pngpriv.h@ 88461

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2	/* pngpriv.h - private declarations for use inside libpng
3	*
4	* Copyright (c) 2018 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__)
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	#endif /* PNG_ARM_NEON_OPT > 0 */
189
190	#ifndef PNG_MIPS_MSA_OPT
191	# if defined(__mips_msa) && (__mips_isa_rev >= 5) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
192	# define PNG_MIPS_MSA_OPT 2
193	# else
194	# define PNG_MIPS_MSA_OPT 0
195	# endif
196	#endif
197
198	#ifndef PNG_POWERPC_VSX_OPT
199	# if defined(__PPC64__) && defined(__ALTIVEC__) && defined(__VSX__)
200	# define PNG_POWERPC_VSX_OPT 2
201	# else
202	# define PNG_POWERPC_VSX_OPT 0
203	# endif
204	#endif
205
206	#ifndef PNG_INTEL_SSE_OPT
207	# ifdef PNG_INTEL_SSE
208	/* Only check for SSE if the build configuration has been modified to
209	* enable SSE optimizations. This means that these optimizations will
210	* be off by default. See contrib/intel for more details.
211	*/
212	# if defined(__SSE4_1__) \|\| defined(__AVX__) \|\| defined(__SSSE3__) \|\| \
213	defined(__SSE2__) \|\| defined(_M_X64) \|\| defined(_M_AMD64) \|\| \
214	(defined(_M_IX86_FP) && _M_IX86_FP >= 2)
215	# define PNG_INTEL_SSE_OPT 1
216	# else
217	# define PNG_INTEL_SSE_OPT 0
218	# endif
219	# else
220	# define PNG_INTEL_SSE_OPT 0
221	# endif
222	#endif
223
224	#if PNG_INTEL_SSE_OPT > 0
225	# ifndef PNG_INTEL_SSE_IMPLEMENTATION
226	# if defined(__SSE4_1__) \|\| defined(__AVX__)
227	/* We are not actually using AVX, but checking for AVX is the best
228	way we can detect SSE4.1 and SSSE3 on MSVC.
229	*/
230	# define PNG_INTEL_SSE_IMPLEMENTATION 3
231	# elif defined(__SSSE3__)
232	# define PNG_INTEL_SSE_IMPLEMENTATION 2
233	# elif defined(__SSE2__) \|\| defined(_M_X64) \|\| defined(_M_AMD64) \|\| \
234	(defined(_M_IX86_FP) && _M_IX86_FP >= 2)
235	# define PNG_INTEL_SSE_IMPLEMENTATION 1
236	# else
237	# define PNG_INTEL_SSE_IMPLEMENTATION 0
238	# endif
239	# endif
240
241	# if PNG_INTEL_SSE_IMPLEMENTATION > 0
242	# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
243	# endif
244	#else
245	# define PNG_INTEL_SSE_IMPLEMENTATION 0
246	#endif
247
248	#if PNG_MIPS_MSA_OPT > 0
249	# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_msa
250	# ifndef PNG_MIPS_MSA_IMPLEMENTATION
251	# if defined(__mips_msa)
252	# if defined(__clang__)
253	# elif defined(__GNUC__)
254	# if __GNUC__ < 4 \|\| (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
255	# define PNG_MIPS_MSA_IMPLEMENTATION 2
256	# endif /* no GNUC support */
257	# endif /* __GNUC__ */
258	# else /* !defined __mips_msa */
259	# define PNG_MIPS_MSA_IMPLEMENTATION 2
260	# endif /* __mips_msa */
261	# endif /* !PNG_MIPS_MSA_IMPLEMENTATION */
262
263	# ifndef PNG_MIPS_MSA_IMPLEMENTATION
264	# define PNG_MIPS_MSA_IMPLEMENTATION 1
265	# endif
266	#endif /* PNG_MIPS_MSA_OPT > 0 */
267
268	#if PNG_POWERPC_VSX_OPT > 0
269	# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx
270	# define PNG_POWERPC_VSX_IMPLEMENTATION 1
271	#endif
272
273
274	/* Is this a build of a DLL where compilation of the object modules requires
275	* different preprocessor settings to those required for a simple library? If
276	* so PNG_BUILD_DLL must be set.
277	*
278	* If libpng is used inside a DLL but that DLL does not export the libpng APIs
279	* PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
280	* static library of libpng then link the DLL against that.
281	*/
282	#ifndef PNG_BUILD_DLL
283	# ifdef DLL_EXPORT
284	/* This is set by libtool when files are compiled for a DLL; libtool
285	* always compiles twice, even on systems where it isn't necessary. Set
286	* PNG_BUILD_DLL in case it is necessary:
287	*/
288	# define PNG_BUILD_DLL
289	# else
290	# ifdef _WINDLL
291	/* This is set by the Microsoft Visual Studio IDE in projects that
292	* build a DLL. It can't easily be removed from those projects (it
293	* isn't visible in the Visual Studio UI) so it is a fairly reliable
294	* indication that PNG_IMPEXP needs to be set to the DLL export
295	* attributes.
296	*/
297	# define PNG_BUILD_DLL
298	# else
299	# ifdef __DLL__
300	/* This is set by the Borland C system when compiling for a DLL
301	* (as above.)
302	*/
303	# define PNG_BUILD_DLL
304	# else
305	/* Add additional compiler cases here. */
306	# endif
307	# endif
308	# endif
309	#endif /* Setting PNG_BUILD_DLL if required */
310
311	/* See pngconf.h for more details: the builder of the library may set this on
312	* the command line to the right thing for the specific compilation system or it
313	* may be automagically set above (at present we know of no system where it does
314	* need to be set on the command line.)
315	*
316	* PNG_IMPEXP must be set here when building the library to prevent pngconf.h
317	* setting it to the "import" setting for a DLL build.
318	*/
319	#ifndef PNG_IMPEXP
320	# ifdef PNG_BUILD_DLL
321	# define PNG_IMPEXP PNG_DLL_EXPORT
322	# else
323	/* Not building a DLL, or the DLL doesn't require specific export
324	* definitions.
325	*/
326	# define PNG_IMPEXP
327	# endif
328	#endif
329
330	/* No warnings for private or deprecated functions in the build: */
331	#ifndef PNG_DEPRECATED
332	# define PNG_DEPRECATED
333	#endif
334	#ifndef PNG_PRIVATE
335	# define PNG_PRIVATE
336	#endif
337
338	/* Symbol preprocessing support.
339	*
340	* To enable listing global, but internal, symbols the following macros should
341	* always be used to declare an extern data or function object in this file.
342	*/
343	#ifndef PNG_INTERNAL_DATA
344	# define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array
345	#endif
346
347	#ifndef PNG_INTERNAL_FUNCTION
348	# define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
349	PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
350	#endif
351
352	#ifndef PNG_INTERNAL_CALLBACK
353	# define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
354	PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\
355	PNG_EMPTY attributes)
356	#endif
357
358	/* If floating or fixed point APIs are disabled they may still be compiled
359	* internally. To handle this make sure they are declared as the appropriate
360	* internal extern function (otherwise the symbol prefixing stuff won't work and
361	* the functions will be used without definitions.)
362	*
363	* NOTE: although all the API functions are declared here they are not all
364	* actually built! Because the declarations are still made it is necessary to
365	* fake out types that they depend on.
366	*/
367	#ifndef PNG_FP_EXPORT
368	# ifndef PNG_FLOATING_POINT_SUPPORTED
369	# define PNG_FP_EXPORT(ordinal, type, name, args)\
370	PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
371	# ifndef PNG_VERSION_INFO_ONLY
372	typedef struct png_incomplete png_double;
373	typedef png_double* png_doublep;
374	typedef const png_double* png_const_doublep;
375	typedef png_double** png_doublepp;
376	# endif
377	# endif
378	#endif
379	#ifndef PNG_FIXED_EXPORT
380	# ifndef PNG_FIXED_POINT_SUPPORTED
381	# define PNG_FIXED_EXPORT(ordinal, type, name, args)\
382	PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
383	# endif
384	#endif
385
386	#include "png.h"
387
388	/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
389	#ifndef PNG_DLL_EXPORT
390	# define PNG_DLL_EXPORT
391	#endif
392
393	/* This is a global switch to set the compilation for an installed system
394	* (a release build). It can be set for testing debug builds to ensure that
395	* they will compile when the build type is switched to RC or STABLE, the
396	* default is just to use PNG_LIBPNG_BUILD_BASE_TYPE. Set this in CPPFLAGS
397	* with either:
398	*
399	* -DPNG_RELEASE_BUILD Turns on the release compile path
400	* -DPNG_RELEASE_BUILD=0 Turns it off
401	* or in your pngusr.h with
402	* #define PNG_RELEASE_BUILD=1 Turns on the release compile path
403	* #define PNG_RELEASE_BUILD=0 Turns it off
404	*/
405	#ifndef PNG_RELEASE_BUILD
406	# define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
407	#endif
408
409	/* SECURITY and SAFETY:
410	*
411	* libpng is built with support for internal limits on image dimensions and
412	* memory usage. These are documented in scripts/pnglibconf.dfa of the
413	* source and recorded in the machine generated header file pnglibconf.h.
414	*/
415
416	/* If you are running on a machine where you cannot allocate more
417	* than 64K of memory at once, uncomment this. While libpng will not
418	* normally need that much memory in a chunk (unless you load up a very
419	* large file), zlib needs to know how big of a chunk it can use, and
420	* libpng thus makes sure to check any memory allocation to verify it
421	* will fit into memory.
422	*
423	* zlib provides 'MAXSEG_64K' which, if defined, indicates the
424	* same limit and pngconf.h (already included) sets the limit
425	* if certain operating systems are detected.
426	*/
427	#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
428	# define PNG_MAX_MALLOC_64K
429	#endif
430
431	#ifndef PNG_UNUSED
432	/* Unused formal parameter warnings are silenced using the following macro
433	* which is expected to have no bad effects on performance (optimizing
434	* compilers will probably remove it entirely). Note that if you replace
435	* it with something other than whitespace, you must include the terminating
436	* semicolon.
437	*/
438	# define PNG_UNUSED(param) (void)param;
439	#endif
440
441	/* Just a little check that someone hasn't tried to define something
442	* contradictory.
443	*/
444	#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
445	# undef PNG_ZBUF_SIZE
446	# define PNG_ZBUF_SIZE 65536L
447	#endif
448
449	/* If warnings or errors are turned off the code is disabled or redirected here.
450	* From 1.5.4 functions have been added to allow very limited formatting of
451	* error and warning messages - this code will also be disabled here.
452	*/
453	#ifdef PNG_WARNINGS_SUPPORTED
454	# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
455	#else
456	# define png_warning_parameter(p,number,string) ((void)0)
457	# define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
458	# define png_warning_parameter_signed(p,number,format,value) ((void)0)
459	# define png_formatted_warning(pp,p,message) ((void)(pp))
460	# define PNG_WARNING_PARAMETERS(p)
461	#endif
462	#ifndef PNG_ERROR_TEXT_SUPPORTED
463	# define png_fixed_error(s1,s2) png_err(s1)
464	#endif
465
466	/* Some fixed point APIs are still required even if not exported because
467	* they get used by the corresponding floating point APIs. This magic
468	* deals with this:
469	*/
470	#ifdef PNG_FIXED_POINT_SUPPORTED
471	# define PNGFAPI PNGAPI
472	#else
473	# define PNGFAPI /* PRIVATE */
474	#endif
475
476	#ifndef PNG_VERSION_INFO_ONLY
477	/* Other defines specific to compilers can go here. Try to keep
478	* them inside an appropriate ifdef/endif pair for portability.
479	*/
480
481	/* C allows up-casts from (void) to any pointer and (const void) to any
482	* pointer to a const object. C++ regards this as a type error and requires an
483	* explicit, static, cast and provides the static_cast<> rune to ensure that
484	* const is not cast away.
485	*/
486	#ifdef __cplusplus
487	# define png_voidcast(type, value) static_cast<type>(value)
488	# define png_constcast(type, value) const_cast<type>(value)
489	# define png_aligncast(type, value) \
490	static_cast<type>(static_cast<void*>(value))
491	# define png_aligncastconst(type, value) \
492	static_cast<type>(static_cast<const void*>(value))
493	#else
494	# define png_voidcast(type, value) (value)
495	# ifdef _WIN64
496	# ifdef __GNUC__
497	typedef unsigned long long png_ptruint;
498	# else
499	typedef unsigned __int64 png_ptruint;
500	# endif
501	# else
502	typedef unsigned long png_ptruint;
503	# endif
504	# define png_constcast(type, value) ((type)(png_ptruint)(const void*)(value))
505	# define png_aligncast(type, value) ((void*)(value))
506	# define png_aligncastconst(type, value) ((const void*)(value))
507	#endif /* __cplusplus */
508
509	#if defined(PNG_FLOATING_POINT_SUPPORTED) \|\|\
510	defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
511	/* png.c requires the following ANSI-C constants if the conversion of
512	* floating point to ASCII is implemented therein:
513	*
514	* DBL_DIG Maximum number of decimal digits (can be set to any constant)
515	* DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
516	* DBL_MAX Maximum floating point number (can be set to an arbitrary value)
517	*/
518	# include <float.h>
519
520	# if (defined(__MWERKS__) && defined(macintosh)) \|\| defined(applec) \|\| \
521	defined(THINK_C) \|\| defined(__SC__) \|\| defined(TARGET_OS_MAC)
522	/* We need to check that <math.h> hasn't already been included earlier
523	* as it seems it doesn't agree with <fp.h>, yet we should really use
524	* <fp.h> if possible.
525	*/
526	# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
527	# include <fp.h>
528	# endif
529	# else
530	# include <math.h>
531	# endif
532	# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
533	/* Amiga SAS/C: We must include builtin FPU functions when compiling using
534	* MATH=68881
535	*/
536	# include <m68881.h>
537	# endif
538	#endif
539
540	/* This provides the non-ANSI (far) memory allocation routines. */
541	#if defined(__TURBOC__) && defined(__MSDOS__)
542	# include <mem.h>
543	# include <alloc.h>
544	#endif
545
546	#if defined(WIN32) \|\| defined(_Windows) \|\| defined(_WINDOWS) \|\| \
547	defined(_WIN32) \|\| defined(__WIN32__)
548	# ifdef VBOX
549	# include <iprt/win/windows.h> /* defines _WINDOWS_ macro */
550	# else
551	# include <windows.h> /* defines _WINDOWS_ macro */
552	# endif
553	#endif
554	#endif /* PNG_VERSION_INFO_ONLY */
555
556	/* Moved here around 1.5.0beta36 from pngconf.h */
557	/* Users may want to use these so they are not private. Any library
558	* functions that are passed far data must be model-independent.
559	*/
560
561	/* Memory model/platform independent fns */
562	#ifndef PNG_ABORT
563	# ifdef _WINDOWS_
564	# define PNG_ABORT() ExitProcess(0)
565	# else
566	# define PNG_ABORT() abort()
567	# endif
568	#endif
569
570	/* These macros may need to be architecture dependent. */
571	#define PNG_ALIGN_NONE 0 /* do not use data alignment */
572	#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
573	#ifdef offsetof
574	# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
575	#else
576	# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
577	#endif
578	#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
579
580	#ifndef PNG_ALIGN_TYPE
581	/* Default to using aligned access optimizations and requiring alignment to a
582	* multiple of the data type size. Override in a compiler specific fashion
583	* if necessary by inserting tests here:
584	*/
585	# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
586	#endif
587
588	#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
589	/* This is used because in some compiler implementations non-aligned
590	* structure members are supported, so the offsetof approach below fails.
591	* Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
592	* is good for performance. Do not do this unless you have tested the result
593	* and understand it.
594	*/
595	# define png_alignof(type) (sizeof (type))
596	#else
597	# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
598	# define png_alignof(type) offsetof(struct{char c; type t;}, t)
599	# else
600	# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
601	# define png_alignof(type) (1)
602	# endif
603	/* Else leave png_alignof undefined to prevent use thereof */
604	# endif
605	#endif
606
607	/* This implicitly assumes alignment is always to a power of 2. */
608	#ifdef png_alignof
609	# define png_isaligned(ptr, type)\
610	(((type)((const char)ptr-(const char)0) & \
611	(type)(png_alignof(type)-1)) == 0)
612	#else
613	# define png_isaligned(ptr, type) 0
614	#endif
615
616	/* End of memory model/platform independent support */
617	/* End of 1.5.0beta36 move from pngconf.h */
618
619	/* CONSTANTS and UTILITY MACROS
620	* These are used internally by libpng and not exposed in the API
621	*/
622
623	/* Various modes of operation. Note that after an init, mode is set to
624	* zero automatically when the structure is created. Three of these
625	* are defined in png.h because they need to be visible to applications
626	* that call png_set_unknown_chunk().
627	*/
628	/* #define PNG_HAVE_IHDR 0x01U (defined in png.h) */
629	/* #define PNG_HAVE_PLTE 0x02U (defined in png.h) */
630	#define PNG_HAVE_IDAT 0x04U
631	/* #define PNG_AFTER_IDAT 0x08U (defined in png.h) */
632	#define PNG_HAVE_IEND 0x10U
633	/* 0x20U (unused) */
634	/* 0x40U (unused) */
635	/* 0x80U (unused) */
636	#define PNG_HAVE_CHUNK_HEADER 0x100U
637	#define PNG_WROTE_tIME 0x200U
638	#define PNG_WROTE_INFO_BEFORE_PLTE 0x400U
639	#define PNG_BACKGROUND_IS_GRAY 0x800U
640	#define PNG_HAVE_PNG_SIGNATURE 0x1000U
641	#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
642	/* 0x4000U (unused) */
643	#define PNG_IS_READ_STRUCT 0x8000U /* Else is a write struct */
644
645	/* Flags for the transformations the PNG library does on the image data */
646	#define PNG_BGR 0x0001U
647	#define PNG_INTERLACE 0x0002U
648	#define PNG_PACK 0x0004U
649	#define PNG_SHIFT 0x0008U
650	#define PNG_SWAP_BYTES 0x0010U
651	#define PNG_INVERT_MONO 0x0020U
652	#define PNG_QUANTIZE 0x0040U
653	#define PNG_COMPOSE 0x0080U /* Was PNG_BACKGROUND */
654	#define PNG_BACKGROUND_EXPAND 0x0100U
655	#define PNG_EXPAND_16 0x0200U /* Added to libpng 1.5.2 */
656	#define PNG_16_TO_8 0x0400U /* Becomes 'chop' in 1.5.4 */
657	#define PNG_RGBA 0x0800U
658	#define PNG_EXPAND 0x1000U
659	#define PNG_GAMMA 0x2000U
660	#define PNG_GRAY_TO_RGB 0x4000U
661	#define PNG_FILLER 0x8000U
662	#define PNG_PACKSWAP 0x10000U
663	#define PNG_SWAP_ALPHA 0x20000U
664	#define PNG_STRIP_ALPHA 0x40000U
665	#define PNG_INVERT_ALPHA 0x80000U
666	#define PNG_USER_TRANSFORM 0x100000U
667	#define PNG_RGB_TO_GRAY_ERR 0x200000U
668	#define PNG_RGB_TO_GRAY_WARN 0x400000U
669	#define PNG_RGB_TO_GRAY 0x600000U /* two bits, RGB_TO_GRAY_ERR\|WARN */
670	#define PNG_ENCODE_ALPHA 0x800000U /* Added to libpng-1.5.4 */
671	#define PNG_ADD_ALPHA 0x1000000U /* Added to libpng-1.2.7 */
672	#define PNG_EXPAND_tRNS 0x2000000U /* Added to libpng-1.2.9 */
673	#define PNG_SCALE_16_TO_8 0x4000000U /* Added to libpng-1.5.4 */
674	/* 0x8000000U unused */
675	/* 0x10000000U unused */
676	/* 0x20000000U unused */
677	/* 0x40000000U unused */
678	/* Flags for png_create_struct */
679	#define PNG_STRUCT_PNG 0x0001U
680	#define PNG_STRUCT_INFO 0x0002U
681
682	/* Flags for the png_ptr->flags rather than declaring a byte for each one */
683	#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001U
684	#define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002U /* Added to libpng-1.6.0 */
685	/* 0x0004U unused */
686	#define PNG_FLAG_ZSTREAM_ENDED 0x0008U /* Added to libpng-1.6.0 */
687	/* 0x0010U unused */
688	/* 0x0020U unused */
689	#define PNG_FLAG_ROW_INIT 0x0040U
690	#define PNG_FLAG_FILLER_AFTER 0x0080U
691	#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100U
692	#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200U
693	#define PNG_FLAG_CRC_CRITICAL_USE 0x0400U
694	#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800U
695	#define PNG_FLAG_ASSUME_sRGB 0x1000U /* Added to libpng-1.5.4 */
696	#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000U /* Added to libpng-1.5.4 */
697	#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000U /* Added to libpng-1.5.4 */
698	/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000U */
699	/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000U */
700	#define PNG_FLAG_LIBRARY_MISMATCH 0x20000U
701	#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000U
702	#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000U
703	#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000U /* Added to libpng-1.4.0 */
704	#define PNG_FLAG_APP_WARNINGS_WARN 0x200000U /* Added to libpng-1.6.0 */
705	#define PNG_FLAG_APP_ERRORS_WARN 0x400000U /* Added to libpng-1.6.0 */
706	/* 0x800000U unused */
707	/* 0x1000000U unused */
708	/* 0x2000000U unused */
709	/* 0x4000000U unused */
710	/* 0x8000000U unused */
711	/* 0x10000000U unused */
712	/* 0x20000000U unused */
713	/* 0x40000000U unused */
714
715	#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE \| \
716	PNG_FLAG_CRC_ANCILLARY_NOWARN)
717
718	#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE \| \
719	PNG_FLAG_CRC_CRITICAL_IGNORE)
720
721	#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK \| \
722	PNG_FLAG_CRC_CRITICAL_MASK)
723
724	/* Save typing and make code easier to understand */
725
726	#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
727	abs((int)((c1).green) - (int)((c2).green)) + \
728	abs((int)((c1).blue) - (int)((c2).blue)))
729
730	/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
731	* by dividing by 257 with rounding. This macro is exact for the given range.
732	* See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
733	* macro were established by experiment (modifying the added value). The macro
734	* has a second variant that takes a value already scaled by 255 and divides by
735	* 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
736	* only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
737	*/
738	#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
739	#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
740
741	/* Added to libpng-1.2.6 JB */
742	#define PNG_ROWBYTES(pixel_bits, width) \
743	((pixel_bits) >= 8 ? \
744	((size_t)(width) * (((size_t)(pixel_bits)) >> 3)) : \
745	(( ((size_t)(width) * ((size_t)(pixel_bits))) + 7) >> 3) )
746
747	/* This returns the number of trailing bits in the last byte of a row, 0 if the
748	* last byte is completely full of pixels. It is, in principle, (pixel_bits x
749	* width) % 8, but that would overflow for large 'width'. The second macro is
750	* the same except that it returns the number of unused bits in the last byte;
751	* (8-TRAILBITS), but 0 when TRAILBITS is 0.
752	*
753	* NOTE: these macros are intended to be self-evidently correct and never
754	* overflow on the assumption that pixel_bits is in the range 0..255. The
755	* arguments are evaluated only once and they can be signed (e.g. as a result of
756	* the integral promotions). The result of the expression always has type
757	* (png_uint_32), however the compiler always knows it is in the range 0..7.
758	*/
759	#define PNG_TRAILBITS(pixel_bits, width) \
760	(((pixel_bits) * ((width) % (png_uint_32)8)) % 8)
761
762	#define PNG_PADBITS(pixel_bits, width) \
763	((8 - PNG_TRAILBITS(pixel_bits, width)) % 8)
764
765	/* PNG_OUT_OF_RANGE returns true if value is outside the range
766	* ideal-delta..ideal+delta. Each argument is evaluated twice.
767	* "ideal" and "delta" should be constants, normally simple
768	* integers, "value" a variable. Added to libpng-1.2.6 JB
769	*/
770	#define PNG_OUT_OF_RANGE(value, ideal, delta) \
771	( (value) < (ideal)-(delta) \|\| (value) > (ideal)+(delta) )
772
773	/* Conversions between fixed and floating point, only defined if
774	* required (to make sure the code doesn't accidentally use float
775	* when it is supposedly disabled.)
776	*/
777	#ifdef PNG_FLOATING_POINT_SUPPORTED
778	/* The floating point conversion can't overflow, though it can and
779	* does lose accuracy relative to the original fixed point value.
780	* In practice this doesn't matter because png_fixed_point only
781	* stores numbers with very low precision. The png_ptr and s
782	* arguments are unused by default but are there in case error
783	* checking becomes a requirement.
784	*/
785	#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
786
787	/* The fixed point conversion performs range checking and evaluates
788	* its argument multiple times, so must be used with care. The
789	* range checking uses the PNG specification values for a signed
790	* 32-bit fixed point value except that the values are deliberately
791	* rounded-to-zero to an integral value - 21474 (21474.83 is roughly
792	* (2^31-1) * 100000). 's' is a string that describes the value being
793	* converted.
794	*
795	* NOTE: this macro will raise a png_error if the range check fails,
796	* therefore it is normally only appropriate to use this on values
797	* that come from API calls or other sources where an out of range
798	* error indicates a programming error, not a data error!
799	*
800	* NOTE: by default this is off - the macro is not used - because the
801	* function call saves a lot of code.
802	*/
803	#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
804	#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
805	((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
806	#endif
807	/* else the corresponding function is defined below, inside the scope of the
808	* cplusplus test.
809	*/
810	#endif
811
812	/* Constants for known chunk types. If you need to add a chunk, define the name
813	* here. For historical reasons these constants have the form png_<name>; i.e.
814	* the prefix is lower case. Please use decimal values as the parameters to
815	* match the ISO PNG specification and to avoid relying on the C locale
816	* interpretation of character values.
817	*
818	* Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
819	* are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
820	* to be generated if required.
821	*
822	* PNG_32b correctly produces a value shifted by up to 24 bits, even on
823	* architectures where (int) is only 16 bits.
824	*/
825	#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
826	#define PNG_U32(b1,b2,b3,b4) \
827	(PNG_32b(b1,24) \| PNG_32b(b2,16) \| PNG_32b(b3,8) \| PNG_32b(b4,0))
828
829	/* Constants for known chunk types.
830	*
831	* MAINTAINERS: If you need to add a chunk, define the name here.
832	* For historical reasons these constants have the form png_<name>; i.e.
833	* the prefix is lower case. Please use decimal values as the parameters to
834	* match the ISO PNG specification and to avoid relying on the C locale
835	* interpretation of character values. Please keep the list sorted.
836	*
837	* Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
838	* type. In fact the specification does not express chunk types this way,
839	* however using a 32-bit value means that the chunk type can be read from the
840	* stream using exactly the same code as used for a 32-bit unsigned value and
841	* can be examined far more efficiently (using one arithmetic compare).
842	*
843	* Prior to 1.5.6 the chunk type constants were expressed as C strings. The
844	* libpng API still uses strings for 'unknown' chunks and a macro,
845	* PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice
846	* that for portable code numeric values must still be used; the string "IHDR"
847	* is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
848	*
849	* In 1.7.0 the definitions will be made public in png.h to avoid having to
850	* duplicate the same definitions in application code.
851	*/
852	#define png_IDAT PNG_U32( 73, 68, 65, 84)
853	#define png_IEND PNG_U32( 73, 69, 78, 68)
854	#define png_IHDR PNG_U32( 73, 72, 68, 82)
855	#define png_PLTE PNG_U32( 80, 76, 84, 69)
856	#define png_bKGD PNG_U32( 98, 75, 71, 68)
857	#define png_cHRM PNG_U32( 99, 72, 82, 77)
858	#define png_eXIf PNG_U32(101, 88, 73, 102) /* registered July 2017 */
859	#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */
860	#define png_gAMA PNG_U32(103, 65, 77, 65)
861	#define png_gIFg PNG_U32(103, 73, 70, 103)
862	#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */
863	#define png_gIFx PNG_U32(103, 73, 70, 120)
864	#define png_hIST PNG_U32(104, 73, 83, 84)
865	#define png_iCCP PNG_U32(105, 67, 67, 80)
866	#define png_iTXt PNG_U32(105, 84, 88, 116)
867	#define png_oFFs PNG_U32(111, 70, 70, 115)
868	#define png_pCAL PNG_U32(112, 67, 65, 76)
869	#define png_pHYs PNG_U32(112, 72, 89, 115)
870	#define png_sBIT PNG_U32(115, 66, 73, 84)
871	#define png_sCAL PNG_U32(115, 67, 65, 76)
872	#define png_sPLT PNG_U32(115, 80, 76, 84)
873	#define png_sRGB PNG_U32(115, 82, 71, 66)
874	#define png_sTER PNG_U32(115, 84, 69, 82)
875	#define png_tEXt PNG_U32(116, 69, 88, 116)
876	#define png_tIME PNG_U32(116, 73, 77, 69)
877	#define png_tRNS PNG_U32(116, 82, 78, 83)
878	#define png_zTXt PNG_U32(122, 84, 88, 116)
879
880	/* The following will work on (signed char*) strings, whereas the get_uint_32
881	* macro will fail on top-bit-set values because of the sign extension.
882	*/
883	#define PNG_CHUNK_FROM_STRING(s)\
884	PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
885
886	/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
887	* signed and the argument is a (char[]) This macro will fail miserably on
888	* systems where (char) is more than 8 bits.
889	*/
890	#define PNG_STRING_FROM_CHUNK(s,c)\
891	(void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
892	((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
893	((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
894	((char*)(s))[3]=(char)((c & 0xff)))
895
896	/* Do the same but terminate with a null character. */
897	#define PNG_CSTRING_FROM_CHUNK(s,c)\
898	(void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
899
900	/* Test on flag values as defined in the spec (section 5.4): */
901	#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29))
902	#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
903	#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
904	#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
905	#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
906
907	/* Gamma values (new at libpng-1.5.4): */
908	#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
909	#define PNG_GAMMA_MAC_INVERSE 65909
910	#define PNG_GAMMA_sRGB_INVERSE 45455
911
912	/* Almost everything below is C specific; the #defines above can be used in
913	* non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
914	*/
915	#ifndef PNG_VERSION_INFO_ONLY
916
917	#include "pngstruct.h"
918	#include "pnginfo.h"
919
920	/* Validate the include paths - the include path used to generate pnglibconf.h
921	* must match that used in the build, or we must be using pnglibconf.h.prebuilt:
922	*/
923	#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
924	# error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
925	"-I (include path) error: see the notes in pngpriv.h"
926	/* This means that when pnglibconf.h was built the copy of zlib.h that it
927	* used is not the same as the one being used here. Because the build of
928	* libpng makes decisions to use inflateInit2 and inflateReset2 based on the
929	* zlib version number and because this affects handling of certain broken
930	* PNG files the -I directives must match.
931	*
932	* The most likely explanation is that you passed a -I in CFLAGS. This will
933	* not work; all the preprocessor directives and in particular all the -I
934	* directives must be in CPPFLAGS.
935	*/
936	#endif
937
938	/* This is used for 16-bit gamma tables -- only the top level pointers are
939	* const; this could be changed:
940	*/
941	typedef const png_uint_16p * png_const_uint_16pp;
942
943	/* Added to libpng-1.5.7: sRGB conversion tables */
944	#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) \|\|\
945	defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
946	#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
947	PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
948	/* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
949	* 0..65535. This table gives the closest 16-bit answers (no errors).
950	*/
951	#endif
952
953	PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
954	PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
955
956	#define PNG_sRGB_FROM_LINEAR(linear) \
957	((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
958	+ ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
959	/* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
960	* encoded value with maximum error 0.646365. Note that the input is not a
961	* 16-bit value; it has been multiplied by 255! */
962	#endif /* SIMPLIFIED_READ/WRITE */
963
964
965	/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
966	#ifdef __cplusplus
967	extern "C" {
968	#endif /* __cplusplus */
969
970	/* Internal functions; these are not exported from a DLL however because they
971	* are used within several of the C source files they have to be C extern.
972	*
973	* All of these functions must be declared with PNG_INTERNAL_FUNCTION.
974	*/
975
976	/* Zlib support */
977	#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
978	PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
979	PNG_EMPTY);
980	/* Used by the zlib handling functions to ensure that z_stream::msg is always
981	* set before they return.
982	*/
983
984	#ifdef PNG_WRITE_SUPPORTED
985	PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
986	png_compression_bufferp *list),PNG_EMPTY);
987	/* Free the buffer list used by the compressed write code. */
988	#endif
989
990	#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
991	!defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
992	(defined(PNG_gAMA_SUPPORTED) \|\| defined(PNG_cHRM_SUPPORTED) \|\| \
993	defined(PNG_sCAL_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED) \|\| \
994	defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) \|\| \
995	(defined(PNG_sCAL_SUPPORTED) && \
996	defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
997	PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
998	double fp, png_const_charp text),PNG_EMPTY);
999	#endif
1000
1001	/* Check the user version string for compatibility, returns false if the version
1002	* numbers aren't compatible.
1003	*/
1004	PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
1005	png_const_charp user_png_ver),PNG_EMPTY);
1006
1007	/* Internal base allocator - no messages, NULL on failure to allocate. This
1008	* does, however, call the application provided allocator and that could call
1009	* png_error (although that would be a bug in the application implementation.)
1010	*/
1011	PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
1012	png_alloc_size_t size),PNG_ALLOCATED);
1013
1014	#if defined(PNG_TEXT_SUPPORTED) \|\| defined(PNG_sPLT_SUPPORTED) \|\|\
1015	defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
1016	/* Internal array allocator, outputs no error or warning messages on failure,
1017	* just returns NULL.
1018	*/
1019	PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
1020	int nelements, size_t element_size),PNG_ALLOCATED);
1021
1022	/* The same but an existing array is extended by add_elements. This function
1023	* also memsets the new elements to 0 and copies the old elements. The old
1024	* array is not freed or altered.
1025	*/
1026	PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
1027	png_const_voidp array, int old_elements, int add_elements,
1028	size_t element_size),PNG_ALLOCATED);
1029	#endif /* text, sPLT or unknown chunks */
1030
1031	/* Magic to create a struct when there is no struct to call the user supplied
1032	* memory allocators. Because error handling has not been set up the memory
1033	* handlers can't safely call png_error, but this is an obscure and undocumented
1034	* restriction so libpng has to assume that the 'free' handler, at least, might
1035	* call png_error.
1036	*/
1037	PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
1038	(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1039	png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
1040	png_free_ptr free_fn),PNG_ALLOCATED);
1041
1042	/* Free memory from internal libpng struct */
1043	PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
1044	PNG_EMPTY);
1045
1046	/* Free an allocated jmp_buf (always succeeds) */
1047	PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
1048
1049	/* Function to allocate memory for zlib. PNGAPI is disallowed. */
1050	PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
1051	PNG_ALLOCATED);
1052
1053	/* Function to free memory for zlib. PNGAPI is disallowed. */
1054	PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
1055
1056	/* Next four functions are used internally as callbacks. PNGCBAPI is required
1057	* but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
1058	* PNGCBAPI at 1.5.0
1059	*/
1060
1061	PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
1062	png_bytep data, size_t length),PNG_EMPTY);
1063
1064	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1065	PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
1066	png_bytep buffer, size_t length),PNG_EMPTY);
1067	#endif
1068
1069	PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
1070	png_bytep data, size_t length),PNG_EMPTY);
1071
1072	#ifdef PNG_WRITE_FLUSH_SUPPORTED
1073	# ifdef PNG_STDIO_SUPPORTED
1074	PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
1075	PNG_EMPTY);
1076	# endif
1077	#endif
1078
1079	/* Reset the CRC variable */
1080	PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
1081
1082	/* Write the "data" buffer to whatever output you are using */
1083	PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
1084	png_const_bytep data, size_t length),PNG_EMPTY);
1085
1086	/* Read and check the PNG file signature */
1087	PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
1088	png_inforp info_ptr),PNG_EMPTY);
1089
1090	/* Read the chunk header (length + type name) */
1091	PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
1092	PNG_EMPTY);
1093
1094	/* Read data from whatever input you are using into the "data" buffer */
1095	PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
1096	size_t length),PNG_EMPTY);
1097
1098	/* Read bytes into buf, and update png_ptr->crc */
1099	PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
1100	png_uint_32 length),PNG_EMPTY);
1101
1102	/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
1103	PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
1104	png_uint_32 skip),PNG_EMPTY);
1105
1106	/* Read the CRC from the file and compare it to the libpng calculated CRC */
1107	PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
1108
1109	/* Calculate the CRC over a section of data. Note that we are only
1110	* passing a maximum of 64K on systems that have this as a memory limit,
1111	* since this is the maximum buffer size we can specify.
1112	*/
1113	PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
1114	png_const_bytep ptr, size_t length),PNG_EMPTY);
1115
1116	#ifdef PNG_WRITE_FLUSH_SUPPORTED
1117	PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
1118	#endif
1119
1120	/* Write various chunks */
1121
1122	/* Write the IHDR chunk, and update the png_struct with the necessary
1123	* information.
1124	*/
1125	PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
1126	png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1127	int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
1128
1129	PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
1130	png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
1131
1132	PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
1133	png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
1134	PNG_EMPTY);
1135
1136	PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
1137
1138	#ifdef PNG_WRITE_gAMA_SUPPORTED
1139	PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
1140	png_fixed_point file_gamma),PNG_EMPTY);
1141	#endif
1142
1143	#ifdef PNG_WRITE_sBIT_SUPPORTED
1144	PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
1145	png_const_color_8p sbit, int color_type),PNG_EMPTY);
1146	#endif
1147
1148	#ifdef PNG_WRITE_cHRM_SUPPORTED
1149	PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
1150	const png_xy *xy), PNG_EMPTY);
1151	/* The xy value must have been previously validated */
1152	#endif
1153
1154	#ifdef PNG_WRITE_sRGB_SUPPORTED
1155	PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1156	int intent),PNG_EMPTY);
1157	#endif
1158
1159	#ifdef PNG_WRITE_eXIf_SUPPORTED
1160	PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr,
1161	png_bytep exif, int num_exif),PNG_EMPTY);
1162	#endif
1163
1164	#ifdef PNG_WRITE_iCCP_SUPPORTED
1165	PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1166	png_const_charp name, png_const_bytep profile), PNG_EMPTY);
1167	/* The profile must have been previously validated for correctness, the
1168	* length comes from the first four bytes. Only the base, deflate,
1169	* compression is supported.
1170	*/
1171	#endif
1172
1173	#ifdef PNG_WRITE_sPLT_SUPPORTED
1174	PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1175	png_const_sPLT_tp palette),PNG_EMPTY);
1176	#endif
1177
1178	#ifdef PNG_WRITE_tRNS_SUPPORTED
1179	PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1180	png_const_bytep trans, png_const_color_16p values, int number,
1181	int color_type),PNG_EMPTY);
1182	#endif
1183
1184	#ifdef PNG_WRITE_bKGD_SUPPORTED
1185	PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1186	png_const_color_16p values, int color_type),PNG_EMPTY);
1187	#endif
1188
1189	#ifdef PNG_WRITE_hIST_SUPPORTED
1190	PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1191	png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1192	#endif
1193
1194	/* Chunks that have keywords */
1195	#ifdef PNG_WRITE_tEXt_SUPPORTED
1196	PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1197	png_const_charp key, png_const_charp text, size_t text_len),PNG_EMPTY);
1198	#endif
1199
1200	#ifdef PNG_WRITE_zTXt_SUPPORTED
1201	PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1202	key, png_const_charp text, int compression),PNG_EMPTY);
1203	#endif
1204
1205	#ifdef PNG_WRITE_iTXt_SUPPORTED
1206	PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1207	int compression, png_const_charp key, png_const_charp lang,
1208	png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1209	#endif
1210
1211	#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
1212	PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1213	png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1214	#endif
1215
1216	#ifdef PNG_WRITE_oFFs_SUPPORTED
1217	PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1218	png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1219	#endif
1220
1221	#ifdef PNG_WRITE_pCAL_SUPPORTED
1222	PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1223	png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1224	png_const_charp units, png_charpp params),PNG_EMPTY);
1225	#endif
1226
1227	#ifdef PNG_WRITE_pHYs_SUPPORTED
1228	PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1229	png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1230	int unit_type),PNG_EMPTY);
1231	#endif
1232
1233	#ifdef PNG_WRITE_tIME_SUPPORTED
1234	PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1235	png_const_timep mod_time),PNG_EMPTY);
1236	#endif
1237
1238	#ifdef PNG_WRITE_sCAL_SUPPORTED
1239	PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1240	int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1241	#endif
1242
1243	/* Called when finished processing a row of data */
1244	PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1245	PNG_EMPTY);
1246
1247	/* Internal use only. Called before first row of data */
1248	PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1249	PNG_EMPTY);
1250
1251	/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
1252	* array of png_ptr->width pixels. If the image is not interlaced or this
1253	* is the final pass this just does a memcpy, otherwise the "display" flag
1254	* is used to determine whether to copy pixels that are not in the current pass.
1255	*
1256	* Because 'png_do_read_interlace' (below) replicates pixels this allows this
1257	* function to achieve the documented 'blocky' appearance during interlaced read
1258	* if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1259	* are not changed if they are not in the current pass, when display is 0.
1260	*
1261	* 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1262	*
1263	* The API always reads from the png_struct row buffer and always assumes that
1264	* it is full width (png_do_read_interlace has already been called.)
1265	*
1266	* This function is only ever used to write to row buffers provided by the
1267	* caller of the relevant libpng API and the row must have already been
1268	* transformed by the read transformations.
1269	*
1270	* The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1271	* bitmasks for use within the code, otherwise runtime generated masks are used.
1272	* The default is compile time masks.
1273	*/
1274	#ifndef PNG_USE_COMPILE_TIME_MASKS
1275	# define PNG_USE_COMPILE_TIME_MASKS 1
1276	#endif
1277	PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1278	png_bytep row, int display),PNG_EMPTY);
1279
1280	#ifdef PNG_READ_INTERLACING_SUPPORTED
1281	/* Expand an interlaced row: the 'row_info' describes the pass data that has
1282	* been read in and must correspond to the pixels in 'row', the pixels are
1283	* expanded (moved apart) in 'row' to match the final layout, when doing this
1284	* the pixels are replicated to the intervening space. This is essential for
1285	* the correct operation of png_combine_row, above.
1286	*/
1287	PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1288	png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1289	#endif
1290
1291	/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
1292
1293	#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1294	/* Grab pixels out of a row for an interlaced pass */
1295	PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1296	png_bytep row, int pass),PNG_EMPTY);
1297	#endif
1298
1299	/* Unfilter a row: check the filter value before calling this, there is no point
1300	* calling it for PNG_FILTER_VALUE_NONE.
1301	*/
1302	PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1303	row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1304
1305	#if PNG_ARM_NEON_OPT > 0
1306	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1307	png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1308	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1309	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1310	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1311	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1312	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1313	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1314	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1315	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1316	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1317	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1318	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1319	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1320	#endif
1321
1322	#if PNG_MIPS_MSA_OPT > 0
1323	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_msa,(png_row_infop row_info,
1324	png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1325	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_msa,(png_row_infop
1326	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1327	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_msa,(png_row_infop
1328	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1329	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_msa,(png_row_infop
1330	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1331	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop
1332	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1333	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop
1334	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1335	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop
1336	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1337	#endif
1338
1339	#if PNG_POWERPC_VSX_OPT > 0
1340	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_vsx,(png_row_infop row_info,
1341	png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1342	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_vsx,(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_sub4_vsx,(png_row_infop
1345	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1346	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_vsx,(png_row_infop
1347	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1348	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_vsx,(png_row_infop
1349	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1350	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_vsx,(png_row_infop
1351	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1352	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_vsx,(png_row_infop
1353	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1354	#endif
1355
1356	#if PNG_INTEL_SSE_IMPLEMENTATION > 0
1357	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(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_sub4_sse2,(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_avg3_sse2,(png_row_infop
1362	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1363	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
1364	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1365	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
1366	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1367	PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
1368	row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1369	#endif
1370
1371	/* Choose the best filter to use and filter the row data */
1372	PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1373	png_row_infop row_info),PNG_EMPTY);
1374
1375	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1376	PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1377	png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1378	/* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
1379	* is NULL the function checks, instead, for the end of the stream. In this
1380	* case a benign error will be issued if the stream end is not found or if
1381	* extra data has to be consumed.
1382	*/
1383	PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1384	PNG_EMPTY);
1385	/* This cleans up when the IDAT LZ stream does not end when the last image
1386	* byte is read; there is still some pending input.
1387	*/
1388
1389	PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1390	PNG_EMPTY);
1391	/* Finish a row while reading, dealing with interlacing passes, etc. */
1392	#endif /* SEQUENTIAL_READ */
1393
1394	/* Initialize the row buffers, etc. */
1395	PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1396
1397	#if ZLIB_VERNUM >= 0x1240
1398	PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
1399	PNG_EMPTY);
1400	# define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
1401	#else /* Zlib < 1.2.4 */
1402	# define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
1403	#endif /* Zlib < 1.2.4 */
1404
1405	#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1406	/* Optional call to update the users info structure */
1407	PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1408	png_inforp info_ptr),PNG_EMPTY);
1409	#endif
1410
1411	/* Shared transform functions, defined in pngtran.c */
1412	#if defined(PNG_WRITE_FILLER_SUPPORTED) \|\| \
1413	defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1414	PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1415	png_bytep row, int at_start),PNG_EMPTY);
1416	#endif
1417
1418	#ifdef PNG_16BIT_SUPPORTED
1419	#if defined(PNG_READ_SWAP_SUPPORTED) \|\| defined(PNG_WRITE_SWAP_SUPPORTED)
1420	PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1421	png_bytep row),PNG_EMPTY);
1422	#endif
1423	#endif
1424
1425	#if defined(PNG_READ_PACKSWAP_SUPPORTED) \|\| \
1426	defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1427	PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1428	png_bytep row),PNG_EMPTY);
1429	#endif
1430
1431	#if defined(PNG_READ_INVERT_SUPPORTED) \|\| defined(PNG_WRITE_INVERT_SUPPORTED)
1432	PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1433	png_bytep row),PNG_EMPTY);
1434	#endif
1435
1436	#if defined(PNG_READ_BGR_SUPPORTED) \|\| defined(PNG_WRITE_BGR_SUPPORTED)
1437	PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1438	png_bytep row),PNG_EMPTY);
1439	#endif
1440
1441	/* The following decodes the appropriate chunks, and does error correction,
1442	* then calls the appropriate callback for the chunk if it is valid.
1443	*/
1444
1445	/* Decode the IHDR chunk */
1446	PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1447	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1448	PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1449	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1450	PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1451	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1452
1453	#ifdef PNG_READ_bKGD_SUPPORTED
1454	PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1455	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1456	#endif
1457
1458	#ifdef PNG_READ_cHRM_SUPPORTED
1459	PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1460	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1461	#endif
1462
1463	#ifdef PNG_READ_eXIf_SUPPORTED
1464	PNG_INTERNAL_FUNCTION(void,png_handle_eXIf,(png_structrp png_ptr,
1465	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1466	#endif
1467
1468	#ifdef PNG_READ_gAMA_SUPPORTED
1469	PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1470	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1471	#endif
1472
1473	#ifdef PNG_READ_hIST_SUPPORTED
1474	PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1475	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1476	#endif
1477
1478	#ifdef PNG_READ_iCCP_SUPPORTED
1479	PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1480	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1481	#endif /* READ_iCCP */
1482
1483	#ifdef PNG_READ_iTXt_SUPPORTED
1484	PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1485	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1486	#endif
1487
1488	#ifdef PNG_READ_oFFs_SUPPORTED
1489	PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1490	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1491	#endif
1492
1493	#ifdef PNG_READ_pCAL_SUPPORTED
1494	PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1495	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1496	#endif
1497
1498	#ifdef PNG_READ_pHYs_SUPPORTED
1499	PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1500	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1501	#endif
1502
1503	#ifdef PNG_READ_sBIT_SUPPORTED
1504	PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1505	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1506	#endif
1507
1508	#ifdef PNG_READ_sCAL_SUPPORTED
1509	PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1510	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1511	#endif
1512
1513	#ifdef PNG_READ_sPLT_SUPPORTED
1514	PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1515	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1516	#endif /* READ_sPLT */
1517
1518	#ifdef PNG_READ_sRGB_SUPPORTED
1519	PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1520	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1521	#endif
1522
1523	#ifdef PNG_READ_tEXt_SUPPORTED
1524	PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1525	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1526	#endif
1527
1528	#ifdef PNG_READ_tIME_SUPPORTED
1529	PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1530	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1531	#endif
1532
1533	#ifdef PNG_READ_tRNS_SUPPORTED
1534	PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1535	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1536	#endif
1537
1538	#ifdef PNG_READ_zTXt_SUPPORTED
1539	PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1540	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1541	#endif
1542
1543	PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_const_structrp png_ptr,
1544	png_uint_32 chunk_name),PNG_EMPTY);
1545
1546	PNG_INTERNAL_FUNCTION(void,png_check_chunk_length,(png_const_structrp png_ptr,
1547	png_uint_32 chunk_length),PNG_EMPTY);
1548
1549	PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1550	png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1551	/* This is the function that gets called for unknown chunks. The 'keep'
1552	* argument is either non-zero for a known chunk that has been set to be
1553	* handled as unknown or zero for an unknown chunk. By default the function
1554	* just skips the chunk or errors out if it is critical.
1555	*/
1556
1557	#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) \|\|\
1558	defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1559	PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1560	(png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1561	/* Exactly as the API png_handle_as_unknown() except that the argument is a
1562	* 32-bit chunk name, not a string.
1563	*/
1564	#endif /* READ_UNKNOWN_CHUNKS \|\| HANDLE_AS_UNKNOWN */
1565
1566	/* Handle the transformations for reading and writing */
1567	#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1568	PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1569	png_row_infop row_info),PNG_EMPTY);
1570	#endif
1571	#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1572	PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1573	png_row_infop row_info),PNG_EMPTY);
1574	#endif
1575
1576	#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1577	PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1578	PNG_EMPTY);
1579	#endif
1580
1581	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1582	PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1583	png_inforp info_ptr),PNG_EMPTY);
1584	PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1585	png_inforp info_ptr),PNG_EMPTY);
1586	PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1587	PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1588	PNG_EMPTY);
1589	PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1590	png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1591	PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1592	PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1593	png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1594	PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1595	PNG_EMPTY);
1596	PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1597	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1598	PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1599	png_inforp info_ptr),PNG_EMPTY);
1600	PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1601	png_inforp info_ptr),PNG_EMPTY);
1602	PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1603	png_bytep row),PNG_EMPTY);
1604	PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1605	png_inforp info_ptr),PNG_EMPTY);
1606	PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1607	png_inforp info_ptr),PNG_EMPTY);
1608	PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1609	PNG_EMPTY);
1610	# ifdef PNG_READ_tEXt_SUPPORTED
1611	PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1612	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1613	PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1614	png_inforp info_ptr),PNG_EMPTY);
1615	# endif
1616	# ifdef PNG_READ_zTXt_SUPPORTED
1617	PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1618	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1619	PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1620	png_inforp info_ptr),PNG_EMPTY);
1621	# endif
1622	# ifdef PNG_READ_iTXt_SUPPORTED
1623	PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1624	png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1625	PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1626	png_inforp info_ptr),PNG_EMPTY);
1627	# endif
1628
1629	#endif /* PROGRESSIVE_READ */
1630
1631	/* Added at libpng version 1.6.0 */
1632	#ifdef PNG_GAMMA_SUPPORTED
1633	PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1634	png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1635	/* Set the colorspace gamma with a value provided by the application or by
1636	* the gAMA chunk on read. The value will override anything set by an ICC
1637	* profile.
1638	*/
1639
1640	PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1641	png_inforp info_ptr), PNG_EMPTY);
1642	/* Synchronize the info 'valid' flags with the colorspace */
1643
1644	PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1645	png_inforp info_ptr), PNG_EMPTY);
1646	/* Copy the png_struct colorspace to the info_struct and call the above to
1647	* synchronize the flags. Checks for NULL info_ptr and does nothing.
1648	*/
1649	#endif
1650
1651	/* Added at libpng version 1.4.0 */
1652	#ifdef PNG_COLORSPACE_SUPPORTED
1653	/* These internal functions are for maintaining the colorspace structure within
1654	* a png_info or png_struct (or, indeed, both).
1655	*/
1656	PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1657	(png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1658	int preferred), PNG_EMPTY);
1659
1660	PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1661	(png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1662	int preferred), PNG_EMPTY);
1663
1664	#ifdef PNG_sRGB_SUPPORTED
1665	PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1666	png_colorspacerp colorspace, int intent), PNG_EMPTY);
1667	/* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1668	* flags to write them, if it returns false there was a problem and an error
1669	* message has already been output (but the colorspace may still need to be
1670	* synced to record the invalid flag).
1671	*/
1672	#endif /* sRGB */
1673
1674	#ifdef PNG_iCCP_SUPPORTED
1675	PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1676	png_colorspacerp colorspace, png_const_charp name,
1677	png_uint_32 profile_length, png_const_bytep profile, int color_type),
1678	PNG_EMPTY);
1679	/* The 'name' is used for information only */
1680
1681	/* Routines for checking parts of an ICC profile. */
1682	#ifdef PNG_READ_iCCP_SUPPORTED
1683	PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1684	png_colorspacerp colorspace, png_const_charp name,
1685	png_uint_32 profile_length), PNG_EMPTY);
1686	#endif /* READ_iCCP */
1687	PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1688	png_colorspacerp colorspace, png_const_charp name,
1689	png_uint_32 profile_length,
1690	png_const_bytep profile /* first 132 bytes only */, int color_type),
1691	PNG_EMPTY);
1692	PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1693	png_colorspacerp colorspace, png_const_charp name,
1694	png_uint_32 profile_length,
1695	png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1696	#ifdef PNG_sRGB_SUPPORTED
1697	PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1698	png_const_structrp png_ptr, png_colorspacerp colorspace,
1699	png_const_bytep profile, uLong adler), PNG_EMPTY);
1700	/* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1701	* be zero to indicate that it is not available. It is used, if provided,
1702	* as a fast check on the profile when checking to see if it is sRGB.
1703	*/
1704	#endif
1705	#endif /* iCCP */
1706
1707	#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1708	PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1709	(png_structrp png_ptr), PNG_EMPTY);
1710	/* Set the rgb_to_gray coefficients from the colorspace Y values */
1711	#endif /* READ_RGB_TO_GRAY */
1712	#endif /* COLORSPACE */
1713
1714	/* Added at libpng version 1.4.0 */
1715	PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1716	png_uint_32 width, png_uint_32 height, int bit_depth,
1717	int color_type, int interlace_type, int compression_type,
1718	int filter_type),PNG_EMPTY);
1719
1720	/* Added at libpng version 1.5.10 */
1721	#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) \|\| \
1722	defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1723	PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1724	(png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1725	#endif
1726
1727	#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1728	PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1729	png_const_charp name),PNG_NORETURN);
1730	#endif
1731
1732	/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1733	* the end. Always leaves the buffer nul terminated. Never errors out (and
1734	* there is no error code.)
1735	*/
1736	PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1737	size_t pos, png_const_charp string),PNG_EMPTY);
1738
1739	/* Various internal functions to handle formatted warning messages, currently
1740	* only implemented for warnings.
1741	*/
1742	#if defined(PNG_WARNINGS_SUPPORTED) \|\| defined(PNG_TIME_RFC1123_SUPPORTED)
1743	/* Utility to dump an unsigned value into a buffer, given a start pointer and
1744	* and end pointer (which should point just beyond the end of the buffer!)
1745	* Returns the pointer to the start of the formatted string. This utility only
1746	* does unsigned values.
1747	*/
1748	PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1749	png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1750
1751	/* Convenience macro that takes an array: */
1752	#define PNG_FORMAT_NUMBER(buffer,format,number) \
1753	png_format_number(buffer, buffer + (sizeof buffer), format, number)
1754
1755	/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1756	#define PNG_NUMBER_BUFFER_SIZE 24
1757
1758	/* These are the integer formats currently supported, the name is formed from
1759	* the standard printf(3) format string.
1760	*/
1761	#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
1762	#define PNG_NUMBER_FORMAT_02u 2
1763	#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
1764	#define PNG_NUMBER_FORMAT_02d 2
1765	#define PNG_NUMBER_FORMAT_x 3
1766	#define PNG_NUMBER_FORMAT_02x 4
1767	#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1768	#endif
1769
1770	#ifdef PNG_WARNINGS_SUPPORTED
1771	/* New defines and members adding in libpng-1.5.4 */
1772	# define PNG_WARNING_PARAMETER_SIZE 32
1773	# define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1774
1775	/* An l-value of this type has to be passed to the APIs below to cache the
1776	* values of the parameters to a formatted warning message.
1777	*/
1778	typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1779	PNG_WARNING_PARAMETER_SIZE];
1780
1781	PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1782	int number, png_const_charp string),PNG_EMPTY);
1783	/* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1784	* including the trailing '\0'.
1785	*/
1786	PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1787	(png_warning_parameters p, int number, int format, png_alloc_size_t value),
1788	PNG_EMPTY);
1789	/* Use png_alloc_size_t because it is an unsigned type as big as any we
1790	* need to output. Use the following for a signed value.
1791	*/
1792	PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1793	(png_warning_parameters p, int number, int format, png_int_32 value),
1794	PNG_EMPTY);
1795
1796	PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1797	png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1798	/* 'message' follows the X/Open approach of using @1, @2 to insert
1799	* parameters previously supplied using the above functions. Errors in
1800	* specifying the parameters will simply result in garbage substitutions.
1801	*/
1802	#endif
1803
1804	#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1805	/* Application errors (new in 1.6); use these functions (declared below) for
1806	* errors in the parameters or order of API function calls on read. The
1807	* 'warning' should be used for an error that can be handled completely; the
1808	* 'error' for one which can be handled safely but which may lose application
1809	* information or settings.
1810	*
1811	* By default these both result in a png_error call prior to release, while in a
1812	* released version the 'warning' is just a warning. However if the application
1813	* explicitly disables benign errors (explicitly permitting the code to lose
1814	* information) they both turn into warnings.
1815	*
1816	* If benign errors aren't supported they end up as the corresponding base call
1817	* (png_warning or png_error.)
1818	*/
1819	PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1820	png_const_charp message),PNG_EMPTY);
1821	/* The application provided invalid parameters to an API function or called
1822	* an API function at the wrong time, libpng can completely recover.
1823	*/
1824
1825	PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1826	png_const_charp message),PNG_EMPTY);
1827	/* As above but libpng will ignore the call, or attempt some other partial
1828	* recovery from the error.
1829	*/
1830	#else
1831	# define png_app_warning(pp,s) png_warning(pp,s)
1832	# define png_app_error(pp,s) png_error(pp,s)
1833	#endif
1834
1835	PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1836	png_const_charp message, int error),PNG_EMPTY);
1837	/* Report a recoverable issue in chunk data. On read this is used to report
1838	* a problem found while reading a particular chunk and the
1839	* png_chunk_benign_error or png_chunk_warning function is used as
1840	* appropriate. On write this is used to report an error that comes from
1841	* data set via an application call to a png_set_ API and png_app_error or
1842	* png_app_warning is used as appropriate.
1843	*
1844	* The 'error' parameter must have one of the following values:
1845	*/
1846	#define PNG_CHUNK_WARNING 0 /* never an error */
1847	#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1848	#define PNG_CHUNK_ERROR 2 /* always an error */
1849
1850	/* ASCII to FP interfaces, currently only implemented if sCAL
1851	* support is required.
1852	*/
1853	#if defined(PNG_sCAL_SUPPORTED)
1854	/* MAX_DIGITS is actually the maximum number of characters in an sCAL
1855	* width or height, derived from the precision (number of significant
1856	* digits - a build time settable option) and assumptions about the
1857	* maximum ridiculous exponent.
1858	*/
1859	#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/./+1/E/+10/exponent/)
1860
1861	#ifdef PNG_FLOATING_POINT_SUPPORTED
1862	PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1863	png_charp ascii, size_t size, double fp, unsigned int precision),
1864	PNG_EMPTY);
1865	#endif /* FLOATING_POINT */
1866
1867	#ifdef PNG_FIXED_POINT_SUPPORTED
1868	PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1869	png_charp ascii, size_t size, png_fixed_point fp),PNG_EMPTY);
1870	#endif /* FIXED_POINT */
1871	#endif /* sCAL */
1872
1873	#if defined(PNG_sCAL_SUPPORTED) \|\| defined(PNG_pCAL_SUPPORTED)
1874	/* An internal API to validate the format of a floating point number.
1875	* The result is the index of the next character. If the number is
1876	* not valid it will be the index of a character in the supposed number.
1877	*
1878	* The format of a number is defined in the PNG extensions specification
1879	* and this API is strictly conformant to that spec, not anyone elses!
1880	*
1881	* The format as a regular expression is:
1882	*
1883	* [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1884	*
1885	* or:
1886	*
1887	* [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1888	*
1889	* The complexity is that either integer or fraction must be present and the
1890	* fraction is permitted to have no digits only if the integer is present.
1891	*
1892	* NOTE: The dangling E problem.
1893	* There is a PNG valid floating point number in the following:
1894	*
1895	* PNG floating point numbers are not greedy.
1896	*
1897	* Working this out requires TWO character lookahead (because of the
1898	* sign), the parser does not do this - it will fail at the 'r' - this
1899	* doesn't matter for PNG sCAL chunk values, but it requires more care
1900	* if the value were ever to be embedded in something more complex. Use
1901	* ANSI-C strtod if you need the lookahead.
1902	*/
1903	/* State table for the parser. */
1904	#define PNG_FP_INTEGER 0 /* before or in integer */
1905	#define PNG_FP_FRACTION 1 /* before or in fraction */
1906	#define PNG_FP_EXPONENT 2 /* before or in exponent */
1907	#define PNG_FP_STATE 3 /* mask for the above */
1908	#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
1909	#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
1910	#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
1911	#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
1912	#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
1913
1914	/* These three values don't affect the parser. They are set but not used.
1915	*/
1916	#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
1917	#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
1918	#define PNG_FP_NONZERO 256 /* A non-zero value */
1919	#define PNG_FP_STICKY 448 /* The above three flags */
1920
1921	/* This is available for the caller to store in 'state' if required. Do not
1922	* call the parser after setting it (the parser sometimes clears it.)
1923	*/
1924	#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
1925
1926	/* Result codes for the parser (boolean - true meants ok, false means
1927	* not ok yet.)
1928	*/
1929	#define PNG_FP_MAYBE 0 /* The number may be valid in the future */
1930	#define PNG_FP_OK 1 /* The number is valid */
1931
1932	/* Tests on the sticky non-zero and negative flags. To pass these checks
1933	* the state must also indicate that the whole number is valid - this is
1934	* achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1935	* is equivalent to PNG_FP_OK above.)
1936	*/
1937	#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT \| PNG_FP_NEGATIVE \| PNG_FP_NONZERO)
1938	/* NZ_MASK: the string is valid and a non-zero negative value */
1939	#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT \| PNG_FP_NONZERO)
1940	/* Z MASK: the string is valid and a non-zero value. */
1941	/* PNG_FP_SAW_DIGIT: the string is valid. */
1942	#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1943	#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1944	#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1945
1946	/* The actual parser. This can be called repeatedly. It updates
1947	* the index into the string and the state variable (which must
1948	* be initialized to 0). It returns a result code, as above. There
1949	* is no point calling the parser any more if it fails to advance to
1950	* the end of the string - it is stuck on an invalid character (or
1951	* terminated by '\0').
1952	*
1953	* Note that the pointer will consume an E or even an E+ and then leave
1954	* a 'maybe' state even though a preceding integer.fraction is valid.
1955	* The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1956	* a valid number. It's possible to recover from this by calling
1957	* the parser again (from the start, with state 0) but with a string
1958	* that omits the last character (i.e. set the size to the index of
1959	* the problem character.) This has not been tested within libpng.
1960	*/
1961	PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
1962	size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
1963
1964	/* This is the same but it checks a complete string and returns true
1965	* only if it just contains a floating point number. As of 1.5.4 this
1966	* function also returns the state at the end of parsing the number if
1967	* it was valid (otherwise it returns 0.) This can be used for testing
1968	* for negative or zero values using the sticky flag.
1969	*/
1970	PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
1971	size_t size),PNG_EMPTY);
1972	#endif /* pCAL \|\| sCAL */
1973
1974	#if defined(PNG_GAMMA_SUPPORTED) \|\|\
1975	defined(PNG_INCH_CONVERSIONS_SUPPORTED) \|\| defined(PNG_READ_pHYs_SUPPORTED)
1976	/* Added at libpng version 1.5.0 */
1977	/* This is a utility to provide a*times/div (rounded) and indicate
1978	* if there is an overflow. The result is a boolean - false (0)
1979	* for overflow, true (1) if no overflow, in which case *res
1980	* holds the result.
1981	*/
1982	PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
1983	png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
1984	#endif
1985
1986	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1987	/* Same deal, but issue a warning on overflow and return 0. */
1988	PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
1989	(png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
1990	png_int_32 divided_by),PNG_EMPTY);
1991	#endif
1992
1993	#ifdef PNG_GAMMA_SUPPORTED
1994	/* Calculate a reciprocal - used for gamma values. This returns
1995	* 0 if the argument is 0 in order to maintain an undefined value;
1996	* there are no warnings.
1997	*/
1998	PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
1999	PNG_EMPTY);
2000
2001	#ifdef PNG_READ_GAMMA_SUPPORTED
2002	/* The same but gives a reciprocal of the product of two fixed point
2003	* values. Accuracy is suitable for gamma calculations but this is
2004	* not exact - use png_muldiv for that. Only required at present on read.
2005	*/
2006	PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
2007	png_fixed_point b),PNG_EMPTY);
2008	#endif
2009
2010	/* Return true if the gamma value is significantly different from 1.0 */
2011	PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
2012	PNG_EMPTY);
2013	#endif
2014
2015	#ifdef PNG_READ_GAMMA_SUPPORTED
2016	/* Internal fixed point gamma correction. These APIs are called as
2017	* required to convert single values - they don't need to be fast,
2018	* they are not used when processing image pixel values.
2019	*
2020	* While the input is an 'unsigned' value it must actually be the
2021	* correct bit value - 0..255 or 0..65535 as required.
2022	*/
2023	PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
2024	unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
2025	PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
2026	png_fixed_point gamma_value),PNG_EMPTY);
2027	PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
2028	png_fixed_point gamma_value),PNG_EMPTY);
2029	PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
2030	PNG_EMPTY);
2031	PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
2032	int bit_depth),PNG_EMPTY);
2033	#endif
2034
2035	/* SIMPLIFIED READ/WRITE SUPPORT */
2036	#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) \|\|\
2037	defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2038	/* The internal structure that png_image::opaque points to. */
2039	typedef struct png_control
2040	{
2041	png_structp png_ptr;
2042	png_infop info_ptr;
2043	png_voidp error_buf; /* Always a jmp_buf at present. */
2044
2045	png_const_bytep memory; /* Memory buffer. */
2046	size_t size; /* Size of the memory buffer. */
2047
2048	unsigned int for_write :1; /* Otherwise it is a read structure */
2049	unsigned int owned_file :1; /* We own the file in io_ptr */
2050	} png_control;
2051
2052	/* Return the pointer to the jmp_buf from a png_control: necessary because C
2053	* does not reveal the type of the elements of jmp_buf.
2054	*/
2055	#ifdef __cplusplus
2056	# define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
2057	#else
2058	# define png_control_jmp_buf(pc) ((pc)->error_buf)
2059	#endif
2060
2061	/* Utility to safely execute a piece of libpng code catching and logging any
2062	* errors that might occur. Returns true on success, false on failure (either
2063	* of the function or as a result of a png_error.)
2064	*/
2065	PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
2066	png_const_charp error_message),PNG_NORETURN);
2067
2068	#ifdef PNG_WARNINGS_SUPPORTED
2069	PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
2070	png_const_charp warning_message),PNG_EMPTY);
2071	#else
2072	# define png_safe_warning 0/dummy argument/
2073	#endif
2074
2075	PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
2076	int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
2077
2078	/* Utility to log an error; this also cleans up the png_image; the function
2079	* always returns 0 (false).
2080	*/
2081	PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
2082	png_const_charp error_message),PNG_EMPTY);
2083
2084	#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
2085	/* png_image_free is used by the write code but not exported */
2086	PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
2087	#endif /* !SIMPLIFIED_READ */
2088
2089	#endif /* SIMPLIFIED READ/WRITE */
2090
2091	/* These are initialization functions for hardware specific PNG filter
2092	* optimizations; list these here then select the appropriate one at compile
2093	* time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined
2094	* the generic code is used.
2095	*/
2096	#ifdef PNG_FILTER_OPTIMIZATIONS
2097	PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
2098	unsigned int bpp), PNG_EMPTY);
2099	/* Just declare the optimization that will be used */
2100	#else
2101	/* List all the possible optimizations here - this branch is required if
2102	* the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
2103	* CFLAGS in place of CPPFLAGS and uses symbol prefixing.
2104	*/
2105	# if PNG_ARM_NEON_OPT > 0
2106	PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
2107	(png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2108	#endif
2109
2110	#if PNG_MIPS_MSA_OPT > 0
2111	PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_msa,
2112	(png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2113	#endif
2114
2115	# if PNG_INTEL_SSE_IMPLEMENTATION > 0
2116	PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
2117	(png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2118	# endif
2119	#endif
2120
2121	PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
2122	png_const_charp key, png_bytep new_key), PNG_EMPTY);
2123
2124	#if PNG_ARM_NEON_IMPLEMENTATION == 1
2125	PNG_INTERNAL_FUNCTION(void,
2126	png_riffle_palette_rgba,
2127	(png_structrp, png_row_infop),
2128	PNG_EMPTY);
2129	PNG_INTERNAL_FUNCTION(int,
2130	png_do_expand_palette_neon_rgba,
2131	(png_structrp,
2132	png_row_infop,
2133	png_const_bytep,
2134	const png_bytepp,
2135	const png_bytepp),
2136	PNG_EMPTY);
2137	PNG_INTERNAL_FUNCTION(int,
2138	png_do_expand_palette_neon_rgb,
2139	(png_structrp,
2140	png_row_infop,
2141	png_const_bytep,
2142	const png_bytepp,
2143	const png_bytepp),
2144	PNG_EMPTY);
2145	#endif
2146
2147	/* Maintainer: Put new private prototypes here ^ */
2148
2149	#include "pngdebug.h"
2150
2151	#ifdef __cplusplus
2152	}
2153	#endif
2154
2155	#endif /* PNG_VERSION_INFO_ONLY */
2156	#endif /* PNGPRIV_H */

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