// Called when the mouse wheel is rotated
public void onMouseWheelMoved(MouseWheelEvent e) {
// If the wheel rotation is negative it means that it is moved forward.
// Set move direction = forward, if wheel is moved forward.
// Otherwise, set move direction = backward
moveDirection = (e.getWheelRotation() < 0) ? 1 : -1;
// Set the amount to move = absolute wheel rotation amount * 5 (speed)
// Here 5 means 5 pixels per wheel rotation step. The higher value, the
// more speed
moveAmount += Math.abs(e.getWheelRotation()) * 5;
}
