public SoccerBall(Vector2D pos, double ballSize, double mass, ArrayList<Wall2D> pitchBoundary) {
// set up the base class
super();
setPositionParams(pos);
setDirectionParams(ballSize, new Vector2D(0d, 0d), new Vector2D(0d, 1d), new Vector2D(1d, 1d));
setEnergy(
mass, -1.0, // max speed - unused
0, // turn rate - unused
0); // max force - unused
this.pitchBoundary = pitchBoundary;
oldPos = new Vector2D(0d, 0d);
// oldPos = pos.cloneVec();
}
