1 /*
2 * Copyright 2011 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.h"
9 #include "SkCanvas.h"
10 #include "SkColorPriv.h"
11 #include "SkShader.h"
12
13 #include "SkArithmeticMode.h"
14 #include "SkGradientShader.h"
15 #define WW 100
16 #define HH 32
17
make_bm()18 static SkBitmap make_bm() {
19 SkBitmap bm;
20 bm.allocN32Pixels(WW, HH);
21 bm.eraseColor(SK_ColorTRANSPARENT);
22 return bm;
23 }
24
make_src()25 static SkBitmap make_src() {
26 SkBitmap bm = make_bm();
27 SkCanvas canvas(bm);
28 SkPaint paint;
29 SkPoint pts[] = { {0, 0}, {SkIntToScalar(WW), SkIntToScalar(HH)} };
30 SkColor colors[] = {
31 SK_ColorTRANSPARENT, SK_ColorGREEN, SK_ColorCYAN,
32 SK_ColorRED, SK_ColorMAGENTA, SK_ColorWHITE,
33 };
34 SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
35 SkShader::kClamp_TileMode);
36 paint.setShader(s)->unref();
37 canvas.drawPaint(paint);
38 return bm;
39 }
40
make_dst()41 static SkBitmap make_dst() {
42 SkBitmap bm = make_bm();
43 SkCanvas canvas(bm);
44 SkPaint paint;
45 SkPoint pts[] = { {0, SkIntToScalar(HH)}, {SkIntToScalar(WW), 0} };
46 SkColor colors[] = {
47 SK_ColorBLUE, SK_ColorYELLOW, SK_ColorBLACK, SK_ColorGREEN, SK_ColorGRAY
48 };
49 SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
50 SkShader::kClamp_TileMode);
51 paint.setShader(s)->unref();
52 canvas.drawPaint(paint);
53 return bm;
54 }
55
show_k_text(SkCanvas * canvas,SkScalar x,SkScalar y,const SkScalar k[])56 static void show_k_text(SkCanvas* canvas, SkScalar x, SkScalar y, const SkScalar k[]) {
57 SkPaint paint;
58 paint.setTextSize(SkIntToScalar(24));
59 paint.setAntiAlias(true);
60 for (int i = 0; i < 4; ++i) {
61 SkString str;
62 str.appendScalar(k[i]);
63 SkScalar width = paint.measureText(str.c_str(), str.size());
64 canvas->drawText(str.c_str(), str.size(), x, y + paint.getTextSize(), paint);
65 x += width + SkIntToScalar(10);
66 }
67 }
68
69 class ArithmodeGM : public skiagm::GM {
70 public:
ArithmodeGM()71 ArithmodeGM () {}
72
73 protected:
74
onShortName()75 virtual SkString onShortName() {
76 return SkString("arithmode");
77 }
78
onISize()79 virtual SkISize onISize() { return SkISize::Make(640, 480); }
80
onDraw(SkCanvas * canvas)81 virtual void onDraw(SkCanvas* canvas) {
82 SkBitmap src = make_src();
83 SkBitmap dst = make_dst();
84
85 const SkScalar one = SK_Scalar1;
86 static const SkScalar K[] = {
87 0, 0, 0, 0,
88 0, 0, 0, one,
89 0, one, 0, 0,
90 0, 0, one, 0,
91 0, one, one, 0,
92 0, one, -one, 0,
93 0, one/2, one/2, 0,
94 0, one/2, one/2, one/4,
95 0, one/2, one/2, -one/4,
96 one/4, one/2, one/2, 0,
97 -one/4, one/2, one/2, 0,
98 };
99
100 const SkScalar* k = K;
101 const SkScalar* stop = k + SK_ARRAY_COUNT(K);
102 SkScalar y = 0;
103 SkScalar gap = SkIntToScalar(src.width() + 20);
104 while (k < stop) {
105 SkScalar x = 0;
106 canvas->drawBitmap(src, x, y, NULL);
107 x += gap;
108 canvas->drawBitmap(dst, x, y, NULL);
109 x += gap;
110 SkRect rect = SkRect::MakeXYWH(x, y, SkIntToScalar(WW), SkIntToScalar(HH));
111 canvas->saveLayer(&rect, NULL);
112 canvas->drawBitmap(dst, x, y, NULL);
113 SkXfermode* xfer = SkArithmeticMode::Create(k[0], k[1], k[2], k[3]);
114 SkPaint paint;
115 paint.setXfermode(xfer)->unref();
116 canvas->drawBitmap(src, x, y, &paint);
117 canvas->restore();
118 x += gap;
119 show_k_text(canvas, x, y, k);
120 k += 4;
121 y += SkIntToScalar(src.height() + 12);
122 }
123 }
124
125 private:
126 typedef GM INHERITED;
127 };
128
129 ///////////////////////////////////////////////////////////////////////////////
130
MyFactory(void *)131 static skiagm::GM* MyFactory(void*) { return new ArithmodeGM; }
132 static skiagm::GMRegistry reg(MyFactory);
133