1 
2 /* pngpriv.h - private declarations for use inside libpng
3  *
4  * For conditions of distribution and use, see copyright notice in png.h
5  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
6  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8  *
9  * Last changed in libpng 1.6.3 [July 18, 2013]
10  *
11  * This code is released under the libpng license.
12  * For conditions of distribution and use, see the disclaimer
13  * and license in png.h
14  */
15 
16 /* The symbols declared in this file (including the functions declared
17  * as extern) are PRIVATE.  They are not part of the libpng public
18  * interface, and are not recommended for use by regular applications.
19  * Some of them may become public in the future; others may stay private,
20  * change in an incompatible way, or even disappear.
21  * Although the libpng users are not forbidden to include this header,
22  * they should be well aware of the issues that may arise from doing so.
23  */
24 
25 #ifndef PNGPRIV_H
26 #define PNGPRIV_H
27 
28 /* Feature Test Macros.  The following are defined here to ensure that correctly
29  * implemented libraries reveal the APIs libpng needs to build and hide those
30  * that are not needed and potentially damaging to the compilation.
31  *
32  * Feature Test Macros must be defined before any system header is included (see
33  * POSIX 1003.1 2.8.2 "POSIX Symbols."
34  *
35  * These macros only have an effect if the operating system supports either
36  * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
37  * Windows/Visual Studio) there is no effect; the OS specific tests below are
38  * still required (as of 2011-05-02.)
39  */
40 #define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
41 
42 #ifndef PNG_VERSION_INFO_ONLY
43 /* Standard library headers not required by png.h: */
44 #  include <stdlib.h>
45 #  include <string.h>
46 #endif
47 
48 #define PNGLIB_BUILD /*libpng is being built, not used*/
49 
50 /* If HAVE_CONFIG_H is defined during the build then the build system must
51  * provide an appropriate "config.h" file on the include path.  The header file
52  * must provide definitions as required below (search for "HAVE_CONFIG_H");
53  * see configure.ac for more details of the requirements.  The macro
54  * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
55  * 'configure'; define this macro to prevent the configure build including the
56  * configure generated config.h.  Libpng is expected to compile without *any*
57  * special build system support on a reasonably ANSI-C compliant system.
58  */
59 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
60 #  include <config.h>
61 
62    /* Pick up the definition of 'restrict' from config.h if it was read: */
63 #  define PNG_RESTRICT restrict
64 #endif
65 
66 /* To support symbol prefixing it is necessary to know *before* including png.h
67  * whether the fixed point (and maybe other) APIs are exported, because if they
68  * are not internal definitions may be required.  This is handled below just
69  * before png.h is included, but load the configuration now if it is available.
70  */
71 #ifndef PNGLCONF_H
72 #  include "pnglibconf.h"
73 #endif
74 
75 /* Local renames may change non-exported API functions from png.h */
76 #if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
77 #  include "pngprefix.h"
78 #endif
79 
80 #ifdef PNG_USER_CONFIG
81 #  include "pngusr.h"
82    /* These should have been defined in pngusr.h */
83 #  ifndef PNG_USER_PRIVATEBUILD
84 #    define PNG_USER_PRIVATEBUILD "Custom libpng build"
85 #  endif
86 #  ifndef PNG_USER_DLLFNAME_POSTFIX
87 #    define PNG_USER_DLLFNAME_POSTFIX "Cb"
88 #  endif
89 #endif
90 
91 /* Compile time options.
92  * =====================
93  * In a multi-arch build the compiler may compile the code several times for the
94  * same object module, producing different binaries for different architectures.
95  * When this happens configure-time setting of the target host options cannot be
96  * done and this interferes with the handling of the ARM NEON optimizations, and
97  * possibly other similar optimizations.  Put additional tests here; in general
98  * this is needed when the same option can be changed at both compile time and
99  * run time depending on the target OS (i.e. iOS vs Android.)
100  *
101  * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
102  * this is not possible with certain compilers (Oracle SUN OS CC), as a result
103  * it is necessary to ensure that all extern functions that *might* be used
104  * regardless of $(CFLAGS) get declared in this file.  The test on __ARM_NEON__
105  * below is one example of this behavior because it is controlled by the
106  * presence or not of -mfpu=neon on the GCC command line, it is possible to do
107  * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
108  * do this.
109  */
110 /*
111  * pdfium: This version of libpng does not contain the arm neon optimized code
112  * so we should never try to reference it.
113  */
114 #if 0
115 #ifndef PNG_ARM_NEON_OPT
116    /* ARM NEON optimizations are being controlled by the compiler settings,
117     * typically the target FPU.  If the FPU has been set to NEON (-mfpu=neon
118     * with GCC) then the compiler will define __ARM_NEON__ and we can rely
119     * unconditionally on NEON instructions not crashing, otherwise we must
120     * disable use of NEON instructions:
121     */
122 #  ifdef __ARM_NEON__
123 #     define PNG_ARM_NEON_OPT 2
124 #  else
125 #     define PNG_ARM_NEON_OPT 0
126 #  endif
127 #endif
128 
129 #if PNG_ARM_NEON_OPT > 0
130    /* NEON optimizations are to be at least considered by libpng, so enable the
131     * callbacks to do this.
132     */
133 #  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
134 #endif
135 #endif
136 
137 /* Is this a build of a DLL where compilation of the object modules requires
138  * different preprocessor settings to those required for a simple library?  If
139  * so PNG_BUILD_DLL must be set.
140  *
141  * If libpng is used inside a DLL but that DLL does not export the libpng APIs
142  * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
143  * static library of libpng then link the DLL against that.
144  */
145 #ifndef PNG_BUILD_DLL
146 #  ifdef DLL_EXPORT
147       /* This is set by libtool when files are compiled for a DLL; libtool
148        * always compiles twice, even on systems where it isn't necessary.  Set
149        * PNG_BUILD_DLL in case it is necessary:
150        */
151 #     define PNG_BUILD_DLL
152 #  else
153 #     ifdef _WINDLL
154          /* This is set by the Microsoft Visual Studio IDE in projects that
155           * build a DLL.  It can't easily be removed from those projects (it
156           * isn't visible in the Visual Studio UI) so it is a fairly reliable
157           * indication that PNG_IMPEXP needs to be set to the DLL export
158           * attributes.
159           */
160 #        define PNG_BUILD_DLL
161 #     else
162 #        ifdef __DLL__
163             /* This is set by the Borland C system when compiling for a DLL
164              * (as above.)
165              */
166 #           define PNG_BUILD_DLL
167 #        else
168             /* Add additional compiler cases here. */
169 #        endif
170 #     endif
171 #  endif
172 #endif /* Setting PNG_BUILD_DLL if required */
173 
174 /* See pngconf.h for more details: the builder of the library may set this on
175  * the command line to the right thing for the specific compilation system or it
176  * may be automagically set above (at present we know of no system where it does
177  * need to be set on the command line.)
178  *
179  * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
180  * setting it to the "import" setting for a DLL build.
181  */
182 #ifndef PNG_IMPEXP
183 #  ifdef PNG_BUILD_DLL
184 #     define PNG_IMPEXP PNG_DLL_EXPORT
185 #  else
186       /* Not building a DLL, or the DLL doesn't require specific export
187        * definitions.
188        */
189 #     define PNG_IMPEXP
190 #  endif
191 #endif
192 
193 /* No warnings for private or deprecated functions in the build: */
194 #ifndef PNG_DEPRECATED
195 #  define PNG_DEPRECATED
196 #endif
197 #ifndef PNG_PRIVATE
198 #  define PNG_PRIVATE
199 #endif
200 
201 /* Symbol preprocessing support.
202  *
203  * To enable listing global, but internal, symbols the following macros should
204  * always be used to declare an extern data or function object in this file.
205  */
206 #ifndef PNG_INTERNAL_DATA
207 #  define PNG_INTERNAL_DATA(type, name, array) extern type name array
208 #endif
209 
210 #ifndef PNG_INTERNAL_FUNCTION
211 #  define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
212       extern PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
213 #endif
214 
215 /* If floating or fixed point APIs are disabled they may still be compiled
216  * internally.  To handle this make sure they are declared as the appropriate
217  * internal extern function (otherwise the symbol prefixing stuff won't work and
218  * the functions will be used without definitions.)
219  *
220  * NOTE: although all the API functions are declared here they are not all
221  * actually built!  Because the declarations are still made it is necessary to
222  * fake out types that they depend on.
223  */
224 #ifndef PNG_FP_EXPORT
225 #  ifndef PNG_FLOATING_POINT_SUPPORTED
226 #     define PNG_FP_EXPORT(ordinal, type, name, args)\
227          PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
228 #     ifndef PNG_VERSION_INFO_ONLY
229          typedef struct png_incomplete png_double;
230          typedef png_double*           png_doublep;
231          typedef const png_double*     png_const_doublep;
232          typedef png_double**          png_doublepp;
233 #     endif
234 #  endif
235 #endif
236 #ifndef PNG_FIXED_EXPORT
237 #  ifndef PNG_FIXED_POINT_SUPPORTED
238 #     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
239          PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
240 #  endif
241 #endif
242 
243 #include "png.h"
244 
245 /* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
246 #ifndef PNG_DLL_EXPORT
247 #  define PNG_DLL_EXPORT
248 #endif
249 
250 /* SECURITY and SAFETY:
251  *
252  * By default libpng is built without any internal limits on image size,
253  * individual heap (png_malloc) allocations or the total amount of memory used.
254  * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
255  * (unless individually overridden).  These limits are believed to be fairly
256  * safe, but builders of secure systems should verify the values against the
257  * real system capabilities.
258  */
259 #ifdef PNG_SAFE_LIMITS_SUPPORTED
260    /* 'safe' limits */
261 #  ifndef PNG_USER_WIDTH_MAX
262 #     define PNG_USER_WIDTH_MAX 1000000
263 #  endif
264 #  ifndef PNG_USER_HEIGHT_MAX
265 #     define PNG_USER_HEIGHT_MAX 1000000
266 #  endif
267 #  ifndef PNG_USER_CHUNK_CACHE_MAX
268 #     define PNG_USER_CHUNK_CACHE_MAX 128
269 #  endif
270 #  ifndef PNG_USER_CHUNK_MALLOC_MAX
271 #     define PNG_USER_CHUNK_MALLOC_MAX 8000000
272 #  endif
273 #else
274    /* values for no limits */
275 #  ifndef PNG_USER_WIDTH_MAX
276 #     define PNG_USER_WIDTH_MAX 0x7fffffff
277 #  endif
278 #  ifndef PNG_USER_HEIGHT_MAX
279 #     define PNG_USER_HEIGHT_MAX 0x7fffffff
280 #  endif
281 #  ifndef PNG_USER_CHUNK_CACHE_MAX
282 #     define PNG_USER_CHUNK_CACHE_MAX 0
283 #  endif
284 #  ifndef PNG_USER_CHUNK_MALLOC_MAX
285 #     define PNG_USER_CHUNK_MALLOC_MAX 0
286 #  endif
287 #endif
288 
289 /* Moved to pngpriv.h at libpng-1.5.0 */
290 /* NOTE: some of these may have been used in external applications as
291  * these definitions were exposed in pngconf.h prior to 1.5.
292  */
293 
294 /* If you are running on a machine where you cannot allocate more
295  * than 64K of memory at once, uncomment this.  While libpng will not
296  * normally need that much memory in a chunk (unless you load up a very
297  * large file), zlib needs to know how big of a chunk it can use, and
298  * libpng thus makes sure to check any memory allocation to verify it
299  * will fit into memory.
300  *
301  * zlib provides 'MAXSEG_64K' which, if defined, indicates the
302  * same limit and pngconf.h (already included) sets the limit
303  * if certain operating systems are detected.
304  */
305 #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
306 #  define PNG_MAX_MALLOC_64K
307 #endif
308 
309 #ifndef PNG_UNUSED
310 /* Unused formal parameter warnings are silenced using the following macro
311  * which is expected to have no bad effects on performance (optimizing
312  * compilers will probably remove it entirely).  Note that if you replace
313  * it with something other than whitespace, you must include the terminating
314  * semicolon.
315  */
316 #  define PNG_UNUSED(param) (void)param;
317 #endif
318 
319 /* Just a little check that someone hasn't tried to define something
320  * contradictory.
321  */
322 #if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
323 #  undef PNG_ZBUF_SIZE
324 #  define PNG_ZBUF_SIZE 65536L
325 #endif
326 
327 /* If warnings or errors are turned off the code is disabled or redirected here.
328  * From 1.5.4 functions have been added to allow very limited formatting of
329  * error and warning messages - this code will also be disabled here.
330  */
331 #ifdef PNG_WARNINGS_SUPPORTED
332 #  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
333 #else
334 #  define png_warning(s1,s2) ((void)(s1))
335 #  define png_chunk_warning(s1,s2) ((void)(s1))
336 #  define png_warning_parameter(p,number,string) ((void)0)
337 #  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
338 #  define png_warning_parameter_signed(p,number,format,value) ((void)0)
339 #  define png_formatted_warning(pp,p,message) ((void)(pp))
340 #  define PNG_WARNING_PARAMETERS(p)
341 #endif
342 #ifndef PNG_ERROR_TEXT_SUPPORTED
343 #  define png_error(s1,s2) png_err(s1)
344 #  define png_chunk_error(s1,s2) png_err(s1)
345 #  define png_fixed_error(s1,s2) png_err(s1)
346 #endif
347 
348 /* C allows up-casts from (void*) to any pointer and (const void*) to any
349  * pointer to a const object.  C++ regards this as a type error and requires an
350  * explicit, static, cast and provides the static_cast<> rune to ensure that
351  * const is not cast away.
352  */
353 #ifdef __cplusplus
354 #  define png_voidcast(type, value) static_cast<type>(value)
355 #  define png_constcast(type, value) const_cast<type>(value)
356 #  define png_aligncast(type, value) \
357    static_cast<type>(static_cast<void*>(value))
358 #  define png_aligncastconst(type, value) \
359    static_cast<type>(static_cast<const void*>(value))
360 #else
361 #  define png_voidcast(type, value) (value)
362 #  define png_constcast(type, value) ((type)(value))
363 #  define png_aligncast(type, value) ((void*)(value))
364 #  define png_aligncastconst(type, value) ((const void*)(value))
365 #endif /* __cplusplus */
366 
367 /* Some fixed point APIs are still required even if not exported because
368  * they get used by the corresponding floating point APIs.  This magic
369  * deals with this:
370  */
371 #ifdef PNG_FIXED_POINT_SUPPORTED
372 #  define PNGFAPI PNGAPI
373 #else
374 #  define PNGFAPI /* PRIVATE */
375 #endif
376 
377 #ifndef PNG_VERSION_INFO_ONLY
378 /* Other defines specific to compilers can go here.  Try to keep
379  * them inside an appropriate ifdef/endif pair for portability.
380  */
381 #if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
382     defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
383    /* png.c requires the following ANSI-C constants if the conversion of
384     * floating point to ASCII is implemented therein:
385     *
386     *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
387     *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
388     *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
389     */
390 #  include <float.h>
391 
392 #  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
393     defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
394      /* We need to check that <math.h> hasn't already been included earlier
395       * as it seems it doesn't agree with <fp.h>, yet we should really use
396       * <fp.h> if possible.
397       */
398 #    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
399 #      include <fp.h>
400 #    endif
401 #  else
402 #    include <math.h>
403 #  endif
404 #  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
405      /* Amiga SAS/C: We must include builtin FPU functions when compiling using
406       * MATH=68881
407       */
408 #    include <m68881.h>
409 #  endif
410 #endif
411 
412 /* This provides the non-ANSI (far) memory allocation routines. */
413 #if defined(__TURBOC__) && defined(__MSDOS__)
414 #  include <mem.h>
415 #  include <alloc.h>
416 #endif
417 
418 #if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
419     defined(_WIN32) || defined(__WIN32__)
420 #  include <windows.h>  /* defines _WINDOWS_ macro */
421 #endif
422 #endif /* PNG_VERSION_INFO_ONLY */
423 
424 /* Moved here around 1.5.0beta36 from pngconf.h */
425 /* Users may want to use these so they are not private.  Any library
426  * functions that are passed far data must be model-independent.
427  */
428 
429 /* Memory model/platform independent fns */
430 #ifndef PNG_ABORT
431 #  ifdef _WINDOWS_
432 #    define PNG_ABORT() ExitProcess(0)
433 #  else
434 #    define PNG_ABORT() abort()
435 #  endif
436 #endif
437 
438 /* These macros may need to be architecture dependent. */
439 #define PNG_ALIGN_NONE   0 /* do not use data alignment */
440 #define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
441 #ifdef offsetof
442 #  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
443 #else
444 #  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
445 #endif
446 #define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
447 
448 #ifndef PNG_ALIGN_TYPE
449    /* Default to using aligned access optimizations and requiring alignment to a
450     * multiple of the data type size.  Override in a compiler specific fashion
451     * if necessary by inserting tests here:
452     */
453 #  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
454 #endif
455 
456 #if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
457    /* This is used because in some compiler implementations non-aligned
458     * structure members are supported, so the offsetof approach below fails.
459     * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
460     * is good for performance.  Do not do this unless you have tested the result
461     * and understand it.
462     */
463 #  define png_alignof(type) (sizeof (type))
464 #else
465 #  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
466 #     define png_alignof(type) offsetof(struct{char c; type t;}, t)
467 #  else
468 #     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
469 #        define png_alignof(type) (1)
470 #     endif
471       /* Else leave png_alignof undefined to prevent use thereof */
472 #  endif
473 #endif
474 
475 /* This implicitly assumes alignment is always to a power of 2. */
476 #ifdef png_alignof
477 #  define png_isaligned(ptr, type)\
478    ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
479 #else
480 #  define png_isaligned(ptr, type) 0
481 #endif
482 
483 /* End of memory model/platform independent support */
484 /* End of 1.5.0beta36 move from pngconf.h */
485 
486 /* CONSTANTS and UTILITY MACROS
487  * These are used internally by libpng and not exposed in the API
488  */
489 
490 /* Various modes of operation.  Note that after an init, mode is set to
491  * zero automatically when the structure is created.  Three of these
492  * are defined in png.h because they need to be visible to applications
493  * that call png_set_unknown_chunk().
494  */
495 /* #define PNG_HAVE_IHDR            0x01 (defined in png.h) */
496 /* #define PNG_HAVE_PLTE            0x02 (defined in png.h) */
497 #define PNG_HAVE_IDAT               0x04
498 /* #define PNG_AFTER_IDAT           0x08 (defined in png.h) */
499 #define PNG_HAVE_IEND               0x10
500                    /*               0x20 (unused) */
501                    /*               0x40 (unused) */
502                    /*               0x80 (unused) */
503 #define PNG_HAVE_CHUNK_HEADER      0x100
504 #define PNG_WROTE_tIME             0x200
505 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
506 #define PNG_BACKGROUND_IS_GRAY     0x800
507 #define PNG_HAVE_PNG_SIGNATURE    0x1000
508 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
509                    /*             0x4000 (unused) */
510 #define PNG_IS_READ_STRUCT        0x8000 /* Else is a write struct */
511 
512 /* Flags for the transformations the PNG library does on the image data */
513 #define PNG_BGR                 0x0001
514 #define PNG_INTERLACE           0x0002
515 #define PNG_PACK                0x0004
516 #define PNG_SHIFT               0x0008
517 #define PNG_SWAP_BYTES          0x0010
518 #define PNG_INVERT_MONO         0x0020
519 #define PNG_QUANTIZE            0x0040
520 #define PNG_COMPOSE             0x0080     /* Was PNG_BACKGROUND */
521 #define PNG_BACKGROUND_EXPAND   0x0100
522 #define PNG_EXPAND_16           0x0200     /* Added to libpng 1.5.2 */
523 #define PNG_16_TO_8             0x0400     /* Becomes 'chop' in 1.5.4 */
524 #define PNG_RGBA                0x0800
525 #define PNG_EXPAND              0x1000
526 #define PNG_GAMMA               0x2000
527 #define PNG_GRAY_TO_RGB         0x4000
528 #define PNG_FILLER              0x8000
529 #define PNG_PACKSWAP           0x10000
530 #define PNG_SWAP_ALPHA         0x20000
531 #define PNG_STRIP_ALPHA        0x40000
532 #define PNG_INVERT_ALPHA       0x80000
533 #define PNG_USER_TRANSFORM    0x100000
534 #define PNG_RGB_TO_GRAY_ERR   0x200000
535 #define PNG_RGB_TO_GRAY_WARN  0x400000
536 #define PNG_RGB_TO_GRAY       0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
537 #define PNG_ENCODE_ALPHA      0x800000 /* Added to libpng-1.5.4 */
538 #define PNG_ADD_ALPHA         0x1000000 /* Added to libpng-1.2.7 */
539 #define PNG_EXPAND_tRNS       0x2000000 /* Added to libpng-1.2.9 */
540 #define PNG_SCALE_16_TO_8     0x4000000 /* Added to libpng-1.5.4 */
541                        /*   0x8000000 unused */
542                        /*  0x10000000 unused */
543                        /*  0x20000000 unused */
544                        /*  0x40000000 unused */
545 /* Flags for png_create_struct */
546 #define PNG_STRUCT_PNG   0x0001
547 #define PNG_STRUCT_INFO  0x0002
548 
549 /* Scaling factor for filter heuristic weighting calculations */
550 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
551 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
552 
553 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
554 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
555 #define PNG_FLAG_ZSTREAM_INITIALIZED      0x0002 /* Added to libpng-1.6.0 */
556                                   /*      0x0004    unused */
557 #define PNG_FLAG_ZSTREAM_ENDED            0x0008 /* Added to libpng-1.6.0 */
558                                   /*      0x0010    unused */
559                                   /*      0x0020    unused */
560 #define PNG_FLAG_ROW_INIT                 0x0040
561 #define PNG_FLAG_FILLER_AFTER             0x0080
562 #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
563 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
564 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
565 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
566 #define PNG_FLAG_ASSUME_sRGB              0x1000 /* Added to libpng-1.5.4 */
567 #define PNG_FLAG_OPTIMIZE_ALPHA           0x2000 /* Added to libpng-1.5.4 */
568 #define PNG_FLAG_DETECT_UNINITIALIZED     0x4000 /* Added to libpng-1.5.4 */
569 /* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000 */
570 /* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS      0x10000 */
571 #define PNG_FLAG_LIBRARY_MISMATCH        0x20000
572 #define PNG_FLAG_STRIP_ERROR_NUMBERS     0x40000
573 #define PNG_FLAG_STRIP_ERROR_TEXT        0x80000
574 #define PNG_FLAG_BENIGN_ERRORS_WARN     0x100000 /* Added to libpng-1.4.0 */
575 #define PNG_FLAG_APP_WARNINGS_WARN      0x200000 /* Added to libpng-1.6.0 */
576 #define PNG_FLAG_APP_ERRORS_WARN        0x400000 /* Added to libpng-1.6.0 */
577                                   /*    0x800000    unused */
578                                   /*   0x1000000    unused */
579                                   /*   0x2000000    unused */
580                                   /*   0x4000000    unused */
581                                   /*   0x8000000    unused */
582                                   /*  0x10000000    unused */
583                                   /*  0x20000000    unused */
584                                   /*  0x40000000    unused */
585 
586 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
587                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
588 
589 #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
590                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
591 
592 #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
593                                      PNG_FLAG_CRC_CRITICAL_MASK)
594 
595 /* Save typing and make code easier to understand */
596 
597 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
598    abs((int)((c1).green) - (int)((c2).green)) + \
599    abs((int)((c1).blue) - (int)((c2).blue)))
600 
601 /* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
602  * by dividing by 257 *with rounding*.  This macro is exact for the given range.
603  * See the discourse in pngrtran.c png_do_scale_16_to_8.  The values in the
604  * macro were established by experiment (modifying the added value).  The macro
605  * has a second variant that takes a value already scaled by 255 and divides by
606  * 65535 - this has a maximum error of .502.  Over the range 0..65535*65535 it
607  * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
608  */
609 #define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
610 #define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
611 
612 /* Added to libpng-1.2.6 JB */
613 #define PNG_ROWBYTES(pixel_bits, width) \
614     ((pixel_bits) >= 8 ? \
615     ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
616     (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
617 
618 /* PNG_OUT_OF_RANGE returns true if value is outside the range
619  * ideal-delta..ideal+delta.  Each argument is evaluated twice.
620  * "ideal" and "delta" should be constants, normally simple
621  * integers, "value" a variable. Added to libpng-1.2.6 JB
622  */
623 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
624    ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
625 
626 /* Conversions between fixed and floating point, only defined if
627  * required (to make sure the code doesn't accidentally use float
628  * when it is supposedly disabled.)
629  */
630 #ifdef PNG_FLOATING_POINT_SUPPORTED
631 /* The floating point conversion can't overflow, though it can and
632  * does lose accuracy relative to the original fixed point value.
633  * In practice this doesn't matter because png_fixed_point only
634  * stores numbers with very low precision.  The png_ptr and s
635  * arguments are unused by default but are there in case error
636  * checking becomes a requirement.
637  */
638 #define png_float(png_ptr, fixed, s) (.00001 * (fixed))
639 
640 /* The fixed point conversion performs range checking and evaluates
641  * its argument multiple times, so must be used with care.  The
642  * range checking uses the PNG specification values for a signed
643  * 32 bit fixed point value except that the values are deliberately
644  * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
645  * (2^31-1) * 100000). 's' is a string that describes the value being
646  * converted.
647  *
648  * NOTE: this macro will raise a png_error if the range check fails,
649  * therefore it is normally only appropriate to use this on values
650  * that come from API calls or other sources where an out of range
651  * error indicates a programming error, not a data error!
652  *
653  * NOTE: by default this is off - the macro is not used - because the
654  * function call saves a lot of code.
655  */
656 #ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
657 #define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
658     ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
659 #endif
660 /* else the corresponding function is defined below, inside the scope of the
661  * cplusplus test.
662  */
663 #endif
664 
665 /* Constants for known chunk types.  If you need to add a chunk, define the name
666  * here.  For historical reasons these constants have the form png_<name>; i.e.
667  * the prefix is lower case.  Please use decimal values as the parameters to
668  * match the ISO PNG specification and to avoid relying on the C locale
669  * interpretation of character values.
670  *
671  * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
672  * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
673  * to be generated if required.
674  *
675  * PNG_32b correctly produces a value shifted by up to 24 bits, even on
676  * architectures where (int) is only 16 bits.
677  */
678 #define PNG_32b(b,s) ((png_uint_32)(b) << (s))
679 #define PNG_U32(b1,b2,b3,b4) \
680    (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
681 
682 /* Constants for known chunk types.
683  *
684  * MAINTAINERS: If you need to add a chunk, define the name here.
685  * For historical reasons these constants have the form png_<name>; i.e.
686  * the prefix is lower case.  Please use decimal values as the parameters to
687  * match the ISO PNG specification and to avoid relying on the C locale
688  * interpretation of character values.  Please keep the list sorted.
689  *
690  * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
691  * type.  In fact the specification does not express chunk types this way,
692  * however using a 32-bit value means that the chunk type can be read from the
693  * stream using exactly the same code as used for a 32-bit unsigned value and
694  * can be examined far more efficiently (using one arithmetic compare).
695  *
696  * Prior to 1.5.6 the chunk type constants were expressed as C strings.  The
697  * libpng API still uses strings for 'unknown' chunks and a macro,
698  * PNG_STRING_FROM_CHUNK, allows a string to be generated if required.  Notice
699  * that for portable code numeric values must still be used; the string "IHDR"
700  * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
701  *
702  * In 1.7.0 the definitions will be made public in png.h to avoid having to
703  * duplicate the same definitions in application code.
704  */
705 #define png_IDAT PNG_U32( 73,  68,  65,  84)
706 #define png_IEND PNG_U32( 73,  69,  78,  68)
707 #define png_IHDR PNG_U32( 73,  72,  68,  82)
708 #define png_PLTE PNG_U32( 80,  76,  84,  69)
709 #define png_bKGD PNG_U32( 98,  75,  71,  68)
710 #define png_cHRM PNG_U32( 99,  72,  82,  77)
711 #define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
712 #define png_gAMA PNG_U32(103,  65,  77,  65)
713 #define png_gIFg PNG_U32(103,  73,  70, 103)
714 #define png_gIFt PNG_U32(103,  73,  70, 116) /* deprecated */
715 #define png_gIFx PNG_U32(103,  73,  70, 120)
716 #define png_hIST PNG_U32(104,  73,  83,  84)
717 #define png_iCCP PNG_U32(105,  67,  67,  80)
718 #define png_iTXt PNG_U32(105,  84,  88, 116)
719 #define png_oFFs PNG_U32(111,  70,  70, 115)
720 #define png_pCAL PNG_U32(112,  67,  65,  76)
721 #define png_pHYs PNG_U32(112,  72,  89, 115)
722 #define png_sBIT PNG_U32(115,  66,  73,  84)
723 #define png_sCAL PNG_U32(115,  67,  65,  76)
724 #define png_sPLT PNG_U32(115,  80,  76,  84)
725 #define png_sRGB PNG_U32(115,  82,  71,  66)
726 #define png_sTER PNG_U32(115,  84,  69,  82)
727 #define png_tEXt PNG_U32(116,  69,  88, 116)
728 #define png_tIME PNG_U32(116,  73,  77,  69)
729 #define png_tRNS PNG_U32(116,  82,  78,  83)
730 #define png_zTXt PNG_U32(122,  84,  88, 116)
731 
732 /* The following will work on (signed char*) strings, whereas the get_uint_32
733  * macro will fail on top-bit-set values because of the sign extension.
734  */
735 #define PNG_CHUNK_FROM_STRING(s)\
736    PNG_U32(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
737 
738 /* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
739  * signed and the argument is a (char[])  This macro will fail miserably on
740  * systems where (char) is more than 8 bits.
741  */
742 #define PNG_STRING_FROM_CHUNK(s,c)\
743    (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
744    ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
745 
746 /* Do the same but terminate with a null character. */
747 #define PNG_CSTRING_FROM_CHUNK(s,c)\
748    (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
749 
750 /* Test on flag values as defined in the spec (section 5.4): */
751 #define PNG_CHUNK_ANCILLARY(c)   (1 & ((c) >> 29))
752 #define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLARY(c))
753 #define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
754 #define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
755 #define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
756 
757 /* Gamma values (new at libpng-1.5.4): */
758 #define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
759 #define PNG_GAMMA_MAC_INVERSE 65909
760 #define PNG_GAMMA_sRGB_INVERSE 45455
761 
762 /* Almost everything below is C specific; the #defines above can be used in
763  * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
764  */
765 #ifndef PNG_VERSION_INFO_ONLY
766 
767 #include "pngstruct.h"
768 #include "pnginfo.h"
769 
770 /* Validate the include paths - the include path used to generate pnglibconf.h
771  * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
772  */
773 #if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
774 #  error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
775       "-I (include path) error: see the notes in pngpriv.h"
776    /* This means that when pnglibconf.h was built the copy of zlib.h that it
777     * used is not the same as the one being used here.  Because the build of
778     * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
779     * zlib version number and because this affects handling of certain broken
780     * PNG files the -I directives must match.
781     *
782     * The most likely explanation is that you passed a -I in CFLAGS, this will
783     * not work; all the preprocessor directories and in particular all the -I
784     * directives must be in CPPFLAGS.
785     */
786 #endif
787 
788 /* This is used for 16 bit gamma tables -- only the top level pointers are
789  * const; this could be changed:
790  */
791 typedef const png_uint_16p * png_const_uint_16pp;
792 
793 /* Added to libpng-1.5.7: sRGB conversion tables */
794 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
795    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
796 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
797 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
798    /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
799     * 0..65535.  This table gives the closest 16-bit answers (no errors).
800     */
801 #endif
802 
803 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
804 PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
805 
806 #define PNG_sRGB_FROM_LINEAR(linear) ((png_byte)((png_sRGB_base[(linear)>>15] +\
807    ((((linear)&0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))
808    /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
809     * encoded value with maximum error 0.646365.  Note that the input is not a
810     * 16-bit value; it has been multiplied by 255! */
811 #endif /* PNG_SIMPLIFIED_READ/WRITE */
812 
813 
814 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
815 #ifdef __cplusplus
816 extern "C" {
817 #endif /* __cplusplus */
818 
819 /* Internal functions; these are not exported from a DLL however because they
820  * are used within several of the C source files they have to be C extern.
821  *
822  * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
823  */
824 
825 /* Zlib support */
826 #define PNG_UNEXPECTED_ZLIB_RETURN (-7)
827 PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
828    PNG_EMPTY);
829    /* Used by the zlib handling functions to ensure that z_stream::msg is always
830     * set before they return.
831     */
832 
833 #ifdef PNG_WRITE_SUPPORTED
834 PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
835    png_compression_bufferp *list),PNG_EMPTY);
836    /* Free the buffer list used by the compressed write code. */
837 #endif
838 
839 #if defined(PNG_FLOATING_POINT_SUPPORTED) && \
840    !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
841    (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
842    defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
843    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
844    (defined(PNG_sCAL_SUPPORTED) && \
845    defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
846 PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
847    double fp, png_const_charp text),PNG_EMPTY);
848 #endif
849 
850 /* Check the user version string for compatibility, returns false if the version
851  * numbers aren't compatible.
852  */
853 PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
854    png_const_charp user_png_ver),PNG_EMPTY);
855 
856 /* Internal base allocator - no messages, NULL on failure to allocate.  This
857  * does, however, call the application provided allocator and that could call
858  * png_error (although that would be a bug in the application implementation.)
859  */
860 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
861    png_alloc_size_t size),PNG_ALLOCATED);
862 
863 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
864    defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
865 /* Internal array allocator, outputs no error or warning messages on failure,
866  * just returns NULL.
867  */
868 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
869    int nelements, size_t element_size),PNG_ALLOCATED);
870 
871 /* The same but an existing array is extended by add_elements.  This function
872  * also memsets the new elements to 0 and copies the old elements.  The old
873  * array is not freed or altered.
874  */
875 PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
876    png_const_voidp array, int old_elements, int add_elements,
877    size_t element_size),PNG_ALLOCATED);
878 #endif /* text, sPLT or unknown chunks */
879 
880 /* Magic to create a struct when there is no struct to call the user supplied
881  * memory allocators.  Because error handling has not been set up the memory
882  * handlers can't safely call png_error, but this is an obscure and undocumented
883  * restriction so libpng has to assume that the 'free' handler, at least, might
884  * call png_error.
885  */
886 PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
887    (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
888     png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
889     png_free_ptr free_fn),PNG_ALLOCATED);
890 
891 /* Free memory from internal libpng struct */
892 PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
893    PNG_EMPTY);
894 
895 /* Free an allocated jmp_buf (always succeeds) */
896 PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
897 
898 /* Function to allocate memory for zlib.  PNGAPI is disallowed. */
899 PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
900    PNG_ALLOCATED);
901 
902 /* Function to free memory for zlib.  PNGAPI is disallowed. */
903 PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
904 
905 /* Next four functions are used internally as callbacks.  PNGCBAPI is required
906  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
907  * PNGCBAPI at 1.5.0
908  */
909 
910 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
911     png_bytep data, png_size_t length),PNG_EMPTY);
912 
913 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
914 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
915     png_bytep buffer, png_size_t length),PNG_EMPTY);
916 #endif
917 
918 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
919     png_bytep data, png_size_t length),PNG_EMPTY);
920 
921 #ifdef PNG_WRITE_FLUSH_SUPPORTED
922 #  ifdef PNG_STDIO_SUPPORTED
923 PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
924    PNG_EMPTY);
925 #  endif
926 #endif
927 
928 /* Reset the CRC variable */
929 PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
930 
931 /* Write the "data" buffer to whatever output you are using */
932 PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
933     png_const_bytep data, png_size_t length),PNG_EMPTY);
934 
935 /* Read and check the PNG file signature */
936 PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
937    png_inforp info_ptr),PNG_EMPTY);
938 
939 /* Read the chunk header (length + type name) */
940 PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
941    PNG_EMPTY);
942 
943 /* Read data from whatever input you are using into the "data" buffer */
944 PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
945     png_size_t length),PNG_EMPTY);
946 
947 /* Read bytes into buf, and update png_ptr->crc */
948 PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
949     png_uint_32 length),PNG_EMPTY);
950 
951 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
952 PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
953    png_uint_32 skip),PNG_EMPTY);
954 
955 /* Read the CRC from the file and compare it to the libpng calculated CRC */
956 PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
957 
958 /* Calculate the CRC over a section of data.  Note that we are only
959  * passing a maximum of 64K on systems that have this as a memory limit,
960  * since this is the maximum buffer size we can specify.
961  */
962 PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
963    png_const_bytep ptr, png_size_t length),PNG_EMPTY);
964 
965 #ifdef PNG_WRITE_FLUSH_SUPPORTED
966 PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
967 #endif
968 
969 /* Write various chunks */
970 
971 /* Write the IHDR chunk, and update the png_struct with the necessary
972  * information.
973  */
974 PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
975    png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
976    int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
977 
978 PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
979    png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
980 
981 PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
982    png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
983    PNG_EMPTY);
984 
985 PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
986 
987 #ifdef PNG_WRITE_gAMA_SUPPORTED
988 PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
989     png_fixed_point file_gamma),PNG_EMPTY);
990 #endif
991 
992 #ifdef PNG_WRITE_sBIT_SUPPORTED
993 PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
994     png_const_color_8p sbit, int color_type),PNG_EMPTY);
995 #endif
996 
997 #ifdef PNG_WRITE_cHRM_SUPPORTED
998 PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
999     const png_xy *xy), PNG_EMPTY);
1000     /* The xy value must have been previously validated */
1001 #endif
1002 
1003 #ifdef PNG_WRITE_sRGB_SUPPORTED
1004 PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
1005     int intent),PNG_EMPTY);
1006 #endif
1007 
1008 #ifdef PNG_WRITE_iCCP_SUPPORTED
1009 PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
1010    png_const_charp name, png_const_bytep profile), PNG_EMPTY);
1011    /* The profile must have been previously validated for correctness, the
1012     * length comes from the first four bytes.  Only the base, deflate,
1013     * compression is supported.
1014     */
1015 #endif
1016 
1017 #ifdef PNG_WRITE_sPLT_SUPPORTED
1018 PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
1019     png_const_sPLT_tp palette),PNG_EMPTY);
1020 #endif
1021 
1022 #ifdef PNG_WRITE_tRNS_SUPPORTED
1023 PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
1024     png_const_bytep trans, png_const_color_16p values, int number,
1025     int color_type),PNG_EMPTY);
1026 #endif
1027 
1028 #ifdef PNG_WRITE_bKGD_SUPPORTED
1029 PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
1030     png_const_color_16p values, int color_type),PNG_EMPTY);
1031 #endif
1032 
1033 #ifdef PNG_WRITE_hIST_SUPPORTED
1034 PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
1035     png_const_uint_16p hist, int num_hist),PNG_EMPTY);
1036 #endif
1037 
1038 /* Chunks that have keywords */
1039 #ifdef PNG_WRITE_tEXt_SUPPORTED
1040 PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
1041    png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
1042 #endif
1043 
1044 #ifdef PNG_WRITE_zTXt_SUPPORTED
1045 PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
1046     key, png_const_charp text, png_size_t text_len, int compression),PNG_EMPTY);
1047 #endif
1048 
1049 #ifdef PNG_WRITE_iTXt_SUPPORTED
1050 PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
1051     int compression, png_const_charp key, png_const_charp lang,
1052     png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
1053 #endif
1054 
1055 #ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
1056 PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
1057     png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
1058 #endif
1059 
1060 #ifdef PNG_WRITE_oFFs_SUPPORTED
1061 PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
1062     png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
1063 #endif
1064 
1065 #ifdef PNG_WRITE_pCAL_SUPPORTED
1066 PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
1067     png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
1068     png_const_charp units, png_charpp params),PNG_EMPTY);
1069 #endif
1070 
1071 #ifdef PNG_WRITE_pHYs_SUPPORTED
1072 PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
1073     png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
1074     int unit_type),PNG_EMPTY);
1075 #endif
1076 
1077 #ifdef PNG_WRITE_tIME_SUPPORTED
1078 PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
1079     png_const_timep mod_time),PNG_EMPTY);
1080 #endif
1081 
1082 #ifdef PNG_WRITE_sCAL_SUPPORTED
1083 PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
1084     int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
1085 #endif
1086 
1087 /* Called when finished processing a row of data */
1088 PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
1089     PNG_EMPTY);
1090 
1091 /* Internal use only.   Called before first row of data */
1092 PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
1093     PNG_EMPTY);
1094 
1095 /* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
1096  * array of png_ptr->width pixels.  If the image is not interlaced or this
1097  * is the final pass this just does a memcpy, otherwise the "display" flag
1098  * is used to determine whether to copy pixels that are not in the current pass.
1099  *
1100  * Because 'png_do_read_interlace' (below) replicates pixels this allows this
1101  * function to achieve the documented 'blocky' appearance during interlaced read
1102  * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
1103  * are not changed if they are not in the current pass, when display is 0.
1104  *
1105  * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
1106  *
1107  * The API always reads from the png_struct row buffer and always assumes that
1108  * it is full width (png_do_read_interlace has already been called.)
1109  *
1110  * This function is only ever used to write to row buffers provided by the
1111  * caller of the relevant libpng API and the row must have already been
1112  * transformed by the read transformations.
1113  *
1114  * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
1115  * bitmasks for use within the code, otherwise runtime generated masks are used.
1116  * The default is compile time masks.
1117  */
1118 #ifndef PNG_USE_COMPILE_TIME_MASKS
1119 #  define PNG_USE_COMPILE_TIME_MASKS 1
1120 #endif
1121 PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
1122     png_bytep row, int display),PNG_EMPTY);
1123 
1124 #ifdef PNG_READ_INTERLACING_SUPPORTED
1125 /* Expand an interlaced row: the 'row_info' describes the pass data that has
1126  * been read in and must correspond to the pixels in 'row', the pixels are
1127  * expanded (moved apart) in 'row' to match the final layout, when doing this
1128  * the pixels are *replicated* to the intervening space.  This is essential for
1129  * the correct operation of png_combine_row, above.
1130  */
1131 PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
1132     png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
1133 #endif
1134 
1135 /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
1136 
1137 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
1138 /* Grab pixels out of a row for an interlaced pass */
1139 PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
1140     png_bytep row, int pass),PNG_EMPTY);
1141 #endif
1142 
1143 /* Unfilter a row: check the filter value before calling this, there is no point
1144  * calling it for PNG_FILTER_VALUE_NONE.
1145  */
1146 PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
1147     row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
1148 
1149 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
1150     png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1151 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
1152     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1153 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
1154     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1155 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
1156     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1157 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
1158     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1159 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
1160     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1161 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
1162     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
1163 
1164 /* Choose the best filter to use and filter the row data */
1165 PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
1166     png_row_infop row_info),PNG_EMPTY);
1167 
1168 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1169 PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
1170    png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
1171    /* Read 'avail_out' bytes of data from the IDAT stream.  If the output buffer
1172     * is NULL the function checks, instead, for the end of the stream.  In this
1173     * case a benign error will be issued if the stream end is not found or if
1174     * extra data has to be consumed.
1175     */
1176 PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
1177    PNG_EMPTY);
1178    /* This cleans up when the IDAT LZ stream does not end when the last image
1179     * byte is read; there is still some pending input.
1180     */
1181 
1182 PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
1183    PNG_EMPTY);
1184    /* Finish a row while reading, dealing with interlacing passes, etc. */
1185 #endif
1186 
1187 /* Initialize the row buffers, etc. */
1188 PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
1189 
1190 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1191 /* Optional call to update the users info structure */
1192 PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
1193     png_inforp info_ptr),PNG_EMPTY);
1194 #endif
1195 
1196 /* These are the functions that do the transformations */
1197 #ifdef PNG_READ_FILLER_SUPPORTED
1198 PNG_INTERNAL_FUNCTION(void,png_do_read_filler,(png_row_infop row_info,
1199     png_bytep row, png_uint_32 filler, png_uint_32 flags),PNG_EMPTY);
1200 #endif
1201 
1202 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
1203 PNG_INTERNAL_FUNCTION(void,png_do_read_swap_alpha,(png_row_infop row_info,
1204     png_bytep row),PNG_EMPTY);
1205 #endif
1206 
1207 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1208 PNG_INTERNAL_FUNCTION(void,png_do_write_swap_alpha,(png_row_infop row_info,
1209     png_bytep row),PNG_EMPTY);
1210 #endif
1211 
1212 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
1213 PNG_INTERNAL_FUNCTION(void,png_do_read_invert_alpha,(png_row_infop row_info,
1214     png_bytep row),PNG_EMPTY);
1215 #endif
1216 
1217 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1218 PNG_INTERNAL_FUNCTION(void,png_do_write_invert_alpha,(png_row_infop row_info,
1219     png_bytep row),PNG_EMPTY);
1220 #endif
1221 
1222 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
1223     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1224 PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
1225     png_bytep row, int at_start),PNG_EMPTY);
1226 #endif
1227 
1228 #ifdef PNG_16BIT_SUPPORTED
1229 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1230 PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
1231     png_bytep row),PNG_EMPTY);
1232 #endif
1233 #endif
1234 
1235 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1236     defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1237 PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
1238     png_bytep row),PNG_EMPTY);
1239 #endif
1240 
1241 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1242 PNG_INTERNAL_FUNCTION(int,png_do_rgb_to_gray,(png_structrp png_ptr,
1243     png_row_infop row_info, png_bytep row),PNG_EMPTY);
1244 #endif
1245 
1246 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1247 PNG_INTERNAL_FUNCTION(void,png_do_gray_to_rgb,(png_row_infop row_info,
1248     png_bytep row),PNG_EMPTY);
1249 #endif
1250 
1251 #ifdef PNG_READ_PACK_SUPPORTED
1252 PNG_INTERNAL_FUNCTION(void,png_do_unpack,(png_row_infop row_info,
1253     png_bytep row),PNG_EMPTY);
1254 #endif
1255 
1256 #ifdef PNG_READ_SHIFT_SUPPORTED
1257 PNG_INTERNAL_FUNCTION(void,png_do_unshift,(png_row_infop row_info,
1258     png_bytep row, png_const_color_8p sig_bits),PNG_EMPTY);
1259 #endif
1260 
1261 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1262 PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
1263     png_bytep row),PNG_EMPTY);
1264 #endif
1265 
1266 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1267 PNG_INTERNAL_FUNCTION(void,png_do_scale_16_to_8,(png_row_infop row_info,
1268     png_bytep row),PNG_EMPTY);
1269 #endif
1270 
1271 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1272 PNG_INTERNAL_FUNCTION(void,png_do_chop,(png_row_infop row_info,
1273     png_bytep row),PNG_EMPTY);
1274 #endif
1275 
1276 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1277 PNG_INTERNAL_FUNCTION(void,png_do_quantize,(png_row_infop row_info,
1278     png_bytep row, png_const_bytep palette_lookup,
1279     png_const_bytep quantize_lookup),PNG_EMPTY);
1280 
1281 #  ifdef PNG_CORRECT_PALETTE_SUPPORTED
1282 PNG_INTERNAL_FUNCTION(void,png_correct_palette,(png_structrp png_ptr,
1283     png_colorp palette, int num_palette),PNG_EMPTY);
1284 #  endif
1285 #endif
1286 
1287 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1288 PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
1289     png_bytep row),PNG_EMPTY);
1290 #endif
1291 
1292 #ifdef PNG_WRITE_PACK_SUPPORTED
1293 PNG_INTERNAL_FUNCTION(void,png_do_pack,(png_row_infop row_info,
1294    png_bytep row, png_uint_32 bit_depth),PNG_EMPTY);
1295 #endif
1296 
1297 #ifdef PNG_WRITE_SHIFT_SUPPORTED
1298 PNG_INTERNAL_FUNCTION(void,png_do_shift,(png_row_infop row_info,
1299     png_bytep row, png_const_color_8p bit_depth),PNG_EMPTY);
1300 #endif
1301 
1302 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
1303     defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1304 PNG_INTERNAL_FUNCTION(void,png_do_compose,(png_row_infop row_info,
1305     png_bytep row, png_structrp png_ptr),PNG_EMPTY);
1306 #endif
1307 
1308 #ifdef PNG_READ_GAMMA_SUPPORTED
1309 PNG_INTERNAL_FUNCTION(void,png_do_gamma,(png_row_infop row_info,
1310     png_bytep row, png_structrp png_ptr),PNG_EMPTY);
1311 #endif
1312 
1313 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1314 PNG_INTERNAL_FUNCTION(void,png_do_encode_alpha,(png_row_infop row_info,
1315    png_bytep row, png_structrp png_ptr),PNG_EMPTY);
1316 #endif
1317 
1318 #ifdef PNG_READ_EXPAND_SUPPORTED
1319 PNG_INTERNAL_FUNCTION(void,png_do_expand_palette,(png_row_infop row_info,
1320     png_bytep row, png_const_colorp palette, png_const_bytep trans,
1321     int num_trans),PNG_EMPTY);
1322 PNG_INTERNAL_FUNCTION(void,png_do_expand,(png_row_infop row_info,
1323     png_bytep row, png_const_color_16p trans_color),PNG_EMPTY);
1324 #endif
1325 
1326 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1327 PNG_INTERNAL_FUNCTION(void,png_do_expand_16,(png_row_infop row_info,
1328     png_bytep row),PNG_EMPTY);
1329 #endif
1330 
1331 /* The following decodes the appropriate chunks, and does error correction,
1332  * then calls the appropriate callback for the chunk if it is valid.
1333  */
1334 
1335 /* Decode the IHDR chunk */
1336 PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
1337     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1338 PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
1339     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1340 PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
1341     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1342 
1343 #ifdef PNG_READ_bKGD_SUPPORTED
1344 PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
1345     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1346 #endif
1347 
1348 #ifdef PNG_READ_cHRM_SUPPORTED
1349 PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
1350     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1351 #endif
1352 
1353 #ifdef PNG_READ_gAMA_SUPPORTED
1354 PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
1355     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1356 #endif
1357 
1358 #ifdef PNG_READ_hIST_SUPPORTED
1359 PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
1360     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1361 #endif
1362 
1363 #ifdef PNG_READ_iCCP_SUPPORTED
1364 PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
1365     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1366 #endif /* PNG_READ_iCCP_SUPPORTED */
1367 
1368 #ifdef PNG_READ_iTXt_SUPPORTED
1369 PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
1370     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1371 #endif
1372 
1373 #ifdef PNG_READ_oFFs_SUPPORTED
1374 PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
1375     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1376 #endif
1377 
1378 #ifdef PNG_READ_pCAL_SUPPORTED
1379 PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
1380     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1381 #endif
1382 
1383 #ifdef PNG_READ_pHYs_SUPPORTED
1384 PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
1385     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1386 #endif
1387 
1388 #ifdef PNG_READ_sBIT_SUPPORTED
1389 PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
1390     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1391 #endif
1392 
1393 #ifdef PNG_READ_sCAL_SUPPORTED
1394 PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
1395     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1396 #endif
1397 
1398 #ifdef PNG_READ_sPLT_SUPPORTED
1399 PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
1400     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1401 #endif /* PNG_READ_sPLT_SUPPORTED */
1402 
1403 #ifdef PNG_READ_sRGB_SUPPORTED
1404 PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
1405     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1406 #endif
1407 
1408 #ifdef PNG_READ_tEXt_SUPPORTED
1409 PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
1410     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1411 #endif
1412 
1413 #ifdef PNG_READ_tIME_SUPPORTED
1414 PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
1415     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1416 #endif
1417 
1418 #ifdef PNG_READ_tRNS_SUPPORTED
1419 PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
1420     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1421 #endif
1422 
1423 #ifdef PNG_READ_zTXt_SUPPORTED
1424 PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
1425     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1426 #endif
1427 
1428 PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
1429     png_uint_32 chunk_name),PNG_EMPTY);
1430 
1431 #ifdef PNG_READ_SUPPORTED
1432 PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
1433     png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
1434    /* This is the function that gets called for unknown chunks.  The 'keep'
1435     * argument is either non-zero for a known chunk that has been set to be
1436     * handled as unknown or zero for an unknown chunk.  By default the function
1437     * just skips the chunk or errors out if it is critical.
1438     */
1439 
1440 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
1441 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
1442 PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
1443     (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
1444    /* Exactly as the API png_handle_as_unknown() except that the argument is a
1445     * 32-bit chunk name, not a string.
1446     */
1447 #endif
1448 #endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
1449 #endif /* PNG_READ_SUPPORTED */
1450 
1451 /* Handle the transformations for reading and writing */
1452 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1453 PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
1454    png_row_infop row_info),PNG_EMPTY);
1455 #endif
1456 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
1457 PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
1458    png_row_infop row_info),PNG_EMPTY);
1459 #endif
1460 
1461 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
1462 PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
1463     PNG_EMPTY);
1464 #endif
1465 
1466 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1467 PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
1468     png_inforp info_ptr),PNG_EMPTY);
1469 PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
1470     png_inforp info_ptr),PNG_EMPTY);
1471 PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
1472 PNG_INTERNAL_FUNCTION(void,png_push_crc_skip,(png_structrp png_ptr,
1473     png_uint_32 length),PNG_EMPTY);
1474 PNG_INTERNAL_FUNCTION(void,png_push_crc_finish,(png_structrp png_ptr),
1475     PNG_EMPTY);
1476 PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
1477     PNG_EMPTY);
1478 PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
1479     png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1480 PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
1481 PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
1482     png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
1483 PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
1484     PNG_EMPTY);
1485 PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
1486    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1487 PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
1488    png_inforp info_ptr),PNG_EMPTY);
1489 PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
1490    png_inforp info_ptr),PNG_EMPTY);
1491 PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
1492      png_bytep row),PNG_EMPTY);
1493 PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
1494     png_inforp info_ptr),PNG_EMPTY);
1495 PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
1496     png_inforp info_ptr),PNG_EMPTY);
1497 PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
1498     PNG_EMPTY);
1499 #  ifdef PNG_READ_tEXt_SUPPORTED
1500 PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
1501     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1502 PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
1503     png_inforp info_ptr),PNG_EMPTY);
1504 #  endif
1505 #  ifdef PNG_READ_zTXt_SUPPORTED
1506 PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
1507     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1508 PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
1509     png_inforp info_ptr),PNG_EMPTY);
1510 #  endif
1511 #  ifdef PNG_READ_iTXt_SUPPORTED
1512 PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
1513     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
1514 PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
1515     png_inforp info_ptr),PNG_EMPTY);
1516 #  endif
1517 
1518 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1519 
1520 #ifdef PNG_MNG_FEATURES_SUPPORTED
1521 PNG_INTERNAL_FUNCTION(void,png_do_read_intrapixel,(png_row_infop row_info,
1522     png_bytep row),PNG_EMPTY);
1523 PNG_INTERNAL_FUNCTION(void,png_do_write_intrapixel,(png_row_infop row_info,
1524     png_bytep row),PNG_EMPTY);
1525 #endif
1526 
1527 /* Added at libpng version 1.6.0 */
1528 #ifdef PNG_GAMMA_SUPPORTED
1529 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
1530     png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
1531    /* Set the colorspace gamma with a value provided by the application or by
1532     * the gAMA chunk on read.  The value will override anything set by an ICC
1533     * profile.
1534     */
1535 
1536 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
1537     png_inforp info_ptr), PNG_EMPTY);
1538     /* Synchronize the info 'valid' flags with the colorspace */
1539 
1540 PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
1541     png_inforp info_ptr), PNG_EMPTY);
1542     /* Copy the png_struct colorspace to the info_struct and call the above to
1543      * synchronize the flags.  Checks for NULL info_ptr and does nothing.
1544      */
1545 #endif
1546 
1547 /* Added at libpng version 1.4.0 */
1548 #ifdef PNG_COLORSPACE_SUPPORTED
1549 /* These internal functions are for maintaining the colorspace structure within
1550  * a png_info or png_struct (or, indeed, both).
1551  */
1552 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
1553    (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
1554     int preferred), PNG_EMPTY);
1555 
1556 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
1557    (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
1558     int preferred), PNG_EMPTY);
1559 
1560 #ifdef PNG_sRGB_SUPPORTED
1561 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
1562    png_colorspacerp colorspace, int intent), PNG_EMPTY);
1563    /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
1564     * flags to write them, if it returns false there was a problem and an error
1565     * message has already been output (but the colorspace may still need to be
1566     * synced to record the invalid flag).
1567     */
1568 #endif /* sRGB */
1569 
1570 #ifdef PNG_iCCP_SUPPORTED
1571 PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
1572    png_colorspacerp colorspace, png_const_charp name,
1573    png_uint_32 profile_length, png_const_bytep profile, int color_type),
1574    PNG_EMPTY);
1575    /* The 'name' is used for information only */
1576 
1577 /* Routines for checking parts of an ICC profile. */
1578 PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
1579    png_colorspacerp colorspace, png_const_charp name,
1580    png_uint_32 profile_length), PNG_EMPTY);
1581 PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
1582    png_colorspacerp colorspace, png_const_charp name,
1583    png_uint_32 profile_length,
1584    png_const_bytep profile /* first 132 bytes only */, int color_type),
1585    PNG_EMPTY);
1586 PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
1587    png_colorspacerp colorspace, png_const_charp name,
1588    png_uint_32 profile_length,
1589    png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
1590 #ifdef PNG_sRGB_SUPPORTED
1591 PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
1592    png_const_structrp png_ptr, png_colorspacerp colorspace,
1593    png_const_bytep profile, uLong adler), PNG_EMPTY);
1594    /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
1595     * be zero to indicate that it is not available.  It is used, if provided,
1596     * as a fast check on the profile when checking to see if it is sRGB.
1597     */
1598 #endif
1599 #endif /* iCCP */
1600 
1601 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1602 PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
1603    (png_structrp png_ptr), PNG_EMPTY);
1604    /* Set the rgb_to_gray coefficients from the colorspace Y values */
1605 #endif /* READ_RGB_TO_GRAY */
1606 #endif /* COLORSPACE */
1607 
1608 /* Added at libpng version 1.4.0 */
1609 PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
1610     png_uint_32 width, png_uint_32 height, int bit_depth,
1611     int color_type, int interlace_type, int compression_type,
1612     int filter_type),PNG_EMPTY);
1613 
1614 /* Added at libpng version 1.5.10 */
1615 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
1616     defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
1617 PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
1618    (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
1619 #endif
1620 
1621 #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
1622 PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
1623    png_const_charp name),PNG_NORETURN);
1624 #endif
1625 
1626 /* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
1627  * the end.  Always leaves the buffer nul terminated.  Never errors out (and
1628  * there is no error code.)
1629  */
1630 PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
1631    size_t pos, png_const_charp string),PNG_EMPTY);
1632 
1633 /* Various internal functions to handle formatted warning messages, currently
1634  * only implemented for warnings.
1635  */
1636 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
1637 /* Utility to dump an unsigned value into a buffer, given a start pointer and
1638  * and end pointer (which should point just *beyond* the end of the buffer!)
1639  * Returns the pointer to the start of the formatted string.  This utility only
1640  * does unsigned values.
1641  */
1642 PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
1643    png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
1644 
1645 /* Convenience macro that takes an array: */
1646 #define PNG_FORMAT_NUMBER(buffer,format,number) \
1647    png_format_number(buffer, buffer + (sizeof buffer), format, number)
1648 
1649 /* Suggested size for a number buffer (enough for 64 bits and a sign!) */
1650 #define PNG_NUMBER_BUFFER_SIZE 24
1651 
1652 /* These are the integer formats currently supported, the name is formed from
1653  * the standard printf(3) format string.
1654  */
1655 #define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
1656 #define PNG_NUMBER_FORMAT_02u   2
1657 #define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
1658 #define PNG_NUMBER_FORMAT_02d   2
1659 #define PNG_NUMBER_FORMAT_x     3
1660 #define PNG_NUMBER_FORMAT_02x   4
1661 #define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
1662 #endif
1663 
1664 #ifdef PNG_WARNINGS_SUPPORTED
1665 /* New defines and members adding in libpng-1.5.4 */
1666 #  define PNG_WARNING_PARAMETER_SIZE 32
1667 #  define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
1668 
1669 /* An l-value of this type has to be passed to the APIs below to cache the
1670  * values of the parameters to a formatted warning message.
1671  */
1672 typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
1673    PNG_WARNING_PARAMETER_SIZE];
1674 
1675 PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
1676    int number, png_const_charp string),PNG_EMPTY);
1677    /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
1678     * including the trailing '\0'.
1679     */
1680 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
1681    (png_warning_parameters p, int number, int format, png_alloc_size_t value),
1682    PNG_EMPTY);
1683    /* Use png_alloc_size_t because it is an unsigned type as big as any we
1684     * need to output.  Use the following for a signed value.
1685     */
1686 PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
1687    (png_warning_parameters p, int number, int format, png_int_32 value),
1688    PNG_EMPTY);
1689 
1690 PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
1691    png_warning_parameters p, png_const_charp message),PNG_EMPTY);
1692    /* 'message' follows the X/Open approach of using @1, @2 to insert
1693     * parameters previously supplied using the above functions.  Errors in
1694     * specifying the parameters will simply result in garbage substitutions.
1695     */
1696 #endif
1697 
1698 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1699 /* Application errors (new in 1.6); use these functions (declared below) for
1700  * errors in the parameters or order of API function calls on read.  The
1701  * 'warning' should be used for an error that can be handled completely; the
1702  * 'error' for one which can be handled safely but which may lose application
1703  * information or settings.
1704  *
1705  * By default these both result in a png_error call prior to release, while in a
1706  * released version the 'warning' is just a warning.  However if the application
1707  * explicitly disables benign errors (explicitly permitting the code to lose
1708  * information) they both turn into warnings.
1709  *
1710  * If benign errors aren't supported they end up as the corresponding base call
1711  * (png_warning or png_error.)
1712  */
1713 PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
1714    png_const_charp message),PNG_EMPTY);
1715    /* The application provided invalid parameters to an API function or called
1716     * an API function at the wrong time, libpng can completely recover.
1717     */
1718 
1719 PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
1720    png_const_charp message),PNG_EMPTY);
1721    /* As above but libpng will ignore the call, or attempt some other partial
1722     * recovery from the error.
1723     */
1724 #else
1725 #  define png_app_warning(pp,s) png_warning(pp,s)
1726 #  define png_app_error(pp,s) png_error(pp,s)
1727 #endif
1728 
1729 PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
1730    png_const_charp message, int error),PNG_EMPTY);
1731    /* Report a recoverable issue in chunk data.  On read this is used to report
1732     * a problem found while reading a particular chunk and the
1733     * png_chunk_benign_error or png_chunk_warning function is used as
1734     * appropriate.  On write this is used to report an error that comes from
1735     * data set via an application call to a png_set_ API and png_app_error or
1736     * png_app_warning is used as appropriate.
1737     *
1738     * The 'error' parameter must have one of the following values:
1739     */
1740 #define PNG_CHUNK_WARNING     0 /* never an error */
1741 #define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
1742 #define PNG_CHUNK_ERROR       2 /* always an error */
1743 
1744 /* ASCII to FP interfaces, currently only implemented if sCAL
1745  * support is required.
1746  */
1747 #if defined(PNG_sCAL_SUPPORTED)
1748 /* MAX_DIGITS is actually the maximum number of characters in an sCAL
1749  * width or height, derived from the precision (number of significant
1750  * digits - a build time settable option) and assumptions about the
1751  * maximum ridiculous exponent.
1752  */
1753 #define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
1754 
1755 #ifdef PNG_FLOATING_POINT_SUPPORTED
1756 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
1757    png_charp ascii, png_size_t size, double fp, unsigned int precision),
1758    PNG_EMPTY);
1759 #endif /* FLOATING_POINT */
1760 
1761 #ifdef PNG_FIXED_POINT_SUPPORTED
1762 PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
1763    png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
1764 #endif /* FIXED_POINT */
1765 #endif /* sCAL */
1766 
1767 #if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
1768 /* An internal API to validate the format of a floating point number.
1769  * The result is the index of the next character.  If the number is
1770  * not valid it will be the index of a character in the supposed number.
1771  *
1772  * The format of a number is defined in the PNG extensions specification
1773  * and this API is strictly conformant to that spec, not anyone elses!
1774  *
1775  * The format as a regular expression is:
1776  *
1777  * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
1778  *
1779  * or:
1780  *
1781  * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
1782  *
1783  * The complexity is that either integer or fraction must be present and the
1784  * fraction is permitted to have no digits only if the integer is present.
1785  *
1786  * NOTE: The dangling E problem.
1787  *   There is a PNG valid floating point number in the following:
1788  *
1789  *       PNG floating point numbers are not greedy.
1790  *
1791  *   Working this out requires *TWO* character lookahead (because of the
1792  *   sign), the parser does not do this - it will fail at the 'r' - this
1793  *   doesn't matter for PNG sCAL chunk values, but it requires more care
1794  *   if the value were ever to be embedded in something more complex.  Use
1795  *   ANSI-C strtod if you need the lookahead.
1796  */
1797 /* State table for the parser. */
1798 #define PNG_FP_INTEGER    0  /* before or in integer */
1799 #define PNG_FP_FRACTION   1  /* before or in fraction */
1800 #define PNG_FP_EXPONENT   2  /* before or in exponent */
1801 #define PNG_FP_STATE      3  /* mask for the above */
1802 #define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
1803 #define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
1804 #define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
1805 #define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
1806 #define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
1807 
1808 /* These three values don't affect the parser.  They are set but not used.
1809  */
1810 #define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
1811 #define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
1812 #define PNG_FP_NONZERO  256  /* A non-zero value */
1813 #define PNG_FP_STICKY   448  /* The above three flags */
1814 
1815 /* This is available for the caller to store in 'state' if required.  Do not
1816  * call the parser after setting it (the parser sometimes clears it.)
1817  */
1818 #define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
1819 
1820 /* Result codes for the parser (boolean - true meants ok, false means
1821  * not ok yet.)
1822  */
1823 #define PNG_FP_MAYBE      0  /* The number may be valid in the future */
1824 #define PNG_FP_OK         1  /* The number is valid */
1825 
1826 /* Tests on the sticky non-zero and negative flags.  To pass these checks
1827  * the state must also indicate that the whole number is valid - this is
1828  * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
1829  * is equivalent to PNG_FP_OK above.)
1830  */
1831 #define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
1832    /* NZ_MASK: the string is valid and a non-zero negative value */
1833 #define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
1834    /* Z MASK: the string is valid and a non-zero value. */
1835    /* PNG_FP_SAW_DIGIT: the string is valid. */
1836 #define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
1837 #define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
1838 #define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
1839 
1840 /* The actual parser.  This can be called repeatedly. It updates
1841  * the index into the string and the state variable (which must
1842  * be initialized to 0).  It returns a result code, as above.  There
1843  * is no point calling the parser any more if it fails to advance to
1844  * the end of the string - it is stuck on an invalid character (or
1845  * terminated by '\0').
1846  *
1847  * Note that the pointer will consume an E or even an E+ and then leave
1848  * a 'maybe' state even though a preceding integer.fraction is valid.
1849  * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
1850  * a valid number.  It's possible to recover from this by calling
1851  * the parser again (from the start, with state 0) but with a string
1852  * that omits the last character (i.e. set the size to the index of
1853  * the problem character.)  This has not been tested within libpng.
1854  */
1855 PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
1856    png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
1857 
1858 /* This is the same but it checks a complete string and returns true
1859  * only if it just contains a floating point number.  As of 1.5.4 this
1860  * function also returns the state at the end of parsing the number if
1861  * it was valid (otherwise it returns 0.)  This can be used for testing
1862  * for negative or zero values using the sticky flag.
1863  */
1864 PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
1865    png_size_t size),PNG_EMPTY);
1866 #endif /* pCAL || sCAL */
1867 
1868 #if defined(PNG_READ_GAMMA_SUPPORTED) ||\
1869     defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
1870 /* Added at libpng version 1.5.0 */
1871 /* This is a utility to provide a*times/div (rounded) and indicate
1872  * if there is an overflow.  The result is a boolean - false (0)
1873  * for overflow, true (1) if no overflow, in which case *res
1874  * holds the result.
1875  */
1876 PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
1877    png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
1878 #endif
1879 
1880 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
1881 /* Same deal, but issue a warning on overflow and return 0. */
1882 PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
1883    (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
1884    png_int_32 divided_by),PNG_EMPTY);
1885 #endif
1886 
1887 #ifdef PNG_GAMMA_SUPPORTED
1888 /* Calculate a reciprocal - used for gamma values.  This returns
1889  * 0 if the argument is 0 in order to maintain an undefined value;
1890  * there are no warnings.
1891  */
1892 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
1893    PNG_EMPTY);
1894 
1895 #ifdef PNG_READ_GAMMA_SUPPORTED
1896 /* The same but gives a reciprocal of the product of two fixed point
1897  * values.  Accuracy is suitable for gamma calculations but this is
1898  * not exact - use png_muldiv for that.  Only required at present on read.
1899  */
1900 PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
1901    png_fixed_point b),PNG_EMPTY);
1902 #endif
1903 
1904 /* Return true if the gamma value is significantly different from 1.0 */
1905 PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
1906    PNG_EMPTY);
1907 #endif
1908 
1909 #ifdef PNG_READ_GAMMA_SUPPORTED
1910 /* Internal fixed point gamma correction.  These APIs are called as
1911  * required to convert single values - they don't need to be fast,
1912  * they are not used when processing image pixel values.
1913  *
1914  * While the input is an 'unsigned' value it must actually be the
1915  * correct bit value - 0..255 or 0..65535 as required.
1916  */
1917 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
1918    unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
1919 PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
1920    png_fixed_point gamma_value),PNG_EMPTY);
1921 PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
1922    png_fixed_point gamma_value),PNG_EMPTY);
1923 PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
1924    PNG_EMPTY);
1925 PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
1926    int bit_depth),PNG_EMPTY);
1927 #endif
1928 
1929 /* SIMPLIFIED READ/WRITE SUPPORT */
1930 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
1931    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
1932 /* The internal structure that png_image::opaque points to. */
1933 typedef struct png_control
1934 {
1935    png_structp png_ptr;
1936    png_infop   info_ptr;
1937    png_voidp   error_buf;           /* Always a jmp_buf at present. */
1938 
1939    png_const_bytep memory;          /* Memory buffer. */
1940    png_size_t      size;            /* Size of the memory buffer. */
1941 
1942    unsigned int for_write       :1; /* Otherwise it is a read structure */
1943    unsigned int owned_file      :1; /* We own the file in io_ptr */
1944 } png_control;
1945 
1946 /* Return the pointer to the jmp_buf from a png_control: necessary because C
1947  * does not reveal the type of the elements of jmp_buf.
1948  */
1949 #ifdef __cplusplus
1950 #  define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
1951 #else
1952 #  define png_control_jmp_buf(pc) ((pc)->error_buf)
1953 #endif
1954 
1955 /* Utility to safely execute a piece of libpng code catching and logging any
1956  * errors that might occur.  Returns true on success, false on failure (either
1957  * of the function or as a result of a png_error.)
1958  */
1959 PNG_INTERNAL_FUNCTION(void,png_safe_error,(png_structp png_ptr,
1960    png_const_charp error_message),PNG_NORETURN);
1961 
1962 #ifdef PNG_WARNINGS_SUPPORTED
1963 PNG_INTERNAL_FUNCTION(void,png_safe_warning,(png_structp png_ptr,
1964    png_const_charp warning_message),PNG_EMPTY);
1965 #else
1966 #  define png_safe_warning 0/*dummy argument*/
1967 #endif
1968 
1969 PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
1970    int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
1971 
1972 /* Utility to log an error; this also cleans up the png_image; the function
1973  * always returns 0 (false).
1974  */
1975 PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
1976    png_const_charp error_message),PNG_EMPTY);
1977 
1978 #ifndef PNG_SIMPLIFIED_READ_SUPPORTED
1979 /* png_image_free is used by the write code but not exported */
1980 PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
1981 #endif /* !SIMPLIFIED_READ */
1982 
1983 #endif /* SIMPLIFIED READ/WRITE */
1984 
1985 /* These are initialization functions for hardware specific PNG filter
1986  * optimizations; list these here then select the appropriate one at compile
1987  * time using the macro PNG_FILTER_OPTIMIZATIONS.  If the macro is not defined
1988  * the generic code is used.
1989  */
1990 #ifdef PNG_FILTER_OPTIMIZATIONS
1991 PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
1992    unsigned int bpp), PNG_EMPTY);
1993    /* Just declare the optimization that will be used */
1994 #else
1995    /* List *all* the possible optimizations here - this branch is required if
1996     * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
1997     * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
1998     */
1999 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
2000    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
2001 #endif
2002 
2003 /* Maintainer: Put new private prototypes here ^ */
2004 
2005 #include "pngdebug.h"
2006 
2007 #ifdef __cplusplus
2008 }
2009 #endif
2010 
2011 #endif /* PNG_VERSION_INFO_ONLY */
2012 #endif /* PNGPRIV_H */
2013