hairmodes.cpp revision fbc21172885fe1f028594bc9b181246c71eb106c 
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
13static SkCanvas* create_canvas(int w, int h) {
14    SkBitmap bm;
15    bm.setConfig(SkBitmap::kARGB_8888_Config, w, h);
16    bm.allocPixels();
17    bm.eraseColor(0);
18    return new SkCanvas(bm);
19}
20
21static const SkBitmap& extract_bitmap(SkCanvas* canvas) {
22    return canvas->getDevice()->accessBitmap(false);
23}
24
25static const struct {
26    SkXfermode::Mode  fMode;
27    const char*         fLabel;
28} gModes[] = {
29    { SkXfermode::kClear_Mode,    "Clear"     },
30    { SkXfermode::kSrc_Mode,      "Src"       },
31    { SkXfermode::kDst_Mode,      "Dst"       },
32    { SkXfermode::kSrcOver_Mode,  "SrcOver"   },
33    { SkXfermode::kDstOver_Mode,  "DstOver"   },
34    { SkXfermode::kSrcIn_Mode,    "SrcIn"     },
35    { SkXfermode::kDstIn_Mode,    "DstIn"     },
36    { SkXfermode::kSrcOut_Mode,   "SrcOut"    },
37    { SkXfermode::kDstOut_Mode,   "DstOut"    },
38    { SkXfermode::kSrcATop_Mode,  "SrcATop"   },
39    { SkXfermode::kDstATop_Mode,  "DstATop"   },
40    { SkXfermode::kXor_Mode,      "Xor"       },
41};
42
43const int gWidth = 64;
44const int gHeight = 64;
45const SkScalar W = SkIntToScalar(gWidth);
46const SkScalar H = SkIntToScalar(gHeight);
47
48static SkScalar drawCell(SkCanvas* canvas, SkXfermode* mode, SkAlpha a0, SkAlpha a1) {
49
50    SkPaint paint;
51    paint.setAntiAlias(true);
52
53    SkRect r = SkRect::MakeWH(W, H);
54    r.inset(W/10, H/10);
55
56    paint.setColor(SK_ColorBLUE);
57    paint.setAlpha(a0);
58    canvas->drawOval(r, paint);
59
60    paint.setColor(SK_ColorRED);
61    paint.setAlpha(a1);
62    paint.setXfermode(mode);
63    for (int angle = 0; angle < 24; ++angle) {
64        SkScalar x = SkScalarCos(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gWidth;
65        SkScalar y = SkScalarSin(SkIntToScalar(angle) * (SK_ScalarPI * 2) / 24) * gHeight;
66        paint.setStrokeWidth(SK_Scalar1 * angle * 2 / 24);
67        canvas->drawLine(W/2, H/2, W/2 + x, H/2 + y, paint);
68    }
69
70    return H;
71}
72
73static SkShader* make_bg_shader() {
74    SkBitmap bm;
75    bm.setConfig(SkBitmap::kARGB_8888_Config, 2, 2);
76    bm.allocPixels();
77    *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
78    *bm.getAddr32(1, 0) = *bm.getAddr32(0, 1) = SkPackARGB32(0xFF, 0xCC, 0xCC, 0xCC);
79
80    SkShader* s = SkShader::CreateBitmapShader(bm,
81                                               SkShader::kRepeat_TileMode,
82                                               SkShader::kRepeat_TileMode);
83
84    SkMatrix m;
85    m.setScale(SkIntToScalar(6), SkIntToScalar(6));
86    s->setLocalMatrix(m);
87    return s;
88}
89
90namespace skiagm {
91
92    class HairModesGM : public GM {
93        SkPaint fBGPaint;
94    public:
95        HairModesGM() {
96            fBGPaint.setShader(make_bg_shader())->unref();
97        }
98
99    protected:
100
101        virtual SkString onShortName() {
102            return SkString("hairmodes");
103        }
104
105        virtual SkISize onISize() { return make_isize(640, 480); }
106
107        virtual void onDraw(SkCanvas* canvas) {
108            canvas->drawColor(SK_ColorWHITE);
109
110            const SkRect bounds = SkRect::MakeWH(W, H);
111            static const SkAlpha gAlphaValue[] = { 0xFF, 0x88, 0x88 };
112
113            canvas->translate(SkIntToScalar(4), SkIntToScalar(4));
114
115            for (int alpha = 0; alpha < 4; ++alpha) {
116                canvas->save();
117                canvas->save();
118                for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); ++i) {
119                    if (6 == i) {
120                        canvas->restore();
121                        canvas->translate(W * 5, 0);
122                        canvas->save();
123                    }
124                    SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
125
126                    canvas->drawRect(bounds, fBGPaint);
127                    canvas->saveLayer(&bounds, NULL);
128                    SkScalar dy = drawCell(canvas, mode,
129                                           gAlphaValue[alpha & 1],
130                                           gAlphaValue[alpha & 2]);
131                    canvas->restore();
132
133                    canvas->translate(0, dy * 5 / 4);
134                    SkSafeUnref(mode);
135                }
136                canvas->restore();
137                canvas->restore();
138                canvas->translate(W * 5 / 4, 0);
139            }
140        }
141
142        // disable pdf for now, since it crashes on mac
143        virtual uint32_t onGetFlags() const { return kSkipPDF_Flag; }
144
145    private:
146        typedef GM INHERITED;
147    };
148
149    //////////////////////////////////////////////////////////////////////////////
150
151    static GM* MyFactory(void*) { return new HairModesGM; }
152    static GMRegistry reg(MyFactory);
153
154}
155