aosp12/external/skia/samplecode/SampleLayers.cpp

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2023-01-09 17:11:35 +08:00
/*
* 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 "include/core/SkCanvas.h"
#include "include/core/SkColorFilter.h"
#include "include/core/SkColorPriv.h"
#include "include/core/SkImage.h"
#include "include/core/SkMaskFilter.h"
#include "include/core/SkPath.h"
#include "include/core/SkRegion.h"
#include "include/core/SkShader.h"
#include "include/core/SkTime.h"
#include "include/core/SkTypeface.h"
#include "include/effects/SkGradientShader.h"
#include "include/utils/SkCamera.h"
#include "samplecode/Sample.h"
#include "src/core/SkClipOpPriv.h"
#include "src/utils/SkUTF.h"
static void make_paint(SkPaint* paint, const SkMatrix& localMatrix) {
SkColor colors[] = { 0, SK_ColorWHITE };
SkPoint pts[] = { { 0, 0 }, { 0, SK_Scalar1*20 } };
paint->setShader(SkGradientShader::MakeLinear(pts, colors, nullptr, 2,
SkTileMode::kClamp, 0, &localMatrix));
paint->setBlendMode(SkBlendMode::kDstIn);
}
// test drawing with strips of fading gradient above and below
static void test_fade(SkCanvas* canvas) {
SkAutoCanvasRestore ar(canvas, true);
SkRect r;
SkPaint p;
p.setAlpha(0x88);
SkAutoCanvasRestore ar2(canvas, false);
// create the layers
r.setWH(100, 100);
canvas->clipRect(r);
r.fBottom = SkIntToScalar(20);
canvas->saveLayer(&r, nullptr);
r.fTop = SkIntToScalar(80);
r.fBottom = SkIntToScalar(100);
canvas->saveLayer(&r, nullptr);
// now draw the "content"
if (true) {
r.setWH(100, 100);
canvas->saveLayerAlpha(&r, 0x80);
SkPaint p;
p.setColor(SK_ColorRED);
p.setAntiAlias(true);
canvas->drawOval(r, p);
canvas->restore();
} else {
r.setWH(100, 100);
SkPaint p;
p.setColor(SK_ColorRED);
p.setAntiAlias(true);
canvas->drawOval(r, p);
}
// return;
// now apply an effect
SkMatrix m;
m.setScale(SK_Scalar1, -SK_Scalar1);
m.postTranslate(0, SkIntToScalar(100));
SkPaint paint;
make_paint(&paint, m);
r.setWH(100, 20);
// SkDebugf("--------- draw top grad\n");
canvas->drawRect(r, paint);
r.fTop = SkIntToScalar(80);
r.fBottom = SkIntToScalar(100);
// SkDebugf("--------- draw bot grad\n");
canvas->drawRect(r, paint);
}
class LayersView : public Sample {
public:
LayersView() {}
protected:
SkString name() override { return SkString("Layers"); }
void drawBG(SkCanvas* canvas) {
canvas->drawColor(SK_ColorGRAY);
}
void onDrawContent(SkCanvas* canvas) override {
this->drawBG(canvas);
if (true) {
SkRect r;
r.setWH(220, 120);
SkPaint p;
canvas->saveLayer(&r, &p);
canvas->drawColor(0xFFFF0000);
p.setAlpha(0); // or 0
p.setBlendMode(SkBlendMode::kSrc);
canvas->drawOval(r, p);
canvas->restore();
return;
}
if (false) {
SkRect r;
r.setWH(220, 120);
SkPaint p;
p.setAlpha(0x88);
p.setAntiAlias(true);
if (true) {
canvas->saveLayer(&r, &p);
p.setColor(0xFFFF0000);
canvas->drawOval(r, p);
canvas->restore();
}
p.setColor(0xFF0000FF);
r.offset(SkIntToScalar(20), SkIntToScalar(50));
canvas->drawOval(r, p);
}
if (false) {
SkPaint p;
p.setAlpha(0x88);
p.setAntiAlias(true);
canvas->translate(SkIntToScalar(300), 0);
SkRect r;
r.setWH(220, 60);
canvas->saveLayer(&r, &p);
r.setWH(220, 120);
p.setColor(SK_ColorBLUE);
canvas->drawOval(r, p);
canvas->restore();
return;
}
test_fade(canvas);
}
private:
using INHERITED = Sample;
};
DEF_SAMPLE( return new LayersView; )
//////////////////////////////////////////////////////////////////////////////
#include "include/effects/SkImageFilters.h"
#include "tools/Resources.h"
class BackdropView : public Sample {
SkPoint fCenter;
SkScalar fAngle;
sk_sp<SkImage> fImage;
sk_sp<SkImageFilter> fFilter;
public:
BackdropView() {
fCenter.set(200, 150);
fAngle = 0;
fImage = GetResourceAsImage("images/mandrill_512.png");
fFilter = SkImageFilters::Dilate(8, 8, nullptr);
}
protected:
SkString name() override { return SkString("Backdrop"); }
void onDrawContent(SkCanvas* canvas) override {
canvas->drawImage(fImage.get(), 0, 0);
const SkScalar w = 250;
const SkScalar h = 150;
SkPath path;
path.addOval(SkRect::MakeXYWH(-w/2, -h/2, w, h));
SkMatrix m;
m.setRotate(fAngle);
m.postTranslate(fCenter.x(), fCenter.y());
path.transform(m);
canvas->clipPath(path, kIntersect_SkClipOp, true);
const SkRect bounds = path.getBounds();
SkPaint paint;
paint.setAlpha(0xCC);
canvas->saveLayer(SkCanvas::SaveLayerRec(&bounds, &paint, fFilter.get(), 0));
canvas->restore();
}
bool onAnimate(double nanos) override {
fAngle = SkDoubleToScalar(fmod(1e-9 * nanos * 360 / 5, 360));
return true;
}
Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi) override {
return new Click();
}
bool onClick(Click* click) override {
fCenter = click->fCurr;
return true;
}
private:
using INHERITED = Sample;
};
DEF_SAMPLE( return new BackdropView; )