def custom_draw(self, player): # getting the offset self.offset.x = player.rect.centerx - self.half_width self.offset.y = player.rect.centery - self.half_height # drawing the floor floor_offset_pos = self.floor_rect.topleft - self.offset self.display_surface.blit(self.floor_surf, floor_offset_pos) # for sprite in self.sprites(): for sprite in sorted(self.sprites(), key=lambda sprite: sprite.rect.centery): offset_pos = sprite.rect.topleft - self.offset self.display_surface.blit(sprite.image, offset_pos)对代码进行注解

好的，下面是对这段代码的详细注释：

def custom_draw(self, player):
    # getting the offset
    # 计算偏移量，使玩家的位置居中
    self.offset.x = player.rect.centerx - self.half_width
    self.offset.y = player.rect.centery - self.half_height
    
    # drawing the floor
    # 绘制地面
    floor_offset_pos = self.floor_rect.topleft - self.offset
    self.display_surface.blit(self.floor_surf, floor_offset_pos)
    
    # for sprite in self.sprites():
    # 对所有精灵进行循环绘制
    for sprite in sorted(self.sprites(), key=lambda sprite: sprite.rect.centery):
        # 计算精灵在屏幕上的位置
        offset_pos = sprite.rect.topleft - self.offset
        # 绘制精灵
        self.display_surface.blit(sprite.image, offset_pos)

以上是对代码的注释，希望能够帮助你更好地理解它的作用。