third_party/libpng/pngwrite.c

   1
   2 /* pngwrite.c - general routines to write a PNG file
   3  *
   4  * Last changed in libpng 1.2.45 [July 7, 2011]
   5  * Copyright (c) 1998-2011 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
  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
 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
 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
 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
 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
 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
 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)
 529    {
 530       i = 0;
 531       do
 532       {
 533          if (user_png_ver[i] != png_libpng_ver[i])
 534             png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 535       } while (png_libpng_ver[i++]);
 536    }
 537
 538    if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
 539    {
 540      /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
 541       * we must recompile any applications that use any older library version.
 542       * For versions after libpng 1.0, we will be compatible, so we need
 543       * only check the first digit.
 544       */
 545      if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
 546          (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
 547          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
 548      {
 549 #if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
 550         char msg[80];
 551         if (user_png_ver)
 552         {
 553            png_snprintf(msg, 80,
 554               "Application was compiled with png.h from libpng-%.20s",
 555               user_png_ver);
 556            png_warning(png_ptr, msg);
 557         }
 558         png_snprintf(msg, 80,
 559            "Application  is  running with png.c from libpng-%.20s",
 560            png_libpng_ver);
 561         png_warning(png_ptr, msg);
 562 #endif
 563 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 564         png_ptr->flags = 0;
 565 #endif
 566         png_error(png_ptr,
 567            "Incompatible libpng version in application and library");
 568      }
 569    }
 570
 571    /* Initialize zbuf - compression buffer */
 572    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
 573    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
 574      (png_uint_32)png_ptr->zbuf_size);
 575
 576    png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
 577       png_flush_ptr_NULL);
 578
 579 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 580    png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
 581       1, png_doublep_NULL, png_doublep_NULL);
 582 #endif
 583
 584 #ifdef PNG_SETJMP_SUPPORTED
 585    /* Applications that neglect to set up their own setjmp() and then
 586     * encounter a png_error() will longjmp here.  Since the jmpbuf is
 587     * then meaningless we abort instead of returning.
 588     */
 589 #ifdef USE_FAR_KEYWORD
 590    if (setjmp(jmpbuf))
 591       PNG_ABORT();
 592    png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
 593 #else
 594    if (setjmp(png_ptr->jmpbuf))
 595       PNG_ABORT();
 596 #endif
 597 #endif
 598    return (png_ptr);
 599 }
 600
 601 /* Initialize png_ptr structure, and allocate any memory needed */
 602 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
 603 /* Deprecated. */
 604 #undef png_write_init
 605 void PNGAPI
 606 png_write_init(png_structp png_ptr)
 607 {
 608    /* We only come here via pre-1.0.7-compiled applications */
 609    png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
 610 }
 611
 612 void PNGAPI
 613 png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
 614    png_size_t png_struct_size, png_size_t png_info_size)
 615 {
 616    /* We only come here via pre-1.0.12-compiled applications */
 617    if (png_ptr == NULL) return;
 618 #if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
 619    if (png_sizeof(png_struct) > png_struct_size ||
 620       png_sizeof(png_info) > png_info_size)
 621    {
 622       char msg[80];
 623       png_ptr->warning_fn = NULL;
 624       if (user_png_ver)
 625       {
 626          png_snprintf(msg, 80,
 627             "Application was compiled with png.h from libpng-%.20s",
 628             user_png_ver);
 629          png_warning(png_ptr, msg);
 630       }
 631       png_snprintf(msg, 80,
 632          "Application  is  running with png.c from libpng-%.20s",
 633          png_libpng_ver);
 634       png_warning(png_ptr, msg);
 635    }
 636 #endif
 637    if (png_sizeof(png_struct) > png_struct_size)
 638    {
 639       png_ptr->error_fn = NULL;
 640 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 641       png_ptr->flags = 0;
 642 #endif
 643       png_error(png_ptr,
 644       "The png struct allocated by the application for writing is"
 645       " too small.");
 646    }
 647    if (png_sizeof(png_info) > png_info_size)
 648    {
 649       png_ptr->error_fn = NULL;
 650 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 651       png_ptr->flags = 0;
 652 #endif
 653       png_error(png_ptr,
 654       "The info struct allocated by the application for writing is"
 655       " too small.");
 656    }
 657    png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
 658 }
 659 #endif /* PNG_1_0_X || PNG_1_2_X */
 660
 661
 662 void PNGAPI
 663 png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 664    png_size_t png_struct_size)
 665 {
 666    png_structp png_ptr = *ptr_ptr;
 667 #ifdef PNG_SETJMP_SUPPORTED
 668    jmp_buf tmp_jmp; /* to save current jump buffer */
 669 #endif
 670
 671    int i = 0;
 672
 673    if (png_ptr == NULL)
 674       return;
 675
 676    do
 677    {
 678       if (user_png_ver[i] != png_libpng_ver[i])
 679       {
 680 #ifdef PNG_LEGACY_SUPPORTED
 681          png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 682 #else
 683          png_ptr->warning_fn = NULL;
 684          png_warning(png_ptr,
 685  "Application uses deprecated png_write_init() and should be recompiled.");
 686 #endif
 687       }
 688    } while (png_libpng_ver[i++]);
 689
 690    png_debug(1, "in png_write_init_3");
 691
 692 #ifdef PNG_SETJMP_SUPPORTED
 693    /* Save jump buffer and error functions */
 694    png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 695 #endif
 696
 697    if (png_sizeof(png_struct) > png_struct_size)
 698    {
 699       png_destroy_struct(png_ptr);
 700       png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
 701       *ptr_ptr = png_ptr;
 702    }
 703
 704    /* Reset all variables to 0 */
 705    png_memset(png_ptr, 0, png_sizeof(png_struct));
 706
 707    /* Added at libpng-1.2.6 */
 708 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
 709    png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
 710    png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
 711 #endif
 712
 713 #ifdef PNG_SETJMP_SUPPORTED
 714    /* Restore jump buffer */
 715    png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
 716 #endif
 717
 718    png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
 719       png_flush_ptr_NULL);
 720
 721    /* Initialize zbuf - compression buffer */
 722    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
 723    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
 724      (png_uint_32)png_ptr->zbuf_size);
 725 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 726    png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
 727       1, png_doublep_NULL, png_doublep_NULL);
 728 #endif
 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
 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
 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
 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
 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
 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
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 */
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_WRITE_WEIGHTED_FILTER_SUPPORTED
1145    png_free(png_ptr, png_ptr->prev_filters);
1146    png_free(png_ptr, png_ptr->filter_weights);
1147    png_free(png_ptr, png_ptr->inv_filter_weights);
1148    png_free(png_ptr, png_ptr->filter_costs);
1149    png_free(png_ptr, png_ptr->inv_filter_costs);
1150 #endif
1151
1152 #ifdef PNG_SETJMP_SUPPORTED
1153    /* Reset structure */
1154    png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
1155 #endif
1156
1157    error_fn = png_ptr->error_fn;
1158    warning_fn = png_ptr->warning_fn;
1159    error_ptr = png_ptr->error_ptr;
1160 #ifdef PNG_USER_MEM_SUPPORTED
1161    free_fn = png_ptr->free_fn;
1162 #endif
1163
1164    png_memset(png_ptr, 0, png_sizeof(png_struct));
1165
1166    png_ptr->error_fn = error_fn;
1167    png_ptr->warning_fn = warning_fn;
1168    png_ptr->error_ptr = error_ptr;
1169 #ifdef PNG_USER_MEM_SUPPORTED
1170    png_ptr->free_fn = free_fn;
1171 #endif
1172
1173 #ifdef PNG_SETJMP_SUPPORTED
1174    png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1175 #endif
1176 }
1177
1178 /* Allow the application to select one or more row filters to use. */
1179 void PNGAPI
1180 png_set_filter(png_structp png_ptr, int method, int filters)
1181 {
1182    png_debug(1, "in png_set_filter");
1183
1184    if (png_ptr == NULL)
1185       return;
1186 #ifdef PNG_MNG_FEATURES_SUPPORTED
1187    if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1188       (method == PNG_INTRAPIXEL_DIFFERENCING))
1189          method = PNG_FILTER_TYPE_BASE;
1190 #endif
1191    if (method == PNG_FILTER_TYPE_BASE)
1192    {
1193       switch (filters & (PNG_ALL_FILTERS | 0x07))
1194       {
1195 #ifdef PNG_WRITE_FILTER_SUPPORTED
1196          case 5:
1197          case 6:
1198          case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1199 #endif /* PNG_WRITE_FILTER_SUPPORTED */
1200          case PNG_FILTER_VALUE_NONE:
1201               png_ptr->do_filter = PNG_FILTER_NONE; break;
1202 #ifdef PNG_WRITE_FILTER_SUPPORTED
1203          case PNG_FILTER_VALUE_SUB:
1204               png_ptr->do_filter = PNG_FILTER_SUB; break;
1205          case PNG_FILTER_VALUE_UP:
1206               png_ptr->do_filter = PNG_FILTER_UP; break;
1207          case PNG_FILTER_VALUE_AVG:
1208               png_ptr->do_filter = PNG_FILTER_AVG; break;
1209          case PNG_FILTER_VALUE_PAETH:
1210               png_ptr->do_filter = PNG_FILTER_PAETH; break;
1211          default: png_ptr->do_filter = (png_byte)filters; break;
1212 #else
1213          default: png_warning(png_ptr, "Unknown row filter for method 0");
1214 #endif /* PNG_WRITE_FILTER_SUPPORTED */
1215       }
1216
1217       /* If we have allocated the row_buf, this means we have already started
1218        * with the image and we should have allocated all of the filter buffers
1219        * that have been selected.  If prev_row isn't already allocated, then
1220        * it is too late to start using the filters that need it, since we
1221        * will be missing the data in the previous row.  If an application
1222        * wants to start and stop using particular filters during compression,
1223        * it should start out with all of the filters, and then add and
1224        * remove them after the start of compression.
1225        */
1226       if (png_ptr->row_buf != NULL)
1227       {
1228 #ifdef PNG_WRITE_FILTER_SUPPORTED
1229          if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1230          {
1231             png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1232               (png_ptr->rowbytes + 1));
1233             png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1234          }
1235
1236          if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1237          {
1238             if (png_ptr->prev_row == NULL)
1239             {
1240                png_warning(png_ptr, "Can't add Up filter after starting");
1241                png_ptr->do_filter &= ~PNG_FILTER_UP;
1242             }
1243             else
1244             {
1245                png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1246                   (png_ptr->rowbytes + 1));
1247                png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1248             }
1249          }
1250
1251          if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1252          {
1253             if (png_ptr->prev_row == NULL)
1254             {
1255                png_warning(png_ptr, "Can't add Average filter after starting");
1256                png_ptr->do_filter &= ~PNG_FILTER_AVG;
1257             }
1258             else
1259             {
1260                png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1261                   (png_ptr->rowbytes + 1));
1262                png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1263             }
1264          }
1265
1266          if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1267              png_ptr->paeth_row == NULL)
1268          {
1269             if (png_ptr->prev_row == NULL)
1270             {
1271                png_warning(png_ptr, "Can't add Paeth filter after starting");
1272                png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1273             }
1274             else
1275             {
1276                png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1277                   (png_ptr->rowbytes + 1));
1278                png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1279             }
1280          }
1281
1282          if (png_ptr->do_filter == PNG_NO_FILTERS)
1283 #endif /* PNG_WRITE_FILTER_SUPPORTED */
1284             png_ptr->do_filter = PNG_FILTER_NONE;
1285       }
1286    }
1287    else
1288       png_error(png_ptr, "Unknown custom filter method");
1289 }
1290
1291 /* This allows us to influence the way in which libpng chooses the "best"
1292  * filter for the current scanline.  While the "minimum-sum-of-absolute-
1293  * differences metric is relatively fast and effective, there is some
1294  * question as to whether it can be improved upon by trying to keep the
1295  * filtered data going to zlib more consistent, hopefully resulting in
1296  * better compression.
1297  */
1298 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED      /* GRR 970116 */
1299 void PNGAPI
1300 png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1301    int num_weights, png_doublep filter_weights,
1302    png_doublep filter_costs)
1303 {
1304    int i;
1305
1306    png_debug(1, "in png_set_filter_heuristics");
1307
1308    if (png_ptr == NULL)
1309       return;
1310    if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1311    {
1312       png_warning(png_ptr, "Unknown filter heuristic method");
1313       return;
1314    }
1315
1316    if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1317    {
1318       heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1319    }
1320
1321    if (num_weights < 0 || filter_weights == NULL ||
1322       heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1323    {
1324       num_weights = 0;
1325    }
1326
1327    png_ptr->num_prev_filters = (png_byte)num_weights;
1328    png_ptr->heuristic_method = (png_byte)heuristic_method;
1329
1330    if (num_weights > 0)
1331    {
1332       if (png_ptr->prev_filters == NULL)
1333       {
1334          png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1335             (png_uint_32)(png_sizeof(png_byte) * num_weights));
1336
1337          /* To make sure that the weighting starts out fairly */
1338          for (i = 0; i < num_weights; i++)
1339          {
1340             png_ptr->prev_filters[i] = 255;
1341          }
1342       }
1343
1344       if (png_ptr->filter_weights == NULL)
1345       {
1346          png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1347             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1348
1349          png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1350             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1351          for (i = 0; i < num_weights; i++)
1352          {
1353             png_ptr->inv_filter_weights[i] =
1354             png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1355          }
1356       }
1357
1358       for (i = 0; i < num_weights; i++)
1359       {
1360          if (filter_weights[i] < 0.0)
1361          {
1362             png_ptr->inv_filter_weights[i] =
1363             png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1364          }
1365          else
1366          {
1367             png_ptr->inv_filter_weights[i] =
1368                (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1369             png_ptr->filter_weights[i] =
1370                (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1371          }
1372       }
1373    }
1374
1375    /* If, in the future, there are other filter methods, this would
1376     * need to be based on png_ptr->filter.
1377     */
1378    if (png_ptr->filter_costs == NULL)
1379    {
1380       png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1381          (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1382
1383       png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1384          (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1385
1386       for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1387       {
1388          png_ptr->inv_filter_costs[i] =
1389          png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1390       }
1391    }
1392
1393    /* Here is where we set the relative costs of the different filters.  We
1394     * should take the desired compression level into account when setting
1395     * the costs, so that Paeth, for instance, has a high relative cost at low
1396     * compression levels, while it has a lower relative cost at higher
1397     * compression settings.  The filter types are in order of increasing
1398     * relative cost, so it would be possible to do this with an algorithm.
1399     */
1400    for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1401    {
1402       if (filter_costs == NULL || filter_costs[i] < 0.0)
1403       {
1404          png_ptr->inv_filter_costs[i] =
1405          png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1406       }
1407       else if (filter_costs[i] >= 1.0)
1408       {
1409          png_ptr->inv_filter_costs[i] =
1410             (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1411          png_ptr->filter_costs[i] =
1412             (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1413       }
1414    }
1415 }
1416 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1417
1418 void PNGAPI
1419 png_set_compression_level(png_structp png_ptr, int level)
1420 {
1421    png_debug(1, "in png_set_compression_level");
1422
1423    if (png_ptr == NULL)
1424       return;
1425    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1426    png_ptr->zlib_level = level;
1427 }
1428
1429 void PNGAPI
1430 png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1431 {
1432    png_debug(1, "in png_set_compression_mem_level");
1433
1434    if (png_ptr == NULL)
1435       return;
1436    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1437    png_ptr->zlib_mem_level = mem_level;
1438 }
1439
1440 void PNGAPI
1441 png_set_compression_strategy(png_structp png_ptr, int strategy)
1442 {
1443    png_debug(1, "in png_set_compression_strategy");
1444
1445    if (png_ptr == NULL)
1446       return;
1447    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1448    png_ptr->zlib_strategy = strategy;
1449 }
1450
1451 void PNGAPI
1452 png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1453 {
1454    if (png_ptr == NULL)
1455       return;
1456    if (window_bits > 15)
1457       png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1458    else if (window_bits < 8)
1459       png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1460 #ifndef WBITS_8_OK
1461    /* Avoid libpng bug with 256-byte windows */
1462    if (window_bits == 8)
1463      {
1464        png_warning(png_ptr, "Compression window is being reset to 512");
1465        window_bits = 9;
1466      }
1467 #endif
1468    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1469    png_ptr->zlib_window_bits = window_bits;
1470 }
1471
1472 void PNGAPI
1473 png_set_compression_method(png_structp png_ptr, int method)
1474 {
1475    png_debug(1, "in png_set_compression_method");
1476
1477    if (png_ptr == NULL)
1478       return;
1479    if (method != 8)
1480       png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1481    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1482    png_ptr->zlib_method = method;
1483 }
1484
1485 void PNGAPI
1486 png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1487 {
1488    if (png_ptr == NULL)
1489       return;
1490    png_ptr->write_row_fn = write_row_fn;
1491 }
1492
1493 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1494 void PNGAPI
1495 png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1496    write_user_transform_fn)
1497 {
1498    png_debug(1, "in png_set_write_user_transform_fn");
1499
1500    if (png_ptr == NULL)
1501       return;
1502    png_ptr->transformations |= PNG_USER_TRANSFORM;
1503    png_ptr->write_user_transform_fn = write_user_transform_fn;
1504 }
1505 #endif
1506
1507
1508 #ifdef PNG_INFO_IMAGE_SUPPORTED
1509 void PNGAPI
1510 png_write_png(png_structp png_ptr, png_infop info_ptr,
1511               int transforms, voidp params)
1512 {
1513    if (png_ptr == NULL || info_ptr == NULL)
1514       return;
1515
1516    /* Write the file header information. */
1517    png_write_info(png_ptr, info_ptr);
1518
1519    /* ------ these transformations don't touch the info structure ------- */
1520
1521 #ifdef PNG_WRITE_INVERT_SUPPORTED
1522    /* Invert monochrome pixels */
1523    if (transforms & PNG_TRANSFORM_INVERT_MONO)
1524       png_set_invert_mono(png_ptr);
1525 #endif
1526
1527 #ifdef PNG_WRITE_SHIFT_SUPPORTED
1528    /* Shift the pixels up to a legal bit depth and fill in
1529     * as appropriate to correctly scale the image.
1530     */
1531    if ((transforms & PNG_TRANSFORM_SHIFT)
1532                && (info_ptr->valid & PNG_INFO_sBIT))
1533       png_set_shift(png_ptr, &info_ptr->sig_bit);
1534 #endif
1535
1536 #ifdef PNG_WRITE_PACK_SUPPORTED
1537    /* Pack pixels into bytes */
1538    if (transforms & PNG_TRANSFORM_PACKING)
1539        png_set_packing(png_ptr);
1540 #endif
1541
1542 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1543    /* Swap location of alpha bytes from ARGB to RGBA */
1544    if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1545       png_set_swap_alpha(png_ptr);
1546 #endif
1547
1548 #ifdef PNG_WRITE_FILLER_SUPPORTED
1549    /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */
1550    if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
1551       png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
1552    else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
1553       png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1554 #endif
1555
1556 #ifdef PNG_WRITE_BGR_SUPPORTED
1557    /* Flip BGR pixels to RGB */
1558    if (transforms & PNG_TRANSFORM_BGR)
1559       png_set_bgr(png_ptr);
1560 #endif
1561
1562 #ifdef PNG_WRITE_SWAP_SUPPORTED
1563    /* Swap bytes of 16-bit files to most significant byte first */
1564    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1565       png_set_swap(png_ptr);
1566 #endif
1567
1568 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED
1569    /* Swap bits of 1, 2, 4 bit packed pixel formats */
1570    if (transforms & PNG_TRANSFORM_PACKSWAP)
1571       png_set_packswap(png_ptr);
1572 #endif
1573
1574 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1575    /* Invert the alpha channel from opacity to transparency */
1576    if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1577       png_set_invert_alpha(png_ptr);
1578 #endif
1579
1580    /* ----------------------- end of transformations ------------------- */
1581
1582    /* Write the bits */
1583    if (info_ptr->valid & PNG_INFO_IDAT)
1584        png_write_image(png_ptr, info_ptr->row_pointers);
1585
1586    /* It is REQUIRED to call this to finish writing the rest of the file */
1587    png_write_end(png_ptr, info_ptr);
1588
1589    transforms = transforms; /* Quiet compiler warnings */
1590    params = params;
1591 }
1592 #endif
1593 #endif /* PNG_WRITE_SUPPORTED */