public static float Angle(Segment2D a, Segment2D b)
{
if (a.Intersects(b))
{
return(Angle(a.IntersectionPoint(b), a.Vector, b.Vector));
}
Vector2 origin = a.ToLine().IntersectionPoint(b.ToLine());
return(Angle(origin, a.Vector, b.Vector));
}
/// <summary>
/// Calculates the intersection of the lines or segments AB and CD.
/// </summary>
/// <param name="A">First point of Line 1.</param>
/// <param name="B">Second point of Line 1.</param>
/// <param name="C">First point of Line 2.</param>
/// <param name="D">Second point of Line 2.</param>
/// <param name="onSegment">If true, point must be contained in both segments.</param>
/// <returns>The intersection point of two lines or segments.(NaN, NaN) will be returned
/// if they are parallel or the intersection point is not contained on both segments,
/// should On Segment be true.</returns>
public static Vector2 IntersectionPoint(Vector2 A, Vector2 B, Vector2 C, Vector2 D, bool onSegment)
{
if (onSegment)
{
Segment2D L1 = new Segment2D(A, B);
Segment2D L2 = new Segment2D(C, D);
return(L1.IntersectionPoint(L2));
}
else
{
Line2D L1 = new Line2D(A, B);
Line2D L2 = new Line2D(C, D);
return(L1.IntersectionPoint(L2));
}
}
/// <summary>
/// Calculates the intersection point of a segment with this polygon.
/// </summary>
/// <param name="segment"></param>
/// <returns>The intersection points of a segment with this polygon.</returns>
public virtual List <Vector2> IntersectionPoints(Segment2D segment)
{
List <Vector2> intersections = new List <Vector2>();
Vector2 point;
for (int i = 0; i < Edges.Length; i++)
{
point = segment.IntersectionPoint(Edges[i]);
if (!point.IsNaN() && !point.IsInfinity())
{
intersections.Add(point);
}
}
return(intersections);
}
