SampleShaders.cpp revision da342a891779e0839a645d6634a2f0100bf2c0d6 
1#include "SampleCode.h"
2#include "SkView.h"
3#include "SkCanvas.h"
4#include "SkGradientShader.h"
5#include "SkGraphics.h"
6#include "SkImageDecoder.h"
7#include "SkPath.h"
8#include "SkPorterDuff.h"
9#include "SkRegion.h"
10#include "SkShader.h"
11#include "SkUtils.h"
12#include "SkXfermode.h"
13#include "SkComposeShader.h"
14#include "SkColorPriv.h"
15#include "SkColorFilter.h"
16#include "SkTime.h"
17#include "SkTransparentShader.h"
18#include "SkTypeface.h"
19
20static SkShader* make_bitmapfade(const SkBitmap& bm)
21{
22    SkPoint pts[2];
23    SkColor colors[2];
24
25    pts[0].set(0, 0);
26    pts[1].set(0, SkIntToScalar(bm.height()));
27    colors[0] = SK_ColorBLACK;
28    colors[1] = SkColorSetARGB(0, 0, 0, 0);
29    SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
30
31    SkShader* shaderB = SkShader::CreateBitmapShader(bm,
32                        SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
33
34    SkXfermode* mode = SkPorterDuff::CreateXfermode(SkPorterDuff::kDstIn_Mode);
35
36    SkShader* shader = new SkComposeShader(shaderB, shaderA, mode);
37    shaderA->unref();
38    shaderB->unref();
39    mode->unref();
40
41    return shader;
42}
43
44class ShaderView : public SkView {
45public:
46    SkShader*   fShader;
47    SkBitmap    fBitmap;
48
49	ShaderView()
50    {
51        SkImageDecoder::DecodeFile("/cover.png", &fBitmap);
52
53        SkPoint pts[2];
54        SkColor colors[2];
55
56        pts[0].set(0, 0);
57        pts[1].set(SkIntToScalar(100), 0);
58        colors[0] = SK_ColorRED;
59        colors[1] = SK_ColorBLUE;
60        SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
61
62        pts[0].set(0, 0);
63        pts[1].set(0, SkIntToScalar(100));
64        colors[0] = SK_ColorBLACK;
65        colors[1] = SkColorSetARGB(0x80, 0, 0, 0);
66        SkShader* shaderB = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
67
68        SkXfermode* mode = SkPorterDuff::CreateXfermode(SkPorterDuff::kDstIn_Mode);
69
70        fShader = new SkComposeShader(shaderA, shaderB, mode);
71        shaderA->unref();
72        shaderB->unref();
73        mode->unref();
74    }
75    virtual ~ShaderView()
76    {
77        fShader->safeUnref();
78    }
79
80protected:
81    // overrides from SkEventSink
82    virtual bool onQuery(SkEvent* evt)
83    {
84            if (SampleCode::TitleQ(*evt))
85            {
86                SampleCode::TitleR(evt, "Shaders");
87                return true;
88            }
89            return this->INHERITED::onQuery(evt);
90    }
91
92    void drawBG(SkCanvas* canvas)
93    {
94//        canvas->drawColor(0xFFDDDDDD);
95        canvas->drawColor(SK_ColorWHITE);
96    }
97
98    virtual void onDraw(SkCanvas* canvas)
99    {
100        this->drawBG(canvas);
101
102        canvas->drawBitmap(fBitmap, 0, 0);
103
104        {
105            SkIRect src;
106            SkRect  dst;
107
108            src.set(20, 50, 120, 70);
109            dst.set(src);
110            dst.offset(SkIntToScalar(300), 0);
111
112            canvas->drawBitmapRect(fBitmap, &src, dst);
113        }
114
115        canvas->translate(SkIntToScalar(80), SkIntToScalar(80));
116
117        SkPaint paint;
118        SkRect  r;
119
120        paint.setColor(SK_ColorGREEN);
121        canvas->drawRectCoords(0, 0, SkIntToScalar(100), SkIntToScalar(100), paint);
122        paint.setShader(fShader);
123        canvas->drawRectCoords(0, 0, SkIntToScalar(100), SkIntToScalar(100), paint);
124
125        canvas->translate(SkIntToScalar(110), 0);
126
127        r.set(0, 0, SkIntToScalar(fBitmap.width()), SkIntToScalar(fBitmap.height()));
128
129        paint.setShader(NULL);
130        canvas->drawRect(r, paint);
131        paint.setShader(make_bitmapfade(fBitmap))->unref();
132        canvas->drawRect(r, paint);
133
134        paint.setShader(new SkTransparentShader)->unref();
135        canvas->drawRect(r, paint);
136    }
137
138    virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y)
139    {
140        this->inval(NULL);
141        return this->INHERITED::onFindClickHandler(x, y);
142    }
143
144    virtual bool onClick(Click* click)
145    {
146        return this->INHERITED::onClick(click);
147    }
148
149private:
150    typedef SkView INHERITED;
151};
152
153//////////////////////////////////////////////////////////////////////////////
154
155static SkView* MyFactory() { return new ShaderView; }
156static SkViewRegister reg(MyFactory);
157
158