| /* |
| * Copyright 2014 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "src/gpu/ganesh/effects/GrConvexPolyEffect.h" |
| |
| #include "include/private/base/SkPathEnums.h" |
| #include "src/core/SkPathPriv.h" |
| #include "src/gpu/KeyBuilder.h" |
| #include "src/gpu/ganesh/glsl/GrGLSLFragmentShaderBuilder.h" |
| #include "src/gpu/ganesh/glsl/GrGLSLProgramDataManager.h" |
| #include "src/gpu/ganesh/glsl/GrGLSLUniformHandler.h" |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| GrFPResult GrConvexPolyEffect::Make(std::unique_ptr<GrFragmentProcessor> inputFP, |
| GrClipEdgeType type, const SkPath& path) { |
| if (path.getSegmentMasks() != SkPath::kLine_SegmentMask || !path.isConvex()) { |
| return GrFPFailure(std::move(inputFP)); |
| } |
| |
| SkPathFirstDirection dir = SkPathPriv::ComputeFirstDirection(path); |
| // The only way this should fail is if the clip is effectively a infinitely thin line. In that |
| // case nothing is inside the clip. It'd be nice to detect this at a higher level and either |
| // skip the draw or omit the clip element. |
| if (dir == SkPathFirstDirection::kUnknown) { |
| if (GrClipEdgeTypeIsInverseFill(type)) { |
| return GrFPSuccess( |
| GrFragmentProcessor::ModulateRGBA(std::move(inputFP), SK_PMColor4fWHITE)); |
| } |
| // This could use ConstColor instead of ModulateRGBA but it would trigger a debug print |
| // about a coverage processor not being compatible with the alpha-as-coverage optimization. |
| // We don't really care about this unlikely case so we just use ModulateRGBA to suppress |
| // the print. |
| return GrFPSuccess( |
| GrFragmentProcessor::ModulateRGBA(std::move(inputFP), SK_PMColor4fTRANSPARENT)); |
| } |
| |
| SkScalar edges[3 * kMaxEdges]; |
| SkPoint pts[4]; |
| SkPath::Verb verb; |
| SkPath::Iter iter(path, true); |
| |
| // SkPath considers itself convex so long as there is a convex contour within it, |
| // regardless of any degenerate contours such as a string of moveTos before it. |
| // Iterate here to consume any degenerate contours and only process the points |
| // on the actual convex contour. |
| int n = 0; |
| while ((verb = iter.next(pts)) != SkPath::kDone_Verb) { |
| switch (verb) { |
| case SkPath::kMove_Verb: |
| case SkPath::kClose_Verb: |
| break; |
| case SkPath::kLine_Verb: { |
| if (n >= kMaxEdges) { |
| return GrFPFailure(std::move(inputFP)); |
| } |
| if (pts[0] != pts[1]) { |
| SkVector v = pts[1] - pts[0]; |
| v.normalize(); |
| if (SkPathFirstDirection::kCCW == dir) { |
| edges[3 * n] = v.fY; |
| edges[3 * n + 1] = -v.fX; |
| } else { |
| edges[3 * n] = -v.fY; |
| edges[3 * n + 1] = v.fX; |
| } |
| edges[3 * n + 2] = -(edges[3 * n] * pts[1].fX + edges[3 * n + 1] * pts[1].fY); |
| ++n; |
| } |
| break; |
| } |
| default: |
| // Non-linear segment so not a polygon. |
| return GrFPFailure(std::move(inputFP)); |
| } |
| } |
| |
| if (path.isInverseFillType()) { |
| type = GrInvertClipEdgeType(type); |
| } |
| return GrConvexPolyEffect::Make(std::move(inputFP), type, n, edges); |
| } |
| |
| GrConvexPolyEffect::~GrConvexPolyEffect() {} |
| |
| void GrConvexPolyEffect::onAddToKey(const GrShaderCaps& caps, skgpu::KeyBuilder* b) const { |
| static_assert(kGrClipEdgeTypeCnt <= 8); |
| uint32_t key = (fEdgeCount << 3) | static_cast<int>(fEdgeType); |
| b->add32(key); |
| } |
| |
| std::unique_ptr<GrFragmentProcessor::ProgramImpl> GrConvexPolyEffect::onMakeProgramImpl() const { |
| class Impl : public ProgramImpl { |
| public: |
| void emitCode(EmitArgs& args) override { |
| const GrConvexPolyEffect& cpe = args.fFp.cast<GrConvexPolyEffect>(); |
| |
| const char *edgeArrayName; |
| fEdgeUniform = args.fUniformHandler->addUniformArray(&cpe, |
| kFragment_GrShaderFlag, |
| SkSLType::kHalf3, |
| "edgeArray", |
| cpe.fEdgeCount, |
| &edgeArrayName); |
| GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder; |
| fragBuilder->codeAppend("half alpha = 1.0;\n" |
| "half edge;\n"); |
| for (int i = 0; i < cpe.fEdgeCount; ++i) { |
| fragBuilder->codeAppendf("edge = dot(%s[%d], half3(sk_FragCoord.xy1));\n", |
| edgeArrayName, i); |
| if (GrClipEdgeTypeIsAA(cpe.fEdgeType)) { |
| fragBuilder->codeAppend("alpha *= saturate(edge);\n"); |
| } else { |
| fragBuilder->codeAppend("alpha *= step(0.5, edge);\n"); |
| } |
| } |
| |
| if (GrClipEdgeTypeIsInverseFill(cpe.fEdgeType)) { |
| fragBuilder->codeAppend("alpha = 1.0 - alpha;\n"); |
| } |
| |
| SkString inputSample = this->invokeChild(/*childIndex=*/0, args); |
| |
| fragBuilder->codeAppendf("return %s * alpha;\n", inputSample.c_str()); |
| } |
| |
| private: |
| void onSetData(const GrGLSLProgramDataManager& pdman, |
| const GrFragmentProcessor& fp) override { |
| const GrConvexPolyEffect& cpe = fp.cast<GrConvexPolyEffect>(); |
| size_t n = 3*cpe.fEdgeCount; |
| if (!std::equal(fPrevEdges.begin(), fPrevEdges.begin() + n, cpe.fEdges.begin())) { |
| pdman.set3fv(fEdgeUniform, cpe.fEdgeCount, cpe.fEdges.data()); |
| std::copy_n(cpe.fEdges.begin(), n, fPrevEdges.begin()); |
| } |
| } |
| |
| GrGLSLProgramDataManager::UniformHandle fEdgeUniform; |
| std::array<float, 3 * GrConvexPolyEffect::kMaxEdges> fPrevEdges = {SK_FloatNaN}; |
| }; |
| |
| return std::make_unique<Impl>(); |
| } |
| |
| GrConvexPolyEffect::GrConvexPolyEffect(std::unique_ptr<GrFragmentProcessor> inputFP, |
| GrClipEdgeType edgeType, |
| int n, |
| const float edges[]) |
| : INHERITED(kGrConvexPolyEffect_ClassID, |
| ProcessorOptimizationFlags(inputFP.get()) & |
| kCompatibleWithCoverageAsAlpha_OptimizationFlag) |
| , fEdgeType(edgeType) |
| , fEdgeCount(n) { |
| // Factory function should have already ensured this. |
| SkASSERT(n <= kMaxEdges); |
| std::copy_n(edges, 3*n, fEdges.begin()); |
| // Outset the edges by 0.5 so that a pixel with center on an edge is 50% covered in the AA case |
| // and 100% covered in the non-AA case. |
| for (int i = 0; i < n; ++i) { |
| fEdges[3 * i + 2] += SK_ScalarHalf; |
| } |
| |
| this->registerChild(std::move(inputFP)); |
| } |
| |
| GrConvexPolyEffect::GrConvexPolyEffect(const GrConvexPolyEffect& that) |
| : INHERITED(that) |
| , fEdgeType(that.fEdgeType) |
| , fEdgeCount(that.fEdgeCount) { |
| std::copy_n(that.fEdges.begin(), 3*that.fEdgeCount, fEdges.begin()); |
| } |
| |
| std::unique_ptr<GrFragmentProcessor> GrConvexPolyEffect::clone() const { |
| return std::unique_ptr<GrFragmentProcessor>(new GrConvexPolyEffect(*this)); |
| } |
| |
| bool GrConvexPolyEffect::onIsEqual(const GrFragmentProcessor& other) const { |
| const GrConvexPolyEffect& cpe = other.cast<GrConvexPolyEffect>(); |
| int n = 3*cpe.fEdgeCount; |
| return cpe.fEdgeType == fEdgeType && |
| cpe.fEdgeCount == fEdgeCount && |
| std::equal(cpe.fEdges.begin(), cpe.fEdges.begin() + n, fEdges.begin()); |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrConvexPolyEffect) |
| |
| #if GR_TEST_UTILS |
| std::unique_ptr<GrFragmentProcessor> GrConvexPolyEffect::TestCreate(GrProcessorTestData* d) { |
| int count = d->fRandom->nextULessThan(kMaxEdges) + 1; |
| SkScalar edges[kMaxEdges * 3]; |
| for (int i = 0; i < 3 * count; ++i) { |
| edges[i] = d->fRandom->nextSScalar1(); |
| } |
| |
| bool success; |
| std::unique_ptr<GrFragmentProcessor> fp = d->inputFP(); |
| do { |
| GrClipEdgeType edgeType = |
| static_cast<GrClipEdgeType>(d->fRandom->nextULessThan(kGrClipEdgeTypeCnt)); |
| std::tie(success, fp) = GrConvexPolyEffect::Make(std::move(fp), edgeType, count, edges); |
| } while (!success); |
| return fp; |
| } |
| #endif |