func _ready():
    var brick_y_size = brick_y_idx.size()
    var brick_x_size = brick_x_idx.size()
    for l in range(0,brick_y_size):
        for i in range(0,brick_x_size):
            randomize()
            var add_brick = randi()%2
            if add_brick == 1:
                var brick = pre_brick.instance()
                brick.global_position = Vector2(brick_x_idx[i],brick_y_idx[l])
                add_child(brick)
                brick.add_to_group("bricks")
                brick.connect("pts" , self , "on_pts")

    $shoot.connect("empty" , $bottom/area , "on_empty")
    $bottom/area.connect("recharge" , $shoot , "on_recharge")
    $bottom/area.connect("game_over" , self , "on_game_over")
    $bottom/area.connect("brick_down" , self , "on_brick_down")
    self.connect("stop_shoot" , $shoot , "on_stop_shoot")