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1
2/* pngwrite.c - general routines to write a PNG file
3 *
4 * libpng 1.2.7 - September 12, 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/* get internal access to png.h */
12#define PNG_INTERNAL
13#include "png.h"
14#ifdef PNG_WRITE_SUPPORTED
15
16/* Writes all the PNG information. This is the suggested way to use the
17 * library. If you have a new chunk to add, make a function to write it,
18 * and put it in the correct location here. If you want the chunk written
19 * after the image data, put it in png_write_end(). I strongly encourage
20 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
21 * the chunk, as that will keep the code from breaking if you want to just
22 * write a plain PNG file. If you have long comments, I suggest writing
23 * them in png_write_end(), and compressing them.
24 */
25void PNGAPI
26png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
27{
28 png_debug(1, "in png_write_info_before_PLTE\n");
29 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
30 {
31 png_write_sig(png_ptr); /* write PNG signature */
32#if defined(PNG_MNG_FEATURES_SUPPORTED)
33 if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
34 {
35 png_warning(png_ptr,"MNG features are not allowed in a PNG datastream\n");
36 png_ptr->mng_features_permitted=0;
37 }
38#endif
39 /* write IHDR information. */
40 png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
41 info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
42 info_ptr->filter_type,
43#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
44 info_ptr->interlace_type);
45#else
46 0);
47#endif
48 /* the rest of these check to see if the valid field has the appropriate
49 flag set, and if it does, writes the chunk. */
50#if defined(PNG_WRITE_gAMA_SUPPORTED)
51 if (info_ptr->valid & PNG_INFO_gAMA)
52 {
53# ifdef PNG_FLOATING_POINT_SUPPORTED
54 png_write_gAMA(png_ptr, info_ptr->gamma);
55#else
56#ifdef PNG_FIXED_POINT_SUPPORTED
57 png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
58# endif
59#endif
60 }
61#endif
62#if defined(PNG_WRITE_sRGB_SUPPORTED)
63 if (info_ptr->valid & PNG_INFO_sRGB)
64 png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
65#endif
66#if defined(PNG_WRITE_iCCP_SUPPORTED)
67 if (info_ptr->valid & PNG_INFO_iCCP)
68 png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
69 info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
70#endif
71#if defined(PNG_WRITE_sBIT_SUPPORTED)
72 if (info_ptr->valid & PNG_INFO_sBIT)
73 png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
74#endif
75#if defined(PNG_WRITE_cHRM_SUPPORTED)
76 if (info_ptr->valid & PNG_INFO_cHRM)
77 {
78#ifdef PNG_FLOATING_POINT_SUPPORTED
79 png_write_cHRM(png_ptr,
80 info_ptr->x_white, info_ptr->y_white,
81 info_ptr->x_red, info_ptr->y_red,
82 info_ptr->x_green, info_ptr->y_green,
83 info_ptr->x_blue, info_ptr->y_blue);
84#else
85# ifdef PNG_FIXED_POINT_SUPPORTED
86 png_write_cHRM_fixed(png_ptr,
87 info_ptr->int_x_white, info_ptr->int_y_white,
88 info_ptr->int_x_red, info_ptr->int_y_red,
89 info_ptr->int_x_green, info_ptr->int_y_green,
90 info_ptr->int_x_blue, info_ptr->int_y_blue);
91# endif
92#endif
93 }
94#endif
95#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
96 if (info_ptr->unknown_chunks_num)
97 {
98 png_unknown_chunk *up;
99
100 png_debug(5, "writing extra chunks\n");
101
102 for (up = info_ptr->unknown_chunks;
103 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
104 up++)
105 {
106 int keep=png_handle_as_unknown(png_ptr, up->name);
107 if (keep != PNG_HANDLE_CHUNK_NEVER &&
108 up->location && !(up->location & PNG_HAVE_PLTE) &&
109 !(up->location & PNG_HAVE_IDAT) &&
110 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
111 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
112 {
113 png_write_chunk(png_ptr, up->name, up->data, up->size);
114 }
115 }
116 }
117#endif
118 png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
119 }
120}
121
122void PNGAPI
123png_write_info(png_structp png_ptr, png_infop info_ptr)
124{
125#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
126 int i;
127#endif
128
129 png_debug(1, "in png_write_info\n");
130
131 png_write_info_before_PLTE(png_ptr, info_ptr);
132
133 if (info_ptr->valid & PNG_INFO_PLTE)
134 png_write_PLTE(png_ptr, info_ptr->palette,
135 (png_uint_32)info_ptr->num_palette);
136 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
137 png_error(png_ptr, "Valid palette required for paletted images\n");
138
139#if defined(PNG_WRITE_tRNS_SUPPORTED)
140 if (info_ptr->valid & PNG_INFO_tRNS)
141 {
142#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
143 /* invert the alpha channel (in tRNS) */
144 if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
145 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
146 {
147 int j;
148 for (j=0; j<(int)info_ptr->num_trans; j++)
149 info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
150 }
151#endif
152 png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
153 info_ptr->num_trans, info_ptr->color_type);
154 }
155#endif
156#if defined(PNG_WRITE_bKGD_SUPPORTED)
157 if (info_ptr->valid & PNG_INFO_bKGD)
158 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
159#endif
160#if defined(PNG_WRITE_hIST_SUPPORTED)
161 if (info_ptr->valid & PNG_INFO_hIST)
162 png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
163#endif
164#if defined(PNG_WRITE_oFFs_SUPPORTED)
165 if (info_ptr->valid & PNG_INFO_oFFs)
166 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
167 info_ptr->offset_unit_type);
168#endif
169#if defined(PNG_WRITE_pCAL_SUPPORTED)
170 if (info_ptr->valid & PNG_INFO_pCAL)
171 png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
172 info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
173 info_ptr->pcal_units, info_ptr->pcal_params);
174#endif
175#if defined(PNG_WRITE_sCAL_SUPPORTED)
176 if (info_ptr->valid & PNG_INFO_sCAL)
177#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
178 png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
179 info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
180#else
181#ifdef PNG_FIXED_POINT_SUPPORTED
182 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
183 info_ptr->scal_s_width, info_ptr->scal_s_height);
184#else
185 png_warning(png_ptr,
186 "png_write_sCAL not supported; sCAL chunk not written.\n");
187#endif
188#endif
189#endif
190#if defined(PNG_WRITE_pHYs_SUPPORTED)
191 if (info_ptr->valid & PNG_INFO_pHYs)
192 png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
193 info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
194#endif
195#if defined(PNG_WRITE_tIME_SUPPORTED)
196 if (info_ptr->valid & PNG_INFO_tIME)
197 {
198 png_write_tIME(png_ptr, &(info_ptr->mod_time));
199 png_ptr->mode |= PNG_WROTE_tIME;
200 }
201#endif
202#if defined(PNG_WRITE_sPLT_SUPPORTED)
203 if (info_ptr->valid & PNG_INFO_sPLT)
204 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
205 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
206#endif
207#if defined(PNG_WRITE_TEXT_SUPPORTED)
208 /* Check to see if we need to write text chunks */
209 for (i = 0; i < info_ptr->num_text; i++)
210 {
211 png_debug2(2, "Writing header text chunk %d, type %d\n", i,
212 info_ptr->text[i].compression);
213 /* an internationalized chunk? */
214 if (info_ptr->text[i].compression > 0)
215 {
216#if defined(PNG_WRITE_iTXt_SUPPORTED)
217 /* write international chunk */
218 png_write_iTXt(png_ptr,
219 info_ptr->text[i].compression,
220 info_ptr->text[i].key,
221 info_ptr->text[i].lang,
222 info_ptr->text[i].lang_key,
223 info_ptr->text[i].text);
224#else
225 png_warning(png_ptr, "Unable to write international text\n");
226#endif
227 /* Mark this chunk as written */
228 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
229 }
230 /* If we want a compressed text chunk */
231 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
232 {
233#if defined(PNG_WRITE_zTXt_SUPPORTED)
234 /* write compressed chunk */
235 png_write_zTXt(png_ptr, info_ptr->text[i].key,
236 info_ptr->text[i].text, 0,
237 info_ptr->text[i].compression);
238#else
239 png_warning(png_ptr, "Unable to write compressed text\n");
240#endif
241 /* Mark this chunk as written */
242 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
243 }
244 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
245 {
246#if defined(PNG_WRITE_tEXt_SUPPORTED)
247 /* write uncompressed chunk */
248 png_write_tEXt(png_ptr, info_ptr->text[i].key,
249 info_ptr->text[i].text,
250 0);
251#else
252 png_warning(png_ptr, "Unable to write uncompressed text\n");
253#endif
254 /* Mark this chunk as written */
255 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
256 }
257 }
258#endif
259#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
260 if (info_ptr->unknown_chunks_num)
261 {
262 png_unknown_chunk *up;
263
264 png_debug(5, "writing extra chunks\n");
265
266 for (up = info_ptr->unknown_chunks;
267 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
268 up++)
269 {
270 int keep=png_handle_as_unknown(png_ptr, up->name);
271 if (keep != PNG_HANDLE_CHUNK_NEVER &&
272 up->location && (up->location & PNG_HAVE_PLTE) &&
273 !(up->location & PNG_HAVE_IDAT) &&
274 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
275 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
276 {
277 png_write_chunk(png_ptr, up->name, up->data, up->size);
278 }
279 }
280 }
281#endif
282}
283
284/* Writes the end of the PNG file. If you don't want to write comments or
285 * time information, you can pass NULL for info. If you already wrote these
286 * in png_write_info(), do not write them again here. If you have long
287 * comments, I suggest writing them here, and compressing them.
288 */
289void PNGAPI
290png_write_end(png_structp png_ptr, png_infop info_ptr)
291{
292 png_debug(1, "in png_write_end\n");
293 if (!(png_ptr->mode & PNG_HAVE_IDAT))
294 png_error(png_ptr, "No IDATs written into file");
295
296 /* see if user wants us to write information chunks */
297 if (info_ptr != NULL)
298 {
299#if defined(PNG_WRITE_TEXT_SUPPORTED)
300 int i; /* local index variable */
301#endif
302#if defined(PNG_WRITE_tIME_SUPPORTED)
303 /* check to see if user has supplied a time chunk */
304 if ((info_ptr->valid & PNG_INFO_tIME) &&
305 !(png_ptr->mode & PNG_WROTE_tIME))
306 png_write_tIME(png_ptr, &(info_ptr->mod_time));
307#endif
308#if defined(PNG_WRITE_TEXT_SUPPORTED)
309 /* loop through comment chunks */
310 for (i = 0; i < info_ptr->num_text; i++)
311 {
312 png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,
313 info_ptr->text[i].compression);
314 /* an internationalized chunk? */
315 if (info_ptr->text[i].compression > 0)
316 {
317#if defined(PNG_WRITE_iTXt_SUPPORTED)
318 /* write international chunk */
319 png_write_iTXt(png_ptr,
320 info_ptr->text[i].compression,
321 info_ptr->text[i].key,
322 info_ptr->text[i].lang,
323 info_ptr->text[i].lang_key,
324 info_ptr->text[i].text);
325#else
326 png_warning(png_ptr, "Unable to write international text\n");
327#endif
328 /* Mark this chunk as written */
329 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
330 }
331 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
332 {
333#if defined(PNG_WRITE_zTXt_SUPPORTED)
334 /* write compressed chunk */
335 png_write_zTXt(png_ptr, info_ptr->text[i].key,
336 info_ptr->text[i].text, 0,
337 info_ptr->text[i].compression);
338#else
339 png_warning(png_ptr, "Unable to write compressed text\n");
340#endif
341 /* Mark this chunk as written */
342 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
343 }
344 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
345 {
346#if defined(PNG_WRITE_tEXt_SUPPORTED)
347 /* write uncompressed chunk */
348 png_write_tEXt(png_ptr, info_ptr->text[i].key,
349 info_ptr->text[i].text, 0);
350#else
351 png_warning(png_ptr, "Unable to write uncompressed text\n");
352#endif
353
354 /* Mark this chunk as written */
355 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
356 }
357 }
358#endif
359#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
360 if (info_ptr->unknown_chunks_num)
361 {
362 png_unknown_chunk *up;
363
364 png_debug(5, "writing extra chunks\n");
365
366 for (up = info_ptr->unknown_chunks;
367 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
368 up++)
369 {
370 int keep=png_handle_as_unknown(png_ptr, up->name);
371 if (keep != PNG_HANDLE_CHUNK_NEVER &&
372 up->location && (up->location & PNG_AFTER_IDAT) &&
373 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
374 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
375 {
376 png_write_chunk(png_ptr, up->name, up->data, up->size);
377 }
378 }
379 }
380#endif
381 }
382
383 png_ptr->mode |= PNG_AFTER_IDAT;
384
385 /* write end of PNG file */
386 png_write_IEND(png_ptr);
387#if 0
388/* This flush, added in libpng-1.0.8, causes some applications to crash
389 because they do not set png_ptr->output_flush_fn */
390 png_flush(png_ptr);
391#endif
392}
393
394#if defined(PNG_WRITE_tIME_SUPPORTED)
395#if !defined(_WIN32_WCE)
396/* "time.h" functions are not supported on WindowsCE */
397void PNGAPI
398png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
399{
400 png_debug(1, "in png_convert_from_struct_tm\n");
401 ptime->year = (png_uint_16)(1900 + ttime->tm_year);
402 ptime->month = (png_byte)(ttime->tm_mon + 1);
403 ptime->day = (png_byte)ttime->tm_mday;
404 ptime->hour = (png_byte)ttime->tm_hour;
405 ptime->minute = (png_byte)ttime->tm_min;
406 ptime->second = (png_byte)ttime->tm_sec;
407}
408
409void PNGAPI
410png_convert_from_time_t(png_timep ptime, time_t ttime)
411{
412 struct tm *tbuf;
413
414 png_debug(1, "in png_convert_from_time_t\n");
415 tbuf = gmtime(&ttime);
416 png_convert_from_struct_tm(ptime, tbuf);
417}
418#endif
419#endif
420
421/* Initialize png_ptr structure, and allocate any memory needed */
422png_structp PNGAPI
423png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
424 png_error_ptr error_fn, png_error_ptr warn_fn)
425{
426#ifdef PNG_USER_MEM_SUPPORTED
427 return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
428 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
429}
430
431/* Alternate initialize png_ptr structure, and allocate any memory needed */
432png_structp PNGAPI
433png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
434 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
435 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
436{
437#endif /* PNG_USER_MEM_SUPPORTED */
438 png_structp png_ptr;
439#ifdef PNG_SETJMP_SUPPORTED
440#ifdef USE_FAR_KEYWORD
441 jmp_buf jmpbuf;
442#endif
443#endif
444 int i;
445 png_debug(1, "in png_create_write_struct\n");
446#ifdef PNG_USER_MEM_SUPPORTED
447 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
448 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
449#else
450 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
451#endif /* PNG_USER_MEM_SUPPORTED */
452 if (png_ptr == NULL)
453 return (NULL);
454
455#if !defined(PNG_1_0_X)
456#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
457 png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
458#endif
459#endif /* PNG_1_0_X */
460
461 /* added at libpng-1.2.6 */
462#ifdef PNG_SET_USER_LIMITS_SUPPORTED
463 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
464 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
465#endif
466
467#ifdef PNG_SETJMP_SUPPORTED
468#ifdef USE_FAR_KEYWORD
469 if (setjmp(jmpbuf))
470#else
471 if (setjmp(png_ptr->jmpbuf))
472#endif
473 {
474 png_free(png_ptr, png_ptr->zbuf);
475 png_ptr->zbuf=NULL;
476 png_destroy_struct(png_ptr);
477 return (NULL);
478 }
479#ifdef USE_FAR_KEYWORD
480 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
481#endif
482#endif
483
484#ifdef PNG_USER_MEM_SUPPORTED
485 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
486#endif /* PNG_USER_MEM_SUPPORTED */
487 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
488
489 i=0;
490 do
491 {
492 if(user_png_ver[i] != png_libpng_ver[i])
493 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
494 } while (png_libpng_ver[i++]);
495
496 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
497 {
498 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
499 * we must recompile any applications that use any older library version.
500 * For versions after libpng 1.0, we will be compatible, so we need
501 * only check the first digit.
502 */
503 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
504 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
505 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
506 {
507#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
508 char msg[80];
509 if (user_png_ver)
510 {
511 sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
512 user_png_ver);
513 png_warning(png_ptr, msg);
514 }
515 sprintf(msg, "Application is running with png.c from libpng-%.20s",
516 png_libpng_ver);
517 png_warning(png_ptr, msg);
518#endif
519#ifdef PNG_ERROR_NUMBERS_SUPPORTED
520 png_ptr->flags=0;
521#endif
522 png_error(png_ptr,
523 "Incompatible libpng version in application and library");
524 }
525 }
526
527 /* initialize zbuf - compression buffer */
528 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
529 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
530 (png_uint_32)png_ptr->zbuf_size);
531
532 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
533 png_flush_ptr_NULL);
534
535#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
536 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
537 1, png_doublep_NULL, png_doublep_NULL);
538#endif
539
540#ifdef PNG_SETJMP_SUPPORTED
541/* Applications that neglect to set up their own setjmp() and then encounter
542 a png_error() will longjmp here. Since the jmpbuf is then meaningless we
543 abort instead of returning. */
544#ifdef USE_FAR_KEYWORD
545 if (setjmp(jmpbuf))
546 PNG_ABORT();
547 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
548#else
549 if (setjmp(png_ptr->jmpbuf))
550 PNG_ABORT();
551#endif
552#endif
553 return (png_ptr);
554}
555
556/* Initialize png_ptr structure, and allocate any memory needed */
557#undef png_write_init
558void PNGAPI
559png_write_init(png_structp png_ptr)
560{
561 /* We only come here via pre-1.0.7-compiled applications */
562 png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
563}
564
565void PNGAPI
566png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
567 png_size_t png_struct_size, png_size_t png_info_size)
568{
569 /* We only come here via pre-1.0.12-compiled applications */
570#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
571 if(png_sizeof(png_struct) > png_struct_size ||
572 png_sizeof(png_info) > png_info_size)
573 {
574 char msg[80];
575 png_ptr->warning_fn=NULL;
576 if (user_png_ver)
577 {
578 sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
579 user_png_ver);
580 png_warning(png_ptr, msg);
581 }
582 sprintf(msg, "Application is running with png.c from libpng-%.20s",
583 png_libpng_ver);
584 png_warning(png_ptr, msg);
585 }
586#endif
587 if(png_sizeof(png_struct) > png_struct_size)
588 {
589 png_ptr->error_fn=NULL;
590#ifdef PNG_ERROR_NUMBERS_SUPPORTED
591 png_ptr->flags=0;
592#endif
593 png_error(png_ptr,
594 "The png struct allocated by the application for writing is too small.");
595 }
596 if(png_sizeof(png_info) > png_info_size)
597 {
598 png_ptr->error_fn=NULL;
599#ifdef PNG_ERROR_NUMBERS_SUPPORTED
600 png_ptr->flags=0;
601#endif
602 png_error(png_ptr,
603 "The info struct allocated by the application for writing is too small.");
604 }
605 png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
606}
607
608
609void PNGAPI
610png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
611 png_size_t png_struct_size)
612{
613 png_structp png_ptr=*ptr_ptr;
614#ifdef PNG_SETJMP_SUPPORTED
615 jmp_buf tmp_jmp; /* to save current jump buffer */
616#endif
617 int i = 0;
618 do
619 {
620 if (user_png_ver[i] != png_libpng_ver[i])
621 {
622#ifdef PNG_LEGACY_SUPPORTED
623 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
624#else
625 png_ptr->warning_fn=NULL;
626 png_warning(png_ptr,
627 "Application uses deprecated png_write_init() and should be recompiled.");
628 break;
629#endif
630 }
631 } while (png_libpng_ver[i++]);
632
633 png_debug(1, "in png_write_init_3\n");
634
635#ifdef PNG_SETJMP_SUPPORTED
636 /* save jump buffer and error functions */
637 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
638#endif
639
640 if (png_sizeof(png_struct) > png_struct_size)
641 {
642 png_destroy_struct(png_ptr);
643 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
644 *ptr_ptr = png_ptr;
645 }
646
647 /* reset all variables to 0 */
648 png_memset(png_ptr, 0, png_sizeof (png_struct));
649
650 /* added at libpng-1.2.6 */
651#ifdef PNG_SET_USER_LIMITS_SUPPORTED
652 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
653 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
654#endif
655
656#if !defined(PNG_1_0_X)
657#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
658 png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
659#endif
660#endif /* PNG_1_0_X */
661
662#ifdef PNG_SETJMP_SUPPORTED
663 /* restore jump buffer */
664 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
665#endif
666
667 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
668 png_flush_ptr_NULL);
669
670 /* initialize zbuf - compression buffer */
671 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
672 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
673 (png_uint_32)png_ptr->zbuf_size);
674
675#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
676 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
677 1, png_doublep_NULL, png_doublep_NULL);
678#endif
679}
680
681/* Write a few rows of image data. If the image is interlaced,
682 * either you will have to write the 7 sub images, or, if you
683 * have called png_set_interlace_handling(), you will have to
684 * "write" the image seven times.
685 */
686void PNGAPI
687png_write_rows(png_structp png_ptr, png_bytepp row,
688 png_uint_32 num_rows)
689{
690 png_uint_32 i; /* row counter */
691 png_bytepp rp; /* row pointer */
692
693 png_debug(1, "in png_write_rows\n");
694 /* loop through the rows */
695 for (i = 0, rp = row; i < num_rows; i++, rp++)
696 {
697 png_write_row(png_ptr, *rp);
698 }
699}
700
701/* Write the image. You only need to call this function once, even
702 * if you are writing an interlaced image.
703 */
704void PNGAPI
705png_write_image(png_structp png_ptr, png_bytepp image)
706{
707 png_uint_32 i; /* row index */
708 int pass, num_pass; /* pass variables */
709 png_bytepp rp; /* points to current row */
710
711 png_debug(1, "in png_write_image\n");
712#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
713 /* intialize interlace handling. If image is not interlaced,
714 this will set pass to 1 */
715 num_pass = png_set_interlace_handling(png_ptr);
716#else
717 num_pass = 1;
718#endif
719 /* loop through passes */
720 for (pass = 0; pass < num_pass; pass++)
721 {
722 /* loop through image */
723 for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
724 {
725 png_write_row(png_ptr, *rp);
726 }
727 }
728}
729
730/* called by user to write a row of image data */
731void PNGAPI
732png_write_row(png_structp png_ptr, png_bytep row)
733{
734 png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
735 png_ptr->row_number, png_ptr->pass);
736 /* initialize transformations and other stuff if first time */
737 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
738 {
739 /* make sure we wrote the header info */
740 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
741 png_error(png_ptr,
742 "png_write_info was never called before png_write_row.");
743
744 /* check for transforms that have been set but were defined out */
745#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
746 if (png_ptr->transformations & PNG_INVERT_MONO)
747 png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
748#endif
749#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
750 if (png_ptr->transformations & PNG_FILLER)
751 png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
752#endif
753#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
754 if (png_ptr->transformations & PNG_PACKSWAP)
755 png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
756#endif
757#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
758 if (png_ptr->transformations & PNG_PACK)
759 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
760#endif
761#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
762 if (png_ptr->transformations & PNG_SHIFT)
763 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
764#endif
765#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
766 if (png_ptr->transformations & PNG_BGR)
767 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
768#endif
769#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
770 if (png_ptr->transformations & PNG_SWAP_BYTES)
771 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
772#endif
773
774 png_write_start_row(png_ptr);
775 }
776
777#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
778 /* if interlaced and not interested in row, return */
779 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
780 {
781 switch (png_ptr->pass)
782 {
783 case 0:
784 if (png_ptr->row_number & 0x07)
785 {
786 png_write_finish_row(png_ptr);
787 return;
788 }
789 break;
790 case 1:
791 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
792 {
793 png_write_finish_row(png_ptr);
794 return;
795 }
796 break;
797 case 2:
798 if ((png_ptr->row_number & 0x07) != 4)
799 {
800 png_write_finish_row(png_ptr);
801 return;
802 }
803 break;
804 case 3:
805 if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
806 {
807 png_write_finish_row(png_ptr);
808 return;
809 }
810 break;
811 case 4:
812 if ((png_ptr->row_number & 0x03) != 2)
813 {
814 png_write_finish_row(png_ptr);
815 return;
816 }
817 break;
818 case 5:
819 if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
820 {
821 png_write_finish_row(png_ptr);
822 return;
823 }
824 break;
825 case 6:
826 if (!(png_ptr->row_number & 0x01))
827 {
828 png_write_finish_row(png_ptr);
829 return;
830 }
831 break;
832 }
833 }
834#endif
835
836 /* set up row info for transformations */
837 png_ptr->row_info.color_type = png_ptr->color_type;
838 png_ptr->row_info.width = png_ptr->usr_width;
839 png_ptr->row_info.channels = png_ptr->usr_channels;
840 png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
841 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
842 png_ptr->row_info.channels);
843
844 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
845 png_ptr->row_info.width);
846
847 png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);
848 png_debug1(3, "row_info->width = %lu\n", png_ptr->row_info.width);
849 png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);
850 png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);
851 png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);
852 png_debug1(3, "row_info->rowbytes = %lu\n", png_ptr->row_info.rowbytes);
853
854 /* Copy user's row into buffer, leaving room for filter byte. */
855 png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
856 png_ptr->row_info.rowbytes);
857
858#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
859 /* handle interlacing */
860 if (png_ptr->interlaced && png_ptr->pass < 6 &&
861 (png_ptr->transformations & PNG_INTERLACE))
862 {
863 png_do_write_interlace(&(png_ptr->row_info),
864 png_ptr->row_buf + 1, png_ptr->pass);
865 /* this should always get caught above, but still ... */
866 if (!(png_ptr->row_info.width))
867 {
868 png_write_finish_row(png_ptr);
869 return;
870 }
871 }
872#endif
873
874 /* handle other transformations */
875 if (png_ptr->transformations)
876 png_do_write_transformations(png_ptr);
877
878#if defined(PNG_MNG_FEATURES_SUPPORTED)
879 /* Write filter_method 64 (intrapixel differencing) only if
880 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
881 * 2. Libpng did not write a PNG signature (this filter_method is only
882 * used in PNG datastreams that are embedded in MNG datastreams) and
883 * 3. The application called png_permit_mng_features with a mask that
884 * included PNG_FLAG_MNG_FILTER_64 and
885 * 4. The filter_method is 64 and
886 * 5. The color_type is RGB or RGBA
887 */
888 if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
889 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
890 {
891 /* Intrapixel differencing */
892 png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
893 }
894#endif
895
896 /* Find a filter if necessary, filter the row and write it out. */
897 png_write_find_filter(png_ptr, &(png_ptr->row_info));
898
899 if (png_ptr->write_row_fn != NULL)
900 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
901}
902
903#if defined(PNG_WRITE_FLUSH_SUPPORTED)
904/* Set the automatic flush interval or 0 to turn flushing off */
905void PNGAPI
906png_set_flush(png_structp png_ptr, int nrows)
907{
908 png_debug(1, "in png_set_flush\n");
909 png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
910}
911
912/* flush the current output buffers now */
913void PNGAPI
914png_write_flush(png_structp png_ptr)
915{
916 int wrote_IDAT;
917
918 png_debug(1, "in png_write_flush\n");
919 /* We have already written out all of the data */
920 if (png_ptr->row_number >= png_ptr->num_rows)
921 return;
922
923 do
924 {
925 int ret;
926
927 /* compress the data */
928 ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
929 wrote_IDAT = 0;
930
931 /* check for compression errors */
932 if (ret != Z_OK)
933 {
934 if (png_ptr->zstream.msg != NULL)
935 png_error(png_ptr, png_ptr->zstream.msg);
936 else
937 png_error(png_ptr, "zlib error");
938 }
939
940 if (!(png_ptr->zstream.avail_out))
941 {
942 /* write the IDAT and reset the zlib output buffer */
943 png_write_IDAT(png_ptr, png_ptr->zbuf,
944 png_ptr->zbuf_size);
945 png_ptr->zstream.next_out = png_ptr->zbuf;
946 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
947 wrote_IDAT = 1;
948 }
949 } while(wrote_IDAT == 1);
950
951 /* If there is any data left to be output, write it into a new IDAT */
952 if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
953 {
954 /* write the IDAT and reset the zlib output buffer */
955 png_write_IDAT(png_ptr, png_ptr->zbuf,
956 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
957 png_ptr->zstream.next_out = png_ptr->zbuf;
958 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
959 }
960 png_ptr->flush_rows = 0;
961 png_flush(png_ptr);
962}
963#endif /* PNG_WRITE_FLUSH_SUPPORTED */
964
965/* free all memory used by the write */
966void PNGAPI
967png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
968{
969 png_structp png_ptr = NULL;
970 png_infop info_ptr = NULL;
971#ifdef PNG_USER_MEM_SUPPORTED
972 png_free_ptr free_fn = NULL;
973 png_voidp mem_ptr = NULL;
974#endif
975
976 png_debug(1, "in png_destroy_write_struct\n");
977 if (png_ptr_ptr != NULL)
978 {
979 png_ptr = *png_ptr_ptr;
980#ifdef PNG_USER_MEM_SUPPORTED
981 free_fn = png_ptr->free_fn;
982 mem_ptr = png_ptr->mem_ptr;
983#endif
984 }
985
986 if (info_ptr_ptr != NULL)
987 info_ptr = *info_ptr_ptr;
988
989 if (info_ptr != NULL)
990 {
991 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
992
993#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
994 if (png_ptr->num_chunk_list)
995 {
996 png_free(png_ptr, png_ptr->chunk_list);
997 png_ptr->chunk_list=NULL;
998 png_ptr->num_chunk_list=0;
999 }
1000#endif
1001
1002#ifdef PNG_USER_MEM_SUPPORTED
1003 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1004 (png_voidp)mem_ptr);
1005#else
1006 png_destroy_struct((png_voidp)info_ptr);
1007#endif
1008 *info_ptr_ptr = NULL;
1009 }
1010
1011 if (png_ptr != NULL)
1012 {
1013 png_write_destroy(png_ptr);
1014#ifdef PNG_USER_MEM_SUPPORTED
1015 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1016 (png_voidp)mem_ptr);
1017#else
1018 png_destroy_struct((png_voidp)png_ptr);
1019#endif
1020 *png_ptr_ptr = NULL;
1021 }
1022}
1023
1024
1025/* Free any memory used in png_ptr struct (old method) */
1026void /* PRIVATE */
1027png_write_destroy(png_structp png_ptr)
1028{
1029#ifdef PNG_SETJMP_SUPPORTED
1030 jmp_buf tmp_jmp; /* save jump buffer */
1031#endif
1032 png_error_ptr error_fn;
1033 png_error_ptr warning_fn;
1034 png_voidp error_ptr;
1035#ifdef PNG_USER_MEM_SUPPORTED
1036 png_free_ptr free_fn;
1037#endif
1038
1039 png_debug(1, "in png_write_destroy\n");
1040 /* free any memory zlib uses */
1041 deflateEnd(&png_ptr->zstream);
1042
1043 /* free our memory. png_free checks NULL for us. */
1044 png_free(png_ptr, png_ptr->zbuf);
1045 png_free(png_ptr, png_ptr->row_buf);
1046 png_free(png_ptr, png_ptr->prev_row);
1047 png_free(png_ptr, png_ptr->sub_row);
1048 png_free(png_ptr, png_ptr->up_row);
1049 png_free(png_ptr, png_ptr->avg_row);
1050 png_free(png_ptr, png_ptr->paeth_row);
1051
1052#if defined(PNG_TIME_RFC1123_SUPPORTED)
1053 png_free(png_ptr, png_ptr->time_buffer);
1054#endif
1055
1056#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1057 png_free(png_ptr, png_ptr->prev_filters);
1058 png_free(png_ptr, png_ptr->filter_weights);
1059 png_free(png_ptr, png_ptr->inv_filter_weights);
1060 png_free(png_ptr, png_ptr->filter_costs);
1061 png_free(png_ptr, png_ptr->inv_filter_costs);
1062#endif
1063
1064#ifdef PNG_SETJMP_SUPPORTED
1065 /* reset structure */
1066 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
1067#endif
1068
1069 error_fn = png_ptr->error_fn;
1070 warning_fn = png_ptr->warning_fn;
1071 error_ptr = png_ptr->error_ptr;
1072#ifdef PNG_USER_MEM_SUPPORTED
1073 free_fn = png_ptr->free_fn;
1074#endif
1075
1076 png_memset(png_ptr, 0, png_sizeof (png_struct));
1077
1078 png_ptr->error_fn = error_fn;
1079 png_ptr->warning_fn = warning_fn;
1080 png_ptr->error_ptr = error_ptr;
1081#ifdef PNG_USER_MEM_SUPPORTED
1082 png_ptr->free_fn = free_fn;
1083#endif
1084
1085#ifdef PNG_SETJMP_SUPPORTED
1086 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
1087#endif
1088}
1089
1090/* Allow the application to select one or more row filters to use. */
1091void PNGAPI
1092png_set_filter(png_structp png_ptr, int method, int filters)
1093{
1094 png_debug(1, "in png_set_filter\n");
1095#if defined(PNG_MNG_FEATURES_SUPPORTED)
1096 if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1097 (method == PNG_INTRAPIXEL_DIFFERENCING))
1098 method = PNG_FILTER_TYPE_BASE;
1099#endif
1100 if (method == PNG_FILTER_TYPE_BASE)
1101 {
1102 switch (filters & (PNG_ALL_FILTERS | 0x07))
1103 {
1104 case 5:
1105 case 6:
1106 case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1107 case PNG_FILTER_VALUE_NONE: png_ptr->do_filter=PNG_FILTER_NONE; break;
1108 case PNG_FILTER_VALUE_SUB: png_ptr->do_filter=PNG_FILTER_SUB; break;
1109 case PNG_FILTER_VALUE_UP: png_ptr->do_filter=PNG_FILTER_UP; break;
1110 case PNG_FILTER_VALUE_AVG: png_ptr->do_filter=PNG_FILTER_AVG; break;
1111 case PNG_FILTER_VALUE_PAETH: png_ptr->do_filter=PNG_FILTER_PAETH;break;
1112 default: png_ptr->do_filter = (png_byte)filters; break;
1113 }
1114
1115 /* If we have allocated the row_buf, this means we have already started
1116 * with the image and we should have allocated all of the filter buffers
1117 * that have been selected. If prev_row isn't already allocated, then
1118 * it is too late to start using the filters that need it, since we
1119 * will be missing the data in the previous row. If an application
1120 * wants to start and stop using particular filters during compression,
1121 * it should start out with all of the filters, and then add and
1122 * remove them after the start of compression.
1123 */
1124 if (png_ptr->row_buf != NULL)
1125 {
1126 if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1127 {
1128 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1129 (png_ptr->rowbytes + 1));
1130 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1131 }
1132
1133 if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1134 {
1135 if (png_ptr->prev_row == NULL)
1136 {
1137 png_warning(png_ptr, "Can't add Up filter after starting");
1138 png_ptr->do_filter &= ~PNG_FILTER_UP;
1139 }
1140 else
1141 {
1142 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1143 (png_ptr->rowbytes + 1));
1144 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1145 }
1146 }
1147
1148 if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1149 {
1150 if (png_ptr->prev_row == NULL)
1151 {
1152 png_warning(png_ptr, "Can't add Average filter after starting");
1153 png_ptr->do_filter &= ~PNG_FILTER_AVG;
1154 }
1155 else
1156 {
1157 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1158 (png_ptr->rowbytes + 1));
1159 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1160 }
1161 }
1162
1163 if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1164 png_ptr->paeth_row == NULL)
1165 {
1166 if (png_ptr->prev_row == NULL)
1167 {
1168 png_warning(png_ptr, "Can't add Paeth filter after starting");
1169 png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1170 }
1171 else
1172 {
1173 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1174 (png_ptr->rowbytes + 1));
1175 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1176 }
1177 }
1178
1179 if (png_ptr->do_filter == PNG_NO_FILTERS)
1180 png_ptr->do_filter = PNG_FILTER_NONE;
1181 }
1182 }
1183 else
1184 png_error(png_ptr, "Unknown custom filter method");
1185}
1186
1187/* This allows us to influence the way in which libpng chooses the "best"
1188 * filter for the current scanline. While the "minimum-sum-of-absolute-
1189 * differences metric is relatively fast and effective, there is some
1190 * question as to whether it can be improved upon by trying to keep the
1191 * filtered data going to zlib more consistent, hopefully resulting in
1192 * better compression.
1193 */
1194#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */
1195void PNGAPI
1196png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1197 int num_weights, png_doublep filter_weights,
1198 png_doublep filter_costs)
1199{
1200 int i;
1201
1202 png_debug(1, "in png_set_filter_heuristics\n");
1203 if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1204 {
1205 png_warning(png_ptr, "Unknown filter heuristic method");
1206 return;
1207 }
1208
1209 if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1210 {
1211 heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1212 }
1213
1214 if (num_weights < 0 || filter_weights == NULL ||
1215 heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1216 {
1217 num_weights = 0;
1218 }
1219
1220 png_ptr->num_prev_filters = (png_byte)num_weights;
1221 png_ptr->heuristic_method = (png_byte)heuristic_method;
1222
1223 if (num_weights > 0)
1224 {
1225 if (png_ptr->prev_filters == NULL)
1226 {
1227 png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1228 (png_uint_32)(png_sizeof(png_byte) * num_weights));
1229
1230 /* To make sure that the weighting starts out fairly */
1231 for (i = 0; i < num_weights; i++)
1232 {
1233 png_ptr->prev_filters[i] = 255;
1234 }
1235 }
1236
1237 if (png_ptr->filter_weights == NULL)
1238 {
1239 png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1240 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1241
1242 png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1243 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1244 for (i = 0; i < num_weights; i++)
1245 {
1246 png_ptr->inv_filter_weights[i] =
1247 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1248 }
1249 }
1250
1251 for (i = 0; i < num_weights; i++)
1252 {
1253 if (filter_weights[i] < 0.0)
1254 {
1255 png_ptr->inv_filter_weights[i] =
1256 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1257 }
1258 else
1259 {
1260 png_ptr->inv_filter_weights[i] =
1261 (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1262 png_ptr->filter_weights[i] =
1263 (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1264 }
1265 }
1266 }
1267
1268 /* If, in the future, there are other filter methods, this would
1269 * need to be based on png_ptr->filter.
1270 */
1271 if (png_ptr->filter_costs == NULL)
1272 {
1273 png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1274 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1275
1276 png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1277 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1278
1279 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1280 {
1281 png_ptr->inv_filter_costs[i] =
1282 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1283 }
1284 }
1285
1286 /* Here is where we set the relative costs of the different filters. We
1287 * should take the desired compression level into account when setting
1288 * the costs, so that Paeth, for instance, has a high relative cost at low
1289 * compression levels, while it has a lower relative cost at higher
1290 * compression settings. The filter types are in order of increasing
1291 * relative cost, so it would be possible to do this with an algorithm.
1292 */
1293 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1294 {
1295 if (filter_costs == NULL || filter_costs[i] < 0.0)
1296 {
1297 png_ptr->inv_filter_costs[i] =
1298 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1299 }
1300 else if (filter_costs[i] >= 1.0)
1301 {
1302 png_ptr->inv_filter_costs[i] =
1303 (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1304 png_ptr->filter_costs[i] =
1305 (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1306 }
1307 }
1308}
1309#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1310
1311void PNGAPI
1312png_set_compression_level(png_structp png_ptr, int level)
1313{
1314 png_debug(1, "in png_set_compression_level\n");
1315 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1316 png_ptr->zlib_level = level;
1317}
1318
1319void PNGAPI
1320png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1321{
1322 png_debug(1, "in png_set_compression_mem_level\n");
1323 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1324 png_ptr->zlib_mem_level = mem_level;
1325}
1326
1327void PNGAPI
1328png_set_compression_strategy(png_structp png_ptr, int strategy)
1329{
1330 png_debug(1, "in png_set_compression_strategy\n");
1331 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1332 png_ptr->zlib_strategy = strategy;
1333}
1334
1335void PNGAPI
1336png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1337{
1338 if (window_bits > 15)
1339 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1340 else if (window_bits < 8)
1341 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1342#ifndef WBITS_8_OK
1343 /* avoid libpng bug with 256-byte windows */
1344 if (window_bits == 8)
1345 {
1346 png_warning(png_ptr, "Compression window is being reset to 512");
1347 window_bits=9;
1348 }
1349#endif
1350 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1351 png_ptr->zlib_window_bits = window_bits;
1352}
1353
1354void PNGAPI
1355png_set_compression_method(png_structp png_ptr, int method)
1356{
1357 png_debug(1, "in png_set_compression_method\n");
1358 if (method != 8)
1359 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1360 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1361 png_ptr->zlib_method = method;
1362}
1363
1364void PNGAPI
1365png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1366{
1367 png_ptr->write_row_fn = write_row_fn;
1368}
1369
1370#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1371void PNGAPI
1372png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1373 write_user_transform_fn)
1374{
1375 png_debug(1, "in png_set_write_user_transform_fn\n");
1376 png_ptr->transformations |= PNG_USER_TRANSFORM;
1377 png_ptr->write_user_transform_fn = write_user_transform_fn;
1378}
1379#endif
1380
1381
1382#if defined(PNG_INFO_IMAGE_SUPPORTED)
1383void PNGAPI
1384png_write_png(png_structp png_ptr, png_infop info_ptr,
1385 int transforms, voidp params)
1386{
1387#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1388 /* invert the alpha channel from opacity to transparency */
1389 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1390 png_set_invert_alpha(png_ptr);
1391#endif
1392
1393 /* Write the file header information. */
1394 png_write_info(png_ptr, info_ptr);
1395
1396 /* ------ these transformations don't touch the info structure ------- */
1397
1398#if defined(PNG_WRITE_INVERT_SUPPORTED)
1399 /* invert monochrome pixels */
1400 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1401 png_set_invert_mono(png_ptr);
1402#endif
1403
1404#if defined(PNG_WRITE_SHIFT_SUPPORTED)
1405 /* Shift the pixels up to a legal bit depth and fill in
1406 * as appropriate to correctly scale the image.
1407 */
1408 if ((transforms & PNG_TRANSFORM_SHIFT)
1409 && (info_ptr->valid & PNG_INFO_sBIT))
1410 png_set_shift(png_ptr, &info_ptr->sig_bit);
1411#endif
1412
1413#if defined(PNG_WRITE_PACK_SUPPORTED)
1414 /* pack pixels into bytes */
1415 if (transforms & PNG_TRANSFORM_PACKING)
1416 png_set_packing(png_ptr);
1417#endif
1418
1419#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1420 /* swap location of alpha bytes from ARGB to RGBA */
1421 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1422 png_set_swap_alpha(png_ptr);
1423#endif
1424
1425#if defined(PNG_WRITE_FILLER_SUPPORTED)
1426 /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
1427 * RGB (4 channels -> 3 channels). The second parameter is not used.
1428 */
1429 if (transforms & PNG_TRANSFORM_STRIP_FILLER)
1430 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1431#endif
1432
1433#if defined(PNG_WRITE_BGR_SUPPORTED)
1434 /* flip BGR pixels to RGB */
1435 if (transforms & PNG_TRANSFORM_BGR)
1436 png_set_bgr(png_ptr);
1437#endif
1438
1439#if defined(PNG_WRITE_SWAP_SUPPORTED)
1440 /* swap bytes of 16-bit files to most significant byte first */
1441 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1442 png_set_swap(png_ptr);
1443#endif
1444
1445#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1446 /* swap bits of 1, 2, 4 bit packed pixel formats */
1447 if (transforms & PNG_TRANSFORM_PACKSWAP)
1448 png_set_packswap(png_ptr);
1449#endif
1450
1451 /* ----------------------- end of transformations ------------------- */
1452
1453 /* write the bits */
1454 if (info_ptr->valid & PNG_INFO_IDAT)
1455 png_write_image(png_ptr, info_ptr->row_pointers);
1456
1457 /* It is REQUIRED to call this to finish writing the rest of the file */
1458 png_write_end(png_ptr, info_ptr);
1459
1460 if(transforms == 0 || params == NULL)
1461 /* quiet compiler warnings */ return;
1462}
1463#endif
1464#endif /* PNG_WRITE_SUPPORTED */
wxWidgets (Impactor)