1
2/*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8#include "SampleCode.h"
9#include "SkView.h"
10#include "SkCanvas.h"
11#include "SkGradientShader.h"
12#include "SkGraphics.h"
13#include "SkImageDecoder.h"
14#include "SkPath.h"
15#include "SkRegion.h"
16#include "SkShader.h"
17#include "SkUtils.h"
18#include "SkXfermode.h"
19#include "SkComposeShader.h"
20#include "SkColorPriv.h"
21#include "SkColorFilter.h"
22#include "SkTime.h"
23#include "SkTransparentShader.h"
24#include "SkTypeface.h"
25
26static SkShader* make_bitmapfade(const SkBitmap& bm)
27{
28    SkPoint pts[2];
29    SkColor colors[2];
30
31    pts[0].set(0, 0);
32    pts[1].set(0, SkIntToScalar(bm.height()));
33    colors[0] = SK_ColorBLACK;
34    colors[1] = SkColorSetARGB(0, 0, 0, 0);
35    SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
36
37    SkShader* shaderB = SkShader::CreateBitmapShader(bm,
38                        SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
39
40    SkXfermode* mode = SkXfermode::Create(SkXfermode::kDstIn_Mode);
41
42    SkShader* shader = new SkComposeShader(shaderB, shaderA, mode);
43    shaderA->unref();
44    shaderB->unref();
45    mode->unref();
46
47    return shader;
48}
49
50class ShaderView : public SampleView {
51public:
52    SkShader*   fShader;
53    SkBitmap    fBitmap;
54
55    ShaderView() {
56        SkImageDecoder::DecodeFile("/skimages/logo.gif", &fBitmap);
57
58        SkPoint pts[2];
59        SkColor colors[2];
60
61        pts[0].set(0, 0);
62        pts[1].set(SkIntToScalar(100), 0);
63        colors[0] = SK_ColorRED;
64        colors[1] = SK_ColorBLUE;
65        SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
66
67        pts[0].set(0, 0);
68        pts[1].set(0, SkIntToScalar(100));
69        colors[0] = SK_ColorBLACK;
70        colors[1] = SkColorSetARGB(0x80, 0, 0, 0);
71        SkShader* shaderB = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
72
73        SkXfermode* mode = SkXfermode::Create(SkXfermode::kDstIn_Mode);
74
75        fShader = new SkComposeShader(shaderA, shaderB, mode);
76        shaderA->unref();
77        shaderB->unref();
78        mode->unref();
79    }
80    virtual ~ShaderView() {
81        SkSafeUnref(fShader);
82    }
83
84protected:
85    // overrides from SkEventSink
86    virtual bool onQuery(SkEvent* evt) {
87        if (SampleCode::TitleQ(*evt)) {
88            SampleCode::TitleR(evt, "Shaders");
89            return true;
90        }
91        return this->INHERITED::onQuery(evt);
92    }
93
94    virtual void onDrawContent(SkCanvas* canvas) {
95        canvas->drawBitmap(fBitmap, 0, 0);
96
97        canvas->translate(SkIntToScalar(20), SkIntToScalar(120));
98
99        SkPaint paint;
100        SkRect  r;
101
102        paint.setColor(SK_ColorGREEN);
103        canvas->drawRectCoords(0, 0, SkIntToScalar(100), SkIntToScalar(100), paint);
104        paint.setShader(fShader);
105        canvas->drawRectCoords(0, 0, SkIntToScalar(100), SkIntToScalar(100), paint);
106
107        canvas->translate(SkIntToScalar(110), 0);
108
109        int w = fBitmap.width();
110        int h = fBitmap.height();
111        w = 120;
112        h = 80;
113        r.set(0, 0, SkIntToScalar(w), SkIntToScalar(h));
114
115        paint.setShader(NULL);
116        canvas->drawRect(r, paint);
117        paint.setShader(make_bitmapfade(fBitmap))->unref();
118        canvas->drawRect(r, paint);
119
120        paint.setShader(new SkTransparentShader)->unref();
121        canvas->drawRect(r, paint);
122    }
123
124    virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y,
125                                              unsigned modi) SK_OVERRIDE {
126        this->inval(NULL);
127        return this->INHERITED::onFindClickHandler(x, y, modi);
128    }
129
130    virtual bool onClick(Click* click) {
131        return this->INHERITED::onClick(click);
132    }
133
134private:
135    typedef SampleView INHERITED;
136};
137
138//////////////////////////////////////////////////////////////////////////////
139
140static SkView* MyFactory() { return new ShaderView; }
141static SkViewRegister reg(MyFactory);
142