From: Pavel Charvat <pavel.charvat@netcentrum.cz>
Date: Mon, 31 Jul 2006 12:22:44 +0000 (+0200)
Subject: added support for PNG with transparent colors in the palette
X-Git-Tag: holmes-import~620
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=bed0e58916a622b1b66f5dedcda121e7e848355b;p=libucw.git

added support for PNG with transparent colors in the palette
---

diff --git a/images/alpha.c b/images/alpha.c
index 5c75e69f..9f6dfd14 100644
--- a/images/alpha.c
+++ b/images/alpha.c
@@ -7,7 +7,7 @@
  *	of the GNU Lesser General Public License.
  */
 
-#define LOCAL_DEBUG
+#undef LOCAL_DEBUG
 
 #include "lib/lib.h"
 #include "images/images.h"
diff --git a/images/io-libpng.c b/images/io-libpng.c
index fe60fef6..a1705a37 100644
--- a/images/io-libpng.c
+++ b/images/io-libpng.c
@@ -217,7 +217,6 @@ libpng_read_data(struct image_io *io)
   switch (rd->color_type)
     {
       case PNG_COLOR_TYPE_PALETTE:
-	/* FIXME: add support for palette with colors */
 	if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
 	  {
 	    png_set_palette_to_rgb(rd->png_ptr);
@@ -225,10 +224,20 @@ libpng_read_data(struct image_io *io)
 	  }
 	else
 	  png_set_palette_to_rgb(rd->png_ptr);
-	if ((io->flags & IMAGE_ALPHA) || (io->flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
-          png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
+	if (!(io->flags & IMAGE_ALPHA))
+	  {
+	    if (io->flags & IMAGE_IO_USE_BACKGROUND)
+	      {
+                png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
+	        read_flags |= IMAGE_ALPHA;
+	      }
+	    else if ((io->flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
+              png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
+            else
+	      png_set_strip_alpha(rd->png_ptr);
+	  }
 	else
-	  png_set_strip_alpha(rd->png_ptr);
+          png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
 	break;
       case PNG_COLOR_TYPE_GRAY:
 	if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_RGB)