# Screen

A screen is an object representing the context-independent part of a device.

## Flags and enumerations

XXX some of these don’t belong in this section.

### pipe_caps

Capability about the features and limits of the driver/GPU.

- `pipe_caps.graphics`: Whether graphics is supported. If not, contexts can only be created with PIPE_CONTEXT_COMPUTE_ONLY.

- `pipe_caps.npot_textures`: Whether NPOT textures may have repeat modes, normalized coordinates, and mipmaps.

- `pipe_caps.max_dual_source_render_targets`: How many dual-source blend RTs are support. Blend for more information.

- `pipe_caps.anisotropic_filter`: Whether textures can be filtered anisotropically.

- `pipe_caps.max_render_targets`: The maximum number of render targets that may be bound.

- `pipe_caps.occlusion_query`: Whether occlusion queries are available.

- `pipe_caps.query_time_elapsed`: Whether PIPE_QUERY_TIME_ELAPSED queries are available.

- `pipe_caps.texture_shadow_map`: indicates whether the fragment shader hardware can do the depth texture / Z comparison operation in TEX instructions for shadow testing.

- `pipe_caps.texture_swizzle`: Whether swizzling through sampler views is supported.

- `pipe_caps.max_texture_2d_size`: The maximum size of 2D (and 1D) textures.

- `pipe_caps.max_texture_3d_levels`: The maximum number of mipmap levels available for a 3D texture.

- `pipe_caps.max_texture_cube_levels`: The maximum number of mipmap levels available for a cubemap.

- `pipe_caps.texture_mirror_clamp_to_edge`: Whether mirrored texture coordinates are supported with the clamp-to-edge wrap mode.

- `pipe_caps.texture_mirror_clamp`: Whether mirrored texture coordinates are supported with clamp or clamp-to-border wrap modes.

- `pipe_caps.blend_equation_separate`: Whether alpha blend equations may be different from color blend equations, in Blend state.

- `pipe_caps.max_stream_output_buffers`: The maximum number of stream buffers.

- `pipe_caps.primitive_restart`: Whether primitive restart is supported.

- `pipe_caps.primitive_restart_fixed_index`: Subset of PRIMITIVE_RESTART where the restart index is always the fixed maximum value for the index type.

- `pipe_caps.indep_blend_enable`: Whether per-rendertarget blend enabling and channel masks are supported. If 0, then the first rendertarget’s blend mask is replicated across all MRTs.

- `pipe_caps.indep_blend_func`: Whether per-rendertarget blend functions are available. If 0, then the first rendertarget’s blend functions affect all MRTs.

- `pipe_caps.max_texture_array_layers`: The maximum number of texture array layers supported. If 0, the array textures are not supported at all and the ARRAY texture targets are invalid.

- `pipe_caps.fs_coord_origin_upper_left`: Whether the upper-left origin fragment convention is supported.

- `pipe_caps.fs_coord_origin_lower_left`: Whether the lower-left origin fragment convention is supported.

- `pipe_caps.fs_coord_pixel_center_half_integer`: Whether the half-integer pixel-center fragment convention is supported.

- `pipe_caps.fs_coord_pixel_center_integer`: Whether the integer pixel-center fragment convention is supported.

- `pipe_caps.depth_clip_disable`: Whether the driver is capable of disabling depth clipping (through pipe_rasterizer_state).

- `pipe_caps.depth_clip_disable_separate`: Whether the driver is capable of disabling depth clipping (through pipe_rasterizer_state) separately for the near and far plane. If not, depth_clip_near and depth_clip_far will be equal. `pipe_caps.depth_clamp_enable`: Whether the driver is capable of enabling depth clamping (through pipe_rasterizer_state) separately from depth clipping. If not, depth_clamp will be the inverse of depth_clip_far.

- `pipe_caps.shader_stencil_export`: Whether a stencil reference value can be written from a fragment shader.

- `pipe_caps.vs_instanceid`: Whether `SYSTEM_VALUE_INSTANCE_ID` is supported in the vertex shader.

- `pipe_caps.vertex_element_instance_divisor`: Whether the driver supports per-instance vertex attribs.

- `pipe_caps.fragment_color_clamped`: Whether fragment color clamping is supported. That is, is the pipe_rasterizer_state::clamp_fragment_color flag supported by the driver? If not, gallium frontends will insert clamping code into the fragment shaders when needed.

- `pipe_caps.mixed_colorbuffer_formats`: Whether mixed colorbuffer formats are supported, e.g. RGBA8 and RGBA32F as the first and second colorbuffer, resp.

- `pipe_caps.vertex_color_unclamped`: Whether the driver is capable of outputting unclamped vertex colors from a vertex shader. If unsupported, the vertex colors are always clamped. This is the default for DX9 hardware.

- `pipe_caps.vertex_color_clamped`: Whether the driver is capable of clamping vertex colors when they come out of a vertex shader, as specified by the pipe_rasterizer_state::clamp_vertex_color flag. If unsupported, the vertex colors are never clamped. This is the default for DX10 hardware. If both clamped and unclamped CAPs are supported, the clamping can be controlled through pipe_rasterizer_state. If the driver cannot do vertex color clamping, gallium frontends may insert clamping code into the vertex shader.

- `pipe_caps.glsl_feature_level`: Whether the driver supports features equivalent to a specific GLSL version. E.g. for GLSL 1.3, report 130.

- `pipe_caps.glsl_feature_level_compatibility`: Whether the driver supports features equivalent to a specific GLSL version including all legacy OpenGL features only present in the OpenGL compatibility profile. The only legacy features that Gallium drivers must implement are the legacy shader inputs and outputs (colors, texcoords, fog, clipvertex, edge flag).

- `pipe_caps.essl_feature_level`: An optional cap to allow drivers to report a higher GLSL version for GLES contexts. This is useful when a driver does not support all the required features for a higher GL version, but does support the required features for a higher GLES version. A driver is allowed to return `0` in which case `pipe_caps.glsl_feature_level` is used. Note that simply returning the same value as the GLSL feature level cap is incorrect. For example, GLSL version 3.30 does not require GL_EXT_gpu_shader5, but ESSL version 3.20 es does require GL_EXT_gpu_shader5

- `pipe_caps.quads_follow_provoking_vertex_convention`: Whether quads adhere to the flatshade_first setting in `pipe_rasterizer_state`.

- `pipe_caps.user_vertex_buffers`: Whether the driver supports user vertex buffers. If not, gallium frontends must upload all data which is not in HW resources. If user-space buffers are supported, the driver must also still accept HW resource buffers.

- `pipe_caps.vertex_input_alignment`: This CAP describes a HW limitation. If `PIPE_VERTEX_INPUT_ALIGNMENT_4BYTE``, pipe_vertex_buffer::buffer_offset must always be aligned to 4, and pipe_vertex_buffer::stride must always be aligned to 4, and pipe_vertex_element::src_offset must always be aligned to 4. If `PIPE_VERTEX_INPUT_ALIGNMENT_ELEMENT`, the sum of `pipe_vertex_element::src_offset + pipe_vertex_buffer::buffer_offset + pipe_vertex_buffer::stride` must always be aligned to the component size for the vertex attributes which access that buffer. If `PIPE_VERTEX_INPUT_ALIGNMENT_NONE`, there are no restrictions on these values.

- `pipe_caps.compute`: Whether the implementation supports the compute entry points defined in pipe_context and pipe_screen.

- `pipe_caps.constant_buffer_offset_alignment`: Describes the required alignment of pipe_constant_buffer::buffer_offset.

- `pipe_caps.start_instance`: Whether the driver supports pipe_draw_info::start_instance.

- `pipe_caps.query_timestamp`: Whether PIPE_QUERY_TIMESTAMP and the pipe_screen::get_timestamp hook are implemented.

- `pipe_caps.query_timestamp_bits`: How many bits the driver uses for the results of GL_TIMESTAMP queries.

- `pipe_caps.timer_resolution`: The resolution of the timer in nanos.

- `pipe_caps.texture_multisample`: Whether all MSAA resources supported for rendering are also supported for texturing.

- `pipe_caps.min_map_buffer_alignment`: The minimum alignment that should be expected for a pointer returned by transfer_map if the resource is PIPE_BUFFER. In other words, the pointer returned by transfer_map is always aligned to this value.

- `pipe_caps.texture_buffer_offset_alignment`: Describes the required alignment for pipe_sampler_view::u.buf.offset, in bytes. If a driver does not support offset/size, it should return 0.

- `pipe_caps.linear_image_pitch_alignment`: Describes the row pitch alignment size that pipe_sampler_view::u.tex2d_from_buf must be multiple of, in pixels. If a driver does not support images created from buffers, it should return 0.

- `pipe_caps.linear_image_base_address_alignment`: Describes the minimum alignment in pixels of the offset of a host pointer for images created from buffers. If a driver does not support images created from buffers, it should return 0.

- `pipe_caps.buffer_sampler_view_rgba_only`: Whether the driver only supports R, RG, RGB and RGBA formats for PIPE_BUFFER sampler views. When this is the case it should be assumed that the swizzle parameters in the sampler view have no effect.

- `pipe_caps.tgsi_texcoord`: This CAP describes a HW limitation. If true, the hardware cannot replace arbitrary shader inputs with sprite coordinates and hence the inputs that are desired to be replaceable must be declared with TGSI_SEMANTIC_TEXCOORD instead of TGSI_SEMANTIC_GENERIC. The rasterizer’s sprite_coord_enable state therefore also applies to the TEXCOORD semantic. Also, TGSI_SEMANTIC_PCOORD becomes available, which labels a fragment shader input that will always be replaced with sprite coordinates.

- `pipe_caps.texture_transfer_modes`: The `pipe_texture_transfer_mode` modes that are supported for implementing a texture transfer which needs format conversions and swizzling in gallium frontends. Generally, all hardware drivers with dedicated memory should return PIPE_TEXTURE_TRANSFER_BLIT and all software rasterizers should return PIPE_TEXTURE_TRANSFER_DEFAULT. PIPE_TEXTURE_TRANSFER_COMPUTE requires drivers to support 8bit and 16bit shader storage buffer writes and to implement pipe_screen::is_compute_copy_faster.

- `pipe_caps.query_pipeline_statistics`: Whether PIPE_QUERY_PIPELINE_STATISTICS is supported.

- `pipe_caps.texture_border_color_quirk`: Bitmask indicating whether special considerations have to be given to the interaction between the border color in the sampler object and the sampler view used with it. If PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_R600 is set, the border color may be affected in undefined ways for any kind of permutational swizzle (any swizzle XYZW where X/Y/Z/W are not ZERO, ONE, or R/G/B/A respectively) in the sampler view. If PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_NV50 is set, the border color state should be swizzled manually according to the swizzle in the sampler view it is intended to be used with, or herein undefined results may occur for permutational swizzles.

- `pipe_caps.max_texel_buffer_elements`: The maximum accessible number of elements within a sampler buffer view and image buffer view. This is unsigned integer with the maximum of 4G - 1.

- `pipe_caps.max_viewports`: The maximum number of viewports (and scissors since they are linked) a driver can support. Returning 0 is equivalent to returning 1 because every driver has to support at least a single viewport/scissor combination.

- `pipe_caps.endianness`:: The endianness of the device. Either PIPE_ENDIAN_BIG or PIPE_ENDIAN_LITTLE.

- `pipe_caps.mixed_framebuffer_sizes`: Whether it is allowed to have different sizes for fb color/zs attachments. This controls whether GL_ARB_framebuffer_object is provided.

- `pipe_caps.vs_layer_viewport`: Whether `VARYING_SLOT_LAYER` and `VARYING_SLOT_VIEWPORT` are supported as vertex shader outputs. Note that the viewport will only be used if multiple viewports are exposed.

- `pipe_caps.max_geometry_output_vertices`: The maximum number of vertices output by a single invocation of a geometry shader.

- `pipe_caps.max_geometry_total_output_components`: The maximum number of vertex components output by a single invocation of a geometry shader. This is the product of the number of attribute components per vertex and the number of output vertices.

- `pipe_caps.max_texture_gather_components`: Max number of components in format that texture gather can operate on. 1 == RED, ALPHA etc, 4 == All formats.

- `pipe_caps.texture_gather_sm5`: Whether the texture gather hardware implements the SM5 features, component selection, shadow comparison, and run-time offsets.

- `pipe_caps.buffer_map_persistent_coherent`: Whether PIPE_MAP_PERSISTENT and PIPE_MAP_COHERENT are supported for buffers.

- `pipe_caps.texture_query_lod`: Whether the `LODQ` instruction is supported.

- `pipe_caps.min_texture_gather_offset`: The minimum offset that can be used in conjunction with a texture gather opcode.

- `pipe_caps.max_texture_gather_offset`: The maximum offset that can be used in conjunction with a texture gather opcode.

- `pipe_caps.sample_shading`: Whether there is support for per-sample shading. The context->set_min_samples function will be expected to be implemented.

- `pipe_caps.texture_gather_offsets`: Whether the `TG4` instruction can accept 4 offsets.

- `pipe_caps.vs_window_space_position`: Whether window-space position is supported, which disables clipping and viewport transformation.

- `pipe_caps.max_vertex_streams`: The maximum number of vertex streams supported by the geometry shader. If stream-out is supported, this should be at least 1. If stream-out is not supported, this should be 0.

- `pipe_caps.draw_indirect`: Whether the driver supports taking draw arguments { count, instance_count, start, index_bias } from a PIPE_BUFFER resource. See pipe_draw_info.

- `pipe_caps.multi_draw_indirect`: Whether the driver supports pipe_draw_info::indirect_stride and ::indirect_count

- `pipe_caps.multi_draw_indirect_params`: Whether the driver supports taking the number of indirect draws from a separate parameter buffer, see pipe_draw_indirect_info::indirect_draw_count.

- `pipe_caps.multi_draw_indirect_partial_stride`: Whether the driver supports indirect draws with an arbitrary stride.

- `pipe_caps.fs_fine_derivative`: Whether the fragment shader supports the FINE versions of DDX/DDY.

- `pipe_caps.vendor_id`: The vendor ID of the underlying hardware. If it’s not available one should return 0xFFFFFFFF.

- `pipe_caps.device_id`: The device ID (PCI ID) of the underlying hardware. 0xFFFFFFFF if not available.

- `pipe_caps.accelerated`: Whether the renderer is hardware accelerated. 0 means not accelerated (i.e. CPU rendering), 1 means accelerated (i.e. GPU rendering), -1 means unknown (i.e. an API translation driver which doesn’t known what kind of hardware it’s running above).

- `pipe_caps.video_memory`: The amount of video memory in megabytes.

- `pipe_caps.uma`: If the device has a unified memory architecture or on-card memory and GART.

- `pipe_caps.conditional_render_inverted`: Whether the driver supports inverted condition for conditional rendering.

- `pipe_caps.max_vertex_attrib_stride`: The maximum supported vertex stride.

- `pipe_caps.sampler_view_target`: Whether the sampler view’s target can be different than the underlying resource’s, as permitted by GL_ARB_texture_view. For example a 2d array texture may be reinterpreted as a cube (array) texture and vice-versa.

- `pipe_caps.clip_halfz`: Whether the driver supports the pipe_rasterizer_state::clip_halfz being set to true. This is required for enabling GL_ARB_clip_control.

- `pipe_caps.polygon_offset_clamp`: If true, the driver implements support for `pipe_rasterizer_state::offset_clamp`.

- `pipe_caps.multisample_z_resolve`: Whether the driver supports blitting a multisampled depth buffer into a single-sampled texture (or depth buffer). Only the first sampled should be copied.

- `pipe_caps.resource_from_user_memory`: Whether the driver can create a pipe_resource where an already-existing piece of (malloc’d) user memory is used as its backing storage. In other words, whether the driver can map existing user memory into the device address space for direct device access. The create function is pipe_screen::resource_from_user_memory. The address and size must be page-aligned.

- `pipe_caps.resource_from_user_memory_compute_only`: Same as `pipe_caps.resource_from_user_memory` but indicates it is only supported from the compute engines.

- `pipe_caps.device_reset_status_query`: Whether pipe_context::get_device_reset_status is implemented.

- `pipe_caps.max_shader_patch_varyings`: How many per-patch outputs and inputs are supported between tessellation control and tessellation evaluation shaders, not counting in TESSINNER and TESSOUTER. The minimum allowed value for OpenGL is 30.

- `pipe_caps.texture_float_linear`: Whether the linear minification and magnification filters are supported with single-precision floating-point textures.

- `pipe_caps.texture_half_float_linear`: Whether the linear minification and magnification filters are supported with half-precision floating-point textures.

- `pipe_caps.depth_bounds_test`: Whether bounds_test, bounds_min, and bounds_max states of pipe_depth_stencil_alpha_state behave according to the GL_EXT_depth_bounds_test specification.

- `pipe_caps.texture_query_samples`: Whether the `TXQS` opcode is supported

- `pipe_caps.force_persample_interp`: If the driver can force per-sample interpolation for all fragment shader inputs if pipe_rasterizer_state::force_persample_interp is set. This is only used by GL3-level sample shading (GL_ARB_sample_shading). GL4-level sample shading (GL_ARB_gpu_shader5) doesn’t use this. While GL3 hardware has a state for it, GL4 hardware will likely need to emulate it with a shader variant, or by selecting the interpolation weights with a conditional assignment in the shader.

- `pipe_caps.shareable_shaders`: Whether shader CSOs can be used by any pipe_context. Important for reducing jank at draw time by letting GL shaders linked in one thread be used in another thread without recompiling.

- `pipe_caps.copy_between_compressed_and_plain_formats`: Whether copying between compressed and plain formats is supported where a compressed block is copied to/from a plain pixel of the same size.

- `pipe_caps.clear_scissored`: Whether `clear` can accept a scissored bounding box.

- `pipe_caps.draw_parameters`: Whether `TGSI_SEMANTIC_BASEVERTEX`, `TGSI_SEMANTIC_BASEINSTANCE`, and `TGSI_SEMANTIC_DRAWID` are supported in vertex shaders.

- `pipe_caps.shader_pack_half_float`: Whether packed 16-bit float packing/unpacking opcodes are supported.

- `pipe_caps.fs_position_is_sysval`: If gallium frontends should use a system value for the POSITION fragment shader input.

- `pipe_caps.fs_point_is_sysval`: If gallium frontends should use a system value for the POINT fragment shader input.

- `pipe_caps.fs_face_is_integer_sysval`: If gallium frontends should use a system value for the FACE fragment shader input. Also, the FACE system value is integer, not float.

- `pipe_caps.shader_buffer_offset_alignment`: Describes the required alignment for pipe_shader_buffer::buffer_offset, in bytes. Maximum value allowed is 256 (for GL conformance). 0 is only allowed if shader buffers are not supported.

- `pipe_caps.invalidate_buffer`: Whether the use of `invalidate_resource` for buffers is supported.

- `pipe_caps.generate_mipmap`: Indicates whether pipe_context::generate_mipmap is supported.

- `pipe_caps.string_marker`: Whether pipe->emit_string_marker() is supported.

- `pipe_caps.surface_reinterpret_blocks`: Indicates whether pipe_context::create_surface supports reinterpreting a texture as a surface of a format with different block width/height (but same block size in bits). For example, a compressed texture image can be interpreted as a non-compressed surface whose texels are the same number of bits as the compressed blocks, and vice versa. The width and height of the surface is adjusted appropriately.

- `pipe_caps.query_buffer_object`: Driver supports context::get_query_result_resource callback.

- `pipe_caps.pci_group`: Return the PCI segment group number.

- `pipe_caps.pci_bus`: Return the PCI bus number.

- `pipe_caps.pci_device`: Return the PCI device number.

- `pipe_caps.pci_function`: Return the PCI function number.

- `pipe_caps.framebuffer_no_attachment`: If non-zero, rendering to framebuffers with no surface attachments is supported. The context->is_format_supported function will be expected to be implemented with PIPE_FORMAT_NONE yielding the MSAA modes the hardware supports. N.B., The maximum number of layers supported for rasterizing a primitive on a layer is obtained from `pipe_caps.max_texture_array_layers` even though it can be larger than the number of layers supported by either rendering or textures.

- `pipe_caps.robust_buffer_access_behavior`: Implementation uses bounds checking on resource accesses by shader if the context is created with PIPE_CONTEXT_ROBUST_BUFFER_ACCESS. See the GL_ARB_robust_buffer_access_behavior extension for information on the required behavior for out of bounds accesses and accesses to unbound resources.

- `pipe_caps.cull_distance`: Whether the driver supports the GL_ARB_cull_distance extension and thus implements proper support for culling planes.

- `pipe_caps.primitive_restart_for_patches`: Whether primitive restart is supported for patch primitives.

- `pipe_caps.shader_group_vote`: Whether the `VOTE_*` ops can be used in shaders.

- `pipe_caps.max_window_rectangles`: The maximum number of window rectangles supported in `set_window_rectangles`.

- `pipe_caps.polygon_offset_units_unscaled`: If true, the driver implements support for `pipe_rasterizer_state::offset_units_unscaled`.

- `pipe_caps.viewport_subpixel_bits`: Number of bits of subpixel precision for floating point viewport bounds.

- `pipe_caps.rasterizer_subpixel_bits`: Number of bits of subpixel precision used by the rasterizer.

- `pipe_caps.mixed_color_depth_bits`: Whether there is non-fallback support for color/depth format combinations that use a different number of bits. For the purpose of this cap, Z24 is treated as 32-bit. If set to off, that means that a B5G6R5 + Z24 or RGBA8 + Z16 combination will require a driver fallback, and should not be advertised in the GLX/EGL config list.

- `pipe_caps.shader_array_components`: If true, the driver interprets the UsageMask of input and output declarations and allows declaring arrays in overlapping ranges. The components must be a contiguous range, e.g. a UsageMask of xy or yzw is allowed, but xz or yw isn’t. Declarations with overlapping locations must have matching semantic names and indices, and equal interpolation qualifiers. Components may overlap, notably when the gaps in an array of dvec3 are filled in.

- `pipe_caps.stream_output_pause_resume`: Whether GL_ARB_transform_feedback2 is supported, including pausing/resuming queries and having `count_from_stream_output` set on indirect draws to implement glDrawTransformFeedback. Required for OpenGL 4.0.

- `pipe_caps.stream_output_interleave_buffers`: Whether interleaved stream output mode is able to interleave across buffers. This is required for GL_ARB_transform_feedback3.

- `pipe_caps.fbfetch`: The number of render targets whose value in the current framebuffer can be read in the shader. 0 means framebuffer fetch is not supported. 1 means that only the first render target can be read, and a larger value would mean that multiple render targets are supported.

- `pipe_caps.fbfetch_coherent`: Whether framebuffer fetches from the fragment shader can be guaranteed to be coherent with framebuffer writes.

- `pipe_caps.fbfetch_zs`: Whether fragment shader can fetch current values of Z/S attachments. These fetches are always coherent with framebuffer writes.

- `pipe_caps.legacy_math_rules`: Whether NIR shaders support the `shader_info.use_legacy_math_rules` flag (see documentation there), and TGSI shaders support the corresponding `TGSI_PROPERTY_LEGACY_MATH_RULES`.

- `pipe_caps.fp16`: Whether 16-bit float operations are supported.

- `pipe_caps.doubles`: Whether double precision floating-point operations are supported.

- `pipe_caps.int64`: Whether 64-bit integer operations are supported.

- `pipe_caps.tgsi_tex_txf_lz`: Whether TEX_LZ and TXF_LZ opcodes are supported.

- `pipe_caps.shader_clock`: Whether the CLOCK opcode is supported.

- `pipe_caps.polygon_mode_fill_rectangle`: Whether the PIPE_POLYGON_MODE_FILL_RECTANGLE mode is supported for `pipe_rasterizer_state::fill_front` and `pipe_rasterizer_state::fill_back`.

- `pipe_caps.sparse_buffer_page_size`: The page size of sparse buffers in bytes, or 0 if sparse buffers are not supported. The page size must be at most 64KB.

- `pipe_caps.shader_ballot`: Whether the BALLOT and READ_* opcodes as well as the SUBGROUP_* semantics are supported.

- `pipe_caps.tes_layer_viewport`: Whether `VARYING_SLOT_LAYER` and `VARYING_SLOT_VIEWPORT` are supported as tessellation evaluation shader outputs.

- `pipe_caps.can_bind_const_buffer_as_vertex`: Whether a buffer with just PIPE_BIND_CONSTANT_BUFFER can be legally passed to set_vertex_buffers.

- `pipe_caps.allow_mapped_buffers_during_execution`: As the name says.

- `pipe_caps.post_depth_coverage`: whether `TGSI_PROPERTY_FS_POST_DEPTH_COVERAGE` is supported.

- `pipe_caps.bindless_texture`: Whether bindless texture operations are supported.

- `pipe_caps.nir_samplers_as_deref`: Whether NIR tex instructions should reference texture and sampler as NIR derefs instead of by indices.

- `pipe_caps.query_so_overflow`: Whether the `PIPE_QUERY_SO_OVERFLOW_PREDICATE` and `PIPE_QUERY_SO_OVERFLOW_ANY_PREDICATE` query types are supported. Note that for a driver that does not support multiple output streams (i.e., `pipe_caps.max_vertex_streams` is 1), both query types are identical.

- `pipe_caps.memobj`: Whether operations on memory objects are supported.

- `pipe_caps.load_constbuf`: True if the driver supports `TGSI_OPCODE_LOAD` use with constant buffers.

- `pipe_caps.tile_raster_order`: Whether the driver supports GL_MESA_tile_raster_order, using the tile_raster_order_* fields in pipe_rasterizer_state.

- `pipe_caps.max_combined_shader_output_resources`: Limit on combined shader output resources (images + buffers + fragment outputs). If 0 the state tracker works it out.

- `pipe_caps.framebuffer_msaa_constraints`: This determines limitations on the number of samples that framebuffer attachments can have. Possible values:

  > 0. color.nr_samples == zs.nr_samples == color.nr_storage_samples (standard MSAA quality)

  > 1. color.nr_samples >= zs.nr_samples == color.nr_storage_samples (enhanced MSAA quality)

  > 2. color.nr_samples >= zs.nr_samples >= color.nr_storage_samples (full flexibility in tuning MSAA quality and performance)

  All color attachments must have the same number of samples and the same number of storage samples.

- `pipe_caps.signed_vertex_buffer_offset`: Whether pipe_vertex_buffer::buffer_offset is treated as signed. The u_vbuf module needs this for optimal performance in workstation applications.

- `pipe_caps.context_priority_mask`: For drivers that support per-context priorities, this returns a bitmask of `PIPE_CONTEXT_PRIORITY_x` for the supported priority levels. A driver that does not support prioritized contexts can return 0.

- `pipe_caps.fence_signal`: True if the driver supports signaling semaphores using fence_server_signal().

- `pipe_caps.constbuf0_flags`: The bits of pipe_resource::flags that must be set when binding that buffer as constant buffer 0. If the buffer doesn’t have those bits set, pipe_context::set_constant_buffer(.., 0, ..) is ignored by the driver, and the driver can throw assertion failures.

- `pipe_caps.packed_uniforms`: True if the driver supports packed uniforms as opposed to padding to vec4s. Requires `PIPE_SHADER_CAP_INTEGERS` if `lower_uniforms_to_ubo` is set.

- `pipe_caps.conservative_raster_post_snap_triangles`: Whether the `PIPE_CONSERVATIVE_RASTER_POST_SNAP` mode is supported for triangles. The post-snap mode means the conservative rasterization occurs after the conversion from floating-point to fixed-point coordinates on the subpixel grid.

- `pipe_caps.conservative_raster_post_snap_points_lines`: Whether the `PIPE_CONSERVATIVE_RASTER_POST_SNAP` mode is supported for points and lines.

- `pipe_caps.conservative_raster_pre_snap_triangles`: Whether the `PIPE_CONSERVATIVE_RASTER_PRE_SNAP` mode is supported for triangles. The pre-snap mode means the conservative rasterization occurs before the conversion from floating-point to fixed-point coordinates.

- `pipe_caps.conservative_raster_pre_snap_points_lines`: Whether the `PIPE_CONSERVATIVE_RASTER_PRE_SNAP` mode is supported for points and lines.

- `pipe_caps.conservative_raster_post_depth_coverage`: Whether `pipe_caps.post_depth_coverage` works with conservative rasterization.

- `pipe_caps.conservative_raster_inner_coverage`: Whether inner_coverage from GL_INTEL_conservative_rasterization is supported.

- `pipe_caps.max_conservative_raster_subpixel_precision_bias`: The maximum subpixel precision bias in bits during conservative rasterization.

- `pipe_caps.programmable_sample_locations`: True is the driver supports programmable sample location through ``get_sample_pixel_grid`` and ``set_sample_locations``.

- `pipe_caps.max_gs_invocations`: Maximum supported value of TGSI_PROPERTY_GS_INVOCATIONS.

- `pipe_caps.max_shader_buffer_size`: Maximum supported size for binding with set_shader_buffers. This is unsigned integer with the maximum of 4GB - 1.

- `pipe_caps.max_combined_shader_buffers`: Maximum total number of shader buffers. A value of 0 means the sum of all per-shader stage maximums (see `PIPE_SHADER_CAP_MAX_SHADER_BUFFERS`).

- `pipe_caps.max_combined_hw_atomic_counters`: Maximum total number of atomic counters. A value of 0 means the default value (MAX_ATOMIC_COUNTERS = 4096).

- `pipe_caps.max_combined_hw_atomic_counter_buffers`: Maximum total number of atomic counter buffers. A value of 0 means the sum of all per-shader stage maximums (see `PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTER_BUFFERS`).

- `pipe_caps.max_texture_upload_memory_budget`: Maximum recommend memory size for all active texture uploads combined. This is a performance hint. 0 means no limit.

- `pipe_caps.max_vertex_element_src_offset`: The maximum supported value for of pipe_vertex_element::src_offset.

- `pipe_caps.surface_sample_count`: Whether the driver supports pipe_surface overrides of resource nr_samples. If set, will enable GL_EXT_multisampled_render_to_texture.

- `pipe_caps.image_atomic_float_add`: Atomic floating point adds are supported on images, buffers, and shared memory.

- `pipe_caps.glsl_tess_levels_as_inputs`: True if the driver wants TESSINNER and TESSOUTER to be inputs (rather than system values) for tessellation evaluation shaders.

- `pipe_caps.dest_surface_srgb_control`: Indicates whether the drivers supports switching the format between sRGB and linear for a surface that is used as destination in draw and blit calls.

- `pipe_caps.max_varyings`: The maximum number of fragment shader varyings. This will generally correspond to `PIPE_SHADER_CAP_MAX_INPUTS` for the fragment shader, but in some cases may be a smaller number.

- `pipe_caps.compute_grid_info_last_block`: Whether pipe_grid_info::last_block is implemented by the driver. See struct pipe_grid_info for more details.

- `pipe_caps.compute_shader_derivative`: True if the driver supports derivatives (and texture lookups with implicit derivatives) in compute shaders.

- `pipe_caps.image_load_formatted`: True if a format for image loads does not need to be specified in the shader IR

- `pipe_caps.image_store_formatted`: True if a format for image stores does not need to be specified in the shader IR

- `pipe_caps.throttle`: Whether or not gallium frontends should throttle pipe_context execution. 0 = throttling is disabled.

- `pipe_caps.dmabuf`: Whether Linux DMABUF handles are supported by resource_from_handle and resource_get_handle. Possible bit field values:

  > 1. `DRM_PRIME_CAP_IMPORT`: resource_from_handle is supported

  > 2. `DRM_PRIME_CAP_EXPORT`: resource_get_handle is supported

- `pipe_caps.cl_gl_sharing`: True if driver supports everything required by a frontend implementing the CL extension, and also supports importing/exporting all of pipe_texture_target via dma buffers.

- `pipe_caps.prefer_compute_for_multimedia`: Whether VDPAU and VAAPI should use a compute-based blit instead of pipe_context::blit and compute pipeline for compositing images.

- `pipe_caps.fragment_shader_interlock`: True if fragment shader interlock functionality is supported.

- `pipe_caps.atomic_float_minmax`: Atomic float point minimum, maximum, exchange and compare-and-swap support to buffer and shared variables.

- `pipe_caps.tgsi_div`: Whether opcode DIV is supported

- `pipe_caps.dithering`: Whether dithering is supported

- `pipe_caps.fragment_shader_texture_lod`: Whether texture lookups with explicit LOD is supported in the fragment shader.

- `pipe_caps.fragment_shader_derivatives`: True if the driver supports derivatives in fragment shaders.

- `pipe_caps.texture_shadow_lod`: True if the driver supports shadow sampler types with texture functions having interaction with LOD of texture lookup.

- `pipe_caps.shader_samples_identical`: True if the driver supports a shader query to tell whether all samples of a multisampled surface are definitely identical.

- `pipe_caps.image_atomic_inc_wrap`: Atomic increment/decrement + wrap around are supported.

- `pipe_caps.prefer_imm_arrays_as_constbuf`: True if gallium frontends should turn arrays whose contents can be deduced at compile time into constant buffer loads, or false if the driver can handle such arrays itself in a more efficient manner (such as through nir_opt_large_constants() and nir->constant_data).

- `pipe_caps.gl_spirv`: True if the driver supports GL_ARB_gl_spirv extension.

- `pipe_caps.gl_spirv_variable_pointers`: True if the driver supports Variable Pointers in SPIR-V shaders.

- `pipe_caps.demote_to_helper_invocation`: True if driver supports demote keyword in GLSL programs.

- `pipe_caps.tgsi_tg4_component_in_swizzle`: True if driver wants the TG4 component encoded in sampler swizzle rather than as a separate source.

- `pipe_caps.flatshade`: Driver supports pipe_rasterizer_state::flatshade. Must be 1

    for non-NIR drivers or gallium nine.

- `pipe_caps.alpha_test`: Driver supports alpha-testing. Must be 1

    for non-NIR drivers or gallium nine. If set, frontend may set `pipe_depth_stencil_alpha_state->alpha_enabled` and `alpha_func`. Otherwise, alpha test will be lowered to a comparison and discard_if in the fragment shader.

- `pipe_caps.point_size_fixed`: Driver supports point-sizes that are fixed, as opposed to writing gl_PointSize for every point.

- `pipe_caps.two_sided_color`: Driver supports two-sided coloring. Must be 1

    for non-NIR drivers. If set, pipe_rasterizer_state may be set to indicate that back-facing primitives should use the back-side color as the FS input color. If unset, mesa/st will lower it to gl_FrontFacing reads in the fragment shader.

- `pipe_caps.clip_planes`: Driver supports user-defined clip-planes. 0 denotes none, 1 denotes MAX_CLIP_PLANES. > 1 overrides MAX. When is 0, pipe_rasterizer_state::clip_plane_enable is unused.

- `pipe_caps.max_vertex_buffers`: Number of supported vertex buffers.

- `pipe_caps.opencl_integer_functions`: Driver supports extended OpenCL-style integer functions. This includes average, saturating addition, saturating subtraction, absolute difference, count leading zeros, and count trailing zeros.

- `pipe_caps.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.

- `pipe_caps.nir_images_as_deref`: Whether NIR image load/store intrinsics should be nir_intrinsic_image_deref_* instead of nir_intrinsic_image_*. Defaults to true.

- `pipe_caps.packed_stream_output`: Driver supports packing optimization for stream output (e.g. GL transform feedback captured variables). Defaults to true.

- `pipe_caps.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.

- `pipe_caps.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.

- `pipe_caps.gl_begin_end_buffer_size`: Buffer size used to upload vertices for glBegin/glEnd.

- `pipe_caps.viewport_swizzle`: Whether pipe_viewport_state::swizzle can be used to specify pre-clipping swizzling of coordinates (see GL_NV_viewport_swizzle).

- `pipe_caps.system_svm`: True if all application memory can be shared with the GPU without explicit mapping.

- `pipe_caps.viewport_mask`: Whether `TGSI_SEMANTIC_VIEWPORT_MASK` and `TGSI_PROPERTY_LAYER_VIEWPORT_RELATIVE` are supported (see GL_NV_viewport_array2).

- `pipe_caps.map_unsynchronized_thread_safe`: Whether mapping a buffer as unsynchronized from any thread is safe.

- `pipe_caps.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.

- `pipe_caps.blend_equation_advanced`: Driver supports blend equation advanced without necessarily supporting FBFETCH.

- `pipe_caps.nir_atomics_as_deref`: Whether NIR atomics instructions should reference atomics as NIR derefs instead of by indices.

- `pipe_caps.no_clip_on_copy_tex`: Driver doesn’t want x/y/width/height clipped based on src size when doing a copy texture operation (e.g.: may want out-of-bounds reads that produce 0 instead of leaving the texture content undefined)

- `pipe_caps.max_texture_mb`: Maximum texture size in MB (default is 1024)

- `pipe_caps.device_protected_surface`: Whether the device support protected / encrypted content.

- `pipe_caps.prefer_real_buffer_in_constbuf0`: The state tracker is encouraged to upload constants into a real buffer and bind it into constant buffer 0 instead of binding a user pointer. This may enable a faster code-path in a gallium frontend for drivers that really prefer a real buffer.

- `pipe_caps.gl_clamp`: Driver natively supports GL_CLAMP. Required for non-NIR drivers with the GL frontend. NIR drivers with the cap unavailable will have GL_CLAMP lowered to txd/txl with a saturate on the coordinates.

- `pipe_caps.texrect`: Driver supports rectangle textures. Required for OpenGL on `!prefers_nir` drivers. If this cap is not present, st/mesa will lower the NIR to use normal 2D texture sampling by using either `txs` or `nir_intrinsic_load_texture_scaling` to normalize the texture coordinates.

- `pipe_caps.sampler_reduction_minmax`: Driver supports EXT min/max sampler reduction.

- `pipe_caps.sampler_reduction_minmax_arb`: Driver supports ARB min/max sampler reduction with format queries.

- `pipe_caps.emulate_nonfixed_primitive_restart`: Driver requests all draws using a non-fixed restart index to be rewritten to use a fixed restart index.

- `pipe_caps.supported_prim_modes`: A bitmask of the `mesa_prim` enum values that the driver can natively support.

- `pipe_caps.supported_prim_modes_with_restart`: A bitmask of the `mesa_prim` enum values that the driver can natively support for primitive restart. Only useful if `pipe_caps.primitive_restart` is also exported.

- `pipe_caps.prefer_back_buffer_reuse`: Only applies to DRI_PRIME. If 1, the driver prefers that DRI3 tries to use the same back buffer each frame. If 0, this means DRI3 will at least use 2 back buffers and ping-pong between them to allow the tiled->linear copy to run in parallel.

- `pipe_caps.draw_vertex_state`: Driver supports `pipe_screen::create_vertex_state/vertex_state_destroy` and `pipe_context::draw_vertex_state`. Only used by display lists and designed to serve vbo_save.

- `pipe_caps.prefer_pot_aligned_varyings`: Driver prefers varyings to be aligned to power of two in a slot. If this cap is enabled, vec4 varying will be placed in .xyzw components of the varying slot, vec3 in .xyz and vec2 in .xy or .zw

- `pipe_caps.max_sparse_texture_size`: Maximum 1D/2D/rectangle texture image dimension for a sparse texture.

- `pipe_caps.max_sparse_3d_texture_size`: Maximum 3D texture image dimension for a sparse texture.

- `pipe_caps.max_sparse_array_texture_layers`: Maximum number of layers in a sparse array texture.

- `pipe_caps.sparse_texture_full_array_cube_mipmaps`: TRUE if there are no restrictions on the allocation of mipmaps in sparse textures and FALSE otherwise. See SPARSE_TEXTURE_FULL_ARRAY_CUBE_MIPMAPS_ARB description in GL_ARB_sparse_texture extension spec.

- `pipe_caps.query_sparse_texture_residency`: TRUE if shader sparse texture sample instruction could also return the residency information.

- `pipe_caps.clamp_sparse_texture_lod`: TRUE if shader sparse texture sample instruction support clamp the minimal lod to prevent read from uncommitted pages.

- `pipe_caps.allow_draw_out_of_order`: TRUE if the driver allows the “draw out of order” optimization to be enabled. See _mesa_update_allow_draw_out_of_order for more details.

- `pipe_caps.max_constant_buffer_size`: Maximum bound constant buffer size in bytes. This is unsigned integer with the maximum of 4GB - 1. This applies to all constant buffers used by UBOs, unlike `PIPE_SHADER_CAP_MAX_CONST_BUFFER0_SIZE`, which is specifically for GLSL uniforms.

- `pipe_caps.hardware_gl_select`: Enable hardware accelerated GL_SELECT for this driver.

- `pipe_caps.device_protected_context`: Whether the device supports protected / encrypted context which can manipulate protected / encrypted content (some devices might need protected contexts to access protected content, whereas `pipe_caps.device_protected_surface` does not require any particular context to do so).

- `pipe_caps.allow_glthread_buffer_subdata_opt`: Whether to allow glthread to convert glBufferSubData to glCopyBufferSubData. This may improve or worsen performance depending on your driver.

- `pipe_caps.null_textures` : Whether the driver supports sampling from NULL textures.

- `pipe_caps.astc_void_extents_need_denorm_flush` : True if the driver/hardware needs denormalized values in ASTC void extent blocks flushed to zero.

- `pipe_caps.validate_all_dirty_states` : Whether state validation must also validate the state changes for resources types used in the previous shader but not in the current shader.

- `pipe_caps.has_const_bw`: Whether the driver only supports non-data-dependent layouts (ie. not bandwidth compressed formats like AFBC, UBWC, etc), or supports `PIPE_BIND_CONST_BW` to disable data-dependent layouts on requested resources.

- `pipe_caps.performance_monitor`: Whether GL_AMD_performance_monitor should be exposed.

- `pipe_caps.texture_sampler_independent`: Whether sampler views and sampler states are independent objects, meaning both can be freely mixed and matched by the frontend. This isn’t required for OpenGL where on the shader level those are the same object. However for proper gallium nine and OpenCL support this is required.

- `pipe_caps.astc_decode_mode`: Whether the driver supports ASTC decode precision. The GL_EXT_texture_compression_astc_decode_mode extension will only get exposed if GL_KHR_texture_compression_astc_ldr is also supported.

- `pipe_caps.shader_subgroup_size`: A fixed subgroup size shader runs on GPU when GLSL GL_KHR_shader_subgroup_* extensions are enabled.

- `pipe_caps.shader_subgroup_supported_stages`: Bitmask of shader stages which support GL_KHR_shader_subgroup_* intrinsics.

- `pipe_caps.shader_subgroup_supported_features`: Bitmask of shader subgroup features listed in GL_KHR_shader_subgroup.

- `pipe_caps.shader_subgroup_quad_all_stages`: Whether shader subgroup quad operations are supported by shader stages other than fragment shader.

- `pipe_caps.multiview`: Whether multiview rendering of array textures is supported. A return of `1` indicates support for OVR_multiview, and `2` additionally supports OVR_multiview2.

- `pipe_caps.call_finalize_nir_in_linker`: Whether `pipe_screen::finalize_nir` can be called in the GLSL linker before the NIR is stored in the shader cache. It’s always called again after st/mesa adds code for shader variants. It must be 1 if the driver wants to report compile failures to the GLSL linker. It must be 0 if two consecutive `finalize_nir` calls on the same shader can break it, or if `finalize_nir` can’t handle NIR that isn’t fully lowered for the driver, or if `finalize_nir` breaks passes that st/mesa runs after it. Setting it to 1 is generally safe for drivers that expose nir_io_has_intrinsics and that don’t enable any optional shader variants in st/mesa. Since it’s difficult to support, any future refactoring can change it to 0.

- `pipe_caps.min_line_width`: The minimum width of a regular line.

- `pipe_caps.min_line_width_aa`: The minimum width of a smoothed line.

- `pipe_caps.max_line_width`: The maximum width of a regular line.

- `pipe_caps.max_line_width_aa`: The maximum width of a smoothed line.

- `pipe_caps.line_width_granularity`: The line width is rounded to a multiple of this number.

- `pipe_caps.min_point_size`: The minimum width and height of a point.

- `pipe_caps.min_point_size_aa`: The minimum width and height of a smoothed point.

- `pipe_caps.max_point_size`: The maximum width and height of a point.

- `pipe_caps.max_point_size_aa`: The maximum width and height of a smoothed point.

- `pipe_caps.point_size_granularity`: The point size is rounded to a multiple of this number.

- `pipe_caps.max_texture_anisotropy`: The maximum level of anisotropy that can be applied to anisotropically filtered textures.

- `pipe_caps.max_texture_lod_bias`: The maximum LOD bias that may be applied to filtered textures.

- `pipe_caps.min_conservative_raster_dilate`: The minimum conservative rasterization dilation.

- `pipe_caps.max_conservative_raster_dilate`: The maximum conservative rasterization dilation.

- `pipe_caps.conservative_raster_dilate_granularity`: The conservative rasterization dilation granularity for values relative to the minimum dilation.

### PIPE_SHADER_CAP_*

These are per-shader-stage capabitity queries. Different shader stages may support different features.

- `PIPE_SHADER_CAP_MAX_INSTRUCTIONS`: The maximum number of instructions.

- `PIPE_SHADER_CAP_MAX_ALU_INSTRUCTIONS`: The maximum number of arithmetic instructions.

- `PIPE_SHADER_CAP_MAX_TEX_INSTRUCTIONS`: The maximum number of texture instructions.

- `PIPE_SHADER_CAP_MAX_TEX_INDIRECTIONS`: The maximum number of texture indirections.

- `PIPE_SHADER_CAP_MAX_CONTROL_FLOW_DEPTH`: The maximum nested control flow depth.

- `PIPE_SHADER_CAP_MAX_INPUTS`: The maximum number of input registers.

- `PIPE_SHADER_CAP_MAX_OUTPUTS`: The maximum number of output registers. This is valid for all shaders except the fragment shader.

- `PIPE_SHADER_CAP_MAX_CONST_BUFFER0_SIZE`: The maximum size of constant buffer 0 in bytes.

- `PIPE_SHADER_CAP_MAX_CONST_BUFFERS`: Maximum number of constant buffers that can be bound to any shader stage using `set_constant_buffer`. If 0 or 1, the pipe will only permit binding one constant buffer per shader.

  If a value greater than 0 is returned, the driver can have multiple constant buffers bound to shader stages. The CONST register file is accessed with two-dimensional indices, like in the example below.

      DCL CONST[0][0..7]       # declare first 8 vectors of constbuf 0
      DCL CONST[3][0]          # declare first vector of constbuf 3
      MOV OUT[0], CONST[0][3]  # copy vector 3 of constbuf 0

- `PIPE_SHADER_CAP_MAX_TEMPS`: The maximum number of temporary registers.

- `PIPE_SHADER_CAP_CONT_SUPPORTED`: Whether continue is supported.

- `PIPE_SHADER_CAP_INDIRECT_TEMP_ADDR`: Whether indirect addressing of the temporary file is supported.

- `PIPE_SHADER_CAP_INDIRECT_CONST_ADDR`: Whether indirect addressing of the constant file is supported.

- `PIPE_SHADER_CAP_SUBROUTINES`: Whether subroutines are supported, i.e. BGNSUB, ENDSUB, CAL, and RET, including RET in the main block.

- `PIPE_SHADER_CAP_INTEGERS`: Whether integer opcodes are supported. If unsupported, only float opcodes are supported.

- `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.

- `PIPE_SHADER_CAP_FP16`: Whether half precision floating-point opcodes are supported.

    If unsupported, half precision ops need to be lowered to full precision.

- `PIPE_SHADER_CAP_FP16_DERIVATIVES`: Whether half precision floating-point DDX and DDY opcodes are supported.

- `PIPE_SHADER_CAP_FP16_CONST_BUFFERS`: Whether half precision floating-point constant buffer loads are supported. Drivers are recommended to report 0 if x86 F16C is not supported by the CPU (or an equivalent instruction set on other CPU architectures), otherwise they could be impacted by emulated FP16 conversions in glUniform.

- `PIPE_SHADER_CAP_INT16`: Whether 16-bit signed and unsigned integer types are supported.

- `PIPE_SHADER_CAP_GLSL_16BIT_CONSTS`: Lower mediump constants to 16-bit. Note that 16-bit constants are not lowered to uniforms in GLSL.

- `PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS`: The maximum number of texture samplers.

- `PIPE_SHADER_CAP_MAX_SAMPLER_VIEWS`: The maximum number of texture sampler views. Must not be lower than PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS.

- `PIPE_SHADER_CAP_TGSI_ANY_INOUT_DECL_RANGE`: Whether the driver doesn’t ignore tgsi_declaration_range::Last for shader inputs and outputs.

- `PIPE_SHADER_CAP_MAX_SHADER_BUFFERS`: Maximum number of memory buffers (also used to implement atomic counters). Having this be non-0 also implies support for the `LOAD`, `STORE`, and `ATOM*` TGSI opcodes.

- `PIPE_SHADER_CAP_SUPPORTED_IRS`: Supported representations of the program. It should be a mask of `pipe_shader_ir` bits.

- `PIPE_SHADER_CAP_MAX_SHADER_IMAGES`: Maximum number of image units.

- `PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTERS`: If atomic counters are separate, how many HW counters are available for this stage. (0 uses SSBO atomics).

- `PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTER_BUFFERS`: If atomic counters are separate, how many atomic counter buffers are available for this stage.

### PIPE_COMPUTE_CAP_*

Compute-specific capabilities. They can be queried using pipe_screen::get_compute_param.

- `PIPE_COMPUTE_CAP_IR_TARGET`: A description of the target of the form `processor-arch-manufacturer-os` that will be passed on to the compiler. This CAP is only relevant for drivers that specify PIPE_SHADER_IR_NATIVE for their preferred IR. Value type: null-terminated string. Shader IR type dependent.

- `PIPE_COMPUTE_CAP_GRID_DIMENSION`: Number of supported dimensions for grid and block coordinates. Value type: `uint64_t`. Shader IR type dependent.

- `PIPE_COMPUTE_CAP_MAX_GRID_SIZE`: Maximum grid size in block units. Value type: `uint64_t []`. Shader IR type dependent.

- `PIPE_COMPUTE_CAP_MAX_BLOCK_SIZE`: Maximum block size in thread units. Value type: `uint64_t []`. Shader IR type dependent.

- `PIPE_COMPUTE_CAP_MAX_THREADS_PER_BLOCK`: Maximum number of threads that a single block can contain. Value type: `uint64_t`. Shader IR type dependent. This may be less than the product of the components of MAX_BLOCK_SIZE and is usually limited by the number of threads that can be resident simultaneously on a compute unit.

- `PIPE_COMPUTE_CAP_MAX_GLOBAL_SIZE`: Maximum size of the GLOBAL resource. Value type: `uint64_t`. Shader IR type dependent.

- `PIPE_COMPUTE_CAP_MAX_LOCAL_SIZE`: Maximum size of the LOCAL resource. Value type: `uint64_t`. Shader IR type dependent.

- `PIPE_COMPUTE_CAP_MAX_PRIVATE_SIZE`: Maximum size of the PRIVATE resource. Value type: `uint64_t`. Shader IR type dependent.

- `PIPE_COMPUTE_CAP_MAX_INPUT_SIZE`: Maximum size of the INPUT resource. Value type: `uint64_t`. Shader IR type dependent.

- `PIPE_COMPUTE_CAP_MAX_MEM_ALLOC_SIZE`: Maximum size of a memory object allocation in bytes. Value type: `uint64_t`.

- `PIPE_COMPUTE_CAP_MAX_CLOCK_FREQUENCY`: Maximum frequency of the GPU clock in MHz. Value type: `uint32_t`

- `PIPE_COMPUTE_CAP_MAX_COMPUTE_UNITS`: Maximum number of compute units Value type: `uint32_t`

- `PIPE_COMPUTE_CAP_MAX_SUBGROUPS`: The max amount of subgroups there can be inside a block. Non 0 indicates support for OpenCL subgroups including implementing `get_compute_state_subgroup_size` if multiple subgroup sizes are supported.

- `PIPE_COMPUTE_CAP_IMAGES_SUPPORTED`: Whether images are supported non-zero means yes, zero means no. Value type: `uint32_t`

- `PIPE_COMPUTE_CAP_SUBGROUP_SIZES`: Ored power of two sizes of a basic execution unit in threads. Also known as wavefront size, warp size or SIMD width. E.g. `64 | 32`.

- `PIPE_COMPUTE_CAP_ADDRESS_BITS`: The default compute device address space size specified as an unsigned integer value in bits.

- `PIPE_COMPUTE_CAP_MAX_VARIABLE_THREADS_PER_BLOCK`: Maximum variable number of threads that a single block can contain. This is similar to PIPE_COMPUTE_CAP_MAX_THREADS_PER_BLOCK, except that the variable size is not known a compile-time but at dispatch-time.

### PIPE_BIND_*

These flags indicate how a resource will be used and are specified at resource creation time. Resources may be used in different roles during their life cycle. Bind flags are cumulative and may be combined to create a resource which can be used for multiple things. Depending on the pipe driver’s memory management and these bind flags, resources might be created and handled quite differently.

- `PIPE_BIND_RENDER_TARGET`: A color buffer or pixel buffer which will be rendered to. Any surface/resource attached to pipe_framebuffer_state::cbufs must have this flag set.

- `PIPE_BIND_DEPTH_STENCIL`: A depth (Z) buffer and/or stencil buffer. Any depth/stencil surface/resource attached to pipe_framebuffer_state::zsbuf must have this flag set.

- `PIPE_BIND_BLENDABLE`: Used in conjunction with PIPE_BIND_RENDER_TARGET to query whether a device supports blending for a given format. If this flag is set, surface creation may fail if blending is not supported for the specified format. If it is not set, a driver may choose to ignore blending on surfaces with formats that would require emulation.

- `PIPE_BIND_DISPLAY_TARGET`: A surface that can be presented to screen. Arguments to pipe_screen::flush_front_buffer must have this flag set.

- `PIPE_BIND_SAMPLER_VIEW`: A texture that may be sampled from in a fragment or vertex shader.

- `PIPE_BIND_VERTEX_BUFFER`: A vertex buffer.

- `PIPE_BIND_INDEX_BUFFER`: An vertex index/element buffer.

- `PIPE_BIND_CONSTANT_BUFFER`: A buffer of shader constants.

- `PIPE_BIND_STREAM_OUTPUT`: A stream output buffer.

- `PIPE_BIND_CUSTOM`:

- `PIPE_BIND_SCANOUT`: A front color buffer or scanout buffer.

- `PIPE_BIND_SHARED`: A shareable buffer that can be given to another process.

- `PIPE_BIND_GLOBAL`: A buffer that can be mapped into the global address space of a compute program.

- `PIPE_BIND_SHADER_BUFFER`: A buffer without a format that can be bound to a shader and can be used with load, store, and atomic instructions.

- `PIPE_BIND_SHADER_IMAGE`: A buffer or texture with a format that can be bound to a shader and can be used with load, store, and atomic instructions.

- `PIPE_BIND_COMPUTE_RESOURCE`: A buffer or texture that can be bound to the compute program as a shader resource.

- `PIPE_BIND_COMMAND_ARGS_BUFFER`: A buffer that may be sourced by the GPU command processor. It can contain, for example, the arguments to indirect draw calls.

### PIPE_USAGE_*

The PIPE_USAGE enums are hints about the expected usage pattern of a resource. Note that drivers must always support read and write CPU access at any time no matter which hint they got.

- `PIPE_USAGE_DEFAULT`: Optimized for fast GPU access.

- `PIPE_USAGE_IMMUTABLE`: Optimized for fast GPU access and the resource is not expected to be mapped or changed (even by the GPU) after the first upload.

- `PIPE_USAGE_DYNAMIC`: Expect frequent write-only CPU access. What is uploaded is expected to be used at least several times by the GPU.

- `PIPE_USAGE_STREAM`: Expect frequent write-only CPU access. What is uploaded is expected to be used only once by the GPU.

- `PIPE_USAGE_STAGING`: Optimized for fast CPU access.

## Methods

XXX to-do

### get_name

Returns an identifying name for the screen.

The returned string should remain valid and immutable for the lifetime of pipe_screen.

### get_vendor

Returns the screen vendor.

The returned string should remain valid and immutable for the lifetime of pipe_screen.

### get_device_vendor

Returns the actual vendor of the device driving the screen (as opposed to the driver vendor).

The returned string should remain valid and immutable for the lifetime of pipe_screen.

### context_create

Create a pipe_context.

priv is private data of the caller, which may be put to various unspecified uses, typically to do with implementing swapbuffers and/or front-buffer rendering.

### is_format_supported

Determine if a resource in the given format can be used in a specific manner.

format the resource format

target one of the PIPE_TEXTURE_x flags

sample_count the number of samples. 0 and 1 mean no multisampling, the maximum allowed legal value is 32.

storage_sample_count the number of storage samples. This must be <= sample_count. See the documentation of `pipe_resource::nr_storage_samples`.

bindings is a bitmask of PIPE_BIND_* flags.

Returns TRUE if all usages can be satisfied.

### can_create_resource

Check if a resource can actually be created (but don’t actually allocate any memory). This is used to implement OpenGL’s proxy textures. Typically, a driver will simply check if the total size of the given resource is less than some limit.

For PIPE_TEXTURE_CUBE, the pipe_resource::array_size field should be 6.

### resource_create

Create a new resource from a template. The following fields of the pipe_resource must be specified in the template:

target one of the pipe_texture_target enums. Note that PIPE_BUFFER and PIPE_TEXTURE_X are not really fundamentally different. Modern APIs allow using buffers as shader resources.

format one of the pipe_format enums.

width0 the width of the base mip level of the texture or size of the buffer.

height0 the height of the base mip level of the texture (1 for 1D or 1D array textures).

depth0 the depth of the base mip level of the texture (1 for everything else).

array_size the array size for 1D and 2D array textures. For cube maps this must be 6, for other textures 1.

last_level the last mip map level present.

nr_samples: Number of samples determining quality, driving the rasterizer, shading, and framebuffer. It is the number of samples seen by the whole graphics pipeline. 0 and 1 specify a resource which isn’t multisampled.

nr_storage_samples: Only color buffers can set this lower than nr_samples. Multiple samples within a pixel can have the same color. `nr_storage_samples` determines how many slots for different colors there are per pixel. If there are not enough slots to store all sample colors, some samples will have an undefined color (called “undefined samples”).

The resolve blit behavior is driver-specific, but can be one of these two:

1. Only defined samples will be averaged. Undefined samples will be ignored.

2. Undefined samples will be approximated by looking at surrounding defined samples (even in different pixels).

Blits and MSAA texturing: If the sample being fetched is undefined, one of the defined samples is returned instead.

Sample shading (`set_min_samples`) will operate at a sample frequency that is at most `nr_storage_samples`. Greater `min_samples` values will be replaced by `nr_storage_samples`.

usage one of the PIPE_USAGE_* flags.

bind bitmask of the PIPE_BIND_* flags.

flags bitmask of PIPE_RESOURCE_FLAG flags.

next: Pointer to the next plane for resources that consist of multiple memory planes.

As a corollary, this mean resources for an image with multiple planes have to be created starting from the highest plane.

### resource_changed

Mark a resource as changed so derived internal resources will be recreated on next use.

When importing external images that can’t be directly used as texture sampler source, internal copies may have to be created that the hardware can sample from. When those resources are reimported, the image data may have changed, and the previously derived internal resources must be invalidated to avoid sampling from old copies.

### resource_destroy

Destroy a resource. A resource is destroyed if it has no more references.

### get_timestamp

Query a timestamp in nanoseconds. The returned value should match PIPE_QUERY_TIMESTAMP. This function returns immediately and doesn’t wait for rendering to complete (which cannot be achieved with queries).

### get_driver_query_info

Return a driver-specific query. If the info parameter is NULL, the number of available queries is returned. Otherwise, the driver query at the specified index is returned in info. The function returns non-zero on success. The driver-specific query is described with the pipe_driver_query_info structure.

### get_driver_query_group_info

Return a driver-specific query group. If the info parameter is NULL, the number of available groups is returned. Otherwise, the driver query group at the specified index is returned in info. The function returns non-zero on success. The driver-specific query group is described with the pipe_driver_query_group_info structure.

### get_disk_shader_cache

Returns a pointer to a driver-specific on-disk shader cache. If the driver failed to create the cache or does not support an on-disk shader cache NULL is returned. The callback itself may also be NULL if the driver doesn’t support an on-disk shader cache.

### is_dmabuf_modifier_supported

Query whether the driver supports a modifier in combination with a format, and whether it is only supported with “external” texture targets. If the combination is supported in any fashion, true is returned. If the external_only parameter is not NULL, the bool it points to is set to false if non-external texture targets are supported with the specified modifier+ format, or true if only external texture targets are supported.

### get_dmabuf_modifier_planes

Query the number of planes required by the image layout specified by the modifier and format parameters. The value returned includes both planes dictated by format and any additional planes required for driver-specific auxiliary data necessary for the layout defined by modifier. If the proc is NULL, no auxiliary planes are required for any layout supported by screen and the number of planes can be derived directly from format.

## Thread safety

Screen methods are required to be thread safe. While gallium rendering contexts are not required to be thread safe, it is required to be safe to use different contexts created with the same screen in different threads without locks. It is also required to be safe using screen methods in a thread, while using one of its contexts in another (without locks).