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 "SkCanvas.h"
10 #include "SkGradientShader.h"
11
12 class GradientView : public SampleView {
13 public:
GradientView()14 GradientView() {
15 this->setBGColor(0xFFDDDDDD);
16 }
17
18 protected:
19 struct GradData {
20 int fCount;
21 const SkColor* fColors;
22 const SkScalar* fPos;
23 };
24 // overrides from SkEventSink
onQuery(SkEvent * evt)25 virtual bool onQuery(SkEvent* evt) {
26 if (SampleCode::TitleQ(*evt)) {
27 SampleCode::TitleR(evt, "Gradients");
28 return true;
29 }
30 return this->INHERITED::onQuery(evt);
31 }
onDrawContent(SkCanvas * canvas)32 virtual void onDrawContent(SkCanvas* canvas) {
33 SkPaint paint;
34 paint.setAntiAlias(true);
35 paint.setStyle(SkPaint::kStroke_Style);
36 paint.setStrokeWidth(SkScalarHalf(SkIntToScalar(3)));
37 paint.setStyle(SkPaint::kFill_Style);
38
39 SkPoint p = SkPoint::Make(0,0);
40 SkPoint q = SkPoint::Make(100,100);
41 SkPoint pts[] = {p, q};
42
43 SkScalar t, temp, x, y;
44 SkColor gColors[] = {
45 SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK
46 };
47 t = SampleCode::GetAnimScalar(SkIntToScalar(2), SkIntToScalar(20));
48 temp = SampleCode::GetAnimScalar(SkIntToScalar(1), SkIntToScalar(8));
49 SkScalar step = SK_ScalarPI / (10);
50 SkScalar angle = t * step;
51 x = SkScalarSinCos(angle, &y);
52 SkScalar colorPositions[] = { 0, 0.1 + x, 0.4 + y, 0.9 - x + y, 1.0};
53 GradData data = { 5, gColors, colorPositions };
54
55
56 SkRect r = { 0, 0, SkIntToScalar(200), SkIntToScalar(200) };
57 SkShader* shader1 = SkGradientShader::CreateLinear(
58 pts, data.fColors, data.fPos,data.fCount,
59 SkShader::kMirror_TileMode);
60 paint.setShader(shader1)->unref();
61
62 canvas->drawRect(r, paint);
63
64
65 SkPoint s = SkPoint::Make(100,100);
66 SkShader* shader2 = SkGradientShader::CreateRadial(
67 s, 100, data.fColors, data.fPos, data.fCount,
68 SkShader::kMirror_TileMode);
69 paint.setShader(shader2)->unref();
70 canvas->translate(250, 0);
71 canvas->drawRect(r, paint);
72
73 SkShader* shader3 = SkGradientShader::CreateTwoPointRadial(
74 p, 0, q, 100, data.fColors, data.fPos, data.fCount,
75 SkShader::kMirror_TileMode);
76 paint.setShader(shader3)->unref();
77 canvas->translate(0, 250);
78 canvas->drawRect(r, paint);
79
80 SkShader* shader4 = SkGradientShader::CreateSweep(
81 100, 100, data.fColors, data.fPos, data.fCount);
82
83 paint.setShader(shader4)->unref();
84 canvas->translate(-250, 0);
85 canvas->drawRect(r, paint);
86
87 this->inval(NULL);
88 }
89
90 private:
91 typedef SampleView INHERITED;
92 };
93
94 //////////////////////////////////////////////////////////////////////////////
95
MyFactory()96 static SkView* MyFactory() { return new GradientView; }
97 static SkViewRegister reg(MyFactory);