1 /*
2  * Copyright 2017 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 "src/gpu/ccpr/GrCCClipProcessor.h"
9 
10 #include "include/gpu/GrTexture.h"
11 #include "src/core/SkMakeUnique.h"
12 #include "src/gpu/GrTextureProxy.h"
13 #include "src/gpu/ccpr/GrCCClipPath.h"
14 #include "src/gpu/glsl/GrGLSLFragmentProcessor.h"
15 #include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h"
16 
GrCCClipProcessor(const GrCCClipPath * clipPath,IsCoverageCount isCoverageCount,MustCheckBounds mustCheckBounds)17 GrCCClipProcessor::GrCCClipProcessor(const GrCCClipPath* clipPath, IsCoverageCount isCoverageCount,
18                                      MustCheckBounds mustCheckBounds)
19         : INHERITED(kGrCCClipProcessor_ClassID, kCompatibleWithCoverageAsAlpha_OptimizationFlag)
20         , fClipPath(clipPath)
21         , fIsCoverageCount(IsCoverageCount::kYes == isCoverageCount)
22         , fMustCheckBounds(MustCheckBounds::kYes == mustCheckBounds)
23         , fAtlasAccess(sk_ref_sp(fClipPath->atlasLazyProxy()), GrSamplerState::ClampNearest()) {
24     SkASSERT(fAtlasAccess.proxy());
25     this->setTextureSamplerCnt(1);
26 }
27 
clone() const28 std::unique_ptr<GrFragmentProcessor> GrCCClipProcessor::clone() const {
29     return skstd::make_unique<GrCCClipProcessor>(
30             fClipPath, IsCoverageCount(fIsCoverageCount), MustCheckBounds(fMustCheckBounds));
31 }
32 
onGetGLSLProcessorKey(const GrShaderCaps &,GrProcessorKeyBuilder * b) const33 void GrCCClipProcessor::onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder* b) const {
34     const SkPath& clipPath = fClipPath->deviceSpacePath();
35     uint32_t key = (fIsCoverageCount) ? (uint32_t)GrFillRuleForSkPath(clipPath) : 0;
36     key = (key << 1) | ((clipPath.isInverseFillType()) ? 1 : 0);
37     key = (key << 1) | ((fMustCheckBounds) ? 1 : 0);
38     b->add32(key);
39 }
40 
onIsEqual(const GrFragmentProcessor & fp) const41 bool GrCCClipProcessor::onIsEqual(const GrFragmentProcessor& fp) const {
42     const GrCCClipProcessor& that = fp.cast<GrCCClipProcessor>();
43     // Each ClipPath path has a unique atlas proxy, so hasSameSamplersAndAccesses should have
44     // already weeded out FPs with different ClipPaths.
45     SkASSERT(that.fClipPath->deviceSpacePath().getGenerationID() ==
46              fClipPath->deviceSpacePath().getGenerationID());
47     return that.fClipPath->deviceSpacePath().getFillType() ==
48                    fClipPath->deviceSpacePath().getFillType() &&
49            that.fIsCoverageCount == fIsCoverageCount && that.fMustCheckBounds == fMustCheckBounds;
50 }
51 
52 class GrCCClipProcessor::Impl : public GrGLSLFragmentProcessor {
53 public:
emitCode(EmitArgs & args)54     void emitCode(EmitArgs& args) override {
55         const GrCCClipProcessor& proc = args.fFp.cast<GrCCClipProcessor>();
56         GrGLSLUniformHandler* uniHandler = args.fUniformHandler;
57         GrGLSLFPFragmentBuilder* f = args.fFragBuilder;
58 
59         f->codeAppend ("half coverage;");
60 
61         if (proc.fMustCheckBounds) {
62             const char* pathIBounds;
63             fPathIBoundsUniform = uniHandler->addUniform(kFragment_GrShaderFlag, kFloat4_GrSLType,
64                                                          "path_ibounds", &pathIBounds);
65             f->codeAppendf("if (all(greaterThan(float4(sk_FragCoord.xy, %s.zw), "
66                                                "float4(%s.xy, sk_FragCoord.xy)))) {",
67                                                pathIBounds, pathIBounds);
68         }
69 
70         const char* atlasTransform;
71         fAtlasTransformUniform = uniHandler->addUniform(kFragment_GrShaderFlag, kFloat4_GrSLType,
72                                                         "atlas_transform", &atlasTransform);
73         f->codeAppendf("float2 texcoord = sk_FragCoord.xy * %s.xy + %s.zw;",
74                        atlasTransform, atlasTransform);
75 
76         f->codeAppend ("coverage = ");
77         f->appendTextureLookup(args.fTexSamplers[0], "texcoord", kHalf2_GrSLType);
78         f->codeAppend (".a;");
79 
80         if (proc.fIsCoverageCount) {
81             auto fillRule = GrFillRuleForSkPath(proc.fClipPath->deviceSpacePath());
82             if (GrFillRule::kEvenOdd == fillRule) {
83                 f->codeAppend ("half t = mod(abs(coverage), 2);");
84                 f->codeAppend ("coverage = 1 - abs(t - 1);");
85             } else {
86                 SkASSERT(GrFillRule::kNonzero == fillRule);
87                 f->codeAppend ("coverage = min(abs(coverage), 1);");
88             }
89         }
90 
91         if (proc.fMustCheckBounds) {
92             f->codeAppend ("} else {");
93             f->codeAppend (    "coverage = 0;");
94             f->codeAppend ("}");
95         }
96 
97         if (proc.fClipPath->deviceSpacePath().isInverseFillType()) {
98             f->codeAppend ("coverage = 1 - coverage;");
99         }
100 
101         f->codeAppendf("%s = %s * coverage;", args.fOutputColor, args.fInputColor);
102     }
103 
onSetData(const GrGLSLProgramDataManager & pdman,const GrFragmentProcessor & fp)104     void onSetData(const GrGLSLProgramDataManager& pdman,
105                    const GrFragmentProcessor& fp) override {
106         const GrCCClipProcessor& proc = fp.cast<GrCCClipProcessor>();
107         if (proc.fMustCheckBounds) {
108             const SkRect pathIBounds = SkRect::Make(proc.fClipPath->pathDevIBounds());
109             pdman.set4f(fPathIBoundsUniform, pathIBounds.left(), pathIBounds.top(),
110                         pathIBounds.right(), pathIBounds.bottom());
111         }
112         const SkVector& scale = proc.fClipPath->atlasScale();
113         const SkVector& trans = proc.fClipPath->atlasTranslate();
114         pdman.set4f(fAtlasTransformUniform, scale.x(), scale.y(), trans.x(), trans.y());
115     }
116 
117 private:
118     UniformHandle fPathIBoundsUniform;
119     UniformHandle fAtlasTransformUniform;
120 };
121 
onCreateGLSLInstance() const122 GrGLSLFragmentProcessor* GrCCClipProcessor::onCreateGLSLInstance() const {
123     return new Impl();
124 }
125