png.c@ 13005

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export libpng and zlib so Windows and OS/2 builds cleanly.
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1
2	/* png.c - location for general purpose libpng functions
3	*
4	* libpng version 1.2.8 - December 3, 2004
5	* For conditions of distribution and use, see copyright notice in png.h
6	* Copyright (c) 1998-2004 Glenn Randers-Pehrson
7	* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8	* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9	*/
10
11	#define PNG_INTERNAL
12	#define PNG_NO_EXTERN
13	#include "png.h"
14
15	/* Generate a compiler error if there is an old png.h in the search path. */
16	typedef version_1_2_8 Your_png_h_is_not_version_1_2_8;
17
18	/* Version information for C files. This had better match the version
19	* string defined in png.h. */
20
21	#ifdef PNG_USE_GLOBAL_ARRAYS
22	/* png_libpng_ver was changed to a function in version 1.0.5c */
23	const char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING;
24
25	/* png_sig was changed to a function in version 1.0.5c */
26	/* Place to hold the signature string for a PNG file. */
27	const png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
28
29	/* Invoke global declarations for constant strings for known chunk types */
30	PNG_IHDR;
31	PNG_IDAT;
32	PNG_IEND;
33	PNG_PLTE;
34	PNG_bKGD;
35	PNG_cHRM;
36	PNG_gAMA;
37	PNG_hIST;
38	PNG_iCCP;
39	PNG_iTXt;
40	PNG_oFFs;
41	PNG_pCAL;
42	PNG_sCAL;
43	PNG_pHYs;
44	PNG_sBIT;
45	PNG_sPLT;
46	PNG_sRGB;
47	PNG_tEXt;
48	PNG_tIME;
49	PNG_tRNS;
50	PNG_zTXt;
51
52	/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
53
54	/* start of interlace block */
55	const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
56
57	/* offset to next interlace block */
58	const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
59
60	/* start of interlace block in the y direction */
61	const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
62
63	/* offset to next interlace block in the y direction */
64	const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
65
66	/* width of interlace block (used in assembler routines only) */
67	#ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
68	const int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
69	#endif
70
71	/* Height of interlace block. This is not currently used - if you need
72	* it, uncomment it here and in png.h
73	const int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
74	*/
75
76	/* Mask to determine which pixels are valid in a pass */
77	const int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
78
79	/* Mask to determine which pixels to overwrite while displaying */
80	const int FARDATA png_pass_dsp_mask[]
81	= {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
82
83	#endif /* PNG_USE_GLOBAL_ARRAYS */
84
85	/* Tells libpng that we have already handled the first "num_bytes" bytes
86	* of the PNG file signature. If the PNG data is embedded into another
87	* stream we can set num_bytes = 8 so that libpng will not attempt to read
88	* or write any of the magic bytes before it starts on the IHDR.
89	*/
90
91	void PNGAPI
92	png_set_sig_bytes(png_structp png_ptr, int num_bytes)
93	{
94	png_debug(1, "in png_set_sig_bytes\n");
95	if (num_bytes > 8)
96	png_error(png_ptr, "Too many bytes for PNG signature.");
97
98	png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
99	}
100
101	/* Checks whether the supplied bytes match the PNG signature. We allow
102	* checking less than the full 8-byte signature so that those apps that
103	* already read the first few bytes of a file to determine the file type
104	* can simply check the remaining bytes for extra assurance. Returns
105	* an integer less than, equal to, or greater than zero if sig is found,
106	* respectively, to be less than, to match, or be greater than the correct
107	* PNG signature (this is the same behaviour as strcmp, memcmp, etc).
108	*/
109	int PNGAPI
110	png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
111	{
112	png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
113	if (num_to_check > 8)
114	num_to_check = 8;
115	else if (num_to_check < 1)
116	return (0);
117
118	if (start > 7)
119	return (0);
120
121	if (start + num_to_check > 8)
122	num_to_check = 8 - start;
123
124	return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
125	}
126
127	/* (Obsolete) function to check signature bytes. It does not allow one
128	* to check a partial signature. This function might be removed in the
129	* future - use png_sig_cmp(). Returns true (nonzero) if the file is a PNG.
130	*/
131	int PNGAPI
132	png_check_sig(png_bytep sig, int num)
133	{
134	return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
135	}
136
137	/* Function to allocate memory for zlib and clear it to 0. */
138	#ifdef PNG_1_0_X
139	voidpf PNGAPI
140	#else
141	voidpf /* private */
142	#endif
143	png_zalloc(voidpf png_ptr, uInt items, uInt size)
144	{
145	png_voidp ptr;
146	png_structp p=png_ptr;
147	png_uint_32 save_flags=p->flags;
148	png_uint_32 num_bytes;
149
150	if (items > PNG_UINT_32_MAX/size)
151	{
152	png_warning (png_ptr, "Potential overflow in png_zalloc()");
153	return (NULL);
154	}
155	num_bytes = (png_uint_32)items * size;
156
157	p->flags\|=PNG_FLAG_MALLOC_NULL_MEM_OK;
158	ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
159	p->flags=save_flags;
160
161	#if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
162	if (ptr == NULL)
163	return ((voidpf)ptr);
164
165	if (num_bytes > (png_uint_32)0x8000L)
166	{
167	png_memset(ptr, 0, (png_size_t)0x8000L);
168	png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
169	(png_size_t)(num_bytes - (png_uint_32)0x8000L));
170	}
171	else
172	{
173	png_memset(ptr, 0, (png_size_t)num_bytes);
174	}
175	#endif
176	return ((voidpf)ptr);
177	}
178
179	/* function to free memory for zlib */
180	#ifdef PNG_1_0_X
181	void PNGAPI
182	#else
183	void /* private */
184	#endif
185	png_zfree(voidpf png_ptr, voidpf ptr)
186	{
187	png_free((png_structp)png_ptr, (png_voidp)ptr);
188	}
189
190	/* Reset the CRC variable to 32 bits of 1's. Care must be taken
191	* in case CRC is > 32 bits to leave the top bits 0.
192	*/
193	void /* PRIVATE */
194	png_reset_crc(png_structp png_ptr)
195	{
196	png_ptr->crc = crc32(0, Z_NULL, 0);
197	}
198
199	/* Calculate the CRC over a section of data. We can only pass as
200	* much data to this routine as the largest single buffer size. We
201	* also check that this data will actually be used before going to the
202	* trouble of calculating it.
203	*/
204	void /* PRIVATE */
205	png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
206	{
207	int need_crc = 1;
208
209	if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
210	{
211	if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
212	(PNG_FLAG_CRC_ANCILLARY_USE \| PNG_FLAG_CRC_ANCILLARY_NOWARN))
213	need_crc = 0;
214	}
215	else /* critical */
216	{
217	if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
218	need_crc = 0;
219	}
220
221	if (need_crc)
222	png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
223	}
224
225	/* Allocate the memory for an info_struct for the application. We don't
226	* really need the png_ptr, but it could potentially be useful in the
227	* future. This should be used in favour of malloc(png_sizeof(png_info))
228	* and png_info_init() so that applications that want to use a shared
229	* libpng don't have to be recompiled if png_info changes size.
230	*/
231	png_infop PNGAPI
232	png_create_info_struct(png_structp png_ptr)
233	{
234	png_infop info_ptr;
235
236	png_debug(1, "in png_create_info_struct\n");
237	if(png_ptr == NULL) return (NULL);
238	#ifdef PNG_USER_MEM_SUPPORTED
239	info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
240	png_ptr->malloc_fn, png_ptr->mem_ptr);
241	#else
242	info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
243	#endif
244	if (info_ptr != NULL)
245	png_info_init_3(&info_ptr, png_sizeof(png_info));
246
247	return (info_ptr);
248	}
249
250	/* This function frees the memory associated with a single info struct.
251	* Normally, one would use either png_destroy_read_struct() or
252	* png_destroy_write_struct() to free an info struct, but this may be
253	* useful for some applications.
254	*/
255	void PNGAPI
256	png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
257	{
258	png_infop info_ptr = NULL;
259
260	png_debug(1, "in png_destroy_info_struct\n");
261	if (info_ptr_ptr != NULL)
262	info_ptr = *info_ptr_ptr;
263
264	if (info_ptr != NULL)
265	{
266	png_info_destroy(png_ptr, info_ptr);
267
268	#ifdef PNG_USER_MEM_SUPPORTED
269	png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
270	png_ptr->mem_ptr);
271	#else
272	png_destroy_struct((png_voidp)info_ptr);
273	#endif
274	*info_ptr_ptr = NULL;
275	}
276	}
277
278	/* Initialize the info structure. This is now an internal function (0.89)
279	* and applications using it are urged to use png_create_info_struct()
280	* instead.
281	*/
282	#if defined(PNG_1_0_X) \|\| defined (PNG_1_2_X)
283	#undef png_info_init
284	void PNGAPI
285	png_info_init(png_infop info_ptr)
286	{
287	/* We only come here via pre-1.0.12-compiled applications */
288	png_info_init_3(&info_ptr, 0);
289	}
290	#endif
291
292	void PNGAPI
293	png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
294	{
295	png_infop info_ptr = *ptr_ptr;
296
297	png_debug(1, "in png_info_init_3\n");
298
299	if(png_sizeof(png_info) > png_info_struct_size)
300	{
301	png_destroy_struct(info_ptr);
302	info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
303	*ptr_ptr = info_ptr;
304	}
305
306	/* set everything to 0 */
307	png_memset(info_ptr, 0, png_sizeof (png_info));
308	}
309
310	#ifdef PNG_FREE_ME_SUPPORTED
311	void PNGAPI
312	png_data_freer(png_structp png_ptr, png_infop info_ptr,
313	int freer, png_uint_32 mask)
314	{
315	png_debug(1, "in png_data_freer\n");
316	if (png_ptr == NULL \|\| info_ptr == NULL)
317	return;
318	if(freer == PNG_DESTROY_WILL_FREE_DATA)
319	info_ptr->free_me \|= mask;
320	else if(freer == PNG_USER_WILL_FREE_DATA)
321	info_ptr->free_me &= ~mask;
322	else
323	png_warning(png_ptr,
324	"Unknown freer parameter in png_data_freer.");
325	}
326	#endif
327
328	void PNGAPI
329	png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
330	int num)
331	{
332	png_debug(1, "in png_free_data\n");
333	if (png_ptr == NULL \|\| info_ptr == NULL)
334	return;
335
336	#if defined(PNG_TEXT_SUPPORTED)
337	/* free text item num or (if num == -1) all text items */
338	#ifdef PNG_FREE_ME_SUPPORTED
339	if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
340	#else
341	if (mask & PNG_FREE_TEXT)
342	#endif
343	{
344	if (num != -1)
345	{
346	if (info_ptr->text && info_ptr->text[num].key)
347	{
348	png_free(png_ptr, info_ptr->text[num].key);
349	info_ptr->text[num].key = NULL;
350	}
351	}
352	else
353	{
354	int i;
355	for (i = 0; i < info_ptr->num_text; i++)
356	png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
357	png_free(png_ptr, info_ptr->text);
358	info_ptr->text = NULL;
359	info_ptr->num_text=0;
360	}
361	}
362	#endif
363
364	#if defined(PNG_tRNS_SUPPORTED)
365	/* free any tRNS entry */
366	#ifdef PNG_FREE_ME_SUPPORTED
367	if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
368	#else
369	if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
370	#endif
371	{
372	png_free(png_ptr, info_ptr->trans);
373	info_ptr->valid &= ~PNG_INFO_tRNS;
374	#ifndef PNG_FREE_ME_SUPPORTED
375	png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
376	#endif
377	info_ptr->trans = NULL;
378	}
379	#endif
380
381	#if defined(PNG_sCAL_SUPPORTED)
382	/* free any sCAL entry */
383	#ifdef PNG_FREE_ME_SUPPORTED
384	if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
385	#else
386	if (mask & PNG_FREE_SCAL)
387	#endif
388	{
389	#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
390	png_free(png_ptr, info_ptr->scal_s_width);
391	png_free(png_ptr, info_ptr->scal_s_height);
392	info_ptr->scal_s_width = NULL;
393	info_ptr->scal_s_height = NULL;
394	#endif
395	info_ptr->valid &= ~PNG_INFO_sCAL;
396	}
397	#endif
398
399	#if defined(PNG_pCAL_SUPPORTED)
400	/* free any pCAL entry */
401	#ifdef PNG_FREE_ME_SUPPORTED
402	if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
403	#else
404	if (mask & PNG_FREE_PCAL)
405	#endif
406	{
407	png_free(png_ptr, info_ptr->pcal_purpose);
408	png_free(png_ptr, info_ptr->pcal_units);
409	info_ptr->pcal_purpose = NULL;
410	info_ptr->pcal_units = NULL;
411	if (info_ptr->pcal_params != NULL)
412	{
413	int i;
414	for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
415	{
416	png_free(png_ptr, info_ptr->pcal_params[i]);
417	info_ptr->pcal_params[i]=NULL;
418	}
419	png_free(png_ptr, info_ptr->pcal_params);
420	info_ptr->pcal_params = NULL;
421	}
422	info_ptr->valid &= ~PNG_INFO_pCAL;
423	}
424	#endif
425
426	#if defined(PNG_iCCP_SUPPORTED)
427	/* free any iCCP entry */
428	#ifdef PNG_FREE_ME_SUPPORTED
429	if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
430	#else
431	if (mask & PNG_FREE_ICCP)
432	#endif
433	{
434	png_free(png_ptr, info_ptr->iccp_name);
435	png_free(png_ptr, info_ptr->iccp_profile);
436	info_ptr->iccp_name = NULL;
437	info_ptr->iccp_profile = NULL;
438	info_ptr->valid &= ~PNG_INFO_iCCP;
439	}
440	#endif
441
442	#if defined(PNG_sPLT_SUPPORTED)
443	/* free a given sPLT entry, or (if num == -1) all sPLT entries */
444	#ifdef PNG_FREE_ME_SUPPORTED
445	if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
446	#else
447	if (mask & PNG_FREE_SPLT)
448	#endif
449	{
450	if (num != -1)
451	{
452	if(info_ptr->splt_palettes)
453	{
454	png_free(png_ptr, info_ptr->splt_palettes[num].name);
455	png_free(png_ptr, info_ptr->splt_palettes[num].entries);
456	info_ptr->splt_palettes[num].name = NULL;
457	info_ptr->splt_palettes[num].entries = NULL;
458	}
459	}
460	else
461	{
462	if(info_ptr->splt_palettes_num)
463	{
464	int i;
465	for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
466	png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
467
468	png_free(png_ptr, info_ptr->splt_palettes);
469	info_ptr->splt_palettes = NULL;
470	info_ptr->splt_palettes_num = 0;
471	}
472	info_ptr->valid &= ~PNG_INFO_sPLT;
473	}
474	}
475	#endif
476
477	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
478	#ifdef PNG_FREE_ME_SUPPORTED
479	if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
480	#else
481	if (mask & PNG_FREE_UNKN)
482	#endif
483	{
484	if (num != -1)
485	{
486	if(info_ptr->unknown_chunks)
487	{
488	png_free(png_ptr, info_ptr->unknown_chunks[num].data);
489	info_ptr->unknown_chunks[num].data = NULL;
490	}
491	}
492	else
493	{
494	int i;
495
496	if(info_ptr->unknown_chunks_num)
497	{
498	for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
499	png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
500
501	png_free(png_ptr, info_ptr->unknown_chunks);
502	info_ptr->unknown_chunks = NULL;
503	info_ptr->unknown_chunks_num = 0;
504	}
505	}
506	}
507	#endif
508
509	#if defined(PNG_hIST_SUPPORTED)
510	/* free any hIST entry */
511	#ifdef PNG_FREE_ME_SUPPORTED
512	if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
513	#else
514	if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
515	#endif
516	{
517	png_free(png_ptr, info_ptr->hist);
518	info_ptr->hist = NULL;
519	info_ptr->valid &= ~PNG_INFO_hIST;
520	#ifndef PNG_FREE_ME_SUPPORTED
521	png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
522	#endif
523	}
524	#endif
525
526	/* free any PLTE entry that was internally allocated */
527	#ifdef PNG_FREE_ME_SUPPORTED
528	if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
529	#else
530	if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
531	#endif
532	{
533	png_zfree(png_ptr, info_ptr->palette);
534	info_ptr->palette = NULL;
535	info_ptr->valid &= ~PNG_INFO_PLTE;
536	#ifndef PNG_FREE_ME_SUPPORTED
537	png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
538	#endif
539	info_ptr->num_palette = 0;
540	}
541
542	#if defined(PNG_INFO_IMAGE_SUPPORTED)
543	/* free any image bits attached to the info structure */
544	#ifdef PNG_FREE_ME_SUPPORTED
545	if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
546	#else
547	if (mask & PNG_FREE_ROWS)
548	#endif
549	{
550	if(info_ptr->row_pointers)
551	{
552	int row;
553	for (row = 0; row < (int)info_ptr->height; row++)
554	{
555	png_free(png_ptr, info_ptr->row_pointers[row]);
556	info_ptr->row_pointers[row]=NULL;
557	}
558	png_free(png_ptr, info_ptr->row_pointers);
559	info_ptr->row_pointers=NULL;
560	}
561	info_ptr->valid &= ~PNG_INFO_IDAT;
562	}
563	#endif
564
565	#ifdef PNG_FREE_ME_SUPPORTED
566	if(num == -1)
567	info_ptr->free_me &= ~mask;
568	else
569	info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
570	#endif
571	}
572
573	/* This is an internal routine to free any memory that the info struct is
574	* pointing to before re-using it or freeing the struct itself. Recall
575	* that png_free() checks for NULL pointers for us.
576	*/
577	void /* PRIVATE */
578	png_info_destroy(png_structp png_ptr, png_infop info_ptr)
579	{
580	png_debug(1, "in png_info_destroy\n");
581
582	png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
583
584	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
585	if (png_ptr->num_chunk_list)
586	{
587	png_free(png_ptr, png_ptr->chunk_list);
588	png_ptr->chunk_list=NULL;
589	png_ptr->num_chunk_list=0;
590	}
591	#endif
592
593	png_info_init_3(&info_ptr, png_sizeof(png_info));
594	}
595
596	/* This function returns a pointer to the io_ptr associated with the user
597	* functions. The application should free any memory associated with this
598	* pointer before png_write_destroy() or png_read_destroy() are called.
599	*/
600	png_voidp PNGAPI
601	png_get_io_ptr(png_structp png_ptr)
602	{
603	return (png_ptr->io_ptr);
604	}
605
606	#if !defined(PNG_NO_STDIO)
607	/* Initialize the default input/output functions for the PNG file. If you
608	* use your own read or write routines, you can call either png_set_read_fn()
609	* or png_set_write_fn() instead of png_init_io(). If you have defined
610	* PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
611	* necessarily available.
612	*/
613	void PNGAPI
614	png_init_io(png_structp png_ptr, png_FILE_p fp)
615	{
616	png_debug(1, "in png_init_io\n");
617	png_ptr->io_ptr = (png_voidp)fp;
618	}
619	#endif
620
621	#if defined(PNG_TIME_RFC1123_SUPPORTED)
622	/* Convert the supplied time into an RFC 1123 string suitable for use in
623	* a "Creation Time" or other text-based time string.
624	*/
625	png_charp PNGAPI
626	png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
627	{
628	static PNG_CONST char short_months[12][4] =
629	{"Jan", "Feb", "Mar", "Apr", "May", "Jun",
630	"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
631
632	if (png_ptr->time_buffer == NULL)
633	{
634	png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
635	png_sizeof(char)));
636	}
637
638	#if defined(_WIN32_WCE)
639	{
640	wchar_t time_buf[29];
641	wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
642	ptime->day % 32, short_months[(ptime->month - 1) % 12],
643	ptime->year, ptime->hour % 24, ptime->minute % 60,
644	ptime->second % 61);
645	WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
646	NULL, NULL);
647	}
648	#else
649	#ifdef USE_FAR_KEYWORD
650	{
651	char near_time_buf[29];
652	sprintf(near_time_buf, "%d %s %d %02d:%02d:%02d +0000",
653	ptime->day % 32, short_months[(ptime->month - 1) % 12],
654	ptime->year, ptime->hour % 24, ptime->minute % 60,
655	ptime->second % 61);
656	png_memcpy(png_ptr->time_buffer, near_time_buf,
657	29*png_sizeof(char));
658	}
659	#else
660	sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000",
661	ptime->day % 32, short_months[(ptime->month - 1) % 12],
662	ptime->year, ptime->hour % 24, ptime->minute % 60,
663	ptime->second % 61);
664	#endif
665	#endif /* _WIN32_WCE */
666	return ((png_charp)png_ptr->time_buffer);
667	}
668	#endif /* PNG_TIME_RFC1123_SUPPORTED */
669
670	#if 0
671	/* Signature string for a PNG file. */
672	png_bytep PNGAPI
673	png_sig_bytes(void)
674	{
675	return ((png_bytep)"\211\120\116\107\015\012\032\012");
676	}
677	#endif
678
679	png_charp PNGAPI
680	png_get_copyright(png_structp png_ptr)
681	{
682	if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
683	return ((png_charp) "\n libpng version 1.2.8 - December 3, 2004\n\
684	Copyright (c) 1998-2004 Glenn Randers-Pehrson\n\
685	Copyright (c) 1996-1997 Andreas Dilger\n\
686	Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n");
687	return ((png_charp) "");
688	}
689
690	/* The following return the library version as a short string in the
691	* format 1.0.0 through 99.99.99zz. To get the version of *.h files
692	* used with your application, print out PNG_LIBPNG_VER_STRING, which
693	* is defined in png.h.
694	* Note: now there is no difference between png_get_libpng_ver() and
695	* png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
696	* it is guaranteed that png.c uses the correct version of png.h.
697	*/
698	png_charp PNGAPI
699	png_get_libpng_ver(png_structp png_ptr)
700	{
701	/* Version of .c files used when building libpng /
702	if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
703	return ((png_charp) PNG_LIBPNG_VER_STRING);
704	return ((png_charp) "");
705	}
706
707	png_charp PNGAPI
708	png_get_header_ver(png_structp png_ptr)
709	{
710	/* Version of .h files used when building libpng /
711	if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
712	return ((png_charp) PNG_LIBPNG_VER_STRING);
713	return ((png_charp) "");
714	}
715
716	png_charp PNGAPI
717	png_get_header_version(png_structp png_ptr)
718	{
719	/* Returns longer string containing both version and date */
720	if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
721	return ((png_charp) PNG_HEADER_VERSION_STRING);
722	return ((png_charp) "");
723	}
724
725	#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
726	int PNGAPI
727	png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
728	{
729	/* check chunk_name and return "keep" value if it's on the list, else 0 */
730	int i;
731	png_bytep p;
732	if((png_ptr == NULL && chunk_name == NULL) \|\| png_ptr->num_chunk_list<=0)
733	return 0;
734	p=png_ptr->chunk_list+png_ptr->num_chunk_list*5-5;
735	for (i = png_ptr->num_chunk_list; i; i--, p-=5)
736	if (!png_memcmp(chunk_name, p, 4))
737	return ((int)*(p+4));
738	return 0;
739	}
740	#endif
741
742	/* This function, added to libpng-1.0.6g, is untested. */
743	int PNGAPI
744	png_reset_zstream(png_structp png_ptr)
745	{
746	return (inflateReset(&png_ptr->zstream));
747	}
748
749	/* This function was added to libpng-1.0.7 */
750	png_uint_32 PNGAPI
751	png_access_version_number(void)
752	{
753	/* Version of .c files used when building libpng /
754	return((png_uint_32) PNG_LIBPNG_VER);
755	}
756
757
758	#if !defined(PNG_1_0_X)
759	#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
760	/* GRR: could add this: && defined(PNG_MMX_CODE_SUPPORTED) */
761	/* this INTERNAL function was added to libpng 1.2.0 */
762	void /* PRIVATE */
763	png_init_mmx_flags (png_structp png_ptr)
764	{
765	png_ptr->mmx_rowbytes_threshold = 0;
766	png_ptr->mmx_bitdepth_threshold = 0;
767
768	# if (defined(PNG_USE_PNGVCRD) \|\| defined(PNG_USE_PNGGCCRD))
769
770	png_ptr->asm_flags \|= PNG_ASM_FLAG_MMX_SUPPORT_COMPILED;
771
772	if (png_mmx_support() > 0) {
773	png_ptr->asm_flags \|= PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
774	# ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
775	\| PNG_ASM_FLAG_MMX_READ_COMBINE_ROW
776	# endif
777	# ifdef PNG_HAVE_ASSEMBLER_READ_INTERLACE
778	\| PNG_ASM_FLAG_MMX_READ_INTERLACE
779	# endif
780	# ifndef PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
781	;
782	# else
783	\| PNG_ASM_FLAG_MMX_READ_FILTER_SUB
784	\| PNG_ASM_FLAG_MMX_READ_FILTER_UP
785	\| PNG_ASM_FLAG_MMX_READ_FILTER_AVG
786	\| PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ;
787
788	png_ptr->mmx_rowbytes_threshold = PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT;
789	png_ptr->mmx_bitdepth_threshold = PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT;
790	# endif
791	} else {
792	png_ptr->asm_flags &= ~( PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
793	\| PNG_MMX_READ_FLAGS
794	\| PNG_MMX_WRITE_FLAGS );
795	}
796
797	# else /* !((PNGVCRD \|\| PNGGCCRD) && PNG_ASSEMBLER_CODE_SUPPORTED)) */
798
799	/* clear all MMX flags; no support is compiled in */
800	png_ptr->asm_flags &= ~( PNG_MMX_FLAGS );
801
802	# endif /* ?(PNGVCRD \|\| PNGGCCRD) */
803	}
804
805	#endif /* !(PNG_ASSEMBLER_CODE_SUPPORTED) */
806
807	/* this function was added to libpng 1.2.0 */
808	#if !defined(PNG_USE_PNGGCCRD) && \
809	!(defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_USE_PNGVCRD))
810	int PNGAPI
811	png_mmx_support(void)
812	{
813	return -1;
814	}
815	#endif
816	#endif /* PNG_1_0_X */
817
818	#ifdef PNG_SIZE_T
819	/* Added at libpng version 1.2.6 */
820	PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
821	png_size_t PNGAPI
822	png_convert_size(size_t size)
823	{
824	if (size > (png_size_t)-1)
825	PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */
826	return ((png_size_t)size);
827	}
828	#endif /* PNG_SIZE_T */

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