

1544
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
1545
    defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1546
PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1547
    (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1548
   /* Exactly as the API png_handle_as_unknown() except that the argument is a
1549
    * 32-bit chunk name, not a string.
1550
    */
1551
#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
1552

1553
/* Handle the transformations for reading and writing */
1554
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1555
PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1556
   png_row_infop row_info),PNG_EMPTY);
1557
#endif
1558
#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1559
PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1560
   png_row_infop row_info),PNG_EMPTY);
1561
#endif
1562

1563
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1564
PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1565
    PNG_EMPTY);
1566
#endif
1567

1568
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1569
PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1570
    png_inforp info_ptr),PNG_EMPTY);
1571
PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1572
    png_inforp info_ptr),PNG_EMPTY);
1573
PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1574
PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1575
    PNG_EMPTY);
1576
PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1577
    png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1578
PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1579
PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1580
    png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1581
PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1582
    PNG_EMPTY);
1583
PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1584
   png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1585
PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1586
   png_inforp info_ptr),PNG_EMPTY);
1587
PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1588
   png_inforp info_ptr),PNG_EMPTY);
1589
PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1590
    png_bytep row),PNG_EMPTY);
1591
PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1592
    png_inforp info_ptr),PNG_EMPTY);
1593
PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1594
    png_inforp info_ptr),PNG_EMPTY);
1595
PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1596
    PNG_EMPTY);
1597
#  ifdef PNG_READ_tEXt_SUPPORTED
1598
PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1599
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1600
PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1601
    png_inforp info_ptr),PNG_EMPTY);
1602
#  endif
1603
#  ifdef PNG_READ_zTXt_SUPPORTED
1604
PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1605
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1606
PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1607
    png_inforp info_ptr),PNG_EMPTY);
1608
#  endif
1609
#  ifdef PNG_READ_iTXt_SUPPORTED
1610
PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1611
    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1612
PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1613
    png_inforp info_ptr),PNG_EMPTY);
1614
#  endif
1615

1616
#endif /* PROGRESSIVE_READ */
1617

1618
/* Added at libpng version 1.6.0 */
1619
#ifdef PNG_GAMMA_SUPPORTED
1620
PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1621
    png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1622
   /* Set the colorspace gamma with a value provided by the application or by
1623
    * the gAMA chunk on read.  The value will override anything set by an ICC
1624
    * profile.
1625
    */
1626

1627
PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1628
    png_inforp info_ptr), PNG_EMPTY);
1629
   /* Synchronize the info 'valid' flags with the colorspace */
1630

1631
PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1632
    png_inforp info_ptr), PNG_EMPTY);
1633
   /* Copy the png_struct colorspace to the info_struct and call the above to
1634
    * synchronize the flags.  Checks for NULL info_ptr and does nothing.
1635
    */
1636
#endif
1637

1638
/* Added at libpng version 1.4.0 */
1639
#ifdef PNG_COLORSPACE_SUPPORTED
1640
/* These internal functions are for maintaining the colorspace structure within
1641
 * a png_info or png_struct (or, indeed, both).
1642
 */
1643
PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1644
   (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1645
    int preferred), PNG_EMPTY);
1646

1647
PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1648
   (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1649
    int preferred), PNG_EMPTY);
1650

1651
#ifdef PNG_sRGB_SUPPORTED
1652
PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1653
   png_colorspacerp colorspace, int intent), PNG_EMPTY);
1654
   /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1655
    * flags to write them, if it returns false there was a problem and an error
1656
    * message has already been output (but the colorspace may still need to be
1657
    * synced to record the invalid flag).
1658
    */
1659
#endif /* sRGB */
1660

1661
#ifdef PNG_iCCP_SUPPORTED
1662
PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1663
   png_colorspacerp colorspace, png_const_charp name,
1664
   png_uint_32 profile_length, png_const_bytep profile, int color_type),
1665
   PNG_EMPTY);
1666
   /* The 'name' is used for information only */
1667

1668
/* Routines for checking parts of an ICC profile. */
1669
#ifdef PNG_READ_iCCP_SUPPORTED
1670
PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1671
   png_colorspacerp colorspace, png_const_charp name,
1672
   png_uint_32 profile_length), PNG_EMPTY);
1673
#endif /* READ_iCCP */
1674
PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1675
   png_colorspacerp colorspace, png_const_charp name,
1676
   png_uint_32 profile_length,
1677
   png_const_bytep profile /* first 132 bytes only */, int color_type),
1678
   PNG_EMPTY);
1679
PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1680
   png_colorspacerp colorspace, png_const_charp name,
1681
   png_uint_32 profile_length,
1682
   png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1683
#ifdef PNG_sRGB_SUPPORTED
1684
PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1685
   png_const_structrp png_ptr, png_colorspacerp colorspace,
1686
   png_const_bytep profile, uLong adler), PNG_EMPTY);
1687
   /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1688
    * be zero to indicate that it is not available.  It is used, if provided,
1689
    * as a fast check on the profile when checking to see if it is sRGB.
1690
    */
1691
#endif
1692
#endif /* iCCP */
1693

1694
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1695
PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1696
   (png_structrp png_ptr), PNG_EMPTY);
1697
   /* Set the rgb_to_gray coefficients from the colorspace Y values */
1698
#endif /* READ_RGB_TO_GRAY */
1699
#endif /* COLORSPACE */
1700

1701
/* Added at libpng version 1.4.0 */
1702
PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1703
    png_uint_32 width, png_uint_32 height, int bit_depth,
1704
    int color_type, int interlace_type, int compression_type,
1705
    int filter_type),PNG_EMPTY);
1706

1707
/* Added at libpng version 1.5.10 */
1708
#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1709
    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1710
PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1711
   (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1712
#endif
1713

1714
#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1715
PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1716
   png_const_charp name),PNG_NORETURN);
1717
#endif
1718

1719
/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1720
 * the end.  Always leaves the buffer nul terminated.  Never errors out (and
1721
 * there is no error code.)
1722
 */
1723
PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1724
   size_t pos, png_const_charp string),PNG_EMPTY);
1725

1726
/* Various internal functions to handle formatted warning messages, currently
1727
 * only implemented for warnings.
1728
 */
1729
#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1730
/* Utility to dump an unsigned value into a buffer, given a start pointer and
1731
 * and end pointer (which should point just *beyond* the end of the buffer!)
1732
 * Returns the pointer to the start of the formatted string.  This utility only
1733
 * does unsigned values.
1734
 */
1735
PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1736
   png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1737

1738
/* Convenience macro that takes an array: */
1739
#define PNG_FORMAT_NUMBER(buffer,format,number) \
1740
   png_format_number(buffer, buffer + (sizeof buffer), format, number)
1741

1742
/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1743
#define PNG_NUMBER_BUFFER_SIZE 24
1744

1745
/* These are the integer formats currently supported, the name is formed from
1746
 * the standard printf(3) format string.
1747
 */
1748
#define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
1749
#define PNG_NUMBER_FORMAT_02u   2
1750
#define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
1751
#define PNG_NUMBER_FORMAT_02d   2
1752
#define PNG_NUMBER_FORMAT_x     3
1753
#define PNG_NUMBER_FORMAT_02x   4
1754
#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1755
#endif
1756

1757
#ifdef PNG_WARNINGS_SUPPORTED
1758
/* New defines and members adding in libpng-1.5.4 */
1759
#  define PNG_WARNING_PARAMETER_SIZE 32
1760
#  define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1761

1762
/* An l-value of this type has to be passed to the APIs below to cache the
1763
 * values of the parameters to a formatted warning message.
1764
 */
1765
typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1766
   PNG_WARNING_PARAMETER_SIZE];
1767

1768
PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1769
   int number, png_const_charp string),PNG_EMPTY);
1770
   /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1771
    * including the trailing '\0'.
1772
    */
1773
PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1774
   (png_warning_parameters p, int number, int format, png_alloc_size_t value),
1775
   PNG_EMPTY);
1776
   /* Use png_alloc_size_t because it is an unsigned type as big as any we
1777
    * need to output.  Use the following for a signed value.
1778
    */
1779
PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1780
   (png_warning_parameters p, int number, int format, png_int_32 value),
1781
   PNG_EMPTY);
1782

1783
PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1784
   png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1785
   /* 'message' follows the X/Open approach of using @1, @2 to insert
1786
    * parameters previously supplied using the above functions.  Errors in
1787
    * specifying the parameters will simply result in garbage substitutions.
1788
    */
1789
#endif
1790

1791
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1792
/* Application errors (new in 1.6); use these functions (declared below) for
1793
 * errors in the parameters or order of API function calls on read.  The
1794
 * 'warning' should be used for an error that can be handled completely; the
1795
 * 'error' for one which can be handled safely but which may lose application
1796
 * information or settings.
1797
 *
1798
 * By default these both result in a png_error call prior to release, while in a
1799
 * released version the 'warning' is just a warning.  However if the application
1800
 * explicitly disables benign errors (explicitly permitting the code to lose
1801
 * information) they both turn into warnings.
1802
 *
1803
 * If benign errors aren't supported they end up as the corresponding base call
1804
 * (png_warning or png_error.)
1805
 */
1806
PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1807
   png_const_charp message),PNG_EMPTY);
1808
   /* The application provided invalid parameters to an API function or called
1809
    * an API function at the wrong time, libpng can completely recover.
1810
    */
1811

1812
PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1813
   png_const_charp message),PNG_EMPTY);
1814
   /* As above but libpng will ignore the call, or attempt some other partial
1815
    * recovery from the error.
1816
    */
1817
#else
1818
#  define png_app_warning(pp,s) png_warning(pp,s)
1819
#  define png_app_error(pp,s) png_error(pp,s)
1820
#endif
1821

1822
PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1823
   png_const_charp message, int error),PNG_EMPTY);
1824
   /* Report a recoverable issue in chunk data.  On read this is used to report
1825
    * a problem found while reading a particular chunk and the
1826
    * png_chunk_benign_error or png_chunk_warning function is used as
1827
    * appropriate.  On write this is used to report an error that comes from
1828
    * data set via an application call to a png_set_ API and png_app_error or
1829
    * png_app_warning is used as appropriate.
1830
    *
1831
    * The 'error' parameter must have one of the following values:
1832
    */
1833
#define PNG_CHUNK_WARNING     0 /* never an error */
1834
#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1835
#define PNG_CHUNK_ERROR       2 /* always an error */
1836

1837
/* ASCII to FP interfaces, currently only implemented if sCAL
1838
 * support is required.
1839
 */
1840
#if defined(PNG_sCAL_SUPPORTED)
1841
/* MAX_DIGITS is actually the maximum number of characters in an sCAL
1842
 * width or height, derived from the precision (number of significant
1843
 * digits - a build time settable option) and assumptions about the
1844
 * maximum ridiculous exponent.
1845
 */
1846
#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1847

1848
#ifdef PNG_FLOATING_POINT_SUPPORTED
1849
PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1850
   png_charp ascii, png_size_t size, double fp, unsigned int precision),
1851
   PNG_EMPTY);
1852
#endif /* FLOATING_POINT */
1853

1854
#ifdef PNG_FIXED_POINT_SUPPORTED
1855
PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1856
   png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
1857
#endif /* FIXED_POINT */
1858
#endif /* sCAL */
1859

1860
#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1861
/* An internal API to validate the format of a floating point number.
1862
 * The result is the index of the next character.  If the number is
1863
 * not valid it will be the index of a character in the supposed number.
1864
 *
1865
 * The format of a number is defined in the PNG extensions specification
1866
 * and this API is strictly conformant to that spec, not anyone elses!
1867
 *
1868
 * The format as a regular expression is:
1869
 *
1870
 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1871
 *
1872
 * or:
1873
 *
1874
 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1875
 *
1876
 * The complexity is that either integer or fraction must be present and the
1877
 * fraction is permitted to have no digits only if the integer is present.
1878
 *
1879
 * NOTE: The dangling E problem.
1880
 *   There is a PNG valid floating point number in the following:
1881
 *
1882
 *       PNG floating point numbers are not greedy.
1883
 *
1884
 *   Working this out requires *TWO* character lookahead (because of the
1885
 *   sign), the parser does not do this - it will fail at the 'r' - this
1886
 *   doesn't matter for PNG sCAL chunk values, but it requires more care
1887
 *   if the value were ever to be embedded in something more complex.  Use
1888
 *   ANSI-C strtod if you need the lookahead.
1889
 */
1890
/* State table for the parser. */
1891
#define PNG_FP_INTEGER    0  /* before or in integer */
1892
#define PNG_FP_FRACTION   1  /* before or in fraction */
1893
#define PNG_FP_EXPONENT   2  /* before or in exponent */
1894
#define PNG_FP_STATE      3  /* mask for the above */
1895
#define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
1896
#define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
1897
#define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
1898
#define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
1899
#define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
1900

1901
/* These three values don't affect the parser.  They are set but not used.
1902
 */
1903
#define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
1904
#define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
1905
#define PNG_FP_NONZERO  256  /* A non-zero value */
1906
#define PNG_FP_STICKY   448  /* The above three flags */
1907

1908
/* This is available for the caller to store in 'state' if required.  Do not
1909
 * call the parser after setting it (the parser sometimes clears it.)
1910
 */
1911
#define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
1912

1913
/* Result codes for the parser (boolean - true meants ok, false means
1914
 * not ok yet.)
1915
 */
1916
#define PNG_FP_MAYBE      0  /* The number may be valid in the future */
1917
#define PNG_FP_OK         1  /* The number is valid */
1918

1919
/* Tests on the sticky non-zero and negative flags.  To pass these checks
1920
 * the state must also indicate that the whole number is valid - this is
1921
 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1922
 * is equivalent to PNG_FP_OK above.)
1923
 */
1924
#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1925
   /* NZ_MASK: the string is valid and a non-zero negative value */
1926
#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1927
   /* Z MASK: the string is valid and a non-zero value. */
1928
   /* PNG_FP_SAW_DIGIT: the string is valid. */
1929
#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1930
#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1931
#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1932

1933
/* The actual parser.  This can be called repeatedly. It updates
1934
 * the index into the string and the state variable (which must
1935
 * be initialized to 0).  It returns a result code, as above.  There
1936
 * is no point calling the parser any more if it fails to advance to
1937
 * the end of the string - it is stuck on an invalid character (or
1938
 * terminated by '\0').
1939
 *
1940
 * Note that the pointer will consume an E or even an E+ and then leave
1941
 * a 'maybe' state even though a preceding integer.fraction is valid.
1942
 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1943
 * a valid number.  It's possible to recover from this by calling
1944
 * the parser again (from the start, with state 0) but with a string
1945
 * that omits the last character (i.e. set the size to the index of
1946
 * the problem character.)  This has not been tested within libpng.
1947
 */
1948
PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
1949
   png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
1950

1951
/* This is the same but it checks a complete string and returns true
1952
 * only if it just contains a floating point number.  As of 1.5.4 this
1953
 * function also returns the state at the end of parsing the number if
1954
 * it was valid (otherwise it returns 0.)  This can be used for testing
1955
 * for negative or zero values using the sticky flag.
1956
 */
1957
PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
1958
   png_size_t size),PNG_EMPTY);
1959
#endif /* pCAL || sCAL */
1960

1961
#if defined(PNG_GAMMA_SUPPORTED) ||\
1962
    defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1963
/* Added at libpng version 1.5.0 */
1964
/* This is a utility to provide a*times/div (rounded) and indicate
1965
 * if there is an overflow.  The result is a boolean - false (0)
1966
 * for overflow, true (1) if no overflow, in which case *res
1967
 * holds the result.
1968
 */
1969
PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
1970
   png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
1971
#endif
1972

1973
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1974
/* Same deal, but issue a warning on overflow and return 0. */
1975
PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
1976
   (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
1977
   png_int_32 divided_by),PNG_EMPTY);
1978
#endif
1979

1980
#ifdef PNG_GAMMA_SUPPORTED
1981
/* Calculate a reciprocal - used for gamma values.  This returns
1982
 * 0 if the argument is 0 in order to maintain an undefined value;
1983
 * there are no warnings.
1984
 */
1985
PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
1986
   PNG_EMPTY);
1987

1988
#ifdef PNG_READ_GAMMA_SUPPORTED
1989
/* The same but gives a reciprocal of the product of two fixed point
1990
 * values.  Accuracy is suitable for gamma calculations but this is
1991
 * not exact - use png_muldiv for that.  Only required at present on read.
1992
 */
1993
PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
1994
   png_fixed_point b),PNG_EMPTY);
1995
#endif
1996

1997
/* Return true if the gamma value is significantly different from 1.0 */
1998
PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
1999
   PNG_EMPTY);
2000
#endif
2001

2002
#ifdef PNG_READ_GAMMA_SUPPORTED
2003
/* Internal fixed point gamma correction.  These APIs are called as
2004
 * required to convert single values - they don't need to be fast,
2005
 * they are not used when processing image pixel values.
2006
 *
2007
 * While the input is an 'unsigned' value it must actually be the
2008
 * correct bit value - 0..255 or 0..65535 as required.
2009
 */
2010
PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
2011
   unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
2012
PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
2013
   png_fixed_point gamma_value),PNG_EMPTY);
2014
PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
2015
   png_fixed_point gamma_value),PNG_EMPTY);
2016
PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
2017
   PNG_EMPTY);
2018
PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
2019
   int bit_depth),PNG_EMPTY);
2020
#endif
2021

2022
/* SIMPLIFIED READ/WRITE SUPPORT */
2023
#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
2024
   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2025
/* The internal structure that png_image::opaque points to. */
2026
typedef struct png_control
2027
{
2028
   png_structp png_ptr;
2029
   png_infop   info_ptr;
2030
   png_voidp   error_buf;           /* Always a jmp_buf at present. */
2031

2032
   png_const_bytep memory;          /* Memory buffer. */
2033
   png_size_t      size;            /* Size of the memory buffer. */
2034

2035
   unsigned int for_write       :1; /* Otherwise it is a read structure */
2036
   unsigned int owned_file      :1; /* We own the file in io_ptr */
2037
} png_control;
2038

2039
/* Return the pointer to the jmp_buf from a png_control: necessary because C
2040
 * does not reveal the type of the elements of jmp_buf.
2041
 */
2042
#ifdef __cplusplus
2043
#  define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
2044
#else
2045
#  define png_control_jmp_buf(pc) ((pc)->error_buf)
2046
#endif
2047

2048
/* Utility to safely execute a piece of libpng code catching and logging any
2049
 * errors that might occur.  Returns true on success, false on failure (either
2050
 * of the function or as a result of a png_error.)
2051
 */
2052
PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
2053
   png_const_charp error_message),PNG_NORETURN);
2054

2055
#ifdef PNG_WARNINGS_SUPPORTED
2056
PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
2057
   png_const_charp warning_message),PNG_EMPTY);
2058
#else
2059
#  define png_safe_warning 0/*dummy argument*/
2060
#endif
2061

2062
PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
2063
   int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
2064

2065
/* Utility to log an error; this also cleans up the png_image; the function
2066
 * always returns 0 (false).
2067
 */
2068
PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
2069
   png_const_charp error_message),PNG_EMPTY);
2070

2071
#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
2072
/* png_image_free is used by the write code but not exported */
2073
PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
2074
#endif /* !SIMPLIFIED_READ */
2075

2076
#endif /* SIMPLIFIED READ/WRITE */
2077

2078
/* These are initialization functions for hardware specific PNG filter
2079
 * optimizations; list these here then select the appropriate one at compile
2080
 * time using the macro PNG_FILTER_OPTIMIZATIONS.  If the macro is not defined
2081
 * the generic code is used.
2082
 */
2083
#ifdef PNG_FILTER_OPTIMIZATIONS
2084
PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
2085
   unsigned int bpp), PNG_EMPTY);
2086
   /* Just declare the optimization that will be used */
2087
#else
2088
   /* List *all* the possible optimizations here - this branch is required if
2089
    * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
2090
    * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
2091
    */
2092
#  if PNG_ARM_NEON_OPT > 0
2093
PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
2094
   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2095
#endif
2096

2097
#if PNG_MIPS_MSA_OPT > 0
2098
PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_msa,
2099
   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2100
#endif
2101

2102
#  if defined(PNG_INTEL_SSE_IMPLEMENTATION) && PNG_INTEL_SSE_IMPLEMENTATION > 0
2103
PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
2104
   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2105
#  endif
2106
#endif
2107

2108
PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
2109
   png_const_charp key, png_bytep new_key), PNG_EMPTY);
2110

2111
/* Maintainer: Put new private prototypes here ^ */
2112

2113
#include "pngdebug.h"
2114

2115
#ifdef __cplusplus
2116
}
2117
#endif
2118

2119
#endif /* PNG_VERSION_INFO_ONLY */
2120
#endif /* PNGPRIV_H */
2121

2122
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