python - 使用带有函数的pygame的角色动画问题

Question

我想请你帮忙解决我的这个问题。我需要在 pygame 中仅使用函数(无类)开发游戏。

我已经设法运行游戏，但动画或 Sprite 没有按预期更新。图像应该在移动时发生变化，但始终保持不变。

我做错了什么？

代码如下:

import pygame               

WIDTH = 800     
HEIGHT= 600      
pygame.display.set_caption("Nico's worst adventure")    
window = pygame.display.set_mode((WIDTH, HEIGHT))        

#Color         #R       #G      #B
White =      (255,     255,    255)
Black =       (0,       0,      0)
Red =        (255,     0,      0)
Blue =        (0,       0,      255)

#Position
x = 50
y = 425

imageWidth = 64

vel = 5                 #Velocity of movement

isJumping = False   
jumpCount = 10     

left = False       
right = False         
walkCount = 0   

#Image port
walkRight = [pygame.image.load('Nico right(1).png'), pygame.image.load('Nico right(2).png'), pygame.image.load('Nico right(3).png'), pygame.image.load('Nico right(4).png')]
walkLeft = [pygame.image.load('Nico left(1).png'), pygame.image.load('Nico left(2).png'), pygame.image.load('Nico left(3).png'), pygame.image.load('Nico left(4).png')]
still = pygame.image.load('Nico still.png')
backgorund = pygame.image.load('Fondo.png')



def drawCharacter():
    global walkCount                              
    window.blit(backgorund, (0,0))                           
    if walkCount + 1 >= 12:            
        walkCount = 0                  

    if left:
        window.blit(walkLeft[walkCount//3], (x, y))
        walkCount += 1
    elif right:
        window.blit(walkRight[walkCount//3], (x, y))
        walkCount += 1
    else:
        window.blit(still, (x, y))

    pygame.display.update()


def draw():
    global imageWidth
    global WIDTH
    global x                                           
    global y                                             
    global vel                                           
    global jumpCount                               
    global isJumping                                
    clock = pygame.time.Clock()                          
    play = True                                    
    #Main loop
    while play:                                       
        clock.tick(27)                                   
        pygame.init()                                  

        for event in pygame.event.get():               
            if event.type == pygame.QUIT:               
                play = False                          

        key = pygame.key.get_pressed()                 
        if key[pygame.K_LEFT] and x > vel:               
            x -= vel
            left = True
            right = False

        elif key[pygame.K_RIGHT] and x < WIDTH - imageWidth - vel:              
            x += vel
            right = True
            left = False
        else:                                          
            right = False
            left = False
            walkCount = 0                         

        if not(isJumping):                            
            if key[pygame.K_SPACE]:
                isJumping = True
                right = False
                left = False
                walkCount = 0

        else:
            if jumpCount >= -10:                        
                neg = 1                                    
                if jumpCount < 0:
                    neg = -1
                y -= (jumpCount ** 2) * 0.5 * neg      
                jumpCount -= 1
            else:
                isJumping = False
                jumpCount = 10


        drawCharacter()
        pygame.display.flip()


    pygame.quit()

draw()

我已经检查过它并与其他代码进行了比较，但我就是找不到真正的问题所在。

Answer 1

已经提到了简单的修复方法，但我更愿意建议完全摆脱全局变量，将它们移动到带有主循环的函数中，使它们成为局部变量。

此外，drawCharacter 函数不应该负责更新 walkCount 以及 blitting 图像。我只是删除它并更新 if key[pygame.K_LEFT]... 子句中的 walkCount ，然后使用它将当前玩家图像分配给一个变量(player_image)，稍后您可以在绘图部分进行 blit。这也允许您摆脱 left 和 right 变量。

drawCharacter 函数将只包含这两行，

window.blit(background, (0, 0))
window.blit(player_image, (x, y))

因此您也可以简单地在主循环中调用它们，而不是在函数中调用它们(您必须将这些参数传递给函数)。

另外，加载图片时调用convert或convert_alpha方法可以提高性能。

这是更新后的代码:

import pygame


pygame.init()
WIDTH = 800
HEIGHT= 600
pygame.display.set_caption("Nico's worst adventure")
window = pygame.display.set_mode((WIDTH, HEIGHT))

White = (255, 255, 255)
Black = (0, 0, 0)
Red = (255, 0, 0)
Blue = (0, 0, 255)
# Images (I assume you're using pictures with a transparent background
# so I call the `convert_alpha` method).
walkRight = [
    pygame.image.load('Nico right(1).png').convert_alpha(),
    pygame.image.load('Nico right(2).png').convert_alpha(),
    pygame.image.load('Nico right(3).png').convert_alpha(),
    pygame.image.load('Nico right(4).png').convert_alpha(),
    ]
walkLeft = [
    pygame.image.load('Nico left(1).png').convert_alpha(),
    pygame.image.load('Nico left(2).png').convert_alpha(),
    pygame.image.load('Nico left(3).png').convert_alpha(),
    pygame.image.load('Nico left(4).png').convert_alpha(),
    ]
still = pygame.image.load('Nico still.png').convert_alpha()
background = pygame.image.load('Fondo.png').convert()



def game():
    clock = pygame.time.Clock()
    # Player related variables.
    x = 50
    y = 425
    imageWidth = 64
    vel = 5
    isJumping = False
    jumpCount = 10
    walkCount = 0
    player_image = still  # Assign the current image to a variable.

    play = True
    while play:
        clock.tick(27)

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                play = False

        key = pygame.key.get_pressed()
        if key[pygame.K_LEFT] and x > vel:
            x -= vel
            # Update the walkCount and image here.
            walkCount += 1
            player_image = walkRight[walkCount//3]
        elif key[pygame.K_RIGHT] and x < WIDTH - imageWidth - vel:
            x += vel
            walkCount += 1
            player_image = walkLeft[walkCount//3]
        else:
            player_image = still
            walkCount = 0

        if walkCount + 1 >= 12:
            walkCount = 0

        if not isJumping:
            if key[pygame.K_SPACE]:
                isJumping = True
                walkCount = 0
        else:
            if jumpCount >= -10:
                neg = 1
                if jumpCount < 0:
                    neg = -1
                y -= (jumpCount ** 2) * 0.5 * neg
                jumpCount -= 1
            else:
                isJumping = False
                jumpCount = 10

        window.blit(background, (0, 0))
        window.blit(player_image, (x, y))  # Just blit the current image.
        pygame.display.flip()  # Only one `flip()` or `update()` call per frame.


game()
pygame.quit()