void DrawBoard()
 {
     foreach (GameObject piece in lastPieces)
     {
         Destroy(piece);
     }
     for (int i = 0; i < gameBoard.Size; i++)
     {
         Vector2 nextPos = bottomLeft + new Vector2((i % 3) * gridSize, (i / 3) * gridSize);
         if (gameBoard.GetPiece(i) == TTTBoard.TTTPiece.X)
         {
             lastPieces.Add((GameObject)Instantiate(X, nextPos, Quaternion.identity));
         }
         else if (gameBoard.GetPiece(i) == TTTBoard.TTTPiece.O)
         {
             lastPieces.Add((GameObject)Instantiate(O, nextPos, Quaternion.identity));
         }
     }
 }