pygame的事件追踪

davidmou

import pygame
import sys
pygame.init()
size = width, height = 600,400
screen = pygame.display.set_mode(size)
pygame.display.set_caption("欢迎来到黑客帝国")
font = pygame.font.Font(None,20)
position = 0
line_height = font.get_linesize()
while 1:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        screen.blit(font.render(str(event),True,[0,255,0]),(0,position))
        position += line_height
        
        if position > height:
            position = 0
            screen.fill([0,0,0])
        
        pygame.display.flip()

有哪位大神能帮忙解释一下 这段代码是什么意思？
screen.blit(font.render(str(event),True,[0,255,0]),(0,position))
position += line_height

if position > height:
position = 0
screen.fill([0,0,0])