diff options
| author | Brian Paul <[email protected]> | 2017-06-12 11:33:30 -0600 |
|---|---|---|
| committer | Brian Paul <[email protected]> | 2017-06-13 08:02:43 -0600 |
| commit | def8d1d23f5b6cf289e9247a41cc902113831a67 (patch) | |
| tree | 260adaf4b3f2e149003789d523b1b3ded6f1290b /src/gallium/docs | |
| parent | 26500c3fad822ebcd7e2df186d59f96ae550ef64 (diff) | |
gallium/docs: clarify TGSI_SEMANTIC_SAMPLEMASK, again
I've since discovered the fragment shader sample mask system value (which
corresponds to gl_SampleMaskIn).
v2: It's a system value, not a shader input.
Reviewed-by: Nicolai Hähnle <[email protected]>
Diffstat (limited to 'src/gallium/docs')
| -rw-r--r-- | src/gallium/docs/source/tgsi.rst | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst index 7fb963fde5a..c65d721decb 100644 --- a/src/gallium/docs/source/tgsi.rst +++ b/src/gallium/docs/source/tgsi.rst @@ -3297,10 +3297,17 @@ and Y values are used. TGSI_SEMANTIC_SAMPLEMASK """""""""""""""""""""""" -For fragment shaders, this semantic label indicates that an output contains -the sample mask used to disable further sample processing. The output's -type is uint[4] but only the X component is used (i.e. gl_SampleMask[0]). -Each bit corresponds to one sample position (up to 32x MSAA is supported). +For fragment shaders, this semantic label can be applied to either a +shader system value input or output. + +For a system value, the sample mask indicates the set of samples covered by +the current primitive. If MSAA is not enabled, the value is (1, 0, 0, 0). + +For an output, the sample mask is used to disable further sample processing. + +For both, the register type is uint[4] but only the X component is used +(i.e. gl_SampleMask[0]). Each bit corresponds to one sample position (up +to 32x MSAA is supported). TGSI_SEMANTIC_INVOCATIONID """""""""""""""""""""""""" |