| /* |
| * Copyright 2013 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrGLSLGeometryProcessor_DEFINED |
| #define GrGLSLGeometryProcessor_DEFINED |
| |
| #include "src/gpu/GrFragmentProcessor.h" |
| #include "src/gpu/GrGeometryProcessor.h" |
| #include "src/gpu/GrShaderCaps.h" |
| #include "src/gpu/glsl/GrGLSLProgramDataManager.h" |
| #include "src/gpu/glsl/GrGLSLUniformHandler.h" |
| #include "src/gpu/glsl/GrGLSLVarying.h" |
| |
| #include <unordered_map> |
| |
| class GrGeometryProcessor; |
| class GrGLSLFPFragmentBuilder; |
| class GrGLSLGeometryBuilder; |
| class GrGLSLGPBuilder; |
| class GrGLSLVaryingHandler; |
| class GrGLSLVertexBuilder; |
| class GrShaderCaps; |
| |
| /** |
| * GrGeometryProcessor-derived classes that need to emit GLSL vertex shader code should be paired |
| * with a sibling class derived from GrGLSLGeometryProcessor (and return an instance of it from |
| * createGLSLInstance). |
| */ |
| class GrGLSLGeometryProcessor { |
| public: |
| using UniformHandle = GrGLSLProgramDataManager::UniformHandle; |
| using SamplerHandle = GrGLSLUniformHandler::SamplerHandle; |
| /** |
| * Struct of optional varying that replaces the input coords and bool indicating whether the FP |
| * should take a coord param as an argument. The latter may be false if the coords are simply |
| * unused or if the GP has lifted their computation to a varying emitted by the VS. |
| */ |
| struct FPCoords {GrShaderVar coordsVarying; bool hasCoordsParam;}; |
| using FPCoordsMap = std::unordered_map<const GrFragmentProcessor*, FPCoords>; |
| |
| virtual ~GrGLSLGeometryProcessor() {} |
| |
| |
| struct EmitArgs { |
| EmitArgs(GrGLSLVertexBuilder* vertBuilder, |
| GrGLSLGeometryBuilder* geomBuilder, |
| GrGLSLFPFragmentBuilder* fragBuilder, |
| GrGLSLVaryingHandler* varyingHandler, |
| GrGLSLUniformHandler* uniformHandler, |
| const GrShaderCaps* caps, |
| const GrGeometryProcessor& geomProc, |
| const char* outputColor, |
| const char* outputCoverage, |
| const SamplerHandle* texSamplers) |
| : fVertBuilder(vertBuilder) |
| , fGeomBuilder(geomBuilder) |
| , fFragBuilder(fragBuilder) |
| , fVaryingHandler(varyingHandler) |
| , fUniformHandler(uniformHandler) |
| , fShaderCaps(caps) |
| , fGeomProc(geomProc) |
| , fOutputColor(outputColor) |
| , fOutputCoverage(outputCoverage) |
| , fTexSamplers(texSamplers) {} |
| GrGLSLVertexBuilder* fVertBuilder; |
| GrGLSLGeometryBuilder* fGeomBuilder; |
| GrGLSLFPFragmentBuilder* fFragBuilder; |
| GrGLSLVaryingHandler* fVaryingHandler; |
| GrGLSLUniformHandler* fUniformHandler; |
| const GrShaderCaps* fShaderCaps; |
| const GrGeometryProcessor& fGeomProc; |
| const char* fOutputColor; |
| const char* fOutputCoverage; |
| const SamplerHandle* fTexSamplers; |
| }; |
| |
| /** |
| * Emits the code from this geometry processor into the shaders. For any FP in the pipeline that |
| * has its input coords implemented by the GP as a varying, the varying will be accessible in |
| * the returned map and should be used when the FP code is emitted. |
| **/ |
| FPCoordsMap emitCode(EmitArgs&, const GrPipeline& pipeline); |
| |
| /** |
| * Called after all effect emitCode() functions, to give the processor a chance to write out |
| * additional transformation code now that all uniforms have been emitted. |
| * It generates the final code for assigning transformed coordinates to the varyings recorded |
| * in the call to collectTransforms(). This must happen after FP code emission so that it has |
| * access to any uniforms the FPs registered for uniform sample matrix invocations. |
| */ |
| void emitTransformCode(GrGLSLVertexBuilder* vb, |
| GrGLSLUniformHandler* uniformHandler); |
| |
| /** |
| * A GrGLSLGeometryProcessor instance can be reused with any GrGLSLGeometryProcessor that |
| * produces the same stage key; this function reads data from a GrGLSLGeometryProcessor and |
| * uploads any uniform variables required by the shaders created in emitCode(). The |
| * GrGeometryProcessor parameter is guaranteed to be of the same type and to have an |
| * identical processor key as the GrGeometryProcessor that created this |
| * GrGLSLGeometryProcessor. |
| */ |
| virtual void setData(const GrGLSLProgramDataManager&, |
| const GrShaderCaps&, |
| const GrGeometryProcessor&) = 0; |
| |
| // We use these methods as a temporary back door to inject OpenGL tessellation code. Once |
| // tessellation is supported by SkSL we can remove these. |
| virtual SkString getTessControlShaderGLSL(const GrGeometryProcessor&, |
| const char* versionAndExtensionDecls, |
| const GrGLSLUniformHandler&, |
| const GrShaderCaps&) const { |
| SK_ABORT("Not implemented."); |
| } |
| virtual SkString getTessEvaluationShaderGLSL(const GrGeometryProcessor&, |
| const char* versionAndExtensionDecls, |
| const GrGLSLUniformHandler&, |
| const GrShaderCaps&) const { |
| SK_ABORT("Not implemented."); |
| } |
| |
| protected: |
| void setupUniformColor(GrGLSLFPFragmentBuilder* fragBuilder, |
| GrGLSLUniformHandler* uniformHandler, |
| const char* outputName, |
| UniformHandle* colorUniform); |
| |
| // A helper for setting the matrix on a uniform handle initialized through |
| // writeOutputPosition or writeLocalCoord. Automatically handles elided uniforms, |
| // scale+translate matrices, and state tracking (if provided state pointer is non-null). |
| static void SetTransform(const GrGLSLProgramDataManager&, |
| const GrShaderCaps&, |
| const UniformHandle& uniform, |
| const SkMatrix& matrix, |
| SkMatrix* state = nullptr); |
| |
| struct GrGPArgs { |
| // Used to specify the output variable used by the GP to store its device position. It can |
| // either be a float2 or a float3 (in order to handle perspective). The subclass sets this |
| // in its onEmitCode(). |
| GrShaderVar fPositionVar; |
| // Used to specify the variable storing the draw's local coordinates. It can be either a |
| // float2, float3, or void. It can only be void when no FP needs local coordinates. This |
| // variable can be an attribute or local variable, but should not itself be a varying. |
| // GrGLSLGeometryProcessor automatically determines if this must be passed to a FS. |
| GrShaderVar fLocalCoordVar; |
| }; |
| |
| // Helpers for adding code to write the transformed vertex position. The first simple version |
| // just writes a variable named by 'posName' into the position output variable with the |
| // assumption that the position is 2D. The second version transforms the input position by a |
| // view matrix and the output variable is 2D or 3D depending on whether the view matrix is |
| // perspective. Both versions declare the output position variable and will set |
| // GrGPArgs::fPositionVar. |
| static void WriteOutputPosition(GrGLSLVertexBuilder*, GrGPArgs*, const char* posName); |
| static void WriteOutputPosition(GrGLSLVertexBuilder*, |
| GrGLSLUniformHandler*, |
| const GrShaderCaps&, |
| GrGPArgs*, |
| const char* posName, |
| const SkMatrix& viewMatrix, |
| UniformHandle* viewMatrixUniform); |
| |
| // Helper to transform an existing variable by a given local matrix (e.g. the inverse view |
| // matrix). It will declare the transformed local coord variable and will set |
| // GrGPArgs::fLocalCoordVar. |
| static void WriteLocalCoord(GrGLSLVertexBuilder*, |
| GrGLSLUniformHandler*, |
| const GrShaderCaps&, |
| GrGPArgs*, |
| GrShaderVar localVar, |
| const SkMatrix& localMatrix, |
| UniformHandle* localMatrixUniform); |
| |
| // GPs that use writeOutputPosition and/or writeLocalCoord must incorporate the matrix type |
| // into their key, and should use this function or one of the other related helpers. |
| static uint32_t ComputeMatrixKey(const GrShaderCaps& caps, const SkMatrix& mat) { |
| if (!caps.reducedShaderMode()) { |
| if (mat.isIdentity()) { |
| return 0b00; |
| } |
| if (mat.isScaleTranslate()) { |
| return 0b01; |
| } |
| } |
| if (!mat.hasPerspective()) { |
| return 0b10; |
| } |
| return 0b11; |
| } |
| static uint32_t ComputeMatrixKeys(const GrShaderCaps& shaderCaps, |
| const SkMatrix& viewMatrix, |
| const SkMatrix& localMatrix) { |
| return (ComputeMatrixKey(shaderCaps, viewMatrix) << kMatrixKeyBits) | |
| ComputeMatrixKey(shaderCaps, localMatrix); |
| } |
| static uint32_t AddMatrixKeys(const GrShaderCaps& shaderCaps, |
| uint32_t flags, |
| const SkMatrix& viewMatrix, |
| const SkMatrix& localMatrix) { |
| // Shifting to make room for the matrix keys shouldn't lose bits |
| SkASSERT(((flags << (2 * kMatrixKeyBits)) >> (2 * kMatrixKeyBits)) == flags); |
| return (flags << (2 * kMatrixKeyBits)) | |
| ComputeMatrixKeys(shaderCaps, viewMatrix, localMatrix); |
| } |
| static constexpr int kMatrixKeyBits = 2; |
| |
| private: |
| virtual void onEmitCode(EmitArgs&, GrGPArgs*) = 0; |
| |
| // Iterates over the FPs beginning with the passed iter to register additional varyings and |
| // uniforms to support VS-promoted local coord evaluation for the FPs. |
| // |
| // This must happen before FP code emission so that the FPs can find the appropriate varying |
| // handles they use in place of explicit coord sampling; it is automatically called after |
| // onEmitCode() returns using the value stored in GpArgs::fLocalCoordVar. |
| FPCoordsMap collectTransforms(GrGLSLVertexBuilder* vb, |
| GrGLSLVaryingHandler* varyingHandler, |
| GrGLSLUniformHandler* uniformHandler, |
| const GrShaderVar& localCoordsVar, |
| const GrPipeline& pipeline); |
| |
| struct TransformInfo { |
| // The varying that conveys the coordinates to one or more FPs in the FS. |
| GrGLSLVarying varying; |
| // The coordinate to be transformed. varying is computed from this. |
| GrShaderVar localCoords; |
| // Used to sort so that ancestor FP varyings are initialized before descendant FP varyings. |
| int traversalOrder; |
| }; |
| // Populated by collectTransforms() for use in emitTransformCode(). When we lift the computation |
| // of a FP's input coord to a varying we propagate that varying up the FP tree to the highest |
| // node that shares the same coordinates. This allows multiple FPs in a subtree to share a |
| // varying. |
| std::unordered_map<const GrFragmentProcessor*, TransformInfo> fTransformVaryingsMap; |
| }; |
| |
| #endif |