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) 1998-2002,2004,2006-2015 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  */
29 void PNGAPI
png_write_info_before_PLTE(png_structp png_ptr,png_infop info_ptr)30 png_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 
134 void PNGAPI
png_write_info(png_structp png_ptr,png_infop info_ptr)135 png_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  */
314 void PNGAPI
png_write_end(png_structp png_ptr,png_infop info_ptr)315 png_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 */
431 void PNGAPI
png_convert_from_struct_tm(png_timep ptime,struct tm FAR * ttime)432 png_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 
444 void PNGAPI
png_convert_from_time_t(png_timep ptime,time_t ttime)445 png_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 */
457 png_structp PNGAPI
png_create_write_struct(png_const_charp user_png_ver,png_voidp error_ptr,png_error_ptr error_fn,png_error_ptr warn_fn)458 png_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 */
467 png_structp PNGAPI
png_create_write_struct_2(png_const_charp user_png_ver,png_voidp error_ptr,png_error_ptr error_fn,png_error_ptr warn_fn,png_voidp mem_ptr,png_malloc_ptr malloc_fn,png_free_ptr free_fn)468 png_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
608 void PNGAPI
png_write_init(png_structp png_ptr)609 png_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 
615 void PNGAPI
png_write_init_2(png_structp png_ptr,png_const_charp user_png_ver,png_size_t png_struct_size,png_size_t png_info_size)616 png_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 
665 void PNGAPI
png_write_init_3(png_structpp ptr_ptr,png_const_charp user_png_ver,png_size_t png_struct_size)666 png_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  */
736 void PNGAPI
png_write_rows(png_structp png_ptr,png_bytepp row,png_uint_32 num_rows)737 png_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  */
758 void PNGAPI
png_write_image(png_structp png_ptr,png_bytepp image)759 png_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 */
790 void PNGAPI
png_write_row(png_structp png_ptr,png_bytep row)791 png_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 */
972 void PNGAPI
png_set_flush(png_structp png_ptr,int nrows)973 png_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 */
983 void PNGAPI
png_write_flush(png_structp png_ptr)984 png_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 */
1039 void PNGAPI
png_destroy_write_struct(png_structpp png_ptr_ptr,png_infopp info_ptr_ptr)1040 png_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) */
1111 void /* PRIVATE */
png_write_destroy(png_structp png_ptr)1112 png_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. */
1171 void PNGAPI
png_set_filter(png_structp png_ptr,int method,int filters)1172 png_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 */
1291 void PNGAPI
png_set_filter_heuristics(png_structp png_ptr,int heuristic_method,int num_weights,png_doublep filter_weights,png_doublep filter_costs)1292 png_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 
1304 void PNGAPI
png_set_compression_level(png_structp png_ptr,int level)1305 png_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 
1315 void PNGAPI
png_set_compression_mem_level(png_structp png_ptr,int mem_level)1316 png_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 
1326 void PNGAPI
png_set_compression_strategy(png_structp png_ptr,int strategy)1327 png_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 
1337 void PNGAPI
png_set_compression_window_bits(png_structp png_ptr,int window_bits)1338 png_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 
1358 void PNGAPI
png_set_compression_method(png_structp png_ptr,int method)1359 png_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 
1371 void PNGAPI
png_set_write_status_fn(png_structp png_ptr,png_write_status_ptr write_row_fn)1372 png_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
1380 void PNGAPI
png_set_write_user_transform_fn(png_structp png_ptr,png_user_transform_ptr write_user_transform_fn)1381 png_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
1395 void PNGAPI
png_write_png(png_structp png_ptr,png_infop info_ptr,int transforms,voidp params)1396 png_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 */
1480