-
Notifications
You must be signed in to change notification settings - Fork 0
/
Circle.cs
90 lines (74 loc) · 2.6 KB
/
Circle.cs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
namespace LinkageHinge
{
partial class Box
{
public class Circle
{
public class CirclePoint
{
public double x;
public double y;
public CirclePoint(double px, double py)
{
x = px;
y = py;
}
public CirclePoint sub(CirclePoint p2)
{
return new CirclePoint(x - p2.x, y - p2.y);
}
public CirclePoint add(CirclePoint p2)
{
return new CirclePoint(x + p2.x, y + p2.y);
}
public double distance(CirclePoint p2)
{
return Math.Sqrt((x - p2.x) * (x - p2.x) + (y - p2.y) * (y - p2.y));
}
public CirclePoint normal()
{
double length = Math.Sqrt(x * x + y * y);
return new CirclePoint(x / length, y / length);
}
public CirclePoint scale(double s)
{
return new CirclePoint(x * s, y * s);
}
}
private double x;
private double y;
private double r;
private double left;
public double Diameter { get { return r + r; } }
public Point TopLeft { get { return new Point(x - r, y - r); } }
public Circle(double cx, double cy, double cr)
{
x = cx;
y = cy;
r = cr;
left = x - r;
}
public Tuple<CirclePoint, CirclePoint> intersections(Circle c)
{
var P0 = new CirclePoint(x, y);
var P1 = new CirclePoint(c.x, c.y);
double d = P0.distance(P1);
double a = (r * r - c.r * c.r + d * d) / (2 * d);
if (a > r)
throw new ArithmeticException();
double h = Math.Sqrt(r * r - a * a);
var P2 = P1.sub(P0).scale(a / d).add(P0);
double x3 = P2.x + h * (P1.y - P0.y) / d;
double y3 = P2.y - h * (P1.x - P0.x) / d;
double x4 = P2.x - h * (P1.y - P0.y) / d;
double y4 = P2.y + h * (P1.x - P0.x) / d;
return new Tuple<CirclePoint, CirclePoint>(new CirclePoint(x3, y3), new CirclePoint(x4, y4));
}
}
}
}