1/*
2 * Copyright 2014 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 "gm.h"
9#include "SkPath.h"
10#include "SkScan.h"
11
12#define W   800
13#define H   800
14
15class AnalyticAntiAliasConvexGM : public skiagm::GM {
16public:
17    AnalyticAntiAliasConvexGM() {}
18
19protected:
20
21    SkString onShortName() override {
22        return SkString("analytic_antialias_convex");
23    }
24
25    SkISize onISize() override {
26        return SkISize::Make(W, H);
27    }
28
29    void onDraw(SkCanvas* canvas) override {
30        SkPaint p;
31        p.setColor(SK_ColorRED);
32        p.setAntiAlias(true);
33
34        canvas->clear(0xFFFFFFFF);
35
36        canvas->save();
37
38        SkScalar y = 0;
39
40        canvas->translate(0, y);
41        canvas->rotate(1);
42        canvas->drawRect({ 20, 20, 200, 200 }, p);
43        canvas->restore();
44
45        y += 200;
46
47        canvas->translate(0, y);
48        canvas->rotate(1);
49        canvas->drawRect({ 20, 20, 20.2f, 200 }, p);
50        canvas->drawRect({ 20, 200, 200, 200.1f }, p);
51        canvas->drawCircle(100, 100, 30, p);
52        canvas->restore();
53
54        // The following path is empty but it'll reveal bug chrome:662914
55        SkPath path;
56        path.moveTo(SkBits2Float(0x429b9d5c), SkBits2Float(0x4367a041));  // 77.8073f, 231.626f
57        // 77.8075f, 231.626f, 77.8074f, 231.625f, 77.8073f, 231.625f
58        path.cubicTo(SkBits2Float(0x429b9d71), SkBits2Float(0x4367a022),
59                SkBits2Float(0x429b9d64), SkBits2Float(0x4367a009),
60                SkBits2Float(0x429b9d50), SkBits2Float(0x43679ff2));
61        path.lineTo(SkBits2Float(0x429b9d5c), SkBits2Float(0x4367a041));  // 77.8073f, 231.626f
62        path.close();
63        canvas->drawPath(path, p);
64
65        // The following path reveals a subtle SkAnalyticQuadraticEdge::updateQuadratic bug:
66        // we should not use any snapped y for the intermediate values whose error may accumulate;
67        // snapping should only be allowed once before updateLine.
68        path.reset();
69        path.moveTo(SkBits2Float(0x434ba71e), SkBits2Float(0x438a06d0));  // 203.653f, 276.053f
70        path.lineTo(SkBits2Float(0x43492a74), SkBits2Float(0x4396d70d));  // 201.166f, 301.68f
71        // 200.921f, 304.207f, 196.939f, 303.82f, 0.707107f
72        path.conicTo(SkBits2Float(0x4348ebaf), SkBits2Float(0x43981a75),
73                SkBits2Float(0x4344f079), SkBits2Float(0x4397e900), SkBits2Float(0x3f3504f3));
74        path.close();
75        // Manually setting convexity is required. Otherwise, this path will be considered concave.
76        path.setConvexity(SkPath::kConvex_Convexity);
77        canvas->drawPath(path, p);
78    }
79
80private:
81    typedef skiagm::GM INHERITED;
82};
83
84class AnalyticAntiAliasGeneralGM : public skiagm::GM {
85public:
86    AnalyticAntiAliasGeneralGM() {}
87
88protected:
89
90    SkString onShortName() override {
91        return SkString("analytic_antialias_general");
92    }
93
94    SkISize onISize() override {
95        return SkISize::Make(W, H);
96    }
97
98    void onDraw(SkCanvas* canvas) override {
99        SkPaint p;
100        p.setColor(SK_ColorRED);
101        p.setAntiAlias(true);
102
103        canvas->clear(0xFFFFFFFF);
104
105        canvas->save();
106        canvas->rotate(1);
107        const SkScalar R = 115.2f, C = 128.0f;
108        SkPath path;
109        path.moveTo(C + R, C);
110        for (int i = 1; i < 8; ++i) {
111            SkScalar a = 2.6927937f * i;
112            SkScalar cosine;
113            SkScalar sine = SkScalarSinCos(a, &cosine);
114            path.lineTo(C + R * cosine, C + R * sine);
115        }
116        canvas->drawPath(path, p);
117        canvas->restore();
118
119        canvas->save();
120        canvas->translate(200, 0);
121        canvas->rotate(1);
122        p.setStyle(SkPaint::kStroke_Style);
123        p.setStrokeWidth(5);
124        canvas->drawPath(path, p);
125        canvas->restore();
126
127
128        // The following two paths test if we correctly cumulates the alpha on the middle pixel
129        // column where the left rect and the right rect abut.
130        p.setStyle(SkPaint::kFill_Style);
131        canvas->translate(0, 300);
132        path.reset();
133        path.addRect({20, 20, 100.4999f, 100});
134        path.addRect({100.5001f, 20, 200, 100});
135        canvas->drawPath(path, p);
136
137        canvas->translate(300, 0);
138        path.reset();
139        path.addRect({20, 20, 100.1f, 100});
140        path.addRect({100.9f, 20, 200, 100});
141        canvas->drawPath(path, p);
142    }
143
144private:
145    typedef skiagm::GM INHERITED;
146};
147
148class AnalyticAntiAliasInverseGM : public skiagm::GM {
149public:
150    AnalyticAntiAliasInverseGM() {}
151
152protected:
153
154    SkString onShortName() override {
155        return SkString("analytic_antialias_inverse");
156    }
157
158    SkISize onISize() override {
159        return SkISize::Make(W, H);
160    }
161
162    void onDraw(SkCanvas* canvas) override {
163        SkPaint p;
164        p.setColor(SK_ColorRED);
165        p.setAntiAlias(true);
166
167        canvas->save();
168
169        SkPath path;
170        path.addCircle(100, 100, 30);
171        path.setFillType(SkPath::kInverseWinding_FillType);
172        canvas->drawPath(path, p);
173        canvas->restore();
174    }
175
176private:
177    typedef skiagm::GM INHERITED;
178};
179
180DEF_GM( return new AnalyticAntiAliasConvexGM; )
181DEF_GM( return new AnalyticAntiAliasGeneralGM; )
182DEF_GM( return new AnalyticAntiAliasInverseGM; )
183