This accelerates spans operations using GPU-based geometry computation
-wellipse500 goes from about 4k/sec before the patch, to ~8k/sec in
the GLES2 fallback loop, to ~100k/sec in desktop mode.
v2: Rebase on skipping the prepare rewrite for now, and fix the GLSL
1.20 and GLES2 cases (changes by anholt).
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
