按下空格时让精灵出现并在X秒后消失？

Question

好的，所以我有一个用 pygame 制作的游戏。游戏是在屏幕底部有一个人从屏幕顶部向上射击以击中敌人。这个人可以左右移动。

要射你按空格键。

当你射击时，我希望在枪管末端出现一个小精灵，这样看起来就好像火焰像真正的枪击一样冒出来。

我已经设法让火精灵在按下空格键时出现，但我也希望精灵在 0.3 秒后消失（一旦我让它消失，我会调整时间）。

我该怎么做呢？我感觉有点迷失在这里

我尝试用谷歌搜索并查看stackoverflow，但找不到我需要的。

游戏.py

# -- SNIP --


def run_game():

    # -- SNIP ---

    # Start the main loop for the game.
    while True:
        # Watch for keyboard and mouse events.
        gf.check_events(ai_settings, screen, stats, sb, play_button, man, 
        enemies, bullets)

        if stats.game_active:
            man.update()
            gf.update_bullets(ai_settings, screen, stats, sb, man, enemies,
                              bullets)
            gf.update_enemies(ai_settings, stats, screen, sb, man, enemies,
                             bullets)

        gf.update_screen(ai_settings, screen, stats, sb, man, enemies, 
        bullets, play_button)


run_game()

game_functions.py

# -- SNIP --


def check_events(ai_settings, screen, stats, sb, play_button, man, enemies,
                 bullets):
    """Respond to keypresses and mouse events."""
    # -- SNIP --
        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event, ai_settings, screen, stats, sb, man,
                                 enemies, bullets)
        # -- SNIP --



def check_keydown_events(event, ai_settings, screen, stats, sb, man, enemies, bullets):
    """Respond to key presses."""
    if event.key == pygame.K_RIGHT:
        man.moving_right = True
        man.orientation = "Right"
    elif event.key == pygame.K_LEFT:
        man.moving_left = True
        man.orientation = "Left"

    # Draw sprite if space is pressed
    elif event.key == pygame.K_SPACE:
        fire_bullet(ai_settings, bullets, screen, man)
        man.fire_screen.blit(man.fire, man.fire_rect)
    # --- SNIP ---

# -- SNIP --

man.py

class Man(Sprite):
    # -- SNIP --
        # Load the man image and get its rect.
        self.image = pygame.image.load('images/man_gun_large.bmp')
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()

        # Gun fire sprite
        self.fire = pygame.image.load('images/fire.bmp')
        self.fire_rect = self.fire.get_rect()
        self.screen_fire_rect = self.image.get_rect()
        self.fire_screen = self.image

        self.ai_settings = ai_settings

        # Start each new man at the bottom center of the screen.
        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom

        # Load the fire sprite at the end of the mans gunbarrel
        self.fire_rect.centerx = self.screen_fire_rect.left + 20
        self.fire_rect.top = self.screen_fire_rect.top

# ---SNIP---

        # Movement flags
        self.moving_right = False
        self.moving_left = False

        self.orientation = False


    def blitme(self):
        """Draw the man at its current location."""
        self.screen.blit(self.image, self.rect)
        if self.orientation == "Right":
            self.screen.blit(self.image, self.rect)
        elif self.orientation == "Left":
            self.screen.blit(pygame.transform.flip(self.image, True, False), self.rect)

Answer 1

使用pygame.time.get_ticks() 管理子弹的生命周期。

添加一个列表，其中包含子弹寿命结束时间和子弹本身的元组。

bullets = []

当子弹产生时，计算结束时间并将信息附加到列表中：

def check_keydown_events(event, ai_settings, screen, stats, sb, man, enemies, bullets):

    # [...]

    # Draw sprite if space is pressed
    elif event.key == pygame.K_SPACE:

        bullet = # [...]

        end_time = pygame.time.get_ticks() + 300 # 300 millisconds = 0.3 seconds
        bullets.append( (end_time, bullet) )

检查子弹是否已到使用寿命并决定保留子弹或.kill它：

current_time = pygame.time.get_ticks()
current_bullets = bullets
bullets = []
for end_time, bullet in current_bullets:
    if current_time > end_time:
        bullet.kill()
    else:
        bullets.append( (end_time, bullet) )