// Code from: http://local.wasp.uwa.edu.au/~pbourke/geometry/lineline2d/
public Vector? Intersection(LineSegment that)
{
double d =
(that.V2.Y - that.V1.Y) * (this.V2.X - this.V1.X)
-
(that.V2.X - that.V1.X) * (this.V2.Y - this.V1.Y);
double n_a =
(that.V2.X - that.V1.X) * (this.V1.Y - that.V1.Y)
-
(that.V2.Y - that.V1.Y) * (this.V1.X - that.V1.X);
double n_b =
(this.V2.X - this.V1.X) * (this.V1.Y - that.V1.Y)
-
(this.V2.Y - this.V1.Y) * (this.V1.X - that.V1.X);
// parallel lines
if (d == 0)
return null;
double ua = n_a / d;
double ub = n_b / d;
if (ua >= 0d && ua <= 1d && ub >= 0d && ub <= 1d)
{
double x = this.V1.X + (ua * (this.V2.X - this.V1.X));
double y = this.V1.Y + (ua * (this.V2.Y - this.V1.Y));
return Vector.FromCart(x, y);
}
return null;
}
internal Tuple<Player, Vector> intersect(LineSegment ls1, IEnumerable<Tuple<Player, IEnumerable<LineSegment>>> tanks)
{
return (from tank in tanks
from ls2 in tank.Item2
let intersection = ls1.Intersection(ls2)
where intersection != null
select new Tuple<Player, Vector>(tank.Item1, (Vector)intersection)
).FirstOrDefault();
}
