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.
15 If set, TGSI_SEMANTIC_COLOR registers are clamped to the [0, 1] range after
16 the execution of the vertex shader, before being passed to the geometry
17 shader or fragment shader.
19 OpenGL: glClampColor(GL_CLAMP_VERTEX_COLOR) in GL 3.0 or GL_ARB_color_buffer_float
21 D3D11: seems always disabled
23 Note the PIPE_CAP_VERTEX_COLOR_CLAMPED query indicates whether or not the
24 driver supports this control. If it's not supported, the state tracker may
25 have to insert extra clamping code.
31 Controls whether TGSI_SEMANTIC_COLOR outputs of the fragment shader
32 are clamped to [0, 1].
34 OpenGL: glClampColor(GL_CLAMP_FRAGMENT_COLOR) in GL 3.0 or ARB_color_buffer_float
36 D3D11: seems always disabled
38 Note the PIPE_CAP_FRAGMENT_COLOR_CLAMPED query indicates whether or not the
39 driver supports this control. If it's not supported, the state tracker may
40 have to insert extra clamping code.
49 If set, the provoking vertex of each polygon is used to determine the color
50 of the entire polygon. If not set, fragment colors will be interpolated
51 between the vertex colors.
53 The actual interpolated shading algorithm is obviously
54 implementation-dependent, but will usually be Gourard for most hardware.
58 This is separate from the fragment shader input attributes
59 CONSTANT, LINEAR and PERSPECTIVE. The flatshade state is needed at
60 clipping time to determine how to set the color of new vertices.
62 :ref:`Draw` can implement flat shading by copying the provoking vertex
63 color to all the other vertices in the primitive.
68 Whether the first vertex should be the provoking vertex, for most primitives.
69 If not set, the last vertex is the provoking vertex.
71 There are a few important exceptions to the specification of this rule.
73 * ``PIPE_PRIMITIVE_POLYGON``: The provoking vertex is always the first
74 vertex. If the caller wishes to change the provoking vertex, they merely
75 need to rotate the vertices themselves.
76 * ``PIPE_PRIMITIVE_QUAD``, ``PIPE_PRIMITIVE_QUAD_STRIP``: The option only has
77 an effect if ``PIPE_CAP_QUADS_FOLLOW_PROVOKING_VERTEX_CONVENTION`` is true.
78 If it is not, the provoking vertex is always the last vertex.
79 * ``PIPE_PRIMITIVE_TRIANGLE_FAN``: When set, the provoking vertex is the
80 second vertex, not the first. This permits each segment of the fan to have
89 If set, there are per-vertex back-facing colors. The hardware
90 (perhaps assisted by :ref:`Draw`) should be set up to use this state
91 along with the front/back information to set the final vertex colors
92 prior to rasterization.
94 The frontface vertex shader color output is marked with TGSI semantic
95 COLOR[0], and backface COLOR[1].
98 Indicates whether the window order of front-facing polygons is
99 counter-clockwise (TRUE) or clockwise (FALSE).
102 Indicates which faces of polygons to cull, either PIPE_FACE_NONE
103 (cull no polygons), PIPE_FACE_FRONT (cull front-facing polygons),
104 PIPE_FACE_BACK (cull back-facing polygons), or
105 PIPE_FACE_FRONT_AND_BACK (cull all polygons).
108 Indicates how to fill front-facing polygons, either
109 PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE or
110 PIPE_POLYGON_MODE_POINT.
112 Indicates how to fill back-facing polygons, either
113 PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE or
114 PIPE_POLYGON_MODE_POINT.
117 Whether polygon stippling is enabled.
119 Controls OpenGL-style polygon smoothing/antialiasing
122 If set, point-filled polygons will have polygon offset factors applied
124 If set, line-filled polygons will have polygon offset factors applied
126 If set, filled polygons will have polygon offset factors applied
129 Specifies the polygon offset bias
131 Specifies the polygon offset scale
133 Upper (if > 0) or lower (if < 0) bound on the polygon offset result
143 Whether lines should be smoothed. Line smoothing is simply anti-aliasing.
145 Whether line stippling is enabled.
147 16-bit bitfield of on/off flags, used to pattern the line stipple.
149 When drawing a stippled line, each bit in the stipple pattern is
150 repeated N times, where N = line_stipple_factor + 1.
152 Controls whether the last pixel in a line is drawn or not. OpenGL
153 omits the last pixel to avoid double-drawing pixels at the ends of lines
154 when drawing connected lines.
162 The effect of this state depends on PIPE_CAP_TGSI_TEXCOORD !
164 Controls automatic texture coordinate generation for rendering sprite points.
166 If PIPE_CAP_TGSI_TEXCOORD is false:
167 When bit k in the sprite_coord_enable bitfield is set, then generic
168 input k to the fragment shader will get an automatically computed
171 If PIPE_CAP_TGSI_TEXCOORD is true:
172 The bitfield refers to inputs with TEXCOORD semantic instead of generic inputs.
174 The texture coordinate will be of the form (s, t, 0, 1) where s varies
175 from 0 to 1 from left to right while t varies from 0 to 1 according to
176 the state of 'sprite_coord_mode' (see below).
178 If any bit is set, then point_smooth MUST be disabled (there are no
179 round sprites) and point_quad_rasterization MUST be true (sprites are
180 always rasterized as quads). Any mismatch between these states should
181 be considered a bug in the state-tracker.
183 This feature is implemented in the :ref:`Draw` module but may also be
184 implemented natively by GPUs or implemented with a geometry shader.
190 Specifies how the value for each shader output should be computed when drawing
191 point sprites. For PIPE_SPRITE_COORD_LOWER_LEFT, the lower-left vertex will
192 have coordinates (0,0,0,1). For PIPE_SPRITE_COORD_UPPER_LEFT, the upper-left
193 vertex will have coordinates (0,0,0,1).
194 This state is used by :ref:`Draw` to generate texcoords.
197 point_quad_rasterization
198 ^^^^^^^^^^^^^^^^^^^^^^^^
200 Determines if points should be rasterized according to quad or point
203 OpenGL actually has quite different rasterization rules for points and
204 point sprites - hence this indicates if points should be rasterized as
205 points or according to point sprite (which decomposes them into quads,
208 Additionally Direct3D will always use quad rasterization rules for
209 points, regardless of whether point sprites are enabled or not.
211 If this state is enabled, point smoothing and antialiasing are
212 disabled. If it is disabled, point sprite coordinates are not
217 Some renderers always internally translate points into quads; this state
218 still affects those renderers by overriding other rasterization state.
221 Whether points should be smoothed. Point smoothing turns rectangular
222 points into circles or ovals.
223 point_size_per_vertex
224 Whether the vertex shader is expected to have a point size output.
225 Undefined behaviour is permitted if there is disagreement between
226 this flag and the actual bound shader.
228 The size of points, if not specified per-vertex.
236 Whether the scissor test is enabled.
239 Whether :term:`MSAA` is enabled.
241 gl_rasterization_rules
242 Whether the rasterizer should use (0.5, 0.5) pixel centers. When not set,
243 the rasterizer will use (0, 0) for pixel centers.
246 When true clip space in the z axis goes from [0..1] (D3D). When false
250 When false, the near and far depth clipping planes of the view volume are
251 disabled and the depth value will be clamped at the per-pixel level, after
252 polygon offset has been applied and before depth testing.
255 For each k in [0, PIPE_MAX_CLIP_PLANES), if bit k of this field is set,
256 clipping half-space k is enabled, if it is clear, it is disabled.
257 The clipping half-spaces are defined either by the user clip planes in
258 ``pipe_clip_state``, or by the clip distance outputs of the shader stage
259 preceding the fragment shader.
260 If any clip distance output is written, those half-spaces for which no
261 clip distance is written count as disabled; i.e. user clip planes and
262 shader clip distances cannot be mixed, and clip distances take precedence.