python - 在pygame中循环移动对象

Question

正如您在这张图片中看到的，

有我正在控制的矩形(红色)和我没有控制的绿色矩形。我希望这些绿色矩形不断从左向右移动(每隔一个就向相反方向移动)。我试着这么做，但我只让他们走到一侧，然后他们就停了下来。我不知道如何让他们回到另一边，然后不断地这样做。这是我的 if 语句结束后的样子。

import pygame


pygame.init()
win = pygame.display.set_mode((1200, 600))
clock = pygame.time.Clock()
BLACK = (0, 0, 0)
WHITE = (255,255,255)
RED = (255, 0, 0)
GREEN = (13, 255, 0)

player = pygame.Rect(40, 45, 30, 30)
vel = 4


walls = [
pygame.Rect(0, 0, 1200, 20), pygame.Rect(0, 0, 20, 600),
pygame.Rect(0, 580, 1200, 20), pygame.Rect(1180, 0, 20, 600),
pygame.Rect(300, 0, 20, 530), pygame.Rect(20, 100, 230, 20),
pygame.Rect(70, 200, 230, 20), pygame.Rect(20, 300, 230, 20),
pygame.Rect(70, 400, 230, 20), pygame.Rect(600, 100, 20, 500),
]

movingobjectsleft = [
pygame.Rect(320, 120, 30, 30),
pygame.Rect(320, 240, 30, 30),
pygame.Rect(320, 360, 30, 30),
]

movingobjectsright = [
pygame.Rect(570, 180, 30, 30),
pygame.Rect(570, 300, 30, 30),
pygame.Rect(570, 420, 30, 30)
]

run = True
while run:
# Handle the events.
for event in pygame.event.get():
    if event.type == pygame.QUIT:
        run = False

keys = pygame.key.get_pressed()

# Update the player coordinates.
if keys[pygame.K_LEFT] and player.x > 0:
    player.x -= vel
if keys[pygame.K_RIGHT] and player.x < 1200 - player.width:
    player.x += vel
if keys[pygame.K_UP] and player.y > 0:
    player.y -= vel
if keys[pygame.K_DOWN] and player.y < 600 - player.height:
    player.y += vel

# Game logic for walls and moving objects
for wall in walls:
    # Check if the player rect collides with a wall rect.
    if player.colliderect(wall):
        print("Game over")

for object in movingobjectsleft:
    if player.colliderect(object):
        print("Game over")
    if object.x < 570:
        object.x += vel


for object in movingobjectsright:
    if player.colliderect(object):
        print("Game over")
    if object.x > 320:
        object.x -= vel

# Draw everything.
win.fill(WHITE)
pygame.draw.rect(win, RED, player)
# Drawing walls and moving objects
for wall in walls:
    pygame.draw.rect(win, BLACK, wall)

for object in movingobjectsright:
    pygame.draw.rect(win, GREEN, object)

for object in movingobjectsleft:
    pygame.draw.rect(win, GREEN, object)

pygame.display.update()
clock.tick(60)

pygame.quit()

我认为这里需要做一些事情

for object in movingobjectsleft:
    if player.colliderect(object):
        print("Game over")
    if object.x < 570:
        object.x += vel


for object in movingobjectsright:
    if player.colliderect(object):
        print("Game over")
    if object.x > 320:
        object.x -= vel

Answer 1

您可以创建一个pygame.Rect具有附加 vel 的子类属性和 update移动矩形并进行边界检查的方法(或创建一个具有 rect 和 vel 属性的类):

class MovingRect(pygame.Rect):

    def __init__(self, x, y, w, h, vel):
        # Call the __init__ method of the parent class.
        super().__init__(x, y, w, h)
        self.vel = vel

    def update(self):
        self.x += self.vel  # Move.
        if self.right > 600 or self.left < 320:  # If it's not in this area.
            self.vel = -self.vel  # Invert the direction.


vel_left = 4
vel_right = -4

movingrects = [
    MovingRect(320, 120, 30, 30, vel_left),
    MovingRect(320, 240, 30, 30, vel_left),
    MovingRect(320, 360, 30, 30, vel_left),
    MovingRect(570, 180, 30, 30, vel_right),
    MovingRect(570, 300, 30, 30, vel_right),
    MovingRect(570, 420, 30, 30, vel_right),
]

在 while 循环中:

for movingrect in movingrects:
    movingrect.update()  # Movement and bounds checking.
    if player.colliderect(movingrect):
        print("Game over")

# Draw everything.
# ...
for movingrect in movingrects:
    pygame.draw.rect(win, GREEN, movingrect)

如果您需要计时器，请查看以下答案:Countdown timer in Pygame

<小时/>

如果您还不知道类是如何工作的，您可以定义一个 bool 标志( invert_direction )并将其设置为 True当其中一个矩形离开指定区域时。如果是True for之后循环，反转vel_left/vel_right变量。

vel_left = 4
vel_right = -4

run = True
while run:
    # Handle the events.
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    keys = pygame.key.get_pressed()

    # Update the player coordinates.
    if keys[pygame.K_LEFT] and player.left > 0:
        player.x -= vel
    if keys[pygame.K_RIGHT] and player.right < 1200:
        player.x += vel
    if keys[pygame.K_UP] and player.top > 0:
        player.y -= vel
    if keys[pygame.K_DOWN] and player.bottom < 600:
        player.y += vel

    # Game logic for walls and moving objects
    for wall in walls:
        # Check if the player rect collides with a wall rect.
        if player.colliderect(wall):
            print("Game over")

    # Set this variable to True if the direction should be inverted.
    invert_left = False
    for object in movingobjectsleft:
        if player.colliderect(object):
            print("Game over")

        object.x += vel_left  # Move the object.

        # Check if the object has left the area.
        if object.right > 600 or object.left < 320:
            # Invert the direction after the loop.
            invert_left = True

    if invert_left:  # Invert the direction.
        vel_left = -vel_left

    # Now do the same for the right objects.
    invert_right = False
    for object in movingobjectsright:
        if player.colliderect(object):
            print("Game over")

        object.x += vel_right

        if object.right > 600 or object.left < 320:
            invert_right = True

    if invert_right:
        vel_right = -vel_right