aboutsummaryrefslogtreecommitdiffhomepage
path: root/samplecode/SampleLayers.cpp
blob: 430c832f77549948683ebbc09b68288c6afa5a76 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "SampleCode.h"
#include "SkView.h"
#include "SkCanvas.h"
#include "SkBlurMaskFilter.h"
#include "SkCamera.h"
#include "SkColorFilter.h"
#include "SkColorPriv.h"
#include "SkDevice.h"
#include "SkGradientShader.h"
#include "SkImageDecoder.h"
#include "SkInterpolator.h"
#include "SkMaskFilter.h"
#include "SkPath.h"
#include "SkRegion.h"
#include "SkShader.h"
#include "SkTime.h"
#include "SkTypeface.h"
#include "SkUtils.h"
#include "SkKey.h"
#include "SkXfermode.h"
#include "SkDrawFilter.h"

static void make_paint(SkPaint* paint) {
    SkColor colors[] = { 0, SK_ColorWHITE };
    SkPoint pts[] = { { 0, 0 }, { 0, SK_Scalar1*20 } };
    SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);

    paint->setShader(s)->unref();
    paint->setXfermodeMode(SkXfermode::kDstIn_Mode);
}

static void dump_layers(const char label[], SkCanvas* canvas) {
    SkDebugf("Dump Layers(%s)\n", label);

    SkCanvas::LayerIter iter(canvas, true);
    int index = 0;
    while (!iter.done()) {
        SkImageInfo info = iter.device()->imageInfo();
        const SkIRect& clip = iter.clip().getBounds();
        SkDebugf("Layer[%d] bitmap [%d %d] X=%d Y=%d clip=[%d %d %d %d] alpha=%d\n", index++,
                 info.width(), info.height(), iter.x(), iter.y(),
                 clip.fLeft, clip.fTop, clip.fRight, clip.fBottom,
                 iter.paint().getAlpha());
        iter.next();
    }
}

// test drawing with strips of fading gradient above and below
static void test_fade(SkCanvas* canvas) {
    SkAutoCanvasRestore ar(canvas, true);

    SkRect r;

    SkPaint p;
    p.setAlpha(0x88);

    SkAutoCanvasRestore ar2(canvas, false);

    // create the layers

    r.set(0, 0, SkIntToScalar(100), SkIntToScalar(100));
    canvas->clipRect(r);

    r.fBottom = SkIntToScalar(20);
    canvas->saveLayer(&r, NULL, (SkCanvas::SaveFlags)(SkCanvas::kHasAlphaLayer_SaveFlag | SkCanvas::kFullColorLayer_SaveFlag));

    r.fTop = SkIntToScalar(80);
    r.fBottom = SkIntToScalar(100);
    canvas->saveLayer(&r, NULL, (SkCanvas::SaveFlags)(SkCanvas::kHasAlphaLayer_SaveFlag | SkCanvas::kFullColorLayer_SaveFlag));

    // now draw the "content"

    if (true) {
        r.set(0, 0, SkIntToScalar(100), SkIntToScalar(100));

        canvas->saveLayerAlpha(&r, 0x80);

        SkPaint p;
        p.setColor(SK_ColorRED);
        p.setAntiAlias(true);
        canvas->drawOval(r, p);

        dump_layers("inside layer alpha", canvas);

        canvas->restore();
    } else {
        r.set(0, 0, SkIntToScalar(100), SkIntToScalar(100));

        SkPaint p;
        p.setColor(SK_ColorRED);
        p.setAntiAlias(true);
        canvas->drawOval(r, p);
    }

//    return;

    dump_layers("outside layer alpha", canvas);

    // now apply an effect

    SkPaint paint;
    make_paint(&paint);
    r.set(0, 0, SkIntToScalar(100), SkIntToScalar(20));
//    SkDebugf("--------- draw top grad\n");
    canvas->drawRect(r, paint);

    SkMatrix m;
    SkShader* s = paint.getShader();
    m.setScale(SK_Scalar1, -SK_Scalar1);
    m.postTranslate(0, SkIntToScalar(100));
    s->setLocalMatrix(m);

    r.fTop = SkIntToScalar(80);
    r.fBottom = SkIntToScalar(100);
//    SkDebugf("--------- draw bot grad\n");
    canvas->drawRect(r, paint);
}

class RedFilter : public SkDrawFilter {
public:
    virtual bool filter(SkPaint* p, SkDrawFilter::Type) SK_OVERRIDE {
        fColor = p->getColor();
        if (fColor == SK_ColorRED) {
            p->setColor(SK_ColorGREEN);
        }
        return true;
    }

private:
    SkColor fColor;
};

class LayersView : public SkView {
public:
    LayersView() {}

protected:
    // overrides from SkEventSink
    virtual bool onQuery(SkEvent* evt) {
        if (SampleCode::TitleQ(*evt)) {
            SampleCode::TitleR(evt, "Layers");
            return true;
        }
        return this->INHERITED::onQuery(evt);
    }

    void drawBG(SkCanvas* canvas) {
        canvas->drawColor(SK_ColorGRAY);
    }

    virtual void onDraw(SkCanvas* canvas) {
        this->drawBG(canvas);

        if (true) {
            SkRect r;
            r.set(SkIntToScalar(0), SkIntToScalar(0),
                  SkIntToScalar(220), SkIntToScalar(120));
            SkPaint p;
            canvas->saveLayer(&r, &p);
            canvas->drawColor(0xFFFF0000);
            p.setAlpha(0);  // or 0
            p.setXfermodeMode(SkXfermode::kSrc_Mode);
            canvas->drawOval(r, p);
            canvas->restore();
            return;
        }

        if (false) {
            SkRect r;
            r.set(SkIntToScalar(0), SkIntToScalar(0),
                  SkIntToScalar(220), SkIntToScalar(120));
            SkPaint p;
            p.setAlpha(0x88);
            p.setAntiAlias(true);

            if (true) {
                canvas->saveLayer(&r, &p);
                p.setColor(0xFFFF0000);
                canvas->drawOval(r, p);
                canvas->restore();
            }

            p.setColor(0xFF0000FF);
            r.offset(SkIntToScalar(20), SkIntToScalar(50));
            canvas->drawOval(r, p);
        }

        if (false) {
            SkPaint p;
            p.setAlpha(0x88);
            p.setAntiAlias(true);

            canvas->translate(SkIntToScalar(300), 0);

            SkRect r;
            r.set(SkIntToScalar(0), SkIntToScalar(0),
                  SkIntToScalar(220), SkIntToScalar(60));

            canvas->saveLayer(&r, &p, (SkCanvas::SaveFlags)(SkCanvas::kHasAlphaLayer_SaveFlag | SkCanvas::kFullColorLayer_SaveFlag));

            r.set(SkIntToScalar(0), SkIntToScalar(0),
                  SkIntToScalar(220), SkIntToScalar(120));
            p.setColor(SK_ColorBLUE);
            canvas->drawOval(r, p);
            canvas->restore();
            return;
        }

        test_fade(canvas);
    }

    virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y,
                                              unsigned modi) SK_OVERRIDE {
        this->inval(NULL);

        return this->INHERITED::onFindClickHandler(x, y, modi);
    }

    virtual bool onClick(Click* click) {
        return this->INHERITED::onClick(click);
    }

    virtual bool handleKey(SkKey) {
        this->inval(NULL);
        return true;
    }

private:
    typedef SkView INHERITED;
};

//////////////////////////////////////////////////////////////////////////////

static SkView* MyFactory() { return new LayersView; }
static SkViewRegister reg(MyFactory);