samplecode/SampleCCPRGeometry.cpp - platform/external/skia - Gitiles

 /*
  * Copyright 2017 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "SkTypes.h"

 #if SK_SUPPORT_GPU

 #include "GrContextPriv.h"
 #include "GrPathUtils.h"
 #include "GrRenderTargetContext.h"
 #include "GrRenderTargetContextPriv.h"
 #include "GrResourceProvider.h"
 #include "SampleCode.h"
 #include "SkCanvas.h"
 #include "SkMakeUnique.h"
 #include "SkPaint.h"
 #include "SkPath.h"
 #include "SkRectPriv.h"
 #include "SkView.h"
 #include "ccpr/GrCCCoverageProcessor.h"
 #include "ccpr/GrCCGeometry.h"
 #include "gl/GrGLGpu.cpp"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "ops/GrDrawOp.h"

 using TriPointInstance = GrCCCoverageProcessor::TriPointInstance;
 using QuadPointInstance = GrCCCoverageProcessor::QuadPointInstance;
 using PrimitiveType = GrCCCoverageProcessor::PrimitiveType;

 static constexpr float kDebugBloat = 40;

 /**
  * This sample visualizes the AA bloat geometry generated by the ccpr geometry shaders. It
  * increases the AA bloat by 50x and outputs color instead of coverage (coverage=+1 -> green,
  * coverage=0 -> black, coverage=-1 -> red). Use the keys 1-7 to cycle through the different
  * geometry processors.
  */
 class CCPRGeometryView : public SampleView {
 public:
     CCPRGeometryView() { this->updateGpuData(); }
     void onDrawContent(SkCanvas*) override;

     SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned) override;
     bool onClick(SampleView::Click*) override;
     bool onQuery(SkEvent* evt) override;

 private:
     class Click;
     class DrawCoverageCountOp;
     class VisualizeCoverageCountFP;

     void updateAndInval() { this->updateGpuData(); }

     void updateGpuData();

     PrimitiveType fPrimitiveType = PrimitiveType::kTriangles;
     SkCubicType fCubicType;
     SkMatrix fCubicKLM;

     SkPoint fPoints[4] = {
             {100.05f, 100.05f}, {400.75f, 100.05f}, {400.75f, 300.95f}, {100.05f, 300.95f}};

     float fConicWeight = .5;

     SkTArray<TriPointInstance> fTriPointInstances;
     SkTArray<QuadPointInstance> fQuadPointInstances;

     typedef SampleView INHERITED;
 };

 class CCPRGeometryView::DrawCoverageCountOp : public GrDrawOp {
     DEFINE_OP_CLASS_ID

 public:
     DrawCoverageCountOp(CCPRGeometryView* view) : INHERITED(ClassID()), fView(view) {
         this->setBounds(SkRectPriv::MakeLargest(), GrOp::HasAABloat::kNo, GrOp::IsZeroArea::kNo);
     }

     const char* name() const override {
         return "[Testing/Sample code] CCPRGeometryView::DrawCoverageCountOp";
     }

 private:
     FixedFunctionFlags fixedFunctionFlags() const override { return FixedFunctionFlags::kNone; }
     RequiresDstTexture finalize(const GrCaps&, const GrAppliedClip*,
                                 GrPixelConfigIsClamped) override {
         return RequiresDstTexture::kNo;
     }
     bool onCombineIfPossible(GrOp* other, const GrCaps& caps) override { return false; }
     void onPrepare(GrOpFlushState*) override {}
     void onExecute(GrOpFlushState*) override;

     CCPRGeometryView* fView;

     typedef GrDrawOp INHERITED;
 };

 class CCPRGeometryView::VisualizeCoverageCountFP : public GrFragmentProcessor {
 public:
     VisualizeCoverageCountFP() : GrFragmentProcessor(kTestFP_ClassID, kNone_OptimizationFlags) {}

 private:
     const char* name() const override {
         return "[Testing/Sample code] CCPRGeometryView::VisualizeCoverageCountFP";
     }
     std::unique_ptr<GrFragmentProcessor> clone() const override {
         return skstd::make_unique<VisualizeCoverageCountFP>();
     }
     void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override {}
     bool onIsEqual(const GrFragmentProcessor&) const override { return true; }

     class Impl : public GrGLSLFragmentProcessor {
         void emitCode(EmitArgs& args) override {
             GrGLSLFPFragmentBuilder* f = args.fFragBuilder;
             f->codeAppendf("half count = %s.a;", args.fInputColor);
             f->codeAppendf("%s = half4(clamp(-count, 0, 1), clamp(+count, 0, 1), 0, abs(count));",
                            args.fOutputColor);
         }
     };

     GrGLSLFragmentProcessor* onCreateGLSLInstance() const override { return new Impl; }
 };

 static void draw_klm_line(int w, int h, SkCanvas* canvas, const SkScalar line[3], SkColor color) {
     SkPoint p1, p2;
     if (SkScalarAbs(line[1]) > SkScalarAbs(line[0])) {
         // Draw from vertical edge to vertical edge.
         p1 = {0, -line[2] / line[1]};
         p2 = {(SkScalar)w, (-line[2] - w * line[0]) / line[1]};
     } else {
         // Draw from horizontal edge to horizontal edge.
         p1 = {-line[2] / line[0], 0};
         p2 = {(-line[2] - h * line[1]) / line[0], (SkScalar)h};
     }

     SkPaint linePaint;
     linePaint.setColor(color);
     linePaint.setAlpha(128);
     linePaint.setStyle(SkPaint::kStroke_Style);
     linePaint.setStrokeWidth(0);
     linePaint.setAntiAlias(true);
     canvas->drawLine(p1, p2, linePaint);
 }

 void CCPRGeometryView::onDrawContent(SkCanvas* canvas) {
     canvas->clear(SK_ColorBLACK);

     SkPath outline;
     outline.moveTo(fPoints[0]);
     switch (fPrimitiveType) {
         case PrimitiveType::kTriangles:
         case PrimitiveType::kWeightedTriangles:
             outline.lineTo(fPoints[1]);
             outline.lineTo(fPoints[3]);
             outline.close();
             break;
         case PrimitiveType::kQuadratics:
             outline.quadTo(fPoints[1], fPoints[3]);
             break;
         case PrimitiveType::kCubics:
             outline.cubicTo(fPoints[1], fPoints[2], fPoints[3]);
             break;
         case PrimitiveType::kConics:
             outline.conicTo(fPoints[1], fPoints[3], fConicWeight);
             break;
     }

     SkPaint outlinePaint;
     outlinePaint.setColor(0x80ffffff);
     outlinePaint.setStyle(SkPaint::kStroke_Style);
     outlinePaint.setStrokeWidth(0);
     outlinePaint.setAntiAlias(true);
     canvas->drawPath(outline, outlinePaint);

 #if 0
     SkPaint gridPaint;
     gridPaint.setColor(0x10000000);
     gridPaint.setStyle(SkPaint::kStroke_Style);
     gridPaint.setStrokeWidth(0);
     gridPaint.setAntiAlias(true);
     for (int y = 0; y < this->height(); y += kDebugBloat) {
         canvas->drawLine(0, y, this->width(), y, gridPaint);
     }
     for (int x = 0; x < this->width(); x += kDebugBloat) {
         canvas->drawLine(x, 0, x, this->height(), outlinePaint);
     }
 #endif

     SkString caption;
     if (GrRenderTargetContext* rtc = canvas->internal_private_accessTopLayerRenderTargetContext()) {
         // Render coverage count.
         GrContext* ctx = canvas->getGrContext();
         SkASSERT(ctx);
         sk_sp<GrRenderTargetContext> ccbuff =
                 ctx->contextPriv().makeDeferredRenderTargetContext(SkBackingFit::kApprox,
                                                                    this->width(), this->height(),
                                                                    kAlpha_half_GrPixelConfig,
                                                                    nullptr);
         SkASSERT(ccbuff);
         ccbuff->clear(nullptr, 0, GrRenderTargetContext::CanClearFullscreen::kYes);
         ccbuff->priv().testingOnly_addDrawOp(skstd::make_unique<DrawCoverageCountOp>(this));

         // Visualize coverage count in main canvas.
         GrPaint paint;
         paint.addColorFragmentProcessor(
                 GrSimpleTextureEffect::Make(sk_ref_sp(ccbuff->asTextureProxy()), SkMatrix::I()));
         paint.addColorFragmentProcessor(
                 skstd::make_unique<VisualizeCoverageCountFP>());
         paint.setPorterDuffXPFactory(SkBlendMode::kSrcOver);
         rtc->drawRect(GrNoClip(), std::move(paint), GrAA::kNo, SkMatrix::I(),
                       SkRect::MakeIWH(this->width(), this->height()));

         // Add label.
         caption.appendf("PrimitiveType_%s",
                         GrCCCoverageProcessor::PrimitiveTypeName(fPrimitiveType));
         if (PrimitiveType::kCubics == fPrimitiveType) {
             caption.appendf(" (%s)", SkCubicTypeName(fCubicType));
         } else if (PrimitiveType::kConics == fPrimitiveType) {
             caption.appendf(" (w=%f)", fConicWeight);
         }
     } else {
         caption = "Use GPU backend to visualize geometry.";
     }

     SkPaint pointsPaint;
     pointsPaint.setColor(SK_ColorBLUE);
     pointsPaint.setStrokeWidth(8);
     pointsPaint.setAntiAlias(true);

     if (PrimitiveType::kCubics == fPrimitiveType) {
         int w = this->width(), h = this->height();
         canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, fPoints, pointsPaint);
         draw_klm_line(w, h, canvas, &fCubicKLM[0], SK_ColorYELLOW);
         draw_klm_line(w, h, canvas, &fCubicKLM[3], SK_ColorBLUE);
         draw_klm_line(w, h, canvas, &fCubicKLM[6], SK_ColorRED);
     } else {
         canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, fPoints, pointsPaint);
         canvas->drawPoints(SkCanvas::kPoints_PointMode, 1, fPoints + 3, pointsPaint);
     }

     SkPaint captionPaint;
     captionPaint.setTextSize(20);
     captionPaint.setColor(SK_ColorWHITE);
     captionPaint.setAntiAlias(true);
     canvas->drawText(caption.c_str(), caption.size(), 10, 30, captionPaint);
 }

 void CCPRGeometryView::updateGpuData() {
     fTriPointInstances.reset();
     fQuadPointInstances.reset();

     if (PrimitiveType::kCubics == fPrimitiveType) {
         double t[2], s[2];
         fCubicType = GrPathUtils::getCubicKLM(fPoints, &fCubicKLM, t, s);
         GrCCGeometry geometry;
         geometry.beginContour(fPoints[0]);
         geometry.cubicTo(fPoints, kDebugBloat / 2, kDebugBloat / 2);
         geometry.endContour();
         int ptsIdx = 0;
         for (GrCCGeometry::Verb verb : geometry.verbs()) {
             switch (verb) {
                 case GrCCGeometry::Verb::kLineTo:
                     ++ptsIdx;
                     continue;
                 case GrCCGeometry::Verb::kMonotonicQuadraticTo:
                     ptsIdx += 2;
                     continue;
                 case GrCCGeometry::Verb::kMonotonicCubicTo:
                     fQuadPointInstances.push_back().set(&geometry.points()[ptsIdx], 0, 0);
                     ptsIdx += 3;
                     continue;
                 default:
                     continue;
             }
         }
     } else if (PrimitiveType::kTriangles != fPrimitiveType) {
         SkPoint P3[3] = {fPoints[0], fPoints[1], fPoints[3]};
         GrCCGeometry geometry;
         geometry.beginContour(P3[0]);
         if (PrimitiveType::kQuadratics == fPrimitiveType) {
             geometry.quadraticTo(P3);
         } else {
             SkASSERT(PrimitiveType::kConics == fPrimitiveType);
             geometry.conicTo(P3, fConicWeight);
         }
         geometry.endContour();
         int ptsIdx = 0, conicWeightIdx = 0;
         for (GrCCGeometry::Verb verb : geometry.verbs()) {
             if (GrCCGeometry::Verb::kBeginContour == verb ||
                 GrCCGeometry::Verb::kEndOpenContour == verb ||
                 GrCCGeometry::Verb::kEndClosedContour == verb) {
                 continue;
             }
             if (GrCCGeometry::Verb::kLineTo == verb) {
                 ++ptsIdx;
                 continue;
             }
             SkASSERT(GrCCGeometry::Verb::kMonotonicQuadraticTo == verb ||
                      GrCCGeometry::Verb::kMonotonicConicTo == verb);
             if (PrimitiveType::kQuadratics == fPrimitiveType &&
                 GrCCGeometry::Verb::kMonotonicQuadraticTo == verb) {
                 fTriPointInstances.push_back().set(&geometry.points()[ptsIdx], Sk2f(0, 0));
             } else if (PrimitiveType::kConics == fPrimitiveType &&
                        GrCCGeometry::Verb::kMonotonicConicTo == verb) {
                 fQuadPointInstances.push_back().setW(&geometry.points()[ptsIdx], Sk2f(0, 0),
                                                      geometry.getConicWeight(conicWeightIdx++));
             }
             ptsIdx += 2;
         }
     } else {
         fTriPointInstances.push_back().set(fPoints[0], fPoints[1], fPoints[3], Sk2f(0, 0));
     }
 }

 void CCPRGeometryView::DrawCoverageCountOp::onExecute(GrOpFlushState* state) {
     GrResourceProvider* rp = state->resourceProvider();
     GrContext* context = state->gpu()->getContext();
     GrGLGpu* glGpu = kOpenGL_GrBackend == context->contextPriv().getBackend()
                              ? static_cast<GrGLGpu*>(state->gpu())
                              : nullptr;

     GrCCCoverageProcessor proc(rp, fView->fPrimitiveType);
     SkDEBUGCODE(proc.enableDebugBloat(kDebugBloat));

     SkSTArray<1, GrMesh> mesh;
     if (PrimitiveType::kCubics == fView->fPrimitiveType ||
         PrimitiveType::kConics == fView->fPrimitiveType) {
         sk_sp<GrBuffer> instBuff(rp->createBuffer(
                 fView->fQuadPointInstances.count() * sizeof(QuadPointInstance),
                 kVertex_GrBufferType, kDynamic_GrAccessPattern,
                 GrResourceProvider::kNoPendingIO_Flag | GrResourceProvider::kRequireGpuMemory_Flag,
                 fView->fQuadPointInstances.begin()));
         if (!fView->fQuadPointInstances.empty() && instBuff) {
             proc.appendMesh(instBuff.get(), fView->fQuadPointInstances.count(), 0, &mesh);
         }
     } else {
         sk_sp<GrBuffer> instBuff(rp->createBuffer(
                 fView->fTriPointInstances.count() * sizeof(TriPointInstance), kVertex_GrBufferType,
                 kDynamic_GrAccessPattern,
                 GrResourceProvider::kNoPendingIO_Flag | GrResourceProvider::kRequireGpuMemory_Flag,
                 fView->fTriPointInstances.begin()));
         if (!fView->fTriPointInstances.empty() && instBuff) {
             proc.appendMesh(instBuff.get(), fView->fTriPointInstances.count(), 0, &mesh);
         }
     }

     GrPipeline pipeline(state->drawOpArgs().fProxy, GrPipeline::ScissorState::kDisabled,
                         SkBlendMode::kPlus);

     if (glGpu) {
         glGpu->handleDirtyContext();
         // GR_GL_CALL(glGpu->glInterface(), PolygonMode(GR_GL_FRONT_AND_BACK, GR_GL_LINE));
         GR_GL_CALL(glGpu->glInterface(), Enable(GR_GL_LINE_SMOOTH));
     }

     if (!mesh.empty()) {
         SkASSERT(1 == mesh.count());
         proc.draw(state, pipeline, nullptr, mesh.begin(), 1, this->bounds());
     }

     if (glGpu) {
         context->resetContext(kMisc_GrGLBackendState);
     }
 }

 class CCPRGeometryView::Click : public SampleView::Click {
 public:
     Click(SkView* target, int ptIdx) : SampleView::Click(target), fPtIdx(ptIdx) {}

     void doClick(SkPoint points[]) {
         if (fPtIdx >= 0) {
             this->dragPoint(points, fPtIdx);
         } else {
             for (int i = 0; i < 4; ++i) {
                 this->dragPoint(points, i);
             }
         }
     }

 private:
     void dragPoint(SkPoint points[], int idx) {
         SkIPoint delta = fICurr - fIPrev;
         points[idx] += SkPoint::Make(delta.x(), delta.y());
     }

     int fPtIdx;
 };

 SkView::Click* CCPRGeometryView::onFindClickHandler(SkScalar x, SkScalar y, unsigned) {
     for (int i = 0; i < 4; ++i) {
         if (PrimitiveType::kCubics != fPrimitiveType && 2 == i) {
             continue;
         }
         if (fabs(x - fPoints[i].x()) < 20 && fabsf(y - fPoints[i].y()) < 20) {
             return new Click(this, i);
         }
     }
     return new Click(this, -1);
 }

 bool CCPRGeometryView::onClick(SampleView::Click* click) {
     Click* myClick = (Click*)click;
     myClick->doClick(fPoints);
     this->updateAndInval();
     return true;
 }

 bool CCPRGeometryView::onQuery(SkEvent* evt) {
     if (SampleCode::TitleQ(*evt)) {
         SampleCode::TitleR(evt, "CCPRGeometry");
         return true;
     }
     SkUnichar unichar;
     if (SampleCode::CharQ(*evt, &unichar)) {
         if (unichar >= '1' && unichar <= '4') {
             fPrimitiveType = PrimitiveType(unichar - '1');
             if (fPrimitiveType >= PrimitiveType::kWeightedTriangles) {
                 fPrimitiveType = (PrimitiveType) ((int)fPrimitiveType + 1);
             }
             this->updateAndInval();
             return true;
         }
         if (PrimitiveType::kConics == fPrimitiveType) {
             if (unichar == '+') {
                 fConicWeight *= 2;
                 this->updateAndInval();
                 return true;
             }
             if (unichar == '+' || unichar == '=') {
                 fConicWeight *= 5/4.f;
                 this->updateAndInval();
                 return true;
             }
             if (unichar == '-') {
                 fConicWeight *= 4/5.f;
                 this->updateAndInval();
                 return true;
             }
             if (unichar == '_') {
                 fConicWeight *= .5f;
                 this->updateAndInval();
                 return true;
             }
         }
         if (unichar == 'D') {
             SkDebugf("    SkPoint fPoints[4] = {\n");
             SkDebugf("        {%ff, %ff},\n", fPoints[0].x(), fPoints[0].y());
             SkDebugf("        {%ff, %ff},\n", fPoints[1].x(), fPoints[1].y());
             SkDebugf("        {%ff, %ff},\n", fPoints[2].x(), fPoints[2].y());
             SkDebugf("        {%ff, %ff}\n", fPoints[3].x(), fPoints[3].y());
             SkDebugf("    };\n");
             return true;
         }
     }
     return this->INHERITED::onQuery(evt);
 }

 DEF_SAMPLE(return new CCPRGeometryView;)

 #endif  // SK_SUPPORT_GPU
	/*
	* Copyright 2017 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "SkTypes.h"

	#if SK_SUPPORT_GPU

	#include "GrContextPriv.h"
	#include "GrPathUtils.h"
	#include "GrRenderTargetContext.h"
	#include "GrRenderTargetContextPriv.h"
	#include "GrResourceProvider.h"
	#include "SampleCode.h"
	#include "SkCanvas.h"
	#include "SkMakeUnique.h"
	#include "SkPaint.h"
	#include "SkPath.h"
	#include "SkRectPriv.h"
	#include "SkView.h"
	#include "ccpr/GrCCCoverageProcessor.h"
	#include "ccpr/GrCCGeometry.h"
	#include "gl/GrGLGpu.cpp"
	#include "glsl/GrGLSLFragmentProcessor.h"
	#include "ops/GrDrawOp.h"

	using TriPointInstance = GrCCCoverageProcessor::TriPointInstance;
	using QuadPointInstance = GrCCCoverageProcessor::QuadPointInstance;
	using PrimitiveType = GrCCCoverageProcessor::PrimitiveType;

	static constexpr float kDebugBloat = 40;

	/**
	* This sample visualizes the AA bloat geometry generated by the ccpr geometry shaders. It
	* increases the AA bloat by 50x and outputs color instead of coverage (coverage=+1 -> green,
	* coverage=0 -> black, coverage=-1 -> red). Use the keys 1-7 to cycle through the different
	* geometry processors.
	*/
	class CCPRGeometryView : public SampleView {
	public:
	CCPRGeometryView() { this->updateGpuData(); }
	void onDrawContent(SkCanvas*) override;

	SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned) override;
	bool onClick(SampleView::Click*) override;
	bool onQuery(SkEvent* evt) override;

	private:
	class Click;
	class DrawCoverageCountOp;
	class VisualizeCoverageCountFP;

	void updateAndInval() { this->updateGpuData(); }

	void updateGpuData();

	PrimitiveType fPrimitiveType = PrimitiveType::kTriangles;
	SkCubicType fCubicType;
	SkMatrix fCubicKLM;

	SkPoint fPoints[4] = {
	{100.05f, 100.05f}, {400.75f, 100.05f}, {400.75f, 300.95f}, {100.05f, 300.95f}};

	float fConicWeight = .5;

	SkTArray<TriPointInstance> fTriPointInstances;
	SkTArray<QuadPointInstance> fQuadPointInstances;

	typedef SampleView INHERITED;
	};

	class CCPRGeometryView::DrawCoverageCountOp : public GrDrawOp {
	DEFINE_OP_CLASS_ID

	public:
	DrawCoverageCountOp(CCPRGeometryView* view) : INHERITED(ClassID()), fView(view) {
	this->setBounds(SkRectPriv::MakeLargest(), GrOp::HasAABloat::kNo, GrOp::IsZeroArea::kNo);
	}

	const char* name() const override {
	return "[Testing/Sample code] CCPRGeometryView::DrawCoverageCountOp";
	}

	private:
	FixedFunctionFlags fixedFunctionFlags() const override { return FixedFunctionFlags::kNone; }
	RequiresDstTexture finalize(const GrCaps&, const GrAppliedClip*,
	GrPixelConfigIsClamped) override {
	return RequiresDstTexture::kNo;
	}
	bool onCombineIfPossible(GrOp* other, const GrCaps& caps) override { return false; }
	void onPrepare(GrOpFlushState*) override {}
	void onExecute(GrOpFlushState*) override;

	CCPRGeometryView* fView;

	typedef GrDrawOp INHERITED;
	};

	class CCPRGeometryView::VisualizeCoverageCountFP : public GrFragmentProcessor {
	public:
	VisualizeCoverageCountFP() : GrFragmentProcessor(kTestFP_ClassID, kNone_OptimizationFlags) {}

	private:
	const char* name() const override {
	return "[Testing/Sample code] CCPRGeometryView::VisualizeCoverageCountFP";
	}
	std::unique_ptr<GrFragmentProcessor> clone() const override {
	return skstd::make_unique<VisualizeCoverageCountFP>();
	}
	void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override {}
	bool onIsEqual(const GrFragmentProcessor&) const override { return true; }

	class Impl : public GrGLSLFragmentProcessor {
	void emitCode(EmitArgs& args) override {
	GrGLSLFPFragmentBuilder* f = args.fFragBuilder;
	f->codeAppendf("half count = %s.a;", args.fInputColor);
	f->codeAppendf("%s = half4(clamp(-count, 0, 1), clamp(+count, 0, 1), 0, abs(count));",
	args.fOutputColor);
	}
	};

	GrGLSLFragmentProcessor* onCreateGLSLInstance() const override { return new Impl; }
	};

	static void draw_klm_line(int w, int h, SkCanvas* canvas, const SkScalar line[3], SkColor color) {
	SkPoint p1, p2;
	if (SkScalarAbs(line[1]) > SkScalarAbs(line[0])) {
	// Draw from vertical edge to vertical edge.
	p1 = {0, -line[2] / line[1]};
	p2 = {(SkScalar)w, (-line[2] - w * line[0]) / line[1]};
	} else {
	// Draw from horizontal edge to horizontal edge.
	p1 = {-line[2] / line[0], 0};
	p2 = {(-line[2] - h * line[1]) / line[0], (SkScalar)h};
	}

	SkPaint linePaint;
	linePaint.setColor(color);
	linePaint.setAlpha(128);
	linePaint.setStyle(SkPaint::kStroke_Style);
	linePaint.setStrokeWidth(0);
	linePaint.setAntiAlias(true);
	canvas->drawLine(p1, p2, linePaint);
	}

	void CCPRGeometryView::onDrawContent(SkCanvas* canvas) {
	canvas->clear(SK_ColorBLACK);

	SkPath outline;
	outline.moveTo(fPoints[0]);
	switch (fPrimitiveType) {
	case PrimitiveType::kTriangles:
	case PrimitiveType::kWeightedTriangles:
	outline.lineTo(fPoints[1]);
	outline.lineTo(fPoints[3]);
	outline.close();
	break;
	case PrimitiveType::kQuadratics:
	outline.quadTo(fPoints[1], fPoints[3]);
	break;
	case PrimitiveType::kCubics:
	outline.cubicTo(fPoints[1], fPoints[2], fPoints[3]);
	break;
	case PrimitiveType::kConics:
	outline.conicTo(fPoints[1], fPoints[3], fConicWeight);
	break;
	}

	SkPaint outlinePaint;
	outlinePaint.setColor(0x80ffffff);
	outlinePaint.setStyle(SkPaint::kStroke_Style);
	outlinePaint.setStrokeWidth(0);
	outlinePaint.setAntiAlias(true);
	canvas->drawPath(outline, outlinePaint);

	#if 0
	SkPaint gridPaint;
	gridPaint.setColor(0x10000000);
	gridPaint.setStyle(SkPaint::kStroke_Style);
	gridPaint.setStrokeWidth(0);
	gridPaint.setAntiAlias(true);
	for (int y = 0; y < this->height(); y += kDebugBloat) {
	canvas->drawLine(0, y, this->width(), y, gridPaint);
	}
	for (int x = 0; x < this->width(); x += kDebugBloat) {
	canvas->drawLine(x, 0, x, this->height(), outlinePaint);
	}
	#endif

	SkString caption;
	if (GrRenderTargetContext* rtc = canvas->internal_private_accessTopLayerRenderTargetContext()) {
	// Render coverage count.
	GrContext* ctx = canvas->getGrContext();
	SkASSERT(ctx);
	sk_sp<GrRenderTargetContext> ccbuff =
	ctx->contextPriv().makeDeferredRenderTargetContext(SkBackingFit::kApprox,
	this->width(), this->height(),
	kAlpha_half_GrPixelConfig,
	nullptr);
	SkASSERT(ccbuff);
	ccbuff->clear(nullptr, 0, GrRenderTargetContext::CanClearFullscreen::kYes);
	ccbuff->priv().testingOnly_addDrawOp(skstd::make_unique<DrawCoverageCountOp>(this));

	// Visualize coverage count in main canvas.
	GrPaint paint;
	paint.addColorFragmentProcessor(
	GrSimpleTextureEffect::Make(sk_ref_sp(ccbuff->asTextureProxy()), SkMatrix::I()));
	paint.addColorFragmentProcessor(
	skstd::make_unique<VisualizeCoverageCountFP>());
	paint.setPorterDuffXPFactory(SkBlendMode::kSrcOver);
	rtc->drawRect(GrNoClip(), std::move(paint), GrAA::kNo, SkMatrix::I(),
	SkRect::MakeIWH(this->width(), this->height()));

	// Add label.
	caption.appendf("PrimitiveType_%s",
	GrCCCoverageProcessor::PrimitiveTypeName(fPrimitiveType));
	if (PrimitiveType::kCubics == fPrimitiveType) {
	caption.appendf(" (%s)", SkCubicTypeName(fCubicType));
	} else if (PrimitiveType::kConics == fPrimitiveType) {
	caption.appendf(" (w=%f)", fConicWeight);
	}
	} else {
	caption = "Use GPU backend to visualize geometry.";
	}

	SkPaint pointsPaint;
	pointsPaint.setColor(SK_ColorBLUE);
	pointsPaint.setStrokeWidth(8);
	pointsPaint.setAntiAlias(true);

	if (PrimitiveType::kCubics == fPrimitiveType) {
	int w = this->width(), h = this->height();
	canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, fPoints, pointsPaint);
	draw_klm_line(w, h, canvas, &fCubicKLM[0], SK_ColorYELLOW);
	draw_klm_line(w, h, canvas, &fCubicKLM[3], SK_ColorBLUE);
	draw_klm_line(w, h, canvas, &fCubicKLM[6], SK_ColorRED);
	} else {
	canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, fPoints, pointsPaint);
	canvas->drawPoints(SkCanvas::kPoints_PointMode, 1, fPoints + 3, pointsPaint);
	}

	SkPaint captionPaint;
	captionPaint.setTextSize(20);
	captionPaint.setColor(SK_ColorWHITE);
	captionPaint.setAntiAlias(true);
	canvas->drawText(caption.c_str(), caption.size(), 10, 30, captionPaint);
	}

	void CCPRGeometryView::updateGpuData() {
	fTriPointInstances.reset();
	fQuadPointInstances.reset();

	if (PrimitiveType::kCubics == fPrimitiveType) {
	double t[2], s[2];
	fCubicType = GrPathUtils::getCubicKLM(fPoints, &fCubicKLM, t, s);
	GrCCGeometry geometry;
	geometry.beginContour(fPoints[0]);
	geometry.cubicTo(fPoints, kDebugBloat / 2, kDebugBloat / 2);
	geometry.endContour();
	int ptsIdx = 0;
	for (GrCCGeometry::Verb verb : geometry.verbs()) {
	switch (verb) {
	case GrCCGeometry::Verb::kLineTo:
	++ptsIdx;
	continue;
	case GrCCGeometry::Verb::kMonotonicQuadraticTo:
	ptsIdx += 2;
	continue;
	case GrCCGeometry::Verb::kMonotonicCubicTo:
	fQuadPointInstances.push_back().set(&geometry.points()[ptsIdx], 0, 0);
	ptsIdx += 3;
	continue;
	default:
	continue;
	}
	}
	} else if (PrimitiveType::kTriangles != fPrimitiveType) {
	SkPoint P3[3] = {fPoints[0], fPoints[1], fPoints[3]};
	GrCCGeometry geometry;
	geometry.beginContour(P3[0]);
	if (PrimitiveType::kQuadratics == fPrimitiveType) {
	geometry.quadraticTo(P3);
	} else {
	SkASSERT(PrimitiveType::kConics == fPrimitiveType);
	geometry.conicTo(P3, fConicWeight);
	}
	geometry.endContour();
	int ptsIdx = 0, conicWeightIdx = 0;
	for (GrCCGeometry::Verb verb : geometry.verbs()) {
	if (GrCCGeometry::Verb::kBeginContour == verb \|\|
	GrCCGeometry::Verb::kEndOpenContour == verb \|\|
	GrCCGeometry::Verb::kEndClosedContour == verb) {
	continue;
	}
	if (GrCCGeometry::Verb::kLineTo == verb) {
	++ptsIdx;
	continue;
	}
	SkASSERT(GrCCGeometry::Verb::kMonotonicQuadraticTo == verb \|\|
	GrCCGeometry::Verb::kMonotonicConicTo == verb);
	if (PrimitiveType::kQuadratics == fPrimitiveType &&
	GrCCGeometry::Verb::kMonotonicQuadraticTo == verb) {
	fTriPointInstances.push_back().set(&geometry.points()[ptsIdx], Sk2f(0, 0));
	} else if (PrimitiveType::kConics == fPrimitiveType &&
	GrCCGeometry::Verb::kMonotonicConicTo == verb) {
	fQuadPointInstances.push_back().setW(&geometry.points()[ptsIdx], Sk2f(0, 0),
	geometry.getConicWeight(conicWeightIdx++));
	}
	ptsIdx += 2;
	}
	} else {
	fTriPointInstances.push_back().set(fPoints[0], fPoints[1], fPoints[3], Sk2f(0, 0));
	}
	}

	void CCPRGeometryView::DrawCoverageCountOp::onExecute(GrOpFlushState* state) {
	GrResourceProvider* rp = state->resourceProvider();
	GrContext* context = state->gpu()->getContext();
	GrGLGpu* glGpu = kOpenGL_GrBackend == context->contextPriv().getBackend()
	? static_cast<GrGLGpu*>(state->gpu())
	: nullptr;

	GrCCCoverageProcessor proc(rp, fView->fPrimitiveType);
	SkDEBUGCODE(proc.enableDebugBloat(kDebugBloat));

	SkSTArray<1, GrMesh> mesh;
	if (PrimitiveType::kCubics == fView->fPrimitiveType \|\|
	PrimitiveType::kConics == fView->fPrimitiveType) {
	sk_sp<GrBuffer> instBuff(rp->createBuffer(
	fView->fQuadPointInstances.count() * sizeof(QuadPointInstance),
	kVertex_GrBufferType, kDynamic_GrAccessPattern,
	GrResourceProvider::kNoPendingIO_Flag \| GrResourceProvider::kRequireGpuMemory_Flag,
	fView->fQuadPointInstances.begin()));
	if (!fView->fQuadPointInstances.empty() && instBuff) {
	proc.appendMesh(instBuff.get(), fView->fQuadPointInstances.count(), 0, &mesh);
	}
	} else {
	sk_sp<GrBuffer> instBuff(rp->createBuffer(
	fView->fTriPointInstances.count() * sizeof(TriPointInstance), kVertex_GrBufferType,
	kDynamic_GrAccessPattern,
	GrResourceProvider::kNoPendingIO_Flag \| GrResourceProvider::kRequireGpuMemory_Flag,
	fView->fTriPointInstances.begin()));
	if (!fView->fTriPointInstances.empty() && instBuff) {
	proc.appendMesh(instBuff.get(), fView->fTriPointInstances.count(), 0, &mesh);
	}
	}

	GrPipeline pipeline(state->drawOpArgs().fProxy, GrPipeline::ScissorState::kDisabled,
	SkBlendMode::kPlus);

	if (glGpu) {
	glGpu->handleDirtyContext();
	// GR_GL_CALL(glGpu->glInterface(), PolygonMode(GR_GL_FRONT_AND_BACK, GR_GL_LINE));
	GR_GL_CALL(glGpu->glInterface(), Enable(GR_GL_LINE_SMOOTH));
	}

	if (!mesh.empty()) {
	SkASSERT(1 == mesh.count());
	proc.draw(state, pipeline, nullptr, mesh.begin(), 1, this->bounds());
	}

	if (glGpu) {
	context->resetContext(kMisc_GrGLBackendState);
	}
	}

	class CCPRGeometryView::Click : public SampleView::Click {
	public:
	Click(SkView* target, int ptIdx) : SampleView::Click(target), fPtIdx(ptIdx) {}

	void doClick(SkPoint points[]) {
	if (fPtIdx >= 0) {
	this->dragPoint(points, fPtIdx);
	} else {
	for (int i = 0; i < 4; ++i) {
	this->dragPoint(points, i);
	}
	}
	}

	private:
	void dragPoint(SkPoint points[], int idx) {
	SkIPoint delta = fICurr - fIPrev;
	points[idx] += SkPoint::Make(delta.x(), delta.y());
	}

	int fPtIdx;
	};

	SkView::Click* CCPRGeometryView::onFindClickHandler(SkScalar x, SkScalar y, unsigned) {
	for (int i = 0; i < 4; ++i) {
	if (PrimitiveType::kCubics != fPrimitiveType && 2 == i) {
	continue;
	}
	if (fabs(x - fPoints[i].x()) < 20 && fabsf(y - fPoints[i].y()) < 20) {
	return new Click(this, i);
	}
	}
	return new Click(this, -1);
	}

	bool CCPRGeometryView::onClick(SampleView::Click* click) {
	Click* myClick = (Click*)click;
	myClick->doClick(fPoints);
	this->updateAndInval();
	return true;
	}

	bool CCPRGeometryView::onQuery(SkEvent* evt) {
	if (SampleCode::TitleQ(*evt)) {
	SampleCode::TitleR(evt, "CCPRGeometry");
	return true;
	}
	SkUnichar unichar;
	if (SampleCode::CharQ(*evt, &unichar)) {
	if (unichar >= '1' && unichar <= '4') {
	fPrimitiveType = PrimitiveType(unichar - '1');
	if (fPrimitiveType >= PrimitiveType::kWeightedTriangles) {
	fPrimitiveType = (PrimitiveType) ((int)fPrimitiveType + 1);
	}
	this->updateAndInval();
	return true;
	}
	if (PrimitiveType::kConics == fPrimitiveType) {
	if (unichar == '+') {
	fConicWeight *= 2;
	this->updateAndInval();
	return true;
	}
	if (unichar == '+' \|\| unichar == '=') {
	fConicWeight *= 5/4.f;
	this->updateAndInval();
	return true;
	}
	if (unichar == '-') {
	fConicWeight *= 4/5.f;
	this->updateAndInval();
	return true;
	}
	if (unichar == '_') {
	fConicWeight *= .5f;
	this->updateAndInval();
	return true;
	}
	}
	if (unichar == 'D') {
	SkDebugf(" SkPoint fPoints[4] = {\n");
	SkDebugf(" {%ff, %ff},\n", fPoints[0].x(), fPoints[0].y());
	SkDebugf(" {%ff, %ff},\n", fPoints[1].x(), fPoints[1].y());
	SkDebugf(" {%ff, %ff},\n", fPoints[2].x(), fPoints[2].y());
	SkDebugf(" {%ff, %ff}\n", fPoints[3].x(), fPoints[3].y());
	SkDebugf(" };\n");
	return true;
	}
	}
	return this->INHERITED::onQuery(evt);
	}

	DEF_SAMPLE(return new CCPRGeometryView;)

	#endif // SK_SUPPORT_GPU