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
setgrad(const SkRect & r,SkColor c0,SkColor c1)13 static SkShader* setgrad(const SkRect& r, SkColor c0, SkColor c1) {
14 SkColor colors[] = { c0, c1 };
15 SkPoint pts[] = { { r.fLeft, r.fTop }, { r.fRight, r.fTop } };
16 return SkGradientShader::CreateLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
17 }
18
test_alphagradients(SkCanvas * canvas)19 static void test_alphagradients(SkCanvas* canvas) {
20 SkRect r;
21 r.set(SkIntToScalar(10), SkIntToScalar(10),
22 SkIntToScalar(410), SkIntToScalar(30));
23 SkPaint p, p2;
24 p2.setStyle(SkPaint::kStroke_Style);
25
26 p.setShader(setgrad(r, 0xFF00FF00, 0x0000FF00))->unref();
27 canvas->drawRect(r, p);
28 canvas->drawRect(r, p2);
29
30 r.offset(0, r.height() + SkIntToScalar(4));
31 p.setShader(setgrad(r, 0xFF00FF00, 0x00000000))->unref();
32 canvas->drawRect(r, p);
33 canvas->drawRect(r, p2);
34
35 r.offset(0, r.height() + SkIntToScalar(4));
36 p.setShader(setgrad(r, 0xFF00FF00, 0x00FF0000))->unref();
37 canvas->drawRect(r, p);
38 canvas->drawRect(r, p2);
39 }
40
41 ///////////////////////////////////////////////////////////////////////////////
42
43 struct GradData {
44 int fCount;
45 const SkColor* fColors;
46 const SkScalar* fPos;
47 };
48
49 static const SkColor gColors[] = {
50 SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK
51 };
52 static const SkScalar gPos0[] = { 0, SK_Scalar1 };
53 static const SkScalar gPos1[] = { SK_Scalar1/4, SK_Scalar1*3/4 };
54 static const SkScalar gPos2[] = {
55 0, SK_Scalar1/8, SK_Scalar1/2, SK_Scalar1*7/8, SK_Scalar1
56 };
57
58 static const GradData gGradData[] = {
59 { 2, gColors, nullptr },
60 { 2, gColors, gPos0 },
61 { 2, gColors, gPos1 },
62 { 5, gColors, nullptr },
63 { 5, gColors, gPos2 }
64 };
65
MakeLinear(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm)66 static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
67 return SkGradientShader::CreateLinear(pts, data.fColors, data.fPos, data.fCount, tm);
68 }
69
MakeRadial(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm)70 static SkShader* MakeRadial(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
71 SkPoint center;
72 center.set(SkScalarAve(pts[0].fX, pts[1].fX),
73 SkScalarAve(pts[0].fY, pts[1].fY));
74 return SkGradientShader::CreateRadial(center, center.fX, data.fColors,
75 data.fPos, data.fCount, tm);
76 }
77
MakeSweep(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm)78 static SkShader* MakeSweep(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
79 SkPoint center;
80 center.set(SkScalarAve(pts[0].fX, pts[1].fX),
81 SkScalarAve(pts[0].fY, pts[1].fY));
82 return SkGradientShader::CreateSweep(center.fX, center.fY, data.fColors, data.fPos, data.fCount);
83 }
84
Make2Conical(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm)85 static SkShader* Make2Conical(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
86 SkPoint center0, center1;
87 center0.set(SkScalarAve(pts[0].fX, pts[1].fX),
88 SkScalarAve(pts[0].fY, pts[1].fY));
89 center1.set(SkScalarInterp(pts[0].fX, pts[1].fX, SkIntToScalar(3)/5),
90 SkScalarInterp(pts[0].fY, pts[1].fY, SkIntToScalar(1)/4));
91 return SkGradientShader::CreateTwoPointConical(
92 center1, (pts[1].fX - pts[0].fX) / 7,
93 center0, (pts[1].fX - pts[0].fX) / 2,
94 data.fColors, data.fPos, data.fCount, tm);
95 }
96
Make2ConicalConcentric(const SkPoint pts[2],const GradData & data,SkShader::TileMode tm)97 static SkShader* Make2ConicalConcentric(const SkPoint pts[2], const GradData& data,
98 SkShader::TileMode tm) {
99 SkPoint center;
100 center.set(SkScalarAve(pts[0].fX, pts[1].fX),
101 SkScalarAve(pts[0].fY, pts[1].fY));
102 return SkGradientShader::CreateTwoPointConical(
103 center, (pts[1].fX - pts[0].fX) / 7,
104 center, (pts[1].fX - pts[0].fX) / 2,
105 data.fColors, data.fPos, data.fCount, tm);
106 }
107
108 typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm);
109
110 static const GradMaker gGradMakers[] = {
111 MakeLinear, MakeRadial, MakeSweep, Make2Conical, Make2ConicalConcentric
112 };
113
114 ///////////////////////////////////////////////////////////////////////////////
115
116 class GradientsView : public SampleView {
117 public:
GradientsView()118 GradientsView() {
119 this->setBGColor(0xFFDDDDDD);
120 }
121
122 protected:
123 // overrides from SkEventSink
onQuery(SkEvent * evt)124 virtual bool onQuery(SkEvent* evt) {
125 if (SampleCode::TitleQ(*evt)) {
126 SampleCode::TitleR(evt, "Gradients");
127 return true;
128 }
129 return this->INHERITED::onQuery(evt);
130 }
131
onDrawContent(SkCanvas * canvas)132 virtual void onDrawContent(SkCanvas* canvas) {
133 SkPoint pts[2] = {
134 { 0, 0 },
135 { SkIntToScalar(100), SkIntToScalar(100) }
136 };
137 SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) };
138 SkPaint paint;
139 paint.setDither(true);
140
141 canvas->save();
142 canvas->translate(SkIntToScalar(20), SkIntToScalar(10));
143
144 for (int tm = 0; tm < SkShader::kTileModeCount; ++tm) {
145 canvas->save();
146 for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) {
147 canvas->save();
148 for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) {
149 SkShader* shader;
150 shader = gGradMakers[j](pts, gGradData[i], (SkShader::TileMode)tm);
151 paint.setShader(shader)->unref();
152 canvas->drawRect(r, paint);
153 canvas->translate(0, SkIntToScalar(120));
154 }
155 canvas->restore();
156 canvas->translate(SkIntToScalar(120), 0);
157 }
158 canvas->restore();
159 canvas->translate(SK_ARRAY_COUNT(gGradData)*SkIntToScalar(120), 0);
160 }
161 canvas->restore();
162
163 canvas->translate(0, SkIntToScalar(370));
164 if (false) { // avoid bit rot, suppress warning
165 test_alphagradients(canvas);
166 }
167 this->inval(nullptr);
168 }
169
170 private:
171 typedef SampleView INHERITED;
172 };
173
174 ///////////////////////////////////////////////////////////////////////////////
175
MyFactory()176 static SkView* MyFactory() { return new GradientsView; }
177 static SkViewRegister reg(MyFactory);
178