我在此乒乓球比赛中划了一个边界，但球拍可以划过边界。如何停止呢？

Question

我在此乒乓球游戏中做了一个边框，屏幕上的桨可以越过它。我之前在另一段代码中已经做到了，但是现在一切都不同了。我有一个主要的想法如何做，您可能需要一个if语句，但是我没有所有的东西。

您可以删除“ pygame.load.image（）”，因为您需要在文件夹中包含带有代码的图像，因此可以将其删除。会更好，因为您可以在python上尝试一下

#import modules
import pygame 
pygame.init()
#setting the variables for the window
WIDTH = 750
HEIGHT = 500
#making the wind\ow
win = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Pong Game")
#setting the most important variables
dest = (0, 0)
dest2 = (200, 200)
dest3 = (200, 50)
white = (255, 255, 255)
black = (0, 0, 0) 
green = (0, 255, 0)
red = (255, 0, 0)
yellow = (255, 255, 222)
#load the images
image = pygame.image.load("birdupbg.png")
image2 = pygame.image.load("birdup.png")
#making the paddle class
class Paddle(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface([10, 75])
        self.image.fill(yellow)
        self.rect = self.image.get_rect()
        self.points = 0
#making the ball class
class Ball(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface([10, 10])
        self.image.fill(red)
        self.rect = self.image.get_rect()
        self.speed = 15 
        self.dx = 1
        self.dy = 1
        self.dx2 = 1
        self.dy2 = 1
#making the paddles
paddle1 = Paddle()
paddle1.rect.x = 25
paddle1.rect.y = 100

paddle2 = Paddle()
paddle2.rect.x = 715
paddle2.rect.y = 225


paddle3 = Paddle()
paddle3.rect.x = 715
paddle3.rect.y = 100

paddle4 = Paddle()
paddle4.rect.x = 25
paddle4.rect.y = 225
#paddle speed
paddle_speed = 50

pong = Ball()
pong.rect.x = 375
pong.rect.y = 250

ball = Ball()

all_sprites = pygame.sprite.Group()
all_sprites.add(paddle1, paddle2, paddle3, paddle4, pong)

#drawing the score and the word "pong" 
def redraw():
    win.fill(black)
    win.blit(image, dest)
    pygame.draw.line(win, (255, 255, 255), [0, 200], [900, 200], 10)
    font = pygame.font.SysFont("impact", 40)
    text = font.render("PONG", False, white)
    textRect = text.get_rect()
    textRect.center = (750//2, 25)
    win.blit(text, textRect)


    p1_score = font.render(str(paddle1.points), False, white)
    p1Rect = p1_score.get_rect()
    p1Rect.center = (50, 50)
    win.blit(p1_score, p1Rect)

    p2_score = font.render(str(paddle2.points), False, white)
    p2Rect = p2_score.get_rect()
    p1Rect.center = (700, 50)
    win.blit(p2_score, p1Rect)

    all_sprites.draw(win)
    pygame.display.update()
#what happens when the window runs
run = True

while run:
    pygame.time.delay(100)

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
    #if a certain key is pressed, move something
    key = pygame.key.get_pressed()
    if key[pygame.K_w]:
        paddle1.rect.y += -paddle_speed
    if key[pygame.K_s]:
        paddle1.rect.y +=  paddle_speed
    if key[pygame.K_UP]:
        paddle2.rect.y += -paddle_speed
    if key[pygame.K_DOWN]:
        paddle2.rect.y +=  paddle_speed
    if key[pygame.K_i]:
        paddle3.rect.y += -paddle_speed
    if key[pygame.K_j]:
        paddle3.rect.y += paddle_speed
    if key[pygame.K_1]:
        paddle4.rect.y += -paddle_speed
    if key[pygame.K_2]:
        paddle4.rect.y += paddle_speed
    pong.rect.x += pong.speed * pong.dx
    pong.rect.y += pong.speed * pong.dy
    #scoring system
    if pong.rect.y > 480:
        pong.dy = -1
    if pong.rect.x > 735:
        pong.rect.x, pong.rect.y = 375, 250
        pong.dx = -1
        paddle1.points += 1
        if pong.rect.y < -1:
            pong.dy = 1

    if pong.rect.x < 10:
        pong.rect.x, pong.rect.y = 375, 250
        pong.dx = 1
        paddle2.points += 1

    #if the ball and paddle collide, bounce off it
    if paddle1.rect.colliderect(pong.rect):
        pong.dx = 1
    if paddle2.rect.colliderect(pong.rect):
        pong.dx = -1
    if paddle1.rect.colliderect(pong.rect):
        pong.dx = 1
    if paddle3.rect.colliderect(pong.rect):
        pong.dx = -1
    if paddle4.rect.colliderect(pong.rect):
        pong.dx = 1
    #Call the redraw function
    redraw()  
    #update the window and quit it
    pygame.display.flip()
pygame.quit()

Answer 1

为了使球拍保持在场地上，请在游戏循环中添加一个复选标记，以在球拍到达边缘时阻止球拍移动。

.......
if pong.rect.x < 10:
    pong.rect.x, pong.rect.y = 375, 250
    pong.dx = 1
    paddle2.points += 1

# keep paddles in correct range     # add this section
if paddle1.rect.y < 0 : paddle1.rect.y = 0
if paddle3.rect.y < 0 : paddle3.rect.y = 0
if paddle2.rect.y < 200 : paddle2.rect.y = 200
if paddle4.rect.y < 200 : paddle4.rect.y = 200
if paddle1.rect.y > 200 - 75 : paddle1.rect.y = 200 - 75
if paddle3.rect.y > 200 - 75 : paddle3.rect.y = 200 - 75
if paddle2.rect.y > 500 - 75 : paddle2.rect.y = 500 - 75
if paddle4.rect.y > 500 - 75 : paddle4.rect.y = 500 - 75

#if the ball and paddle collide, bounce off it
if paddle1.rect.colliderect(pong.rect):
    pong.dx = 1
if paddle2.rect.colliderect(pong.rect):
    pong.dx = -1
.....