/* * 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/GrAARectEffect.h" #include "effects/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(); 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(sk_FragCoord.x, 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(); 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(); GR_STATIC_ASSERT(kGrClipEdgeTypeCnt <= 8); uint32_t key = (cpe.getEdgeCount() << 3) | (int) cpe.getEdgeType(); b->add32(key); } ////////////////////////////////////////////////////////////////////////////// std::unique_ptr 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 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 GrConvexPolyEffect::clone() const { return std::unique_ptr(new GrConvexPolyEffect(*this)); } bool GrConvexPolyEffect::onIsEqual(const GrFragmentProcessor& other) const { const GrConvexPolyEffect& cpe = other.cast(); // 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 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 fp; do { GrClipEdgeType edgeType = static_cast( d->fRandom->nextULessThan(kGrClipEdgeTypeCnt)); fp = GrConvexPolyEffect::Make(edgeType, count, edges); } while (nullptr == fp); return fp; } #endif