1 
2 /* pngwrite.c - general routines to write a PNG file
3  *
4  * Last changed in libpng 1.2.15 January 5, 2007
5  * For conditions of distribution and use, see copyright notice in png.h
6  * Copyright (c) 1998-2007 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
acpi_create_fadt(struct acpi_fadt * fadt,struct acpi_facs * facs,void * dsdt)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  */
25 void PNGAPI
26 png_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 == NULL || info_ptr == NULL)
30       return;
31    if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
32    {
33    png_write_sig(png_ptr); /* write PNG signature */
34 #if defined(PNG_MNG_FEATURES_SUPPORTED)
35    if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
36    {
37       png_warning(png_ptr,"MNG features are not allowed in a PNG datastream");
38       png_ptr->mng_features_permitted=0;
39    }
40 #endif
41    /* write IHDR information. */
42    png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
43       info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
44       info_ptr->filter_type,
45 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
46       info_ptr->interlace_type);
47 #else
48       0);
49 #endif
50    /* the rest of these check to see if the valid field has the appropriate
51       flag set, and if it does, writes the chunk. */
52 #if defined(PNG_WRITE_gAMA_SUPPORTED)
53    if (info_ptr->valid & PNG_INFO_gAMA)
54    {
55 #  ifdef PNG_FLOATING_POINT_SUPPORTED
56       png_write_gAMA(png_ptr, info_ptr->gamma);
57 #else
58 #ifdef PNG_FIXED_POINT_SUPPORTED
59       png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
60 #  endif
61 #endif
62    }
63 #endif
64 #if defined(PNG_WRITE_sRGB_SUPPORTED)
65    if (info_ptr->valid & PNG_INFO_sRGB)
66       png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
67 #endif
68 #if defined(PNG_WRITE_iCCP_SUPPORTED)
69    if (info_ptr->valid & PNG_INFO_iCCP)
70       png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
71                      info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
72 #endif
73 #if defined(PNG_WRITE_sBIT_SUPPORTED)
74    if (info_ptr->valid & PNG_INFO_sBIT)
75       png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
76 #endif
77 #if defined(PNG_WRITE_cHRM_SUPPORTED)
78    if (info_ptr->valid & PNG_INFO_cHRM)
79    {
80 #ifdef PNG_FLOATING_POINT_SUPPORTED
81       png_write_cHRM(png_ptr,
82          info_ptr->x_white, info_ptr->y_white,
83          info_ptr->x_red, info_ptr->y_red,
84          info_ptr->x_green, info_ptr->y_green,
85          info_ptr->x_blue, info_ptr->y_blue);
86 #else
87 #  ifdef PNG_FIXED_POINT_SUPPORTED
88       png_write_cHRM_fixed(png_ptr,
89          info_ptr->int_x_white, info_ptr->int_y_white,
90          info_ptr->int_x_red, info_ptr->int_y_red,
91          info_ptr->int_x_green, info_ptr->int_y_green,
92          info_ptr->int_x_blue, info_ptr->int_y_blue);
93 #  endif
94 #endif
95    }
96 #endif
97 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
98    if (info_ptr->unknown_chunks_num)
99    {
100        png_unknown_chunk *up;
101 
102        png_debug(5, "writing extra chunks\n");
103 
104        for (up = info_ptr->unknown_chunks;
105             up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
106             up++)
107        {
108          int keep=png_handle_as_unknown(png_ptr, up->name);
109          if (keep != PNG_HANDLE_CHUNK_NEVER &&
110             up->location && !(up->location & PNG_HAVE_PLTE) &&
111             !(up->location & PNG_HAVE_IDAT) &&
112             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
113             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
114          {
115             png_write_chunk(png_ptr, up->name, up->data, up->size);
116          }
117        }
118    }
119 #endif
120       png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
121    }
122 }
123 
124 void PNGAPI
125 png_write_info(png_structp png_ptr, png_infop info_ptr)
126 {
127 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
128    int i;
129 #endif
130 
131    png_debug(1, "in png_write_info\n");
132 
133    if (png_ptr == NULL || info_ptr == NULL)
134       return;
135 
136    png_write_info_before_PLTE(png_ptr, info_ptr);
acpi_create_gnvs(struct acpi_global_nvs * gnvs)137 
138    if (info_ptr->valid & PNG_INFO_PLTE)
139       png_write_PLTE(png_ptr, info_ptr->palette,
140          (png_uint_32)info_ptr->num_palette);
141    else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
142       png_error(png_ptr, "Valid palette required for paletted images");
143 
144 #if defined(PNG_WRITE_tRNS_SUPPORTED)
145    if (info_ptr->valid & PNG_INFO_tRNS)
146       {
147 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
148          /* invert the alpha channel (in tRNS) */
149          if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
150             info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
151          {
152             int j;
153             for (j=0; j<(int)info_ptr->num_trans; j++)
154                info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
155          }
156 #endif
157       png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
158          info_ptr->num_trans, info_ptr->color_type);
159       }
160 #endif
161 #if defined(PNG_WRITE_bKGD_SUPPORTED)
162    if (info_ptr->valid & PNG_INFO_bKGD)
163       png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
164 #endif
165 #if defined(PNG_WRITE_hIST_SUPPORTED)
166    if (info_ptr->valid & PNG_INFO_hIST)
167       png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
168 #endif
169 #if defined(PNG_WRITE_oFFs_SUPPORTED)
170    if (info_ptr->valid & PNG_INFO_oFFs)
171       png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
172          info_ptr->offset_unit_type);
173 #endif
174 #if defined(PNG_WRITE_pCAL_SUPPORTED)
175    if (info_ptr->valid & PNG_INFO_pCAL)
176       png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
177          info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
178          info_ptr->pcal_units, info_ptr->pcal_params);
179 #endif
180 #if defined(PNG_WRITE_sCAL_SUPPORTED)
181    if (info_ptr->valid & PNG_INFO_sCAL)
182 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
183       png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
184           info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
185 #else
186 #ifdef PNG_FIXED_POINT_SUPPORTED
187       png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
188           info_ptr->scal_s_width, info_ptr->scal_s_height);
189 #else
190       png_warning(png_ptr,
191           "png_write_sCAL not supported; sCAL chunk not written.");
192 #endif
193 #endif
194 #endif
195 #if defined(PNG_WRITE_pHYs_SUPPORTED)
196    if (info_ptr->valid & PNG_INFO_pHYs)
197       png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
198          info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
199 #endif
200 #if defined(PNG_WRITE_tIME_SUPPORTED)
201    if (info_ptr->valid & PNG_INFO_tIME)
202    {
203       png_write_tIME(png_ptr, &(info_ptr->mod_time));
204       png_ptr->mode |= PNG_WROTE_tIME;
205    }
206 #endif
207 #if defined(PNG_WRITE_sPLT_SUPPORTED)
208    if (info_ptr->valid & PNG_INFO_sPLT)
209      for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
210        png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
211 #endif
212 #if defined(PNG_WRITE_TEXT_SUPPORTED)
213    /* Check to see if we need to write text chunks */
214    for (i = 0; i < info_ptr->num_text; i++)
215    {
216       png_debug2(2, "Writing header text chunk %d, type %d\n", i,
217          info_ptr->text[i].compression);
218       /* an internationalized chunk? */
219       if (info_ptr->text[i].compression > 0)
220       {
221 #if defined(PNG_WRITE_iTXt_SUPPORTED)
222           /* write international chunk */
223           png_write_iTXt(png_ptr,
224                          info_ptr->text[i].compression,
225                          info_ptr->text[i].key,
226                          info_ptr->text[i].lang,
227                          info_ptr->text[i].lang_key,
228                          info_ptr->text[i].text);
229 #else
230           png_warning(png_ptr, "Unable to write international text");
231 #endif
232           /* Mark this chunk as written */
233           info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
234       }
235       /* If we want a compressed text chunk */
236       else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
237       {
238 #if defined(PNG_WRITE_zTXt_SUPPORTED)
239          /* write compressed chunk */
240          png_write_zTXt(png_ptr, info_ptr->text[i].key,
241             info_ptr->text[i].text, 0,
242             info_ptr->text[i].compression);
243 #else
244          png_warning(png_ptr, "Unable to write compressed text");
245 #endif
246          /* Mark this chunk as written */
247          info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
248       }
249       else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
250       {
251 #if defined(PNG_WRITE_tEXt_SUPPORTED)
252          /* write uncompressed chunk */
253          png_write_tEXt(png_ptr, info_ptr->text[i].key,
254                          info_ptr->text[i].text,
255                          0);
256 #else
257          png_warning(png_ptr, "Unable to write uncompressed text");
258 #endif
259          /* Mark this chunk as written */
260          info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
261       }
262    }
263 #endif
264 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
265    if (info_ptr->unknown_chunks_num)
266    {
267        png_unknown_chunk *up;
268 
269        png_debug(5, "writing extra chunks\n");
270 
271        for (up = info_ptr->unknown_chunks;
272             up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
273             up++)
274        {
275          int keep=png_handle_as_unknown(png_ptr, up->name);
276          if (keep != PNG_HANDLE_CHUNK_NEVER &&
277             up->location && (up->location & PNG_HAVE_PLTE) &&
278             !(up->location & PNG_HAVE_IDAT) &&
279             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
280             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
281          {
282             png_write_chunk(png_ptr, up->name, up->data, up->size);
283          }
284        }
285    }
286 #endif
287 }
288 
289 /* Writes the end of the PNG file.  If you don't want to write comments or
290  * time information, you can pass NULL for info.  If you already wrote these
291  * in png_write_info(), do not write them again here.  If you have long
292  * comments, I suggest writing them here, and compressing them.
293  */
294 void PNGAPI
295 png_write_end(png_structp png_ptr, png_infop info_ptr)
296 {
297    png_debug(1, "in png_write_end\n");
298    if (png_ptr == NULL)
299       return;
300    if (!(png_ptr->mode & PNG_HAVE_IDAT))
301       png_error(png_ptr, "No IDATs written into file");
302 
303    /* see if user wants us to write information chunks */
304    if (info_ptr != NULL)
305    {
306 #if defined(PNG_WRITE_TEXT_SUPPORTED)
307       int i; /* local index variable */
308 #endif
309 #if defined(PNG_WRITE_tIME_SUPPORTED)
310       /* check to see if user has supplied a time chunk */
311       if ((info_ptr->valid & PNG_INFO_tIME) &&
312          !(png_ptr->mode & PNG_WROTE_tIME))
313          png_write_tIME(png_ptr, &(info_ptr->mod_time));
314 #endif
315 #if defined(PNG_WRITE_TEXT_SUPPORTED)
316       /* loop through comment chunks */
317       for (i = 0; i < info_ptr->num_text; i++)
318       {
319          png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,
320             info_ptr->text[i].compression);
321          /* an internationalized chunk? */
322          if (info_ptr->text[i].compression > 0)
323          {
324 #if defined(PNG_WRITE_iTXt_SUPPORTED)
325              /* write international chunk */
326              png_write_iTXt(png_ptr,
327                          info_ptr->text[i].compression,
328                          info_ptr->text[i].key,
329                          info_ptr->text[i].lang,
330                          info_ptr->text[i].lang_key,
331                          info_ptr->text[i].text);
332 #else
333              png_warning(png_ptr, "Unable to write international text");
334 #endif
335              /* Mark this chunk as written */
336              info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
337          }
338          else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
339          {
340 #if defined(PNG_WRITE_zTXt_SUPPORTED)
341             /* write compressed chunk */
342             png_write_zTXt(png_ptr, info_ptr->text[i].key,
343                info_ptr->text[i].text, 0,
344                info_ptr->text[i].compression);
345 #else
346             png_warning(png_ptr, "Unable to write compressed text");
347 #endif
348             /* Mark this chunk as written */
349             info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
350          }
351          else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
352          {
353 #if defined(PNG_WRITE_tEXt_SUPPORTED)
354             /* write uncompressed chunk */
355             png_write_tEXt(png_ptr, info_ptr->text[i].key,
356                info_ptr->text[i].text, 0);
357 #else
358             png_warning(png_ptr, "Unable to write uncompressed text");
359 #endif
360 
361             /* Mark this chunk as written */
362             info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
363          }
364       }
365 #endif
366 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
367    if (info_ptr->unknown_chunks_num)
368    {
369        png_unknown_chunk *up;
370 
371        png_debug(5, "writing extra chunks\n");
372 
373        for (up = info_ptr->unknown_chunks;
374             up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
375             up++)
376        {
377          int keep=png_handle_as_unknown(png_ptr, up->name);
378          if (keep != PNG_HANDLE_CHUNK_NEVER &&
379             up->location && (up->location & PNG_AFTER_IDAT) &&
380             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
381             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
382          {
383             png_write_chunk(png_ptr, up->name, up->data, up->size);
384          }
385        }
386    }
387 #endif
388    }
389 
390    png_ptr->mode |= PNG_AFTER_IDAT;
391 
392    /* write end of PNG file */
393    png_write_IEND(png_ptr);
394 #if 0
395 /* This flush, added in libpng-1.0.8,  causes some applications to crash
396    because they do not set png_ptr->output_flush_fn */
397    png_flush(png_ptr);
398 #endif
399 }
400 
401 #if defined(PNG_WRITE_tIME_SUPPORTED)
402 #if !defined(_WIN32_WCE)
403 /* "time.h" functions are not supported on WindowsCE */
404 void PNGAPI
405 png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
406 {
407    png_debug(1, "in png_convert_from_struct_tm\n");
408    ptime->year = (png_uint_16)(1900 + ttime->tm_year);
409    ptime->month = (png_byte)(ttime->tm_mon + 1);
410    ptime->day = (png_byte)ttime->tm_mday;
411    ptime->hour = (png_byte)ttime->tm_hour;
412    ptime->minute = (png_byte)ttime->tm_min;
413    ptime->second = (png_byte)ttime->tm_sec;
414 }
415 
416 void PNGAPI
417 png_convert_from_time_t(png_timep ptime, time_t ttime)
418 {
419    struct tm *tbuf;
420 
421    png_debug(1, "in png_convert_from_time_t\n");
422    tbuf = gmtime(&ttime);
423    png_convert_from_struct_tm(ptime, tbuf);
424 }
425 #endif
426 #endif
427 
428 /* Initialize png_ptr structure, and allocate any memory needed */
429 png_structp PNGAPI
430 png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
431    png_error_ptr error_fn, png_error_ptr warn_fn)
432 {
433 #ifdef PNG_USER_MEM_SUPPORTED
434    return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
435       warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
436 }
437 
438 /* Alternate initialize png_ptr structure, and allocate any memory needed */
439 png_structp PNGAPI
440 png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
441    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
442    png_malloc_ptr malloc_fn, png_free_ptr free_fn)
443 {
444 #endif /* PNG_USER_MEM_SUPPORTED */
445    png_structp png_ptr;
446 #ifdef PNG_SETJMP_SUPPORTED
447 #ifdef USE_FAR_KEYWORD
448    jmp_buf jmpbuf;
449 #endif
450 #endif
451    int i;
452    png_debug(1, "in png_create_write_struct\n");
453 #ifdef PNG_USER_MEM_SUPPORTED
454    png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
455       (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
456 #else
457    png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
458 #endif /* PNG_USER_MEM_SUPPORTED */
459    if (png_ptr == NULL)
460       return (NULL);
461 
462 #if !defined(PNG_1_0_X)
463 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
464 #ifdef PNG_MMX_CODE_SUPPORTED
465    png_init_mmx_flags(png_ptr);   /* 1.2.0 addition */
466 #endif
467 #endif
468 #endif /* PNG_1_0_X */
469 
470    /* added at libpng-1.2.6 */
471 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
472    png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
473    png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
474 #endif
475 
476 #ifdef PNG_SETJMP_SUPPORTED
477 #ifdef USE_FAR_KEYWORD
478    if (setjmp(jmpbuf))
479 #else
480    if (setjmp(png_ptr->jmpbuf))
481 #endif
482    {
483       png_free(png_ptr, png_ptr->zbuf);
484       png_ptr->zbuf=NULL;
485       png_destroy_struct(png_ptr);
486       return (NULL);
487    }
488 #ifdef USE_FAR_KEYWORD
489    png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
490 #endif
491 #endif
492 
493 #ifdef PNG_USER_MEM_SUPPORTED
494    png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
495 #endif /* PNG_USER_MEM_SUPPORTED */
496    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
497 
498    i=0;
499    do
500    {
501      if(user_png_ver[i] != png_libpng_ver[i])
502         png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
503    } while (png_libpng_ver[i++]);
504 
505    if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
506    {
507      /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
508       * we must recompile any applications that use any older library version.
509       * For versions after libpng 1.0, we will be compatible, so we need
510       * only check the first digit.
511       */
512      if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
513          (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
514          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
515      {
516 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
517         char msg[80];
518         if (user_png_ver)
519         {
520           sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
521              user_png_ver);
522           png_warning(png_ptr, msg);
523         }
524         sprintf(msg, "Application  is  running with png.c from libpng-%.20s",
525            png_libpng_ver);
526         png_warning(png_ptr, msg);
527 #endif
528 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
529         png_ptr->flags=0;
530 #endif
531         png_error(png_ptr,
532            "Incompatible libpng version in application and library");
533      }
534    }
535 
536    /* initialize zbuf - compression buffer */
537    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
538    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
539       (png_uint_32)png_ptr->zbuf_size);
540 
541    png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
542       png_flush_ptr_NULL);
543 
544 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
545    png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
546       1, png_doublep_NULL, png_doublep_NULL);
547 #endif
548 
549 #ifdef PNG_SETJMP_SUPPORTED
550 /* Applications that neglect to set up their own setjmp() and then encounter
551    a png_error() will longjmp here.  Since the jmpbuf is then meaningless we
552    abort instead of returning. */
553 #ifdef USE_FAR_KEYWORD
554    if (setjmp(jmpbuf))
555       PNG_ABORT();
556    png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
557 #else
558    if (setjmp(png_ptr->jmpbuf))
559       PNG_ABORT();
560 #endif
561 #endif
562    return (png_ptr);
563 }
564 
565 /* Initialize png_ptr structure, and allocate any memory needed */
566 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
567 /* Deprecated. */
568 #undef png_write_init
569 void PNGAPI
570 png_write_init(png_structp png_ptr)
571 {
572    /* We only come here via pre-1.0.7-compiled applications */
573    png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
574 }
575 
576 void PNGAPI
577 png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
578    png_size_t png_struct_size, png_size_t png_info_size)
579 {
580    /* We only come here via pre-1.0.12-compiled applications */
581    if(png_ptr == NULL) return;
582 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
583    if(png_sizeof(png_struct) > png_struct_size ||
584       png_sizeof(png_info) > png_info_size)
585    {
586       char msg[80];
587       png_ptr->warning_fn=NULL;
588       if (user_png_ver)
589       {
590         sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
591            user_png_ver);
592         png_warning(png_ptr, msg);
593       }
594       sprintf(msg, "Application  is  running with png.c from libpng-%.20s",
595          png_libpng_ver);
596       png_warning(png_ptr, msg);
597    }
598 #endif
599    if(png_sizeof(png_struct) > png_struct_size)
600      {
601        png_ptr->error_fn=NULL;
602 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
603        png_ptr->flags=0;
604 #endif
605        png_error(png_ptr,
606        "The png struct allocated by the application for writing is too small.");
607      }
608    if(png_sizeof(png_info) > png_info_size)
609      {
610        png_ptr->error_fn=NULL;
611 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
612        png_ptr->flags=0;
613 #endif
614        png_error(png_ptr,
615        "The info struct allocated by the application for writing is too small.");
616      }
617    png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
618 }
619 #endif /* PNG_1_0_X || PNG_1_2_X */
620 
621 
622 void PNGAPI
623 png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
624    png_size_t png_struct_size)
625 {
626    png_structp png_ptr=*ptr_ptr;
627 #ifdef PNG_SETJMP_SUPPORTED
628    jmp_buf tmp_jmp; /* to save current jump buffer */
629 #endif
630 
631    int i = 0;
632 
633    if (png_ptr == NULL)
634       return;
635 
636    do
637    {
638      if (user_png_ver[i] != png_libpng_ver[i])
639      {
640 #ifdef PNG_LEGACY_SUPPORTED
641        png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
642 #else
643        png_ptr->warning_fn=NULL;
644        png_warning(png_ptr,
645      "Application uses deprecated png_write_init() and should be recompiled.");
646        break;
647 #endif
648      }
649    } while (png_libpng_ver[i++]);
650 
651    png_debug(1, "in png_write_init_3\n");
652 
653 #ifdef PNG_SETJMP_SUPPORTED
654    /* save jump buffer and error functions */
655    png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
656 #endif
657 
658    if (png_sizeof(png_struct) > png_struct_size)
659      {
660        png_destroy_struct(png_ptr);
661        png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
662        *ptr_ptr = png_ptr;
663      }
664 
665    /* reset all variables to 0 */
666    png_memset(png_ptr, 0, png_sizeof (png_struct));
667 
668    /* added at libpng-1.2.6 */
669 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
670    png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
671    png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
672 #endif
673 
674 #if !defined(PNG_1_0_X)
675 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
676 #ifdef PNG_MMX_CODE_SUPPORTED
677    png_init_mmx_flags(png_ptr);   /* 1.2.0 addition */
678 #endif
679 #endif
680 #endif /* PNG_1_0_X */
681 
682 #ifdef PNG_SETJMP_SUPPORTED
683    /* restore jump buffer */
684    png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
685 #endif
686 
687    png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
688       png_flush_ptr_NULL);
689 
690    /* initialize zbuf - compression buffer */
691    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
692    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
693       (png_uint_32)png_ptr->zbuf_size);
694 
695 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
696    png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
697       1, png_doublep_NULL, png_doublep_NULL);
698 #endif
699 }
700 
701 /* Write a few rows of image data.  If the image is interlaced,
702  * either you will have to write the 7 sub images, or, if you
703  * have called png_set_interlace_handling(), you will have to
704  * "write" the image seven times.
705  */
706 void PNGAPI
707 png_write_rows(png_structp png_ptr, png_bytepp row,
708    png_uint_32 num_rows)
709 {
710    png_uint_32 i; /* row counter */
711    png_bytepp rp; /* row pointer */
712 
713    png_debug(1, "in png_write_rows\n");
714 
715    if (png_ptr == NULL)
716       return;
717 
718    /* loop through the rows */
719    for (i = 0, rp = row; i < num_rows; i++, rp++)
720    {
721       png_write_row(png_ptr, *rp);
722    }
723 }
724 
725 /* Write the image.  You only need to call this function once, even
726  * if you are writing an interlaced image.
727  */
728 void PNGAPI
729 png_write_image(png_structp png_ptr, png_bytepp image)
730 {
731    png_uint_32 i; /* row index */
732    int pass, num_pass; /* pass variables */
733    png_bytepp rp; /* points to current row */
734 
735    if (png_ptr == NULL)
736       return;
737 
738    png_debug(1, "in png_write_image\n");
739 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
740    /* intialize interlace handling.  If image is not interlaced,
741       this will set pass to 1 */
742    num_pass = png_set_interlace_handling(png_ptr);
743 #else
744    num_pass = 1;
745 #endif
746    /* loop through passes */
747    for (pass = 0; pass < num_pass; pass++)
748    {
749       /* loop through image */
750       for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
751       {
752          png_write_row(png_ptr, *rp);
753       }
754    }
755 }
756 
757 /* called by user to write a row of image data */
758 void PNGAPI
759 png_write_row(png_structp png_ptr, png_bytep row)
760 {
761    if (png_ptr == NULL)
762       return;
763    png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
764       png_ptr->row_number, png_ptr->pass);
765 
766    /* initialize transformations and other stuff if first time */
767    if (png_ptr->row_number == 0 && png_ptr->pass == 0)
768    {
769    /* make sure we wrote the header info */
770    if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
771       png_error(png_ptr,
772          "png_write_info was never called before png_write_row.");
773 
774    /* check for transforms that have been set but were defined out */
775 #if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
776    if (png_ptr->transformations & PNG_INVERT_MONO)
777       png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
778 #endif
779 #if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
780    if (png_ptr->transformations & PNG_FILLER)
781       png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
782 #endif
783 #if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
784    if (png_ptr->transformations & PNG_PACKSWAP)
785       png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
786 #endif
787 #if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
788    if (png_ptr->transformations & PNG_PACK)
789       png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
790 #endif
791 #if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
792    if (png_ptr->transformations & PNG_SHIFT)
793       png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
794 #endif
795 #if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
796    if (png_ptr->transformations & PNG_BGR)
797       png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
798 #endif
799 #if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
800    if (png_ptr->transformations & PNG_SWAP_BYTES)
801       png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
802 #endif
803 
804       png_write_start_row(png_ptr);
805    }
806 
807 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
808    /* if interlaced and not interested in row, return */
809    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
810    {
811       switch (png_ptr->pass)
812       {
813          case 0:
814             if (png_ptr->row_number & 0x07)
815             {
816                png_write_finish_row(png_ptr);
817                return;
818             }
819             break;
820          case 1:
821             if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
822             {
823                png_write_finish_row(png_ptr);
824                return;
825             }
826             break;
827          case 2:
828             if ((png_ptr->row_number & 0x07) != 4)
829             {
830                png_write_finish_row(png_ptr);
831                return;
832             }
833             break;
834          case 3:
835             if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
836             {
837                png_write_finish_row(png_ptr);
838                return;
839             }
840             break;
841          case 4:
842             if ((png_ptr->row_number & 0x03) != 2)
843             {
844                png_write_finish_row(png_ptr);
845                return;
846             }
847             break;
848          case 5:
849             if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
850             {
851                png_write_finish_row(png_ptr);
852                return;
853             }
854             break;
855          case 6:
856             if (!(png_ptr->row_number & 0x01))
857             {
858                png_write_finish_row(png_ptr);
859                return;
860             }
861             break;
862       }
863    }
864 #endif
865 
866    /* set up row info for transformations */
867    png_ptr->row_info.color_type = png_ptr->color_type;
868    png_ptr->row_info.width = png_ptr->usr_width;
869    png_ptr->row_info.channels = png_ptr->usr_channels;
870    png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
871    png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
872       png_ptr->row_info.channels);
873 
874    png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
875       png_ptr->row_info.width);
876 
877    png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);
878    png_debug1(3, "row_info->width = %lu\n", png_ptr->row_info.width);
879    png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);
880    png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);
881    png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);
882    png_debug1(3, "row_info->rowbytes = %lu\n", png_ptr->row_info.rowbytes);
883 
884    /* Copy user's row into buffer, leaving room for filter byte. */
885    png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
886       png_ptr->row_info.rowbytes);
887 
888 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
889    /* handle interlacing */
890    if (png_ptr->interlaced && png_ptr->pass < 6 &&
891       (png_ptr->transformations & PNG_INTERLACE))
892    {
893       png_do_write_interlace(&(png_ptr->row_info),
894          png_ptr->row_buf + 1, png_ptr->pass);
895       /* this should always get caught above, but still ... */
896       if (!(png_ptr->row_info.width))
897       {
898          png_write_finish_row(png_ptr);
899          return;
900       }
901    }
902 #endif
903 
904    /* handle other transformations */
905    if (png_ptr->transformations)
906       png_do_write_transformations(png_ptr);
907 
908 #if defined(PNG_MNG_FEATURES_SUPPORTED)
909    /* Write filter_method 64 (intrapixel differencing) only if
910     * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
911     * 2. Libpng did not write a PNG signature (this filter_method is only
912     *    used in PNG datastreams that are embedded in MNG datastreams) and
913     * 3. The application called png_permit_mng_features with a mask that
914     *    included PNG_FLAG_MNG_FILTER_64 and
915     * 4. The filter_method is 64 and
916     * 5. The color_type is RGB or RGBA
917     */
918    if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
919       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
920    {
921       /* Intrapixel differencing */
922       png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
923    }
924 #endif
925 
926    /* Find a filter if necessary, filter the row and write it out. */
927    png_write_find_filter(png_ptr, &(png_ptr->row_info));
928 
929    if (png_ptr->write_row_fn != NULL)
930       (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
931 }
932 
933 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
934 /* Set the automatic flush interval or 0 to turn flushing off */
935 void PNGAPI
936 png_set_flush(png_structp png_ptr, int nrows)
937 {
938    png_debug(1, "in png_set_flush\n");
939    if (png_ptr == NULL)
940       return;
941    png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
942 }
943 
944 /* flush the current output buffers now */
945 void PNGAPI
946 png_write_flush(png_structp png_ptr)
947 {
948    int wrote_IDAT;
949 
950    png_debug(1, "in png_write_flush\n");
951    if (png_ptr == NULL)
952       return;
953    /* We have already written out all of the data */
954    if (png_ptr->row_number >= png_ptr->num_rows)
955      return;
956 
957    do
958    {
959       int ret;
960 
961       /* compress the data */
962       ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
963       wrote_IDAT = 0;
964 
965       /* check for compression errors */
966       if (ret != Z_OK)
967       {
968          if (png_ptr->zstream.msg != NULL)
969             png_error(png_ptr, png_ptr->zstream.msg);
970          else
971             png_error(png_ptr, "zlib error");
972       }
973 
974       if (!(png_ptr->zstream.avail_out))
975       {
976          /* write the IDAT and reset the zlib output buffer */
977          png_write_IDAT(png_ptr, png_ptr->zbuf,
978                         png_ptr->zbuf_size);
979          png_ptr->zstream.next_out = png_ptr->zbuf;
980          png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
981          wrote_IDAT = 1;
982       }
983    } while(wrote_IDAT == 1);
984 
985    /* If there is any data left to be output, write it into a new IDAT */
986    if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
987    {
988       /* write the IDAT and reset the zlib output buffer */
989       png_write_IDAT(png_ptr, png_ptr->zbuf,
990                      png_ptr->zbuf_size - png_ptr->zstream.avail_out);
991       png_ptr->zstream.next_out = png_ptr->zbuf;
992       png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
993    }
994    png_ptr->flush_rows = 0;
995    png_flush(png_ptr);
996 }
997 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
998 
999 /* free all memory used by the write */
1000 void PNGAPI
1001 png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
1002 {
1003    png_structp png_ptr = NULL;
1004    png_infop info_ptr = NULL;
1005 #ifdef PNG_USER_MEM_SUPPORTED
1006    png_free_ptr free_fn = NULL;
1007    png_voidp mem_ptr = NULL;
1008 #endif
1009 
1010    png_debug(1, "in png_destroy_write_struct\n");
1011    if (png_ptr_ptr != NULL)
1012    {
1013       png_ptr = *png_ptr_ptr;
1014 #ifdef PNG_USER_MEM_SUPPORTED
1015       free_fn = png_ptr->free_fn;
1016       mem_ptr = png_ptr->mem_ptr;
1017 #endif
1018    }
1019 
1020    if (info_ptr_ptr != NULL)
1021       info_ptr = *info_ptr_ptr;
1022 
1023    if (info_ptr != NULL)
1024    {
1025       png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
1026 
1027 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1028       if (png_ptr->num_chunk_list)
1029       {
1030          png_free(png_ptr, png_ptr->chunk_list);
1031          png_ptr->chunk_list=NULL;
1032          png_ptr->num_chunk_list=0;
1033       }
1034 #endif
1035 
1036 #ifdef PNG_USER_MEM_SUPPORTED
1037       png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1038          (png_voidp)mem_ptr);
1039 #else
1040       png_destroy_struct((png_voidp)info_ptr);
1041 #endif
1042       *info_ptr_ptr = NULL;
1043    }
1044 
1045    if (png_ptr != NULL)
1046    {
1047       png_write_destroy(png_ptr);
1048 #ifdef PNG_USER_MEM_SUPPORTED
1049       png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1050          (png_voidp)mem_ptr);
1051 #else
1052       png_destroy_struct((png_voidp)png_ptr);
1053 #endif
1054       *png_ptr_ptr = NULL;
1055    }
1056 }
1057 
1058 
1059 /* Free any memory used in png_ptr struct (old method) */
1060 void /* PRIVATE */
1061 png_write_destroy(png_structp png_ptr)
1062 {
1063 #ifdef PNG_SETJMP_SUPPORTED
1064    jmp_buf tmp_jmp; /* save jump buffer */
1065 #endif
1066    png_error_ptr error_fn;
1067    png_error_ptr warning_fn;
1068    png_voidp error_ptr;
1069 #ifdef PNG_USER_MEM_SUPPORTED
1070    png_free_ptr free_fn;
1071 #endif
1072 
1073    png_debug(1, "in png_write_destroy\n");
1074    /* free any memory zlib uses */
1075    deflateEnd(&png_ptr->zstream);
1076 
1077    /* free our memory.  png_free checks NULL for us. */
1078    png_free(png_ptr, png_ptr->zbuf);
1079    png_free(png_ptr, png_ptr->row_buf);
1080    png_free(png_ptr, png_ptr->prev_row);
1081    png_free(png_ptr, png_ptr->sub_row);
1082    png_free(png_ptr, png_ptr->up_row);
1083    png_free(png_ptr, png_ptr->avg_row);
1084    png_free(png_ptr, png_ptr->paeth_row);
1085 
1086 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1087    png_free(png_ptr, png_ptr->time_buffer);
1088 #endif
1089 
1090 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1091    png_free(png_ptr, png_ptr->prev_filters);
1092    png_free(png_ptr, png_ptr->filter_weights);
1093    png_free(png_ptr, png_ptr->inv_filter_weights);
1094    png_free(png_ptr, png_ptr->filter_costs);
1095    png_free(png_ptr, png_ptr->inv_filter_costs);
1096 #endif
1097 
1098 #ifdef PNG_SETJMP_SUPPORTED
1099    /* reset structure */
1100    png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
1101 #endif
1102 
1103    error_fn = png_ptr->error_fn;
1104    warning_fn = png_ptr->warning_fn;
1105    error_ptr = png_ptr->error_ptr;
1106 #ifdef PNG_USER_MEM_SUPPORTED
1107    free_fn = png_ptr->free_fn;
1108 #endif
1109 
1110    png_memset(png_ptr, 0, png_sizeof (png_struct));
1111 
1112    png_ptr->error_fn = error_fn;
1113    png_ptr->warning_fn = warning_fn;
1114    png_ptr->error_ptr = error_ptr;
1115 #ifdef PNG_USER_MEM_SUPPORTED
1116    png_ptr->free_fn = free_fn;
1117 #endif
1118 
1119 #ifdef PNG_SETJMP_SUPPORTED
1120    png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
1121 #endif
1122 }
1123 
1124 /* Allow the application to select one or more row filters to use. */
1125 void PNGAPI
1126 png_set_filter(png_structp png_ptr, int method, int filters)
1127 {
1128    png_debug(1, "in png_set_filter\n");
1129    if (png_ptr == NULL)
1130       return;
1131 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1132    if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1133       (method == PNG_INTRAPIXEL_DIFFERENCING))
1134          method = PNG_FILTER_TYPE_BASE;
1135 #endif
1136    if (method == PNG_FILTER_TYPE_BASE)
1137    {
1138       switch (filters & (PNG_ALL_FILTERS | 0x07))
1139       {
1140          case 5:
1141          case 6:
1142          case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1143          case PNG_FILTER_VALUE_NONE:  png_ptr->do_filter=PNG_FILTER_NONE; break;
1144          case PNG_FILTER_VALUE_SUB:   png_ptr->do_filter=PNG_FILTER_SUB;  break;
1145          case PNG_FILTER_VALUE_UP:    png_ptr->do_filter=PNG_FILTER_UP;   break;
1146          case PNG_FILTER_VALUE_AVG:   png_ptr->do_filter=PNG_FILTER_AVG;  break;
1147          case PNG_FILTER_VALUE_PAETH: png_ptr->do_filter=PNG_FILTER_PAETH;break;
1148          default: png_ptr->do_filter = (png_byte)filters; break;
1149       }
1150 
1151       /* If we have allocated the row_buf, this means we have already started
1152        * with the image and we should have allocated all of the filter buffers
1153        * that have been selected.  If prev_row isn't already allocated, then
1154        * it is too late to start using the filters that need it, since we
1155        * will be missing the data in the previous row.  If an application
1156        * wants to start and stop using particular filters during compression,
1157        * it should start out with all of the filters, and then add and
1158        * remove them after the start of compression.
1159        */
1160       if (png_ptr->row_buf != NULL)
1161       {
1162          if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1163          {
1164             png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1165               (png_ptr->rowbytes + 1));
1166             png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1167          }
1168 
1169          if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1170          {
1171             if (png_ptr->prev_row == NULL)
1172             {
1173                png_warning(png_ptr, "Can't add Up filter after starting");
1174                png_ptr->do_filter &= ~PNG_FILTER_UP;
1175             }
1176             else
1177             {
1178                png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1179                   (png_ptr->rowbytes + 1));
1180                png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1181             }
1182          }
1183 
1184          if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1185          {
1186             if (png_ptr->prev_row == NULL)
1187             {
1188                png_warning(png_ptr, "Can't add Average filter after starting");
1189                png_ptr->do_filter &= ~PNG_FILTER_AVG;
1190             }
1191             else
1192             {
1193                png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1194                   (png_ptr->rowbytes + 1));
1195                png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1196             }
1197          }
1198 
1199          if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1200              png_ptr->paeth_row == NULL)
1201          {
1202             if (png_ptr->prev_row == NULL)
1203             {
1204                png_warning(png_ptr, "Can't add Paeth filter after starting");
1205                png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1206             }
1207             else
1208             {
1209                png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1210                   (png_ptr->rowbytes + 1));
1211                png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1212             }
1213          }
1214 
1215          if (png_ptr->do_filter == PNG_NO_FILTERS)
1216             png_ptr->do_filter = PNG_FILTER_NONE;
1217       }
1218    }
1219    else
1220       png_error(png_ptr, "Unknown custom filter method");
1221 }
1222 
1223 /* This allows us to influence the way in which libpng chooses the "best"
1224  * filter for the current scanline.  While the "minimum-sum-of-absolute-
1225  * differences metric is relatively fast and effective, there is some
1226  * question as to whether it can be improved upon by trying to keep the
1227  * filtered data going to zlib more consistent, hopefully resulting in
1228  * better compression.
1229  */
1230 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)      /* GRR 970116 */
1231 void PNGAPI
1232 png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1233    int num_weights, png_doublep filter_weights,
1234    png_doublep filter_costs)
1235 {
1236    int i;
1237 
1238    png_debug(1, "in png_set_filter_heuristics\n");
1239    if (png_ptr == NULL)
1240       return;
1241    if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1242    {
1243       png_warning(png_ptr, "Unknown filter heuristic method");
1244       return;
1245    }
1246 
1247    if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1248    {
1249       heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1250    }
1251 
1252    if (num_weights < 0 || filter_weights == NULL ||
1253       heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1254    {
1255       num_weights = 0;
1256    }
1257 
1258    png_ptr->num_prev_filters = (png_byte)num_weights;
1259    png_ptr->heuristic_method = (png_byte)heuristic_method;
1260 
1261    if (num_weights > 0)
1262    {
1263       if (png_ptr->prev_filters == NULL)
1264       {
1265          png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1266             (png_uint_32)(png_sizeof(png_byte) * num_weights));
1267 
1268          /* To make sure that the weighting starts out fairly */
1269          for (i = 0; i < num_weights; i++)
1270          {
1271             png_ptr->prev_filters[i] = 255;
1272          }
1273       }
1274 
1275       if (png_ptr->filter_weights == NULL)
1276       {
1277          png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1278             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1279 
1280          png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1281             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1282          for (i = 0; i < num_weights; i++)
1283          {
1284             png_ptr->inv_filter_weights[i] =
1285             png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1286          }
1287       }
1288 
1289       for (i = 0; i < num_weights; i++)
1290       {
1291          if (filter_weights[i] < 0.0)
1292          {
1293             png_ptr->inv_filter_weights[i] =
1294             png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1295          }
1296          else
1297          {
1298             png_ptr->inv_filter_weights[i] =
1299                (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1300             png_ptr->filter_weights[i] =
1301                (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1302          }
1303       }
1304    }
1305 
1306    /* If, in the future, there are other filter methods, this would
1307     * need to be based on png_ptr->filter.
1308     */
1309    if (png_ptr->filter_costs == NULL)
1310    {
1311       png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1312          (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1313 
1314       png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1315          (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1316 
1317       for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1318       {
1319          png_ptr->inv_filter_costs[i] =
1320          png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1321       }
1322    }
1323 
1324    /* Here is where we set the relative costs of the different filters.  We
1325     * should take the desired compression level into account when setting
1326     * the costs, so that Paeth, for instance, has a high relative cost at low
1327     * compression levels, while it has a lower relative cost at higher
1328     * compression settings.  The filter types are in order of increasing
1329     * relative cost, so it would be possible to do this with an algorithm.
1330     */
1331    for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1332    {
1333       if (filter_costs == NULL || filter_costs[i] < 0.0)
1334       {
1335          png_ptr->inv_filter_costs[i] =
1336          png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1337       }
1338       else if (filter_costs[i] >= 1.0)
1339       {
1340          png_ptr->inv_filter_costs[i] =
1341             (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1342          png_ptr->filter_costs[i] =
1343             (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1344       }
1345    }
1346 }
1347 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1348 
1349 void PNGAPI
1350 png_set_compression_level(png_structp png_ptr, int level)
1351 {
1352    png_debug(1, "in png_set_compression_level\n");
1353    if (png_ptr == NULL)
1354       return;
1355    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1356    png_ptr->zlib_level = level;
1357 }
1358 
1359 void PNGAPI
1360 png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1361 {
1362    png_debug(1, "in png_set_compression_mem_level\n");
1363    if (png_ptr == NULL)
1364       return;
1365    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1366    png_ptr->zlib_mem_level = mem_level;
1367 }
1368 
1369 void PNGAPI
1370 png_set_compression_strategy(png_structp png_ptr, int strategy)
1371 {
1372    png_debug(1, "in png_set_compression_strategy\n");
1373    if (png_ptr == NULL)
1374       return;
1375    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1376    png_ptr->zlib_strategy = strategy;
1377 }
1378 
1379 void PNGAPI
1380 png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1381 {
1382    if (png_ptr == NULL)
1383       return;
1384    if (window_bits > 15)
1385       png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1386    else if (window_bits < 8)
1387       png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1388 #ifndef WBITS_8_OK
1389    /* avoid libpng bug with 256-byte windows */
1390    if (window_bits == 8)
1391      {
1392        png_warning(png_ptr, "Compression window is being reset to 512");
1393        window_bits=9;
1394      }
1395 #endif
1396    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1397    png_ptr->zlib_window_bits = window_bits;
1398 }
1399 
1400 void PNGAPI
1401 png_set_compression_method(png_structp png_ptr, int method)
1402 {
1403    png_debug(1, "in png_set_compression_method\n");
1404    if (png_ptr == NULL)
1405       return;
1406    if (method != 8)
1407       png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1408    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1409    png_ptr->zlib_method = method;
1410 }
1411 
1412 void PNGAPI
1413 png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1414 {
1415    if (png_ptr == NULL)
1416       return;
1417    png_ptr->write_row_fn = write_row_fn;
1418 }
1419 
1420 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1421 void PNGAPI
1422 png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1423    write_user_transform_fn)
1424 {
1425    png_debug(1, "in png_set_write_user_transform_fn\n");
1426    if (png_ptr == NULL)
1427       return;
1428    png_ptr->transformations |= PNG_USER_TRANSFORM;
1429    png_ptr->write_user_transform_fn = write_user_transform_fn;
1430 }
1431 #endif
1432 
1433 
1434 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1435 void PNGAPI
1436 png_write_png(png_structp png_ptr, png_infop info_ptr,
1437               int transforms, voidp params)
1438 {
1439    if (png_ptr == NULL || info_ptr == NULL)
1440       return;
1441 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1442    /* invert the alpha channel from opacity to transparency */
1443    if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1444        png_set_invert_alpha(png_ptr);
1445 #endif
1446 
1447    /* Write the file header information. */
1448    png_write_info(png_ptr, info_ptr);
1449 
1450    /* ------ these transformations don't touch the info structure ------- */
1451 
1452 #if defined(PNG_WRITE_INVERT_SUPPORTED)
1453    /* invert monochrome pixels */
1454    if (transforms & PNG_TRANSFORM_INVERT_MONO)
1455        png_set_invert_mono(png_ptr);
1456 #endif
1457 
1458 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
1459    /* Shift the pixels up to a legal bit depth and fill in
1460     * as appropriate to correctly scale the image.
1461     */
1462    if ((transforms & PNG_TRANSFORM_SHIFT)
1463                && (info_ptr->valid & PNG_INFO_sBIT))
1464        png_set_shift(png_ptr, &info_ptr->sig_bit);
1465 #endif
1466 
1467 #if defined(PNG_WRITE_PACK_SUPPORTED)
1468    /* pack pixels into bytes */
1469    if (transforms & PNG_TRANSFORM_PACKING)
1470        png_set_packing(png_ptr);
1471 #endif
1472 
1473 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1474    /* swap location of alpha bytes from ARGB to RGBA */
1475    if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1476        png_set_swap_alpha(png_ptr);
1477 #endif
1478 
1479 #if defined(PNG_WRITE_FILLER_SUPPORTED)
1480    /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
1481     * RGB (4 channels -> 3 channels). The second parameter is not used.
1482     */
1483    if (transforms & PNG_TRANSFORM_STRIP_FILLER)
1484        png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1485 #endif
1486 
1487 #if defined(PNG_WRITE_BGR_SUPPORTED)
1488    /* flip BGR pixels to RGB */
1489    if (transforms & PNG_TRANSFORM_BGR)
1490        png_set_bgr(png_ptr);
1491 #endif
1492 
1493 #if defined(PNG_WRITE_SWAP_SUPPORTED)
1494    /* swap bytes of 16-bit files to most significant byte first */
1495    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1496        png_set_swap(png_ptr);
1497 #endif
1498 
1499 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1500    /* swap bits of 1, 2, 4 bit packed pixel formats */
1501    if (transforms & PNG_TRANSFORM_PACKSWAP)
1502        png_set_packswap(png_ptr);
1503 #endif
1504 
1505    /* ----------------------- end of transformations ------------------- */
1506 
1507    /* write the bits */
1508    if (info_ptr->valid & PNG_INFO_IDAT)
1509        png_write_image(png_ptr, info_ptr->row_pointers);
1510 
1511    /* It is REQUIRED to call this to finish writing the rest of the file */
1512    png_write_end(png_ptr, info_ptr);
1513 
1514    if(transforms == 0 || params == NULL)
1515       /* quiet compiler warnings */ return;
1516 }
1517 #endif
1518 #endif /* PNG_WRITE_SUPPORTED */
1519