[GRASS-SVN] r40501 - grass/trunk/lib/cairodriver

[svn_grass at osgeo.org]

Author: glynn
Date: 2010-01-17 08:34:10 -0500 (Sun, 17 Jan 2010)
New Revision: 40501

Modified:
   grass/trunk/lib/cairodriver/Raster.c
Log:
Fix drawing transparent cells over opaque cells
  (cairo uses pre-multiplied alpha)


Modified: grass/trunk/lib/cairodriver/Raster.c
===================================================================
--- grass/trunk/lib/cairodriver/Raster.c	2010-01-17 13:33:19 UTC (rev 40500)
+++ grass/trunk/lib/cairodriver/Raster.c	2010-01-17 13:34:10 UTC (rev 40501)
@@ -91,13 +91,16 @@
     G_debug(3, "Cairo_raster: %d %d", n, row);
 
     for (i = 0; i < n; i++) {
-	unsigned int r = red[i];
-	unsigned int g = grn[i];
-	unsigned int b = blu[i];
-	unsigned int a = (masked && nul && nul[i])
-	    ? 0x00 : 0xFF;
+	if (masked && nul && nul[i])
+	    *dst++ = 0;
+	else {
+	    unsigned int r = red[i];
+	    unsigned int g = grn[i];
+	    unsigned int b = blu[i];
+	    unsigned int a = 0xFF;
 
-	*dst++ = (a << 24) + (r << 16) + (g << 8) + (b << 0);
+	    *dst++ = (a << 24) + (r << 16) + (g << 8) + (b << 0);
+	}
     }
 
     return row + 1;