i965: Support MESA_FORMAT_SIGNED_RGBA_16.

The hardware supports this format with no known quirks, so we may as
well enable it.

Alpha blending is not supported until Sandybridge, but as far as I can
tell, OpenGL doesn't require alpha blending on SNORM formats.  Plus, we
already expose R8G8B8A8_SNORM which has a similar restriction.

Fixes 6 piglit texwrap-2D-*SNORM* cases,
gl-3.1/required-sized-texture-formats, and 10 oglconform snorm-textures
subcases

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
index 65ca2fc..8bb0410 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
@@ -430,7 +430,7 @@ brw_format_for_mesa_format(gl_format mesa_format)
       [MESA_FORMAT_SIGNED_R16] = BRW_SURFACEFORMAT_R16_SNORM,
       [MESA_FORMAT_SIGNED_GR1616] = BRW_SURFACEFORMAT_R16G16_SNORM,
       [MESA_FORMAT_SIGNED_RGB_16] = 0,
-      [MESA_FORMAT_SIGNED_RGBA_16] = 0,
+      [MESA_FORMAT_SIGNED_RGBA_16] = BRW_SURFACEFORMAT_R16G16B16A16_SNORM,
       [MESA_FORMAT_RGBA_16] = BRW_SURFACEFORMAT_R16G16B16A16_UNORM,
 
       [MESA_FORMAT_RED_RGTC1] = BRW_SURFACEFORMAT_BC4_UNORM,