1 
2 /* pngpriv.h - private declarations for use inside libpng
3  *
4  * Copyright (c) 2018-2019 Cosmin Truta
5  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
6  * Copyright (c) 1996-1997 Andreas Dilger
7  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
8  *
9  * This code is released under the libpng license.
10  * For conditions of distribution and use, see the disclaimer
11  * and license in png.h
12  */
13 
14 /* The symbols declared in this file (including the functions declared
15  * as extern) are PRIVATE.  They are not part of the libpng public
16  * interface, and are not recommended for use by regular applications.
17  * Some of them may become public in the future; others may stay private,
18  * change in an incompatible way, or even disappear.
19  * Although the libpng users are not forbidden to include this header,
20  * they should be well aware of the issues that may arise from doing so.
21  */
22 
23 #ifndef PNGPRIV_H
24 #define PNGPRIV_H
25 
26 #ifdef _MSC_VER
27 #  ifndef _CRT_SECURE_NO_DEPRECATE
28 #    define _CRT_SECURE_NO_DEPRECATE
29 #  endif
30 #endif
31 
32 /* Feature Test Macros.  The following are defined here to ensure that correctly
33  * implemented libraries reveal the APIs libpng needs to build and hide those
34  * that are not needed and potentially damaging to the compilation.
35  *
36  * Feature Test Macros must be defined before any system header is included (see
37  * POSIX 1003.1 2.8.2 "POSIX Symbols."
38  *
39  * These macros only have an effect if the operating system supports either
40  * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
41  * Windows/Visual Studio) there is no effect; the OS specific tests below are
42  * still required (as of 2011-05-02.)
43  */
44 #ifndef _POSIX_SOURCE
45 # define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
46 #endif
47 
48 #ifndef PNG_VERSION_INFO_ONLY
49 /* Standard library headers not required by png.h: */
50 #  include <stdlib.h>
51 #  include <string.h>
52 #endif
53 
54 #define PNGLIB_BUILD /*libpng is being built, not used*/
55 
56 /* If HAVE_CONFIG_H is defined during the build then the build system must
57  * provide an appropriate "config.h" file on the include path.  The header file
58  * must provide definitions as required below (search for "HAVE_CONFIG_H");
59  * see configure.ac for more details of the requirements.  The macro
60  * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
61  * 'configure'; define this macro to prevent the configure build including the
62  * configure generated config.h.  Libpng is expected to compile without *any*
63  * special build system support on a reasonably ANSI-C compliant system.
64  */
65 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
66 #  include <config.h>
67 
68    /* Pick up the definition of 'restrict' from config.h if it was read: */
69 #  define PNG_RESTRICT restrict
70 #endif
71 
72 /* To support symbol prefixing it is necessary to know *before* including png.h
73  * whether the fixed point (and maybe other) APIs are exported, because if they
74  * are not internal definitions may be required.  This is handled below just
75  * before png.h is included, but load the configuration now if it is available.
76  */
77 #ifndef PNGLCONF_H
78 #  include "pnglibconf.h"
79 #endif
80 
81 /* Local renames may change non-exported API functions from png.h */
82 #if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
83 #  include "pngprefix.h"
84 #endif
85 
86 #ifdef PNG_USER_CONFIG
87 #  include "pngusr.h"
88    /* These should have been defined in pngusr.h */
89 #  ifndef PNG_USER_PRIVATEBUILD
90 #    define PNG_USER_PRIVATEBUILD "Custom libpng build"
91 #  endif
92 #  ifndef PNG_USER_DLLFNAME_POSTFIX
93 #    define PNG_USER_DLLFNAME_POSTFIX "Cb"
94 #  endif
95 #endif
96 
97 /* Compile time options.
98  * =====================
99  * In a multi-arch build the compiler may compile the code several times for the
100  * same object module, producing different binaries for different architectures.
101  * When this happens configure-time setting of the target host options cannot be
102  * done and this interferes with the handling of the ARM NEON optimizations, and
103  * possibly other similar optimizations.  Put additional tests here; in general
104  * this is needed when the same option can be changed at both compile time and
105  * run time depending on the target OS (i.e. iOS vs Android.)
106  *
107  * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
108  * this is not possible with certain compilers (Oracle SUN OS CC), as a result
109  * it is necessary to ensure that all extern functions that *might* be used
110  * regardless of $(CFLAGS) get declared in this file.  The test on __ARM_NEON__
111  * below is one example of this behavior because it is controlled by the
112  * presence or not of -mfpu=neon on the GCC command line, it is possible to do
113  * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
114  * do this.
115  */
116 #ifndef PNG_ARM_NEON_OPT
117    /* ARM NEON optimizations are being controlled by the compiler settings,
118     * typically the target FPU.  If the FPU has been set to NEON (-mfpu=neon
119     * with GCC) then the compiler will define __ARM_NEON__ and we can rely
120     * unconditionally on NEON instructions not crashing, otherwise we must
121     * disable use of NEON instructions.
122     *
123     * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
124     * can only be turned on automatically if that is supported too.  If
125     * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
126     * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
127     * off.
128     *
129     * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated
130     * __ARM_NEON__, so we check both variants.
131     *
132     * To disable ARM_NEON optimizations entirely, and skip compiling the
133     * associated assembler code, pass --enable-arm-neon=no to configure
134     * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS.
135     */
136 #  if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
137    defined(PNG_ALIGNED_MEMORY_SUPPORTED)
138 #     define PNG_ARM_NEON_OPT 2
139 #  else
140 #     define PNG_ARM_NEON_OPT 0
141 #  endif
142 #endif
143 
144 #if PNG_ARM_NEON_OPT > 0
145    /* NEON optimizations are to be at least considered by libpng, so enable the
146     * callbacks to do this.
147     */
148 #  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
149 
150    /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
151     * if possible - if __ARM_NEON__ is set and the compiler version is not known
152     * to be broken.  This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
153     * be:
154     *
155     *    1  The intrinsics code (the default with __ARM_NEON__)
156     *    2  The hand coded assembler (the default without __ARM_NEON__)
157     *
158     * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
159     * this is *NOT* supported and may cease to work even after a minor revision
160     * to libpng.  It *is* valid to do this for testing purposes, e.g. speed
161     * testing or a new compiler, but the results should be communicated to the
162     * libpng implementation list for incorporation in the next minor release.
163     */
164 #  ifndef PNG_ARM_NEON_IMPLEMENTATION
165 #     if defined(__ARM_NEON__) || defined(__ARM_NEON)
166 #        if defined(__clang__)
167             /* At present it is unknown by the libpng developers which versions
168              * of clang support the intrinsics, however some or perhaps all
169              * versions do not work with the assembler so this may be
170              * irrelevant, so just use the default (do nothing here.)
171              */
172 #        elif defined(__GNUC__)
173             /* GCC 4.5.4 NEON support is known to be broken.  4.6.3 is known to
174              * work, so if this *is* GCC, or G++, look for a version >4.5
175              */
176 #           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
177 #              define PNG_ARM_NEON_IMPLEMENTATION 2
178 #           endif /* no GNUC support */
179 #        endif /* __GNUC__ */
180 #     else /* !defined __ARM_NEON__ */
181          /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
182           */
183 #        if !defined(__aarch64__)
184             /* The assembler code currently does not work on ARM64 */
185 #          define PNG_ARM_NEON_IMPLEMENTATION 2
186 #        endif /* __aarch64__ */
187 #     endif /* __ARM_NEON__ */
188 #  endif /* !PNG_ARM_NEON_IMPLEMENTATION */
189 
190 #  ifndef PNG_ARM_NEON_IMPLEMENTATION
191       /* Use the intrinsics code by default. */
192 #     define PNG_ARM_NEON_IMPLEMENTATION 1
193 #  endif
194 #endif /* PNG_ARM_NEON_OPT > 0 */
195 
196 #ifndef PNG_MIPS_MSA_OPT
197 #  if defined(__mips_msa) && (__mips_isa_rev >= 5) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
198 #     define PNG_MIPS_MSA_OPT 2
199 #  else
200 #     define PNG_MIPS_MSA_OPT 0
201 #  endif
202 #endif
203 
204 #ifndef PNG_POWERPC_VSX_OPT
205 #  if defined(__PPC64__) && defined(__ALTIVEC__) && defined(__VSX__)
206 #     define PNG_POWERPC_VSX_OPT 2
207 #  else
208 #     define PNG_POWERPC_VSX_OPT 0
209 #  endif
210 #endif
211 
212 #ifndef PNG_INTEL_SSE_OPT
213 #   ifdef PNG_INTEL_SSE
214       /* Only check for SSE if the build configuration has been modified to
215        * enable SSE optimizations.  This means that these optimizations will
216        * be off by default.  See contrib/intel for more details.
217        */
218 #     if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
219        defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
220        (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
221 #         define PNG_INTEL_SSE_OPT 1
222 #      else
223 #         define PNG_INTEL_SSE_OPT 0
224 #      endif
225 #   else
226 #      define PNG_INTEL_SSE_OPT 0
227 #   endif
228 #endif
229 
230 #if PNG_INTEL_SSE_OPT > 0
231 #   ifndef PNG_INTEL_SSE_IMPLEMENTATION
232 #      if defined(__SSE4_1__) || defined(__AVX__)
233           /* We are not actually using AVX, but checking for AVX is the best
234              way we can detect SSE4.1 and SSSE3 on MSVC.
235           */
236 #         define PNG_INTEL_SSE_IMPLEMENTATION 3
237 #      elif defined(__SSSE3__)
238 #         define PNG_INTEL_SSE_IMPLEMENTATION 2
239 #      elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
240        (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
241 #         define PNG_INTEL_SSE_IMPLEMENTATION 1
242 #      else
243 #         define PNG_INTEL_SSE_IMPLEMENTATION 0
244 #      endif
245 #   endif
246 
247 #   if PNG_INTEL_SSE_IMPLEMENTATION > 0
248 #      define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
249 #   endif
250 #else
251 #   define PNG_INTEL_SSE_IMPLEMENTATION 0
252 #endif
253 
254 #if PNG_MIPS_MSA_OPT > 0
255 #  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_msa
256 #  ifndef PNG_MIPS_MSA_IMPLEMENTATION
257 #     if defined(__mips_msa)
258 #        if defined(__clang__)
259 #        elif defined(__GNUC__)
260 #           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
261 #              define PNG_MIPS_MSA_IMPLEMENTATION 2
262 #           endif /* no GNUC support */
263 #        endif /* __GNUC__ */
264 #     else /* !defined __mips_msa */
265 #        define PNG_MIPS_MSA_IMPLEMENTATION 2
266 #     endif /* __mips_msa */
267 #  endif /* !PNG_MIPS_MSA_IMPLEMENTATION */
268 
269 #  ifndef PNG_MIPS_MSA_IMPLEMENTATION
270 #     define PNG_MIPS_MSA_IMPLEMENTATION 1
271 #  endif
272 #endif /* PNG_MIPS_MSA_OPT > 0 */
273 
274 #if PNG_POWERPC_VSX_OPT > 0
275 #  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx
276 #  define PNG_POWERPC_VSX_IMPLEMENTATION 1
277 #endif
278 
279 
280 /* Is this a build of a DLL where compilation of the object modules requires
281  * different preprocessor settings to those required for a simple library?  If
282  * so PNG_BUILD_DLL must be set.
283  *
284  * If libpng is used inside a DLL but that DLL does not export the libpng APIs
285  * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
286  * static library of libpng then link the DLL against that.
287  */
288 #ifndef PNG_BUILD_DLL
289 #  ifdef DLL_EXPORT
290       /* This is set by libtool when files are compiled for a DLL; libtool
291        * always compiles twice, even on systems where it isn't necessary.  Set
292        * PNG_BUILD_DLL in case it is necessary:
293        */
294 #     define PNG_BUILD_DLL
295 #  else
296 #     ifdef _WINDLL
297          /* This is set by the Microsoft Visual Studio IDE in projects that
298           * build a DLL.  It can't easily be removed from those projects (it
299           * isn't visible in the Visual Studio UI) so it is a fairly reliable
300           * indication that PNG_IMPEXP needs to be set to the DLL export
301           * attributes.
302           */
303 #        define PNG_BUILD_DLL
304 #     else
305 #        ifdef __DLL__
306             /* This is set by the Borland C system when compiling for a DLL
307              * (as above.)
308              */
309 #           define PNG_BUILD_DLL
310 #        else
311             /* Add additional compiler cases here. */
312 #        endif
313 #     endif
314 #  endif
315 #endif /* Setting PNG_BUILD_DLL if required */
316 
317 /* Modfied for usage in Qt: Do not export the libpng APIs */
318 #ifdef PNG_BUILD_DLL
319 #undef PNG_BUILD_DLL
320 #endif
321 
322 /* See pngconf.h for more details: the builder of the library may set this on
323  * the command line to the right thing for the specific compilation system or it
324  * may be automagically set above (at present we know of no system where it does
325  * need to be set on the command line.)
326  *
327  * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
328  * setting it to the "import" setting for a DLL build.
329  */
330 #ifndef PNG_IMPEXP
331 #  ifdef PNG_BUILD_DLL
332 #     define PNG_IMPEXP PNG_DLL_EXPORT
333 #  else
334       /* Not building a DLL, or the DLL doesn't require specific export
335        * definitions.
336        */
337 #     define PNG_IMPEXP
338 #  endif
339 #endif
340 
341 /* No warnings for private or deprecated functions in the build: */
342 #ifndef PNG_DEPRECATED
343 #  define PNG_DEPRECATED
344 #endif
345 #ifndef PNG_PRIVATE
346 #  define PNG_PRIVATE
347 #endif
348 
349 /* Symbol preprocessing support.
350  *
351  * To enable listing global, but internal, symbols the following macros should
352  * always be used to declare an extern data or function object in this file.
353  */
354 #ifndef PNG_INTERNAL_DATA
355 #  define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array
356 #endif
357 
358 #ifndef PNG_INTERNAL_FUNCTION
359 #  define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
360       PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
361 #endif
362 
363 #ifndef PNG_INTERNAL_CALLBACK
364 #  define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
365       PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\
366          PNG_EMPTY attributes)
367 #endif
368 
369 /* If floating or fixed point APIs are disabled they may still be compiled
370  * internally.  To handle this make sure they are declared as the appropriate
371  * internal extern function (otherwise the symbol prefixing stuff won't work and
372  * the functions will be used without definitions.)
373  *
374  * NOTE: although all the API functions are declared here they are not all
375  * actually built!  Because the declarations are still made it is necessary to
376  * fake out types that they depend on.
377  */
378 #ifndef PNG_FP_EXPORT
379 #  ifndef PNG_FLOATING_POINT_SUPPORTED
380 #     define PNG_FP_EXPORT(ordinal, type, name, args)\
381          PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
382 #     ifndef PNG_VERSION_INFO_ONLY
383          typedef struct png_incomplete png_double;
384          typedef png_double*           png_doublep;
385          typedef const png_double*     png_const_doublep;
386          typedef png_double**          png_doublepp;
387 #     endif
388 #  endif
389 #endif
390 #ifndef PNG_FIXED_EXPORT
391 #  ifndef PNG_FIXED_POINT_SUPPORTED
392 #     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
393          PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
394 #  endif
395 #endif
396 
397 #include "png.h"
398 
399 /* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
400 #ifndef PNG_DLL_EXPORT
401 #  define PNG_DLL_EXPORT
402 #endif
403 
404 /* This is a global switch to set the compilation for an installed system
405  * (a release build).  It can be set for testing debug builds to ensure that
406  * they will compile when the build type is switched to RC or STABLE, the
407  * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE.  Set this in CPPFLAGS
408  * with either:
409  *
410  *   -DPNG_RELEASE_BUILD Turns on the release compile path
411  *   -DPNG_RELEASE_BUILD=0 Turns it off
412  * or in your pngusr.h with
413  *   #define PNG_RELEASE_BUILD=1 Turns on the release compile path
414  *   #define PNG_RELEASE_BUILD=0 Turns it off
415  */
416 #ifndef PNG_RELEASE_BUILD
417 #  define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
418 #endif
419 
420 /* SECURITY and SAFETY:
421  *
422  * libpng is built with support for internal limits on image dimensions and
423  * memory usage.  These are documented in scripts/pnglibconf.dfa of the
424  * source and recorded in the machine generated header file pnglibconf.h.
425  */
426 
427 /* If you are running on a machine where you cannot allocate more
428  * than 64K of memory at once, uncomment this.  While libpng will not
429  * normally need that much memory in a chunk (unless you load up a very
430  * large file), zlib needs to know how big of a chunk it can use, and
431  * libpng thus makes sure to check any memory allocation to verify it
432  * will fit into memory.
433  *
434  * zlib provides 'MAXSEG_64K' which, if defined, indicates the
435  * same limit and pngconf.h (already included) sets the limit
436  * if certain operating systems are detected.
437  */
438 #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
439 #  define PNG_MAX_MALLOC_64K
440 #endif
441 
442 #ifndef PNG_UNUSED
443 /* Unused formal parameter warnings are silenced using the following macro
444  * which is expected to have no bad effects on performance (optimizing
445  * compilers will probably remove it entirely).  Note that if you replace
446  * it with something other than whitespace, you must include the terminating
447  * semicolon.
448  */
449 #  define PNG_UNUSED(param) (void)param;
450 #endif
451 
452 /* Just a little check that someone hasn't tried to define something
453  * contradictory.
454  */
455 #if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
456 #  undef PNG_ZBUF_SIZE
457 #  define PNG_ZBUF_SIZE 65536L
458 #endif
459 
460 /* If warnings or errors are turned off the code is disabled or redirected here.
461  * From 1.5.4 functions have been added to allow very limited formatting of
462  * error and warning messages - this code will also be disabled here.
463  */
464 #ifdef PNG_WARNINGS_SUPPORTED
465 #  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
466 #else
467 #  define png_warning_parameter(p,number,string) ((void)0)
468 #  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
469 #  define png_warning_parameter_signed(p,number,format,value) ((void)0)
470 #  define png_formatted_warning(pp,p,message) ((void)(pp))
471 #  define PNG_WARNING_PARAMETERS(p)
472 #endif
473 #ifndef PNG_ERROR_TEXT_SUPPORTED
474 #  define png_fixed_error(s1,s2) png_err(s1)
475 #endif
476 
477 /* Some fixed point APIs are still required even if not exported because
478  * they get used by the corresponding floating point APIs.  This magic
479  * deals with this:
480  */
481 #ifdef PNG_FIXED_POINT_SUPPORTED
482 #  define PNGFAPI PNGAPI
483 #else
484 #  define PNGFAPI /* PRIVATE */
485 #endif
486 
487 #ifndef PNG_VERSION_INFO_ONLY
488 /* Other defines specific to compilers can go here.  Try to keep
489  * them inside an appropriate ifdef/endif pair for portability.
490  */
491 
492 /* C allows up-casts from (void*) to any pointer and (const void*) to any
493  * pointer to a const object.  C++ regards this as a type error and requires an
494  * explicit, static, cast and provides the static_cast<> rune to ensure that
495  * const is not cast away.
496  */
497 #ifdef __cplusplus
498 #  define png_voidcast(type, value) static_cast<type>(value)
499 #  define png_constcast(type, value) const_cast<type>(value)
500 #  define png_aligncast(type, value) \
501    static_cast<type>(static_cast<void*>(value))
502 #  define png_aligncastconst(type, value) \
503    static_cast<type>(static_cast<const void*>(value))
504 #else
505 #  define png_voidcast(type, value) (value)
506 #  ifdef _WIN64
507 #     ifdef __GNUC__
508          typedef unsigned long long png_ptruint;
509 #     else
510          typedef unsigned __int64 png_ptruint;
511 #     endif
512 #  else
513       typedef unsigned long png_ptruint;
514 #  endif
515 #  define png_constcast(type, value) ((type)(png_ptruint)(const void*)(value))
516 #  define png_aligncast(type, value) ((void*)(value))
517 #  define png_aligncastconst(type, value) ((const void*)(value))
518 #endif /* __cplusplus */
519 
520 #if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
521     defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
522    /* png.c requires the following ANSI-C constants if the conversion of
523     * floating point to ASCII is implemented therein:
524     *
525     *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
526     *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
527     *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
528     */
529 #  include <float.h>
530 
531 #  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
532     defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
533    /* We need to check that <math.h> hasn't already been included earlier
534     * as it seems it doesn't agree with <fp.h>, yet we should really use
535     * <fp.h> if possible.
536     */
537 #    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
538 #      include <fp.h>
539 #    endif
540 #  else
541 #    include <math.h>
542 #  endif
543 #  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
544    /* Amiga SAS/C: We must include builtin FPU functions when compiling using
545     * MATH=68881
546     */
547 #    include <m68881.h>
548 #  endif
549 #endif
550 
551 /* This provides the non-ANSI (far) memory allocation routines. */
552 #if defined(__TURBOC__) && defined(__MSDOS__)
553 #  include <mem.h>
554 #  include <alloc.h>
555 #endif
556 
557 #if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
558     defined(_WIN32) || defined(__WIN32__)
559 #  include <windows.h>  /* defines _WINDOWS_ macro */
560 #  if defined(WINAPI_FAMILY) && (WINAPI_FAMILY==WINAPI_FAMILY_APP || WINAPI_FAMILY==WINAPI_FAMILY_PHONE_APP)
561 #    define _WINRT_ /* Define a macro for Windows Runtime builds */
562 #  endif
563 #endif
564 #endif /* PNG_VERSION_INFO_ONLY */
565 
566 /* Moved here around 1.5.0beta36 from pngconf.h */
567 /* Users may want to use these so they are not private.  Any library
568  * functions that are passed far data must be model-independent.
569  */
570 
571 /* Memory model/platform independent fns */
572 #ifndef PNG_ABORT
573 #  if (defined(_WINDOWS_) || defined(_WIN32_WCE)) && !defined(_WINRT_)
574 #    define PNG_ABORT() ExitProcess(0)
575 #  else
576 #    define PNG_ABORT() abort()
577 #  endif
578 #endif
579 
580 /* These macros may need to be architecture dependent. */
581 #define PNG_ALIGN_NONE   0 /* do not use data alignment */
582 #define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
583 #ifdef offsetof
584 #  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
585 #else
586 #  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
587 #endif
588 #define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
589 
590 #ifndef PNG_ALIGN_TYPE
591    /* Default to using aligned access optimizations and requiring alignment to a
592     * multiple of the data type size.  Override in a compiler specific fashion
593     * if necessary by inserting tests here:
594     */
595 #  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
596 #endif
597 
598 #if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
599    /* This is used because in some compiler implementations non-aligned
600     * structure members are supported, so the offsetof approach below fails.
601     * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
602     * is good for performance.  Do not do this unless you have tested the result
603     * and understand it.
604     */
605 #  define png_alignof(type) (sizeof (type))
606 #else
607 #  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
608 #     define png_alignof(type) offsetof(struct{char c; type t;}, t)
609 #  else
610 #     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
611 #        define png_alignof(type) (1)
612 #     endif
613       /* Else leave png_alignof undefined to prevent use thereof */
614 #  endif
615 #endif
616 
617 /* This implicitly assumes alignment is always to a power of 2. */
618 #ifdef png_alignof
619 #  define png_isaligned(ptr, type)\
620    (((type)((const char*)ptr-(const char*)0) & \
621    (type)(png_alignof(type)-1)) == 0)
622 #else
623 #  define png_isaligned(ptr, type) 0
624 #endif
625 
626 /* End of memory model/platform independent support */
627 /* End of 1.5.0beta36 move from pngconf.h */
628 
629 /* CONSTANTS and UTILITY MACROS
630  * These are used internally by libpng and not exposed in the API
631  */
632 
633 /* Various modes of operation.  Note that after an init, mode is set to
634  * zero automatically when the structure is created.  Three of these
635  * are defined in png.h because they need to be visible to applications
636  * that call png_set_unknown_chunk().
637  */
638 /* #define PNG_HAVE_IHDR            0x01U (defined in png.h) */
639 /* #define PNG_HAVE_PLTE            0x02U (defined in png.h) */
640 #define PNG_HAVE_IDAT               0x04U
641 /* #define PNG_AFTER_IDAT           0x08U (defined in png.h) */
642 #define PNG_HAVE_IEND               0x10U
643                    /*               0x20U (unused) */
644                    /*               0x40U (unused) */
645                    /*               0x80U (unused) */
646 #define PNG_HAVE_CHUNK_HEADER      0x100U
647 #define PNG_WROTE_tIME             0x200U
648 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400U
649 #define PNG_BACKGROUND_IS_GRAY     0x800U
650 #define PNG_HAVE_PNG_SIGNATURE    0x1000U
651 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
652                    /*             0x4000U (unused) */
653 #define PNG_IS_READ_STRUCT        0x8000U /* Else is a write struct */
654 
655 /* Flags for the transformations the PNG library does on the image data */
656 #define PNG_BGR                 0x0001U
657 #define PNG_INTERLACE           0x0002U
658 #define PNG_PACK                0x0004U
659 #define PNG_SHIFT               0x0008U
660 #define PNG_SWAP_BYTES          0x0010U
661 #define PNG_INVERT_MONO         0x0020U
662 #define PNG_QUANTIZE            0x0040U
663 #define PNG_COMPOSE             0x0080U    /* Was PNG_BACKGROUND */
664 #define PNG_BACKGROUND_EXPAND   0x0100U
665 #define PNG_EXPAND_16           0x0200U    /* Added to libpng 1.5.2 */
666 #define PNG_16_TO_8             0x0400U    /* Becomes 'chop' in 1.5.4 */
667 #define PNG_RGBA                0x0800U
668 #define PNG_EXPAND              0x1000U
669 #define PNG_GAMMA               0x2000U
670 #define PNG_GRAY_TO_RGB         0x4000U
671 #define PNG_FILLER              0x8000U
672 #define PNG_PACKSWAP           0x10000U
673 #define PNG_SWAP_ALPHA         0x20000U
674 #define PNG_STRIP_ALPHA        0x40000U
675 #define PNG_INVERT_ALPHA       0x80000U
676 #define PNG_USER_TRANSFORM    0x100000U
677 #define PNG_RGB_TO_GRAY_ERR   0x200000U
678 #define PNG_RGB_TO_GRAY_WARN  0x400000U
679 #define PNG_RGB_TO_GRAY       0x600000U /* two bits, RGB_TO_GRAY_ERR|WARN */
680 #define PNG_ENCODE_ALPHA      0x800000U /* Added to libpng-1.5.4 */
681 #define PNG_ADD_ALPHA        0x1000000U /* Added to libpng-1.2.7 */
682 #define PNG_EXPAND_tRNS      0x2000000U /* Added to libpng-1.2.9 */
683 #define PNG_SCALE_16_TO_8    0x4000000U /* Added to libpng-1.5.4 */
684                        /*    0x8000000U unused */
685                        /*   0x10000000U unused */
686                        /*   0x20000000U unused */
687                        /*   0x40000000U unused */
688 /* Flags for png_create_struct */
689 #define PNG_STRUCT_PNG   0x0001U
690 #define PNG_STRUCT_INFO  0x0002U
691 
692 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
693 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001U
694 #define PNG_FLAG_ZSTREAM_INITIALIZED      0x0002U /* Added to libpng-1.6.0 */
695                                   /*      0x0004U    unused */
696 #define PNG_FLAG_ZSTREAM_ENDED            0x0008U /* Added to libpng-1.6.0 */
697                                   /*      0x0010U    unused */
698                                   /*      0x0020U    unused */
699 #define PNG_FLAG_ROW_INIT                 0x0040U
700 #define PNG_FLAG_FILLER_AFTER             0x0080U
701 #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100U
702 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200U
703 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400U
704 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800U
705 #define PNG_FLAG_ASSUME_sRGB              0x1000U /* Added to libpng-1.5.4 */
706 #define PNG_FLAG_OPTIMIZE_ALPHA           0x2000U /* Added to libpng-1.5.4 */
707 #define PNG_FLAG_DETECT_UNINITIALIZED     0x4000U /* Added to libpng-1.5.4 */
708 /* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000U */
709 /* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS      0x10000U */
710 #define PNG_FLAG_LIBRARY_MISMATCH        0x20000U
711 #define PNG_FLAG_STRIP_ERROR_NUMBERS     0x40000U
712 #define PNG_FLAG_STRIP_ERROR_TEXT        0x80000U
713 #define PNG_FLAG_BENIGN_ERRORS_WARN     0x100000U /* Added to libpng-1.4.0 */
714 #define PNG_FLAG_APP_WARNINGS_WARN      0x200000U /* Added to libpng-1.6.0 */
715 #define PNG_FLAG_APP_ERRORS_WARN        0x400000U /* Added to libpng-1.6.0 */
716                                   /*    0x800000U    unused */
717                                   /*   0x1000000U    unused */
718                                   /*   0x2000000U    unused */
719                                   /*   0x4000000U    unused */
720                                   /*   0x8000000U    unused */
721                                   /*  0x10000000U    unused */
722                                   /*  0x20000000U    unused */
723                                   /*  0x40000000U    unused */
724 
725 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
726                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
727 
728 #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
729                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
730 
731 #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
732                                      PNG_FLAG_CRC_CRITICAL_MASK)
733 
734 /* Save typing and make code easier to understand */
735 
736 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
737    abs((int)((c1).green) - (int)((c2).green)) + \
738    abs((int)((c1).blue) - (int)((c2).blue)))
739 
740 /* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
741  * by dividing by 257 *with rounding*.  This macro is exact for the given range.
742  * See the discourse in pngrtran.c png_do_scale_16_to_8.  The values in the
743  * macro were established by experiment (modifying the added value).  The macro
744  * has a second variant that takes a value already scaled by 255 and divides by
745  * 65535 - this has a maximum error of .502.  Over the range 0..65535*65535 it
746  * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
747  */
748 #define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
749 #define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
750 
751 /* Added to libpng-1.2.6 JB */
752 #define PNG_ROWBYTES(pixel_bits, width) \
753     ((pixel_bits) >= 8 ? \
754     ((size_t)(width) * (((size_t)(pixel_bits)) >> 3)) : \
755     (( ((size_t)(width) * ((size_t)(pixel_bits))) + 7) >> 3) )
756 
757 /* This returns the number of trailing bits in the last byte of a row, 0 if the
758  * last byte is completely full of pixels.  It is, in principle, (pixel_bits x
759  * width) % 8, but that would overflow for large 'width'.  The second macro is
760  * the same except that it returns the number of unused bits in the last byte;
761  * (8-TRAILBITS), but 0 when TRAILBITS is 0.
762  *
763  * NOTE: these macros are intended to be self-evidently correct and never
764  * overflow on the assumption that pixel_bits is in the range 0..255.  The
765  * arguments are evaluated only once and they can be signed (e.g. as a result of
766  * the integral promotions).  The result of the expression always has type
767  * (png_uint_32), however the compiler always knows it is in the range 0..7.
768  */
769 #define PNG_TRAILBITS(pixel_bits, width) \
770     (((pixel_bits) * ((width) % (png_uint_32)8)) % 8)
771 
772 #define PNG_PADBITS(pixel_bits, width) \
773     ((8 - PNG_TRAILBITS(pixel_bits, width)) % 8)
774 
775 /* PNG_OUT_OF_RANGE returns true if value is outside the range
776  * ideal-delta..ideal+delta.  Each argument is evaluated twice.
777  * "ideal" and "delta" should be constants, normally simple
778  * integers, "value" a variable. Added to libpng-1.2.6 JB
779  */
780 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
781    ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
782 
783 /* Conversions between fixed and floating point, only defined if
784  * required (to make sure the code doesn't accidentally use float
785  * when it is supposedly disabled.)
786  */
787 #ifdef PNG_FLOATING_POINT_SUPPORTED
788 /* The floating point conversion can't overflow, though it can and
789  * does lose accuracy relative to the original fixed point value.
790  * In practice this doesn't matter because png_fixed_point only
791  * stores numbers with very low precision.  The png_ptr and s
792  * arguments are unused by default but are there in case error
793  * checking becomes a requirement.
794  */
795 #define png_float(png_ptr, fixed, s) (.00001 * (fixed))
796 
797 /* The fixed point conversion performs range checking and evaluates
798  * its argument multiple times, so must be used with care.  The
799  * range checking uses the PNG specification values for a signed
800  * 32-bit fixed point value except that the values are deliberately
801  * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
802  * (2^31-1) * 100000). 's' is a string that describes the value being
803  * converted.
804  *
805  * NOTE: this macro will raise a png_error if the range check fails,
806  * therefore it is normally only appropriate to use this on values
807  * that come from API calls or other sources where an out of range
808  * error indicates a programming error, not a data error!
809  *
810  * NOTE: by default this is off - the macro is not used - because the
811  * function call saves a lot of code.
812  */
813 #ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
814 #define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
815     ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
816 #endif
817 /* else the corresponding function is defined below, inside the scope of the
818  * cplusplus test.
819  */
820 #endif
821 
822 /* Constants for known chunk types.  If you need to add a chunk, define the name
823  * here.  For historical reasons these constants have the form png_<name>; i.e.
824  * the prefix is lower case.  Please use decimal values as the parameters to
825  * match the ISO PNG specification and to avoid relying on the C locale
826  * interpretation of character values.
827  *
828  * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
829  * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
830  * to be generated if required.
831  *
832  * PNG_32b correctly produces a value shifted by up to 24 bits, even on
833  * architectures where (int) is only 16 bits.
834  */
835 #define PNG_32b(b,s) ((png_uint_32)(b) << (s))
836 #define PNG_U32(b1,b2,b3,b4) \
837    (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
838 
839 /* Constants for known chunk types.
840  *
841  * MAINTAINERS: If you need to add a chunk, define the name here.
842  * For historical reasons these constants have the form png_<name>; i.e.
843  * the prefix is lower case.  Please use decimal values as the parameters to
844  * match the ISO PNG specification and to avoid relying on the C locale
845  * interpretation of character values.  Please keep the list sorted.
846  *
847  * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
848  * type.  In fact the specification does not express chunk types this way,
849  * however using a 32-bit value means that the chunk type can be read from the
850  * stream using exactly the same code as used for a 32-bit unsigned value and
851  * can be examined far more efficiently (using one arithmetic compare).
852  *
853  * Prior to 1.5.6 the chunk type constants were expressed as C strings.  The
854  * libpng API still uses strings for 'unknown' chunks and a macro,
855  * PNG_STRING_FROM_CHUNK, allows a string to be generated if required.  Notice
856  * that for portable code numeric values must still be used; the string "IHDR"
857  * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
858  *
859  * In 1.7.0 the definitions will be made public in png.h to avoid having to
860  * duplicate the same definitions in application code.
861  */
862 #define png_IDAT PNG_U32( 73,  68,  65,  84)
863 #define png_IEND PNG_U32( 73,  69,  78,  68)
864 #define png_IHDR PNG_U32( 73,  72,  68,  82)
865 #define png_PLTE PNG_U32( 80,  76,  84,  69)
866 #define png_bKGD PNG_U32( 98,  75,  71,  68)
867 #define png_cHRM PNG_U32( 99,  72,  82,  77)
868 #define png_eXIf PNG_U32(101,  88,  73, 102) /* registered July 2017 */
869 #define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
870 #define png_gAMA PNG_U32(103,  65,  77,  65)
871 #define png_gIFg PNG_U32(103,  73,  70, 103)
872 #define png_gIFt PNG_U32(103,  73,  70, 116) /* deprecated */
873 #define png_gIFx PNG_U32(103,  73,  70, 120)
874 #define png_hIST PNG_U32(104,  73,  83,  84)
875 #define png_iCCP PNG_U32(105,  67,  67,  80)
876 #define png_iTXt PNG_U32(105,  84,  88, 116)
877 #define png_oFFs PNG_U32(111,  70,  70, 115)
878 #define png_pCAL PNG_U32(112,  67,  65,  76)
879 #define png_pHYs PNG_U32(112,  72,  89, 115)
880 #define png_sBIT PNG_U32(115,  66,  73,  84)
881 #define png_sCAL PNG_U32(115,  67,  65,  76)
882 #define png_sPLT PNG_U32(115,  80,  76,  84)
883 #define png_sRGB PNG_U32(115,  82,  71,  66)
884 #define png_sTER PNG_U32(115,  84,  69,  82)
885 #define png_tEXt PNG_U32(116,  69,  88, 116)
886 #define png_tIME PNG_U32(116,  73,  77,  69)
887 #define png_tRNS PNG_U32(116,  82,  78,  83)
888 #define png_zTXt PNG_U32(122,  84,  88, 116)
889 
890 /* The following will work on (signed char*) strings, whereas the get_uint_32
891  * macro will fail on top-bit-set values because of the sign extension.
892  */
893 #define PNG_CHUNK_FROM_STRING(s)\
894    PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
895 
896 /* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
897  * signed and the argument is a (char[])  This macro will fail miserably on
898  * systems where (char) is more than 8 bits.
899  */
900 #define PNG_STRING_FROM_CHUNK(s,c)\
901    (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
902    ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
903    ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
904    ((char*)(s))[3]=(char)((c & 0xff)))
905 
906 /* Do the same but terminate with a null character. */
907 #define PNG_CSTRING_FROM_CHUNK(s,c)\
908    (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
909 
910 /* Test on flag values as defined in the spec (section 5.4): */
911 #define PNG_CHUNK_ANCILLARY(c)   (1 & ((c) >> 29))
912 #define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLARY(c))
913 #define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
914 #define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
915 #define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
916 
917 /* Gamma values (new at libpng-1.5.4): */
918 #define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
919 #define PNG_GAMMA_MAC_INVERSE 65909
920 #define PNG_GAMMA_sRGB_INVERSE 45455
921 
922 /* Almost everything below is C specific; the #defines above can be used in
923  * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
924  */
925 #ifndef PNG_VERSION_INFO_ONLY
926 
927 #include "pngstruct.h"
928 #include "pnginfo.h"
929 
930 /* Validate the include paths - the include path used to generate pnglibconf.h
931  * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
932  */
933 #if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
934 #  error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
935       "-I (include path) error: see the notes in pngpriv.h"
936    /* This means that when pnglibconf.h was built the copy of zlib.h that it
937     * used is not the same as the one being used here.  Because the build of
938     * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
939     * zlib version number and because this affects handling of certain broken
940     * PNG files the -I directives must match.
941     *
942     * The most likely explanation is that you passed a -I in CFLAGS. This will
943     * not work; all the preprocessor directives and in particular all the -I
944     * directives must be in CPPFLAGS.
945     */
946 #endif
947 
948 /* This is used for 16-bit gamma tables -- only the top level pointers are
949  * const; this could be changed:
950  */
951 typedef const png_uint_16p * png_const_uint_16pp;
952 
953 /* Added to libpng-1.5.7: sRGB conversion tables */
954 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
955    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
956 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
957 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
958    /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
959     * 0..65535.  This table gives the closest 16-bit answers (no errors).
960     */
961 #endif
962 
963 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
964 PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
965 
966 #define PNG_sRGB_FROM_LINEAR(linear) \
967   ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
968    + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
969    /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
970     * encoded value with maximum error 0.646365.  Note that the input is not a
971     * 16-bit value; it has been multiplied by 255! */
972 #endif /* SIMPLIFIED_READ/WRITE */
973 
974 
975 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
976 #ifdef __cplusplus
977 extern "C" {
978 #endif /* __cplusplus */
979 
980 /* Internal functions; these are not exported from a DLL however because they
981  * are used within several of the C source files they have to be C extern.
982  *
983  * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
984  */
985 
986 /* Zlib support */
987 #define PNG_UNEXPECTED_ZLIB_RETURN (-7)
988 PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
989    PNG_EMPTY);
990    /* Used by the zlib handling functions to ensure that z_stream::msg is always
991     * set before they return.
992     */
993 
994 #ifdef PNG_WRITE_SUPPORTED
995 PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
996    png_compression_bufferp *list),PNG_EMPTY);
997    /* Free the buffer list used by the compressed write code. */
998 #endif
999 
1000 #if defined(PNG_FLOATING_POINT_SUPPORTED) && \
1001    !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
1002    (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
1003    defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
1004    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
1005    (defined(PNG_sCAL_SUPPORTED) && \
1006    defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
1007 PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
1008    double fp, png_const_charp text),PNG_EMPTY);
1009 #endif
1010 
1011 /* Check the user version string for compatibility, returns false if the version
1012  * numbers aren't compatible.
1013  */
1014 PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
1015    png_const_charp user_png_ver),PNG_EMPTY);
1016 
1017 /* Internal base allocator - no messages, NULL on failure to allocate.  This
1018  * does, however, call the application provided allocator and that could call
1019  * png_error (although that would be a bug in the application implementation.)
1020  */
1021 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
1022    png_alloc_size_t size),PNG_ALLOCATED);
1023 
1024 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
1025    defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
1026 /* Internal array allocator, outputs no error or warning messages on failure,
1027  * just returns NULL.
1028  */
1029 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
1030    int nelements, size_t element_size),PNG_ALLOCATED);
1031 
1032 /* The same but an existing array is extended by add_elements.  This function
1033  * also memsets the new elements to 0 and copies the old elements.  The old
1034  * array is not freed or altered.
1035  */
1036 PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
1037    png_const_voidp array, int old_elements, int add_elements,
1038    size_t element_size),PNG_ALLOCATED);
1039 #endif /* text, sPLT or unknown chunks */
1040 
1041 /* Magic to create a struct when there is no struct to call the user supplied
1042  * memory allocators.  Because error handling has not been set up the memory
1043  * handlers can't safely call png_error, but this is an obscure and undocumented
1044  * restriction so libpng has to assume that the 'free' handler, at least, might
1045  * call png_error.
1046  */
1047 PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
1048    (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1049     png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
1050     png_free_ptr free_fn),PNG_ALLOCATED);
1051 
1052 /* Free memory from internal libpng struct */
1053 PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
1054    PNG_EMPTY);
1055 
1056 /* Free an allocated jmp_buf (always succeeds) */
1057 PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
1058 
1059 /* Function to allocate memory for zlib.  PNGAPI is disallowed. */
1060 PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
1061    PNG_ALLOCATED);
1062 
1063 /* Function to free memory for zlib.  PNGAPI is disallowed. */
1064 PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
1065 
1066 /* Next four functions are used internally as callbacks.  PNGCBAPI is required
1067  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
1068  * PNGCBAPI at 1.5.0
1069  */
1070 
1071 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
1072     png_bytep data, size_t length),PNG_EMPTY);
1073 
1074 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1075 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
1076     png_bytep buffer, size_t length),PNG_EMPTY);
1077 #endif
1078 
1079 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
1080     png_bytep data, size_t length),PNG_EMPTY);
1081 
1082 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1083 #  ifdef PNG_STDIO_SUPPORTED
1084 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
1085    PNG_EMPTY);
1086 #  endif
1087 #endif
1088 
1089 /* Reset the CRC variable */
1090 PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
1091 
1092 /* Write the "data" buffer to whatever output you are using */
1093 PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
1094     png_const_bytep data, size_t length),PNG_EMPTY);
1095 
1096 /* Read and check the PNG file signature */
1097 PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
1098    png_inforp info_ptr),PNG_EMPTY);
1099 
1100 /* Read the chunk header (length + type name) */
1101 PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
1102    PNG_EMPTY);
1103 
1104 /* Read data from whatever input you are using into the "data" buffer */
1105 PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
1106     size_t length),PNG_EMPTY);
1107 
1108 /* Read bytes into buf, and update png_ptr->crc */
1109 PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
1110     png_uint_32 length),PNG_EMPTY);
1111 
1112 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
1113 PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
1114    png_uint_32 skip),PNG_EMPTY);
1115 
1116 /* Read the CRC from the file and compare it to the libpng calculated CRC */
1117 PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
1118 
1119 /* Calculate the CRC over a section of data.  Note that we are only
1120  * passing a maximum of 64K on systems that have this as a memory limit,
1121  * since this is the maximum buffer size we can specify.
1122  */
1123 PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
1124    png_const_bytep ptr, size_t length),PNG_EMPTY);
1125 
1126 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1127 PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
1128 #endif
1129 
1130 /* Write various chunks */
1131 
1132 /* Write the IHDR chunk, and update the png_struct with the necessary
1133  * information.
1134  */
1135 PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
1136    png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
1137    int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
1138 
1139 PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
1140    png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
1141 
1142 PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
1143    png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
1144    PNG_EMPTY);
1145 
1146 PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
1147 
1148 #ifdef PNG_WRITE_gAMA_SUPPORTED
1149 PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
1150     png_fixed_point file_gamma),PNG_EMPTY);
1151 #endif
1152 
1153 #ifdef PNG_WRITE_sBIT_SUPPORTED
1154 PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
1155     png_const_color_8p sbit, int color_type),PNG_EMPTY);
1156 #endif
1157 
1158 #ifdef PNG_WRITE_cHRM_SUPPORTED
1159 PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
1160     const png_xy *xy), PNG_EMPTY);
1161    /* The xy value must have been previously validated */
1162 #endif
1163 
1164 #ifdef PNG_WRITE_sRGB_SUPPORTED
1165 PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1166     int intent),PNG_EMPTY);
1167 #endif
1168 
1169 #ifdef PNG_WRITE_eXIf_SUPPORTED
1170 PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr,
1171     png_bytep exif, int num_exif),PNG_EMPTY);
1172 #endif
1173 
1174 #ifdef PNG_WRITE_iCCP_SUPPORTED
1175 PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1176    png_const_charp name, png_const_bytep profile), PNG_EMPTY);
1177    /* The profile must have been previously validated for correctness, the
1178     * length comes from the first four bytes.  Only the base, deflate,
1179     * compression is supported.
1180     */
1181 #endif
1182 
1183 #ifdef PNG_WRITE_sPLT_SUPPORTED
1184 PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1185     png_const_sPLT_tp palette),PNG_EMPTY);
1186 #endif
1187 
1188 #ifdef PNG_WRITE_tRNS_SUPPORTED
1189 PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1190     png_const_bytep trans, png_const_color_16p values, int number,
1191     int color_type),PNG_EMPTY);
1192 #endif
1193 
1194 #ifdef PNG_WRITE_bKGD_SUPPORTED
1195 PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1196     png_const_color_16p values, int color_type),PNG_EMPTY);
1197 #endif
1198 
1199 #ifdef PNG_WRITE_hIST_SUPPORTED
1200 PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1201     png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1202 #endif
1203 
1204 /* Chunks that have keywords */
1205 #ifdef PNG_WRITE_tEXt_SUPPORTED
1206 PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1207    png_const_charp key, png_const_charp text, size_t text_len),PNG_EMPTY);
1208 #endif
1209 
1210 #ifdef PNG_WRITE_zTXt_SUPPORTED
1211 PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1212     key, png_const_charp text, int compression),PNG_EMPTY);
1213 #endif
1214 
1215 #ifdef PNG_WRITE_iTXt_SUPPORTED
1216 PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1217     int compression, png_const_charp key, png_const_charp lang,
1218     png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1219 #endif
1220 
1221 #ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
1222 PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1223     png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1224 #endif
1225 
1226 #ifdef PNG_WRITE_oFFs_SUPPORTED
1227 PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1228     png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1229 #endif
1230 
1231 #ifdef PNG_WRITE_pCAL_SUPPORTED
1232 PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1233     png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1234     png_const_charp units, png_charpp params),PNG_EMPTY);
1235 #endif
1236 
1237 #ifdef PNG_WRITE_pHYs_SUPPORTED
1238 PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1239     png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1240     int unit_type),PNG_EMPTY);
1241 #endif
1242 
1243 #ifdef PNG_WRITE_tIME_SUPPORTED
1244 PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1245     png_const_timep mod_time),PNG_EMPTY);
1246 #endif
1247 
1248 #ifdef PNG_WRITE_sCAL_SUPPORTED
1249 PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1250     int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1251 #endif
1252 
1253 /* Called when finished processing a row of data */
1254 PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1255     PNG_EMPTY);
1256 
1257 /* Internal use only.   Called before first row of data */
1258 PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1259     PNG_EMPTY);
1260 
1261 /* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
1262  * array of png_ptr->width pixels.  If the image is not interlaced or this
1263  * is the final pass this just does a memcpy, otherwise the "display" flag
1264  * is used to determine whether to copy pixels that are not in the current pass.
1265  *
1266  * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1267  * function to achieve the documented 'blocky' appearance during interlaced read
1268  * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1269  * are not changed if they are not in the current pass, when display is 0.
1270  *
1271  * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1272  *
1273  * The API always reads from the png_struct row buffer and always assumes that
1274  * it is full width (png_do_read_interlace has already been called.)
1275  *
1276  * This function is only ever used to write to row buffers provided by the
1277  * caller of the relevant libpng API and the row must have already been
1278  * transformed by the read transformations.
1279  *
1280  * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1281  * bitmasks for use within the code, otherwise runtime generated masks are used.
1282  * The default is compile time masks.
1283  */
1284 #ifndef PNG_USE_COMPILE_TIME_MASKS
1285 #  define PNG_USE_COMPILE_TIME_MASKS 1
1286 #endif
1287 PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1288     png_bytep row, int display),PNG_EMPTY);
1289 
1290 #ifdef PNG_READ_INTERLACING_SUPPORTED
1291 /* Expand an interlaced row: the 'row_info' describes the pass data that has
1292  * been read in and must correspond to the pixels in 'row', the pixels are
1293  * expanded (moved apart) in 'row' to match the final layout, when doing this
1294  * the pixels are *replicated* to the intervening space.  This is essential for
1295  * the correct operation of png_combine_row, above.
1296  */
1297 PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1298     png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1299 #endif
1300 
1301 /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
1302 
1303 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1304 /* Grab pixels out of a row for an interlaced pass */
1305 PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1306     png_bytep row, int pass),PNG_EMPTY);
1307 #endif
1308 
1309 /* Unfilter a row: check the filter value before calling this, there is no point
1310  * calling it for PNG_FILTER_VALUE_NONE.
1311  */
1312 PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1313     row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1314 
1315 #if PNG_ARM_NEON_OPT > 0
1316 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1317     png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1318 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1319     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1320 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1321     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1322 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1323     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1324 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1325     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1326 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1327     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1328 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1329     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1330 #endif
1331 
1332 #if PNG_MIPS_MSA_OPT > 0
1333 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_msa,(png_row_infop row_info,
1334     png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1335 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_msa,(png_row_infop
1336     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1337 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_msa,(png_row_infop
1338     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1339 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_msa,(png_row_infop
1340     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1341 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop
1342     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1343 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop
1344     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1345 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop
1346     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1347 #endif
1348 
1349 #if PNG_POWERPC_VSX_OPT > 0
1350 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_vsx,(png_row_infop row_info,
1351     png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1352 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_vsx,(png_row_infop
1353     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1354 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_vsx,(png_row_infop
1355     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1356 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_vsx,(png_row_infop
1357     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1358 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_vsx,(png_row_infop
1359     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1360 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_vsx,(png_row_infop
1361     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1362 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_vsx,(png_row_infop
1363     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1364 #endif
1365 
1366 #if PNG_INTEL_SSE_IMPLEMENTATION > 0
1367 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
1368     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1369 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
1370     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1371 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
1372     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1373 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
1374     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1375 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
1376     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1377 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
1378     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1379 #endif
1380 
1381 /* Choose the best filter to use and filter the row data */
1382 PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1383     png_row_infop row_info),PNG_EMPTY);
1384 
1385 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1386 PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1387    png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1388    /* Read 'avail_out' bytes of data from the IDAT stream.  If the output buffer
1389     * is NULL the function checks, instead, for the end of the stream.  In this
1390     * case a benign error will be issued if the stream end is not found or if
1391     * extra data has to be consumed.
1392     */
1393 PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1394    PNG_EMPTY);
1395    /* This cleans up when the IDAT LZ stream does not end when the last image
1396     * byte is read; there is still some pending input.
1397     */
1398 
1399 PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1400    PNG_EMPTY);
1401    /* Finish a row while reading, dealing with interlacing passes, etc. */
1402 #endif /* SEQUENTIAL_READ */
1403 
1404 /* Initialize the row buffers, etc. */
1405 PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1406 
1407 #if ZLIB_VERNUM >= 0x1240
1408 PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
1409       PNG_EMPTY);
1410 #  define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
1411 #else /* Zlib < 1.2.4 */
1412 #  define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
1413 #endif /* Zlib < 1.2.4 */
1414 
1415 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1416 /* Optional call to update the users info structure */
1417 PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1418     png_inforp info_ptr),PNG_EMPTY);
1419 #endif
1420 
1421 /* Shared transform functions, defined in pngtran.c */
1422 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1423     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1424 PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1425     png_bytep row, int at_start),PNG_EMPTY);
1426 #endif
1427 
1428 #ifdef PNG_16BIT_SUPPORTED
1429 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1430 PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1431     png_bytep row),PNG_EMPTY);
1432 #endif
1433 #endif
1434 
1435 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1436     defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1437 PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1438     png_bytep row),PNG_EMPTY);
1439 #endif
1440 
1441 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1442 PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1443     png_bytep row),PNG_EMPTY);
1444 #endif
1445 
1446 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1447 PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1448     png_bytep row),PNG_EMPTY);
1449 #endif
1450 
1451 /* The following decodes the appropriate chunks, and does error correction,
1452  * then calls the appropriate callback for the chunk if it is valid.
1453  */
1454 
1455 /* Decode the IHDR chunk */
1456 PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1457     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1458 PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1459     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1460 PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1461     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1462 
1463 #ifdef PNG_READ_bKGD_SUPPORTED
1464 PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1465     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1466 #endif
1467 
1468 #ifdef PNG_READ_cHRM_SUPPORTED
1469 PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1470     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1471 #endif
1472 
1473 #ifdef PNG_READ_eXIf_SUPPORTED
1474 PNG_INTERNAL_FUNCTION(void,png_handle_eXIf,(png_structrp png_ptr,
1475     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1476 #endif
1477 
1478 #ifdef PNG_READ_gAMA_SUPPORTED
1479 PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1480     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1481 #endif
1482 
1483 #ifdef PNG_READ_hIST_SUPPORTED
1484 PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1485     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1486 #endif
1487 
1488 #ifdef PNG_READ_iCCP_SUPPORTED
1489 PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1490     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1491 #endif /* READ_iCCP */
1492 
1493 #ifdef PNG_READ_iTXt_SUPPORTED
1494 PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1495     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1496 #endif
1497 
1498 #ifdef PNG_READ_oFFs_SUPPORTED
1499 PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1500     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1501 #endif
1502 
1503 #ifdef PNG_READ_pCAL_SUPPORTED
1504 PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1505     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1506 #endif
1507 
1508 #ifdef PNG_READ_pHYs_SUPPORTED
1509 PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1510     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1511 #endif
1512 
1513 #ifdef PNG_READ_sBIT_SUPPORTED
1514 PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1515     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1516 #endif
1517 
1518 #ifdef PNG_READ_sCAL_SUPPORTED
1519 PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1520     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1521 #endif
1522 
1523 #ifdef PNG_READ_sPLT_SUPPORTED
1524 PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1525     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1526 #endif /* READ_sPLT */
1527 
1528 #ifdef PNG_READ_sRGB_SUPPORTED
1529 PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1530     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1531 #endif
1532 
1533 #ifdef PNG_READ_tEXt_SUPPORTED
1534 PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1535     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1536 #endif
1537 
1538 #ifdef PNG_READ_tIME_SUPPORTED
1539 PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1540     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1541 #endif
1542 
1543 #ifdef PNG_READ_tRNS_SUPPORTED
1544 PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1545     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1546 #endif
1547 
1548 #ifdef PNG_READ_zTXt_SUPPORTED
1549 PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1550     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1551 #endif
1552 
1553 PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_const_structrp png_ptr,
1554     png_uint_32 chunk_name),PNG_EMPTY);
1555 
1556 PNG_INTERNAL_FUNCTION(void,png_check_chunk_length,(png_const_structrp png_ptr,
1557     png_uint_32 chunk_length),PNG_EMPTY);
1558 
1559 PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1560     png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1561    /* This is the function that gets called for unknown chunks.  The 'keep'
1562     * argument is either non-zero for a known chunk that has been set to be
1563     * handled as unknown or zero for an unknown chunk.  By default the function
1564     * just skips the chunk or errors out if it is critical.
1565     */
1566 
1567 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
1568     defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1569 PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1570     (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1571    /* Exactly as the API png_handle_as_unknown() except that the argument is a
1572     * 32-bit chunk name, not a string.
1573     */
1574 #endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
1575 
1576 /* Handle the transformations for reading and writing */
1577 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1578 PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1579    png_row_infop row_info),PNG_EMPTY);
1580 #endif
1581 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1582 PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1583    png_row_infop row_info),PNG_EMPTY);
1584 #endif
1585 
1586 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1587 PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1588     PNG_EMPTY);
1589 #endif
1590 
1591 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1592 PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1593     png_inforp info_ptr),PNG_EMPTY);
1594 PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1595     png_inforp info_ptr),PNG_EMPTY);
1596 PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1597 PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1598     PNG_EMPTY);
1599 PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1600     png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1601 PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1602 PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1603     png_bytep buffer, size_t buffer_length),PNG_EMPTY);
1604 PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1605     PNG_EMPTY);
1606 PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1607    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1608 PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1609    png_inforp info_ptr),PNG_EMPTY);
1610 PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1611    png_inforp info_ptr),PNG_EMPTY);
1612 PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1613     png_bytep row),PNG_EMPTY);
1614 PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1615     png_inforp info_ptr),PNG_EMPTY);
1616 PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1617     png_inforp info_ptr),PNG_EMPTY);
1618 PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1619     PNG_EMPTY);
1620 #  ifdef PNG_READ_tEXt_SUPPORTED
1621 PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1622     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1623 PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1624     png_inforp info_ptr),PNG_EMPTY);
1625 #  endif
1626 #  ifdef PNG_READ_zTXt_SUPPORTED
1627 PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1628     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1629 PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1630     png_inforp info_ptr),PNG_EMPTY);
1631 #  endif
1632 #  ifdef PNG_READ_iTXt_SUPPORTED
1633 PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1634     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1635 PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1636     png_inforp info_ptr),PNG_EMPTY);
1637 #  endif
1638 
1639 #endif /* PROGRESSIVE_READ */
1640 
1641 /* Added at libpng version 1.6.0 */
1642 #ifdef PNG_GAMMA_SUPPORTED
1643 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1644     png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1645    /* Set the colorspace gamma with a value provided by the application or by
1646     * the gAMA chunk on read.  The value will override anything set by an ICC
1647     * profile.
1648     */
1649 
1650 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1651     png_inforp info_ptr), PNG_EMPTY);
1652    /* Synchronize the info 'valid' flags with the colorspace */
1653 
1654 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1655     png_inforp info_ptr), PNG_EMPTY);
1656    /* Copy the png_struct colorspace to the info_struct and call the above to
1657     * synchronize the flags.  Checks for NULL info_ptr and does nothing.
1658     */
1659 #endif
1660 
1661 /* Added at libpng version 1.4.0 */
1662 #ifdef PNG_COLORSPACE_SUPPORTED
1663 /* These internal functions are for maintaining the colorspace structure within
1664  * a png_info or png_struct (or, indeed, both).
1665  */
1666 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1667    (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1668     int preferred), PNG_EMPTY);
1669 
1670 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1671    (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1672     int preferred), PNG_EMPTY);
1673 
1674 #ifdef PNG_sRGB_SUPPORTED
1675 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1676    png_colorspacerp colorspace, int intent), PNG_EMPTY);
1677    /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1678     * flags to write them, if it returns false there was a problem and an error
1679     * message has already been output (but the colorspace may still need to be
1680     * synced to record the invalid flag).
1681     */
1682 #endif /* sRGB */
1683 
1684 #ifdef PNG_iCCP_SUPPORTED
1685 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1686    png_colorspacerp colorspace, png_const_charp name,
1687    png_uint_32 profile_length, png_const_bytep profile, int color_type),
1688    PNG_EMPTY);
1689    /* The 'name' is used for information only */
1690 
1691 /* Routines for checking parts of an ICC profile. */
1692 #ifdef PNG_READ_iCCP_SUPPORTED
1693 PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1694    png_colorspacerp colorspace, png_const_charp name,
1695    png_uint_32 profile_length), PNG_EMPTY);
1696 #endif /* READ_iCCP */
1697 PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1698    png_colorspacerp colorspace, png_const_charp name,
1699    png_uint_32 profile_length,
1700    png_const_bytep profile /* first 132 bytes only */, int color_type),
1701    PNG_EMPTY);
1702 PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1703    png_colorspacerp colorspace, png_const_charp name,
1704    png_uint_32 profile_length,
1705    png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1706 #ifdef PNG_sRGB_SUPPORTED
1707 PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1708    png_const_structrp png_ptr, png_colorspacerp colorspace,
1709    png_const_bytep profile, uLong adler), PNG_EMPTY);
1710    /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1711     * be zero to indicate that it is not available.  It is used, if provided,
1712     * as a fast check on the profile when checking to see if it is sRGB.
1713     */
1714 #endif
1715 #endif /* iCCP */
1716 
1717 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1718 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1719    (png_structrp png_ptr), PNG_EMPTY);
1720    /* Set the rgb_to_gray coefficients from the colorspace Y values */
1721 #endif /* READ_RGB_TO_GRAY */
1722 #endif /* COLORSPACE */
1723 
1724 /* Added at libpng version 1.4.0 */
1725 PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1726     png_uint_32 width, png_uint_32 height, int bit_depth,
1727     int color_type, int interlace_type, int compression_type,
1728     int filter_type),PNG_EMPTY);
1729 
1730 /* Added at libpng version 1.5.10 */
1731 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1732     defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1733 PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1734    (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1735 #endif
1736 
1737 #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1738 PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1739    png_const_charp name),PNG_NORETURN);
1740 #endif
1741 
1742 /* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1743  * the end.  Always leaves the buffer nul terminated.  Never errors out (and
1744  * there is no error code.)
1745  */
1746 PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1747    size_t pos, png_const_charp string),PNG_EMPTY);
1748 
1749 /* Various internal functions to handle formatted warning messages, currently
1750  * only implemented for warnings.
1751  */
1752 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1753 /* Utility to dump an unsigned value into a buffer, given a start pointer and
1754  * and end pointer (which should point just *beyond* the end of the buffer!)
1755  * Returns the pointer to the start of the formatted string.  This utility only
1756  * does unsigned values.
1757  */
1758 PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1759    png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1760 
1761 /* Convenience macro that takes an array: */
1762 #define PNG_FORMAT_NUMBER(buffer,format,number) \
1763    png_format_number(buffer, buffer + (sizeof buffer), format, number)
1764 
1765 /* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1766 #define PNG_NUMBER_BUFFER_SIZE 24
1767 
1768 /* These are the integer formats currently supported, the name is formed from
1769  * the standard printf(3) format string.
1770  */
1771 #define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
1772 #define PNG_NUMBER_FORMAT_02u   2
1773 #define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
1774 #define PNG_NUMBER_FORMAT_02d   2
1775 #define PNG_NUMBER_FORMAT_x     3
1776 #define PNG_NUMBER_FORMAT_02x   4
1777 #define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1778 #endif
1779 
1780 #ifdef PNG_WARNINGS_SUPPORTED
1781 /* New defines and members adding in libpng-1.5.4 */
1782 #  define PNG_WARNING_PARAMETER_SIZE 32
1783 #  define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1784 
1785 /* An l-value of this type has to be passed to the APIs below to cache the
1786  * values of the parameters to a formatted warning message.
1787  */
1788 typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1789    PNG_WARNING_PARAMETER_SIZE];
1790 
1791 PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1792    int number, png_const_charp string),PNG_EMPTY);
1793    /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1794     * including the trailing '\0'.
1795     */
1796 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1797    (png_warning_parameters p, int number, int format, png_alloc_size_t value),
1798    PNG_EMPTY);
1799    /* Use png_alloc_size_t because it is an unsigned type as big as any we
1800     * need to output.  Use the following for a signed value.
1801     */
1802 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1803    (png_warning_parameters p, int number, int format, png_int_32 value),
1804    PNG_EMPTY);
1805 
1806 PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1807    png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1808    /* 'message' follows the X/Open approach of using @1, @2 to insert
1809     * parameters previously supplied using the above functions.  Errors in
1810     * specifying the parameters will simply result in garbage substitutions.
1811     */
1812 #endif
1813 
1814 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1815 /* Application errors (new in 1.6); use these functions (declared below) for
1816  * errors in the parameters or order of API function calls on read.  The
1817  * 'warning' should be used for an error that can be handled completely; the
1818  * 'error' for one which can be handled safely but which may lose application
1819  * information or settings.
1820  *
1821  * By default these both result in a png_error call prior to release, while in a
1822  * released version the 'warning' is just a warning.  However if the application
1823  * explicitly disables benign errors (explicitly permitting the code to lose
1824  * information) they both turn into warnings.
1825  *
1826  * If benign errors aren't supported they end up as the corresponding base call
1827  * (png_warning or png_error.)
1828  */
1829 PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1830    png_const_charp message),PNG_EMPTY);
1831    /* The application provided invalid parameters to an API function or called
1832     * an API function at the wrong time, libpng can completely recover.
1833     */
1834 
1835 PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1836    png_const_charp message),PNG_EMPTY);
1837    /* As above but libpng will ignore the call, or attempt some other partial
1838     * recovery from the error.
1839     */
1840 #else
1841 #  define png_app_warning(pp,s) png_warning(pp,s)
1842 #  define png_app_error(pp,s) png_error(pp,s)
1843 #endif
1844 
1845 PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1846    png_const_charp message, int error),PNG_EMPTY);
1847    /* Report a recoverable issue in chunk data.  On read this is used to report
1848     * a problem found while reading a particular chunk and the
1849     * png_chunk_benign_error or png_chunk_warning function is used as
1850     * appropriate.  On write this is used to report an error that comes from
1851     * data set via an application call to a png_set_ API and png_app_error or
1852     * png_app_warning is used as appropriate.
1853     *
1854     * The 'error' parameter must have one of the following values:
1855     */
1856 #define PNG_CHUNK_WARNING     0 /* never an error */
1857 #define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1858 #define PNG_CHUNK_ERROR       2 /* always an error */
1859 
1860 /* ASCII to FP interfaces, currently only implemented if sCAL
1861  * support is required.
1862  */
1863 #if defined(PNG_sCAL_SUPPORTED)
1864 /* MAX_DIGITS is actually the maximum number of characters in an sCAL
1865  * width or height, derived from the precision (number of significant
1866  * digits - a build time settable option) and assumptions about the
1867  * maximum ridiculous exponent.
1868  */
1869 #define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1870 
1871 #ifdef PNG_FLOATING_POINT_SUPPORTED
1872 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1873    png_charp ascii, size_t size, double fp, unsigned int precision),
1874    PNG_EMPTY);
1875 #endif /* FLOATING_POINT */
1876 
1877 #ifdef PNG_FIXED_POINT_SUPPORTED
1878 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1879    png_charp ascii, size_t size, png_fixed_point fp),PNG_EMPTY);
1880 #endif /* FIXED_POINT */
1881 #endif /* sCAL */
1882 
1883 #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1884 /* An internal API to validate the format of a floating point number.
1885  * The result is the index of the next character.  If the number is
1886  * not valid it will be the index of a character in the supposed number.
1887  *
1888  * The format of a number is defined in the PNG extensions specification
1889  * and this API is strictly conformant to that spec, not anyone elses!
1890  *
1891  * The format as a regular expression is:
1892  *
1893  * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1894  *
1895  * or:
1896  *
1897  * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1898  *
1899  * The complexity is that either integer or fraction must be present and the
1900  * fraction is permitted to have no digits only if the integer is present.
1901  *
1902  * NOTE: The dangling E problem.
1903  *   There is a PNG valid floating point number in the following:
1904  *
1905  *       PNG floating point numbers are not greedy.
1906  *
1907  *   Working this out requires *TWO* character lookahead (because of the
1908  *   sign), the parser does not do this - it will fail at the 'r' - this
1909  *   doesn't matter for PNG sCAL chunk values, but it requires more care
1910  *   if the value were ever to be embedded in something more complex.  Use
1911  *   ANSI-C strtod if you need the lookahead.
1912  */
1913 /* State table for the parser. */
1914 #define PNG_FP_INTEGER    0  /* before or in integer */
1915 #define PNG_FP_FRACTION   1  /* before or in fraction */
1916 #define PNG_FP_EXPONENT   2  /* before or in exponent */
1917 #define PNG_FP_STATE      3  /* mask for the above */
1918 #define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
1919 #define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
1920 #define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
1921 #define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
1922 #define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
1923 
1924 /* These three values don't affect the parser.  They are set but not used.
1925  */
1926 #define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
1927 #define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
1928 #define PNG_FP_NONZERO  256  /* A non-zero value */
1929 #define PNG_FP_STICKY   448  /* The above three flags */
1930 
1931 /* This is available for the caller to store in 'state' if required.  Do not
1932  * call the parser after setting it (the parser sometimes clears it.)
1933  */
1934 #define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
1935 
1936 /* Result codes for the parser (boolean - true meants ok, false means
1937  * not ok yet.)
1938  */
1939 #define PNG_FP_MAYBE      0  /* The number may be valid in the future */
1940 #define PNG_FP_OK         1  /* The number is valid */
1941 
1942 /* Tests on the sticky non-zero and negative flags.  To pass these checks
1943  * the state must also indicate that the whole number is valid - this is
1944  * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1945  * is equivalent to PNG_FP_OK above.)
1946  */
1947 #define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1948    /* NZ_MASK: the string is valid and a non-zero negative value */
1949 #define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1950    /* Z MASK: the string is valid and a non-zero value. */
1951    /* PNG_FP_SAW_DIGIT: the string is valid. */
1952 #define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1953 #define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1954 #define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1955 
1956 /* The actual parser.  This can be called repeatedly. It updates
1957  * the index into the string and the state variable (which must
1958  * be initialized to 0).  It returns a result code, as above.  There
1959  * is no point calling the parser any more if it fails to advance to
1960  * the end of the string - it is stuck on an invalid character (or
1961  * terminated by '\0').
1962  *
1963  * Note that the pointer will consume an E or even an E+ and then leave
1964  * a 'maybe' state even though a preceding integer.fraction is valid.
1965  * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1966  * a valid number.  It's possible to recover from this by calling
1967  * the parser again (from the start, with state 0) but with a string
1968  * that omits the last character (i.e. set the size to the index of
1969  * the problem character.)  This has not been tested within libpng.
1970  */
1971 PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
1972    size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
1973 
1974 /* This is the same but it checks a complete string and returns true
1975  * only if it just contains a floating point number.  As of 1.5.4 this
1976  * function also returns the state at the end of parsing the number if
1977  * it was valid (otherwise it returns 0.)  This can be used for testing
1978  * for negative or zero values using the sticky flag.
1979  */
1980 PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
1981    size_t size),PNG_EMPTY);
1982 #endif /* pCAL || sCAL */
1983 
1984 #if defined(PNG_GAMMA_SUPPORTED) ||\
1985     defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1986 /* Added at libpng version 1.5.0 */
1987 /* This is a utility to provide a*times/div (rounded) and indicate
1988  * if there is an overflow.  The result is a boolean - false (0)
1989  * for overflow, true (1) if no overflow, in which case *res
1990  * holds the result.
1991  */
1992 PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
1993    png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
1994 #endif
1995 
1996 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1997 /* Same deal, but issue a warning on overflow and return 0. */
1998 PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
1999    (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
2000    png_int_32 divided_by),PNG_EMPTY);
2001 #endif
2002 
2003 #ifdef PNG_GAMMA_SUPPORTED
2004 /* Calculate a reciprocal - used for gamma values.  This returns
2005  * 0 if the argument is 0 in order to maintain an undefined value;
2006  * there are no warnings.
2007  */
2008 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
2009    PNG_EMPTY);
2010 
2011 #ifdef PNG_READ_GAMMA_SUPPORTED
2012 /* The same but gives a reciprocal of the product of two fixed point
2013  * values.  Accuracy is suitable for gamma calculations but this is
2014  * not exact - use png_muldiv for that.  Only required at present on read.
2015  */
2016 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
2017    png_fixed_point b),PNG_EMPTY);
2018 #endif
2019 
2020 /* Return true if the gamma value is significantly different from 1.0 */
2021 PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
2022    PNG_EMPTY);
2023 #endif
2024 
2025 #ifdef PNG_READ_GAMMA_SUPPORTED
2026 /* Internal fixed point gamma correction.  These APIs are called as
2027  * required to convert single values - they don't need to be fast,
2028  * they are not used when processing image pixel values.
2029  *
2030  * While the input is an 'unsigned' value it must actually be the
2031  * correct bit value - 0..255 or 0..65535 as required.
2032  */
2033 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
2034    unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
2035 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
2036    png_fixed_point gamma_value),PNG_EMPTY);
2037 PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
2038    png_fixed_point gamma_value),PNG_EMPTY);
2039 PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
2040    PNG_EMPTY);
2041 PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
2042    int bit_depth),PNG_EMPTY);
2043 #endif
2044 
2045 /* SIMPLIFIED READ/WRITE SUPPORT */
2046 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
2047    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2048 /* The internal structure that png_image::opaque points to. */
2049 typedef struct png_control
2050 {
2051    png_structp png_ptr;
2052    png_infop   info_ptr;
2053    png_voidp   error_buf;           /* Always a jmp_buf at present. */
2054 
2055    png_const_bytep memory;          /* Memory buffer. */
2056    size_t          size;            /* Size of the memory buffer. */
2057 
2058    unsigned int for_write       :1; /* Otherwise it is a read structure */
2059    unsigned int owned_file      :1; /* We own the file in io_ptr */
2060 } png_control;
2061 
2062 /* Return the pointer to the jmp_buf from a png_control: necessary because C
2063  * does not reveal the type of the elements of jmp_buf.
2064  */
2065 #ifdef __cplusplus
2066 #  define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
2067 #else
2068 #  define png_control_jmp_buf(pc) ((pc)->error_buf)
2069 #endif
2070 
2071 /* Utility to safely execute a piece of libpng code catching and logging any
2072  * errors that might occur.  Returns true on success, false on failure (either
2073  * of the function or as a result of a png_error.)
2074  */
2075 PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
2076    png_const_charp error_message),PNG_NORETURN);
2077 
2078 #ifdef PNG_WARNINGS_SUPPORTED
2079 PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
2080    png_const_charp warning_message),PNG_EMPTY);
2081 #else
2082 #  define png_safe_warning 0/*dummy argument*/
2083 #endif
2084 
2085 PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
2086    int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
2087 
2088 /* Utility to log an error; this also cleans up the png_image; the function
2089  * always returns 0 (false).
2090  */
2091 PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
2092    png_const_charp error_message),PNG_EMPTY);
2093 
2094 #ifndef PNG_SIMPLIFIED_READ_SUPPORTED
2095 /* png_image_free is used by the write code but not exported */
2096 PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
2097 #endif /* !SIMPLIFIED_READ */
2098 
2099 #endif /* SIMPLIFIED READ/WRITE */
2100 
2101 /* These are initialization functions for hardware specific PNG filter
2102  * optimizations; list these here then select the appropriate one at compile
2103  * time using the macro PNG_FILTER_OPTIMIZATIONS.  If the macro is not defined
2104  * the generic code is used.
2105  */
2106 #ifdef PNG_FILTER_OPTIMIZATIONS
2107 PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
2108    unsigned int bpp), PNG_EMPTY);
2109    /* Just declare the optimization that will be used */
2110 #else
2111    /* List *all* the possible optimizations here - this branch is required if
2112     * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
2113     * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
2114     */
2115 #  if PNG_ARM_NEON_OPT > 0
2116 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
2117    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2118 #endif
2119 
2120 #if PNG_MIPS_MSA_OPT > 0
2121 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_msa,
2122    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2123 #endif
2124 
2125 #  if PNG_INTEL_SSE_IMPLEMENTATION > 0
2126 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
2127    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2128 #  endif
2129 #endif
2130 
2131 PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
2132    png_const_charp key, png_bytep new_key), PNG_EMPTY);
2133 
2134 #if PNG_ARM_NEON_IMPLEMENTATION == 1
2135 PNG_INTERNAL_FUNCTION(void,
2136                       png_riffle_palette_neon,
2137                       (png_structrp),
2138                       PNG_EMPTY);
2139 PNG_INTERNAL_FUNCTION(int,
2140                       png_do_expand_palette_rgba8_neon,
2141                       (png_structrp,
2142                        png_row_infop,
2143                        png_const_bytep,
2144                        const png_bytepp,
2145                        const png_bytepp),
2146                       PNG_EMPTY);
2147 PNG_INTERNAL_FUNCTION(int,
2148                       png_do_expand_palette_rgb8_neon,
2149                       (png_structrp,
2150                        png_row_infop,
2151                        png_const_bytep,
2152                        const png_bytepp,
2153                        const png_bytepp),
2154                       PNG_EMPTY);
2155 #endif
2156 
2157 /* Maintainer: Put new private prototypes here ^ */
2158 
2159 #include "pngdebug.h"
2160 
2161 #ifdef __cplusplus
2162 }
2163 #endif
2164 
2165 #endif /* PNG_VERSION_INFO_ONLY */
2166 #endif /* PNGPRIV_H */
2167