1 /* 2 * Copyright 2016 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 #include "GrShadowGeoProc.h" 9 10 #include "glsl/GrGLSLFragmentShaderBuilder.h" 11 #include "glsl/GrGLSLGeometryProcessor.h" 12 #include "glsl/GrGLSLUniformHandler.h" 13 #include "glsl/GrGLSLVarying.h" 14 #include "glsl/GrGLSLVertexGeoBuilder.h" 15 16 class GrGLSLRRectShadowGeoProc : public GrGLSLGeometryProcessor { 17 public: 18 GrGLSLRRectShadowGeoProc() {} 19 20 void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override { 21 const GrRRectShadowGeoProc& rsgp = args.fGP.cast<GrRRectShadowGeoProc>(); 22 GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder; 23 GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler; 24 GrGLSLUniformHandler* uniformHandler = args.fUniformHandler; 25 GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder; 26 27 // emit attributes 28 varyingHandler->emitAttributes(rsgp); 29 fragBuilder->codeAppend("half3 shadowParams;"); 30 varyingHandler->addPassThroughAttribute(rsgp.inShadowParams(), "shadowParams"); 31 32 // setup pass through color 33 varyingHandler->addPassThroughAttribute(rsgp.inColor(), args.fOutputColor); 34 35 // Setup position 36 this->writeOutputPosition(vertBuilder, gpArgs, rsgp.inPosition().name()); 37 38 // emit transforms 39 this->emitTransforms(vertBuilder, 40 varyingHandler, 41 uniformHandler, 42 rsgp.inPosition().asShaderVar(), 43 args.fFPCoordTransformHandler); 44 45 fragBuilder->codeAppend("half d = length(shadowParams.xy);"); 46 fragBuilder->codeAppend("half distance = shadowParams.z * (1.0 - d);"); 47 48 fragBuilder->codeAppend("half factor = 1.0 - clamp(distance, 0.0, 1.0);"); 49 fragBuilder->codeAppend("factor = exp(-factor * factor * 4.0) - 0.018;"); 50 fragBuilder->codeAppendf("%s = half4(factor);", 51 args.fOutputCoverage); 52 } 53 54 void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& proc, 55 FPCoordTransformIter&& transformIter) override { 56 this->setTransformDataHelper(SkMatrix::I(), pdman, &transformIter); 57 } 58 59 private: 60 typedef GrGLSLGeometryProcessor INHERITED; 61 }; 62 63 /////////////////////////////////////////////////////////////////////////////// 64 65 GrRRectShadowGeoProc::GrRRectShadowGeoProc() : INHERITED(kGrRRectShadowGeoProc_ClassID) { 66 fInPosition = {"inPosition", kFloat2_GrVertexAttribType, kFloat2_GrSLType}; 67 fInColor = {"inColor", kUByte4_norm_GrVertexAttribType, kHalf4_GrSLType}; 68 fInShadowParams = {"inShadowParams", kFloat3_GrVertexAttribType, kHalf3_GrSLType}; 69 this->setVertexAttributes(&fInPosition, 3); 70 } 71 72 GrGLSLPrimitiveProcessor* GrRRectShadowGeoProc::createGLSLInstance(const GrShaderCaps&) const { 73 return new GrGLSLRRectShadowGeoProc(); 74 } 75 76 /////////////////////////////////////////////////////////////////////////////// 77 78 GR_DEFINE_GEOMETRY_PROCESSOR_TEST(GrRRectShadowGeoProc); 79 80 #if GR_TEST_UTILS 81 sk_sp<GrGeometryProcessor> GrRRectShadowGeoProc::TestCreate(GrProcessorTestData* d) { 82 return GrRRectShadowGeoProc::Make(); 83 } 84 #endif 85