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authorCorbin Simpson <MostAwesomeDude@gmail.com>2010-03-22 18:12:16 -0700
committerCorbin Simpson <MostAwesomeDude@gmail.com>2010-03-22 18:42:42 -0700
commitd5b2cecb03e8985aae589f1a8118e60eb693452a (patch)
tree41e093423ebc50e4fddb74ce0851e747a87d9a7f /src/gallium/docs/source/cso
parented61faec7ea307ff22738b4fcc96933f910e4145 (diff)
gallium/docs: Cleanup and clarify point ras info.
...This state's interdependent? Really? Needs moar cleanup.
Diffstat (limited to 'src/gallium/docs/source/cso')
-rw-r--r--src/gallium/docs/source/cso/rasterizer.rst76
1 files changed, 44 insertions, 32 deletions
diff --git a/src/gallium/docs/source/cso/rasterizer.rst b/src/gallium/docs/source/cso/rasterizer.rst
index ccd9136a2e..e8dc82964f 100644
--- a/src/gallium/docs/source/cso/rasterizer.rst
+++ b/src/gallium/docs/source/cso/rasterizer.rst
@@ -7,7 +7,7 @@ The rasterizer state controls the rendering of points, lines and triangles.
Attributes include polygon culling state, line width, line stipple,
multisample state, scissoring and flat/smooth shading.
-Members
+Shading
-------
flatshade
@@ -46,6 +46,49 @@ There are several important exceptions to the specification of this rule.
second vertex, not the first. This permits each segment of the fan to have
a different color.
+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. If any bit is set, then
+point_smooth and point_quad_rasterization are ignored; point smoothing is
+disabled and points are always rasterized as quads. If enabled, the four
+vertices of the resulting quad will be assigned texture coordinates,
+according to sprite_coord_mode.
+
+sprite_coord_mode
+^^^^^^^^^^^^^^^^^
+
+Specifies how the value for each shader output should be computed when drawing
+point sprites. For PIPE_SPRITE_COORD_LOWER_LEFT, the lower-left vertex will
+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.
+
+.. note::
+
+ When geometry shaders are available, a special geometry shader could be
+ used instead of this functionality, to convert incoming points into quads
+ with the proper texture coordinates.
+
+point_quad_rasterization
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Determines if points should be rasterized as quads or points. Certain APIs,
+like Direct3D, always use quad rasterization for points, regardless of
+whether point sprites are enabled or not. If this state is enabled, point
+smoothing and antialiasing are disabled, and sprite coordinates are not
+generated.
+
+.. note::
+
+ Some renderers always internally translate points into quads; this state
+ still affects those renderers by overriding other rasterization state.
+
Other Members
^^^^^^^^^^^^^
@@ -107,37 +150,6 @@ point_size_per_vertex
Whether vertices have a point size element.
point_size
The size of points, if not specified per-vertex.
-sprite_coord_enable
- Specifies if a coord has its texture coordinates replaced or not. This
- is a packed bitfield containing the enable for all coords - if all are 0
- point sprites are effectively disabled, though points may still be
- rendered slightly different according to point_quad_rasterization.
- If any coord is non-zero, point_smooth should be disabled, and
- point_quad_rasterization enabled.
- If enabled, the four vertices of the resulting quad will be assigned
- texture coordinates, according to sprite_coord_mode.
-sprite_coord_mode
- Specifies how the value for each shader output should be computed when
- drawing sprites, for each coord which has sprite_coord_enable set.
- For PIPE_SPRITE_COORD_LOWER_LEFT, the lower left vertex will have
- coordinate (0,0,0,1).
- For PIPE_SPRITE_COORD_UPPER_LEFT, the upper-left vertex will have
- coordinate (0,0,0,1).
- This state is needed by :ref:`Draw` because that's where each
- point vertex is converted into four quad vertices. There's no other
- place to emit the new vertex texture coordinates which are required for
- sprite rendering.
- Note that when geometry shaders are available, this state could be
- removed. A special geometry shader defined by the state tracker could
- convert the incoming points into quads with the proper texture coords.
-point_quad_rasterization
- This determines if points should be rasterized as quads or points.
- d3d always uses quad rasterization for points, regardless if point sprites
- are enabled or not, but OGL has different rules. If point_quad_rasterization
- is set, point_smooth should be disabled, and points will be rendered as
- squares even if multisample is enabled.
- sprite_coord_enable should be zero if point_quad_rasterization is not
- enabled.
scissor
Whether the scissor test is enabled.