pygame精灵组绘制不是绘制所有精灵

Question

我写了一个程序，创建了4个精灵作为矩形，在pygame表面上反弹。位置在精灵的更新过程中更新。当我运行程序时，只有1-3个矩形出现，哪些矩形是随机出现的。我添加了一个print语句，可以看到每个sprite都在更新。你知道吗

代码如下：

# import pygame library so we can use it!
import pygame
import random
import mygame_colors

# run initialization code on the library
pygame.init()

# setup display dimensions
display_width = 1200
display_height = 600
FPS = 30

gameSurface = pygame.display.set_mode((display_width, display_height))
pygame.display.set_caption('Window Caption!')
colors = (mygame_colors.RED,mygame_colors.GREEN,mygame_colors.WHITE,mygame_colors.BLUE)

# game code that needs to run only once

class Enemy(pygame.sprite.Sprite):
    def __init__(self, number):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface((10*(number+1), 10))
        self.number = number
        # self.color = (random.randint(100,255),random.randint(100,255),random.randint(100,255))
        self.color = colors[x]
        self.image.fill(self.color)
        self.rect = self.image.get_rect()
        self.rect.center = (random.randint(0,display_width), random.randint(0,display_width))
        self.x_speed = random.randint(-30,30)
        if self.x_speed == 0:
            self.x_speed += 1
        self.y_speed = random.randint(-30,30)
        if self.y_speed == 0:
            self.y_speed += 1
    def update(self,*args):
        super().update(self,*args)
        self.rect.x += self.x_speed
        self.rect.y += self.y_speed
        x,y = self.rect.center
        if x > display_width or x < 0:
            self.x_speed *= -1
        if y > display_height or y < 0:
            self.y_speed *= -1
        print ("%s %s: %s,%s,%s"%(self.number,self.color,self.rect.x,self.rect.y,self.image))


# create game clock
clock = pygame.time.Clock()

# create a sprite group to keep track of sprites
all_sprites = pygame.sprite.Group()

for x in range(4):
   player = Enemy(x)
   all_sprites.add(player)

# fill entire screen with color
gameSurface.fill(mygame_colors.BLACK)

# main game loop
running = True  # when running is True game loop will run
while running == True:
    # get input events and respond to them
    # if event is .QUIT
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
    clock.tick(FPS)

    # game code that repeats every frame
    # clear display (redraw background)
    gameSurface.fill(mygame_colors.BLACK)


    # update
    all_sprites.update()    # draw all sprites
    all_sprites.draw(gameSurface)

    # pygame.draw.rect(gameSurface, r_color, [rectX, rectY, 25, 25])
    # pygame.draw.circle(gameSurface,r_color,(int(rectX),int(rectY)),25)
    # gameSurface.blit(image1, [rectX, rectY])


    # update and redraw entire screen
    pygame.display.flip()
    # pygame.display.update()

class Player(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface((50, 50))
        self.image.fill(pygameColors.GREEN)
        self.rect = self.image.get_rect()
        self.rect.center = (display_width / 2, display_height / 2)

Answer 1

一些矩形是随机出现在窗口外的，因为矩形位于区域display_width*display_width而不是display_width*display_height：

更改矩形的位置以解决问题：

self.rect.center = (random.randint(0,display_width), random.randint(0,display_width))self.rect.center = (random.randint(0,display_width), random.randint(0,display_height))