skia2/gm/aaa.cpp

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/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "gm.h"
#include "SkPath.h"
#include "SkScan.h"
#define W 800
#define H 800
class AnalyticAntiAliasConvexGM : public skiagm::GM {
public:
AnalyticAntiAliasConvexGM() {}
protected:
SkString onShortName() override {
return SkString("analytic_antialias_convex");
}
SkISize onISize() override {
return SkISize::Make(W, H);
}
void onDraw(SkCanvas* canvas) override {
SkPaint p;
p.setColor(SK_ColorRED);
p.setAntiAlias(true);
canvas->clear(0xFFFFFFFF);
canvas->save();
SkScalar y = 0;
canvas->translate(0, y);
canvas->rotate(1);
canvas->drawRect({ 20, 20, 200, 200 }, p);
canvas->restore();
y += 200;
canvas->translate(0, y);
canvas->rotate(1);
canvas->drawRect({ 20, 20, 20.2f, 200 }, p);
canvas->drawRect({ 20, 200, 200, 200.1f }, p);
canvas->drawCircle(100, 100, 30, p);
canvas->restore();
// The following path is empty but it'll reveal bug chrome:662914
SkPath path;
path.moveTo(SkBits2Float(0x429b9d5c), SkBits2Float(0x4367a041)); // 77.8073f, 231.626f
// 77.8075f, 231.626f, 77.8074f, 231.625f, 77.8073f, 231.625f
path.cubicTo(SkBits2Float(0x429b9d71), SkBits2Float(0x4367a022),
SkBits2Float(0x429b9d64), SkBits2Float(0x4367a009),
SkBits2Float(0x429b9d50), SkBits2Float(0x43679ff2));
path.lineTo(SkBits2Float(0x429b9d5c), SkBits2Float(0x4367a041)); // 77.8073f, 231.626f
path.close();
canvas->drawPath(path, p);
// The following path reveals a subtle SkAnalyticQuadraticEdge::updateQuadratic bug:
// we should not use any snapped y for the intermediate values whose error may accumulate;
// snapping should only be allowed once before updateLine.
path.reset();
path.moveTo(SkBits2Float(0x434ba71e), SkBits2Float(0x438a06d0)); // 203.653f, 276.053f
path.lineTo(SkBits2Float(0x43492a74), SkBits2Float(0x4396d70d)); // 201.166f, 301.68f
// 200.921f, 304.207f, 196.939f, 303.82f, 0.707107f
path.conicTo(SkBits2Float(0x4348ebaf), SkBits2Float(0x43981a75),
SkBits2Float(0x4344f079), SkBits2Float(0x4397e900), SkBits2Float(0x3f3504f3));
path.close();
// Manually setting convexity is required. Otherwise, this path will be considered concave.
path.setConvexity(SkPath::kConvex_Convexity);
canvas->drawPath(path, p);
}
private:
typedef skiagm::GM INHERITED;
};
class AnalyticAntiAliasGeneralGM : public skiagm::GM {
public:
AnalyticAntiAliasGeneralGM() {}
protected:
SkString onShortName() override {
return SkString("analytic_antialias_general");
}
SkISize onISize() override {
return SkISize::Make(W, H);
}
void onDraw(SkCanvas* canvas) override {
SkPaint p;
p.setColor(SK_ColorRED);
p.setAntiAlias(true);
canvas->clear(0xFFFFFFFF);
canvas->save();
canvas->rotate(1);
const SkScalar R = 115.2f, C = 128.0f;
SkPath path;
path.moveTo(C + R, C);
for (int i = 1; i < 8; ++i) {
SkScalar a = 2.6927937f * i;
SkScalar cosine;
SkScalar sine = SkScalarSinCos(a, &cosine);
path.lineTo(C + R * cosine, C + R * sine);
}
canvas->drawPath(path, p);
canvas->restore();
canvas->save();
canvas->translate(200, 0);
canvas->rotate(1);
p.setStyle(SkPaint::kStroke_Style);
p.setStrokeWidth(5);
canvas->drawPath(path, p);
canvas->restore();
}
private:
typedef skiagm::GM INHERITED;
};
class AnalyticAntiAliasInverseGM : public skiagm::GM {
public:
AnalyticAntiAliasInverseGM() {}
protected:
SkString onShortName() override {
return SkString("analytic_antialias_inverse");
}
SkISize onISize() override {
return SkISize::Make(W, H);
}
void onDraw(SkCanvas* canvas) override {
SkPaint p;
p.setColor(SK_ColorRED);
p.setAntiAlias(true);
canvas->save();
SkPath path;
path.addCircle(100, 100, 30);
path.setFillType(SkPath::kInverseWinding_FillType);
canvas->drawPath(path, p);
canvas->restore();
}
private:
typedef skiagm::GM INHERITED;
};
DEF_GM( return new AnalyticAntiAliasConvexGM; )
DEF_GM( return new AnalyticAntiAliasGeneralGM; )
DEF_GM( return new AnalyticAntiAliasInverseGM; )