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[libpng17] Imported from libpng-1.7.0beta66.tar

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This commit is contained in:
Glenn Randers-Pehrson
2015-10-02 13:31:29 -05:00
parent 33d4b5b66d
commit 2ddd06c392
17 changed files with 63 additions and 56 deletions
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57
contrib/gregbook/readpng2.c
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@@ -4,7 +4,7 @@
---------------------------------------------------------------------------
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
@@ -51,6 +51,11 @@
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)
---------------------------------------------------------------------------*/
@@ -104,7 +109,7 @@ int readpng2_init(mainprog_info *mainprog_ptr)
/* 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 */
@@ -261,36 +266,38 @@ static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
/* 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);
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;
/* 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;
}
}
}