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 "SkPaint.h"
11 #include "SkPath.h"
12 #include "SkView.h"
13
14 // ensure that we don't accidentally screw up the bounds when the oval is
15 // fractional, and the impl computes the center and radii, and uses them to
16 // reconstruct the edges of the circle.
17 // see bug# 1504910
test_circlebounds(SkCanvas *)18 static void test_circlebounds(SkCanvas*) {
19 SkRect r = { 1.39999998f, 1, 21.3999996f, 21 };
20 SkPath p;
21 p.addOval(r);
22 SkASSERT(r == p.getBounds());
23 }
24
25 class CircleView : public SampleView {
26 public:
27 static const SkScalar ANIM_DX;
28 static const SkScalar ANIM_DY;
29 static const SkScalar ANIM_RAD;
30 SkScalar fDX, fDY, fRAD;
31
CircleView()32 CircleView() {
33 fDX = fDY = fRAD = 0;
34 fN = 3;
35 }
36
37 protected:
38 // overrides from SkEventSink
onQuery(SkEvent * evt)39 virtual bool onQuery(SkEvent* evt) {
40 if (SampleCode::TitleQ(*evt)) {
41 SampleCode::TitleR(evt, "Circles");
42 return true;
43 }
44 return this->INHERITED::onQuery(evt);
45 }
46
circle(SkCanvas * canvas,int width,bool aa)47 void circle(SkCanvas* canvas, int width, bool aa) {
48 SkPaint paint;
49
50 paint.setAntiAlias(aa);
51 if (width < 0) {
52 paint.setStyle(SkPaint::kFill_Style);
53 } else {
54 paint.setStyle(SkPaint::kStroke_Style);
55 paint.setStrokeWidth(SkIntToScalar(width));
56 }
57 canvas->drawCircle(0, 0, SkIntToScalar(9) + fRAD, paint);
58 if (false) { // avoid bit rot, suppress warning
59 test_circlebounds(canvas);
60 }
61 }
62
drawSix(SkCanvas * canvas,SkScalar dx,SkScalar dy)63 void drawSix(SkCanvas* canvas, SkScalar dx, SkScalar dy) {
64 for (int width = -1; width <= 1; width++) {
65 canvas->save();
66 circle(canvas, width, false);
67 canvas->translate(0, dy);
68 circle(canvas, width, true);
69 canvas->restore();
70 canvas->translate(dx, 0);
71 }
72 }
73
make_poly(SkPath * path,int n)74 static void make_poly(SkPath* path, int n) {
75 if (n <= 0) {
76 return;
77 }
78 path->incReserve(n + 1);
79 path->moveTo(SK_Scalar1, 0);
80 SkScalar step = SK_ScalarPI * 2 / n;
81 SkScalar angle = 0;
82 for (int i = 1; i < n; i++) {
83 angle += step;
84 SkScalar c, s = SkScalarSinCos(angle, &c);
85 path->lineTo(c, s);
86 }
87 path->close();
88 }
89
onDrawContent(SkCanvas * canvas)90 virtual void onDrawContent(SkCanvas* canvas) {
91 SkPaint paint;
92 paint.setAntiAlias(true);
93 paint.setStyle(SkPaint::kStroke_Style);
94 SkMatrix matrix;
95 matrix.setScale(SkIntToScalar(100), SkIntToScalar(100));
96 matrix.postTranslate(SkIntToScalar(200), SkIntToScalar(200));
97 canvas->concat(matrix);
98 for (int n = 3; n < 20; n++) {
99 SkPath path;
100 make_poly(&path, n);
101 SkAutoCanvasRestore acr(canvas, true);
102 canvas->rotate(SkIntToScalar(10) * (n - 3));
103 canvas->translate(-SK_Scalar1, 0);
104 canvas->drawPath(path, paint);
105 }
106 }
107
108 private:
109 int fN;
110 typedef SampleView INHERITED;
111 };
112
113 const SkScalar CircleView::ANIM_DX(SK_Scalar1 / 67);
114 const SkScalar CircleView::ANIM_DY(SK_Scalar1 / 29);
115 const SkScalar CircleView::ANIM_RAD(SK_Scalar1 / 19);
116
117 //////////////////////////////////////////////////////////////////////////////
118
MyFactory()119 static SkView* MyFactory() { return new CircleView; }
120 static SkViewRegister reg(MyFactory);
121