From: Brian Paul Date: Mon, 12 Jun 2017 17:33:30 +0000 (-0600) Subject: gallium/docs: clarify TGSI_SEMANTIC_SAMPLEMASK, again X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=def8d1d23f5b6cf289e9247a41cc902113831a67;p=mesa.git 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 --- 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 """"""""""""""""""""""""""