6
The rasterizer state controls the rendering of points, lines and triangles.
7
Attributes include polygon culling state, line width, line stipple,
8
multisample state, scissoring and flat/smooth shading.
16
If set, the provoking vertex of each polygon is used to determine the color
17
of the entire polygon. If not set, fragment colors will be interpolated
18
between the vertex colors.
20
The actual interpolated shading algorithm is obviously
21
implementation-dependent, but will usually be Gourard for most hardware.
25
This is separate from the fragment shader input attributes
26
CONSTANT, LINEAR and PERSPECTIVE. The flatshade state is needed at
27
clipping time to determine how to set the color of new vertices.
29
:ref:`Draw` can implement flat shading by copying the provoking vertex
30
color to all the other vertices in the primitive.
35
Whether the first vertex should be the provoking vertex, for most primitives.
36
If not set, the last vertex is the provoking vertex.
38
There are several important exceptions to the specification of this rule.
40
* ``PIPE_PRIMITIVE_POLYGON``: The provoking vertex is always the first
41
vertex. If the caller wishes to change the provoking vertex, they merely
42
need to rotate the vertices themselves.
43
* ``PIPE_PRIMITIVE_QUAD``, ``PIPE_PRIMITIVE_QUAD_STRIP``: This option has no
44
effect; the provoking vertex is always the last vertex.
45
* ``PIPE_PRIMITIVE_TRIANGLE_FAN``: When set, the provoking vertex is the
46
second vertex, not the first. This permits each segment of the fan to have
55
If set, there are per-vertex back-facing colors. The hardware
56
(perhaps assisted by :ref:`Draw`) should be set up to use this state
57
along with the front/back information to set the final vertex colors
58
prior to rasterization.
60
The frontface vertex shader color output is marked with TGSI semantic
61
COLOR[0], and backface COLOR[1].
64
Indicates whether the window order of front-facing polygons is
65
counter-clockwise (TRUE) or clockwise (FALSE).
68
Indicates which faces of polygons to cull, either PIPE_FACE_NONE
69
(cull no polygons), PIPE_FACE_FRONT (cull front-facing polygons),
70
PIPE_FACE_BACK (cull back-facing polygons), or
71
PIPE_FACE_FRONT_AND_BACK (cull all polygons).
74
Indicates how to fill front-facing polygons, either
75
PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE or
76
PIPE_POLYGON_MODE_POINT.
78
Indicates how to fill back-facing polygons, either
79
PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE or
80
PIPE_POLYGON_MODE_POINT.
83
Whether polygon stippling is enabled.
85
Controls OpenGL-style polygon smoothing/antialiasing
88
If set, point-filled polygons will have polygon offset factors applied
90
If set, line-filled polygons will have polygon offset factors applied
92
If set, filled polygons will have polygon offset factors applied
95
Specifies the polygon offset bias
97
Specifies the polygon offset scale
107
Whether lines should be smoothed. Line smoothing is simply anti-aliasing.
109
Whether line stippling is enabled.
111
16-bit bitfield of on/off flags, used to pattern the line stipple.
113
When drawing a stippled line, each bit in the stipple pattern is
114
repeated N times, where N = line_stipple_factor + 1.
116
Controls whether the last pixel in a line is drawn or not. OpenGL
117
omits the last pixel to avoid double-drawing pixels at the ends of lines
118
when drawing connected lines.
127
Specifies if a texture unit has its texture coordinates replaced or not. This
128
is a packed bitfield containing the enable for all texcoords -- if all bits
129
are zero, point sprites are effectively disabled.
131
If any bit is set, then point_smooth MUST be disabled (there are no
132
round sprites) and point_quad_rasterization MUST be true (sprites are
133
always rasterized as quads). Any mismatch between these states should
134
be considered a bug in the state-tracker.
136
If enabled, the four vertices of the resulting quad will be assigned
137
texture coordinates, according to sprite_coord_mode.
142
Specifies how the value for each shader output should be computed when drawing
143
point sprites. For PIPE_SPRITE_COORD_LOWER_LEFT, the lower-left vertex will
144
have coordinates (0,0,0,1). For PIPE_SPRITE_COORD_UPPER_LEFT, the upper-left
145
vertex will have coordinates (0,0,0,1).
146
This state is used by :ref:`Draw` to generate texcoords.
148
point_quad_rasterization
149
^^^^^^^^^^^^^^^^^^^^^^^^
151
Determines if points should be rasterized according to quad or point
154
OpenGL actually has quite different rasterization rules for points and
155
point sprites - hence this indicates if points should be rasterized as
156
points or according to point sprite (which decomposes them into quads,
159
Additionally Direct3D will always use quad rasterization rules for
160
points, regardless of whether point sprites are enabled or not.
162
If this state is enabled, point smoothing and antialiasing are
163
disabled. If it is disabled, point sprite coordinates are not
168
Some renderers always internally translate points into quads; this state
169
still affects those renderers by overriding other rasterization state.
172
Whether points should be smoothed. Point smoothing turns rectangular
173
points into circles or ovals.
174
point_size_per_vertex
175
Whether the vertex shader is expected to have a point size output.
176
Undefined behaviour is permitted if there is disagreement between
177
this flag and the actual bound shader.
179
The size of points, if not specified per-vertex.
187
Whether the scissor test is enabled.
190
Whether :term:`MSAA` is enabled.
192
gl_rasterization_rules
193
Whether the rasterizer should use (0.5, 0.5) pixel centers. When not set,
194
the rasterizer will use (0, 0) for pixel centers.