f (curTile !== null && curTile !== undefined) {
                curTile.normal();
            }

            if (curOp) {
                var lastTile = curTile;
                if (nextTile != null) {
                    curTile = nextTile;
                    nextTile = null;
                } else {
                    curTile = curOp();
                }

                if (curTile) {
                    var ctime = player.curTime();
                    // if we are consistently late we should shutdown