Attributes include polygon culling state, line width, line stipple,
multisample state, scissoring and flat/smooth shading.
-
Members
-------
+bypass_vs_clip_and_viewport
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Whether the entire TCL pipeline should be bypassed. This implies that
+vertices are pre-transformed for the viewport, and will not be run
+through the vertex shader.
+
+.. note::
+
+ Implementations may still clip away vertices that are not in the viewport
+ when this is set.
+
flatshade
- If set, the provoking vertex of each polygon is used to determine the
- color of the entire polygon. If not set, fragment colors will be
- interpolated between the vertex colors.
- Note that this is separate from the fragment shader input attributes
- CONSTANT, LINEAR and PERSPECTIVE. We need the flatshade state at
+^^^^^^^^^
+
+If set, the provoking vertex of each polygon is used to determine the color
+of the entire polygon. If not set, fragment colors will be interpolated
+between the vertex colors.
+
+The actual interpolated shading algorithm is obviously
+implementation-dependent, but will usually be Gourard for most hardware.
+
+.. note::
+
+ This is separate from the fragment shader input attributes
+ CONSTANT, LINEAR and PERSPECTIVE. The flatshade state is needed at
clipping time to determine how to set the color of new vertices.
- Also note that the draw module can implement flat shading by copying
- the provoking vertex color to all the other vertices in the primitive.
+
+ :ref:`Draw` can implement flat shading by copying the provoking vertex
+ color to all the other vertices in the primitive.
flatshade_first
- Whether the first vertex should be the provoking vertex, for most
- primitives. If not set, the last vertex is the provoking vertex.
+^^^^^^^^^^^^^^^
+
+Whether the first vertex should be the provoking vertex, for most primitives.
+If not set, the last vertex is the provoking vertex.
+
+There are several important exceptions to the specification of this rule.
+
+* ``PIPE_PRIMITIVE_POLYGON``: The provoking vertex is always the first
+ vertex. If the caller wishes to change the provoking vertex, they merely
+ need to rotate the vertices themselves.
+* ``PIPE_PRIMITIVE_QUAD``, ``PIPE_PRIMITIVE_QUAD_STRIP``: This option has no
+ effect; the provoking vertex is always the last vertex.
+* ``PIPE_PRIMITIVE_TRIANGLE_FAN``: When set, the provoking vertex is the
+ second vertex, not the first. This permits each segment of the fan to have
+ a different color.
+
+Other Members
+^^^^^^^^^^^^^
light_twoside
- If set, there are per-vertex back-facing colors. The draw module
+ If set, there are per-vertex back-facing colors. :ref:`Draw`
uses this state along with the front/back information to set the
final vertex colors prior to rasterization.
front_winding
Indicates the window order of front-facing polygons, either
PIPE_WINDING_CW or PIPE_WINDING_CCW
+
cull_mode
Indicates which polygons to cull, either PIPE_WINDING_NONE (cull no
polygons), PIPE_WINDING_CW (cull clockwise-winding polygons),
line_stipple_pattern
16-bit bitfield of on/off flags, used to pattern the line stipple.
line_stipple_factor
- When drawinga stippled line, each bit in the stipple pattern is
+ When drawing a stippled line, each bit in the stipple pattern is
repeated N times, where N = line_stipple_factor + 1.
line_last_pixel
Controls whether the last pixel in a line is drawn or not. OpenGL
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 the 'draw' module because that's where each
+ 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.
Whether the scissor test is enabled.
multisample
- Whether :ref:`MSAA` is enabled.
-
-bypass_vs_clip_and_viewport
- Whether the entire TCL pipeline should be bypassed. This implies that
- vertices are pre-transformed for the viewport, and will not be run
- through the vertex shader. Note that implementations may still clip away
- vertices that are not in the viewport.
+ Whether :term:`MSAA` is enabled.
gl_rasterization_rules
Whether the rasterizer should use (0.5, 0.5) pixel centers. When not set,
the rasterizer will use (0, 0) for pixel centers.
-
-Notes
------
-
-flatshade
-^^^^^^^^^
-
-The actual interpolated shading algorithm is obviously
-implementation-dependent, but will usually be Gourard for most hardware.
-
-bypass_vs_clip_and_viewport
-^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-When set, this implies that vertices are pre-transformed for the viewport, and
-will not be run through the vertex shader. Note that implementations may still
-clip away vertices that are not visible.
-
-flatshade_first
-^^^^^^^^^^^^^^^
-
-There are several important exceptions to the specification of this rule.
-
-* ``PIPE_PRIMITIVE_POLYGON``: The provoking vertex is always the first
- vertex. If the caller wishes to change the provoking vertex, they merely
- need to rotate the vertices themselves.
-* ``PIPE_PRIMITIVE_QUAD``, ``PIPE_PRIMITIVE_QUAD_STRIP``: This option has no
- effect; the provoking vertex is always the last vertex.
-* ``PIPE_PRIMITIVE_TRIANGLE_FAN``: When set, the provoking vertex is the
- second vertex, not the first. This permits each segment of the fan to have
- a different color.