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authorBrian Paul <[email protected]>2010-06-23 17:38:58 -0600
committerBrian Paul <[email protected]>2010-06-23 17:38:58 -0600
commit7315300fa5a5e63c16b9e258feb4df76176b5b4b (patch)
tree462a1dd2deaff69a753937d79642e9388ea2135e /src/gallium/docs/source/tgsi.rst
parenta544a8a82a74885e0c4bfb3a2c90d1bec07bd01e (diff)
gallium/docs: document TGSI_SEMANTIC_EDGEFLAG
Diffstat (limited to 'src/gallium/docs/source/tgsi.rst')
-rw-r--r--src/gallium/docs/source/tgsi.rst10
1 files changed, 9 insertions, 1 deletions
diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst
index f5678c744b5..205e7b8539d 100644
--- a/src/gallium/docs/source/tgsi.rst
+++ b/src/gallium/docs/source/tgsi.rst
@@ -1397,7 +1397,15 @@ back-facing.
TGSI_SEMANTIC_EDGEFLAG
""""""""""""""""""""""
-XXX no clue
+For vertex shaders, this sematic label indicates that an input or
+output is a boolean edge flag. The register layout is [F, x, x, x]
+where F is 0.0 or 1.0 and x = don't care. Normally, the vertex shader
+simply copies the edge flag input to the edgeflag output.
+
+Edge flags are used to control which lines or points are actually
+drawn when the polygon mode converts triangles/quads/polygons into
+points or lines.
+
Properties