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source: vbox/trunk/src/libs/libpng-1.2.54/pngwrite.c@ 75439

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libpng 1.2.54 unmodified
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1
2/* pngwrite.c - general routines to write a PNG file
3 *
4 * Last changed in libpng 1.2.54 [November 12, 2015]
5 * Copyright (c) 1998-2015 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/* Get internal access to png.h */
15#define PNG_INTERNAL
16#define PNG_NO_PEDANTIC_WARNINGS
17#include "png.h"
18#ifdef PNG_WRITE_SUPPORTED
19
20/* Writes all the PNG information. This is the suggested way to use the
21 * library. If you have a new chunk to add, make a function to write it,
22 * and put it in the correct location here. If you want the chunk written
23 * after the image data, put it in png_write_end(). I strongly encourage
24 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
25 * the chunk, as that will keep the code from breaking if you want to just
26 * write a plain PNG file. If you have long comments, I suggest writing
27 * them in png_write_end(), and compressing them.
28 */
29void PNGAPI
30png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
31{
32 png_debug(1, "in png_write_info_before_PLTE");
33
34 if (png_ptr == NULL || info_ptr == NULL)
35 return;
36 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
37 {
38 /* Write PNG signature */
39 png_write_sig(png_ptr);
40#ifdef PNG_MNG_FEATURES_SUPPORTED
41 if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
42 (png_ptr->mng_features_permitted))
43 {
44 png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
45 png_ptr->mng_features_permitted = 0;
46 }
47#endif
48 /* Write IHDR information. */
49 png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
50 info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
51 info_ptr->filter_type,
52#ifdef PNG_WRITE_INTERLACING_SUPPORTED
53 info_ptr->interlace_type);
54#else
55 0);
56#endif
57 /* The rest of these check to see if the valid field has the appropriate
58 * flag set, and if it does, writes the chunk.
59 */
60#ifdef PNG_WRITE_gAMA_SUPPORTED
61 if (info_ptr->valid & PNG_INFO_gAMA)
62 {
63# ifdef PNG_FLOATING_POINT_SUPPORTED
64 png_write_gAMA(png_ptr, info_ptr->gamma);
65#else
66#ifdef PNG_FIXED_POINT_SUPPORTED
67 png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
68# endif
69#endif
70 }
71#endif
72#ifdef PNG_WRITE_sRGB_SUPPORTED
73 if (info_ptr->valid & PNG_INFO_sRGB)
74 png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
75#endif
76#ifdef PNG_WRITE_iCCP_SUPPORTED
77 if (info_ptr->valid & PNG_INFO_iCCP)
78 png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
79 info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
80#endif
81#ifdef PNG_WRITE_sBIT_SUPPORTED
82 if (info_ptr->valid & PNG_INFO_sBIT)
83 png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
84#endif
85#ifdef PNG_WRITE_cHRM_SUPPORTED
86 if (info_ptr->valid & PNG_INFO_cHRM)
87 {
88#ifdef PNG_FLOATING_POINT_SUPPORTED
89 png_write_cHRM(png_ptr,
90 info_ptr->x_white, info_ptr->y_white,
91 info_ptr->x_red, info_ptr->y_red,
92 info_ptr->x_green, info_ptr->y_green,
93 info_ptr->x_blue, info_ptr->y_blue);
94#else
95# ifdef PNG_FIXED_POINT_SUPPORTED
96 png_write_cHRM_fixed(png_ptr,
97 info_ptr->int_x_white, info_ptr->int_y_white,
98 info_ptr->int_x_red, info_ptr->int_y_red,
99 info_ptr->int_x_green, info_ptr->int_y_green,
100 info_ptr->int_x_blue, info_ptr->int_y_blue);
101# endif
102#endif
103 }
104#endif
105#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
106 if (info_ptr->unknown_chunks_num)
107 {
108 png_unknown_chunk *up;
109
110 png_debug(5, "writing extra chunks");
111
112 for (up = info_ptr->unknown_chunks;
113 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
114 up++)
115 {
116 int keep = png_handle_as_unknown(png_ptr, up->name);
117 if (keep != PNG_HANDLE_CHUNK_NEVER &&
118 up->location && !(up->location & PNG_HAVE_PLTE) &&
119 !(up->location & PNG_HAVE_IDAT) &&
120 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
121 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
122 {
123 if (up->size == 0)
124 png_warning(png_ptr, "Writing zero-length unknown chunk");
125 png_write_chunk(png_ptr, up->name, up->data, up->size);
126 }
127 }
128 }
129#endif
130 png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
131 }
132}
133
134void PNGAPI
135png_write_info(png_structp png_ptr, png_infop info_ptr)
136{
137#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
138 int i;
139#endif
140
141 png_debug(1, "in png_write_info");
142
143 if (png_ptr == NULL || info_ptr == NULL)
144 return;
145
146 png_write_info_before_PLTE(png_ptr, info_ptr);
147
148 if (info_ptr->valid & PNG_INFO_PLTE)
149 png_write_PLTE(png_ptr, info_ptr->palette,
150 (png_uint_32)info_ptr->num_palette);
151 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
152 png_error(png_ptr, "Valid palette required for paletted images");
153
154#ifdef PNG_WRITE_tRNS_SUPPORTED
155 if (info_ptr->valid & PNG_INFO_tRNS)
156 {
157#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
158 /* Invert the alpha channel (in tRNS) */
159 if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
160 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
161 {
162 int j;
163 for (j = 0; j<(int)info_ptr->num_trans; j++)
164 info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
165 }
166#endif
167 png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
168 info_ptr->num_trans, info_ptr->color_type);
169 }
170#endif
171#ifdef PNG_WRITE_bKGD_SUPPORTED
172 if (info_ptr->valid & PNG_INFO_bKGD)
173 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
174#endif
175#ifdef PNG_WRITE_hIST_SUPPORTED
176 if (info_ptr->valid & PNG_INFO_hIST)
177 png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
178#endif
179#ifdef PNG_WRITE_oFFs_SUPPORTED
180 if (info_ptr->valid & PNG_INFO_oFFs)
181 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
182 info_ptr->offset_unit_type);
183#endif
184#ifdef PNG_WRITE_pCAL_SUPPORTED
185 if (info_ptr->valid & PNG_INFO_pCAL)
186 png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
187 info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
188 info_ptr->pcal_units, info_ptr->pcal_params);
189#endif
190
191#ifdef PNG_sCAL_SUPPORTED
192 if (info_ptr->valid & PNG_INFO_sCAL)
193#ifdef PNG_WRITE_sCAL_SUPPORTED
194#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
195 png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
196 info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
197#else /* !FLOATING_POINT */
198#ifdef PNG_FIXED_POINT_SUPPORTED
199 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
200 info_ptr->scal_s_width, info_ptr->scal_s_height);
201#endif /* FIXED_POINT */
202#endif /* FLOATING_POINT */
203#else /* !WRITE_sCAL */
204 png_warning(png_ptr,
205 "png_write_sCAL not supported; sCAL chunk not written.");
206#endif /* WRITE_sCAL */
207#endif /* sCAL */
208
209#ifdef PNG_WRITE_pHYs_SUPPORTED
210 if (info_ptr->valid & PNG_INFO_pHYs)
211 png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
212 info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
213#endif /* pHYs */
214
215#ifdef PNG_WRITE_tIME_SUPPORTED
216 if (info_ptr->valid & PNG_INFO_tIME)
217 {
218 png_write_tIME(png_ptr, &(info_ptr->mod_time));
219 png_ptr->mode |= PNG_WROTE_tIME;
220 }
221#endif /* tIME */
222
223#ifdef PNG_WRITE_sPLT_SUPPORTED
224 if (info_ptr->valid & PNG_INFO_sPLT)
225 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
226 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
227#endif /* sPLT */
228
229#ifdef PNG_WRITE_TEXT_SUPPORTED
230 /* Check to see if we need to write text chunks */
231 for (i = 0; i < info_ptr->num_text; i++)
232 {
233 png_debug2(2, "Writing header text chunk %d, type %d", i,
234 info_ptr->text[i].compression);
235 /* An internationalized chunk? */
236 if (info_ptr->text[i].compression > 0)
237 {
238#ifdef PNG_WRITE_iTXt_SUPPORTED
239 /* Write international chunk */
240 png_write_iTXt(png_ptr,
241 info_ptr->text[i].compression,
242 info_ptr->text[i].key,
243 info_ptr->text[i].lang,
244 info_ptr->text[i].lang_key,
245 info_ptr->text[i].text);
246#else
247 png_warning(png_ptr, "Unable to write international text");
248#endif
249 /* Mark this chunk as written */
250 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
251 }
252 /* If we want a compressed text chunk */
253 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
254 {
255#ifdef PNG_WRITE_zTXt_SUPPORTED
256 /* Write compressed chunk */
257 png_write_zTXt(png_ptr, info_ptr->text[i].key,
258 info_ptr->text[i].text, 0,
259 info_ptr->text[i].compression);
260#else
261 png_warning(png_ptr, "Unable to write compressed text");
262#endif
263 /* Mark this chunk as written */
264 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
265 }
266 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
267 {
268#ifdef PNG_WRITE_tEXt_SUPPORTED
269 /* Write uncompressed chunk */
270 png_write_tEXt(png_ptr, info_ptr->text[i].key,
271 info_ptr->text[i].text,
272 0);
273 /* Mark this chunk as written */
274 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
275#else
276 /* Can't get here */
277 png_warning(png_ptr, "Unable to write uncompressed text");
278#endif
279 }
280 }
281#endif /* tEXt */
282
283#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
284 if (info_ptr->unknown_chunks_num)
285 {
286 png_unknown_chunk *up;
287
288 png_debug(5, "writing extra chunks");
289
290 for (up = info_ptr->unknown_chunks;
291 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
292 up++)
293 {
294 int keep = png_handle_as_unknown(png_ptr, up->name);
295 if (keep != PNG_HANDLE_CHUNK_NEVER &&
296 up->location && (up->location & PNG_HAVE_PLTE) &&
297 !(up->location & PNG_HAVE_IDAT) &&
298 !(up->location & PNG_AFTER_IDAT) &&
299 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
300 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
301 {
302 png_write_chunk(png_ptr, up->name, up->data, up->size);
303 }
304 }
305 }
306#endif
307}
308
309/* Writes the end of the PNG file. If you don't want to write comments or
310 * time information, you can pass NULL for info. If you already wrote these
311 * in png_write_info(), do not write them again here. If you have long
312 * comments, I suggest writing them here, and compressing them.
313 */
314void PNGAPI
315png_write_end(png_structp png_ptr, png_infop info_ptr)
316{
317 png_debug(1, "in png_write_end");
318
319 if (png_ptr == NULL)
320 return;
321 if (!(png_ptr->mode & PNG_HAVE_IDAT))
322 png_error(png_ptr, "No IDATs written into file");
323
324 /* See if user wants us to write information chunks */
325 if (info_ptr != NULL)
326 {
327#ifdef PNG_WRITE_TEXT_SUPPORTED
328 int i; /* local index variable */
329#endif
330#ifdef PNG_WRITE_tIME_SUPPORTED
331 /* Check to see if user has supplied a time chunk */
332 if ((info_ptr->valid & PNG_INFO_tIME) &&
333 !(png_ptr->mode & PNG_WROTE_tIME))
334 png_write_tIME(png_ptr, &(info_ptr->mod_time));
335#endif
336#ifdef PNG_WRITE_TEXT_SUPPORTED
337 /* Loop through comment chunks */
338 for (i = 0; i < info_ptr->num_text; i++)
339 {
340 png_debug2(2, "Writing trailer text chunk %d, type %d", i,
341 info_ptr->text[i].compression);
342 /* An internationalized chunk? */
343 if (info_ptr->text[i].compression > 0)
344 {
345#ifdef PNG_WRITE_iTXt_SUPPORTED
346 /* Write international chunk */
347 png_write_iTXt(png_ptr,
348 info_ptr->text[i].compression,
349 info_ptr->text[i].key,
350 info_ptr->text[i].lang,
351 info_ptr->text[i].lang_key,
352 info_ptr->text[i].text);
353#else
354 png_warning(png_ptr, "Unable to write international text");
355#endif
356 /* Mark this chunk as written */
357 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
358 }
359 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
360 {
361#ifdef PNG_WRITE_zTXt_SUPPORTED
362 /* Write compressed chunk */
363 png_write_zTXt(png_ptr, info_ptr->text[i].key,
364 info_ptr->text[i].text, 0,
365 info_ptr->text[i].compression);
366#else
367 png_warning(png_ptr, "Unable to write compressed text");
368#endif
369 /* Mark this chunk as written */
370 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
371 }
372 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
373 {
374#ifdef PNG_WRITE_tEXt_SUPPORTED
375 /* Write uncompressed chunk */
376 png_write_tEXt(png_ptr, info_ptr->text[i].key,
377 info_ptr->text[i].text, 0);
378#else
379 png_warning(png_ptr, "Unable to write uncompressed text");
380#endif
381
382 /* Mark this chunk as written */
383 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
384 }
385 }
386#endif
387#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
388 if (info_ptr->unknown_chunks_num)
389 {
390 png_unknown_chunk *up;
391
392 png_debug(5, "writing extra chunks");
393
394 for (up = info_ptr->unknown_chunks;
395 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
396 up++)
397 {
398 int keep = png_handle_as_unknown(png_ptr, up->name);
399 if (keep != PNG_HANDLE_CHUNK_NEVER &&
400 up->location && (up->location & PNG_AFTER_IDAT) &&
401 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
402 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
403 {
404 png_write_chunk(png_ptr, up->name, up->data, up->size);
405 }
406 }
407 }
408#endif
409 }
410
411 png_ptr->mode |= PNG_AFTER_IDAT;
412
413 /* Write end of PNG file */
414 png_write_IEND(png_ptr);
415 /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
416 * and restored again in libpng-1.2.30, may cause some applications that
417 * do not set png_ptr->output_flush_fn to crash. If your application
418 * experiences a problem, please try building libpng with
419 * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
420 * png-mng-implement at lists.sf.net .
421 */
422#ifdef PNG_WRITE_FLUSH_SUPPORTED
423# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
424 png_flush(png_ptr);
425# endif
426#endif
427}
428
429#ifdef PNG_CONVERT_tIME_SUPPORTED
430/* "tm" structure is not supported on WindowsCE */
431void PNGAPI
432png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
433{
434 png_debug(1, "in png_convert_from_struct_tm");
435
436 ptime->year = (png_uint_16)(1900 + ttime->tm_year);
437 ptime->month = (png_byte)(ttime->tm_mon + 1);
438 ptime->day = (png_byte)ttime->tm_mday;
439 ptime->hour = (png_byte)ttime->tm_hour;
440 ptime->minute = (png_byte)ttime->tm_min;
441 ptime->second = (png_byte)ttime->tm_sec;
442}
443
444void PNGAPI
445png_convert_from_time_t(png_timep ptime, time_t ttime)
446{
447 struct tm *tbuf;
448
449 png_debug(1, "in png_convert_from_time_t");
450
451 tbuf = gmtime(&ttime);
452 png_convert_from_struct_tm(ptime, tbuf);
453}
454#endif
455
456/* Initialize png_ptr structure, and allocate any memory needed */
457png_structp PNGAPI
458png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
459 png_error_ptr error_fn, png_error_ptr warn_fn)
460{
461#ifdef PNG_USER_MEM_SUPPORTED
462 return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
463 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
464}
465
466/* Alternate initialize png_ptr structure, and allocate any memory needed */
467png_structp PNGAPI
468png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
469 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
470 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
471{
472#endif /* PNG_USER_MEM_SUPPORTED */
473#ifdef PNG_SETJMP_SUPPORTED
474 volatile
475#endif
476 png_structp png_ptr;
477#ifdef PNG_SETJMP_SUPPORTED
478#ifdef USE_FAR_KEYWORD
479 jmp_buf jmpbuf;
480#endif
481#endif
482 int i;
483
484 png_debug(1, "in png_create_write_struct");
485
486#ifdef PNG_USER_MEM_SUPPORTED
487 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
488 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
489#else
490 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
491#endif /* PNG_USER_MEM_SUPPORTED */
492 if (png_ptr == NULL)
493 return (NULL);
494
495 /* Added at libpng-1.2.6 */
496#ifdef PNG_SET_USER_LIMITS_SUPPORTED
497 png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
498 png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
499#endif
500
501#ifdef PNG_SETJMP_SUPPORTED
502#ifdef USE_FAR_KEYWORD
503 if (setjmp(jmpbuf))
504#else
505 if (setjmp(png_ptr->jmpbuf))
506#endif
507 {
508 png_free(png_ptr, png_ptr->zbuf);
509 png_ptr->zbuf = NULL;
510#ifdef PNG_USER_MEM_SUPPORTED
511 png_destroy_struct_2((png_voidp)png_ptr,
512 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
513#else
514 png_destroy_struct((png_voidp)png_ptr);
515#endif
516 return (NULL);
517 }
518#ifdef USE_FAR_KEYWORD
519 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
520#endif
521#endif
522
523#ifdef PNG_USER_MEM_SUPPORTED
524 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
525#endif /* PNG_USER_MEM_SUPPORTED */
526 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
527
528 if (user_png_ver != NULL)
529 {
530 int found_dots = 0;
531 i = -1;
532
533 do
534 {
535 i++;
536 if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i])
537 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
538 if (user_png_ver[i] == '.')
539 found_dots++;
540 } while (found_dots < 2 && user_png_ver[i] != 0 &&
541 PNG_LIBPNG_VER_STRING[i] != 0);
542 }
543 else
544 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
545
546 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
547 {
548 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
549 * we must recompile any applications that use any older library version.
550 * For versions after libpng 1.0, we will be compatible, so we need
551 * only check the first digit.
552 */
553 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
554 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
555 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
556 {
557#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
558 char msg[80];
559 if (user_png_ver)
560 {
561 png_snprintf(msg, 80,
562 "Application was compiled with png.h from libpng-%.20s",
563 user_png_ver);
564 png_warning(png_ptr, msg);
565 }
566 png_snprintf(msg, 80,
567 "Application is running with png.c from libpng-%.20s",
568 png_libpng_ver);
569 png_warning(png_ptr, msg);
570#endif
571#ifdef PNG_ERROR_NUMBERS_SUPPORTED
572 png_ptr->flags = 0;
573#endif
574 png_error(png_ptr,
575 "Incompatible libpng version in application and library");
576 }
577 }
578
579 /* Initialize zbuf - compression buffer */
580 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
581 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
582 (png_uint_32)png_ptr->zbuf_size);
583
584 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
585 png_flush_ptr_NULL);
586
587#ifdef PNG_SETJMP_SUPPORTED
588 /* Applications that neglect to set up their own setjmp() and then
589 * encounter a png_error() will longjmp here. Since the jmpbuf is
590 * then meaningless we abort instead of returning.
591 */
592#ifdef USE_FAR_KEYWORD
593 if (setjmp(jmpbuf))
594 PNG_ABORT();
595 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
596#else
597 if (setjmp(png_ptr->jmpbuf))
598 PNG_ABORT();
599#endif
600#endif
601 return (png_ptr);
602}
603
604/* Initialize png_ptr structure, and allocate any memory needed */
605#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
606/* Deprecated. */
607#undef png_write_init
608void PNGAPI
609png_write_init(png_structp png_ptr)
610{
611 /* We only come here via pre-1.0.7-compiled applications */
612 png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
613}
614
615void PNGAPI
616png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
617 png_size_t png_struct_size, png_size_t png_info_size)
618{
619 /* We only come here via pre-1.0.12-compiled applications */
620 if (png_ptr == NULL) return;
621#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
622 if (png_sizeof(png_struct) > png_struct_size ||
623 png_sizeof(png_info) > png_info_size)
624 {
625 char msg[80];
626 png_ptr->warning_fn = NULL;
627 if (user_png_ver)
628 {
629 png_snprintf(msg, 80,
630 "Application was compiled with png.h from libpng-%.20s",
631 user_png_ver);
632 png_warning(png_ptr, msg);
633 }
634 png_snprintf(msg, 80,
635 "Application is running with png.c from libpng-%.20s",
636 png_libpng_ver);
637 png_warning(png_ptr, msg);
638 }
639#endif
640 if (png_sizeof(png_struct) > png_struct_size)
641 {
642 png_ptr->error_fn = NULL;
643#ifdef PNG_ERROR_NUMBERS_SUPPORTED
644 png_ptr->flags = 0;
645#endif
646 png_error(png_ptr,
647 "The png struct allocated by the application for writing is"
648 " too small.");
649 }
650 if (png_sizeof(png_info) > png_info_size)
651 {
652 png_ptr->error_fn = NULL;
653#ifdef PNG_ERROR_NUMBERS_SUPPORTED
654 png_ptr->flags = 0;
655#endif
656 png_error(png_ptr,
657 "The info struct allocated by the application for writing is"
658 " too small.");
659 }
660 png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
661}
662#endif /* PNG_1_0_X || PNG_1_2_X */
663
664
665void PNGAPI
666png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
667 png_size_t png_struct_size)
668{
669 png_structp png_ptr = *ptr_ptr;
670#ifdef PNG_SETJMP_SUPPORTED
671 jmp_buf tmp_jmp; /* to save current jump buffer */
672#endif
673
674 int i = 0;
675
676 if (png_ptr == NULL)
677 return;
678
679 do
680 {
681 if (user_png_ver[i] != png_libpng_ver[i])
682 {
683#ifdef PNG_LEGACY_SUPPORTED
684 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
685#else
686 png_ptr->warning_fn = NULL;
687 png_warning(png_ptr,
688 "Application uses deprecated png_write_init() and should be recompiled.");
689#endif
690 }
691 i++;
692 } while (png_libpng_ver[i] != 0 && user_png_ver[i] != 0);
693
694 png_debug(1, "in png_write_init_3");
695
696#ifdef PNG_SETJMP_SUPPORTED
697 /* Save jump buffer and error functions */
698 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
699#endif
700
701 if (png_sizeof(png_struct) > png_struct_size)
702 {
703 png_destroy_struct(png_ptr);
704 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
705 *ptr_ptr = png_ptr;
706 }
707
708 /* Reset all variables to 0 */
709 png_memset(png_ptr, 0, png_sizeof(png_struct));
710
711 /* Added at libpng-1.2.6 */
712#ifdef PNG_SET_USER_LIMITS_SUPPORTED
713 png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
714 png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
715#endif
716
717#ifdef PNG_SETJMP_SUPPORTED
718 /* Restore jump buffer */
719 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
720#endif
721
722 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
723 png_flush_ptr_NULL);
724
725 /* Initialize zbuf - compression buffer */
726 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
727 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
728 (png_uint_32)png_ptr->zbuf_size);
729}
730
731/* Write a few rows of image data. If the image is interlaced,
732 * either you will have to write the 7 sub images, or, if you
733 * have called png_set_interlace_handling(), you will have to
734 * "write" the image seven times.
735 */
736void PNGAPI
737png_write_rows(png_structp png_ptr, png_bytepp row,
738 png_uint_32 num_rows)
739{
740 png_uint_32 i; /* row counter */
741 png_bytepp rp; /* row pointer */
742
743 png_debug(1, "in png_write_rows");
744
745 if (png_ptr == NULL)
746 return;
747
748 /* Loop through the rows */
749 for (i = 0, rp = row; i < num_rows; i++, rp++)
750 {
751 png_write_row(png_ptr, *rp);
752 }
753}
754
755/* Write the image. You only need to call this function once, even
756 * if you are writing an interlaced image.
757 */
758void PNGAPI
759png_write_image(png_structp png_ptr, png_bytepp image)
760{
761 png_uint_32 i; /* row index */
762 int pass, num_pass; /* pass variables */
763 png_bytepp rp; /* points to current row */
764
765 if (png_ptr == NULL)
766 return;
767
768 png_debug(1, "in png_write_image");
769
770#ifdef PNG_WRITE_INTERLACING_SUPPORTED
771 /* Initialize interlace handling. If image is not interlaced,
772 * this will set pass to 1
773 */
774 num_pass = png_set_interlace_handling(png_ptr);
775#else
776 num_pass = 1;
777#endif
778 /* Loop through passes */
779 for (pass = 0; pass < num_pass; pass++)
780 {
781 /* Loop through image */
782 for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
783 {
784 png_write_row(png_ptr, *rp);
785 }
786 }
787}
788
789/* Called by user to write a row of image data */
790void PNGAPI
791png_write_row(png_structp png_ptr, png_bytep row)
792{
793 if (png_ptr == NULL)
794 return;
795
796 png_debug2(1, "in png_write_row (row %ld, pass %d)",
797 png_ptr->row_number, png_ptr->pass);
798
799 /* Initialize transformations and other stuff if first time */
800 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
801 {
802 /* Make sure we wrote the header info */
803 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
804 png_error(png_ptr,
805 "png_write_info was never called before png_write_row.");
806
807 /* Check for transforms that have been set but were defined out */
808#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
809 if (png_ptr->transformations & PNG_INVERT_MONO)
810 png_warning(png_ptr,
811 "PNG_WRITE_INVERT_SUPPORTED is not defined.");
812#endif
813#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
814 if (png_ptr->transformations & PNG_FILLER)
815 png_warning(png_ptr,
816 "PNG_WRITE_FILLER_SUPPORTED is not defined.");
817#endif
818#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
819 defined(PNG_READ_PACKSWAP_SUPPORTED)
820 if (png_ptr->transformations & PNG_PACKSWAP)
821 png_warning(png_ptr,
822 "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
823#endif
824#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
825 if (png_ptr->transformations & PNG_PACK)
826 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
827#endif
828#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
829 if (png_ptr->transformations & PNG_SHIFT)
830 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
831#endif
832#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
833 if (png_ptr->transformations & PNG_BGR)
834 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
835#endif
836#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
837 if (png_ptr->transformations & PNG_SWAP_BYTES)
838 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
839#endif
840
841 png_write_start_row(png_ptr);
842 }
843
844#ifdef PNG_WRITE_INTERLACING_SUPPORTED
845 /* If interlaced and not interested in row, return */
846 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
847 {
848 switch (png_ptr->pass)
849 {
850 case 0:
851 if (png_ptr->row_number & 0x07)
852 {
853 png_write_finish_row(png_ptr);
854 return;
855 }
856 break;
857 case 1:
858 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
859 {
860 png_write_finish_row(png_ptr);
861 return;
862 }
863 break;
864 case 2:
865 if ((png_ptr->row_number & 0x07) != 4)
866 {
867 png_write_finish_row(png_ptr);
868 return;
869 }
870 break;
871 case 3:
872 if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
873 {
874 png_write_finish_row(png_ptr);
875 return;
876 }
877 break;
878 case 4:
879 if ((png_ptr->row_number & 0x03) != 2)
880 {
881 png_write_finish_row(png_ptr);
882 return;
883 }
884 break;
885 case 5:
886 if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
887 {
888 png_write_finish_row(png_ptr);
889 return;
890 }
891 break;
892 case 6:
893 if (!(png_ptr->row_number & 0x01))
894 {
895 png_write_finish_row(png_ptr);
896 return;
897 }
898 break;
899 }
900 }
901#endif
902
903 /* Set up row info for transformations */
904 png_ptr->row_info.color_type = png_ptr->color_type;
905 png_ptr->row_info.width = png_ptr->usr_width;
906 png_ptr->row_info.channels = png_ptr->usr_channels;
907 png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
908 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
909 png_ptr->row_info.channels);
910
911 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
912 png_ptr->row_info.width);
913
914 png_debug1(3, "row_info->color_type = %d", png_ptr->row_info.color_type);
915 png_debug1(3, "row_info->width = %lu", png_ptr->row_info.width);
916 png_debug1(3, "row_info->channels = %d", png_ptr->row_info.channels);
917 png_debug1(3, "row_info->bit_depth = %d", png_ptr->row_info.bit_depth);
918 png_debug1(3, "row_info->pixel_depth = %d", png_ptr->row_info.pixel_depth);
919 png_debug1(3, "row_info->rowbytes = %lu", png_ptr->row_info.rowbytes);
920
921 /* Copy user's row into buffer, leaving room for filter byte. */
922 png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
923 png_ptr->row_info.rowbytes);
924
925#ifdef PNG_WRITE_INTERLACING_SUPPORTED
926 /* Handle interlacing */
927 if (png_ptr->interlaced && png_ptr->pass < 6 &&
928 (png_ptr->transformations & PNG_INTERLACE))
929 {
930 png_do_write_interlace(&(png_ptr->row_info),
931 png_ptr->row_buf + 1, png_ptr->pass);
932 /* This should always get caught above, but still ... */
933 if (!(png_ptr->row_info.width))
934 {
935 png_write_finish_row(png_ptr);
936 return;
937 }
938 }
939#endif
940
941 /* Handle other transformations */
942 if (png_ptr->transformations)
943 png_do_write_transformations(png_ptr);
944
945#ifdef PNG_MNG_FEATURES_SUPPORTED
946 /* Write filter_method 64 (intrapixel differencing) only if
947 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
948 * 2. Libpng did not write a PNG signature (this filter_method is only
949 * used in PNG datastreams that are embedded in MNG datastreams) and
950 * 3. The application called png_permit_mng_features with a mask that
951 * included PNG_FLAG_MNG_FILTER_64 and
952 * 4. The filter_method is 64 and
953 * 5. The color_type is RGB or RGBA
954 */
955 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
956 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
957 {
958 /* Intrapixel differencing */
959 png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
960 }
961#endif
962
963 /* Find a filter if necessary, filter the row and write it out. */
964 png_write_find_filter(png_ptr, &(png_ptr->row_info));
965
966 if (png_ptr->write_row_fn != NULL)
967 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
968}
969
970#ifdef PNG_WRITE_FLUSH_SUPPORTED
971/* Set the automatic flush interval or 0 to turn flushing off */
972void PNGAPI
973png_set_flush(png_structp png_ptr, int nrows)
974{
975 png_debug(1, "in png_set_flush");
976
977 if (png_ptr == NULL)
978 return;
979 png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
980}
981
982/* Flush the current output buffers now */
983void PNGAPI
984png_write_flush(png_structp png_ptr)
985{
986 int wrote_IDAT;
987
988 png_debug(1, "in png_write_flush");
989
990 if (png_ptr == NULL)
991 return;
992 /* We have already written out all of the data */
993 if (png_ptr->row_number >= png_ptr->num_rows)
994 return;
995
996 do
997 {
998 int ret;
999
1000 /* Compress the data */
1001 ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
1002 wrote_IDAT = 0;
1003
1004 /* Check for compression errors */
1005 if (ret != Z_OK)
1006 {
1007 if (png_ptr->zstream.msg != NULL)
1008 png_error(png_ptr, png_ptr->zstream.msg);
1009 else
1010 png_error(png_ptr, "zlib error");
1011 }
1012
1013 if (!(png_ptr->zstream.avail_out))
1014 {
1015 /* Write the IDAT and reset the zlib output buffer */
1016 png_write_IDAT(png_ptr, png_ptr->zbuf,
1017 png_ptr->zbuf_size);
1018 png_ptr->zstream.next_out = png_ptr->zbuf;
1019 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1020 wrote_IDAT = 1;
1021 }
1022 } while(wrote_IDAT == 1);
1023
1024 /* If there is any data left to be output, write it into a new IDAT */
1025 if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
1026 {
1027 /* Write the IDAT and reset the zlib output buffer */
1028 png_write_IDAT(png_ptr, png_ptr->zbuf,
1029 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1030 png_ptr->zstream.next_out = png_ptr->zbuf;
1031 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1032 }
1033 png_ptr->flush_rows = 0;
1034 png_flush(png_ptr);
1035}
1036#endif /* PNG_WRITE_FLUSH_SUPPORTED */
1037
1038/* Free all memory used by the write */
1039void PNGAPI
1040png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
1041{
1042 png_structp png_ptr = NULL;
1043 png_infop info_ptr = NULL;
1044#ifdef PNG_USER_MEM_SUPPORTED
1045 png_free_ptr free_fn = NULL;
1046 png_voidp mem_ptr = NULL;
1047#endif
1048
1049 png_debug(1, "in png_destroy_write_struct");
1050
1051 if (png_ptr_ptr != NULL)
1052 {
1053 png_ptr = *png_ptr_ptr;
1054#ifdef PNG_USER_MEM_SUPPORTED
1055 free_fn = png_ptr->free_fn;
1056 mem_ptr = png_ptr->mem_ptr;
1057#endif
1058 }
1059
1060#ifdef PNG_USER_MEM_SUPPORTED
1061 if (png_ptr != NULL)
1062 {
1063 free_fn = png_ptr->free_fn;
1064 mem_ptr = png_ptr->mem_ptr;
1065 }
1066#endif
1067
1068 if (info_ptr_ptr != NULL)
1069 info_ptr = *info_ptr_ptr;
1070
1071 if (info_ptr != NULL)
1072 {
1073 if (png_ptr != NULL)
1074 {
1075 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
1076
1077#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1078 if (png_ptr->num_chunk_list)
1079 {
1080 png_free(png_ptr, png_ptr->chunk_list);
1081 png_ptr->chunk_list = NULL;
1082 png_ptr->num_chunk_list = 0;
1083 }
1084#endif
1085 }
1086
1087#ifdef PNG_USER_MEM_SUPPORTED
1088 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1089 (png_voidp)mem_ptr);
1090#else
1091 png_destroy_struct((png_voidp)info_ptr);
1092#endif
1093 *info_ptr_ptr = NULL;
1094 }
1095
1096 if (png_ptr != NULL)
1097 {
1098 png_write_destroy(png_ptr);
1099#ifdef PNG_USER_MEM_SUPPORTED
1100 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1101 (png_voidp)mem_ptr);
1102#else
1103 png_destroy_struct((png_voidp)png_ptr);
1104#endif
1105 *png_ptr_ptr = NULL;
1106 }
1107}
1108
1109
1110/* Free any memory used in png_ptr struct (old method) */
1111void /* PRIVATE */
1112png_write_destroy(png_structp png_ptr)
1113{
1114#ifdef PNG_SETJMP_SUPPORTED
1115 jmp_buf tmp_jmp; /* Save jump buffer */
1116#endif
1117 png_error_ptr error_fn;
1118 png_error_ptr warning_fn;
1119 png_voidp error_ptr;
1120#ifdef PNG_USER_MEM_SUPPORTED
1121 png_free_ptr free_fn;
1122#endif
1123
1124 png_debug(1, "in png_write_destroy");
1125
1126 /* Free any memory zlib uses */
1127 deflateEnd(&png_ptr->zstream);
1128
1129 /* Free our memory. png_free checks NULL for us. */
1130 png_free(png_ptr, png_ptr->zbuf);
1131 png_free(png_ptr, png_ptr->row_buf);
1132#ifdef PNG_WRITE_FILTER_SUPPORTED
1133 png_free(png_ptr, png_ptr->prev_row);
1134 png_free(png_ptr, png_ptr->sub_row);
1135 png_free(png_ptr, png_ptr->up_row);
1136 png_free(png_ptr, png_ptr->avg_row);
1137 png_free(png_ptr, png_ptr->paeth_row);
1138#endif
1139
1140#ifdef PNG_TIME_RFC1123_SUPPORTED
1141 png_free(png_ptr, png_ptr->time_buffer);
1142#endif
1143
1144#ifdef PNG_SETJMP_SUPPORTED
1145 /* Reset structure */
1146 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
1147#endif
1148
1149 error_fn = png_ptr->error_fn;
1150 warning_fn = png_ptr->warning_fn;
1151 error_ptr = png_ptr->error_ptr;
1152#ifdef PNG_USER_MEM_SUPPORTED
1153 free_fn = png_ptr->free_fn;
1154#endif
1155
1156 png_memset(png_ptr, 0, png_sizeof(png_struct));
1157
1158 png_ptr->error_fn = error_fn;
1159 png_ptr->warning_fn = warning_fn;
1160 png_ptr->error_ptr = error_ptr;
1161#ifdef PNG_USER_MEM_SUPPORTED
1162 png_ptr->free_fn = free_fn;
1163#endif
1164
1165#ifdef PNG_SETJMP_SUPPORTED
1166 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1167#endif
1168}
1169
1170/* Allow the application to select one or more row filters to use. */
1171void PNGAPI
1172png_set_filter(png_structp png_ptr, int method, int filters)
1173{
1174 png_debug(1, "in png_set_filter");
1175
1176 if (png_ptr == NULL)
1177 return;
1178#ifdef PNG_MNG_FEATURES_SUPPORTED
1179 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1180 (method == PNG_INTRAPIXEL_DIFFERENCING))
1181 method = PNG_FILTER_TYPE_BASE;
1182#endif
1183 if (method == PNG_FILTER_TYPE_BASE)
1184 {
1185 switch (filters & (PNG_ALL_FILTERS | 0x07))
1186 {
1187 case PNG_FILTER_VALUE_NONE:
1188 png_ptr->do_filter = PNG_FILTER_NONE; break;
1189#ifdef PNG_WRITE_FILTER_SUPPORTED
1190 case 5:
1191 case 6:
1192 case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1193 break;
1194 case PNG_FILTER_VALUE_SUB:
1195 png_ptr->do_filter = PNG_FILTER_SUB; break;
1196 case PNG_FILTER_VALUE_UP:
1197 png_ptr->do_filter = PNG_FILTER_UP; break;
1198 case PNG_FILTER_VALUE_AVG:
1199 png_ptr->do_filter = PNG_FILTER_AVG; break;
1200 case PNG_FILTER_VALUE_PAETH:
1201 png_ptr->do_filter = PNG_FILTER_PAETH; break;
1202 default: png_ptr->do_filter = (png_byte)filters; break;
1203#else
1204 default: png_warning(png_ptr, "Unknown row filter for method 0");
1205 break;
1206#endif /* PNG_WRITE_FILTER_SUPPORTED */
1207 }
1208
1209 /* If we have allocated the row_buf, this means we have already started
1210 * with the image and we should have allocated all of the filter buffers
1211 * that have been selected. If prev_row isn't already allocated, then
1212 * it is too late to start using the filters that need it, since we
1213 * will be missing the data in the previous row. If an application
1214 * wants to start and stop using particular filters during compression,
1215 * it should start out with all of the filters, and then add and
1216 * remove them after the start of compression.
1217 */
1218 if (png_ptr->row_buf != NULL)
1219 {
1220#ifdef PNG_WRITE_FILTER_SUPPORTED
1221 if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1222 {
1223 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1224 (png_ptr->rowbytes + 1));
1225 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1226 }
1227
1228 if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1229 {
1230 if (png_ptr->prev_row == NULL)
1231 {
1232 png_warning(png_ptr, "Can't add Up filter after starting");
1233 png_ptr->do_filter &= ~PNG_FILTER_UP;
1234 }
1235 else
1236 {
1237 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1238 (png_ptr->rowbytes + 1));
1239 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1240 }
1241 }
1242
1243 if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1244 {
1245 if (png_ptr->prev_row == NULL)
1246 {
1247 png_warning(png_ptr, "Can't add Average filter after starting");
1248 png_ptr->do_filter &= ~PNG_FILTER_AVG;
1249 }
1250 else
1251 {
1252 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1253 (png_ptr->rowbytes + 1));
1254 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1255 }
1256 }
1257
1258 if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1259 png_ptr->paeth_row == NULL)
1260 {
1261 if (png_ptr->prev_row == NULL)
1262 {
1263 png_warning(png_ptr, "Can't add Paeth filter after starting");
1264 png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1265 }
1266 else
1267 {
1268 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1269 (png_ptr->rowbytes + 1));
1270 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1271 }
1272 }
1273
1274 if (png_ptr->do_filter == PNG_NO_FILTERS)
1275#endif /* PNG_WRITE_FILTER_SUPPORTED */
1276 png_ptr->do_filter = PNG_FILTER_NONE;
1277 }
1278 }
1279 else
1280 png_error(png_ptr, "Unknown custom filter method");
1281}
1282
1283/* This allows us to influence the way in which libpng chooses the "best"
1284 * filter for the current scanline. While the "minimum-sum-of-absolute-
1285 * differences metric is relatively fast and effective, there is some
1286 * question as to whether it can be improved upon by trying to keep the
1287 * filtered data going to zlib more consistent, hopefully resulting in
1288 * better compression.
1289 */
1290#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */
1291void PNGAPI
1292png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1293 int num_weights, png_doublep filter_weights,
1294 png_doublep filter_costs)
1295{
1296 PNG_UNUSED(png_ptr)
1297 PNG_UNUSED(heuristic_method)
1298 PNG_UNUSED(num_weights)
1299 PNG_UNUSED(filter_weights)
1300 PNG_UNUSED(filter_costs)
1301}
1302#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1303
1304void PNGAPI
1305png_set_compression_level(png_structp png_ptr, int level)
1306{
1307 png_debug(1, "in png_set_compression_level");
1308
1309 if (png_ptr == NULL)
1310 return;
1311 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1312 png_ptr->zlib_level = level;
1313}
1314
1315void PNGAPI
1316png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1317{
1318 png_debug(1, "in png_set_compression_mem_level");
1319
1320 if (png_ptr == NULL)
1321 return;
1322 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1323 png_ptr->zlib_mem_level = mem_level;
1324}
1325
1326void PNGAPI
1327png_set_compression_strategy(png_structp png_ptr, int strategy)
1328{
1329 png_debug(1, "in png_set_compression_strategy");
1330
1331 if (png_ptr == NULL)
1332 return;
1333 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1334 png_ptr->zlib_strategy = strategy;
1335}
1336
1337void PNGAPI
1338png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1339{
1340 if (png_ptr == NULL)
1341 return;
1342 if (window_bits > 15)
1343 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1344 else if (window_bits < 8)
1345 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1346#ifndef WBITS_8_OK
1347 /* Avoid libpng bug with 256-byte windows */
1348 if (window_bits == 8)
1349 {
1350 png_warning(png_ptr, "Compression window is being reset to 512");
1351 window_bits = 9;
1352 }
1353#endif
1354 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1355 png_ptr->zlib_window_bits = window_bits;
1356}
1357
1358void PNGAPI
1359png_set_compression_method(png_structp png_ptr, int method)
1360{
1361 png_debug(1, "in png_set_compression_method");
1362
1363 if (png_ptr == NULL)
1364 return;
1365 if (method != 8)
1366 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1367 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1368 png_ptr->zlib_method = method;
1369}
1370
1371void PNGAPI
1372png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1373{
1374 if (png_ptr == NULL)
1375 return;
1376 png_ptr->write_row_fn = write_row_fn;
1377}
1378
1379#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1380void PNGAPI
1381png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1382 write_user_transform_fn)
1383{
1384 png_debug(1, "in png_set_write_user_transform_fn");
1385
1386 if (png_ptr == NULL)
1387 return;
1388 png_ptr->transformations |= PNG_USER_TRANSFORM;
1389 png_ptr->write_user_transform_fn = write_user_transform_fn;
1390}
1391#endif
1392
1393
1394#ifdef PNG_INFO_IMAGE_SUPPORTED
1395void PNGAPI
1396png_write_png(png_structp png_ptr, png_infop info_ptr,
1397 int transforms, voidp params)
1398{
1399 if (png_ptr == NULL || info_ptr == NULL)
1400 return;
1401
1402 /* Write the file header information. */
1403 png_write_info(png_ptr, info_ptr);
1404
1405 /* ------ these transformations don't touch the info structure ------- */
1406
1407#ifdef PNG_WRITE_INVERT_SUPPORTED
1408 /* Invert monochrome pixels */
1409 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1410 png_set_invert_mono(png_ptr);
1411#endif
1412
1413#ifdef PNG_WRITE_SHIFT_SUPPORTED
1414 /* Shift the pixels up to a legal bit depth and fill in
1415 * as appropriate to correctly scale the image.
1416 */
1417 if ((transforms & PNG_TRANSFORM_SHIFT)
1418 && (info_ptr->valid & PNG_INFO_sBIT))
1419 png_set_shift(png_ptr, &info_ptr->sig_bit);
1420#endif
1421
1422#ifdef PNG_WRITE_PACK_SUPPORTED
1423 /* Pack pixels into bytes */
1424 if (transforms & PNG_TRANSFORM_PACKING)
1425 png_set_packing(png_ptr);
1426#endif
1427
1428#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1429 /* Swap location of alpha bytes from ARGB to RGBA */
1430 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1431 png_set_swap_alpha(png_ptr);
1432#endif
1433
1434#ifdef PNG_WRITE_FILLER_SUPPORTED
1435 /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */
1436 if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
1437 png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
1438 else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
1439 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1440#endif
1441
1442#ifdef PNG_WRITE_BGR_SUPPORTED
1443 /* Flip BGR pixels to RGB */
1444 if (transforms & PNG_TRANSFORM_BGR)
1445 png_set_bgr(png_ptr);
1446#endif
1447
1448#ifdef PNG_WRITE_SWAP_SUPPORTED
1449 /* Swap bytes of 16-bit files to most significant byte first */
1450 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1451 png_set_swap(png_ptr);
1452#endif
1453
1454#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
1455 /* Swap bits of 1, 2, 4 bit packed pixel formats */
1456 if (transforms & PNG_TRANSFORM_PACKSWAP)
1457 png_set_packswap(png_ptr);
1458#endif
1459
1460#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1461 /* Invert the alpha channel from opacity to transparency */
1462 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1463 png_set_invert_alpha(png_ptr);
1464#endif
1465
1466 /* ----------------------- end of transformations ------------------- */
1467
1468 /* Write the bits */
1469 if (info_ptr->valid & PNG_INFO_IDAT)
1470 png_write_image(png_ptr, info_ptr->row_pointers);
1471
1472 /* It is REQUIRED to call this to finish writing the rest of the file */
1473 png_write_end(png_ptr, info_ptr);
1474
1475 PNG_UNUSED(transforms) /* Quiet compiler warnings */
1476 PNG_UNUSED(params)
1477}
1478#endif
1479#endif /* PNG_WRITE_SUPPORTED */
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