1 /* 2 * Copyright 2013 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef GrGLSLGeometryProcessor_DEFINED 9 #define GrGLSLGeometryProcessor_DEFINED 10 11 #include "GrGLSLPrimitiveProcessor.h" 12 13 class GrGLSLGPBuilder; 14 15 /** 16 * If a GL effect needs a GrGLFullShaderBuilder* object to emit vertex code, then it must inherit 17 * from this class. Since paths don't have vertices, this class is only meant to be used internally 18 * by skia, for special cases. 19 */ 20 class GrGLSLGeometryProcessor : public GrGLSLPrimitiveProcessor { 21 public: 22 /* Any general emit code goes in the base class emitCode. Subclasses override onEmitCode */ 23 void emitCode(EmitArgs&) final; 24 25 protected: 26 // A helper which subclasses can use to upload coord transform matrices in setData(). 27 void setTransformDataHelper(const SkMatrix& localMatrix, 28 const GrGLSLProgramDataManager& pdman, 29 FPCoordTransformIter*); 30 31 // Emit transformed local coords from the vertex shader as a uniform matrix and varying per 32 // coord-transform. localCoordsVar must be a 2- or 3-component vector. If it is 3 then it is 33 // assumed to be a 2D homogeneous coordinate. 34 void emitTransforms(GrGLSLVertexBuilder*, 35 GrGLSLVaryingHandler*, 36 GrGLSLUniformHandler*, 37 const GrShaderVar& localCoordsVar, 38 const SkMatrix& localMatrix, 39 FPCoordTransformHandler*); 40 41 // Version of above that assumes identity for the local matrix. emitTransforms(GrGLSLVertexBuilder * vb,GrGLSLVaryingHandler * varyingHandler,GrGLSLUniformHandler * uniformHandler,const GrShaderVar & localCoordsVar,FPCoordTransformHandler * handler)42 void emitTransforms(GrGLSLVertexBuilder* vb, 43 GrGLSLVaryingHandler* varyingHandler, 44 GrGLSLUniformHandler* uniformHandler, 45 const GrShaderVar& localCoordsVar, 46 FPCoordTransformHandler* handler) { 47 this->emitTransforms(vb, varyingHandler, uniformHandler, localCoordsVar, SkMatrix::I(), 48 handler); 49 } 50 51 struct GrGPArgs { 52 // Used to specify the output variable used by the GP to store its device position. It can 53 // either be a float2 or a float3 (in order to handle perspective). The subclass sets this 54 // in its onEmitCode(). 55 GrShaderVar fPositionVar; 56 }; 57 58 // Helpers for adding code to write the transformed vertex position. The first simple version 59 // just writes a variable named by 'posName' into the position output variable with the 60 // assumption that the position is 2D. The second version transforms the input position by a 61 // view matrix and the output variable is 2D or 3D depending on whether the view matrix is 62 // perspective. Both versions declare the output position variable and will set 63 // GrGPArgs::fPositionVar. 64 void writeOutputPosition(GrGLSLVertexBuilder*, GrGPArgs*, const char* posName); 65 void writeOutputPosition(GrGLSLVertexBuilder*, 66 GrGLSLUniformHandler* uniformHandler, 67 GrGPArgs*, 68 const char* posName, 69 const SkMatrix& mat, 70 UniformHandle* viewMatrixUniform); 71 ComputePosKey(const SkMatrix & mat)72 static uint32_t ComputePosKey(const SkMatrix& mat) { 73 if (mat.isIdentity()) { 74 return 0x0; 75 } else if (!mat.hasPerspective()) { 76 return 0x01; 77 } else { 78 return 0x02; 79 } 80 } 81 82 private: 83 virtual void onEmitCode(EmitArgs&, GrGPArgs*) = 0; 84 85 struct TransformUniform { 86 UniformHandle fHandle; 87 SkMatrix fCurrentValue = SkMatrix::InvalidMatrix(); 88 }; 89 90 SkTArray<TransformUniform, true> fInstalledTransforms; 91 92 typedef GrGLSLPrimitiveProcessor INHERITED; 93 }; 94 95 #endif 96