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
|
/*
* 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 "sk_tool_utils.h"
#include "SkShader.h"
// This class of GMs test how edges/verts snap near rounding boundaries in device space without
// anti-aliaing.
class PixelSnapGM : public skiagm::GM {
public:
PixelSnapGM() {}
protected:
// kTrans should be even or checkboards wont agree in different test cases.
static constexpr int kTrans = 14;
static constexpr int kLabelPad = 4;
// The inverse of this value should be a perfect SkScalar.
static constexpr int kSubPixelSteps = 8;
static constexpr int kLabelTextSize = 9;
static_assert(kSubPixelSteps < 99, "label_offset_too_small");
static constexpr int kLabelOffsetX = 2 * kLabelTextSize + kLabelPad;
static constexpr int kLabelOffsetY = kLabelTextSize + kLabelPad;
SkISize onISize() override {
return SkISize::Make((kSubPixelSteps + 1) * kTrans + kLabelOffsetX + kLabelPad,
(kSubPixelSteps + 1) * kTrans + kLabelOffsetY + kLabelPad);
}
void onDraw(SkCanvas* canvas) override {
SkPaint bgPaint;
bgPaint.setShader(
sk_tool_utils::create_checkerboard_shader(
sk_tool_utils::color_to_565(0xFFAAAAAA),
sk_tool_utils::color_to_565(0xFF777777), 1));
canvas->drawPaint(bgPaint);
SkString offset;
SkPaint labelPaint;
labelPaint.setAntiAlias(true);
labelPaint.setColor(SK_ColorWHITE);
labelPaint.setTextSize(SkIntToScalar(kLabelTextSize));
sk_tool_utils::set_portable_typeface(&labelPaint);
SkPaint linePaint;
linePaint.setColor(SK_ColorWHITE);
// Draw row labels
canvas->save();
canvas->translate(0, SkIntToScalar(kLabelOffsetY));
for (int i = 0; i <= kSubPixelSteps; ++i) {
offset.printf("%d", i);
canvas->drawString(offset,
0, i * kTrans + labelPaint.getTextSize(),
labelPaint);
}
canvas->restore();
// Draw col labels
canvas->save();
canvas->translate(SkIntToScalar(kLabelOffsetX), 0);
for (int i = 0; i <= kSubPixelSteps; ++i) {
offset.printf("%d", i);
canvas->drawString(offset,
i * SkIntToScalar(kTrans), labelPaint.getTextSize(),
labelPaint);
}
canvas->restore();
canvas->translate(SkIntToScalar(kLabelOffsetX), SkIntToScalar(kLabelOffsetY));
// Draw test case grid lines (Draw them all at pixel centers to hopefully avoid any
// snapping issues).
for (int i = 0; i <= kSubPixelSteps + 1; ++i) {
canvas->drawLine(0.5f,
i * SkIntToScalar(kTrans) + 0.5f,
SkIntToScalar(kTrans) * (kSubPixelSteps + 1) + 0.5f,
i * SkIntToScalar(kTrans) + 0.5f,
linePaint);
canvas->drawLine(i * SkIntToScalar(kTrans) + 0.5f,
0.5f,
i * SkIntToScalar(kTrans) + 0.5f,
SkIntToScalar(kTrans) * (kSubPixelSteps + 1) + 0.5f,
linePaint);
}
for (int i = 0; i <= kSubPixelSteps; ++i) {
for (int j = 0; j <= kSubPixelSteps; ++j) {
canvas->save();
// +1's account for the grid lines around each test case.
canvas->translate(j * (kTrans + 1.f/kSubPixelSteps) + 1,
i * (kTrans + 1.f/kSubPixelSteps) + 1);
this->drawElement(canvas);
canvas->restore();
}
}
}
virtual void drawElement(SkCanvas*) = 0;
private:
typedef skiagm::GM INHERITED;
};
class PointSnapGM : public PixelSnapGM {
protected:
SkString onShortName() override { return SkString("pixel_snap_point"); }
void drawElement(SkCanvas* canvas) override {
const SkPoint pt = { 1, 1 };
SkPaint paint;
paint.setColor(SK_ColorBLUE);
canvas->drawPoints(SkCanvas::kPoints_PointMode, 1, &pt, paint);
}
private:
typedef PixelSnapGM INHERITED;
};
class LineSnapGM : public PixelSnapGM {
protected:
SkString onShortName() override { return SkString("pixel_snap_line"); }
void drawElement(SkCanvas* canvas) override {
SkPaint paint;
paint.setColor(SK_ColorGREEN);
// Draw a horizontal and vertical line, each length 3.
canvas->drawLine(1, 1, 4, 1, paint);
canvas->drawLine(6, 1, 6, 4, paint);
}
private:
typedef PixelSnapGM INHERITED;
};
class RectSnapGM : public PixelSnapGM {
protected:
SkString onShortName() override { return SkString("pixel_snap_rect"); }
void drawElement(SkCanvas* canvas) override {
SkPaint paint;
paint.setColor(SK_ColorRED);
canvas->drawRect(SkRect::MakeXYWH(1, 1, 3, 3), paint);
}
private:
typedef PixelSnapGM INHERITED;
};
class ComboSnapGM : public PixelSnapGM {
protected:
SkString onShortName() override { return SkString("pixel_snap_combo"); }
void drawElement(SkCanvas* canvas) override {
SkPaint paint;
paint.setAntiAlias(false);
// A rectangle that exactly covers a pixel, a point at each corner, 8 horiz/vert lines
// at rect corners (two at each corner, extending away from rect). They are drawn in this
// order lines (green), points (blue), rect(red).
SkRect rect = SkRect::MakeXYWH(3, 3, 1, 1);
paint.setColor(SK_ColorGREEN);
const SkPoint lines[] = {
{ 3, 3 }, { 0, 3 },
{ 3, 3 }, { 3, 0 },
{ 4, 3 }, { 7, 3 },
{ 4, 3 }, { 4, 0 },
{ 3, 4 }, { 0, 4 },
{ 3, 4 }, { 3, 7 },
{ 4, 4 }, { 7, 4 },
{ 4, 4 }, { 4, 7 },
};
canvas->drawPoints(SkCanvas::kLines_PointMode, SK_ARRAY_COUNT(lines), lines, paint);
const SkPoint pts[] = {
{ 4, 3 }, { 4, 4, }, { 3, 3 }, { 3, 4 },
};
paint.setColor(SK_ColorBLUE);
canvas->drawPoints(SkCanvas::kPoints_PointMode, SK_ARRAY_COUNT(pts), pts, paint);
paint.setColor(SK_ColorRED);
canvas->drawRect(rect, paint);
}
private:
typedef PixelSnapGM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_GM(return new PointSnapGM;)
DEF_GM(return new LineSnapGM;)
DEF_GM(return new RectSnapGM;)
DEF_GM(return new ComboSnapGM;)
|
