//rotate this point about another point
public void Rotate(double angle, Point2D point)
{
x -= point.x;
y -= point.y;
var ox = x;
var oy = y;
x = Math.Cos(angle)*ox - Math.Sin(angle)*oy;
y = Math.Sin(angle)*ox + Math.Cos(angle)*oy;
x += point.x;
y += point.y;
}
//what is the squared dist to another point
public double distance_sq(Point2D point)
{
var dx = point.x - x;
var dy = point.y - y;
return dx*dx + dy*dy;
}
public Point2D(Point2D another)
{
x = another.x;
y = another.y;
}
//what is the squared distance from this line to a point
public double distance_sq(Point2D n)
{
var utop = (n.x - P1.x)*(P2.x - P1.x) + (n.y - P1.y)*(P2.y - P1.y);
var ubot = P1.distance_sq(P2);
var u = utop/ubot;
if (u < 0 || u > 1)
{
var d1 = P1.distance_sq(n);
var d2 = P2.distance_sq(n);
if (d1 < d2) return d1;
return d2;
}
var p = new Point2D(0.0, 0.0) {x = P1.x + u*(P2.x - P1.x), y = P1.y + u*(P2.y - P1.y)};
return p.distance_sq(n);
}
//what is the distance from this line to a point
public double Distance(Point2D n)
{
return Math.Sqrt(distance_sq(n));
}
public Circle2D(Point2D a, double rad)
{
Radius = rad;
p = a;
}
//calculate the point of intersection between two line segments
public Point2D Intersection(Line2D L, out bool found)
{
var pt = new Point2D(0.0, 0.0);
var a = P1;
var b = P2;
var c = L.P1;
var d = L.P2;
var rTop = (a.y - c.y)*(d.x - c.x) - (a.x - c.x)*(d.y - c.y);
var rBot = (b.x - a.x)*(d.y - c.y) - (b.y - a.y)*(d.x - c.x);
var sTop = (a.y - c.y)*(b.x - a.x) - (a.x - c.x)*(b.y - a.y);
var sBot = (b.x - a.x)*(d.y - c.y) - (b.y - a.y)*(d.x - c.x);
if ((rBot == 0 || sBot == 0))
{
found = false;
return pt;
}
var r = rTop/rBot;
var s = sTop/sBot;
if ((r > 0) && (r < 1) && (s > 0) && (s < 1))
{
pt.x = a.x + r*(b.x - a.x);
pt.y = a.y + r*(b.y - a.y);
found = true;
return pt;
}
found = false;
return pt;
}
public Circle2D(Circle2D other)
{
p = other.p;
Radius = other.Radius;
}
public Line2D(Line2D other)
{
P1 = other.P1;
P2 = other.P2;
}
public Line2D(Point2D a, Point2D b)
{
P1 = a;
P2 = b;
}
//what is the distance to another point
public double Distance(Point2D point)
{
return Math.Sqrt(distance_sq(point));
}
public double ManhattanDistance(Point2D point)
{
var dx = Math.Abs(point.x - x);
var dy = Math.Abs(point.y - y);
return dx + dy;
}