Fixed bug 1346

alarantalara@gmail.com 2011-12-19 20:43:13 PST On little endian systems using the Quartz code, an unusual set of RBGA masks is used when using the windowed video mode. This set is not taken into account in SDL_DisplayFormatAlpha and so it converts the supplied surface to a format that does not match the video surface, preventing fast blitting. This was observed in recent builds of Battle for Wesnoth when SDL was updated to cover the problem when switching to full screen in Lion (https://gna.org/bugs/?18319). You can observe the performance issue if you download Wesnoth 1.9.13 for OS X at http://sourceforge.net/projects/wesnoth/files/wesnoth/wesnoth-1.9.13/Wesnoth_1.9.13.dmg/download and replace the included SDL library with any build of SDL 1.2.14 or later. (I have already patched the included version, so the problem is not observable without replacement.) A patch resolving the issue is attached.
libsdl-org · Dec 29, 2011 · 52cad26 · 52cad26
1 parent d1eccbd
commit 52cad26
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/src/video/SDL_video.c b/src/video/SDL_video.c
@@ -979,6 +979,11 @@ SDL_Surface *SDL_DisplayFormatAlpha(SDL_Surface *surface)
 		if ( (vf->Rmask == 0xff) && (vf->Bmask == 0xff0000) ) {
 			rmask = 0xff;
 			bmask = 0xff0000;
+		} else if ( vf->Rmask == 0xFF00 && (vf->Bmask = 0xFF000000) ) {
+			amask = 0x000000FF;
+			rmask = 0x0000FF00;
+			gmask = 0x00FF0000;
+			bmask = 0xFF000000;
 		}
 		break;