1 /* pngpriv.h - private declarations for use inside libpng
3 * For conditions of distribution and use, see copyright notice in png.h
4 * Copyright (c) 1998-2013 Glenn Randers-Pehrson
5 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
6 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 * Last changed in libpng 1.6.2 [April 25, 2013]
10 * This code is released under the libpng license.
11 * For conditions of distribution and use, see the disclaimer
12 * and license in png.h
15 /* The symbols declared in this file (including the functions declared
16 * as extern) are PRIVATE. They are not part of the libpng public
17 * interface, and are not recommended for use by regular applications.
18 * Some of them may become public in the future; others may stay private,
19 * change in an incompatible way, or even disappear.
20 * Although the libpng users are not forbidden to include this header,
21 * they should be well aware of the issues that may arise from doing so.
27 /* Feature Test Macros. The following are defined here to ensure that correctly
28 * implemented libraries reveal the APIs libpng needs to build and hide those
29 * that are not needed and potentially damaging to the compilation.
31 * Feature Test Macros must be defined before any system header is included (see
32 * POSIX 1003.1 2.8.2 "POSIX Symbols."
34 * These macros only have an effect if the operating system supports either
35 * POSIX 1003.1 or C99, or both. On other operating systems (particularly
36 * Windows/Visual Studio) there is no effect; the OS specific tests below are
37 * still required (as of 2011-05-02.)
39 #define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
41 #ifndef PNG_VERSION_INFO_ONLY
42 /* Standard library headers not required by png.h: */
47 #define PNGLIB_BUILD /*libpng is being built, not used*/
49 /* If HAVE_CONFIG_H is defined during the build then the build system must
50 * provide an appropriate "config.h" file on the include path. The header file
51 * must provide definitions as required below (search for "HAVE_CONFIG_H");
52 * see configure.ac for more details of the requirements. The macro
53 * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
54 * 'configure'; define this macro to prevent the configure build including the
55 * configure generated config.h. Libpng is expected to compile without *any*
56 * special build system support on a reasonably ANSI-C compliant system.
58 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
61 /* Pick up the definition of 'restrict' from config.h if it was read: */
62 # define PNG_RESTRICT restrict
65 /* To support symbol prefixing it is necessary to know *before* including png.h
66 * whether the fixed point (and maybe other) APIs are exported, because if they
67 * are not internal definitions may be required. This is handled below just
68 * before png.h is included, but load the configuration now if it is available.
71 # include "pnglibconf.h"
74 /* Local renames may change non-exported API functions from png.h */
75 #if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
76 # include "pngprefix.h"
79 #ifdef PNG_USER_CONFIG
81 /* These should have been defined in pngusr.h */
82 # ifndef PNG_USER_PRIVATEBUILD
83 # define PNG_USER_PRIVATEBUILD "Custom libpng build"
85 # ifndef PNG_USER_DLLFNAME_POSTFIX
86 # define PNG_USER_DLLFNAME_POSTFIX "Cb"
90 /* Is this a build of a DLL where compilation of the object modules requires
91 * different preprocessor settings to those required for a simple library? If
92 * so PNG_BUILD_DLL must be set.
94 * If libpng is used inside a DLL but that DLL does not export the libpng APIs
95 * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
96 * static library of libpng then link the DLL against that.
100 /* This is set by libtool when files are compiled for a DLL; libtool
101 * always compiles twice, even on systems where it isn't necessary. Set
102 * PNG_BUILD_DLL in case it is necessary:
104 # define PNG_BUILD_DLL
107 /* This is set by the Microsoft Visual Studio IDE in projects that
108 * build a DLL. It can't easily be removed from those projects (it
109 * isn't visible in the Visual Studio UI) so it is a fairly reliable
110 * indication that PNG_IMPEXP needs to be set to the DLL export
113 # define PNG_BUILD_DLL
116 /* This is set by the Borland C system when compiling for a DLL
119 # define PNG_BUILD_DLL
121 /* Add additional compiler cases here. */
125 #endif /* Setting PNG_BUILD_DLL if required */
127 /* See pngconf.h for more details: the builder of the library may set this on
128 * the command line to the right thing for the specific compilation system or it
129 * may be automagically set above (at present we know of no system where it does
130 * need to be set on the command line.)
132 * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
133 * setting it to the "import" setting for a DLL build.
136 # ifdef PNG_BUILD_DLL
137 # define PNG_IMPEXP PNG_DLL_EXPORT
139 /* Not building a DLL, or the DLL doesn't require specific export
146 /* No warnings for private or deprecated functions in the build: */
147 #ifndef PNG_DEPRECATED
148 # define PNG_DEPRECATED
154 /* Symbol preprocessing support.
156 * To enable listing global, but internal, symbols the following macros should
157 * always be used to declare an extern data or function object in this file.
159 #ifndef PNG_INTERNAL_DATA
160 # define PNG_INTERNAL_DATA(type, name, array) extern type name array
163 #ifndef PNG_INTERNAL_FUNCTION
164 # define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
165 extern PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
168 /* If floating or fixed point APIs are disabled they may still be compiled
169 * internally. To handle this make sure they are declared as the appropriate
170 * internal extern function (otherwise the symbol prefixing stuff won't work and
171 * the functions will be used without definitions.)
173 * NOTE: although all the API functions are declared here they are not all
174 * actually built! Because the declarations are still made it is necessary to
175 * fake out types that they depend on.
177 #ifndef PNG_FP_EXPORT
178 # ifndef PNG_FLOATING_POINT_SUPPORTED
179 # define PNG_FP_EXPORT(ordinal, type, name, args)\
180 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
181 # ifndef PNG_VERSION_INFO_ONLY
182 typedef struct png_incomplete png_double
;
183 typedef png_double
* png_doublep
;
184 typedef const png_double
* png_const_doublep
;
185 typedef png_double
** png_doublepp
;
189 #ifndef PNG_FIXED_EXPORT
190 # ifndef PNG_FIXED_POINT_SUPPORTED
191 # define PNG_FIXED_EXPORT(ordinal, type, name, args)\
192 PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
198 /* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
199 #ifndef PNG_DLL_EXPORT
200 # define PNG_DLL_EXPORT
203 /* SECURITY and SAFETY:
205 * By default libpng is built without any internal limits on image size,
206 * individual heap (png_malloc) allocations or the total amount of memory used.
207 * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
208 * (unless individually overridden). These limits are believed to be fairly
209 * safe, but builders of secure systems should verify the values against the
210 * real system capabilities.
212 #ifdef PNG_SAFE_LIMITS_SUPPORTED
214 # ifndef PNG_USER_WIDTH_MAX
215 # define PNG_USER_WIDTH_MAX 1000000
217 # ifndef PNG_USER_HEIGHT_MAX
218 # define PNG_USER_HEIGHT_MAX 1000000
220 # ifndef PNG_USER_CHUNK_CACHE_MAX
221 # define PNG_USER_CHUNK_CACHE_MAX 128
223 # ifndef PNG_USER_CHUNK_MALLOC_MAX
224 # define PNG_USER_CHUNK_MALLOC_MAX 8000000
227 /* values for no limits */
228 # ifndef PNG_USER_WIDTH_MAX
229 # define PNG_USER_WIDTH_MAX 0x7fffffff
231 # ifndef PNG_USER_HEIGHT_MAX
232 # define PNG_USER_HEIGHT_MAX 0x7fffffff
234 # ifndef PNG_USER_CHUNK_CACHE_MAX
235 # define PNG_USER_CHUNK_CACHE_MAX 0
237 # ifndef PNG_USER_CHUNK_MALLOC_MAX
238 # define PNG_USER_CHUNK_MALLOC_MAX 0
242 /* Moved to pngpriv.h at libpng-1.5.0 */
243 /* NOTE: some of these may have been used in external applications as
244 * these definitions were exposed in pngconf.h prior to 1.5.
247 /* If you are running on a machine where you cannot allocate more
248 * than 64K of memory at once, uncomment this. While libpng will not
249 * normally need that much memory in a chunk (unless you load up a very
250 * large file), zlib needs to know how big of a chunk it can use, and
251 * libpng thus makes sure to check any memory allocation to verify it
252 * will fit into memory.
254 * zlib provides 'MAXSEG_64K' which, if defined, indicates the
255 * same limit and pngconf.h (already included) sets the limit
256 * if certain operating systems are detected.
258 #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
259 # define PNG_MAX_MALLOC_64K
263 /* Unused formal parameter warnings are silenced using the following macro
264 * which is expected to have no bad effects on performance (optimizing
265 * compilers will probably remove it entirely). Note that if you replace
266 * it with something other than whitespace, you must include the terminating
269 # define PNG_UNUSED(param) (void)param;
272 /* Just a little check that someone hasn't tried to define something
275 #if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
276 # undef PNG_ZBUF_SIZE
277 # define PNG_ZBUF_SIZE 65536L
280 /* If warnings or errors are turned off the code is disabled or redirected here.
281 * From 1.5.4 functions have been added to allow very limited formatting of
282 * error and warning messages - this code will also be disabled here.
284 #ifdef PNG_WARNINGS_SUPPORTED
285 # define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
287 # define png_warning(s1,s2) ((void)(s1))
288 # define png_chunk_warning(s1,s2) ((void)(s1))
289 # define png_warning_parameter(p,number,string) ((void)0)
290 # define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
291 # define png_warning_parameter_signed(p,number,format,value) ((void)0)
292 # define png_formatted_warning(pp,p,message) ((void)(pp))
293 # define PNG_WARNING_PARAMETERS(p)
295 #ifndef PNG_ERROR_TEXT_SUPPORTED
296 # define png_error(s1,s2) png_err(s1)
297 # define png_chunk_error(s1,s2) png_err(s1)
298 # define png_fixed_error(s1,s2) png_err(s1)
301 /* C allows up-casts from (void*) to any pointer and (const void*) to any
302 * pointer to a const object. C++ regards this as a type error and requires an
303 * explicit, static, cast and provides the static_cast<> rune to ensure that
304 * const is not cast away.
307 # define png_voidcast(type, value) static_cast<type>(value)
308 # define png_constcast(type, value) const_cast<type>(value)
309 # define png_aligncast(type, value) \
310 static_cast<type>(static_cast<void*>(value))
311 # define png_aligncastconst(type, value) \
312 static_cast<type>(static_cast<const void*>(value))
314 # define png_voidcast(type, value) (value)
315 # define png_constcast(type, value) ((type)(value))
316 # define png_aligncast(type, value) ((void*)(value))
317 # define png_aligncastconst(type, value) ((const void*)(value))
318 #endif /* __cplusplus */
320 /* Some fixed point APIs are still required even if not exported because
321 * they get used by the corresponding floating point APIs. This magic
324 #ifdef PNG_FIXED_POINT_SUPPORTED
325 # define PNGFAPI PNGAPI
327 # define PNGFAPI /* PRIVATE */
330 #ifndef PNG_VERSION_INFO_ONLY
331 /* Other defines specific to compilers can go here. Try to keep
332 * them inside an appropriate ifdef/endif pair for portability.
334 #if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
335 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
336 /* png.c requires the following ANSI-C constants if the conversion of
337 * floating point to ASCII is implemented therein:
339 * DBL_DIG Maximum number of decimal digits (can be set to any constant)
340 * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
341 * DBL_MAX Maximum floating point number (can be set to an arbitrary value)
345 # if ( ( (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
346 defined(THINK_C) || defined(TARGET_OS_MAC) ) && !wxOSX_USE_IPHONE ) || defined(__SC__)
347 /* We need to check that <math.h> hasn't already been included earlier
348 * as it seems it doesn't agree with <fp.h>, yet we should really use
349 * <fp.h> if possible.
351 # if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
357 # if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
358 /* Amiga SAS/C: We must include builtin FPU functions when compiling using
365 /* This provides the non-ANSI (far) memory allocation routines. */
366 #if defined(__TURBOC__) && defined(__MSDOS__)
371 #if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
372 defined(_WIN32) || defined(__WIN32__)
373 # include <windows.h> /* defines _WINDOWS_ macro */
375 #endif /* PNG_VERSION_INFO_ONLY */
377 /* Moved here around 1.5.0beta36 from pngconf.h */
378 /* Users may want to use these so they are not private. Any library
379 * functions that are passed far data must be model-independent.
382 /* Memory model/platform independent fns */
385 # define PNG_ABORT() ExitProcess(0)
387 # define PNG_ABORT() abort()
391 /* These macros may need to be architecture dependent. */
392 #define PNG_ALIGN_NONE 0 /* do not use data alignment */
393 #define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
395 # define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
397 # define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
399 #define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
401 #ifndef PNG_ALIGN_TYPE
402 /* Default to using aligned access optimizations and requiring alignment to a
403 * multiple of the data type size. Override in a compiler specific fashion
404 * if necessary by inserting tests here:
406 # define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
409 #if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
410 /* This is used because in some compiler implementations non-aligned
411 * structure members are supported, so the offsetof approach below fails.
412 * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
413 * is good for performance. Do not do this unless you have tested the result
416 # define png_alignof(type) (sizeof (type))
418 # if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
419 # define png_alignof(type) offsetof(struct{char c; type t;}, t)
421 # if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
422 # define png_alignof(type) (1)
424 /* Else leave png_alignof undefined to prevent use thereof */
428 /* This implicitly assumes alignment is always to a power of 2. */
430 # define png_isaligned(ptr, type)\
431 ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
433 # define png_isaligned(ptr, type) 0
436 /* End of memory model/platform independent support */
437 /* End of 1.5.0beta36 move from pngconf.h */
439 /* CONSTANTS and UTILITY MACROS
440 * These are used internally by libpng and not exposed in the API
443 /* Various modes of operation. Note that after an init, mode is set to
444 * zero automatically when the structure is created. Three of these
445 * are defined in png.h because they need to be visible to applications
446 * that call png_set_unknown_chunk().
448 /* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */
449 /* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */
450 #define PNG_HAVE_IDAT 0x04
451 /* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */
452 #define PNG_HAVE_IEND 0x10
456 #define PNG_HAVE_CHUNK_HEADER 0x100
457 #define PNG_WROTE_tIME 0x200
458 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
459 #define PNG_BACKGROUND_IS_GRAY 0x800
460 #define PNG_HAVE_PNG_SIGNATURE 0x1000
461 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
462 /* 0x4000 (unused) */
463 #define PNG_IS_READ_STRUCT 0x8000 /* Else is a write struct */
465 /* Flags for the transformations the PNG library does on the image data */
466 #define PNG_BGR 0x0001
467 #define PNG_INTERLACE 0x0002
468 #define PNG_PACK 0x0004
469 #define PNG_SHIFT 0x0008
470 #define PNG_SWAP_BYTES 0x0010
471 #define PNG_INVERT_MONO 0x0020
472 #define PNG_QUANTIZE 0x0040
473 #define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */
474 #define PNG_BACKGROUND_EXPAND 0x0100
475 #define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */
476 #define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */
477 #define PNG_RGBA 0x0800
478 #define PNG_EXPAND 0x1000
479 #define PNG_GAMMA 0x2000
480 #define PNG_GRAY_TO_RGB 0x4000
481 #define PNG_FILLER 0x8000
482 #define PNG_PACKSWAP 0x10000
483 #define PNG_SWAP_ALPHA 0x20000
484 #define PNG_STRIP_ALPHA 0x40000
485 #define PNG_INVERT_ALPHA 0x80000
486 #define PNG_USER_TRANSFORM 0x100000
487 #define PNG_RGB_TO_GRAY_ERR 0x200000
488 #define PNG_RGB_TO_GRAY_WARN 0x400000
489 #define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
490 #define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */
491 #define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */
492 #define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */
493 #define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */
494 /* 0x8000000 unused */
495 /* 0x10000000 unused */
496 /* 0x20000000 unused */
497 /* 0x40000000 unused */
498 /* Flags for png_create_struct */
499 #define PNG_STRUCT_PNG 0x0001
500 #define PNG_STRUCT_INFO 0x0002
502 /* Scaling factor for filter heuristic weighting calculations */
503 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
504 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
506 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
507 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
508 #define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002 /* Added to libpng-1.6.0 */
510 #define PNG_FLAG_ZSTREAM_ENDED 0x0008 /* Added to libpng-1.6.0 */
513 #define PNG_FLAG_ROW_INIT 0x0040
514 #define PNG_FLAG_FILLER_AFTER 0x0080
515 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
516 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
517 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400
518 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
519 #define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */
520 #define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */
521 #define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */
522 /* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 */
523 /* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 */
524 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000
525 #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000
526 #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000
527 #define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000 /* Added to libpng-1.4.0 */
528 #define PNG_FLAG_APP_WARNINGS_WARN 0x200000 /* Added to libpng-1.6.0 */
529 #define PNG_FLAG_APP_ERRORS_WARN 0x400000 /* Added to libpng-1.6.0 */
530 /* 0x800000 unused */
531 /* 0x1000000 unused */
532 /* 0x2000000 unused */
533 /* 0x4000000 unused */
534 /* 0x8000000 unused */
535 /* 0x10000000 unused */
536 /* 0x20000000 unused */
537 /* 0x40000000 unused */
539 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
540 PNG_FLAG_CRC_ANCILLARY_NOWARN)
542 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
543 PNG_FLAG_CRC_CRITICAL_IGNORE)
545 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
546 PNG_FLAG_CRC_CRITICAL_MASK)
548 /* Save typing and make code easier to understand */
550 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
551 abs((int)((c1).green) - (int)((c2).green)) + \
552 abs((int)((c1).blue) - (int)((c2).blue)))
554 /* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
555 * by dividing by 257 *with rounding*. This macro is exact for the given range.
556 * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
557 * macro were established by experiment (modifying the added value). The macro
558 * has a second variant that takes a value already scaled by 255 and divides by
559 * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
560 * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
562 #define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
563 #define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
565 /* Added to libpng-1.2.6 JB */
566 #define PNG_ROWBYTES(pixel_bits, width) \
567 ((pixel_bits) >= 8 ? \
568 ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
569 (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
571 /* PNG_OUT_OF_RANGE returns true if value is outside the range
572 * ideal-delta..ideal+delta. Each argument is evaluated twice.
573 * "ideal" and "delta" should be constants, normally simple
574 * integers, "value" a variable. Added to libpng-1.2.6 JB
576 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
577 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
579 /* Conversions between fixed and floating point, only defined if
580 * required (to make sure the code doesn't accidentally use float
581 * when it is supposedly disabled.)
583 #ifdef PNG_FLOATING_POINT_SUPPORTED
584 /* The floating point conversion can't overflow, though it can and
585 * does lose accuracy relative to the original fixed point value.
586 * In practice this doesn't matter because png_fixed_point only
587 * stores numbers with very low precision. The png_ptr and s
588 * arguments are unused by default but are there in case error
589 * checking becomes a requirement.
591 #define png_float(png_ptr, fixed, s) (.00001 * (fixed))
593 /* The fixed point conversion performs range checking and evaluates
594 * its argument multiple times, so must be used with care. The
595 * range checking uses the PNG specification values for a signed
596 * 32 bit fixed point value except that the values are deliberately
597 * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
598 * (2^31-1) * 100000). 's' is a string that describes the value being
601 * NOTE: this macro will raise a png_error if the range check fails,
602 * therefore it is normally only appropriate to use this on values
603 * that come from API calls or other sources where an out of range
604 * error indicates a programming error, not a data error!
606 * NOTE: by default this is off - the macro is not used - because the
607 * function call saves a lot of code.
609 #ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
610 #define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
611 ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
613 /* else the corresponding function is defined below, inside the scope of the
618 /* Constants for known chunk types. If you need to add a chunk, define the name
619 * here. For historical reasons these constants have the form png_<name>; i.e.
620 * the prefix is lower case. Please use decimal values as the parameters to
621 * match the ISO PNG specification and to avoid relying on the C locale
622 * interpretation of character values.
624 * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
625 * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
626 * to be generated if required.
628 * PNG_32b correctly produces a value shifted by up to 24 bits, even on
629 * architectures where (int) is only 16 bits.
631 #define PNG_32b(b,s) ((png_uint_32)(b) << (s))
632 #define PNG_CHUNK(b1,b2,b3,b4) \
633 (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
635 #define png_IHDR PNG_CHUNK( 73, 72, 68, 82)
636 #define png_IDAT PNG_CHUNK( 73, 68, 65, 84)
637 #define png_IEND PNG_CHUNK( 73, 69, 78, 68)
638 #define png_PLTE PNG_CHUNK( 80, 76, 84, 69)
639 #define png_bKGD PNG_CHUNK( 98, 75, 71, 68)
640 #define png_cHRM PNG_CHUNK( 99, 72, 82, 77)
641 #define png_gAMA PNG_CHUNK(103, 65, 77, 65)
642 #define png_hIST PNG_CHUNK(104, 73, 83, 84)
643 #define png_iCCP PNG_CHUNK(105, 67, 67, 80)
644 #define png_iTXt PNG_CHUNK(105, 84, 88, 116)
645 #define png_oFFs PNG_CHUNK(111, 70, 70, 115)
646 #define png_pCAL PNG_CHUNK(112, 67, 65, 76)
647 #define png_sCAL PNG_CHUNK(115, 67, 65, 76)
648 #define png_pHYs PNG_CHUNK(112, 72, 89, 115)
649 #define png_sBIT PNG_CHUNK(115, 66, 73, 84)
650 #define png_sPLT PNG_CHUNK(115, 80, 76, 84)
651 #define png_sRGB PNG_CHUNK(115, 82, 71, 66)
652 #define png_sTER PNG_CHUNK(115, 84, 69, 82)
653 #define png_tEXt PNG_CHUNK(116, 69, 88, 116)
654 #define png_tIME PNG_CHUNK(116, 73, 77, 69)
655 #define png_tRNS PNG_CHUNK(116, 82, 78, 83)
656 #define png_zTXt PNG_CHUNK(122, 84, 88, 116)
658 /* The following will work on (signed char*) strings, whereas the get_uint_32
659 * macro will fail on top-bit-set values because of the sign extension.
661 #define PNG_CHUNK_FROM_STRING(s)\
662 PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
664 /* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
665 * signed and the argument is a (char[]) This macro will fail miserably on
666 * systems where (char) is more than 8 bits.
668 #define PNG_STRING_FROM_CHUNK(s,c)\
669 (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
670 ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
672 /* Do the same but terminate with a null character. */
673 #define PNG_CSTRING_FROM_CHUNK(s,c)\
674 (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
676 /* Test on flag values as defined in the spec (section 5.4): */
677 #define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29))
678 #define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
679 #define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
680 #define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
681 #define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
683 /* Gamma values (new at libpng-1.5.4): */
684 #define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
685 #define PNG_GAMMA_MAC_INVERSE 65909
686 #define PNG_GAMMA_sRGB_INVERSE 45455
688 /* Almost everything below is C specific; the #defines above can be used in
689 * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
691 #ifndef PNG_VERSION_INFO_ONLY
693 #include "pngstruct.h"
696 /* This is used for 16 bit gamma tables -- only the top level pointers are
697 * const; this could be changed:
699 typedef const png_uint_16p
* png_const_uint_16pp
;
701 /* Added to libpng-1.5.7: sRGB conversion tables */
702 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
703 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
704 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
705 PNG_INTERNAL_DATA(const png_uint_16
, png_sRGB_table
, [256]);
706 /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
707 * 0..65535. This table gives the closest 16-bit answers (no errors).
711 PNG_INTERNAL_DATA(const png_uint_16
, png_sRGB_base
, [512]);
712 PNG_INTERNAL_DATA(const png_byte
, png_sRGB_delta
, [512]);
714 #define PNG_sRGB_FROM_LINEAR(linear) ((png_byte)((png_sRGB_base[(linear)>>15] +\
715 ((((linear)&0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))
716 /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
717 * encoded value with maximum error 0.646365. Note that the input is not a
718 * 16-bit value; it has been multiplied by 255! */
719 #endif /* PNG_SIMPLIFIED_READ/WRITE */
722 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
725 #endif /* __cplusplus */
727 /* Internal functions; these are not exported from a DLL however because they
728 * are used within several of the C source files they have to be C extern.
730 * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
734 #define PNG_UNEXPECTED_ZLIB_RETURN (-7)
735 PNG_INTERNAL_FUNCTION(void, png_zstream_error
,(png_structrp png_ptr
, int ret
),
737 /* Used by the zlib handling functions to ensure that z_stream::msg is always
738 * set before they return.
741 #ifdef PNG_WRITE_SUPPORTED
742 PNG_INTERNAL_FUNCTION(void,png_free_buffer_list
,(png_structrp png_ptr
,
743 png_compression_bufferp
*list
),PNG_EMPTY
);
744 /* Free the buffer list used by the compressed write code. */
747 #if defined(PNG_FLOATING_POINT_SUPPORTED) && \
748 !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
749 (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
750 defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
751 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
752 (defined(PNG_sCAL_SUPPORTED) && \
753 defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
754 PNG_INTERNAL_FUNCTION(png_fixed_point
,png_fixed
,(png_const_structrp png_ptr
,
755 double fp
, png_const_charp text
),PNG_EMPTY
);
758 /* Check the user version string for compatibility, returns false if the version
759 * numbers aren't compatible.
761 PNG_INTERNAL_FUNCTION(int,png_user_version_check
,(png_structrp png_ptr
,
762 png_const_charp user_png_ver
),PNG_EMPTY
);
764 /* Internal base allocator - no messages, NULL on failure to allocate. This
765 * does, however, call the application provided allocator and that could call
766 * png_error (although that would be a bug in the application implementation.)
768 PNG_INTERNAL_FUNCTION(png_voidp
,png_malloc_base
,(png_const_structrp png_ptr
,
769 png_alloc_size_t size
),PNG_ALLOCATED
);
771 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
772 defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
773 /* Internal array allocator, outputs no error or warning messages on failure,
776 PNG_INTERNAL_FUNCTION(png_voidp
,png_malloc_array
,(png_const_structrp png_ptr
,
777 int nelements
, size_t element_size
),PNG_ALLOCATED
);
779 /* The same but an existing array is extended by add_elements. This function
780 * also memsets the new elements to 0 and copies the old elements. The old
781 * array is not freed or altered.
783 PNG_INTERNAL_FUNCTION(png_voidp
,png_realloc_array
,(png_const_structrp png_ptr
,
784 png_const_voidp array
, int old_elements
, int add_elements
,
785 size_t element_size
),PNG_ALLOCATED
);
786 #endif /* text, sPLT or unknown chunks */
788 /* Magic to create a struct when there is no struct to call the user supplied
789 * memory allocators. Because error handling has not been set up the memory
790 * handlers can't safely call png_error, but this is an obscure and undocumented
791 * restriction so libpng has to assume that the 'free' handler, at least, might
794 PNG_INTERNAL_FUNCTION(png_structp
,png_create_png_struct
,
795 (png_const_charp user_png_ver
, png_voidp error_ptr
, png_error_ptr error_fn
,
796 png_error_ptr warn_fn
, png_voidp mem_ptr
, png_malloc_ptr malloc_fn
,
797 png_free_ptr free_fn
),PNG_ALLOCATED
);
799 /* Free memory from internal libpng struct */
800 PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct
,(png_structrp png_ptr
),
803 /* Free an allocated jmp_buf (always succeeds) */
804 PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf
,(png_structrp png_ptr
),PNG_EMPTY
);
806 /* Function to allocate memory for zlib. PNGAPI is disallowed. */
807 PNG_INTERNAL_FUNCTION(voidpf
,png_zalloc
,(voidpf png_ptr
, uInt items
, uInt size
),
810 /* Function to free memory for zlib. PNGAPI is disallowed. */
811 PNG_INTERNAL_FUNCTION(void,png_zfree
,(voidpf png_ptr
, voidpf ptr
),PNG_EMPTY
);
813 /* Next four functions are used internally as callbacks. PNGCBAPI is required
814 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
818 PNG_INTERNAL_FUNCTION(void PNGCBAPI
,png_default_read_data
,(png_structp png_ptr
,
819 png_bytep data
, png_size_t length
),PNG_EMPTY
);
821 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
822 PNG_INTERNAL_FUNCTION(void PNGCBAPI
,png_push_fill_buffer
,(png_structp png_ptr
,
823 png_bytep buffer
, png_size_t length
),PNG_EMPTY
);
826 PNG_INTERNAL_FUNCTION(void PNGCBAPI
,png_default_write_data
,(png_structp png_ptr
,
827 png_bytep data
, png_size_t length
),PNG_EMPTY
);
829 #ifdef PNG_WRITE_FLUSH_SUPPORTED
830 # ifdef PNG_STDIO_SUPPORTED
831 PNG_INTERNAL_FUNCTION(void PNGCBAPI
,png_default_flush
,(png_structp png_ptr
),
836 /* Reset the CRC variable */
837 PNG_INTERNAL_FUNCTION(void,png_reset_crc
,(png_structrp png_ptr
),PNG_EMPTY
);
839 /* Write the "data" buffer to whatever output you are using */
840 PNG_INTERNAL_FUNCTION(void,png_write_data
,(png_structrp png_ptr
,
841 png_const_bytep data
, png_size_t length
),PNG_EMPTY
);
843 /* Read and check the PNG file signature */
844 PNG_INTERNAL_FUNCTION(void,png_read_sig
,(png_structrp png_ptr
,
845 png_inforp info_ptr
),PNG_EMPTY
);
847 /* Read the chunk header (length + type name) */
848 PNG_INTERNAL_FUNCTION(png_uint_32
,png_read_chunk_header
,(png_structrp png_ptr
),
851 /* Read data from whatever input you are using into the "data" buffer */
852 PNG_INTERNAL_FUNCTION(void,png_read_data
,(png_structrp png_ptr
, png_bytep data
,
853 png_size_t length
),PNG_EMPTY
);
855 /* Read bytes into buf, and update png_ptr->crc */
856 PNG_INTERNAL_FUNCTION(void,png_crc_read
,(png_structrp png_ptr
, png_bytep buf
,
857 png_uint_32 length
),PNG_EMPTY
);
859 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
860 PNG_INTERNAL_FUNCTION(int,png_crc_finish
,(png_structrp png_ptr
,
861 png_uint_32 skip
),PNG_EMPTY
);
863 /* Read the CRC from the file and compare it to the libpng calculated CRC */
864 PNG_INTERNAL_FUNCTION(int,png_crc_error
,(png_structrp png_ptr
),PNG_EMPTY
);
866 /* Calculate the CRC over a section of data. Note that we are only
867 * passing a maximum of 64K on systems that have this as a memory limit,
868 * since this is the maximum buffer size we can specify.
870 PNG_INTERNAL_FUNCTION(void,png_calculate_crc
,(png_structrp png_ptr
,
871 png_const_bytep ptr
, png_size_t length
),PNG_EMPTY
);
873 #ifdef PNG_WRITE_FLUSH_SUPPORTED
874 PNG_INTERNAL_FUNCTION(void,png_flush
,(png_structrp png_ptr
),PNG_EMPTY
);
877 /* Write various chunks */
879 /* Write the IHDR chunk, and update the png_struct with the necessary
882 PNG_INTERNAL_FUNCTION(void,png_write_IHDR
,(png_structrp png_ptr
,
883 png_uint_32 width
, png_uint_32 height
, int bit_depth
, int color_type
,
884 int compression_method
, int filter_method
, int interlace_method
),PNG_EMPTY
);
886 PNG_INTERNAL_FUNCTION(void,png_write_PLTE
,(png_structrp png_ptr
,
887 png_const_colorp palette
, png_uint_32 num_pal
),PNG_EMPTY
);
889 PNG_INTERNAL_FUNCTION(void,png_compress_IDAT
,(png_structrp png_ptr
,
890 png_const_bytep row_data
, png_alloc_size_t row_data_length
, int flush
),
893 PNG_INTERNAL_FUNCTION(void,png_write_IEND
,(png_structrp png_ptr
),PNG_EMPTY
);
895 #ifdef PNG_WRITE_gAMA_SUPPORTED
896 PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed
,(png_structrp png_ptr
,
897 png_fixed_point file_gamma
),PNG_EMPTY
);
900 #ifdef PNG_WRITE_sBIT_SUPPORTED
901 PNG_INTERNAL_FUNCTION(void,png_write_sBIT
,(png_structrp png_ptr
,
902 png_const_color_8p sbit
, int color_type
),PNG_EMPTY
);
905 #ifdef PNG_WRITE_cHRM_SUPPORTED
906 PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed
,(png_structrp png_ptr
,
907 const png_xy
*xy
), PNG_EMPTY
);
908 /* The xy value must have been previously validated */
911 #ifdef PNG_WRITE_sRGB_SUPPORTED
912 PNG_INTERNAL_FUNCTION(void,png_write_sRGB
,(png_structrp png_ptr
,
913 int intent
),PNG_EMPTY
);
916 #ifdef PNG_WRITE_iCCP_SUPPORTED
917 PNG_INTERNAL_FUNCTION(void,png_write_iCCP
,(png_structrp png_ptr
,
918 png_const_charp name
, png_const_bytep profile
), PNG_EMPTY
);
919 /* The profile must have been previously validated for correctness, the
920 * length comes from the first four bytes. Only the base, deflate,
921 * compression is supported.
925 #ifdef PNG_WRITE_sPLT_SUPPORTED
926 PNG_INTERNAL_FUNCTION(void,png_write_sPLT
,(png_structrp png_ptr
,
927 png_const_sPLT_tp palette
),PNG_EMPTY
);
930 #ifdef PNG_WRITE_tRNS_SUPPORTED
931 PNG_INTERNAL_FUNCTION(void,png_write_tRNS
,(png_structrp png_ptr
,
932 png_const_bytep trans
, png_const_color_16p values
, int number
,
933 int color_type
),PNG_EMPTY
);
936 #ifdef PNG_WRITE_bKGD_SUPPORTED
937 PNG_INTERNAL_FUNCTION(void,png_write_bKGD
,(png_structrp png_ptr
,
938 png_const_color_16p values
, int color_type
),PNG_EMPTY
);
941 #ifdef PNG_WRITE_hIST_SUPPORTED
942 PNG_INTERNAL_FUNCTION(void,png_write_hIST
,(png_structrp png_ptr
,
943 png_const_uint_16p hist
, int num_hist
),PNG_EMPTY
);
946 /* Chunks that have keywords */
947 #ifdef PNG_WRITE_tEXt_SUPPORTED
948 PNG_INTERNAL_FUNCTION(void,png_write_tEXt
,(png_structrp png_ptr
,
949 png_const_charp key
, png_const_charp text
, png_size_t text_len
),PNG_EMPTY
);
952 #ifdef PNG_WRITE_zTXt_SUPPORTED
953 PNG_INTERNAL_FUNCTION(void,png_write_zTXt
,(png_structrp png_ptr
, png_const_charp
954 key
, png_const_charp text
, png_size_t text_len
, int compression
),PNG_EMPTY
);
957 #ifdef PNG_WRITE_iTXt_SUPPORTED
958 PNG_INTERNAL_FUNCTION(void,png_write_iTXt
,(png_structrp png_ptr
,
959 int compression
, png_const_charp key
, png_const_charp lang
,
960 png_const_charp lang_key
, png_const_charp text
),PNG_EMPTY
);
963 #ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
964 PNG_INTERNAL_FUNCTION(int,png_set_text_2
,(png_const_structrp png_ptr
,
965 png_inforp info_ptr
, png_const_textp text_ptr
, int num_text
),PNG_EMPTY
);
968 #ifdef PNG_WRITE_oFFs_SUPPORTED
969 PNG_INTERNAL_FUNCTION(void,png_write_oFFs
,(png_structrp png_ptr
,
970 png_int_32 x_offset
, png_int_32 y_offset
, int unit_type
),PNG_EMPTY
);
973 #ifdef PNG_WRITE_pCAL_SUPPORTED
974 PNG_INTERNAL_FUNCTION(void,png_write_pCAL
,(png_structrp png_ptr
,
975 png_charp purpose
, png_int_32 X0
, png_int_32 X1
, int type
, int nparams
,
976 png_const_charp units
, png_charpp params
),PNG_EMPTY
);
979 #ifdef PNG_WRITE_pHYs_SUPPORTED
980 PNG_INTERNAL_FUNCTION(void,png_write_pHYs
,(png_structrp png_ptr
,
981 png_uint_32 x_pixels_per_unit
, png_uint_32 y_pixels_per_unit
,
982 int unit_type
),PNG_EMPTY
);
985 #ifdef PNG_WRITE_tIME_SUPPORTED
986 PNG_INTERNAL_FUNCTION(void,png_write_tIME
,(png_structrp png_ptr
,
987 png_const_timep mod_time
),PNG_EMPTY
);
990 #ifdef PNG_WRITE_sCAL_SUPPORTED
991 PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s
,(png_structrp png_ptr
,
992 int unit
, png_const_charp width
, png_const_charp height
),PNG_EMPTY
);
995 /* Called when finished processing a row of data */
996 PNG_INTERNAL_FUNCTION(void,png_write_finish_row
,(png_structrp png_ptr
),
999 /* Internal use only. Called before first row of data */
1000 PNG_INTERNAL_FUNCTION(void,png_write_start_row
,(png_structrp png_ptr
),
1003 /* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
1004 * array of png_ptr->width pixels. If the image is not interlaced or this
1005 * is the final pass this just does a memcpy, otherwise the "display" flag
1006 * is used to determine whether to copy pixels that are not in the current pass.
1008 * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1009 * function to achieve the documented 'blocky' appearance during interlaced read
1010 * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1011 * are not changed if they are not in the current pass, when display is 0.
1013 * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1015 * The API always reads from the png_struct row buffer and always assumes that
1016 * it is full width (png_do_read_interlace has already been called.)
1018 * This function is only ever used to write to row buffers provided by the
1019 * caller of the relevant libpng API and the row must have already been
1020 * transformed by the read transformations.
1022 * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1023 * bitmasks for use within the code, otherwise runtime generated masks are used.
1024 * The default is compile time masks.
1026 #ifndef PNG_USE_COMPILE_TIME_MASKS
1027 # define PNG_USE_COMPILE_TIME_MASKS 1
1029 PNG_INTERNAL_FUNCTION(void,png_combine_row
,(png_const_structrp png_ptr
,
1030 png_bytep row
, int display
),PNG_EMPTY
);
1032 #ifdef PNG_READ_INTERLACING_SUPPORTED
1033 /* Expand an interlaced row: the 'row_info' describes the pass data that has
1034 * been read in and must correspond to the pixels in 'row', the pixels are
1035 * expanded (moved apart) in 'row' to match the final layout, when doing this
1036 * the pixels are *replicated* to the intervening space. This is essential for
1037 * the correct operation of png_combine_row, above.
1039 PNG_INTERNAL_FUNCTION(void,png_do_read_interlace
,(png_row_infop row_info
,
1040 png_bytep row
, int pass
, png_uint_32 transformations
),PNG_EMPTY
);
1043 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
1045 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1046 /* Grab pixels out of a row for an interlaced pass */
1047 PNG_INTERNAL_FUNCTION(void,png_do_write_interlace
,(png_row_infop row_info
,
1048 png_bytep row
, int pass
),PNG_EMPTY
);
1051 /* Unfilter a row: check the filter value before calling this, there is no point
1052 * calling it for PNG_FILTER_VALUE_NONE.
1054 PNG_INTERNAL_FUNCTION(void,png_read_filter_row
,(png_structrp pp
, png_row_infop
1055 row_info
, png_bytep row
, png_const_bytep prev_row
, int filter
),PNG_EMPTY
);
1057 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon
,(png_row_infop row_info
,
1058 png_bytep row
, png_const_bytep prev_row
),PNG_EMPTY
);
1059 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon
,(png_row_infop
1060 row_info
, png_bytep row
, png_const_bytep prev_row
),PNG_EMPTY
);
1061 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon
,(png_row_infop
1062 row_info
, png_bytep row
, png_const_bytep prev_row
),PNG_EMPTY
);
1063 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon
,(png_row_infop
1064 row_info
, png_bytep row
, png_const_bytep prev_row
),PNG_EMPTY
);
1065 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon
,(png_row_infop
1066 row_info
, png_bytep row
, png_const_bytep prev_row
),PNG_EMPTY
);
1067 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon
,(png_row_infop
1068 row_info
, png_bytep row
, png_const_bytep prev_row
),PNG_EMPTY
);
1069 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon
,(png_row_infop
1070 row_info
, png_bytep row
, png_const_bytep prev_row
),PNG_EMPTY
);
1072 /* Choose the best filter to use and filter the row data */
1073 PNG_INTERNAL_FUNCTION(void,png_write_find_filter
,(png_structrp png_ptr
,
1074 png_row_infop row_info
),PNG_EMPTY
);
1076 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1077 PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data
,(png_structrp png_ptr
,
1078 png_bytep output
, png_alloc_size_t avail_out
),PNG_EMPTY
);
1079 /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
1080 * is NULL the function checks, instead, for the end of the stream. In this
1081 * case a benign error will be issued if the stream end is not found or if
1082 * extra data has to be consumed.
1084 PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT
,(png_structrp png_ptr
),
1086 /* This cleans up when the IDAT LZ stream does not end when the last image
1087 * byte is read; there is still some pending input.
1090 PNG_INTERNAL_FUNCTION(void,png_read_finish_row
,(png_structrp png_ptr
),
1092 /* Finish a row while reading, dealing with interlacing passes, etc. */
1095 /* Initialize the row buffers, etc. */
1096 PNG_INTERNAL_FUNCTION(void,png_read_start_row
,(png_structrp png_ptr
),PNG_EMPTY
);
1098 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1099 /* Optional call to update the users info structure */
1100 PNG_INTERNAL_FUNCTION(void,png_read_transform_info
,(png_structrp png_ptr
,
1101 png_inforp info_ptr
),PNG_EMPTY
);
1104 /* These are the functions that do the transformations */
1105 #ifdef PNG_READ_FILLER_SUPPORTED
1106 PNG_INTERNAL_FUNCTION(void,png_do_read_filler
,(png_row_infop row_info
,
1107 png_bytep row
, png_uint_32 filler
, png_uint_32 flags
),PNG_EMPTY
);
1110 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
1111 PNG_INTERNAL_FUNCTION(void,png_do_read_swap_alpha
,(png_row_infop row_info
,
1112 png_bytep row
),PNG_EMPTY
);
1115 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1116 PNG_INTERNAL_FUNCTION(void,png_do_write_swap_alpha
,(png_row_infop row_info
,
1117 png_bytep row
),PNG_EMPTY
);
1120 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
1121 PNG_INTERNAL_FUNCTION(void,png_do_read_invert_alpha
,(png_row_infop row_info
,
1122 png_bytep row
),PNG_EMPTY
);
1125 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1126 PNG_INTERNAL_FUNCTION(void,png_do_write_invert_alpha
,(png_row_infop row_info
,
1127 png_bytep row
),PNG_EMPTY
);
1130 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1131 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1132 PNG_INTERNAL_FUNCTION(void,png_do_strip_channel
,(png_row_infop row_info
,
1133 png_bytep row
, int at_start
),PNG_EMPTY
);
1136 #ifdef PNG_16BIT_SUPPORTED
1137 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1138 PNG_INTERNAL_FUNCTION(void,png_do_swap
,(png_row_infop row_info
,
1139 png_bytep row
),PNG_EMPTY
);
1143 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1144 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1145 PNG_INTERNAL_FUNCTION(void,png_do_packswap
,(png_row_infop row_info
,
1146 png_bytep row
),PNG_EMPTY
);
1149 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1150 PNG_INTERNAL_FUNCTION(int,png_do_rgb_to_gray
,(png_structrp png_ptr
,
1151 png_row_infop row_info
, png_bytep row
),PNG_EMPTY
);
1154 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1155 PNG_INTERNAL_FUNCTION(void,png_do_gray_to_rgb
,(png_row_infop row_info
,
1156 png_bytep row
),PNG_EMPTY
);
1159 #ifdef PNG_READ_PACK_SUPPORTED
1160 PNG_INTERNAL_FUNCTION(void,png_do_unpack
,(png_row_infop row_info
,
1161 png_bytep row
),PNG_EMPTY
);
1164 #ifdef PNG_READ_SHIFT_SUPPORTED
1165 PNG_INTERNAL_FUNCTION(void,png_do_unshift
,(png_row_infop row_info
,
1166 png_bytep row
, png_const_color_8p sig_bits
),PNG_EMPTY
);
1169 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1170 PNG_INTERNAL_FUNCTION(void,png_do_invert
,(png_row_infop row_info
,
1171 png_bytep row
),PNG_EMPTY
);
1174 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1175 PNG_INTERNAL_FUNCTION(void,png_do_scale_16_to_8
,(png_row_infop row_info
,
1176 png_bytep row
),PNG_EMPTY
);
1179 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1180 PNG_INTERNAL_FUNCTION(void,png_do_chop
,(png_row_infop row_info
,
1181 png_bytep row
),PNG_EMPTY
);
1184 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1185 PNG_INTERNAL_FUNCTION(void,png_do_quantize
,(png_row_infop row_info
,
1186 png_bytep row
, png_const_bytep palette_lookup
,
1187 png_const_bytep quantize_lookup
),PNG_EMPTY
);
1189 # ifdef PNG_CORRECT_PALETTE_SUPPORTED
1190 PNG_INTERNAL_FUNCTION(void,png_correct_palette
,(png_structrp png_ptr
,
1191 png_colorp palette
, int num_palette
),PNG_EMPTY
);
1195 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1196 PNG_INTERNAL_FUNCTION(void,png_do_bgr
,(png_row_infop row_info
,
1197 png_bytep row
),PNG_EMPTY
);
1200 #ifdef PNG_WRITE_PACK_SUPPORTED
1201 PNG_INTERNAL_FUNCTION(void,png_do_pack
,(png_row_infop row_info
,
1202 png_bytep row
, png_uint_32 bit_depth
),PNG_EMPTY
);
1205 #ifdef PNG_WRITE_SHIFT_SUPPORTED
1206 PNG_INTERNAL_FUNCTION(void,png_do_shift
,(png_row_infop row_info
,
1207 png_bytep row
, png_const_color_8p bit_depth
),PNG_EMPTY
);
1210 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
1211 defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1212 PNG_INTERNAL_FUNCTION(void,png_do_compose
,(png_row_infop row_info
,
1213 png_bytep row
, png_structrp png_ptr
),PNG_EMPTY
);
1216 #ifdef PNG_READ_GAMMA_SUPPORTED
1217 PNG_INTERNAL_FUNCTION(void,png_do_gamma
,(png_row_infop row_info
,
1218 png_bytep row
, png_structrp png_ptr
),PNG_EMPTY
);
1221 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1222 PNG_INTERNAL_FUNCTION(void,png_do_encode_alpha
,(png_row_infop row_info
,
1223 png_bytep row
, png_structrp png_ptr
),PNG_EMPTY
);
1226 #ifdef PNG_READ_EXPAND_SUPPORTED
1227 PNG_INTERNAL_FUNCTION(void,png_do_expand_palette
,(png_row_infop row_info
,
1228 png_bytep row
, png_const_colorp palette
, png_const_bytep trans
,
1229 int num_trans
),PNG_EMPTY
);
1230 PNG_INTERNAL_FUNCTION(void,png_do_expand
,(png_row_infop row_info
,
1231 png_bytep row
, png_const_color_16p trans_color
),PNG_EMPTY
);
1234 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1235 PNG_INTERNAL_FUNCTION(void,png_do_expand_16
,(png_row_infop row_info
,
1236 png_bytep row
),PNG_EMPTY
);
1239 /* The following decodes the appropriate chunks, and does error correction,
1240 * then calls the appropriate callback for the chunk if it is valid.
1243 /* Decode the IHDR chunk */
1244 PNG_INTERNAL_FUNCTION(void,png_handle_IHDR
,(png_structrp png_ptr
,
1245 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1246 PNG_INTERNAL_FUNCTION(void,png_handle_PLTE
,(png_structrp png_ptr
,
1247 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1248 PNG_INTERNAL_FUNCTION(void,png_handle_IEND
,(png_structrp png_ptr
,
1249 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1251 #ifdef PNG_READ_bKGD_SUPPORTED
1252 PNG_INTERNAL_FUNCTION(void,png_handle_bKGD
,(png_structrp png_ptr
,
1253 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1256 #ifdef PNG_READ_cHRM_SUPPORTED
1257 PNG_INTERNAL_FUNCTION(void,png_handle_cHRM
,(png_structrp png_ptr
,
1258 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1261 #ifdef PNG_READ_gAMA_SUPPORTED
1262 PNG_INTERNAL_FUNCTION(void,png_handle_gAMA
,(png_structrp png_ptr
,
1263 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1266 #ifdef PNG_READ_hIST_SUPPORTED
1267 PNG_INTERNAL_FUNCTION(void,png_handle_hIST
,(png_structrp png_ptr
,
1268 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1271 #ifdef PNG_READ_iCCP_SUPPORTED
1272 PNG_INTERNAL_FUNCTION(void,png_handle_iCCP
,(png_structrp png_ptr
,
1273 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1274 #endif /* PNG_READ_iCCP_SUPPORTED */
1276 #ifdef PNG_READ_iTXt_SUPPORTED
1277 PNG_INTERNAL_FUNCTION(void,png_handle_iTXt
,(png_structrp png_ptr
,
1278 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1281 #ifdef PNG_READ_oFFs_SUPPORTED
1282 PNG_INTERNAL_FUNCTION(void,png_handle_oFFs
,(png_structrp png_ptr
,
1283 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1286 #ifdef PNG_READ_pCAL_SUPPORTED
1287 PNG_INTERNAL_FUNCTION(void,png_handle_pCAL
,(png_structrp png_ptr
,
1288 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1291 #ifdef PNG_READ_pHYs_SUPPORTED
1292 PNG_INTERNAL_FUNCTION(void,png_handle_pHYs
,(png_structrp png_ptr
,
1293 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1296 #ifdef PNG_READ_sBIT_SUPPORTED
1297 PNG_INTERNAL_FUNCTION(void,png_handle_sBIT
,(png_structrp png_ptr
,
1298 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1301 #ifdef PNG_READ_sCAL_SUPPORTED
1302 PNG_INTERNAL_FUNCTION(void,png_handle_sCAL
,(png_structrp png_ptr
,
1303 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1306 #ifdef PNG_READ_sPLT_SUPPORTED
1307 PNG_INTERNAL_FUNCTION(void,png_handle_sPLT
,(png_structrp png_ptr
,
1308 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1309 #endif /* PNG_READ_sPLT_SUPPORTED */
1311 #ifdef PNG_READ_sRGB_SUPPORTED
1312 PNG_INTERNAL_FUNCTION(void,png_handle_sRGB
,(png_structrp png_ptr
,
1313 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1316 #ifdef PNG_READ_tEXt_SUPPORTED
1317 PNG_INTERNAL_FUNCTION(void,png_handle_tEXt
,(png_structrp png_ptr
,
1318 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1321 #ifdef PNG_READ_tIME_SUPPORTED
1322 PNG_INTERNAL_FUNCTION(void,png_handle_tIME
,(png_structrp png_ptr
,
1323 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1326 #ifdef PNG_READ_tRNS_SUPPORTED
1327 PNG_INTERNAL_FUNCTION(void,png_handle_tRNS
,(png_structrp png_ptr
,
1328 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1331 #ifdef PNG_READ_zTXt_SUPPORTED
1332 PNG_INTERNAL_FUNCTION(void,png_handle_zTXt
,(png_structrp png_ptr
,
1333 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1336 PNG_INTERNAL_FUNCTION(void,png_check_chunk_name
,(png_structrp png_ptr
,
1337 png_uint_32 chunk_name
),PNG_EMPTY
);
1339 #ifdef PNG_READ_SUPPORTED
1340 PNG_INTERNAL_FUNCTION(void,png_handle_unknown
,(png_structrp png_ptr
,
1341 png_inforp info_ptr
, png_uint_32 length
, int keep
),PNG_EMPTY
);
1342 /* This is the function that gets called for unknown chunks. The 'keep'
1343 * argument is either non-zero for a known chunk that has been set to be
1344 * handled as unknown or zero for an unknown chunk. By default the function
1345 * just skips the chunk or errors out if it is critical.
1348 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1349 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
1350 PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling
,
1351 (png_const_structrp png_ptr
, png_uint_32 chunk_name
),PNG_EMPTY
);
1352 /* Exactly as the API png_handle_as_unknown() except that the argument is a
1353 * 32-bit chunk name, not a string.
1356 #endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
1357 #endif /* PNG_READ_SUPPORTED */
1359 /* Handle the transformations for reading and writing */
1360 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1361 PNG_INTERNAL_FUNCTION(void,png_do_read_transformations
,(png_structrp png_ptr
,
1362 png_row_infop row_info
),PNG_EMPTY
);
1364 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1365 PNG_INTERNAL_FUNCTION(void,png_do_write_transformations
,(png_structrp png_ptr
,
1366 png_row_infop row_info
),PNG_EMPTY
);
1369 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1370 PNG_INTERNAL_FUNCTION(void,png_init_read_transformations
,(png_structrp png_ptr
),
1374 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1375 PNG_INTERNAL_FUNCTION(void,png_push_read_chunk
,(png_structrp png_ptr
,
1376 png_inforp info_ptr
),PNG_EMPTY
);
1377 PNG_INTERNAL_FUNCTION(void,png_push_read_sig
,(png_structrp png_ptr
,
1378 png_inforp info_ptr
),PNG_EMPTY
);
1379 PNG_INTERNAL_FUNCTION(void,png_push_check_crc
,(png_structrp png_ptr
),PNG_EMPTY
);
1380 PNG_INTERNAL_FUNCTION(void,png_push_crc_skip
,(png_structrp png_ptr
,
1381 png_uint_32 length
),PNG_EMPTY
);
1382 PNG_INTERNAL_FUNCTION(void,png_push_crc_finish
,(png_structrp png_ptr
),
1384 PNG_INTERNAL_FUNCTION(void,png_push_save_buffer
,(png_structrp png_ptr
),
1386 PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer
,(png_structrp png_ptr
,
1387 png_bytep buffer
, png_size_t buffer_length
),PNG_EMPTY
);
1388 PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT
,(png_structrp png_ptr
),PNG_EMPTY
);
1389 PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data
,(png_structrp png_ptr
,
1390 png_bytep buffer
, png_size_t buffer_length
),PNG_EMPTY
);
1391 PNG_INTERNAL_FUNCTION(void,png_push_process_row
,(png_structrp png_ptr
),
1393 PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown
,(png_structrp png_ptr
,
1394 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1395 PNG_INTERNAL_FUNCTION(void,png_push_have_info
,(png_structrp png_ptr
,
1396 png_inforp info_ptr
),PNG_EMPTY
);
1397 PNG_INTERNAL_FUNCTION(void,png_push_have_end
,(png_structrp png_ptr
,
1398 png_inforp info_ptr
),PNG_EMPTY
);
1399 PNG_INTERNAL_FUNCTION(void,png_push_have_row
,(png_structrp png_ptr
,
1400 png_bytep row
),PNG_EMPTY
);
1401 PNG_INTERNAL_FUNCTION(void,png_push_read_end
,(png_structrp png_ptr
,
1402 png_inforp info_ptr
),PNG_EMPTY
);
1403 PNG_INTERNAL_FUNCTION(void,png_process_some_data
,(png_structrp png_ptr
,
1404 png_inforp info_ptr
),PNG_EMPTY
);
1405 PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row
,(png_structrp png_ptr
),
1407 # ifdef PNG_READ_tEXt_SUPPORTED
1408 PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt
,(png_structrp png_ptr
,
1409 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1410 PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt
,(png_structrp png_ptr
,
1411 png_inforp info_ptr
),PNG_EMPTY
);
1413 # ifdef PNG_READ_zTXt_SUPPORTED
1414 PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt
,(png_structrp png_ptr
,
1415 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1416 PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt
,(png_structrp png_ptr
,
1417 png_inforp info_ptr
),PNG_EMPTY
);
1419 # ifdef PNG_READ_iTXt_SUPPORTED
1420 PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt
,(png_structrp png_ptr
,
1421 png_inforp info_ptr
, png_uint_32 length
),PNG_EMPTY
);
1422 PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt
,(png_structrp png_ptr
,
1423 png_inforp info_ptr
),PNG_EMPTY
);
1426 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1428 #ifdef PNG_MNG_FEATURES_SUPPORTED
1429 PNG_INTERNAL_FUNCTION(void,png_do_read_intrapixel
,(png_row_infop row_info
,
1430 png_bytep row
),PNG_EMPTY
);
1431 PNG_INTERNAL_FUNCTION(void,png_do_write_intrapixel
,(png_row_infop row_info
,
1432 png_bytep row
),PNG_EMPTY
);
1435 /* Added at libpng version 1.6.0 */
1436 #ifdef PNG_GAMMA_SUPPORTED
1437 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma
,(png_const_structrp png_ptr
,
1438 png_colorspacerp colorspace
, png_fixed_point gAMA
), PNG_EMPTY
);
1439 /* Set the colorspace gamma with a value provided by the application or by
1440 * the gAMA chunk on read. The value will override anything set by an ICC
1444 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info
,(png_const_structrp png_ptr
,
1445 png_inforp info_ptr
), PNG_EMPTY
);
1446 /* Synchronize the info 'valid' flags with the colorspace */
1448 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync
,(png_const_structrp png_ptr
,
1449 png_inforp info_ptr
), PNG_EMPTY
);
1450 /* Copy the png_struct colorspace to the info_struct and call the above to
1451 * synchronize the flags. Checks for NULL info_ptr and does nothing.
1455 /* Added at libpng version 1.4.0 */
1456 #ifdef PNG_COLORSPACE_SUPPORTED
1457 /* These internal functions are for maintaining the colorspace structure within
1458 * a png_info or png_struct (or, indeed, both).
1460 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities
,
1461 (png_const_structrp png_ptr
, png_colorspacerp colorspace
, const png_xy
*xy
,
1462 int preferred
), PNG_EMPTY
);
1464 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints
,
1465 (png_const_structrp png_ptr
, png_colorspacerp colorspace
, const png_XYZ
*XYZ
,
1466 int preferred
), PNG_EMPTY
);
1468 #ifdef PNG_sRGB_SUPPORTED
1469 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB
,(png_const_structrp png_ptr
,
1470 png_colorspacerp colorspace
, int intent
), PNG_EMPTY
);
1471 /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1472 * flags to write them, if it returns false there was a problem and an error
1473 * message has already been output (but the colorspace may still need to be
1474 * synced to record the invalid flag).
1478 #ifdef PNG_iCCP_SUPPORTED
1479 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC
,(png_const_structrp png_ptr
,
1480 png_colorspacerp colorspace
, png_const_charp name
,
1481 png_uint_32 profile_length
, png_const_bytep profile
, int color_type
),
1483 /* The 'name' is used for information only */
1485 /* Routines for checking parts of an ICC profile. */
1486 PNG_INTERNAL_FUNCTION(int,png_icc_check_length
,(png_const_structrp png_ptr
,
1487 png_colorspacerp colorspace
, png_const_charp name
,
1488 png_uint_32 profile_length
), PNG_EMPTY
);
1489 PNG_INTERNAL_FUNCTION(int,png_icc_check_header
,(png_const_structrp png_ptr
,
1490 png_colorspacerp colorspace
, png_const_charp name
,
1491 png_uint_32 profile_length
,
1492 png_const_bytep profile
/* first 132 bytes only */, int color_type
),
1494 PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table
,(png_const_structrp png_ptr
,
1495 png_colorspacerp colorspace
, png_const_charp name
,
1496 png_uint_32 profile_length
,
1497 png_const_bytep profile
/* header plus whole tag table */), PNG_EMPTY
);
1498 #ifdef PNG_sRGB_SUPPORTED
1499 PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB
,(
1500 png_const_structrp png_ptr
, png_colorspacerp colorspace
,
1501 png_const_bytep profile
, uLong adler
), PNG_EMPTY
);
1502 /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1503 * be zero to indicate that it is not available. It is used, if provided,
1504 * as a fast check on the profile when checking to see if it is sRGB.
1509 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1510 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients
,
1511 (png_structrp png_ptr
), PNG_EMPTY
);
1512 /* Set the rgb_to_gray coefficients from the colorspace Y values */
1513 #endif /* READ_RGB_TO_GRAY */
1514 #endif /* COLORSPACE */
1516 /* Added at libpng version 1.4.0 */
1517 PNG_INTERNAL_FUNCTION(void,png_check_IHDR
,(png_const_structrp png_ptr
,
1518 png_uint_32 width
, png_uint_32 height
, int bit_depth
,
1519 int color_type
, int interlace_type
, int compression_type
,
1520 int filter_type
),PNG_EMPTY
);
1522 /* Added at libpng version 1.5.10 */
1523 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1524 defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1525 PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes
,
1526 (png_structrp png_ptr
, png_row_infop row_info
),PNG_EMPTY
);
1529 #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1530 PNG_INTERNAL_FUNCTION(void,png_fixed_error
,(png_const_structrp png_ptr
,
1531 png_const_charp name
),PNG_NORETURN
);
1534 /* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1535 * the end. Always leaves the buffer nul terminated. Never errors out (and
1536 * there is no error code.)
1538 PNG_INTERNAL_FUNCTION(size_t,png_safecat
,(png_charp buffer
, size_t bufsize
,
1539 size_t pos
, png_const_charp string
),PNG_EMPTY
);
1541 /* Various internal functions to handle formatted warning messages, currently
1542 * only implemented for warnings.
1544 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1545 /* Utility to dump an unsigned value into a buffer, given a start pointer and
1546 * and end pointer (which should point just *beyond* the end of the buffer!)
1547 * Returns the pointer to the start of the formatted string. This utility only
1548 * does unsigned values.
1550 PNG_INTERNAL_FUNCTION(png_charp
,png_format_number
,(png_const_charp start
,
1551 png_charp end
, int format
, png_alloc_size_t number
),PNG_EMPTY
);
1553 /* Convenience macro that takes an array: */
1554 #define PNG_FORMAT_NUMBER(buffer,format,number) \
1555 png_format_number(buffer, buffer + (sizeof buffer), format, number)
1557 /* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1558 #define PNG_NUMBER_BUFFER_SIZE 24
1560 /* These are the integer formats currently supported, the name is formed from
1561 * the standard printf(3) format string.
1563 #define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
1564 #define PNG_NUMBER_FORMAT_02u 2
1565 #define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
1566 #define PNG_NUMBER_FORMAT_02d 2
1567 #define PNG_NUMBER_FORMAT_x 3
1568 #define PNG_NUMBER_FORMAT_02x 4
1569 #define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1572 #ifdef PNG_WARNINGS_SUPPORTED
1573 /* New defines and members adding in libpng-1.5.4 */
1574 # define PNG_WARNING_PARAMETER_SIZE 32
1575 # define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1577 /* An l-value of this type has to be passed to the APIs below to cache the
1578 * values of the parameters to a formatted warning message.
1580 typedef char png_warning_parameters
[PNG_WARNING_PARAMETER_COUNT
][
1581 PNG_WARNING_PARAMETER_SIZE
];
1583 PNG_INTERNAL_FUNCTION(void,png_warning_parameter
,(png_warning_parameters p
,
1584 int number
, png_const_charp string
),PNG_EMPTY
);
1585 /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1586 * including the trailing '\0'.
1588 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned
,
1589 (png_warning_parameters p
, int number
, int format
, png_alloc_size_t value
),
1591 /* Use png_alloc_size_t because it is an unsigned type as big as any we
1592 * need to output. Use the following for a signed value.
1594 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed
,
1595 (png_warning_parameters p
, int number
, int format
, png_int_32 value
),
1598 PNG_INTERNAL_FUNCTION(void,png_formatted_warning
,(png_const_structrp png_ptr
,
1599 png_warning_parameters p
, png_const_charp message
),PNG_EMPTY
);
1600 /* 'message' follows the X/Open approach of using @1, @2 to insert
1601 * parameters previously supplied using the above functions. Errors in
1602 * specifying the parameters will simply result in garbage substitutions.
1606 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1607 /* Application errors (new in 1.6); use these functions (declared below) for
1608 * errors in the parameters or order of API function calls on read. The
1609 * 'warning' should be used for an error that can be handled completely; the
1610 * 'error' for one which can be handled safely but which may lose application
1611 * information or settings.
1613 * By default these both result in a png_error call prior to release, while in a
1614 * released version the 'warning' is just a warning. However if the application
1615 * explicitly disables benign errors (explicitly permitting the code to lose
1616 * information) they both turn into warnings.
1618 * If benign errors aren't supported they end up as the corresponding base call
1619 * (png_warning or png_error.)
1621 PNG_INTERNAL_FUNCTION(void,png_app_warning
,(png_const_structrp png_ptr
,
1622 png_const_charp message
),PNG_EMPTY
);
1623 /* The application provided invalid parameters to an API function or called
1624 * an API function at the wrong time, libpng can completely recover.
1627 PNG_INTERNAL_FUNCTION(void,png_app_error
,(png_const_structrp png_ptr
,
1628 png_const_charp message
),PNG_EMPTY
);
1629 /* As above but libpng will ignore the call, or attempt some other partial
1630 * recovery from the error.
1633 # define png_app_warning(pp,s) png_warning(pp,s)
1634 # define png_app_error(pp,s) png_error(pp,s)
1637 PNG_INTERNAL_FUNCTION(void,png_chunk_report
,(png_const_structrp png_ptr
,
1638 png_const_charp message
, int error
),PNG_EMPTY
);
1639 /* Report a recoverable issue in chunk data. On read this is used to report
1640 * a problem found while reading a particular chunk and the
1641 * png_chunk_benign_error or png_chunk_warning function is used as
1642 * appropriate. On write this is used to report an error that comes from
1643 * data set via an application call to a png_set_ API and png_app_error or
1644 * png_app_warning is used as appropriate.
1646 * The 'error' parameter must have one of the following values:
1648 #define PNG_CHUNK_WARNING 0 /* never an error */
1649 #define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1650 #define PNG_CHUNK_ERROR 2 /* always an error */
1652 /* ASCII to FP interfaces, currently only implemented if sCAL
1653 * support is required.
1655 #if defined(PNG_sCAL_SUPPORTED)
1656 /* MAX_DIGITS is actually the maximum number of characters in an sCAL
1657 * width or height, derived from the precision (number of significant
1658 * digits - a build time settable option) and assumptions about the
1659 * maximum ridiculous exponent.
1661 #define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1663 #ifdef PNG_FLOATING_POINT_SUPPORTED
1664 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp
,(png_const_structrp png_ptr
,
1665 png_charp ascii
, png_size_t size
, double fp
, unsigned int precision
),
1667 #endif /* FLOATING_POINT */
1669 #ifdef PNG_FIXED_POINT_SUPPORTED
1670 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed
,(png_const_structrp png_ptr
,
1671 png_charp ascii
, png_size_t size
, png_fixed_point fp
),PNG_EMPTY
);
1672 #endif /* FIXED_POINT */
1675 #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1676 /* An internal API to validate the format of a floating point number.
1677 * The result is the index of the next character. If the number is
1678 * not valid it will be the index of a character in the supposed number.
1680 * The format of a number is defined in the PNG extensions specification
1681 * and this API is strictly conformant to that spec, not anyone elses!
1683 * The format as a regular expression is:
1685 * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1689 * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1691 * The complexity is that either integer or fraction must be present and the
1692 * fraction is permitted to have no digits only if the integer is present.
1694 * NOTE: The dangling E problem.
1695 * There is a PNG valid floating point number in the following:
1697 * PNG floating point numbers are not greedy.
1699 * Working this out requires *TWO* character lookahead (because of the
1700 * sign), the parser does not do this - it will fail at the 'r' - this
1701 * doesn't matter for PNG sCAL chunk values, but it requires more care
1702 * if the value were ever to be embedded in something more complex. Use
1703 * ANSI-C strtod if you need the lookahead.
1705 /* State table for the parser. */
1706 #define PNG_FP_INTEGER 0 /* before or in integer */
1707 #define PNG_FP_FRACTION 1 /* before or in fraction */
1708 #define PNG_FP_EXPONENT 2 /* before or in exponent */
1709 #define PNG_FP_STATE 3 /* mask for the above */
1710 #define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
1711 #define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
1712 #define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
1713 #define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
1714 #define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
1716 /* These three values don't affect the parser. They are set but not used.
1718 #define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
1719 #define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
1720 #define PNG_FP_NONZERO 256 /* A non-zero value */
1721 #define PNG_FP_STICKY 448 /* The above three flags */
1723 /* This is available for the caller to store in 'state' if required. Do not
1724 * call the parser after setting it (the parser sometimes clears it.)
1726 #define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
1728 /* Result codes for the parser (boolean - true meants ok, false means
1731 #define PNG_FP_MAYBE 0 /* The number may be valid in the future */
1732 #define PNG_FP_OK 1 /* The number is valid */
1734 /* Tests on the sticky non-zero and negative flags. To pass these checks
1735 * the state must also indicate that the whole number is valid - this is
1736 * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1737 * is equivalent to PNG_FP_OK above.)
1739 #define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1740 /* NZ_MASK: the string is valid and a non-zero negative value */
1741 #define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1742 /* Z MASK: the string is valid and a non-zero value. */
1743 /* PNG_FP_SAW_DIGIT: the string is valid. */
1744 #define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1745 #define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1746 #define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1748 /* The actual parser. This can be called repeatedly. It updates
1749 * the index into the string and the state variable (which must
1750 * be initialized to 0). It returns a result code, as above. There
1751 * is no point calling the parser any more if it fails to advance to
1752 * the end of the string - it is stuck on an invalid character (or
1753 * terminated by '\0').
1755 * Note that the pointer will consume an E or even an E+ and then leave
1756 * a 'maybe' state even though a preceding integer.fraction is valid.
1757 * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1758 * a valid number. It's possible to recover from this by calling
1759 * the parser again (from the start, with state 0) but with a string
1760 * that omits the last character (i.e. set the size to the index of
1761 * the problem character.) This has not been tested within libpng.
1763 PNG_INTERNAL_FUNCTION(int,png_check_fp_number
,(png_const_charp string
,
1764 png_size_t size
, int *statep
, png_size_tp whereami
),PNG_EMPTY
);
1766 /* This is the same but it checks a complete string and returns true
1767 * only if it just contains a floating point number. As of 1.5.4 this
1768 * function also returns the state at the end of parsing the number if
1769 * it was valid (otherwise it returns 0.) This can be used for testing
1770 * for negative or zero values using the sticky flag.
1772 PNG_INTERNAL_FUNCTION(int,png_check_fp_string
,(png_const_charp string
,
1773 png_size_t size
),PNG_EMPTY
);
1774 #endif /* pCAL || sCAL */
1776 #if defined(PNG_READ_GAMMA_SUPPORTED) ||\
1777 defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1778 /* Added at libpng version 1.5.0 */
1779 /* This is a utility to provide a*times/div (rounded) and indicate
1780 * if there is an overflow. The result is a boolean - false (0)
1781 * for overflow, true (1) if no overflow, in which case *res
1784 PNG_INTERNAL_FUNCTION(int,png_muldiv
,(png_fixed_point_p res
, png_fixed_point a
,
1785 png_int_32 multiplied_by
, png_int_32 divided_by
),PNG_EMPTY
);
1788 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1789 /* Same deal, but issue a warning on overflow and return 0. */
1790 PNG_INTERNAL_FUNCTION(png_fixed_point
,png_muldiv_warn
,
1791 (png_const_structrp png_ptr
, png_fixed_point a
, png_int_32 multiplied_by
,
1792 png_int_32 divided_by
),PNG_EMPTY
);
1795 #ifdef PNG_GAMMA_SUPPORTED
1796 /* Calculate a reciprocal - used for gamma values. This returns
1797 * 0 if the argument is 0 in order to maintain an undefined value;
1798 * there are no warnings.
1800 PNG_INTERNAL_FUNCTION(png_fixed_point
,png_reciprocal
,(png_fixed_point a
),
1803 #ifdef PNG_READ_GAMMA_SUPPORTED
1804 /* The same but gives a reciprocal of the product of two fixed point
1805 * values. Accuracy is suitable for gamma calculations but this is
1806 * not exact - use png_muldiv for that. Only required at present on read.
1808 PNG_INTERNAL_FUNCTION(png_fixed_point
,png_reciprocal2
,(png_fixed_point a
,
1809 png_fixed_point b
),PNG_EMPTY
);
1812 /* Return true if the gamma value is significantly different from 1.0 */
1813 PNG_INTERNAL_FUNCTION(int,png_gamma_significant
,(png_fixed_point gamma_value
),
1817 #ifdef PNG_READ_GAMMA_SUPPORTED
1818 /* Internal fixed point gamma correction. These APIs are called as
1819 * required to convert single values - they don't need to be fast,
1820 * they are not used when processing image pixel values.
1822 * While the input is an 'unsigned' value it must actually be the
1823 * correct bit value - 0..255 or 0..65535 as required.
1825 PNG_INTERNAL_FUNCTION(png_uint_16
,png_gamma_correct
,(png_structrp png_ptr
,
1826 unsigned int value
, png_fixed_point gamma_value
),PNG_EMPTY
);
1827 PNG_INTERNAL_FUNCTION(png_uint_16
,png_gamma_16bit_correct
,(unsigned int value
,
1828 png_fixed_point gamma_value
),PNG_EMPTY
);
1829 PNG_INTERNAL_FUNCTION(png_byte
,png_gamma_8bit_correct
,(unsigned int value
,
1830 png_fixed_point gamma_value
),PNG_EMPTY
);
1831 PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table
,(png_structrp png_ptr
),
1833 PNG_INTERNAL_FUNCTION(void,png_build_gamma_table
,(png_structrp png_ptr
,
1834 int bit_depth
),PNG_EMPTY
);
1837 /* SIMPLIFIED READ/WRITE SUPPORT */
1838 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
1839 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
1840 /* The internal structure that png_image::opaque points to. */
1841 typedef struct png_control
1843 png_structp png_ptr
;
1845 png_voidp error_buf
; /* Always a jmp_buf at present. */
1847 png_const_bytep memory
; /* Memory buffer. */
1848 png_size_t size
; /* Size of the memory buffer. */
1850 unsigned int for_write
:1; /* Otherwise it is a read structure */
1851 unsigned int owned_file
:1; /* We own the file in io_ptr */
1854 /* Return the pointer to the jmp_buf from a png_control: necessary because C
1855 * does not reveal the type of the elements of jmp_buf.
1858 # define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
1860 # define png_control_jmp_buf(pc) ((pc)->error_buf)
1863 /* Utility to safely execute a piece of libpng code catching and logging any
1864 * errors that might occur. Returns true on success, false on failure (either
1865 * of the function or as a result of a png_error.)
1867 PNG_INTERNAL_FUNCTION(void,png_safe_error
,(png_structp png_ptr
,
1868 png_const_charp error_message
),PNG_NORETURN
);
1870 #ifdef PNG_WARNINGS_SUPPORTED
1871 PNG_INTERNAL_FUNCTION(void,png_safe_warning
,(png_structp png_ptr
,
1872 png_const_charp warning_message
),PNG_EMPTY
);
1874 # define png_safe_warning 0/*dummy argument*/
1877 PNG_INTERNAL_FUNCTION(int,png_safe_execute
,(png_imagep image
,
1878 int (*function
)(png_voidp
), png_voidp arg
),PNG_EMPTY
);
1880 /* Utility to log an error; this also cleans up the png_image; the function
1881 * always returns 0 (false).
1883 PNG_INTERNAL_FUNCTION(int,png_image_error
,(png_imagep image
,
1884 png_const_charp error_message
),PNG_EMPTY
);
1886 #ifndef PNG_SIMPLIFIED_READ_SUPPORTED
1887 /* png_image_free is used by the write code but not exported */
1888 PNG_INTERNAL_FUNCTION(void, png_image_free
, (png_imagep image
), PNG_EMPTY
);
1889 #endif /* !SIMPLIFIED_READ */
1891 #endif /* SIMPLIFIED READ/WRITE */
1893 #ifdef PNG_FILTER_OPTIMIZATIONS
1894 PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS
, (png_structp png_ptr
,
1895 unsigned int bpp
), PNG_EMPTY
);
1896 /* This is the initialization function for hardware specific optimizations,
1897 * one implementation (for ARM NEON machines) is contained in
1898 * arm/filter_neon.c. It need not be defined - the generic code will be used
1903 /* Maintainer: Put new private prototypes here ^ */
1905 #include "pngdebug.h"
1911 #endif /* PNG_VERSION_INFO_ONLY */
1912 #endif /* PNGPRIV_H */
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