SampleHairModes.cpp revision f7834221ac5342a3446b9b299398ea3ff7976946 
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 "SampleCode.h"
9#include "SkView.h"
10#include "SkCanvas.h"
11#include "SkDevice.h"
12#include "SkColorPriv.h"
13#include "SkShader.h"
14
15static const struct {
16    SkXfermode::Mode  fMode;
17    const char*         fLabel;
18} gModes[] = {
19    { SkXfermode::kClear_Mode,    "Clear"     },
20    { SkXfermode::kSrc_Mode,      "Src"       },
21    { SkXfermode::kDst_Mode,      "Dst"       },
22    { SkXfermode::kSrcOver_Mode,  "SrcOver"   },
23    { SkXfermode::kDstOver_Mode,  "DstOver"   },
24    { SkXfermode::kSrcIn_Mode,    "SrcIn"     },
25    { SkXfermode::kDstIn_Mode,    "DstIn"     },
26    { SkXfermode::kSrcOut_Mode,   "SrcOut"    },
27    { SkXfermode::kDstOut_Mode,   "DstOut"    },
28    { SkXfermode::kSrcATop_Mode,  "SrcATop"   },
29    { SkXfermode::kDstATop_Mode,  "DstATop"   },
30    { SkXfermode::kXor_Mode,      "Xor"       },
31};
32
33const int gWidth = 64;
34const int gHeight = 64;
35const SkScalar W = SkIntToScalar(gWidth);
36const SkScalar H = SkIntToScalar(gHeight);
37
38static SkScalar drawCell(SkCanvas* canvas, SkXfermode* mode, SkAlpha a0, SkAlpha a1) {
39
40    SkPaint paint;
41    paint.setAntiAlias(true);
42
43    SkRect r = SkRect::MakeWH(W, H);
44    r.inset(W/10, H/10);
45
46    paint.setColor(SK_ColorBLUE);
47    paint.setAlpha(a0);
48    canvas->drawOval(r, paint);
49
50    paint.setColor(SK_ColorRED);
51    paint.setAlpha(a1);
52    paint.setXfermode(mode);
53    for (int angle = 0; angle < 24; ++angle) {
54        SkScalar x = SkScalarCos(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gWidth;
55        SkScalar y = SkScalarSin(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gHeight;
56        paint.setStrokeWidth(SK_Scalar1 * angle * 2 / 24);
57        canvas->drawLine(W/2, H/2, W/2 + x, H/2 + y, paint);
58    }
59
60    return H;
61}
62
63static SkShader* make_bg_shader() {
64    SkBitmap bm;
65    bm.allocN32Pixels(2, 2);
66    *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
67    *bm.getAddr32(1, 0) = *bm.getAddr32(0, 1) = SkPackARGB32(0xFF, 0xCC, 0xCC, 0xCC);
68
69    SkMatrix m;
70    m.setScale(SkIntToScalar(6), SkIntToScalar(6));
71
72    return SkShader::CreateBitmapShader(bm,
73                                        SkShader::kRepeat_TileMode,
74                                        SkShader::kRepeat_TileMode,
75                                        &m);
76}
77
78class HairModesView : public SampleView {
79    SkPaint fBGPaint;
80public:
81    HairModesView() {
82        fBGPaint.setShader(make_bg_shader())->unref();
83    }
84
85protected:
86    // overrides from SkEventSink
87    virtual bool onQuery(SkEvent* evt) {
88        if (SampleCode::TitleQ(*evt)) {
89            SampleCode::TitleR(evt, "HairlineModes");
90            return true;
91        }
92        return this->INHERITED::onQuery(evt);
93    }
94
95    virtual void onDrawContent(SkCanvas* canvas) {
96        const SkRect bounds = SkRect::MakeWH(W, H);
97        static const SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
98
99        canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
100
101        for (int alpha = 0; alpha < 4; ++alpha) {
102            canvas->save();
103            canvas->save();
104            for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); ++i) {
105                if (6 == i) {
106                    canvas->restore();
107                    canvas->translate(W * 5, 0);
108                    canvas->save();
109                }
110                SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
111
112                canvas->drawRect(bounds, fBGPaint);
113                canvas->saveLayer(&bounds, NULL);
114                SkScalar dy = drawCell(canvas, mode,
115                                       gAlphaValue[alpha & 1],
116                                       gAlphaValue[alpha & 2]);
117                canvas->restore();
118
119                canvas->translate(0, dy * 5 / 4);
120                SkSafeUnref(mode);
121            }
122            canvas->restore();
123            canvas->restore();
124            canvas->translate(W * 5 / 4, 0);
125        }
126    }
127
128private:
129    typedef SampleView INHERITED;
130};
131
132///////////////////////////////////////////////////////////////////////////////
133
134static SkView* MyFactory() { return new HairModesView; }
135static SkViewRegister reg(MyFactory);
136