在 pygame 中只运行一次 if 语句

Question

我有一个跑步游戏，您可以在其中移动和收集硬币。对于每枚硬币，我都有一个 if 语句：

if cn1+25 < x and cn1 + 50 > x:
        cn1 = -1000
        if cn1 < -3:
            coincount += 1
            textObj = INVFONT.render(str(coincount+1), True, WHITE, BLACK)

这个 if 语句一遍又一遍地发生，将数百个硬币添加到变量中coincount。稍后在我的代码中，我将 coincount 中的硬币数量 blit 到屏幕上。

有没有办法确保这只运行一次？

（这是我的其余代码，您可能会有所帮助）

import pygame,sys,random
pygame.init()

width = 900
height = 300
screenDim = (width,height)
green=(0,255,0)
yellow=(255,255,0)
red=(255,0,0)
WHITE = (0,0,0)
BLACK = (255,255,255)
screen = pygame.display.set_mode(screenDim)

placePlatformX = 0
placePlatformY = 275
coin = pygame.image.load('C:\\Users\\eliya_s1suf2x\\Desktop\\coin.png').convert_alpha()
coin = pygame.transform.scale(coin, (25,25))
background = pygame.image.load('C:\\Users\\eliya_s1suf2x\\Desktop\\background.jpg').convert_alpha()
background = pygame.transform.scale(background, (width,height))
guy = pygame.image.load('C:\\Users\\eliya_s1suf2x\\Desktop\\guy.png').convert_alpha()
guy = pygame.transform.rotate(guy,90)
cloud1 = pygame.image.load('C:\\Users\\eliya_s1suf2x\\Downloads\\cloud.png').convert_alpha()
cloud1 = pygame.transform.scale(cloud1,(156,88))
cloud2 = pygame.image.load('C:\\Users\\eliya_s1suf2x\\Downloads\\cloud.png').convert_alpha()
cloud2 = pygame.transform.scale(cloud1,(131,53))
cloud3 = pygame.image.load('C:\\Users\\eliya_s1suf2x\\Downloads\\cloud.png').convert_alpha()
cloud3 = pygame.transform.scale(cloud1,(200,100))
cloud4 = pygame.image.load('C:\\Users\\eliya_s1suf2x\\Downloads\\cloud.png').convert_alpha()
cloud4 = pygame.transform.scale(cloud1,(39,20))


bplatform = pygame.image.load('C:\\Users\\eliya_s1suf2x\\Desktop\\platform.jpg').convert_alpha()
coincount = 0    
x = 450
y = -20
block = 1000
cn1 = 100
cn2 = 100
cn3 = 100
cn4 = 100
cn5 = 100
cloudmove = 20

INVFONT = pygame.font.Font('C:\\Users\\eliya_s1suf2x\\Desktop\\MINECRAFT\\Raleway-ExtraBold.ttf', 18)
textObj = INVFONT.render(str(coincount), True, WHITE, BLACK)

def update():


    screen.blit(background,(0,0))

    screen.blit(textObj,(860,0))
    screen.blit(cloud1,(cloudmove,0))
    screen.blit(cloud2,(cloudmove+120,30))
    screen.blit(cloud3, (cloudmove+500,10))
    screen.blit(cloud4, (cloudmove + 340,20))

    screen.blit(bplatform,(placePlatformX,placePlatformY))
    screen.blit(bplatform,(placePlatformX+190,placePlatformY))
    screen.blit(bplatform,(placePlatformX+380,placePlatformY))
    screen.blit(bplatform,(placePlatformX+570,placePlatformY))
    screen.blit(bplatform,(placePlatformX+760,placePlatformY))
    screen.blit(bplatform,(placePlatformX+1760,placePlatformY+100))
    #block list update
    screen.blit(bplatform,(block-500,190))
    screen.blit(bplatform,(block,100))
    screen.blit(bplatform,(block+250,200))
    screen.blit(bplatform,(block+500,210))
    screen.blit(bplatform,(block+830,190))
    screen.blit(bplatform,(block+1000,140))

    screen.blit(coin,(cn1 + 40,245))
    screen.blit(coin,(cn2 + 80,245))
    screen.blit(coin,(cn3 + 120,245))
    screen.blit(coin,(cn4+ 160,245))
    screen.blit(coin,(cn5 + 200,245))
    screen.blit(coin,(830,0))
    screen.blit(guy,(x,y))

#pygame.sprite.spritecollide()




standOnBrick = 255   
speed = 2
gravity = 3
pygame.display.set_caption("Run")
finished = False
while finished == False:

    #processing all the events
    for event in pygame.event.get(): # event1, event2,..
        if event.type == pygame.QUIT:
            finished = True
            pygame.quit()
            sys.exit()

    if y < standOnBrick:
        y += gravity
        update()

        #where the block   #where the block
        #starts             #ends
    elif cn1+25 < x and cn1 + 50 > x:
        cn1 = -1000
        if cn1 < -3:
            coincount += 1
            textObj = INVFONT.render(str(coincount+1), True, WHITE, BLACK)

        #WORK ON THIS
    elif cn2 + 50 < x and cn2 + 100 > x:
        cn2 = -1025
        if cn2 < -3:
            coincount += 1
            print('coincount',coincount)
            textObj = INVFONT.render(str(coincount+1), True, WHITE, BLACK)
    elif cn3 + 75 < x and cn3 + 150 > x:
        cn3 = -1050
        if cn3 < -3:
            coincount += 1
            print('coincount',coincount)
            textObj = INVFONT.render(str(coincount+1), True, WHITE, BLACK)

    elif cn4 + 100 < x and cn2 + 200 > x:
        cn4 = -1000
        if cn4 < -3:
            coincount += 1
            print('coincount',coincount)
            textObj = INVFONT.render(str(coincount+1), True, WHITE, BLACK)

    elif cn5 + 125 < x and cn5 + 230 > x:
        cn5 = -1000
        if cn5 < -3:
            coincount += 1
            print('coincount',coincount)
            print('hello')
            textObj = INVFONT.render(str(coincount+1), True, WHITE, BLACK)

    elif block-525 < x and block-330 > x:
        #how high guy is
        standOnBrick = 167
    elif block-16 < x and block+180 > x:
        standOnBrick = 79
    elif block + 230 < x and block + 426 > x:
        standOnBrick = 179
    elif block + 480 < x and block + 480+196>x:
        standOnBrick = 189
    elif block + 810 < x and block + 1026 > x:
        standOnBrick = 169
    elif block + 980 < x and block +1176 > x:
        standOnBrick = 119

    else:
        standOnBrick = 255
    pressedKeys = pygame.key.get_pressed()
    if pressedKeys[pygame.K_LEFT] == 1:
        x -= speed
        print(x)
        update()



    elif pressedKeys[pygame.K_RIGHT] == 1:
        block -= 0.5
        cn1 -= 0.5
        cn2 -= 0.5
        cn3 -= 0.5
        cn4 -= 0.5
        cn5 -= 0.5
        cloudmove -= 0.2
        update()
        if x < 450:
            cloudmove += 0.25
            x+=speed
            cn1 += 0.5
            cn2 += 0.5
            cn3 += 0.5
            cn4 += 0.5
            cn5 += 0.5
            update()
            print(x)
            block += 0.5
    elif pressedKeys[pygame.K_UP] == 1:
        y -= 5


        print(y)
        update()

#bounderies

    if x < 2:
        x += 2.1

    pygame.display.flip()#Update method/load next frame

#pygame.quit()

Answer 1

您的代码缺少的是抽象。

使用列表代替一堆screen.blit和大量的if语句。使用包含它们需要的所有信息的数据结构（在您的情况下，对象）
而不是硬编码值（如cn1+25 < x and cn1 + 50 > x）。

这是一个简单的例子。

假设我们有一个美好的世界，云在晴天移动：

import pygame

screen = pygame.display.set_mode((300, 300))
clock = pygame.time.Clock()

cloud = pygame.Surface((50, 20))
cloud.set_colorkey((11, 12, 13))
cloud.fill((11, 12, 13))
pygame.draw.ellipse(cloud, pygame.Color('white'), cloud.get_rect())

cloudmove = 20

while True:
    for e in pygame.event.get():
        if e.type == pygame.QUIT:
            quit()
    screen.fill(pygame.Color('lightblue'))
    screen.blit(cloud, (cloudmove+120,30))
    cloudmove += 1
    pygame.display.flip()
    clock.tick(30)

但是，当然，我们希望更多的不是一个单一的云。我们不想要的是重复代码并提高复杂性。我们可以这样做：

import pygame

screen = pygame.display.set_mode((300, 300))
clock = pygame.time.Clock()

cloud = pygame.Surface((50, 20))
cloud.set_colorkey((11, 12, 13))
cloud.fill((11, 12, 13))
pygame.draw.ellipse(cloud, pygame.Color('white'), cloud.get_rect())

cloud2 = pygame.Surface((50, 20))
cloud2.set_colorkey((11, 12, 13))
cloud2.fill((11, 12, 13))
pygame.draw.ellipse(cloud2, pygame.Color('white'), cloud2.get_rect())

cloud3 = pygame.Surface((50, 20))
cloud3.set_colorkey((11, 12, 13))
cloud3.fill((11, 12, 13))
pygame.draw.ellipse(cloud3, pygame.Color('white'), cloud3.get_rect())

cloudmove = 20

while True:
    for e in pygame.event.get():
        if e.type == pygame.QUIT:
            quit()
    screen.fill(pygame.Color('lightblue'))
    screen.blit(cloud, (cloudmove-120,30))
    screen.blit(cloud2, (cloudmove-220,40))
    screen.blit(cloud3, (cloudmove-170,50))
    cloudmove += 1
    pygame.display.flip()
    clock.tick(30)

如果我们再添加一打对象，您已经可以看到它会在哪里结束。

因此，让我们尝试在此处使用代表云的对象：

import pygame

screen = pygame.display.set_mode((300, 300))
clock = pygame.time.Clock()

class Cloud:
    def __init__(self, x, y):
        self.image = pygame.Surface((50, 20))
        self.image.set_colorkey((11, 12, 13))
        self.image.fill((11, 12, 13))
        pygame.draw.ellipse(self.image, pygame.Color('white'), self.image.get_rect())
        self.x = x
        self.y = y

    def update(self):
        self.x += 1
        if self.x > 300:
            self.x = 0

clouds = [Cloud(0, 30), Cloud(100, 40), Cloud(50, 50)]

while True:
    for e in pygame.event.get():
        if e.type == pygame.QUIT:
            quit()
    screen.fill(pygame.Color('lightblue'))
    for cloud in clouds:
        screen.blit(cloud.image, (cloud.x, cloud.y))
        cloud.update()
    pygame.display.flip()
    clock.tick(30)

（这里没有新图片，因为它看起来基本一样）

好多了！现在，要添加更多云，我们只需Cloud向clouds列表中添加一个新实例。看看我们如何在类中不仅存储云的图像，还存储位置。我们已经把云的行为（沿着天空移动，一旦我们离开屏幕从左边开始）到类中。

但我们还可以做得更好！Pygame 提供了一些我们可以使用的方便的类和函数。看看下面的代码：

import pygame

screen = pygame.display.set_mode((300, 300))
clock = pygame.time.Clock()

class Coin(pygame.sprite.Sprite):
    def __init__(self, x, y):
        super().__init__()
        self.image = pygame.Surface((44, 40))
        self.image.set_colorkey((11, 12, 13))
        self.image.fill((11, 12, 13))
        cx, cy = self.image.get_rect().center
        pygame.draw.circle(self.image, pygame.Color('grey'), (cx + 2, cy), 20)
        pygame.draw.circle(self.image, pygame.Color('orange'), (cx - 2, cy), 20)
        self.rect = self.image.get_rect(topleft=(x, y))

    def update(self):
        mouse_pos = pygame.mouse.get_pos()
        if self.rect.collidepoint(mouse_pos) and pygame.mouse.get_pressed()[0]:
            self.kill()

class Cloud(pygame.sprite.Sprite):
    def __init__(self, x, y):
        super().__init__()
        self.image = pygame.Surface((50, 20))
        self.image.set_colorkey((11, 12, 13))
        self.image.fill((11, 12, 13))
        pygame.draw.ellipse(self.image, pygame.Color('white'), self.image.get_rect())
        self.rect = self.image.get_rect(topleft=(x, y))

    def update(self):
        self.rect.move_ip(1, 0)
        if not pygame.display.get_surface().get_rect().colliderect(self.rect):
            self.rect.right = 0

stuff = pygame.sprite.Group(Cloud(0, 30), Cloud(100, 40), Cloud(50, 50), 
                             Coin(100, 100), Coin(150, 180), Coin(80, 200))

while True:
    for e in pygame.event.get():
        if e.type == pygame.QUIT:
            quit()
    screen.fill(pygame.Color('lightblue'))
    stuff.draw(screen)
    stuff.update()
    pygame.display.flip()
    clock.tick(30)

我们通过使用 pygameGroup和Sprite类来抽象绘制和更新我们的对象。

看看在我们的小游戏中添加新东西是多么容易。我添加了币你可以点击我收集，币的所有行为都位于Coin类中。单击硬币后，将调用该类的kill方法，该方法Sprite只是将对象从其所有组中删除，因此它不再在该stuff组中，并且不再在屏幕上绘制，并有效地从游戏中删除（并回答您的问题“仅运行一次 if 语句”）。