class Settings:
    """存储游戏《外星人入侵》中所有设置的类"""

    def __init__(self):
        """初始化游戏设置。"""
        # 屏幕设置
        self.screen_width = 1200
        self.screen_height = 800
        self.bg_color = (230, 230, 230)
        self.title = "Alien Invasion"

        # 子弹设置
        self.bullet_speed = 1.5
        self.bullet_width = 3
        self.bullet_height = 15
        self.bullet_color = (60,60,60)
        self.bullet_allowed = 3

        # 飞船设置
        self.ship_speed = 3.0
        self.ship_limit = 3

        # 外星人设置
        self.alien_speed = 1.0
        self.fleet_drop_speed = 10
        # fleet_direction为1表示向右，为-1表示向左移。
        self.fleet_direction = 1


