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 "SkUnitMappers.h"
13
14static void makebm(SkBitmap* bm, SkBitmap::Config config, int w, int h) {
15    bm->setConfig(config, w, h);
16    bm->allocPixels();
17    bm->eraseColor(0);
18
19    SkCanvas    canvas(*bm);
20    SkScalar s = SkIntToScalar(w < h ? w : h);
21    SkPoint     pts[] = { { 0, 0 }, { s, s } };
22    SkColor     colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
23    SkScalar    pos[] = { 0, SK_Scalar1/2, SK_Scalar1 };
24    SkPaint     paint;
25
26    SkUnitMapper*   um = NULL;
27
28    um = new SkCosineMapper;
29
30    SkAutoUnref au(um);
31
32    paint.setDither(true);
33    paint.setShader(SkGradientShader::CreateLinear(pts, colors, pos,
34                SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode, um))->unref();
35    canvas.drawPaint(paint);
36}
37
38SkShader* MakeBitmapShader(SkShader::TileMode tx, SkShader::TileMode ty,
39                           int w, int h) {
40    static SkBitmap bmp;
41    if (bmp.isNull()) {
42        makebm(&bmp, SkBitmap::kARGB_8888_Config, w/2, h/4);
43    }
44    return SkShader::CreateBitmapShader(bmp, tx, ty);
45}
46
47///////////////////////////////////////////////////////////////////////////////
48
49struct GradData {
50    int             fCount;
51    const SkColor*  fColors;
52    const SkScalar* fPos;
53};
54
55static const SkColor gColors[] = {
56    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK
57};
58
59static const GradData gGradData[] = {
60    { 2, gColors, NULL },
61    { 5, gColors, NULL },
62};
63
64static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data,
65                            SkShader::TileMode tm, SkUnitMapper* mapper) {
66    return SkGradientShader::CreateLinear(pts, data.fColors, data.fPos,
67                                          data.fCount, tm, mapper);
68}
69
70static SkShader* MakeRadial(const SkPoint pts[2], const GradData& data,
71                            SkShader::TileMode tm, SkUnitMapper* mapper) {
72    SkPoint center;
73    center.set(SkScalarAve(pts[0].fX, pts[1].fX),
74               SkScalarAve(pts[0].fY, pts[1].fY));
75    return SkGradientShader::CreateRadial(center, center.fX, data.fColors,
76                                          data.fPos, data.fCount, tm, mapper);
77}
78
79static SkShader* MakeSweep(const SkPoint pts[2], const GradData& data,
80                           SkShader::TileMode tm, SkUnitMapper* mapper) {
81    SkPoint center;
82    center.set(SkScalarAve(pts[0].fX, pts[1].fX),
83               SkScalarAve(pts[0].fY, pts[1].fY));
84    return SkGradientShader::CreateSweep(center.fX, center.fY, data.fColors,
85                                         data.fPos, data.fCount, mapper);
86}
87
88static SkShader* Make2Radial(const SkPoint pts[2], const GradData& data,
89                           SkShader::TileMode tm, SkUnitMapper* mapper) {
90    SkPoint center0, center1;
91    center0.set(SkScalarAve(pts[0].fX, pts[1].fX),
92                SkScalarAve(pts[0].fY, pts[1].fY));
93    center1.set(SkScalarInterp(pts[0].fX, pts[1].fX, SkIntToScalar(3)/5),
94                SkScalarInterp(pts[0].fY, pts[1].fY, SkIntToScalar(1)/4));
95    return SkGradientShader::CreateTwoPointRadial(
96                            center1, (pts[1].fX - pts[0].fX) / 7,
97                            center0, (pts[1].fX - pts[0].fX) / 2,
98                            data.fColors, data.fPos, data.fCount, tm, mapper);
99}
100
101typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data,
102                     SkShader::TileMode tm, SkUnitMapper* mapper);
103static const GradMaker gGradMakers[] = {
104    MakeLinear, MakeRadial, MakeSweep, Make2Radial
105};
106
107///////////////////////////////////////////////////////////////////////////////
108
109class ShaderTextView : public SampleView {
110public:
111	ShaderTextView() {
112        this->setBGColor(0xFFDDDDDD);
113    }
114
115protected:
116    // overrides from SkEventSink
117    virtual bool onQuery(SkEvent* evt) {
118        if (SampleCode::TitleQ(*evt)) {
119            SampleCode::TitleR(evt, "Shader Text");
120            return true;
121        }
122        return this->INHERITED::onQuery(evt);
123    }
124
125    virtual void onDrawContent(SkCanvas* canvas) {
126        const char text[] = "Shaded Text";
127        const int textLen = SK_ARRAY_COUNT(text) - 1;
128        static int pointSize = 36;
129
130        int w = pointSize * textLen;
131        int h = pointSize;
132
133        SkPoint pts[2] = {
134            { 0, 0 },
135            { SkIntToScalar(w), SkIntToScalar(h) }
136        };
137        SkScalar textBase = SkIntToScalar(h/2);
138
139        SkShader::TileMode tileModes[] = {
140            SkShader::kClamp_TileMode,
141            SkShader::kRepeat_TileMode,
142            SkShader::kMirror_TileMode
143        };
144
145        static const int gradCount = SK_ARRAY_COUNT(gGradData) *
146                                     SK_ARRAY_COUNT(gGradMakers);
147        static const int bmpCount = SK_ARRAY_COUNT(tileModes) *
148                                    SK_ARRAY_COUNT(tileModes);
149        SkShader* shaders[gradCount + bmpCount];
150
151        int shdIdx = 0;
152        for (size_t d = 0; d < SK_ARRAY_COUNT(gGradData); ++d) {
153            for (size_t m = 0; m < SK_ARRAY_COUNT(gGradMakers); ++m) {
154                shaders[shdIdx++] = gGradMakers[m](pts,
155                                                   gGradData[d],
156                                                   SkShader::kClamp_TileMode,
157                                                   NULL);
158            }
159        }
160        for (size_t tx = 0; tx < SK_ARRAY_COUNT(tileModes); ++tx) {
161            for (size_t ty = 0; ty < SK_ARRAY_COUNT(tileModes); ++ty) {
162                shaders[shdIdx++] = MakeBitmapShader(tileModes[tx],
163                                                     tileModes[ty],
164                                                     w/8, h);
165            }
166        }
167
168        SkPaint paint;
169        paint.setDither(true);
170        paint.setAntiAlias(true);
171        paint.setTextSize(SkIntToScalar(pointSize));
172
173        canvas->save();
174        canvas->translate(SkIntToScalar(20), SkIntToScalar(10));
175
176        SkPath path;
177        path.arcTo(SkRect::MakeXYWH(SkIntToScalar(-40), SkIntToScalar(15),
178                                    SkIntToScalar(300), SkIntToScalar(90)),
179                                    SkIntToScalar(225), SkIntToScalar(90),
180                                    false);
181        path.close();
182
183        static const int testsPerCol = 8;
184        static const int rowHeight = 60;
185        static const int colWidth = 300;
186        canvas->save();
187        for (size_t s = 0; s < SK_ARRAY_COUNT(shaders); s++) {
188            canvas->save();
189            int i = 2*s;
190            canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
191                              SkIntToScalar((i % testsPerCol) * rowHeight));
192            paint.setShader(shaders[s])->unref();
193            canvas->drawText(text, textLen, 0, textBase, paint);
194            canvas->restore();
195            canvas->save();
196            ++i;
197            canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
198                              SkIntToScalar((i % testsPerCol) * rowHeight));
199            canvas->drawTextOnPath(text, textLen, path, NULL, paint);
200            canvas->restore();
201        }
202        canvas->restore();
203
204        canvas->translate(0, SkIntToScalar(370));
205        this->inval(NULL);
206    }
207
208private:
209    typedef SampleView INHERITED;
210};
211
212///////////////////////////////////////////////////////////////////////////////
213
214static SkView* MyFactory() { return new ShaderTextView; }
215static SkViewRegister reg(MyFactory);
216
217