/// <summary>
/// Returns whether this line intersects the other.
/// Edge cases such as if the endpoint of one line lies on the other line
/// have no definite behaviour.
/// </summary>
public bool Intersects(Line other)
{
var n = LeftNormal;
var h = n.Dot(other.Origin - Origin);
if (h * n.Dot(other.Destination - Origin) > 0)
{
return(false);
}
else if (h * n.Dot(other.Destination - Origin) == 0)
{
if ((Offset.Dot(other.Origin - Origin) < 0 && Offset.Dot(other.Destination - Origin) < 0) ||
(Offset.Dot(other.Origin - Destination) > 0 && Offset.Dot(other.Destination - Destination) > 0))
{
return(false);
}
else
{
return(true);
}
}
var angle = other.Offset.Angle(this.Offset);
if (angle.Degrees == 0 || angle.Degrees == 180)
{
if (h != 0)
{
return(false);
}
return(_isPointAdjacent(other.Origin) || _isPointAdjacent(other.Destination));
}
var sign = n.Dot(other.Offset) > 0 ? 1 : -1;
var p = other.Origin - sign * new Vector(h / GMath.Sin(angle), angle);
return(_isPointAdjacent(p));
}