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 "SkCanvas.h"
10 #include "SkGradientShader.h"
11 #include "SkPath.h"
12 #include "SkView.h"
13
makebm(SkBitmap * bm,int w,int h)14 static 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(w < h ? 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
MakeBitmapShader(SkShader::TileMode tx,SkShader::TileMode ty,int w,int h)31 static 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
42 struct GradData {
43 int fCount;
44 const SkColor* fColors;
45 const SkScalar* fPos;
46 };
47
48 static const SkColor gColors[] = {
49 SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK
50 };
51
52 static const GradData gGradData[] = {
53 { 2, gColors, nullptr },
54 { 5, gColors, nullptr },
55 };
56
MakeLinear(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm)57 static 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
MakeRadial(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm)61 static 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
MakeSweep(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm)69 static SkShader* MakeSweep(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
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
Make2Conical(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm)76 static SkShader* Make2Conical(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::CreateTwoPointConical(
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
88 typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm);
89
90 static const GradMaker gGradMakers[] = {
91 MakeLinear, MakeRadial, MakeSweep, Make2Conical
92 };
93
94 ///////////////////////////////////////////////////////////////////////////////
95
96 class ShaderTextView : public SampleView {
97 public:
ShaderTextView()98 ShaderTextView() {
99 this->setBGColor(0xFFDDDDDD);
100 }
101
102 protected:
103 // overrides from SkEventSink
onQuery(SkEvent * evt)104 virtual bool onQuery(SkEvent* evt) {
105 if (SampleCode::TitleQ(*evt)) {
106 SampleCode::TitleR(evt, "Shader Text");
107 return true;
108 }
109 return this->INHERITED::onQuery(evt);
110 }
111
onDrawContent(SkCanvas * canvas)112 virtual void onDrawContent(SkCanvas* canvas) {
113 const char text[] = "Shaded Text";
114 const int textLen = SK_ARRAY_COUNT(text) - 1;
115 static int pointSize = 36;
116
117 int w = pointSize * textLen;
118 int h = pointSize;
119
120 SkPoint pts[2] = {
121 { 0, 0 },
122 { SkIntToScalar(w), SkIntToScalar(h) }
123 };
124 SkScalar textBase = SkIntToScalar(h/2);
125
126 SkShader::TileMode tileModes[] = {
127 SkShader::kClamp_TileMode,
128 SkShader::kRepeat_TileMode,
129 SkShader::kMirror_TileMode
130 };
131
132 static const int gradCount = SK_ARRAY_COUNT(gGradData) *
133 SK_ARRAY_COUNT(gGradMakers);
134 static const int bmpCount = SK_ARRAY_COUNT(tileModes) *
135 SK_ARRAY_COUNT(tileModes);
136 SkShader* shaders[gradCount + bmpCount];
137
138 int shdIdx = 0;
139 for (size_t d = 0; d < SK_ARRAY_COUNT(gGradData); ++d) {
140 for (size_t m = 0; m < SK_ARRAY_COUNT(gGradMakers); ++m) {
141 shaders[shdIdx++] = gGradMakers[m](pts,
142 gGradData[d],
143 SkShader::kClamp_TileMode);
144 }
145 }
146 for (size_t tx = 0; tx < SK_ARRAY_COUNT(tileModes); ++tx) {
147 for (size_t ty = 0; ty < SK_ARRAY_COUNT(tileModes); ++ty) {
148 shaders[shdIdx++] = MakeBitmapShader(tileModes[tx],
149 tileModes[ty],
150 w/8, h);
151 }
152 }
153
154 SkPaint paint;
155 paint.setDither(true);
156 paint.setAntiAlias(true);
157 paint.setTextSize(SkIntToScalar(pointSize));
158
159 canvas->save();
160 canvas->translate(SkIntToScalar(20), SkIntToScalar(10));
161
162 SkPath path;
163 path.arcTo(SkRect::MakeXYWH(SkIntToScalar(-40), SkIntToScalar(15),
164 SkIntToScalar(300), SkIntToScalar(90)),
165 SkIntToScalar(225), SkIntToScalar(90),
166 false);
167 path.close();
168
169 static const int testsPerCol = 8;
170 static const int rowHeight = 60;
171 static const int colWidth = 300;
172 canvas->save();
173 for (size_t s = 0; s < SK_ARRAY_COUNT(shaders); s++) {
174 canvas->save();
175 size_t i = 2*s;
176 canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
177 SkIntToScalar((i % testsPerCol) * rowHeight));
178 paint.setShader(shaders[s])->unref();
179 canvas->drawText(text, textLen, 0, textBase, paint);
180 canvas->restore();
181 canvas->save();
182 ++i;
183 canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
184 SkIntToScalar((i % testsPerCol) * rowHeight));
185 canvas->drawTextOnPath(text, textLen, path, nullptr, paint);
186 canvas->restore();
187 }
188 canvas->restore();
189 }
190
191 private:
192 typedef SampleView INHERITED;
193 };
194
195 ///////////////////////////////////////////////////////////////////////////////
196
MyFactory()197 static SkView* MyFactory() { return new ShaderTextView; }
198 static SkViewRegister reg(MyFactory);
199