CoCalc -- pngpriv.h

GitHub Repository: wine-mirror/wine
Path: blob/master/libs/png/pngpriv.h
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/* pngpriv.h - private declarations for use inside libpng
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 *
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 * Copyright (c) 2018-2025 Cosmin Truta
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 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
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 * Copyright (c) 1996-1997 Andreas Dilger
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 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
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 *
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 * This code is released under the libpng license.
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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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/* pngpriv.h must be included first in each translation unit inside libpng.
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 * On the other hand, it must not be included at all, directly or indirectly,
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 * by any application code that uses the libpng API.
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 */
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#ifndef PNGPRIV_H
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#  define PNGPRIV_H
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#else
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#  error Duplicate inclusion of pngpriv.h; please check the libpng source files
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#endif
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#if defined(PNG_H) || defined(PNGCONF_H) || defined(PNGLCONF_H)
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#  error This file must not be included by applications; please include <png.h>
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#endif
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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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#include "pnglibconf.h"
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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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#ifndef PNG_RISCV_RVV_OPT
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   /* RISCV_RVV optimizations are being controlled by the compiler settings,
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    * typically the target compiler will define __riscv but the rvv extension
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    * availability has to be explicitly stated. This is why if no
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    * PNG_RISCV_RVV_OPT was defined then a runtime check will be executed.
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    *
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    * To enable RISCV_RVV optimizations unconditionally, and compile the
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    * associated code, pass --enable-riscv-rvv=yes or --enable-riscv-rvv=on
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    * to configure or put -DPNG_RISCV_RVV_OPT=2 in CPPFLAGS.
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    */
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#  define PNG_RISCV_RVV_OPT 0
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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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#  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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#else /* PNG_ARM_NEON_OPT == 0 */
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#     define PNG_ARM_NEON_IMPLEMENTATION 0
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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) && \
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   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_MIPS_MMI_OPT
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#  ifdef PNG_MIPS_MMI
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#    if defined(__mips_loongson_mmi) && (_MIPS_SIM == _ABI64) && \
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     defined(PNG_ALIGNED_MEMORY_SUPPORTED)
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#       define PNG_MIPS_MMI_OPT 1
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#    else
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#       define PNG_MIPS_MMI_OPT 0
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#    endif
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#  else
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#    define PNG_MIPS_MMI_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_LOONGARCH_LSX_OPT
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#  if defined(__loongarch_sx)
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#     define PNG_LOONGARCH_LSX_OPT 1
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#  else
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#     define PNG_LOONGARCH_LSX_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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#      else
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#         define PNG_INTEL_SSE_OPT 0
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#      endif
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#   else
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#      define PNG_INTEL_SSE_OPT 0
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#   endif
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#endif
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#if 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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#else
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#   define PNG_INTEL_SSE_IMPLEMENTATION 0
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#endif
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#if PNG_MIPS_MSA_OPT > 0
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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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#     define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_mips
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#  endif
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#else
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#  define PNG_MIPS_MSA_IMPLEMENTATION 0
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#endif /* PNG_MIPS_MSA_OPT > 0 */
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#if PNG_MIPS_MMI_OPT > 0
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#  ifndef PNG_MIPS_MMI_IMPLEMENTATION
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#     if defined(__mips_loongson_mmi) && (_MIPS_SIM == _ABI64)
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#        define PNG_MIPS_MMI_IMPLEMENTATION 2
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#     else /* !defined __mips_loongson_mmi  || _MIPS_SIM != _ABI64 */
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#        define PNG_MIPS_MMI_IMPLEMENTATION 0
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#     endif /* __mips_loongson_mmi  && _MIPS_SIM == _ABI64 */
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#  endif /* !PNG_MIPS_MMI_IMPLEMENTATION */
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#   if PNG_MIPS_MMI_IMPLEMENTATION > 0
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#      define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_mips
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#   endif
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#else
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#   define PNG_MIPS_MMI_IMPLEMENTATION 0
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#endif /* PNG_MIPS_MMI_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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#else
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#  define PNG_POWERPC_VSX_IMPLEMENTATION 0
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#endif
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#if PNG_LOONGARCH_LSX_OPT > 0
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#   define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_lsx
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#   define PNG_LOONGARCH_LSX_IMPLEMENTATION 1
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#else
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#   define PNG_LOONGARCH_LSX_IMPLEMENTATION 0
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#endif
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#if PNG_RISCV_RVV_OPT > 0
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#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_rvv
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#  ifndef PNG_RISCV_RVV_IMPLEMENTATION
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      /* Use the intrinsics code by default. */
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#     define PNG_RISCV_RVV_IMPLEMENTATION 1
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#  endif
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#else
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#  define PNG_RISCV_RVV_IMPLEMENTATION 0
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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
436
 * 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:
451
 *
452
 * libpng is built with support for internal limits on image dimensions and
453
 * memory usage.  These are documented in scripts/pnglibconf.dfa of the
454
 * source and recorded in the machine generated header file pnglibconf.h.
455
 */
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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
459
 * normally need that much memory in a chunk (unless you load up a very
460
 * 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
462
 * will fit into memory.
463
 *
464
 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
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 * same limit and pngconf.h (already included) sets the limit
466
 * if certain operating systems are detected.
467
 */
468
#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
469
#  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
474
 * which is expected to have no bad effects on performance (optimizing
475
 * compilers will probably remove it entirely).  Note that if you replace
476
 * it with something other than whitespace, you must include the terminating
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 * semicolon.
478
 */
479
#  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.
484
 */
485
#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
486
#  undef PNG_ZBUF_SIZE
487
#  define PNG_ZBUF_SIZE 65536L
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#endif
489

490
/* 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
492
 * error and warning messages - this code will also be disabled here.
493
 */
494
#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
508
 * they get used by the corresponding floating point APIs.  This magic
509
 * deals with this:
510
 */
511
#ifdef PNG_FIXED_POINT_SUPPORTED
512
#  define PNGFAPI PNGAPI
513
#else
514
#  define PNGFAPI /* PRIVATE */
515
#endif
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517
#ifndef PNG_VERSION_INFO_ONLY
518
/* Other defines specific to compilers can go here.  Try to keep
519
 * them inside an appropriate ifdef/endif pair for portability.
520
 */
521

522
/* C allows up-casts from (void*) to any pointer and (const void*) to any
523
 * pointer to a const object.  C++ regards this as a type error and requires an
524
 * explicit, static, cast and provides the static_cast<> rune to ensure that
525
 * const is not cast away.
526
 */
527
#ifdef __cplusplus
528
#  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) \
531
   static_cast<type>(static_cast<void*>(value))
532
#  define png_aligncastconst(type, value) \
533
   static_cast<type>(static_cast<const void*>(value))
534
#else
535
#  define png_voidcast(type, value) (value)
536
#  define png_constcast(type, value) ((type)(void*)(const void*)(value))
537
#  define png_aligncast(type, value) ((void*)(value))
538
#  define png_aligncastconst(type, value) ((const void*)(value))
539
#endif /* __cplusplus */
540

541
#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
542
    defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
543
   /* png.c requires the following ANSI-C constants if the conversion of
544
    * floating point to ASCII is implemented therein:
545
    *
546
    *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
547
    *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
548
    *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
549
    */
550
#  include <float.h>
551

552
#  include <math.h>
553

554
#  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
555
   /* Amiga SAS/C: We must include builtin FPU functions when compiling using
556
    * MATH=68881
557
    */
558
#    include <m68881.h>
559
#  endif
560
#endif
561

562
/* This provides the non-ANSI (far) memory allocation routines. */
563
#if defined(__TURBOC__) && defined(__MSDOS__)
564
#  include <mem.h>
565
#  include <alloc.h>
566
#endif
567

568
#if defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
569
#  include <windows.h>
570
#endif
571
#endif /* PNG_VERSION_INFO_ONLY */
572

573
/* Moved here around 1.5.0beta36 from pngconf.h */
574
/* Users may want to use these so they are not private.  Any library
575
 * functions that are passed far data must be model-independent.
576
 */
577

578
/* Platform-independent functions */
579
#ifndef PNG_ABORT
580
#  define PNG_ABORT() abort()
581
#endif
582

583
/* These macros may need to be architecture dependent. */
584
#define PNG_ALIGN_NONE      0 /* do not use data alignment */
585
#define PNG_ALIGN_ALWAYS    1 /* assume unaligned accesses are OK */
586
#ifdef offsetof
587
#  define PNG_ALIGN_OFFSET  2 /* use offsetof to determine alignment */
588
#else
589
#  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
590
#endif
591
#define PNG_ALIGN_SIZE      3 /* use sizeof to determine alignment */
592

593
#ifndef PNG_ALIGN_TYPE
594
   /* Default to using aligned access optimizations and requiring alignment to a
595
    * multiple of the data type size.  Override in a compiler specific fashion
596
    * if necessary by inserting tests here:
597
    */
598
#  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
599
#endif
600

601
#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
602
   /* This is used because in some compiler implementations non-aligned
603
    * structure members are supported, so the offsetof approach below fails.
604
    * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
605
    * is good for performance.  Do not do this unless you have tested the
606
    * result and understand it.
607
    */
608
#  define png_alignof(type) (sizeof(type))
609
#else
610
#  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
611
#    define png_alignof(type) offsetof(struct{char c; type t;}, t)
612
#  else
613
#    if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
614
#      define png_alignof(type) 1
615
#    endif
616
     /* Else leave png_alignof undefined to prevent use thereof */
617
#  endif
618
#endif
619

620
/* This implicitly assumes alignment is always a multiple of 2. */
621
#ifdef png_alignof
622
#  define png_isaligned(ptr, type) \
623
   (((type)(size_t)((const void*)(ptr)) & (type)(png_alignof(type)-1)) == 0)
624
#else
625
#  define png_isaligned(ptr, type) 0
626
#endif
627

628
/* End of memory model/platform independent support */
629
/* End of 1.5.0beta36 move from pngconf.h */
630

631
/* CONSTANTS and UTILITY MACROS
632
 * These are used internally by libpng and not exposed in the API
633
 */
634

635
/* Various modes of operation.  Note that after an init, mode is set to
636
 * zero automatically when the structure is created.  Three of these
637
 * are defined in png.h because they need to be visible to applications
638
 * that call png_set_unknown_chunk().
639
 */
640
/* #define PNG_HAVE_IHDR            0x01U (defined in png.h) */
641
/* #define PNG_HAVE_PLTE            0x02U (defined in png.h) */
642
#define PNG_HAVE_IDAT               0x04U
643
/* #define PNG_AFTER_IDAT           0x08U (defined in png.h) */
644
#define PNG_HAVE_IEND               0x10U
645
                   /*               0x20U (unused) */
646
                   /*               0x40U (unused) */
647
                   /*               0x80U (unused) */
648
#define PNG_HAVE_CHUNK_HEADER      0x100U
649
#define PNG_WROTE_tIME             0x200U
650
#define PNG_WROTE_INFO_BEFORE_PLTE 0x400U
651
#define PNG_BACKGROUND_IS_GRAY     0x800U
652
#define PNG_HAVE_PNG_SIGNATURE    0x1000U
653
#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
654
#define PNG_WROTE_eXIf            0x4000U
655
#define PNG_IS_READ_STRUCT        0x8000U /* Else is a write struct */
656

657
/* Flags for the transformations the PNG library does on the image data */
658
#define PNG_BGR                 0x0001U
659
#define PNG_INTERLACE           0x0002U
660
#define PNG_PACK                0x0004U
661
#define PNG_SHIFT               0x0008U
662
#define PNG_SWAP_BYTES          0x0010U
663
#define PNG_INVERT_MONO         0x0020U
664
#define PNG_QUANTIZE            0x0040U
665
#define PNG_COMPOSE             0x0080U    /* Was PNG_BACKGROUND */
666
#define PNG_BACKGROUND_EXPAND   0x0100U
667
#define PNG_EXPAND_16           0x0200U    /* Added to libpng 1.5.2 */
668
#define PNG_16_TO_8             0x0400U    /* Becomes 'chop' in 1.5.4 */
669
#define PNG_RGBA                0x0800U
670
#define PNG_EXPAND              0x1000U
671
#define PNG_GAMMA               0x2000U
672
#define PNG_GRAY_TO_RGB         0x4000U
673
#define PNG_FILLER              0x8000U
674
#define PNG_PACKSWAP           0x10000U
675
#define PNG_SWAP_ALPHA         0x20000U
676
#define PNG_STRIP_ALPHA        0x40000U
677
#define PNG_INVERT_ALPHA       0x80000U
678
#define PNG_USER_TRANSFORM    0x100000U
679
#define PNG_RGB_TO_GRAY_ERR   0x200000U
680
#define PNG_RGB_TO_GRAY_WARN  0x400000U
681
#define PNG_RGB_TO_GRAY       0x600000U /* two bits, RGB_TO_GRAY_ERR|WARN */
682
#define PNG_ENCODE_ALPHA      0x800000U /* Added to libpng-1.5.4 */
683
#define PNG_ADD_ALPHA        0x1000000U /* Added to libpng-1.2.7 */
684
#define PNG_EXPAND_tRNS      0x2000000U /* Added to libpng-1.2.9 */
685
#define PNG_SCALE_16_TO_8    0x4000000U /* Added to libpng-1.5.4 */
686
                       /*    0x8000000U unused */
687
                       /*   0x10000000U unused */
688
                       /*   0x20000000U unused */
689
                       /*   0x40000000U unused */
690
/* Flags for png_create_struct */
691
#define PNG_STRUCT_PNG   0x0001U
692
#define PNG_STRUCT_INFO  0x0002U
693

694
/* Flags for the png_ptr->flags rather than declaring a byte for each one */
695
#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001U
696
#define PNG_FLAG_ZSTREAM_INITIALIZED      0x0002U /* Added to libpng-1.6.0 */
697
                                  /*      0x0004U    unused */
698
#define PNG_FLAG_ZSTREAM_ENDED            0x0008U /* Added to libpng-1.6.0 */
699
                                  /*      0x0010U    unused */
700
                                  /*      0x0020U    unused */
701
#define PNG_FLAG_ROW_INIT                 0x0040U
702
#define PNG_FLAG_FILLER_AFTER             0x0080U
703
#define PNG_FLAG_CRC_ANCILLARY_USE        0x0100U
704
#define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200U
705
#define PNG_FLAG_CRC_CRITICAL_USE         0x0400U
706
#define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800U
707
/*      PNG_FLAG_ASSUME_sRGB unused       0x1000U  * Added to libpng-1.5.4 */
708
#define PNG_FLAG_OPTIMIZE_ALPHA           0x2000U /* Added to libpng-1.5.4 */
709
#define PNG_FLAG_DETECT_UNINITIALIZED     0x4000U /* Added to libpng-1.5.4 */
710
/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000U */
711
/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS      0x10000U */
712
#define PNG_FLAG_LIBRARY_MISMATCH        0x20000U
713
#define PNG_FLAG_STRIP_ERROR_NUMBERS     0x40000U
714
#define PNG_FLAG_STRIP_ERROR_TEXT        0x80000U
715
#define PNG_FLAG_BENIGN_ERRORS_WARN     0x100000U /* Added to libpng-1.4.0 */
716
#define PNG_FLAG_APP_WARNINGS_WARN      0x200000U /* Added to libpng-1.6.0 */
717
#define PNG_FLAG_APP_ERRORS_WARN        0x400000U /* Added to libpng-1.6.0 */
718
                                  /*    0x800000U    unused */
719
                                  /*   0x1000000U    unused */
720
                                  /*   0x2000000U    unused */
721
                                  /*   0x4000000U    unused */
722
                                  /*   0x8000000U    unused */
723
                                  /*  0x10000000U    unused */
724
                                  /*  0x20000000U    unused */
725
                                  /*  0x40000000U    unused */
726

727
#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
728
                                     PNG_FLAG_CRC_ANCILLARY_NOWARN)
729

730
#define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
731
                                     PNG_FLAG_CRC_CRITICAL_IGNORE)
732

733
#define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
734
                                     PNG_FLAG_CRC_CRITICAL_MASK)
735

736
/* Save typing and make code easier to understand */
737

738
#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
739
   abs((int)((c1).green) - (int)((c2).green)) + \
740
   abs((int)((c1).blue) - (int)((c2).blue)))
741

742
/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
743
 * by dividing by 257 *with rounding*.  This macro is exact for the given range.
744
 * See the discourse in pngrtran.c png_do_scale_16_to_8.  The values in the
745
 * macro were established by experiment (modifying the added value).  The macro
746
 * has a second variant that takes a value already scaled by 255 and divides by
747
 * 65535 - this has a maximum error of .502.  Over the range 0..65535*65535 it
748
 * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
749
 */
750
#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
751
#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
752

753
/* Added to libpng-1.2.6 JB */
754
#define PNG_ROWBYTES(pixel_bits, width) \
755
    ((pixel_bits) >= 8 ? \
756
    ((size_t)(width) * (((size_t)(pixel_bits)) >> 3)) : \
757
    (( ((size_t)(width) * ((size_t)(pixel_bits))) + 7) >> 3) )
758

759
/* This returns the number of trailing bits in the last byte of a row, 0 if the
760
 * last byte is completely full of pixels.  It is, in principle, (pixel_bits x
761
 * width) % 8, but that would overflow for large 'width'.  The second macro is
762
 * the same except that it returns the number of unused bits in the last byte;
763
 * (8-TRAILBITS), but 0 when TRAILBITS is 0.
764
 *
765
 * NOTE: these macros are intended to be self-evidently correct and never
766
 * overflow on the assumption that pixel_bits is in the range 0..255.  The
767
 * arguments are evaluated only once and they can be signed (e.g. as a result of
768
 * the integral promotions).  The result of the expression always has type
769
 * (png_uint_32), however the compiler always knows it is in the range 0..7.
770
 */
771
#define PNG_TRAILBITS(pixel_bits, width) \
772
    (((pixel_bits) * ((width) % (png_uint_32)8)) % 8)
773

774
#define PNG_PADBITS(pixel_bits, width) \
775
    ((8 - PNG_TRAILBITS(pixel_bits, width)) % 8)
776

777
/* PNG_OUT_OF_RANGE returns true if value is outside the range
778
 * ideal-delta..ideal+delta.  Each argument is evaluated twice.
779
 * "ideal" and "delta" should be constants, normally simple
780
 * integers, "value" a variable. Added to libpng-1.2.6 JB
781
 */
782
#define PNG_OUT_OF_RANGE(value, ideal, delta) \
783
   ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
784

785
/* Conversions between fixed and floating point, only defined if
786
 * required (to make sure the code doesn't accidentally use float
787
 * when it is supposedly disabled.)
788
 */
789
#ifdef PNG_FLOATING_POINT_SUPPORTED
790
/* The floating point conversion can't overflow, though it can and
791
 * does lose accuracy relative to the original fixed point value.
792
 * In practice this doesn't matter because png_fixed_point only
793
 * stores numbers with very low precision.  The png_ptr and s
794
 * arguments are unused by default but are there in case error
795
 * checking becomes a requirement.
796
 */
797
#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
798

799
/* The fixed point conversion performs range checking and evaluates
800
 * its argument multiple times, so must be used with care.  The
801
 * range checking uses the PNG specification values for a signed
802
 * 32-bit fixed point value except that the values are deliberately
803
 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
804
 * (2^31-1) * 100000). 's' is a string that describes the value being
805
 * converted.
806
 *
807
 * NOTE: this macro will raise a png_error if the range check fails,
808
 * therefore it is normally only appropriate to use this on values
809
 * that come from API calls or other sources where an out of range
810
 * error indicates a programming error, not a data error!
811
 *
812
 * NOTE: by default this is off - the macro is not used - because the
813
 * function call saves a lot of code.
814
 */
815
#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
816
#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
817
    ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
818
#define png_fixed_ITU(png_ptr, fp, s) ((fp) <= 214748 && (fp) >= 0 ?\
819
    ((png_uint_32)(10000 * (fp))) : (png_fixed_error(png_ptr, s),0))
820
#endif
821
/* else the corresponding function is defined below, inside the scope of the
822
 * cplusplus test.
823
 */
824
#endif
825

826
/* Constants for known chunk types.  If you need to add a chunk, define the name
827
 * here.  For historical reasons these constants have the form png_<name>; i.e.
828
 * the prefix is lower case.  Please use decimal values as the parameters to
829
 * match the ISO PNG specification and to avoid relying on the C locale
830
 * interpretation of character values.
831
 *
832
 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
833
 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
834
 * to be generated if required.
835
 *
836
 * PNG_32b correctly produces a value shifted by up to 24 bits, even on
837
 * architectures where (int) is only 16 bits.
838
 *
839
 * 1.6.47: PNG_32b was made into a preprocessor evaluable macro by replacing the
840
 * static_cast with a promoting binary operation using a guaranteed 32-bit
841
 * (minimum) unsigned value.
842
 */
843
#define PNG_32b(b,s) (((0xFFFFFFFFU)&(b)) << (s))
844
#define PNG_U32(b1,b2,b3,b4) \
845
   (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
846

847
/* Chunk name validation.  When using these macros all the arguments should be
848
 * constants, otherwise code bloat may well occur.  The macros are provided
849
 * primarily for use in #if checks.
850
 *
851
 * PNG_32to8 produces a byte value with the right shift; used to extract the
852
 * byte value from a chunk name.
853
 */
854
#define PNG_32to8(cn,s) (((cn) >> (s)) & 0xffU)
855
#define PNG_CN_VALID_UPPER(b) ((b) >= 65 && (b) <= 90) /* upper-case ASCII */
856
#define PNG_CN_VALID_ASCII(b) PNG_CN_VALID_UPPER((b) & ~32U)
857
#define PNG_CHUNK_NAME_VALID(cn) (\
858
   PNG_CN_VALID_ASCII(PNG_32to8(cn,24)) && /* critical, !ancillary */\
859
   PNG_CN_VALID_ASCII(PNG_32to8(cn,16)) && /* public, !privately defined */\
860
   PNG_CN_VALID_UPPER(PNG_32to8(cn, 8)) && /* VALID, !reserved */\
861
   PNG_CN_VALID_ASCII(PNG_32to8(cn, 0))   /* data-dependent, !copy ok */)
862

863
/* Constants for known chunk types.
864
 *
865
 * MAINTAINERS: If you need to add a chunk, define the name here.
866
 * For historical reasons these constants have the form png_<name>; i.e.
867
 * the prefix is lower case.  Please use decimal values as the parameters to
868
 * match the ISO PNG specification and to avoid relying on the C locale
869
 * interpretation of character values.  Please keep the list sorted.
870
 *
871
 * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
872
 * type.  In fact the specification does not express chunk types this way,
873
 * however using a 32-bit value means that the chunk type can be read from the
874
 * stream using exactly the same code as used for a 32-bit unsigned value and
875
 * can be examined far more efficiently (using one arithmetic compare).
876
 *
877
 * Prior to 1.5.6 the chunk type constants were expressed as C strings.  The
878
 * libpng API still uses strings for 'unknown' chunks and a macro,
879
 * PNG_STRING_FROM_CHUNK, allows a string to be generated if required.  Notice
880
 * that for portable code numeric values must still be used; the string "IHDR"
881
 * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
882
 *
883
 * In 1.7.0 the definitions will be made public in png.h to avoid having to
884
 * duplicate the same definitions in application code.
885
 */
886
#define png_IDAT PNG_U32( 73,  68,  65,  84)
887
#define png_IEND PNG_U32( 73,  69,  78,  68)
888
#define png_IHDR PNG_U32( 73,  72,  68,  82)
889
#define png_PLTE PNG_U32( 80,  76,  84,  69)
890
#define png_acTL PNG_U32( 97,  99,  84,  76) /* PNGv3: APNG */
891
#define png_bKGD PNG_U32( 98,  75,  71,  68)
892
#define png_cHRM PNG_U32( 99,  72,  82,  77)
893
#define png_cICP PNG_U32( 99,  73,  67,  80) /* PNGv3 */
894
#define png_cLLI PNG_U32( 99,  76,  76,  73) /* PNGv3 */
895
#define png_eXIf PNG_U32(101,  88,  73, 102) /* registered July 2017 */
896
#define png_fcTL PNG_U32(102,  99,  84,  76) /* PNGv3: APNG */
897
#define png_fdAT PNG_U32(102, 100,  65,  84) /* PNGv3: APNG */
898
#define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
899
#define png_gAMA PNG_U32(103,  65,  77,  65)
900
#define png_gIFg PNG_U32(103,  73,  70, 103)
901
#define png_gIFt PNG_U32(103,  73,  70, 116) /* deprecated */
902
#define png_gIFx PNG_U32(103,  73,  70, 120)
903
#define png_hIST PNG_U32(104,  73,  83,  84)
904
#define png_iCCP PNG_U32(105,  67,  67,  80)
905
#define png_iTXt PNG_U32(105,  84,  88, 116)
906
#define png_mDCV PNG_U32(109,  68,  67,  86) /* PNGv3 */
907
#define png_oFFs PNG_U32(111,  70,  70, 115)
908
#define png_pCAL PNG_U32(112,  67,  65,  76)
909
#define png_pHYs PNG_U32(112,  72,  89, 115)
910
#define png_sBIT PNG_U32(115,  66,  73,  84)
911
#define png_sCAL PNG_U32(115,  67,  65,  76)
912
#define png_sPLT PNG_U32(115,  80,  76,  84)
913
#define png_sRGB PNG_U32(115,  82,  71,  66)
914
#define png_sTER PNG_U32(115,  84,  69,  82)
915
#define png_tEXt PNG_U32(116,  69,  88, 116)
916
#define png_tIME PNG_U32(116,  73,  77,  69)
917
#define png_tRNS PNG_U32(116,  82,  78,  83)
918
#define png_zTXt PNG_U32(122,  84,  88, 116)
919

920
/* The following will work on (signed char*) strings, whereas the get_uint_32
921
 * macro will fail on top-bit-set values because of the sign extension.
922
 */
923
#define PNG_CHUNK_FROM_STRING(s)\
924
   PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
925

926
/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
927
 * signed and the argument is a (char[])  This macro will fail miserably on
928
 * systems where (char) is more than 8 bits.
929
 */
930
#define PNG_STRING_FROM_CHUNK(s,c)\
931
   (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
932
   ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
933
   ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
934
   ((char*)(s))[3]=(char)((c & 0xff)))
935

936
/* Do the same but terminate with a null character. */
937
#define PNG_CSTRING_FROM_CHUNK(s,c)\
938
   (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
939

940
/* Test on flag values as defined in the spec (section 5.4): */
941
#define PNG_CHUNK_ANCILLARY(c)   (1 & ((c) >> 29))
942
#define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLARY(c))
943
#define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
944
#define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
945
#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
946

947
/* Known chunks.  All supported chunks must be listed here.  The macro PNG_CHUNK
948
 * contains the four character ASCII name by which the chunk is identified.  The
949
 * macro is implemented as required to build tables or switch statements which
950
 * require entries for every known chunk.  The macro also contains an index
951
 * value which should be in order (this is checked in png.c).
952
 *
953
 * Notice that "known" does not require "SUPPORTED"; tables should be built in
954
 * such a way that chunks unsupported in a build require no more than the table
955
 * entry (which should be small.)  In particular function pointers for
956
 * unsupported chunks should be NULL.
957
 *
958
 * At present these index values are not exported (not part of the public API)
959
 * so can be changed at will.  For convenience the names are in lexical sort
960
 * order but with the critical chunks at the start in the order of occurence in
961
 * a PNG.
962
 *
963
 * PNG_INFO_ values do not exist for every one of these chunk handles; for
964
 * example PNG_INFO_{IDAT,IEND,tEXt,iTXt,zTXt} and possibly other chunks in the
965
 * future.
966
 */
967
#define PNG_KNOWN_CHUNKS\
968
   PNG_CHUNK(IHDR,  0)\
969
   PNG_CHUNK(PLTE,  1)\
970
   PNG_CHUNK(IDAT,  2)\
971
   PNG_CHUNK(IEND,  3)\
972
   PNG_CHUNK(acTL,  4)\
973
   PNG_CHUNK(bKGD,  5)\
974
   PNG_CHUNK(cHRM,  6)\
975
   PNG_CHUNK(cICP,  7)\
976
   PNG_CHUNK(cLLI,  8)\
977
   PNG_CHUNK(eXIf,  9)\
978
   PNG_CHUNK(fcTL, 10)\
979
   PNG_CHUNK(fdAT, 11)\
980
   PNG_CHUNK(gAMA, 12)\
981
   PNG_CHUNK(hIST, 13)\
982
   PNG_CHUNK(iCCP, 14)\
983
   PNG_CHUNK(iTXt, 15)\
984
   PNG_CHUNK(mDCV, 16)\
985
   PNG_CHUNK(oFFs, 17)\
986
   PNG_CHUNK(pCAL, 18)\
987
   PNG_CHUNK(pHYs, 19)\
988
   PNG_CHUNK(sBIT, 20)\
989
   PNG_CHUNK(sCAL, 21)\
990
   PNG_CHUNK(sPLT, 22)\
991
   PNG_CHUNK(sRGB, 23)\
992
   PNG_CHUNK(tEXt, 24)\
993
   PNG_CHUNK(tIME, 25)\
994
   PNG_CHUNK(tRNS, 26)\
995
   PNG_CHUNK(zTXt, 27)
996

997
/* Gamma values (new at libpng-1.5.4): */
998
#define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
999
#define PNG_GAMMA_MAC_INVERSE 65909
1000
#define PNG_GAMMA_sRGB_INVERSE 45455
1001

1002
/* gamma sanity check.  libpng cannot implement gamma transforms outside a
1003
 * certain limit because of its use of 16-bit fixed point intermediate values.
1004
 * Gamma values that are too large or too small will zap the 16-bit values all
1005
 * to 0 or 65535 resulting in an obvious 'bad' image.
1006
 *
1007
 * In libpng 1.6.0 the limits were changed from 0.07..3 to 0.01..100 to
1008
 * accommodate the optimal 16-bit gamma of 36 and its reciprocal.
1009
 *
1010
 * These are png_fixed_point integral values:
1011
 */
1012
#define PNG_LIB_GAMMA_MIN 1000
1013
#define PNG_LIB_GAMMA_MAX 10000000
1014

1015
/* Almost everything below is C specific; the #defines above can be used in
1016
 * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
1017
 */
1018
#ifndef PNG_VERSION_INFO_ONLY
1019

1020
#include "pngstruct.h"
1021
#include "pnginfo.h"
1022

1023
/* Validate the include paths - the include path used to generate pnglibconf.h
1024
 * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
1025
 */
1026
#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
1027
#  error The include path of <zlib.h> is incorrect
1028
   /* When pnglibconf.h was built, the copy of zlib.h that it used was not the
1029
    * same as the one being used here.  Considering how libpng makes decisions
1030
    * to use the zlib API based on the zlib version number, the -I options must
1031
    * match.
1032
    *
1033
    * A possible cause of this mismatch is that you passed an -I option in
1034
    * CFLAGS, which is unlikely to work.  All the preprocessor options, and all
1035
    * the -I options in particular, should be in CPPFLAGS.
1036
    */
1037
#endif
1038

1039
/* This is used for 16-bit gamma tables -- only the top level pointers are
1040
 * const; this could be changed:
1041
 */
1042
typedef const png_uint_16p * png_const_uint_16pp;
1043

1044
/* Added to libpng-1.5.7: sRGB conversion tables */
1045
#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
1046
   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
1047
#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
1048
PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
1049
   /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
1050
    * 0..65535.  This table gives the closest 16-bit answers (no errors).
1051
    */
1052
#endif
1053

1054
PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
1055
PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
1056

1057
#define PNG_sRGB_FROM_LINEAR(linear) \
1058
  ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
1059
   + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
1060
   /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
1061
    * encoded value with maximum error 0.646365.  Note that the input is not a
1062
    * 16-bit value; it has been multiplied by 255! */
1063
#endif /* SIMPLIFIED_READ/WRITE */
1064

1065

1066
/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
1067
#ifdef __cplusplus
1068
extern "C" {
1069
#endif /* __cplusplus */
1070

1071
/* Internal functions; these are not exported from a DLL however because they
1072
 * are used within several of the C source files they have to be C extern.
1073
 *
1074
 * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
1075
 */
1076
/* Zlib support */
1077
#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
1078
PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
1079
   PNG_EMPTY);
1080
   /* Used by the zlib handling functions to ensure that z_stream::msg is always
1081
    * set before they return.
1082
    */
1083

1084
#ifdef PNG_WRITE_SUPPORTED
1085
PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
1086
   png_compression_bufferp *list),PNG_EMPTY);
1087
   /* Free the buffer list used by the compressed write code. */
1088
#endif
1089

1090
#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
1091
   !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
1092
   (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
1093
   defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
1094
   defined(PNG_mDCV_SUPPORTED) || \
1095
   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
1096
   (defined(PNG_sCAL_SUPPORTED) && \
1097
   defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
1098
PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
1099
   double fp, png_const_charp text),PNG_EMPTY);
1100
#endif
1101

1102
#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
1103
   !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
1104
   (defined(PNG_cLLI_SUPPORTED) || defined(PNG_mDCV_SUPPORTED))
1105
PNG_INTERNAL_FUNCTION(png_uint_32,png_fixed_ITU,(png_const_structrp png_ptr,
1106
   double fp, png_const_charp text),PNG_EMPTY);
1107
#endif
1108

1109
/* Check the user version string for compatibility, returns false if the version
1110
 * numbers aren't compatible.
1111
 */
1112
PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
1113
   png_const_charp user_png_ver),PNG_EMPTY);
1114

1115
#ifdef PNG_READ_SUPPORTED /* should only be used on read */
1116
/* Security: read limits on the largest allocations while reading a PNG.  This
1117
 * avoids very large allocations caused by PNG files with damaged or altered
1118
 * chunk 'length' fields.
1119
 */
1120
#ifdef PNG_SET_USER_LIMITS_SUPPORTED /* run-time limit */
1121
#  define png_chunk_max(png_ptr) ((png_ptr)->user_chunk_malloc_max)
1122

1123
#elif PNG_USER_CHUNK_MALLOC_MAX > 0 /* compile-time limit */
1124
#  define png_chunk_max(png_ptr) ((void)png_ptr, PNG_USER_CHUNK_MALLOC_MAX)
1125

1126
#elif (defined PNG_MAX_MALLOC_64K)  /* legacy system limit */
1127
#  define png_chunk_max(png_ptr) ((void)png_ptr, 65536U)
1128

1129
#else                               /* modern system limit SIZE_MAX (C99) */
1130
#  define png_chunk_max(png_ptr) ((void)png_ptr, PNG_SIZE_MAX)
1131
#endif
1132
#endif /* READ */
1133

1134
/* Internal base allocator - no messages, NULL on failure to allocate.  This
1135
 * does, however, call the application provided allocator and that could call
1136
 * png_error (although that would be a bug in the application implementation.)
1137
 */
1138
PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
1139
   png_alloc_size_t size),PNG_ALLOCATED);
1140

1141
#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
1142
   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
1143
/* Internal array allocator, outputs no error or warning messages on failure,
1144
 * just returns NULL.
1145
 */
1146
PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
1147
   int nelements, size_t element_size),PNG_ALLOCATED);
1148

1149
/* The same but an existing array is extended by add_elements.  This function
1150
 * also memsets the new elements to 0 and copies the old elements.  The old
1151
 * array is not freed or altered.
1152
 */
1153
PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
1154
   png_const_voidp array, int old_elements, int add_elements,
1155
   size_t element_size),PNG_ALLOCATED);
1156
#endif /* text, sPLT or unknown chunks */
1157

1158
/* Magic to create a struct when there is no struct to call the user supplied
1159
 * memory allocators.  Because error handling has not been set up the memory
1160
 * handlers can't safely call png_error, but this is an obscure and undocumented
1161
 * restriction so libpng has to assume that the 'free' handler, at least, might
1162
 * call png_error.
1163
 */
1164
PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
1165
   (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1166
    png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
1167
    png_free_ptr free_fn),PNG_ALLOCATED);
1168

1169
/* Free memory from internal libpng struct */
1170
PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
1171
   PNG_EMPTY);
1172

1173
/* Free an allocated jmp_buf (always succeeds) */
1174
PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
1175

1176
/* Function to allocate memory for zlib.  PNGAPI is disallowed. */
1177
PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
1178
   PNG_ALLOCATED);
1179

1180
/* Function to free memory for zlib.  PNGAPI is disallowed. */
1181
PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
1182

1183
/* Next four functions are used internally as callbacks.  PNGCBAPI is required
1184
 * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
1185
 * PNGCBAPI at 1.5.0
1186
 */
1187

1188
PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
1189
    png_bytep data, size_t length),PNG_EMPTY);
1190

1191
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1192
PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
1193
    png_bytep buffer, size_t length),PNG_EMPTY);
1194
#endif
1195

1196
PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
1197
    png_bytep data, size_t length),PNG_EMPTY);
1198

1199
#ifdef PNG_WRITE_FLUSH_SUPPORTED
1200
#  ifdef PNG_STDIO_SUPPORTED
1201
PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
1202
   PNG_EMPTY);
1203
#  endif
1204
#endif
1205

1206
/* Reset the CRC variable */
1207
PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
1208

1209
/* Write the "data" buffer to whatever output you are using */
1210
PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
1211
    png_const_bytep data, size_t length),PNG_EMPTY);
1212

1213
/* Read and check the PNG file signature */
1214
PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
1215
   png_inforp info_ptr),PNG_EMPTY);
1216

1217
/* Read the chunk header (length + type name) */
1218
PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
1219
   PNG_EMPTY);
1220

1221
/* Read data from whatever input you are using into the "data" buffer */
1222
PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
1223
    size_t length),PNG_EMPTY);
1224

1225
/* Read bytes into buf, and update png_ptr->crc */
1226
PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
1227
    png_uint_32 length),PNG_EMPTY);
1228

1229
/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
1230
PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
1231
   png_uint_32 skip),PNG_EMPTY);
1232

1233
/* Calculate the CRC over a section of data.  Note that we are only
1234
 * passing a maximum of 64K on systems that have this as a memory limit,
1235
 * since this is the maximum buffer size we can specify.
1236
 */
1237
PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
1238
   png_const_bytep ptr, size_t length),PNG_EMPTY);
1239

1240
#ifdef PNG_WRITE_FLUSH_SUPPORTED
1241
PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
1242
#endif
1243

1244
/* Write various chunks */
1245

1246
/* Write the IHDR chunk, and update the png_struct with the necessary
1247
 * information.
1248
 */
1249
PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
1250
   png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1251
   int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
1252

1253
PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
1254
   png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
1255

1256
PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
1257
   png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
1258
   PNG_EMPTY);
1259

1260
PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
1261

1262
#ifdef PNG_WRITE_gAMA_SUPPORTED
1263
PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
1264
    png_fixed_point file_gamma),PNG_EMPTY);
1265
#endif
1266

1267
#ifdef PNG_WRITE_sBIT_SUPPORTED
1268
PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
1269
    png_const_color_8p sbit, int color_type),PNG_EMPTY);
1270
#endif
1271

1272
#ifdef PNG_WRITE_cHRM_SUPPORTED
1273
PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
1274
    const png_xy *xy), PNG_EMPTY);
1275
   /* The xy value must have been previously validated */
1276
#endif
1277

1278
#ifdef PNG_WRITE_cICP_SUPPORTED
1279
PNG_INTERNAL_FUNCTION(void,png_write_cICP,(png_structrp png_ptr,
1280
    png_byte colour_primaries, png_byte transfer_function,
1281
    png_byte matrix_coefficients, png_byte video_full_range_flag), PNG_EMPTY);
1282
#endif
1283

1284
#ifdef PNG_WRITE_cLLI_SUPPORTED
1285
PNG_INTERNAL_FUNCTION(void,png_write_cLLI_fixed,(png_structrp png_ptr,
1286
   png_uint_32 maxCLL, png_uint_32 maxFALL), PNG_EMPTY);
1287
#endif
1288

1289
#ifdef PNG_WRITE_mDCV_SUPPORTED
1290
PNG_INTERNAL_FUNCTION(void,png_write_mDCV_fixed,(png_structrp png_ptr,
1291
   png_uint_16 red_x, png_uint_16 red_y,
1292
   png_uint_16 green_x, png_uint_16 green_y,
1293
   png_uint_16 blue_x, png_uint_16 blue_y,
1294
   png_uint_16 white_x, png_uint_16 white_y,
1295
   png_uint_32 maxDL, png_uint_32 minDL), PNG_EMPTY);
1296
#endif
1297

1298
#ifdef PNG_WRITE_sRGB_SUPPORTED
1299
PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1300
    int intent),PNG_EMPTY);
1301
#endif
1302

1303
#ifdef PNG_WRITE_eXIf_SUPPORTED
1304
PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr,
1305
    png_bytep exif, int num_exif),PNG_EMPTY);
1306
#endif
1307

1308
#ifdef PNG_WRITE_iCCP_SUPPORTED
1309
PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1310
   png_const_charp name, png_const_bytep profile, png_uint_32 proflen),
1311
   PNG_EMPTY);
1312
   /* Writes a previously 'set' profile.  The profile argument is **not**
1313
    * compressed.
1314
    */
1315
#endif
1316

1317
#ifdef PNG_WRITE_sPLT_SUPPORTED
1318
PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1319
    png_const_sPLT_tp palette),PNG_EMPTY);
1320
#endif
1321

1322
#ifdef PNG_WRITE_tRNS_SUPPORTED
1323
PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1324
    png_const_bytep trans, png_const_color_16p values, int number,
1325
    int color_type),PNG_EMPTY);
1326
#endif
1327

1328
#ifdef PNG_WRITE_bKGD_SUPPORTED
1329
PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1330
    png_const_color_16p values, int color_type),PNG_EMPTY);
1331
#endif
1332

1333
#ifdef PNG_WRITE_hIST_SUPPORTED
1334
PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1335
    png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1336
#endif
1337

1338
/* Chunks that have keywords */
1339
#ifdef PNG_WRITE_tEXt_SUPPORTED
1340
PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1341
   png_const_charp key, png_const_charp text, size_t text_len),PNG_EMPTY);
1342
#endif
1343

1344
#ifdef PNG_WRITE_zTXt_SUPPORTED
1345
PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1346
    key, png_const_charp text, int compression),PNG_EMPTY);
1347
#endif
1348

1349
#ifdef PNG_WRITE_iTXt_SUPPORTED
1350
PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1351
    int compression, png_const_charp key, png_const_charp lang,
1352
    png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1353
#endif
1354

1355
#ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
1356
PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1357
    png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1358
#endif
1359

1360
#ifdef PNG_WRITE_oFFs_SUPPORTED
1361
PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1362
    png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1363
#endif
1364

1365
#ifdef PNG_WRITE_pCAL_SUPPORTED
1366
PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1367
    png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1368
    png_const_charp units, png_charpp params),PNG_EMPTY);
1369
#endif
1370

1371
#ifdef PNG_WRITE_pHYs_SUPPORTED
1372
PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1373
    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1374
    int unit_type),PNG_EMPTY);
1375
#endif
1376

1377
#ifdef PNG_WRITE_tIME_SUPPORTED
1378
PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1379
    png_const_timep mod_time),PNG_EMPTY);
1380
#endif
1381

1382
#ifdef PNG_WRITE_sCAL_SUPPORTED
1383
PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1384
    int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1385
#endif
1386

1387
/* Called when finished processing a row of data */
1388
PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1389
    PNG_EMPTY);
1390

1391
/* Internal use only.   Called before first row of data */
1392
PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1393
    PNG_EMPTY);
1394

1395
/* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
1396
 * array of png_ptr->width pixels.  If the image is not interlaced or this
1397
 * is the final pass this just does a memcpy, otherwise the "display" flag
1398
 * is used to determine whether to copy pixels that are not in the current pass.
1399
 *
1400
 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1401
 * function to achieve the documented 'blocky' appearance during interlaced read
1402
 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1403
 * are not changed if they are not in the current pass, when display is 0.
1404
 *
1405
 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1406
 *
1407
 * The API always reads from the png_struct row buffer and always assumes that
1408
 * it is full width (png_do_read_interlace has already been called.)
1409
 *
1410
 * This function is only ever used to write to row buffers provided by the
1411
 * caller of the relevant libpng API and the row must have already been
1412
 * transformed by the read transformations.
1413
 *
1414
 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1415
 * bitmasks for use within the code, otherwise runtime generated masks are used.
1416
 * The default is compile time masks.
1417
 */
1418
#ifndef PNG_USE_COMPILE_TIME_MASKS
1419
#  define PNG_USE_COMPILE_TIME_MASKS 1
1420
#endif
1421
PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1422
    png_bytep row, int display),PNG_EMPTY);
1423

1424
#ifdef PNG_READ_INTERLACING_SUPPORTED
1425
/* Expand an interlaced row: the 'row_info' describes the pass data that has
1426
 * been read in and must correspond to the pixels in 'row', the pixels are
1427
 * expanded (moved apart) in 'row' to match the final layout, when doing this
1428
 * the pixels are *replicated* to the intervening space.  This is essential for
1429
 * the correct operation of png_combine_row, above.
1430
 */
1431
PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1432
    png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1433
#endif
1434

1435
/* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
1436

1437
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1438
/* Grab pixels out of a row for an interlaced pass */
1439
PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1440
    png_bytep row, int pass),PNG_EMPTY);
1441
#endif
1442

1443
/* Unfilter a row: check the filter value before calling this, there is no point
1444
 * calling it for PNG_FILTER_VALUE_NONE.
1445
 */
1446
PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1447
    row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1448

1449
#if PNG_ARM_NEON_OPT > 0
1450
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1451
    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1452
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1453
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1454
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1455
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1456
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1457
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1458
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1459
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1460
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1461
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1462
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1463
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1464
#endif
1465

1466
#if PNG_MIPS_MSA_IMPLEMENTATION == 1
1467
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_msa,(png_row_infop row_info,
1468
    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1469
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_msa,(png_row_infop
1470
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1471
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_msa,(png_row_infop
1472
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1473
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_msa,(png_row_infop
1474
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1475
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop
1476
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1477
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop
1478
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1479
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop
1480
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1481
#endif
1482

1483
#if PNG_MIPS_MMI_IMPLEMENTATION > 0
1484
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_mmi,(png_row_infop row_info,
1485
    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1486
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_mmi,(png_row_infop
1487
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1488
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_mmi,(png_row_infop
1489
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1490
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_mmi,(png_row_infop
1491
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1492
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_mmi,(png_row_infop
1493
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1494
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_mmi,(png_row_infop
1495
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1496
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_mmi,(png_row_infop
1497
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1498
#endif
1499

1500
#if PNG_POWERPC_VSX_OPT > 0
1501
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_vsx,(png_row_infop row_info,
1502
    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1503
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_vsx,(png_row_infop
1504
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1505
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_vsx,(png_row_infop
1506
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1507
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_vsx,(png_row_infop
1508
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1509
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_vsx,(png_row_infop
1510
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1511
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_vsx,(png_row_infop
1512
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1513
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_vsx,(png_row_infop
1514
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1515
#endif
1516

1517
#if PNG_INTEL_SSE_IMPLEMENTATION > 0
1518
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
1519
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1520
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
1521
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1522
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
1523
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1524
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
1525
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1526
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
1527
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1528
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
1529
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1530
#endif
1531

1532
#if PNG_LOONGARCH_LSX_IMPLEMENTATION == 1
1533
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_lsx,(png_row_infop
1534
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1535
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_lsx,(png_row_infop
1536
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1537
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_lsx,(png_row_infop
1538
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1539
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_lsx,(png_row_infop
1540
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1541
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_lsx,(png_row_infop
1542
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1543
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_lsx,(png_row_infop
1544
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1545
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_lsx,(png_row_infop
1546
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1547
#endif
1548

1549
#if PNG_RISCV_RVV_OPT > 0
1550
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_rvv,(png_row_infop
1551
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1552
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_rvv,(png_row_infop
1553
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1554
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_rvv,(png_row_infop
1555
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1556
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_rvv,(png_row_infop
1557
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1558
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_rvv,(png_row_infop
1559
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1560
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_rvv,(png_row_infop
1561
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1562
PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_rvv,(png_row_infop
1563
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1564
#endif
1565

1566
/* Choose the best filter to use and filter the row data */
1567
PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1568
    png_row_infop row_info),PNG_EMPTY);
1569

1570
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1571
PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1572
   png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1573
   /* Read 'avail_out' bytes of data from the IDAT stream.  If the output buffer
1574
    * is NULL the function checks, instead, for the end of the stream.  In this
1575
    * case a benign error will be issued if the stream end is not found or if
1576
    * extra data has to be consumed.
1577
    */
1578
PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1579
   PNG_EMPTY);
1580
   /* This cleans up when the IDAT LZ stream does not end when the last image
1581
    * byte is read; there is still some pending input.
1582
    */
1583

1584
PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1585
   PNG_EMPTY);
1586
   /* Finish a row while reading, dealing with interlacing passes, etc. */
1587
#endif /* SEQUENTIAL_READ */
1588

1589
/* Initialize the row buffers, etc. */
1590
PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1591

1592
#if ZLIB_VERNUM >= 0x1240
1593
PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
1594
      PNG_EMPTY);
1595
#  define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
1596
#else /* Zlib < 1.2.4 */
1597
#  define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
1598
#endif /* Zlib < 1.2.4 */
1599

1600
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1601
/* Optional call to update the users info structure */
1602
PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1603
    png_inforp info_ptr),PNG_EMPTY);
1604
#endif
1605

1606
/* Shared transform functions, defined in pngtran.c */
1607
#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1608
    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1609
PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1610
    png_bytep row, int at_start),PNG_EMPTY);
1611
#endif
1612

1613
#ifdef PNG_16BIT_SUPPORTED
1614
#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1615
PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1616
    png_bytep row),PNG_EMPTY);
1617
#endif
1618
#endif
1619

1620
#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1621
    defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1622
PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1623
    png_bytep row),PNG_EMPTY);
1624
#endif
1625

1626
#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1627
PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1628
    png_bytep row),PNG_EMPTY);
1629
#endif
1630

1631
#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1632
PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1633
    png_bytep row),PNG_EMPTY);
1634
#endif
1635

1636
/* The following decodes the appropriate chunks, and does error correction,
1637
 * then calls the appropriate callback for the chunk if it is valid.
1638
 */
1639
typedef enum
1640
{
1641
   /* Result of a call to png_handle_chunk made to handle the current chunk
1642
    * png_struct::chunk_name on read.  Always informational, either the stream
1643
    * is read for the next chunk or the routine will call png_error.
1644
    *
1645
    * NOTE: order is important internally.  handled_saved and above are regarded
1646
    * as handling the chunk.
1647
    */
1648
   handled_error = 0,  /* bad crc or known and bad format or too long */
1649
   handled_discarded,  /* not saved in the unknown chunk list */
1650
   handled_saved,      /* saved in the unknown chunk list */
1651
   handled_ok          /* known, supported and handled without error */
1652
} png_handle_result_code;
1653

1654
PNG_INTERNAL_FUNCTION(png_handle_result_code,png_handle_unknown,
1655
    (png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length, int keep),
1656
    PNG_EMPTY);
1657
   /* This is the function that gets called for unknown chunks.  The 'keep'
1658
    * argument is either non-zero for a known chunk that has been set to be
1659
    * handled as unknown or zero for an unknown chunk.  By default the function
1660
    * just skips the chunk or errors out if it is critical.
1661
    */
1662

1663
PNG_INTERNAL_FUNCTION(png_handle_result_code,png_handle_chunk,
1664
    (png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1665
   /* This handles the current chunk png_ptr->chunk_name with unread
1666
    * data[length] and returns one of the above result codes.
1667
    */
1668

1669
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
1670
    defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1671
PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1672
    (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1673
   /* Exactly as the API png_handle_as_unknown() except that the argument is a
1674
    * 32-bit chunk name, not a string.
1675
    */
1676
#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
1677

1678
/* Handle the transformations for reading and writing */
1679
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1680
PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1681
   png_row_infop row_info),PNG_EMPTY);
1682
#endif
1683
#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1684
PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1685
   png_row_infop row_info),PNG_EMPTY);
1686
#endif
1687

1688
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1689
PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1690
    PNG_EMPTY);
1691
#endif
1692

1693
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1694
PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1695
    png_inforp info_ptr),PNG_EMPTY);
1696
PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1697
    png_inforp info_ptr),PNG_EMPTY);
1698
PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1699
PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1700
    PNG_EMPTY);
1701
PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1702
    png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1703
PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1704
PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1705
    png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1706
PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1707
    PNG_EMPTY);
1708
PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1709
   png_inforp info_ptr),PNG_EMPTY);
1710
PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1711
   png_inforp info_ptr),PNG_EMPTY);
1712
PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1713
    png_bytep row),PNG_EMPTY);
1714
PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1715
    png_inforp info_ptr),PNG_EMPTY);
1716
PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1717
    png_inforp info_ptr),PNG_EMPTY);
1718
PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1719
    PNG_EMPTY);
1720
#endif /* PROGRESSIVE_READ */
1721

1722
#ifdef PNG_iCCP_SUPPORTED
1723
/* Routines for checking parts of an ICC profile. */
1724
#ifdef PNG_READ_iCCP_SUPPORTED
1725
PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1726
   png_const_charp name, png_uint_32 profile_length), PNG_EMPTY);
1727
#endif /* READ_iCCP */
1728
PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1729
   png_const_charp name, png_uint_32 profile_length,
1730
   png_const_bytep profile /* first 132 bytes only */, int color_type),
1731
   PNG_EMPTY);
1732
PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1733
   png_const_charp name, png_uint_32 profile_length,
1734
   png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1735
#endif /* iCCP */
1736

1737
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1738
PNG_INTERNAL_FUNCTION(void,png_set_rgb_coefficients, (png_structrp png_ptr),
1739
   PNG_EMPTY);
1740
   /* Set the rgb_to_gray coefficients from the cHRM Y values (if unset) */
1741
#endif /* READ_RGB_TO_GRAY */
1742

1743
/* Added at libpng version 1.4.0 */
1744
PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1745
    png_uint_32 width, png_uint_32 height, int bit_depth,
1746
    int color_type, int interlace_type, int compression_type,
1747
    int filter_type),PNG_EMPTY);
1748

1749
/* Added at libpng version 1.5.10 */
1750
#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1751
    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1752
PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1753
   (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1754
#endif
1755

1756
#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1757
PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1758
   png_const_charp name),PNG_NORETURN);
1759
#endif
1760

1761
/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1762
 * the end.  Always leaves the buffer nul terminated.  Never errors out (and
1763
 * there is no error code.)
1764
 */
1765
PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1766
   size_t pos, png_const_charp string),PNG_EMPTY);
1767

1768
/* Various internal functions to handle formatted warning messages, currently
1769
 * only implemented for warnings.
1770
 */
1771
#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1772
/* Utility to dump an unsigned value into a buffer, given a start pointer and
1773
 * and end pointer (which should point just *beyond* the end of the buffer!)
1774
 * Returns the pointer to the start of the formatted string.  This utility only
1775
 * does unsigned values.
1776
 */
1777
PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1778
   png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1779

1780
/* Convenience macro that takes an array: */
1781
#define PNG_FORMAT_NUMBER(buffer,format,number) \
1782
   png_format_number(buffer, buffer + (sizeof buffer), format, number)
1783

1784
/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1785
#define PNG_NUMBER_BUFFER_SIZE 24
1786

1787
/* These are the integer formats currently supported, the name is formed from
1788
 * the standard printf(3) format string.
1789
 */
1790
#define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
1791
#define PNG_NUMBER_FORMAT_02u   2
1792
#define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
1793
#define PNG_NUMBER_FORMAT_02d   2
1794
#define PNG_NUMBER_FORMAT_x     3
1795
#define PNG_NUMBER_FORMAT_02x   4
1796
#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1797
#endif
1798

1799
#ifdef PNG_WARNINGS_SUPPORTED
1800
/* New defines and members adding in libpng-1.5.4 */
1801
#  define PNG_WARNING_PARAMETER_SIZE 32
1802
#  define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1803

1804
/* An l-value of this type has to be passed to the APIs below to cache the
1805
 * values of the parameters to a formatted warning message.
1806
 */
1807
typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1808
   PNG_WARNING_PARAMETER_SIZE];
1809

1810
PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1811
   int number, png_const_charp string),PNG_EMPTY);
1812
   /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1813
    * including the trailing '\0'.
1814
    */
1815
PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1816
   (png_warning_parameters p, int number, int format, png_alloc_size_t value),
1817
   PNG_EMPTY);
1818
   /* Use png_alloc_size_t because it is an unsigned type as big as any we
1819
    * need to output.  Use the following for a signed value.
1820
    */
1821
PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1822
   (png_warning_parameters p, int number, int format, png_int_32 value),
1823
   PNG_EMPTY);
1824

1825
PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1826
   png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1827
   /* 'message' follows the X/Open approach of using @1, @2 to insert
1828
    * parameters previously supplied using the above functions.  Errors in
1829
    * specifying the parameters will simply result in garbage substitutions.
1830
    */
1831
#endif
1832

1833
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1834
/* Application errors (new in 1.6); use these functions (declared below) for
1835
 * errors in the parameters or order of API function calls on read.  The
1836
 * 'warning' should be used for an error that can be handled completely; the
1837
 * 'error' for one which can be handled safely but which may lose application
1838
 * information or settings.
1839
 *
1840
 * By default these both result in a png_error call prior to release, while in a
1841
 * released version the 'warning' is just a warning.  However if the application
1842
 * explicitly disables benign errors (explicitly permitting the code to lose
1843
 * information) they both turn into warnings.
1844
 *
1845
 * If benign errors aren't supported they end up as the corresponding base call
1846
 * (png_warning or png_error.)
1847
 */
1848
PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1849
   png_const_charp message),PNG_EMPTY);
1850
   /* The application provided invalid parameters to an API function or called
1851
    * an API function at the wrong time, libpng can completely recover.
1852
    */
1853

1854
PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1855
   png_const_charp message),PNG_EMPTY);
1856
   /* As above but libpng will ignore the call, or attempt some other partial
1857
    * recovery from the error.
1858
    */
1859
#else
1860
#  define png_app_warning(pp,s) png_warning(pp,s)
1861
#  define png_app_error(pp,s) png_error(pp,s)
1862
#endif
1863

1864
PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1865
   png_const_charp message, int error),PNG_EMPTY);
1866
   /* Report a recoverable issue in chunk data.  On read this is used to report
1867
    * a problem found while reading a particular chunk and the
1868
    * png_chunk_benign_error or png_chunk_warning function is used as
1869
    * appropriate.  On write this is used to report an error that comes from
1870
    * data set via an application call to a png_set_ API and png_app_error or
1871
    * png_app_warning is used as appropriate.
1872
    *
1873
    * The 'error' parameter must have one of the following values:
1874
    */
1875
#define PNG_CHUNK_WARNING     0 /* never an error */
1876
#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1877
#define PNG_CHUNK_ERROR       2 /* always an error */
1878

1879
/* ASCII to FP interfaces, currently only implemented if sCAL
1880
 * support is required.
1881
 */
1882
#if defined(PNG_sCAL_SUPPORTED)
1883
/* MAX_DIGITS is actually the maximum number of characters in an sCAL
1884
 * width or height, derived from the precision (number of significant
1885
 * digits - a build time settable option) and assumptions about the
1886
 * maximum ridiculous exponent.
1887
 */
1888
#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1889

1890
#ifdef PNG_FLOATING_POINT_SUPPORTED
1891
PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1892
   png_charp ascii, size_t size, double fp, unsigned int precision),
1893
   PNG_EMPTY);
1894
#endif /* FLOATING_POINT */
1895

1896
#ifdef PNG_FIXED_POINT_SUPPORTED
1897
PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1898
   png_charp ascii, size_t size, png_fixed_point fp),PNG_EMPTY);
1899
#endif /* FIXED_POINT */
1900
#endif /* sCAL */
1901

1902
#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1903
/* An internal API to validate the format of a floating point number.
1904
 * The result is the index of the next character.  If the number is
1905
 * not valid it will be the index of a character in the supposed number.
1906
 *
1907
 * The format of a number is defined in the PNG extensions specification
1908
 * and this API is strictly conformant to that spec, not anyone elses!
1909
 *
1910
 * The format as a regular expression is:
1911
 *
1912
 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1913
 *
1914
 * or:
1915
 *
1916
 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1917
 *
1918
 * The complexity is that either integer or fraction must be present and the
1919
 * fraction is permitted to have no digits only if the integer is present.
1920
 *
1921
 * NOTE: The dangling E problem.
1922
 *   There is a PNG valid floating point number in the following:
1923
 *
1924
 *       PNG floating point numbers are not greedy.
1925
 *
1926
 *   Working this out requires *TWO* character lookahead (because of the
1927
 *   sign), the parser does not do this - it will fail at the 'r' - this
1928
 *   doesn't matter for PNG sCAL chunk values, but it requires more care
1929
 *   if the value were ever to be embedded in something more complex.  Use
1930
 *   ANSI-C strtod if you need the lookahead.
1931
 */
1932
/* State table for the parser. */
1933
#define PNG_FP_INTEGER    0  /* before or in integer */
1934
#define PNG_FP_FRACTION   1  /* before or in fraction */
1935
#define PNG_FP_EXPONENT   2  /* before or in exponent */
1936
#define PNG_FP_STATE      3  /* mask for the above */
1937
#define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
1938
#define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
1939
#define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
1940
#define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
1941
#define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
1942

1943
/* These three values don't affect the parser.  They are set but not used.
1944
 */
1945
#define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
1946
#define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
1947
#define PNG_FP_NONZERO  256  /* A non-zero value */
1948
#define PNG_FP_STICKY   448  /* The above three flags */
1949

1950
/* This is available for the caller to store in 'state' if required.  Do not
1951
 * call the parser after setting it (the parser sometimes clears it.)
1952
 */
1953
#define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
1954

1955
/* Result codes for the parser (boolean - true means ok, false means
1956
 * not ok yet.)
1957
 */
1958
#define PNG_FP_MAYBE      0  /* The number may be valid in the future */
1959
#define PNG_FP_OK         1  /* The number is valid */
1960

1961
/* Tests on the sticky non-zero and negative flags.  To pass these checks
1962
 * the state must also indicate that the whole number is valid - this is
1963
 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1964
 * is equivalent to PNG_FP_OK above.)
1965
 */
1966
#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1967
   /* NZ_MASK: the string is valid and a non-zero negative value */
1968
#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1969
   /* Z MASK: the string is valid and a non-zero value. */
1970
   /* PNG_FP_SAW_DIGIT: the string is valid. */
1971
#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1972
#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1973
#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1974

1975
/* The actual parser.  This can be called repeatedly. It updates
1976
 * the index into the string and the state variable (which must
1977
 * be initialized to 0).  It returns a result code, as above.  There
1978
 * is no point calling the parser any more if it fails to advance to
1979
 * the end of the string - it is stuck on an invalid character (or
1980
 * terminated by '\0').
1981
 *
1982
 * Note that the pointer will consume an E or even an E+ and then leave
1983
 * a 'maybe' state even though a preceding integer.fraction is valid.
1984
 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1985
 * a valid number.  It's possible to recover from this by calling
1986
 * the parser again (from the start, with state 0) but with a string
1987
 * that omits the last character (i.e. set the size to the index of
1988
 * the problem character.)  This has not been tested within libpng.
1989
 */
1990
PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
1991
   size_t size, int *statep, size_t *whereami),PNG_EMPTY);
1992

1993
/* This is the same but it checks a complete string and returns true
1994
 * only if it just contains a floating point number.  As of 1.5.4 this
1995
 * function also returns the state at the end of parsing the number if
1996
 * it was valid (otherwise it returns 0.)  This can be used for testing
1997
 * for negative or zero values using the sticky flag.
1998
 */
1999
PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
2000
   size_t size),PNG_EMPTY);
2001
#endif /* pCAL || sCAL */
2002

2003
#if defined(PNG_READ_GAMMA_SUPPORTED) ||\
2004
    defined(PNG_COLORSPACE_SUPPORTED) ||\
2005
    defined(PNG_INCH_CONVERSIONS_SUPPORTED) ||\
2006
    defined(PNG_READ_pHYs_SUPPORTED)
2007
/* Added at libpng version 1.5.0 */
2008
/* This is a utility to provide a*times/div (rounded) and indicate
2009
 * if there is an overflow.  The result is a boolean - false (0)
2010
 * for overflow, true (1) if no overflow, in which case *res
2011
 * holds the result.
2012
 */
2013
PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
2014
   png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
2015

2016
/* Calculate a reciprocal - used for gamma values.  This returns
2017
 * 0 if the argument is 0 in order to maintain an undefined value;
2018
 * there are no warnings.
2019
 */
2020
PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
2021
   PNG_EMPTY);
2022
#endif
2023

2024
#ifdef PNG_READ_GAMMA_SUPPORTED
2025
/* The same but gives a reciprocal of the product of two fixed point
2026
 * values.  Accuracy is suitable for gamma calculations but this is
2027
 * not exact - use png_muldiv for that.  Only required at present on read.
2028
 */
2029
PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
2030
   png_fixed_point b),PNG_EMPTY);
2031

2032
/* Return true if the gamma value is significantly different from 1.0 */
2033
PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
2034
   PNG_EMPTY);
2035

2036
/* PNGv3: 'resolve' the file gamma according to the new PNGv3 rules for colour
2037
 * space information.
2038
 *
2039
 * NOTE: this uses precisely those chunks that libpng supports.  For example it
2040
 * doesn't use iCCP and it can only use cICP for known and manageable
2041
 * transforms.  For this reason a gamma specified by png_set_gamma always takes
2042
 * precedence.
2043
 */
2044
PNG_INTERNAL_FUNCTION(png_fixed_point,png_resolve_file_gamma,
2045
   (png_const_structrp png_ptr),PNG_EMPTY);
2046

2047
/* Internal fixed point gamma correction.  These APIs are called as
2048
 * required to convert single values - they don't need to be fast,
2049
 * they are not used when processing image pixel values.
2050
 *
2051
 * While the input is an 'unsigned' value it must actually be the
2052
 * correct bit value - 0..255 or 0..65535 as required.
2053
 */
2054
PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
2055
   unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
2056
PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
2057
   png_fixed_point gamma_value),PNG_EMPTY);
2058
PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
2059
   png_fixed_point gamma_value),PNG_EMPTY);
2060
PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
2061
   PNG_EMPTY);
2062
PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
2063
   int bit_depth),PNG_EMPTY);
2064
#endif /* READ_GAMMA */
2065

2066
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
2067
/* Set the RGB coefficients if not already set by png_set_rgb_to_gray */
2068
PNG_INTERNAL_FUNCTION(void,png_set_rgb_coefficients,(png_structrp png_ptr),
2069
   PNG_EMPTY);
2070
#endif
2071

2072
#if defined(PNG_cHRM_SUPPORTED) || defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
2073
PNG_INTERNAL_FUNCTION(int,png_XYZ_from_xy,(png_XYZ *XYZ, const png_xy *xy),
2074
   PNG_EMPTY);
2075
#endif /* cHRM || READ_RGB_TO_GRAY */
2076

2077
#ifdef PNG_COLORSPACE_SUPPORTED
2078
PNG_INTERNAL_FUNCTION(int,png_xy_from_XYZ,(png_xy *xy, const png_XYZ *XYZ),
2079
   PNG_EMPTY);
2080
#endif
2081

2082
/* SIMPLIFIED READ/WRITE SUPPORT */
2083
#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
2084
   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2085
/* The internal structure that png_image::opaque points to. */
2086
typedef struct png_control
2087
{
2088
   png_structp png_ptr;
2089
   png_infop   info_ptr;
2090
   png_voidp   error_buf;           /* Always a jmp_buf at present. */
2091

2092
   png_const_bytep memory;          /* Memory buffer. */
2093
   size_t          size;            /* Size of the memory buffer. */
2094

2095
   unsigned int for_write       :1; /* Otherwise it is a read structure */
2096
   unsigned int owned_file      :1; /* We own the file in io_ptr */
2097
} png_control;
2098

2099
/* Return the pointer to the jmp_buf from a png_control: necessary because C
2100
 * does not reveal the type of the elements of jmp_buf.
2101
 */
2102
#ifdef __cplusplus
2103
#  define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
2104
#else
2105
#  define png_control_jmp_buf(pc) ((pc)->error_buf)
2106
#endif
2107

2108
/* Utility to safely execute a piece of libpng code catching and logging any
2109
 * errors that might occur.  Returns true on success, false on failure (either
2110
 * of the function or as a result of a png_error.)
2111
 */
2112
PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
2113
   png_const_charp error_message),PNG_NORETURN);
2114

2115
#ifdef PNG_WARNINGS_SUPPORTED
2116
PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
2117
   png_const_charp warning_message),PNG_EMPTY);
2118
#else
2119
#  define png_safe_warning 0/*dummy argument*/
2120
#endif
2121

2122
PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
2123
   int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
2124

2125
/* Utility to log an error; this also cleans up the png_image; the function
2126
 * always returns 0 (false).
2127
 */
2128
PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
2129
   png_const_charp error_message),PNG_EMPTY);
2130

2131
#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
2132
/* png_image_free is used by the write code but not exported */
2133
PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
2134
#endif /* !SIMPLIFIED_READ */
2135

2136
#endif /* SIMPLIFIED READ/WRITE */
2137

2138
/* These are initialization functions for hardware specific PNG filter
2139
 * optimizations; list these here then select the appropriate one at compile
2140
 * time using the macro PNG_FILTER_OPTIMIZATIONS.  If the macro is not defined
2141
 * the generic code is used.
2142
 */
2143
#ifdef PNG_FILTER_OPTIMIZATIONS
2144
PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
2145
   unsigned int bpp), PNG_EMPTY);
2146
   /* Just declare the optimization that will be used */
2147
#else
2148
   /* List *all* the possible optimizations here - this branch is required if
2149
    * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
2150
    * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
2151
    */
2152
#  if PNG_ARM_NEON_OPT > 0
2153
PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
2154
   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2155
#endif
2156

2157
#if PNG_MIPS_MSA_IMPLEMENTATION == 1
2158
PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_mips,
2159
   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2160
#endif
2161

2162
#  if PNG_MIPS_MMI_IMPLEMENTATION > 0
2163
PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_mips,
2164
   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2165
#  endif
2166

2167
#  if PNG_INTEL_SSE_IMPLEMENTATION > 0
2168
PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
2169
   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2170
#  endif
2171
#endif
2172

2173
#if PNG_LOONGARCH_LSX_OPT > 0
2174
PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_lsx,
2175
    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2176
#endif
2177

2178
#  if PNG_RISCV_RVV_OPT > 0
2179
PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_rvv,
2180
   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2181
#endif
2182

2183
PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
2184
   png_const_charp key, png_bytep new_key), PNG_EMPTY);
2185

2186
#if PNG_ARM_NEON_IMPLEMENTATION == 1
2187
PNG_INTERNAL_FUNCTION(void,
2188
                      png_riffle_palette_neon,
2189
                      (png_structrp),
2190
                      PNG_EMPTY);
2191
PNG_INTERNAL_FUNCTION(int,
2192
                      png_do_expand_palette_rgba8_neon,
2193
                      (png_structrp,
2194
                       png_row_infop,
2195
                       png_const_bytep,
2196
                       const png_bytepp,
2197
                       const png_bytepp),
2198
                      PNG_EMPTY);
2199
PNG_INTERNAL_FUNCTION(int,
2200
                      png_do_expand_palette_rgb8_neon,
2201
                      (png_structrp,
2202
                       png_row_infop,
2203
                       png_const_bytep,
2204
                       const png_bytepp,
2205
                       const png_bytepp),
2206
                      PNG_EMPTY);
2207
#endif
2208

2209
/* Maintainer: Put new private prototypes here ^ */
2210

2211
#include "pngdebug.h"
2212

2213
#ifdef __cplusplus
2214
}
2215
#endif
2216

2217
#endif /* PNG_VERSION_INFO_ONLY */
2218

2219
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