Pygame填充和blit不会编辑屏幕

Question

I'm getting familiar with Pygame and I want to write a simple game, I already have following code:

import sys, pygame
pygame.init()

size = width, height = 640, 480
speed = [2, 2]
black = 0, 0, 0

screen = pygame.display.set_mode(size)

ball = pygame.image.load("intro_ball.gif")
ballrect = ball.get_rect()

bar = pygame.image.load("bar_low.gif")
barrect = bar.get_rect(center=(320,475))

over = pygame.image.load("game_over.gif")
overrect = over.get_rect(center=(width/2, height/2 ))

while 1:
    for event in pygame.event.get():
        if event.type == pygame.QUIT: sys.exit()
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_w:
                screen.fill(black)
                screen.blit(over, overrect)
                pygame.display.flip()
                pygame.time.delay(2000)


    keys = pygame.key.get_pressed()
    if keys[pygame.K_RIGHT] and barrect.right < width:
        barrect = barrect.move(4, 0)
        screen.blit(bar, barrect)
        pygame.display.update()
    if keys[pygame.K_LEFT] and barrect.left > 0:
        barrect = barrect.move(-4, 0)
        screen.blit(bar, barrect)
        pygame.display.update()
    ballrect = ballrect.move(speed)
    if ballrect.left < 0 or ballrect.right > width:
        speed[0] = -speed[0]
    if ballrect.top < 0 or (ballrect.bottom > height - bar.get_height() and ballrect.left < barrect.right and ballrect.right > barrect.left):
        speed[1] = -speed[1]
    if ballrect.bottom > height:
        #irrelevant


    screen.fill(black)
    screen.blit(ball, ballrect)
    screen.blit(bar, barrect)
    pygame.display.flip()

It works fine apart the "if ' w ' is pressed" part: what it should do is to fill black, show the " game_over " image for two seconds and continue to work. Instead of this it freezes everything for two seconds and continues to work, like the following lines never existed.

screen.fill(black)
screen.blit(over, overrect)
pygame.display.flip()

Could you tell what do I do wrong?

Answer 1

The positions of the bar ( barrect ), the the position of the ball ( ballrect ) and the speed ( speed ) have to be set to the initial state, when the game is restarted:

Create an function which initializes the game states:

def InitGame():
    global ballrect, barrect, speed
    speed = [2, 2]
    ballrect = ball.get_rect()
    barrect = bar.get_rect(center=(320,475))  

Call it once at startup:

screen = pygame.display.set_mode(size)

ball = pygame.image.load("intro_ball.gif")
bar = pygame.image.load("bar_low.gif")
over = pygame.image.load("game_over.gif")
overrect = over.get_rect(center=(width/2, height/2 ))

InitGame();

Call it again when the game has to be restarted. I recommend not to delay the game by pygame.time.delay() . Calculate the time when the game has to be restarted starttime . Draw either the game screen or the "game over" screen dependent on the time:

starttime = 0
while 1:
    for event in pygame.event.get():
        if event.type == pygame.QUIT: sys.exit()
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_w:

                # reset game and init the new start time
                InitGame()
                starttime = pygame.time.get_ticks() + 2000

    if pygame.time.get_ticks() > starttime: 

        keys = pygame.key.get_pressed()
        # [...]

        screen.fill(black)
        screen.blit(ball, ballrect)
        screen.blit(bar, barrect)

    else:

        screen.fill(black)
        screen.blit(over, overrect)

    pygame.display.flip()