python - pygame中的类问题

Question

我一直在使用 pygame 开发游戏。到目前为止，我已经开始拍摄了。这是代码:

def game_loop():
    global x
    global y
    x=0
    y=0
    second_x=0
    second_y=0
    change_x=0
    change_y=0

    xlist=[]
    ylist=[]
    # paused=True


    while True:
        game_display.blit(background, (0, 0))


        mouseclk=pygame.mouse.get_pressed()


        for event in pygame.event.get():

            if event.type==pygame.QUIT:
                pygame.quit()
                quit()


            x, y = pygame.mouse.get_pos()
            xlist.append(x)
            ylist.append(y)


            if x>=display_width-40:
                x=display_width-40

            if y>=display_height-48:
                y=display_height-48


            if event.type == pygame.MOUSEBUTTONUP :
                if event.button==1:
                    bullets.append([x+16,y])
                    shoot.play()


        for bullet in bullets:
            game_display.blit(bulletpic, (bullet[0], bullet[1]+10))


        for b in range(len(bullets)):
            bullets[b][-1] -= 10


        for bullet in bullets:
            if bullet[1]>display_height:
                bullets.remove(bullet)


        mainship=Ship(spaceship, x, y, pygame.mouse.get_focused())
        mainship.MakeShip()


        if pygame.mouse.get_focused()==0:
            pause()


        pygame.display.update()


        clock.tick(60)

射击效果很好，但我真的很想在我的游戏中使用类。我试过这样上课:

class Bullet:

    def __init__(self, xpos, ypos, sprite, speed, llist):

        self.xpos=xpos
        self.ypos=ypos
        self.sprite=sprite
        self.speed=speed
        self.list=llist


        self.list.append([self.xpos+16,self.ypos])


        for bullet in self.list:
            game_display.blit(self.sprite, (bullet[0], bullet[1]+10))


        for b in range(len(self.list)):
            self.list[b][-1] -= self.speed

        for bullet in self.list:
            if bullet[1]>display_height:
                self.list.remove(bullet)

现在，尽管这看起来可行，但它只会使子弹出现故障且速度变慢，有时甚至无法正常生成子弹。

有什么方法可以使它正常工作吗？我是一个新手程序员，一般来说是新手，所以我们将不胜感激任何帮助。

Answer 1

我认为您的 Bullet 做得太多了。您可以像这样对子弹建模:

class Bullet: 
    """This is a bullet. It knows about its position, direction and speed.
    It can move. It knows when it crosses the classvariables bounds."""

    # bounds as class variable for _all_ bullets - set it to dimensions of your game field
    bounds = (0,0,10,10) # if position is lower or higher that these it is out of bounds

    # if you got only 1 spite for all bullets (no acid-, fire-, waterbullets) you could
    # set it here. I would not, I would leave bullets simply to do the movement and tell
    # me if they get out of bounds

    def __init__(self, xpos, ypos, xdir, ydir, speed):
        # where does the bullet start (f.e. muzzle position)
        self.xpos=xpos
        self.ypos=ypos
        # direction that the bullet flies
        self.xdir=xdir
        self.ydir=ydir
        # initial speed of the bullet
        self.speed=speed

    def moveBullet(self):
        self.xpos += int(self.xdir * self.speed) # speed may be 0.8 or so
        self.ypos += int(self.ydir * self.speed)

    def outOfBounds(self):
        minX,minY,maxX,maxY = Bullet.bounds
        return self.xpos < minX or self.ypos < minY or self.xpos > maxX or self.ypos > maxY

    def __repr__(self):
        """Pretty print stuff"""
        return "({},{}){}".format(self.xpos,self.ypos,"" if 
                                  not self.outOfBounds() 
                                  else " : Out Of Bounds {}".format(Bullet.bounds))

然后您的游戏会设置所有子弹的边界并跟踪子弹列表。如果您需要新的项目符号，只需将其放入列表即可

Bullet.bounds = (0,0,90,90)
bullets = [ Bullet(10,10,12,0,3), Bullet(10,10,11,9,3), Bullet(10,10,0,5,1)]

while bullets:
    # you should move this into some kind of `def moveBullets(bulletlist): ...` 
    # that you then call inside your game loop
    for b in bullets:
        b.moveBullet()
        print(b)  # instead draw a spirte at b.xpos, b.ypos
    print("")
    # return from moveBullets(..)

    # remove all out of bounds bullets from list
    bullets = filter(lambda b: not b.outOfBounds(),bullets) 

输出:

(46,10)
(43,37)
(10,15)

(82,10)
(76,64)
(10,20)

(118,10) : Out Of Bounds (0, 0, 90, 90)
(109,91) : Out Of Bounds (0, 0, 90, 90)
(10,25)

(10,30)

(10,35)

(10,40)

(10,45)

(10,50)

(10,55)

(10,60)

(10,65)

(10,70)

(10,75)

(10,80)

(10,85)

(10,90)

(10,95) : Out Of Bounds (0, 0, 90, 90)