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
|
/*
* 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 "SkCanvas.h"
#include "SkRSXform.h"
#include "SkSurface.h"
class DrawAtlasGM : public skiagm::GM {
static sk_sp<SkImage> MakeAtlas(SkCanvas* caller, const SkRect& target) {
SkImageInfo info = SkImageInfo::MakeN32Premul(100, 100);
auto surface(caller->makeSurface(info));
if (nullptr == surface) {
surface = SkSurface::MakeRaster(info);
}
SkCanvas* canvas = surface->getCanvas();
// draw red everywhere, but we don't expect to see it in the draw, testing the notion
// that drawAtlas draws a subset-region of the atlas.
canvas->clear(SK_ColorRED);
SkPaint paint;
paint.setXfermodeMode(SkXfermode::kClear_Mode);
SkRect r(target);
r.inset(-1, -1);
// zero out a place (with a 1-pixel border) to land our drawing.
canvas->drawRect(r, paint);
paint.setXfermode(nullptr);
paint.setColor(SK_ColorBLUE);
paint.setAntiAlias(true);
canvas->drawOval(target, paint);
return surface->makeImageSnapshot();
}
sk_sp<SkImage> fAtlas;
public:
DrawAtlasGM() {}
protected:
SkString onShortName() override {
return SkString("draw-atlas");
}
SkISize onISize() override {
return SkISize::Make(640, 480);
}
void onDraw(SkCanvas* canvas) override {
const SkRect target = { 50, 50, 80, 90 };
if (nullptr == fAtlas) {
fAtlas = MakeAtlas(canvas, target);
}
const struct {
SkScalar fScale;
SkScalar fDegrees;
SkScalar fTx;
SkScalar fTy;
void apply(SkRSXform* xform) const {
const SkScalar rad = SkDegreesToRadians(fDegrees);
xform->fSCos = fScale * SkScalarCos(rad);
xform->fSSin = fScale * SkScalarSin(rad);
xform->fTx = fTx;
xform->fTy = fTy;
}
} rec[] = {
{ 1, 0, 10, 10 }, // just translate
{ 2, 0, 110, 10 }, // scale + translate
{ 1, 30, 210, 10 }, // rotate + translate
{ 2, -30, 310, 30 }, // scale + rotate + translate
};
const int N = SK_ARRAY_COUNT(rec);
SkRSXform xform[N];
SkRect tex[N];
SkColor colors[N];
for (int i = 0; i < N; ++i) {
rec[i].apply(&xform[i]);
tex[i] = target;
colors[i] = 0x80FF0000 + (i * 40 * 256);
}
SkPaint paint;
paint.setFilterQuality(kLow_SkFilterQuality);
paint.setAntiAlias(true);
canvas->drawAtlas(fAtlas.get(), xform, tex, N, nullptr, &paint);
canvas->translate(0, 100);
canvas->drawAtlas(fAtlas.get(), xform, tex, colors, N, SkXfermode::kSrcIn_Mode, nullptr, &paint);
}
private:
typedef GM INHERITED;
};
DEF_GM( return new DrawAtlasGM; )
///////////////////////////////////////////////////////////////////////////////////////////////////
#include "SkPath.h"
#include "SkPathMeasure.h"
static void draw_text_on_path_rigid(SkCanvas* canvas, const void* text, size_t length,
const SkPoint xy[], const SkPath& path, const SkPaint& paint) {
SkPathMeasure meas(path, false);
int count = paint.countText(text, length);
size_t size = count * (sizeof(SkRSXform) + sizeof(SkScalar));
SkAutoSMalloc<512> storage(size);
SkRSXform* xform = (SkRSXform*)storage.get();
SkScalar* widths = (SkScalar*)(xform + count);
paint.getTextWidths(text, length, widths);
for (int i = 0; i < count; ++i) {
// we want to position each character on the center of its advance
const SkScalar offset = SkScalarHalf(widths[i]);
SkPoint pos;
SkVector tan;
if (!meas.getPosTan(xy[i].x() + offset, &pos, &tan)) {
pos = xy[i];
tan.set(1, 0);
}
xform[i].fSCos = tan.x();
xform[i].fSSin = tan.y();
xform[i].fTx = pos.x() - tan.y() * xy[i].y() - tan.x() * offset;
xform[i].fTy = pos.y() + tan.x() * xy[i].y() - tan.y() * offset;
}
// Compute a conservative bounds so we can cull the draw
const SkRect font = paint.getFontBounds();
const SkScalar max = SkTMax(SkTMax(SkScalarAbs(font.fLeft), SkScalarAbs(font.fRight)),
SkTMax(SkScalarAbs(font.fTop), SkScalarAbs(font.fBottom)));
const SkRect bounds = path.getBounds().makeOutset(max, max);
canvas->drawTextRSXform(text, length, &xform[0], &bounds, paint);
if (true) {
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
canvas->drawRect(bounds, p);
}
}
DEF_SIMPLE_GM(drawTextRSXform, canvas, 860, 860) {
const char text0[] = "ABCDFGHJKLMNOPQRSTUVWXYZ";
const int N = sizeof(text0) - 1;
SkPoint pos[N];
SkPaint paint;
paint.setAntiAlias(true);
paint.setTextSize(100);
SkScalar x = 0;
for (int i = 0; i < N; ++i) {
pos[i].set(x, 0);
x += paint.measureText(&text0[i], 1);
}
SkPath path;
path.addOval(SkRect::MakeXYWH(160, 160, 540, 540));
draw_text_on_path_rigid(canvas, text0, N, pos, path, paint);
paint.setStyle(SkPaint::kStroke_Style);
canvas->drawPath(path, paint);
}
|
