获取外接矩形

def update_collision_rect(self):
        """ 获取外接矩形 """
        self.min_x = min(self.points[::2])
        self.max_x = max(self.points[::2])
        self.min_y = min(self.points[1::2])
        self.max_y = max(self.points[1::2])