Fix SDL_MapRGB and implement SDL_MapRGBA.

Also provide a test case.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/library_sdl.js b/src/library_sdl.js
index 88649c38..73848502 100644
--- a/src/library_sdl.js
+++ b/src/library_sdl.js
@@ -952,7 +952,12 @@ var LibrarySDL = {
 
   SDL_MapRGB: function(fmt, r, g, b) {
     // Canvas screens are always RGBA
-    return r + (g << 8) + (b << 16);
+    return 0xff+((b&0xff)<<8)+((g&0xff)<<16)+((r&0xff)<<24)
+  },
+
+  SDL_MapRGBA: function(fmt, r, g, b, a) {
+    // Canvas screens are always RGBA
+    return (a&0xff)+((b&0xff)<<8)+((g&0xff)<<16)+((r&0xff)<<24)
   },
 
   SDL_WM_GrabInput: function() {},