SampleMipMap.cpp revision 0baf19375466cfc24c96532df406e7c5b1d1aae8 
1#include "SampleCode.h"
2#include "SkView.h"
3#include "SkCanvas.h"
4#include "SkDevice.h"
5#include "SkPaint.h"
6
7static SkBitmap createBitmap(int n) {
8    SkBitmap bitmap;
9    bitmap.setConfig(SkBitmap::kARGB_8888_Config, n, n);
10    bitmap.allocPixels();
11    bitmap.eraseColor(0);
12
13    SkCanvas canvas(bitmap);
14    SkRect r;
15    r.set(0, 0, SkIntToScalar(n), SkIntToScalar(n));
16    SkPaint paint;
17    paint.setAntiAlias(true);
18
19    paint.setColor(SK_ColorRED);
20    canvas.drawOval(r, paint);
21    paint.setColor(SK_ColorBLUE);
22    paint.setStrokeWidth(SkIntToScalar(n)/15);
23    paint.setStyle(SkPaint::kStroke_Style);
24    canvas.drawLine(0, 0, r.fRight, r.fBottom, paint);
25    canvas.drawLine(0, r.fBottom, r.fRight, 0, paint);
26
27    return bitmap;
28}
29
30class MipMapView : public SkView {
31    SkBitmap fBitmap;
32    enum {
33        N = 128
34    };
35public:
36    MipMapView() {
37        fBitmap = createBitmap(N);
38
39        fWidth = N;
40        fDW = -1;
41    }
42
43protected:
44    // overrides from SkEventSink
45    virtual bool onQuery(SkEvent* evt) {
46        if (SampleCode::TitleQ(*evt)) {
47            SampleCode::TitleR(evt, "MapMaps");
48            return true;
49        }
50        return this->INHERITED::onQuery(evt);
51    }
52
53    void drawN(SkCanvas* canvas, const SkBitmap& bitmap) {
54        SkAutoCanvasRestore acr(canvas, true);
55        for (int i = N; i > 1; i >>= 1) {
56            canvas->drawBitmap(bitmap, 0, 0, NULL);
57            canvas->translate(SkIntToScalar(N + 8), 0);
58            canvas->scale(SK_ScalarHalf, SK_ScalarHalf);
59        }
60    }
61
62    void drawN2(SkCanvas* canvas, const SkBitmap& bitmap) {
63        SkBitmap bg;
64        bg.setConfig(SkBitmap::kARGB_8888_Config, N, N);
65        bg.allocPixels();
66
67        SkAutoCanvasRestore acr(canvas, true);
68        for (int i = 0; i < 6; i++) {
69            bg.eraseColor(0);
70            SkCanvas c(bg);
71            c.scale(SK_Scalar1 / (1 << i), SK_Scalar1 / (1 << i));
72            c.drawBitmap(bitmap, 0, 0, NULL);
73
74            canvas->save();
75            canvas->scale(SkIntToScalar(1 << i), SkIntToScalar(1 << i));
76            canvas->drawBitmap(bg, 0, 0, NULL);
77            canvas->restore();
78            canvas->translate(SkIntToScalar(N + 8), 0);
79        }
80    }
81
82    void drawBG(SkCanvas* canvas) {
83        canvas->drawColor(SK_ColorWHITE);
84    }
85
86    virtual void onDraw(SkCanvas* canvas) {
87        this->drawBG(canvas);
88
89        canvas->translate(SkIntToScalar(10), SkIntToScalar(10));
90
91        canvas->scale(1.00000001, 0.9999999);
92
93        drawN2(canvas, fBitmap);
94
95        canvas->translate(0, SkIntToScalar(N + 8));
96        SkBitmap bitmap(fBitmap);
97        bitmap.buildMipMap();
98        drawN2(canvas, bitmap);
99
100        fWidth += fDW;
101        if (fDW > 0 && fWidth > N) {
102            fDW = -fDW;
103            fWidth = N;
104        } else if (fDW < 0 && fWidth < 8) {
105            fDW = -fDW;
106            fWidth = 8;
107        }
108
109        SkRect dst;
110        dst.set(0, 0, SkIntToScalar(fWidth), SkIntToScalar(fWidth));
111
112        SkPaint paint;
113        paint.setFilterBitmap(true);
114        paint.setAntiAlias(true);
115
116        canvas->translate(0, SkIntToScalar(N + 8));
117        canvas->drawBitmapRect(fBitmap, NULL, dst, NULL);
118        canvas->translate(SkIntToScalar(N + 8), 0);
119        canvas->drawBitmapRect(fBitmap, NULL, dst, &paint);
120        canvas->translate(SkIntToScalar(N + 8), 0);
121        canvas->drawBitmapRect(bitmap, NULL, dst, NULL);
122        canvas->translate(SkIntToScalar(N + 8), 0);
123        canvas->drawBitmapRect(bitmap, NULL, dst, &paint);
124
125        this->inval(NULL);
126    }
127
128private:
129    int fWidth, fDW;
130
131    typedef SkView INHERITED;
132};
133
134//////////////////////////////////////////////////////////////////////////////
135
136static SkView* MyFactory() { return new MipMapView; }
137static SkViewRegister reg(MyFactory);
138
139