1 /*
2  * Copyright 2013 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 "Sample.h"
9 #include "SkCanvas.h"
10 #include "SkPath.h"
11 
12 // Reproduces https://code.google.com/p/chromium/issues/detail?id=279014
13 
14 // Renders a string art shape.
15 // The particular shape rendered can be controlled by clicking horizontally, thereby
16 // generating an angle from 0 to 1.
17 
18 class StringArtView : public Sample {
19 public:
StringArtView()20     StringArtView() : fAngle(0.305f) {}
21 
22 protected:
onQuery(Sample::Event * evt)23     bool onQuery(Sample::Event* evt) override {
24         if (Sample::TitleQ(*evt)) {
25             Sample::TitleR(evt, "StringArt");
26             return true;
27         }
28         return this->INHERITED::onQuery(evt);
29     }
30 
onDrawContent(SkCanvas * canvas)31     void onDrawContent(SkCanvas* canvas) override {
32         SkScalar angle = fAngle*SK_ScalarPI + SkScalarHalf(SK_ScalarPI);
33 
34         SkPoint center = SkPoint::Make(SkScalarHalf(this->width()), SkScalarHalf(this->height()));
35         SkScalar length = 5;
36         SkScalar step = angle;
37 
38         SkPath path;
39         path.moveTo(center);
40 
41         while (length < (SkScalarHalf(SkMinScalar(this->width(), this->height())) - 10.f))
42         {
43             SkPoint rp = SkPoint::Make(length*SkScalarCos(step) + center.fX,
44                                        length*SkScalarSin(step) + center.fY);
45             path.lineTo(rp);
46             length += angle / SkScalarHalf(SK_ScalarPI);
47             step += angle;
48         }
49         path.close();
50 
51         SkPaint paint;
52         paint.setAntiAlias(true);
53         paint.setStyle(SkPaint::kStroke_Style);
54         paint.setColor(0xFF007700);
55 
56         canvas->drawPath(path, paint);
57     }
58 
onFindClickHandler(SkScalar x,SkScalar y,unsigned)59     Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned) override {
60         fAngle = x/width();
61         return nullptr;
62     }
63 private:
64 
65     SkScalar fAngle;
66     typedef Sample INHERITED;
67 };
68 
69 //////////////////////////////////////////////////////////////////////////////
70 
71 DEF_SAMPLE( return new StringArtView(); )
72