public void setDirection(double fh, double fv)
    {
        fhLast = fh;
        fvLast = fv;
        this.fh = fh;
        this.fv = fv;
        fixForce();
    }
public void setDirection ( double fh , double fv ) { fhLast = fh ; fvLast = fv ; this . fh = fh ; this . fv = fv ; fixForce ( ) ; }
Set directions.

@param fh The horizontal direction.
@param fv The vertical direction.