OpenGL specification 3.3 (page 196), section 4.1.3 says:
If drawbuffer zero is not NONE and the buffer it references has an
integer format, the SAMPLE_ALPHA_TO_COVERAGE and SAMPLE_ALPHA_TO_ONE
operations are skipped."
This should work properly even if there are other draw buffers that
are not in integer format.
This patch makes following piglit tests pass on mesa:
int-draw-buffers-alpha-to-coverage
int-draw-buffers-alpha-to-one
Note: Patches for these piglit tests are under review on piglit mailing
list.
Signed-off-by: Anuj Phogat <anuj.pho...@gmail.com>
---
src/mesa/drivers/dri/i965/gen6_cc.c | 29 ++++++++++++++++++++++-------
1 files changed, 22 insertions(+), 7 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/gen6_cc.c
b/src/mesa/drivers/dri/i965/gen6_cc.c
index e0523ef..427cca9 100644
--- a/src/mesa/drivers/dri/i965/gen6_cc.c
+++ b/src/mesa/drivers/dri/i965/gen6_cc.c
@@ -35,6 +35,7 @@
static void
gen6_upload_blend_state(struct brw_context *brw)
{
+ bool is_buffer_zero_integer_format = false;
struct gl_context *ctx = &brw->intel.ctx;
struct gen6_blend_state *blend;
int b;
@@ -76,6 +77,9 @@ gen6_upload_blend_state(struct brw_context *brw)
*/
integer = (rb_type == GL_INT || rb_type == GL_UNSIGNED_INT);
+ if(b == 0 && integer)
+ is_buffer_zero_integer_format = true;
+
/* _NEW_COLOR */
if (ctx->Color.ColorLogicOpEnabled) {
/* Floating point RTs should have no effect from LogicOp,
@@ -161,13 +165,24 @@ gen6_upload_blend_state(struct brw_context *brw)
blend[b].blend1.write_disable_g = !ctx->Color.ColorMask[b][1];
blend[b].blend1.write_disable_b = !ctx->Color.ColorMask[b][2];
blend[b].blend1.write_disable_a = !ctx->Color.ColorMask[b][3];
-
- /* _NEW_MULTISAMPLE */
- blend[b].blend1.alpha_to_coverage =
- ctx->Multisample._Enabled && ctx->Multisample.SampleAlphaToCoverage;
- blend[b].blend1.alpha_to_one =
- ctx->Multisample._Enabled && ctx->Multisample.SampleAlphaToOne;
- blend[b].blend1.alpha_to_coverage_dither = (brw->intel.gen >= 7);
+
+ /* OpenGL specification 3.3 (page 196), section 4.1.3 says:
+ * "If drawbuffer zero is not NONE and the buffer it references has an
+ * integer format, the SAMPLE_ALPHA_TO_COVERAGE and SAMPLE_ALPHA_TO_ONE
+ * operations are skipped."
+ */
+ if(!is_buffer_zero_integer_format) {
+ /* _NEW_MULTISAMPLE */
+ blend[b].blend1.alpha_to_coverage =
+ ctx->Multisample._Enabled &&
ctx->Multisample.SampleAlphaToCoverage;
+ blend[b].blend1.alpha_to_one =
+ ctx->Multisample._Enabled && ctx->Multisample.SampleAlphaToOne;
+ blend[b].blend1.alpha_to_coverage_dither = (brw->intel.gen >= 7);
+ }
+ else {
+ blend[b].blend1.alpha_to_coverage = false;
+ blend[b].blend1.alpha_to_one = false;
+ }
}
brw->state.dirty.cache |= CACHE_NEW_BLEND_STATE;
--
1.7.7.6
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