1 2 /* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 #include "SampleCode.h" 9 #include "SkCanvas.h" 10 #include "SkPaint.h" 11 #include "SkView.h" 12 13 /////////////////////////////////////////////////////////////////////////////// 14 15 class LayerMaskView : public SampleView { 16 public: 17 LayerMaskView() { 18 this->setBGColor(0xFFDDDDDD); 19 } 20 21 protected: 22 // overrides from SkEventSink 23 virtual bool onQuery(SkEvent* evt) { 24 if (SampleCode::TitleQ(*evt)) { 25 SampleCode::TitleR(evt, "LayerMask"); 26 return true; 27 } 28 return this->INHERITED::onQuery(evt); 29 } 30 31 void drawMask(SkCanvas* canvas, const SkRect& r) { 32 SkPaint paint; 33 paint.setAntiAlias(true); 34 35 if (true) { 36 SkBitmap mask; 37 int w = SkScalarRoundToInt(r.width()); 38 int h = SkScalarRoundToInt(r.height()); 39 mask.allocN32Pixels(w, h); 40 mask.eraseColor(SK_ColorTRANSPARENT); 41 SkCanvas c(mask); 42 SkRect bounds = r; 43 bounds.offset(-bounds.fLeft, -bounds.fTop); 44 c.drawOval(bounds, paint); 45 46 paint.setXfermodeMode(SkXfermode::kDstIn_Mode); 47 canvas->drawBitmap(mask, r.fLeft, r.fTop, &paint); 48 } else { 49 SkPath p; 50 p.addOval(r); 51 p.setFillType(SkPath::kInverseWinding_FillType); 52 paint.setXfermodeMode(SkXfermode::kDstOut_Mode); 53 canvas->drawPath(p, paint); 54 } 55 } 56 57 virtual void onDrawContent(SkCanvas* canvas) { 58 SkRect r; 59 r.set(SkIntToScalar(20), SkIntToScalar(20), SkIntToScalar(120), SkIntToScalar(120)); 60 canvas->saveLayer(&r, NULL); 61 canvas->drawColor(SK_ColorRED); 62 drawMask(canvas, r); 63 canvas->restore(); 64 } 65 66 private: 67 typedef SampleView INHERITED; 68 }; 69 70 /////////////////////////////////////////////////////////////////////////////// 71 72 static SkView* MyFactory() { return new LayerMaskView; } 73 static SkViewRegister reg(MyFactory); 74
