public float angle(Vector2fc v) {
        float dot = x*v.x() + y*v.y();
        float det = x*v.y() - y*v.x();
        return (float) Math.atan2(det, dot);
    }
public float angle ( Vector2fc v ) { float dot = x * v . x ( ) + y * v . y ( ) ; float det = x * v . y ( ) - y * v . x ( ) ; return ( float ) Math . atan2 ( det , dot ) ; }
/* (non-Javadoc)
@see org.joml.Vector2fc#angle(org.joml.Vector2fc)