#include <ComputeStep.h>

Inheritance diagram for skgpu::graphite::ComputeStep:

Classes
struct	NativeShaderSource

struct	ResourceDesc

struct	WorkgroupBufferDesc

Public Types
enum class	DataFlow { kPrivate , kShared }

enum class	ResourceType { kUniformBuffer , kStorageBuffer , kReadOnlyStorageBuffer , kIndirectBuffer , kWriteOnlyStorageTexture , kReadOnlyTexture , kSampledTexture }

enum class	ResourcePolicy { kNone , kClear , kMapped }

enum class	NativeShaderFormat { kWGSL , kMSL }

Public Member Functions
virtual	~ComputeStep ()=default

virtual std::string	computeSkSL () const

virtual NativeShaderSource	nativeShaderSource (NativeShaderFormat) const

virtual size_t	calculateBufferSize (int resourceIndex, const ResourceDesc &) const

virtual std::tuple< SkISize, SkColorType >	calculateTextureParameters (int resourceIndex, const ResourceDesc &) const

virtual SamplerDesc	calculateSamplerParameters (int resourceIndex, const ResourceDesc &) const

virtual WorkgroupSize	calculateGlobalDispatchSize () const

virtual void	prepareStorageBuffer (int resourceIndex, const ResourceDesc &resource, void *buffer, size_t bufferSize) const

virtual void	prepareUniformBuffer (int resourceIndex, const ResourceDesc &, UniformManager *) const

SkSpan< const ResourceDesc >	resources () const

SkSpan< const WorkgroupBufferDesc >	workgroupBuffers () const

uint32_t	uniqueID () const

const char *	name () const

WorkgroupSize	localDispatchSize () const

bool	supportsNativeShader () const

Protected Types
enum class	Flags : uint8_t { kNone = 0b00000 , kSupportsNativeShader = 0b00010 }

Protected Member Functions
	ComputeStep (std::string_view name, WorkgroupSize localDispatchSize, SkSpan< const ResourceDesc > resources, SkSpan< const WorkgroupBufferDesc > workgroupBuffers={}, Flags baseFlags=Flags::kNone)

Detailed Description

A ComputeStep represents a compute pass within a wider draw operation. A ComputeStep implementation describes an invocation of a compute program and its data binding layout.

A ComputeStep can perform arbitrary operations on the GPU over various types of data, including geometry and image processing. The data processed by a ComputeStep can be inputs (textures or buffers) populated on the CPU, data forwarded to and from other ComputeStep invocations (via "slots"), transient storage buffers/textures that are only used within an individual dispatch, geometry attribute (vertex/index/instance) and indirect draw parameters of a subsequent raster pipeline stage, as well as texture outputs.

The data flow between sequential ComputeStep invocations within a DispatchGroup is achieved by operating over a shared "resource table". ComputeSteps can declare a resource with a slot number. Multiple ComputeSteps in a group that declare a resource with the same slot number will have access to the same backing resource object through that slot:

 _______________                _______________
|               |              |               |
|                ---[Slot 0]---                |
|               |              |               |
|                ---[Slot 1]---                |
| ComputeStep 1 |              | ComputeStep 2 |
|                ---[Slot 2]   |               |
|               |              |               |
|               |   [Slot 3]---                |
|               |              |               |
 ---------------                ---------------

In the example above, slots 0 and 1 are accessed by both ComputeSteps, while slots 2 and 3 are exclusively accessed by ComputeStep 1 and 2 respectively. Alternately, slots 2 and 3 could be declared as "private" resources which are visible to a single ComputeStep.

Similarly, raster stage geometry buffers that are specified as the output of a ComputeStep can be used to assign the draw buffers of a RenderStep.

It is the responsibility of the owning entity (e.g. a RendererProvider) to ensure that a chain of ComputeStep and RenderStep invocations have a compatible resource and data-flow layout.

Definition at line 67 of file ComputeStep.h.

Member Enumeration Documentation

◆ DataFlow

enum class skgpu::graphite::ComputeStep::DataFlow

strong

Enumerator
kPrivate
kShared

Definition at line 69 of file ComputeStep.h.

                        {
        // A private binding is a resource that is only visible to a single ComputeStep invocation.
        kPrivate,
 
        // Bindings with a slot number that can be used to forward data between a series of
        // `ComputeStep`s. This DataFlow type is accompanied with a "slot number" that can be
        // shared by multiple `ComputeStep`s in a group.
        kShared,
    };

◆ Flags

enum class skgpu::graphite::ComputeStep::Flags : uint8_t

strongprotected

Enumerator
kNone
kSupportsNativeShader

Definition at line 254 of file ComputeStep.h.

                     : uint8_t {
        kNone                 = 0b00000,
        kSupportsNativeShader = 0b00010,
    };

◆ NativeShaderFormat

enum class skgpu::graphite::ComputeStep::NativeShaderFormat

strong

Enumerator
kWGSL
kMSL

Definition at line 171 of file ComputeStep.h.

◆ ResourcePolicy

enum class skgpu::graphite::ComputeStep::ResourcePolicy

strong

Enumerator
kNone
kClear
kMapped

Definition at line 95 of file ComputeStep.h.

                              {
        kNone,
 
        // The memory of the resource will be initialized to 0
        kClear,
 
        // The ComputeStep will be asked to initialize the memory on the CPU via
        // `ComputeStep::prepareStorageBuffer` or `ComputeStep::prepareUniformBuffer` prior to
        // pipeline execution. This may incur a transfer cost on platforms that do not allow buffers
        // to be mapped in shared memory.
        //
        // If multiple ComputeSteps in a DispatchGroup declare a mapped resource with the same
        // shared slot number, only the first ComputeStep in the group will receive a call to
        // prepare the buffer.
        //
        // This only has meaning for buffer resources. A resource with the `kUniformBuffer` resource
        // type must specify the `kMapped` resource policy.
        kMapped,
    };

◆ ResourceType

enum class skgpu::graphite::ComputeStep::ResourceType

strong

Enumerator
kUniformBuffer
kStorageBuffer
kReadOnlyStorageBuffer
kIndirectBuffer
kWriteOnlyStorageTexture
kReadOnlyTexture
kSampledTexture

Definition at line 79 of file ComputeStep.h.

                            {
        kUniformBuffer,
        kStorageBuffer,
        kReadOnlyStorageBuffer,
 
        // An indirect buffer is a storage buffer populated by this ComputeStep to determine the
        // global dispatch size of a subsequent ComputeStep within the same DispatchGroup. The
        // contents of the buffer must be laid out according to the `IndirectDispatchArgs` struct
        // definition declared in ComputeTypes.h.
        kIndirectBuffer,
 
        kWriteOnlyStorageTexture,
        kReadOnlyTexture,
        kSampledTexture,
    };

Constructor & Destructor Documentation

◆ ~ComputeStep()

virtual skgpu::graphite::ComputeStep::~ComputeStep ( )

virtualdefault

◆ ComputeStep()

skgpu::graphite::ComputeStep::ComputeStep	(	std::string_view	name,
		WorkgroupSize	localDispatchSize,
		SkSpan< const ResourceDesc >	resources,
		SkSpan< const WorkgroupBufferDesc >	workgroupBuffers = `{}`,
		Flags	baseFlags = `Flags::kNone`
	)

protected

Definition at line 28 of file ComputeStep.cpp.

        : fUniqueID(next_id())
        , fFlags(baseFlags)
        , fName(name)
        , fResources(resources.data(), resources.size())
        , fWorkgroupBuffers(workgroupBuffers.data(), workgroupBuffers.size())
        , fLocalDispatchSize(localDispatchSize) {
#ifdef SK_DEBUG
    std::unordered_set<int> slots;
    for (const ResourceDesc& r : fResources) {
        // Validate that slot assignments within a ComputeStep are unique.
        if (r.fFlow == DataFlow::kShared) {
            SkASSERT(r.fSlot > -1);
            SkASSERT(r.fSlot < kMaxComputeDataFlowSlots);
            auto [_, inserted] = slots.insert(r.fSlot);
            SkASSERT(inserted);
        }
    }
#endif  // SK_DEBUG
}

Member Function Documentation

◆ calculateBufferSize()

size_t skgpu::graphite::ComputeStep::calculateBufferSize	(	int	resourceIndex,
		const ResourceDesc &
	)		const

virtual

Reimplemented in skgpu::graphite::VelloFineMsaaStepBase< S, T, MaskLutBuilder >, skgpu::graphite::VelloFineMsaaStepBase< vello_cpp::ShaderStage::FineMsaa16, kRGBA_8888_SkColorType, vello_cpp::build_mask_lut_16 >, skgpu::graphite::VelloFineMsaaStepBase< vello_cpp::ShaderStage::FineMsaa16R8, kAlpha_8_SkColorType, vello_cpp::build_mask_lut_16 >, skgpu::graphite::VelloFineMsaaStepBase< vello_cpp::ShaderStage::FineMsaa8, kRGBA_8888_SkColorType, vello_cpp::build_mask_lut_8 >, and skgpu::graphite::VelloFineMsaaStepBase< vello_cpp::ShaderStage::FineMsaa8R8, kAlpha_8_SkColorType, vello_cpp::build_mask_lut_8 >.

Definition at line 72 of file ComputeStep.cpp.

                                                                      {
    SK_ABORT("ComputeSteps that initialize a storage buffer must override calculateBufferSize()");
    return 0u;
}

◆ calculateGlobalDispatchSize()

WorkgroupSize skgpu::graphite::ComputeStep::calculateGlobalDispatchSize ( ) const

virtual

Definition at line 89 of file ComputeStep.cpp.

                                                             {
    SK_ABORT("ComputeSteps must override calculateGlobalDispatchSize() unless "
             "the workgroup count is determined out-of-band");
    return WorkgroupSize();
}

◆ calculateSamplerParameters()

SamplerDesc skgpu::graphite::ComputeStep::calculateSamplerParameters	(	int	resourceIndex,
		const ResourceDesc &
	)		const

virtual

Definition at line 83 of file ComputeStep.cpp.

                                                                                                {
    SK_ABORT("ComputeSteps that initialize a sampler must override calculateSamplerParameters()");
    constexpr SkTileMode kTileModes[2] = {SkTileMode::kClamp, SkTileMode::kClamp};
    return {{}, kTileModes};
}

◆ calculateTextureParameters()

std::tuple< SkISize, SkColorType > skgpu::graphite::ComputeStep::calculateTextureParameters	(	int	resourceIndex,
		const ResourceDesc &
	)		const

virtual

Reimplemented in skgpu::graphite::VelloFineStepBase< S, T >, skgpu::graphite::VelloFineStepBase< vello_cpp::ShaderStage::FineArea, kRGBA_8888_SkColorType >, and skgpu::graphite::VelloFineStepBase< vello_cpp::ShaderStage::FineAreaR8, kAlpha_8_SkColorType >.

Definition at line 77 of file ComputeStep.cpp.

                                        {
    SK_ABORT("ComputeSteps that initialize a texture must override calculateTextureParameters()");
    return {SkISize::MakeEmpty(), kUnknown_SkColorType};
}

◆ computeSkSL()

std::string skgpu::graphite::ComputeStep::computeSkSL ( ) const

virtual

Definition at line 62 of file ComputeStep.cpp.

                                         {
    SK_ABORT("ComputeSteps must override computeSkSL() unless they support native shader source");
    return "";
}

◆ localDispatchSize()

WorkgroupSize skgpu::graphite::ComputeStep::localDispatchSize ( ) const

inline

Definition at line 249 of file ComputeStep.h.

249{ return fLocalDispatchSize; }

◆ name()

const char * skgpu::graphite::ComputeStep::name ( ) const

inline

Definition at line 244 of file ComputeStep.h.

244{ return fName.c_str(); }

◆ nativeShaderSource()

ComputeStep::NativeShaderSource skgpu::graphite::ComputeStep::nativeShaderSource ( NativeShaderFormat ) const

virtual

Reimplemented in skgpu::graphite::VelloStep< S >.

Definition at line 67 of file ComputeStep.cpp.

                                                                                      {
    SK_ABORT("ComputeSteps that support native shader source must override nativeShaderSource()");
    return {};
}

◆ prepareStorageBuffer()

void skgpu::graphite::ComputeStep::prepareStorageBuffer	(	int	resourceIndex,
		const ResourceDesc &	resource,
		void *	buffer,
		size_t	bufferSize
	)		const

virtual

Reimplemented in skgpu::graphite::VelloFineMsaaStepBase< S, T, MaskLutBuilder >, skgpu::graphite::VelloFineMsaaStepBase< vello_cpp::ShaderStage::FineMsaa16, kRGBA_8888_SkColorType, vello_cpp::build_mask_lut_16 >, skgpu::graphite::VelloFineMsaaStepBase< vello_cpp::ShaderStage::FineMsaa16R8, kAlpha_8_SkColorType, vello_cpp::build_mask_lut_16 >, skgpu::graphite::VelloFineMsaaStepBase< vello_cpp::ShaderStage::FineMsaa8, kRGBA_8888_SkColorType, vello_cpp::build_mask_lut_8 >, and skgpu::graphite::VelloFineMsaaStepBase< vello_cpp::ShaderStage::FineMsaa8R8, kAlpha_8_SkColorType, vello_cpp::build_mask_lut_8 >.

Definition at line 53 of file ComputeStep.cpp.

                                                                                    {
    SK_ABORT("ComputeSteps that initialize a mapped storage buffer must override "
             "prepareStorageBuffer()");
}

◆ prepareUniformBuffer()

void skgpu::graphite::ComputeStep::prepareUniformBuffer	(	int	resourceIndex,
		const ResourceDesc &	,
		UniformManager *
	)		const

virtual

Definition at line 58 of file ComputeStep.cpp.

                                                                                      {
    SK_ABORT("ComputeSteps that initialize a uniform buffer must override prepareUniformBuffer()");
}

◆ resources()

SkSpan< const ResourceDesc > skgpu::graphite::ComputeStep::resources ( ) const

inline

Definition at line 236 of file ComputeStep.h.

236{ return SkSpan(fResources); }

SkSpan

Definition SkSpan_impl.h:65

◆ supportsNativeShader()

bool skgpu::graphite::ComputeStep::supportsNativeShader ( ) const

inline

Definition at line 251 of file ComputeStep.h.

251{ return SkToBool(fFlags & Flags::kSupportsNativeShader); }

SkToBool

static constexpr bool SkToBool(const T &x)

Definition SkTo.h:35

◆ uniqueID()

uint32_t skgpu::graphite::ComputeStep::uniqueID ( ) const

inline

Definition at line 241 of file ComputeStep.h.

241{ return fUniqueID; }

◆ workgroupBuffers()

SkSpan< const WorkgroupBufferDesc > skgpu::graphite::ComputeStep::workgroupBuffers ( ) const

inline

Definition at line 237 of file ComputeStep.h.

237{ return SkSpan(fWorkgroupBuffers); }

The documentation for this class was generated from the following files:

third_party/skia/src/gpu/graphite/compute/ComputeStep.h
third_party/skia/src/gpu/graphite/compute/ComputeStep.cpp

Classes

Public Types

Public Member Functions

Protected Types

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ DataFlow

◆ Flags

◆ NativeShaderFormat

◆ ResourcePolicy

◆ ResourceType

Constructor & Destructor Documentation

◆ ~ComputeStep()

◆ ComputeStep()

Member Function Documentation

◆ calculateBufferSize()

◆ calculateGlobalDispatchSize()

◆ calculateSamplerParameters()

◆ calculateTextureParameters()

◆ computeSkSL()

◆ localDispatchSize()

◆ name()

◆ nativeShaderSource()

◆ prepareStorageBuffer()

◆ prepareUniformBuffer()

◆ resources()

◆ supportsNativeShader()

◆ uniqueID()

◆ workgroupBuffers()