pngpriv.h@ 106097

Last change on this file since 106097 was 103316, checked in by vboxsync, 10 months ago
libpng-1.6.42: Applied and adjusted our libpng changes to 1.6.42. bugref:8515
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File size: 90.7 KB

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1
2	/* pngpriv.h - private declarations for use inside libpng
3	*
4	* Copyright (c) 2018-2024 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.
8	*
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
12	*/
13
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.
21	*/
22
23	#ifndef PNGPRIV_H
24	#define PNGPRIV_H
25
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.
29	*
30	* Feature Test Macros must be defined before any system header is included (see
31	* POSIX 1003.1 2.8.2 "POSIX Symbols."
32	*
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.)
37	*/
38	#ifndef _POSIX_SOURCE
39	# define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
40	#endif
41
42	#ifndef PNG_VERSION_INFO_ONLY
43	/* Standard library headers not required by png.h: */
44	# include <stdlib.h>
45	# include <string.h>
46	#endif
47
48	#define PNGLIB_BUILD /libpng is being built, not used/
49
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.
58	*/
59	#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
60	# include <config.h>
61
62	/* Pick up the definition of 'restrict' from config.h if it was read: */
63	# define PNG_RESTRICT restrict
64	#endif
65
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.
70	*/
71	#ifndef PNGLCONF_H
72	# include "pnglibconf.h"
73	#endif
74
75	/* Local renames may change non-exported API functions from png.h */
76	#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
77	# include "pngprefix.h"
78	#endif
79
80	#ifdef PNG_USER_CONFIG
81	# include "pngusr.h"
82	/* These should have been defined in pngusr.h */
83	# ifndef PNG_USER_PRIVATEBUILD
84	# define PNG_USER_PRIVATEBUILD "Custom libpng build"
85	# endif
86	# ifndef PNG_USER_DLLFNAME_POSTFIX
87	# define PNG_USER_DLLFNAME_POSTFIX "Cb"
88	# endif
89	#endif
90
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.)
100	*
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
108	* do this.
109	*/
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.
116	*
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
121	* off.
122	*
123	* Note that gcc-4.9 defines __ARM_NEON instead of the deprecated
124	* __ARM_NEON__, so we check both variants.
125	*
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.
129	*/
130	# if (defined(__ARM_NEON__) \|\| defined(__ARM_NEON)) && \
131	defined(PNG_ALIGNED_MEMORY_SUPPORTED)
132	# define PNG_ARM_NEON_OPT 2
133	# else
134	# define PNG_ARM_NEON_OPT 0
135	# endif
136	#endif
137
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.
141	*/
142	# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
143
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
147	* be:
148	*
149	* 1 The intrinsics code (the default with __ARM_NEON__)
150	* 2 The hand coded assembler (the default without __ARM_NEON__)
151	*
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.
157	*/
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.)
165	*/
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
169	*/
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:
176	*/
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 */
183
184	# ifndef PNG_ARM_NEON_IMPLEMENTATION
185	/* Use the intrinsics code by default. */
186	# define PNG_ARM_NEON_IMPLEMENTATION 1
187	# endif
188	#else /* PNG_ARM_NEON_OPT == 0 */
189	# define PNG_ARM_NEON_IMPLEMENTATION 0
190	#endif /* PNG_ARM_NEON_OPT > 0 */
191
192	#ifndef PNG_MIPS_MSA_OPT
193	# if defined(__mips_msa) && (__mips_isa_rev >= 5) && \
194	defined(PNG_ALIGNED_MEMORY_SUPPORTED)
195	# define PNG_MIPS_MSA_OPT 2
196	# else
197	# define PNG_MIPS_MSA_OPT 0
198	# endif
199	#endif
200
201	#ifndef PNG_MIPS_MMI_OPT
202	# ifdef PNG_MIPS_MMI
203	# if defined(__mips_loongson_mmi) && (_MIPS_SIM == _ABI64) && \
204	defined(PNG_ALIGNED_MEMORY_SUPPORTED)
205	# define PNG_MIPS_MMI_OPT 1
206	# else
207	# define PNG_MIPS_MMI_OPT 0
208	# endif
209	# else
210	# define PNG_MIPS_MMI_OPT 0
211	# endif
212	#endif
213
214	#ifndef PNG_POWERPC_VSX_OPT
215	# if defined(__PPC64__) && defined(__ALTIVEC__) && defined(__VSX__)
216	# define PNG_POWERPC_VSX_OPT 2
217	# else
218	# define PNG_POWERPC_VSX_OPT 0
219	# endif
220	#endif
221
222	#ifndef PNG_LOONGARCH_LSX_OPT
223	# if defined(__loongarch_sx)
224	# define PNG_LOONGARCH_LSX_OPT 1
225	# else
226	# define PNG_LOONGARCH_LSX_OPT 0
227	# endif
228	#endif
229
230	#ifndef PNG_INTEL_SSE_OPT
231	# ifdef PNG_INTEL_SSE
232	/* Only check for SSE if the build configuration has been modified to
233	* enable SSE optimizations. This means that these optimizations will
234	* be off by default. See contrib/intel for more details.
235	*/
236	# if defined(__SSE4_1__) \|\| defined(__AVX__) \|\| defined(__SSSE3__) \|\| \
237	defined(__SSE2__) \|\| defined(_M_X64) \|\| defined(_M_AMD64) \|\| \
238	(defined(_M_IX86_FP) && _M_IX86_FP >= 2)
239	# define PNG_INTEL_SSE_OPT 1
240	# else
241	# define PNG_INTEL_SSE_OPT 0
242	# endif
243	# else
244	# define PNG_INTEL_SSE_OPT 0
245	# endif
246	#endif
247
248	#if PNG_INTEL_SSE_OPT > 0
249	# ifndef PNG_INTEL_SSE_IMPLEMENTATION
250	# if defined(__SSE4_1__) \|\| defined(__AVX__)
251	/* We are not actually using AVX, but checking for AVX is the best
252	way we can detect SSE4.1 and SSSE3 on MSVC.
253	*/
254	# define PNG_INTEL_SSE_IMPLEMENTATION 3
255	# elif defined(__SSSE3__)
256	# define PNG_INTEL_SSE_IMPLEMENTATION 2
257	# elif defined(__SSE2__) \|\| defined(_M_X64) \|\| defined(_M_AMD64) \|\| \
258	(defined(_M_IX86_FP) && _M_IX86_FP >= 2)
259	# define PNG_INTEL_SSE_IMPLEMENTATION 1
260	# else
261	# define PNG_INTEL_SSE_IMPLEMENTATION 0
262	# endif
263	# endif
264
265	# if PNG_INTEL_SSE_IMPLEMENTATION > 0
266	# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
267	# endif
268	#else
269	# define PNG_INTEL_SSE_IMPLEMENTATION 0
270	#endif
271
272	#if PNG_MIPS_MSA_OPT > 0
273	# ifndef PNG_MIPS_MSA_IMPLEMENTATION
274	# if defined(__mips_msa)
275	# if defined(__clang__)
276	# elif defined(__GNUC__)
277	# if __GNUC__ < 4 \|\| (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
278	# define PNG_MIPS_MSA_IMPLEMENTATION 2
279	# endif /* no GNUC support */
280	# endif /* __GNUC__ */
281	# else /* !defined __mips_msa */
282	# define PNG_MIPS_MSA_IMPLEMENTATION 2
283	# endif /* __mips_msa */
284	# endif /* !PNG_MIPS_MSA_IMPLEMENTATION */
285
286	# ifndef PNG_MIPS_MSA_IMPLEMENTATION
287	# define PNG_MIPS_MSA_IMPLEMENTATION 1
288	# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_mips
289	# endif
290	#else
291	# define PNG_MIPS_MSA_IMPLEMENTATION 0
292	#endif /* PNG_MIPS_MSA_OPT > 0 */
293
294	#if PNG_MIPS_MMI_OPT > 0
295	# ifndef PNG_MIPS_MMI_IMPLEMENTATION
296	# if defined(__mips_loongson_mmi) && (_MIPS_SIM == _ABI64)
297	# define PNG_MIPS_MMI_IMPLEMENTATION 2
298	# else /* !defined __mips_loongson_mmi \|\| _MIPS_SIM != _ABI64 */
299	# define PNG_MIPS_MMI_IMPLEMENTATION 0
300	# endif /* __mips_loongson_mmi && _MIPS_SIM == _ABI64 */
301	# endif /* !PNG_MIPS_MMI_IMPLEMENTATION */
302
303	# if PNG_MIPS_MMI_IMPLEMENTATION > 0
304	# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_mips
305	# endif
306	#else
307	# define PNG_MIPS_MMI_IMPLEMENTATION 0
308	#endif /* PNG_MIPS_MMI_OPT > 0 */
309
310	#if PNG_POWERPC_VSX_OPT > 0
311	# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx
312	# define PNG_POWERPC_VSX_IMPLEMENTATION 1
313	#else
314	# define PNG_POWERPC_VSX_IMPLEMENTATION 0
315	#endif
316
317	#if PNG_LOONGARCH_LSX_OPT > 0
318	# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_lsx
319	# define PNG_LOONGARCH_LSX_IMPLEMENTATION 1
320	#else
321	# define PNG_LOONGARCH_LSX_IMPLEMENTATION 0
322	#endif
323
324	/* Is this a build of a DLL where compilation of the object modules requires
325	* different preprocessor settings to those required for a simple library? If
326	* so PNG_BUILD_DLL must be set.
327	*
328	* If libpng is used inside a DLL but that DLL does not export the libpng APIs
329	* PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
330	* static library of libpng then link the DLL against that.
331	*/
332	#ifndef PNG_BUILD_DLL
333	# ifdef DLL_EXPORT
334	/* This is set by libtool when files are compiled for a DLL; libtool
335	* always compiles twice, even on systems where it isn't necessary. Set
336	* PNG_BUILD_DLL in case it is necessary:
337	*/
338	# define PNG_BUILD_DLL
339	# else
340	# ifdef _WINDLL
341	/* This is set by the Microsoft Visual Studio IDE in projects that
342	* build a DLL. It can't easily be removed from those projects (it
343	* isn't visible in the Visual Studio UI) so it is a fairly reliable
344	* indication that PNG_IMPEXP needs to be set to the DLL export
345	* attributes.
346	*/
347	# define PNG_BUILD_DLL
348	# else
349	# ifdef __DLL__
350	/* This is set by the Borland C system when compiling for a DLL
351	* (as above.)
352	*/
353	# define PNG_BUILD_DLL
354	# else
355	/* Add additional compiler cases here. */
356	# endif
357	# endif
358	# endif
359	#endif /* Setting PNG_BUILD_DLL if required */
360
361	/* See pngconf.h for more details: the builder of the library may set this on
362	* the command line to the right thing for the specific compilation system or it
363	* may be automagically set above (at present we know of no system where it does
364	* need to be set on the command line.)
365	*
366	* PNG_IMPEXP must be set here when building the library to prevent pngconf.h
367	* setting it to the "import" setting for a DLL build.
368	*/
369	#ifndef PNG_IMPEXP
370	# ifdef PNG_BUILD_DLL
371	# define PNG_IMPEXP PNG_DLL_EXPORT
372	# else
373	/* Not building a DLL, or the DLL doesn't require specific export
374	* definitions.
375	*/
376	# define PNG_IMPEXP
377	# endif
378	#endif
379
380	/* No warnings for private or deprecated functions in the build: */
381	#ifndef PNG_DEPRECATED
382	# define PNG_DEPRECATED
383	#endif
384	#ifndef PNG_PRIVATE
385	# define PNG_PRIVATE
386	#endif
387
388	/* Symbol preprocessing support.
389	*
390	* To enable listing global, but internal, symbols the following macros should
391	* always be used to declare an extern data or function object in this file.
392	*/
393	#ifndef PNG_INTERNAL_DATA
394	# define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array
395	#endif
396
397	#ifndef PNG_INTERNAL_FUNCTION
398	# define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
399	PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
400	#endif
401
402	#ifndef PNG_INTERNAL_CALLBACK
403	# define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
404	PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\
405	PNG_EMPTY attributes)
406	#endif
407
408	/* If floating or fixed point APIs are disabled they may still be compiled
409	* internally. To handle this make sure they are declared as the appropriate
410	* internal extern function (otherwise the symbol prefixing stuff won't work and
411	* the functions will be used without definitions.)
412	*
413	* NOTE: although all the API functions are declared here they are not all
414	* actually built! Because the declarations are still made it is necessary to
415	* fake out types that they depend on.
416	*/
417	#ifndef PNG_FP_EXPORT
418	# ifndef PNG_FLOATING_POINT_SUPPORTED
419	# define PNG_FP_EXPORT(ordinal, type, name, args)\
420	PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
421	# ifndef PNG_VERSION_INFO_ONLY
422	typedef struct png_incomplete png_double;
423	typedef png_double* png_doublep;
424	typedef const png_double* png_const_doublep;
425	typedef png_double** png_doublepp;
426	# endif
427	# endif
428	#endif
429	#ifndef PNG_FIXED_EXPORT
430	# ifndef PNG_FIXED_POINT_SUPPORTED
431	# define PNG_FIXED_EXPORT(ordinal, type, name, args)\
432	PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
433	# endif
434	#endif
435
436	#include "png.h"
437
438	/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
439	#ifndef PNG_DLL_EXPORT
440	# define PNG_DLL_EXPORT
441	#endif
442
443	/* This is a global switch to set the compilation for an installed system
444	* (a release build). It can be set for testing debug builds to ensure that
445	* they will compile when the build type is switched to RC or STABLE, the
446	* default is just to use PNG_LIBPNG_BUILD_BASE_TYPE. Set this in CPPFLAGS
447	* with either:
448	*
449	* -DPNG_RELEASE_BUILD Turns on the release compile path
450	* -DPNG_RELEASE_BUILD=0 Turns it off
451	* or in your pngusr.h with
452	* #define PNG_RELEASE_BUILD=1 Turns on the release compile path
453	* #define PNG_RELEASE_BUILD=0 Turns it off
454	*/
455	#ifndef PNG_RELEASE_BUILD
456	# define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
457	#endif
458
459	/* SECURITY and SAFETY:
460	*
461	* libpng is built with support for internal limits on image dimensions and
462	* memory usage. These are documented in scripts/pnglibconf.dfa of the
463	* source and recorded in the machine generated header file pnglibconf.h.
464	*/
465
466	/* If you are running on a machine where you cannot allocate more
467	* than 64K of memory at once, uncomment this. While libpng will not
468	* normally need that much memory in a chunk (unless you load up a very
469	* large file), zlib needs to know how big of a chunk it can use, and
470	* libpng thus makes sure to check any memory allocation to verify it
471	* will fit into memory.
472	*
473	* zlib provides 'MAXSEG_64K' which, if defined, indicates the
474	* same limit and pngconf.h (already included) sets the limit
475	* if certain operating systems are detected.
476	*/
477	#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
478	# define PNG_MAX_MALLOC_64K
479	#endif
480
481	#ifndef PNG_UNUSED
482	/* Unused formal parameter warnings are silenced using the following macro
483	* which is expected to have no bad effects on performance (optimizing
484	* compilers will probably remove it entirely). Note that if you replace
485	* it with something other than whitespace, you must include the terminating
486	* semicolon.
487	*/
488	# define PNG_UNUSED(param) (void)param;
489	#endif
490
491	/* Just a little check that someone hasn't tried to define something
492	* contradictory.
493	*/
494	#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
495	# undef PNG_ZBUF_SIZE
496	# define PNG_ZBUF_SIZE 65536L
497	#endif
498
499	/* If warnings or errors are turned off the code is disabled or redirected here.
500	* From 1.5.4 functions have been added to allow very limited formatting of
501	* error and warning messages - this code will also be disabled here.
502	*/
503	#ifdef PNG_WARNINGS_SUPPORTED
504	# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
505	#else
506	# define png_warning_parameter(p,number,string) ((void)0)
507	# define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
508	# define png_warning_parameter_signed(p,number,format,value) ((void)0)
509	# define png_formatted_warning(pp,p,message) ((void)(pp))
510	# define PNG_WARNING_PARAMETERS(p)
511	#endif
512	#ifndef PNG_ERROR_TEXT_SUPPORTED
513	# define png_fixed_error(s1,s2) png_err(s1)
514	#endif
515
516	/* Some fixed point APIs are still required even if not exported because
517	* they get used by the corresponding floating point APIs. This magic
518	* deals with this:
519	*/
520	#ifdef PNG_FIXED_POINT_SUPPORTED
521	# define PNGFAPI PNGAPI
522	#else
523	# define PNGFAPI /* PRIVATE */
524	#endif
525
526	#ifndef PNG_VERSION_INFO_ONLY
527	/* Other defines specific to compilers can go here. Try to keep
528	* them inside an appropriate ifdef/endif pair for portability.
529	*/
530
531	/* C allows up-casts from (void) to any pointer and (const void) to any
532	* pointer to a const object. C++ regards this as a type error and requires an
533	* explicit, static, cast and provides the static_cast<> rune to ensure that
534	* const is not cast away.
535	*/
536	#ifdef __cplusplus
537	# define png_voidcast(type, value) static_cast<type>(value)
538	# define png_constcast(type, value) const_cast<type>(value)
539	# define png_aligncast(type, value) \
540	static_cast<type>(static_cast<void*>(value))
541	# define png_aligncastconst(type, value) \
542	static_cast<type>(static_cast<const void*>(value))
543	#else
544	# define png_voidcast(type, value) (value)
545	# define png_constcast(type, value) ((type)(void)(const void)(value))
546	# define png_aligncast(type, value) ((void*)(value))
547	# define png_aligncastconst(type, value) ((const void*)(value))
548	#endif /* __cplusplus */
549
550	#if defined(PNG_FLOATING_POINT_SUPPORTED) \|\|\
551	defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
552	/* png.c requires the following ANSI-C constants if the conversion of
553	* floating point to ASCII is implemented therein:
554	*
555	* DBL_DIG Maximum number of decimal digits (can be set to any constant)
556	* DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
557	* DBL_MAX Maximum floating point number (can be set to an arbitrary value)
558	*/
559	# include <float.h>
560
561	# include <math.h>
562
563	# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
564	/* Amiga SAS/C: We must include builtin FPU functions when compiling using
565	* MATH=68881
566	*/
567	# include <m68881.h>
568	# endif
569	#endif
570
571	/* This provides the non-ANSI (far) memory allocation routines. */
572	#if defined(__TURBOC__) && defined(__MSDOS__)
573	# include <mem.h>
574	# include <alloc.h>
575	#endif
576
577	#if defined(WIN32) \|\| defined(_Windows) \|\| defined(_WINDOWS) \|\| \
578	defined(_WIN32) \|\| defined(__WIN32__)
579	# ifdef VBOX
580	# include <iprt/win/windows.h> /* defines _WINDOWS_ macro */
581	# else
582	# include <windows.h> /* defines _WINDOWS_ macro */
583	# endif
584	#endif
585	#endif /* PNG_VERSION_INFO_ONLY */
586
587	/* Moved here around 1.5.0beta36 from pngconf.h */
588	/* Users may want to use these so they are not private. Any library
589	* functions that are passed far data must be model-independent.
590	*/
591
592	/* Platform-independent functions */
593	#ifndef PNG_ABORT
594	# define PNG_ABORT() abort()
595	#endif
596
597	/* These macros may need to be architecture dependent. */
598	#define PNG_ALIGN_NONE 0 /* do not use data alignment */
599	#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
600	#ifdef offsetof
601	# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
602	#else
603	# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
604	#endif
605	#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
606
607	#ifndef PNG_ALIGN_TYPE
608	/* Default to using aligned access optimizations and requiring alignment to a
609	* multiple of the data type size. Override in a compiler specific fashion
610	* if necessary by inserting tests here:
611	*/
612	# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
613	#endif
614
615	#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
616	/* This is used because in some compiler implementations non-aligned
617	* structure members are supported, so the offsetof approach below fails.
618	* Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
619	* is good for performance. Do not do this unless you have tested the
620	* result and understand it.
621	*/
622	# define png_alignof(type) (sizeof(type))
623	#else
624	# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
625	# define png_alignof(type) offsetof(struct{char c; type t;}, t)
626	# else
627	# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
628	# define png_alignof(type) 1
629	# endif
630	/* Else leave png_alignof undefined to prevent use thereof */
631	# endif
632	#endif
633
634	/* This implicitly assumes alignment is always a multiple of 2. */
635	#ifdef png_alignof
636	# define png_isaligned(ptr, type) \
637	(((type)(size_t)((const void*)(ptr)) & (type)(png_alignof(type)-1)) == 0)
638	#else
639	# define png_isaligned(ptr, type) 0
640	#endif
641
642	/* End of memory model/platform independent support */
643	/* End of 1.5.0beta36 move from pngconf.h */
644
645	/* CONSTANTS and UTILITY MACROS
646	* These are used internally by libpng and not exposed in the API
647	*/
648
649	/* Various modes of operation. Note that after an init, mode is set to
650	* zero automatically when the structure is created. Three of these
651	* are defined in png.h because they need to be visible to applications
652	* that call png_set_unknown_chunk().
653	*/
654	/* #define PNG_HAVE_IHDR 0x01U (defined in png.h) */
655	/* #define PNG_HAVE_PLTE 0x02U (defined in png.h) */
656	#define PNG_HAVE_IDAT 0x04U
657	/* #define PNG_AFTER_IDAT 0x08U (defined in png.h) */
658	#define PNG_HAVE_IEND 0x10U
659	/* 0x20U (unused) */
660	/* 0x40U (unused) */
661	/* 0x80U (unused) */
662	#define PNG_HAVE_CHUNK_HEADER 0x100U
663	#define PNG_WROTE_tIME 0x200U
664	#define PNG_WROTE_INFO_BEFORE_PLTE 0x400U
665	#define PNG_BACKGROUND_IS_GRAY 0x800U
666	#define PNG_HAVE_PNG_SIGNATURE 0x1000U
667	#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
668	#define PNG_WROTE_eXIf 0x4000U
669	#define PNG_IS_READ_STRUCT 0x8000U /* Else is a write struct */
670
671	/* Flags for the transformations the PNG library does on the image data */
672	#define PNG_BGR 0x0001U
673	#define PNG_INTERLACE 0x0002U
674	#define PNG_PACK 0x0004U
675	#define PNG_SHIFT 0x0008U
676	#define PNG_SWAP_BYTES 0x0010U
677	#define PNG_INVERT_MONO 0x0020U
678	#define PNG_QUANTIZE 0x0040U
679	#define PNG_COMPOSE 0x0080U /* Was PNG_BACKGROUND */
680	#define PNG_BACKGROUND_EXPAND 0x0100U
681	#define PNG_EXPAND_16 0x0200U /* Added to libpng 1.5.2 */
682	#define PNG_16_TO_8 0x0400U /* Becomes 'chop' in 1.5.4 */
683	#define PNG_RGBA 0x0800U
684	#define PNG_EXPAND 0x1000U
685	#define PNG_GAMMA 0x2000U
686	#define PNG_GRAY_TO_RGB 0x4000U
687	#define PNG_FILLER 0x8000U
688	#define PNG_PACKSWAP 0x10000U
689	#define PNG_SWAP_ALPHA 0x20000U
690	#define PNG_STRIP_ALPHA 0x40000U
691	#define PNG_INVERT_ALPHA 0x80000U
692	#define PNG_USER_TRANSFORM 0x100000U
693	#define PNG_RGB_TO_GRAY_ERR 0x200000U
694	#define PNG_RGB_TO_GRAY_WARN 0x400000U
695	#define PNG_RGB_TO_GRAY 0x600000U /* two bits, RGB_TO_GRAY_ERR\|WARN */
696	#define PNG_ENCODE_ALPHA 0x800000U /* Added to libpng-1.5.4 */
697	#define PNG_ADD_ALPHA 0x1000000U /* Added to libpng-1.2.7 */
698	#define PNG_EXPAND_tRNS 0x2000000U /* Added to libpng-1.2.9 */
699	#define PNG_SCALE_16_TO_8 0x4000000U /* Added to libpng-1.5.4 */
700	/* 0x8000000U unused */
701	/* 0x10000000U unused */
702	/* 0x20000000U unused */
703	/* 0x40000000U unused */
704	/* Flags for png_create_struct */
705	#define PNG_STRUCT_PNG 0x0001U
706	#define PNG_STRUCT_INFO 0x0002U
707
708	/* Flags for the png_ptr->flags rather than declaring a byte for each one */
709	#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001U
710	#define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002U /* Added to libpng-1.6.0 */
711	/* 0x0004U unused */
712	#define PNG_FLAG_ZSTREAM_ENDED 0x0008U /* Added to libpng-1.6.0 */
713	/* 0x0010U unused */
714	/* 0x0020U unused */
715	#define PNG_FLAG_ROW_INIT 0x0040U
716	#define PNG_FLAG_FILLER_AFTER 0x0080U
717	#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100U
718	#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200U
719	#define PNG_FLAG_CRC_CRITICAL_USE 0x0400U
720	#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800U
721	#define PNG_FLAG_ASSUME_sRGB 0x1000U /* Added to libpng-1.5.4 */
722	#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000U /* Added to libpng-1.5.4 */
723	#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000U /* Added to libpng-1.5.4 */
724	/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000U */
725	/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000U */
726	#define PNG_FLAG_LIBRARY_MISMATCH 0x20000U
727	#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000U
728	#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000U
729	#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000U /* Added to libpng-1.4.0 */
730	#define PNG_FLAG_APP_WARNINGS_WARN 0x200000U /* Added to libpng-1.6.0 */
731	#define PNG_FLAG_APP_ERRORS_WARN 0x400000U /* Added to libpng-1.6.0 */
732	/* 0x800000U unused */
733	/* 0x1000000U unused */
734	/* 0x2000000U unused */
735	/* 0x4000000U unused */
736	/* 0x8000000U unused */
737	/* 0x10000000U unused */
738	/* 0x20000000U unused */
739	/* 0x40000000U unused */
740
741	#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE \| \
742	PNG_FLAG_CRC_ANCILLARY_NOWARN)
743
744	#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE \| \
745	PNG_FLAG_CRC_CRITICAL_IGNORE)
746
747	#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK \| \
748	PNG_FLAG_CRC_CRITICAL_MASK)
749
750	/* Save typing and make code easier to understand */
751
752	#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
753	abs((int)((c1).green) - (int)((c2).green)) + \
754	abs((int)((c1).blue) - (int)((c2).blue)))
755
756	/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
757	* by dividing by 257 with rounding. This macro is exact for the given range.
758	* See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
759	* macro were established by experiment (modifying the added value). The macro
760	* has a second variant that takes a value already scaled by 255 and divides by
761	* 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
762	* only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
763	*/
764	#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
765	#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
766
767	/* Added to libpng-1.2.6 JB */
768	#define PNG_ROWBYTES(pixel_bits, width) \
769	((pixel_bits) >= 8 ? \
770	((size_t)(width) * (((size_t)(pixel_bits)) >> 3)) : \
771	(( ((size_t)(width) * ((size_t)(pixel_bits))) + 7) >> 3) )
772
773	/* This returns the number of trailing bits in the last byte of a row, 0 if the
774	* last byte is completely full of pixels. It is, in principle, (pixel_bits x
775	* width) % 8, but that would overflow for large 'width'. The second macro is
776	* the same except that it returns the number of unused bits in the last byte;
777	* (8-TRAILBITS), but 0 when TRAILBITS is 0.
778	*
779	* NOTE: these macros are intended to be self-evidently correct and never
780	* overflow on the assumption that pixel_bits is in the range 0..255. The
781	* arguments are evaluated only once and they can be signed (e.g. as a result of
782	* the integral promotions). The result of the expression always has type
783	* (png_uint_32), however the compiler always knows it is in the range 0..7.
784	*/
785	#define PNG_TRAILBITS(pixel_bits, width) \
786	(((pixel_bits) * ((width) % (png_uint_32)8)) % 8)
787
788	#define PNG_PADBITS(pixel_bits, width) \
789	((8 - PNG_TRAILBITS(pixel_bits, width)) % 8)
790
791	/* PNG_OUT_OF_RANGE returns true if value is outside the range
792	* ideal-delta..ideal+delta. Each argument is evaluated twice.
793	* "ideal" and "delta" should be constants, normally simple
794	* integers, "value" a variable. Added to libpng-1.2.6 JB
795	*/
796	#define PNG_OUT_OF_RANGE(value, ideal, delta) \
797	( (value) < (ideal)-(delta) \|\| (value) > (ideal)+(delta) )
798
799	/* Conversions between fixed and floating point, only defined if
800	* required (to make sure the code doesn't accidentally use float
801	* when it is supposedly disabled.)
802	*/
803	#ifdef PNG_FLOATING_POINT_SUPPORTED
804	/* The floating point conversion can't overflow, though it can and
805	* does lose accuracy relative to the original fixed point value.
806	* In practice this doesn't matter because png_fixed_point only
807	* stores numbers with very low precision. The png_ptr and s
808	* arguments are unused by default but are there in case error
809	* checking becomes a requirement.
810	*/
811	#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
812
813	/* The fixed point conversion performs range checking and evaluates
814	* its argument multiple times, so must be used with care. The
815	* range checking uses the PNG specification values for a signed
816	* 32-bit fixed point value except that the values are deliberately
817	* rounded-to-zero to an integral value - 21474 (21474.83 is roughly
818	* (2^31-1) * 100000). 's' is a string that describes the value being
819	* converted.
820	*
821	* NOTE: this macro will raise a png_error if the range check fails,
822	* therefore it is normally only appropriate to use this on values
823	* that come from API calls or other sources where an out of range
824	* error indicates a programming error, not a data error!
825	*
826	* NOTE: by default this is off - the macro is not used - because the
827	* function call saves a lot of code.
828	*/
829	#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
830	#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
831	((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
832	#endif
833	/* else the corresponding function is defined below, inside the scope of the
834	* cplusplus test.
835	*/
836	#endif
837
838	/* Constants for known chunk types. If you need to add a chunk, define the name
839	* here. For historical reasons these constants have the form png_<name>; i.e.
840	* the prefix is lower case. Please use decimal values as the parameters to
841	* match the ISO PNG specification and to avoid relying on the C locale
842	* interpretation of character values.
843	*
844	* Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
845	* are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
846	* to be generated if required.
847	*
848	* PNG_32b correctly produces a value shifted by up to 24 bits, even on
849	* architectures where (int) is only 16 bits.
850	*/
851	#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
852	#define PNG_U32(b1,b2,b3,b4) \
853	(PNG_32b(b1,24) \| PNG_32b(b2,16) \| PNG_32b(b3,8) \| PNG_32b(b4,0))
854
855	/* Constants for known chunk types.
856	*
857	* MAINTAINERS: If you need to add a chunk, define the name here.
858	* For historical reasons these constants have the form png_<name>; i.e.
859	* the prefix is lower case. Please use decimal values as the parameters to
860	* match the ISO PNG specification and to avoid relying on the C locale
861	* interpretation of character values. Please keep the list sorted.
862	*
863	* Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
864	* type. In fact the specification does not express chunk types this way,
865	* however using a 32-bit value means that the chunk type can be read from the
866	* stream using exactly the same code as used for a 32-bit unsigned value and
867	* can be examined far more efficiently (using one arithmetic compare).
868	*
869	* Prior to 1.5.6 the chunk type constants were expressed as C strings. The
870	* libpng API still uses strings for 'unknown' chunks and a macro,
871	* PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice
872	* that for portable code numeric values must still be used; the string "IHDR"
873	* is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
874	*
875	* In 1.7.0 the definitions will be made public in png.h to avoid having to
876	* duplicate the same definitions in application code.
877	*/
878	#define png_IDAT PNG_U32( 73, 68, 65, 84)
879	#define png_IEND PNG_U32( 73, 69, 78, 68)
880	#define png_IHDR PNG_U32( 73, 72, 68, 82)
881	#define png_PLTE PNG_U32( 80, 76, 84, 69)
882	#define png_bKGD PNG_U32( 98, 75, 71, 68)
883	#define png_cHRM PNG_U32( 99, 72, 82, 77)
884	#define png_eXIf PNG_U32(101, 88, 73, 102) /* registered July 2017 */
885	#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */
886	#define png_gAMA PNG_U32(103, 65, 77, 65)
887	#define png_gIFg PNG_U32(103, 73, 70, 103)
888	#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */
889	#define png_gIFx PNG_U32(103, 73, 70, 120)
890	#define png_hIST PNG_U32(104, 73, 83, 84)
891	#define png_iCCP PNG_U32(105, 67, 67, 80)
892	#define png_iTXt PNG_U32(105, 84, 88, 116)
893	#define png_oFFs PNG_U32(111, 70, 70, 115)
894	#define png_pCAL PNG_U32(112, 67, 65, 76)
895	#define png_pHYs PNG_U32(112, 72, 89, 115)
896	#define png_sBIT PNG_U32(115, 66, 73, 84)
897	#define png_sCAL PNG_U32(115, 67, 65, 76)
898	#define png_sPLT PNG_U32(115, 80, 76, 84)
899	#define png_sRGB PNG_U32(115, 82, 71, 66)
900	#define png_sTER PNG_U32(115, 84, 69, 82)
901	#define png_tEXt PNG_U32(116, 69, 88, 116)
902	#define png_tIME PNG_U32(116, 73, 77, 69)
903	#define png_tRNS PNG_U32(116, 82, 78, 83)
904	#define png_zTXt PNG_U32(122, 84, 88, 116)
905
906	/* The following will work on (signed char*) strings, whereas the get_uint_32
907	* macro will fail on top-bit-set values because of the sign extension.
908	*/
909	#define PNG_CHUNK_FROM_STRING(s)\
910	PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
911
912	/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
913	* signed and the argument is a (char[]) This macro will fail miserably on
914	* systems where (char) is more than 8 bits.
915	*/
916	#define PNG_STRING_FROM_CHUNK(s,c)\
917	(void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
918	((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
919	((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
920	((char*)(s))[3]=(char)((c & 0xff)))
921
922	/* Do the same but terminate with a null character. */
923	#define PNG_CSTRING_FROM_CHUNK(s,c)\
924	(void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
925
926	/* Test on flag values as defined in the spec (section 5.4): */
927	#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29))
928	#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
929	#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
930	#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
931	#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
932
933	/* Gamma values (new at libpng-1.5.4): */
934	#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
935	#define PNG_GAMMA_MAC_INVERSE 65909
936	#define PNG_GAMMA_sRGB_INVERSE 45455
937
938	/* Almost everything below is C specific; the #defines above can be used in
939	* non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
940	*/
941	#ifndef PNG_VERSION_INFO_ONLY
942
943	#include "pngstruct.h"
944	#include "pnginfo.h"
945
946	/* Validate the include paths - the include path used to generate pnglibconf.h
947	* must match that used in the build, or we must be using pnglibconf.h.prebuilt:
948	*/
949	#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
950	# error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
951	"-I (include path) error: see the notes in pngpriv.h"
952	/* This means that when pnglibconf.h was built the copy of zlib.h that it
953	* used is not the same as the one being used here. Because the build of
954	* libpng makes decisions to use inflateInit2 and inflateReset2 based on the
955	* zlib version number and because this affects handling of certain broken
956	* PNG files the -I directives must match.
957	*
958	* The most likely explanation is that you passed a -I in CFLAGS. This will
959	* not work; all the preprocessor directives and in particular all the -I
960	* directives must be in CPPFLAGS.
961	*/
962	#endif
963
964	/* This is used for 16-bit gamma tables -- only the top level pointers are
965	* const; this could be changed:
966	*/
967	typedef const png_uint_16p * png_const_uint_16pp;
968
969	/* Added to libpng-1.5.7: sRGB conversion tables */
970	#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) \|\|\
971	defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
972	#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
973	PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
974	/* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
975	* 0..65535. This table gives the closest 16-bit answers (no errors).
976	*/
977	#endif
978
979	PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
980	PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
981
982	#define PNG_sRGB_FROM_LINEAR(linear) \
983	((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
984	+ ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
985	/* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
986	* encoded value with maximum error 0.646365. Note that the input is not a
987	* 16-bit value; it has been multiplied by 255! */
988	#endif /* SIMPLIFIED_READ/WRITE */
989
990
991	/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
992	#ifdef __cplusplus
993	extern "C" {
994	#endif /* __cplusplus */
995
996	/* Internal functions; these are not exported from a DLL however because they
997	* are used within several of the C source files they have to be C extern.
998	*
999	* All of these functions must be declared with PNG_INTERNAL_FUNCTION.
1000	*/
1001
1002	/* Zlib support */
1003	#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
1004	PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
1005	PNG_EMPTY);
1006	/* Used by the zlib handling functions to ensure that z_stream::msg is always
1007	* set before they return.
1008	*/
1009
1010	#ifdef PNG_WRITE_SUPPORTED
1011	PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
1012	png_compression_bufferp *list),PNG_EMPTY);
1013	/* Free the buffer list used by the compressed write code. */
1014	#endif
1015
1016	#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
1017	!defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
1018	(defined(PNG_gAMA_SUPPORTED) \|\| defined(PNG_cHRM_SUPPORTED) \|\| \
1019	defined(PNG_sCAL_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED) \|\| \
1020	defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) \|\| \
1021	(defined(PNG_sCAL_SUPPORTED) && \
1022	defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
1023	PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
1024	double fp, png_const_charp text),PNG_EMPTY);
1025	#endif
1026
1027	/* Check the user version string for compatibility, returns false if the version
1028	* numbers aren't compatible.
1029	*/
1030	PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
1031	png_const_charp user_png_ver),PNG_EMPTY);
1032
1033	/* Internal base allocator - no messages, NULL on failure to allocate. This
1034	* does, however, call the application provided allocator and that could call
1035	* png_error (although that would be a bug in the application implementation.)
1036	*/
1037	PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
1038	png_alloc_size_t size),PNG_ALLOCATED);
1039
1040	#if defined(PNG_TEXT_SUPPORTED) \|\| defined(PNG_sPLT_SUPPORTED) \|\|\
1041	defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
1042	/* Internal array allocator, outputs no error or warning messages on failure,
1043	* just returns NULL.
1044	*/
1045	PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
1046	int nelements, size_t element_size),PNG_ALLOCATED);
1047
1048	/* The same but an existing array is extended by add_elements. This function
1049	* also memsets the new elements to 0 and copies the old elements. The old
1050	* array is not freed or altered.
1051	*/
1052	PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
1053	png_const_voidp array, int old_elements, int add_elements,
1054	size_t element_size),PNG_ALLOCATED);
1055	#endif /* text, sPLT or unknown chunks */
1056
1057	/* Magic to create a struct when there is no struct to call the user supplied
1058	* memory allocators. Because error handling has not been set up the memory
1059	* handlers can't safely call png_error, but this is an obscure and undocumented
1060	* restriction so libpng has to assume that the 'free' handler, at least, might
1061	* call png_error.
1062	*/
1063	PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
1064	(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1065	png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
1066	png_free_ptr free_fn),PNG_ALLOCATED);
1067
1068	/* Free memory from internal libpng struct */
1069	PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
1070	PNG_EMPTY);
1071
1072	/* Free an allocated jmp_buf (always succeeds) */
1073	PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
1074
1075	/* Function to allocate memory for zlib. PNGAPI is disallowed. */
1076	PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
1077	PNG_ALLOCATED);
1078
1079	/* Function to free memory for zlib. PNGAPI is disallowed. */
1080	PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
1081
1082	/* Next four functions are used internally as callbacks. PNGCBAPI is required
1083	* but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
1084	* PNGCBAPI at 1.5.0
1085	*/
1086
1087	PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
1088	png_bytep data, size_t length),PNG_EMPTY);
1089
1090	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1091	PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
1092	png_bytep buffer, size_t length),PNG_EMPTY);
1093	#endif
1094
1095	PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
1096	png_bytep data, size_t length),PNG_EMPTY);
1097
1098	#ifdef PNG_WRITE_FLUSH_SUPPORTED
1099	# ifdef PNG_STDIO_SUPPORTED
1100	PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
1101	PNG_EMPTY);
1102	# endif
1103	#endif
1104
1105	/* Reset the CRC variable */
1106	PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
1107
1108	/* Write the "data" buffer to whatever output you are using */
1109	PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
1110	png_const_bytep data, size_t length),PNG_EMPTY);
1111
1112	/* Read and check the PNG file signature */
1113	PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
1114	png_inforp info_ptr),PNG_EMPTY);
1115
1116	/* Read the chunk header (length + type name) */
1117	PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
1118	PNG_EMPTY);
1119
1120	/* Read data from whatever input you are using into the "data" buffer */
1121	PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
1122	size_t length),PNG_EMPTY);
1123
1124	/* Read bytes into buf, and update png_ptr->crc */
1125	PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
1126	png_uint_32 length),PNG_EMPTY);
1127
1128	/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
1129	PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
1130	png_uint_32 skip),PNG_EMPTY);
1131
1132	/* Read the CRC from the file and compare it to the libpng calculated CRC */
1133	PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
1134
1135	/* Calculate the CRC over a section of data. Note that we are only
1136	* passing a maximum of 64K on systems that have this as a memory limit,
1137	* since this is the maximum buffer size we can specify.
1138	*/
1139	PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
1140	png_const_bytep ptr, size_t length),PNG_EMPTY);
1141
1142	#ifdef PNG_WRITE_FLUSH_SUPPORTED
1143	PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
1144	#endif
1145
1146	/* Write various chunks */
1147
1148	/* Write the IHDR chunk, and update the png_struct with the necessary
1149	* information.
1150	*/
1151	PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
1152	png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1153	int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
1154
1155	PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
1156	png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
1157
1158	PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
1159	png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
1160	PNG_EMPTY);
1161
1162	PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
1163
1164	#ifdef PNG_WRITE_gAMA_SUPPORTED
1165	PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
1166	png_fixed_point file_gamma),PNG_EMPTY);
1167	#endif
1168
1169	#ifdef PNG_WRITE_sBIT_SUPPORTED
1170	PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
1171	png_const_color_8p sbit, int color_type),PNG_EMPTY);
1172	#endif
1173
1174	#ifdef PNG_WRITE_cHRM_SUPPORTED
1175	PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
1176	const png_xy *xy), PNG_EMPTY);
1177	/* The xy value must have been previously validated */
1178	#endif
1179
1180	#ifdef PNG_WRITE_sRGB_SUPPORTED
1181	PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1182	int intent),PNG_EMPTY);
1183	#endif
1184
1185	#ifdef PNG_WRITE_eXIf_SUPPORTED
1186	PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr,
1187	png_bytep exif, int num_exif),PNG_EMPTY);
1188	#endif
1189
1190	#ifdef PNG_WRITE_iCCP_SUPPORTED
1191	PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1192	png_const_charp name, png_const_bytep profile), PNG_EMPTY);
1193	/* The profile must have been previously validated for correctness, the
1194	* length comes from the first four bytes. Only the base, deflate,
1195	* compression is supported.
1196	*/
1197	#endif
1198
1199	#ifdef PNG_WRITE_sPLT_SUPPORTED
1200	PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1201	png_const_sPLT_tp palette),PNG_EMPTY);
1202	#endif
1203
1204	#ifdef PNG_WRITE_tRNS_SUPPORTED
1205	PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1206	png_const_bytep trans, png_const_color_16p values, int number,
1207	int color_type),PNG_EMPTY);
1208	#endif
1209
1210	#ifdef PNG_WRITE_bKGD_SUPPORTED
1211	PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1212	png_const_color_16p values, int color_type),PNG_EMPTY);
1213	#endif
1214
1215	#ifdef PNG_WRITE_hIST_SUPPORTED
1216	PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1217	png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1218	#endif
1219
1220	/* Chunks that have keywords */
1221	#ifdef PNG_WRITE_tEXt_SUPPORTED
1222	PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1223	png_const_charp key, png_const_charp text, size_t text_len),PNG_EMPTY);
1224	#endif
1225
1226	#ifdef PNG_WRITE_zTXt_SUPPORTED
1227	PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1228	key, png_const_charp text, int compression),PNG_EMPTY);
1229	#endif
1230
1231	#ifdef PNG_WRITE_iTXt_SUPPORTED
1232	PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1233	int compression, png_const_charp key, png_const_charp lang,
1234	png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1235	#endif
1236
1237	#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
1238	PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1239	png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1240	#endif
1241
1242	#ifdef PNG_WRITE_oFFs_SUPPORTED
1243	PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1244	png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1245	#endif
1246
1247	#ifdef PNG_WRITE_pCAL_SUPPORTED
1248	PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1249	png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1250	png_const_charp units, png_charpp params),PNG_EMPTY);
1251	#endif
1252
1253	#ifdef PNG_WRITE_pHYs_SUPPORTED
1254	PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1255	png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1256	int unit_type),PNG_EMPTY);
1257	#endif
1258
1259	#ifdef PNG_WRITE_tIME_SUPPORTED
1260	PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1261	png_const_timep mod_time),PNG_EMPTY);
1262	#endif
1263
1264	#ifdef PNG_WRITE_sCAL_SUPPORTED
1265	PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1266	int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1267	#endif
1268
1269	/* Called when finished processing a row of data */
1270	PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1271	PNG_EMPTY);
1272
1273	/* Internal use only. Called before first row of data */
1274	PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1275	PNG_EMPTY);
1276
1277	/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
1278	* array of png_ptr->width pixels. If the image is not interlaced or this
1279	* is the final pass this just does a memcpy, otherwise the "display" flag
1280	* is used to determine whether to copy pixels that are not in the current pass.
1281	*
1282	* Because 'png_do_read_interlace' (below) replicates pixels this allows this
1283	* function to achieve the documented 'blocky' appearance during interlaced read
1284	* if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1285	* are not changed if they are not in the current pass, when display is 0.
1286	*
1287	* 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1288	*
1289	* The API always reads from the png_struct row buffer and always assumes that
1290	* it is full width (png_do_read_interlace has already been called.)
1291	*
1292	* This function is only ever used to write to row buffers provided by the
1293	* caller of the relevant libpng API and the row must have already been
1294	* transformed by the read transformations.
1295	*
1296	* The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1297	* bitmasks for use within the code, otherwise runtime generated masks are used.
1298	* The default is compile time masks.
1299	*/
1300	#ifndef PNG_USE_COMPILE_TIME_MASKS
1301	# define PNG_USE_COMPILE_TIME_MASKS 1
1302	#endif
1303	PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1304	png_bytep row, int display),PNG_EMPTY);
1305
1306	#ifdef PNG_READ_INTERLACING_SUPPORTED
1307	/* Expand an interlaced row: the 'row_info' describes the pass data that has
1308	* been read in and must correspond to the pixels in 'row', the pixels are
1309	* expanded (moved apart) in 'row' to match the final layout, when doing this
1310	* the pixels are replicated to the intervening space. This is essential for
1311	* the correct operation of png_combine_row, above.
1312	*/
1313	PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1314	png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1315	#endif
1316
1317	/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
1318
1319	#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1320	/* Grab pixels out of a row for an interlaced pass */
1321	PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1322	png_bytep row, int pass),PNG_EMPTY);
1323	#endif
1324
1325	/* Unfilter a row: check the filter value before calling this, there is no point
1326	* calling it for PNG_FILTER_VALUE_NONE.
1327	*/
1328	PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1329	row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1330
1331	#if PNG_ARM_NEON_OPT > 0
1332	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1333	png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1334	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(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_sub4_neon,(png_row_infop
1337	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1338	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1339	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1340	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1341	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1342	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1343	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1344	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1345	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1346	#endif
1347
1348	#if PNG_MIPS_MSA_IMPLEMENTATION == 1
1349	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_msa,(png_row_infop row_info,
1350	png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1351	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_msa,(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_sub4_msa,(png_row_infop
1354	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1355	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_msa,(png_row_infop
1356	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1357	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop
1358	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1359	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop
1360	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1361	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop
1362	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1363	#endif
1364
1365	#if PNG_MIPS_MMI_IMPLEMENTATION > 0
1366	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_mmi,(png_row_infop row_info,
1367	png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1368	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_mmi,(png_row_infop
1369	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1370	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_mmi,(png_row_infop
1371	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1372	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_mmi,(png_row_infop
1373	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1374	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_mmi,(png_row_infop
1375	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1376	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_mmi,(png_row_infop
1377	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1378	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_mmi,(png_row_infop
1379	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1380	#endif
1381
1382	#if PNG_POWERPC_VSX_OPT > 0
1383	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_vsx,(png_row_infop row_info,
1384	png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1385	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_vsx,(png_row_infop
1386	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1387	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_vsx,(png_row_infop
1388	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1389	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_vsx,(png_row_infop
1390	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1391	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_vsx,(png_row_infop
1392	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1393	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_vsx,(png_row_infop
1394	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1395	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_vsx,(png_row_infop
1396	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1397	#endif
1398
1399	#if PNG_INTEL_SSE_IMPLEMENTATION > 0
1400	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
1401	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1402	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
1403	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1404	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
1405	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1406	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
1407	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1408	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
1409	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1410	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
1411	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1412	#endif
1413
1414	#if PNG_LOONGARCH_LSX_IMPLEMENTATION == 1
1415	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_lsx,(png_row_infop
1416	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1417	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_lsx,(png_row_infop
1418	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1419	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_lsx,(png_row_infop
1420	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1421	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_lsx,(png_row_infop
1422	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1423	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_lsx,(png_row_infop
1424	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1425	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_lsx,(png_row_infop
1426	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1427	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_lsx,(png_row_infop
1428	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1429	#endif
1430
1431	/* Choose the best filter to use and filter the row data */
1432	PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1433	png_row_infop row_info),PNG_EMPTY);
1434
1435	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1436	PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1437	png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1438	/* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
1439	* is NULL the function checks, instead, for the end of the stream. In this
1440	* case a benign error will be issued if the stream end is not found or if
1441	* extra data has to be consumed.
1442	*/
1443	PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1444	PNG_EMPTY);
1445	/* This cleans up when the IDAT LZ stream does not end when the last image
1446	* byte is read; there is still some pending input.
1447	*/
1448
1449	PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1450	PNG_EMPTY);
1451	/* Finish a row while reading, dealing with interlacing passes, etc. */
1452	#endif /* SEQUENTIAL_READ */
1453
1454	/* Initialize the row buffers, etc. */
1455	PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1456
1457	#if ZLIB_VERNUM >= 0x1240
1458	PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
1459	PNG_EMPTY);
1460	# define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
1461	#else /* Zlib < 1.2.4 */
1462	# define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
1463	#endif /* Zlib < 1.2.4 */
1464
1465	#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1466	/* Optional call to update the users info structure */
1467	PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1468	png_inforp info_ptr),PNG_EMPTY);
1469	#endif
1470
1471	/* Shared transform functions, defined in pngtran.c */
1472	#if defined(PNG_WRITE_FILLER_SUPPORTED) \|\| \
1473	defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1474	PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1475	png_bytep row, int at_start),PNG_EMPTY);
1476	#endif
1477
1478	#ifdef PNG_16BIT_SUPPORTED
1479	#if defined(PNG_READ_SWAP_SUPPORTED) \|\| defined(PNG_WRITE_SWAP_SUPPORTED)
1480	PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1481	png_bytep row),PNG_EMPTY);
1482	#endif
1483	#endif
1484
1485	#if defined(PNG_READ_PACKSWAP_SUPPORTED) \|\| \
1486	defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1487	PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1488	png_bytep row),PNG_EMPTY);
1489	#endif
1490
1491	#if defined(PNG_READ_INVERT_SUPPORTED) \|\| defined(PNG_WRITE_INVERT_SUPPORTED)
1492	PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1493	png_bytep row),PNG_EMPTY);
1494	#endif
1495
1496	#if defined(PNG_READ_BGR_SUPPORTED) \|\| defined(PNG_WRITE_BGR_SUPPORTED)
1497	PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1498	png_bytep row),PNG_EMPTY);
1499	#endif
1500
1501	/* The following decodes the appropriate chunks, and does error correction,
1502	* then calls the appropriate callback for the chunk if it is valid.
1503	*/
1504
1505	/* Decode the IHDR chunk */
1506	PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1507	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1508	PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1509	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1510	PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1511	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1512
1513	#ifdef PNG_READ_bKGD_SUPPORTED
1514	PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1515	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1516	#endif
1517
1518	#ifdef PNG_READ_cHRM_SUPPORTED
1519	PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1520	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1521	#endif
1522
1523	#ifdef PNG_READ_eXIf_SUPPORTED
1524	PNG_INTERNAL_FUNCTION(void,png_handle_eXIf,(png_structrp png_ptr,
1525	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1526	#endif
1527
1528	#ifdef PNG_READ_gAMA_SUPPORTED
1529	PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1530	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1531	#endif
1532
1533	#ifdef PNG_READ_hIST_SUPPORTED
1534	PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1535	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1536	#endif
1537
1538	#ifdef PNG_READ_iCCP_SUPPORTED
1539	PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1540	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1541	#endif /* READ_iCCP */
1542
1543	#ifdef PNG_READ_iTXt_SUPPORTED
1544	PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1545	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1546	#endif
1547
1548	#ifdef PNG_READ_oFFs_SUPPORTED
1549	PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1550	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1551	#endif
1552
1553	#ifdef PNG_READ_pCAL_SUPPORTED
1554	PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1555	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1556	#endif
1557
1558	#ifdef PNG_READ_pHYs_SUPPORTED
1559	PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1560	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1561	#endif
1562
1563	#ifdef PNG_READ_sBIT_SUPPORTED
1564	PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1565	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1566	#endif
1567
1568	#ifdef PNG_READ_sCAL_SUPPORTED
1569	PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1570	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1571	#endif
1572
1573	#ifdef PNG_READ_sPLT_SUPPORTED
1574	PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1575	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1576	#endif /* READ_sPLT */
1577
1578	#ifdef PNG_READ_sRGB_SUPPORTED
1579	PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1580	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1581	#endif
1582
1583	#ifdef PNG_READ_tEXt_SUPPORTED
1584	PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1585	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1586	#endif
1587
1588	#ifdef PNG_READ_tIME_SUPPORTED
1589	PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1590	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1591	#endif
1592
1593	#ifdef PNG_READ_tRNS_SUPPORTED
1594	PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1595	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1596	#endif
1597
1598	#ifdef PNG_READ_zTXt_SUPPORTED
1599	PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1600	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1601	#endif
1602
1603	PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_const_structrp png_ptr,
1604	png_uint_32 chunk_name),PNG_EMPTY);
1605
1606	PNG_INTERNAL_FUNCTION(void,png_check_chunk_length,(png_const_structrp png_ptr,
1607	png_uint_32 chunk_length),PNG_EMPTY);
1608
1609	PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1610	png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1611	/* This is the function that gets called for unknown chunks. The 'keep'
1612	* argument is either non-zero for a known chunk that has been set to be
1613	* handled as unknown or zero for an unknown chunk. By default the function
1614	* just skips the chunk or errors out if it is critical.
1615	*/
1616
1617	#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) \|\|\
1618	defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1619	PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1620	(png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1621	/* Exactly as the API png_handle_as_unknown() except that the argument is a
1622	* 32-bit chunk name, not a string.
1623	*/
1624	#endif /* READ_UNKNOWN_CHUNKS \|\| HANDLE_AS_UNKNOWN */
1625
1626	/* Handle the transformations for reading and writing */
1627	#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1628	PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1629	png_row_infop row_info),PNG_EMPTY);
1630	#endif
1631	#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1632	PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1633	png_row_infop row_info),PNG_EMPTY);
1634	#endif
1635
1636	#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1637	PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1638	PNG_EMPTY);
1639	#endif
1640
1641	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1642	PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1643	png_inforp info_ptr),PNG_EMPTY);
1644	PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1645	png_inforp info_ptr),PNG_EMPTY);
1646	PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1647	PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1648	PNG_EMPTY);
1649	PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1650	png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1651	PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1652	PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1653	png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1654	PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1655	PNG_EMPTY);
1656	PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1657	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1658	PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1659	png_inforp info_ptr),PNG_EMPTY);
1660	PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1661	png_inforp info_ptr),PNG_EMPTY);
1662	PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1663	png_bytep row),PNG_EMPTY);
1664	PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1665	png_inforp info_ptr),PNG_EMPTY);
1666	PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1667	png_inforp info_ptr),PNG_EMPTY);
1668	PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1669	PNG_EMPTY);
1670	# ifdef PNG_READ_tEXt_SUPPORTED
1671	PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1672	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1673	PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1674	png_inforp info_ptr),PNG_EMPTY);
1675	# endif
1676	# ifdef PNG_READ_zTXt_SUPPORTED
1677	PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1678	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1679	PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1680	png_inforp info_ptr),PNG_EMPTY);
1681	# endif
1682	# ifdef PNG_READ_iTXt_SUPPORTED
1683	PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1684	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1685	PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1686	png_inforp info_ptr),PNG_EMPTY);
1687	# endif
1688
1689	#endif /* PROGRESSIVE_READ */
1690
1691	/* Added at libpng version 1.6.0 */
1692	#ifdef PNG_GAMMA_SUPPORTED
1693	PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1694	png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1695	/* Set the colorspace gamma with a value provided by the application or by
1696	* the gAMA chunk on read. The value will override anything set by an ICC
1697	* profile.
1698	*/
1699
1700	PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1701	png_inforp info_ptr), PNG_EMPTY);
1702	/* Synchronize the info 'valid' flags with the colorspace */
1703
1704	PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1705	png_inforp info_ptr), PNG_EMPTY);
1706	/* Copy the png_struct colorspace to the info_struct and call the above to
1707	* synchronize the flags. Checks for NULL info_ptr and does nothing.
1708	*/
1709	#endif
1710
1711	/* Added at libpng version 1.4.0 */
1712	#ifdef PNG_COLORSPACE_SUPPORTED
1713	/* These internal functions are for maintaining the colorspace structure within
1714	* a png_info or png_struct (or, indeed, both).
1715	*/
1716	PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1717	(png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1718	int preferred), PNG_EMPTY);
1719
1720	PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1721	(png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1722	int preferred), PNG_EMPTY);
1723
1724	#ifdef PNG_sRGB_SUPPORTED
1725	PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1726	png_colorspacerp colorspace, int intent), PNG_EMPTY);
1727	/* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1728	* flags to write them, if it returns false there was a problem and an error
1729	* message has already been output (but the colorspace may still need to be
1730	* synced to record the invalid flag).
1731	*/
1732	#endif /* sRGB */
1733
1734	#ifdef PNG_iCCP_SUPPORTED
1735	PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1736	png_colorspacerp colorspace, png_const_charp name,
1737	png_uint_32 profile_length, png_const_bytep profile, int color_type),
1738	PNG_EMPTY);
1739	/* The 'name' is used for information only */
1740
1741	/* Routines for checking parts of an ICC profile. */
1742	#ifdef PNG_READ_iCCP_SUPPORTED
1743	PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1744	png_colorspacerp colorspace, png_const_charp name,
1745	png_uint_32 profile_length), PNG_EMPTY);
1746	#endif /* READ_iCCP */
1747	PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1748	png_colorspacerp colorspace, png_const_charp name,
1749	png_uint_32 profile_length,
1750	png_const_bytep profile /* first 132 bytes only */, int color_type),
1751	PNG_EMPTY);
1752	PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1753	png_colorspacerp colorspace, png_const_charp name,
1754	png_uint_32 profile_length,
1755	png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1756	#ifdef PNG_sRGB_SUPPORTED
1757	PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1758	png_const_structrp png_ptr, png_colorspacerp colorspace,
1759	png_const_bytep profile, uLong adler), PNG_EMPTY);
1760	/* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1761	* be zero to indicate that it is not available. It is used, if provided,
1762	* as a fast check on the profile when checking to see if it is sRGB.
1763	*/
1764	#endif
1765	#endif /* iCCP */
1766
1767	#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1768	PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1769	(png_structrp png_ptr), PNG_EMPTY);
1770	/* Set the rgb_to_gray coefficients from the colorspace Y values */
1771	#endif /* READ_RGB_TO_GRAY */
1772	#endif /* COLORSPACE */
1773
1774	/* Added at libpng version 1.4.0 */
1775	PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1776	png_uint_32 width, png_uint_32 height, int bit_depth,
1777	int color_type, int interlace_type, int compression_type,
1778	int filter_type),PNG_EMPTY);
1779
1780	/* Added at libpng version 1.5.10 */
1781	#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) \|\| \
1782	defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1783	PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1784	(png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1785	#endif
1786
1787	#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1788	PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1789	png_const_charp name),PNG_NORETURN);
1790	#endif
1791
1792	/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1793	* the end. Always leaves the buffer nul terminated. Never errors out (and
1794	* there is no error code.)
1795	*/
1796	PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1797	size_t pos, png_const_charp string),PNG_EMPTY);
1798
1799	/* Various internal functions to handle formatted warning messages, currently
1800	* only implemented for warnings.
1801	*/
1802	#if defined(PNG_WARNINGS_SUPPORTED) \|\| defined(PNG_TIME_RFC1123_SUPPORTED)
1803	/* Utility to dump an unsigned value into a buffer, given a start pointer and
1804	* and end pointer (which should point just beyond the end of the buffer!)
1805	* Returns the pointer to the start of the formatted string. This utility only
1806	* does unsigned values.
1807	*/
1808	PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1809	png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1810
1811	/* Convenience macro that takes an array: */
1812	#define PNG_FORMAT_NUMBER(buffer,format,number) \
1813	png_format_number(buffer, buffer + (sizeof buffer), format, number)
1814
1815	/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1816	#define PNG_NUMBER_BUFFER_SIZE 24
1817
1818	/* These are the integer formats currently supported, the name is formed from
1819	* the standard printf(3) format string.
1820	*/
1821	#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
1822	#define PNG_NUMBER_FORMAT_02u 2
1823	#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
1824	#define PNG_NUMBER_FORMAT_02d 2
1825	#define PNG_NUMBER_FORMAT_x 3
1826	#define PNG_NUMBER_FORMAT_02x 4
1827	#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1828	#endif
1829
1830	#ifdef PNG_WARNINGS_SUPPORTED
1831	/* New defines and members adding in libpng-1.5.4 */
1832	# define PNG_WARNING_PARAMETER_SIZE 32
1833	# define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1834
1835	/* An l-value of this type has to be passed to the APIs below to cache the
1836	* values of the parameters to a formatted warning message.
1837	*/
1838	typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1839	PNG_WARNING_PARAMETER_SIZE];
1840
1841	PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1842	int number, png_const_charp string),PNG_EMPTY);
1843	/* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1844	* including the trailing '\0'.
1845	*/
1846	PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1847	(png_warning_parameters p, int number, int format, png_alloc_size_t value),
1848	PNG_EMPTY);
1849	/* Use png_alloc_size_t because it is an unsigned type as big as any we
1850	* need to output. Use the following for a signed value.
1851	*/
1852	PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1853	(png_warning_parameters p, int number, int format, png_int_32 value),
1854	PNG_EMPTY);
1855
1856	PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1857	png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1858	/* 'message' follows the X/Open approach of using @1, @2 to insert
1859	* parameters previously supplied using the above functions. Errors in
1860	* specifying the parameters will simply result in garbage substitutions.
1861	*/
1862	#endif
1863
1864	#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1865	/* Application errors (new in 1.6); use these functions (declared below) for
1866	* errors in the parameters or order of API function calls on read. The
1867	* 'warning' should be used for an error that can be handled completely; the
1868	* 'error' for one which can be handled safely but which may lose application
1869	* information or settings.
1870	*
1871	* By default these both result in a png_error call prior to release, while in a
1872	* released version the 'warning' is just a warning. However if the application
1873	* explicitly disables benign errors (explicitly permitting the code to lose
1874	* information) they both turn into warnings.
1875	*
1876	* If benign errors aren't supported they end up as the corresponding base call
1877	* (png_warning or png_error.)
1878	*/
1879	PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1880	png_const_charp message),PNG_EMPTY);
1881	/* The application provided invalid parameters to an API function or called
1882	* an API function at the wrong time, libpng can completely recover.
1883	*/
1884
1885	PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1886	png_const_charp message),PNG_EMPTY);
1887	/* As above but libpng will ignore the call, or attempt some other partial
1888	* recovery from the error.
1889	*/
1890	#else
1891	# define png_app_warning(pp,s) png_warning(pp,s)
1892	# define png_app_error(pp,s) png_error(pp,s)
1893	#endif
1894
1895	PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1896	png_const_charp message, int error),PNG_EMPTY);
1897	/* Report a recoverable issue in chunk data. On read this is used to report
1898	* a problem found while reading a particular chunk and the
1899	* png_chunk_benign_error or png_chunk_warning function is used as
1900	* appropriate. On write this is used to report an error that comes from
1901	* data set via an application call to a png_set_ API and png_app_error or
1902	* png_app_warning is used as appropriate.
1903	*
1904	* The 'error' parameter must have one of the following values:
1905	*/
1906	#define PNG_CHUNK_WARNING 0 /* never an error */
1907	#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1908	#define PNG_CHUNK_ERROR 2 /* always an error */
1909
1910	/* ASCII to FP interfaces, currently only implemented if sCAL
1911	* support is required.
1912	*/
1913	#if defined(PNG_sCAL_SUPPORTED)
1914	/* MAX_DIGITS is actually the maximum number of characters in an sCAL
1915	* width or height, derived from the precision (number of significant
1916	* digits - a build time settable option) and assumptions about the
1917	* maximum ridiculous exponent.
1918	*/
1919	#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/./+1/E/+10/exponent/)
1920
1921	#ifdef PNG_FLOATING_POINT_SUPPORTED
1922	PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1923	png_charp ascii, size_t size, double fp, unsigned int precision),
1924	PNG_EMPTY);
1925	#endif /* FLOATING_POINT */
1926
1927	#ifdef PNG_FIXED_POINT_SUPPORTED
1928	PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1929	png_charp ascii, size_t size, png_fixed_point fp),PNG_EMPTY);
1930	#endif /* FIXED_POINT */
1931	#endif /* sCAL */
1932
1933	#if defined(PNG_sCAL_SUPPORTED) \|\| defined(PNG_pCAL_SUPPORTED)
1934	/* An internal API to validate the format of a floating point number.
1935	* The result is the index of the next character. If the number is
1936	* not valid it will be the index of a character in the supposed number.
1937	*
1938	* The format of a number is defined in the PNG extensions specification
1939	* and this API is strictly conformant to that spec, not anyone elses!
1940	*
1941	* The format as a regular expression is:
1942	*
1943	* [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1944	*
1945	* or:
1946	*
1947	* [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1948	*
1949	* The complexity is that either integer or fraction must be present and the
1950	* fraction is permitted to have no digits only if the integer is present.
1951	*
1952	* NOTE: The dangling E problem.
1953	* There is a PNG valid floating point number in the following:
1954	*
1955	* PNG floating point numbers are not greedy.
1956	*
1957	* Working this out requires TWO character lookahead (because of the
1958	* sign), the parser does not do this - it will fail at the 'r' - this
1959	* doesn't matter for PNG sCAL chunk values, but it requires more care
1960	* if the value were ever to be embedded in something more complex. Use
1961	* ANSI-C strtod if you need the lookahead.
1962	*/
1963	/* State table for the parser. */
1964	#define PNG_FP_INTEGER 0 /* before or in integer */
1965	#define PNG_FP_FRACTION 1 /* before or in fraction */
1966	#define PNG_FP_EXPONENT 2 /* before or in exponent */
1967	#define PNG_FP_STATE 3 /* mask for the above */
1968	#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
1969	#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
1970	#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
1971	#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
1972	#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
1973
1974	/* These three values don't affect the parser. They are set but not used.
1975	*/
1976	#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
1977	#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
1978	#define PNG_FP_NONZERO 256 /* A non-zero value */
1979	#define PNG_FP_STICKY 448 /* The above three flags */
1980
1981	/* This is available for the caller to store in 'state' if required. Do not
1982	* call the parser after setting it (the parser sometimes clears it.)
1983	*/
1984	#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
1985
1986	/* Result codes for the parser (boolean - true means ok, false means
1987	* not ok yet.)
1988	*/
1989	#define PNG_FP_MAYBE 0 /* The number may be valid in the future */
1990	#define PNG_FP_OK 1 /* The number is valid */
1991
1992	/* Tests on the sticky non-zero and negative flags. To pass these checks
1993	* the state must also indicate that the whole number is valid - this is
1994	* achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1995	* is equivalent to PNG_FP_OK above.)
1996	*/
1997	#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT \| PNG_FP_NEGATIVE \| PNG_FP_NONZERO)
1998	/* NZ_MASK: the string is valid and a non-zero negative value */
1999	#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT \| PNG_FP_NONZERO)
2000	/* Z MASK: the string is valid and a non-zero value. */
2001	/* PNG_FP_SAW_DIGIT: the string is valid. */
2002	#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
2003	#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
2004	#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
2005
2006	/* The actual parser. This can be called repeatedly. It updates
2007	* the index into the string and the state variable (which must
2008	* be initialized to 0). It returns a result code, as above. There
2009	* is no point calling the parser any more if it fails to advance to
2010	* the end of the string - it is stuck on an invalid character (or
2011	* terminated by '\0').
2012	*
2013	* Note that the pointer will consume an E or even an E+ and then leave
2014	* a 'maybe' state even though a preceding integer.fraction is valid.
2015	* The PNG_FP_WAS_VALID flag indicates that a preceding substring was
2016	* a valid number. It's possible to recover from this by calling
2017	* the parser again (from the start, with state 0) but with a string
2018	* that omits the last character (i.e. set the size to the index of
2019	* the problem character.) This has not been tested within libpng.
2020	*/
2021	PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
2022	size_t size, int statep, size_t whereami),PNG_EMPTY);
2023
2024	/* This is the same but it checks a complete string and returns true
2025	* only if it just contains a floating point number. As of 1.5.4 this
2026	* function also returns the state at the end of parsing the number if
2027	* it was valid (otherwise it returns 0.) This can be used for testing
2028	* for negative or zero values using the sticky flag.
2029	*/
2030	PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
2031	size_t size),PNG_EMPTY);
2032	#endif /* pCAL \|\| sCAL */
2033
2034	#if defined(PNG_GAMMA_SUPPORTED) \|\|\
2035	defined(PNG_INCH_CONVERSIONS_SUPPORTED) \|\| defined(PNG_READ_pHYs_SUPPORTED)
2036	/* Added at libpng version 1.5.0 */
2037	/* This is a utility to provide a*times/div (rounded) and indicate
2038	* if there is an overflow. The result is a boolean - false (0)
2039	* for overflow, true (1) if no overflow, in which case *res
2040	* holds the result.
2041	*/
2042	PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
2043	png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
2044	#endif
2045
2046	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2047	/* Same deal, but issue a warning on overflow and return 0. */
2048	PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
2049	(png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
2050	png_int_32 divided_by),PNG_EMPTY);
2051	#endif
2052
2053	#ifdef PNG_GAMMA_SUPPORTED
2054	/* Calculate a reciprocal - used for gamma values. This returns
2055	* 0 if the argument is 0 in order to maintain an undefined value;
2056	* there are no warnings.
2057	*/
2058	PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
2059	PNG_EMPTY);
2060
2061	#ifdef PNG_READ_GAMMA_SUPPORTED
2062	/* The same but gives a reciprocal of the product of two fixed point
2063	* values. Accuracy is suitable for gamma calculations but this is
2064	* not exact - use png_muldiv for that. Only required at present on read.
2065	*/
2066	PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
2067	png_fixed_point b),PNG_EMPTY);
2068	#endif
2069
2070	/* Return true if the gamma value is significantly different from 1.0 */
2071	PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
2072	PNG_EMPTY);
2073	#endif
2074
2075	#ifdef PNG_READ_GAMMA_SUPPORTED
2076	/* Internal fixed point gamma correction. These APIs are called as
2077	* required to convert single values - they don't need to be fast,
2078	* they are not used when processing image pixel values.
2079	*
2080	* While the input is an 'unsigned' value it must actually be the
2081	* correct bit value - 0..255 or 0..65535 as required.
2082	*/
2083	PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
2084	unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
2085	PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
2086	png_fixed_point gamma_value),PNG_EMPTY);
2087	PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
2088	png_fixed_point gamma_value),PNG_EMPTY);
2089	PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
2090	PNG_EMPTY);
2091	PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
2092	int bit_depth),PNG_EMPTY);
2093	#endif
2094
2095	/* SIMPLIFIED READ/WRITE SUPPORT */
2096	#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) \|\|\
2097	defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2098	/* The internal structure that png_image::opaque points to. */
2099	typedef struct png_control
2100	{
2101	png_structp png_ptr;
2102	png_infop info_ptr;
2103	png_voidp error_buf; /* Always a jmp_buf at present. */
2104
2105	png_const_bytep memory; /* Memory buffer. */
2106	size_t size; /* Size of the memory buffer. */
2107
2108	unsigned int for_write :1; /* Otherwise it is a read structure */
2109	unsigned int owned_file :1; /* We own the file in io_ptr */
2110	} png_control;
2111
2112	/* Return the pointer to the jmp_buf from a png_control: necessary because C
2113	* does not reveal the type of the elements of jmp_buf.
2114	*/
2115	#ifdef __cplusplus
2116	# define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
2117	#else
2118	# define png_control_jmp_buf(pc) ((pc)->error_buf)
2119	#endif
2120
2121	/* Utility to safely execute a piece of libpng code catching and logging any
2122	* errors that might occur. Returns true on success, false on failure (either
2123	* of the function or as a result of a png_error.)
2124	*/
2125	PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
2126	png_const_charp error_message),PNG_NORETURN);
2127
2128	#ifdef PNG_WARNINGS_SUPPORTED
2129	PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
2130	png_const_charp warning_message),PNG_EMPTY);
2131	#else
2132	# define png_safe_warning 0/dummy argument/
2133	#endif
2134
2135	PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
2136	int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
2137
2138	/* Utility to log an error; this also cleans up the png_image; the function
2139	* always returns 0 (false).
2140	*/
2141	PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
2142	png_const_charp error_message),PNG_EMPTY);
2143
2144	#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
2145	/* png_image_free is used by the write code but not exported */
2146	PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
2147	#endif /* !SIMPLIFIED_READ */
2148
2149	#endif /* SIMPLIFIED READ/WRITE */
2150
2151	/* These are initialization functions for hardware specific PNG filter
2152	* optimizations; list these here then select the appropriate one at compile
2153	* time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined
2154	* the generic code is used.
2155	*/
2156	#ifdef PNG_FILTER_OPTIMIZATIONS
2157	PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
2158	unsigned int bpp), PNG_EMPTY);
2159	/* Just declare the optimization that will be used */
2160	#else
2161	/* List all the possible optimizations here - this branch is required if
2162	* the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
2163	* CFLAGS in place of CPPFLAGS and uses symbol prefixing.
2164	*/
2165	# if PNG_ARM_NEON_OPT > 0
2166	PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
2167	(png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2168	#endif
2169
2170	#if PNG_MIPS_MSA_IMPLEMENTATION == 1
2171	PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_mips,
2172	(png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2173	#endif
2174
2175	# if PNG_MIPS_MMI_IMPLEMENTATION > 0
2176	PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_mips,
2177	(png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2178	# endif
2179
2180	# if PNG_INTEL_SSE_IMPLEMENTATION > 0
2181	PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
2182	(png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2183	# endif
2184	#endif
2185
2186	#if PNG_LOONGARCH_LSX_OPT > 0
2187	PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_lsx,
2188	(png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2189	#endif
2190
2191	PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
2192	png_const_charp key, png_bytep new_key), PNG_EMPTY);
2193
2194	#if PNG_ARM_NEON_IMPLEMENTATION == 1
2195	PNG_INTERNAL_FUNCTION(void,
2196	png_riffle_palette_neon,
2197	(png_structrp),
2198	PNG_EMPTY);
2199	PNG_INTERNAL_FUNCTION(int,
2200	png_do_expand_palette_rgba8_neon,
2201	(png_structrp,
2202	png_row_infop,
2203	png_const_bytep,
2204	const png_bytepp,
2205	const png_bytepp),
2206	PNG_EMPTY);
2207	PNG_INTERNAL_FUNCTION(int,
2208	png_do_expand_palette_rgb8_neon,
2209	(png_structrp,
2210	png_row_infop,
2211	png_const_bytep,
2212	const png_bytepp,
2213	const png_bytepp),
2214	PNG_EMPTY);
2215	#endif
2216
2217	/* Maintainer: Put new private prototypes here ^ */
2218
2219	#include "pngdebug.h"
2220
2221	#ifdef __cplusplus
2222	}
2223	#endif
2224
2225	#endif /* PNG_VERSION_INFO_ONLY */
2226	#endif /* PNGPRIV_H */

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