| /* |
| * Copyright 2021 Google LLC |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef skgpu_graphite_Renderer_DEFINED |
| #define skgpu_graphite_Renderer_DEFINED |
| |
| #include "include/core/SkSpan.h" |
| #include "include/core/SkString.h" |
| #include "include/core/SkTypes.h" |
| #include "src/core/SkEnumBitMask.h" |
| #include "src/gpu/graphite/Attribute.h" |
| #include "src/gpu/graphite/DrawTypes.h" |
| #include "src/gpu/graphite/ResourceTypes.h" |
| #include "src/gpu/graphite/Uniform.h" |
| |
| #include <array> |
| #include <initializer_list> |
| #include <string> |
| #include <string_view> |
| #include <vector> |
| |
| enum class SkPathFillType; |
| |
| namespace skgpu { enum class MaskFormat; } |
| |
| namespace skgpu::graphite { |
| |
| class DrawWriter; |
| class DrawParams; |
| class PipelineDataGatherer; |
| class ResourceProvider; |
| class TextureDataBlock; |
| |
| struct ResourceBindingRequirements; |
| |
| struct Varying { |
| const char* fName; |
| SkSLType fType; |
| // TODO: add modifier (e.g., flat and noperspective) support |
| }; |
| |
| /** |
| * The actual technique for rasterizing a high-level draw recorded in a DrawList is handled by a |
| * specific Renderer. Each technique has an associated singleton Renderer that decomposes the |
| * technique into a series of RenderSteps that must be executed in the specified order for the draw. |
| * However, the RenderStep executions for multiple draws can be re-arranged so batches of each |
| * step can be performed in a larger GPU operation. This re-arranging relies on accurate |
| * determination of the DisjointStencilIndex for each draw so that stencil steps are not corrupted |
| * by another draw before its cover step is executed. It also relies on the CompressedPaintersOrder |
| * for each draw to ensure steps are not re-arranged in a way that violates the original draw order. |
| * |
| * Renderer itself is non-virtual since it simply has to point to a list of RenderSteps. RenderSteps |
| * on the other hand are virtual implement the technique specific functionality. It is entirely |
| * possible for certain types of steps, e.g. a bounding box cover, to be re-used across different |
| * Renderers even if the preceeding steps were different. |
| * |
| * All Renderers are accessed through the SharedContext's RendererProvider. |
| */ |
| class RenderStep { |
| public: |
| virtual ~RenderStep() = default; |
| |
| // The DrawWriter is configured with the vertex and instance strides of the RenderStep, and its |
| // primitive type. The recorded draws will be executed with a graphics pipeline compatible with |
| // this RenderStep. |
| virtual void writeVertices(DrawWriter*, const DrawParams&, int ssboIndex) const = 0; |
| |
| // Write out the uniform values (aligned for the layout), textures, and samplers. The uniform |
| // values will be de-duplicated across all draws using the RenderStep before uploading to the |
| // GPU, but it can be assumed the uniforms will be bound before the draws recorded in |
| // 'writeVertices' are executed. |
| virtual void writeUniformsAndTextures(const DrawParams&, PipelineDataGatherer*) const = 0; |
| |
| // Returns the body of a vertex function, which must define a float4 devPosition variable and |
| // must write to an already-defined float2 stepLocalCoords variable. This will be automatically |
| // set to a varying for the fragment shader if the paint requires local coords. This SkSL has |
| // access to the variables declared by vertexAttributes(), instanceAttributes(), and uniforms(). |
| // The 'devPosition' variable's z must store the PaintDepth normalized to a float from [0, 1], |
| // for each processed draw although the RenderStep can choose to upload it in any manner. |
| // |
| // NOTE: The above contract is mainly so that the entire SkSL program can be created by just str |
| // concatenating struct definitions generated from the RenderStep and paint Combination |
| // and then including the function bodies returned here. |
| virtual std::string vertexSkSL() const = 0; |
| |
| // Emits code to set up textures and samplers. Should only be defined if hasTextures is true. |
| virtual std::string texturesAndSamplersSkSL(const ResourceBindingRequirements&, |
| int* nextBindingIndex) const { |
| return R"()"; |
| } |
| |
| // Emits code to set up coverage value. Should only be defined if overridesCoverage is true. |
| // When implemented the returned SkSL fragment should write its coverage into a |
| // 'half4 outputCoverage' variable (defined in the calling code) with the actual |
| // coverage splatted out into all four channels. |
| virtual const char* fragmentCoverageSkSL() const { return R"()"; } |
| |
| // Emits code to set up a primitive color value. Should only be defined if emitsPrimitiveColor |
| // is true. When implemented, the returned SkSL fragment should write its color into a |
| // 'half4 primitiveColor' variable (defined in the calling code). |
| virtual const char* fragmentColorSkSL() const { return R"()"; } |
| |
| uint32_t uniqueID() const { return fUniqueID; } |
| |
| // Returns a name formatted as "Subclass[variant]", where "Subclass" matches the C++ class name |
| // and variant is a unique term describing instance's specific configuration. |
| const char* name() const { return fName.c_str(); } |
| |
| bool requiresMSAA() const { return fFlags & Flags::kRequiresMSAA; } |
| bool performsShading() const { return fFlags & Flags::kPerformsShading; } |
| bool hasTextures() const { return fFlags & Flags::kHasTextures; } |
| bool emitsCoverage() const { return fFlags & Flags::kEmitsCoverage; } |
| bool emitsPrimitiveColor() const { return fFlags & Flags::kEmitsPrimitiveColor; } |
| |
| PrimitiveType primitiveType() const { return fPrimitiveType; } |
| size_t vertexStride() const { return fVertexStride; } |
| size_t instanceStride() const { return fInstanceStride; } |
| |
| size_t numUniforms() const { return fUniforms.size(); } |
| size_t numVertexAttributes() const { return fVertexAttrs.size(); } |
| size_t numInstanceAttributes() const { return fInstanceAttrs.size(); } |
| |
| static const char* ssboIndex() { return "ssboIndex"; } |
| |
| // The uniforms of a RenderStep are bound to the kRenderStep slot, the rest of the pipeline |
| // may still use uniforms bound to other slots. |
| SkSpan<const Uniform> uniforms() const { return SkSpan(fUniforms); } |
| SkSpan<const Attribute> vertexAttributes() const { return SkSpan(fVertexAttrs); } |
| SkSpan<const Attribute> instanceAttributes() const { return SkSpan(fInstanceAttrs); } |
| SkSpan<const Varying> varyings() const { return SkSpan(fVaryings); } |
| |
| const DepthStencilSettings& depthStencilSettings() const { return fDepthStencilSettings; } |
| |
| SkEnumBitMask<DepthStencilFlags> depthStencilFlags() const { |
| return (fDepthStencilSettings.fStencilTestEnabled |
| ? DepthStencilFlags::kStencil : DepthStencilFlags::kNone) | |
| (fDepthStencilSettings.fDepthTestEnabled || fDepthStencilSettings.fDepthWriteEnabled |
| ? DepthStencilFlags::kDepth : DepthStencilFlags::kNone); |
| } |
| |
| // TODO: Actual API to do things |
| // 6. Some Renderers benefit from being able to share vertices between RenderSteps. Must find a |
| // way to support that. It may mean that RenderSteps get state per draw. |
| // - Does Renderer make RenderStepFactories that create steps for each DrawList::Draw? |
| // - Does DrawList->DrawPass conversion build a separate array of blind data that the |
| // stateless Renderstep can refer to for {draw,step} pairs? |
| // - Does each DrawList::Draw have extra space (e.g. 8 bytes) that steps can cache data in? |
| protected: |
| enum class Flags : unsigned { |
| kNone = 0b00000, |
| kRequiresMSAA = 0b00001, |
| kPerformsShading = 0b00010, |
| kHasTextures = 0b00100, |
| kEmitsCoverage = 0b01000, |
| kEmitsPrimitiveColor = 0b10000, |
| }; |
| SK_DECL_BITMASK_OPS_FRIENDS(Flags); |
| |
| // While RenderStep does not define the full program that's run for a draw, it defines the |
| // entire vertex layout of the pipeline. This is not allowed to change, so can be provided to |
| // the RenderStep constructor by subclasses. |
| RenderStep(std::string_view className, |
| std::string_view variantName, |
| SkEnumBitMask<Flags> flags, |
| std::initializer_list<Uniform> uniforms, |
| PrimitiveType primitiveType, |
| DepthStencilSettings depthStencilSettings, |
| SkSpan<const Attribute> vertexAttrs, |
| SkSpan<const Attribute> instanceAttrs, |
| SkSpan<const Varying> varyings = {}); |
| |
| private: |
| friend class Renderer; // for Flags |
| |
| // Cannot copy or move |
| RenderStep(const RenderStep&) = delete; |
| RenderStep(RenderStep&&) = delete; |
| |
| uint32_t fUniqueID; |
| SkEnumBitMask<Flags> fFlags; |
| PrimitiveType fPrimitiveType; |
| |
| DepthStencilSettings fDepthStencilSettings; |
| |
| // TODO: When we always use C++17 for builds, we should be able to just let subclasses declare |
| // constexpr arrays and point to those, but we need explicit storage for C++14. |
| // Alternatively, if we imposed a max attr count, similar to Renderer's num render steps, we |
| // could just have this be std::array and keep all attributes inline with the RenderStep memory. |
| // On the other hand, the attributes are only needed when creating a new pipeline so it's not |
| // that performance sensitive. |
| std::vector<Uniform> fUniforms; |
| std::vector<Attribute> fVertexAttrs; |
| std::vector<Attribute> fInstanceAttrs; |
| std::vector<Varying> fVaryings; |
| |
| size_t fVertexStride; // derived from vertex attribute set |
| size_t fInstanceStride; // derived from instance attribute set |
| |
| std::string fName; |
| }; |
| SK_MAKE_BITMASK_OPS(RenderStep::Flags); |
| |
| class Renderer { |
| using StepFlags = RenderStep::Flags; |
| public: |
| // The maximum number of render steps that any Renderer is allowed to have. |
| static constexpr int kMaxRenderSteps = 4; |
| |
| const RenderStep& step(int i) const { |
| SkASSERT(i >= 0 && i < fStepCount); |
| return *fSteps[i]; |
| } |
| SkSpan<const RenderStep* const> steps() const { |
| SkASSERT(fStepCount > 0); // steps() should only be called on valid Renderers. |
| return {fSteps.data(), static_cast<size_t>(fStepCount) }; |
| } |
| |
| const char* name() const { return fName.c_str(); } |
| DrawTypeFlags drawTypes() const { return fDrawTypes; } |
| int numRenderSteps() const { return fStepCount; } |
| |
| bool requiresMSAA() const { return fStepFlags & StepFlags::kRequiresMSAA; } |
| bool emitsCoverage() const { return fStepFlags & StepFlags::kEmitsCoverage; } |
| bool emitsPrimitiveColor() const { return fStepFlags & StepFlags::kEmitsPrimitiveColor; } |
| |
| SkEnumBitMask<DepthStencilFlags> depthStencilFlags() const { return fDepthStencilFlags; } |
| |
| private: |
| friend class RendererProvider; // for ctors |
| |
| // Max render steps is 4, so just spell the options out for now... |
| Renderer(std::string_view name, DrawTypeFlags drawTypes, const RenderStep* s1) |
| : Renderer(name, drawTypes, std::array<const RenderStep*, 1>{s1}) {} |
| |
| Renderer(std::string_view name, DrawTypeFlags drawTypes, |
| const RenderStep* s1, const RenderStep* s2) |
| : Renderer(name, drawTypes, std::array<const RenderStep*, 2>{s1, s2}) {} |
| |
| Renderer(std::string_view name, DrawTypeFlags drawTypes, |
| const RenderStep* s1, const RenderStep* s2, const RenderStep* s3) |
| : Renderer(name, drawTypes, std::array<const RenderStep*, 3>{s1, s2, s3}) {} |
| |
| Renderer(std::string_view name, DrawTypeFlags drawTypes, |
| const RenderStep* s1, const RenderStep* s2, const RenderStep* s3, const RenderStep* s4) |
| : Renderer(name, drawTypes, std::array<const RenderStep*, 4>{s1, s2, s3, s4}) {} |
| |
| template<size_t N> |
| Renderer(std::string_view name, DrawTypeFlags drawTypes, std::array<const RenderStep*, N> steps) |
| : fName(name) |
| , fDrawTypes(drawTypes) |
| , fStepCount(SkTo<int>(N)) { |
| static_assert(N <= kMaxRenderSteps); |
| for (int i = 0 ; i < fStepCount; ++i) { |
| fSteps[i] = steps[i]; |
| fStepFlags |= fSteps[i]->fFlags; |
| fDepthStencilFlags |= fSteps[i]->depthStencilFlags(); |
| } |
| // At least one step needs to actually shade. |
| SkASSERT(fStepFlags & RenderStep::Flags::kPerformsShading); |
| } |
| |
| // For RendererProvider to manage initialization; it will never expose a Renderer that is only |
| // default-initialized and not replaced because it's algorithm is disabled by caps/options. |
| Renderer() : fSteps(), fName(""), fStepCount(0) {} |
| Renderer& operator=(Renderer&&) = default; |
| |
| std::array<const RenderStep*, kMaxRenderSteps> fSteps; |
| std::string fName; |
| DrawTypeFlags fDrawTypes = DrawTypeFlags::kAll; |
| int fStepCount; |
| |
| SkEnumBitMask<StepFlags> fStepFlags = StepFlags::kNone; |
| SkEnumBitMask<DepthStencilFlags> fDepthStencilFlags = DepthStencilFlags::kNone; |
| }; |
| |
| } // namespace skgpu::graphite |
| |
| #endif // skgpu_graphite_Renderer_DEFINED |