private function getExtent2(dx:int, dy:int):uint
        {
            var start:Point2i = player.getIndex();
            var result:uint = 1;
            var tile:int = getTile(start.x, start.y);
            var i:int = start.x;
            var j:int = start.y;
            while (tile !== -1)
            {
                if (!Tile.isSlippery(getTile(i + dx, j + dy)))
                {
                    return result;
                }
                result += 1;
                i += dx;
                j += dy;
                tile = getTile(i, j);
                if (tile !== -1 && !Tile.isWalkable(getTile(i+dx, j+dy)))
                {
                   result -= 1;
                   break;
                }
            }
            return result;
        }