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2 /* pngpriv.h - private declarations for use inside libpng
4 * For conditions of distribution and use, see copyright notice in png.h
5 * Copyright (c) 1998-2014 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.)
9 * Last changed in libpng 1.6.10 [March 6, 1014]]
11 * This code is released under the libpng license.
12 * For conditions of distribution and use, see the disclaimer
13 * and license in png.h
16 /* The symbols declared in this file (including the functions declared
17 * as extern) are PRIVATE. They are not part of the libpng public
18 * interface, and are not recommended for use by regular applications.
19 * Some of them may become public in the future; others may stay private,
20 * change in an incompatible way, or even disappear.
21 * Although the libpng users are not forbidden to include this header,
22 * they should be well aware of the issues that may arise from doing so.
25 #ifndef PNGPRIV_H
26 #define PNGPRIV_H
28 /* Feature Test Macros. The following are defined here to ensure that correctly
29 * implemented libraries reveal the APIs libpng needs to build and hide those
30 * that are not needed and potentially damaging to the compilation.
32 * Feature Test Macros must be defined before any system header is included (see
33 * POSIX 1003.1 2.8.2 "POSIX Symbols."
35 * These macros only have an effect if the operating system supports either
36 * POSIX 1003.1 or C99, or both. On other operating systems (particularly
37 * Windows/Visual Studio) there is no effect; the OS specific tests below are
38 * still required (as of 2011-05-02.)
40 #define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
42 #ifndef PNG_VERSION_INFO_ONLY
43 /* Standard library headers not required by png.h: */
44 # include <stdlib.h>
45 # include <string.h>
46 #endif
48 #define PNGLIB_BUILD /*libpng is being built, not used*/
50 /* If HAVE_CONFIG_H is defined during the build then the build system must
51 * provide an appropriate "config.h" file on the include path. The header file
52 * must provide definitions as required below (search for "HAVE_CONFIG_H");
53 * see configure.ac for more details of the requirements. The macro
54 * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
55 * 'configure'; define this macro to prevent the configure build including the
56 * configure generated config.h. Libpng is expected to compile without *any*
57 * special build system support on a reasonably ANSI-C compliant system.
59 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
60 # include <config.h>
62 /* Pick up the definition of 'restrict' from config.h if it was read: */
63 # define PNG_RESTRICT restrict
64 #endif
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.
71 #ifndef PNGLCONF_H
72 # include "pnglibconf.h"
73 #endif
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
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
91 /* Compile time options.
92 * =====================
93 * In a multi-arch build the compiler may compile the code several times for the
94 * same object module, producing different binaries for different architectures.
95 * When this happens configure-time setting of the target host options cannot be
96 * done and this interferes with the handling of the ARM NEON optimizations, and
97 * possibly other similar optimizations. Put additional tests here; in general
98 * this is needed when the same option can be changed at both compile time and
99 * run time depending on the target OS (i.e. iOS vs Android.)
101 * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
102 * this is not possible with certain compilers (Oracle SUN OS CC), as a result
103 * it is necessary to ensure that all extern functions that *might* be used
104 * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__
105 * below is one example of this behavior because it is controlled by the
106 * presence or not of -mfpu=neon on the GCC command line, it is possible to do
107 * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
108 * do this.
110 #ifndef PNG_ARM_NEON_OPT
111 /* ARM NEON optimizations are being controlled by the compiler settings,
112 * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon
113 * with GCC) then the compiler will define __ARM_NEON__ and we can rely
114 * unconditionally on NEON instructions not crashing, otherwise we must
115 * disable use of NEON instructions.
117 * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
118 * can only be turned on automatically if that is supported too. If
119 * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
120 * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
121 * off.
123 * Note that gcc-4.9 defines __ARM_NEON instead of __ARM_NEON__, so we
124 * check both variants.
126 # if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
127 defined(PNG_ALIGNED_MEMORY_SUPPORTED)
128 # define PNG_ARM_NEON_OPT 2
129 # else
130 # define PNG_ARM_NEON_OPT 0
131 # endif
132 #endif
134 #if PNG_ARM_NEON_OPT > 0
135 /* NEON optimizations are to be at least considered by libpng, so enable the
136 * callbacks to do this.
138 # define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
140 /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
141 * if possible - if __ARM_NEON__ is set and the compiler version is not known
142 * to be broken. This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
143 * be:
145 * 1 The intrinsics code (the default with __ARM_NEON__)
146 * 2 The hand coded assembler (the default without __ARM_NEON__)
148 * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
149 * this is *NOT* supported and may cease to work even after a minor revision
150 * to libpng. It *is* valid to do this for testing purposes, e.g. speed
151 * testing or a new compiler, but the results should be communicated to the
152 * libpng implementation list for incorporation in the next minor release.
154 # ifndef PNG_ARM_NEON_IMPLEMENTATION
155 # if defined(__ARM_NEON__) || defined(__ARM_NEON)
156 # if defined(__clang__)
157 /* At present it is unknown by the libpng developers which versions
158 * of clang support the intrinsics, however some or perhaps all
159 * versions do not work with the assembler so this may be
160 * irrelevant, so just use the default (do nothing here.)
162 # elif defined(__GNUC__)
163 /* GCC 4.5.4 NEON support is known to be broken. 4.6.3 is known to
164 * work, so if this *is* GCC, or G++, look for a version >4.5
166 # if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
167 # define PNG_ARM_NEON_IMPLEMENTATION 2
168 # endif /* no GNUC support */
169 # endif /* __GNUC__ */
170 # else /* !defined __ARM_NEON__ */
171 /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
173 # define PNG_ARM_NEON_IMPLEMENTATION 2
174 # endif /* __ARM_NEON__ */
175 # endif /* !PNG_ARM_NEON_IMPLEMENTATION */
177 # ifndef PNG_ARM_NEON_IMPLEMENTATION
178 /* Use the intrinsics code by default. */
179 # define PNG_ARM_NEON_IMPLEMENTATION 1
180 # endif
181 #endif /* PNG_ARM_NEON_OPT > 0 */
183 /* Is this a build of a DLL where compilation of the object modules requires
184 * different preprocessor settings to those required for a simple library? If
185 * so PNG_BUILD_DLL must be set.
187 * If libpng is used inside a DLL but that DLL does not export the libpng APIs
188 * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
189 * static library of libpng then link the DLL against that.
191 #ifndef PNG_BUILD_DLL
192 # ifdef DLL_EXPORT
193 /* This is set by libtool when files are compiled for a DLL; libtool
194 * always compiles twice, even on systems where it isn't necessary. Set
195 * PNG_BUILD_DLL in case it is necessary:
197 # define PNG_BUILD_DLL
198 # else
199 # ifdef _WINDLL
200 /* This is set by the Microsoft Visual Studio IDE in projects that
201 * build a DLL. It can't easily be removed from those projects (it
202 * isn't visible in the Visual Studio UI) so it is a fairly reliable
203 * indication that PNG_IMPEXP needs to be set to the DLL export
204 * attributes.
206 # define PNG_BUILD_DLL
207 # else
208 # ifdef __DLL__
209 /* This is set by the Borland C system when compiling for a DLL
210 * (as above.)
212 # define PNG_BUILD_DLL
213 # else
214 /* Add additional compiler cases here. */
215 # endif
216 # endif
217 # endif
218 #endif /* Setting PNG_BUILD_DLL if required */
220 /* See pngconf.h for more details: the builder of the library may set this on
221 * the command line to the right thing for the specific compilation system or it
222 * may be automagically set above (at present we know of no system where it does
223 * need to be set on the command line.)
225 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
226 * setting it to the "import" setting for a DLL build.
228 #ifndef PNG_IMPEXP
229 # ifdef PNG_BUILD_DLL
230 # define PNG_IMPEXP PNG_DLL_EXPORT
231 # else
232 /* Not building a DLL, or the DLL doesn't require specific export
233 * definitions.
235 # define PNG_IMPEXP
236 # endif
237 #endif
239 /* No warnings for private or deprecated functions in the build: */
240 #ifndef PNG_DEPRECATED
241 # define PNG_DEPRECATED
242 #endif
243 #ifndef PNG_PRIVATE
244 # define PNG_PRIVATE
245 #endif
247 /* Symbol preprocessing support.
249 * To enable listing global, but internal, symbols the following macros should
250 * always be used to declare an extern data or function object in this file.
252 #ifndef PNG_INTERNAL_DATA
253 # define PNG_INTERNAL_DATA(type, name, array) extern type name array
254 #endif
256 #ifndef PNG_INTERNAL_FUNCTION
257 # define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
258 extern PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
259 #endif
261 #ifndef PNG_INTERNAL_CALLBACK
262 # define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
263 extern PNG_FUNCTION(type, (PNGCBAPI name), args, PNG_EMPTY attributes)
264 #endif
266 /* If floating or fixed point APIs are disabled they may still be compiled
267 * internally. To handle this make sure they are declared as the appropriate
268 * internal extern function (otherwise the symbol prefixing stuff won't work and
269 * the functions will be used without definitions.)
271 * NOTE: although all the API functions are declared here they are not all
272 * actually built! Because the declarations are still made it is necessary to
273 * fake out types that they depend on.
275 #ifndef PNG_FP_EXPORT
276 # ifndef PNG_FLOATING_POINT_SUPPORTED
277 # define PNG_FP_EXPORT(ordinal, type, name, args)\
278 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
279 # ifndef PNG_VERSION_INFO_ONLY
280 typedef struct png_incomplete png_double;
281 typedef png_double* png_doublep;
282 typedef const png_double* png_const_doublep;
283 typedef png_double** png_doublepp;
284 # endif
285 # endif
286 #endif
287 #ifndef PNG_FIXED_EXPORT
288 # ifndef PNG_FIXED_POINT_SUPPORTED
289 # define PNG_FIXED_EXPORT(ordinal, type, name, args)\
290 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
291 # endif
292 #endif
294 #include "png.h"
296 /* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
297 #ifndef PNG_DLL_EXPORT
298 # define PNG_DLL_EXPORT
299 #endif
301 /* SECURITY and SAFETY:
303 * By default libpng is built without any internal limits on image size,
304 * individual heap (png_malloc) allocations or the total amount of memory used.
305 * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
306 * (unless individually overridden). These limits are believed to be fairly
307 * safe, but builders of secure systems should verify the values against the
308 * real system capabilities.
310 #ifdef PNG_SAFE_LIMITS_SUPPORTED
311 /* 'safe' limits */
312 # ifndef PNG_USER_WIDTH_MAX
313 # define PNG_USER_WIDTH_MAX 1000000
314 # endif
315 # ifndef PNG_USER_HEIGHT_MAX
316 # define PNG_USER_HEIGHT_MAX 1000000
317 # endif
318 # ifndef PNG_USER_CHUNK_CACHE_MAX
319 # define PNG_USER_CHUNK_CACHE_MAX 128
320 # endif
321 # ifndef PNG_USER_CHUNK_MALLOC_MAX
322 # define PNG_USER_CHUNK_MALLOC_MAX 8000000
323 # endif
324 #else
325 /* values for no limits */
326 # ifndef PNG_USER_WIDTH_MAX
327 # define PNG_USER_WIDTH_MAX 0x7fffffff
328 # endif
329 # ifndef PNG_USER_HEIGHT_MAX
330 # define PNG_USER_HEIGHT_MAX 0x7fffffff
331 # endif
332 # ifndef PNG_USER_CHUNK_CACHE_MAX
333 # define PNG_USER_CHUNK_CACHE_MAX 0
334 # endif
335 # ifndef PNG_USER_CHUNK_MALLOC_MAX
336 # define PNG_USER_CHUNK_MALLOC_MAX 0
337 # endif
338 #endif
340 /* Moved to pngpriv.h at libpng-1.5.0 */
341 /* NOTE: some of these may have been used in external applications as
342 * these definitions were exposed in pngconf.h prior to 1.5.
345 /* If you are running on a machine where you cannot allocate more
346 * than 64K of memory at once, uncomment this. While libpng will not
347 * normally need that much memory in a chunk (unless you load up a very
348 * large file), zlib needs to know how big of a chunk it can use, and
349 * libpng thus makes sure to check any memory allocation to verify it
350 * will fit into memory.
352 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
353 * same limit and pngconf.h (already included) sets the limit
354 * if certain operating systems are detected.
356 #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
357 # define PNG_MAX_MALLOC_64K
358 #endif
360 #ifndef PNG_UNUSED
361 /* Unused formal parameter warnings are silenced using the following macro
362 * which is expected to have no bad effects on performance (optimizing
363 * compilers will probably remove it entirely). Note that if you replace
364 * it with something other than whitespace, you must include the terminating
365 * semicolon.
367 # define PNG_UNUSED(param) (void)param;
368 #endif
370 /* Just a little check that someone hasn't tried to define something
371 * contradictory.
373 #if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
374 # undef PNG_ZBUF_SIZE
375 # define PNG_ZBUF_SIZE 65536L
376 #endif
378 /* If warnings or errors are turned off the code is disabled or redirected here.
379 * From 1.5.4 functions have been added to allow very limited formatting of
380 * error and warning messages - this code will also be disabled here.
382 #ifdef PNG_WARNINGS_SUPPORTED
383 # define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
384 #else
385 # define png_warning_parameter(p,number,string) ((void)0)
386 # define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
387 # define png_warning_parameter_signed(p,number,format,value) ((void)0)
388 # define png_formatted_warning(pp,p,message) ((void)(pp))
389 # define PNG_WARNING_PARAMETERS(p)
390 #endif
391 #ifndef PNG_ERROR_TEXT_SUPPORTED
392 # define png_fixed_error(s1,s2) png_err(s1)
393 #endif
395 /* C allows up-casts from (void*) to any pointer and (const void*) to any
396 * pointer to a const object. C++ regards this as a type error and requires an
397 * explicit, static, cast and provides the static_cast<> rune to ensure that
398 * const is not cast away.
400 #ifdef __cplusplus
401 # define png_voidcast(type, value) static_cast<type>(value)
402 # define png_constcast(type, value) const_cast<type>(value)
403 # define png_aligncast(type, value) \
404 static_cast<type>(static_cast<void*>(value))
405 # define png_aligncastconst(type, value) \
406 static_cast<type>(static_cast<const void*>(value))
407 #else
408 # define png_voidcast(type, value) (value)
409 # define png_constcast(type, value) ((type)(value))
410 # define png_aligncast(type, value) ((void*)(value))
411 # define png_aligncastconst(type, value) ((const void*)(value))
412 #endif /* __cplusplus */
414 /* Some fixed point APIs are still required even if not exported because
415 * they get used by the corresponding floating point APIs. This magic
416 * deals with this:
418 #ifdef PNG_FIXED_POINT_SUPPORTED
419 # define PNGFAPI PNGAPI
420 #else
421 # define PNGFAPI /* PRIVATE */
422 #endif
424 #ifndef PNG_VERSION_INFO_ONLY
425 /* Other defines specific to compilers can go here. Try to keep
426 * them inside an appropriate ifdef/endif pair for portability.
428 #if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
429 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
430 /* png.c requires the following ANSI-C constants if the conversion of
431 * floating point to ASCII is implemented therein:
433 * DBL_DIG Maximum number of decimal digits (can be set to any constant)
434 * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
435 * DBL_MAX Maximum floating point number (can be set to an arbitrary value)
437 # include <float.h>
439 # if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
440 defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
441 /* We need to check that <math.h> hasn't already been included earlier
442 * as it seems it doesn't agree with <fp.h>, yet we should really use
443 * <fp.h> if possible.
445 # if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
446 # include <fp.h>
447 # endif
448 # else
449 # include <math.h>
450 # endif
451 # if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
452 /* Amiga SAS/C: We must include builtin FPU functions when compiling using
453 * MATH=68881
455 # include <m68881.h>
456 # endif
457 #endif
459 /* This provides the non-ANSI (far) memory allocation routines. */
460 #if defined(__TURBOC__) && defined(__MSDOS__)
461 # include <mem.h>
462 # include <alloc.h>
463 #endif
465 #if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
466 defined(_WIN32) || defined(__WIN32__)
467 # include <windows.h> /* defines _WINDOWS_ macro */
468 #endif
469 #endif /* PNG_VERSION_INFO_ONLY */
471 /* Moved here around 1.5.0beta36 from pngconf.h */
472 /* Users may want to use these so they are not private. Any library
473 * functions that are passed far data must be model-independent.
476 /* Memory model/platform independent fns */
477 #ifndef PNG_ABORT
478 # ifdef _WINDOWS_
479 # define PNG_ABORT() ExitProcess(0)
480 # else
481 # define PNG_ABORT() abort()
482 # endif
483 #endif
485 /* These macros may need to be architecture dependent. */
486 #define PNG_ALIGN_NONE 0 /* do not use data alignment */
487 #define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
488 #ifdef offsetof
489 # define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
490 #else
491 # define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
492 #endif
493 #define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
495 #ifndef PNG_ALIGN_TYPE
496 /* Default to using aligned access optimizations and requiring alignment to a
497 * multiple of the data type size. Override in a compiler specific fashion
498 * if necessary by inserting tests here:
500 # define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
501 #endif
503 #if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
504 /* This is used because in some compiler implementations non-aligned
505 * structure members are supported, so the offsetof approach below fails.
506 * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
507 * is good for performance. Do not do this unless you have tested the result
508 * and understand it.
510 # define png_alignof(type) (sizeof (type))
511 #else
512 # if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
513 # define png_alignof(type) offsetof(struct{char c; type t;}, t)
514 # else
515 # if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
516 # define png_alignof(type) (1)
517 # endif
518 /* Else leave png_alignof undefined to prevent use thereof */
519 # endif
520 #endif
522 /* This implicitly assumes alignment is always to a power of 2. */
523 #ifdef png_alignof
524 # define png_isaligned(ptr, type)\
525 ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
526 #else
527 # define png_isaligned(ptr, type) 0
528 #endif
530 /* End of memory model/platform independent support */
531 /* End of 1.5.0beta36 move from pngconf.h */
533 /* CONSTANTS and UTILITY MACROS
534 * These are used internally by libpng and not exposed in the API
537 /* Various modes of operation. Note that after an init, mode is set to
538 * zero automatically when the structure is created. Three of these
539 * are defined in png.h because they need to be visible to applications
540 * that call png_set_unknown_chunk().
542 /* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */
543 /* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */
544 #define PNG_HAVE_IDAT 0x04
545 /* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */
546 #define PNG_HAVE_IEND 0x10
547 /* 0x20 (unused) */
548 /* 0x40 (unused) */
549 /* 0x80 (unused) */
550 #define PNG_HAVE_CHUNK_HEADER 0x100
551 #define PNG_WROTE_tIME 0x200
552 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
553 #define PNG_BACKGROUND_IS_GRAY 0x800
554 #define PNG_HAVE_PNG_SIGNATURE 0x1000
555 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
556 /* 0x4000 (unused) */
557 #define PNG_IS_READ_STRUCT 0x8000 /* Else is a write struct */
558 #ifdef PNG_APNG_SUPPORTED
559 #define PNG_HAVE_acTL 0x10000
560 #define PNG_HAVE_fcTL 0x20000
561 #endif
563 /* Flags for the transformations the PNG library does on the image data */
564 #define PNG_BGR 0x0001
565 #define PNG_INTERLACE 0x0002
566 #define PNG_PACK 0x0004
567 #define PNG_SHIFT 0x0008
568 #define PNG_SWAP_BYTES 0x0010
569 #define PNG_INVERT_MONO 0x0020
570 #define PNG_QUANTIZE 0x0040
571 #define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */
572 #define PNG_BACKGROUND_EXPAND 0x0100
573 #define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */
574 #define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */
575 #define PNG_RGBA 0x0800
576 #define PNG_EXPAND 0x1000
577 #define PNG_GAMMA 0x2000
578 #define PNG_GRAY_TO_RGB 0x4000
579 #define PNG_FILLER 0x8000
580 #define PNG_PACKSWAP 0x10000
581 #define PNG_SWAP_ALPHA 0x20000
582 #define PNG_STRIP_ALPHA 0x40000
583 #define PNG_INVERT_ALPHA 0x80000
584 #define PNG_USER_TRANSFORM 0x100000
585 #define PNG_RGB_TO_GRAY_ERR 0x200000
586 #define PNG_RGB_TO_GRAY_WARN 0x400000
587 #define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
588 #define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */
589 #define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */
590 #define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */
591 #define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */
592 /* 0x8000000 unused */
593 /* 0x10000000 unused */
594 /* 0x20000000 unused */
595 /* 0x40000000 unused */
596 /* Flags for png_create_struct */
597 #define PNG_STRUCT_PNG 0x0001
598 #define PNG_STRUCT_INFO 0x0002
600 /* Scaling factor for filter heuristic weighting calculations */
601 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
602 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
604 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
605 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
606 #define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002 /* Added to libpng-1.6.0 */
607 /* 0x0004 unused */
608 #define PNG_FLAG_ZSTREAM_ENDED 0x0008 /* Added to libpng-1.6.0 */
609 /* 0x0010 unused */
610 /* 0x0020 unused */
611 #define PNG_FLAG_ROW_INIT 0x0040
612 #define PNG_FLAG_FILLER_AFTER 0x0080
613 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
614 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
615 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400
616 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
617 #define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */
618 #define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */
619 #define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */
620 /* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 */
621 /* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 */
622 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000
623 #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000
624 #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000
625 #define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000 /* Added to libpng-1.4.0 */
626 #define PNG_FLAG_APP_WARNINGS_WARN 0x200000 /* Added to libpng-1.6.0 */
627 #define PNG_FLAG_APP_ERRORS_WARN 0x400000 /* Added to libpng-1.6.0 */
628 /* 0x800000 unused */
629 /* 0x1000000 unused */
630 /* 0x2000000 unused */
631 /* 0x4000000 unused */
632 /* 0x8000000 unused */
633 /* 0x10000000 unused */
634 /* 0x20000000 unused */
635 /* 0x40000000 unused */
637 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
638 PNG_FLAG_CRC_ANCILLARY_NOWARN)
640 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
641 PNG_FLAG_CRC_CRITICAL_IGNORE)
643 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
644 PNG_FLAG_CRC_CRITICAL_MASK)
646 /* Save typing and make code easier to understand */
648 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
649 abs((int)((c1).green) - (int)((c2).green)) + \
650 abs((int)((c1).blue) - (int)((c2).blue)))
652 /* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
653 * by dividing by 257 *with rounding*. This macro is exact for the given range.
654 * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
655 * macro were established by experiment (modifying the added value). The macro
656 * has a second variant that takes a value already scaled by 255 and divides by
657 * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
658 * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
660 #define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
661 #define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
663 /* Added to libpng-1.2.6 JB */
664 #define PNG_ROWBYTES(pixel_bits, width) \
665 ((pixel_bits) >= 8 ? \
666 ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
667 (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
669 /* PNG_OUT_OF_RANGE returns true if value is outside the range
670 * ideal-delta..ideal+delta. Each argument is evaluated twice.
671 * "ideal" and "delta" should be constants, normally simple
672 * integers, "value" a variable. Added to libpng-1.2.6 JB
674 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
675 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
677 /* Conversions between fixed and floating point, only defined if
678 * required (to make sure the code doesn't accidentally use float
679 * when it is supposedly disabled.)
681 #ifdef PNG_FLOATING_POINT_SUPPORTED
682 /* The floating point conversion can't overflow, though it can and
683 * does lose accuracy relative to the original fixed point value.
684 * In practice this doesn't matter because png_fixed_point only
685 * stores numbers with very low precision. The png_ptr and s
686 * arguments are unused by default but are there in case error
687 * checking becomes a requirement.
689 #define png_float(png_ptr, fixed, s) (.00001 * (fixed))
691 /* The fixed point conversion performs range checking and evaluates
692 * its argument multiple times, so must be used with care. The
693 * range checking uses the PNG specification values for a signed
694 * 32 bit fixed point value except that the values are deliberately
695 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
696 * (2^31-1) * 100000). 's' is a string that describes the value being
697 * converted.
699 * NOTE: this macro will raise a png_error if the range check fails,
700 * therefore it is normally only appropriate to use this on values
701 * that come from API calls or other sources where an out of range
702 * error indicates a programming error, not a data error!
704 * NOTE: by default this is off - the macro is not used - because the
705 * function call saves a lot of code.
707 #ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
708 #define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
709 ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
710 #endif
711 /* else the corresponding function is defined below, inside the scope of the
712 * cplusplus test.
714 #endif
716 /* Constants for known chunk types. If you need to add a chunk, define the name
717 * here. For historical reasons these constants have the form png_<name>; i.e.
718 * the prefix is lower case. Please use decimal values as the parameters to
719 * match the ISO PNG specification and to avoid relying on the C locale
720 * interpretation of character values.
722 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
723 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
724 * to be generated if required.
726 * PNG_32b correctly produces a value shifted by up to 24 bits, even on
727 * architectures where (int) is only 16 bits.
729 #define PNG_32b(b,s) ((png_uint_32)(b) << (s))
730 #define PNG_U32(b1,b2,b3,b4) \
731 (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
733 /* Constants for known chunk types.
735 * MAINTAINERS: If you need to add a chunk, define the name here.
736 * For historical reasons these constants have the form png_<name>; i.e.
737 * the prefix is lower case. Please use decimal values as the parameters to
738 * match the ISO PNG specification and to avoid relying on the C locale
739 * interpretation of character values. Please keep the list sorted.
741 * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
742 * type. In fact the specification does not express chunk types this way,
743 * however using a 32-bit value means that the chunk type can be read from the
744 * stream using exactly the same code as used for a 32-bit unsigned value and
745 * can be examined far more efficiently (using one arithmetic compare).
747 * Prior to 1.5.6 the chunk type constants were expressed as C strings. The
748 * libpng API still uses strings for 'unknown' chunks and a macro,
749 * PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice
750 * that for portable code numeric values must still be used; the string "IHDR"
751 * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
753 * In 1.7.0 the definitions will be made public in png.h to avoid having to
754 * duplicate the same definitions in application code.
756 #define png_IDAT PNG_U32( 73, 68, 65, 84)
757 #define png_IEND PNG_U32( 73, 69, 78, 68)
758 #define png_IHDR PNG_U32( 73, 72, 68, 82)
759 #define png_PLTE PNG_U32( 80, 76, 84, 69)
760 #define png_bKGD PNG_U32( 98, 75, 71, 68)
761 #define png_cHRM PNG_U32( 99, 72, 82, 77)
762 #define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */
763 #define png_gAMA PNG_U32(103, 65, 77, 65)
764 #define png_gIFg PNG_U32(103, 73, 70, 103)
765 #define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */
766 #define png_gIFx PNG_U32(103, 73, 70, 120)
767 #define png_hIST PNG_U32(104, 73, 83, 84)
768 #define png_iCCP PNG_U32(105, 67, 67, 80)
769 #define png_iTXt PNG_U32(105, 84, 88, 116)
770 #define png_oFFs PNG_U32(111, 70, 70, 115)
771 #define png_pCAL PNG_U32(112, 67, 65, 76)
772 #define png_pHYs PNG_U32(112, 72, 89, 115)
773 #define png_sBIT PNG_U32(115, 66, 73, 84)
774 #define png_sCAL PNG_U32(115, 67, 65, 76)
775 #define png_sPLT PNG_U32(115, 80, 76, 84)
776 #define png_sRGB PNG_U32(115, 82, 71, 66)
777 #define png_sTER PNG_U32(115, 84, 69, 82)
778 #define png_tEXt PNG_U32(116, 69, 88, 116)
779 #define png_tIME PNG_U32(116, 73, 77, 69)
780 #define png_tRNS PNG_U32(116, 82, 78, 83)
781 #define png_zTXt PNG_U32(122, 84, 88, 116)
783 #ifdef PNG_APNG_SUPPORTED
784 #define png_acTL PNG_U32( 97, 99, 84, 76)
785 #define png_fcTL PNG_U32(102, 99, 84, 76)
786 #define png_fdAT PNG_U32(102, 100, 65, 84)
788 /* For png_struct.apng_flags: */
789 #define PNG_FIRST_FRAME_HIDDEN 0x0001
790 #define PNG_APNG_APP 0x0002
791 #endif
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.
796 #define PNG_CHUNK_FROM_STRING(s)\
797 PNG_U32(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
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.
803 #define PNG_STRING_FROM_CHUNK(s,c)\
804 (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
805 ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
807 /* Do the same but terminate with a null character. */
808 #define PNG_CSTRING_FROM_CHUNK(s,c)\
809 (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
811 /* Test on flag values as defined in the spec (section 5.4): */
812 #define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29))
813 #define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
814 #define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
815 #define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
816 #define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
818 /* Gamma values (new at libpng-1.5.4): */
819 #define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
820 #define PNG_GAMMA_MAC_INVERSE 65909
821 #define PNG_GAMMA_sRGB_INVERSE 45455
823 /* Almost everything below is C specific; the #defines above can be used in
824 * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
826 #ifndef PNG_VERSION_INFO_ONLY
828 #include "pngstruct.h"
829 #include "pnginfo.h"
831 /* Validate the include paths - the include path used to generate pnglibconf.h
832 * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
834 #if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
835 # error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
836 "-I (include path) error: see the notes in pngpriv.h"
837 /* This means that when pnglibconf.h was built the copy of zlib.h that it
838 * used is not the same as the one being used here. Because the build of
839 * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
840 * zlib version number and because this affects handling of certain broken
841 * PNG files the -I directives must match.
843 * The most likely explanation is that you passed a -I in CFLAGS. This will
844 * not work; all the preprocessor directories and in particular all the -I
845 * directives must be in CPPFLAGS.
847 #endif
849 /* This is used for 16 bit gamma tables -- only the top level pointers are
850 * const; this could be changed:
852 typedef const png_uint_16p * png_const_uint_16pp;
854 /* Added to libpng-1.5.7: sRGB conversion tables */
855 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
856 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
857 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
858 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
859 /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
860 * 0..65535. This table gives the closest 16-bit answers (no errors).
862 #endif
864 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
865 PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
867 #define PNG_sRGB_FROM_LINEAR(linear) ((png_byte)((png_sRGB_base[(linear)>>15] +\
868 ((((linear)&0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))
869 /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
870 * encoded value with maximum error 0.646365. Note that the input is not a
871 * 16-bit value; it has been multiplied by 255! */
872 #endif /* SIMPLIFIED_READ/WRITE */
875 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
876 #ifdef __cplusplus
877 extern "C" {
878 #endif /* __cplusplus */
880 /* Internal functions; these are not exported from a DLL however because they
881 * are used within several of the C source files they have to be C extern.
883 * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
886 /* Zlib support */
887 #define PNG_UNEXPECTED_ZLIB_RETURN (-7)
888 PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
889 PNG_EMPTY);
890 /* Used by the zlib handling functions to ensure that z_stream::msg is always
891 * set before they return.
894 #ifdef PNG_WRITE_SUPPORTED
895 PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
896 png_compression_bufferp *list),PNG_EMPTY);
897 /* Free the buffer list used by the compressed write code. */
898 #endif
900 #if defined(PNG_FLOATING_POINT_SUPPORTED) && \
901 !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
902 (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
903 defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
904 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
905 (defined(PNG_sCAL_SUPPORTED) && \
906 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
907 PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
908 double fp, png_const_charp text),PNG_EMPTY);
909 #endif
911 /* Check the user version string for compatibility, returns false if the version
912 * numbers aren't compatible.
914 PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
915 png_const_charp user_png_ver),PNG_EMPTY);
917 /* Internal base allocator - no messages, NULL on failure to allocate. This
918 * does, however, call the application provided allocator and that could call
919 * png_error (although that would be a bug in the application implementation.)
921 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
922 png_alloc_size_t size),PNG_ALLOCATED);
924 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
925 defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
926 /* Internal array allocator, outputs no error or warning messages on failure,
927 * just returns NULL.
929 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
930 int nelements, size_t element_size),PNG_ALLOCATED);
932 /* The same but an existing array is extended by add_elements. This function
933 * also memsets the new elements to 0 and copies the old elements. The old
934 * array is not freed or altered.
936 PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
937 png_const_voidp array, int old_elements, int add_elements,
938 size_t element_size),PNG_ALLOCATED);
939 #endif /* text, sPLT or unknown chunks */
941 /* Magic to create a struct when there is no struct to call the user supplied
942 * memory allocators. Because error handling has not been set up the memory
943 * handlers can't safely call png_error, but this is an obscure and undocumented
944 * restriction so libpng has to assume that the 'free' handler, at least, might
945 * call png_error.
947 PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
948 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
949 png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
950 png_free_ptr free_fn),PNG_ALLOCATED);
952 /* Free memory from internal libpng struct */
953 PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
954 PNG_EMPTY);
956 /* Free an allocated jmp_buf (always succeeds) */
957 PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
959 /* Function to allocate memory for zlib. PNGAPI is disallowed. */
960 PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
961 PNG_ALLOCATED);
963 /* Function to free memory for zlib. PNGAPI is disallowed. */
964 PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
966 /* Next four functions are used internally as callbacks. PNGCBAPI is required
967 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
968 * PNGCBAPI at 1.5.0
971 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
972 png_bytep data, png_size_t length),PNG_EMPTY);
974 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
975 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
976 png_bytep buffer, png_size_t length),PNG_EMPTY);
977 #endif
979 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
980 png_bytep data, png_size_t length),PNG_EMPTY);
982 #ifdef PNG_WRITE_FLUSH_SUPPORTED
983 # ifdef PNG_STDIO_SUPPORTED
984 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
985 PNG_EMPTY);
986 # endif
987 #endif
989 /* Reset the CRC variable */
990 PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
992 /* Write the "data" buffer to whatever output you are using */
993 PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
994 png_const_bytep data, png_size_t length),PNG_EMPTY);
996 /* Read and check the PNG file signature */
997 PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
998 png_inforp info_ptr),PNG_EMPTY);
1000 /* Read the chunk header (length + type name) */
1001 PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
1002 PNG_EMPTY);
1004 /* Read data from whatever input you are using into the "data" buffer */
1005 PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
1006 png_size_t length),PNG_EMPTY);
1008 /* Read bytes into buf, and update png_ptr->crc */
1009 PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
1010 png_uint_32 length),PNG_EMPTY);
1012 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
1013 PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
1014 png_uint_32 skip),PNG_EMPTY);
1016 /* Read the CRC from the file and compare it to the libpng calculated CRC */
1017 PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
1019 /* Calculate the CRC over a section of data. Note that we are only
1020 * passing a maximum of 64K on systems that have this as a memory limit,
1021 * since this is the maximum buffer size we can specify.
1023 PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
1024 png_const_bytep ptr, png_size_t length),PNG_EMPTY);
1026 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1027 PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
1028 #endif
1030 /* Write various chunks */
1032 /* Write the IHDR chunk, and update the png_struct with the necessary
1033 * information.
1035 PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
1036 png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1037 int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
1039 PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
1040 png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
1042 PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
1043 png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
1044 PNG_EMPTY);
1046 PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
1048 #ifdef PNG_WRITE_gAMA_SUPPORTED
1049 PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
1050 png_fixed_point file_gamma),PNG_EMPTY);
1051 #endif
1053 #ifdef PNG_WRITE_sBIT_SUPPORTED
1054 PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
1055 png_const_color_8p sbit, int color_type),PNG_EMPTY);
1056 #endif
1058 #ifdef PNG_WRITE_cHRM_SUPPORTED
1059 PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
1060 const png_xy *xy), PNG_EMPTY);
1061 /* The xy value must have been previously validated */
1062 #endif
1064 #ifdef PNG_WRITE_sRGB_SUPPORTED
1065 PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1066 int intent),PNG_EMPTY);
1067 #endif
1069 #ifdef PNG_WRITE_iCCP_SUPPORTED
1070 PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1071 png_const_charp name, png_const_bytep profile), PNG_EMPTY);
1072 /* The profile must have been previously validated for correctness, the
1073 * length comes from the first four bytes. Only the base, deflate,
1074 * compression is supported.
1076 #endif
1078 #ifdef PNG_WRITE_sPLT_SUPPORTED
1079 PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1080 png_const_sPLT_tp palette),PNG_EMPTY);
1081 #endif
1083 #ifdef PNG_WRITE_tRNS_SUPPORTED
1084 PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1085 png_const_bytep trans, png_const_color_16p values, int number,
1086 int color_type),PNG_EMPTY);
1087 #endif
1089 #ifdef PNG_WRITE_bKGD_SUPPORTED
1090 PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1091 png_const_color_16p values, int color_type),PNG_EMPTY);
1092 #endif
1094 #ifdef PNG_WRITE_hIST_SUPPORTED
1095 PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1096 png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1097 #endif
1099 /* Chunks that have keywords */
1100 #ifdef PNG_WRITE_tEXt_SUPPORTED
1101 PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1102 png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
1103 #endif
1105 #ifdef PNG_WRITE_zTXt_SUPPORTED
1106 PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1107 key, png_const_charp text, int compression),PNG_EMPTY);
1108 #endif
1110 #ifdef PNG_WRITE_iTXt_SUPPORTED
1111 PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1112 int compression, png_const_charp key, png_const_charp lang,
1113 png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1114 #endif
1116 #ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
1117 PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1118 png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1119 #endif
1121 #ifdef PNG_WRITE_oFFs_SUPPORTED
1122 PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1123 png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1124 #endif
1126 #ifdef PNG_WRITE_pCAL_SUPPORTED
1127 PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1128 png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1129 png_const_charp units, png_charpp params),PNG_EMPTY);
1130 #endif
1132 #ifdef PNG_WRITE_pHYs_SUPPORTED
1133 PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1134 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1135 int unit_type),PNG_EMPTY);
1136 #endif
1138 #ifdef PNG_WRITE_tIME_SUPPORTED
1139 PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1140 png_const_timep mod_time),PNG_EMPTY);
1141 #endif
1143 #ifdef PNG_WRITE_sCAL_SUPPORTED
1144 PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1145 int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1146 #endif
1148 /* Called when finished processing a row of data */
1149 PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1150 PNG_EMPTY);
1152 /* Internal use only. Called before first row of data */
1153 PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1154 PNG_EMPTY);
1156 /* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
1157 * array of png_ptr->width pixels. If the image is not interlaced or this
1158 * is the final pass this just does a memcpy, otherwise the "display" flag
1159 * is used to determine whether to copy pixels that are not in the current pass.
1161 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1162 * function to achieve the documented 'blocky' appearance during interlaced read
1163 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1164 * are not changed if they are not in the current pass, when display is 0.
1166 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1168 * The API always reads from the png_struct row buffer and always assumes that
1169 * it is full width (png_do_read_interlace has already been called.)
1171 * This function is only ever used to write to row buffers provided by the
1172 * caller of the relevant libpng API and the row must have already been
1173 * transformed by the read transformations.
1175 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1176 * bitmasks for use within the code, otherwise runtime generated masks are used.
1177 * The default is compile time masks.
1179 #ifndef PNG_USE_COMPILE_TIME_MASKS
1180 # define PNG_USE_COMPILE_TIME_MASKS 1
1181 #endif
1182 PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1183 png_bytep row, int display),PNG_EMPTY);
1185 #ifdef PNG_READ_INTERLACING_SUPPORTED
1186 /* Expand an interlaced row: the 'row_info' describes the pass data that has
1187 * been read in and must correspond to the pixels in 'row', the pixels are
1188 * expanded (moved apart) in 'row' to match the final layout, when doing this
1189 * the pixels are *replicated* to the intervening space. This is essential for
1190 * the correct operation of png_combine_row, above.
1192 PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1193 png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1194 #endif
1196 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
1198 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1199 /* Grab pixels out of a row for an interlaced pass */
1200 PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1201 png_bytep row, int pass),PNG_EMPTY);
1202 #endif
1204 /* Unfilter a row: check the filter value before calling this, there is no point
1205 * calling it for PNG_FILTER_VALUE_NONE.
1207 PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1208 row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1210 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1211 png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1212 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1213 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1214 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1215 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1216 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1217 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1218 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1219 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1220 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1221 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1222 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1223 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1225 /* Choose the best filter to use and filter the row data */
1226 PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1227 png_row_infop row_info),PNG_EMPTY);
1229 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1230 PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1231 png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1232 /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
1233 * is NULL the function checks, instead, for the end of the stream. In this
1234 * case a benign error will be issued if the stream end is not found or if
1235 * extra data has to be consumed.
1237 PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1238 PNG_EMPTY);
1239 /* This cleans up when the IDAT LZ stream does not end when the last image
1240 * byte is read; there is still some pending input.
1243 PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1244 PNG_EMPTY);
1245 /* Finish a row while reading, dealing with interlacing passes, etc. */
1246 #endif /* SEQUENTIAL_READ */
1248 /* Initialize the row buffers, etc. */
1249 PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1251 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1252 /* Optional call to update the users info structure */
1253 PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1254 png_inforp info_ptr),PNG_EMPTY);
1255 #endif
1257 /* Shared transform functions, defined in pngtran.c */
1258 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1259 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1260 PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1261 png_bytep row, int at_start),PNG_EMPTY);
1262 #endif
1264 #ifdef PNG_16BIT_SUPPORTED
1265 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1266 PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1267 png_bytep row),PNG_EMPTY);
1268 #endif
1269 #endif
1271 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1272 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1273 PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1274 png_bytep row),PNG_EMPTY);
1275 #endif
1277 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1278 PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1279 png_bytep row),PNG_EMPTY);
1280 #endif
1282 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1283 PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1284 png_bytep row),PNG_EMPTY);
1285 #endif
1287 /* The following decodes the appropriate chunks, and does error correction,
1288 * then calls the appropriate callback for the chunk if it is valid.
1291 /* Decode the IHDR chunk */
1292 PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1293 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1294 PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1295 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1296 PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1297 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1299 #ifdef PNG_READ_bKGD_SUPPORTED
1300 PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1301 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1302 #endif
1304 #ifdef PNG_READ_cHRM_SUPPORTED
1305 PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1306 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1307 #endif
1309 #ifdef PNG_READ_gAMA_SUPPORTED
1310 PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1311 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1312 #endif
1314 #ifdef PNG_READ_hIST_SUPPORTED
1315 PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1316 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1317 #endif
1319 #ifdef PNG_READ_iCCP_SUPPORTED
1320 PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1321 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1322 #endif /* READ_iCCP */
1324 #ifdef PNG_READ_iTXt_SUPPORTED
1325 PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1326 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1327 #endif
1329 #ifdef PNG_READ_oFFs_SUPPORTED
1330 PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1331 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1332 #endif
1334 #ifdef PNG_READ_pCAL_SUPPORTED
1335 PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1336 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1337 #endif
1339 #ifdef PNG_READ_pHYs_SUPPORTED
1340 PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1341 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1342 #endif
1344 #ifdef PNG_READ_sBIT_SUPPORTED
1345 PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1346 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1347 #endif
1349 #ifdef PNG_READ_sCAL_SUPPORTED
1350 PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1351 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1352 #endif
1354 #ifdef PNG_READ_sPLT_SUPPORTED
1355 PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1356 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1357 #endif /* READ_sPLT */
1359 #ifdef PNG_READ_sRGB_SUPPORTED
1360 PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1361 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1362 #endif
1364 #ifdef PNG_READ_tEXt_SUPPORTED
1365 PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1366 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1367 #endif
1369 #ifdef PNG_READ_tIME_SUPPORTED
1370 PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1371 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1372 #endif
1374 #ifdef PNG_READ_tRNS_SUPPORTED
1375 PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1376 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1377 #endif
1379 #ifdef PNG_READ_zTXt_SUPPORTED
1380 PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1381 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1382 #endif
1384 PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
1385 png_uint_32 chunk_name),PNG_EMPTY);
1387 PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1388 png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1389 /* This is the function that gets called for unknown chunks. The 'keep'
1390 * argument is either non-zero for a known chunk that has been set to be
1391 * handled as unknown or zero for an unknown chunk. By default the function
1392 * just skips the chunk or errors out if it is critical.
1395 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
1396 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1397 PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1398 (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1399 /* Exactly as the API png_handle_as_unknown() except that the argument is a
1400 * 32-bit chunk name, not a string.
1402 #endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
1404 /* Handle the transformations for reading and writing */
1405 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1406 PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1407 png_row_infop row_info),PNG_EMPTY);
1408 #endif
1409 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1410 PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1411 png_row_infop row_info),PNG_EMPTY);
1412 #endif
1414 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1415 PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1416 PNG_EMPTY);
1417 #endif
1419 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1420 PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1421 png_inforp info_ptr),PNG_EMPTY);
1422 PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1423 png_inforp info_ptr),PNG_EMPTY);
1424 PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1425 PNG_INTERNAL_FUNCTION(void,png_push_crc_skip,(png_structrp png_ptr,
1426 png_uint_32 length),PNG_EMPTY);
1427 PNG_INTERNAL_FUNCTION(void,png_push_crc_finish,(png_structrp png_ptr),
1428 PNG_EMPTY);
1429 PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1430 PNG_EMPTY);
1431 PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1432 png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1433 PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1434 PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1435 png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1436 PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1437 PNG_EMPTY);
1438 PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1439 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1440 PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1441 png_inforp info_ptr),PNG_EMPTY);
1442 PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1443 png_inforp info_ptr),PNG_EMPTY);
1444 PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1445 png_bytep row),PNG_EMPTY);
1446 PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1447 png_inforp info_ptr),PNG_EMPTY);
1448 PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1449 png_inforp info_ptr),PNG_EMPTY);
1450 PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1451 PNG_EMPTY);
1452 # ifdef PNG_READ_tEXt_SUPPORTED
1453 PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1454 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1455 PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1456 png_inforp info_ptr),PNG_EMPTY);
1457 # endif
1458 # ifdef PNG_READ_zTXt_SUPPORTED
1459 PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1460 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1461 PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1462 png_inforp info_ptr),PNG_EMPTY);
1463 # endif
1464 # ifdef PNG_READ_iTXt_SUPPORTED
1465 PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1466 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1467 PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1468 png_inforp info_ptr),PNG_EMPTY);
1469 # endif
1471 #endif /* PROGRESSIVE_READ */
1473 #ifdef PNG_APNG_SUPPORTED
1474 PNG_INTERNAL_FUNCTION(void,png_ensure_fcTL_is_valid,(png_structp png_ptr,
1475 png_uint_32 width, png_uint_32 height,
1476 png_uint_32 x_offset, png_uint_32 y_offset,
1477 png_uint_16 delay_num, png_uint_16 delay_den,
1478 png_byte dispose_op, png_byte blend_op),PNG_EMPTY);
1480 #ifdef PNG_READ_APNG_SUPPORTED
1481 PNG_INTERNAL_FUNCTION(void,png_handle_acTL,(png_structp png_ptr,
1482 png_infop info_ptr, png_uint_32 length),PNG_EMPTY);
1483 PNG_INTERNAL_FUNCTION(void,png_handle_fcTL,(png_structp png_ptr,
1484 png_infop info_ptr, png_uint_32 length),PNG_EMPTY);
1485 PNG_INTERNAL_FUNCTION(void,png_handle_fdAT,(png_structp png_ptr,
1486 png_infop info_ptr, png_uint_32 length),PNG_EMPTY);
1487 PNG_INTERNAL_FUNCTION(void,png_have_info,(png_structp png_ptr,
1488 png_infop info_ptr),PNG_EMPTY);
1489 PNG_INTERNAL_FUNCTION(void,png_ensure_sequence_number,(png_structp png_ptr,
1490 png_uint_32 length),PNG_EMPTY);
1491 PNG_INTERNAL_FUNCTION(void,png_read_reset,(png_structp png_ptr),PNG_EMPTY);
1492 PNG_INTERNAL_FUNCTION(void,png_read_reinit,(png_structp png_ptr,
1493 png_infop info_ptr),PNG_EMPTY);
1494 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1495 PNG_INTERNAL_FUNCTION(void,png_progressive_read_reset,(png_structp png_ptr),
1496 PNG_EMPTY);
1497 #endif /* PROGRESSIVE_READ */
1498 #endif /* READ_APNG */
1500 #ifdef PNG_WRITE_APNG_SUPPORTED
1501 PNG_INTERNAL_FUNCTION(void,png_write_acTL,(png_structp png_ptr,
1502 png_uint_32 num_frames, png_uint_32 num_plays),PNG_EMPTY);
1503 PNG_INTERNAL_FUNCTION(void,png_write_fcTL,(png_structp png_ptr,
1504 png_uint_32 width, png_uint_32 height,
1505 png_uint_32 x_offset, png_uint_32 y_offset,
1506 png_uint_16 delay_num, png_uint_16 delay_den,
1507 png_byte dispose_op, png_byte blend_op),PNG_EMPTY);
1508 PNG_INTERNAL_FUNCTION(void,png_write_fdAT,(png_structp png_ptr,
1509 png_const_bytep data, png_size_t length),PNG_EMPTY);
1510 PNG_INTERNAL_FUNCTION(void,png_write_reset,(png_structp png_ptr),PNG_EMPTY);
1511 PNG_INTERNAL_FUNCTION(void,png_write_reinit,(png_structp png_ptr,
1512 png_infop info_ptr, png_uint_32 width, png_uint_32 height),PNG_EMPTY);
1513 #endif /* WRITE_APNG */
1514 #endif /* APNG */
1516 /* Added at libpng version 1.6.0 */
1517 #ifdef PNG_GAMMA_SUPPORTED
1518 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1519 png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1520 /* Set the colorspace gamma with a value provided by the application or by
1521 * the gAMA chunk on read. The value will override anything set by an ICC
1522 * profile.
1525 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1526 png_inforp info_ptr), PNG_EMPTY);
1527 /* Synchronize the info 'valid' flags with the colorspace */
1529 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1530 png_inforp info_ptr), PNG_EMPTY);
1531 /* Copy the png_struct colorspace to the info_struct and call the above to
1532 * synchronize the flags. Checks for NULL info_ptr and does nothing.
1534 #endif
1536 /* Added at libpng version 1.4.0 */
1537 #ifdef PNG_COLORSPACE_SUPPORTED
1538 /* These internal functions are for maintaining the colorspace structure within
1539 * a png_info or png_struct (or, indeed, both).
1541 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1542 (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1543 int preferred), PNG_EMPTY);
1545 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1546 (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1547 int preferred), PNG_EMPTY);
1549 #ifdef PNG_sRGB_SUPPORTED
1550 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1551 png_colorspacerp colorspace, int intent), PNG_EMPTY);
1552 /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1553 * flags to write them, if it returns false there was a problem and an error
1554 * message has already been output (but the colorspace may still need to be
1555 * synced to record the invalid flag).
1557 #endif /* sRGB */
1559 #ifdef PNG_iCCP_SUPPORTED
1560 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1561 png_colorspacerp colorspace, png_const_charp name,
1562 png_uint_32 profile_length, png_const_bytep profile, int color_type),
1563 PNG_EMPTY);
1564 /* The 'name' is used for information only */
1566 /* Routines for checking parts of an ICC profile. */
1567 PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1568 png_colorspacerp colorspace, png_const_charp name,
1569 png_uint_32 profile_length), PNG_EMPTY);
1570 PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1571 png_colorspacerp colorspace, png_const_charp name,
1572 png_uint_32 profile_length,
1573 png_const_bytep profile /* first 132 bytes only */, int color_type),
1574 PNG_EMPTY);
1575 PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1576 png_colorspacerp colorspace, png_const_charp name,
1577 png_uint_32 profile_length,
1578 png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1579 #ifdef PNG_sRGB_SUPPORTED
1580 PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1581 png_const_structrp png_ptr, png_colorspacerp colorspace,
1582 png_const_bytep profile, uLong adler), PNG_EMPTY);
1583 /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1584 * be zero to indicate that it is not available. It is used, if provided,
1585 * as a fast check on the profile when checking to see if it is sRGB.
1587 #endif
1588 #endif /* iCCP */
1590 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1591 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1592 (png_structrp png_ptr), PNG_EMPTY);
1593 /* Set the rgb_to_gray coefficients from the colorspace Y values */
1594 #endif /* READ_RGB_TO_GRAY */
1595 #endif /* COLORSPACE */
1597 /* Added at libpng version 1.4.0 */
1598 PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1599 png_uint_32 width, png_uint_32 height, int bit_depth,
1600 int color_type, int interlace_type, int compression_type,
1601 int filter_type),PNG_EMPTY);
1603 /* Added at libpng version 1.5.10 */
1604 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1605 defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1606 PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1607 (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1608 #endif
1610 #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1611 PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1612 png_const_charp name),PNG_NORETURN);
1613 #endif
1615 /* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1616 * the end. Always leaves the buffer nul terminated. Never errors out (and
1617 * there is no error code.)
1619 PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1620 size_t pos, png_const_charp string),PNG_EMPTY);
1622 /* Various internal functions to handle formatted warning messages, currently
1623 * only implemented for warnings.
1625 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1626 /* Utility to dump an unsigned value into a buffer, given a start pointer and
1627 * and end pointer (which should point just *beyond* the end of the buffer!)
1628 * Returns the pointer to the start of the formatted string. This utility only
1629 * does unsigned values.
1631 PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1632 png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1634 /* Convenience macro that takes an array: */
1635 #define PNG_FORMAT_NUMBER(buffer,format,number) \
1636 png_format_number(buffer, buffer + (sizeof buffer), format, number)
1638 /* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1639 #define PNG_NUMBER_BUFFER_SIZE 24
1641 /* These are the integer formats currently supported, the name is formed from
1642 * the standard printf(3) format string.
1644 #define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
1645 #define PNG_NUMBER_FORMAT_02u 2
1646 #define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
1647 #define PNG_NUMBER_FORMAT_02d 2
1648 #define PNG_NUMBER_FORMAT_x 3
1649 #define PNG_NUMBER_FORMAT_02x 4
1650 #define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1651 #endif
1653 #ifdef PNG_WARNINGS_SUPPORTED
1654 /* New defines and members adding in libpng-1.5.4 */
1655 # define PNG_WARNING_PARAMETER_SIZE 32
1656 # define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1658 /* An l-value of this type has to be passed to the APIs below to cache the
1659 * values of the parameters to a formatted warning message.
1661 typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1662 PNG_WARNING_PARAMETER_SIZE];
1664 PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1665 int number, png_const_charp string),PNG_EMPTY);
1666 /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1667 * including the trailing '\0'.
1669 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1670 (png_warning_parameters p, int number, int format, png_alloc_size_t value),
1671 PNG_EMPTY);
1672 /* Use png_alloc_size_t because it is an unsigned type as big as any we
1673 * need to output. Use the following for a signed value.
1675 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1676 (png_warning_parameters p, int number, int format, png_int_32 value),
1677 PNG_EMPTY);
1679 PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1680 png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1681 /* 'message' follows the X/Open approach of using @1, @2 to insert
1682 * parameters previously supplied using the above functions. Errors in
1683 * specifying the parameters will simply result in garbage substitutions.
1685 #endif
1687 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1688 /* Application errors (new in 1.6); use these functions (declared below) for
1689 * errors in the parameters or order of API function calls on read. The
1690 * 'warning' should be used for an error that can be handled completely; the
1691 * 'error' for one which can be handled safely but which may lose application
1692 * information or settings.
1694 * By default these both result in a png_error call prior to release, while in a
1695 * released version the 'warning' is just a warning. However if the application
1696 * explicitly disables benign errors (explicitly permitting the code to lose
1697 * information) they both turn into warnings.
1699 * If benign errors aren't supported they end up as the corresponding base call
1700 * (png_warning or png_error.)
1702 PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1703 png_const_charp message),PNG_EMPTY);
1704 /* The application provided invalid parameters to an API function or called
1705 * an API function at the wrong time, libpng can completely recover.
1708 PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1709 png_const_charp message),PNG_EMPTY);
1710 /* As above but libpng will ignore the call, or attempt some other partial
1711 * recovery from the error.
1713 #else
1714 # define png_app_warning(pp,s) png_warning(pp,s)
1715 # define png_app_error(pp,s) png_error(pp,s)
1716 #endif
1718 PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1719 png_const_charp message, int error),PNG_EMPTY);
1720 /* Report a recoverable issue in chunk data. On read this is used to report
1721 * a problem found while reading a particular chunk and the
1722 * png_chunk_benign_error or png_chunk_warning function is used as
1723 * appropriate. On write this is used to report an error that comes from
1724 * data set via an application call to a png_set_ API and png_app_error or
1725 * png_app_warning is used as appropriate.
1727 * The 'error' parameter must have one of the following values:
1729 #define PNG_CHUNK_WARNING 0 /* never an error */
1730 #define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1731 #define PNG_CHUNK_ERROR 2 /* always an error */
1733 /* ASCII to FP interfaces, currently only implemented if sCAL
1734 * support is required.
1736 #if defined(PNG_sCAL_SUPPORTED)
1737 /* MAX_DIGITS is actually the maximum number of characters in an sCAL
1738 * width or height, derived from the precision (number of significant
1739 * digits - a build time settable option) and assumptions about the
1740 * maximum ridiculous exponent.
1742 #define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1744 #ifdef PNG_FLOATING_POINT_SUPPORTED
1745 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1746 png_charp ascii, png_size_t size, double fp, unsigned int precision),
1747 PNG_EMPTY);
1748 #endif /* FLOATING_POINT */
1750 #ifdef PNG_FIXED_POINT_SUPPORTED
1751 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1752 png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
1753 #endif /* FIXED_POINT */
1754 #endif /* sCAL */
1756 #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1757 /* An internal API to validate the format of a floating point number.
1758 * The result is the index of the next character. If the number is
1759 * not valid it will be the index of a character in the supposed number.
1761 * The format of a number is defined in the PNG extensions specification
1762 * and this API is strictly conformant to that spec, not anyone elses!
1764 * The format as a regular expression is:
1766 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1768 * or:
1770 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1772 * The complexity is that either integer or fraction must be present and the
1773 * fraction is permitted to have no digits only if the integer is present.
1775 * NOTE: The dangling E problem.
1776 * There is a PNG valid floating point number in the following:
1778 * PNG floating point numbers are not greedy.
1780 * Working this out requires *TWO* character lookahead (because of the
1781 * sign), the parser does not do this - it will fail at the 'r' - this
1782 * doesn't matter for PNG sCAL chunk values, but it requires more care
1783 * if the value were ever to be embedded in something more complex. Use
1784 * ANSI-C strtod if you need the lookahead.
1786 /* State table for the parser. */
1787 #define PNG_FP_INTEGER 0 /* before or in integer */
1788 #define PNG_FP_FRACTION 1 /* before or in fraction */
1789 #define PNG_FP_EXPONENT 2 /* before or in exponent */
1790 #define PNG_FP_STATE 3 /* mask for the above */
1791 #define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
1792 #define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
1793 #define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
1794 #define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
1795 #define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
1797 /* These three values don't affect the parser. They are set but not used.
1799 #define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
1800 #define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
1801 #define PNG_FP_NONZERO 256 /* A non-zero value */
1802 #define PNG_FP_STICKY 448 /* The above three flags */
1804 /* This is available for the caller to store in 'state' if required. Do not
1805 * call the parser after setting it (the parser sometimes clears it.)
1807 #define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
1809 /* Result codes for the parser (boolean - true meants ok, false means
1810 * not ok yet.)
1812 #define PNG_FP_MAYBE 0 /* The number may be valid in the future */
1813 #define PNG_FP_OK 1 /* The number is valid */
1815 /* Tests on the sticky non-zero and negative flags. To pass these checks
1816 * the state must also indicate that the whole number is valid - this is
1817 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1818 * is equivalent to PNG_FP_OK above.)
1820 #define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1821 /* NZ_MASK: the string is valid and a non-zero negative value */
1822 #define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1823 /* Z MASK: the string is valid and a non-zero value. */
1824 /* PNG_FP_SAW_DIGIT: the string is valid. */
1825 #define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1826 #define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1827 #define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1829 /* The actual parser. This can be called repeatedly. It updates
1830 * the index into the string and the state variable (which must
1831 * be initialized to 0). It returns a result code, as above. There
1832 * is no point calling the parser any more if it fails to advance to
1833 * the end of the string - it is stuck on an invalid character (or
1834 * terminated by '\0').
1836 * Note that the pointer will consume an E or even an E+ and then leave
1837 * a 'maybe' state even though a preceding integer.fraction is valid.
1838 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1839 * a valid number. It's possible to recover from this by calling
1840 * the parser again (from the start, with state 0) but with a string
1841 * that omits the last character (i.e. set the size to the index of
1842 * the problem character.) This has not been tested within libpng.
1844 PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
1845 png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
1847 /* This is the same but it checks a complete string and returns true
1848 * only if it just contains a floating point number. As of 1.5.4 this
1849 * function also returns the state at the end of parsing the number if
1850 * it was valid (otherwise it returns 0.) This can be used for testing
1851 * for negative or zero values using the sticky flag.
1853 PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
1854 png_size_t size),PNG_EMPTY);
1855 #endif /* pCAL || sCAL */
1857 #if defined(PNG_GAMMA_SUPPORTED) ||\
1858 defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1859 /* Added at libpng version 1.5.0 */
1860 /* This is a utility to provide a*times/div (rounded) and indicate
1861 * if there is an overflow. The result is a boolean - false (0)
1862 * for overflow, true (1) if no overflow, in which case *res
1863 * holds the result.
1865 PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
1866 png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
1867 #endif
1869 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1870 /* Same deal, but issue a warning on overflow and return 0. */
1871 PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
1872 (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
1873 png_int_32 divided_by),PNG_EMPTY);
1874 #endif
1876 #ifdef PNG_GAMMA_SUPPORTED
1877 /* Calculate a reciprocal - used for gamma values. This returns
1878 * 0 if the argument is 0 in order to maintain an undefined value;
1879 * there are no warnings.
1881 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
1882 PNG_EMPTY);
1884 #ifdef PNG_READ_GAMMA_SUPPORTED
1885 /* The same but gives a reciprocal of the product of two fixed point
1886 * values. Accuracy is suitable for gamma calculations but this is
1887 * not exact - use png_muldiv for that. Only required at present on read.
1889 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
1890 png_fixed_point b),PNG_EMPTY);
1891 #endif
1893 /* Return true if the gamma value is significantly different from 1.0 */
1894 PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
1895 PNG_EMPTY);
1896 #endif
1898 #ifdef PNG_READ_GAMMA_SUPPORTED
1899 /* Internal fixed point gamma correction. These APIs are called as
1900 * required to convert single values - they don't need to be fast,
1901 * they are not used when processing image pixel values.
1903 * While the input is an 'unsigned' value it must actually be the
1904 * correct bit value - 0..255 or 0..65535 as required.
1906 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
1907 unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
1908 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
1909 png_fixed_point gamma_value),PNG_EMPTY);
1910 PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
1911 png_fixed_point gamma_value),PNG_EMPTY);
1912 PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
1913 PNG_EMPTY);
1914 PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
1915 int bit_depth),PNG_EMPTY);
1916 #endif
1918 /* SIMPLIFIED READ/WRITE SUPPORT */
1919 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
1920 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
1921 /* The internal structure that png_image::opaque points to. */
1922 typedef struct png_control
1924 png_structp png_ptr;
1925 png_infop info_ptr;
1926 png_voidp error_buf; /* Always a jmp_buf at present. */
1928 png_const_bytep memory; /* Memory buffer. */
1929 png_size_t size; /* Size of the memory buffer. */
1931 unsigned int for_write :1; /* Otherwise it is a read structure */
1932 unsigned int owned_file :1; /* We own the file in io_ptr */
1933 } png_control;
1935 /* Return the pointer to the jmp_buf from a png_control: necessary because C
1936 * does not reveal the type of the elements of jmp_buf.
1938 #ifdef __cplusplus
1939 # define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
1940 #else
1941 # define png_control_jmp_buf(pc) ((pc)->error_buf)
1942 #endif
1944 /* Utility to safely execute a piece of libpng code catching and logging any
1945 * errors that might occur. Returns true on success, false on failure (either
1946 * of the function or as a result of a png_error.)
1948 PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
1949 png_const_charp error_message),PNG_NORETURN);
1951 #ifdef PNG_WARNINGS_SUPPORTED
1952 PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
1953 png_const_charp warning_message),PNG_EMPTY);
1954 #else
1955 # define png_safe_warning 0/*dummy argument*/
1956 #endif
1958 PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
1959 int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
1961 /* Utility to log an error; this also cleans up the png_image; the function
1962 * always returns 0 (false).
1964 PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
1965 png_const_charp error_message),PNG_EMPTY);
1967 #ifndef PNG_SIMPLIFIED_READ_SUPPORTED
1968 /* png_image_free is used by the write code but not exported */
1969 PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
1970 #endif /* !SIMPLIFIED_READ */
1972 #endif /* SIMPLIFIED READ/WRITE */
1974 /* These are initialization functions for hardware specific PNG filter
1975 * optimizations; list these here then select the appropriate one at compile
1976 * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined
1977 * the generic code is used.
1979 #ifdef PNG_FILTER_OPTIMIZATIONS
1980 PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
1981 unsigned int bpp), PNG_EMPTY);
1982 /* Just declare the optimization that will be used */
1983 #else
1984 /* List *all* the possible optimizations here - this branch is required if
1985 * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
1986 * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
1988 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
1989 (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
1990 #endif
1992 /* Maintainer: Put new private prototypes here ^ */
1994 #include "pngdebug.h"
1996 #ifdef __cplusplus
1998 #endif
2000 #endif /* PNG_VERSION_INFO_ONLY */
2001 #endif /* PNGPRIV_H */