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 1.7.0 [(PENDING RELEASE)]
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.
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 /* Keep standard libraries at the top of this file */
45 /* Standard library headers not required by png.h: */
49 /* For headers only required with some build configurations see the lines after
50 * pnglibconf.h is included!
53 #endif /* VERSION_INFO_ONLY */
55 #define PNGLIB_BUILD /*libpng is being built, not used*/
57 /* If HAVE_CONFIG_H is defined during the build then the build system must
58 * provide an appropriate "config.h" file on the include path. The header file
59 * must provide definitions as required below (search for "HAVE_CONFIG_H");
60 * see configure.ac for more details of the requirements. The macro
61 * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
62 * 'configure'; define this macro to prevent the configure build including the
63 * configure generated config.h. Libpng is expected to compile without *any*
64 * special build system support on a reasonably ANSI-C compliant system.
66 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
69 /* Pick up the definition of 'restrict' from config.h if it was read: */
70 # define PNG_RESTRICT restrict
73 /* To support symbol prefixing it is necessary to know *before* including png.h
74 * whether the fixed point (and maybe other) APIs are exported, because if they
75 * are not internal definitions may be required. This is handled below just
76 * before png.h is included, but load the configuration now if it is available.
79 # include "pnglibconf.h"
82 /* Local renames may change non-exported API functions from png.h */
83 #if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
84 # include "pngprefix.h"
87 #ifdef PNG_USER_CONFIG
89 /* These should have been defined in pngusr.h */
90 # ifndef PNG_USER_PRIVATEBUILD
91 # define PNG_USER_PRIVATEBUILD "Custom libpng build"
93 # ifndef PNG_USER_DLLFNAME_POSTFIX
94 # define PNG_USER_DLLFNAME_POSTFIX "Cb"
98 #ifndef PNG_VERSION_INFO_ONLY
99 /* Additional standard libaries required in certain cases, put only standard
100 * ANSI-C89 headers here. If not available, or non-functional, the problem
101 * should be fixed by writing a wrapper for the header and the file on your
104 #if defined(PNG_sCAL_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
105 /* png.c requires the following ANSI-C constants if the conversion of
106 * floating point to ASCII is implemented therein:
108 * DBL_MIN_10_EXP Minimum negative integer such that 10^integer is a
109 * normalized (double) value.
110 * DBL_DIG Maximum number of decimal digits (can be set to any constant)
111 * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
112 * DBL_MAX Maximum floating point number (can be set to an arbitrary value)
115 #endif /* sCAL && FLOATING_POINT */
117 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) ||\
118 defined(PNG_FLOATING_POINT_SUPPORTED)
119 /* ANSI-C90 math functions are required. Full compliance with the standard
120 * is probably not a requirement, but the functions must exist and be
121 * declared in <math.h>
124 #endif /* FLOATING_ARITHMETIC || FLOATING_POINT */
126 #endif /* VERSION_INFO_ONLY */
128 /* Compile time options.
129 * =====================
130 * In a multi-arch build the compiler may compile the code several times for the
131 * same object module, producing different binaries for different architectures.
132 * When this happens configure-time setting of the target host options cannot be
133 * done and this interferes with the handling of the ARM NEON optimizations, and
134 * possibly other similar optimizations. Put additional tests here; in general
135 * this is needed when the same option can be changed at both compile time and
136 * run time depending on the target OS (i.e. iOS vs Android.)
138 * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
139 * this is not possible with certain compilers (Oracle SUN OS CC), as a result
140 * it is necessary to ensure that all extern functions that *might* be used
141 * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__
142 * below is one example of this behavior because it is controlled by the
143 * presence or not of -mfpu=neon on the GCC command line, it is possible to do
144 * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
147 #ifndef PNG_ARM_NEON_OPT
148 /* ARM NEON optimizations are being controlled by the compiler settings,
149 * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon
150 * with GCC) then the compiler will define __ARM_NEON__ and we can rely
151 * unconditionally on NEON instructions not crashing, otherwise we must
152 * disable use of NEON instructions.
154 * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
155 * can only be turned on automatically if that is supported too. If
156 * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
157 * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
160 # if defined(__ARM_NEON__) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
161 # define PNG_ARM_NEON_OPT 2
163 # define PNG_ARM_NEON_OPT 0
167 #if PNG_ARM_NEON_OPT > 0
168 /* NEON optimizations are to be at least considered by libpng, so enable the
169 * callbacks to do this.
171 # define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
173 /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
174 * if possible - if __ARM_NEON__ is set and the compiler version is not known
175 * to be broken. This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
178 * 1 The intrinsics code (the default with __ARM_NEON__)
179 * 2 The hand coded assembler (the default without __ARM_NEON__)
181 * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
182 * this is *NOT* supported and may cease to work even after a minor revision
183 * to libpng. It *is* valid to do this for testing purposes, e.g. speed
184 * testing or a new compiler, but the results should be communicated to the
185 * libpng implementation list for incorporation in the next minor release.
187 # ifndef PNG_ARM_NEON_IMPLEMENTATION
189 # if defined(__clang__)
190 /* At present it is unknown by the libpng developers which versions
191 * of clang support the intrinsics, however some or perhaps all
192 * versions do not work with the assembler so this may be
193 * irrelevant, so just use the default (do nothing here.)
195 # elif defined(__GNUC__)
196 /* GCC 4.5.4 NEON support is known to be broken. 4.6.3 is known to
197 * work, so if this *is* GCC, or G++, look for a version >4.5
199 # if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
200 # define PNG_ARM_NEON_IMPLEMENTATION 2
201 # endif /* no GNUC support */
202 # endif /* __GNUC__ */
203 # else /* !defined __ARM_NEON__ */
204 /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
206 # define PNG_ARM_NEON_IMPLEMENTATION 2
207 # endif /* __ARM_NEON__ */
208 # endif /* !defined PNG_ARM_NEON_IMPLEMENTATION */
210 # ifndef PNG_ARM_NEON_IMPLEMENTATION
211 /* Use the intrinsics code by default. */
212 # define PNG_ARM_NEON_IMPLEMENTATION 1
214 #endif /* PNG_ARM_NEON_OPT > 0 */
216 /* Is this a build of a DLL where compilation of the object modules requires
217 * different preprocessor settings to those required for a simple library? If
218 * so PNG_BUILD_DLL must be set.
220 * If libpng is used inside a DLL but that DLL does not export the libpng APIs
221 * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
222 * static library of libpng then link the DLL against that.
224 #ifndef PNG_BUILD_DLL
226 /* This is set by libtool when files are compiled for a DLL; libtool
227 * always compiles twice, even on systems where it isn't necessary. Set
228 * PNG_BUILD_DLL in case it is necessary:
230 # define PNG_BUILD_DLL
233 /* This is set by the Microsoft Visual Studio IDE in projects that
234 * build a DLL. It can't easily be removed from those projects (it
235 * isn't visible in the Visual Studio UI) so it is a fairly reliable
236 * indication that PNG_IMPEXP needs to be set to the DLL export
239 # define PNG_BUILD_DLL
242 /* This is set by the Borland C system when compiling for a DLL
245 # define PNG_BUILD_DLL
247 /* Add additional compiler cases here. */
251 #endif /* Setting PNG_BUILD_DLL if required */
253 /* See pngconf.h for more details: the builder of the library may set this on
254 * the command line to the right thing for the specific compilation system or it
255 * may be automagically set above (at present we know of no system where it does
256 * need to be set on the command line.)
258 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
259 * setting it to the "import" setting for a DLL build.
262 # ifdef PNG_BUILD_DLL
263 # define PNG_IMPEXP PNG_DLL_EXPORT
265 /* Not building a DLL, or the DLL doesn't require specific export
272 /* No warnings for private or deprecated functions in the build: */
273 #ifndef PNG_DEPRECATED
274 # define PNG_DEPRECATED
280 /* Symbol preprocessing support.
282 * To enable listing global, but internal, symbols the following macros should
283 * always be used to declare an extern data or function object in this file.
285 #ifndef PNG_INTERNAL_DATA
286 # define PNG_INTERNAL_DATA(type, name, array) extern type name array
289 #ifndef PNG_INTERNAL_FUNCTION
290 # define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
291 extern PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
294 #ifndef PNG_INTERNAL_CALLBACK
295 # define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
296 extern PNG_FUNCTION(type, (PNGCBAPI name), args, PNG_EMPTY attributes)
299 /* If floating or fixed point APIs are disabled they may still be compiled
300 * internally. To handle this make sure they are declared as the appropriate
301 * internal extern function (otherwise the symbol prefixing stuff won't work and
302 * the functions will be used without definitions.)
304 * NOTE: although all the API functions are declared here they are not all
305 * actually built! Because the declarations are still made it is necessary to
306 * fake out types that they depend on.
308 #ifndef PNG_FP_EXPORT
309 # ifndef PNG_FLOATING_POINT_SUPPORTED
310 # define PNG_FP_EXPORT(ordinal, type, name, args)\
311 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
312 # ifndef PNG_VERSION_INFO_ONLY
313 typedef struct png_incomplete png_double;
314 typedef png_double* png_doublep;
315 typedef const png_double* png_const_doublep;
316 typedef png_double** png_doublepp;
320 #ifndef PNG_FIXED_EXPORT
321 # ifndef PNG_FIXED_POINT_SUPPORTED
322 # define PNG_FIXED_EXPORT(ordinal, type, name, args)\
323 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
327 /* Include png.h here to get the version info and other macros, pngstruct.h and
328 * pnginfo.h are included later under the protection of !PNG_VERSION_INFO_ONLY
332 /* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
333 #ifndef PNG_DLL_EXPORT
334 # define PNG_DLL_EXPORT
337 /* asserts are turned off in release code, but are in even in release candidates
338 * because often system builders only check future libpng releases when a
339 * release candidate is available.
341 #if PNG_LIBPNG_BUILD_BASE_TYPE == PNG_LIBPNG_BUILD_STABLE
344 #ifndef PNG_VERSION_INFO_ONLY
348 /* SECURITY and SAFETY:
350 * By default libpng is built without any internal limits on image size,
351 * individual heap (png_malloc) allocations or the total amount of memory used.
352 * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
353 * (unless individually overridden). These limits are believed to be fairly
354 * safe, but builders of secure systems should verify the values against the
355 * real system capabilities.
357 #ifdef PNG_SAFE_LIMITS_SUPPORTED
359 # ifndef PNG_USER_WIDTH_MAX
360 # define PNG_USER_WIDTH_MAX 1000000
362 # ifndef PNG_USER_HEIGHT_MAX
363 # define PNG_USER_HEIGHT_MAX 1000000
365 # ifndef PNG_USER_CHUNK_CACHE_MAX
366 # define PNG_USER_CHUNK_CACHE_MAX 128
368 # ifndef PNG_USER_CHUNK_MALLOC_MAX
369 # define PNG_USER_CHUNK_MALLOC_MAX 8000000
372 /* values for no limits */
373 # ifndef PNG_USER_WIDTH_MAX
374 # define PNG_USER_WIDTH_MAX 0x7fffffff
376 # ifndef PNG_USER_HEIGHT_MAX
377 # define PNG_USER_HEIGHT_MAX 0x7fffffff
379 # ifndef PNG_USER_CHUNK_CACHE_MAX
380 # define PNG_USER_CHUNK_CACHE_MAX 0
382 # ifndef PNG_USER_CHUNK_MALLOC_MAX
383 # define PNG_USER_CHUNK_MALLOC_MAX 0
387 /* Moved to pngpriv.h at libpng-1.5.0 */
388 /* NOTE: some of these may have been used in external applications as
389 * these definitions were exposed in pngconf.h prior to 1.5.
392 /* If you are running on a machine where you cannot allocate more
393 * than 64K of memory at once, uncomment this. While libpng will not
394 * normally need that much memory in a chunk (unless you load up a very
395 * large file), zlib needs to know how big of a chunk it can use, and
396 * libpng thus makes sure to check any memory allocation to verify it
397 * will fit into memory.
399 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
400 * same limit and pngconf.h (already included) sets the limit
401 * if certain operating systems are detected.
403 #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
404 # define PNG_MAX_MALLOC_64K
408 /* Unused formal parameter warnings are silenced using the following macro
409 * which is expected to have no bad effects on performance (optimizing
410 * compilers will probably remove it entirely). Note that if you replace
411 * it with something other than whitespace, you must include the terminating
414 # define PNG_UNUSED(param) (void)param;
417 /* Just a little check that someone hasn't tried to define something
420 #if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
421 # undef PNG_ZBUF_SIZE
422 # define PNG_ZBUF_SIZE 65536L
425 /* If warnings or errors are turned off the code is disabled or redirected here.
426 * From 1.5.4 functions have been added to allow very limited formatting of
427 * error and warning messages - this code will also be disabled here.
429 #ifdef PNG_WARNINGS_SUPPORTED
430 # define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
432 # define png_warning(s1,s2) ((void)(s1))
433 # define png_chunk_warning(s1,s2) ((void)(s1))
434 # define png_warning_parameter(p,number,string) ((void)0)
435 # define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
436 # define png_warning_parameter_signed(p,number,format,value) ((void)0)
437 # define png_formatted_warning(pp,p,message) ((void)(pp))
438 # define PNG_WARNING_PARAMETERS(p)
440 #ifndef PNG_ERROR_TEXT_SUPPORTED
441 # define png_error(s1,s2) png_err(s1)
442 # define png_chunk_error(s1,s2) png_err(s1)
443 # define png_fixed_error(s1,s2) png_err(s1)
446 /* C allows up-casts from (void*) to any pointer and (const void*) to any
447 * pointer to a const object. C++ regards this as a type error and requires an
448 * explicit, static, cast and provides the static_cast<> rune to ensure that
449 * const is not cast away.
452 # define png_voidcast(type, value) static_cast<type>(value)
453 # define png_constcast(type, value) const_cast<type>(value)
454 # define png_aligncast(type, value) \
455 static_cast<type>(static_cast<void*>(value))
456 # define png_aligncastconst(type, value) \
457 static_cast<type>(static_cast<const void*>(value))
459 # define png_voidcast(type, value) (value)
460 # define png_constcast(type, value) ((type)(value))
461 # define png_aligncast(type, value) ((void*)(value))
462 # define png_aligncastconst(type, value) ((const void*)(value))
463 #endif /* __cplusplus */
465 /* Some fixed point APIs are still required even if not exported because
466 * they get used by the corresponding floating point APIs. This magic
469 #ifdef PNG_FIXED_POINT_SUPPORTED
470 # define PNGFAPI PNGAPI
472 # define PNGFAPI /* PRIVATE */
475 /* These macros may need to be architecture dependent. */
476 #define PNG_ALIGN_NONE 0 /* do not use data alignment */
477 #define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
479 # define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
481 # define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
483 #define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
485 #ifndef PNG_ALIGN_TYPE
486 /* Default to using aligned access optimizations and requiring alignment to a
487 * multiple of the data type size. Override in a compiler specific fashion
488 * if necessary by inserting tests here:
490 # define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
493 #if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
494 /* This is used because in some compiler implementations non-aligned
495 * structure members are supported, so the offsetof approach below fails.
496 * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
497 * is good for performance. Do not do this unless you have tested the result
500 # define png_alignof(type) (sizeof (type))
502 # if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
503 # define png_alignof(type) offsetof(struct{char c; type t;}, t)
505 # if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
506 # define png_alignof(type) (1)
508 /* Else leave png_alignof undefined to prevent use thereof */
512 /* This implicitly assumes alignment is always to a power of 2. */
514 # define png_isaligned(ptr, type)\
515 ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
517 # define png_isaligned(ptr, type) 0
520 /* End of memory model/platform independent support */
521 /* End of 1.5.0beta36 move from pngconf.h */
523 /* CONSTANTS and UTILITY MACROS
524 * These are used internally by libpng and not exposed in the API
527 /* Various modes of operation. Note that after an init, mode is set to
528 * zero automatically when the structure is created. Three of these
529 * are defined in png.h because they need to be visible to applications
530 * that call png_set_unknown_chunk().
532 /* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */
533 /* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */
534 #define PNG_HAVE_IDAT 0x04
535 /* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */
536 #define PNG_HAVE_IEND 0x10
540 #define PNG_HAVE_CHUNK_HEADER 0x100
541 #define PNG_WROTE_tIME 0x200
542 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
544 #define PNG_HAVE_PNG_SIGNATURE 0x1000
545 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
546 /* 0x4000 (unused) */
547 #define PNG_IS_READ_STRUCT 0x8000 /* Else is a write struct */
549 /* Flags for the transformations the PNG library does on the image data */
550 #define PNG_BGR 0x0001
551 #define PNG_INTERLACE 0x0002
552 #define PNG_PACK 0x0004
553 #define PNG_SHIFT 0x0008
554 #define PNG_SWAP_BYTES 0x0010
555 #define PNG_INVERT_MONO 0x0020
556 #define PNG_QUANTIZE 0x0040
557 #define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */
559 #define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */
560 #define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */
561 #define PNG_RGBA 0x0800
562 #define PNG_EXPAND 0x1000
563 #define PNG_GAMMA 0x2000
564 #define PNG_GRAY_TO_RGB 0x4000
565 #define PNG_FILLER 0x8000
566 #define PNG_PACKSWAP 0x10000
567 #define PNG_SWAP_ALPHA 0x20000
568 #define PNG_STRIP_ALPHA 0x40000
569 #define PNG_INVERT_ALPHA 0x80000
570 #define PNG_USER_TRANSFORM 0x100000
571 #define PNG_RGB_TO_GRAY_ERR 0x200000
572 #define PNG_RGB_TO_GRAY_WARN 0x400000
573 #define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
574 #define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */
575 #define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */
576 #define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */
577 #define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */
578 /* 0x8000000 unused */
579 /* 0x10000000 unused */
580 /* 0x20000000 unused */
581 /* 0x40000000 unused */
582 /* Flags for png_create_struct */
583 #define PNG_STRUCT_PNG 0x0001
584 #define PNG_STRUCT_INFO 0x0002
586 /* Scaling factor for filter heuristic weighting calculations */
587 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
588 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
590 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
591 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
592 #define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002 /* Added to libpng-1.6.0 */
594 #define PNG_FLAG_ZSTREAM_ENDED 0x0008 /* Added to libpng-1.6.0 */
597 #define PNG_FLAG_ROW_INIT 0x0040
598 #define PNG_FLAG_FILLER_AFTER 0x0080
599 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
600 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
601 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400
602 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
603 #define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */
604 #define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */
605 #define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */
606 /* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 */
607 /* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 */
608 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000
609 #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000
610 #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000
611 #define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000 /* Added to libpng-1.4.0 */
612 #define PNG_FLAG_APP_WARNINGS_WARN 0x200000 /* Added to libpng-1.6.0 */
613 #define PNG_FLAG_APP_ERRORS_WARN 0x400000 /* Added to libpng-1.6.0 */
614 #define PNG_FLAG_BACKGROUND_IS_GRAY 0x800000
615 #define PNG_FLAG_BACKGROUND_EXPAND 0x1000000
616 /* 0x2000000 unused */
617 /* 0x4000000 unused */
618 /* 0x8000000 unused */
619 /* 0x10000000 unused */
620 /* 0x20000000 unused */
621 /* 0x40000000 unused */
623 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
624 PNG_FLAG_CRC_ANCILLARY_NOWARN)
626 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
627 PNG_FLAG_CRC_CRITICAL_IGNORE)
629 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
630 PNG_FLAG_CRC_CRITICAL_MASK)
632 /* Save typing and make code easier to understand */
634 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
635 abs((int)((c1).green) - (int)((c2).green)) + \
636 abs((int)((c1).blue) - (int)((c2).blue)))
638 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
639 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
640 /* See below for the definitions of the tables used in these macros */
641 #define PNG_sRGB_FROM_LINEAR(linear) ((png_byte)((png_sRGB_base[(linear)>>15] +\
642 ((((linear)&0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))
643 /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
644 * encoded value with maximum error 0.646365. Note that the input is not a
645 * 16-bit value; it has been multiplied by 255! */
646 #endif /* PNG_SIMPLIFIED_READ/WRITE */
648 /* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
649 * by dividing by 257 *with rounding*. This macro is exact for the given range.
650 * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
651 * macro were established by experiment (modifying the added value). The macro
652 * has a second variant that takes a value already scaled by 255 and divides by
653 * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
654 * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
656 #define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
657 #define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
659 /* Added to libpng-1.2.6 JB */
660 #define PNG_ROWBYTES(pixel_bits, width) \
661 ((pixel_bits) >= 8 ? \
662 ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
663 (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
665 /* PNG_OUT_OF_RANGE returns true if value is outside the range
666 * ideal-delta..ideal+delta. Each argument is evaluated twice.
667 * "ideal" and "delta" should be constants, normally simple
668 * integers, "value" a variable. Added to libpng-1.2.6 JB
670 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
671 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
673 /* Conversions between fixed and floating point, only defined if
674 * required (to make sure the code doesn't accidentally use float
675 * when it is supposedly disabled.)
677 #ifdef PNG_FLOATING_POINT_SUPPORTED
678 /* The floating point conversion can't overflow, though it can and
679 * does lose accuracy relative to the original fixed point value.
680 * In practice this doesn't matter because png_fixed_point only
681 * stores numbers with very low precision. The png_ptr and s
682 * arguments are unused by default but are there in case error
683 * checking becomes a requirement.
685 #define png_float(png_ptr, fixed, s) (.00001 * (fixed))
687 /* The fixed point conversion performs range checking and evaluates
688 * its argument multiple times, so must be used with care. The
689 * range checking uses the PNG specification values for a signed
690 * 32 bit fixed point value except that the values are deliberately
691 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
692 * (2^31-1) * 100000). 's' is a string that describes the value being
695 * NOTE: this macro will raise a png_error if the range check fails,
696 * therefore it is normally only appropriate to use this on values
697 * that come from API calls or other sources where an out of range
698 * error indicates a programming error, not a data error!
700 * NOTE: by default this is off - the macro is not used - because the
701 * function call saves a lot of code.
703 #ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
704 #define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
705 ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
707 /* else the corresponding function is defined below, inside the scope of the
712 /* Gamma values (new at libpng-1.5.4): */
713 #define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
714 #define PNG_GAMMA_MAC_INVERSE 65909
715 #define PNG_GAMMA_sRGB_INVERSE 45455
717 /* Almost everything below is C specific; the #defines above can be used in
718 * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
720 #ifndef PNG_VERSION_INFO_ONLY
722 #include "pngstruct.h"
725 /* Validate the include paths - the include path used to generate pnglibconf.h
726 * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
728 #if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
729 # error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
730 "-I (include path) error: see the notes in pngpriv.h"
731 /* This means that when pnglibconf.h was built the copy of zlib.h that it
732 * used is not the same as the one being used here. Because the build of
733 * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
734 * zlib version number and because this affects handling of certain broken
735 * PNG files the -I directives must match.
737 * The most likely explanation is that you passed a -I in CFLAGS, this will
738 * not work; all the preprocessor directories and in particular all the -I
739 * directives must be in CPPFLAGS.
743 /* This is used for 16 bit gamma tables -- only the top level pointers are
744 * const; this could be changed:
746 typedef const png_uint_16p * png_const_uint_16pp;
748 /* Added to libpng-1.5.7: sRGB conversion tables */
749 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
750 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
751 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
752 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
753 /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
754 * 0..65535. This table gives the closest 16-bit answers (no errors).
758 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
759 PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
760 #endif /* PNG_SIMPLIFIED_READ/WRITE */
763 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
766 #endif /* __cplusplus */
768 /* Internal functions; these are not exported from a DLL however because they
769 * are used within several of the C source files they have to be C extern.
771 * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
775 #define PNG_UNEXPECTED_ZLIB_RETURN (-7)
776 PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
778 /* Used by the zlib handling functions to ensure that z_stream::msg is always
779 * set before they return.
782 #ifdef PNG_WRITE_SUPPORTED
783 PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
784 png_compression_bufferp *list),PNG_EMPTY);
785 /* Free the buffer list used by the compressed write code. */
788 #ifdef PNG_WRITE_FILTER_SUPPORTED
789 PNG_INTERNAL_FUNCTION(void,png_write_alloc_filter_row_buffers,
790 (png_structrp png_ptr, int filters),PNG_EMPTY);
791 /* Allocate pixel row buffers to cache filtered rows while testing candidate
793 * TODO: avoid this, only one spare row buffer (at most) is required, this
794 * wastes a lot of memory for large images.
798 #if defined(PNG_FLOATING_POINT_SUPPORTED) && \
799 !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
800 (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
801 defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
802 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
803 (defined(PNG_sCAL_SUPPORTED) && \
804 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
805 PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
806 double fp, png_const_charp text),PNG_EMPTY);
809 /* Check the user version string for compatibility, returns false if the version
810 * numbers aren't compatible.
812 PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
813 png_const_charp user_png_ver),PNG_EMPTY);
815 /* Internal base allocator - no messages, NULL on failure to allocate. This
816 * does, however, call the application provided allocator and that could call
817 * png_error (although that would be a bug in the application implementation.)
819 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
820 png_alloc_size_t size),PNG_ALLOCATED);
822 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
823 defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
824 /* Internal array allocator, outputs no error or warning messages on failure,
827 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
828 int nelements, size_t element_size),PNG_ALLOCATED);
830 /* The same but an existing array is extended by add_elements. This function
831 * also memsets the new elements to 0 and copies the old elements. The old
832 * array is not freed or altered.
834 PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_structrp png_ptr,
835 png_const_voidp array, int old_elements, int add_elements,
836 size_t element_size),PNG_ALLOCATED);
837 #endif /* text, sPLT or unknown chunks */
839 /* Magic to create a struct when there is no struct to call the user supplied
840 * memory allocators. Because error handling has not been set up the memory
841 * handlers can't safely call png_error, but this is an obscure and undocumented
842 * restriction so libpng has to assume that the 'free' handler, at least, might
845 PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
846 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
847 png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
848 png_free_ptr free_fn),PNG_ALLOCATED);
850 /* Free memory from internal libpng struct */
851 PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
854 /* Free an allocated jmp_buf (always succeeds) */
855 PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
857 /* Function to allocate memory for zlib. PNGAPI is disallowed. */
858 PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
861 /* Function to free memory for zlib. PNGAPI is disallowed. */
862 PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
864 /* Next four functions are used internally as callbacks. PNGCBAPI is required
865 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
869 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
870 png_bytep data, png_size_t length),PNG_EMPTY);
872 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
873 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
874 png_bytep buffer, png_size_t length),PNG_EMPTY);
877 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
878 png_bytep data, png_size_t length),PNG_EMPTY);
880 #ifdef PNG_WRITE_FLUSH_SUPPORTED
881 # ifdef PNG_STDIO_SUPPORTED
882 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
887 /* Reset the CRC variable */
888 PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
890 /* Write the "data" buffer to whatever output you are using */
891 PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
892 png_const_bytep data, png_size_t length),PNG_EMPTY);
894 /* Read and check the PNG file signature */
895 PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
896 png_inforp info_ptr),PNG_EMPTY);
898 /* Read the chunk header (length + type name) */
899 PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
902 /* Read data from whatever input you are using into the "data" buffer */
903 PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
904 png_size_t length),PNG_EMPTY);
906 /* Read bytes into buf, and update png_ptr->crc */
907 PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
908 png_uint_32 length),PNG_EMPTY);
910 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
911 PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
912 png_uint_32 skip),PNG_EMPTY);
914 /* Read the CRC from the file and compare it to the libpng calculated CRC */
915 PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
917 /* Calculate the CRC over a section of data. Note that we are only
918 * passing a maximum of 64K on systems that have this as a memory limit,
919 * since this is the maximum buffer size we can specify.
921 PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
922 png_const_bytep ptr, png_size_t length),PNG_EMPTY);
924 #ifdef PNG_WRITE_FLUSH_SUPPORTED
925 PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
928 /* Write various chunks */
930 /* Write the IHDR chunk, and update the png_struct with the necessary
933 PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
934 png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
935 int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
937 PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
938 png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
940 PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
941 png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
944 PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
946 #ifdef PNG_WRITE_gAMA_SUPPORTED
947 PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
948 png_fixed_point file_gamma),PNG_EMPTY);
951 #ifdef PNG_WRITE_sBIT_SUPPORTED
952 PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
953 png_const_color_8p sbit, int color_type),PNG_EMPTY);
956 #ifdef PNG_WRITE_cHRM_SUPPORTED
957 PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
958 const png_xy *xy), PNG_EMPTY);
959 /* The xy value must have been previously validated */
962 #ifdef PNG_WRITE_sRGB_SUPPORTED
963 PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
964 int intent),PNG_EMPTY);
967 #ifdef PNG_WRITE_iCCP_SUPPORTED
968 PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
969 png_const_charp name, png_const_bytep profile), PNG_EMPTY);
970 /* The profile must have been previously validated for correctness, the
971 * length comes from the first four bytes. Only the base, deflate,
972 * compression is supported.
976 #ifdef PNG_WRITE_sPLT_SUPPORTED
977 PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
978 png_const_sPLT_tp palette),PNG_EMPTY);
981 #ifdef PNG_WRITE_tRNS_SUPPORTED
982 PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
983 png_const_bytep trans, png_const_color_16p values, int number,
984 int color_type),PNG_EMPTY);
987 #ifdef PNG_WRITE_bKGD_SUPPORTED
988 PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
989 png_const_color_16p values, int color_type),PNG_EMPTY);
992 #ifdef PNG_WRITE_hIST_SUPPORTED
993 PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
994 png_const_uint_16p hist, int num_hist),PNG_EMPTY);
997 /* Chunks that have keywords */
998 #ifdef PNG_WRITE_tEXt_SUPPORTED
999 PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1000 png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
1003 #ifdef PNG_WRITE_zTXt_SUPPORTED
1004 PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1005 key, png_const_charp text, png_size_t text_len, int compression),PNG_EMPTY);
1008 #ifdef PNG_WRITE_iTXt_SUPPORTED
1009 PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1010 int compression, png_const_charp key, png_const_charp lang,
1011 png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1014 #ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
1015 PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_structrp png_ptr,
1016 png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1019 #ifdef PNG_WRITE_oFFs_SUPPORTED
1020 PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1021 png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1024 #ifdef PNG_WRITE_pCAL_SUPPORTED
1025 PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1026 png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1027 png_const_charp units, png_charpp params),PNG_EMPTY);
1030 #ifdef PNG_WRITE_pHYs_SUPPORTED
1031 PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1032 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1033 int unit_type),PNG_EMPTY);
1036 #ifdef PNG_WRITE_tIME_SUPPORTED
1037 PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1038 png_const_timep mod_time),PNG_EMPTY);
1041 #ifdef PNG_WRITE_sCAL_SUPPORTED
1042 PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1043 int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1046 /* Called when finished processing a row of data */
1047 PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1050 /* Internal use only. Called before first row of data */
1051 PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1054 /* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
1055 * array of png_ptr->width pixels. If the image is not interlaced or this
1056 * is the final pass this just does a memcpy, otherwise the "display" flag
1057 * is used to determine whether to copy pixels that are not in the current pass.
1059 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1060 * function to achieve the documented 'blocky' appearance during interlaced read
1061 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1062 * are not changed if they are not in the current pass, when display is 0.
1064 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1066 * The API always reads from the png_struct row buffer and always assumes that
1067 * it is full width (png_do_read_interlace has already been called.)
1069 * This function is only ever used to write to row buffers provided by the
1070 * caller of the relevant libpng API and the row must have already been
1071 * transformed by the read transformations.
1073 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1074 * bitmasks for use within the code, otherwise runtime generated masks are used.
1075 * The default is compile time masks.
1077 #ifndef PNG_USE_COMPILE_TIME_MASKS
1078 # define PNG_USE_COMPILE_TIME_MASKS 1
1080 PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1081 png_bytep row, int display),PNG_EMPTY);
1083 #ifdef PNG_READ_INTERLACING_SUPPORTED
1084 /* Expand an interlaced row: the 'row_info' describes the pass data that has
1085 * been read in and must correspond to the pixels in 'row', the pixels are
1086 * expanded (moved apart) in 'row' to match the final layout, when doing this
1087 * the pixels are *replicated* to the intervening space. This is essential for
1088 * the correct operation of png_combine_row, above.
1090 PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1091 png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1094 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
1096 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1097 /* Grab pixels out of a row for an interlaced pass */
1098 PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1099 png_bytep row, int pass),PNG_EMPTY);
1102 /* Unfilter a row: check the filter value before calling this, there is no point
1103 * calling it for PNG_FILTER_VALUE_NONE.
1105 PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1106 row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1108 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1109 png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1110 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1111 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1112 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1113 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1114 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1115 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1116 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1117 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1118 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1119 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1120 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1121 row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1123 /* Choose the best filter to use and filter the row data */
1124 PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1125 png_row_infop row_info),PNG_EMPTY);
1127 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1128 PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1129 png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1130 /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
1131 * is NULL the function checks, instead, for the end of the stream. In this
1132 * case a benign error will be issued if the stream end is not found or if
1133 * extra data has to be consumed.
1135 PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1137 /* This cleans up when the IDAT LZ stream does not end when the last image
1138 * byte is read; there is still some pending input.
1141 PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1143 /* Finish a row while reading, dealing with interlacing passes, etc. */
1144 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
1146 /* Initialize the row buffers, etc. */
1147 PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1149 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1150 /* Optional call to update the users info structure */
1151 PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1152 png_inforp info_ptr),PNG_EMPTY);
1155 /* Shared transform functions, defined in pngtran.c */
1156 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1157 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1158 PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1159 png_bytep row, int at_start),PNG_EMPTY);
1162 #ifdef PNG_16BIT_SUPPORTED
1163 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1164 PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1165 png_bytep row),PNG_EMPTY);
1169 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1170 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1171 PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1172 png_bytep row),PNG_EMPTY);
1175 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1176 PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1177 png_bytep row),PNG_EMPTY);
1180 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1181 PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1182 png_bytep row),PNG_EMPTY);
1185 /* The following decodes the appropriate chunks, and does error correction,
1186 * then calls the appropriate callback for the chunk if it is valid.
1189 /* Decode the IHDR chunk */
1190 PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1191 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1192 PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1193 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1194 PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1195 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1197 #ifdef PNG_READ_bKGD_SUPPORTED
1198 PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1199 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1202 #ifdef PNG_READ_cHRM_SUPPORTED
1203 PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1204 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1207 #ifdef PNG_READ_gAMA_SUPPORTED
1208 PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1209 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1212 #ifdef PNG_READ_hIST_SUPPORTED
1213 PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1214 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1217 #ifdef PNG_READ_iCCP_SUPPORTED
1218 PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1219 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1220 #endif /* PNG_READ_iCCP_SUPPORTED */
1222 #ifdef PNG_READ_iTXt_SUPPORTED
1223 PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1224 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1227 #ifdef PNG_READ_oFFs_SUPPORTED
1228 PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1229 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1232 #ifdef PNG_READ_pCAL_SUPPORTED
1233 PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1234 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1237 #ifdef PNG_READ_pHYs_SUPPORTED
1238 PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1239 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1242 #ifdef PNG_READ_sBIT_SUPPORTED
1243 PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1244 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1247 #ifdef PNG_READ_sCAL_SUPPORTED
1248 PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1249 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1252 #ifdef PNG_READ_sPLT_SUPPORTED
1253 PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1254 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1255 #endif /* PNG_READ_sPLT_SUPPORTED */
1257 #ifdef PNG_READ_sRGB_SUPPORTED
1258 PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1259 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1262 #ifdef PNG_READ_tEXt_SUPPORTED
1263 PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1264 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1267 #ifdef PNG_READ_tIME_SUPPORTED
1268 PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1269 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1272 #ifdef PNG_READ_tRNS_SUPPORTED
1273 PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1274 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1277 #ifdef PNG_READ_zTXt_SUPPORTED
1278 PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1279 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1282 PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
1283 png_uint_32 chunk_name),PNG_EMPTY);
1285 PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1286 png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1287 /* This is the function that gets called for unknown chunks. The 'keep'
1288 * argument is either non-zero for a known chunk that has been set to be
1289 * handled as unknown or zero for an unknown chunk. By default the function
1290 * just skips the chunk or errors out if it is critical.
1293 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
1294 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1295 PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1296 (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1297 /* Exactly as the API png_handle_as_unknown() except that the argument is a
1298 * 32-bit chunk name, not a string.
1300 #endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
1302 /* Handle the transformations for reading and writing */
1303 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1304 PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1305 png_row_infop row_info),PNG_EMPTY);
1307 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1308 PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1309 png_row_infop row_info),PNG_EMPTY);
1312 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1313 PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1317 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1318 PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1319 png_inforp info_ptr),PNG_EMPTY);
1320 PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1321 png_inforp info_ptr),PNG_EMPTY);
1322 PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1323 PNG_INTERNAL_FUNCTION(void,png_push_crc_skip,(png_structrp png_ptr,
1324 png_uint_32 length),PNG_EMPTY);
1325 PNG_INTERNAL_FUNCTION(void,png_push_crc_finish,(png_structrp png_ptr),
1327 PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1329 PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1330 png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1331 PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1332 PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1333 png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1334 PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1336 PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1337 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1338 PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1339 png_inforp info_ptr),PNG_EMPTY);
1340 PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1341 png_inforp info_ptr),PNG_EMPTY);
1342 PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1343 png_bytep row),PNG_EMPTY);
1344 PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1345 png_inforp info_ptr),PNG_EMPTY);
1346 PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1347 png_inforp info_ptr),PNG_EMPTY);
1348 PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1350 # ifdef PNG_READ_tEXt_SUPPORTED
1351 PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1352 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1353 PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1354 png_inforp info_ptr),PNG_EMPTY);
1356 # ifdef PNG_READ_zTXt_SUPPORTED
1357 PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1358 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1359 PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1360 png_inforp info_ptr),PNG_EMPTY);
1362 # ifdef PNG_READ_iTXt_SUPPORTED
1363 PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1364 png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1365 PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1366 png_inforp info_ptr),PNG_EMPTY);
1369 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1371 /* Added at libpng version 1.6.0 */
1372 #ifdef PNG_GAMMA_SUPPORTED
1373 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1374 png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1375 /* Set the colorspace gamma with a value provided by the application or by
1376 * the gAMA chunk on read. The value will override anything set by an ICC
1380 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1381 png_inforp info_ptr), PNG_EMPTY);
1382 /* Synchronize the info 'valid' flags with the colorspace */
1384 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1385 png_inforp info_ptr), PNG_EMPTY);
1386 /* Copy the png_struct colorspace to the info_struct and call the above to
1387 * synchronize the flags. Checks for NULL info_ptr and does nothing.
1391 /* Added at libpng version 1.4.0 */
1392 #ifdef PNG_COLORSPACE_SUPPORTED
1393 /* These internal functions are for maintaining the colorspace structure within
1394 * a png_info or png_struct (or, indeed, both).
1396 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1397 (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1398 int preferred), PNG_EMPTY);
1400 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1401 (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1402 int preferred), PNG_EMPTY);
1404 #ifdef PNG_sRGB_SUPPORTED
1405 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1406 png_colorspacerp colorspace, int intent), PNG_EMPTY);
1407 /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1408 * flags to write them, if it returns false there was a problem and an error
1409 * message has already been output (but the colorspace may still need to be
1410 * synced to record the invalid flag).
1414 #ifdef PNG_iCCP_SUPPORTED
1415 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1416 png_colorspacerp colorspace, png_const_charp name,
1417 png_uint_32 profile_length, png_const_bytep profile, int color_type),
1419 /* The 'name' is used for information only */
1421 /* Routines for checking parts of an ICC profile. */
1422 PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1423 png_colorspacerp colorspace, png_const_charp name,
1424 png_uint_32 profile_length), PNG_EMPTY);
1425 PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1426 png_colorspacerp colorspace, png_const_charp name,
1427 png_uint_32 profile_length,
1428 png_const_bytep profile /* first 132 bytes only */, int color_type),
1430 PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1431 png_colorspacerp colorspace, png_const_charp name,
1432 png_uint_32 profile_length,
1433 png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1434 #ifdef PNG_sRGB_SUPPORTED
1435 PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1436 png_const_structrp png_ptr, png_colorspacerp colorspace,
1437 png_const_bytep profile, uLong adler), PNG_EMPTY);
1438 /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1439 * be zero to indicate that it is not available. It is used, if provided,
1440 * as a fast check on the profile when checking to see if it is sRGB.
1445 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1446 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1447 (png_structrp png_ptr), PNG_EMPTY);
1448 /* Set the rgb_to_gray coefficients from the colorspace Y values */
1449 #endif /* READ_RGB_TO_GRAY */
1450 #endif /* COLORSPACE */
1452 /* Added at libpng version 1.4.0 */
1453 PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1454 png_uint_32 width, png_uint_32 height, int bit_depth,
1455 int color_type, int interlace_type, int compression_type,
1456 int filter_type),PNG_EMPTY);
1458 /* Added at libpng version 1.5.10 */
1459 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1460 defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1461 PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1462 (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1465 #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1466 PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1467 png_const_charp name),PNG_NORETURN);
1470 /* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1471 * the end. Always leaves the buffer nul terminated. Never errors out (and
1472 * there is no error code.)
1474 PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1475 size_t pos, png_const_charp string),PNG_EMPTY);
1477 /* Various internal functions to handle formatted warning messages, currently
1478 * only implemented for warnings.
1480 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1481 /* Utility to dump an unsigned value into a buffer, given a start pointer and
1482 * and end pointer (which should point just *beyond* the end of the buffer!)
1483 * Returns the pointer to the start of the formatted string. This utility only
1484 * does unsigned values.
1486 PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1487 png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1489 /* Convenience macro that takes an array: */
1490 #define PNG_FORMAT_NUMBER(buffer,format,number) \
1491 png_format_number(buffer, buffer + (sizeof buffer), format, number)
1493 /* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1494 #define PNG_NUMBER_BUFFER_SIZE 24
1496 /* These are the integer formats currently supported, the name is formed from
1497 * the standard printf(3) format string.
1499 #define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
1500 #define PNG_NUMBER_FORMAT_02u 2
1501 #define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
1502 #define PNG_NUMBER_FORMAT_02d 2
1503 #define PNG_NUMBER_FORMAT_x 3
1504 #define PNG_NUMBER_FORMAT_02x 4
1505 #define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1508 #ifdef PNG_WARNINGS_SUPPORTED
1509 /* New defines and members adding in libpng-1.5.4 */
1510 # define PNG_WARNING_PARAMETER_SIZE 32
1511 # define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1513 /* An l-value of this type has to be passed to the APIs below to cache the
1514 * values of the parameters to a formatted warning message.
1516 typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1517 PNG_WARNING_PARAMETER_SIZE];
1519 PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1520 int number, png_const_charp string),PNG_EMPTY);
1521 /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1522 * including the trailing '\0'.
1524 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1525 (png_warning_parameters p, int number, int format, png_alloc_size_t value),
1527 /* Use png_alloc_size_t because it is an unsigned type as big as any we
1528 * need to output. Use the following for a signed value.
1530 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1531 (png_warning_parameters p, int number, int format, png_int_32 value),
1534 PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1535 png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1536 /* 'message' follows the X/Open approach of using @1, @2 to insert
1537 * parameters previously supplied using the above functions. Errors in
1538 * specifying the parameters will simply result in garbage substitutions.
1542 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1543 /* Application errors (new in 1.6); use these functions (declared below) for
1544 * errors in the parameters or order of API function calls on read. The
1545 * 'warning' should be used for an error that can be handled completely; the
1546 * 'error' for one which can be handled safely but which may lose application
1547 * information or settings.
1549 * By default these both result in a png_error call prior to release, while in a
1550 * released version the 'warning' is just a warning. However if the application
1551 * explicitly disables benign errors (explicitly permitting the code to lose
1552 * information) they both turn into warnings.
1554 * If benign errors aren't supported they end up as the corresponding base call
1555 * (png_warning or png_error.)
1557 PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1558 png_const_charp message),PNG_EMPTY);
1559 /* The application provided invalid parameters to an API function or called
1560 * an API function at the wrong time, libpng can completely recover.
1563 PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1564 png_const_charp message),PNG_EMPTY);
1565 /* As above but libpng will ignore the call, or attempt some other partial
1566 * recovery from the error.
1569 # define png_app_warning(pp,s) png_warning(pp,s)
1570 # define png_app_error(pp,s) png_error(pp,s)
1573 PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1574 png_const_charp message, int error),PNG_EMPTY);
1575 /* Report a recoverable issue in chunk data. On read this is used to report
1576 * a problem found while reading a particular chunk and the
1577 * png_chunk_benign_error or png_chunk_warning function is used as
1578 * appropriate. On write this is used to report an error that comes from
1579 * data set via an application call to a png_set_ API and png_app_error or
1580 * png_app_warning is used as appropriate.
1582 * The 'error' parameter must have one of the following values:
1584 #define PNG_CHUNK_WARNING 0 /* never an error */
1585 #define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1586 #define PNG_CHUNK_ERROR 2 /* always an error */
1588 /* ASCII to FP interfaces, currently only implemented if sCAL
1589 * support is required.
1591 #if defined(PNG_sCAL_SUPPORTED)
1592 /* MAX_DIGITS is actually the maximum number of characters in an sCAL
1593 * width or height, derived from the precision (number of significant
1594 * digits - a build time settable option) and assumptions about the
1595 * maximum ridiculous exponent.
1597 #define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1599 #ifdef PNG_FLOATING_POINT_SUPPORTED
1600 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1601 png_charp ascii, png_size_t size, double fp, unsigned int precision),
1603 #endif /* FLOATING_POINT */
1605 #ifdef PNG_FIXED_POINT_SUPPORTED
1606 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1607 png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
1608 #endif /* FIXED_POINT */
1611 #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1612 /* An internal API to validate the format of a floating point number.
1613 * The result is the index of the next character. If the number is
1614 * not valid it will be the index of a character in the supposed number.
1616 * The format of a number is defined in the PNG extensions specification
1617 * and this API is strictly conformant to that spec, not anyone elses!
1619 * The format as a regular expression is:
1621 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1625 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1627 * The complexity is that either integer or fraction must be present and the
1628 * fraction is permitted to have no digits only if the integer is present.
1630 * NOTE: The dangling E problem.
1631 * There is a PNG valid floating point number in the following:
1633 * PNG floating point numbers are not greedy.
1635 * Working this out requires *TWO* character lookahead (because of the
1636 * sign), the parser does not do this - it will fail at the 'r' - this
1637 * doesn't matter for PNG sCAL chunk values, but it requires more care
1638 * if the value were ever to be embedded in something more complex. Use
1639 * ANSI-C strtod if you need the lookahead.
1641 /* State table for the parser. */
1642 #define PNG_FP_INTEGER 0 /* before or in integer */
1643 #define PNG_FP_FRACTION 1 /* before or in fraction */
1644 #define PNG_FP_EXPONENT 2 /* before or in exponent */
1645 #define PNG_FP_STATE 3 /* mask for the above */
1646 #define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
1647 #define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
1648 #define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
1649 #define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
1650 #define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
1652 /* These three values don't affect the parser. They are set but not used.
1654 #define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
1655 #define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
1656 #define PNG_FP_NONZERO 256 /* A non-zero value */
1657 #define PNG_FP_STICKY 448 /* The above three flags */
1659 /* This is available for the caller to store in 'state' if required. Do not
1660 * call the parser after setting it (the parser sometimes clears it.)
1662 #define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
1664 /* Result codes for the parser (boolean - true meants ok, false means
1667 #define PNG_FP_MAYBE 0 /* The number may be valid in the future */
1668 #define PNG_FP_OK 1 /* The number is valid */
1670 /* Tests on the sticky non-zero and negative flags. To pass these checks
1671 * the state must also indicate that the whole number is valid - this is
1672 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1673 * is equivalent to PNG_FP_OK above.)
1675 #define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1676 /* NZ_MASK: the string is valid and a non-zero negative value */
1677 #define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1678 /* Z MASK: the string is valid and a non-zero value. */
1679 /* PNG_FP_SAW_DIGIT: the string is valid. */
1680 #define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1681 #define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1682 #define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1684 /* The actual parser. This can be called repeatedly. It updates
1685 * the index into the string and the state variable (which must
1686 * be initialized to 0). It returns a result code, as above. There
1687 * is no point calling the parser any more if it fails to advance to
1688 * the end of the string - it is stuck on an invalid character (or
1689 * terminated by '\0').
1691 * Note that the pointer will consume an E or even an E+ and then leave
1692 * a 'maybe' state even though a preceding integer.fraction is valid.
1693 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1694 * a valid number. It's possible to recover from this by calling
1695 * the parser again (from the start, with state 0) but with a string
1696 * that omits the last character (i.e. set the size to the index of
1697 * the problem character.) This has not been tested within libpng.
1699 PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
1700 png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
1702 /* This is the same but it checks a complete string and returns true
1703 * only if it just contains a floating point number. As of 1.5.4 this
1704 * function also returns the state at the end of parsing the number if
1705 * it was valid (otherwise it returns 0.) This can be used for testing
1706 * for negative or zero values using the sticky flag.
1708 PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
1709 png_size_t size),PNG_EMPTY);
1710 #endif /* pCAL || sCAL */
1712 #if defined(PNG_GAMMA_SUPPORTED) ||\
1713 defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1714 /* Added at libpng version 1.5.0 */
1715 /* This is a utility to provide a*times/div (rounded) and indicate
1716 * if there is an overflow. The result is a boolean - false (0)
1717 * for overflow, true (1) if no overflow, in which case *res
1720 PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
1721 png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
1724 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1725 /* Same deal, but issue a warning on overflow and return 0. */
1726 PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
1727 (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
1728 png_int_32 divided_by),PNG_EMPTY);
1731 #ifdef PNG_GAMMA_SUPPORTED
1732 /* Calculate a reciprocal - used for gamma values. This returns
1733 * 0 if the argument is 0 in order to maintain an undefined value;
1734 * there are no warnings.
1736 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
1739 #ifdef PNG_READ_GAMMA_SUPPORTED
1740 /* The same but gives a reciprocal of the product of two fixed point
1741 * values. Accuracy is suitable for gamma calculations but this is
1742 * not exact - use png_muldiv for that. Only required at present on read.
1744 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
1745 png_fixed_point b),PNG_EMPTY);
1748 /* Return true if the gamma value is significantly different from 1.0 */
1749 PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
1753 #ifdef PNG_READ_GAMMA_SUPPORTED
1754 /* Internal fixed point gamma correction. These APIs are called as
1755 * required to convert single values - they don't need to be fast,
1756 * they are not used when processing image pixel values.
1758 * While the input is an 'unsigned' value it must actually be the
1759 * correct bit value - 0..255 or 0..65535 as required.
1761 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
1762 unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
1763 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
1764 png_fixed_point gamma_value),PNG_EMPTY);
1765 PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
1766 png_fixed_point gamma_value),PNG_EMPTY);
1767 PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
1769 PNG_INTERNAL_FUNCTION(void,png_build_gamma_tables,(png_structrp png_ptr,
1770 int bit_depth),PNG_EMPTY);
1773 /* SIMPLIFIED READ/WRITE SUPPORT */
1774 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
1775 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
1776 /* The internal structure that png_image::opaque points to. */
1777 typedef struct png_control
1779 png_structp png_ptr;
1781 png_voidp error_buf; /* Always a jmp_buf at present. */
1783 png_const_bytep memory; /* Memory buffer. */
1784 png_size_t size; /* Size of the memory buffer. */
1786 unsigned int for_write :1; /* Otherwise it is a read structure */
1787 unsigned int owned_file :1; /* We own the file in io_ptr */
1790 /* Return the pointer to the jmp_buf from a png_control: necessary because C
1791 * does not reveal the type of the elements of jmp_buf.
1794 # define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
1796 # define png_control_jmp_buf(pc) ((pc)->error_buf)
1799 /* Utility to safely execute a piece of libpng code catching and logging any
1800 * errors that might occur. Returns true on success, false on failure (either
1801 * of the function or as a result of a png_error.)
1803 PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
1804 png_const_charp error_message),PNG_NORETURN);
1806 #ifdef PNG_WARNINGS_SUPPORTED
1807 PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
1808 png_const_charp warning_message),PNG_EMPTY);
1810 # define png_safe_warning 0/*dummy argument*/
1813 PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
1814 int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
1816 /* Utility to log an error; this also cleans up the png_image; the function
1817 * always returns 0 (false).
1819 PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
1820 png_const_charp error_message),PNG_EMPTY);
1822 #ifndef PNG_SIMPLIFIED_READ_SUPPORTED
1823 /* png_image_free is used by the write code but not exported */
1824 PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
1825 #endif /* !SIMPLIFIED_READ */
1827 #endif /* SIMPLIFIED READ/WRITE */
1829 /* These are initialization functions for hardware specific PNG filter
1830 * optimizations; list these here then select the appropriate one at compile
1831 * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined
1832 * the generic code is used.
1834 #ifdef PNG_FILTER_OPTIMIZATIONS
1835 PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structrp png_ptr,
1836 unsigned int bpp), PNG_EMPTY);
1837 /* Just declare the optimization that will be used */
1839 /* List *all* the possible optimizations here - this branch is required if
1840 * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
1841 * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
1843 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
1844 (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
1847 /* Maintainer: Put new private prototypes here ^ */
1849 #include "pngdebug.h"
1855 #endif /* PNG_VERSION_INFO_ONLY */
1856 #endif /* PNGPRIV_H */