skia2/samplecode/SampleLayerMask.cpp

75 lines
2.1 KiB
C++

/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SampleCode.h"
#include "SkCanvas.h"
#include "SkPaint.h"
#include "SkPath.h"
#include "SkView.h"
///////////////////////////////////////////////////////////////////////////////
class LayerMaskView : public SampleView {
public:
LayerMaskView() {
this->setBGColor(0xFFDDDDDD);
}
protected:
// overrides from SkEventSink
virtual bool onQuery(SkEvent* evt) {
if (SampleCode::TitleQ(*evt)) {
SampleCode::TitleR(evt, "LayerMask");
return true;
}
return this->INHERITED::onQuery(evt);
}
void drawMask(SkCanvas* canvas, const SkRect& r) {
SkPaint paint;
paint.setAntiAlias(true);
if (true) {
SkBitmap mask;
int w = SkScalarRoundToInt(r.width());
int h = SkScalarRoundToInt(r.height());
mask.allocN32Pixels(w, h);
mask.eraseColor(SK_ColorTRANSPARENT);
SkCanvas c(mask);
SkRect bounds = r;
bounds.offset(-bounds.fLeft, -bounds.fTop);
c.drawOval(bounds, paint);
paint.setBlendMode(SkBlendMode::kDstIn);
canvas->drawBitmap(mask, r.fLeft, r.fTop, &paint);
} else {
SkPath p;
p.addOval(r);
p.setFillType(SkPath::kInverseWinding_FillType);
paint.setBlendMode(SkBlendMode::kDstOut);
canvas->drawPath(p, paint);
}
}
virtual void onDrawContent(SkCanvas* canvas) {
SkRect r;
r.set(SkIntToScalar(20), SkIntToScalar(20), SkIntToScalar(120), SkIntToScalar(120));
canvas->saveLayer(&r, nullptr);
canvas->drawColor(SK_ColorRED);
drawMask(canvas, r);
canvas->restore();
}
private:
typedef SampleView INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
static SkView* MyFactory() { return new LayerMaskView; }
static SkViewRegister reg(MyFactory);