tree 1841622f00dda8dcd00a75a86eb89ffa252ecd1b
parent f5fe9030021af830e6c4453f4ad1521cbb697c81
author Ilia Mirkin <imirkin@alum.mit.edu> 1460217654 -0400
committer Ilia Mirkin <imirkin@alum.mit.edu> 1463013567 -0400

nvc0: fix gl_SampleMaskIn computation

The SAMPLEMASK semantic should only return the bits set covered by the
current invocation. However we were always retrieving the covmask, which
returns the covered samples of the whole pixel.

When not doing per-sample invocation, this is precisely what we want.
However when doing per-sample invocation, we have to select the
sampleid'th bit and only return that. Furthermore, this means that we
have to have a 1:1 correlation for invocations and samples.

This fixes most

dEQP-GLES31.functional.shaders.sample_variables.sample_mask_in.*

tests. A few failures remain due to disagreements about nr_samples==1
logic as well as what happens with MSAA x2 RTs when the shading fraction
is 0.5.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>