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 "Sample.h"
9 #include "SkBitmap.h"
10 #include "SkCanvas.h"
11 #include "SkColorPriv.h"
12 #include "SkShader.h"
13 
14 static const SkBlendMode gModes[] = {
15     SkBlendMode::kClear,
16     SkBlendMode::kSrc,
17     SkBlendMode::kDst,
18     SkBlendMode::kSrcOver,
19     SkBlendMode::kDstOver,
20     SkBlendMode::kSrcIn,
21     SkBlendMode::kDstIn,
22     SkBlendMode::kSrcOut,
23     SkBlendMode::kDstOut,
24     SkBlendMode::kSrcATop,
25     SkBlendMode::kDstATop,
26     SkBlendMode::kXor,
27 };
28 
29 const int gWidth = 64;
30 const int gHeight = 64;
31 const SkScalar W = SkIntToScalar(gWidth);
32 const SkScalar H = SkIntToScalar(gHeight);
33 
drawCell(SkCanvas * canvas,SkBlendMode mode,SkAlpha a0,SkAlpha a1)34 static SkScalar drawCell(SkCanvas* canvas, SkBlendMode mode, SkAlpha a0, SkAlpha a1) {
35     SkPaint paint;
36     paint.setAntiAlias(true);
37 
38     SkRect r = SkRect::MakeWH(W, H);
39     r.inset(W/10, H/10);
40 
41     paint.setColor(SK_ColorBLUE);
42     paint.setAlpha(a0);
43     canvas->drawOval(r, paint);
44 
45     paint.setColor(SK_ColorRED);
46     paint.setAlpha(a1);
47     paint.setBlendMode(mode);
48     for (int angle = 0; angle < 24; ++angle) {
49         SkScalar x = SkScalarCos(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gWidth;
50         SkScalar y = SkScalarSin(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gHeight;
51         paint.setStrokeWidth(SK_Scalar1 * angle * 2 / 24);
52         canvas->drawLine(W/2, H/2, W/2 + x, H/2 + y, paint);
53     }
54 
55     return H;
56 }
57 
make_bg_shader()58 static sk_sp<SkShader> make_bg_shader() {
59     SkBitmap bm;
60     bm.allocN32Pixels(2, 2);
61     *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
62     *bm.getAddr32(1, 0) = *bm.getAddr32(0, 1) = SkPackARGB32(0xFF, 0xCC, 0xCC, 0xCC);
63 
64     SkMatrix m;
65     m.setScale(SkIntToScalar(6), SkIntToScalar(6));
66 
67     return SkShader::MakeBitmapShader(bm, SkShader::kRepeat_TileMode,
68                                       SkShader::kRepeat_TileMode, &m);
69 }
70 
71 class HairModesView : public Sample {
72     SkPaint fBGPaint;
73 public:
HairModesView()74     HairModesView() {
75         fBGPaint.setShader(make_bg_shader());
76     }
77 
78 protected:
onQuery(Sample::Event * evt)79     virtual bool onQuery(Sample::Event* evt) {
80         if (Sample::TitleQ(*evt)) {
81             Sample::TitleR(evt, "HairlineModes");
82             return true;
83         }
84         return this->INHERITED::onQuery(evt);
85     }
86 
onDrawContent(SkCanvas * canvas)87     virtual void onDrawContent(SkCanvas* canvas) {
88         const SkRect bounds = SkRect::MakeWH(W, H);
89         static const SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
90 
91         canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
92 
93         for (int alpha = 0; alpha < 4; ++alpha) {
94             canvas->save();
95             canvas->save();
96             for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); ++i) {
97                 if (6 == i) {
98                     canvas->restore();
99                     canvas->translate(W * 5, 0);
100                     canvas->save();
101                 }
102                 canvas->drawRect(bounds, fBGPaint);
103                 canvas->saveLayer(&bounds, nullptr);
104                 SkScalar dy = drawCell(canvas, gModes[i],
105                                        gAlphaValue[alpha & 1],
106                                        gAlphaValue[alpha & 2]);
107                 canvas->restore();
108 
109                 canvas->translate(0, dy * 5 / 4);
110             }
111             canvas->restore();
112             canvas->restore();
113             canvas->translate(W * 5 / 4, 0);
114         }
115     }
116 
117 private:
118     typedef Sample INHERITED;
119 };
120 
121 ///////////////////////////////////////////////////////////////////////////////
122 
123 DEF_SAMPLE( return new HairModesView(); )
124