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 "SkBitmap.h"
10 #include "SkCanvas.h"
11 #include "SkPaint.h"
12 #include "SkPath.h"
13 #include "SkView.h"
14
15 ///////////////////////////////////////////////////////////////////////////////
16
17 class LayerMaskView : public SampleView {
18 public:
LayerMaskView()19 LayerMaskView() {
20 this->setBGColor(0xFFDDDDDD);
21 }
22
23 protected:
24 // overrides from SkEventSink
onQuery(SkEvent * evt)25 virtual bool onQuery(SkEvent* evt) {
26 if (SampleCode::TitleQ(*evt)) {
27 SampleCode::TitleR(evt, "LayerMask");
28 return true;
29 }
30 return this->INHERITED::onQuery(evt);
31 }
32
drawMask(SkCanvas * canvas,const SkRect & r)33 void drawMask(SkCanvas* canvas, const SkRect& r) {
34 SkPaint paint;
35 paint.setAntiAlias(true);
36
37 if (true) {
38 SkBitmap mask;
39 int w = SkScalarRoundToInt(r.width());
40 int h = SkScalarRoundToInt(r.height());
41 mask.allocN32Pixels(w, h);
42 mask.eraseColor(SK_ColorTRANSPARENT);
43 SkCanvas c(mask);
44 SkRect bounds = r;
45 bounds.offset(-bounds.fLeft, -bounds.fTop);
46 c.drawOval(bounds, paint);
47
48 paint.setBlendMode(SkBlendMode::kDstIn);
49 canvas->drawBitmap(mask, r.fLeft, r.fTop, &paint);
50 } else {
51 SkPath p;
52 p.addOval(r);
53 p.setFillType(SkPath::kInverseWinding_FillType);
54 paint.setBlendMode(SkBlendMode::kDstOut);
55 canvas->drawPath(p, paint);
56 }
57 }
58
onDrawContent(SkCanvas * canvas)59 virtual void onDrawContent(SkCanvas* canvas) {
60 SkRect r;
61 r.set(SkIntToScalar(20), SkIntToScalar(20), SkIntToScalar(120), SkIntToScalar(120));
62 canvas->saveLayer(&r, nullptr);
63 canvas->drawColor(SK_ColorRED);
64 drawMask(canvas, r);
65 canvas->restore();
66 }
67
68 private:
69 typedef SampleView INHERITED;
70 };
71
72 ///////////////////////////////////////////////////////////////////////////////
73
MyFactory()74 static SkView* MyFactory() { return new LayerMaskView; }
75 static SkViewRegister reg(MyFactory);
76