fix two bugs with rendering pixel data to SDL: flip R and B to match native behavior, and ignore alpha when rendering to the screen as also done in native behavior

1 files changed, 4 insertions, 3 deletions

diff --git a/src/library_sdl.js b/src/library_sdl.js
index 548f3b0d..b72e239b 100644
--- a/src/library_sdl.js
+++ b/src/library_sdl.js
@@ -460,13 +460,14 @@ mergeInto(LibraryManager.library, {
       assert(buffer % 4 == 0, 'Invalid buffer offset: ' + buffer);
       var src = buffer >> 2;
       var dst = 0;
+      var isScreen = surf == SDL.screen;
       while (dst < num) {
         // TODO: access underlying data buffer and write in 32-bit chunks or more
         var val = HEAP32[src]; // This is optimized. Instead, we could do {{{ makeGetValue('buffer', 'dst', 'i32') }}};
-        data[dst]   = val & 0xff;
+        data[dst+2] = val & 0xff;
         data[dst+1] = (val >> 8) & 0xff;
-        data[dst+2] = (val >> 16) & 0xff;
-        data[dst+3] = (val >> 24) & 0xff;
+        data[dst  ] = (val >> 16) & 0xff;
+        data[dst+3] = isScreen ? 0xff : ((val >> 24) & 0xff);
         src++;
         dst += 4;
       }