+
−
/* pngread.c - read a PNG file+
−
 *+
−
 * Last changed in libpng 1.4.0 [January 3, 2010]+
−
 * Copyright (c) 1998-2010 Glenn Randers-Pehrson+
−
 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)+
−
 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)+
−
 *+
−
 * This code is released under the libpng license.+
−
 * For conditions of distribution and use, see the disclaimer+
−
 * and license in png.h+
−
 *+
−
 * This file contains routines that an application calls directly to+
−
 * read a PNG file or stream.+
−
 */+
−
+
−
#define PNG_NO_PEDANTIC_WARNINGS+
−
#include "png.h"+
−
#ifdef PNG_READ_SUPPORTED+
−
#include "pngpriv.h"+
−
+
−
+
−
/* Create a PNG structure for reading, and allocate any memory needed. */+
−
png_structp PNGAPI+
−
png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,+
−
   png_error_ptr error_fn, png_error_ptr warn_fn)+
−
{+
−
+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
   return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,+
−
      warn_fn, NULL, NULL, NULL));+
−
}+
−
+
−
/* Alternate create PNG structure for reading, and allocate any memory needed. */+
−
png_structp PNGAPI+
−
png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,+
−
   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,+
−
   png_malloc_ptr malloc_fn, png_free_ptr free_fn)+
−
{+
−
#endif /* PNG_USER_MEM_SUPPORTED */+
−
+
−
#ifdef PNG_SETJMP_SUPPORTED+
−
   volatile+
−
#endif+
−
   png_structp png_ptr;+
−
   volatile int png_cleanup_needed = 0;+
−
+
−
#ifdef PNG_SETJMP_SUPPORTED+
−
#ifdef USE_FAR_KEYWORD+
−
   jmp_buf jmpbuf;+
−
#endif+
−
#endif+
−
+
−
   int i;+
−
+
−
   png_debug(1, "in png_create_read_struct");+
−
+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
   png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,+
−
      malloc_fn, mem_ptr);+
−
#else+
−
   png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);+
−
#endif+
−
   if (png_ptr == NULL)+
−
      return (NULL);+
−
+
−
   /* Added at libpng-1.2.6 */+
−
#ifdef PNG_SET_USER_LIMITS_SUPPORTED+
−
   png_ptr->user_width_max = PNG_USER_WIDTH_MAX;+
−
   png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;+
−
   /* Added at libpng-1.4.0 */+
−
   png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;+
−
#endif+
−
+
−
#ifdef PNG_SETJMP_SUPPORTED+
−
/* Applications that neglect to set up their own setjmp() and then+
−
   encounter a png_error() will longjmp here.  Since the jmpbuf is+
−
   then meaningless we abort instead of returning. */+
−
#ifdef USE_FAR_KEYWORD+
−
   if (setjmp(jmpbuf))+
−
#else+
−
   if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */+
−
#endif+
−
      PNG_ABORT();+
−
#ifdef USE_FAR_KEYWORD+
−
   png_memcpy(png_jmpbuf(png_ptr), jmpbuf, png_sizeof(jmp_buf));+
−
#endif+
−
#endif /* PNG_SETJMP_SUPPORTED */+
−
+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);+
−
#endif+
−
+
−
   png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);+
−
+
−
   if (user_png_ver)+
−
   {+
−
      i = 0;+
−
      do+
−
      {+
−
         if (user_png_ver[i] != png_libpng_ver[i])+
−
            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;+
−
      } while (png_libpng_ver[i++]);+
−
    }+
−
    else+
−
         png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;+
−
+
−
+
−
    if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)+
−
    {+
−
       /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so+
−
       * we must recompile any applications that use any older library version.+
−
       * For versions after libpng 1.0, we will be compatible, so we need+
−
       * only check the first digit.+
−
       */+
−
      if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||+
−
          (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||+
−
          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))+
−
      {+
−
#ifdef PNG_STDIO_SUPPORTED+
−
         char msg[80];+
−
         if (user_png_ver)+
−
         {+
−
           png_snprintf(msg, 80,+
−
              "Application was compiled with png.h from libpng-%.20s",+
−
              user_png_ver);+
−
           png_warning(png_ptr, msg);+
−
         }+
−
         png_snprintf(msg, 80,+
−
             "Application  is  running with png.c from libpng-%.20s",+
−
             png_libpng_ver);+
−
         png_warning(png_ptr, msg);+
−
#endif+
−
#ifdef PNG_ERROR_NUMBERS_SUPPORTED+
−
         png_ptr->flags = 0;+
−
#endif+
−
         png_warning(png_ptr,+
−
            "Incompatible libpng version in application and library");+
−
+
−
         png_cleanup_needed = 1;+
−
      }+
−
   }+
−
+
−
   if (!png_cleanup_needed)+
−
   {+
−
   /* Initialize zbuf - compression buffer */+
−
   png_ptr->zbuf_size = PNG_ZBUF_SIZE;+
−
   png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr,+
−
     png_ptr->zbuf_size);+
−
   if (png_ptr->zbuf == NULL)+
−
        png_cleanup_needed = 1;+
−
   }+
−
   png_ptr->zstream.zalloc = png_zalloc;+
−
   png_ptr->zstream.zfree = png_zfree;+
−
   png_ptr->zstream.opaque = (voidpf)png_ptr;+
−
+
−
   if (!png_cleanup_needed)+
−
   {+
−
      switch (inflateInit(&png_ptr->zstream))+
−
      {+
−
         case Z_OK: /* Do nothing */ break;+
−
         case Z_MEM_ERROR:+
−
         case Z_STREAM_ERROR: png_warning(png_ptr, "zlib memory error");+
−
            png_cleanup_needed = 1; break;+
−
         case Z_VERSION_ERROR: png_warning(png_ptr, "zlib version error");+
−
            png_cleanup_needed = 1; break;+
−
         default: png_warning(png_ptr, "Unknown zlib error");+
−
            png_cleanup_needed = 1;+
−
      }+
−
   }+
−
+
−
   if (png_cleanup_needed)+
−
   {+
−
      /* Clean up PNG structure and deallocate any memory. */+
−
      png_free(png_ptr, png_ptr->zbuf);+
−
      png_ptr->zbuf = NULL;+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
      png_destroy_struct_2((png_voidp)png_ptr,+
−
         (png_free_ptr)free_fn, (png_voidp)mem_ptr);+
−
#else+
−
      png_destroy_struct((png_voidp)png_ptr);+
−
#endif+
−
      return (NULL);+
−
   }+
−
+
−
   png_ptr->zstream.next_out = png_ptr->zbuf;+
−
   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;+
−
+
−
   png_set_read_fn(png_ptr, NULL, NULL);+
−
+
−
+
−
   return (png_ptr);+
−
}+
−
+
−
+
−
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED+
−
/* Read the information before the actual image data.  This has been+
−
 * changed in v0.90 to allow reading a file that already has the magic+
−
 * bytes read from the stream.  You can tell libpng how many bytes have+
−
 * been read from the beginning of the stream (up to the maximum of 8)+
−
 * via png_set_sig_bytes(), and we will only check the remaining bytes+
−
 * here.  The application can then have access to the signature bytes we+
−
 * read if it is determined that this isn't a valid PNG file.+
−
 */+
−
void PNGAPI+
−
png_read_info(png_structp png_ptr, png_infop info_ptr)+
−
{+
−
   png_debug(1, "in png_read_info");+
−
 +
−
   if (png_ptr == NULL || info_ptr == NULL)+
−
      return;+
−
 +
−
   /* If we haven't checked all of the PNG signature bytes, do so now. */+
−
   if (png_ptr->sig_bytes < 8)+
−
   {+
−
      png_size_t num_checked = png_ptr->sig_bytes,+
−
                 num_to_check = 8 - num_checked;+
−
+
−
#ifdef PNG_IO_STATE_SUPPORTED+
−
      png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;+
−
#endif+
−
+
−
      png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);+
−
      png_ptr->sig_bytes = 8;+
−
+
−
      if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))+
−
      {+
−
         if (num_checked < 4 &&+
−
             png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))+
−
            png_error(png_ptr, "Not a PNG file");+
−
         else+
−
            png_error(png_ptr, "PNG file corrupted by ASCII conversion");+
−
      }+
−
      if (num_checked < 3)+
−
         png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;+
−
   }+
−
+
−
   for (;;)+
−
   {+
−
      PNG_IHDR;+
−
      PNG_IDAT;+
−
      PNG_IEND;+
−
      PNG_PLTE;+
−
#ifdef PNG_READ_bKGD_SUPPORTED+
−
      PNG_bKGD;+
−
#endif+
−
#ifdef PNG_READ_cHRM_SUPPORTED+
−
      PNG_cHRM;+
−
#endif+
−
#ifdef PNG_READ_gAMA_SUPPORTED+
−
      PNG_gAMA;+
−
#endif+
−
#ifdef PNG_READ_hIST_SUPPORTED+
−
      PNG_hIST;+
−
#endif+
−
#ifdef PNG_READ_iCCP_SUPPORTED+
−
      PNG_iCCP;+
−
#endif+
−
#ifdef PNG_READ_iTXt_SUPPORTED+
−
      PNG_iTXt;+
−
#endif+
−
#ifdef PNG_READ_oFFs_SUPPORTED+
−
      PNG_oFFs;+
−
#endif+
−
#ifdef PNG_READ_pCAL_SUPPORTED+
−
      PNG_pCAL;+
−
#endif+
−
#ifdef PNG_READ_pHYs_SUPPORTED+
−
      PNG_pHYs;+
−
#endif+
−
#ifdef PNG_READ_sBIT_SUPPORTED+
−
      PNG_sBIT;+
−
#endif+
−
#ifdef PNG_READ_sCAL_SUPPORTED+
−
      PNG_sCAL;+
−
#endif+
−
#ifdef PNG_READ_sPLT_SUPPORTED+
−
      PNG_sPLT;+
−
#endif+
−
#ifdef PNG_READ_sRGB_SUPPORTED+
−
      PNG_sRGB;+
−
#endif+
−
#ifdef PNG_READ_tEXt_SUPPORTED+
−
      PNG_tEXt;+
−
#endif+
−
#ifdef PNG_READ_tIME_SUPPORTED+
−
      PNG_tIME;+
−
#endif+
−
#ifdef PNG_READ_tRNS_SUPPORTED+
−
      PNG_tRNS;+
−
#endif+
−
#ifdef PNG_READ_zTXt_SUPPORTED+
−
      PNG_zTXt;+
−
#endif+
−
      png_uint_32 length = png_read_chunk_header(png_ptr);+
−
      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;+
−
+
−
      /* This should be a binary subdivision search or a hash for+
−
       * matching the chunk name rather than a linear search.+
−
       */+
−
      if (!png_memcmp(chunk_name, png_IDAT, 4))+
−
        if (png_ptr->mode & PNG_AFTER_IDAT)+
−
          png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;+
−
+
−
      if (!png_memcmp(chunk_name, png_IHDR, 4))+
−
         png_handle_IHDR(png_ptr, info_ptr, length);+
−
      else if (!png_memcmp(chunk_name, png_IEND, 4))+
−
         png_handle_IEND(png_ptr, info_ptr, length);+
−
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED+
−
      else if (png_handle_as_unknown(png_ptr, chunk_name))+
−
      {+
−
         if (!png_memcmp(chunk_name, png_IDAT, 4))+
−
            png_ptr->mode |= PNG_HAVE_IDAT;+
−
         png_handle_unknown(png_ptr, info_ptr, length);+
−
         if (!png_memcmp(chunk_name, png_PLTE, 4))+
−
            png_ptr->mode |= PNG_HAVE_PLTE;+
−
         else if (!png_memcmp(chunk_name, png_IDAT, 4))+
−
         {+
−
            if (!(png_ptr->mode & PNG_HAVE_IHDR))+
−
               png_error(png_ptr, "Missing IHDR before IDAT");+
−
            else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&+
−
                     !(png_ptr->mode & PNG_HAVE_PLTE))+
−
               png_error(png_ptr, "Missing PLTE before IDAT");+
−
            break;+
−
         }+
−
      }+
−
#endif+
−
      else if (!png_memcmp(chunk_name, png_PLTE, 4))+
−
         png_handle_PLTE(png_ptr, info_ptr, length);+
−
      else if (!png_memcmp(chunk_name, png_IDAT, 4))+
−
      {+
−
         if (!(png_ptr->mode & PNG_HAVE_IHDR))+
−
            png_error(png_ptr, "Missing IHDR before IDAT");+
−
         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&+
−
                  !(png_ptr->mode & PNG_HAVE_PLTE))+
−
            png_error(png_ptr, "Missing PLTE before IDAT");+
−
+
−
         png_ptr->idat_size = length;+
−
         png_ptr->mode |= PNG_HAVE_IDAT;+
−
         break;+
−
      }+
−
#ifdef PNG_READ_bKGD_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_bKGD, 4))+
−
         png_handle_bKGD(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_cHRM_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_cHRM, 4))+
−
         png_handle_cHRM(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_gAMA_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_gAMA, 4))+
−
         png_handle_gAMA(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_hIST_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_hIST, 4))+
−
         png_handle_hIST(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_oFFs_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_oFFs, 4))+
−
         png_handle_oFFs(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_pCAL_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_pCAL, 4))+
−
         png_handle_pCAL(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_sCAL_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_sCAL, 4))+
−
         png_handle_sCAL(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_pHYs_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_pHYs, 4))+
−
         png_handle_pHYs(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_sBIT_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_sBIT, 4))+
−
         png_handle_sBIT(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_sRGB_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_sRGB, 4))+
−
         png_handle_sRGB(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_iCCP_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_iCCP, 4))+
−
         png_handle_iCCP(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_sPLT_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_sPLT, 4))+
−
         png_handle_sPLT(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_tEXt_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_tEXt, 4))+
−
         png_handle_tEXt(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_tIME_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_tIME, 4))+
−
         png_handle_tIME(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_tRNS_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_tRNS, 4))+
−
         png_handle_tRNS(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_zTXt_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_zTXt, 4))+
−
         png_handle_zTXt(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_iTXt_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_iTXt, 4))+
−
         png_handle_iTXt(png_ptr, info_ptr, length);+
−
#endif+
−
      else+
−
         png_handle_unknown(png_ptr, info_ptr, length);+
−
   }+
−
}+
−
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */+
−
+
−
/* Optional call to update the users info_ptr structure */+
−
void PNGAPI+
−
png_read_update_info(png_structp png_ptr, png_infop info_ptr)+
−
{+
−
   png_debug(1, "in png_read_update_info");+
−
 +
−
   if (png_ptr == NULL)+
−
      return;+
−
   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))+
−
      png_read_start_row(png_ptr);+
−
   else+
−
      png_warning(png_ptr,+
−
      "Ignoring extra png_read_update_info() call; row buffer not reallocated");+
−
+
−
   png_read_transform_info(png_ptr, info_ptr);+
−
}+
−
+
−
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED+
−
/* Initialize palette, background, etc, after transformations+
−
 * are set, but before any reading takes place.  This allows+
−
 * the user to obtain a gamma-corrected palette, for example.+
−
 * If the user doesn't call this, we will do it ourselves.+
−
 */+
−
void PNGAPI+
−
png_start_read_image(png_structp png_ptr)+
−
{+
−
   png_debug(1, "in png_start_read_image");+
−
 +
−
   if (png_ptr == NULL)+
−
      return;+
−
   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))+
−
      png_read_start_row(png_ptr);+
−
}+
−
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */+
−
+
−
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED+
−
void PNGAPI+
−
png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)+
−
{+
−
   PNG_IDAT;+
−
   PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,+
−
      0xff};+
−
   PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};+
−
   int ret;+
−
 +
−
   if (png_ptr == NULL)+
−
      return;+
−
 +
−
   png_debug2(1, "in png_read_row (row %lu, pass %d)",+
−
      (unsigned long) png_ptr->row_number, png_ptr->pass);+
−
+
−
   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))+
−
      png_read_start_row(png_ptr);+
−
   if (png_ptr->row_number == 0 && png_ptr->pass == 0)+
−
   {+
−
   /* Check for transforms that have been set but were defined out */+
−
#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)+
−
   if (png_ptr->transformations & PNG_INVERT_MONO)+
−
      png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");+
−
#endif+
−
#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)+
−
   if (png_ptr->transformations & PNG_FILLER)+
−
      png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");+
−
#endif+
−
#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && !defined(PNG_READ_PACKSWAP_SUPPORTED)+
−
   if (png_ptr->transformations & PNG_PACKSWAP)+
−
      png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");+
−
#endif+
−
#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)+
−
   if (png_ptr->transformations & PNG_PACK)+
−
      png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");+
−
#endif+
−
#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)+
−
   if (png_ptr->transformations & PNG_SHIFT)+
−
      png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");+
−
#endif+
−
#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)+
−
   if (png_ptr->transformations & PNG_BGR)+
−
      png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");+
−
#endif+
−
#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)+
−
   if (png_ptr->transformations & PNG_SWAP_BYTES)+
−
      png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");+
−
#endif+
−
   }+
−
+
−
#ifdef PNG_READ_INTERLACING_SUPPORTED+
−
   /* If interlaced and we do not need a new row, combine row and return */+
−
   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))+
−
   {+
−
      switch (png_ptr->pass)+
−
      {+
−
         case 0:+
−
            if (png_ptr->row_number & 0x07)+
−
            {+
−
               if (dsp_row != NULL)+
−
                  png_combine_row(png_ptr, dsp_row,+
−
                     png_pass_dsp_mask[png_ptr->pass]);+
−
               png_read_finish_row(png_ptr);+
−
               return;+
−
            }+
−
            break;+
−
         case 1:+
−
            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)+
−
            {+
−
               if (dsp_row != NULL)+
−
                  png_combine_row(png_ptr, dsp_row,+
−
                     png_pass_dsp_mask[png_ptr->pass]);+
−
               png_read_finish_row(png_ptr);+
−
               return;+
−
            }+
−
            break;+
−
         case 2:+
−
            if ((png_ptr->row_number & 0x07) != 4)+
−
            {+
−
               if (dsp_row != NULL && (png_ptr->row_number & 4))+
−
                  png_combine_row(png_ptr, dsp_row,+
−
                     png_pass_dsp_mask[png_ptr->pass]);+
−
               png_read_finish_row(png_ptr);+
−
               return;+
−
            }+
−
            break;+
−
         case 3:+
−
            if ((png_ptr->row_number & 3) || png_ptr->width < 3)+
−
            {+
−
               if (dsp_row != NULL)+
−
                  png_combine_row(png_ptr, dsp_row,+
−
                     png_pass_dsp_mask[png_ptr->pass]);+
−
               png_read_finish_row(png_ptr);+
−
               return;+
−
            }+
−
            break;+
−
         case 4:+
−
            if ((png_ptr->row_number & 3) != 2)+
−
            {+
−
               if (dsp_row != NULL && (png_ptr->row_number & 2))+
−
                  png_combine_row(png_ptr, dsp_row,+
−
                     png_pass_dsp_mask[png_ptr->pass]);+
−
               png_read_finish_row(png_ptr);+
−
               return;+
−
            }+
−
            break;+
−
         case 5:+
−
            if ((png_ptr->row_number & 1) || png_ptr->width < 2)+
−
            {+
−
               if (dsp_row != NULL)+
−
                  png_combine_row(png_ptr, dsp_row,+
−
                     png_pass_dsp_mask[png_ptr->pass]);+
−
               png_read_finish_row(png_ptr);+
−
               return;+
−
            }+
−
            break;+
−
         case 6:+
−
            if (!(png_ptr->row_number & 1))+
−
            {+
−
               png_read_finish_row(png_ptr);+
−
               return;+
−
            }+
−
            break;+
−
      }+
−
   }+
−
#endif+
−
+
−
   if (!(png_ptr->mode & PNG_HAVE_IDAT))+
−
      png_error(png_ptr, "Invalid attempt to read row data");+
−
+
−
   png_ptr->zstream.next_out = png_ptr->row_buf;+
−
   png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;+
−
   do+
−
   {+
−
      if (!(png_ptr->zstream.avail_in))+
−
      {+
−
         while (!png_ptr->idat_size)+
−
         {+
−
            png_crc_finish(png_ptr, 0);+
−
+
−
            png_ptr->idat_size = png_read_chunk_header(png_ptr);+
−
            if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))+
−
               png_error(png_ptr, "Not enough image data");+
−
         }+
−
         png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;+
−
         png_ptr->zstream.next_in = png_ptr->zbuf;+
−
         if (png_ptr->zbuf_size > png_ptr->idat_size)+
−
            png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;+
−
         png_crc_read(png_ptr, png_ptr->zbuf,+
−
            (png_size_t)png_ptr->zstream.avail_in);+
−
         png_ptr->idat_size -= png_ptr->zstream.avail_in;+
−
      }+
−
      ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);+
−
      if (ret == Z_STREAM_END)+
−
      {+
−
         if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||+
−
            png_ptr->idat_size)+
−
            png_benign_error(png_ptr, "Extra compressed data");+
−
         png_ptr->mode |= PNG_AFTER_IDAT;+
−
         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;+
−
         break;+
−
      }+
−
      if (ret != Z_OK)+
−
         png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :+
−
                   "Decompression error");+
−
+
−
   } while (png_ptr->zstream.avail_out);+
−
+
−
   png_ptr->row_info.color_type = png_ptr->color_type;+
−
   png_ptr->row_info.width = png_ptr->iwidth;+
−
   png_ptr->row_info.channels = png_ptr->channels;+
−
   png_ptr->row_info.bit_depth = png_ptr->bit_depth;+
−
   png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;+
−
   png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,+
−
       png_ptr->row_info.width);+
−
+
−
   if (png_ptr->row_buf[0])+
−
   png_read_filter_row(png_ptr, &(png_ptr->row_info),+
−
      png_ptr->row_buf + 1, png_ptr->prev_row + 1,+
−
      (int)(png_ptr->row_buf[0]));+
−
+
−
   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);+
−
+
−
#ifdef PNG_MNG_FEATURES_SUPPORTED+
−
   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&+
−
      (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))+
−
   {+
−
      /* Intrapixel differencing */+
−
      png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);+
−
   }+
−
#endif+
−
+
−
+
−
   if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))+
−
      png_do_read_transformations(png_ptr);+
−
+
−
#ifdef PNG_READ_INTERLACING_SUPPORTED+
−
   /* Blow up interlaced rows to full size */+
−
   if (png_ptr->interlaced &&+
−
      (png_ptr->transformations & PNG_INTERLACE))+
−
   {+
−
      if (png_ptr->pass < 6)+
−
         /* Old interface (pre-1.0.9):+
−
          * png_do_read_interlace(&(png_ptr->row_info),+
−
          *    png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);+
−
          */+
−
         png_do_read_interlace(png_ptr);+
−
+
−
      if (dsp_row != NULL)+
−
         png_combine_row(png_ptr, dsp_row,+
−
            png_pass_dsp_mask[png_ptr->pass]);+
−
      if (row != NULL)+
−
         png_combine_row(png_ptr, row,+
−
            png_pass_mask[png_ptr->pass]);+
−
   }+
−
   else+
−
#endif+
−
   {+
−
      if (row != NULL)+
−
         png_combine_row(png_ptr, row, 0xff);+
−
      if (dsp_row != NULL)+
−
         png_combine_row(png_ptr, dsp_row, 0xff);+
−
   }+
−
   png_read_finish_row(png_ptr);+
−
+
−
   if (png_ptr->read_row_fn != NULL)+
−
      (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);+
−
}+
−
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */+
−
+
−
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED+
−
/* Read one or more rows of image data.  If the image is interlaced,+
−
 * and png_set_interlace_handling() has been called, the rows need to+
−
 * contain the contents of the rows from the previous pass.  If the+
−
 * image has alpha or transparency, and png_handle_alpha()[*] has been+
−
 * called, the rows contents must be initialized to the contents of the+
−
 * screen.+
−
 *+
−
 * "row" holds the actual image, and pixels are placed in it+
−
 * as they arrive.  If the image is displayed after each pass, it will+
−
 * appear to "sparkle" in.  "display_row" can be used to display a+
−
 * "chunky" progressive image, with finer detail added as it becomes+
−
 * available.  If you do not want this "chunky" display, you may pass+
−
 * NULL for display_row.  If you do not want the sparkle display, and+
−
 * you have not called png_handle_alpha(), you may pass NULL for rows.+
−
 * If you have called png_handle_alpha(), and the image has either an+
−
 * alpha channel or a transparency chunk, you must provide a buffer for+
−
 * rows.  In this case, you do not have to provide a display_row buffer+
−
 * also, but you may.  If the image is not interlaced, or if you have+
−
 * not called png_set_interlace_handling(), the display_row buffer will+
−
 * be ignored, so pass NULL to it.+
−
 *+
−
 * [*] png_handle_alpha() does not exist yet, as of this version of libpng+
−
 */+
−
+
−
void PNGAPI+
−
png_read_rows(png_structp png_ptr, png_bytepp row,+
−
   png_bytepp display_row, png_uint_32 num_rows)+
−
{+
−
   png_uint_32 i;+
−
   png_bytepp rp;+
−
   png_bytepp dp;+
−
+
−
   png_debug(1, "in png_read_rows");+
−
 +
−
   if (png_ptr == NULL)+
−
      return;+
−
   rp = row;+
−
   dp = display_row;+
−
   if (rp != NULL && dp != NULL)+
−
      for (i = 0; i < num_rows; i++)+
−
      {+
−
         png_bytep rptr = *rp++;+
−
         png_bytep dptr = *dp++;+
−
+
−
         png_read_row(png_ptr, rptr, dptr);+
−
      }+
−
   else if (rp != NULL)+
−
      for (i = 0; i < num_rows; i++)+
−
      {+
−
         png_bytep rptr = *rp;+
−
         png_read_row(png_ptr, rptr, NULL);+
−
         rp++;+
−
      }+
−
   else if (dp != NULL)+
−
      for (i = 0; i < num_rows; i++)+
−
      {+
−
         png_bytep dptr = *dp;+
−
         png_read_row(png_ptr, NULL, dptr);+
−
         dp++;+
−
      }+
−
}+
−
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */+
−
+
−
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED+
−
/* Read the entire image.  If the image has an alpha channel or a tRNS+
−
 * chunk, and you have called png_handle_alpha()[*], you will need to+
−
 * initialize the image to the current image that PNG will be overlaying.+
−
 * We set the num_rows again here, in case it was incorrectly set in+
−
 * png_read_start_row() by a call to png_read_update_info() or+
−
 * png_start_read_image() if png_set_interlace_handling() wasn't called+
−
 * prior to either of these functions like it should have been.  You can+
−
 * only call this function once.  If you desire to have an image for+
−
 * each pass of a interlaced image, use png_read_rows() instead.+
−
 *+
−
 * [*] png_handle_alpha() does not exist yet, as of this version of libpng+
−
 */+
−
void PNGAPI+
−
png_read_image(png_structp png_ptr, png_bytepp image)+
−
{+
−
   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+
−
   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;+
−
   png_ptr->num_rows = image_height; /* Make sure this is set correctly */+
−
+
−
   for (j = 0; j < pass; j++)+
−
   {+
−
      rp = image;+
−
      for (i = 0; i < image_height; i++)+
−
      {+
−
         png_read_row(png_ptr, *rp, NULL);+
−
         rp++;+
−
      }+
−
   }+
−
}+
−
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */+
−
+
−
#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_structp png_ptr, png_infop info_ptr)+
−
{+
−
   png_debug(1, "in png_read_end");+
−
 +
−
   if (png_ptr == NULL)+
−
      return;+
−
   png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */+
−
+
−
   do+
−
   {+
−
      PNG_IHDR;+
−
      PNG_IDAT;+
−
      PNG_IEND;+
−
      PNG_PLTE;+
−
#ifdef PNG_READ_bKGD_SUPPORTED+
−
      PNG_bKGD;+
−
#endif+
−
#ifdef PNG_READ_cHRM_SUPPORTED+
−
      PNG_cHRM;+
−
#endif+
−
#ifdef PNG_READ_gAMA_SUPPORTED+
−
      PNG_gAMA;+
−
#endif+
−
#ifdef PNG_READ_hIST_SUPPORTED+
−
      PNG_hIST;+
−
#endif+
−
#ifdef PNG_READ_iCCP_SUPPORTED+
−
      PNG_iCCP;+
−
#endif+
−
#ifdef PNG_READ_iTXt_SUPPORTED+
−
      PNG_iTXt;+
−
#endif+
−
#ifdef PNG_READ_oFFs_SUPPORTED+
−
      PNG_oFFs;+
−
#endif+
−
#ifdef PNG_READ_pCAL_SUPPORTED+
−
      PNG_pCAL;+
−
#endif+
−
#ifdef PNG_READ_pHYs_SUPPORTED+
−
      PNG_pHYs;+
−
#endif+
−
#ifdef PNG_READ_sBIT_SUPPORTED+
−
      PNG_sBIT;+
−
#endif+
−
#ifdef PNG_READ_sCAL_SUPPORTED+
−
      PNG_sCAL;+
−
#endif+
−
#ifdef PNG_READ_sPLT_SUPPORTED+
−
      PNG_sPLT;+
−
#endif+
−
#ifdef PNG_READ_sRGB_SUPPORTED+
−
      PNG_sRGB;+
−
#endif+
−
#ifdef PNG_READ_tEXt_SUPPORTED+
−
      PNG_tEXt;+
−
#endif+
−
#ifdef PNG_READ_tIME_SUPPORTED+
−
      PNG_tIME;+
−
#endif+
−
#ifdef PNG_READ_tRNS_SUPPORTED+
−
      PNG_tRNS;+
−
#endif+
−
#ifdef PNG_READ_zTXt_SUPPORTED+
−
      PNG_zTXt;+
−
#endif+
−
      png_uint_32 length = png_read_chunk_header(png_ptr);+
−
      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;+
−
+
−
      if (!png_memcmp(chunk_name, png_IHDR, 4))+
−
         png_handle_IHDR(png_ptr, info_ptr, length);+
−
      else if (!png_memcmp(chunk_name, png_IEND, 4))+
−
         png_handle_IEND(png_ptr, info_ptr, length);+
−
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED+
−
      else if (png_handle_as_unknown(png_ptr, chunk_name))+
−
      {+
−
         if (!png_memcmp(chunk_name, png_IDAT, 4))+
−
         {+
−
            if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))+
−
               png_benign_error(png_ptr, "Too many IDATs found");+
−
         }+
−
         png_handle_unknown(png_ptr, info_ptr, length);+
−
         if (!png_memcmp(chunk_name, png_PLTE, 4))+
−
            png_ptr->mode |= PNG_HAVE_PLTE;+
−
      }+
−
#endif+
−
      else if (!png_memcmp(chunk_name, png_IDAT, 4))+
−
      {+
−
         /* Zero length IDATs are legal after the last IDAT has been+
−
          * read, but not after other chunks have been read.+
−
          */+
−
         if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))+
−
            png_benign_error(png_ptr, "Too many IDATs found");+
−
         png_crc_finish(png_ptr, length);+
−
      }+
−
      else if (!png_memcmp(chunk_name, png_PLTE, 4))+
−
         png_handle_PLTE(png_ptr, info_ptr, length);+
−
#ifdef PNG_READ_bKGD_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_bKGD, 4))+
−
         png_handle_bKGD(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_cHRM_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_cHRM, 4))+
−
         png_handle_cHRM(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_gAMA_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_gAMA, 4))+
−
         png_handle_gAMA(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_hIST_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_hIST, 4))+
−
         png_handle_hIST(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_oFFs_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_oFFs, 4))+
−
         png_handle_oFFs(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_pCAL_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_pCAL, 4))+
−
         png_handle_pCAL(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_sCAL_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_sCAL, 4))+
−
         png_handle_sCAL(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_pHYs_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_pHYs, 4))+
−
         png_handle_pHYs(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_sBIT_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_sBIT, 4))+
−
         png_handle_sBIT(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_sRGB_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_sRGB, 4))+
−
         png_handle_sRGB(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_iCCP_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_iCCP, 4))+
−
         png_handle_iCCP(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_sPLT_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_sPLT, 4))+
−
         png_handle_sPLT(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_tEXt_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_tEXt, 4))+
−
         png_handle_tEXt(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_tIME_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_tIME, 4))+
−
         png_handle_tIME(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_tRNS_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_tRNS, 4))+
−
         png_handle_tRNS(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_zTXt_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_zTXt, 4))+
−
         png_handle_zTXt(png_ptr, info_ptr, length);+
−
#endif+
−
#ifdef PNG_READ_iTXt_SUPPORTED+
−
      else if (!png_memcmp(chunk_name, png_iTXt, 4))+
−
         png_handle_iTXt(png_ptr, info_ptr, length);+
−
#endif+
−
      else+
−
         png_handle_unknown(png_ptr, info_ptr, length);+
−
   } while (!(png_ptr->mode & PNG_HAVE_IEND));+
−
}+
−
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */+
−
+
−
/* Free all memory used by the read */+
−
void PNGAPI+
−
png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,+
−
   png_infopp end_info_ptr_ptr)+
−
{+
−
   png_structp png_ptr = NULL;+
−
   png_infop info_ptr = NULL, end_info_ptr = NULL;+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
   png_free_ptr free_fn = NULL;+
−
   png_voidp mem_ptr = NULL;+
−
#endif+
−
+
−
   png_debug(1, "in png_destroy_read_struct");+
−
 +
−
   if (png_ptr_ptr != NULL)+
−
      png_ptr = *png_ptr_ptr;+
−
   if (png_ptr == NULL)+
−
      return;+
−
+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
   free_fn = png_ptr->free_fn;+
−
   mem_ptr = png_ptr->mem_ptr;+
−
#endif+
−
+
−
   if (info_ptr_ptr != NULL)+
−
      info_ptr = *info_ptr_ptr;+
−
+
−
   if (end_info_ptr_ptr != NULL)+
−
      end_info_ptr = *end_info_ptr_ptr;+
−
+
−
   png_read_destroy(png_ptr, info_ptr, end_info_ptr);+
−
+
−
   if (info_ptr != NULL)+
−
   {+
−
#ifdef PNG_TEXT_SUPPORTED+
−
      png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);+
−
#endif+
−
+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
      png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,+
−
          (png_voidp)mem_ptr);+
−
#else+
−
      png_destroy_struct((png_voidp)info_ptr);+
−
#endif+
−
      *info_ptr_ptr = NULL;+
−
   }+
−
+
−
   if (end_info_ptr != NULL)+
−
   {+
−
#ifdef PNG_READ_TEXT_SUPPORTED+
−
      png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);+
−
#endif+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
      png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,+
−
         (png_voidp)mem_ptr);+
−
#else+
−
      png_destroy_struct((png_voidp)end_info_ptr);+
−
#endif+
−
      *end_info_ptr_ptr = NULL;+
−
   }+
−
+
−
   if (png_ptr != NULL)+
−
   {+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
      png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,+
−
          (png_voidp)mem_ptr);+
−
#else+
−
      png_destroy_struct((png_voidp)png_ptr);+
−
#endif+
−
      *png_ptr_ptr = NULL;+
−
   }+
−
}+
−
+
−
/* Free all memory used by the read (old method) */+
−
void /* PRIVATE */+
−
png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)+
−
{+
−
#ifdef PNG_SETJMP_SUPPORTED+
−
   jmp_buf tmp_jmp;+
−
#endif+
−
   png_error_ptr error_fn;+
−
   png_error_ptr warning_fn;+
−
   png_voidp error_ptr;+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
   png_free_ptr free_fn;+
−
#endif+
−
+
−
   png_debug(1, "in png_read_destroy");+
−
 +
−
   if (info_ptr != NULL)+
−
      png_info_destroy(png_ptr, info_ptr);+
−
+
−
   if (end_info_ptr != NULL)+
−
      png_info_destroy(png_ptr, end_info_ptr);+
−
+
−
   png_free(png_ptr, png_ptr->zbuf);+
−
   png_free(png_ptr, png_ptr->big_row_buf);+
−
   png_free(png_ptr, png_ptr->prev_row);+
−
   png_free(png_ptr, png_ptr->chunkdata);+
−
#ifdef PNG_READ_DITHER_SUPPORTED+
−
   png_free(png_ptr, png_ptr->palette_lookup);+
−
   png_free(png_ptr, png_ptr->dither_index);+
−
#endif+
−
#ifdef PNG_READ_GAMMA_SUPPORTED+
−
   png_free(png_ptr, png_ptr->gamma_table);+
−
#endif+
−
#ifdef PNG_READ_BACKGROUND_SUPPORTED+
−
   png_free(png_ptr, png_ptr->gamma_from_1);+
−
   png_free(png_ptr, png_ptr->gamma_to_1);+
−
#endif+
−
   if (png_ptr->free_me & PNG_FREE_PLTE)+
−
      png_zfree(png_ptr, png_ptr->palette);+
−
   png_ptr->free_me &= ~PNG_FREE_PLTE;+
−
#if defined(PNG_tRNS_SUPPORTED) || \+
−
    defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)+
−
   if (png_ptr->free_me & PNG_FREE_TRNS)+
−
      png_free(png_ptr, png_ptr->trans_alpha);+
−
   png_ptr->free_me &= ~PNG_FREE_TRNS;+
−
#endif+
−
#ifdef PNG_READ_hIST_SUPPORTED+
−
   if (png_ptr->free_me & PNG_FREE_HIST)+
−
      png_free(png_ptr, png_ptr->hist);+
−
   png_ptr->free_me &= ~PNG_FREE_HIST;+
−
#endif+
−
#ifdef PNG_READ_GAMMA_SUPPORTED+
−
   if (png_ptr->gamma_16_table != NULL)+
−
   {+
−
      int i;+
−
      int istop = (1 << (8 - png_ptr->gamma_shift));+
−
      for (i = 0; i < istop; i++)+
−
      {+
−
         png_free(png_ptr, png_ptr->gamma_16_table[i]);+
−
      }+
−
   png_free(png_ptr, png_ptr->gamma_16_table);+
−
   }+
−
#ifdef PNG_READ_BACKGROUND_SUPPORTED+
−
   if (png_ptr->gamma_16_from_1 != NULL)+
−
   {+
−
      int i;+
−
      int istop = (1 << (8 - png_ptr->gamma_shift));+
−
      for (i = 0; i < istop; i++)+
−
      {+
−
         png_free(png_ptr, png_ptr->gamma_16_from_1[i]);+
−
      }+
−
   png_free(png_ptr, png_ptr->gamma_16_from_1);+
−
   }+
−
   if (png_ptr->gamma_16_to_1 != NULL)+
−
   {+
−
      int i;+
−
      int istop = (1 << (8 - png_ptr->gamma_shift));+
−
      for (i = 0; i < istop; i++)+
−
      {+
−
         png_free(png_ptr, png_ptr->gamma_16_to_1[i]);+
−
      }+
−
   png_free(png_ptr, png_ptr->gamma_16_to_1);+
−
   }+
−
#endif+
−
#endif+
−
#ifdef PNG_TIME_RFC1123_SUPPORTED+
−
   png_free(png_ptr, png_ptr->time_buffer);+
−
#endif+
−
+
−
   inflateEnd(&png_ptr->zstream);+
−
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED+
−
   png_free(png_ptr, png_ptr->save_buffer);+
−
#endif+
−
+
−
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED+
−
#ifdef PNG_TEXT_SUPPORTED+
−
   png_free(png_ptr, png_ptr->current_text);+
−
#endif /* PNG_TEXT_SUPPORTED */+
−
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */+
−
+
−
   /* Save the important info out of the png_struct, in case it is+
−
    * being used again.+
−
    */+
−
#ifdef PNG_SETJMP_SUPPORTED+
−
   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));+
−
#endif+
−
+
−
   error_fn = png_ptr->error_fn;+
−
   warning_fn = png_ptr->warning_fn;+
−
   error_ptr = png_ptr->error_ptr;+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
   free_fn = png_ptr->free_fn;+
−
#endif+
−
+
−
   png_memset(png_ptr, 0, png_sizeof(png_struct));+
−
+
−
   png_ptr->error_fn = error_fn;+
−
   png_ptr->warning_fn = warning_fn;+
−
   png_ptr->error_ptr = error_ptr;+
−
#ifdef PNG_USER_MEM_SUPPORTED+
−
   png_ptr->free_fn = free_fn;+
−
#endif+
−
+
−
#ifdef PNG_SETJMP_SUPPORTED+
−
   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));+
−
#endif+
−
+
−
}+
−
+
−
void PNGAPI+
−
png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)+
−
{+
−
   if (png_ptr == NULL)+
−
      return;+
−
   png_ptr->read_row_fn = read_row_fn;+
−
}+
−
+
−
+
−
#ifdef PNG_SEQUENTIAL_READ_SUPPORTED+
−
#ifdef PNG_INFO_IMAGE_SUPPORTED+
−
void PNGAPI+
−
png_read_png(png_structp png_ptr, png_infop info_ptr,+
−
                           int transforms,+
−
                           voidp params)+
−
{+
−
   int row;+
−
+
−
   if (png_ptr == NULL)+
−
      return;+
−
+
−
   /* png_read_info() gives us all of the information from the+
−
    * PNG file before the first IDAT (image data chunk).+
−
    */+
−
   png_read_info(png_ptr, info_ptr);+
−
   if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))+
−
      png_error(png_ptr, "Image is too high to process with png_read_png()");+
−
+
−
   /* -------------- image transformations start here ------------------- */+
−
+
−
#ifdef PNG_READ_16_TO_8_SUPPORTED+
−
   /* Tell libpng to strip 16 bit/color files down to 8 bits per color.+
−
    */+
−
   if (transforms & PNG_TRANSFORM_STRIP_16)+
−
      png_set_strip_16(png_ptr);+
−
#endif+
−
+
−
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED+
−
   /* Strip alpha bytes from the input data without combining with+
−
    * the background (not recommended).+
−
    */+
−
   if (transforms & PNG_TRANSFORM_STRIP_ALPHA)+
−
      png_set_strip_alpha(png_ptr);+
−
#endif+
−
+
−
#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)+
−
   /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single+
−
    * byte into separate bytes (useful for paletted and grayscale images).+
−
    */+
−
   if (transforms & PNG_TRANSFORM_PACKING)+
−
      png_set_packing(png_ptr);+
−
#endif+
−
+
−
#ifdef PNG_READ_PACKSWAP_SUPPORTED+
−
   /* Change the order of packed pixels to least significant bit first+
−
    * (not useful if you are using png_set_packing).+
−
    */+
−
   if (transforms & PNG_TRANSFORM_PACKSWAP)+
−
      png_set_packswap(png_ptr);+
−
#endif+
−
+
−
#ifdef PNG_READ_EXPAND_SUPPORTED+
−
   /* Expand paletted colors into true RGB triplets+
−
    * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel+
−
    * Expand paletted or RGB images with transparency to full alpha+
−
    * channels so the data will be available as RGBA quartets.+
−
    */+
−
   if (transforms & PNG_TRANSFORM_EXPAND)+
−
      if ((png_ptr->bit_depth < 8) ||+
−
          (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||+
−
          (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))+
−
         png_set_expand(png_ptr);+
−
#endif+
−
+
−
   /* We don't handle background color or gamma transformation or dithering.+
−
    */+
−
+
−
#ifdef PNG_READ_INVERT_SUPPORTED+
−
   /* Invert monochrome files to have 0 as white and 1 as black+
−
    */+
−
   if (transforms & PNG_TRANSFORM_INVERT_MONO)+
−
      png_set_invert_mono(png_ptr);+
−
#endif+
−
+
−
#ifdef PNG_READ_SHIFT_SUPPORTED+
−
   /* If you want to shift the pixel values from the range [0,255] or+
−
    * [0,65535] to the original [0,7] or [0,31], or whatever range the+
−
    * colors were originally in:+
−
    */+
−
   if ((transforms & PNG_TRANSFORM_SHIFT)+
−
       && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))+
−
   {+
−
      png_color_8p sig_bit;+
−
+
−
      png_get_sBIT(png_ptr, info_ptr, &sig_bit);+
−
      png_set_shift(png_ptr, sig_bit);+
−
   }+
−
#endif+
−
+
−
#ifdef PNG_READ_BGR_SUPPORTED+
−
   /* Flip the RGB pixels to BGR (or RGBA to BGRA)+
−
    */+
−
   if (transforms & PNG_TRANSFORM_BGR)+
−
      png_set_bgr(png_ptr);+
−
#endif+
−
+
−
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED+
−
   /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)+
−
    */+
−
   if (transforms & PNG_TRANSFORM_SWAP_ALPHA)+
−
       png_set_swap_alpha(png_ptr);+
−
#endif+
−
+
−
#ifdef PNG_READ_SWAP_SUPPORTED+
−
   /* Swap bytes of 16 bit files to least significant byte first+
−
    */+
−
   if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)+
−
      png_set_swap(png_ptr);+
−
#endif+
−
+
−
/* Added at libpng-1.2.41 */+
−
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED+
−
   /* Invert the alpha channel from opacity to transparency+
−
    */+
−
   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)+
−
       png_set_invert_alpha(png_ptr);+
−
#endif+
−
+
−
/* Added at libpng-1.2.41 */+
−
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED+
−
   /* Expand grayscale image to RGB+
−
    */+
−
   if (transforms & PNG_TRANSFORM_GRAY_TO_RGB)+
−
       png_set_gray_to_rgb(png_ptr);+
−
#endif+
−
+
−
   /* We don't handle adding filler bytes */+
−
+
−
   /* Optional call to gamma correct and add the background to the palette+
−
    * and update info structure.  REQUIRED if you are expecting libpng to+
−
    * update the palette for you (i.e., you selected such a transform above).+
−
    */+
−
   png_read_update_info(png_ptr, info_ptr);+
−
+
−
   /* -------------- image transformations end here ------------------- */+
−
+
−
   png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);+
−
   if (info_ptr->row_pointers == NULL)+
−
   {+
−
    png_uint_32 iptr;+
−
+
−
      info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,+
−
         info_ptr->height * png_sizeof(png_bytep));+
−
      for (iptr=0; iptr<info_ptr->height; iptr++)+
−
         info_ptr->row_pointers[iptr] = NULL;+
−
+
−
      info_ptr->free_me |= PNG_FREE_ROWS;+
−
+
−
      for (row = 0; row < (int)info_ptr->height; row++)+
−
         info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,+
−
            png_get_rowbytes(png_ptr, info_ptr));+
−
   }+
−
+
−
   png_read_image(png_ptr, info_ptr->row_pointers);+
−
   info_ptr->valid |= PNG_INFO_IDAT;+
−
+
−
   /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */+
−
   png_read_end(png_ptr, info_ptr);+
−
+
−
   transforms = transforms; /* Quiet compiler warnings */+
−
   params = params;+
−
+
−
}+
−
#endif /* PNG_INFO_IMAGE_SUPPORTED */+
−
#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */+
−
#endif /* PNG_READ_SUPPORTED */+
−