src/libpng/pngwrite.c

   1
   2 /* pngwrite.c - general routines to write a PNG file
   3  *
   4  * Last changed in libpng 1.2.37 [June 4, 2009]
   5  * For conditions of distribution and use, see copyright notice in png.h
   6  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
   7  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
   8  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
   9  */
  10
  11 /* Get internal access to png.h */
  12 #define PNG_INTERNAL
  13 #include "png.h"
  14 #ifdef PNG_WRITE_SUPPORTED
  15
  16 /* Writes all the PNG information.  This is the suggested way to use the
  17  * library.  If you have a new chunk to add, make a function to write it,
  18  * and put it in the correct location here.  If you want the chunk written
  19  * after the image data, put it in png_write_end().  I strongly encourage
  20  * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
  21  * the chunk, as that will keep the code from breaking if you want to just
  22  * write a plain PNG file.  If you have long comments, I suggest writing
  23  * them in png_write_end(), and compressing them.
  24  */
  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");
  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     */
  53 #if defined(PNG_WRITE_gAMA_SUPPORTED)
  54    if (info_ptr->valid & PNG_INFO_gAMA)
  55    {
  56 #  ifdef PNG_FLOATING_POINT_SUPPORTED
  57       png_write_gAMA(png_ptr, info_ptr->gamma);
  58 #else
  59 #ifdef PNG_FIXED_POINT_SUPPORTED
  60       png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
  61 #  endif
  62 #endif
  63    }
  64 #endif
  65 #if defined(PNG_WRITE_sRGB_SUPPORTED)
  66    if (info_ptr->valid & PNG_INFO_sRGB)
  67       png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
  68 #endif
  69 #if defined(PNG_WRITE_iCCP_SUPPORTED)
  70    if (info_ptr->valid & PNG_INFO_iCCP)
  71       png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
  72                      info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
  73 #endif
  74 #if defined(PNG_WRITE_sBIT_SUPPORTED)
  75    if (info_ptr->valid & PNG_INFO_sBIT)
  76       png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
  77 #endif
  78 #if defined(PNG_WRITE_cHRM_SUPPORTED)
  79    if (info_ptr->valid & PNG_INFO_cHRM)
  80    {
  81 #ifdef PNG_FLOATING_POINT_SUPPORTED
  82       png_write_cHRM(png_ptr,
  83          info_ptr->x_white, info_ptr->y_white,
  84          info_ptr->x_red, info_ptr->y_red,
  85          info_ptr->x_green, info_ptr->y_green,
  86          info_ptr->x_blue, info_ptr->y_blue);
  87 #else
  88 #  ifdef PNG_FIXED_POINT_SUPPORTED
  89       png_write_cHRM_fixed(png_ptr,
  90          info_ptr->int_x_white, info_ptr->int_y_white,
  91          info_ptr->int_x_red, info_ptr->int_y_red,
  92          info_ptr->int_x_green, info_ptr->int_y_green,
  93          info_ptr->int_x_blue, info_ptr->int_y_blue);
  94 #  endif
  95 #endif
  96    }
  97 #endif
  98 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
  99    if (info_ptr->unknown_chunks_num)
 100    {
 101       png_unknown_chunk *up;
 102
 103       png_debug(5, "writing extra chunks");
 104
 105       for (up = info_ptr->unknown_chunks;
 106            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
 107            up++)
 108       {
 109          int keep=png_handle_as_unknown(png_ptr, up->name);
 110          if (keep != PNG_HANDLE_CHUNK_NEVER &&
 111             up->location && !(up->location & PNG_HAVE_PLTE) &&
 112             !(up->location & PNG_HAVE_IDAT) &&
 113             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
 114             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
 115          {
 116             if (up->size == 0)
 117                png_warning(png_ptr, "Writing zero-length unknown chunk");
 118             png_write_chunk(png_ptr, up->name, up->data, up->size);
 119          }
 120       }
 121    }
 122 #endif
 123       png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
 124    }
 125 }
 126
 127 void PNGAPI
 128 png_write_info(png_structp png_ptr, png_infop info_ptr)
 129 {
 130 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
 131    int i;
 132 #endif
 133
 134    png_debug(1, "in png_write_info");
 135
 136    if (png_ptr == NULL || info_ptr == NULL)
 137       return;
 138
 139    png_write_info_before_PLTE(png_ptr, info_ptr);
 140
 141    if (info_ptr->valid & PNG_INFO_PLTE)
 142       png_write_PLTE(png_ptr, info_ptr->palette,
 143          (png_uint_32)info_ptr->num_palette);
 144    else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
 145       png_error(png_ptr, "Valid palette required for paletted images");
 146
 147 #if defined(PNG_WRITE_tRNS_SUPPORTED)
 148    if (info_ptr->valid & PNG_INFO_tRNS)
 149    {
 150 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
 151       /* Invert the alpha channel (in tRNS) */
 152       if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
 153          info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
 154       {
 155          int j;
 156          for (j=0; j<(int)info_ptr->num_trans; j++)
 157             info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
 158       }
 159 #endif
 160       png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
 161          info_ptr->num_trans, info_ptr->color_type);
 162    }
 163 #endif
 164 #if defined(PNG_WRITE_bKGD_SUPPORTED)
 165    if (info_ptr->valid & PNG_INFO_bKGD)
 166       png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
 167 #endif
 168 #if defined(PNG_WRITE_hIST_SUPPORTED)
 169    if (info_ptr->valid & PNG_INFO_hIST)
 170       png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
 171 #endif
 172 #if defined(PNG_WRITE_oFFs_SUPPORTED)
 173    if (info_ptr->valid & PNG_INFO_oFFs)
 174       png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
 175          info_ptr->offset_unit_type);
 176 #endif
 177 #if defined(PNG_WRITE_pCAL_SUPPORTED)
 178    if (info_ptr->valid & PNG_INFO_pCAL)
 179       png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
 180          info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
 181          info_ptr->pcal_units, info_ptr->pcal_params);
 182 #endif
 183
 184 #if defined(PNG_sCAL_SUPPORTED)
 185    if (info_ptr->valid & PNG_INFO_sCAL)
 186 #if defined(PNG_WRITE_sCAL_SUPPORTED)
 187 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
 188       png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
 189           info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
 190 #else /* !FLOATING_POINT */
 191 #ifdef PNG_FIXED_POINT_SUPPORTED
 192       png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
 193           info_ptr->scal_s_width, info_ptr->scal_s_height);
 194 #endif /* FIXED_POINT */
 195 #endif /* FLOATING_POINT */
 196 #else  /* !WRITE_sCAL */
 197       png_warning(png_ptr,
 198           "png_write_sCAL not supported; sCAL chunk not written.");
 199 #endif /* WRITE_sCAL */
 200 #endif /* sCAL */
 201
 202 #if defined(PNG_WRITE_pHYs_SUPPORTED)
 203    if (info_ptr->valid & PNG_INFO_pHYs)
 204       png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
 205          info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
 206 #endif /* pHYs */
 207
 208 #if defined(PNG_WRITE_tIME_SUPPORTED)
 209    if (info_ptr->valid & PNG_INFO_tIME)
 210    {
 211       png_write_tIME(png_ptr, &(info_ptr->mod_time));
 212       png_ptr->mode |= PNG_WROTE_tIME;
 213    }
 214 #endif /* tIME */
 215
 216 #if defined(PNG_WRITE_sPLT_SUPPORTED)
 217    if (info_ptr->valid & PNG_INFO_sPLT)
 218      for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
 219        png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
 220 #endif /* sPLT */
 221
 222 #if defined(PNG_WRITE_TEXT_SUPPORTED)
 223    /* Check to see if we need to write text chunks */
 224    for (i = 0; i < info_ptr->num_text; i++)
 225    {
 226       png_debug2(2, "Writing header text chunk %d, type %d", i,
 227          info_ptr->text[i].compression);
 228       /* An internationalized chunk? */
 229       if (info_ptr->text[i].compression > 0)
 230       {
 231 #if defined(PNG_WRITE_iTXt_SUPPORTED)
 232           /* Write international chunk */
 233           png_write_iTXt(png_ptr,
 234                          info_ptr->text[i].compression,
 235                          info_ptr->text[i].key,
 236                          info_ptr->text[i].lang,
 237                          info_ptr->text[i].lang_key,
 238                          info_ptr->text[i].text);
 239 #else
 240           png_warning(png_ptr, "Unable to write international text");
 241 #endif
 242           /* Mark this chunk as written */
 243           info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
 244       }
 245       /* If we want a compressed text chunk */
 246       else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
 247       {
 248 #if defined(PNG_WRITE_zTXt_SUPPORTED)
 249          /* Write compressed chunk */
 250          png_write_zTXt(png_ptr, info_ptr->text[i].key,
 251             info_ptr->text[i].text, 0,
 252             info_ptr->text[i].compression);
 253 #else
 254          png_warning(png_ptr, "Unable to write compressed text");
 255 #endif
 256          /* Mark this chunk as written */
 257          info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
 258       }
 259       else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
 260       {
 261 #if defined(PNG_WRITE_tEXt_SUPPORTED)
 262          /* Write uncompressed chunk */
 263          png_write_tEXt(png_ptr, info_ptr->text[i].key,
 264                          info_ptr->text[i].text,
 265                          0);
 266          /* Mark this chunk as written */
 267          info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
 268 #else
 269          /* Can't get here */
 270          png_warning(png_ptr, "Unable to write uncompressed text");
 271 #endif
 272       }
 273    }
 274 #endif /* tEXt */
 275
 276 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
 277    if (info_ptr->unknown_chunks_num)
 278    {
 279        png_unknown_chunk *up;
 280
 281        png_debug(5, "writing extra chunks");
 282
 283        for (up = info_ptr->unknown_chunks;
 284             up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
 285             up++)
 286        {
 287          int keep=png_handle_as_unknown(png_ptr, up->name);
 288          if (keep != PNG_HANDLE_CHUNK_NEVER &&
 289             up->location && (up->location & PNG_HAVE_PLTE) &&
 290             !(up->location & PNG_HAVE_IDAT) &&
 291             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
 292             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
 293          {
 294             png_write_chunk(png_ptr, up->name, up->data, up->size);
 295          }
 296        }
 297    }
 298 #endif
 299 }
 300
 301 /* Writes the end of the PNG file.  If you don't want to write comments or
 302  * time information, you can pass NULL for info.  If you already wrote these
 303  * in png_write_info(), do not write them again here.  If you have long
 304  * comments, I suggest writing them here, and compressing them.
 305  */
 306 void PNGAPI
 307 png_write_end(png_structp png_ptr, png_infop info_ptr)
 308 {
 309    png_debug(1, "in png_write_end");
 310    if (png_ptr == NULL)
 311       return;
 312    if (!(png_ptr->mode & PNG_HAVE_IDAT))
 313       png_error(png_ptr, "No IDATs written into file");
 314
 315    /* See if user wants us to write information chunks */
 316    if (info_ptr != NULL)
 317    {
 318 #if defined(PNG_WRITE_TEXT_SUPPORTED)
 319       int i; /* Local index variable */
 320 #endif
 321 #if defined(PNG_WRITE_tIME_SUPPORTED)
 322       /* Check to see if user has supplied a time chunk */
 323       if ((info_ptr->valid & PNG_INFO_tIME) &&
 324          !(png_ptr->mode & PNG_WROTE_tIME))
 325          png_write_tIME(png_ptr, &(info_ptr->mod_time));
 326 #endif
 327 #if defined(PNG_WRITE_TEXT_SUPPORTED)
 328       /* Loop through comment chunks */
 329       for (i = 0; i < info_ptr->num_text; i++)
 330       {
 331          png_debug2(2, "Writing trailer text chunk %d, type %d", i,
 332             info_ptr->text[i].compression);
 333          /* An internationalized chunk? */
 334          if (info_ptr->text[i].compression > 0)
 335          {
 336 #if defined(PNG_WRITE_iTXt_SUPPORTED)
 337              /* Write international chunk */
 338              png_write_iTXt(png_ptr,
 339                          info_ptr->text[i].compression,
 340                          info_ptr->text[i].key,
 341                          info_ptr->text[i].lang,
 342                          info_ptr->text[i].lang_key,
 343                          info_ptr->text[i].text);
 344 #else
 345              png_warning(png_ptr, "Unable to write international text");
 346 #endif
 347              /* Mark this chunk as written */
 348              info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
 349          }
 350          else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
 351          {
 352 #if defined(PNG_WRITE_zTXt_SUPPORTED)
 353             /* Write compressed chunk */
 354             png_write_zTXt(png_ptr, info_ptr->text[i].key,
 355                info_ptr->text[i].text, 0,
 356                info_ptr->text[i].compression);
 357 #else
 358             png_warning(png_ptr, "Unable to write compressed text");
 359 #endif
 360             /* Mark this chunk as written */
 361             info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
 362          }
 363          else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
 364          {
 365 #if defined(PNG_WRITE_tEXt_SUPPORTED)
 366             /* Write uncompressed chunk */
 367             png_write_tEXt(png_ptr, info_ptr->text[i].key,
 368                info_ptr->text[i].text, 0);
 369 #else
 370             png_warning(png_ptr, "Unable to write uncompressed text");
 371 #endif
 372
 373             /* Mark this chunk as written */
 374             info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
 375          }
 376       }
 377 #endif
 378 #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
 379    if (info_ptr->unknown_chunks_num)
 380    {
 381        png_unknown_chunk *up;
 382
 383        png_debug(5, "writing extra chunks");
 384
 385        for (up = info_ptr->unknown_chunks;
 386             up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
 387             up++)
 388        {
 389          int keep=png_handle_as_unknown(png_ptr, up->name);
 390          if (keep != PNG_HANDLE_CHUNK_NEVER &&
 391             up->location && (up->location & PNG_AFTER_IDAT) &&
 392             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
 393             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
 394          {
 395             png_write_chunk(png_ptr, up->name, up->data, up->size);
 396          }
 397        }
 398    }
 399 #endif
 400    }
 401
 402    png_ptr->mode |= PNG_AFTER_IDAT;
 403
 404    /* Write end of PNG file */
 405    png_write_IEND(png_ptr);
 406    /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
 407     * and restored again in libpng-1.2.30, may cause some applications that
 408     * do not set png_ptr->output_flush_fn to crash.  If your application
 409     * experiences a problem, please try building libpng with
 410     * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
 411     * png-mng-implement at lists.sf.net .  This kludge will be removed
 412     * from libpng-1.4.0.
 413     */
 414 #if defined(PNG_WRITE_FLUSH_SUPPORTED) && \
 415     defined(PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED)
 416    png_flush(png_ptr);
 417 #endif
 418 }
 419
 420 #if defined(PNG_WRITE_tIME_SUPPORTED)
 421 #if !defined(_WIN32_WCE)
 422 /* "time.h" functions are not supported on WindowsCE */
 423 void PNGAPI
 424 png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
 425 {
 426    png_debug(1, "in png_convert_from_struct_tm");
 427    ptime->year = (png_uint_16)(1900 + ttime->tm_year);
 428    ptime->month = (png_byte)(ttime->tm_mon + 1);
 429    ptime->day = (png_byte)ttime->tm_mday;
 430    ptime->hour = (png_byte)ttime->tm_hour;
 431    ptime->minute = (png_byte)ttime->tm_min;
 432    ptime->second = (png_byte)ttime->tm_sec;
 433 }
 434
 435 void PNGAPI
 436 png_convert_from_time_t(png_timep ptime, time_t ttime)
 437 {
 438    struct tm *tbuf;
 439
 440    png_debug(1, "in png_convert_from_time_t");
 441    tbuf = gmtime(&ttime);
 442    png_convert_from_struct_tm(ptime, tbuf);
 443 }
 444 #endif
 445 #endif
 446
 447 /* Initialize png_ptr structure, and allocate any memory needed */
 448 png_structp PNGAPI
 449 png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
 450    png_error_ptr error_fn, png_error_ptr warn_fn)
 451 {
 452 #ifdef PNG_USER_MEM_SUPPORTED
 453    return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
 454       warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
 455 }
 456
 457 /* Alternate initialize png_ptr structure, and allocate any memory needed */
 458 png_structp PNGAPI
 459 png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 460    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
 461    png_malloc_ptr malloc_fn, png_free_ptr free_fn)
 462 {
 463 #endif /* PNG_USER_MEM_SUPPORTED */
 464 #ifdef PNG_SETJMP_SUPPORTED
 465     volatile
 466 #endif
 467     png_structp png_ptr;
 468 #ifdef PNG_SETJMP_SUPPORTED
 469 #ifdef USE_FAR_KEYWORD
 470    jmp_buf jmpbuf;
 471 #endif
 472 #endif
 473    int i;
 474    png_debug(1, "in png_create_write_struct");
 475 #ifdef PNG_USER_MEM_SUPPORTED
 476    png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
 477       (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
 478 #else
 479    png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
 480 #endif /* PNG_USER_MEM_SUPPORTED */
 481    if (png_ptr == NULL)
 482       return (NULL);
 483
 484    /* Added at libpng-1.2.6 */
 485 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
 486    png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
 487    png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
 488 #endif
 489
 490 #ifdef PNG_SETJMP_SUPPORTED
 491 #ifdef USE_FAR_KEYWORD
 492    if (setjmp(jmpbuf))
 493 #else
 494    if (setjmp(png_ptr->jmpbuf))
 495 #endif
 496    {
 497       png_free(png_ptr, png_ptr->zbuf);
 498        png_ptr->zbuf=NULL;
 499       png_destroy_struct(png_ptr);
 500       return (NULL);
 501    }
 502 #ifdef USE_FAR_KEYWORD
 503    png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
 504 #endif
 505 #endif
 506
 507 #ifdef PNG_USER_MEM_SUPPORTED
 508    png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
 509 #endif /* PNG_USER_MEM_SUPPORTED */
 510    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 511
 512    if (user_png_ver)
 513    {
 514      i=0;
 515      do
 516      {
 517        if (user_png_ver[i] != png_libpng_ver[i])
 518           png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 519      } while (png_libpng_ver[i++]);
 520    }
 521
 522    if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
 523    {
 524      /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
 525       * we must recompile any applications that use any older library version.
 526       * For versions after libpng 1.0, we will be compatible, so we need
 527       * only check the first digit.
 528       */
 529      if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
 530          (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
 531          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
 532      {
 533 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
 534         char msg[80];
 535         if (user_png_ver)
 536         {
 537           png_snprintf(msg, 80,
 538              "Application was compiled with png.h from libpng-%.20s",
 539              user_png_ver);
 540           png_warning(png_ptr, msg);
 541         }
 542         png_snprintf(msg, 80,
 543            "Application  is  running with png.c from libpng-%.20s",
 544            png_libpng_ver);
 545         png_warning(png_ptr, msg);
 546 #endif
 547 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 548         png_ptr->flags=0;
 549 #endif
 550         png_error(png_ptr,
 551            "Incompatible libpng version in application and library");
 552      }
 553    }
 554
 555    /* Initialize zbuf - compression buffer */
 556    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
 557    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
 558       (png_uint_32)png_ptr->zbuf_size);
 559
 560    png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
 561       png_flush_ptr_NULL);
 562
 563 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
 564    png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
 565       1, png_doublep_NULL, png_doublep_NULL);
 566 #endif
 567
 568 #ifdef PNG_SETJMP_SUPPORTED
 569 /* Applications that neglect to set up their own setjmp() and then encounter
 570    a png_error() will longjmp here.  Since the jmpbuf is then meaningless we
 571    abort instead of returning. */
 572 #ifdef USE_FAR_KEYWORD
 573    if (setjmp(jmpbuf))
 574       PNG_ABORT();
 575    png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
 576 #else
 577    if (setjmp(png_ptr->jmpbuf))
 578       PNG_ABORT();
 579 #endif
 580 #endif
 581    return (png_ptr);
 582 }
 583
 584 /* Initialize png_ptr structure, and allocate any memory needed */
 585 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
 586 /* Deprecated. */
 587 #undef png_write_init
 588 void PNGAPI
 589 png_write_init(png_structp png_ptr)
 590 {
 591    /* We only come here via pre-1.0.7-compiled applications */
 592    png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
 593 }
 594
 595 void PNGAPI
 596 png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
 597    png_size_t png_struct_size, png_size_t png_info_size)
 598 {
 599    /* We only come here via pre-1.0.12-compiled applications */
 600    if (png_ptr == NULL) return;
 601 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
 602    if (png_sizeof(png_struct) > png_struct_size ||
 603       png_sizeof(png_info) > png_info_size)
 604    {
 605       char msg[80];
 606       png_ptr->warning_fn=NULL;
 607       if (user_png_ver)
 608       {
 609         png_snprintf(msg, 80,
 610            "Application was compiled with png.h from libpng-%.20s",
 611            user_png_ver);
 612         png_warning(png_ptr, msg);
 613       }
 614       png_snprintf(msg, 80,
 615          "Application  is  running with png.c from libpng-%.20s",
 616          png_libpng_ver);
 617       png_warning(png_ptr, msg);
 618    }
 619 #endif
 620    if (png_sizeof(png_struct) > png_struct_size)
 621      {
 622        png_ptr->error_fn=NULL;
 623 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 624        png_ptr->flags=0;
 625 #endif
 626        png_error(png_ptr,
 627        "The png struct allocated by the application for writing is too small.");
 628      }
 629    if (png_sizeof(png_info) > png_info_size)
 630      {
 631        png_ptr->error_fn=NULL;
 632 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 633        png_ptr->flags=0;
 634 #endif
 635        png_error(png_ptr,
 636        "The info struct allocated by the application for writing is too small.");
 637      }
 638    png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
 639 }
 640 #endif /* PNG_1_0_X || PNG_1_2_X */
 641
 642
 643 void PNGAPI
 644 png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 645    png_size_t png_struct_size)
 646 {
 647    png_structp png_ptr=*ptr_ptr;
 648 #ifdef PNG_SETJMP_SUPPORTED
 649    jmp_buf tmp_jmp; /* To save current jump buffer */
 650 #endif
 651
 652    int i = 0;
 653
 654    if (png_ptr == NULL)
 655       return;
 656
 657    do
 658    {
 659      if (user_png_ver[i] != png_libpng_ver[i])
 660      {
 661 #ifdef PNG_LEGACY_SUPPORTED
 662        png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 663 #else
 664        png_ptr->warning_fn=NULL;
 665        png_warning(png_ptr,
 666  "Application uses deprecated png_write_init() and should be recompiled.");
 667        break;
 668 #endif
 669      }
 670    } while (png_libpng_ver[i++]);
 671
 672    png_debug(1, "in png_write_init_3");
 673
 674 #ifdef PNG_SETJMP_SUPPORTED
 675    /* Save jump buffer and error functions */
 676    png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 677 #endif
 678
 679    if (png_sizeof(png_struct) > png_struct_size)
 680      {
 681        png_destroy_struct(png_ptr);
 682        png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
 683        *ptr_ptr = png_ptr;
 684      }
 685
 686    /* Reset all variables to 0 */
 687    png_memset(png_ptr, 0, png_sizeof(png_struct));
 688
 689    /* Added at libpng-1.2.6 */
 690 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
 691    png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
 692    png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
 693 #endif
 694
 695 #ifdef PNG_SETJMP_SUPPORTED
 696    /* Restore jump buffer */
 697    png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
 698 #endif
 699
 700    png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
 701       png_flush_ptr_NULL);
 702
 703    /* Initialize zbuf - compression buffer */
 704    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
 705    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
 706       (png_uint_32)png_ptr->zbuf_size);
 707
 708 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
 709    png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
 710       1, png_doublep_NULL, png_doublep_NULL);
 711 #endif
 712 }
 713
 714 /* Write a few rows of image data.  If the image is interlaced,
 715  * either you will have to write the 7 sub images, or, if you
 716  * have called png_set_interlace_handling(), you will have to
 717  * "write" the image seven times.
 718  */
 719 void PNGAPI
 720 png_write_rows(png_structp png_ptr, png_bytepp row,
 721    png_uint_32 num_rows)
 722 {
 723    png_uint_32 i; /* Row counter */
 724    png_bytepp rp; /* Row pointer */
 725
 726    png_debug(1, "in png_write_rows");
 727
 728    if (png_ptr == NULL)
 729       return;
 730
 731    /* Loop through the rows */
 732    for (i = 0, rp = row; i < num_rows; i++, rp++)
 733    {
 734       png_write_row(png_ptr, *rp);
 735    }
 736 }
 737
 738 /* Write the image.  You only need to call this function once, even
 739  * if you are writing an interlaced image.
 740  */
 741 void PNGAPI
 742 png_write_image(png_structp png_ptr, png_bytepp image)
 743 {
 744    png_uint_32 i; /* Row index */
 745    int pass, num_pass; /* Pass variables */
 746    png_bytepp rp; /* Points to current row */
 747
 748    if (png_ptr == NULL)
 749       return;
 750
 751    png_debug(1, "in png_write_image");
 752 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
 753    /* Initialize interlace handling.  If image is not interlaced,
 754     * this will set pass to 1
 755     */
 756    num_pass = png_set_interlace_handling(png_ptr);
 757 #else
 758    num_pass = 1;
 759 #endif
 760    /* Loop through passes */
 761    for (pass = 0; pass < num_pass; pass++)
 762    {
 763       /* Loop through image */
 764       for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
 765       {
 766          png_write_row(png_ptr, *rp);
 767       }
 768    }
 769 }
 770
 771 /* Called by user to write a row of image data */
 772 void PNGAPI
 773 png_write_row(png_structp png_ptr, png_bytep row)
 774 {
 775    if (png_ptr == NULL)
 776       return;
 777    png_debug2(1, "in png_write_row (row %ld, pass %d)",
 778       png_ptr->row_number, png_ptr->pass);
 779
 780    /* Initialize transformations and other stuff if first time */
 781    if (png_ptr->row_number == 0 && png_ptr->pass == 0)
 782    {
 783       /* Make sure we wrote the header info */
 784       if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
 785          png_error(png_ptr,
 786             "png_write_info was never called before png_write_row.");
 787
 788       /* Check for transforms that have been set but were defined out */
 789 #if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
 790       if (png_ptr->transformations & PNG_INVERT_MONO)
 791          png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
 792 #endif
 793 #if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
 794       if (png_ptr->transformations & PNG_FILLER)
 795          png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
 796 #endif
 797 #if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
 798       if (png_ptr->transformations & PNG_PACKSWAP)
 799          png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
 800 #endif
 801 #if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
 802       if (png_ptr->transformations & PNG_PACK)
 803          png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
 804 #endif
 805 #if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
 806       if (png_ptr->transformations & PNG_SHIFT)
 807          png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
 808 #endif
 809 #if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
 810       if (png_ptr->transformations & PNG_BGR)
 811          png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
 812 #endif
 813 #if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
 814       if (png_ptr->transformations & PNG_SWAP_BYTES)
 815          png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
 816 #endif
 817
 818       png_write_start_row(png_ptr);
 819    }
 820
 821 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
 822    /* If interlaced and not interested in row, return */
 823    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
 824    {
 825       switch (png_ptr->pass)
 826       {
 827          case 0:
 828             if (png_ptr->row_number & 0x07)
 829             {
 830                png_write_finish_row(png_ptr);
 831                return;
 832             }
 833             break;
 834          case 1:
 835             if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
 836             {
 837                png_write_finish_row(png_ptr);
 838                return;
 839             }
 840             break;
 841          case 2:
 842             if ((png_ptr->row_number & 0x07) != 4)
 843             {
 844                png_write_finish_row(png_ptr);
 845                return;
 846             }
 847             break;
 848          case 3:
 849             if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
 850             {
 851                png_write_finish_row(png_ptr);
 852                return;
 853             }
 854             break;
 855          case 4:
 856             if ((png_ptr->row_number & 0x03) != 2)
 857             {
 858                png_write_finish_row(png_ptr);
 859                return;
 860             }
 861             break;
 862          case 5:
 863             if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
 864             {
 865                png_write_finish_row(png_ptr);
 866                return;
 867             }
 868             break;
 869          case 6:
 870             if (!(png_ptr->row_number & 0x01))
 871             {
 872                png_write_finish_row(png_ptr);
 873                return;
 874             }
 875             break;
 876       }
 877    }
 878 #endif
 879
 880    /* Set up row info for transformations */
 881    png_ptr->row_info.color_type = png_ptr->color_type;
 882    png_ptr->row_info.width = png_ptr->usr_width;
 883    png_ptr->row_info.channels = png_ptr->usr_channels;
 884    png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
 885    png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
 886       png_ptr->row_info.channels);
 887
 888    png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
 889       png_ptr->row_info.width);
 890
 891    png_debug1(3, "row_info->color_type = %d", png_ptr->row_info.color_type);
 892    png_debug1(3, "row_info->width = %lu", png_ptr->row_info.width);
 893    png_debug1(3, "row_info->channels = %d", png_ptr->row_info.channels);
 894    png_debug1(3, "row_info->bit_depth = %d", png_ptr->row_info.bit_depth);
 895    png_debug1(3, "row_info->pixel_depth = %d", png_ptr->row_info.pixel_depth);
 896    png_debug1(3, "row_info->rowbytes = %lu", png_ptr->row_info.rowbytes);
 897
 898    /* Copy user's row into buffer, leaving room for filter byte. */
 899    png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
 900       png_ptr->row_info.rowbytes);
 901
 902 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
 903    /* Handle interlacing */
 904    if (png_ptr->interlaced && png_ptr->pass < 6 &&
 905       (png_ptr->transformations & PNG_INTERLACE))
 906    {
 907       png_do_write_interlace(&(png_ptr->row_info),
 908          png_ptr->row_buf + 1, png_ptr->pass);
 909       /* This should always get caught above, but still ... */
 910       if (!(png_ptr->row_info.width))
 911       {
 912          png_write_finish_row(png_ptr);
 913          return;
 914       }
 915    }
 916 #endif
 917
 918    /* Handle other transformations */
 919    if (png_ptr->transformations)
 920       png_do_write_transformations(png_ptr);
 921
 922 #if defined(PNG_MNG_FEATURES_SUPPORTED)
 923    /* Write filter_method 64 (intrapixel differencing) only if
 924     * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
 925     * 2. Libpng did not write a PNG signature (this filter_method is only
 926     *    used in PNG datastreams that are embedded in MNG datastreams) and
 927     * 3. The application called png_permit_mng_features with a mask that
 928     *    included PNG_FLAG_MNG_FILTER_64 and
 929     * 4. The filter_method is 64 and
 930     * 5. The color_type is RGB or RGBA
 931     */
 932    if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
 933       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
 934    {
 935       /* Intrapixel differencing */
 936       png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
 937    }
 938 #endif
 939
 940    /* Find a filter if necessary, filter the row and write it out. */
 941    png_write_find_filter(png_ptr, &(png_ptr->row_info));
 942
 943    if (png_ptr->write_row_fn != NULL)
 944       (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
 945 }
 946
 947 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
 948 /* Set the automatic flush interval or 0 to turn flushing off */
 949 void PNGAPI
 950 png_set_flush(png_structp png_ptr, int nrows)
 951 {
 952    png_debug(1, "in png_set_flush");
 953    if (png_ptr == NULL)
 954       return;
 955    png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
 956 }
 957
 958 /* Flush the current output buffers now */
 959 void PNGAPI
 960 png_write_flush(png_structp png_ptr)
 961 {
 962    int wrote_IDAT;
 963
 964    png_debug(1, "in png_write_flush");
 965    if (png_ptr == NULL)
 966       return;
 967    /* We have already written out all of the data */
 968    if (png_ptr->row_number >= png_ptr->num_rows)
 969       return;
 970
 971    do
 972    {
 973       int ret;
 974
 975       /* Compress the data */
 976       ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
 977       wrote_IDAT = 0;
 978
 979       /* Check for compression errors */
 980       if (ret != Z_OK)
 981       {
 982          if (png_ptr->zstream.msg != NULL)
 983             png_error(png_ptr, png_ptr->zstream.msg);
 984          else
 985             png_error(png_ptr, "zlib error");
 986       }
 987
 988       if (!(png_ptr->zstream.avail_out))
 989       {
 990          /* Write the IDAT and reset the zlib output buffer */
 991          png_write_IDAT(png_ptr, png_ptr->zbuf,
 992                         png_ptr->zbuf_size);
 993          png_ptr->zstream.next_out = png_ptr->zbuf;
 994          png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
 995          wrote_IDAT = 1;
 996       }
 997    } while(wrote_IDAT == 1);
 998
 999    /* If there is any data left to be output, write it into a new IDAT */
1000    if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
1001    {
1002       /* Write the IDAT and reset the zlib output buffer */
1003       png_write_IDAT(png_ptr, png_ptr->zbuf,
1004                      png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1005       png_ptr->zstream.next_out = png_ptr->zbuf;
1006       png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1007    }
1008    png_ptr->flush_rows = 0;
1009    png_flush(png_ptr);
1010 }
1011 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
1012
1013 /* Free all memory used by the write */
1014 void PNGAPI
1015 png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
1016 {
1017    png_structp png_ptr = NULL;
1018    png_infop info_ptr = NULL;
1019 #ifdef PNG_USER_MEM_SUPPORTED
1020    png_free_ptr free_fn = NULL;
1021    png_voidp mem_ptr = NULL;
1022 #endif
1023
1024    png_debug(1, "in png_destroy_write_struct");
1025    if (png_ptr_ptr != NULL)
1026    {
1027       png_ptr = *png_ptr_ptr;
1028 #ifdef PNG_USER_MEM_SUPPORTED
1029       free_fn = png_ptr->free_fn;
1030       mem_ptr = png_ptr->mem_ptr;
1031 #endif
1032    }
1033
1034 #ifdef PNG_USER_MEM_SUPPORTED
1035    if (png_ptr != NULL)
1036    {
1037       free_fn = png_ptr->free_fn;
1038       mem_ptr = png_ptr->mem_ptr;
1039    }
1040 #endif
1041
1042    if (info_ptr_ptr != NULL)
1043       info_ptr = *info_ptr_ptr;
1044
1045    if (info_ptr != NULL)
1046    {
1047       if (png_ptr != NULL)
1048       {
1049         png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
1050
1051 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1052         if (png_ptr->num_chunk_list)
1053         {
1054            png_free(png_ptr, png_ptr->chunk_list);
1055            png_ptr->chunk_list=NULL;
1056            png_ptr->num_chunk_list = 0;
1057         }
1058 #endif
1059       }
1060
1061 #ifdef PNG_USER_MEM_SUPPORTED
1062       png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1063          (png_voidp)mem_ptr);
1064 #else
1065       png_destroy_struct((png_voidp)info_ptr);
1066 #endif
1067       *info_ptr_ptr = NULL;
1068    }
1069
1070    if (png_ptr != NULL)
1071    {
1072       png_write_destroy(png_ptr);
1073 #ifdef PNG_USER_MEM_SUPPORTED
1074       png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1075          (png_voidp)mem_ptr);
1076 #else
1077       png_destroy_struct((png_voidp)png_ptr);
1078 #endif
1079       *png_ptr_ptr = NULL;
1080    }
1081 }
1082
1083
1084 /* Free any memory used in png_ptr struct (old method) */
1085 void /* PRIVATE */
1086 png_write_destroy(png_structp png_ptr)
1087 {
1088 #ifdef PNG_SETJMP_SUPPORTED
1089    jmp_buf tmp_jmp; /* Save jump buffer */
1090 #endif
1091    png_error_ptr error_fn;
1092    png_error_ptr warning_fn;
1093    png_voidp error_ptr;
1094 #ifdef PNG_USER_MEM_SUPPORTED
1095    png_free_ptr free_fn;
1096 #endif
1097
1098    png_debug(1, "in png_write_destroy");
1099    /* Free any memory zlib uses */
1100    deflateEnd(&png_ptr->zstream);
1101
1102    /* Free our memory.  png_free checks NULL for us. */
1103    png_free(png_ptr, png_ptr->zbuf);
1104    png_free(png_ptr, png_ptr->row_buf);
1105 #ifndef PNG_NO_WRITE_FILTER
1106    png_free(png_ptr, png_ptr->prev_row);
1107    png_free(png_ptr, png_ptr->sub_row);
1108    png_free(png_ptr, png_ptr->up_row);
1109    png_free(png_ptr, png_ptr->avg_row);
1110    png_free(png_ptr, png_ptr->paeth_row);
1111 #endif
1112
1113 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1114    png_free(png_ptr, png_ptr->time_buffer);
1115 #endif
1116
1117 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1118    png_free(png_ptr, png_ptr->prev_filters);
1119    png_free(png_ptr, png_ptr->filter_weights);
1120    png_free(png_ptr, png_ptr->inv_filter_weights);
1121    png_free(png_ptr, png_ptr->filter_costs);
1122    png_free(png_ptr, png_ptr->inv_filter_costs);
1123 #endif
1124
1125 #ifdef PNG_SETJMP_SUPPORTED
1126    /* Reset structure */
1127    png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
1128 #endif
1129
1130    error_fn = png_ptr->error_fn;
1131    warning_fn = png_ptr->warning_fn;
1132    error_ptr = png_ptr->error_ptr;
1133 #ifdef PNG_USER_MEM_SUPPORTED
1134    free_fn = png_ptr->free_fn;
1135 #endif
1136
1137    png_memset(png_ptr, 0, png_sizeof(png_struct));
1138
1139    png_ptr->error_fn = error_fn;
1140    png_ptr->warning_fn = warning_fn;
1141    png_ptr->error_ptr = error_ptr;
1142 #ifdef PNG_USER_MEM_SUPPORTED
1143    png_ptr->free_fn = free_fn;
1144 #endif
1145
1146 #ifdef PNG_SETJMP_SUPPORTED
1147    png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1148 #endif
1149 }
1150
1151 /* Allow the application to select one or more row filters to use. */
1152 void PNGAPI
1153 png_set_filter(png_structp png_ptr, int method, int filters)
1154 {
1155    png_debug(1, "in png_set_filter");
1156    if (png_ptr == NULL)
1157       return;
1158 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1159    if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1160       (method == PNG_INTRAPIXEL_DIFFERENCING))
1161          method = PNG_FILTER_TYPE_BASE;
1162 #endif
1163    if (method == PNG_FILTER_TYPE_BASE)
1164    {
1165       switch (filters & (PNG_ALL_FILTERS | 0x07))
1166       {
1167 #ifndef PNG_NO_WRITE_FILTER
1168          case 5:
1169          case 6:
1170          case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1171 #endif /* PNG_NO_WRITE_FILTER */
1172          case PNG_FILTER_VALUE_NONE:
1173               png_ptr->do_filter=PNG_FILTER_NONE; break;
1174 #ifndef PNG_NO_WRITE_FILTER
1175          case PNG_FILTER_VALUE_SUB:
1176               png_ptr->do_filter=PNG_FILTER_SUB; break;
1177          case PNG_FILTER_VALUE_UP:
1178               png_ptr->do_filter=PNG_FILTER_UP; break;
1179          case PNG_FILTER_VALUE_AVG:
1180               png_ptr->do_filter=PNG_FILTER_AVG; break;
1181          case PNG_FILTER_VALUE_PAETH:
1182               png_ptr->do_filter=PNG_FILTER_PAETH; break;
1183          default: png_ptr->do_filter = (png_byte)filters; break;
1184 #else
1185          default: png_warning(png_ptr, "Unknown row filter for method 0");
1186 #endif /* PNG_NO_WRITE_FILTER */
1187       }
1188
1189       /* If we have allocated the row_buf, this means we have already started
1190        * with the image and we should have allocated all of the filter buffers
1191        * that have been selected.  If prev_row isn't already allocated, then
1192        * it is too late to start using the filters that need it, since we
1193        * will be missing the data in the previous row.  If an application
1194        * wants to start and stop using particular filters during compression,
1195        * it should start out with all of the filters, and then add and
1196        * remove them after the start of compression.
1197        */
1198       if (png_ptr->row_buf != NULL)
1199       {
1200 #ifndef PNG_NO_WRITE_FILTER
1201          if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1202          {
1203             png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1204               (png_ptr->rowbytes + 1));
1205             png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1206          }
1207
1208          if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1209          {
1210             if (png_ptr->prev_row == NULL)
1211             {
1212                png_warning(png_ptr, "Can't add Up filter after starting");
1213                png_ptr->do_filter &= ~PNG_FILTER_UP;
1214             }
1215             else
1216             {
1217                png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1218                   (png_ptr->rowbytes + 1));
1219                png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1220             }
1221          }
1222
1223          if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1224          {
1225             if (png_ptr->prev_row == NULL)
1226             {
1227                png_warning(png_ptr, "Can't add Average filter after starting");
1228                png_ptr->do_filter &= ~PNG_FILTER_AVG;
1229             }
1230             else
1231             {
1232                png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1233                   (png_ptr->rowbytes + 1));
1234                png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1235             }
1236          }
1237
1238          if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1239              png_ptr->paeth_row == NULL)
1240          {
1241             if (png_ptr->prev_row == NULL)
1242             {
1243                png_warning(png_ptr, "Can't add Paeth filter after starting");
1244                png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1245             }
1246             else
1247             {
1248                png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1249                   (png_ptr->rowbytes + 1));
1250                png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1251             }
1252          }
1253
1254          if (png_ptr->do_filter == PNG_NO_FILTERS)
1255 #endif /* PNG_NO_WRITE_FILTER */
1256             png_ptr->do_filter = PNG_FILTER_NONE;
1257       }
1258    }
1259    else
1260       png_error(png_ptr, "Unknown custom filter method");
1261 }
1262
1263 /* This allows us to influence the way in which libpng chooses the "best"
1264  * filter for the current scanline.  While the "minimum-sum-of-absolute-
1265  * differences metric is relatively fast and effective, there is some
1266  * question as to whether it can be improved upon by trying to keep the
1267  * filtered data going to zlib more consistent, hopefully resulting in
1268  * better compression.
1269  */
1270 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)      /* GRR 970116 */
1271 void PNGAPI
1272 png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1273    int num_weights, png_doublep filter_weights,
1274    png_doublep filter_costs)
1275 {
1276    int i;
1277
1278    png_debug(1, "in png_set_filter_heuristics");
1279    if (png_ptr == NULL)
1280       return;
1281    if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1282    {
1283       png_warning(png_ptr, "Unknown filter heuristic method");
1284       return;
1285    }
1286
1287    if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1288    {
1289       heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1290    }
1291
1292    if (num_weights < 0 || filter_weights == NULL ||
1293       heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1294    {
1295       num_weights = 0;
1296    }
1297
1298    png_ptr->num_prev_filters = (png_byte)num_weights;
1299    png_ptr->heuristic_method = (png_byte)heuristic_method;
1300
1301    if (num_weights > 0)
1302    {
1303       if (png_ptr->prev_filters == NULL)
1304       {
1305          png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1306             (png_uint_32)(png_sizeof(png_byte) * num_weights));
1307
1308          /* To make sure that the weighting starts out fairly */
1309          for (i = 0; i < num_weights; i++)
1310          {
1311             png_ptr->prev_filters[i] = 255;
1312          }
1313       }
1314
1315       if (png_ptr->filter_weights == NULL)
1316       {
1317          png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1318             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1319
1320          png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1321             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1322          for (i = 0; i < num_weights; i++)
1323          {
1324             png_ptr->inv_filter_weights[i] =
1325             png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1326          }
1327       }
1328
1329       for (i = 0; i < num_weights; i++)
1330       {
1331          if (filter_weights[i] < 0.0)
1332          {
1333             png_ptr->inv_filter_weights[i] =
1334             png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1335          }
1336          else
1337          {
1338             png_ptr->inv_filter_weights[i] =
1339                (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1340             png_ptr->filter_weights[i] =
1341                (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1342          }
1343       }
1344    }
1345
1346    /* If, in the future, there are other filter methods, this would
1347     * need to be based on png_ptr->filter.
1348     */
1349    if (png_ptr->filter_costs == NULL)
1350    {
1351       png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1352          (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1353
1354       png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1355          (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1356
1357       for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1358       {
1359          png_ptr->inv_filter_costs[i] =
1360          png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1361       }
1362    }
1363
1364    /* Here is where we set the relative costs of the different filters.  We
1365     * should take the desired compression level into account when setting
1366     * the costs, so that Paeth, for instance, has a high relative cost at low
1367     * compression levels, while it has a lower relative cost at higher
1368     * compression settings.  The filter types are in order of increasing
1369     * relative cost, so it would be possible to do this with an algorithm.
1370     */
1371    for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1372    {
1373       if (filter_costs == NULL || filter_costs[i] < 0.0)
1374       {
1375          png_ptr->inv_filter_costs[i] =
1376          png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1377       }
1378       else if (filter_costs[i] >= 1.0)
1379       {
1380          png_ptr->inv_filter_costs[i] =
1381             (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1382          png_ptr->filter_costs[i] =
1383             (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1384       }
1385    }
1386 }
1387 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1388
1389 void PNGAPI
1390 png_set_compression_level(png_structp png_ptr, int level)
1391 {
1392    png_debug(1, "in png_set_compression_level");
1393    if (png_ptr == NULL)
1394       return;
1395    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1396    png_ptr->zlib_level = level;
1397 }
1398
1399 void PNGAPI
1400 png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1401 {
1402    png_debug(1, "in png_set_compression_mem_level");
1403    if (png_ptr == NULL)
1404       return;
1405    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1406    png_ptr->zlib_mem_level = mem_level;
1407 }
1408
1409 void PNGAPI
1410 png_set_compression_strategy(png_structp png_ptr, int strategy)
1411 {
1412    png_debug(1, "in png_set_compression_strategy");
1413    if (png_ptr == NULL)
1414       return;
1415    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1416    png_ptr->zlib_strategy = strategy;
1417 }
1418
1419 void PNGAPI
1420 png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1421 {
1422    if (png_ptr == NULL)
1423       return;
1424    if (window_bits > 15)
1425       png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1426    else if (window_bits < 8)
1427       png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1428 #ifndef WBITS_8_OK
1429    /* Avoid libpng bug with 256-byte windows */
1430    if (window_bits == 8)
1431      {
1432        png_warning(png_ptr, "Compression window is being reset to 512");
1433        window_bits=9;
1434      }
1435 #endif
1436    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1437    png_ptr->zlib_window_bits = window_bits;
1438 }
1439
1440 void PNGAPI
1441 png_set_compression_method(png_structp png_ptr, int method)
1442 {
1443    png_debug(1, "in png_set_compression_method");
1444    if (png_ptr == NULL)
1445       return;
1446    if (method != 8)
1447       png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1448    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1449    png_ptr->zlib_method = method;
1450 }
1451
1452 void PNGAPI
1453 png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1454 {
1455    if (png_ptr == NULL)
1456       return;
1457    png_ptr->write_row_fn = write_row_fn;
1458 }
1459
1460 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1461 void PNGAPI
1462 png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1463    write_user_transform_fn)
1464 {
1465    png_debug(1, "in png_set_write_user_transform_fn");
1466    if (png_ptr == NULL)
1467       return;
1468    png_ptr->transformations |= PNG_USER_TRANSFORM;
1469    png_ptr->write_user_transform_fn = write_user_transform_fn;
1470 }
1471 #endif
1472
1473
1474 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1475 void PNGAPI
1476 png_write_png(png_structp png_ptr, png_infop info_ptr,
1477               int transforms, voidp params)
1478 {
1479    if (png_ptr == NULL || info_ptr == NULL)
1480       return;
1481 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1482    /* Invert the alpha channel from opacity to transparency */
1483    if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1484       png_set_invert_alpha(png_ptr);
1485 #endif
1486
1487    /* Write the file header information. */
1488    png_write_info(png_ptr, info_ptr);
1489
1490    /* ------ these transformations don't touch the info structure ------- */
1491
1492 #if defined(PNG_WRITE_INVERT_SUPPORTED)
1493    /* Invert monochrome pixels */
1494    if (transforms & PNG_TRANSFORM_INVERT_MONO)
1495       png_set_invert_mono(png_ptr);
1496 #endif
1497
1498 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
1499    /* Shift the pixels up to a legal bit depth and fill in
1500     * as appropriate to correctly scale the image.
1501     */
1502    if ((transforms & PNG_TRANSFORM_SHIFT)
1503                && (info_ptr->valid & PNG_INFO_sBIT))
1504       png_set_shift(png_ptr, &info_ptr->sig_bit);
1505 #endif
1506
1507 #if defined(PNG_WRITE_PACK_SUPPORTED)
1508    /* Pack pixels into bytes */
1509    if (transforms & PNG_TRANSFORM_PACKING)
1510        png_set_packing(png_ptr);
1511 #endif
1512
1513 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1514    /* Swap location of alpha bytes from ARGB to RGBA */
1515    if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1516       png_set_swap_alpha(png_ptr);
1517 #endif
1518
1519 #if defined(PNG_WRITE_FILLER_SUPPORTED)
1520    /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */
1521    if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
1522       png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
1523    else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
1524       png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1525 #endif
1526
1527 #if defined(PNG_WRITE_BGR_SUPPORTED)
1528    /* Flip BGR pixels to RGB */
1529    if (transforms & PNG_TRANSFORM_BGR)
1530       png_set_bgr(png_ptr);
1531 #endif
1532
1533 #if defined(PNG_WRITE_SWAP_SUPPORTED)
1534    /* Swap bytes of 16-bit files to most significant byte first */
1535    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1536       png_set_swap(png_ptr);
1537 #endif
1538
1539 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1540    /* Swap bits of 1, 2, 4 bit packed pixel formats */
1541    if (transforms & PNG_TRANSFORM_PACKSWAP)
1542       png_set_packswap(png_ptr);
1543 #endif
1544
1545    /* ----------------------- end of transformations ------------------- */
1546
1547    /* Write the bits */
1548    if (info_ptr->valid & PNG_INFO_IDAT)
1549        png_write_image(png_ptr, info_ptr->row_pointers);
1550
1551    /* It is REQUIRED to call this to finish writing the rest of the file */
1552    png_write_end(png_ptr, info_ptr);
1553
1554    transforms = transforms; /* Quiet compiler warnings */
1555    params = params;
1556 }
1557 #endif
1558 #endif /* PNG_WRITE_SUPPORTED */