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/gm.h"
9 #include "include/core/SkCanvas.h"
10 #include "include/core/SkColor.h"
11 #include "include/core/SkPaint.h"
12 #include "include/core/SkPathBuilder.h"
13 #include "include/core/SkScalar.h"
14 #include "include/private/SkFloatBits.h"
15 #include "include/private/SkPathRef.h"
16 #include "src/core/SkPathPriv.h"
17 
18 #define W   800
19 #define H   800
20 
DEF_SIMPLE_GM(analytic_antialias_convex,canvas,W,H)21 DEF_SIMPLE_GM(analytic_antialias_convex, canvas, W, H) {
22     SkPaint p;
23     p.setColor(SK_ColorRED);
24     p.setAntiAlias(true);
25 
26     canvas->clear(0xFFFFFFFF);
27 
28     canvas->save();
29 
30     SkScalar y = 0;
31 
32     canvas->translate(0, y);
33     canvas->rotate(1);
34     canvas->drawRect({ 20, 20, 200, 200 }, p);
35     canvas->restore();
36 
37     y += 200;
38 
39     canvas->save();
40     canvas->translate(0, y);
41     canvas->rotate(1);
42     canvas->drawRect({ 20, 20, 20.2f, 200 }, p);
43     canvas->drawRect({ 20, 200, 200, 200.1f }, p);
44     canvas->drawCircle(100, 100, 30, p);
45     canvas->restore();
46 
47     // The following path is empty but it'll reveal bug chrome:662914
48     SkPathBuilder path;
49     path.moveTo(SkBits2Float(0x429b9d5c), SkBits2Float(0x4367a041));  // 77.8073f, 231.626f
50     // 77.8075f, 231.626f, 77.8074f, 231.625f, 77.8073f, 231.625f
51     path.cubicTo(SkBits2Float(0x429b9d71), SkBits2Float(0x4367a022),
52             SkBits2Float(0x429b9d64), SkBits2Float(0x4367a009),
53             SkBits2Float(0x429b9d50), SkBits2Float(0x43679ff2));
54     path.lineTo(SkBits2Float(0x429b9d5c), SkBits2Float(0x4367a041));  // 77.8073f, 231.626f
55     path.close();
56     canvas->drawPath(path.detach(), p);
57 
58     // The following path reveals a subtle SkAnalyticQuadraticEdge::updateQuadratic bug:
59     // we should not use any snapped y for the intermediate values whose error may accumulate;
60     // snapping should only be allowed once before updateLine.
61     path.moveTo(SkBits2Float(0x434ba71e), SkBits2Float(0x438a06d0));  // 203.653f, 276.053f
62     path.lineTo(SkBits2Float(0x43492a74), SkBits2Float(0x4396d70d));  // 201.166f, 301.68f
63     // 200.921f, 304.207f, 196.939f, 303.82f, 0.707107f
64     path.conicTo(SkBits2Float(0x4348ebaf), SkBits2Float(0x43981a75),
65             SkBits2Float(0x4344f079), SkBits2Float(0x4397e900), SkBits2Float(0x3f3504f3));
66     path.close();
67     // Manually setting convexity is required. Otherwise, this path will be considered concave.
68     SkPathPriv::SetConvexity(&path, SkPathConvexity::kConvex);
69     canvas->drawPath(path.detach(), p);
70 
71     // skbug.com/7573
72     y += 200;
73     canvas->save();
74     canvas->translate(0, y);
75     p.setAntiAlias(true);
76     path.moveTo(1.98009784f, 9.0162744f);
77     path.lineTo(47.843992f, 10.1922744f);
78     path.lineTo(47.804008f, 11.7597256f);
79     path.lineTo(1.93990216f, 10.5837256f);
80     canvas->drawPath(path.detach(), p);
81     canvas->restore();
82 
83     // skbug.com/7813
84     // t8888 splits the 800-high canvas into 3 pieces; the boundary is close to 266 and 534
85     path.moveTo(700, 266);
86     path.lineTo(710, 266);
87     path.lineTo(710, 534);
88     path.lineTo(700, 534);
89     canvas->drawPath(path.detach(), p);
90 }
91 
DEF_SIMPLE_GM(analytic_antialias_general,canvas,W,H)92 DEF_SIMPLE_GM(analytic_antialias_general, canvas, W, H) {
93     SkPaint p;
94     p.setColor(SK_ColorRED);
95     p.setAntiAlias(true);
96 
97     canvas->clear(0xFFFFFFFF);
98 
99     canvas->save();
100     canvas->rotate(1);
101     const SkScalar R = 115.2f, C = 128.0f;
102     SkPathBuilder builder;
103     builder.moveTo(C + R, C);
104     for (int i = 1; i < 8; ++i) {
105         SkScalar a = 2.6927937f * i;
106         builder.lineTo(C + R * SkScalarCos(a), C + R * SkScalarSin(a));
107     }
108     SkPath path = builder.detach();
109     canvas->drawPath(path, p);
110     canvas->restore();
111 
112     canvas->save();
113     canvas->translate(200, 0);
114     canvas->rotate(1);
115     p.setStyle(SkPaint::kStroke_Style);
116     p.setStrokeWidth(5);
117     canvas->drawPath(path, p);
118     canvas->restore();
119 
120 
121     // The following two paths test if we correctly cumulates the alpha on the middle pixel
122     // column where the left rect and the right rect abut.
123     p.setStyle(SkPaint::kFill_Style);
124     canvas->translate(0, 300);
125     canvas->drawPath(SkPathBuilder().addRect({20, 20, 100.4999f, 100})
126                                     .addRect({100.5001f, 20, 200, 100})
127                                     .detach(), p);
128 
129     canvas->translate(300, 0);
130     canvas->drawPath(SkPathBuilder().addRect({20, 20, 100.1f, 100})
131                                     .addRect({100.9f, 20, 200, 100})
132                                     .detach(), p);
133 }
134 
DEF_SIMPLE_GM(analytic_antialias_inverse,canvas,W,H)135 DEF_SIMPLE_GM(analytic_antialias_inverse, canvas, W, H) {
136         SkPaint p;
137         p.setColor(SK_ColorRED);
138         p.setAntiAlias(true);
139 
140         canvas->save();
141 
142         SkPath path = SkPath::Circle(100, 100, 30);
143         path.setFillType(SkPathFillType::kInverseWinding);
144         canvas->drawPath(path, p);
145         canvas->restore();
146 }
147