1/*
2 * Copyright 2011 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "gm.h"
9#include "SkCanvas.h"
10#include "SkGradientShader.h"
11
12namespace skiagm {
13
14static void makebm(SkBitmap* bm, int w, int h) {
15    bm->allocN32Pixels(w, h);
16    bm->eraseColor(SK_ColorTRANSPARENT);
17
18    SkCanvas    canvas(*bm);
19    SkScalar    s = SkIntToScalar(SkMin32(w, h));
20    SkPoint     pts[] = { { 0, 0 }, { s, s } };
21    SkColor     colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
22    SkScalar    pos[] = { 0, SK_Scalar1/2, SK_Scalar1 };
23    SkPaint     paint;
24
25    paint.setDither(true);
26    paint.setShader(SkGradientShader::CreateLinear(pts, colors, pos,
27                SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode))->unref();
28    canvas.drawPaint(paint);
29}
30
31static SkShader* MakeBitmapShader(SkShader::TileMode tx, SkShader::TileMode ty,
32                           int w, int h) {
33    static SkBitmap bmp;
34    if (bmp.isNull()) {
35        makebm(&bmp, w/2, h/4);
36    }
37    return SkShader::CreateBitmapShader(bmp, tx, ty);
38}
39
40///////////////////////////////////////////////////////////////////////////////
41
42struct GradData {
43    int             fCount;
44    const SkColor*  fColors;
45    const SkScalar* fPos;
46};
47
48static const SkColor gColors[] = {
49    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK
50};
51
52static const GradData gGradData[] = {
53    { 2, gColors, NULL },
54    { 5, gColors, NULL },
55};
56
57static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
58    return SkGradientShader::CreateLinear(pts, data.fColors, data.fPos, data.fCount, tm);
59}
60
61static SkShader* MakeRadial(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
62    SkPoint center;
63    center.set(SkScalarAve(pts[0].fX, pts[1].fX),
64               SkScalarAve(pts[0].fY, pts[1].fY));
65    return SkGradientShader::CreateRadial(center, center.fX, data.fColors,
66                                          data.fPos, data.fCount, tm);
67}
68
69static SkShader* MakeSweep(const SkPoint pts[2], const GradData& data, SkShader::TileMode) {
70    SkPoint center;
71    center.set(SkScalarAve(pts[0].fX, pts[1].fX),
72               SkScalarAve(pts[0].fY, pts[1].fY));
73    return SkGradientShader::CreateSweep(center.fX, center.fY, data.fColors, data.fPos, data.fCount);
74}
75
76static SkShader* Make2Radial(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
77    SkPoint center0, center1;
78    center0.set(SkScalarAve(pts[0].fX, pts[1].fX),
79                SkScalarAve(pts[0].fY, pts[1].fY));
80    center1.set(SkScalarInterp(pts[0].fX, pts[1].fX, SkIntToScalar(3)/5),
81                SkScalarInterp(pts[0].fY, pts[1].fY, SkIntToScalar(1)/4));
82    return SkGradientShader::CreateTwoPointRadial(
83                            center1, (pts[1].fX - pts[0].fX) / 7,
84                            center0, (pts[1].fX - pts[0].fX) / 2,
85                            data.fColors, data.fPos, data.fCount, tm);
86}
87
88typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm);
89
90static const GradMaker gGradMakers[] = {
91    MakeLinear, MakeRadial, MakeSweep, Make2Radial
92};
93
94///////////////////////////////////////////////////////////////////////////////
95
96class ShaderTextGM : public GM {
97public:
98    ShaderTextGM() {
99        this->setBGColor(0xFFDDDDDD);
100    }
101
102protected:
103    virtual uint32_t onGetFlags() const SK_OVERRIDE {
104        return kSkipTiled_Flag;
105    }
106
107    SkString onShortName() {
108        return SkString("shadertext");
109    }
110
111    SkISize onISize() { return SkISize::Make(1450, 500); }
112
113    virtual void onDraw(SkCanvas* canvas) {
114        const char text[] = "Shaded Text";
115        const int textLen = SK_ARRAY_COUNT(text) - 1;
116        const int pointSize = 36;
117
118        int w = pointSize * textLen;
119        int h = pointSize;
120
121        SkPoint pts[2] = {
122            { 0, 0 },
123            { SkIntToScalar(w), SkIntToScalar(h) }
124        };
125        SkScalar textBase = SkIntToScalar(h/2);
126
127        SkShader::TileMode tileModes[] = {
128            SkShader::kClamp_TileMode,
129            SkShader::kRepeat_TileMode,
130            SkShader::kMirror_TileMode
131        };
132
133        static const int gradCount = SK_ARRAY_COUNT(gGradData) *
134                                     SK_ARRAY_COUNT(gGradMakers);
135        static const int bmpCount = SK_ARRAY_COUNT(tileModes) *
136                                    SK_ARRAY_COUNT(tileModes);
137        SkShader* shaders[gradCount + bmpCount];
138
139        int shdIdx = 0;
140        for (size_t d = 0; d < SK_ARRAY_COUNT(gGradData); ++d) {
141            for (size_t m = 0; m < SK_ARRAY_COUNT(gGradMakers); ++m) {
142                shaders[shdIdx++] = gGradMakers[m](pts,
143                                                   gGradData[d],
144                                                   SkShader::kClamp_TileMode);
145            }
146        }
147        for (size_t tx = 0; tx < SK_ARRAY_COUNT(tileModes); ++tx) {
148            for (size_t ty = 0; ty < SK_ARRAY_COUNT(tileModes); ++ty) {
149                shaders[shdIdx++] = MakeBitmapShader(tileModes[tx],
150                                                     tileModes[ty],
151                                                     w/8, h);
152            }
153        }
154
155        SkPaint paint;
156        paint.setDither(true);
157        paint.setAntiAlias(true);
158        paint.setTextSize(SkIntToScalar(pointSize));
159
160        canvas->save();
161        canvas->translate(SkIntToScalar(20), SkIntToScalar(10));
162
163        SkPath path;
164        path.arcTo(SkRect::MakeXYWH(SkIntToScalar(-40), SkIntToScalar(15),
165                                    SkIntToScalar(300), SkIntToScalar(90)),
166                                    SkIntToScalar(225), SkIntToScalar(90),
167                                    false);
168        path.close();
169
170        static const int testsPerCol = 8;
171        static const int rowHeight = 60;
172        static const int colWidth = 300;
173        canvas->save();
174        for (int s = 0; s < static_cast<int>(SK_ARRAY_COUNT(shaders)); s++) {
175            canvas->save();
176            int i = 2*s;
177            canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
178                              SkIntToScalar((i % testsPerCol) * rowHeight));
179            paint.setShader(shaders[s])->unref();
180            canvas->drawText(text, textLen, 0, textBase, paint);
181            canvas->restore();
182            canvas->save();
183            ++i;
184            canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
185                              SkIntToScalar((i % testsPerCol) * rowHeight));
186            canvas->drawTextOnPath(text, textLen, path, NULL, paint);
187            canvas->restore();
188        }
189        canvas->restore();
190
191    }
192
193private:
194    typedef GM INHERITED;
195};
196
197///////////////////////////////////////////////////////////////////////////////
198
199static GM* MyFactory(void*) { return new ShaderTextGM; }
200static GMRegistry reg(MyFactory);
201}
202