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 
49     SkScalar offset = SK_Scalar1 / 3;
50     SkRect rect = SkRect::MakeXYWH(W / 4 + offset,
51                                    H / 4 + offset,
52                                    W / 2, H / 2);
53     canvas->drawRect(rect, paint);
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,
63                                                              0xCC, 0xCC);
64 
65     SkMatrix m;
66     m.setScale(SkIntToScalar(6), SkIntToScalar(6));
67 
68     return SkShader::MakeBitmapShader(bm,
69                                       SkShader::kRepeat_TileMode,
70                                       SkShader::kRepeat_TileMode,
71                                       &m);
72 }
73 
74 class AARectsModesView : public Sample {
75     SkPaint fBGPaint;
76 public:
AARectsModesView()77     AARectsModesView () {
78         fBGPaint.setShader(make_bg_shader());
79     }
80 
81 protected:
onQuery(Sample::Event * evt)82     virtual bool onQuery(Sample::Event* evt) {
83         if (Sample::TitleQ(*evt)) {
84             Sample::TitleR(evt, "AARectsModes");
85             return true;
86         }
87         return this->INHERITED::onQuery(evt);
88     }
89 
onDrawContent(SkCanvas * canvas)90     virtual void onDrawContent(SkCanvas* canvas) {
91         const SkRect bounds = SkRect::MakeWH(W, H);
92         static const SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
93 
94         canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
95 
96         for (int alpha = 0; alpha < 4; ++alpha) {
97             canvas->save();
98             canvas->save();
99             for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); ++i) {
100                 if (6 == i) {
101                     canvas->restore();
102                     canvas->translate(W * 5, 0);
103                     canvas->save();
104                 }
105 
106                 canvas->drawRect(bounds, fBGPaint);
107                 canvas->saveLayer(&bounds, nullptr);
108                 SkScalar dy = drawCell(canvas, gModes[i], gAlphaValue[alpha & 1],
109                                        gAlphaValue[alpha & 2]);
110                 canvas->restore();
111 
112                 canvas->translate(0, dy * 5 / 4);
113             }
114             canvas->restore();
115             canvas->restore();
116             canvas->translate(W * 5 / 4, 0);
117         }
118     }
119 
120 private:
121     typedef Sample INHERITED;
122 };
123 
124 ///////////////////////////////////////////////////////////////////////////////
125 
126 DEF_SAMPLE( return new AARectsModesView(); )
127