1 /*
2 * Copyright 2011 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "SampleCode.h"
9 #include "SkCanvas.h"
10 #include "SkPaint.h"
11 #include "SkPath.h"
12 #include "SkView.h"
13
14 ///////////////////////////////////////////////////////////////////////////////
15
16 class LayerMaskView : public SampleView {
17 public:
LayerMaskView()18 LayerMaskView() {
19 this->setBGColor(0xFFDDDDDD);
20 }
21
22 protected:
23 // overrides from SkEventSink
onQuery(SkEvent * evt)24 virtual bool onQuery(SkEvent* evt) {
25 if (SampleCode::TitleQ(*evt)) {
26 SampleCode::TitleR(evt, "LayerMask");
27 return true;
28 }
29 return this->INHERITED::onQuery(evt);
30 }
31
drawMask(SkCanvas * canvas,const SkRect & r)32 void drawMask(SkCanvas* canvas, const SkRect& r) {
33 SkPaint paint;
34 paint.setAntiAlias(true);
35
36 if (true) {
37 SkBitmap mask;
38 int w = SkScalarRoundToInt(r.width());
39 int h = SkScalarRoundToInt(r.height());
40 mask.allocN32Pixels(w, h);
41 mask.eraseColor(SK_ColorTRANSPARENT);
42 SkCanvas c(mask);
43 SkRect bounds = r;
44 bounds.offset(-bounds.fLeft, -bounds.fTop);
45 c.drawOval(bounds, paint);
46
47 paint.setXfermodeMode(SkXfermode::kDstIn_Mode);
48 canvas->drawBitmap(mask, r.fLeft, r.fTop, &paint);
49 } else {
50 SkPath p;
51 p.addOval(r);
52 p.setFillType(SkPath::kInverseWinding_FillType);
53 paint.setXfermodeMode(SkXfermode::kDstOut_Mode);
54 canvas->drawPath(p, paint);
55 }
56 }
57
onDrawContent(SkCanvas * canvas)58 virtual void onDrawContent(SkCanvas* canvas) {
59 SkRect r;
60 r.set(SkIntToScalar(20), SkIntToScalar(20), SkIntToScalar(120), SkIntToScalar(120));
61 canvas->saveLayer(&r, nullptr);
62 canvas->drawColor(SK_ColorRED);
63 drawMask(canvas, r);
64 canvas->restore();
65 }
66
67 private:
68 typedef SampleView INHERITED;
69 };
70
71 ///////////////////////////////////////////////////////////////////////////////
72
MyFactory()73 static SkView* MyFactory() { return new LayerMaskView; }
74 static SkViewRegister reg(MyFactory);
75