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/GrGLSLVertexShaderBuilder.h"
15
16 class GrGLSLRRectShadowGeoProc : public GrGLSLGeometryProcessor {
17 public:
GrGLSLRRectShadowGeoProc()18 GrGLSLRRectShadowGeoProc() {}
19
onEmitCode(EmitArgs & args,GrGPArgs * gpArgs)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 GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
26
27 // emit attributes
28 varyingHandler->emitAttributes(rsgp);
29 fragBuilder->codeAppend("vec4 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->setupPosition(vertBuilder, gpArgs, rsgp.inPosition()->fName);
37
38 // emit transforms
39 this->emitTransforms(vertBuilder,
40 varyingHandler,
41 uniformHandler,
42 gpArgs->fPositionVar,
43 rsgp.inPosition()->fName,
44 rsgp.localMatrix(),
45 args.fFPCoordTransformHandler);
46
47 fragBuilder->codeAppend("float d = length(shadowParams.xy);");
48 fragBuilder->codeAppend("float distance = shadowParams.z * (1.0 - d);");
49
50 fragBuilder->codeAppend("float radius = shadowParams.w;");
51
52 fragBuilder->codeAppend("float factor = 1.0 - clamp(distance/radius, 0.0, 1.0);");
53 fragBuilder->codeAppend("factor = exp(-factor * factor * 4.0) - 0.018;");
54 fragBuilder->codeAppendf("%s = vec4(factor);",
55 args.fOutputCoverage);
56 }
57
setData(const GrGLSLProgramDataManager & pdman,const GrPrimitiveProcessor & proc,FPCoordTransformIter && transformIter)58 void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& proc,
59 FPCoordTransformIter&& transformIter) override {
60 this->setTransformDataHelper(proc.cast<GrRRectShadowGeoProc>().localMatrix(),
61 pdman, &transformIter);
62 }
63
GenKey(const GrGeometryProcessor & gp,const GrShaderCaps &,GrProcessorKeyBuilder * b)64 static inline void GenKey(const GrGeometryProcessor& gp,
65 const GrShaderCaps&,
66 GrProcessorKeyBuilder* b) {
67 const GrRRectShadowGeoProc& rsgp = gp.cast<GrRRectShadowGeoProc>();
68 uint16_t key;
69 key = rsgp.localMatrix().hasPerspective() ? 0x1 : 0x0;
70 b->add32(key);
71 }
72
73 private:
74 typedef GrGLSLGeometryProcessor INHERITED;
75 };
76
77 ///////////////////////////////////////////////////////////////////////////////
78
GrRRectShadowGeoProc(const SkMatrix & localMatrix)79 GrRRectShadowGeoProc::GrRRectShadowGeoProc(const SkMatrix& localMatrix)
80 : fLocalMatrix(localMatrix) {
81
82 this->initClassID<GrRRectShadowGeoProc>();
83 fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType,
84 kHigh_GrSLPrecision);
85 fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
86 fInShadowParams = &this->addVertexAttrib("inShadowParams", kVec4f_GrVertexAttribType);
87 }
88
getGLSLProcessorKey(const GrShaderCaps & caps,GrProcessorKeyBuilder * b) const89 void GrRRectShadowGeoProc::getGLSLProcessorKey(const GrShaderCaps& caps,
90 GrProcessorKeyBuilder* b) const {
91 GrGLSLRRectShadowGeoProc::GenKey(*this, caps, b);
92 }
93
createGLSLInstance(const GrShaderCaps &) const94 GrGLSLPrimitiveProcessor* GrRRectShadowGeoProc::createGLSLInstance(const GrShaderCaps&) const {
95 return new GrGLSLRRectShadowGeoProc();
96 }
97
98 ///////////////////////////////////////////////////////////////////////////////
99
100 GR_DEFINE_GEOMETRY_PROCESSOR_TEST(GrRRectShadowGeoProc);
101
102 #if GR_TEST_UTILS
TestCreate(GrProcessorTestData * d)103 sk_sp<GrGeometryProcessor> GrRRectShadowGeoProc::TestCreate(GrProcessorTestData* d) {
104 return GrRRectShadowGeoProc::Make(GrTest::TestMatrix(d->fRandom));
105 }
106 #endif
107