| /* | |
| * 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 "GrConvexPolyEffect.h" | |
| #include "SkPathPriv.h" | |
| #include "effects/generated/GrAARectEffect.h" | |
| #include "effects/generated/GrConstColorProcessor.h" | |
| #include "glsl/GrGLSLFragmentProcessor.h" | |
| #include "glsl/GrGLSLFragmentShaderBuilder.h" | |
| #include "glsl/GrGLSLProgramDataManager.h" | |
| #include "glsl/GrGLSLUniformHandler.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]; | |
| typedef GrGLSLFragmentProcessor INHERITED; | |
| }; | |
| void GrGLConvexPolyEffect::emitCode(EmitArgs& args) { | |
| const GrConvexPolyEffect& cpe = args.fFp.cast<GrConvexPolyEffect>(); | |
| const char *edgeArrayName; | |
| fEdgeUniform = args.fUniformHandler->addUniformArray(kFragment_GrShaderFlag, | |
| kHalf3_GrSLType, | |
| "edges", | |
| cpe.getEdgeCount(), | |
| &edgeArrayName); | |
| GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder; | |
| fragBuilder->codeAppend("\t\thalf alpha = 1.0;\n"); | |
| fragBuilder->codeAppend("\t\thalf edge;\n"); | |
| for (int i = 0; i < cpe.getEdgeCount(); ++i) { | |
| fragBuilder->codeAppendf("\t\tedge = dot(%s[%d], half3(half(sk_FragCoord.x), " | |
| "half(sk_FragCoord.y), " | |
| "1));\n", | |
| edgeArrayName, i); | |
| if (GrProcessorEdgeTypeIsAA(cpe.getEdgeType())) { | |
| fragBuilder->codeAppend("\t\tedge = saturate(edge);\n"); | |
| } else { | |
| fragBuilder->codeAppend("\t\tedge = edge >= 0.5 ? 1.0 : 0.0;\n"); | |
| } | |
| fragBuilder->codeAppend("\t\talpha *= edge;\n"); | |
| } | |
| if (GrProcessorEdgeTypeIsInverseFill(cpe.getEdgeType())) { | |
| fragBuilder->codeAppend("\talpha = 1.0 - alpha;\n"); | |
| } | |
| fragBuilder->codeAppendf("\t%s = %s * alpha;\n", args.fOutputColor, args.fInputColor); | |
| } | |
| 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>(); | |
| GR_STATIC_ASSERT(kGrClipEdgeTypeCnt <= 8); | |
| uint32_t key = (cpe.getEdgeCount() << 3) | (int) cpe.getEdgeType(); | |
| b->add32(key); | |
| } | |
| ////////////////////////////////////////////////////////////////////////////// | |
| std::unique_ptr<GrFragmentProcessor> GrConvexPolyEffect::Make(GrClipEdgeType type, | |
| const SkPath& path) { | |
| if (GrClipEdgeType::kHairlineAA == type) { | |
| return nullptr; | |
| } | |
| if (path.getSegmentMasks() != SkPath::kLine_SegmentMask || | |
| !path.isConvex()) { | |
| return nullptr; | |
| } | |
| SkPathPriv::FirstDirection dir; | |
| // 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 (!SkPathPriv::CheapComputeFirstDirection(path, &dir)) { | |
| if (GrProcessorEdgeTypeIsInverseFill(type)) { | |
| return GrConstColorProcessor::Make(SK_PMColor4fWHITE, | |
| GrConstColorProcessor::InputMode::kModulateRGBA); | |
| } | |
| // This could use kIgnore instead of kModulateRGBA 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 kModulateRGBA to suppress | |
| // the print. | |
| return GrConstColorProcessor::Make(SK_PMColor4fTRANSPARENT, | |
| GrConstColorProcessor::InputMode::kModulateRGBA); | |
| } | |
| 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, true, true)) != SkPath::kDone_Verb) { | |
| switch (verb) { | |
| case SkPath::kMove_Verb: | |
| SkASSERT(n == 0); | |
| case SkPath::kClose_Verb: | |
| break; | |
| case SkPath::kLine_Verb: { | |
| if (n >= kMaxEdges) { | |
| return nullptr; | |
| } | |
| SkVector v = pts[1] - pts[0]; | |
| v.normalize(); | |
| if (SkPathPriv::kCCW_FirstDirection == 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: | |
| return nullptr; | |
| } | |
| } | |
| if (path.isInverseFillType()) { | |
| type = GrInvertProcessorEdgeType(type); | |
| } | |
| return Make(type, n, edges); | |
| } | |
| std::unique_ptr<GrFragmentProcessor> GrConvexPolyEffect::Make(GrClipEdgeType edgeType, | |
| const SkRect& rect) { | |
| if (GrClipEdgeType::kHairlineAA == edgeType){ | |
| return nullptr; | |
| } | |
| return GrAARectEffect::Make(edgeType, rect); | |
| } | |
| GrConvexPolyEffect::~GrConvexPolyEffect() {} | |
| void GrConvexPolyEffect::onGetGLSLProcessorKey(const GrShaderCaps& caps, | |
| GrProcessorKeyBuilder* b) const { | |
| GrGLConvexPolyEffect::GenKey(*this, caps, b); | |
| } | |
| GrGLSLFragmentProcessor* GrConvexPolyEffect::onCreateGLSLInstance() const { | |
| return new GrGLConvexPolyEffect; | |
| } | |
| GrConvexPolyEffect::GrConvexPolyEffect(GrClipEdgeType edgeType, int n, const SkScalar edges[]) | |
| : INHERITED(kGrConvexPolyEffect_ClassID, 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; | |
| } | |
| } | |
| GrConvexPolyEffect::GrConvexPolyEffect(const GrConvexPolyEffect& that) | |
| : INHERITED(kGrConvexPolyEffect_ClassID, kCompatibleWithCoverageAsAlpha_OptimizationFlag) | |
| , fEdgeType(that.fEdgeType) | |
| , fEdgeCount(that.fEdgeCount) { | |
| 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(); | |
| } | |
| std::unique_ptr<GrFragmentProcessor> fp; | |
| do { | |
| GrClipEdgeType edgeType = static_cast<GrClipEdgeType>( | |
| d->fRandom->nextULessThan(kGrClipEdgeTypeCnt)); | |
| fp = GrConvexPolyEffect::Make(edgeType, count, edges); | |
| } while (nullptr == fp); | |
| return fp; | |
| } | |
| #endif |