SampleLayers.cpp revision 8a1c16ff38322f0210116fa7293eb8817c7e477e 
1#include "SampleCode.h"
2#include "SkView.h"
3#include "SkCanvas.h"
4#include "SkBlurMaskFilter.h"
5#include "SkCamera.h"
6#include "SkColorFilter.h"
7#include "SkColorPriv.h"
8#include "SkDevice.h"
9#include "SkGradientShader.h"
10#include "SkImageDecoder.h"
11#include "SkInterpolator.h"
12#include "SkMaskFilter.h"
13#include "SkPath.h"
14#include "SkRegion.h"
15#include "SkShader.h"
16#include "SkShaderExtras.h"
17#include "SkTime.h"
18#include "SkTypeface.h"
19#include "SkUtils.h"
20#include "SkKey.h"
21#include "SkPorterDuff.h"
22#include "SkXfermode.h"
23#include "SkDrawFilter.h"
24
25static void make_paint(SkPaint* paint) {
26    SkColor colors[] = { 0, SK_ColorWHITE };
27    SkPoint pts[] = { 0, 0, 0, SK_Scalar1*20 };
28    SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
29
30    paint->setShader(s)->unref();
31    paint->setXfermode(SkPorterDuff::CreateXfermode(SkPorterDuff::kDstIn_Mode))->unref();
32}
33
34static void dump_layers(const char label[], SkCanvas* canvas) {
35    SkDebugf("Dump Layers(%s)\n", label);
36
37    SkCanvas::LayerIter iter(canvas, true);
38    int index = 0;
39    while (!iter.done()) {
40        const SkBitmap& bm = iter.device()->accessBitmap(false);
41        const SkIRect& clip = iter.clip().getBounds();
42        SkDebugf("Layer[%d] bitmap [%d %d] X=%d Y=%d clip=[%d %d %d %d] alpha=%d\n", index++,
43                 bm.width(), bm.height(), iter.x(), iter.y(),
44                 clip.fLeft, clip.fTop, clip.fRight, clip.fBottom,
45                 iter.paint().getAlpha());
46        iter.next();
47    }
48}
49
50// test drawing with strips of fading gradient above and below
51static void test_fade(SkCanvas* canvas) {
52    SkAutoCanvasRestore ar(canvas, true);
53
54    SkRect r;
55
56    SkPaint p;
57    p.setAlpha(0x88);
58
59    SkAutoCanvasRestore(canvas, false);
60
61    // create the layers
62
63    r.set(0, 0, SkIntToScalar(100), SkIntToScalar(100));
64    canvas->clipRect(r);
65
66    r.fBottom = SkIntToScalar(20);
67    canvas->saveLayer(&r, NULL, (SkCanvas::SaveFlags)(SkCanvas::kHasAlphaLayer_SaveFlag | SkCanvas::kFullColorLayer_SaveFlag));
68
69    r.fTop = SkIntToScalar(80);
70    r.fBottom = SkIntToScalar(100);
71    canvas->saveLayer(&r, NULL, (SkCanvas::SaveFlags)(SkCanvas::kHasAlphaLayer_SaveFlag | SkCanvas::kFullColorLayer_SaveFlag));
72
73    // now draw the "content"
74
75    if (true) {
76        r.set(0, 0, SkIntToScalar(100), SkIntToScalar(100));
77
78        canvas->saveLayerAlpha(&r, 0x80);
79
80        SkPaint p;
81        p.setColor(SK_ColorRED);
82        p.setAntiAlias(true);
83        canvas->drawOval(r, p);
84
85        dump_layers("inside layer alpha", canvas);
86
87        canvas->restore();
88    } else {
89        r.set(0, 0, SkIntToScalar(100), SkIntToScalar(100));
90
91        SkPaint p;
92        p.setColor(SK_ColorRED);
93        p.setAntiAlias(true);
94        canvas->drawOval(r, p);
95    }
96
97//    return;
98
99    dump_layers("outside layer alpha", canvas);
100
101    // now apply an effect
102
103    SkPaint paint;
104    make_paint(&paint);
105    r.set(0, 0, SkIntToScalar(100), SkIntToScalar(20));
106//    SkDebugf("--------- draw top grad\n");
107    canvas->drawRect(r, paint);
108
109    SkMatrix m;
110    SkShader* s = paint.getShader();
111    m.setScale(SK_Scalar1, -SK_Scalar1);
112    m.postTranslate(0, SkIntToScalar(100));
113    s->setLocalMatrix(m);
114
115    r.fTop = SkIntToScalar(80);
116    r.fBottom = SkIntToScalar(100);
117//    SkDebugf("--------- draw bot grad\n");
118    canvas->drawRect(r, paint);
119}
120
121class RedFilter : public SkDrawFilter {
122public:
123    virtual bool filter(SkCanvas*, SkPaint* p, SkDrawFilter::Type) {
124        fColor = p->getColor();
125        if (fColor == SK_ColorRED) {
126            p->setColor(SK_ColorGREEN);
127        }
128        return true;
129    }
130    virtual void restore(SkCanvas*, SkPaint* p, SkDrawFilter::Type) {
131        p->setColor(fColor);
132    }
133
134private:
135    SkColor fColor;
136};
137
138class LayersView : public SkView {
139public:
140	LayersView() {}
141
142protected:
143    // overrides from SkEventSink
144    virtual bool onQuery(SkEvent* evt) {
145        if (SampleCode::TitleQ(*evt)) {
146            SampleCode::TitleR(evt, "Layers");
147            return true;
148        }
149        return this->INHERITED::onQuery(evt);
150    }
151
152    void drawBG(SkCanvas* canvas) {
153        canvas->drawColor(SK_ColorWHITE);
154    }
155
156    virtual void onDraw(SkCanvas* canvas) {
157        this->drawBG(canvas);
158
159        if (false) {
160            SkRect r;
161			r.set(SkIntToScalar(0), SkIntToScalar(0),
162				  SkIntToScalar(220), SkIntToScalar(120));
163            SkPaint p;
164            p.setAlpha(0x88);
165            p.setAntiAlias(true);
166
167            if (true) {
168                canvas->saveLayer(&r, &p);
169                p.setColor(0xFFFF0000);
170                canvas->drawOval(r, p);
171                canvas->restore();
172            }
173
174            p.setColor(0xFF0000FF);
175            r.offset(SkIntToScalar(20), SkIntToScalar(50));
176            canvas->drawOval(r, p);
177        }
178
179        if (false) {
180            SkPaint p;
181            p.setAlpha(0x88);
182            p.setAntiAlias(true);
183
184            canvas->translate(SkIntToScalar(300), 0);
185
186            SkRect r;
187			r.set(SkIntToScalar(0), SkIntToScalar(0),
188				  SkIntToScalar(220), SkIntToScalar(60));
189
190            canvas->saveLayer(&r, &p, (SkCanvas::SaveFlags)(SkCanvas::kHasAlphaLayer_SaveFlag | SkCanvas::kFullColorLayer_SaveFlag));
191//            canvas->clipRect(r, SkRegion::kDifference_Op);
192//            canvas->clipRect(r, SkRegion::kIntersect_Op);
193
194			r.set(SkIntToScalar(0), SkIntToScalar(0),
195				  SkIntToScalar(220), SkIntToScalar(120));
196            p.setColor(SK_ColorBLUE);
197            canvas->drawOval(r, p);
198            canvas->restore();
199            return;
200        }
201
202        //canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
203        test_fade(canvas);
204        return;
205
206    //    canvas->setDrawFilter(new RedFilter)->unref();
207
208        SkRect  r;
209        SkPaint p;
210
211        canvas->translate(SkIntToScalar(220), SkIntToScalar(20));
212
213        p.setAntiAlias(true);
214        r.set(SkIntToScalar(20), SkIntToScalar(20),
215              SkIntToScalar(220), SkIntToScalar(120));
216
217        p.setColor(SK_ColorBLUE);
218     //   p.setMaskFilter(SkBlurMaskFilter::Create(SkIntToScalar(8), SkBlurMaskFilter::kNormal_BlurStyle))->unref();
219        canvas->drawRect(r, p);
220        p.setMaskFilter(NULL);
221
222        SkRect bounds = r;
223        bounds.fBottom = bounds.centerY();
224        canvas->saveLayer(&bounds, NULL, SkCanvas::kARGB_NoClipLayer_SaveFlag);
225
226        p.setColor(SK_ColorRED);
227        canvas->drawOval(r, p);
228
229        p.setAlpha(0x80);
230        p.setPorterDuffXfermode(SkPorterDuff::kDstIn_Mode);
231        canvas->drawRect(bounds, p);
232
233        canvas->restore();
234    }
235
236    virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y) {
237        this->inval(NULL);
238
239        return this->INHERITED::onFindClickHandler(x, y);
240    }
241
242    virtual bool onClick(Click* click) {
243        return this->INHERITED::onClick(click);
244    }
245
246	virtual bool handleKey(SkKey key) {
247        this->inval(NULL);
248        return true;
249    }
250
251private:
252    typedef SkView INHERITED;
253};
254
255//////////////////////////////////////////////////////////////////////////////
256
257static SkView* MyFactory() { return new LayersView; }
258static SkViewRegister reg(MyFactory);
259
260