diff options
author | Roland Scheidegger <[email protected]> | 2014-12-08 19:07:10 +0100 |
---|---|---|
committer | Roland Scheidegger <[email protected]> | 2014-12-10 22:11:16 +0100 |
commit | fe7e6b248f4f97e10adb26db2836ff5accbff94a (patch) | |
tree | 00c59016cdc7005145ddbb99ebc10e6276168e58 | |
parent | ac319d94d38cf3145990002c8216426fe297cd28 (diff) |
gallium/docs: clarify fragment shader position input w component.
The previous language was a bit misleading, since it sounded like
w was interpolated then the reciprocal calculated which isn't what
should be happening.
Reviewed-by: Jose Fonseca <[email protected]>
-rw-r--r-- | src/gallium/docs/source/tgsi.rst | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst index 6f850bf29fb..cbb8f74ab89 100644 --- a/src/gallium/docs/source/tgsi.rst +++ b/src/gallium/docs/source/tgsi.rst @@ -2512,8 +2512,10 @@ The Y component starts at zero and always increases but Y=0 may either indicate the top of the window or the bottom depending on the fragment coordinate origin convention (see TGSI_PROPERTY_FS_COORD_ORIGIN). The Z coordinate ranges from 0 to 1 to represent depth from the front -to the back of the Z buffer. The W component contains the reciprocol -of the interpolated vertex position W component. +to the back of the Z buffer. The W component contains the interpolated +reciprocal of the vertex position W component (corresponding to gl_Fragcoord, +but unlike d3d10 which interpolates the same 1/w but then gives back +the reciprocal of the interpolated value). Fragment shaders may also declare an output register with TGSI_SEMANTIC_POSITION. Only the Z component is writable. This allows |