source: trunk/src/3rdparty/libpng/png.c@ 689

Last change on this file since 689 was 561, checked in by Dmitry A. Kuminov, 16 years ago

trunk: Merged in qt 4.6.1 sources.
File size: 26.1 KB
Line 
1
2/* png.c - location for general purpose libpng functions
3 *
4 * Last changed in libpng 1.2.39 [August 13, 2009]
5 * Copyright (c) 1998-2009 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 * 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#define PNG_INTERNAL
15#define PNG_NO_EXTERN
16#include "png.h"
17
18/* Generate a compiler error if there is an old png.h in the search path. */
19typedef version_1_2_40 Your_png_h_is_not_version_1_2_40;
20
21/* Version information for C files. This had better match the version
22 * string defined in png.h. */
23
24#ifdef PNG_USE_GLOBAL_ARRAYS
25/* png_libpng_ver was changed to a function in version 1.0.5c */
26PNG_CONST char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING;
27
28#ifdef PNG_READ_SUPPORTED
29
30/* png_sig was changed to a function in version 1.0.5c */
31/* Place to hold the signature string for a PNG file. */
32PNG_CONST png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
33#endif /* PNG_READ_SUPPORTED */
34
35/* Invoke global declarations for constant strings for known chunk types */
36PNG_IHDR;
37PNG_IDAT;
38PNG_IEND;
39PNG_PLTE;
40PNG_bKGD;
41PNG_cHRM;
42PNG_gAMA;
43PNG_hIST;
44PNG_iCCP;
45PNG_iTXt;
46PNG_oFFs;
47PNG_pCAL;
48PNG_sCAL;
49PNG_pHYs;
50PNG_sBIT;
51PNG_sPLT;
52PNG_sRGB;
53PNG_tEXt;
54PNG_tIME;
55PNG_tRNS;
56PNG_zTXt;
57
58#ifdef PNG_READ_SUPPORTED
59/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
60
61/* Start of interlace block */
62PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
63
64/* Offset to next interlace block */
65PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
66
67/* Start of interlace block in the y direction */
68PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
69
70/* Offset to next interlace block in the y direction */
71PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
72
73/* Height of interlace block. This is not currently used - if you need
74 * it, uncomment it here and in png.h
75PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
76*/
77
78/* Mask to determine which pixels are valid in a pass */
79PNG_CONST int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
80
81/* Mask to determine which pixels to overwrite while displaying */
82PNG_CONST int FARDATA png_pass_dsp_mask[]
83 = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
84
85#endif /* PNG_READ_SUPPORTED */
86#endif /* PNG_USE_GLOBAL_ARRAYS */
87
88/* Tells libpng that we have already handled the first "num_bytes" bytes
89 * of the PNG file signature. If the PNG data is embedded into another
90 * stream we can set num_bytes = 8 so that libpng will not attempt to read
91 * or write any of the magic bytes before it starts on the IHDR.
92 */
93
94#ifdef PNG_READ_SUPPORTED
95void PNGAPI
96png_set_sig_bytes(png_structp png_ptr, int num_bytes)
97{
98 if (png_ptr == NULL)
99 return;
100 png_debug(1, "in png_set_sig_bytes");
101 if (num_bytes > 8)
102 png_error(png_ptr, "Too many bytes for PNG signature.");
103
104 png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
105}
106
107/* Checks whether the supplied bytes match the PNG signature. We allow
108 * checking less than the full 8-byte signature so that those apps that
109 * already read the first few bytes of a file to determine the file type
110 * can simply check the remaining bytes for extra assurance. Returns
111 * an integer less than, equal to, or greater than zero if sig is found,
112 * respectively, to be less than, to match, or be greater than the correct
113 * PNG signature (this is the same behaviour as strcmp, memcmp, etc).
114 */
115int PNGAPI
116png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
117{
118 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
119 if (num_to_check > 8)
120 num_to_check = 8;
121 else if (num_to_check < 1)
122 return (-1);
123
124 if (start > 7)
125 return (-1);
126
127 if (start + num_to_check > 8)
128 num_to_check = 8 - start;
129
130 return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
131}
132
133#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
134/* (Obsolete) function to check signature bytes. It does not allow one
135 * to check a partial signature. This function might be removed in the
136 * future - use png_sig_cmp(). Returns true (nonzero) if the file is PNG.
137 */
138int PNGAPI
139png_check_sig(png_bytep sig, int num)
140{
141 return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
142}
143#endif
144#endif /* PNG_READ_SUPPORTED */
145
146#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
147/* Function to allocate memory for zlib and clear it to 0. */
148#ifdef PNG_1_0_X
149voidpf PNGAPI
150#else
151voidpf /* PRIVATE */
152#endif
153png_zalloc(voidpf png_ptr, uInt items, uInt size)
154{
155 png_voidp ptr;
156 png_structp p=(png_structp)png_ptr;
157 png_uint_32 save_flags=p->flags;
158 png_uint_32 num_bytes;
159
160 if (png_ptr == NULL)
161 return (NULL);
162 if (items > PNG_UINT_32_MAX/size)
163 {
164 png_warning (p, "Potential overflow in png_zalloc()");
165 return (NULL);
166 }
167 num_bytes = (png_uint_32)items * size;
168
169 p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
170 ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
171 p->flags=save_flags;
172
173#if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
174 if (ptr == NULL)
175 return ((voidpf)ptr);
176
177 if (num_bytes > (png_uint_32)0x8000L)
178 {
179 png_memset(ptr, 0, (png_size_t)0x8000L);
180 png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
181 (png_size_t)(num_bytes - (png_uint_32)0x8000L));
182 }
183 else
184 {
185 png_memset(ptr, 0, (png_size_t)num_bytes);
186 }
187#endif
188 return ((voidpf)ptr);
189}
190
191/* Function to free memory for zlib */
192#ifdef PNG_1_0_X
193void PNGAPI
194#else
195void /* PRIVATE */
196#endif
197png_zfree(voidpf png_ptr, voidpf ptr)
198{
199 png_free((png_structp)png_ptr, (png_voidp)ptr);
200}
201
202/* Reset the CRC variable to 32 bits of 1's. Care must be taken
203 * in case CRC is > 32 bits to leave the top bits 0.
204 */
205void /* PRIVATE */
206png_reset_crc(png_structp png_ptr)
207{
208 png_ptr->crc = crc32(0, Z_NULL, 0);
209}
210
211/* Calculate the CRC over a section of data. We can only pass as
212 * much data to this routine as the largest single buffer size. We
213 * also check that this data will actually be used before going to the
214 * trouble of calculating it.
215 */
216void /* PRIVATE */
217png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
218{
219 int need_crc = 1;
220
221 if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
222 {
223 if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
224 (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
225 need_crc = 0;
226 }
227 else /* critical */
228 {
229 if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
230 need_crc = 0;
231 }
232
233 if (need_crc)
234 png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
235}
236
237/* Allocate the memory for an info_struct for the application. We don't
238 * really need the png_ptr, but it could potentially be useful in the
239 * future. This should be used in favour of malloc(png_sizeof(png_info))
240 * and png_info_init() so that applications that want to use a shared
241 * libpng don't have to be recompiled if png_info changes size.
242 */
243png_infop PNGAPI
244png_create_info_struct(png_structp png_ptr)
245{
246 png_infop info_ptr;
247
248 png_debug(1, "in png_create_info_struct");
249 if (png_ptr == NULL)
250 return (NULL);
251#ifdef PNG_USER_MEM_SUPPORTED
252 info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
253 png_ptr->malloc_fn, png_ptr->mem_ptr);
254#else
255 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
256#endif
257 if (info_ptr != NULL)
258 png_info_init_3(&info_ptr, png_sizeof(png_info));
259
260 return (info_ptr);
261}
262
263/* This function frees the memory associated with a single info struct.
264 * Normally, one would use either png_destroy_read_struct() or
265 * png_destroy_write_struct() to free an info struct, but this may be
266 * useful for some applications.
267 */
268void PNGAPI
269png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
270{
271 png_infop info_ptr = NULL;
272 if (png_ptr == NULL)
273 return;
274
275 png_debug(1, "in png_destroy_info_struct");
276 if (info_ptr_ptr != NULL)
277 info_ptr = *info_ptr_ptr;
278
279 if (info_ptr != NULL)
280 {
281 png_info_destroy(png_ptr, info_ptr);
282
283#ifdef PNG_USER_MEM_SUPPORTED
284 png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
285 png_ptr->mem_ptr);
286#else
287 png_destroy_struct((png_voidp)info_ptr);
288#endif
289 *info_ptr_ptr = NULL;
290 }
291}
292
293/* Initialize the info structure. This is now an internal function (0.89)
294 * and applications using it are urged to use png_create_info_struct()
295 * instead.
296 */
297#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
298#undef png_info_init
299void PNGAPI
300png_info_init(png_infop info_ptr)
301{
302 /* We only come here via pre-1.0.12-compiled applications */
303 png_info_init_3(&info_ptr, 0);
304}
305#endif
306
307void PNGAPI
308png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
309{
310 png_infop info_ptr = *ptr_ptr;
311
312 if (info_ptr == NULL)
313 return;
314
315 png_debug(1, "in png_info_init_3");
316
317 if (png_sizeof(png_info) > png_info_struct_size)
318 {
319 png_destroy_struct(info_ptr);
320 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
321 *ptr_ptr = info_ptr;
322 }
323
324 /* Set everything to 0 */
325 png_memset(info_ptr, 0, png_sizeof(png_info));
326}
327
328#ifdef PNG_FREE_ME_SUPPORTED
329void PNGAPI
330png_data_freer(png_structp png_ptr, png_infop info_ptr,
331 int freer, png_uint_32 mask)
332{
333 png_debug(1, "in png_data_freer");
334 if (png_ptr == NULL || info_ptr == NULL)
335 return;
336 if (freer == PNG_DESTROY_WILL_FREE_DATA)
337 info_ptr->free_me |= mask;
338 else if (freer == PNG_USER_WILL_FREE_DATA)
339 info_ptr->free_me &= ~mask;
340 else
341 png_warning(png_ptr,
342 "Unknown freer parameter in png_data_freer.");
343}
344#endif
345
346void PNGAPI
347png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
348 int num)
349{
350 png_debug(1, "in png_free_data");
351 if (png_ptr == NULL || info_ptr == NULL)
352 return;
353
354#if defined(PNG_TEXT_SUPPORTED)
355 /* Free text item num or (if num == -1) all text items */
356#ifdef PNG_FREE_ME_SUPPORTED
357 if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
358#else
359 if (mask & PNG_FREE_TEXT)
360#endif
361 {
362 if (num != -1)
363 {
364 if (info_ptr->text && info_ptr->text[num].key)
365 {
366 png_free(png_ptr, info_ptr->text[num].key);
367 info_ptr->text[num].key = NULL;
368 }
369 }
370 else
371 {
372 int i;
373 for (i = 0; i < info_ptr->num_text; i++)
374 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
375 png_free(png_ptr, info_ptr->text);
376 info_ptr->text = NULL;
377 info_ptr->num_text=0;
378 }
379 }
380#endif
381
382#if defined(PNG_tRNS_SUPPORTED)
383 /* Free any tRNS entry */
384#ifdef PNG_FREE_ME_SUPPORTED
385 if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
386#else
387 if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
388#endif
389 {
390 png_free(png_ptr, info_ptr->trans);
391 info_ptr->trans = NULL;
392 info_ptr->valid &= ~PNG_INFO_tRNS;
393#ifndef PNG_FREE_ME_SUPPORTED
394 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
395#endif
396 }
397#endif
398
399#if defined(PNG_sCAL_SUPPORTED)
400 /* Free any sCAL entry */
401#ifdef PNG_FREE_ME_SUPPORTED
402 if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
403#else
404 if (mask & PNG_FREE_SCAL)
405#endif
406 {
407#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
408 png_free(png_ptr, info_ptr->scal_s_width);
409 png_free(png_ptr, info_ptr->scal_s_height);
410 info_ptr->scal_s_width = NULL;
411 info_ptr->scal_s_height = NULL;
412#endif
413 info_ptr->valid &= ~PNG_INFO_sCAL;
414 }
415#endif
416
417#if defined(PNG_pCAL_SUPPORTED)
418 /* Free any pCAL entry */
419#ifdef PNG_FREE_ME_SUPPORTED
420 if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
421#else
422 if (mask & PNG_FREE_PCAL)
423#endif
424 {
425 png_free(png_ptr, info_ptr->pcal_purpose);
426 png_free(png_ptr, info_ptr->pcal_units);
427 info_ptr->pcal_purpose = NULL;
428 info_ptr->pcal_units = NULL;
429 if (info_ptr->pcal_params != NULL)
430 {
431 int i;
432 for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
433 {
434 png_free(png_ptr, info_ptr->pcal_params[i]);
435 info_ptr->pcal_params[i]=NULL;
436 }
437 png_free(png_ptr, info_ptr->pcal_params);
438 info_ptr->pcal_params = NULL;
439 }
440 info_ptr->valid &= ~PNG_INFO_pCAL;
441 }
442#endif
443
444#if defined(PNG_iCCP_SUPPORTED)
445 /* Free any iCCP entry */
446#ifdef PNG_FREE_ME_SUPPORTED
447 if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
448#else
449 if (mask & PNG_FREE_ICCP)
450#endif
451 {
452 png_free(png_ptr, info_ptr->iccp_name);
453 png_free(png_ptr, info_ptr->iccp_profile);
454 info_ptr->iccp_name = NULL;
455 info_ptr->iccp_profile = NULL;
456 info_ptr->valid &= ~PNG_INFO_iCCP;
457 }
458#endif
459
460#if defined(PNG_sPLT_SUPPORTED)
461 /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
462#ifdef PNG_FREE_ME_SUPPORTED
463 if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
464#else
465 if (mask & PNG_FREE_SPLT)
466#endif
467 {
468 if (num != -1)
469 {
470 if (info_ptr->splt_palettes)
471 {
472 png_free(png_ptr, info_ptr->splt_palettes[num].name);
473 png_free(png_ptr, info_ptr->splt_palettes[num].entries);
474 info_ptr->splt_palettes[num].name = NULL;
475 info_ptr->splt_palettes[num].entries = NULL;
476 }
477 }
478 else
479 {
480 if (info_ptr->splt_palettes_num)
481 {
482 int i;
483 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
484 png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
485
486 png_free(png_ptr, info_ptr->splt_palettes);
487 info_ptr->splt_palettes = NULL;
488 info_ptr->splt_palettes_num = 0;
489 }
490 info_ptr->valid &= ~PNG_INFO_sPLT;
491 }
492 }
493#endif
494
495#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
496 if (png_ptr->unknown_chunk.data)
497 {
498 png_free(png_ptr, png_ptr->unknown_chunk.data);
499 png_ptr->unknown_chunk.data = NULL;
500 }
501
502#ifdef PNG_FREE_ME_SUPPORTED
503 if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
504#else
505 if (mask & PNG_FREE_UNKN)
506#endif
507 {
508 if (num != -1)
509 {
510 if (info_ptr->unknown_chunks)
511 {
512 png_free(png_ptr, info_ptr->unknown_chunks[num].data);
513 info_ptr->unknown_chunks[num].data = NULL;
514 }
515 }
516 else
517 {
518 int i;
519
520 if (info_ptr->unknown_chunks_num)
521 {
522 for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
523 png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
524
525 png_free(png_ptr, info_ptr->unknown_chunks);
526 info_ptr->unknown_chunks = NULL;
527 info_ptr->unknown_chunks_num = 0;
528 }
529 }
530 }
531#endif
532
533#if defined(PNG_hIST_SUPPORTED)
534 /* Free any hIST entry */
535#ifdef PNG_FREE_ME_SUPPORTED
536 if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
537#else
538 if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
539#endif
540 {
541 png_free(png_ptr, info_ptr->hist);
542 info_ptr->hist = NULL;
543 info_ptr->valid &= ~PNG_INFO_hIST;
544#ifndef PNG_FREE_ME_SUPPORTED
545 png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
546#endif
547 }
548#endif
549
550 /* Free any PLTE entry that was internally allocated */
551#ifdef PNG_FREE_ME_SUPPORTED
552 if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
553#else
554 if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
555#endif
556 {
557 png_zfree(png_ptr, info_ptr->palette);
558 info_ptr->palette = NULL;
559 info_ptr->valid &= ~PNG_INFO_PLTE;
560#ifndef PNG_FREE_ME_SUPPORTED
561 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
562#endif
563 info_ptr->num_palette = 0;
564 }
565
566#if defined(PNG_INFO_IMAGE_SUPPORTED)
567 /* Free any image bits attached to the info structure */
568#ifdef PNG_FREE_ME_SUPPORTED
569 if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
570#else
571 if (mask & PNG_FREE_ROWS)
572#endif
573 {
574 if (info_ptr->row_pointers)
575 {
576 int row;
577 for (row = 0; row < (int)info_ptr->height; row++)
578 {
579 png_free(png_ptr, info_ptr->row_pointers[row]);
580 info_ptr->row_pointers[row]=NULL;
581 }
582 png_free(png_ptr, info_ptr->row_pointers);
583 info_ptr->row_pointers=NULL;
584 }
585 info_ptr->valid &= ~PNG_INFO_IDAT;
586 }
587#endif
588
589#ifdef PNG_FREE_ME_SUPPORTED
590 if (num == -1)
591 info_ptr->free_me &= ~mask;
592 else
593 info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
594#endif
595}
596
597/* This is an internal routine to free any memory that the info struct is
598 * pointing to before re-using it or freeing the struct itself. Recall
599 * that png_free() checks for NULL pointers for us.
600 */
601void /* PRIVATE */
602png_info_destroy(png_structp png_ptr, png_infop info_ptr)
603{
604 png_debug(1, "in png_info_destroy");
605
606 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
607
608#if defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
609 if (png_ptr->num_chunk_list)
610 {
611 png_free(png_ptr, png_ptr->chunk_list);
612 png_ptr->chunk_list=NULL;
613 png_ptr->num_chunk_list = 0;
614 }
615#endif
616
617 png_info_init_3(&info_ptr, png_sizeof(png_info));
618}
619#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
620
621/* This function returns a pointer to the io_ptr associated with the user
622 * functions. The application should free any memory associated with this
623 * pointer before png_write_destroy() or png_read_destroy() are called.
624 */
625png_voidp PNGAPI
626png_get_io_ptr(png_structp png_ptr)
627{
628 if (png_ptr == NULL)
629 return (NULL);
630 return (png_ptr->io_ptr);
631}
632
633#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
634#if !defined(PNG_NO_STDIO)
635/* Initialize the default input/output functions for the PNG file. If you
636 * use your own read or write routines, you can call either png_set_read_fn()
637 * or png_set_write_fn() instead of png_init_io(). If you have defined
638 * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
639 * necessarily available.
640 */
641void PNGAPI
642png_init_io(png_structp png_ptr, png_FILE_p fp)
643{
644 png_debug(1, "in png_init_io");
645 if (png_ptr == NULL)
646 return;
647 png_ptr->io_ptr = (png_voidp)fp;
648}
649#endif
650
651#if defined(PNG_TIME_RFC1123_SUPPORTED)
652/* Convert the supplied time into an RFC 1123 string suitable for use in
653 * a "Creation Time" or other text-based time string.
654 */
655png_charp PNGAPI
656png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
657{
658 static PNG_CONST char short_months[12][4] =
659 {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
660 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
661
662 if (png_ptr == NULL)
663 return (NULL);
664 if (png_ptr->time_buffer == NULL)
665 {
666 png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
667 png_sizeof(char)));
668 }
669
670#if defined(_WIN32_WCE)
671 {
672 wchar_t time_buf[29];
673 wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
674 ptime->day % 32, short_months[(ptime->month - 1) % 12],
675 ptime->year, ptime->hour % 24, ptime->minute % 60,
676 ptime->second % 61);
677 WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
678 NULL, NULL);
679 }
680#else
681#ifdef USE_FAR_KEYWORD
682 {
683 char near_time_buf[29];
684 png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000",
685 ptime->day % 32, short_months[(ptime->month - 1) % 12],
686 ptime->year, ptime->hour % 24, ptime->minute % 60,
687 ptime->second % 61);
688 png_memcpy(png_ptr->time_buffer, near_time_buf,
689 29*png_sizeof(char));
690 }
691#else
692 png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000",
693 ptime->day % 32, short_months[(ptime->month - 1) % 12],
694 ptime->year, ptime->hour % 24, ptime->minute % 60,
695 ptime->second % 61);
696#endif
697#endif /* _WIN32_WCE */
698 return ((png_charp)png_ptr->time_buffer);
699}
700#endif /* PNG_TIME_RFC1123_SUPPORTED */
701
702#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
703
704png_charp PNGAPI
705png_get_copyright(png_structp png_ptr)
706{
707 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
708 return ((png_charp) "\n libpng version 1.2.40 - September 10, 2009\n\
709 Copyright (c) 1998-2009 Glenn Randers-Pehrson\n\
710 Copyright (c) 1996-1997 Andreas Dilger\n\
711 Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n");
712}
713
714/* The following return the library version as a short string in the
715 * format 1.0.0 through 99.99.99zz. To get the version of *.h files
716 * used with your application, print out PNG_LIBPNG_VER_STRING, which
717 * is defined in png.h.
718 * Note: now there is no difference between png_get_libpng_ver() and
719 * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
720 * it is guaranteed that png.c uses the correct version of png.h.
721 */
722png_charp PNGAPI
723png_get_libpng_ver(png_structp png_ptr)
724{
725 /* Version of *.c files used when building libpng */
726 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
727 return ((png_charp) PNG_LIBPNG_VER_STRING);
728}
729
730png_charp PNGAPI
731png_get_header_ver(png_structp png_ptr)
732{
733 /* Version of *.h files used when building libpng */
734 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
735 return ((png_charp) PNG_LIBPNG_VER_STRING);
736}
737
738png_charp PNGAPI
739png_get_header_version(png_structp png_ptr)
740{
741 /* Returns longer string containing both version and date */
742 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
743 return ((png_charp) PNG_HEADER_VERSION_STRING
744#ifndef PNG_READ_SUPPORTED
745 " (NO READ SUPPORT)"
746#endif
747 "\n");
748}
749
750#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
751#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
752int PNGAPI
753png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
754{
755 /* Check chunk_name and return "keep" value if it's on the list, else 0 */
756 int i;
757 png_bytep p;
758 if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0)
759 return 0;
760 p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5;
761 for (i = png_ptr->num_chunk_list; i; i--, p -= 5)
762 if (!png_memcmp(chunk_name, p, 4))
763 return ((int)*(p + 4));
764 return 0;
765}
766#endif
767
768/* This function, added to libpng-1.0.6g, is untested. */
769int PNGAPI
770png_reset_zstream(png_structp png_ptr)
771{
772 if (png_ptr == NULL)
773 return Z_STREAM_ERROR;
774 return (inflateReset(&png_ptr->zstream));
775}
776#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
777
778/* This function was added to libpng-1.0.7 */
779png_uint_32 PNGAPI
780png_access_version_number(void)
781{
782 /* Version of *.c files used when building libpng */
783 return((png_uint_32) PNG_LIBPNG_VER);
784}
785
786
787#if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
788#if !defined(PNG_1_0_X)
789/* This function was added to libpng 1.2.0 */
790int PNGAPI
791png_mmx_support(void)
792{
793 /* Obsolete, to be removed from libpng-1.4.0 */
794 return -1;
795}
796#endif /* PNG_1_0_X */
797#endif /* PNG_READ_SUPPORTED && PNG_ASSEMBLER_CODE_SUPPORTED */
798
799#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
800#ifdef PNG_SIZE_T
801/* Added at libpng version 1.2.6 */
802 PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
803png_size_t PNGAPI
804png_convert_size(size_t size)
805{
806 if (size > (png_size_t)-1)
807 PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */
808 return ((png_size_t)size);
809}
810#endif /* PNG_SIZE_T */
811
812/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
813#if defined(PNG_cHRM_SUPPORTED)
814#if !defined(PNG_NO_CHECK_cHRM)
815
816/*
817 * Multiply two 32-bit numbers, V1 and V2, using 32-bit
818 * arithmetic, to produce a 64 bit result in the HI/LO words.
819 *
820 * A B
821 * x C D
822 * ------
823 * AD || BD
824 * AC || CB || 0
825 *
826 * where A and B are the high and low 16-bit words of V1,
827 * C and D are the 16-bit words of V2, AD is the product of
828 * A and D, and X || Y is (X << 16) + Y.
829*/
830
831void /* PRIVATE */
832png_64bit_product (long v1, long v2, unsigned long *hi_product,
833 unsigned long *lo_product)
834{
835 int a, b, c, d;
836 long lo, hi, x, y;
837
838 a = (v1 >> 16) & 0xffff;
839 b = v1 & 0xffff;
840 c = (v2 >> 16) & 0xffff;
841 d = v2 & 0xffff;
842
843 lo = b * d; /* BD */
844 x = a * d + c * b; /* AD + CB */
845 y = ((lo >> 16) & 0xffff) + x;
846
847 lo = (lo & 0xffff) | ((y & 0xffff) << 16);
848 hi = (y >> 16) & 0xffff;
849
850 hi += a * c; /* AC */
851
852 *hi_product = (unsigned long)hi;
853 *lo_product = (unsigned long)lo;
854}
855
856int /* PRIVATE */
857png_check_cHRM_fixed(png_structp png_ptr,
858 png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
859 png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
860 png_fixed_point blue_x, png_fixed_point blue_y)
861{
862 int ret = 1;
863 unsigned long xy_hi,xy_lo,yx_hi,yx_lo;
864
865 png_debug(1, "in function png_check_cHRM_fixed");
866 if (png_ptr == NULL)
867 return 0;
868
869 if (white_x < 0 || white_y <= 0 ||
870 red_x < 0 || red_y < 0 ||
871 green_x < 0 || green_y < 0 ||
872 blue_x < 0 || blue_y < 0)
873 {
874 png_warning(png_ptr,
875 "Ignoring attempt to set negative chromaticity value");
876 ret = 0;
877 }
878 if (white_x > (png_fixed_point) PNG_UINT_31_MAX ||
879 white_y > (png_fixed_point) PNG_UINT_31_MAX ||
880 red_x > (png_fixed_point) PNG_UINT_31_MAX ||
881 red_y > (png_fixed_point) PNG_UINT_31_MAX ||
882 green_x > (png_fixed_point) PNG_UINT_31_MAX ||
883 green_y > (png_fixed_point) PNG_UINT_31_MAX ||
884 blue_x > (png_fixed_point) PNG_UINT_31_MAX ||
885 blue_y > (png_fixed_point) PNG_UINT_31_MAX )
886 {
887 png_warning(png_ptr,
888 "Ignoring attempt to set chromaticity value exceeding 21474.83");
889 ret = 0;
890 }
891 if (white_x > 100000L - white_y)
892 {
893 png_warning(png_ptr, "Invalid cHRM white point");
894 ret = 0;
895 }
896 if (red_x > 100000L - red_y)
897 {
898 png_warning(png_ptr, "Invalid cHRM red point");
899 ret = 0;
900 }
901 if (green_x > 100000L - green_y)
902 {
903 png_warning(png_ptr, "Invalid cHRM green point");
904 ret = 0;
905 }
906 if (blue_x > 100000L - blue_y)
907 {
908 png_warning(png_ptr, "Invalid cHRM blue point");
909 ret = 0;
910 }
911
912 png_64bit_product(green_x - red_x, blue_y - red_y, &xy_hi, &xy_lo);
913 png_64bit_product(green_y - red_y, blue_x - red_x, &yx_hi, &yx_lo);
914
915 if (xy_hi == yx_hi && xy_lo == yx_lo)
916 {
917 png_warning(png_ptr,
918 "Ignoring attempt to set cHRM RGB triangle with zero area");
919 ret = 0;
920 }
921
922 return ret;
923}
924#endif /* NO_PNG_CHECK_cHRM */
925#endif /* PNG_cHRM_SUPPORTED */
926#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
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