Hello gents, On 2 July 2015 at 08:45, Kenneth Graunke <kenn...@whitecape.org> wrote: > On Wednesday, July 01, 2015 10:16:28 AM Mike Stroyan wrote: >> When there are no color buffer render targets, gen6 and gen7 still >> use the first BLEND_STATE element to determine alpha test. >> gen6_upload_blend_state was allocating zero elements when >> ctx->Color.AlphaEnabled was false. >> That left _3DSTATE_CC_STATE_POINTERS or _3DSTATE_BLEND_STATE_POINTERS >> pointing to random data from some previous brw_state_batch(). >> That sometimes suppressed depth rendering when those bits >> happened to mean COMPAREFUNC_NEVER. >> This produced flickering shadows for dota2 reborn. >> --- >> src/mesa/drivers/dri/i965/gen6_cc.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/src/mesa/drivers/dri/i965/gen6_cc.c >> b/src/mesa/drivers/dri/i965/gen6_cc.c >> index 2bfa271..2b76e24 100644 >> --- a/src/mesa/drivers/dri/i965/gen6_cc.c >> +++ b/src/mesa/drivers/dri/i965/gen6_cc.c >> @@ -51,7 +51,7 @@ gen6_upload_blend_state(struct brw_context *brw) >> * with render target 0, which will reference BLEND_STATE[0] for >> * alpha test enable. >> */ >> - if (nr_draw_buffers == 0 && ctx->Color.AlphaEnabled) >> + if (nr_draw_buffers == 0) >> nr_draw_buffers = 1; >> >> size = sizeof(*blend) * nr_draw_buffers; >> > > Great catch! > > Reviewed-by: Kenneth Graunke <kenn...@whitecape.org> > > And pushed: > 9d408a4..fe2b748 master -> master > > I think we ought to change gen8_blend_state.c as well, but I'm not quite > sure what change to make. Either we should make the same change you did > here, or delete the whole "We need at least 1 BLEND_STATE written" > block. > > On Gen8+, it looks like the alpha test and other functions that might > discard pixels are all in the shared/common DWord, and the per-color > target DWord pairs look relatively harmless. I suppose the null RT > would still refer to BLEND_STATE[0]...so it might still be worth > emitting one. Any thoughts? Should we get this into 10.6 or there are some not so obvious dependencies that we're missing in the 10.6 branch ? Asking every user to rebuild mesa just to play Dota2 seems unreasonable imho.
Cheers, Emil _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
