public static MLine IntersectLine(MCircle c1, MCircle c2)
{
MPoint[] points = new MPoint[2];
points[0] = new MPoint(Double.NaN, Double.NaN);
points[1] = new MPoint(Double.NaN, Double.NaN);
double d = MPoint.Distance(c1.Center, c2.Center);
if (d > c1.Radius + c2.Radius)
{
return(null);
}
if (d < Math.Abs(c1.Radius - c2.Radius))
{
return(null);
}
if (Math.Abs(d) < Double.Epsilon && Math.Abs(c1.Radius - c2.Radius) < Double.Epsilon)
{
return(null);
}
double a = (c1.Radius * c1.Radius - c2.Radius * c2.Radius + d * d) / 2 * d;
double h = Math.Sqrt(c1.Radius * c1.Radius - a * a);
MPoint p2 = c1.Center + (c1.Center - c2.Center) * a / d;
points[0] = new MPoint(p2.X + h * (c2.Center.Y - c1.Center.Y) / d, p2.Y - h * (c2.Center.X - c1.Center.X) / d);
points[1] = new MPoint(p2.X - h * (c2.Center.Y - c1.Center.Y) / d, p2.Y + h * (c2.Center.X - c1.Center.X) / d);
return(new MLine(points[0], points[1]));
}
protected bool Equals(MPoint other)
{
return(X.Equals(other.X) && Y.Equals(other.Y));
}
public static double Distance(MPoint p1, MPoint p2)
{
return(Math.Sqrt((p1.X - p2.X) * (p1.X - p2.X) + (p1.Y - p2.Y) * (p1.Y - p2.Y)));
}
public Boolean onCircle(MPoint p)
{
return(Math.Abs(MPoint.Distance(p, Center) - Radius) < Double.Epsilon);
}
public MCircle(MPoint center, double radius)
{
Center = center;
Radius = radius;
}
public MLine(Point p1, MPoint p2)
{
M = (p1.Y - p2.Y) / (p1.X - p2.X);
B = p1.Y - M * p1.X;
}