diff options
Diffstat (limited to 'src/gallium')
| -rw-r--r-- | src/gallium/docs/source/cso/rasterizer.rst | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/src/gallium/docs/source/cso/rasterizer.rst b/src/gallium/docs/source/cso/rasterizer.rst index ee3419ccfca..d547055096f 100644 --- a/src/gallium/docs/source/cso/rasterizer.rst +++ b/src/gallium/docs/source/cso/rasterizer.rst @@ -124,17 +124,24 @@ Points sprite_coord_enable ^^^^^^^^^^^^^^^^^^^ -Specifies if a texture unit has its texture coordinates replaced or not. This -is a packed bitfield containing the enable for all texcoords -- if all bits -are zero, point sprites are effectively disabled. +Controls automatic texture coordinate generation for rendering sprite points. + +When bit k in the sprite_coord_enable bitfield is set, then generic +input k to the fragment shader will get an automatically computed +texture coordinate. + +The texture coordinate will be of the form (s, t, 0, 1) where s varies +from 0 to 1 from left to right while t varies from 0 to 1 according to +the state of 'sprite_coord_mode' (see below). If any bit is set, then point_smooth MUST be disabled (there are no round sprites) and point_quad_rasterization MUST be true (sprites are always rasterized as quads). Any mismatch between these states should be considered a bug in the state-tracker. -If enabled, the four vertices of the resulting quad will be assigned -texture coordinates, according to sprite_coord_mode. +This feature is implemented in the :ref:`Draw` module but may also be +implemented natively by GPUs or implemented with a geometry shader. + sprite_coord_mode ^^^^^^^^^^^^^^^^^ @@ -145,6 +152,7 @@ have coordinates (0,0,0,1). For PIPE_SPRITE_COORD_UPPER_LEFT, the upper-left vertex will have coordinates (0,0,0,1). This state is used by :ref:`Draw` to generate texcoords. + point_quad_rasterization ^^^^^^^^^^^^^^^^^^^^^^^^ |