samplecode/SampleClipDrawMatch.cpp - skia - Git at Google

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "Sample.h"
 #include "SkCanvas.h"
 #include "SkInterpolator.h"
 #include "SkPath.h"
 #include "SkRRect.h"
 #include "SkTime.h"

 // This slide tests out the match up between BW clipping and rendering. It can
 // draw a large rect through some clip geometry and draw the same geometry
 // normally. Which one is drawn first can be toggled. The pair of objects is translated
 // fractionally (via an animator) to expose snapping bugs. The key bindings are:
 //      1-9: the different geometries
 //      t:   toggle which is drawn first the clip or the normal geometry
 //      f:   flip-flops which corner the bottom AA clip rect occupies in the complex clip cases

 // The possible geometric combinations to test
 enum Geometry {
     kRect_Geometry,
     kRRect_Geometry,
     kCircle_Geometry,
     kConvexPath_Geometry,
     kConcavePath_Geometry,
     kRectAndRect_Geometry,
     kRectAndRRect_Geometry,
     kRectAndConvex_Geometry,
     kRectAndConcave_Geometry
 };

 // The basic rect used is [kMin,kMin]..[kMax,kMax]
 static const float kMin = 100.5f;
 static const float kMid = 200.0f;
 static const float kMax = 299.5f;

 // The translation applied to the base AA rect in the combination cases
 // (i.e., kRectAndRect through kRectAndConcave)
 static const float kXlate = 100.0f;

 SkRect create_rect(const SkPoint& offset) {
     SkRect r = SkRect::MakeLTRB(kMin, kMin, kMax, kMax);
     r.offset(offset);
     return r;
 }

 SkRRect create_rrect(const SkPoint& offset) {
     SkRRect rrect;
     rrect.setRectXY(create_rect(offset), 10, 10);
     return rrect;
 }

 SkRRect create_circle(const SkPoint& offset) {
     SkRRect circle;
     circle.setOval(create_rect(offset));
     return circle;
 }

 SkPath create_convex_path(const SkPoint& offset) {
     SkPath convexPath;
     convexPath.moveTo(kMin, kMin);
     convexPath.lineTo(kMax, kMax);
     convexPath.lineTo(kMin, kMax);
     convexPath.close();
     convexPath.offset(offset.fX, offset.fY);
     return convexPath;
 }

 SkPath create_concave_path(const SkPoint& offset) {
     SkPath concavePath;
     concavePath.moveTo(kMin, kMin);
     concavePath.lineTo(kMid, 105.0f);
     concavePath.lineTo(kMax, kMin);
     concavePath.lineTo(295.0f, kMid);
     concavePath.lineTo(kMax, kMax);
     concavePath.lineTo(kMid, 295.0f);
     concavePath.lineTo(kMin, kMax);
     concavePath.lineTo(105.0f, kMid);
     concavePath.close();

     concavePath.offset(offset.fX, offset.fY);
     return concavePath;
 }

 static void draw_normal_geom(SkCanvas* canvas, const SkPoint& offset, int geom, bool useAA) {
     SkPaint p;
     p.setAntiAlias(useAA);
     p.setColor(SK_ColorBLACK);

     switch (geom) {
     case kRect_Geometry:                // fall thru
     case kRectAndRect_Geometry:
         canvas->drawRect(create_rect(offset), p);
         break;
     case kRRect_Geometry:               // fall thru
     case kRectAndRRect_Geometry:
         canvas->drawRRect(create_rrect(offset), p);
         break;
     case kCircle_Geometry:
         canvas->drawRRect(create_circle(offset), p);
         break;
     case kConvexPath_Geometry:          // fall thru
     case kRectAndConvex_Geometry:
         canvas->drawPath(create_convex_path(offset), p);
         break;
     case kConcavePath_Geometry:         // fall thru
     case kRectAndConcave_Geometry:
         canvas->drawPath(create_concave_path(offset), p);
         break;
     }
 }

 class ClipDrawMatchView : public Sample {
 public:
     ClipDrawMatchView() : fTrans(2, 5), fGeom(kRect_Geometry), fClipFirst(true), fSign(1) {
         SkScalar values[2];

         fTrans.setRepeatCount(999);
         values[0] = values[1] = 0;
         fTrans.setKeyFrame(0, GetMSecs() + 1000, values);
         values[1] = 1;
         fTrans.setKeyFrame(1, GetMSecs() + 2000, values);
         values[0] = values[1] = 1;
         fTrans.setKeyFrame(2, GetMSecs() + 3000, values);
         values[1] = 0;
         fTrans.setKeyFrame(3, GetMSecs() + 4000, values);
         values[0] = 0;
         fTrans.setKeyFrame(4, GetMSecs() + 5000, values);
     }

 protected:
     bool onQuery(Sample::Event* evt) override {
         if (Sample::TitleQ(*evt)) {
             Sample::TitleR(evt, "ClipDrawMatch");
             return true;
         }
         SkUnichar uni;
         if (Sample::CharQ(*evt, &uni)) {
             switch (uni) {
                 case '1': fGeom = kRect_Geometry; return true;
                 case '2': fGeom = kRRect_Geometry; return true;
                 case '3': fGeom = kCircle_Geometry; return true;
                 case '4': fGeom = kConvexPath_Geometry; return true;
                 case '5': fGeom = kConcavePath_Geometry; return true;
                 case '6': fGeom = kRectAndRect_Geometry; return true;
                 case '7': fGeom = kRectAndRRect_Geometry; return true;
                 case '8': fGeom = kRectAndConvex_Geometry; return true;
                 case '9': fGeom = kRectAndConcave_Geometry; return true;
                 case 'f': fSign = -fSign; return true;
                 case 't': fClipFirst = !fClipFirst; return true;
                 default: break;
             }
         }
         return this->INHERITED::onQuery(evt);
     }

     void drawClippedGeom(SkCanvas* canvas, const SkPoint& offset, bool useAA) {

         int count = canvas->save();

         switch (fGeom) {
         case kRect_Geometry:
             canvas->clipRect(create_rect(offset), useAA);
             break;
         case kRRect_Geometry:
             canvas->clipRRect(create_rrect(offset), useAA);
             break;
         case kCircle_Geometry:
             canvas->clipRRect(create_circle(offset), useAA);
             break;
         case kConvexPath_Geometry:
             canvas->clipPath(create_convex_path(offset), useAA);
             break;
         case kConcavePath_Geometry:
             canvas->clipPath(create_concave_path(offset), useAA);
             break;
         case kRectAndRect_Geometry: {
             SkRect r = create_rect(offset);
             r.offset(fSign * kXlate, fSign * kXlate);
             canvas->clipRect(r, true); // AA here forces shader clips
             canvas->clipRect(create_rect(offset), useAA);
             } break;
         case kRectAndRRect_Geometry: {
             SkRect r = create_rect(offset);
             r.offset(fSign * kXlate, fSign * kXlate);
             canvas->clipRect(r, true); // AA here forces shader clips
             canvas->clipRRect(create_rrect(offset), useAA);
             } break;
         case kRectAndConvex_Geometry: {
             SkRect r = create_rect(offset);
             r.offset(fSign * kXlate, fSign * kXlate);
             canvas->clipRect(r, true); // AA here forces shader clips
             canvas->clipPath(create_convex_path(offset), useAA);
             } break;
         case kRectAndConcave_Geometry: {
             SkRect r = create_rect(offset);
             r.offset(fSign * kXlate, fSign * kXlate);
             canvas->clipRect(r, true); // AA here forces shader clips
             canvas->clipPath(create_concave_path(offset), useAA);
             } break;
         }

         SkISize size = canvas->getBaseLayerSize();
         SkRect bigR = SkRect::MakeWH(SkIntToScalar(size.width()), SkIntToScalar(size.height()));

         SkPaint p;
         p.setColor(SK_ColorRED);

         canvas->drawRect(bigR, p);
         canvas->restoreToCount(count);
     }

     // Draw a big red rect through some clip geometry and also draw that same
     // geometry in black. The order in which they are drawn can be swapped.
     // This tests whether the clip and normally drawn geometry match up.
     void drawGeometry(SkCanvas* canvas, const SkPoint& offset, bool useAA) {
         if (fClipFirst) {
             this->drawClippedGeom(canvas, offset, useAA);
         }

         draw_normal_geom(canvas, offset, fGeom, useAA);

         if (!fClipFirst) {
             this->drawClippedGeom(canvas, offset, useAA);
         }
     }

     void onDrawContent(SkCanvas* canvas) override {
         SkScalar trans[2];
         fTrans.timeToValues(GetMSecs(), trans);

         SkPoint offset;
         offset.set(trans[0], trans[1]);

         int saveCount = canvas->save();
         this->drawGeometry(canvas, offset, false);
         canvas->restoreToCount(saveCount);
     }

     SkMSec GetMSecs() const {
         return static_cast<SkMSec>(SkTime::GetMSecs() - fStart);
     }

 private:
     SkInterpolator  fTrans;
     Geometry        fGeom;
     bool            fClipFirst;
     int             fSign;
     const double    fStart = SkTime::GetMSecs();

     typedef Sample INHERITED;
 };

 //////////////////////////////////////////////////////////////////////////////

 DEF_SAMPLE( return new ClipDrawMatchView(); )
	/*
	* Copyright 2015 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "Sample.h"
	#include "SkCanvas.h"
	#include "SkInterpolator.h"
	#include "SkPath.h"
	#include "SkRRect.h"
	#include "SkTime.h"

	// This slide tests out the match up between BW clipping and rendering. It can
	// draw a large rect through some clip geometry and draw the same geometry
	// normally. Which one is drawn first can be toggled. The pair of objects is translated
	// fractionally (via an animator) to expose snapping bugs. The key bindings are:
	// 1-9: the different geometries
	// t: toggle which is drawn first the clip or the normal geometry
	// f: flip-flops which corner the bottom AA clip rect occupies in the complex clip cases

	// The possible geometric combinations to test
	enum Geometry {
	kRect_Geometry,
	kRRect_Geometry,
	kCircle_Geometry,
	kConvexPath_Geometry,
	kConcavePath_Geometry,
	kRectAndRect_Geometry,
	kRectAndRRect_Geometry,
	kRectAndConvex_Geometry,
	kRectAndConcave_Geometry
	};

	// The basic rect used is [kMin,kMin]..[kMax,kMax]
	static const float kMin = 100.5f;
	static const float kMid = 200.0f;
	static const float kMax = 299.5f;

	// The translation applied to the base AA rect in the combination cases
	// (i.e., kRectAndRect through kRectAndConcave)
	static const float kXlate = 100.0f;

	SkRect create_rect(const SkPoint& offset) {
	SkRect r = SkRect::MakeLTRB(kMin, kMin, kMax, kMax);
	r.offset(offset);
	return r;
	}

	SkRRect create_rrect(const SkPoint& offset) {
	SkRRect rrect;
	rrect.setRectXY(create_rect(offset), 10, 10);
	return rrect;
	}

	SkRRect create_circle(const SkPoint& offset) {
	SkRRect circle;
	circle.setOval(create_rect(offset));
	return circle;
	}

	SkPath create_convex_path(const SkPoint& offset) {
	SkPath convexPath;
	convexPath.moveTo(kMin, kMin);
	convexPath.lineTo(kMax, kMax);
	convexPath.lineTo(kMin, kMax);
	convexPath.close();
	convexPath.offset(offset.fX, offset.fY);
	return convexPath;
	}

	SkPath create_concave_path(const SkPoint& offset) {
	SkPath concavePath;
	concavePath.moveTo(kMin, kMin);
	concavePath.lineTo(kMid, 105.0f);
	concavePath.lineTo(kMax, kMin);
	concavePath.lineTo(295.0f, kMid);
	concavePath.lineTo(kMax, kMax);
	concavePath.lineTo(kMid, 295.0f);
	concavePath.lineTo(kMin, kMax);
	concavePath.lineTo(105.0f, kMid);
	concavePath.close();

	concavePath.offset(offset.fX, offset.fY);
	return concavePath;
	}

	static void draw_normal_geom(SkCanvas* canvas, const SkPoint& offset, int geom, bool useAA) {
	SkPaint p;
	p.setAntiAlias(useAA);
	p.setColor(SK_ColorBLACK);

	switch (geom) {
	case kRect_Geometry: // fall thru
	case kRectAndRect_Geometry:
	canvas->drawRect(create_rect(offset), p);
	break;
	case kRRect_Geometry: // fall thru
	case kRectAndRRect_Geometry:
	canvas->drawRRect(create_rrect(offset), p);
	break;
	case kCircle_Geometry:
	canvas->drawRRect(create_circle(offset), p);
	break;
	case kConvexPath_Geometry: // fall thru
	case kRectAndConvex_Geometry:
	canvas->drawPath(create_convex_path(offset), p);
	break;
	case kConcavePath_Geometry: // fall thru
	case kRectAndConcave_Geometry:
	canvas->drawPath(create_concave_path(offset), p);
	break;
	}
	}

	class ClipDrawMatchView : public Sample {
	public:
	ClipDrawMatchView() : fTrans(2, 5), fGeom(kRect_Geometry), fClipFirst(true), fSign(1) {
	SkScalar values[2];

	fTrans.setRepeatCount(999);
	values[0] = values[1] = 0;
	fTrans.setKeyFrame(0, GetMSecs() + 1000, values);
	values[1] = 1;
	fTrans.setKeyFrame(1, GetMSecs() + 2000, values);
	values[0] = values[1] = 1;
	fTrans.setKeyFrame(2, GetMSecs() + 3000, values);
	values[1] = 0;
	fTrans.setKeyFrame(3, GetMSecs() + 4000, values);
	values[0] = 0;
	fTrans.setKeyFrame(4, GetMSecs() + 5000, values);
	}

	protected:
	bool onQuery(Sample::Event* evt) override {
	if (Sample::TitleQ(*evt)) {
	Sample::TitleR(evt, "ClipDrawMatch");
	return true;
	}
	SkUnichar uni;
	if (Sample::CharQ(*evt, &uni)) {
	switch (uni) {
	case '1': fGeom = kRect_Geometry; return true;
	case '2': fGeom = kRRect_Geometry; return true;
	case '3': fGeom = kCircle_Geometry; return true;
	case '4': fGeom = kConvexPath_Geometry; return true;
	case '5': fGeom = kConcavePath_Geometry; return true;
	case '6': fGeom = kRectAndRect_Geometry; return true;
	case '7': fGeom = kRectAndRRect_Geometry; return true;
	case '8': fGeom = kRectAndConvex_Geometry; return true;
	case '9': fGeom = kRectAndConcave_Geometry; return true;
	case 'f': fSign = -fSign; return true;
	case 't': fClipFirst = !fClipFirst; return true;
	default: break;
	}
	}
	return this->INHERITED::onQuery(evt);
	}

	void drawClippedGeom(SkCanvas* canvas, const SkPoint& offset, bool useAA) {

	int count = canvas->save();

	switch (fGeom) {
	case kRect_Geometry:
	canvas->clipRect(create_rect(offset), useAA);
	break;
	case kRRect_Geometry:
	canvas->clipRRect(create_rrect(offset), useAA);
	break;
	case kCircle_Geometry:
	canvas->clipRRect(create_circle(offset), useAA);
	break;
	case kConvexPath_Geometry:
	canvas->clipPath(create_convex_path(offset), useAA);
	break;
	case kConcavePath_Geometry:
	canvas->clipPath(create_concave_path(offset), useAA);
	break;
	case kRectAndRect_Geometry: {
	SkRect r = create_rect(offset);
	r.offset(fSign * kXlate, fSign * kXlate);
	canvas->clipRect(r, true); // AA here forces shader clips
	canvas->clipRect(create_rect(offset), useAA);
	} break;
	case kRectAndRRect_Geometry: {
	SkRect r = create_rect(offset);
	r.offset(fSign * kXlate, fSign * kXlate);
	canvas->clipRect(r, true); // AA here forces shader clips
	canvas->clipRRect(create_rrect(offset), useAA);
	} break;
	case kRectAndConvex_Geometry: {
	SkRect r = create_rect(offset);
	r.offset(fSign * kXlate, fSign * kXlate);
	canvas->clipRect(r, true); // AA here forces shader clips
	canvas->clipPath(create_convex_path(offset), useAA);
	} break;
	case kRectAndConcave_Geometry: {
	SkRect r = create_rect(offset);
	r.offset(fSign * kXlate, fSign * kXlate);
	canvas->clipRect(r, true); // AA here forces shader clips
	canvas->clipPath(create_concave_path(offset), useAA);
	} break;
	}

	SkISize size = canvas->getBaseLayerSize();
	SkRect bigR = SkRect::MakeWH(SkIntToScalar(size.width()), SkIntToScalar(size.height()));

	SkPaint p;
	p.setColor(SK_ColorRED);

	canvas->drawRect(bigR, p);
	canvas->restoreToCount(count);
	}

	// Draw a big red rect through some clip geometry and also draw that same
	// geometry in black. The order in which they are drawn can be swapped.
	// This tests whether the clip and normally drawn geometry match up.
	void drawGeometry(SkCanvas* canvas, const SkPoint& offset, bool useAA) {
	if (fClipFirst) {
	this->drawClippedGeom(canvas, offset, useAA);
	}

	draw_normal_geom(canvas, offset, fGeom, useAA);

	if (!fClipFirst) {
	this->drawClippedGeom(canvas, offset, useAA);
	}
	}

	void onDrawContent(SkCanvas* canvas) override {
	SkScalar trans[2];
	fTrans.timeToValues(GetMSecs(), trans);

	SkPoint offset;
	offset.set(trans[0], trans[1]);

	int saveCount = canvas->save();
	this->drawGeometry(canvas, offset, false);
	canvas->restoreToCount(saveCount);
	}

	SkMSec GetMSecs() const {
	return static_cast<SkMSec>(SkTime::GetMSecs() - fStart);
	}

	private:
	SkInterpolator fTrans;
	Geometry fGeom;
	bool fClipFirst;
	int fSign;
	const double fStart = SkTime::GetMSecs();

	typedef Sample INHERITED;
	};

	//////////////////////////////////////////////////////////////////////////////

	DEF_SAMPLE( return new ClipDrawMatchView(); )