public float angle()
{
return(Maths.ArcTan2(this.y, this.x));
}
public static float angleBetween(VectorF a, VectorF b)
{
float angle = Maths.ArcTan2(b.y, b.x) - Maths.ArcTan2(a.y, a.x);
return(Maths.AnglePiFast(angle));
}