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
|
/*
* Copyright 2011 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 "SkColorPriv.h"
#include "SkShader.h"
#include "SkArithmeticMode.h"
#include "SkGradientShader.h"
#define WW 100
#define HH 32
static SkBitmap make_bm() {
SkBitmap bm;
bm.allocN32Pixels(WW, HH);
bm.eraseColor(SK_ColorTRANSPARENT);
return bm;
}
static SkBitmap make_src() {
SkBitmap bm = make_bm();
SkCanvas canvas(bm);
SkPaint paint;
SkPoint pts[] = { {0, 0}, {SkIntToScalar(WW), SkIntToScalar(HH)} };
SkColor colors[] = {
SK_ColorTRANSPARENT, SK_ColorGREEN, SK_ColorCYAN,
SK_ColorRED, SK_ColorMAGENTA, SK_ColorWHITE,
};
SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
SkShader::kClamp_TileMode);
paint.setShader(s)->unref();
canvas.drawPaint(paint);
return bm;
}
static SkBitmap make_dst() {
SkBitmap bm = make_bm();
SkCanvas canvas(bm);
SkPaint paint;
SkPoint pts[] = { {0, SkIntToScalar(HH)}, {SkIntToScalar(WW), 0} };
SkColor colors[] = {
SK_ColorBLUE, SK_ColorYELLOW, SK_ColorBLACK, SK_ColorGREEN, SK_ColorGRAY
};
SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
SkShader::kClamp_TileMode);
paint.setShader(s)->unref();
canvas.drawPaint(paint);
return bm;
}
static void show_k_text(SkCanvas* canvas, SkScalar x, SkScalar y, const SkScalar k[]) {
SkPaint paint;
paint.setTextSize(SkIntToScalar(24));
paint.setAntiAlias(true);
for (int i = 0; i < 4; ++i) {
SkString str;
str.appendScalar(k[i]);
SkScalar width = paint.measureText(str.c_str(), str.size());
canvas->drawText(str.c_str(), str.size(), x, y + paint.getTextSize(), paint);
x += width + SkIntToScalar(10);
}
}
class ArithmodeGM : public skiagm::GM {
public:
ArithmodeGM () {}
protected:
virtual SkString onShortName() {
return SkString("arithmode");
}
virtual SkISize onISize() { return SkISize::Make(640, 480); }
virtual void onDraw(SkCanvas* canvas) {
SkBitmap src = make_src();
SkBitmap dst = make_dst();
const SkScalar one = SK_Scalar1;
static const SkScalar K[] = {
0, 0, 0, 0,
0, 0, 0, one,
0, one, 0, 0,
0, 0, one, 0,
0, one, one, 0,
0, one, -one, 0,
0, one/2, one/2, 0,
0, one/2, one/2, one/4,
0, one/2, one/2, -one/4,
one/4, one/2, one/2, 0,
-one/4, one/2, one/2, 0,
};
const SkScalar* k = K;
const SkScalar* stop = k + SK_ARRAY_COUNT(K);
SkScalar y = 0;
SkScalar gap = SkIntToScalar(src.width() + 20);
while (k < stop) {
SkScalar x = 0;
canvas->drawBitmap(src, x, y, NULL);
x += gap;
canvas->drawBitmap(dst, x, y, NULL);
x += gap;
SkRect rect = SkRect::MakeXYWH(x, y, SkIntToScalar(WW), SkIntToScalar(HH));
canvas->saveLayer(&rect, NULL);
canvas->drawBitmap(dst, x, y, NULL);
SkXfermode* xfer = SkArithmeticMode::Create(k[0], k[1], k[2], k[3]);
SkPaint paint;
paint.setXfermode(xfer)->unref();
canvas->drawBitmap(src, x, y, &paint);
canvas->restore();
x += gap;
show_k_text(canvas, x, y, k);
k += 4;
y += SkIntToScalar(src.height() + 12);
}
}
private:
typedef GM INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
static skiagm::GM* MyFactory(void*) { return new ArithmodeGM; }
static skiagm::GMRegistry reg(MyFactory);
|