///<summary>Adds a new node to the snake for one turn, with animation if necessary.</summary>
public void grow(float timeToMove, bool shouldMoveSmoothly)
{
// like the move function, but instantiates a new node as the head instead of moving the tail up
SnakeNode newHead = Instantiate(this.snakeNodePrefab, this.head.transform.position, this.head.transform.rotation, this.gameOrigin.transform) as SnakeNode;
newHead.setDirection(this.head.getDirection());
newHead.setCoordinates(this.head.getCoordinates());
this.nodes.Add(newHead);
newHead.StartCoroutine(newHead.moveToCoordinates(this.head.coordinatesOfNextNode(), timeToMove, shouldMoveSmoothly));
this.head.setNodeBefore(newHead);
this.head = newHead;
}