pngwrite.c

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

#endif
   {
      png_free(png_ptr, png_ptr->zbuf);
      png_destroy_struct(png_ptr);
      return ((png_structp)NULL);
   }
#ifdef USE_FAR_KEYWORD
   png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
#endif
#endif

#ifdef PNG_USER_MEM_SUPPORTED
   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
#endif /* PNG_USER_MEM_SUPPORTED */
   png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);

   i=0;
   do
   {
     if(user_png_ver[i] != png_libpng_ver[i])
        png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
   } while (png_libpng_ver[i++]);

   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] == '0' && user_png_ver[2] < '9'))
     {
        png_error(png_ptr,
           "Incompatible libpng version in application and library");
     }

     /* Libpng 1.0.6 was not binary compatible, due to insertion of the
        info_ptr->free_me member.  Note to maintainer: this test can be
        removed from version 2.0.0 and beyond because the previous test
        would have already rejected it. */

     if (user_png_ver[4] == '6' && user_png_ver[2] == '0' && 
         user_png_ver[0] == '1' && user_png_ver[5] == '\0')
     {
        png_error(png_ptr,
           "Application must be recompiled; version 1.0.6 was incompatible");
     }
   }

   /* initialize zbuf - compression buffer */
   png_ptr->zbuf_size = PNG_ZBUF_SIZE;
   png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
      (png_uint_32)png_ptr->zbuf_size);

   png_set_write_fn(png_ptr, NULL, NULL, NULL);

#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
   png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
      1, NULL, NULL);
#endif

   return ((png_structp)png_ptr);
}

/* Initialize png_ptr structure, and allocate any memory needed */
#undef png_write_init
void PNGAPI
png_write_init(png_structp png_ptr)
{
   /* We only come here via pre-1.0.7-compiled applications */
   png_write_init_2(png_ptr, "1.0.0", 10000, 10000);
}

void PNGAPI
png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
   png_size_t png_struct_size, png_size_t png_info_size)
{
#ifdef PNG_SETJMP_SUPPORTED
   jmp_buf tmp_jmp; /* to save current jump buffer */
#endif
   int i = 0;
   do
   {
     if (user_png_ver[i] != png_libpng_ver[i])
     {
#ifdef PNG_LEGACY_SUPPORTED
       png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
#else
       png_ptr->error_fn=(png_error_ptr)NULL;
       png_error(png_ptr,
       "Application uses deprecated png_write_init() and must be recompiled.");
#endif
     }
   } while (png_libpng_ver[i++]);

   if (sizeof(png_struct) > png_struct_size ||
      sizeof(png_info) > png_info_size)
     {
       png_ptr->error_fn=(png_error_ptr)NULL;
       png_error(png_ptr,
      "Application and library have different sized structs. Please recompile.");
     }

   png_debug(1, "in png_write_init_2\n");

#ifdef PNG_SETJMP_SUPPORTED
   /* save jump buffer and error functions */
   png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
#endif

   /* reset all variables to 0 */
   png_memset(png_ptr, 0, sizeof (png_struct));

#ifdef PNG_SETJMP_SUPPORTED
   /* restore jump buffer */
   png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
#endif

   /* initialize zbuf - compression buffer */
   png_ptr->zbuf_size = PNG_ZBUF_SIZE;
   png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
      (png_uint_32)png_ptr->zbuf_size);
   png_set_write_fn(png_ptr, NULL, NULL, NULL);

#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
   png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
      1, NULL, NULL);
#endif
}

/* Write a few rows of image data.  If the image is interlaced,
 * either you will have to write the 7 sub images, or, if you
 * have called png_set_interlace_handling(), you will have to
 * "write" the image seven times.
 */
void PNGAPI
png_write_rows(png_structp png_ptr, png_bytepp row,
   png_uint_32 num_rows)
{
   png_uint_32 i; /* row counter */
   png_bytepp rp; /* row pointer */

   png_debug(1, "in png_write_rows\n");
   /* loop through the rows */
   for (i = 0, rp = row; i < num_rows; i++, rp++)
   {
      png_write_row(png_ptr, *rp);
   }
}

/* Write the image.  You only need to call this function once, even
 * if you are writing an interlaced image.
 */
void PNGAPI
png_write_image(png_structp png_ptr, png_bytepp image)
{
   png_uint_32 i; /* row index */
   int pass, num_pass; /* pass variables */
   png_bytepp rp; /* points to current row */

   png_debug(1, "in png_write_image\n");
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
   /* intialize interlace handling.  If image is not interlaced,
      this will set pass to 1 */
   num_pass = png_set_interlace_handling(png_ptr);
#else
   num_pass = 1;
#endif
   /* loop through passes */
   for (pass = 0; pass < num_pass; pass++)
   {
      /* loop through image */
      for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
      {
         png_write_row(png_ptr, *rp);
      }
   }
}

/* called by user to write a row of image data */
void PNGAPI
png_write_row(png_structp png_ptr, png_bytep row)
{
   png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
      png_ptr->row_number, png_ptr->pass);
   /* initialize transformations and other stuff if first time */
   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_WRITE_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_WRITE_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_WRITE_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_WRITE_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_WRITE_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_WRITE_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_WRITE_SWAP_SUPPORTED is not defined.");
#endif

      png_write_start_row(png_ptr);
   }

#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
   /* if interlaced and not interested in row, return */
   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
   {
      switch (png_ptr->pass)
      {
         case 0:
            if (png_ptr->row_number & 0x07)
            {
               png_write_finish_row(png_ptr);
               return;
            }
            break;
         case 1:
            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
            {
               png_write_finish_row(png_ptr);
               return;
            }
            break;
         case 2:
            if ((png_ptr->row_number & 0x07) != 4)
            {
               png_write_finish_row(png_ptr);
               return;
            }
            break;
         case 3:
            if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
            {
               png_write_finish_row(png_ptr);
               return;
            }
            break;
         case 4:
            if ((png_ptr->row_number & 0x03) != 2)
            {
               png_write_finish_row(png_ptr);
               return;
            }
            break;
         case 5:
            if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
            {
               png_write_finish_row(png_ptr);
               return;
            }
            break;
         case 6:
            if (!(png_ptr->row_number & 0x01))
            {
               png_write_finish_row(png_ptr);
               return;
            }
            break;
      }
   }
#endif

   /* set up row info for transformations */
   png_ptr->row_info.color_type = png_ptr->color_type;
   png_ptr->row_info.width = png_ptr->usr_width;
   png_ptr->row_info.channels = png_ptr->usr_channels;
   png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
   png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
      png_ptr->row_info.channels);

   png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
      (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);

   png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);
   png_debug1(3, "row_info->width = %d\n", png_ptr->row_info.width);
   png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);
   png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);
   png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);
   png_debug1(3, "row_info->rowbytes = %d\n", png_ptr->row_info.rowbytes);

   /* Copy user's row into buffer, leaving room for filter byte. */
   png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
      png_ptr->row_info.rowbytes);

#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
   /* handle interlacing */
   if (png_ptr->interlaced && png_ptr->pass < 6 &&
      (png_ptr->transformations & PNG_INTERLACE))
   {
      png_do_write_interlace(&(png_ptr->row_info),
         png_ptr->row_buf + 1, png_ptr->pass);
      /* this should always get caught above, but still ... */
      if (!(png_ptr->row_info.width))
      {
         png_write_finish_row(png_ptr);
         return;
      }
   }
#endif

   /* handle other transformations */
   if (png_ptr->transformations)
      png_do_write_transformations(png_ptr);

   /* Find a filter if necessary, filter the row and write it out. */
   png_write_find_filter(png_ptr, &(png_ptr->row_info));

   if (png_ptr->write_row_fn != NULL)
      (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
}

#if defined(PNG_WRITE_FLUSH_SUPPORTED)
/* Set the automatic flush interval or 0 to turn flushing off */
void PNGAPI
png_set_flush(png_structp png_ptr, int nrows)
{
   png_debug(1, "in png_set_flush\n");
   png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
}

/* flush the current output buffers now */
void PNGAPI
png_write_flush(png_structp png_ptr)
{
   int wrote_IDAT;

   png_debug(1, "in png_write_flush\n");
   /* We have already written out all of the data */
   if (png_ptr->row_number >= png_ptr->num_rows)
     return;

   do
   {
      int ret;

      /* compress the data */
      ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
      wrote_IDAT = 0;

      /* check for compression errors */
      if (ret != Z_OK)
      {
         if (png_ptr->zstream.msg != NULL)
            png_error(png_ptr, png_ptr->zstream.msg);
         else
            png_error(png_ptr, "zlib error");
      }

      if (!(png_ptr->zstream.avail_out))
      {
         /* write the IDAT and reset the zlib output buffer */
         png_write_IDAT(png_ptr, png_ptr->zbuf,
                        png_ptr->zbuf_size);
         png_ptr->zstream.next_out = png_ptr->zbuf;
         png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
         wrote_IDAT = 1;
      }
   } while(wrote_IDAT == 1);

   /* If there is any data left to be output, write it into a new IDAT */
   if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
   {
      /* write the IDAT and reset the zlib output buffer */
      png_write_IDAT(png_ptr, png_ptr->zbuf,
                     png_ptr->zbuf_size - png_ptr->zstream.avail_out);
      png_ptr->zstream.next_out = png_ptr->zbuf;
      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
   }
   png_ptr->flush_rows = 0;
   png_flush(png_ptr);
}
#endif /* PNG_WRITE_FLUSH_SUPPORTED */

/* free all memory used by the write */
void PNGAPI
png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
{
   png_structp png_ptr = NULL;
   png_infop info_ptr = NULL;
#ifdef PNG_USER_MEM_SUPPORTED
   png_free_ptr free_fn = NULL;
#endif

   png_debug(1, "in png_destroy_write_struct\n");
   if (png_ptr_ptr != NULL)
   {
      png_ptr = *png_ptr_ptr;
#ifdef PNG_USER_MEM_SUPPORTED
      free_fn = png_ptr->free_fn;
#endif
   }

   if (info_ptr_ptr != NULL)
      info_ptr = *info_ptr_ptr;

   if (info_ptr != NULL)
   {
      png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);

#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
      if (png_ptr->num_chunk_list)
      {
         png_free(png_ptr, png_ptr->chunk_list);
         png_ptr->num_chunk_list=0;
      }
#endif

#ifdef PNG_USER_MEM_SUPPORTED
      png_destroy_struct_2((png_voidp)info_ptr, free_fn);
#else
      png_destroy_struct((png_voidp)info_ptr);
#endif
      *info_ptr_ptr = (png_infop)NULL;
   }

   if (png_ptr != NULL)
   {
      png_write_destroy(png_ptr);
#ifdef PNG_USER_MEM_SUPPORTED
      png_destroy_struct_2((png_voidp)png_ptr, free_fn);
#else
      png_destroy_struct((png_voidp)png_ptr);
#endif
      *png_ptr_ptr = (png_structp)NULL;