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