diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/gen6_cc.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/src/mesa/drivers/dri/i965/gen6_cc.c b/src/mesa/drivers/dri/i965/gen6_cc.c index 66357f00fa6..2b16d6cdc01 100644 --- a/src/mesa/drivers/dri/i965/gen6_cc.c +++ b/src/mesa/drivers/dri/i965/gen6_cc.c @@ -39,8 +39,18 @@ prepare_blend_state(struct brw_context *brw) struct gen6_blend_state *blend; int b; int nr_draw_buffers = ctx->DrawBuffer->_NumColorDrawBuffers; - int size = sizeof(*blend) * nr_draw_buffers; - + int size; + + /* We need at least one BLEND_STATE written, because we might do + * thread dispatch even if _NumColorDrawBuffers is 0 (for example + * for computed depth or alpha test), which will do an FB write + * with render target 0, which will reference BLEND_STATE[0] for + * alpha test enable. + */ + if (nr_draw_buffers == 0 && ctx->Color.AlphaEnabled) + nr_draw_buffers = 1; + + size = sizeof(*blend) * nr_draw_buffers; blend = brw_state_batch(brw, size, 64, &brw->cc.blend_state_offset); memset(blend, 0, size); |