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| -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 """""""""""""""""""""""""" |