1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
/*
* Copyright 2015 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 "SkAnimTimer.h"
#include "SkCanvas.h"
#include "SkPathMeasure.h"
#include "SkRandom.h"
class AddArcGM : public skiagm::GM {
public:
AddArcGM() : fRotate(0) {}
protected:
SkString onShortName() override { return SkString("addarc"); }
SkISize onISize() override { return SkISize::Make(1040, 1040); }
void onDraw(SkCanvas* canvas) override {
canvas->translate(20, 20);
SkRect r = SkRect::MakeWH(1000, 1000);
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(15);
const SkScalar inset = paint.getStrokeWidth() + 4;
const SkScalar sweepAngle = 345;
SkRandom rand;
SkScalar sign = 1;
while (r.width() > paint.getStrokeWidth() * 3) {
paint.setColor(rand.nextU() | (0xFF << 24));
SkScalar startAngle = rand.nextUScalar1() * 360;
SkScalar speed = SkScalarSqrt(16 / r.width()) * 0.5f;
startAngle += fRotate * 360 * speed * sign;
SkPath path;
path.addArc(r, startAngle, sweepAngle);
canvas->drawPath(path, paint);
r.inset(inset, inset);
sign = -sign;
}
}
bool onAnimate(const SkAnimTimer& timer) override {
fRotate = timer.scaled(1, 360);
return true;
}
private:
SkScalar fRotate;
typedef skiagm::GM INHERITED;
};
DEF_GM( return new AddArcGM; )
///////////////////////////////////////////////////
#define R 400
class AddArcMeasGM : public skiagm::GM {
public:
AddArcMeasGM() {}
protected:
SkString onShortName() override { return SkString("addarc_meas"); }
SkISize onISize() override { return SkISize::Make(2*R + 40, 2*R + 40); }
void onDraw(SkCanvas* canvas) override {
canvas->translate(R + 20, R + 20);
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
SkPaint measPaint;
measPaint.setAntiAlias(true);
measPaint.setColor(SK_ColorRED);
const SkRect oval = SkRect::MakeLTRB(-R, -R, R, R);
canvas->drawOval(oval, paint);
for (SkScalar deg = 0; deg < 360; deg += 10) {
const SkScalar rad = SkDegreesToRadians(deg);
SkScalar rx = SkScalarCos(rad) * R;
SkScalar ry = SkScalarSin(rad) * R;
canvas->drawLine(0, 0, rx, ry, paint);
SkPath path;
path.addArc(oval, 0, deg);
SkPathMeasure meas(path, false);
SkScalar arcLen = rad * R;
SkPoint pos;
if (meas.getPosTan(arcLen, &pos, NULL)) {
canvas->drawLine(0, 0, pos.x(), pos.y(), measPaint);
}
}
}
private:
typedef skiagm::GM INHERITED;
};
DEF_GM( return new AddArcMeasGM; )
///////////////////////////////////////////////////
// Emphasize drawing a stroked oval (containing conics) and then scaling the results up,
// to ensure that we compute the stroke taking the CTM into account
//
class StrokeCircleGM : public skiagm::GM {
public:
StrokeCircleGM() : fRotate(0) {}
protected:
SkString onShortName() override { return SkString("strokecircle"); }
SkISize onISize() override { return SkISize::Make(520, 520); }
void onDraw(SkCanvas* canvas) override {
canvas->scale(20, 20);
canvas->translate(13, 13);
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(SK_Scalar1 / 2);
const SkScalar delta = paint.getStrokeWidth() * 3 / 2;
SkRect r = SkRect::MakeXYWH(-12, -12, 24, 24);
SkRandom rand;
SkScalar sign = 1;
while (r.width() > paint.getStrokeWidth() * 2) {
SkAutoCanvasRestore acr(canvas, true);
canvas->rotate(fRotate * sign);
paint.setColor(rand.nextU() | (0xFF << 24));
canvas->drawOval(r, paint);
r.inset(delta, delta);
sign = -sign;
}
}
bool onAnimate(const SkAnimTimer& timer) override {
fRotate = timer.scaled(60, 360);
return true;
}
private:
SkScalar fRotate;
typedef skiagm::GM INHERITED;
};
DEF_GM( return new StrokeCircleGM; )
//////////////////////
static void html_canvas_arc(SkPath* path, SkScalar x, SkScalar y, SkScalar r, SkScalar start,
SkScalar end, bool ccw) {
SkRect bounds = { x - r, y - r, x + r, y + r };
SkScalar sweep = ccw ? end - start : start - end;
path->arcTo(bounds, start, sweep, false);
}
// Lifted from canvas-arc-circumference-fill-diffs.html
class ManyArcsGM : public skiagm::GM {
public:
ManyArcsGM() {}
protected:
SkString onShortName() override { return SkString("manyarcs"); }
SkISize onISize() override { return SkISize::Make(620, 330); }
void onDraw(SkCanvas* canvas) override {
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
canvas->translate(10, 10);
// 20 angles.
SkScalar sweepAngles[] = {
-123.7f, -2.3f, -2, -1, -0.3f, -0.000001f, 0, 0.000001f, 0.3f, 0.7f,
1, 1.3f, 1.5f, 1.7f, 1.99999f, 2, 2.00001f, 2.3f, 4.3f, 3934723942837.3f
};
for (size_t i = 0; i < SK_ARRAY_COUNT(sweepAngles); ++i) {
sweepAngles[i] *= 180;
}
SkScalar startAngles[] = { -1, -0.5f, 0, 0.5f };
for (size_t i = 0; i < SK_ARRAY_COUNT(startAngles); ++i) {
startAngles[i] *= 180;
}
bool anticlockwise = false;
SkScalar sign = 1;
for (size_t i = 0; i < SK_ARRAY_COUNT(startAngles) * 2; ++i) {
if (i == SK_ARRAY_COUNT(startAngles)) {
anticlockwise = true;
sign = -1;
}
SkScalar startAngle = startAngles[i % SK_ARRAY_COUNT(startAngles)] * sign;
canvas->save();
for (size_t j = 0; j < SK_ARRAY_COUNT(sweepAngles); ++j) {
SkPath path;
path.moveTo(0, 2);
html_canvas_arc(&path, 18, 15, 10, startAngle, startAngle + (sweepAngles[j] * sign),
anticlockwise);
path.lineTo(0, 28);
canvas->drawPath(path, paint);
canvas->translate(30, 0);
}
canvas->restore();
canvas->translate(0, 40);
}
}
private:
typedef skiagm::GM INHERITED;
};
DEF_GM( return new ManyArcsGM; )
|
