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 "SkDevice.h"
12#include "SkPaint.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
18static 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
25class CircleView : public SampleView {
26public:
27    static const SkScalar ANIM_DX;
28    static const SkScalar ANIM_DY;
29    static const SkScalar ANIM_RAD;
30    SkScalar fDX, fDY, fRAD;
31
32    CircleView() {
33        fDX = fDY = fRAD = 0;
34        fN = 3;
35    }
36
37protected:
38    // overrides from SkEventSink
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
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
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
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
90    static void rotate(SkCanvas* canvas, SkScalar angle, SkScalar px, SkScalar py) {
91        canvas->translate(-px, -py);
92        canvas->rotate(angle);
93        canvas->translate(px, py);
94    }
95
96    virtual void onDrawContent(SkCanvas* canvas) {
97        SkPaint paint;
98        paint.setAntiAlias(true);
99        paint.setStyle(SkPaint::kStroke_Style);
100//        canvas->drawCircle(250, 250, 220, paint);
101        SkMatrix matrix;
102        matrix.setScale(SkIntToScalar(100), SkIntToScalar(100));
103        matrix.postTranslate(SkIntToScalar(200), SkIntToScalar(200));
104        canvas->concat(matrix);
105        for (int n = 3; n < 20; n++) {
106            SkPath path;
107            make_poly(&path, n);
108            SkAutoCanvasRestore acr(canvas, true);
109            canvas->rotate(SkIntToScalar(10) * (n - 3));
110            canvas->translate(-SK_Scalar1, 0);
111            canvas->drawPath(path, paint);
112        }
113    }
114
115private:
116    int fN;
117    typedef SampleView INHERITED;
118};
119
120const SkScalar CircleView::ANIM_DX(SK_Scalar1 / 67);
121const SkScalar CircleView::ANIM_DY(SK_Scalar1 / 29);
122const SkScalar CircleView::ANIM_RAD(SK_Scalar1 / 19);
123
124//////////////////////////////////////////////////////////////////////////////
125
126static SkView* MyFactory() { return new CircleView; }
127static SkViewRegister reg(MyFactory);
128