2 /* pngpriv.h - private declarations for use inside libpng
4 * Copyright (c) 2018-2023 Cosmin Truta
5 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
6 * Copyright (c) 1996-1997 Andreas Dilger
7 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
14 /* The symbols declared in this file (including the functions declared
15 * as extern) are PRIVATE. They are not part of the libpng public
16 * interface, and are not recommended for use by regular applications.
17 * Some of them may become public in the future; others may stay private,
18 * change in an incompatible way, or even disappear.
19 * Although the libpng users are not forbidden to include this header,
20 * they should be well aware of the issues that may arise from doing so.
26 /* Feature Test Macros. The following are defined here to ensure that correctly
27 * implemented libraries reveal the APIs libpng needs to build and hide those
28 * that are not needed and potentially damaging to the compilation.
30 * Feature Test Macros must be defined before any system header is included (see
31 * POSIX 1003.1 2.8.2 "POSIX Symbols."
33 * These macros only have an effect if the operating system supports either
34 * POSIX 1003.1 or C99, or both. On other operating systems (particularly
35 * Windows/Visual Studio) there is no effect; the OS specific tests below are
36 * still required (as of 2011-05-02.)
39 # define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
42 #ifndef PNG_VERSION_INFO_ONLY
43 /* Standard library headers not required by png.h: */
48 #define PNGLIB_BUILD /*libpng is being built, not used*/
50 /* If HAVE_CONFIG_H is defined during the build then the build system must
51 * provide an appropriate "config.h" file on the include path. The header file
52 * must provide definitions as required below (search for "HAVE_CONFIG_H");
53 * see configure.ac for more details of the requirements. The macro
54 * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
55 * 'configure'; define this macro to prevent the configure build including the
56 * configure generated config.h. Libpng is expected to compile without *any*
57 * special build system support on a reasonably ANSI-C compliant system.
59 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
62 /* Pick up the definition of 'restrict' from config.h if it was read: */
63 # define PNG_RESTRICT restrict
66 /* To support symbol prefixing it is necessary to know *before* including png.h
67 * whether the fixed point (and maybe other) APIs are exported, because if they
68 * are not internal definitions may be required. This is handled below just
69 * before png.h is included, but load the configuration now if it is available.
72 # include "pnglibconf.h"
75 /* Local renames may change non-exported API functions from png.h */
76 #if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
77 # include "pngprefix.h"
80 #ifdef PNG_USER_CONFIG
82 /* These should have been defined in pngusr.h */
83 # ifndef PNG_USER_PRIVATEBUILD
84 # define PNG_USER_PRIVATEBUILD "Custom libpng build"
86 # ifndef PNG_USER_DLLFNAME_POSTFIX
87 # define PNG_USER_DLLFNAME_POSTFIX "Cb"
91 /* Compile time options.
92 * =====================
93 * In a multi-arch build the compiler may compile the code several times for the
94 * same object module, producing different binaries for different architectures.
95 * When this happens configure-time setting of the target host options cannot be
96 * done and this interferes with the handling of the ARM NEON optimizations, and
97 * possibly other similar optimizations. Put additional tests here; in general
98 * this is needed when the same option can be changed at both compile time and
99 * run time depending on the target OS (i.e. iOS vs Android.)
101 * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
102 * this is not possible with certain compilers (Oracle SUN OS CC), as a result
103 * it is necessary to ensure that all extern functions that *might* be used
104 * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__
105 * below is one example of this behavior because it is controlled by the
106 * presence or not of -mfpu=neon on the GCC command line, it is possible to do
107 * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
110 #ifndef PNG_ARM_NEON_OPT
111 /* ARM NEON optimizations are being controlled by the compiler settings,
112 * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon
113 * with GCC) then the compiler will define __ARM_NEON__ and we can rely
114 * unconditionally on NEON instructions not crashing, otherwise we must
115 * disable use of NEON instructions.
117 * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
118 * can only be turned on automatically if that is supported too. If
119 * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
120 * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
123 * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated
124 * __ARM_NEON__, so we check both variants.
126 * To disable ARM_NEON optimizations entirely, and skip compiling the
127 * associated assembler code, pass --enable-arm-neon=no to configure
128 * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS.
130 # if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
131 defined(PNG_ALIGNED_MEMORY_SUPPORTED)
132 # define PNG_ARM_NEON_OPT 2
134 # define PNG_ARM_NEON_OPT 0
138 #if PNG_ARM_NEON_OPT > 0
139 /* NEON optimizations are to be at least considered by libpng, so enable the
140 * callbacks to do this.
142 # define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
144 /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
145 * if possible - if __ARM_NEON__ is set and the compiler version is not known
146 * to be broken. This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
149 * 1 The intrinsics code (the default with __ARM_NEON__)
150 * 2 The hand coded assembler (the default without __ARM_NEON__)
152 * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
153 * this is *NOT* supported and may cease to work even after a minor revision
154 * to libpng. It *is* valid to do this for testing purposes, e.g. speed
155 * testing or a new compiler, but the results should be communicated to the
156 * libpng implementation list for incorporation in the next minor release.
158 # ifndef PNG_ARM_NEON_IMPLEMENTATION
159 # if defined(__ARM_NEON__) || defined(__ARM_NEON)
160 # if defined(__clang__)
161 /* At present it is unknown by the libpng developers which versions
162 * of clang support the intrinsics, however some or perhaps all
163 * versions do not work with the assembler so this may be
164 * irrelevant, so just use the default (do nothing here.)
166 # elif defined(__GNUC__)
167 /* GCC 4.5.4 NEON support is known to be broken. 4.6.3 is known to
168 * work, so if this *is* GCC, or G++, look for a version >4.5
170 # if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
171 # define PNG_ARM_NEON_IMPLEMENTATION 2
172 # endif /* no GNUC support */
173 # endif /* __GNUC__ */
174 # else /* !defined __ARM_NEON__ */
175 /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
177 # if !defined(__aarch64__) && !defined(_M_ARM64)
178 /* The assembler code currently does not work on ARM64 */
179 # define PNG_ARM_NEON_IMPLEMENTATION 2
180 # endif /* __aarch64__ */
181 # endif /* __ARM_NEON__ */
182 # endif /* !PNG_ARM_NEON_IMPLEMENTATION */
184 # ifndef PNG_ARM_NEON_IMPLEMENTATION
185 /* Use the intrinsics code by default. */
186 # define PNG_ARM_NEON_IMPLEMENTATION 1
188 #else /* PNG_ARM_NEON_OPT == 0 */
189 # define PNG_ARM_NEON_IMPLEMENTATION 0
190 #endif /* PNG_ARM_NEON_OPT > 0 */
192 #ifndef PNG_MIPS_MSA_OPT
193 # if defined(__mips_msa) && (__mips_isa_rev >= 5) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
194 # define PNG_MIPS_MSA_OPT 2
196 # define PNG_MIPS_MSA_OPT 0
200 #ifndef PNG_POWERPC_VSX_OPT
201 # if defined(__PPC64__) && defined(__ALTIVEC__) && defined(__VSX__)
202 # define PNG_POWERPC_VSX_OPT 2
204 # define PNG_POWERPC_VSX_OPT 0
208 #ifndef PNG_INTEL_SSE_OPT
209 # ifdef PNG_INTEL_SSE
210 /* Only check for SSE if the build configuration has been modified to
211 * enable SSE optimizations. This means that these optimizations will
212 * be off by default. See contrib/intel for more details.
214 # if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
215 defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
216 (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
217 # define PNG_INTEL_SSE_OPT 1
219 # define PNG_INTEL_SSE_OPT 0
222 # define PNG_INTEL_SSE_OPT 0
226 #if PNG_INTEL_SSE_OPT > 0
227 # ifndef PNG_INTEL_SSE_IMPLEMENTATION
228 # if defined(__SSE4_1__) || defined(__AVX__)
229 /* We are not actually using AVX, but checking for AVX is the best
230 way we can detect SSE4.1 and SSSE3 on MSVC.
232 # define PNG_INTEL_SSE_IMPLEMENTATION 3
233 # elif defined(__SSSE3__)
234 # define PNG_INTEL_SSE_IMPLEMENTATION 2
235 # elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
236 (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
237 # define PNG_INTEL_SSE_IMPLEMENTATION 1
239 # define PNG_INTEL_SSE_IMPLEMENTATION 0
243 # if PNG_INTEL_SSE_IMPLEMENTATION > 0
244 # define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
247 # define PNG_INTEL_SSE_IMPLEMENTATION 0
250 #if PNG_MIPS_MSA_OPT > 0
251 # define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_msa
252 # ifndef PNG_MIPS_MSA_IMPLEMENTATION
253 # if defined(__mips_msa)
254 # if defined(__clang__)
255 # elif defined(__GNUC__)
256 # if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
257 # define PNG_MIPS_MSA_IMPLEMENTATION 2
258 # endif /* no GNUC support */
259 # endif /* __GNUC__ */
260 # else /* !defined __mips_msa */
261 # define PNG_MIPS_MSA_IMPLEMENTATION 2
262 # endif /* __mips_msa */
263 # endif /* !PNG_MIPS_MSA_IMPLEMENTATION */
265 # ifndef PNG_MIPS_MSA_IMPLEMENTATION
266 # define PNG_MIPS_MSA_IMPLEMENTATION 1
269 # define PNG_MIPS_MSA_IMPLEMENTATION 0
270 #endif /* PNG_MIPS_MSA_OPT > 0 */
272 #if PNG_POWERPC_VSX_OPT > 0
273 # define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx
274 # define PNG_POWERPC_VSX_IMPLEMENTATION 1
276 # define PNG_POWERPC_VSX_IMPLEMENTATION 0
280 /* Is this a build of a DLL where compilation of the object modules requires
281 * different preprocessor settings to those required for a simple library? If
282 * so PNG_BUILD_DLL must be set.
284 * If libpng is used inside a DLL but that DLL does not export the libpng APIs
285 * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
286 * static library of libpng then link the DLL against that.
288 #ifndef PNG_BUILD_DLL
290 /* This is set by libtool when files are compiled for a DLL; libtool
291 * always compiles twice, even on systems where it isn't necessary. Set
292 * PNG_BUILD_DLL in case it is necessary:
294 # define PNG_BUILD_DLL
297 /* This is set by the Microsoft Visual Studio IDE in projects that
298 * build a DLL. It can't easily be removed from those projects (it
299 * isn't visible in the Visual Studio UI) so it is a fairly reliable
300 * indication that PNG_IMPEXP needs to be set to the DLL export
303 # define PNG_BUILD_DLL
306 /* This is set by the Borland C system when compiling for a DLL
309 # define PNG_BUILD_DLL
311 /* Add additional compiler cases here. */
315 #endif /* Setting PNG_BUILD_DLL if required */
317 /* See pngconf.h for more details: the builder of the library may set this on
318 * the command line to the right thing for the specific compilation system or it
319 * may be automagically set above (at present we know of no system where it does
320 * need to be set on the command line.)
322 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
323 * setting it to the "import" setting for a DLL build.
326 # ifdef PNG_BUILD_DLL
327 # define PNG_IMPEXP PNG_DLL_EXPORT
329 /* Not building a DLL, or the DLL doesn't require specific export
336 /* No warnings for private or deprecated functions in the build: */
337 #ifndef PNG_DEPRECATED
338 # define PNG_DEPRECATED
344 /* Symbol preprocessing support.
346 * To enable listing global, but internal, symbols the following macros should
347 * always be used to declare an extern data or function object in this file.
349 #ifndef PNG_INTERNAL_DATA
350 # define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array
353 #ifndef PNG_INTERNAL_FUNCTION
354 # define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
355 PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
358 #ifndef PNG_INTERNAL_CALLBACK
359 # define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
360 PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\
361 PNG_EMPTY attributes)
364 /* If floating or fixed point APIs are disabled they may still be compiled
365 * internally. To handle this make sure they are declared as the appropriate
366 * internal extern function (otherwise the symbol prefixing stuff won't work and
367 * the functions will be used without definitions.)
369 * NOTE: although all the API functions are declared here they are not all
370 * actually built! Because the declarations are still made it is necessary to
371 * fake out types that they depend on.
373 #ifndef PNG_FP_EXPORT
374 # ifndef PNG_FLOATING_POINT_SUPPORTED
375 # define PNG_FP_EXPORT(ordinal, type, name, args)\
376 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
377 # ifndef PNG_VERSION_INFO_ONLY
378 typedef struct png_incomplete png_double;
379 typedef png_double* png_doublep;
380 typedef const png_double* png_const_doublep;
381 typedef png_double** png_doublepp;
385 #ifndef PNG_FIXED_EXPORT
386 # ifndef PNG_FIXED_POINT_SUPPORTED
387 # define PNG_FIXED_EXPORT(ordinal, type, name, args)\
388 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
394 /* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
395 #ifndef PNG_DLL_EXPORT
396 # define PNG_DLL_EXPORT
399 /* This is a global switch to set the compilation for an installed system
400 * (a release build). It can be set for testing debug builds to ensure that
401 * they will compile when the build type is switched to RC or STABLE, the
402 * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE. Set this in CPPFLAGS
405 * -DPNG_RELEASE_BUILD Turns on the release compile path
406 * -DPNG_RELEASE_BUILD=0 Turns it off
407 * or in your pngusr.h with
408 * #define PNG_RELEASE_BUILD=1 Turns on the release compile path
409 * #define PNG_RELEASE_BUILD=0 Turns it off
411 #ifndef PNG_RELEASE_BUILD
412 # define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
415 /* SECURITY and SAFETY:
417 * libpng is built with support for internal limits on image dimensions and
418 * memory usage. These are documented in scripts/pnglibconf.dfa of the
419 * source and recorded in the machine generated header file pnglibconf.h.
422 /* If you are running on a machine where you cannot allocate more
423 * than 64K of memory at once, uncomment this. While libpng will not
424 * normally need that much memory in a chunk (unless you load up a very
425 * large file), zlib needs to know how big of a chunk it can use, and
426 * libpng thus makes sure to check any memory allocation to verify it
427 * will fit into memory.
429 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
430 * same limit and pngconf.h (already included) sets the limit
431 * if certain operating systems are detected.
433 #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
434 # define PNG_MAX_MALLOC_64K
438 /* Unused formal parameter warnings are silenced using the following macro
439 * which is expected to have no bad effects on performance (optimizing
440 * compilers will probably remove it entirely). Note that if you replace
441 * it with something other than whitespace, you must include the terminating
444 # define PNG_UNUSED(param) (void)param;
447 /* Just a little check that someone hasn't tried to define something
450 #if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
451 # undef PNG_ZBUF_SIZE
452 # define PNG_ZBUF_SIZE 65536L
455 /* If warnings or errors are turned off the code is disabled or redirected here.
456 * From 1.5.4 functions have been added to allow very limited formatting of
457 * error and warning messages - this code will also be disabled here.
459 #ifdef PNG_WARNINGS_SUPPORTED
460 # define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
462 # define png_warning_parameter(p,number,string) ((void)0)
463 # define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
464 # define png_warning_parameter_signed(p,number,format,value) ((void)0)
465 # define png_formatted_warning(pp,p,message) ((void)(pp))
466 # define PNG_WARNING_PARAMETERS(p)
468 #ifndef PNG_ERROR_TEXT_SUPPORTED
469 # define png_fixed_error(s1,s2) png_err(s1)
472 /* Some fixed point APIs are still required even if not exported because
473 * they get used by the corresponding floating point APIs. This magic
476 #ifdef PNG_FIXED_POINT_SUPPORTED
477 # define PNGFAPI PNGAPI
479 # define PNGFAPI /* PRIVATE */
482 #ifndef PNG_VERSION_INFO_ONLY
483 /* Other defines specific to compilers can go here. Try to keep
484 * them inside an appropriate ifdef/endif pair for portability.
487 /* C allows up-casts from (void*) to any pointer and (const void*) to any
488 * pointer to a const object. C++ regards this as a type error and requires an
489 * explicit, static, cast and provides the static_cast<> rune to ensure that
490 * const is not cast away.
493 # define png_voidcast(type, value) static_cast<type>(value)
494 # define png_constcast(type, value) const_cast<type>(value)
495 # define png_aligncast(type, value) \
496 static_cast<type>(static_cast<void*>(value))
497 # define png_aligncastconst(type, value) \
498 static_cast<type>(static_cast<const void*>(value))
500 # define png_voidcast(type, value) (value)
501 # define png_constcast(type, value) ((type)(void*)(const void*)(value))
502 # define png_aligncast(type, value) ((void*)(value))
503 # define png_aligncastconst(type, value) ((const void*)(value))
504 #endif /* __cplusplus */
506 #if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
507 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
508 /* png.c requires the following ANSI-C constants if the conversion of
509 * floating point to ASCII is implemented therein:
511 * DBL_DIG Maximum number of decimal digits (can be set to any constant)
512 * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
513 * DBL_MAX Maximum floating point number (can be set to an arbitrary value)
517 # if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
518 defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
519 /* We need to check that <math.h> hasn't already been included earlier
520 * as it seems it doesn't agree with <fp.h>, yet we should really use
521 * <fp.h> if possible.
523 # if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
529 # if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
530 /* Amiga SAS/C: We must include builtin FPU functions when compiling using
537 /* This provides the non-ANSI (far) memory allocation routines. */
538 #if defined(__TURBOC__) && defined(__MSDOS__)
543 #if defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
544 # include <windows.h>
546 #endif /* PNG_VERSION_INFO_ONLY */
548 /* Moved here around 1.5.0beta36 from pngconf.h */
549 /* Users may want to use these so they are not private. Any library
550 * functions that are passed far data must be model-independent.
553 /* Platform-independent functions */
555 # define PNG_ABORT() abort()
558 /* These macros may need to be architecture dependent. */
559 #define PNG_ALIGN_NONE 0 /* do not use data alignment */
560 #define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
562 # define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
564 # define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
566 #define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
568 #ifndef PNG_ALIGN_TYPE
569 /* Default to using aligned access optimizations and requiring alignment to a
570 * multiple of the data type size. Override in a compiler specific fashion
571 * if necessary by inserting tests here:
573 # define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
576 #if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
577 /* This is used because in some compiler implementations non-aligned
578 * structure members are supported, so the offsetof approach below fails.
579 * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
580 * is good for performance. Do not do this unless you have tested the
581 * result and understand it.
583 # define png_alignof(type) (sizeof(type))
585 # if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
586 # define png_alignof(type) offsetof(struct{char c; type t;}, t)
588 # if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
589 # define png_alignof(type) 1
591 /* Else leave png_alignof undefined to prevent use thereof */
595 /* This implicitly assumes alignment is always a multiple of 2. */
597 # define png_isaligned(ptr, type) \
598 (((type)(size_t)((const void*)(ptr)) & (type)(png_alignof(type)-1)) == 0)
600 # define png_isaligned(ptr, type) 0
603 /* End of memory model/platform independent support */
604 /* End of 1.5.0beta36 move from pngconf.h */
606 /* CONSTANTS and UTILITY MACROS
607 * These are used internally by libpng and not exposed in the API
610 /* Various modes of operation. Note that after an init, mode is set to
611 * zero automatically when the structure is created. Three of these
612 * are defined in png.h because they need to be visible to applications
613 * that call png_set_unknown_chunk().
615 /* #define PNG_HAVE_IHDR 0x01U (defined in png.h) */
616 /* #define PNG_HAVE_PLTE 0x02U (defined in png.h) */
617 #define PNG_HAVE_IDAT 0x04U
618 /* #define PNG_AFTER_IDAT 0x08U (defined in png.h) */
619 #define PNG_HAVE_IEND 0x10U
623 #define PNG_HAVE_CHUNK_HEADER 0x100U
624 #define PNG_WROTE_tIME 0x200U
625 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400U
626 #define PNG_BACKGROUND_IS_GRAY 0x800U
627 #define PNG_HAVE_PNG_SIGNATURE 0x1000U
628 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
629 #define PNG_WROTE_eXIf 0x4000U
630 #define PNG_IS_READ_STRUCT 0x8000U /* Else is a write struct */
631 #ifdef PNG_APNG_SUPPORTED
632 #define PNG_HAVE_acTL 0x10000U
633 #define PNG_HAVE_fcTL 0x20000U
636 /* Flags for the transformations the PNG library does on the image data */
637 #define PNG_BGR 0x0001U
638 #define PNG_INTERLACE 0x0002U
639 #define PNG_PACK 0x0004U
640 #define PNG_SHIFT 0x0008U
641 #define PNG_SWAP_BYTES 0x0010U
642 #define PNG_INVERT_MONO 0x0020U
643 #define PNG_QUANTIZE 0x0040U
644 #define PNG_COMPOSE 0x0080U /* Was PNG_BACKGROUND */
645 #define PNG_BACKGROUND_EXPAND 0x0100U
646 #define PNG_EXPAND_16 0x0200U /* Added to libpng 1.5.2 */
647 #define PNG_16_TO_8 0x0400U /* Becomes 'chop' in 1.5.4 */
648 #define PNG_RGBA 0x0800U
649 #define PNG_EXPAND 0x1000U
650 #define PNG_GAMMA 0x2000U
651 #define PNG_GRAY_TO_RGB 0x4000U
652 #define PNG_FILLER 0x8000U
653 #define PNG_PACKSWAP 0x10000U
654 #define PNG_SWAP_ALPHA 0x20000U
655 #define PNG_STRIP_ALPHA 0x40000U
656 #define PNG_INVERT_ALPHA 0x80000U
657 #define PNG_USER_TRANSFORM 0x100000U
658 #define PNG_RGB_TO_GRAY_ERR 0x200000U
659 #define PNG_RGB_TO_GRAY_WARN 0x400000U
660 #define PNG_RGB_TO_GRAY 0x600000U /* two bits, RGB_TO_GRAY_ERR|WARN */
661 #define PNG_ENCODE_ALPHA 0x800000U /* Added to libpng-1.5.4 */
662 #define PNG_ADD_ALPHA 0x1000000U /* Added to libpng-1.2.7 */
663 #define PNG_EXPAND_tRNS 0x2000000U /* Added to libpng-1.2.9 */
664 #define PNG_SCALE_16_TO_8 0x4000000U /* Added to libpng-1.5.4 */
665 /* 0x8000000U unused */
666 /* 0x10000000U unused */
667 /* 0x20000000U unused */
668 /* 0x40000000U unused */
669 /* Flags for png_create_struct */
670 #define PNG_STRUCT_PNG 0x0001U
671 #define PNG_STRUCT_INFO 0x0002U
673 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
674 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001U
675 #define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002U /* Added to libpng-1.6.0 */
677 #define PNG_FLAG_ZSTREAM_ENDED 0x0008U /* Added to libpng-1.6.0 */
680 #define PNG_FLAG_ROW_INIT 0x0040U
681 #define PNG_FLAG_FILLER_AFTER 0x0080U
682 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100U
683 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200U
684 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400U
685 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800U
686 #define PNG_FLAG_ASSUME_sRGB 0x1000U /* Added to libpng-1.5.4 */
687 #define PNG_FLAG_OPTIMIZE_ALPHA 0x2000U /* Added to libpng-1.5.4 */
688 #define PNG_FLAG_DETECT_UNINITIALIZED 0x4000U /* Added to libpng-1.5.4 */
689 /* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000U */
690 /* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000U */
691 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000U
692 #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000U
693 #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000U
694 #define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000U /* Added to libpng-1.4.0 */
695 #define PNG_FLAG_APP_WARNINGS_WARN 0x200000U /* Added to libpng-1.6.0 */
696 #define PNG_FLAG_APP_ERRORS_WARN 0x400000U /* Added to libpng-1.6.0 */
697 /* 0x800000U unused */
698 /* 0x1000000U unused */
699 /* 0x2000000U unused */
700 /* 0x4000000U unused */
701 /* 0x8000000U unused */
702 /* 0x10000000U unused */
703 /* 0x20000000U unused */
704 /* 0x40000000U unused */
706 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
707 PNG_FLAG_CRC_ANCILLARY_NOWARN)
709 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
710 PNG_FLAG_CRC_CRITICAL_IGNORE)
712 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
713 PNG_FLAG_CRC_CRITICAL_MASK)
715 /* Save typing and make code easier to understand */
717 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
718 abs((int)((c1).green) - (int)((c2).green)) + \
719 abs((int)((c1).blue) - (int)((c2).blue)))
721 /* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
722 * by dividing by 257 *with rounding*. This macro is exact for the given range.
723 * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
724 * macro were established by experiment (modifying the added value). The macro
725 * has a second variant that takes a value already scaled by 255 and divides by
726 * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
727 * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
729 #define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
730 #define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
732 /* Added to libpng-1.2.6 JB */
733 #define PNG_ROWBYTES(pixel_bits, width) \
734 ((pixel_bits) >= 8 ? \
735 ((size_t)(width) * (((size_t)(pixel_bits)) >> 3)) : \
736 (( ((size_t)(width) * ((size_t)(pixel_bits))) + 7) >> 3) )
738 /* This returns the number of trailing bits in the last byte of a row, 0 if the
739 * last byte is completely full of pixels. It is, in principle, (pixel_bits x
740 * width) % 8, but that would overflow for large 'width'. The second macro is
741 * the same except that it returns the number of unused bits in the last byte;
742 * (8-TRAILBITS), but 0 when TRAILBITS is 0.
744 * NOTE: these macros are intended to be self-evidently correct and never
745 * overflow on the assumption that pixel_bits is in the range 0..255. The
746 * arguments are evaluated only once and they can be signed (e.g. as a result of
747 * the integral promotions). The result of the expression always has type
748 * (png_uint_32), however the compiler always knows it is in the range 0..7.
750 #define PNG_TRAILBITS(pixel_bits, width) \
751 (((pixel_bits) * ((width) % (png_uint_32)8)) % 8)
753 #define PNG_PADBITS(pixel_bits, width) \
754 ((8 - PNG_TRAILBITS(pixel_bits, width)) % 8)
756 /* PNG_OUT_OF_RANGE returns true if value is outside the range
757 * ideal-delta..ideal+delta. Each argument is evaluated twice.
758 * "ideal" and "delta" should be constants, normally simple
759 * integers, "value" a variable. Added to libpng-1.2.6 JB
761 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
762 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
764 /* Conversions between fixed and floating point, only defined if
765 * required (to make sure the code doesn't accidentally use float
766 * when it is supposedly disabled.)
768 #ifdef PNG_FLOATING_POINT_SUPPORTED
769 /* The floating point conversion can't overflow, though it can and
770 * does lose accuracy relative to the original fixed point value.
771 * In practice this doesn't matter because png_fixed_point only
772 * stores numbers with very low precision. The png_ptr and s
773 * arguments are unused by default but are there in case error
774 * checking becomes a requirement.
776 #define png_float(png_ptr, fixed, s) (.00001 * (fixed))
778 /* The fixed point conversion performs range checking and evaluates
779 * its argument multiple times, so must be used with care. The
780 * range checking uses the PNG specification values for a signed
781 * 32-bit fixed point value except that the values are deliberately
782 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
783 * (2^31-1) * 100000). 's' is a string that describes the value being
786 * NOTE: this macro will raise a png_error if the range check fails,
787 * therefore it is normally only appropriate to use this on values
788 * that come from API calls or other sources where an out of range
789 * error indicates a programming error, not a data error!
791 * NOTE: by default this is off - the macro is not used - because the
792 * function call saves a lot of code.
794 #ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
795 #define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
796 ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
798 /* else the corresponding function is defined below, inside the scope of the
803 /* Constants for known chunk types. If you need to add a chunk, define the name
804 * here. For historical reasons these constants have the form png_<name>; i.e.
805 * the prefix is lower case. Please use decimal values as the parameters to
806 * match the ISO PNG specification and to avoid relying on the C locale
807 * interpretation of character values.
809 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
810 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
811 * to be generated if required.
813 * PNG_32b correctly produces a value shifted by up to 24 bits, even on
814 * architectures where (int) is only 16 bits.
816 #define PNG_32b(b,s) ((png_uint_32)(b) << (s))
817 #define PNG_U32(b1,b2,b3,b4) \
818 (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
820 /* Constants for known chunk types.
822 * MAINTAINERS: If you need to add a chunk, define the name here.
823 * For historical reasons these constants have the form png_<name>; i.e.
824 * the prefix is lower case. Please use decimal values as the parameters to
825 * match the ISO PNG specification and to avoid relying on the C locale
826 * interpretation of character values. Please keep the list sorted.
828 * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
829 * type. In fact the specification does not express chunk types this way,
830 * however using a 32-bit value means that the chunk type can be read from the
831 * stream using exactly the same code as used for a 32-bit unsigned value and
832 * can be examined far more efficiently (using one arithmetic compare).
834 * Prior to 1.5.6 the chunk type constants were expressed as C strings. The
835 * libpng API still uses strings for 'unknown' chunks and a macro,
836 * PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice
837 * that for portable code numeric values must still be used; the string "IHDR"
838 * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
840 * In 1.7.0 the definitions will be made public in png.h to avoid having to
841 * duplicate the same definitions in application code.
843 #define png_IDAT PNG_U32( 73, 68, 65, 84)
844 #define png_IEND PNG_U32( 73, 69, 78, 68)
845 #define png_IHDR PNG_U32( 73, 72, 68, 82)
846 #define png_PLTE PNG_U32( 80, 76, 84, 69)
847 #define png_bKGD PNG_U32( 98, 75, 71, 68)
848 #define png_cHRM PNG_U32( 99, 72, 82, 77)
849 #define png_eXIf PNG_U32(101, 88, 73, 102) /* registered July 2017 */
850 #define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */
851 #define png_gAMA PNG_U32(103, 65, 77, 65)
852 #define png_gIFg PNG_U32(103, 73, 70, 103)
853 #define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */
854 #define png_gIFx PNG_U32(103, 73, 70, 120)
855 #define png_hIST PNG_U32(104, 73, 83, 84)
856 #define png_iCCP PNG_U32(105, 67, 67, 80)
857 #define png_iTXt PNG_U32(105, 84, 88, 116)
858 #define png_oFFs PNG_U32(111, 70, 70, 115)
859 #define png_pCAL PNG_U32(112, 67, 65, 76)
860 #define png_pHYs PNG_U32(112, 72, 89, 115)
861 #define png_sBIT PNG_U32(115, 66, 73, 84)
862 #define png_sCAL PNG_U32(115, 67, 65, 76)
863 #define png_sPLT PNG_U32(115, 80, 76, 84)
864 #define png_sRGB PNG_U32(115, 82, 71, 66)
865 #define png_sTER PNG_U32(115, 84, 69, 82)
866 #define png_tEXt PNG_U32(116, 69, 88, 116)
867 #define png_tIME PNG_U32(116, 73, 77, 69)
868 #define png_tRNS PNG_U32(116, 82, 78, 83)
869 #define png_zTXt PNG_U32(122, 84, 88, 116)
871 #ifdef PNG_APNG_SUPPORTED
872 #define png_acTL PNG_U32( 97, 99, 84, 76)
873 #define png_fcTL PNG_U32(102, 99, 84, 76)
874 #define png_fdAT PNG_U32(102, 100, 65, 84)
876 /* For png_struct.apng_flags: */
877 #define PNG_FIRST_FRAME_HIDDEN 0x0001U
878 #define PNG_APNG_APP 0x0002U
881 /* The following will work on (signed char*) strings, whereas the get_uint_32
882 * macro will fail on top-bit-set values because of the sign extension.
884 #define PNG_CHUNK_FROM_STRING(s)\
885 PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
887 /* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
888 * signed and the argument is a (char[]) This macro will fail miserably on
889 * systems where (char) is more than 8 bits.
891 #define PNG_STRING_FROM_CHUNK(s,c)\
892 (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
893 ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
894 ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
895 ((char*)(s))[3]=(char)((c & 0xff)))
897 /* Do the same but terminate with a null character. */
898 #define PNG_CSTRING_FROM_CHUNK(s,c)\
899 (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
901 /* Test on flag values as defined in the spec (section 5.4): */
902 #define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29))
903 #define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
904 #define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
905 #define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
906 #define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
908 /* Gamma values (new at libpng-1.5.4): */
909 #define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
910 #define PNG_GAMMA_MAC_INVERSE 65909
911 #define PNG_GAMMA_sRGB_INVERSE 45455
913 /* Almost everything below is C specific; the #defines above can be used in
914 * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
916 #ifndef PNG_VERSION_INFO_ONLY
918 #include "pngstruct.h"
921 /* Validate the include paths - the include path used to generate pnglibconf.h
922 * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
924 #if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
925 # error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
926 "-I (include path) error: see the notes in pngpriv.h"
927 /* This means that when pnglibconf.h was built the copy of zlib.h that it
928 * used is not the same as the one being used here. Because the build of
929 * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
930 * zlib version number and because this affects handling of certain broken
931 * PNG files the -I directives must match.
933 * The most likely explanation is that you passed a -I in CFLAGS. This will
934 * not work; all the preprocessor directives and in particular all the -I
935 * directives must be in CPPFLAGS.
939 /* This is used for 16-bit gamma tables -- only the top level pointers are
940 * const; this could be changed:
942 typedef const png_uint_16p * png_const_uint_16pp;
944 /* Added to libpng-1.5.7: sRGB conversion tables */
945 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
946 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
947 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
948 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
949 /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
950 * 0..65535. This table gives the closest 16-bit answers (no errors).
954 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
955 PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
957 #define PNG_sRGB_FROM_LINEAR(linear) \
958 ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
959 + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
960 /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
961 * encoded value with maximum error 0.646365. Note that the input is not a
962 * 16-bit value; it has been multiplied by 255! */
963 #endif /* SIMPLIFIED_READ/WRITE */
966 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
969 #endif /* __cplusplus */
971 /* Internal functions; these are not exported from a DLL however because they
972 * are used within several of the C source files they have to be C extern.
974 * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
978 #define PNG_UNEXPECTED_ZLIB_RETURN (-7)
979 PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
981 /* Used by the zlib handling functions to ensure that z_stream::msg is always
982 * set before they return.
985 #ifdef PNG_WRITE_SUPPORTED
986 PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
987 png_compression_bufferp *list),PNG_EMPTY);
988 /* Free the buffer list used by the compressed write code. */
991 #if defined(PNG_FLOATING_POINT_SUPPORTED) && \
992 !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
993 (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
994 defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
995 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
996 (defined(PNG_sCAL_SUPPORTED) && \
997 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
998 PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
999 double fp, png_const_charp text),PNG_EMPTY);
1002 /* Check the user version string for compatibility, returns false if the version
1003 * numbers aren't compatible.
1005 PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
1006 png_const_charp user_png_ver),PNG_EMPTY);
1008 /* Internal base allocator - no messages, NULL on failure to allocate. This
1009 * does, however, call the application provided allocator and that could call
1010 * png_error (although that would be a bug in the application implementation.)
1012 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
1013 png_alloc_size_t size),PNG_ALLOCATED);
1015 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
1016 defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
1017 /* Internal array allocator, outputs no error or warning messages on failure,
1018 * just returns NULL.
1020 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
1021 int nelements, size_t element_size),PNG_ALLOCATED);
1023 /* The same but an existing array is extended by add_elements. This function
1024 * also memsets the new elements to 0 and copies the old elements. The old
1025 * array is not freed or altered.
1027 PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
1028 png_const_voidp array, int old_elements, int add_elements,
1029 size_t element_size),PNG_ALLOCATED);
1030 #endif /* text, sPLT or unknown chunks */
1032 /* Magic to create a struct when there is no struct to call the user supplied
1033 * memory allocators. Because error handling has not been set up the memory
1034 * handlers can't safely call png_error, but this is an obscure and undocumented
1035 * restriction so libpng has to assume that the 'free' handler, at least, might
1038 PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
1039 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1040 png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
1041 png_free_ptr free_fn),PNG_ALLOCATED);
1043 /* Free memory from internal libpng struct */
1044 PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
1047 /* Free an allocated jmp_buf (always succeeds) */
1048 PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
1050 /* Function to allocate memory for zlib. PNGAPI is disallowed. */
1051 PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
1054 /* Function to free memory for zlib. PNGAPI is disallowed. */
1055 PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
1057 /* Next four functions are used internally as callbacks. PNGCBAPI is required
1058 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
1062 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
1063 png_bytep data, size_t length),PNG_EMPTY);
1065 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1066 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
1067 png_bytep buffer, size_t length),PNG_EMPTY);
1070 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
1071 png_bytep data, size_t length),PNG_EMPTY);
1073 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1074 # ifdef PNG_STDIO_SUPPORTED
1075 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
1080 /* Reset the CRC variable */
1081 PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
1083 /* Write the "data" buffer to whatever output you are using */
1084 PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
1085 png_const_bytep data, size_t length),PNG_EMPTY);
1087 /* Read and check the PNG file signature */
1088 PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
1089 png_inforp info_ptr),PNG_EMPTY);
1091 /* Read the chunk header (length + type name) */
1092 PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
1095 /* Read data from whatever input you are using into the "data" buffer */
1096 PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
1097 size_t length),PNG_EMPTY);
1099 /* Read bytes into buf, and update png_ptr->crc */
1100 PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
1101 png_uint_32 length),PNG_EMPTY);
1103 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
1104 PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
1105 png_uint_32 skip),PNG_EMPTY);
1107 /* Read the CRC from the file and compare it to the libpng calculated CRC */
1108 PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
1110 /* Calculate the CRC over a section of data. Note that we are only
1111 * passing a maximum of 64K on systems that have this as a memory limit,
1112 * since this is the maximum buffer size we can specify.
1114 PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
1115 png_const_bytep ptr, size_t length),PNG_EMPTY);
1117 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1118 PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
1121 /* Write various chunks */
1123 /* Write the IHDR chunk, and update the png_struct with the necessary
1126 PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
1127 png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1128 int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
1130 PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
1131 png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
1133 PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
1134 png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
1137 PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
1139 #ifdef PNG_WRITE_gAMA_SUPPORTED
1140 PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
1141 png_fixed_point file_gamma),PNG_EMPTY);
1144 #ifdef PNG_WRITE_sBIT_SUPPORTED
1145 PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
1146 png_const_color_8p sbit, int color_type),PNG_EMPTY);
1149 #ifdef PNG_WRITE_cHRM_SUPPORTED
1150 PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
1151 const png_xy *xy), PNG_EMPTY);
1152 /* The xy value must have been previously validated */
1155 #ifdef PNG_WRITE_sRGB_SUPPORTED
1156 PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1157 int intent),PNG_EMPTY);
1160 #ifdef PNG_WRITE_eXIf_SUPPORTED
1161 PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr,
1162 png_bytep exif, int num_exif),PNG_EMPTY);
1165 #ifdef PNG_WRITE_iCCP_SUPPORTED
1166 PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1167 png_const_charp name, png_const_bytep profile), PNG_EMPTY);
1168 /* The profile must have been previously validated for correctness, the
1169 * length comes from the first four bytes. Only the base, deflate,
1170 * compression is supported.
1174 #ifdef PNG_WRITE_sPLT_SUPPORTED
1175 PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1176 png_const_sPLT_tp palette),PNG_EMPTY);
1179 #ifdef PNG_WRITE_tRNS_SUPPORTED
1180 PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1181 png_const_bytep trans, png_const_color_16p values, int number,
1182 int color_type),PNG_EMPTY);
1185 #ifdef PNG_WRITE_bKGD_SUPPORTED
1186 PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1187 png_const_color_16p values, int color_type),PNG_EMPTY);
1190 #ifdef PNG_WRITE_hIST_SUPPORTED
1191 PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1192 png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1195 /* Chunks that have keywords */
1196 #ifdef PNG_WRITE_tEXt_SUPPORTED
1197 PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1198 png_const_charp key, png_const_charp text, size_t text_len),PNG_EMPTY);
1201 #ifdef PNG_WRITE_zTXt_SUPPORTED
1202 PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1203 key, png_const_charp text, int compression),PNG_EMPTY);
1206 #ifdef PNG_WRITE_iTXt_SUPPORTED
1207 PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1208 int compression, png_const_charp key, png_const_charp lang,
1209 png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1212 #ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
1213 PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1214 png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1217 #ifdef PNG_WRITE_oFFs_SUPPORTED
1218 PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1219 png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1222 #ifdef PNG_WRITE_pCAL_SUPPORTED
1223 PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1224 png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1225 png_const_charp units, png_charpp params),PNG_EMPTY);
1228 #ifdef PNG_WRITE_pHYs_SUPPORTED
1229 PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1230 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1231 int unit_type),PNG_EMPTY);
1234 #ifdef PNG_WRITE_tIME_SUPPORTED
1235 PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1236 png_const_timep mod_time),PNG_EMPTY);
1239 #ifdef PNG_WRITE_sCAL_SUPPORTED
1240 PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1241 int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1244 /* Called when finished processing a row of data */
1245 PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1248 /* Internal use only. Called before first row of data */
1249 PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1252 /* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
1253 * array of png_ptr->width pixels. If the image is not interlaced or this
1254 * is the final pass this just does a memcpy, otherwise the "display" flag
1255 * is used to determine whether to copy pixels that are not in the current pass.
1257 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1258 * function to achieve the documented 'blocky' appearance during interlaced read
1259 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1260 * are not changed if they are not in the current pass, when display is 0.
1262 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1264 * The API always reads from the png_struct row buffer and always assumes that
1265 * it is full width (png_do_read_interlace has already been called.)
1267 * This function is only ever used to write to row buffers provided by the
1268 * caller of the relevant libpng API and the row must have already been
1269 * transformed by the read transformations.
1271 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1272 * bitmasks for use within the code, otherwise runtime generated masks are used.
1273 * The default is compile time masks.
1275 #ifndef PNG_USE_COMPILE_TIME_MASKS
1276 # define PNG_USE_COMPILE_TIME_MASKS 1
1278 PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1279 png_bytep row, int display),PNG_EMPTY);
1281 #ifdef PNG_READ_INTERLACING_SUPPORTED
1282 /* Expand an interlaced row: the 'row_info' describes the pass data that has
1283 * been read in and must correspond to the pixels in 'row', the pixels are
1284 * expanded (moved apart) in 'row' to match the final layout, when doing this
1285 * the pixels are *replicated* to the intervening space. This is essential for
1286 * the correct operation of png_combine_row, above.
1288 PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1289 png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1292 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
1294 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1295 /* Grab pixels out of a row for an interlaced pass */
1296 PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1297 png_bytep row, int pass),PNG_EMPTY);
1300 /* Unfilter a row: check the filter value before calling this, there is no point
1301 * calling it for PNG_FILTER_VALUE_NONE.
1303 PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1304 row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1306 #if PNG_ARM_NEON_OPT > 0
1307 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1308 png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1309 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1310 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1311 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1312 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1313 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1314 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1315 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1316 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1317 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1318 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1319 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1320 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1323 #if PNG_MIPS_MSA_OPT > 0
1324 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_msa,(png_row_infop row_info,
1325 png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1326 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_msa,(png_row_infop
1327 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1328 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_msa,(png_row_infop
1329 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1330 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_msa,(png_row_infop
1331 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1332 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop
1333 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1334 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop
1335 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1336 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop
1337 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1340 #if PNG_POWERPC_VSX_OPT > 0
1341 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_vsx,(png_row_infop row_info,
1342 png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1343 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_vsx,(png_row_infop
1344 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1345 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_vsx,(png_row_infop
1346 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1347 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_vsx,(png_row_infop
1348 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1349 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_vsx,(png_row_infop
1350 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1351 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_vsx,(png_row_infop
1352 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1353 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_vsx,(png_row_infop
1354 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1357 #if PNG_INTEL_SSE_IMPLEMENTATION > 0
1358 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
1359 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1360 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
1361 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1362 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
1363 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1364 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
1365 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1366 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
1367 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1368 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
1369 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1372 /* Choose the best filter to use and filter the row data */
1373 PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1374 png_row_infop row_info),PNG_EMPTY);
1376 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1377 PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1378 png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1379 /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
1380 * is NULL the function checks, instead, for the end of the stream. In this
1381 * case a benign error will be issued if the stream end is not found or if
1382 * extra data has to be consumed.
1384 PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1386 /* This cleans up when the IDAT LZ stream does not end when the last image
1387 * byte is read; there is still some pending input.
1390 PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1392 /* Finish a row while reading, dealing with interlacing passes, etc. */
1393 #endif /* SEQUENTIAL_READ */
1395 /* Initialize the row buffers, etc. */
1396 PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1398 #if ZLIB_VERNUM >= 0x1240
1399 PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
1401 # define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
1402 #else /* Zlib < 1.2.4 */
1403 # define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
1404 #endif /* Zlib < 1.2.4 */
1406 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1407 /* Optional call to update the users info structure */
1408 PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1409 png_inforp info_ptr),PNG_EMPTY);
1412 /* Shared transform functions, defined in pngtran.c */
1413 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1414 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1415 PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1416 png_bytep row, int at_start),PNG_EMPTY);
1419 #ifdef PNG_16BIT_SUPPORTED
1420 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1421 PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1422 png_bytep row),PNG_EMPTY);
1426 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1427 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1428 PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1429 png_bytep row),PNG_EMPTY);
1432 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1433 PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1434 png_bytep row),PNG_EMPTY);
1437 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1438 PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1439 png_bytep row),PNG_EMPTY);
1442 /* The following decodes the appropriate chunks, and does error correction,
1443 * then calls the appropriate callback for the chunk if it is valid.
1446 /* Decode the IHDR chunk */
1447 PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1448 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1449 PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1450 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1451 PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1452 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1454 #ifdef PNG_READ_bKGD_SUPPORTED
1455 PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1456 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1459 #ifdef PNG_READ_cHRM_SUPPORTED
1460 PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1461 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1464 #ifdef PNG_READ_eXIf_SUPPORTED
1465 PNG_INTERNAL_FUNCTION(void,png_handle_eXIf,(png_structrp png_ptr,
1466 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1469 #ifdef PNG_READ_gAMA_SUPPORTED
1470 PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1471 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1474 #ifdef PNG_READ_hIST_SUPPORTED
1475 PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1476 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1479 #ifdef PNG_READ_iCCP_SUPPORTED
1480 PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1481 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1482 #endif /* READ_iCCP */
1484 #ifdef PNG_READ_iTXt_SUPPORTED
1485 PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1486 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1489 #ifdef PNG_READ_oFFs_SUPPORTED
1490 PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1491 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1494 #ifdef PNG_READ_pCAL_SUPPORTED
1495 PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1496 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1499 #ifdef PNG_READ_pHYs_SUPPORTED
1500 PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1501 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1504 #ifdef PNG_READ_sBIT_SUPPORTED
1505 PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1506 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1509 #ifdef PNG_READ_sCAL_SUPPORTED
1510 PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1511 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1514 #ifdef PNG_READ_sPLT_SUPPORTED
1515 PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1516 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1517 #endif /* READ_sPLT */
1519 #ifdef PNG_READ_sRGB_SUPPORTED
1520 PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1521 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1524 #ifdef PNG_READ_tEXt_SUPPORTED
1525 PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1526 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1529 #ifdef PNG_READ_tIME_SUPPORTED
1530 PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1531 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1534 #ifdef PNG_READ_tRNS_SUPPORTED
1535 PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1536 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1539 #ifdef PNG_READ_zTXt_SUPPORTED
1540 PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1541 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1544 PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_const_structrp png_ptr,
1545 png_uint_32 chunk_name),PNG_EMPTY);
1547 PNG_INTERNAL_FUNCTION(void,png_check_chunk_length,(png_const_structrp png_ptr,
1548 png_uint_32 chunk_length),PNG_EMPTY);
1550 PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1551 png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1552 /* This is the function that gets called for unknown chunks. The 'keep'
1553 * argument is either non-zero for a known chunk that has been set to be
1554 * handled as unknown or zero for an unknown chunk. By default the function
1555 * just skips the chunk or errors out if it is critical.
1558 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
1559 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1560 PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1561 (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1562 /* Exactly as the API png_handle_as_unknown() except that the argument is a
1563 * 32-bit chunk name, not a string.
1565 #endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
1567 /* Handle the transformations for reading and writing */
1568 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1569 PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1570 png_row_infop row_info),PNG_EMPTY);
1572 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1573 PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1574 png_row_infop row_info),PNG_EMPTY);
1577 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1578 PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1582 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1583 PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1584 png_inforp info_ptr),PNG_EMPTY);
1585 PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1586 png_inforp info_ptr),PNG_EMPTY);
1587 PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1588 PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1590 PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1591 png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1592 PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1593 PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1594 png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1595 PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1597 PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1598 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1599 PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1600 png_inforp info_ptr),PNG_EMPTY);
1601 PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1602 png_inforp info_ptr),PNG_EMPTY);
1603 PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1604 png_bytep row),PNG_EMPTY);
1605 PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1606 png_inforp info_ptr),PNG_EMPTY);
1607 PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1608 png_inforp info_ptr),PNG_EMPTY);
1609 PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1611 # ifdef PNG_READ_tEXt_SUPPORTED
1612 PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1613 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1614 PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1615 png_inforp info_ptr),PNG_EMPTY);
1617 # ifdef PNG_READ_zTXt_SUPPORTED
1618 PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1619 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1620 PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1621 png_inforp info_ptr),PNG_EMPTY);
1623 # ifdef PNG_READ_iTXt_SUPPORTED
1624 PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1625 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1626 PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1627 png_inforp info_ptr),PNG_EMPTY);
1630 #endif /* PROGRESSIVE_READ */
1632 /* Added at libpng version 1.6.0 */
1633 #ifdef PNG_GAMMA_SUPPORTED
1634 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1635 png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1636 /* Set the colorspace gamma with a value provided by the application or by
1637 * the gAMA chunk on read. The value will override anything set by an ICC
1641 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1642 png_inforp info_ptr), PNG_EMPTY);
1643 /* Synchronize the info 'valid' flags with the colorspace */
1645 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1646 png_inforp info_ptr), PNG_EMPTY);
1647 /* Copy the png_struct colorspace to the info_struct and call the above to
1648 * synchronize the flags. Checks for NULL info_ptr and does nothing.
1652 #ifdef PNG_APNG_SUPPORTED
1653 PNG_INTERNAL_FUNCTION(void,png_ensure_fcTL_is_valid,(png_structp png_ptr,
1654 png_uint_32 width, png_uint_32 height,
1655 png_uint_32 x_offset, png_uint_32 y_offset,
1656 png_uint_16 delay_num, png_uint_16 delay_den,
1657 png_byte dispose_op, png_byte blend_op), PNG_EMPTY);
1659 #ifdef PNG_READ_APNG_SUPPORTED
1660 PNG_INTERNAL_FUNCTION(void,png_handle_acTL,(png_structp png_ptr, png_infop info_ptr,
1661 png_uint_32 length),PNG_EMPTY);
1662 PNG_INTERNAL_FUNCTION(void,png_handle_fcTL,(png_structp png_ptr, png_infop info_ptr,
1663 png_uint_32 length),PNG_EMPTY);
1664 PNG_INTERNAL_FUNCTION(void,png_handle_fdAT,(png_structp png_ptr, png_infop info_ptr,
1665 png_uint_32 length),PNG_EMPTY);
1666 PNG_INTERNAL_FUNCTION(void,png_have_info,(png_structp png_ptr, png_infop info_ptr),PNG_EMPTY);
1667 PNG_INTERNAL_FUNCTION(void,png_ensure_sequence_number,(png_structp png_ptr,
1668 png_uint_32 length),PNG_EMPTY);
1669 PNG_INTERNAL_FUNCTION(void,png_read_reset,(png_structp png_ptr),PNG_EMPTY);
1670 PNG_INTERNAL_FUNCTION(void,png_read_reinit,(png_structp png_ptr,
1671 png_infop info_ptr),PNG_EMPTY);
1672 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1673 PNG_INTERNAL_FUNCTION(void,png_progressive_read_reset,(png_structp png_ptr),PNG_EMPTY);
1674 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1675 #endif /* PNG_READ_APNG_SUPPORTED */
1677 #ifdef PNG_WRITE_APNG_SUPPORTED
1678 PNG_INTERNAL_FUNCTION(void,png_write_acTL,(png_structp png_ptr,
1679 png_uint_32 num_frames, png_uint_32 num_plays),PNG_EMPTY);
1680 PNG_INTERNAL_FUNCTION(void,png_write_fcTL,(png_structp png_ptr,
1681 png_uint_32 width, png_uint_32 height,
1682 png_uint_32 x_offset, png_uint_32 y_offset,
1683 png_uint_16 delay_num, png_uint_16 delay_den,
1684 png_byte dispose_op, png_byte blend_op),PNG_EMPTY);
1685 PNG_INTERNAL_FUNCTION(void,png_write_fdAT,(png_structp png_ptr,
1686 png_const_bytep data, png_size_t length),PNG_EMPTY);
1687 PNG_INTERNAL_FUNCTION(void,png_write_reset,(png_structp png_ptr),PNG_EMPTY);
1688 PNG_INTERNAL_FUNCTION(void,png_write_reinit,(png_structp png_ptr,
1689 png_infop info_ptr, png_uint_32 width, png_uint_32 height),PNG_EMPTY);
1690 #endif /* PNG_WRITE_APNG_SUPPORTED */
1691 #endif /* PNG_APNG_SUPPORTED */
1693 /* Added at libpng version 1.4.0 */
1694 #ifdef PNG_COLORSPACE_SUPPORTED
1695 /* These internal functions are for maintaining the colorspace structure within
1696 * a png_info or png_struct (or, indeed, both).
1698 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1699 (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1700 int preferred), PNG_EMPTY);
1702 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1703 (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1704 int preferred), PNG_EMPTY);
1706 #ifdef PNG_sRGB_SUPPORTED
1707 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1708 png_colorspacerp colorspace, int intent), PNG_EMPTY);
1709 /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1710 * flags to write them, if it returns false there was a problem and an error
1711 * message has already been output (but the colorspace may still need to be
1712 * synced to record the invalid flag).
1716 #ifdef PNG_iCCP_SUPPORTED
1717 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1718 png_colorspacerp colorspace, png_const_charp name,
1719 png_uint_32 profile_length, png_const_bytep profile, int color_type),
1721 /* The 'name' is used for information only */
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_colorspacerp colorspace, png_const_charp name,
1727 png_uint_32 profile_length), PNG_EMPTY);
1728 #endif /* READ_iCCP */
1729 PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1730 png_colorspacerp colorspace, png_const_charp name,
1731 png_uint_32 profile_length,
1732 png_const_bytep profile /* first 132 bytes only */, int color_type),
1734 PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1735 png_colorspacerp colorspace, png_const_charp name,
1736 png_uint_32 profile_length,
1737 png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1738 #ifdef PNG_sRGB_SUPPORTED
1739 PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1740 png_const_structrp png_ptr, png_colorspacerp colorspace,
1741 png_const_bytep profile, uLong adler), PNG_EMPTY);
1742 /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1743 * be zero to indicate that it is not available. It is used, if provided,
1744 * as a fast check on the profile when checking to see if it is sRGB.
1749 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1750 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1751 (png_structrp png_ptr), PNG_EMPTY);
1752 /* Set the rgb_to_gray coefficients from the colorspace Y values */
1753 #endif /* READ_RGB_TO_GRAY */
1754 #endif /* COLORSPACE */
1756 /* Added at libpng version 1.4.0 */
1757 PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1758 png_uint_32 width, png_uint_32 height, int bit_depth,
1759 int color_type, int interlace_type, int compression_type,
1760 int filter_type),PNG_EMPTY);
1762 /* Added at libpng version 1.5.10 */
1763 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1764 defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1765 PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1766 (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1769 #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1770 PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1771 png_const_charp name),PNG_NORETURN);
1774 /* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1775 * the end. Always leaves the buffer nul terminated. Never errors out (and
1776 * there is no error code.)
1778 PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1779 size_t pos, png_const_charp string),PNG_EMPTY);
1781 /* Various internal functions to handle formatted warning messages, currently
1782 * only implemented for warnings.
1784 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1785 /* Utility to dump an unsigned value into a buffer, given a start pointer and
1786 * and end pointer (which should point just *beyond* the end of the buffer!)
1787 * Returns the pointer to the start of the formatted string. This utility only
1788 * does unsigned values.
1790 PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1791 png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1793 /* Convenience macro that takes an array: */
1794 #define PNG_FORMAT_NUMBER(buffer,format,number) \
1795 png_format_number(buffer, buffer + (sizeof buffer), format, number)
1797 /* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1798 #define PNG_NUMBER_BUFFER_SIZE 24
1800 /* These are the integer formats currently supported, the name is formed from
1801 * the standard printf(3) format string.
1803 #define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
1804 #define PNG_NUMBER_FORMAT_02u 2
1805 #define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
1806 #define PNG_NUMBER_FORMAT_02d 2
1807 #define PNG_NUMBER_FORMAT_x 3
1808 #define PNG_NUMBER_FORMAT_02x 4
1809 #define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1812 #ifdef PNG_WARNINGS_SUPPORTED
1813 /* New defines and members adding in libpng-1.5.4 */
1814 # define PNG_WARNING_PARAMETER_SIZE 32
1815 # define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1817 /* An l-value of this type has to be passed to the APIs below to cache the
1818 * values of the parameters to a formatted warning message.
1820 typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1821 PNG_WARNING_PARAMETER_SIZE];
1823 PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1824 int number, png_const_charp string),PNG_EMPTY);
1825 /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1826 * including the trailing '\0'.
1828 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1829 (png_warning_parameters p, int number, int format, png_alloc_size_t value),
1831 /* Use png_alloc_size_t because it is an unsigned type as big as any we
1832 * need to output. Use the following for a signed value.
1834 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1835 (png_warning_parameters p, int number, int format, png_int_32 value),
1838 PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1839 png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1840 /* 'message' follows the X/Open approach of using @1, @2 to insert
1841 * parameters previously supplied using the above functions. Errors in
1842 * specifying the parameters will simply result in garbage substitutions.
1846 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1847 /* Application errors (new in 1.6); use these functions (declared below) for
1848 * errors in the parameters or order of API function calls on read. The
1849 * 'warning' should be used for an error that can be handled completely; the
1850 * 'error' for one which can be handled safely but which may lose application
1851 * information or settings.
1853 * By default these both result in a png_error call prior to release, while in a
1854 * released version the 'warning' is just a warning. However if the application
1855 * explicitly disables benign errors (explicitly permitting the code to lose
1856 * information) they both turn into warnings.
1858 * If benign errors aren't supported they end up as the corresponding base call
1859 * (png_warning or png_error.)
1861 PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1862 png_const_charp message),PNG_EMPTY);
1863 /* The application provided invalid parameters to an API function or called
1864 * an API function at the wrong time, libpng can completely recover.
1867 PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1868 png_const_charp message),PNG_EMPTY);
1869 /* As above but libpng will ignore the call, or attempt some other partial
1870 * recovery from the error.
1873 # define png_app_warning(pp,s) png_warning(pp,s)
1874 # define png_app_error(pp,s) png_error(pp,s)
1877 PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1878 png_const_charp message, int error),PNG_EMPTY);
1879 /* Report a recoverable issue in chunk data. On read this is used to report
1880 * a problem found while reading a particular chunk and the
1881 * png_chunk_benign_error or png_chunk_warning function is used as
1882 * appropriate. On write this is used to report an error that comes from
1883 * data set via an application call to a png_set_ API and png_app_error or
1884 * png_app_warning is used as appropriate.
1886 * The 'error' parameter must have one of the following values:
1888 #define PNG_CHUNK_WARNING 0 /* never an error */
1889 #define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1890 #define PNG_CHUNK_ERROR 2 /* always an error */
1892 /* ASCII to FP interfaces, currently only implemented if sCAL
1893 * support is required.
1895 #if defined(PNG_sCAL_SUPPORTED)
1896 /* MAX_DIGITS is actually the maximum number of characters in an sCAL
1897 * width or height, derived from the precision (number of significant
1898 * digits - a build time settable option) and assumptions about the
1899 * maximum ridiculous exponent.
1901 #define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1903 #ifdef PNG_FLOATING_POINT_SUPPORTED
1904 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1905 png_charp ascii, size_t size, double fp, unsigned int precision),
1907 #endif /* FLOATING_POINT */
1909 #ifdef PNG_FIXED_POINT_SUPPORTED
1910 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1911 png_charp ascii, size_t size, png_fixed_point fp),PNG_EMPTY);
1912 #endif /* FIXED_POINT */
1915 #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1916 /* An internal API to validate the format of a floating point number.
1917 * The result is the index of the next character. If the number is
1918 * not valid it will be the index of a character in the supposed number.
1920 * The format of a number is defined in the PNG extensions specification
1921 * and this API is strictly conformant to that spec, not anyone elses!
1923 * The format as a regular expression is:
1925 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1929 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1931 * The complexity is that either integer or fraction must be present and the
1932 * fraction is permitted to have no digits only if the integer is present.
1934 * NOTE: The dangling E problem.
1935 * There is a PNG valid floating point number in the following:
1937 * PNG floating point numbers are not greedy.
1939 * Working this out requires *TWO* character lookahead (because of the
1940 * sign), the parser does not do this - it will fail at the 'r' - this
1941 * doesn't matter for PNG sCAL chunk values, but it requires more care
1942 * if the value were ever to be embedded in something more complex. Use
1943 * ANSI-C strtod if you need the lookahead.
1945 /* State table for the parser. */
1946 #define PNG_FP_INTEGER 0 /* before or in integer */
1947 #define PNG_FP_FRACTION 1 /* before or in fraction */
1948 #define PNG_FP_EXPONENT 2 /* before or in exponent */
1949 #define PNG_FP_STATE 3 /* mask for the above */
1950 #define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
1951 #define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
1952 #define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
1953 #define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
1954 #define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
1956 /* These three values don't affect the parser. They are set but not used.
1958 #define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
1959 #define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
1960 #define PNG_FP_NONZERO 256 /* A non-zero value */
1961 #define PNG_FP_STICKY 448 /* The above three flags */
1963 /* This is available for the caller to store in 'state' if required. Do not
1964 * call the parser after setting it (the parser sometimes clears it.)
1966 #define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
1968 /* Result codes for the parser (boolean - true means ok, false means
1971 #define PNG_FP_MAYBE 0 /* The number may be valid in the future */
1972 #define PNG_FP_OK 1 /* The number is valid */
1974 /* Tests on the sticky non-zero and negative flags. To pass these checks
1975 * the state must also indicate that the whole number is valid - this is
1976 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1977 * is equivalent to PNG_FP_OK above.)
1979 #define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1980 /* NZ_MASK: the string is valid and a non-zero negative value */
1981 #define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1982 /* Z MASK: the string is valid and a non-zero value. */
1983 /* PNG_FP_SAW_DIGIT: the string is valid. */
1984 #define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1985 #define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1986 #define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1988 /* The actual parser. This can be called repeatedly. It updates
1989 * the index into the string and the state variable (which must
1990 * be initialized to 0). It returns a result code, as above. There
1991 * is no point calling the parser any more if it fails to advance to
1992 * the end of the string - it is stuck on an invalid character (or
1993 * terminated by '\0').
1995 * Note that the pointer will consume an E or even an E+ and then leave
1996 * a 'maybe' state even though a preceding integer.fraction is valid.
1997 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1998 * a valid number. It's possible to recover from this by calling
1999 * the parser again (from the start, with state 0) but with a string
2000 * that omits the last character (i.e. set the size to the index of
2001 * the problem character.) This has not been tested within libpng.
2003 PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
2004 size_t size, int *statep, size_t *whereami),PNG_EMPTY);
2006 /* This is the same but it checks a complete string and returns true
2007 * only if it just contains a floating point number. As of 1.5.4 this
2008 * function also returns the state at the end of parsing the number if
2009 * it was valid (otherwise it returns 0.) This can be used for testing
2010 * for negative or zero values using the sticky flag.
2012 PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
2013 size_t size),PNG_EMPTY);
2014 #endif /* pCAL || sCAL */
2016 #if defined(PNG_GAMMA_SUPPORTED) ||\
2017 defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
2018 /* Added at libpng version 1.5.0 */
2019 /* This is a utility to provide a*times/div (rounded) and indicate
2020 * if there is an overflow. The result is a boolean - false (0)
2021 * for overflow, true (1) if no overflow, in which case *res
2024 PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
2025 png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
2028 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2029 /* Same deal, but issue a warning on overflow and return 0. */
2030 PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
2031 (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
2032 png_int_32 divided_by),PNG_EMPTY);
2035 #ifdef PNG_GAMMA_SUPPORTED
2036 /* Calculate a reciprocal - used for gamma values. This returns
2037 * 0 if the argument is 0 in order to maintain an undefined value;
2038 * there are no warnings.
2040 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
2043 #ifdef PNG_READ_GAMMA_SUPPORTED
2044 /* The same but gives a reciprocal of the product of two fixed point
2045 * values. Accuracy is suitable for gamma calculations but this is
2046 * not exact - use png_muldiv for that. Only required at present on read.
2048 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
2049 png_fixed_point b),PNG_EMPTY);
2052 /* Return true if the gamma value is significantly different from 1.0 */
2053 PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
2057 #ifdef PNG_READ_GAMMA_SUPPORTED
2058 /* Internal fixed point gamma correction. These APIs are called as
2059 * required to convert single values - they don't need to be fast,
2060 * they are not used when processing image pixel values.
2062 * While the input is an 'unsigned' value it must actually be the
2063 * correct bit value - 0..255 or 0..65535 as required.
2065 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
2066 unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
2067 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
2068 png_fixed_point gamma_value),PNG_EMPTY);
2069 PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
2070 png_fixed_point gamma_value),PNG_EMPTY);
2071 PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
2073 PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
2074 int bit_depth),PNG_EMPTY);
2077 /* SIMPLIFIED READ/WRITE SUPPORT */
2078 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
2079 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2080 /* The internal structure that png_image::opaque points to. */
2081 typedef struct png_control
2083 png_structp png_ptr;
2085 png_voidp error_buf; /* Always a jmp_buf at present. */
2087 png_const_bytep memory; /* Memory buffer. */
2088 size_t size; /* Size of the memory buffer. */
2090 unsigned int for_write :1; /* Otherwise it is a read structure */
2091 unsigned int owned_file :1; /* We own the file in io_ptr */
2094 /* Return the pointer to the jmp_buf from a png_control: necessary because C
2095 * does not reveal the type of the elements of jmp_buf.
2098 # define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
2100 # define png_control_jmp_buf(pc) ((pc)->error_buf)
2103 /* Utility to safely execute a piece of libpng code catching and logging any
2104 * errors that might occur. Returns true on success, false on failure (either
2105 * of the function or as a result of a png_error.)
2107 PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
2108 png_const_charp error_message),PNG_NORETURN);
2110 #ifdef PNG_WARNINGS_SUPPORTED
2111 PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
2112 png_const_charp warning_message),PNG_EMPTY);
2114 # define png_safe_warning 0/*dummy argument*/
2117 PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
2118 int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
2120 /* Utility to log an error; this also cleans up the png_image; the function
2121 * always returns 0 (false).
2123 PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
2124 png_const_charp error_message),PNG_EMPTY);
2126 #ifndef PNG_SIMPLIFIED_READ_SUPPORTED
2127 /* png_image_free is used by the write code but not exported */
2128 PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
2129 #endif /* !SIMPLIFIED_READ */
2131 #endif /* SIMPLIFIED READ/WRITE */
2133 /* These are initialization functions for hardware specific PNG filter
2134 * optimizations; list these here then select the appropriate one at compile
2135 * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined
2136 * the generic code is used.
2138 #ifdef PNG_FILTER_OPTIMIZATIONS
2139 PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
2140 unsigned int bpp), PNG_EMPTY);
2141 /* Just declare the optimization that will be used */
2143 /* List *all* the possible optimizations here - this branch is required if
2144 * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
2145 * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
2147 # if PNG_ARM_NEON_OPT > 0
2148 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
2149 (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2152 #if PNG_MIPS_MSA_OPT > 0
2153 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_msa,
2154 (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2157 # if PNG_INTEL_SSE_IMPLEMENTATION > 0
2158 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
2159 (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2163 PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
2164 png_const_charp key, png_bytep new_key), PNG_EMPTY);
2166 #if PNG_ARM_NEON_IMPLEMENTATION == 1
2167 PNG_INTERNAL_FUNCTION(void,
2168 png_riffle_palette_neon,
2171 PNG_INTERNAL_FUNCTION(int,
2172 png_do_expand_palette_rgba8_neon,
2179 PNG_INTERNAL_FUNCTION(int,
2180 png_do_expand_palette_rgb8_neon,
2189 /* Maintainer: Put new private prototypes here ^ */
2191 #include "pngdebug.h"
2197 #endif /* PNG_VERSION_INFO_ONLY */
2198 #endif /* PNGPRIV_H */
projects / platform / upstream / libpng.git / blob