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src/Source/LibPNG/pngread.c  view on Meta::CPAN

   png_uint_32 i, image_height;
   int pass, j;
   png_bytepp rp;

   png_debug(1, "in png_read_image");

   if (png_ptr == NULL)
      return;

#ifdef PNG_READ_INTERLACING_SUPPORTED
   if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
   {
      pass = png_set_interlace_handling(png_ptr);
      /* And make sure transforms are initialized. */
      png_start_read_image(png_ptr);
   }
   else
   {
      if (png_ptr->interlaced != 0 &&
          (png_ptr->transformations & PNG_INTERLACE) == 0)
      {
         /* Caller called png_start_read_image or png_read_update_info without
          * first turning on the PNG_INTERLACE transform.  We can fix this here,
          * but the caller should do it!
          */
         png_warning(png_ptr, "Interlace handling should be turned on when "
            "using png_read_image");
         /* Make sure this is set correctly */
         png_ptr->num_rows = png_ptr->height;
      }

      /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in
       * the above error case.
       */
      pass = png_set_interlace_handling(png_ptr);
   }
#else
   if (png_ptr->interlaced)
      png_error(png_ptr,
          "Cannot read interlaced image -- interlace handler disabled");

   pass = 1;
#endif

   image_height=png_ptr->height;

   for (j = 0; j < pass; j++)
   {
      rp = image;
      for (i = 0; i < image_height; i++)
      {
         png_read_row(png_ptr, *rp, NULL);
         rp++;
      }
   }
}
#endif /* SEQUENTIAL_READ */

#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
/* Read the end of the PNG file.  Will not read past the end of the
 * file, will verify the end is accurate, and will read any comments
 * or time information at the end of the file, if info is not NULL.
 */
void PNGAPI
png_read_end(png_structrp png_ptr, png_inforp info_ptr)
{
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
   int keep;
#endif

   png_debug(1, "in png_read_end");

   if (png_ptr == NULL)
      return;

   /* If png_read_end is called in the middle of reading the rows there may
    * still be pending IDAT data and an owned zstream.  Deal with this here.
    */
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
   if (png_chunk_unknown_handling(png_ptr, png_IDAT) == 0)
#endif
      png_read_finish_IDAT(png_ptr);

#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
   /* Report invalid palette index; added at libng-1.5.10 */
   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
      png_ptr->num_palette_max > png_ptr->num_palette)
     png_benign_error(png_ptr, "Read palette index exceeding num_palette");
#endif

   do
   {
      png_uint_32 length = png_read_chunk_header(png_ptr);
      png_uint_32 chunk_name = png_ptr->chunk_name;

      if (chunk_name == png_IEND)
         png_handle_IEND(png_ptr, info_ptr, length);

      else if (chunk_name == png_IHDR)
         png_handle_IHDR(png_ptr, info_ptr, length);

      else if (info_ptr == NULL)
         png_crc_finish(png_ptr, length);

#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
      else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
      {
         if (chunk_name == png_IDAT)
         {
            if ((length > 0) ||
                (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
               png_benign_error(png_ptr, "Too many IDATs found");
         }
         png_handle_unknown(png_ptr, info_ptr, length, keep);
         if (chunk_name == png_PLTE)
            png_ptr->mode |= PNG_HAVE_PLTE;
      }
#endif

      else if (chunk_name == png_IDAT)
      {