From e23cfbb2f0b9e52154401cb96118085811b62f09 Mon Sep 17 00:00:00 2001
From: Owen Taylor <otaylor@fresnel.(none)>
Date: Thu, 29 Apr 2010 19:47:56 -0400
Subject: [PATCH 1/3] Use a native format for atlas textures

Since we create frame buffer objects for atlas textures, we should use
a format that can be used as a rendering target. For this reason, use
an internal format of ARGB instead of RGBA when creating the texture.

(We don't actually render to it, but the Radeon Mesa drivers aren't
sophisticated enough to deal with a FBO that can be read from but
can't be rendered to. On other hardware, this is probably pretty much
neutral for efficiency.)

http://bugzilla.openedhand.com/show_bug.cgi?id=2100
---
 clutter/cogl/cogl/cogl-atlas-texture.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/clutter/cogl/cogl/cogl-atlas-texture.c b/clutter/cogl/cogl/cogl-atlas-texture.c
index b9219e4..3fafb58 100644
--- a/clutter/cogl/cogl/cogl-atlas-texture.c
+++ b/clutter/cogl/cogl/cogl-atlas-texture.c
@@ -70,6 +70,15 @@
 #define GL_FRAMEBUFFER_COMPLETE 0x8CD5
 #endif
 
+/* Best guess at native frame buffer formats; using these makes the
+ * Mesa framebuffer support happier on Radeon cards that can't
+ * render to arbitrarily ordered pixels */
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+#define NATIVE_PIXEL_FORMAT COGL_PIXEL_FORMAT_BGRA_8888_PRE
+#else
+#define NATIVE_PIXEL_FORMAT COGL_PIXEL_FORMAT_ARGB_8888_PRE
+#endif
+
 static void _cogl_atlas_texture_free (CoglAtlasTexture *sub_tex);
 
 COGL_HANDLE_DEFINE (AtlasTexture, atlas_texture);
@@ -868,7 +877,7 @@ _cogl_atlas_texture_reserve_space (CoglAtlasTexture    *new_sub_tex,
             _cogl_texture_2d_new_with_size (_cogl_atlas_get_width (new_atlas),
                                             _cogl_atlas_get_height (new_atlas),
                                             COGL_TEXTURE_NONE,
-                                            COGL_PIXEL_FORMAT_RGBA_8888)) ==
+                                            NATIVE_PIXEL_FORMAT)) ==
            COGL_INVALID_HANDLE)
     {
       COGL_NOTE (ATLAS, "Could not create a CoglTexture2D");
-- 
1.7.0.1