用Python和Pygame写游戏-从入门到精通（8）Move

1、Move

background_image_filename = 'sushiplate.jpg'sprite_image_filename = 'fugu.png'import pygamefrom pygame.locals import *from sys import exitpygame.init()close = Falsescreen = pygame.display.set_mode((640, 480), 0, 32)background = pygame.image.load(background_image_filename).convert()sprite = pygame.image.load(sprite_image_filename).convert_alpha()clock = pygame.time.Clock()x, y = 100., 100.speed_x, speed_y = 133., 170.while True:    for event in pygame.event.get():        if event.type == QUIT:            pygame.quit()            exit            close = True    screen.blit(background, (0,0))    screen.blit(sprite, (x, y))    time_passed = clock.tick(30)    time_passed_seconds = time_passed / 1000.0    x += speed_x * time_passed_seconds    y += speed_y * time_passed_seconds        # 到达边界则把速度反向    if x > 640 - sprite.get_width():        speed_x = -speed_x        x = 640 - sprite.get_width()    elif x < 0:        speed_x = -speed_x        x = 0.    if y > 480 - sprite.get_height():        speed_y = -speed_y        y = 480 - sprite.get_height()    elif y < 0:        speed_y = -speed_y        y = 0        if close == True:        break    pygame.display.update()