[mesa.git] / docs / gallium / screen.rst
1 .. _screen:
3 Screen
4 ======
6 A screen is an object representing the context-independent part of a device.
8 Flags and enumerations
9 ----------------------
11 XXX some of these don't belong in this section.
14 .. _pipe_cap:
17 ^^^^^^^^^^
19 Capability queries return information about the features and limits of the
20 driver/GPU. For floating-point values, use :ref:`get_paramf`, and for boolean
21 or integer values, use :ref:`get_param`.
23 The integer capabilities:
25 * ``PIPE_CAP_GRAPHICS``: Whether graphics is supported. If not, contexts can
26 only be created with PIPE_CONTEXT_COMPUTE_ONLY.
27 * ``PIPE_CAP_NPOT_TEXTURES``: Whether :term:`NPOT` textures may have repeat modes,
28 normalized coordinates, and mipmaps.
29 * ``PIPE_CAP_MAX_DUAL_SOURCE_RENDER_TARGETS``: How many dual-source blend RTs are support.
30 :ref:`Blend` for more information.
31 * ``PIPE_CAP_ANISOTROPIC_FILTER``: Whether textures can be filtered anisotropically.
32 * ``PIPE_CAP_POINT_SPRITE``: Whether point sprites are available.
33 * ``PIPE_CAP_MAX_RENDER_TARGETS``: The maximum number of render targets that may be
34 bound.
35 * ``PIPE_CAP_OCCLUSION_QUERY``: Whether occlusion queries are available.
36 * ``PIPE_CAP_QUERY_TIME_ELAPSED``: Whether PIPE_QUERY_TIME_ELAPSED queries are available.
37 * ``PIPE_CAP_TEXTURE_SHADOW_MAP``: indicates whether the fragment shader hardware
38 can do the depth texture / Z comparison operation in TEX instructions
39 for shadow testing.
40 * ``PIPE_CAP_TEXTURE_SWIZZLE``: Whether swizzling through sampler views is
41 supported.
42 * ``PIPE_CAP_MAX_TEXTURE_2D_SIZE``: The maximum size of 2D (and 1D) textures.
43 * ``PIPE_CAP_MAX_TEXTURE_3D_LEVELS``: The maximum number of mipmap levels available
44 for a 3D texture.
45 * ``PIPE_CAP_MAX_TEXTURE_CUBE_LEVELS``: The maximum number of mipmap levels available
46 for a cubemap.
47 * ``PIPE_CAP_TEXTURE_MIRROR_CLAMP_TO_EDGE``: Whether mirrored texture coordinates are
48 supported with the clamp-to-edge wrap mode.
49 * ``PIPE_CAP_TEXTURE_MIRROR_CLAMP``: Whether mirrored texture coordinates are supported
50 with clamp or clamp-to-border wrap modes.
51 * ``PIPE_CAP_BLEND_EQUATION_SEPARATE``: Whether alpha blend equations may be different
52 from color blend equations, in :ref:`Blend` state.
53 * ``PIPE_CAP_MAX_STREAM_OUTPUT_BUFFERS``: The maximum number of stream buffers.
54 * ``PIPE_CAP_PRIMITIVE_RESTART``: Whether primitive restart is supported.
56 PRIMITIVE_RESTART where the restart index is always the fixed maximum
57 value for the index type.
58 * ``PIPE_CAP_INDEP_BLEND_ENABLE``: Whether per-rendertarget blend enabling and channel
59 masks are supported. If 0, then the first rendertarget's blend mask is
60 replicated across all MRTs.
61 * ``PIPE_CAP_INDEP_BLEND_FUNC``: Whether per-rendertarget blend functions are
62 available. If 0, then the first rendertarget's blend functions affect all
63 MRTs.
64 * ``PIPE_CAP_MAX_TEXTURE_ARRAY_LAYERS``: The maximum number of texture array
65 layers supported. If 0, the array textures are not supported at all and
66 the ARRAY texture targets are invalid.
67 * ``PIPE_CAP_TGSI_FS_COORD_ORIGIN_UPPER_LEFT``: Whether the TGSI property
68 FS_COORD_ORIGIN with value UPPER_LEFT is supported.
69 * ``PIPE_CAP_TGSI_FS_COORD_ORIGIN_LOWER_LEFT``: Whether the TGSI property
70 FS_COORD_ORIGIN with value LOWER_LEFT is supported.
72 property FS_COORD_PIXEL_CENTER with value HALF_INTEGER is supported.
74 property FS_COORD_PIXEL_CENTER with value INTEGER is supported.
75 * ``PIPE_CAP_DEPTH_CLIP_DISABLE``: Whether the driver is capable of disabling
76 depth clipping (=1) (through pipe_rasterizer_state) or supports lowering
77 depth_clamp in the client shader code (=2), for this the driver must
78 currently use TGSI.
79 * ``PIPE_CAP_DEPTH_CLIP_DISABLE_SEPARATE``: Whether the driver is capable of
80 disabling depth clipping (through pipe_rasterizer_state) separately for
81 the near and far plane. If not, depth_clip_near and depth_clip_far will be
82 equal.
83 * ``PIPE_CAP_SHADER_STENCIL_EXPORT``: Whether a stencil reference value can be
84 written from a fragment shader.
86 in the vertex shader.
87 * ``PIPE_CAP_VERTEX_ELEMENT_INSTANCE_DIVISOR``: Whether the driver supports
88 per-instance vertex attribs.
89 * ``PIPE_CAP_FRAGMENT_COLOR_CLAMPED``: Whether fragment color clamping is
90 supported. That is, is the pipe_rasterizer_state::clamp_fragment_color
91 flag supported by the driver? If not, gallium frontends will insert
92 clamping code into the fragment shaders when needed.
94 * ``PIPE_CAP_MIXED_COLORBUFFER_FORMATS``: Whether mixed colorbuffer formats are
95 supported, e.g. RGBA8 and RGBA32F as the first and second colorbuffer, resp.
96 * ``PIPE_CAP_VERTEX_COLOR_UNCLAMPED``: Whether the driver is capable of
97 outputting unclamped vertex colors from a vertex shader. If unsupported,
98 the vertex colors are always clamped. This is the default for DX9 hardware.
99 * ``PIPE_CAP_VERTEX_COLOR_CLAMPED``: Whether the driver is capable of
100 clamping vertex colors when they come out of a vertex shader, as specified
101 by the pipe_rasterizer_state::clamp_vertex_color flag. If unsupported,
102 the vertex colors are never clamped. This is the default for DX10 hardware.
103 If both clamped and unclamped CAPs are supported, the clamping can be
104 controlled through pipe_rasterizer_state. If the driver cannot do vertex
105 color clamping, gallium frontends may insert clamping code into the vertex
106 shader.
107 * ``PIPE_CAP_GLSL_FEATURE_LEVEL``: Whether the driver supports features
108 equivalent to a specific GLSL version. E.g. for GLSL 1.3, report 130.
109 * ``PIPE_CAP_GLSL_FEATURE_LEVEL_COMPATIBILITY``: Whether the driver supports
110 features equivalent to a specific GLSL version including all legacy OpenGL
111 features only present in the OpenGL compatibility profile.
112 The only legacy features that Gallium drivers must implement are
113 the legacy shader inputs and outputs (colors, texcoords, fog, clipvertex,
114 edgeflag).
115 * ``PIPE_CAP_ESSL_FEATURE_LEVEL``: An optional cap to allow drivers to
116 report a higher GLSL version for GLES contexts. This is useful when a
117 driver does not support all the required features for a higher GL version,
118 but does support the required features for a higher GLES version. A driver
119 is allowed to return ``0`` in which case ``PIPE_CAP_GLSL_FEATURE_LEVEL`` is
120 used.
121 Note that simply returning the same value as the GLSL feature level cap is
122 incorrect. For example, GLSL version 3.30 does not require ``ARB_gpu_shader5``,
123 but ESSL version 3.20 es does require ``EXT_gpu_shader5``
125 the flatshade_first setting in ``pipe_rasterizer_state``.
126 * ``PIPE_CAP_USER_VERTEX_BUFFERS``: Whether the driver supports user vertex
127 buffers. If not, gallium frontends must upload all data which is not in hw
128 resources. If user-space buffers are supported, the driver must also still
129 accept HW resource buffers.
131 limitation. If true, pipe_vertex_buffer::buffer_offset must always be aligned
132 to 4. If false, there are no restrictions on the offset.
134 limitation. If true, pipe_vertex_buffer::stride must always be aligned to 4.
135 If false, there are no restrictions on the stride.
137 a hw limitation. If true, pipe_vertex_element::src_offset must always be
138 aligned to 4. If false, there are no restrictions on src_offset.
139 * ``PIPE_CAP_COMPUTE``: Whether the implementation supports the
140 compute entry points defined in pipe_context and pipe_screen.
141 * ``PIPE_CAP_CONSTANT_BUFFER_OFFSET_ALIGNMENT``: Describes the required
142 alignment of pipe_constant_buffer::buffer_offset.
143 * ``PIPE_CAP_START_INSTANCE``: Whether the driver supports
144 pipe_draw_info::start_instance.
146 the pipe_screen::get_timestamp hook are implemented.
147 * ``PIPE_CAP_TEXTURE_MULTISAMPLE``: Whether all MSAA resources supported
148 for rendering are also supported for texturing.
149 * ``PIPE_CAP_MIN_MAP_BUFFER_ALIGNMENT``: The minimum alignment that should be
150 expected for a pointer returned by transfer_map if the resource is
151 PIPE_BUFFER. In other words, the pointer returned by transfer_map is
152 always aligned to this value.
153 * ``PIPE_CAP_TEXTURE_BUFFER_OFFSET_ALIGNMENT``: Describes the required
154 alignment for pipe_sampler_view::u.buf.offset, in bytes.
155 If a driver does not support offset/size, it should return 0.
156 * ``PIPE_CAP_BUFFER_SAMPLER_VIEW_RGBA_ONLY``: Whether the driver only
157 supports R, RG, RGB and RGBA formats for PIPE_BUFFER sampler views.
158 When this is the case it should be assumed that the swizzle parameters
159 in the sampler view have no effect.
160 * ``PIPE_CAP_TGSI_TEXCOORD``: This CAP describes a hw limitation.
161 If true, the hardware cannot replace arbitrary shader inputs with sprite
162 coordinates and hence the inputs that are desired to be replaceable must
164 The rasterizer's sprite_coord_enable state therefore also applies to the
165 TEXCOORD semantic.
166 Also, TGSI_SEMANTIC_PCOORD becomes available, which labels a fragment shader
167 input that will always be replaced with sprite coordinates.
168 * ``PIPE_CAP_PREFER_BLIT_BASED_TEXTURE_TRANSFER``: Whether it is preferable
169 to use a blit to implement a texture transfer which needs format conversions
170 and swizzling in gallium frontends. Generally, all hardware drivers with
171 dedicated memory should return 1 and all software rasterizers should return 0.
173 is supported.
174 * ``PIPE_CAP_TEXTURE_BORDER_COLOR_QUIRK``: Bitmask indicating whether special
175 considerations have to be given to the interaction between the border color
176 in the sampler object and the sampler view used with it.
177 If PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_R600 is set, the border color
178 may be affected in undefined ways for any kind of permutational swizzle
179 (any swizzle XYZW where X/Y/Z/W are not ZERO, ONE, or R/G/B/A respectively)
180 in the sampler view.
181 If PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_NV50 is set, the border color
182 state should be swizzled manually according to the swizzle in the sampler
183 view it is intended to be used with, or herein undefined results may occur
184 for permutational swizzles.
185 * ``PIPE_CAP_MAX_TEXTURE_BUFFER_SIZE``: The maximum accessible size with
186 a buffer sampler view, in texels.
187 * ``PIPE_CAP_MAX_VIEWPORTS``: The maximum number of viewports (and scissors
188 since they are linked) a driver can support. Returning 0 is equivalent
189 to returning 1 because every driver has to support at least a single
190 viewport/scissor combination.
191 * ``PIPE_CAP_ENDIANNESS``:: The endianness of the device. Either
193 * ``PIPE_CAP_MIXED_FRAMEBUFFER_SIZES``: Whether it is allowed to have
194 different sizes for fb color/zs attachments. This controls whether
195 ARB_framebuffer_object is provided.
197 ``TGSI_SEMANTIC_VIEWPORT_INDEX`` are supported as vertex shader
198 outputs. Note that the viewport will only be used if multiple viewports are
199 exposed.
200 * ``PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES``: The maximum number of vertices
201 output by a single invocation of a geometry shader.
203 vertex components output by a single invocation of a geometry shader.
204 This is the product of the number of attribute components per vertex and
205 the number of output vertices.
206 * ``PIPE_CAP_MAX_TEXTURE_GATHER_COMPONENTS``: Max number of components
207 in format that texture gather can operate on. 1 == RED, ALPHA etc,
208 4 == All formats.
209 * ``PIPE_CAP_TEXTURE_GATHER_SM5``: Whether the texture gather
210 hardware implements the SM5 features, component selection,
211 shadow comparison, and run-time offsets.
214 for buffers.
215 * ``PIPE_CAP_TEXTURE_QUERY_LOD``: Whether the ``LODQ`` instruction is
216 supported.
217 * ``PIPE_CAP_MIN_TEXTURE_GATHER_OFFSET``: The minimum offset that can be used
218 in conjunction with a texture gather opcode.
219 * ``PIPE_CAP_MAX_TEXTURE_GATHER_OFFSET``: The maximum offset that can be used
220 in conjunction with a texture gather opcode.
221 * ``PIPE_CAP_SAMPLE_SHADING``: Whether there is support for per-sample
222 shading. The context->set_min_samples function will be expected to be
223 implemented.
224 * ``PIPE_CAP_TEXTURE_GATHER_OFFSETS``: Whether the ``TG4`` instruction can
225 accept 4 offsets.
227 TGSI_PROPERTY_VS_WINDOW_SPACE_POSITION is supported, which disables clipping
228 and viewport transformation.
229 * ``PIPE_CAP_MAX_VERTEX_STREAMS``: The maximum number of vertex streams
230 supported by the geometry shader. If stream-out is supported, this should be
231 at least 1. If stream-out is not supported, this should be 0.
232 * ``PIPE_CAP_DRAW_INDIRECT``: Whether the driver supports taking draw arguments
233 { count, instance_count, start, index_bias } from a PIPE_BUFFER resource.
234 See pipe_draw_info.
235 * ``PIPE_CAP_MULTI_DRAW_INDIRECT``: Whether the driver supports
236 pipe_draw_info::indirect_stride and ::indirect_count
237 * ``PIPE_CAP_MULTI_DRAW_INDIRECT_PARAMS``: Whether the driver supports
238 taking the number of indirect draws from a separate parameter
239 buffer, see pipe_draw_indirect_info::indirect_draw_count.
240 * ``PIPE_CAP_TGSI_FS_FINE_DERIVATIVE``: Whether the fragment shader supports
241 the FINE versions of DDX/DDY.
242 * ``PIPE_CAP_VENDOR_ID``: The vendor ID of the underlying hardware. If it's
243 not available one should return 0xFFFFFFFF.
244 * ``PIPE_CAP_DEVICE_ID``: The device ID (PCI ID) of the underlying hardware.
245 0xFFFFFFFF if not available.
246 * ``PIPE_CAP_ACCELERATED``: Whether the renderer is hardware accelerated.
247 * ``PIPE_CAP_VIDEO_MEMORY``: The amount of video memory in megabytes.
248 * ``PIPE_CAP_UMA``: If the device has a unified memory architecture or on-card
249 memory and GART.
250 * ``PIPE_CAP_CONDITIONAL_RENDER_INVERTED``: Whether the driver supports inverted
251 condition for conditional rendering.
252 * ``PIPE_CAP_MAX_VERTEX_ATTRIB_STRIDE``: The maximum supported vertex stride.
253 * ``PIPE_CAP_SAMPLER_VIEW_TARGET``: Whether the sampler view's target can be
254 different than the underlying resource's, as permitted by
255 ARB_texture_view. For example a 2d array texture may be reinterpreted as a
256 cube (array) texture and vice-versa.
257 * ``PIPE_CAP_CLIP_HALFZ``: Whether the driver supports the
258 pipe_rasterizer_state::clip_halfz being set to true. This is required
259 for enabling ARB_clip_control.
260 * ``PIPE_CAP_VERTEXID_NOBASE``: If true, the driver only supports
262 gallium frontends for APIs whose vertexIDs are offset by basevertex (such as GL)
264 and TGSI_SEMANTIC_BASEVERTEX, so drivers setting this must handle both these
265 semantics. Only relevant if geometry shaders are supported.
266 (BASEVERTEX could be exposed separately too via ``PIPE_CAP_DRAW_PARAMETERS``).
267 * ``PIPE_CAP_POLYGON_OFFSET_CLAMP``: If true, the driver implements support
268 for ``pipe_rasterizer_state::offset_clamp``.
269 * ``PIPE_CAP_MULTISAMPLE_Z_RESOLVE``: Whether the driver supports blitting
270 a multisampled depth buffer into a single-sampled texture (or depth buffer).
271 Only the first sampled should be copied.
272 * ``PIPE_CAP_RESOURCE_FROM_USER_MEMORY``: Whether the driver can create
273 a pipe_resource where an already-existing piece of (malloc'd) user memory
274 is used as its backing storage. In other words, whether the driver can map
275 existing user memory into the device address space for direct device access.
276 The create function is pipe_screen::resource_from_user_memory. The address
277 and size must be page-aligned.
279 Whether pipe_context::get_device_reset_status is implemented.
281 How many per-patch outputs and inputs are supported between tessellation
282 control and tessellation evaluation shaders, not counting in TESSINNER and
283 TESSOUTER. The minimum allowed value for OpenGL is 30.
284 * ``PIPE_CAP_TEXTURE_FLOAT_LINEAR``: Whether the linear minification and
285 magnification filters are supported with single-precision floating-point
286 textures.
287 * ``PIPE_CAP_TEXTURE_HALF_FLOAT_LINEAR``: Whether the linear minification and
288 magnification filters are supported with half-precision floating-point
289 textures.
290 * ``PIPE_CAP_DEPTH_BOUNDS_TEST``: Whether bounds_test, bounds_min, and
291 bounds_max states of pipe_depth_stencil_alpha_state behave according
292 to the GL_EXT_depth_bounds_test specification.
293 * ``PIPE_CAP_TGSI_TXQS``: Whether the `TXQS` opcode is supported
294 * ``PIPE_CAP_FORCE_PERSAMPLE_INTERP``: If the driver can force per-sample
295 interpolation for all fragment shader inputs if
296 pipe_rasterizer_state::force_persample_interp is set. This is only used
297 by GL3-level sample shading (ARB_sample_shading). GL4-level sample shading
298 (ARB_gpu_shader5) doesn't use this. While GL3 hardware has a state for it,
299 GL4 hardware will likely need to emulate it with a shader variant, or by
300 selecting the interpolation weights with a conditional assignment
301 in the shader.
302 * ``PIPE_CAP_SHAREABLE_SHADERS``: Whether shader CSOs can be used by any
303 pipe_context.
305 Whether copying between compressed and plain formats is supported where
306 a compressed block is copied to/from a plain pixel of the same size.
307 * ``PIPE_CAP_CLEAR_TEXTURE``: Whether `clear_texture` will be
308 available in contexts.
309 * ``PIPE_CAP_CLEAR_SCISSORED``: Whether `clear` can accept a scissored
310 bounding box.
313 supported in vertex shaders.
314 * ``PIPE_CAP_TGSI_PACK_HALF_FLOAT``: Whether the ``UP2H`` and ``PK2H``
315 TGSI opcodes are supported.
316 * ``PIPE_CAP_TGSI_FS_POSITION_IS_SYSVAL``: If gallium frontends should use
317 a system value for the POSITION fragment shader input.
318 * ``PIPE_CAP_TGSI_FS_POINT_IS_SYSVAL``: If gallium frontends should use
319 a system value for the POINT fragment shader input.
320 * ``PIPE_CAP_TGSI_FS_FACE_IS_INTEGER_SYSVAL``: If gallium frontends should use
321 a system value for the FACE fragment shader input.
322 Also, the FACE system value is integer, not float.
323 * ``PIPE_CAP_SHADER_BUFFER_OFFSET_ALIGNMENT``: Describes the required
324 alignment for pipe_shader_buffer::buffer_offset, in bytes. Maximum
325 value allowed is 256 (for GL conformance). 0 is only allowed if
326 shader buffers are not supported.
327 * ``PIPE_CAP_INVALIDATE_BUFFER``: Whether the use of ``invalidate_resource``
328 for buffers is supported.
329 * ``PIPE_CAP_GENERATE_MIPMAP``: Indicates whether pipe_context::generate_mipmap
330 is supported.
331 * ``PIPE_CAP_STRING_MARKER``: Whether pipe->emit_string_marker() is supported.
332 * ``PIPE_CAP_SURFACE_REINTERPRET_BLOCKS``: Indicates whether
333 pipe_context::create_surface supports reinterpreting a texture as a surface
334 of a format with different block width/height (but same block size in bits).
335 For example, a compressed texture image can be interpreted as a
336 non-compressed surface whose texels are the same number of bits as the
337 compressed blocks, and vice versa. The width and height of the surface is
338 adjusted appropriately.
339 * ``PIPE_CAP_QUERY_BUFFER_OBJECT``: Driver supports
340 context::get_query_result_resource callback.
341 * ``PIPE_CAP_PCI_GROUP``: Return the PCI segment group number.
342 * ``PIPE_CAP_PCI_BUS``: Return the PCI bus number.
343 * ``PIPE_CAP_PCI_DEVICE``: Return the PCI device number.
344 * ``PIPE_CAP_PCI_FUNCTION``: Return the PCI function number.
346 If non-zero, rendering to framebuffers with no surface attachments
347 is supported. The context->is_format_supported function will be expected
348 to be implemented with PIPE_FORMAT_NONE yeilding the MSAA modes the hardware
349 supports. N.B., The maximum number of layers supported for rasterizing a
350 primitive on a layer is obtained from ``PIPE_CAP_MAX_TEXTURE_ARRAY_LAYERS``
351 even though it can be larger than the number of layers supported by either
352 rendering or textures.
353 * ``PIPE_CAP_ROBUST_BUFFER_ACCESS_BEHAVIOR``: Implementation uses bounds
354 checking on resource accesses by shader if the context is created with
355 PIPE_CONTEXT_ROBUST_BUFFER_ACCESS. See the ARB_robust_buffer_access_behavior
356 extension for information on the required behavior for out of bounds accesses
357 and accesses to unbound resources.
358 * ``PIPE_CAP_CULL_DISTANCE``: Whether the driver supports the arb_cull_distance
359 extension and thus implements proper support for culling planes.
360 * ``PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES``: Whether primitive restart is
361 supported for patch primitives.
362 * ``PIPE_CAP_TGSI_VOTE``: Whether the ``VOTE_*`` ops can be used in shaders.
363 * ``PIPE_CAP_MAX_WINDOW_RECTANGLES``: The maxium number of window rectangles
364 supported in ``set_window_rectangles``.
365 * ``PIPE_CAP_POLYGON_OFFSET_UNITS_UNSCALED``: If true, the driver implements support
366 for ``pipe_rasterizer_state::offset_units_unscaled``.
367 * ``PIPE_CAP_VIEWPORT_SUBPIXEL_BITS``: Number of bits of subpixel precision for
368 floating point viewport bounds.
369 * ``PIPE_CAP_RASTERIZER_SUBPIXEL_BITS``: Number of bits of subpixel precision used
370 by the rasterizer.
371 * ``PIPE_CAP_MIXED_COLOR_DEPTH_BITS``: Whether there is non-fallback
372 support for color/depth format combinations that use a different
373 number of bits. For the purpose of this cap, Z24 is treated as
374 32-bit. If set to off, that means that a B5G6R5 + Z24 or RGBA8 + Z16
375 combination will require a driver fallback, and should not be
376 advertised in the GLX/EGL config list.
377 * ``PIPE_CAP_TGSI_ARRAY_COMPONENTS``: If true, the driver interprets the
378 UsageMask of input and output declarations and allows declaring arrays
379 in overlapping ranges. The components must be a contiguous range, e.g. a
380 UsageMask of xy or yzw is allowed, but xz or yw isn't. Declarations with
381 overlapping locations must have matching semantic names and indices, and
382 equal interpolation qualifiers.
383 Components may overlap, notably when the gaps in an array of dvec3 are
384 filled in.
385 * ``PIPE_CAP_STREAM_OUTPUT_INTERLEAVE_BUFFERS``: Whether interleaved stream
386 output mode is able to interleave across buffers. This is required for
387 ARB_transform_feedback3.
388 * ``PIPE_CAP_TGSI_CAN_READ_OUTPUTS``: Whether every TGSI shader stage can read
389 from the output file.
390 * ``PIPE_CAP_GLSL_OPTIMIZE_CONSERVATIVELY``: Tell the GLSL compiler to use
391 the minimum amount of optimizations just to be able to do all the linking
392 and lowering.
393 * ``PIPE_CAP_FBFETCH``: The number of render targets whose value in the
394 current framebuffer can be read in the shader. 0 means framebuffer fetch
395 is not supported. 1 means that only the first render target can be read,
396 and a larger value would mean that multiple render targets are supported.
397 * ``PIPE_CAP_FBFETCH_COHERENT``: Whether framebuffer fetches from the fragment
398 shader can be guaranteed to be coherent with framebuffer writes.
399 * ``PIPE_CAP_TGSI_MUL_ZERO_WINS``: Whether TGSI shaders support the
400 ``TGSI_PROPERTY_MUL_ZERO_WINS`` shader property.
401 * ``PIPE_CAP_DOUBLES``: Whether double precision floating-point operations
402 are supported.
403 * ``PIPE_CAP_INT64``: Whether 64-bit integer operations are supported.
404 * ``PIPE_CAP_INT64_DIVMOD``: Whether 64-bit integer division/modulo
405 operations are supported.
406 * ``PIPE_CAP_TGSI_TEX_TXF_LZ``: Whether TEX_LZ and TXF_LZ opcodes are
407 supported.
408 * ``PIPE_CAP_TGSI_CLOCK``: Whether the CLOCK opcode is supported.
410 PIPE_POLYGON_MODE_FILL_RECTANGLE mode is supported for
411 ``pipe_rasterizer_state::fill_front`` and
412 ``pipe_rasterizer_state::fill_back``.
413 * ``PIPE_CAP_SPARSE_BUFFER_PAGE_SIZE``: The page size of sparse buffers in
414 bytes, or 0 if sparse buffers are not supported. The page size must be at
415 most 64KB.
416 * ``PIPE_CAP_TGSI_BALLOT``: Whether the BALLOT and READ_* opcodes as well as
417 the SUBGROUP_* semantics are supported.
419 ``TGSI_SEMANTIC_VIEWPORT_INDEX`` are supported as tessellation evaluation
420 shader outputs.
421 * ``PIPE_CAP_CAN_BIND_CONST_BUFFER_AS_VERTEX``: Whether a buffer with just
422 PIPE_BIND_CONSTANT_BUFFER can be legally passed to set_vertex_buffers.
426 * ``PIPE_CAP_BINDLESS_TEXTURE``: Whether bindless texture operations are
427 supported.
428 * ``PIPE_CAP_NIR_SAMPLERS_AS_DEREF``: Whether NIR tex instructions should
429 reference texture and sampler as NIR derefs instead of by indices.
430 * ``PIPE_CAP_QUERY_SO_OVERFLOW``: Whether the
432 ``PIPE_QUERY_SO_OVERFLOW_ANY_PREDICATE`` query types are supported. Note that
433 for a driver that does not support multiple output streams (i.e.,
434 ``PIPE_CAP_MAX_VERTEX_STREAMS`` is 1), both query types are identical.
435 * ``PIPE_CAP_MEMOBJ``: Whether operations on memory objects are supported.
436 * ``PIPE_CAP_LOAD_CONSTBUF``: True if the driver supports ``TGSI_OPCODE_LOAD`` use
437 with constant buffers.
438 * ``PIPE_CAP_TGSI_ANY_REG_AS_ADDRESS``: Any TGSI register can be used as
439 an address for indirect register indexing.
440 * ``PIPE_CAP_TILE_RASTER_ORDER``: Whether the driver supports
441 GL_MESA_tile_raster_order, using the tile_raster_order_* fields in
442 pipe_rasterizer_state.
443 * ``PIPE_CAP_MAX_COMBINED_SHADER_OUTPUT_RESOURCES``: Limit on combined shader
444 output resources (images + buffers + fragment outputs). If 0 the state
445 tracker works it out.
446 * ``PIPE_CAP_FRAMEBUFFER_MSAA_CONSTRAINTS``: This determines limitations
447 on the number of samples that framebuffer attachments can have.
448 Possible values:
450 0. color.nr_samples == zs.nr_samples == color.nr_storage_samples
451 (standard MSAA quality)
452 1. color.nr_samples >= zs.nr_samples == color.nr_storage_samples
453 (enhanced MSAA quality)
454 2. color.nr_samples >= zs.nr_samples >= color.nr_storage_samples
455 (full flexibility in tuning MSAA quality and performance)
457 All color attachments must have the same number of samples and the same
458 number of storage samples.
460 Whether pipe_vertex_buffer::buffer_offset is treated as signed. The u_vbuf
461 module needs this for optimal performance in workstation applications.
462 * ``PIPE_CAP_CONTEXT_PRIORITY_MASK``: For drivers that support per-context
463 priorities, this returns a bitmask of ``PIPE_CONTEXT_PRIORITY_x`` for the
464 supported priority levels. A driver that does not support prioritized
465 contexts can return 0.
466 * ``PIPE_CAP_FENCE_SIGNAL``: True if the driver supports signaling semaphores
467 using fence_server_signal().
468 * ``PIPE_CAP_CONSTBUF0_FLAGS``: The bits of pipe_resource::flags that must be
469 set when binding that buffer as constant buffer 0. If the buffer doesn't have
470 those bits set, pipe_context::set_constant_buffer(.., 0, ..) is ignored
471 by the driver, and the driver can throw assertion failures.
472 * ``PIPE_CAP_PACKED_UNIFORMS``: True if the driver supports packed uniforms
473 as opposed to padding to vec4s.
475 ``PIPE_CONSERVATIVE_RASTER_POST_SNAP`` mode is supported for triangles.
476 The post-snap mode means the conservative rasterization occurs after
477 the conversion from floating-point to fixed-point coordinates
478 on the subpixel grid.
480 ``PIPE_CONSERVATIVE_RASTER_POST_SNAP`` mode is supported for points and lines.
482 ``PIPE_CONSERVATIVE_RASTER_PRE_SNAP`` mode is supported for triangles.
483 The pre-snap mode means the conservative rasterization occurs before
484 the conversion from floating-point to fixed-point coordinates.
486 ``PIPE_CONSERVATIVE_RASTER_PRE_SNAP`` mode is supported for points and lines.
488 ``PIPE_CAP_POST_DEPTH_COVERAGE`` works with conservative rasterization.
490 inner_coverage from GL_INTEL_conservative_rasterization is supported.
492 subpixel precision bias in bits during conservative rasterization.
493 * ``PIPE_CAP_PROGRAMMABLE_SAMPLE_LOCATIONS``: True is the driver supports
494 programmable sample location through ```get_sample_pixel_grid``` and
495 ```set_sample_locations```.
496 * ``PIPE_CAP_MAX_GS_INVOCATIONS``: Maximum supported value of
498 * ``PIPE_CAP_MAX_SHADER_BUFFER_SIZE``: Maximum supported size for binding
499 with set_shader_buffers.
500 * ``PIPE_CAP_MAX_COMBINED_SHADER_BUFFERS``: Maximum total number of shader
501 buffers. A value of 0 means the sum of all per-shader stage maximums (see
503 * ``PIPE_CAP_MAX_COMBINED_HW_ATOMIC_COUNTERS``: Maximum total number of atomic
504 counters. A value of 0 means the default value (MAX_ATOMIC_COUNTERS = 4096).
505 * ``PIPE_CAP_MAX_COMBINED_HW_ATOMIC_COUNTER_BUFFERS``: Maximum total number of
506 atomic counter buffers. A value of 0 means the sum of all per-shader stage
508 * ``PIPE_CAP_MAX_TEXTURE_UPLOAD_MEMORY_BUDGET``: Maximum recommend memory size
509 for all active texture uploads combined. This is a performance hint.
510 0 means no limit.
511 * ``PIPE_CAP_MAX_VERTEX_ELEMENT_SRC_OFFSET``: The maximum supported value for
512 of pipe_vertex_element::src_offset.
513 * ``PIPE_CAP_SURFACE_SAMPLE_COUNT``: Whether the driver
514 supports pipe_surface overrides of resource nr_samples. If set, will
515 enable EXT_multisampled_render_to_texture.
516 * ``PIPE_CAP_TGSI_ATOMFADD``: Atomic floating point adds are supported on
517 images, buffers, and shared memory.
518 * ``PIPE_CAP_RGB_OVERRIDE_DST_ALPHA_BLEND``: True if the driver needs blend state to use zero/one instead of destination alpha for RGB/XRGB formats.
519 * ``PIPE_CAP_GLSL_TESS_LEVELS_AS_INPUTS``: True if the driver wants TESSINNER and TESSOUTER to be inputs (rather than system values) for tessellation evaluation shaders.
520 * ``PIPE_CAP_DEST_SURFACE_SRGB_CONTROL``: Indicates whether the drivers
521 supports switching the format between sRGB and linear for a surface that is
522 used as destination in draw and blit calls.
523 * ``PIPE_CAP_NIR_COMPACT_ARRAYS``: True if the compiler backend supports NIR's compact array feature, for all shader stages.
524 * ``PIPE_CAP_MAX_VARYINGS``: The maximum number of fragment shader
525 varyings. This will generally correspond to
526 ``PIPE_SHADER_CAP_MAX_INPUTS`` for the fragment shader, but in some
527 cases may be a smaller number.
528 * ``PIPE_CAP_COMPUTE_GRID_INFO_LAST_BLOCK``: Whether pipe_grid_info::last_block
529 is implemented by the driver. See struct pipe_grid_info for more details.
530 * ``PIPE_CAP_COMPUTE_SHADER_DERIVATIVE``: True if the driver supports derivatives (and texture lookups with implicit derivatives) in compute shaders.
531 * ``PIPE_CAP_TGSI_SKIP_SHRINK_IO_ARRAYS``: Whether the TGSI pass to shrink IO
532 arrays should be skipped and enforce keeping the declared array sizes instead.
533 A driver might rely on the input mapping that was defined with the original
534 GLSL code.
535 * ``PIPE_CAP_IMAGE_LOAD_FORMATTED``: True if a format for image loads does not need to be specified in the shader IR
536 * ``PIPE_CAP_THROTTLE``: Whether or not gallium frontends should throttle pipe_context
537 execution. 0 = throttling is disabled.
538 * ``PIPE_CAP_DMABUF``: Whether Linux DMABUF handles are supported by
539 resource_from_handle and resource_get_handle.
541 OpenMAX should use a compute-based blit instead of pipe_context::blit and compute pipeline for compositing images.
542 * ``PIPE_CAP_FRAGMENT_SHADER_INTERLOCK``: True if fragment shader interlock
543 functionality is supported.
544 * ``PIPE_CAP_CS_DERIVED_SYSTEM_VALUES_SUPPORTED``: True if driver handles
545 gl_LocalInvocationIndex and gl_GlobalInvocationID. Otherwise, gallium frontends will
546 lower those system values.
547 * ``PIPE_CAP_ATOMIC_FLOAT_MINMAX``: Atomic float point minimum,
548 maximum, exchange and compare-and-swap support to buffer and shared variables.
549 * ``PIPE_CAP_TGSI_DIV``: Whether opcode DIV is supported
550 * ``PIPE_CAP_FRAGMENT_SHADER_TEXTURE_LOD``: Whether texture lookups with
551 explicit LOD is supported in the fragment shader.
552 * ``PIPE_CAP_FRAGMENT_SHADER_DERIVATIVES``: True if the driver supports
553 derivatives in fragment shaders.
554 * ``PIPE_CAP_VERTEX_SHADER_SATURATE``: True if the driver supports saturate
555 modifiers in the vertex shader.
556 * ``PIPE_CAP_TEXTURE_SHADOW_LOD``: True if the driver supports shadow sampler
557 types with texture functions having interaction with LOD of texture lookup.
558 * ``PIPE_CAP_SHADER_SAMPLES_IDENTICAL``: True if the driver supports a shader query to tell whether all samples of a multisampled surface are definitely identical.
559 * ``PIPE_CAP_TGSI_ATOMINC_WRAP``: Atomic increment/decrement + wrap around are supported.
560 * ``PIPE_CAP_PREFER_IMM_ARRAYS_AS_CONSTBUF``: True if gallium frontends should
561 turn arrays whose contents can be deduced at compile time into constant
562 buffer loads, or false if the driver can handle such arrays itself in a more
563 efficient manner.
564 * ``PIPE_CAP_GL_SPIRV``: True if the driver supports ARB_gl_spirv extension.
565 * ``PIPE_CAP_GL_SPIRV_VARIABLE_POINTERS``: True if the driver supports Variable Pointers in SPIR-V shaders.
566 * ``PIPE_CAP_DEMOTE_TO_HELPER_INVOCATION``: True if driver supports demote keyword in GLSL programs.
567 * ``PIPE_CAP_TGSI_TG4_COMPONENT_IN_SWIZZLE``: True if driver wants the TG4 component encoded in sampler swizzle rather than as a separate source.
568 * ``PIPE_CAP_FLATSHADE``: Driver supports pipe_rasterizer_state::flatshade.
569 * ``PIPE_CAP_ALPHA_TEST``: Driver supports alpha-testing.
570 * ``PIPE_CAP_POINT_SIZE_FIXED``: Driver supports point-sizes that are fixed,
571 as opposed to writing gl_PointSize for every point.
572 * ``PIPE_CAP_TWO_SIDED_COLOR``: Driver supports two-sided coloring.
573 * ``PIPE_CAP_CLIP_PLANES``: Driver supports user-defined clip-planes.
574 * ``PIPE_CAP_MAX_VERTEX_BUFFERS``: Number of supported vertex buffers.
575 * ``PIPE_CAP_OPENCL_INTEGER_FUNCTIONS``: Driver supports extended OpenCL-style integer functions. This includes averge, saturating additiong, saturating subtraction, absolute difference, count leading zeros, and count trailing zeros.
576 * ``PIPE_CAP_INTEGER_MULTIPLY_32X16``: Driver supports integer multiplication between a 32-bit integer and a 16-bit integer. If the second operand is 32-bits, the upper 16-bits are ignored, and the low 16-bits are possibly sign extended as necessary.
577 * ``PIPE_CAP_NIR_IMAGES_AS_DEREF``: Whether NIR image load/store intrinsics should be nir_intrinsic_image_deref_* instead of nir_intrinsic_image_*. Defaults to true.
578 * ``PIPE_CAP_PACKED_STREAM_OUTPUT``: Driver supports packing optimization for stream output (e.g. GL transform feedback captured variables). Defaults to true.
579 * ``PIPE_CAP_VIEWPORT_TRANSFORM_LOWERED``: Driver needs the nir_lower_viewport_transform pass to be enabled. This also means that the gl_Position value is modified and should be lowered for transform feedback, if needed. Defaults to false.
580 * ``PIPE_CAP_PSIZ_CLAMPED``: Driver needs for the point size to be clamped. Additionally, the gl_PointSize has been modified and its value should be lowered for transform feedback, if needed. Defaults to false.
581 * ``PIPE_CAP_DRAW_INFO_START_WITH_USER_INDICES``: pipe_draw_info::start can be non-zero with user indices.
582 * ``PIPE_CAP_GL_BEGIN_END_BUFFER_SIZE``: Buffer size used to upload vertices for glBegin/glEnd.
583 * ``PIPE_CAP_VIEWPORT_SWIZZLE``: Whether pipe_viewport_state::swizzle can be used to specify pre-clipping swizzling of coordinates (see GL_NV_viewport_swizzle).
584 * ``PIPE_CAP_SYSTEM_SVM``: True if all application memory can be shared with the GPU without explicit mapping.
585 * ``PIPE_CAP_VIEWPORT_MASK``: Whether ``TGSI_SEMANTIC_VIEWPORT_MASK`` and ``TGSI_PROPERTY_LAYER_VIEWPORT_RELATIVE`` are supported (see GL_NV_viewport_array2).
586 * ``PIPE_CAP_MAP_UNSYNCHRONIZED_THREAD_SAFE``: Whether mapping a buffer as unsynchronized from any thread is safe.
587 * ``PIPE_CAP_GLSL_ZERO_INIT``: Choose a default zero initialization some glsl variables. If `1`, then all glsl shader variables and gl_FragColor are initialized to zero. If `2`, then shader out variables are not initialized but function out variables are.
589 .. _pipe_capf:
592 ^^^^^^^^^^^^^^^^
594 The floating-point capabilities are:
596 * ``PIPE_CAPF_MAX_LINE_WIDTH``: The maximum width of a regular line.
597 * ``PIPE_CAPF_MAX_LINE_WIDTH_AA``: The maximum width of a smoothed line.
598 * ``PIPE_CAPF_MAX_POINT_WIDTH``: The maximum width and height of a point.
599 * ``PIPE_CAPF_MAX_POINT_WIDTH_AA``: The maximum width and height of a smoothed point.
600 * ``PIPE_CAPF_MAX_TEXTURE_ANISOTROPY``: The maximum level of anisotropy that can be
601 applied to anisotropically filtered textures.
602 * ``PIPE_CAPF_MAX_TEXTURE_LOD_BIAS``: The maximum :term:`LOD` bias that may be applied
603 to filtered textures.
604 * ``PIPE_CAPF_MIN_CONSERVATIVE_RASTER_DILATE``: The minimum conservative rasterization
605 dilation.
606 * ``PIPE_CAPF_MAX_CONSERVATIVE_RASTER_DILATE``: The maximum conservative rasterization
607 dilation.
608 * ``PIPE_CAPF_CONSERVATIVE_RASTER_DILATE_GRANULARITY``: The conservative rasterization
609 dilation granularity for values relative to the minimum dilation.
612 .. _pipe_shader_cap:
615 ^^^^^^^^^^^^^^^^^
617 These are per-shader-stage capabitity queries. Different shader stages may
618 support different features.
620 * ``PIPE_SHADER_CAP_MAX_INSTRUCTIONS``: The maximum number of instructions.
621 * ``PIPE_SHADER_CAP_MAX_ALU_INSTRUCTIONS``: The maximum number of arithmetic instructions.
622 * ``PIPE_SHADER_CAP_MAX_TEX_INSTRUCTIONS``: The maximum number of texture instructions.
623 * ``PIPE_SHADER_CAP_MAX_TEX_INDIRECTIONS``: The maximum number of texture indirections.
624 * ``PIPE_SHADER_CAP_MAX_CONTROL_FLOW_DEPTH``: The maximum nested control flow depth.
625 * ``PIPE_SHADER_CAP_MAX_INPUTS``: The maximum number of input registers.
626 * ``PIPE_SHADER_CAP_MAX_OUTPUTS``: The maximum number of output registers.
627 This is valid for all shaders except the fragment shader.
628 * ``PIPE_SHADER_CAP_MAX_CONST_BUFFER_SIZE``: The maximum size per constant buffer in bytes.
629 * ``PIPE_SHADER_CAP_MAX_CONST_BUFFERS``: Maximum number of constant buffers that can be bound
630 to any shader stage using ``set_constant_buffer``. If 0 or 1, the pipe will
631 only permit binding one constant buffer per shader.
633 If a value greater than 0 is returned, the driver can have multiple
634 constant buffers bound to shader stages. The CONST register file is
635 accessed with two-dimensional indices, like in the example below.
637 DCL CONST[0][0..7] # declare first 8 vectors of constbuf 0
638 DCL CONST[3][0] # declare first vector of constbuf 3
639 MOV OUT[0], CONST[0][3] # copy vector 3 of constbuf 0
641 * ``PIPE_SHADER_CAP_MAX_TEMPS``: The maximum number of temporary registers.
642 * ``PIPE_SHADER_CAP_TGSI_CONT_SUPPORTED``: Whether the continue opcode is supported.
643 * ``PIPE_SHADER_CAP_INDIRECT_INPUT_ADDR``: Whether indirect addressing
644 of the input file is supported.
645 * ``PIPE_SHADER_CAP_INDIRECT_OUTPUT_ADDR``: Whether indirect addressing
646 of the output file is supported.
647 * ``PIPE_SHADER_CAP_INDIRECT_TEMP_ADDR``: Whether indirect addressing
648 of the temporary file is supported.
649 * ``PIPE_SHADER_CAP_INDIRECT_CONST_ADDR``: Whether indirect addressing
650 of the constant file is supported.
651 * ``PIPE_SHADER_CAP_SUBROUTINES``: Whether subroutines are supported, i.e.
652 BGNSUB, ENDSUB, CAL, and RET, including RET in the main block.
653 * ``PIPE_SHADER_CAP_INTEGERS``: Whether integer opcodes are supported.
654 If unsupported, only float opcodes are supported.
655 * ``PIPE_SHADER_CAP_INT64_ATOMICS``: Whether int64 atomic opcodes are supported. The device needs to support add, sub, swap, cmpswap, and, or, xor, min, and max.
656 * ``PIPE_SHADER_CAP_FP16``: Whether half precision floating-point opcodes are supported.
657 If unsupported, half precision ops need to be lowered to full precision.
658 * ``PIPE_SHADER_CAP_FP16_DERIVATIVES``: Whether half precision floating-point
659 DDX and DDY opcodes are supported.
660 * ``PIPE_SHADER_CAP_INT16``: Whether 16-bit signed and unsigned integer types
661 are supported.
662 * ``PIPE_SHADER_CAP_GLSL_16BIT_TEMPS``: Lower mediump temporaries to 16-bit.
663 This generates 16-bit phis in NIR, 16-bit loop counters, and 16-bit indirect arrays.
664 * ``PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS``: The maximum number of texture
665 samplers.
666 * ``PIPE_SHADER_CAP_PREFERRED_IR``: Preferred representation of the
667 program. It should be one of the ``pipe_shader_ir`` enum values.
668 * ``PIPE_SHADER_CAP_MAX_SAMPLER_VIEWS``: The maximum number of texture
669 sampler views. Must not be lower than PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS.
670 * ``PIPE_SHADER_CAP_TGSI_DROUND_SUPPORTED``: Whether double precision rounding
671 is supported. If it is, DTRUNC/DCEIL/DFLR/DROUND opcodes may be used.
673 DLDEXP are supported.
674 * ``PIPE_SHADER_CAP_TGSI_LDEXP_SUPPORTED``: Whether LDEXP is supported.
675 * ``PIPE_SHADER_CAP_TGSI_FMA_SUPPORTED``: Whether FMA and DFMA (doubles only)
676 are supported.
677 * ``PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE``: Whether the driver doesn't
678 ignore tgsi_declaration_range::Last for shader inputs and outputs.
679 * ``PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT``: This is the maximum number
680 of iterations that loops are allowed to have to be unrolled. It is only
681 a hint to gallium frontends. Whether any loops will be unrolled is not
682 guaranteed.
683 * ``PIPE_SHADER_CAP_MAX_SHADER_BUFFERS``: Maximum number of memory buffers
684 (also used to implement atomic counters). Having this be non-0 also
685 implies support for the ``LOAD``, ``STORE``, and ``ATOM*`` TGSI
686 opcodes.
687 * ``PIPE_SHADER_CAP_SUPPORTED_IRS``: Supported representations of the
688 program. It should be a mask of ``pipe_shader_ir`` bits.
689 * ``PIPE_SHADER_CAP_MAX_SHADER_IMAGES``: Maximum number of image units.
690 * ``PIPE_SHADER_CAP_LOWER_IF_THRESHOLD``: IF and ELSE branches with a lower
691 cost than this value should be lowered by gallium frontends for better
692 performance. This is a tunable for the GLSL compiler and the behavior is
693 specific to the compiler.
694 * ``PIPE_SHADER_CAP_TGSI_SKIP_MERGE_REGISTERS``: Whether the merge registers
695 TGSI pass is skipped. This might reduce code size and register pressure if
696 the underlying driver has a real backend compiler.
697 * ``PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTERS``: If atomic counters are separate,
698 how many HW counters are available for this stage. (0 uses SSBO atomics).
699 * ``PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTER_BUFFERS``: If atomic counters are
700 separate, how many atomic counter buffers are available for this stage.
702 .. _pipe_compute_cap:
705 ^^^^^^^^^^^^^^^^^^
707 Compute-specific capabilities. They can be queried using
708 pipe_screen::get_compute_param.
710 * ``PIPE_COMPUTE_CAP_IR_TARGET``: A description of the target of the form
711 ``processor-arch-manufacturer-os`` that will be passed on to the compiler.
712 This CAP is only relevant for drivers that specify PIPE_SHADER_IR_NATIVE for
713 their preferred IR.
714 Value type: null-terminated string. Shader IR type dependent.
715 * ``PIPE_COMPUTE_CAP_GRID_DIMENSION``: Number of supported dimensions
716 for grid and block coordinates. Value type: ``uint64_t``. Shader IR type dependent.
717 * ``PIPE_COMPUTE_CAP_MAX_GRID_SIZE``: Maximum grid size in block
718 units. Value type: ``uint64_t []``. Shader IR type dependent.
719 * ``PIPE_COMPUTE_CAP_MAX_BLOCK_SIZE``: Maximum block size in thread
720 units. Value type: ``uint64_t []``. Shader IR type dependent.
721 * ``PIPE_COMPUTE_CAP_MAX_THREADS_PER_BLOCK``: Maximum number of threads that
722 a single block can contain. Value type: ``uint64_t``. Shader IR type dependent.
723 This may be less than the product of the components of MAX_BLOCK_SIZE and is
724 usually limited by the number of threads that can be resident simultaneously
725 on a compute unit.
726 * ``PIPE_COMPUTE_CAP_MAX_GLOBAL_SIZE``: Maximum size of the GLOBAL
727 resource. Value type: ``uint64_t``. Shader IR type dependent.
728 * ``PIPE_COMPUTE_CAP_MAX_LOCAL_SIZE``: Maximum size of the LOCAL
729 resource. Value type: ``uint64_t``. Shader IR type dependent.
730 * ``PIPE_COMPUTE_CAP_MAX_PRIVATE_SIZE``: Maximum size of the PRIVATE
731 resource. Value type: ``uint64_t``. Shader IR type dependent.
732 * ``PIPE_COMPUTE_CAP_MAX_INPUT_SIZE``: Maximum size of the INPUT
733 resource. Value type: ``uint64_t``. Shader IR type dependent.
734 * ``PIPE_COMPUTE_CAP_MAX_MEM_ALLOC_SIZE``: Maximum size of a memory object
735 allocation in bytes. Value type: ``uint64_t``.
736 * ``PIPE_COMPUTE_CAP_MAX_CLOCK_FREQUENCY``: Maximum frequency of the GPU
737 clock in MHz. Value type: ``uint32_t``
738 * ``PIPE_COMPUTE_CAP_MAX_COMPUTE_UNITS``: Maximum number of compute units
739 Value type: ``uint32_t``
740 * ``PIPE_COMPUTE_CAP_IMAGES_SUPPORTED``: Whether images are supported
741 non-zero means yes, zero means no. Value type: ``uint32_t``
742 * ``PIPE_COMPUTE_CAP_SUBGROUP_SIZE``: The size of a basic execution unit in
743 threads. Also known as wavefront size, warp size or SIMD width.
744 * ``PIPE_COMPUTE_CAP_ADDRESS_BITS``: The default compute device address space
745 size specified as an unsigned integer value in bits.
746 * ``PIPE_COMPUTE_CAP_MAX_VARIABLE_THREADS_PER_BLOCK``: Maximum variable number
747 of threads that a single block can contain. This is similar to
748 PIPE_COMPUTE_CAP_MAX_THREADS_PER_BLOCK, except that the variable size is not
749 known a compile-time but at dispatch-time.
751 .. _pipe_bind:
754 ^^^^^^^^^^^
756 These flags indicate how a resource will be used and are specified at resource
757 creation time. Resources may be used in different roles
758 during their lifecycle. Bind flags are cumulative and may be combined to create
759 a resource which can be used for multiple things.
760 Depending on the pipe driver's memory management and these bind flags,
761 resources might be created and handled quite differently.
763 * ``PIPE_BIND_RENDER_TARGET``: A color buffer or pixel buffer which will be
764 rendered to. Any surface/resource attached to pipe_framebuffer_state::cbufs
765 must have this flag set.
766 * ``PIPE_BIND_DEPTH_STENCIL``: A depth (Z) buffer and/or stencil buffer. Any
767 depth/stencil surface/resource attached to pipe_framebuffer_state::zsbuf must
768 have this flag set.
769 * ``PIPE_BIND_BLENDABLE``: Used in conjunction with PIPE_BIND_RENDER_TARGET to
770 query whether a device supports blending for a given format.
771 If this flag is set, surface creation may fail if blending is not supported
772 for the specified format. If it is not set, a driver may choose to ignore
773 blending on surfaces with formats that would require emulation.
774 * ``PIPE_BIND_DISPLAY_TARGET``: A surface that can be presented to screen. Arguments to
775 pipe_screen::flush_front_buffer must have this flag set.
776 * ``PIPE_BIND_SAMPLER_VIEW``: A texture that may be sampled from in a fragment
777 or vertex shader.
778 * ``PIPE_BIND_VERTEX_BUFFER``: A vertex buffer.
779 * ``PIPE_BIND_INDEX_BUFFER``: An vertex index/element buffer.
780 * ``PIPE_BIND_CONSTANT_BUFFER``: A buffer of shader constants.
781 * ``PIPE_BIND_STREAM_OUTPUT``: A stream output buffer.
783 * ``PIPE_BIND_SCANOUT``: A front color buffer or scanout buffer.
784 * ``PIPE_BIND_SHARED``: A sharable buffer that can be given to another
785 process.
786 * ``PIPE_BIND_GLOBAL``: A buffer that can be mapped into the global
787 address space of a compute program.
788 * ``PIPE_BIND_SHADER_BUFFER``: A buffer without a format that can be bound
789 to a shader and can be used with load, store, and atomic instructions.
790 * ``PIPE_BIND_SHADER_IMAGE``: A buffer or texture with a format that can be
791 bound to a shader and can be used with load, store, and atomic instructions.
792 * ``PIPE_BIND_COMPUTE_RESOURCE``: A buffer or texture that can be
793 bound to the compute program as a shader resource.
794 * ``PIPE_BIND_COMMAND_ARGS_BUFFER``: A buffer that may be sourced by the
795 GPU command processor. It can contain, for example, the arguments to
796 indirect draw calls.
798 .. _pipe_usage:
801 ^^^^^^^^^^^^
803 The PIPE_USAGE enums are hints about the expected usage pattern of a resource.
804 Note that drivers must always support read and write CPU access at any time
805 no matter which hint they got.
807 * ``PIPE_USAGE_DEFAULT``: Optimized for fast GPU access.
808 * ``PIPE_USAGE_IMMUTABLE``: Optimized for fast GPU access and the resource is
809 not expected to be mapped or changed (even by the GPU) after the first upload.
810 * ``PIPE_USAGE_DYNAMIC``: Expect frequent write-only CPU access. What is
811 uploaded is expected to be used at least several times by the GPU.
812 * ``PIPE_USAGE_STREAM``: Expect frequent write-only CPU access. What is
813 uploaded is expected to be used only once by the GPU.
814 * ``PIPE_USAGE_STAGING``: Optimized for fast CPU access.
817 Methods
818 -------
820 XXX to-do
822 get_name
823 ^^^^^^^^
825 Returns an identifying name for the screen.
827 The returned string should remain valid and immutable for the lifetime of
828 pipe_screen.
830 get_vendor
831 ^^^^^^^^^^
833 Returns the screen vendor.
835 The returned string should remain valid and immutable for the lifetime of
836 pipe_screen.
838 get_device_vendor
839 ^^^^^^^^^^^^^^^^^
841 Returns the actual vendor of the device driving the screen
842 (as opposed to the driver vendor).
844 The returned string should remain valid and immutable for the lifetime of
845 pipe_screen.
847 .. _get_param:
849 get_param
850 ^^^^^^^^^
852 Get an integer/boolean screen parameter.
854 **param** is one of the :ref:`PIPE_CAP` names.
856 .. _get_paramf:
858 get_paramf
859 ^^^^^^^^^^
861 Get a floating-point screen parameter.
863 **param** is one of the :ref:`PIPE_CAPF` names.
865 context_create
866 ^^^^^^^^^^^^^^
868 Create a pipe_context.
870 **priv** is private data of the caller, which may be put to various
871 unspecified uses, typically to do with implementing swapbuffers
872 and/or front-buffer rendering.
874 is_format_supported
875 ^^^^^^^^^^^^^^^^^^^
877 Determine if a resource in the given format can be used in a specific manner.
879 **format** the resource format
881 **target** one of the PIPE_TEXTURE_x flags
883 **sample_count** the number of samples. 0 and 1 mean no multisampling,
884 the maximum allowed legal value is 32.
886 **storage_sample_count** the number of storage samples. This must be <=
887 sample_count. See the documentation of ``pipe_resource::nr_storage_samples``.
889 **bindings** is a bitmask of :ref:`PIPE_BIND` flags.
891 Returns TRUE if all usages can be satisfied.
894 can_create_resource
895 ^^^^^^^^^^^^^^^^^^^
897 Check if a resource can actually be created (but don't actually allocate any
898 memory). This is used to implement OpenGL's proxy textures. Typically, a
899 driver will simply check if the total size of the given resource is less than
900 some limit.
902 For PIPE_TEXTURE_CUBE, the pipe_resource::array_size field should be 6.
905 .. _resource_create:
907 resource_create
908 ^^^^^^^^^^^^^^^
910 Create a new resource from a template.
911 The following fields of the pipe_resource must be specified in the template:
913 **target** one of the pipe_texture_target enums.
914 Note that PIPE_BUFFER and PIPE_TEXTURE_X are not really fundamentally different.
915 Modern APIs allow using buffers as shader resources.
917 **format** one of the pipe_format enums.
919 **width0** the width of the base mip level of the texture or size of the buffer.
921 **height0** the height of the base mip level of the texture
922 (1 for 1D or 1D array textures).
924 **depth0** the depth of the base mip level of the texture
925 (1 for everything else).
927 **array_size** the array size for 1D and 2D array textures.
928 For cube maps this must be 6, for other textures 1.
930 **last_level** the last mip map level present.
932 **nr_samples**: Number of samples determining quality, driving the rasterizer,
933 shading, and framebuffer. It is the number of samples seen by the whole
934 graphics pipeline. 0 and 1 specify a resource which isn't multisampled.
936 **nr_storage_samples**: Only color buffers can set this lower than nr_samples.
937 Multiple samples within a pixel can have the same color. ``nr_storage_samples``
938 determines how many slots for different colors there are per pixel.
939 If there are not enough slots to store all sample colors, some samples will
940 have an undefined color (called "undefined samples").
942 The resolve blit behavior is driver-specific, but can be one of these two:
944 1. Only defined samples will be averaged. Undefined samples will be ignored.
945 2. Undefined samples will be approximated by looking at surrounding defined
946 samples (even in different pixels).
948 Blits and MSAA texturing: If the sample being fetched is undefined, one of
949 the defined samples is returned instead.
951 Sample shading (``set_min_samples``) will operate at a sample frequency that
952 is at most ``nr_storage_samples``. Greater ``min_samples`` values will be
953 replaced by ``nr_storage_samples``.
955 **usage** one of the :ref:`PIPE_USAGE` flags.
957 **bind** bitmask of the :ref:`PIPE_BIND` flags.
959 **flags** bitmask of PIPE_RESOURCE_FLAG flags.
961 **next**: Pointer to the next plane for resources that consist of multiple
962 memory planes.
964 As a corollary, this mean resources for an image with multiple planes have
965 to be created starting from the highest plane.
967 resource_changed
968 ^^^^^^^^^^^^^^^^
970 Mark a resource as changed so derived internal resources will be recreated
971 on next use.
973 When importing external images that can't be directly used as texture sampler
974 source, internal copies may have to be created that the hardware can sample
975 from. When those resources are reimported, the image data may have changed, and
976 the previously derived internal resources must be invalidated to avoid sampling
977 from old copies.
981 resource_destroy
982 ^^^^^^^^^^^^^^^^
984 Destroy a resource. A resource is destroyed if it has no more references.
988 get_timestamp
989 ^^^^^^^^^^^^^
991 Query a timestamp in nanoseconds. The returned value should match
992 PIPE_QUERY_TIMESTAMP. This function returns immediately and doesn't
993 wait for rendering to complete (which cannot be achieved with queries).
997 get_driver_query_info
998 ^^^^^^^^^^^^^^^^^^^^^
1000 Return a driver-specific query. If the **info** parameter is NULL,
1001 the number of available queries is returned. Otherwise, the driver
1002 query at the specified **index** is returned in **info**.
1003 The function returns non-zero on success.
1004 The driver-specific query is described with the pipe_driver_query_info
1005 structure.
1007 get_driver_query_group_info
1008 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
1010 Return a driver-specific query group. If the **info** parameter is NULL,
1011 the number of available groups is returned. Otherwise, the driver
1012 query group at the specified **index** is returned in **info**.
1013 The function returns non-zero on success.
1014 The driver-specific query group is described with the
1015 pipe_driver_query_group_info structure.
1019 get_disk_shader_cache
1020 ^^^^^^^^^^^^^^^^^^^^^
1022 Returns a pointer to a driver-specific on-disk shader cache. If the driver
1023 failed to create the cache or does not support an on-disk shader cache NULL is
1024 returned. The callback itself may also be NULL if the driver doesn't support
1025 an on-disk shader cache.
1028 Thread safety
1029 -------------
1031 Screen methods are required to be thread safe. While gallium rendering
1032 contexts are not required to be thread safe, it is required to be safe to use
1033 different contexts created with the same screen in different threads without
1034 locks. It is also required to be safe using screen methods in a thread, while
1035 using one of its contexts in another (without locks).