| /* |
| * 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/core/SkPathPriv.h" |
| #include "src/gpu/effects/GrConvexPolyEffect.h" |
| #include "src/gpu/glsl/GrGLSLFragmentProcessor.h" |
| #include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h" |
| #include "src/gpu/glsl/GrGLSLProgramDataManager.h" |
| #include "src/gpu/glsl/GrGLSLUniformHandler.h" |
| #include "src/sksl/dsl/priv/DSLFPs.h" |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| class GrGLConvexPolyEffect : public GrGLSLFragmentProcessor { |
| public: |
| GrGLConvexPolyEffect() { |
| for (size_t i = 0; i < SK_ARRAY_COUNT(fPrevEdges); ++i) { |
| fPrevEdges[i] = SK_ScalarNaN; |
| } |
| } |
| |
| void emitCode(EmitArgs&) override; |
| |
| static inline void GenKey(const GrProcessor&, const GrShaderCaps&, GrProcessorKeyBuilder*); |
| |
| protected: |
| void onSetData(const GrGLSLProgramDataManager&, const GrFragmentProcessor&) override; |
| |
| private: |
| GrGLSLProgramDataManager::UniformHandle fEdgeUniform; |
| SkScalar fPrevEdges[3 * GrConvexPolyEffect::kMaxEdges]; |
| using INHERITED = GrGLSLFragmentProcessor; |
| }; |
| |
| void GrGLConvexPolyEffect::emitCode(EmitArgs& args) { |
| const GrConvexPolyEffect& cpe = args.fFp.cast<GrConvexPolyEffect>(); |
| |
| using namespace SkSL::dsl; |
| StartFragmentProcessor(this, &args); |
| GlobalVar edgeArray(kUniform_Modifier, Array(kHalf3_Type, cpe.getEdgeCount()), "edgeArray"); |
| Declare(edgeArray); |
| fEdgeUniform = VarUniformHandle(edgeArray); |
| Var alpha(kHalf_Type, "alpha", 1); |
| Declare(alpha); |
| Var edge(kHalf_Type, "edge"); |
| Declare(edge); |
| for (int i = 0; i < cpe.getEdgeCount(); ++i) { |
| edge = Dot(edgeArray[i], Half3(Swizzle(sk_FragCoord(), X, Y, ONE))); |
| if (GrClipEdgeTypeIsAA(cpe.getEdgeType())) { |
| edge = Saturate(edge); |
| } else { |
| edge = Select(edge >= 0.5, 1.0, 0.0); |
| } |
| alpha *= edge; |
| } |
| |
| if (GrClipEdgeTypeIsInverseFill(cpe.getEdgeType())) { |
| alpha = 1.0 - alpha; |
| } |
| |
| Return(SampleChild(0) * alpha); |
| EndFragmentProcessor(); |
| } |
| |
| void GrGLConvexPolyEffect::onSetData(const GrGLSLProgramDataManager& pdman, |
| const GrFragmentProcessor& effect) { |
| const GrConvexPolyEffect& cpe = effect.cast<GrConvexPolyEffect>(); |
| size_t byteSize = 3 * cpe.getEdgeCount() * sizeof(SkScalar); |
| if (0 != memcmp(fPrevEdges, cpe.getEdges(), byteSize)) { |
| pdman.set3fv(fEdgeUniform, cpe.getEdgeCount(), cpe.getEdges()); |
| memcpy(fPrevEdges, cpe.getEdges(), byteSize); |
| } |
| } |
| |
| void GrGLConvexPolyEffect::GenKey(const GrProcessor& processor, const GrShaderCaps&, |
| GrProcessorKeyBuilder* b) { |
| const GrConvexPolyEffect& cpe = processor.cast<GrConvexPolyEffect>(); |
| static_assert(kGrClipEdgeTypeCnt <= 8); |
| uint32_t key = (cpe.getEdgeCount() << 3) | (int) cpe.getEdgeType(); |
| b->add32(key); |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| 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, GrProcessorKeyBuilder* b) const { |
| GrGLConvexPolyEffect::GenKey(*this, caps, b); |
| } |
| |
| std::unique_ptr<GrGLSLFragmentProcessor> GrConvexPolyEffect::onMakeProgramImpl() const { |
| return std::make_unique<GrGLConvexPolyEffect>(); |
| } |
| |
| GrConvexPolyEffect::GrConvexPolyEffect(std::unique_ptr<GrFragmentProcessor> inputFP, |
| GrClipEdgeType edgeType, |
| int n, |
| const SkScalar edges[]) |
| : INHERITED(kGrConvexPolyEffect_ClassID, |
| ProcessorOptimizationFlags(inputFP.get()) & |
| kCompatibleWithCoverageAsAlpha_OptimizationFlag) |
| , fEdgeType(edgeType) |
| , fEdgeCount(n) { |
| // Factory function should have already ensured this. |
| SkASSERT(n <= kMaxEdges); |
| memcpy(fEdges, edges, 3 * n * sizeof(SkScalar)); |
| // 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(kGrConvexPolyEffect_ClassID, that.optimizationFlags()) |
| , fEdgeType(that.fEdgeType) |
| , fEdgeCount(that.fEdgeCount) { |
| this->cloneAndRegisterAllChildProcessors(that); |
| memcpy(fEdges, that.fEdges, 3 * that.fEdgeCount * sizeof(SkScalar)); |
| } |
| |
| 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>(); |
| // ignore the fact that 0 == -0 and just use memcmp. |
| return (cpe.fEdgeType == fEdgeType && cpe.fEdgeCount == fEdgeCount && |
| 0 == memcmp(cpe.fEdges, fEdges, 3 * fEdgeCount * sizeof(SkScalar))); |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| 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 |