/// <summary>
/// If the points are stored counter-clockwise and form a convex polygon, this will test if a circle with the origin (0;0) lies inside it.
/// </summary>
/// <param name="radius">The rectangle to test for intersection.</param>
/// <returns><c>true</c> if the circle lies within the quadrangle.</returns>
public bool IntersectCircle(float radius)
{
// Check if a part of the circle lies within the quadrangle
if (P1.Length() < radius || P2.Length() < radius || P3.Length() < radius || P4.Length() < radius)
{
return(true);
}
// Check if the quadrangle has the size 0
if (P1 == P2 && P2 == P3 && P3 == P4)
{
return(false);
}
// Check if the circle lies within the quadrangle completley
if (IntersectWith(new Vector2()))
{
return(true);
}
// If neither, it must be outside of the quadrangle
return(false);
}