---------------------------------------------------------------------------
- Copyright (c) 1998-2007 Greg Roelofs. All rights reserved.
+ Copyright (c) 1998-2015 Greg Roelofs. All rights reserved.
This software is provided "as is," without warranty of any kind,
express or implied. In no event shall the author or contributors
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ ---------------------------------------------------------------------------
+
+ Changelog:
+ %RDATE% - Check return value of png_get_bKGD() (Glenn R-P)
+
---------------------------------------------------------------------------*/
/* could also replace libpng warning-handler (final NULL), but no need: */
- png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+ png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), mainprog_ptr,
readpng2_error_handler, readpng2_warning_handler);
if (!png_ptr)
return 4; /* out of memory */
/* since we know we've read all of the PNG file's "header" (i.e., up
* to IDAT), we can check for a background color here */
- if (mainprog_ptr->need_bgcolor &&
- png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+ if (mainprog_ptr->need_bgcolor)
{
png_color_16p pBackground;
/* it is not obvious from the libpng documentation, but this function
* takes a pointer to a pointer, and it always returns valid red,
* green and blue values, regardless of color_type: */
- png_get_bKGD(png_ptr, info_ptr, &pBackground);
-
- /* however, it always returns the raw bKGD data, regardless of any
- * bit-depth transformations, so check depth and adjust if necessary */
- if (bit_depth == 16) {
- mainprog_ptr->bg_red = pBackground->red >> 8;
- mainprog_ptr->bg_green = pBackground->green >> 8;
- mainprog_ptr->bg_blue = pBackground->blue >> 8;
- } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
- if (bit_depth == 1)
- mainprog_ptr->bg_red = mainprog_ptr->bg_green =
- mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
- else if (bit_depth == 2)
- mainprog_ptr->bg_red = mainprog_ptr->bg_green =
- mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
- else /* bit_depth == 4 */
- mainprog_ptr->bg_red = mainprog_ptr->bg_green =
- mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
- } else {
- mainprog_ptr->bg_red = (uch)pBackground->red;
- mainprog_ptr->bg_green = (uch)pBackground->green;
- mainprog_ptr->bg_blue = (uch)pBackground->blue;
+ if (png_get_bKGD(png_ptr, info_ptr, &pBackground))
+ {
+
+ /* however, it always returns the raw bKGD data, regardless of any
+ * bit-depth transformations, so check depth and adjust if necessary
+ */
+ if (bit_depth == 16) {
+ mainprog_ptr->bg_red = pBackground->red >> 8;
+ mainprog_ptr->bg_green = pBackground->green >> 8;
+ mainprog_ptr->bg_blue = pBackground->blue >> 8;
+ } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+ if (bit_depth == 1)
+ mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+ mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
+ else if (bit_depth == 2)
+ mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+ mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
+ else /* bit_depth == 4 */
+ mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+ mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
+ } else {
+ mainprog_ptr->bg_red = (uch)pBackground->red;
+ mainprog_ptr->bg_green = (uch)pBackground->green;
+ mainprog_ptr->bg_blue = (uch)pBackground->blue;
+ }
}
}