1 #include "SampleCode.h"
2 #include "SkCanvas.h"
3 #include "SkGradientShader.h"
4
5 class GradientView : public SampleView {
6 public:
GradientView()7 GradientView() {
8 this->setBGColor(0xFFDDDDDD);
9 }
10
11 protected:
12 struct GradData {
13 int fCount;
14 const SkColor* fColors;
15 const SkScalar* fPos;
16 };
17 // overrides from SkEventSink
onQuery(SkEvent * evt)18 virtual bool onQuery(SkEvent* evt) {
19 if (SampleCode::TitleQ(*evt)) {
20 SampleCode::TitleR(evt, "Gradients");
21 return true;
22 }
23 return this->INHERITED::onQuery(evt);
24 }
onDrawContent(SkCanvas * canvas)25 virtual void onDrawContent(SkCanvas* canvas) {
26 SkPaint paint;
27 paint.setAntiAlias(true);
28 paint.setStyle(SkPaint::kStroke_Style);
29 paint.setStrokeWidth(SkScalarHalf(SkIntToScalar(3)));
30 paint.setStyle(SkPaint::kFill_Style);
31
32 SkPoint p = SkPoint::Make(0,0);
33 SkPoint q = SkPoint::Make(100,100);
34 SkPoint pts[] = {p, q};
35
36 SkScalar t, temp, x, y;
37 SkColor gColors[] = {
38 SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK
39 };
40 t = SampleCode::GetAnimScalar(SkIntToScalar(2), SkIntToScalar(20));
41 temp = SampleCode::GetAnimScalar(SkIntToScalar(1), SkIntToScalar(8));
42 SkScalar step = SK_ScalarPI / (10);
43 SkScalar angle = t * step;
44 x = SkScalarSinCos(angle, &y);
45 SkScalar colorPositions[] = { 0, 0.1 + x, 0.4 + y, 0.9 - x + y, 1.0};
46 GradData data = { 5, gColors, colorPositions };
47
48
49 SkRect r = { 0, 0, SkIntToScalar(200), SkIntToScalar(200) };
50 SkShader* shader1 = SkGradientShader::CreateLinear(
51 pts, data.fColors, data.fPos,data.fCount,
52 SkShader::kMirror_TileMode);
53 paint.setShader(shader1)->unref();
54
55 canvas->drawRect(r, paint);
56
57
58 SkPoint s = SkPoint::Make(100,100);
59 SkShader* shader2 = SkGradientShader::CreateRadial(
60 s, 100, data.fColors, data.fPos, data.fCount,
61 SkShader::kMirror_TileMode);
62 paint.setShader(shader2)->unref();
63 canvas->translate(250, 0);
64 canvas->drawRect(r, paint);
65
66 SkShader* shader3 = SkGradientShader::CreateTwoPointRadial(
67 p, 0, q, 100, data.fColors, data.fPos, data.fCount,
68 SkShader::kMirror_TileMode);
69 paint.setShader(shader3)->unref();
70 canvas->translate(0, 250);
71 canvas->drawRect(r, paint);
72
73 SkShader* shader4 = SkGradientShader::CreateSweep(
74 100, 100, data.fColors, data.fPos, data.fCount);
75
76 paint.setShader(shader4)->unref();
77 canvas->translate(-250, 0);
78 canvas->drawRect(r, paint);
79
80 this->inval(NULL);
81 }
82
83 private:
84 typedef SampleView INHERITED;
85 };
86
87 //////////////////////////////////////////////////////////////////////////////
88
MyFactory()89 static SkView* MyFactory() { return new GradientView; }
90 static SkViewRegister reg(MyFactory);