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_CAP_*

Capability queries return information about the features and limits of the driver/GPU. For floating-point values, use get_paramf, and for boolean or integer values, use get_param.

The integer capabilities:

  • PIPE_CAP_NPOT_TEXTURES: Whether NPOT textures may have repeat modes, normalized coordinates, and mipmaps.
  • PIPE_CAP_TWO_SIDED_STENCIL: Whether the stencil test can also affect back-facing polygons.
  • PIPE_CAP_MAX_DUAL_SOURCE_RENDER_TARGETS: How many dual-source blend RTs are support. Blend for more information.
  • PIPE_CAP_ANISOTROPIC_FILTER: Whether textures can be filtered anisotropically.
  • PIPE_CAP_POINT_SPRITE: Whether point sprites are available.
  • PIPE_CAP_MAX_RENDER_TARGETS: The maximum number of render targets that may be bound.
  • PIPE_CAP_OCCLUSION_QUERY: Whether occlusion queries are available.
  • PIPE_CAP_TIMER_QUERY: Whether timer queries are available.
  • PIPE_CAP_TEXTURE_SHADOW_MAP: indicates whether the fragment shader hardware can do the depth texture / Z comparison operation in TEX instructions for shadow testing.
  • PIPE_CAP_TEXTURE_SWIZZLE: Whether swizzling through sampler views is supported.
  • PIPE_CAP_MAX_TEXTURE_2D_LEVELS: The maximum number of mipmap levels available for a 2D texture.
  • PIPE_CAP_MAX_TEXTURE_3D_LEVELS: The maximum number of mipmap levels available for a 3D texture.
  • PIPE_CAP_MAX_TEXTURE_CUBE_LEVELS: The maximum number of mipmap levels available for a cubemap.
  • PIPE_CAP_TEXTURE_MIRROR_CLAMP: Whether mirrored texture coordinates with clamp are supported.
  • PIPE_CAP_BLEND_EQUATION_SEPARATE: Whether alpha blend equations may be different from color blend equations, in Blend state.
  • PIPE_CAP_SM3: Whether the vertex shader and fragment shader support equivalent opcodes to the Shader Model 3 specification. XXX oh god this is horrible
  • PIPE_CAP_MAX_STREAM_OUTPUT_BUFFERS: The maximum number of stream buffers.
  • PIPE_CAP_PRIMITIVE_RESTART: Whether primitive restart is supported.
  • PIPE_CAP_MAX_COMBINED_SAMPLERS: The total number of samplers accessible from the vertex and fragment shader, inclusive.
  • PIPE_CAP_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_CAP_INDEP_BLEND_FUNC: Whether per-rendertarget blend functions are available. If 0, then the first rendertarget’s blend functions affect all MRTs.
  • PIPE_CAP_DEPTHSTENCIL_CLEAR_SEPARATE: Whether clearing only depth or only stencil in a combined depth-stencil buffer is supported.
  • PIPE_CAP_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_CAP_TGSI_FS_COORD_ORIGIN_UPPER_LEFT: Whether the TGSI property FS_COORD_ORIGIN with value UPPER_LEFT is supported.
  • PIPE_CAP_TGSI_FS_COORD_ORIGIN_LOWER_LEFT: Whether the TGSI property FS_COORD_ORIGIN with value LOWER_LEFT is supported.
  • PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_HALF_INTEGER: Whether the TGSI property FS_COORD_PIXEL_CENTER with value HALF_INTEGER is supported.
  • PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER: Whether the TGSI property FS_COORD_PIXEL_CENTER with value INTEGER is supported.
  • PIPE_CAP_DEPTH_CLIP_DISABLE: Whether the driver is capable of disabling depth clipping (through pipe_rasterizer_state)
  • PIPE_CAP_SHADER_STENCIL_EXPORT: Whether a stencil reference value can be written from a fragment shader.
  • PIPE_CAP_TGSI_INSTANCEID: Whether TGSI_SEMANTIC_INSTANCEID is supported in the vertex shader.
  • PIPE_CAP_VERTEX_ELEMENT_INSTANCE_DIVISOR: Whether the driver supports per-instance vertex attribs.
  • PIPE_CAP_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, the state tracker will insert clamping code into the fragment shaders when needed.
  • PIPE_CAP_MIXED_COLORBUFFER_FORMATS: Whether mixed colorbuffer formats are supported, e.g. RGBA8 and RGBA32F as the first and second colorbuffer, resp.
  • PIPE_CAP_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_CAP_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, the state tracker may insert clamping code into the vertex shader.
  • PIPE_CAP_GLSL_FEATURE_LEVEL: Whether the driver supports features equivalent to a specific GLSL version. E.g. for GLSL 1.3, report 130.
  • PIPE_CAP_QUADS_FOLLOW_PROVOKING_VERTEX_CONVENTION: Whether quads adhere to the flatshade_first setting in pipe_rasterizer_state.
  • PIPE_CAP_USER_VERTEX_BUFFERS: Whether the driver supports user vertex buffers. If not, the state tracker must upload all data which is not in hw resources.
  • PIPE_CAP_VERTEX_BUFFER_OFFSET_4BYTE_ALIGNED_ONLY: This CAP describes a hw limitation. If true, pipe_vertex_buffer::buffer_offset must always be aligned to 4. If false, there are no restrictions on the offset.
  • PIPE_CAP_VERTEX_BUFFER_STRIDE_4BYTE_ALIGNED_ONLY: This CAP describes a hw limitation. If true, pipe_vertex_buffer::stride must always be aligned to 4. If false, there are no restrictions on the stride.
  • PIPE_CAP_VERTEX_ELEMENT_SRC_OFFSET_4BYTE_ALIGNED_ONLY: This CAP describes a hw limitation. If true, pipe_vertex_element::src_offset must always be aligned to 4. If false, there are no restrictions on src_offset.
  • PIPE_CAP_COMPUTE: Whether the implementation supports the compute entry points defined in pipe_context and pipe_screen.
  • PIPE_CAP_USER_INDEX_BUFFERS: Whether user index buffers are supported. If not, the state tracker must upload all indices which are not in hw resources.
  • PIPE_CAP_USER_CONSTANT_BUFFERS: Whether user constant buffers are supported. If not, the state tracker must upload constants which are not in hw resources.
  • PIPE_CAP_CONSTANT_BUFFER_OFFSET_ALIGNMENT: Describes the required alignment of pipe_constant_buffer::buffer_offset.
  • PIPE_CAP_START_INSTANCE: Whether the driver supports pipe_draw_info::start_instance.
  • PIPE_CAP_QUERY_TIMESTAMP: Whether PIPE_QUERY_TIMESTAMP and the pipe_screen::get_timestamp hook are implemented.

PIPE_CAPF_*

The floating-point capabilities are:

  • PIPE_CAPF_MAX_LINE_WIDTH: The maximum width of a regular line.
  • PIPE_CAPF_MAX_LINE_WIDTH_AA: The maximum width of a smoothed line.
  • PIPE_CAPF_MAX_POINT_WIDTH: The maximum width and height of a point.
  • PIPE_CAPF_MAX_POINT_WIDTH_AA: The maximum width and height of a smoothed point.
  • PIPE_CAPF_MAX_TEXTURE_ANISOTROPY: The maximum level of anisotropy that can be applied to anisotropically filtered textures.
  • PIPE_CAPF_MAX_TEXTURE_LOD_BIAS: The maximum LOD bias that may be applied to filtered textures.
  • PIPE_CAPF_GUARD_BAND_LEFT, PIPE_CAPF_GUARD_BAND_TOP, PIPE_CAPF_GUARD_BAND_RIGHT, PIPE_CAPF_GUARD_BAND_BOTTOM: TODO

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_CONSTS: The maximum number of constants.
  • 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, and the shaders will not permit two-dimensional access to constants.

If a value greater than 0 is returned, the driver can have multiple constant buffers bound to shader stages. The CONST register file can be 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

For backwards compatibility, one-dimensional access to CONST register file is still supported. In that case, the constbuf index is assumed to be 0.

  • PIPE_SHADER_CAP_MAX_TEMPS: The maximum number of temporary registers.
  • PIPE_SHADER_CAP_MAX_ADDRS: The maximum number of address registers.
  • PIPE_SHADER_CAP_MAX_PREDS: The maximum number of predicate registers.
  • PIPE_SHADER_CAP_TGSI_CONT_SUPPORTED: Whether the continue opcode is supported.
  • PIPE_SHADER_CAP_INDIRECT_INPUT_ADDR: Whether indirect addressing of the input file is supported.
  • PIPE_SHADER_CAP_INDIRECT_OUTPUT_ADDR: Whether indirect addressing of the output file 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_MAX_TEXTURE_SAMPLERS: THe maximum number of texture samplers.
  • PIPE_SHADER_CAP_PREFERRED_IR: Preferred representation of the program. It should be one of the pipe_shader_ir enum values.

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 as a target triple specification of the form processor-manufacturer-os that will be passed on to the compiler. This CAP is only relevant for drivers that specify PIPE_SHADER_IR_LLVM for their preferred IR. Value type: null-terminated string.
  • PIPE_COMPUTE_CAP_GRID_DIMENSION: Number of supported dimensions for grid and block coordinates. Value type: uint64_t.
  • PIPE_COMPUTE_CAP_MAX_GRID_SIZE: Maximum grid size in block units. Value type: uint64_t [].
  • PIPE_COMPUTE_CAP_MAX_BLOCK_SIZE: Maximum block size in thread units. Value type: uint64_t [].
  • PIPE_COMPUTE_CAP_MAX_THREADS_PER_BLOCK: Maximum number of threads that a single block can contain. Value type: uint64_t. 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.
  • PIPE_COMPUTE_CAP_MAX_LOCAL_SIZE: Maximum size of the LOCAL resource. Value type: uint64_t.
  • PIPE_COMPUTE_CAP_MAX_PRIVATE_SIZE: Maximum size of the PRIVATE resource. Value type: uint64_t.
  • PIPE_COMPUTE_CAP_MAX_INPUT_SIZE: Maximum size of the INPUT resource. Value type: uint64_t.

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 lifecycle. 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_TRANSFER_WRITE: A transfer object which will be written to.
  • PIPE_BIND_TRANSFER_READ: A transfer object which will be read from.
  • 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 sharable 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_RESOURCE: A buffer or texture that can be bound to the graphics pipeline as a shader resource.
  • PIPE_BIND_COMPUTE_RESOURCE: A buffer or texture that can be bound to the compute program as a shader resource.

PIPE_USAGE_*

The PIPE_USAGE enums are hints about the expected usage pattern of a resource.

  • PIPE_USAGE_DEFAULT: Expect many uploads to the resource, intermixed with draws.
  • PIPE_USAGE_DYNAMIC: Expect many uploads to the resource, intermixed with draws.
  • PIPE_USAGE_STATIC: Same as immutable (?)
  • PIPE_USAGE_IMMUTABLE: Resource will not be changed after first upload.
  • PIPE_USAGE_STREAM: Upload will be followed by draw, followed by upload, ...

Methods

XXX to-do

get_name

Returns an identifying name for the screen.

get_vendor

Returns the screen vendor.

get_param

Get an integer/boolean screen parameter.

param is one of the PIPE_CAP_* names.

get_paramf

Get a floating-point screen parameter.

param is one of the PIPE_CAP_* names.

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.

bindings is a bitmask of PIPE_BIND_* flags.

geom_flags is a bitmask of PIPE_TEXTURE_GEOM_x flags.

Returns TRUE if all usages can be satisfied.

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 the nr of msaa samples. 0 (or 1) specifies a resource which isn’t multisampled.

usage one of the PIPE_USAGE flags.

bind bitmask of the PIPE_BIND flags.

flags bitmask of PIPE_RESOURCE_FLAG flags.

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).