/// <summary> Perform an intersection test between two lines and return result </summary>
public bool Intersect(Line2D other, out Line2DIntersection intersection)
{
float denominator = (ab.y * other.ab.x - ab.x * other.ab.y);
float t1 =
((a.x - other.a.x) * other.ab.y + (other.a.y - a.y) * other.ab.x)
/ denominator;
if (float.IsInfinity(t1))
{
// The lines are parallel (or close enough to it).
intersection = new Line2DIntersection(false, Vector2.zero, Vector2.zero, Vector2.zero, 0, 0);
return(false);
}
float t2 =
((other.a.x - a.x) * ab.y + (a.y - other.a.y) * ab.x)
/ -denominator;
// Find the point of intersection.
Vector2 i_point = new Vector2(a.x + ab.x * t1, a.y + ab.y * t1);
// The segments intersect if t1 and t2 are between 0 and 1.
bool segments_intersect =
((t1 >= 0) && (t1 <= 1) &&
(t2 >= 0) && (t2 <= 1));
float t1cached = t1;
float t2cached = t2;
// Find the closest points on the segments.
if (t1 < 0)
{
t1 = 0;
}
else if (t1 > 1)
{
t1 = 1;
}
if (t2 < 0)
{
t2 = 0;
}
else if (t2 > 1)
{
t2 = 1;
}
Vector2 close_p1 = a + (ab * t1);
Vector2 close_p2 = other.a + (other.ab * t2);
intersection = new Line2DIntersection(segments_intersect, i_point, close_p1, close_p2, t1cached, t2cached);
return(true);
}
/// <summary> Perform an intersection test between a line and a point. The intersection point lies in the point nearest to the line </summary>
public bool Intersect(Vector2 point, out Line2DIntersection intersection)
{
Line2D other = new Line2D(point, point + Normal);
return(Intersect(other, out intersection));
}
