1
2/* pngpriv.h - private declarations for use inside libpng
3 *
4 * Last changed in libpng 1.6.22 [(PENDING RELEASE)]
5 * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 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#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
39
40#ifndef PNG_VERSION_INFO_ONLY
41/* Standard library headers not required by png.h: */
42# include <stdlib.h>
43# include <string.h>
44#endif
45
46#define PNGLIB_BUILD /*libpng is being built, not used*/
47
48/* If HAVE_CONFIG_H is defined during the build then the build system must
49 * provide an appropriate "config.h" file on the include path. The header file
50 * must provide definitions as required below (search for "HAVE_CONFIG_H");
51 * see configure.ac for more details of the requirements. The macro
52 * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
53 * 'configure'; define this macro to prevent the configure build including the
54 * configure generated config.h. Libpng is expected to compile without *any*
55 * special build system support on a reasonably ANSI-C compliant system.
56 */
57#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
58# include <config.h>
59
60 /* Pick up the definition of 'restrict' from config.h if it was read: */
61# define PNG_RESTRICT restrict
62#endif
63
64/* To support symbol prefixing it is necessary to know *before* including png.h
65 * whether the fixed point (and maybe other) APIs are exported, because if they
66 * are not internal definitions may be required. This is handled below just
67 * before png.h is included, but load the configuration now if it is available.
68 */
69#ifndef PNGLCONF_H
70# include "pnglibconf.h"
71#endif
72
73/* Local renames may change non-exported API functions from png.h */
74#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
75# include "pngprefix.h"
76#endif
77
78#ifdef PNG_USER_CONFIG
79# include "pngusr.h"
80 /* These should have been defined in pngusr.h */
81# ifndef PNG_USER_PRIVATEBUILD
82# define PNG_USER_PRIVATEBUILD "Custom libpng build"
83# endif
84# ifndef PNG_USER_DLLFNAME_POSTFIX
85# define PNG_USER_DLLFNAME_POSTFIX "Cb"
86# endif
87#endif
88
89/* Compile time options.
90 * =====================
91 * In a multi-arch build the compiler may compile the code several times for the
92 * same object module, producing different binaries for different architectures.
93 * When this happens configure-time setting of the target host options cannot be
94 * done and this interferes with the handling of the ARM NEON optimizations, and
95 * possibly other similar optimizations. Put additional tests here; in general
96 * this is needed when the same option can be changed at both compile time and
97 * run time depending on the target OS (i.e. iOS vs Android.)
98 *
99 * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
100 * this is not possible with certain compilers (Oracle SUN OS CC), as a result
101 * it is necessary to ensure that all extern functions that *might* be used
102 * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__
103 * below is one example of this behavior because it is controlled by the
104 * presence or not of -mfpu=neon on the GCC command line, it is possible to do
105 * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
106 * do this.
107 */
108#ifndef PNG_ARM_NEON_OPT
109 /* ARM NEON optimizations are being controlled by the compiler settings,
110 * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon
111 * with GCC) then the compiler will define __ARM_NEON__ and we can rely
112 * unconditionally on NEON instructions not crashing, otherwise we must
113 * disable use of NEON instructions.
114 *
115 * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
116 * can only be turned on automatically if that is supported too. If
117 * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
118 * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
119 * off.
120 *
121 * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated
122 * __ARM_NEON__, so we check both variants.
123 *
124 * To disable ARM_NEON optimizations entirely, and skip compiling the
125 * associated assembler code, pass --enable-arm-neon=no to configure
126 * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS.
127 */
128# if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
129 defined(PNG_ALIGNED_MEMORY_SUPPORTED)
130# define PNG_ARM_NEON_OPT 2
131# else
132# define PNG_ARM_NEON_OPT 0
133# endif
134#endif
135
136#if PNG_ARM_NEON_OPT > 0
137 /* NEON optimizations are to be at least considered by libpng, so enable the
138 * callbacks to do this.
139 */
140# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
141
142 /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
143 * if possible - if __ARM_NEON__ is set and the compiler version is not known
144 * to be broken. This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
145 * be:
146 *
147 * 1 The intrinsics code (the default with __ARM_NEON__)
148 * 2 The hand coded assembler (the default without __ARM_NEON__)
149 *
150 * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
151 * this is *NOT* supported and may cease to work even after a minor revision
152 * to libpng. It *is* valid to do this for testing purposes, e.g. speed
153 * testing or a new compiler, but the results should be communicated to the
154 * libpng implementation list for incorporation in the next minor release.
155 */
156# ifndef PNG_ARM_NEON_IMPLEMENTATION
157# if defined(__ARM_NEON__) || defined(__ARM_NEON)
158# if defined(__clang__)
159 /* At present it is unknown by the libpng developers which versions
160 * of clang support the intrinsics, however some or perhaps all
161 * versions do not work with the assembler so this may be
162 * irrelevant, so just use the default (do nothing here.)
163 */
164# elif defined(__GNUC__)
165 /* GCC 4.5.4 NEON support is known to be broken. 4.6.3 is known to
166 * work, so if this *is* GCC, or G++, look for a version >4.5
167 */
168# if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
169# define PNG_ARM_NEON_IMPLEMENTATION 2
170# endif /* no GNUC support */
171# endif /* __GNUC__ */
172# else /* !defined __ARM_NEON__ */
173 /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
174 */
175# define PNG_ARM_NEON_IMPLEMENTATION 2
176# endif /* __ARM_NEON__ */
177# endif /* !PNG_ARM_NEON_IMPLEMENTATION */
178
179# ifndef PNG_ARM_NEON_IMPLEMENTATION
180 /* Use the intrinsics code by default. */
181# define PNG_ARM_NEON_IMPLEMENTATION 1
182# endif
183#endif /* PNG_ARM_NEON_OPT > 0 */
184
185#ifndef PNG_INTEL_SSE_OPT
186# ifdef PNG_INTEL_SSE
187 /* Only check for SSE if the build configuration has been modified to
188 * enable SSE optimizations. This means that these optimizations will
189 * be off by default. See contrib/intel for more details.
190 */
191# if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
192 defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
193 (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
194# define PNG_INTEL_SSE_OPT 1
195# endif
196# endif
197#endif
198
199#if PNG_INTEL_SSE_OPT > 0
200# ifndef PNG_INTEL_SSE_IMPLEMENTATION
201# if defined(__SSE4_1__) || defined(__AVX__)
202 /* We are not actually using AVX, but checking for AVX is the best
203 way we can detect SSE4.1 and SSSE3 on MSVC.
204 */
205# define PNG_INTEL_SSE_IMPLEMENTATION 3
206# elif defined(__SSSE3__)
207# define PNG_INTEL_SSE_IMPLEMENTATION 2
208# elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
209 (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
210# define PNG_INTEL_SSE_IMPLEMENTATION 1
211# else
212# define PNG_INTEL_SSE_IMPLEMENTATION 0
213# endif
214# endif
215
216# if PNG_INTEL_SSE_IMPLEMENTATION > 0
217# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
218# endif
219#endif
220
221/* Is this a build of a DLL where compilation of the object modules requires
222 * different preprocessor settings to those required for a simple library? If
223 * so PNG_BUILD_DLL must be set.
224 *
225 * If libpng is used inside a DLL but that DLL does not export the libpng APIs
226 * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
227 * static library of libpng then link the DLL against that.
228 */
229#ifndef PNG_BUILD_DLL
230# ifdef DLL_EXPORT
231 /* This is set by libtool when files are compiled for a DLL; libtool
232 * always compiles twice, even on systems where it isn't necessary. Set
233 * PNG_BUILD_DLL in case it is necessary:
234 */
235# define PNG_BUILD_DLL
236# else
237# ifdef _WINDLL
238 /* This is set by the Microsoft Visual Studio IDE in projects that
239 * build a DLL. It can't easily be removed from those projects (it
240 * isn't visible in the Visual Studio UI) so it is a fairly reliable
241 * indication that PNG_IMPEXP needs to be set to the DLL export
242 * attributes.
243 */
244# define PNG_BUILD_DLL
245# else
246# ifdef __DLL__
247 /* This is set by the Borland C system when compiling for a DLL
248 * (as above.)
249 */
250# define PNG_BUILD_DLL
251# else
252 /* Add additional compiler cases here. */
253# endif
254# endif
255# endif
256#endif /* Setting PNG_BUILD_DLL if required */
257
258/* See pngconf.h for more details: the builder of the library may set this on
259 * the command line to the right thing for the specific compilation system or it
260 * may be automagically set above (at present we know of no system where it does
261 * need to be set on the command line.)
262 *
263 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
264 * setting it to the "import" setting for a DLL build.
265 */
266#ifndef PNG_IMPEXP
267# ifdef PNG_BUILD_DLL
268# define PNG_IMPEXP PNG_DLL_EXPORT
269# else
270 /* Not building a DLL, or the DLL doesn't require specific export
271 * definitions.
272 */
273# define PNG_IMPEXP
274# endif
275#endif
276
277/* No warnings for private or deprecated functions in the build: */
278#ifndef PNG_DEPRECATED
279# define PNG_DEPRECATED
280#endif
281#ifndef PNG_PRIVATE
282# define PNG_PRIVATE
283#endif
284
285/* Symbol preprocessing support.
286 *
287 * To enable listing global, but internal, symbols the following macros should
288 * always be used to declare an extern data or function object in this file.
289 */
290#ifndef PNG_INTERNAL_DATA
291# define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array
292#endif
293
294#ifndef PNG_INTERNAL_FUNCTION
295# define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
296 PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
297#endif
298
299#ifndef PNG_INTERNAL_CALLBACK
300# define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
301 PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\
302 PNG_EMPTY attributes)
303#endif
304
305/* If floating or fixed point APIs are disabled they may still be compiled
306 * internally. To handle this make sure they are declared as the appropriate
307 * internal extern function (otherwise the symbol prefixing stuff won't work and
308 * the functions will be used without definitions.)
309 *
310 * NOTE: although all the API functions are declared here they are not all
311 * actually built! Because the declarations are still made it is necessary to
312 * fake out types that they depend on.
313 */
314#ifndef PNG_FP_EXPORT
315# ifndef PNG_FLOATING_POINT_SUPPORTED
316# define PNG_FP_EXPORT(ordinal, type, name, args)\
317 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
318# ifndef PNG_VERSION_INFO_ONLY
319 typedef struct png_incomplete png_double;
320 typedef png_double* png_doublep;
321 typedef const png_double* png_const_doublep;
322 typedef png_double** png_doublepp;
323# endif
324# endif
325#endif
326#ifndef PNG_FIXED_EXPORT
327# ifndef PNG_FIXED_POINT_SUPPORTED
328# define PNG_FIXED_EXPORT(ordinal, type, name, args)\
329 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
330# endif
331#endif
332
333#include "png.h"
334
335/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
336#ifndef PNG_DLL_EXPORT
337# define PNG_DLL_EXPORT
338#endif
339
340/* This is a global switch to set the compilation for an installed system
341 * (a release build). It can be set for testing debug builds to ensure that
342 * they will compile when the build type is switched to RC or STABLE, the
343 * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE. Set this in CPPFLAGS
344 * with either:
345 *
346 * -DPNG_RELEASE_BUILD Turns on the release compile path
347 * -DPNG_RELEASE_BUILD=0 Turns it off
348 * or in your pngusr.h with
349 * #define PNG_RELEASE_BUILD=1 Turns on the release compile path
350 * #define PNG_RELEASE_BUILD=0 Turns it off
351 */
352#ifndef PNG_RELEASE_BUILD
353# define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
354#endif
355
356/* SECURITY and SAFETY:
357 *
358 * libpng is built with support for internal limits on image dimensions and
359 * memory usage. These are documented in scripts/pnglibconf.dfa of the
360 * source and recorded in the machine generated header file pnglibconf.h.
361 */
362
363/* If you are running on a machine where you cannot allocate more
364 * than 64K of memory at once, uncomment this. While libpng will not
365 * normally need that much memory in a chunk (unless you load up a very
366 * large file), zlib needs to know how big of a chunk it can use, and
367 * libpng thus makes sure to check any memory allocation to verify it
368 * will fit into memory.
369 *
370 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
371 * same limit and pngconf.h (already included) sets the limit
372 * if certain operating systems are detected.
373 */
374#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
375# define PNG_MAX_MALLOC_64K
376#endif
377
378#ifndef PNG_UNUSED
379/* Unused formal parameter warnings are silenced using the following macro
380 * which is expected to have no bad effects on performance (optimizing
381 * compilers will probably remove it entirely). Note that if you replace
382 * it with something other than whitespace, you must include the terminating
383 * semicolon.
384 */
385# define PNG_UNUSED(param) (void)param;
386#endif
387
388/* Just a little check that someone hasn't tried to define something
389 * contradictory.
390 */
391#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
392# undef PNG_ZBUF_SIZE
393# define PNG_ZBUF_SIZE 65536L
394#endif
395
396/* If warnings or errors are turned off the code is disabled or redirected here.
397 * From 1.5.4 functions have been added to allow very limited formatting of
398 * error and warning messages - this code will also be disabled here.
399 */
400#ifdef PNG_WARNINGS_SUPPORTED
401# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
402#else
403# define png_warning_parameter(p,number,string) ((void)0)
404# define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
405# define png_warning_parameter_signed(p,number,format,value) ((void)0)
406# define png_formatted_warning(pp,p,message) ((void)(pp))
407# define PNG_WARNING_PARAMETERS(p)
408#endif
409#ifndef PNG_ERROR_TEXT_SUPPORTED
410# define png_fixed_error(s1,s2) png_err(s1)
411#endif
412
413/* C allows up-casts from (void*) to any pointer and (const void*) to any
414 * pointer to a const object. C++ regards this as a type error and requires an
415 * explicit, static, cast and provides the static_cast<> rune to ensure that
416 * const is not cast away.
417 */
418#ifdef __cplusplus
419# define png_voidcast(type, value) static_cast<type>(value)
420# define png_constcast(type, value) const_cast<type>(value)
421# define png_aligncast(type, value) \
422 static_cast<type>(static_cast<void*>(value))
423# define png_aligncastconst(type, value) \
424 static_cast<type>(static_cast<const void*>(value))
425#else
426# define png_voidcast(type, value) (value)
427# define png_constcast(type, value) ((type)(value))
428# define png_aligncast(type, value) ((void*)(value))
429# define png_aligncastconst(type, value) ((const void*)(value))
430#endif /* __cplusplus */
431
432/* Some fixed point APIs are still required even if not exported because
433 * they get used by the corresponding floating point APIs. This magic
434 * deals with this:
435 */
436#ifdef PNG_FIXED_POINT_SUPPORTED
437# define PNGFAPI PNGAPI
438#else
439# define PNGFAPI /* PRIVATE */
440#endif
441
442#ifndef PNG_VERSION_INFO_ONLY
443/* Other defines specific to compilers can go here. Try to keep
444 * them inside an appropriate ifdef/endif pair for portability.
445 */
446#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
447 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
448 /* png.c requires the following ANSI-C constants if the conversion of
449 * floating point to ASCII is implemented therein:
450 *
451 * DBL_DIG Maximum number of decimal digits (can be set to any constant)
452 * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
453 * DBL_MAX Maximum floating point number (can be set to an arbitrary value)
454 */
455# include <float.h>
456
457# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
458 defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
459 /* We need to check that <math.h> hasn't already been included earlier
460 * as it seems it doesn't agree with <fp.h>, yet we should really use
461 * <fp.h> if possible.
462 */
463# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
464# include <fp.h>
465# endif
466# else
467# include <math.h>
468# endif
469# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
470 /* Amiga SAS/C: We must include builtin FPU functions when compiling using
471 * MATH=68881
472 */
473# include <m68881.h>
474# endif
475#endif
476
477/* This provides the non-ANSI (far) memory allocation routines. */
478#if defined(__TURBOC__) && defined(__MSDOS__)
479# include <mem.h>
480# include <alloc.h>
481#endif
482
483#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
484 defined(_WIN32) || defined(__WIN32__)
485# include <windows.h> /* defines _WINDOWS_ macro */
486#endif
487#endif /* PNG_VERSION_INFO_ONLY */
488
489/* Moved here around 1.5.0beta36 from pngconf.h */
490/* Users may want to use these so they are not private. Any library
491 * functions that are passed far data must be model-independent.
492 */
493
494/* Memory model/platform independent fns */
495#ifndef PNG_ABORT
496# ifdef _WINDOWS_
497# define PNG_ABORT() ExitProcess(0)
498# else
499# define PNG_ABORT() abort()
500# endif
501#endif
502
503/* These macros may need to be architecture dependent. */
504#define PNG_ALIGN_NONE 0 /* do not use data alignment */
505#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
506#ifdef offsetof
507# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
508#else
509# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
510#endif
511#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
512
513#ifndef PNG_ALIGN_TYPE
514 /* Default to using aligned access optimizations and requiring alignment to a
515 * multiple of the data type size. Override in a compiler specific fashion
516 * if necessary by inserting tests here:
517 */
518# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
519#endif
520
521#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
522 /* This is used because in some compiler implementations non-aligned
523 * structure members are supported, so the offsetof approach below fails.
524 * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
525 * is good for performance. Do not do this unless you have tested the result
526 * and understand it.
527 */
528# define png_alignof(type) (sizeof (type))
529#else
530# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
531# define png_alignof(type) offsetof(struct{char c; type t;}, t)
532# else
533# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
534# define png_alignof(type) (1)
535# endif
536 /* Else leave png_alignof undefined to prevent use thereof */
537# endif
538#endif
539
540/* This implicitly assumes alignment is always to a power of 2. */
541#ifdef png_alignof
542# define png_isaligned(ptr, type)\
543 ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
544#else
545# define png_isaligned(ptr, type) 0
546#endif
547
548/* End of memory model/platform independent support */
549/* End of 1.5.0beta36 move from pngconf.h */
550
551/* CONSTANTS and UTILITY MACROS
552 * These are used internally by libpng and not exposed in the API
553 */
554
555/* Various modes of operation. Note that after an init, mode is set to
556 * zero automatically when the structure is created. Three of these
557 * are defined in png.h because they need to be visible to applications
558 * that call png_set_unknown_chunk().
559 */
560/* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */
561/* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */
562#define PNG_HAVE_IDAT 0x04
563/* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */
564#define PNG_HAVE_IEND 0x10
565 /* 0x20 (unused) */
566 /* 0x40 (unused) */
567 /* 0x80 (unused) */
568#define PNG_HAVE_CHUNK_HEADER 0x100
569#define PNG_WROTE_tIME 0x200
570#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
571#define PNG_BACKGROUND_IS_GRAY 0x800
572#define PNG_HAVE_PNG_SIGNATURE 0x1000
573#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
574 /* 0x4000 (unused) */
575#define PNG_IS_READ_STRUCT 0x8000 /* Else is a write struct */
576
577/* Flags for the transformations the PNG library does on the image data */
578#define PNG_BGR 0x0001
579#define PNG_INTERLACE 0x0002
580#define PNG_PACK 0x0004
581#define PNG_SHIFT 0x0008
582#define PNG_SWAP_BYTES 0x0010
583#define PNG_INVERT_MONO 0x0020
584#define PNG_QUANTIZE 0x0040
585#define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */
586#define PNG_BACKGROUND_EXPAND 0x0100
587#define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */
588#define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */
589#define PNG_RGBA 0x0800
590#define PNG_EXPAND 0x1000
591#define PNG_GAMMA 0x2000
592#define PNG_GRAY_TO_RGB 0x4000
593#define PNG_FILLER 0x8000
594#define PNG_PACKSWAP 0x10000
595#define PNG_SWAP_ALPHA 0x20000
596#define PNG_STRIP_ALPHA 0x40000
597#define PNG_INVERT_ALPHA 0x80000
598#define PNG_USER_TRANSFORM 0x100000
599#define PNG_RGB_TO_GRAY_ERR 0x200000
600#define PNG_RGB_TO_GRAY_WARN 0x400000
601#define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
602#define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */
603#define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */
604#define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */
605#define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */
606 /* 0x8000000 unused */
607 /* 0x10000000 unused */
608 /* 0x20000000 unused */
609 /* 0x40000000 unused */
610/* Flags for png_create_struct */
611#define PNG_STRUCT_PNG 0x0001
612#define PNG_STRUCT_INFO 0x0002
613
614/* Flags for the png_ptr->flags rather than declaring a byte for each one */
615#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
616#define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002 /* Added to libpng-1.6.0 */
617 /* 0x0004 unused */
618#define PNG_FLAG_ZSTREAM_ENDED 0x0008 /* Added to libpng-1.6.0 */
619 /* 0x0010 unused */
620 /* 0x0020 unused */
621#define PNG_FLAG_ROW_INIT 0x0040
622#define PNG_FLAG_FILLER_AFTER 0x0080
623#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
624#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
625#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
626#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
627#define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */
628#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */
629#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */
630/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 */
631/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 */
632#define PNG_FLAG_LIBRARY_MISMATCH 0x20000
633#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000
634#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000
635#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000 /* Added to libpng-1.4.0 */
636#define PNG_FLAG_APP_WARNINGS_WARN 0x200000 /* Added to libpng-1.6.0 */
637#define PNG_FLAG_APP_ERRORS_WARN 0x400000 /* Added to libpng-1.6.0 */
638 /* 0x800000 unused */
639 /* 0x1000000 unused */
640 /* 0x2000000 unused */
641 /* 0x4000000 unused */
642 /* 0x8000000 unused */
643 /* 0x10000000 unused */
644 /* 0x20000000 unused */
645 /* 0x40000000 unused */
646
647#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
648 PNG_FLAG_CRC_ANCILLARY_NOWARN)
649
650#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
651 PNG_FLAG_CRC_CRITICAL_IGNORE)
652
653#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
654 PNG_FLAG_CRC_CRITICAL_MASK)
655
656/* Save typing and make code easier to understand */
657
658#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
659 abs((int)((c1).green) - (int)((c2).green)) + \
660 abs((int)((c1).blue) - (int)((c2).blue)))
661
662/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
663 * by dividing by 257 *with rounding*. This macro is exact for the given range.
664 * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
665 * macro were established by experiment (modifying the added value). The macro
666 * has a second variant that takes a value already scaled by 255 and divides by
667 * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
668 * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
669 */
670#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
671#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
672
673/* Added to libpng-1.2.6 JB */
674#define PNG_ROWBYTES(pixel_bits, width) \
675 ((pixel_bits) >= 8 ? \
676 ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
677 (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
678
679/* PNG_OUT_OF_RANGE returns true if value is outside the range
680 * ideal-delta..ideal+delta. Each argument is evaluated twice.
681 * "ideal" and "delta" should be constants, normally simple
682 * integers, "value" a variable. Added to libpng-1.2.6 JB
683 */
684#define PNG_OUT_OF_RANGE(value, ideal, delta) \
685 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
686
687/* Conversions between fixed and floating point, only defined if
688 * required (to make sure the code doesn't accidentally use float
689 * when it is supposedly disabled.)
690 */
691#ifdef PNG_FLOATING_POINT_SUPPORTED
692/* The floating point conversion can't overflow, though it can and
693 * does lose accuracy relative to the original fixed point value.
694 * In practice this doesn't matter because png_fixed_point only
695 * stores numbers with very low precision. The png_ptr and s
696 * arguments are unused by default but are there in case error
697 * checking becomes a requirement.
698 */
699#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
700
701/* The fixed point conversion performs range checking and evaluates
702 * its argument multiple times, so must be used with care. The
703 * range checking uses the PNG specification values for a signed
704 * 32-bit fixed point value except that the values are deliberately
705 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
706 * (2^31-1) * 100000). 's' is a string that describes the value being
707 * converted.
708 *
709 * NOTE: this macro will raise a png_error if the range check fails,
710 * therefore it is normally only appropriate to use this on values
711 * that come from API calls or other sources where an out of range
712 * error indicates a programming error, not a data error!
713 *
714 * NOTE: by default this is off - the macro is not used - because the
715 * function call saves a lot of code.
716 */
717#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
718#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
719 ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
720#endif
721/* else the corresponding function is defined below, inside the scope of the
722 * cplusplus test.
723 */
724#endif
725
726/* Constants for known chunk types. If you need to add a chunk, define the name
727 * here. For historical reasons these constants have the form png_<name>; i.e.
728 * the prefix is lower case. Please use decimal values as the parameters to
729 * match the ISO PNG specification and to avoid relying on the C locale
730 * interpretation of character values.
731 *
732 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
733 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
734 * to be generated if required.
735 *
736 * PNG_32b correctly produces a value shifted by up to 24 bits, even on
737 * architectures where (int) is only 16 bits.
738 */
739#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
740#define PNG_U32(b1,b2,b3,b4) \
741 (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
742
743/* Constants for known chunk types.
744 *
745 * MAINTAINERS: If you need to add a chunk, define the name here.
746 * For historical reasons these constants have the form png_<name>; i.e.
747 * the prefix is lower case. Please use decimal values as the parameters to
748 * match the ISO PNG specification and to avoid relying on the C locale
749 * interpretation of character values. Please keep the list sorted.
750 *
751 * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
752 * type. In fact the specification does not express chunk types this way,
753 * however using a 32-bit value means that the chunk type can be read from the
754 * stream using exactly the same code as used for a 32-bit unsigned value and
755 * can be examined far more efficiently (using one arithmetic compare).
756 *
757 * Prior to 1.5.6 the chunk type constants were expressed as C strings. The
758 * libpng API still uses strings for 'unknown' chunks and a macro,
759 * PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice
760 * that for portable code numeric values must still be used; the string "IHDR"
761 * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
762 *
763 * In 1.7.0 the definitions will be made public in png.h to avoid having to
764 * duplicate the same definitions in application code.
765 */
766#define png_IDAT PNG_U32( 73, 68, 65, 84)
767#define png_IEND PNG_U32( 73, 69, 78, 68)
768#define png_IHDR PNG_U32( 73, 72, 68, 82)
769#define png_PLTE PNG_U32( 80, 76, 84, 69)
770#define png_bKGD PNG_U32( 98, 75, 71, 68)
771#define png_cHRM PNG_U32( 99, 72, 82, 77)
772#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */
773#define png_gAMA PNG_U32(103, 65, 77, 65)
774#define png_gIFg PNG_U32(103, 73, 70, 103)
775#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */
776#define png_gIFx PNG_U32(103, 73, 70, 120)
777#define png_hIST PNG_U32(104, 73, 83, 84)
778#define png_iCCP PNG_U32(105, 67, 67, 80)
779#define png_iTXt PNG_U32(105, 84, 88, 116)
780#define png_oFFs PNG_U32(111, 70, 70, 115)
781#define png_pCAL PNG_U32(112, 67, 65, 76)
782#define png_pHYs PNG_U32(112, 72, 89, 115)
783#define png_sBIT PNG_U32(115, 66, 73, 84)
784#define png_sCAL PNG_U32(115, 67, 65, 76)
785#define png_sPLT PNG_U32(115, 80, 76, 84)
786#define png_sRGB PNG_U32(115, 82, 71, 66)
787#define png_sTER PNG_U32(115, 84, 69, 82)
788#define png_tEXt PNG_U32(116, 69, 88, 116)
789#define png_tIME PNG_U32(116, 73, 77, 69)
790#define png_tRNS PNG_U32(116, 82, 78, 83)
791#define png_zTXt PNG_U32(122, 84, 88, 116)
792
793/* The following will work on (signed char*) strings, whereas the get_uint_32
794 * macro will fail on top-bit-set values because of the sign extension.
795 */
796#define PNG_CHUNK_FROM_STRING(s)\
797 PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
798
799/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
800 * signed and the argument is a (char[]) This macro will fail miserably on
801 * systems where (char) is more than 8 bits.
802 */
803#define PNG_STRING_FROM_CHUNK(s,c)\
804 (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
805 ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
806 ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
807 ((char*)(s))[3]=(char)((c & 0xff)))
808
809/* Do the same but terminate with a null character. */
810#define PNG_CSTRING_FROM_CHUNK(s,c)\
811 (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
812
813/* Test on flag values as defined in the spec (section 5.4): */
814#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29))
815#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
816#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
817#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
818#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
819
820/* Gamma values (new at libpng-1.5.4): */
821#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
822#define PNG_GAMMA_MAC_INVERSE 65909
823#define PNG_GAMMA_sRGB_INVERSE 45455
824
825/* Almost everything below is C specific; the #defines above can be used in
826 * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
827 */
828#ifndef PNG_VERSION_INFO_ONLY
829
830#include "pngstruct.h"
831#include "pnginfo.h"
832
833/* Validate the include paths - the include path used to generate pnglibconf.h
834 * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
835 */
836#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
837# error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
838 "-I (include path) error: see the notes in pngpriv.h"
839 /* This means that when pnglibconf.h was built the copy of zlib.h that it
840 * used is not the same as the one being used here. Because the build of
841 * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
842 * zlib version number and because this affects handling of certain broken
843 * PNG files the -I directives must match.
844 *
845 * The most likely explanation is that you passed a -I in CFLAGS. This will
846 * not work; all the preprocessor directories and in particular all the -I
847 * directives must be in CPPFLAGS.
848 */
849#endif
850
851/* This is used for 16-bit gamma tables -- only the top level pointers are
852 * const; this could be changed:
853 */
854typedef const png_uint_16p * png_const_uint_16pp;
855
856/* Added to libpng-1.5.7: sRGB conversion tables */
857#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
858 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
859#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
860PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
861 /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
862 * 0..65535. This table gives the closest 16-bit answers (no errors).
863 */
864#endif
865
866PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
867PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
868
869#define PNG_sRGB_FROM_LINEAR(linear) \
870 ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
871 + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
872 /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
873 * encoded value with maximum error 0.646365. Note that the input is not a
874 * 16-bit value; it has been multiplied by 255! */
875#endif /* SIMPLIFIED_READ/WRITE */
876
877
878/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
879#ifdef __cplusplus
880extern "C" {
881#endif /* __cplusplus */
882
883/* Internal functions; these are not exported from a DLL however because they
884 * are used within several of the C source files they have to be C extern.
885 *
886 * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
887 */
888
889/* Zlib support */
890#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
891PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
892 PNG_EMPTY);
893 /* Used by the zlib handling functions to ensure that z_stream::msg is always
894 * set before they return.
895 */
896
897#ifdef PNG_WRITE_SUPPORTED
898PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
899 png_compression_bufferp *list),PNG_EMPTY);
900 /* Free the buffer list used by the compressed write code. */
901#endif
902
903#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
904 !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
905 (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
906 defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
907 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
908 (defined(PNG_sCAL_SUPPORTED) && \
909 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
910PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
911 double fp, png_const_charp text),PNG_EMPTY);
912#endif
913
914/* Check the user version string for compatibility, returns false if the version
915 * numbers aren't compatible.
916 */
917PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
918 png_const_charp user_png_ver),PNG_EMPTY);
919
920/* Internal base allocator - no messages, NULL on failure to allocate. This
921 * does, however, call the application provided allocator and that could call
922 * png_error (although that would be a bug in the application implementation.)
923 */
924PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
925 png_alloc_size_t size),PNG_ALLOCATED);
926
927#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
928 defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
929/* Internal array allocator, outputs no error or warning messages on failure,
930 * just returns NULL.
931 */
932PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
933 int nelements, size_t element_size),PNG_ALLOCATED);
934
935/* The same but an existing array is extended by add_elements. This function
936 * also memsets the new elements to 0 and copies the old elements. The old
937 * array is not freed or altered.
938 */
939PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
940 png_const_voidp array, int old_elements, int add_elements,
941 size_t element_size),PNG_ALLOCATED);
942#endif /* text, sPLT or unknown chunks */
943
944/* Magic to create a struct when there is no struct to call the user supplied
945 * memory allocators. Because error handling has not been set up the memory
946 * handlers can't safely call png_error, but this is an obscure and undocumented
947 * restriction so libpng has to assume that the 'free' handler, at least, might
948 * call png_error.
949 */
950PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
951 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
952 png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
953 png_free_ptr free_fn),PNG_ALLOCATED);
954
955/* Free memory from internal libpng struct */
956PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
957 PNG_EMPTY);
958
959/* Free an allocated jmp_buf (always succeeds) */
960PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
961
962/* Function to allocate memory for zlib. PNGAPI is disallowed. */
963PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
964 PNG_ALLOCATED);
965
966/* Function to free memory for zlib. PNGAPI is disallowed. */
967PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
968
969/* Next four functions are used internally as callbacks. PNGCBAPI is required
970 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
971 * PNGCBAPI at 1.5.0
972 */
973
974PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
975 png_bytep data, png_size_t length),PNG_EMPTY);
976
977#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
978PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
979 png_bytep buffer, png_size_t length),PNG_EMPTY);
980#endif
981
982PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
983 png_bytep data, png_size_t length),PNG_EMPTY);
984
985#ifdef PNG_WRITE_FLUSH_SUPPORTED
986# ifdef PNG_STDIO_SUPPORTED
987PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
988 PNG_EMPTY);
989# endif
990#endif
991
992/* Reset the CRC variable */
993PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
994
995/* Write the "data" buffer to whatever output you are using */
996PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
997 png_const_bytep data, png_size_t length),PNG_EMPTY);
998
999/* Read and check the PNG file signature */
1000PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
1001 png_inforp info_ptr),PNG_EMPTY);
1002
1003/* Read the chunk header (length + type name) */
1004PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
1005 PNG_EMPTY);
1006
1007/* Read data from whatever input you are using into the "data" buffer */
1008PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
1009 png_size_t length),PNG_EMPTY);
1010
1011/* Read bytes into buf, and update png_ptr->crc */
1012PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
1013 png_uint_32 length),PNG_EMPTY);
1014
1015/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
1016PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
1017 png_uint_32 skip),PNG_EMPTY);
1018
1019/* Read the CRC from the file and compare it to the libpng calculated CRC */
1020PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
1021
1022/* Calculate the CRC over a section of data. Note that we are only
1023 * passing a maximum of 64K on systems that have this as a memory limit,
1024 * since this is the maximum buffer size we can specify.
1025 */
1026PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
1027 png_const_bytep ptr, png_size_t length),PNG_EMPTY);
1028
1029#ifdef PNG_WRITE_FLUSH_SUPPORTED
1030PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
1031#endif
1032
1033/* Write various chunks */
1034
1035/* Write the IHDR chunk, and update the png_struct with the necessary
1036 * information.
1037 */
1038PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
1039 png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1040 int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
1041
1042PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
1043 png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
1044
1045PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
1046 png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
1047 PNG_EMPTY);
1048
1049PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
1050
1051#ifdef PNG_WRITE_gAMA_SUPPORTED
1052PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
1053 png_fixed_point file_gamma),PNG_EMPTY);
1054#endif
1055
1056#ifdef PNG_WRITE_sBIT_SUPPORTED
1057PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
1058 png_const_color_8p sbit, int color_type),PNG_EMPTY);
1059#endif
1060
1061#ifdef PNG_WRITE_cHRM_SUPPORTED
1062PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
1063 const png_xy *xy), PNG_EMPTY);
1064 /* The xy value must have been previously validated */
1065#endif
1066
1067#ifdef PNG_WRITE_sRGB_SUPPORTED
1068PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1069 int intent),PNG_EMPTY);
1070#endif
1071
1072#ifdef PNG_WRITE_iCCP_SUPPORTED
1073PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1074 png_const_charp name, png_const_bytep profile), PNG_EMPTY);
1075 /* The profile must have been previously validated for correctness, the
1076 * length comes from the first four bytes. Only the base, deflate,
1077 * compression is supported.
1078 */
1079#endif
1080
1081#ifdef PNG_WRITE_sPLT_SUPPORTED
1082PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1083 png_const_sPLT_tp palette),PNG_EMPTY);
1084#endif
1085
1086#ifdef PNG_WRITE_tRNS_SUPPORTED
1087PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1088 png_const_bytep trans, png_const_color_16p values, int number,
1089 int color_type),PNG_EMPTY);
1090#endif
1091
1092#ifdef PNG_WRITE_bKGD_SUPPORTED
1093PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1094 png_const_color_16p values, int color_type),PNG_EMPTY);
1095#endif
1096
1097#ifdef PNG_WRITE_hIST_SUPPORTED
1098PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1099 png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1100#endif
1101
1102/* Chunks that have keywords */
1103#ifdef PNG_WRITE_tEXt_SUPPORTED
1104PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1105 png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
1106#endif
1107
1108#ifdef PNG_WRITE_zTXt_SUPPORTED
1109PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1110 key, png_const_charp text, int compression),PNG_EMPTY);
1111#endif
1112
1113#ifdef PNG_WRITE_iTXt_SUPPORTED
1114PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1115 int compression, png_const_charp key, png_const_charp lang,
1116 png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1117#endif
1118
1119#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
1120PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1121 png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1122#endif
1123
1124#ifdef PNG_WRITE_oFFs_SUPPORTED
1125PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1126 png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1127#endif
1128
1129#ifdef PNG_WRITE_pCAL_SUPPORTED
1130PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1131 png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1132 png_const_charp units, png_charpp params),PNG_EMPTY);
1133#endif
1134
1135#ifdef PNG_WRITE_pHYs_SUPPORTED
1136PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1137 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1138 int unit_type),PNG_EMPTY);
1139#endif
1140
1141#ifdef PNG_WRITE_tIME_SUPPORTED
1142PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1143 png_const_timep mod_time),PNG_EMPTY);
1144#endif
1145
1146#ifdef PNG_WRITE_sCAL_SUPPORTED
1147PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1148 int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1149#endif
1150
1151/* Called when finished processing a row of data */
1152PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1153 PNG_EMPTY);
1154
1155/* Internal use only. Called before first row of data */
1156PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1157 PNG_EMPTY);
1158
1159/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
1160 * array of png_ptr->width pixels. If the image is not interlaced or this
1161 * is the final pass this just does a memcpy, otherwise the "display" flag
1162 * is used to determine whether to copy pixels that are not in the current pass.
1163 *
1164 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1165 * function to achieve the documented 'blocky' appearance during interlaced read
1166 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1167 * are not changed if they are not in the current pass, when display is 0.
1168 *
1169 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1170 *
1171 * The API always reads from the png_struct row buffer and always assumes that
1172 * it is full width (png_do_read_interlace has already been called.)
1173 *
1174 * This function is only ever used to write to row buffers provided by the
1175 * caller of the relevant libpng API and the row must have already been
1176 * transformed by the read transformations.
1177 *
1178 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1179 * bitmasks for use within the code, otherwise runtime generated masks are used.
1180 * The default is compile time masks.
1181 */
1182#ifndef PNG_USE_COMPILE_TIME_MASKS
1183# define PNG_USE_COMPILE_TIME_MASKS 1
1184#endif
1185PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1186 png_bytep row, int display),PNG_EMPTY);
1187
1188#ifdef PNG_READ_INTERLACING_SUPPORTED
1189/* Expand an interlaced row: the 'row_info' describes the pass data that has
1190 * been read in and must correspond to the pixels in 'row', the pixels are
1191 * expanded (moved apart) in 'row' to match the final layout, when doing this
1192 * the pixels are *replicated* to the intervening space. This is essential for
1193 * the correct operation of png_combine_row, above.
1194 */
1195PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1196 png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1197#endif
1198
1199/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
1200
1201#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1202/* Grab pixels out of a row for an interlaced pass */
1203PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1204 png_bytep row, int pass),PNG_EMPTY);
1205#endif
1206
1207/* Unfilter a row: check the filter value before calling this, there is no point
1208 * calling it for PNG_FILTER_VALUE_NONE.
1209 */
1210PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1211 row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1212
1213PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1214 png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1215PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1216 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1217PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1218 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1219PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1220 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1221PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1222 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1223PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1224 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1225PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1226 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1227
1228PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
1229 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1230PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
1231 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1232PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
1233 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1234PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
1235 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1236PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
1237 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1238PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
1239 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1240
1241/* Choose the best filter to use and filter the row data */
1242PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1243 png_row_infop row_info),PNG_EMPTY);
1244
1245#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1246PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1247 png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1248 /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
1249 * is NULL the function checks, instead, for the end of the stream. In this
1250 * case a benign error will be issued if the stream end is not found or if
1251 * extra data has to be consumed.
1252 */
1253PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1254 PNG_EMPTY);
1255 /* This cleans up when the IDAT LZ stream does not end when the last image
1256 * byte is read; there is still some pending input.
1257 */
1258
1259PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1260 PNG_EMPTY);
1261 /* Finish a row while reading, dealing with interlacing passes, etc. */
1262#endif /* SEQUENTIAL_READ */
1263
1264/* Initialize the row buffers, etc. */
1265PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1266
1267#if PNG_ZLIB_VERNUM >= 0x1240
1268PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
1269 PNG_EMPTY);
1270# define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
1271#else /* Zlib < 1.2.4 */
1272# define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
1273#endif /* Zlib < 1.2.4 */
1274
1275#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1276/* Optional call to update the users info structure */
1277PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1278 png_inforp info_ptr),PNG_EMPTY);
1279#endif
1280
1281/* Shared transform functions, defined in pngtran.c */
1282#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1283 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1284PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1285 png_bytep row, int at_start),PNG_EMPTY);
1286#endif
1287
1288#ifdef PNG_16BIT_SUPPORTED
1289#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1290PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1291 png_bytep row),PNG_EMPTY);
1292#endif
1293#endif
1294
1295#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1296 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1297PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1298 png_bytep row),PNG_EMPTY);
1299#endif
1300
1301#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1302PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1303 png_bytep row),PNG_EMPTY);
1304#endif
1305
1306#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1307PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1308 png_bytep row),PNG_EMPTY);
1309#endif
1310
1311/* The following decodes the appropriate chunks, and does error correction,
1312 * then calls the appropriate callback for the chunk if it is valid.
1313 */
1314
1315/* Decode the IHDR chunk */
1316PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1317 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1318PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1319 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1320PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1321 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1322
1323#ifdef PNG_READ_bKGD_SUPPORTED
1324PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1325 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1326#endif
1327
1328#ifdef PNG_READ_cHRM_SUPPORTED
1329PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1330 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1331#endif
1332
1333#ifdef PNG_READ_gAMA_SUPPORTED
1334PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1335 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1336#endif
1337
1338#ifdef PNG_READ_hIST_SUPPORTED
1339PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1340 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1341#endif
1342
1343#ifdef PNG_READ_iCCP_SUPPORTED
1344PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1345 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1346#endif /* READ_iCCP */
1347
1348#ifdef PNG_READ_iTXt_SUPPORTED
1349PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1350 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1351#endif
1352
1353#ifdef PNG_READ_oFFs_SUPPORTED
1354PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1355 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1356#endif
1357
1358#ifdef PNG_READ_pCAL_SUPPORTED
1359PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1360 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1361#endif
1362
1363#ifdef PNG_READ_pHYs_SUPPORTED
1364PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1365 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1366#endif
1367
1368#ifdef PNG_READ_sBIT_SUPPORTED
1369PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1370 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1371#endif
1372
1373#ifdef PNG_READ_sCAL_SUPPORTED
1374PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1375 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1376#endif
1377
1378#ifdef PNG_READ_sPLT_SUPPORTED
1379PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1380 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1381#endif /* READ_sPLT */
1382
1383#ifdef PNG_READ_sRGB_SUPPORTED
1384PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1385 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1386#endif
1387
1388#ifdef PNG_READ_tEXt_SUPPORTED
1389PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1390 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1391#endif
1392
1393#ifdef PNG_READ_tIME_SUPPORTED
1394PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1395 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1396#endif
1397
1398#ifdef PNG_READ_tRNS_SUPPORTED
1399PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1400 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1401#endif
1402
1403#ifdef PNG_READ_zTXt_SUPPORTED
1404PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1405 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1406#endif
1407
1408PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
1409 png_uint_32 chunk_name),PNG_EMPTY);
1410
1411PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1412 png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1413 /* This is the function that gets called for unknown chunks. The 'keep'
1414 * argument is either non-zero for a known chunk that has been set to be
1415 * handled as unknown or zero for an unknown chunk. By default the function
1416 * just skips the chunk or errors out if it is critical.
1417 */
1418
1419#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
1420 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1421PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1422 (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1423 /* Exactly as the API png_handle_as_unknown() except that the argument is a
1424 * 32-bit chunk name, not a string.
1425 */
1426#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
1427
1428/* Handle the transformations for reading and writing */
1429#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1430PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1431 png_row_infop row_info),PNG_EMPTY);
1432#endif
1433#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1434PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1435 png_row_infop row_info),PNG_EMPTY);
1436#endif
1437
1438#ifdef PNG_READ_TRANSFORMS_SUPPORTED
1439PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1440 PNG_EMPTY);
1441#endif
1442
1443#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1444PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1445 png_inforp info_ptr),PNG_EMPTY);
1446PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1447 png_inforp info_ptr),PNG_EMPTY);
1448PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1449PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1450 PNG_EMPTY);
1451PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1452 png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1453PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1454PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1455 png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1456PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1457 PNG_EMPTY);
1458PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1459 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1460PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1461 png_inforp info_ptr),PNG_EMPTY);
1462PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1463 png_inforp info_ptr),PNG_EMPTY);
1464PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1465 png_bytep row),PNG_EMPTY);
1466PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1467 png_inforp info_ptr),PNG_EMPTY);
1468PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1469 png_inforp info_ptr),PNG_EMPTY);
1470PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1471 PNG_EMPTY);
1472# ifdef PNG_READ_tEXt_SUPPORTED
1473PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1474 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1475PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1476 png_inforp info_ptr),PNG_EMPTY);
1477# endif
1478# ifdef PNG_READ_zTXt_SUPPORTED
1479PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1480 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1481PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1482 png_inforp info_ptr),PNG_EMPTY);
1483# endif
1484# ifdef PNG_READ_iTXt_SUPPORTED
1485PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1486 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1487PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1488 png_inforp info_ptr),PNG_EMPTY);
1489# endif
1490
1491#endif /* PROGRESSIVE_READ */
1492
1493/* Added at libpng version 1.6.0 */
1494#ifdef PNG_GAMMA_SUPPORTED
1495PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1496 png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1497 /* Set the colorspace gamma with a value provided by the application or by
1498 * the gAMA chunk on read. The value will override anything set by an ICC
1499 * profile.
1500 */
1501
1502PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1503 png_inforp info_ptr), PNG_EMPTY);
1504 /* Synchronize the info 'valid' flags with the colorspace */
1505
1506PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1507 png_inforp info_ptr), PNG_EMPTY);
1508 /* Copy the png_struct colorspace to the info_struct and call the above to
1509 * synchronize the flags. Checks for NULL info_ptr and does nothing.
1510 */
1511#endif
1512
1513/* Added at libpng version 1.4.0 */
1514#ifdef PNG_COLORSPACE_SUPPORTED
1515/* These internal functions are for maintaining the colorspace structure within
1516 * a png_info or png_struct (or, indeed, both).
1517 */
1518PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1519 (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1520 int preferred), PNG_EMPTY);
1521
1522PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1523 (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1524 int preferred), PNG_EMPTY);
1525
1526#ifdef PNG_sRGB_SUPPORTED
1527PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1528 png_colorspacerp colorspace, int intent), PNG_EMPTY);
1529 /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1530 * flags to write them, if it returns false there was a problem and an error
1531 * message has already been output (but the colorspace may still need to be
1532 * synced to record the invalid flag).
1533 */
1534#endif /* sRGB */
1535
1536#ifdef PNG_iCCP_SUPPORTED
1537PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1538 png_colorspacerp colorspace, png_const_charp name,
1539 png_uint_32 profile_length, png_const_bytep profile, int color_type),
1540 PNG_EMPTY);
1541 /* The 'name' is used for information only */
1542
1543/* Routines for checking parts of an ICC profile. */
1544PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1545 png_colorspacerp colorspace, png_const_charp name,
1546 png_uint_32 profile_length), PNG_EMPTY);
1547PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1548 png_colorspacerp colorspace, png_const_charp name,
1549 png_uint_32 profile_length,
1550 png_const_bytep profile /* first 132 bytes only */, int color_type),
1551 PNG_EMPTY);
1552PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1553 png_colorspacerp colorspace, png_const_charp name,
1554 png_uint_32 profile_length,
1555 png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1556#ifdef PNG_sRGB_SUPPORTED
1557PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1558 png_const_structrp png_ptr, png_colorspacerp colorspace,
1559 png_const_bytep profile, uLong adler), PNG_EMPTY);
1560 /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1561 * be zero to indicate that it is not available. It is used, if provided,
1562 * as a fast check on the profile when checking to see if it is sRGB.
1563 */
1564#endif
1565#endif /* iCCP */
1566
1567#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1568PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1569 (png_structrp png_ptr), PNG_EMPTY);
1570 /* Set the rgb_to_gray coefficients from the colorspace Y values */
1571#endif /* READ_RGB_TO_GRAY */
1572#endif /* COLORSPACE */
1573
1574/* Added at libpng version 1.4.0 */
1575PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1576 png_uint_32 width, png_uint_32 height, int bit_depth,
1577 int color_type, int interlace_type, int compression_type,
1578 int filter_type),PNG_EMPTY);
1579
1580/* Added at libpng version 1.5.10 */
1581#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1582 defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1583PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1584 (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1585#endif
1586
1587#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1588PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1589 png_const_charp name),PNG_NORETURN);
1590#endif
1591
1592/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1593 * the end. Always leaves the buffer nul terminated. Never errors out (and
1594 * there is no error code.)
1595 */
1596PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1597 size_t pos, png_const_charp string),PNG_EMPTY);
1598
1599/* Various internal functions to handle formatted warning messages, currently
1600 * only implemented for warnings.
1601 */
1602#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1603/* Utility to dump an unsigned value into a buffer, given a start pointer and
1604 * and end pointer (which should point just *beyond* the end of the buffer!)
1605 * Returns the pointer to the start of the formatted string. This utility only
1606 * does unsigned values.
1607 */
1608PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1609 png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1610
1611/* Convenience macro that takes an array: */
1612#define PNG_FORMAT_NUMBER(buffer,format,number) \
1613 png_format_number(buffer, buffer + (sizeof buffer), format, number)
1614
1615/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1616#define PNG_NUMBER_BUFFER_SIZE 24
1617
1618/* These are the integer formats currently supported, the name is formed from
1619 * the standard printf(3) format string.
1620 */
1621#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
1622#define PNG_NUMBER_FORMAT_02u 2
1623#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
1624#define PNG_NUMBER_FORMAT_02d 2
1625#define PNG_NUMBER_FORMAT_x 3
1626#define PNG_NUMBER_FORMAT_02x 4
1627#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1628#endif
1629
1630#ifdef PNG_WARNINGS_SUPPORTED
1631/* New defines and members adding in libpng-1.5.4 */
1632# define PNG_WARNING_PARAMETER_SIZE 32
1633# define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1634
1635/* An l-value of this type has to be passed to the APIs below to cache the
1636 * values of the parameters to a formatted warning message.
1637 */
1638typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1639 PNG_WARNING_PARAMETER_SIZE];
1640
1641PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1642 int number, png_const_charp string),PNG_EMPTY);
1643 /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1644 * including the trailing '\0'.
1645 */
1646PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1647 (png_warning_parameters p, int number, int format, png_alloc_size_t value),
1648 PNG_EMPTY);
1649 /* Use png_alloc_size_t because it is an unsigned type as big as any we
1650 * need to output. Use the following for a signed value.
1651 */
1652PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1653 (png_warning_parameters p, int number, int format, png_int_32 value),
1654 PNG_EMPTY);
1655
1656PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1657 png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1658 /* 'message' follows the X/Open approach of using @1, @2 to insert
1659 * parameters previously supplied using the above functions. Errors in
1660 * specifying the parameters will simply result in garbage substitutions.
1661 */
1662#endif
1663
1664#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1665/* Application errors (new in 1.6); use these functions (declared below) for
1666 * errors in the parameters or order of API function calls on read. The
1667 * 'warning' should be used for an error that can be handled completely; the
1668 * 'error' for one which can be handled safely but which may lose application
1669 * information or settings.
1670 *
1671 * By default these both result in a png_error call prior to release, while in a
1672 * released version the 'warning' is just a warning. However if the application
1673 * explicitly disables benign errors (explicitly permitting the code to lose
1674 * information) they both turn into warnings.
1675 *
1676 * If benign errors aren't supported they end up as the corresponding base call
1677 * (png_warning or png_error.)
1678 */
1679PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1680 png_const_charp message),PNG_EMPTY);
1681 /* The application provided invalid parameters to an API function or called
1682 * an API function at the wrong time, libpng can completely recover.
1683 */
1684
1685PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1686 png_const_charp message),PNG_EMPTY);
1687 /* As above but libpng will ignore the call, or attempt some other partial
1688 * recovery from the error.
1689 */
1690#else
1691# define png_app_warning(pp,s) png_warning(pp,s)
1692# define png_app_error(pp,s) png_error(pp,s)
1693#endif
1694
1695PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1696 png_const_charp message, int error),PNG_EMPTY);
1697 /* Report a recoverable issue in chunk data. On read this is used to report
1698 * a problem found while reading a particular chunk and the
1699 * png_chunk_benign_error or png_chunk_warning function is used as
1700 * appropriate. On write this is used to report an error that comes from
1701 * data set via an application call to a png_set_ API and png_app_error or
1702 * png_app_warning is used as appropriate.
1703 *
1704 * The 'error' parameter must have one of the following values:
1705 */
1706#define PNG_CHUNK_WARNING 0 /* never an error */
1707#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1708#define PNG_CHUNK_ERROR 2 /* always an error */
1709
1710/* ASCII to FP interfaces, currently only implemented if sCAL
1711 * support is required.
1712 */
1713#if defined(PNG_sCAL_SUPPORTED)
1714/* MAX_DIGITS is actually the maximum number of characters in an sCAL
1715 * width or height, derived from the precision (number of significant
1716 * digits - a build time settable option) and assumptions about the
1717 * maximum ridiculous exponent.
1718 */
1719#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1720
1721#ifdef PNG_FLOATING_POINT_SUPPORTED
1722PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1723 png_charp ascii, png_size_t size, double fp, unsigned int precision),
1724 PNG_EMPTY);
1725#endif /* FLOATING_POINT */
1726
1727#ifdef PNG_FIXED_POINT_SUPPORTED
1728PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1729 png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
1730#endif /* FIXED_POINT */
1731#endif /* sCAL */
1732
1733#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1734/* An internal API to validate the format of a floating point number.
1735 * The result is the index of the next character. If the number is
1736 * not valid it will be the index of a character in the supposed number.
1737 *
1738 * The format of a number is defined in the PNG extensions specification
1739 * and this API is strictly conformant to that spec, not anyone elses!
1740 *
1741 * The format as a regular expression is:
1742 *
1743 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1744 *
1745 * or:
1746 *
1747 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1748 *
1749 * The complexity is that either integer or fraction must be present and the
1750 * fraction is permitted to have no digits only if the integer is present.
1751 *
1752 * NOTE: The dangling E problem.
1753 * There is a PNG valid floating point number in the following:
1754 *
1755 * PNG floating point numbers are not greedy.
1756 *
1757 * Working this out requires *TWO* character lookahead (because of the
1758 * sign), the parser does not do this - it will fail at the 'r' - this
1759 * doesn't matter for PNG sCAL chunk values, but it requires more care
1760 * if the value were ever to be embedded in something more complex. Use
1761 * ANSI-C strtod if you need the lookahead.
1762 */
1763/* State table for the parser. */
1764#define PNG_FP_INTEGER 0 /* before or in integer */
1765#define PNG_FP_FRACTION 1 /* before or in fraction */
1766#define PNG_FP_EXPONENT 2 /* before or in exponent */
1767#define PNG_FP_STATE 3 /* mask for the above */
1768#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
1769#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
1770#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
1771#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
1772#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
1773
1774/* These three values don't affect the parser. They are set but not used.
1775 */
1776#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
1777#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
1778#define PNG_FP_NONZERO 256 /* A non-zero value */
1779#define PNG_FP_STICKY 448 /* The above three flags */
1780
1781/* This is available for the caller to store in 'state' if required. Do not
1782 * call the parser after setting it (the parser sometimes clears it.)
1783 */
1784#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
1785
1786/* Result codes for the parser (boolean - true meants ok, false means
1787 * not ok yet.)
1788 */
1789#define PNG_FP_MAYBE 0 /* The number may be valid in the future */
1790#define PNG_FP_OK 1 /* The number is valid */
1791
1792/* Tests on the sticky non-zero and negative flags. To pass these checks
1793 * the state must also indicate that the whole number is valid - this is
1794 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1795 * is equivalent to PNG_FP_OK above.)
1796 */
1797#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1798 /* NZ_MASK: the string is valid and a non-zero negative value */
1799#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1800 /* Z MASK: the string is valid and a non-zero value. */
1801 /* PNG_FP_SAW_DIGIT: the string is valid. */
1802#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1803#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1804#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1805
1806/* The actual parser. This can be called repeatedly. It updates
1807 * the index into the string and the state variable (which must
1808 * be initialized to 0). It returns a result code, as above. There
1809 * is no point calling the parser any more if it fails to advance to
1810 * the end of the string - it is stuck on an invalid character (or
1811 * terminated by '\0').
1812 *
1813 * Note that the pointer will consume an E or even an E+ and then leave
1814 * a 'maybe' state even though a preceding integer.fraction is valid.
1815 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1816 * a valid number. It's possible to recover from this by calling
1817 * the parser again (from the start, with state 0) but with a string
1818 * that omits the last character (i.e. set the size to the index of
1819 * the problem character.) This has not been tested within libpng.
1820 */
1821PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
1822 png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
1823
1824/* This is the same but it checks a complete string and returns true
1825 * only if it just contains a floating point number. As of 1.5.4 this
1826 * function also returns the state at the end of parsing the number if
1827 * it was valid (otherwise it returns 0.) This can be used for testing
1828 * for negative or zero values using the sticky flag.
1829 */
1830PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
1831 png_size_t size),PNG_EMPTY);
1832#endif /* pCAL || sCAL */
1833
1834#if defined(PNG_GAMMA_SUPPORTED) ||\
1835 defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1836/* Added at libpng version 1.5.0 */
1837/* This is a utility to provide a*times/div (rounded) and indicate
1838 * if there is an overflow. The result is a boolean - false (0)
1839 * for overflow, true (1) if no overflow, in which case *res
1840 * holds the result.
1841 */
1842PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
1843 png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
1844#endif
1845
1846#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1847/* Same deal, but issue a warning on overflow and return 0. */
1848PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
1849 (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
1850 png_int_32 divided_by),PNG_EMPTY);
1851#endif
1852
1853#ifdef PNG_GAMMA_SUPPORTED
1854/* Calculate a reciprocal - used for gamma values. This returns
1855 * 0 if the argument is 0 in order to maintain an undefined value;
1856 * there are no warnings.
1857 */
1858PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
1859 PNG_EMPTY);
1860
1861#ifdef PNG_READ_GAMMA_SUPPORTED
1862/* The same but gives a reciprocal of the product of two fixed point
1863 * values. Accuracy is suitable for gamma calculations but this is
1864 * not exact - use png_muldiv for that. Only required at present on read.
1865 */
1866PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
1867 png_fixed_point b),PNG_EMPTY);
1868#endif
1869
1870/* Return true if the gamma value is significantly different from 1.0 */
1871PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
1872 PNG_EMPTY);
1873#endif
1874
1875#ifdef PNG_READ_GAMMA_SUPPORTED
1876/* Internal fixed point gamma correction. These APIs are called as
1877 * required to convert single values - they don't need to be fast,
1878 * they are not used when processing image pixel values.
1879 *
1880 * While the input is an 'unsigned' value it must actually be the
1881 * correct bit value - 0..255 or 0..65535 as required.
1882 */
1883PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
1884 unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
1885PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
1886 png_fixed_point gamma_value),PNG_EMPTY);
1887PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
1888 png_fixed_point gamma_value),PNG_EMPTY);
1889PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
1890 PNG_EMPTY);
1891PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
1892 int bit_depth),PNG_EMPTY);
1893#endif
1894
1895/* SIMPLIFIED READ/WRITE SUPPORT */
1896#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
1897 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
1898/* The internal structure that png_image::opaque points to. */
1899typedef struct png_control
1900{
1901 png_structp png_ptr;
1902 png_infop info_ptr;
1903 png_voidp error_buf; /* Always a jmp_buf at present. */
1904
1905 png_const_bytep memory; /* Memory buffer. */
1906 png_size_t size; /* Size of the memory buffer. */
1907
1908 unsigned int for_write :1; /* Otherwise it is a read structure */
1909 unsigned int owned_file :1; /* We own the file in io_ptr */
1910} png_control;
1911
1912/* Return the pointer to the jmp_buf from a png_control: necessary because C
1913 * does not reveal the type of the elements of jmp_buf.
1914 */
1915#ifdef __cplusplus
1916# define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
1917#else
1918# define png_control_jmp_buf(pc) ((pc)->error_buf)
1919#endif
1920
1921/* Utility to safely execute a piece of libpng code catching and logging any
1922 * errors that might occur. Returns true on success, false on failure (either
1923 * of the function or as a result of a png_error.)
1924 */
1925PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
1926 png_const_charp error_message),PNG_NORETURN);
1927
1928#ifdef PNG_WARNINGS_SUPPORTED
1929PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
1930 png_const_charp warning_message),PNG_EMPTY);
1931#else
1932# define png_safe_warning 0/*dummy argument*/
1933#endif
1934
1935PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
1936 int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
1937
1938/* Utility to log an error; this also cleans up the png_image; the function
1939 * always returns 0 (false).
1940 */
1941PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
1942 png_const_charp error_message),PNG_EMPTY);
1943
1944#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
1945/* png_image_free is used by the write code but not exported */
1946PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
1947#endif /* !SIMPLIFIED_READ */
1948
1949#endif /* SIMPLIFIED READ/WRITE */
1950
1951/* These are initialization functions for hardware specific PNG filter
1952 * optimizations; list these here then select the appropriate one at compile
1953 * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined
1954 * the generic code is used.
1955 */
1956#ifdef PNG_FILTER_OPTIMIZATIONS
1957PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
1958 unsigned int bpp), PNG_EMPTY);
1959 /* Just declare the optimization that will be used */
1960#else
1961 /* List *all* the possible optimizations here - this branch is required if
1962 * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
1963 * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
1964 */
1965PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
1966 (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
1967PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
1968 (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
1969#endif
1970
1971PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
1972 png_const_charp key, png_bytep new_key), PNG_EMPTY);
1973
1974/* Maintainer: Put new private prototypes here ^ */
1975
1976#include "pngdebug.h"
1977
1978#ifdef __cplusplus
1979}
1980#endif
1981
1982#endif /* PNG_VERSION_INFO_ONLY */
1983#endif /* PNGPRIV_H */
1984