Ubuntu 18.04（Virtualbox）上的滑动背景问题

Question

我运行 Ubuntu 18.04 在 VirtualBox Vm 上，我正在尝试编写一个非常简单的游戏。我尝试使用的滑动背景有问题。在第一个图像循环（起始背景和第一次重置）之后，背景出现故障并且不显示任何图像。这可能是与我在虚拟机上运行这个 .py 程序有关的问题吗？还是我使用了错误的代码？我想让背景图像不断循环，而不仅仅是一次。这是我的代码运行:

import pygame
import os

size = width, height = 750, 422
screen = pygame.display.set_mode(size)

img_path = os.path.join(os.getcwd())
background_image = pygame.image.load('background.jpg').convert()
bg_image_rect = background_image.get_rect()
pygame.mixer.pre_init(44100, 16, 2, 4096)

pygame.display.set_caption("BallGame")

class Ball(object):
    def __init__(self):
        self.image = pygame.image.load("ball.png")
        self.image_rect = self.image.get_rect()
        self.image_rect.x
        self.image_rect.y
        self.facing = 'LEFT'

    def handle_keys(self):
        key = pygame.key.get_pressed()
        dist = 5
        if key[pygame.K_DOWN] and self.image_rect.y < 321:
            self.facing = 'DOWN'
            self.image_rect.y += dist
        elif key[pygame.K_UP] and self.image_rect.y > 0:
            self.facing = 'UP'
            self.image_rect.y -= dist
        if key[pygame.K_RIGHT] and self.image_rect.x < 649:
            self.facing = 'RIGHT'
            self.image_rect.x += dist
        elif key[pygame.K_LEFT] and self.image_rect.x > 0:
            self.facing = 'LEFT'
            self.image_rect.x -= dist

    def draw(self, surface):
        if self.facing == "RIGHT":
            surface.blit(pygame.transform.flip(self.image, True, False),(self.image_rect.x,self.image_rect.y))
        elif self.facing == "DOWN":
            surface.blit(pygame.image.load("ball_down.png"),(self.image_rect.x,self.image_rect.y))
        if self.facing == "UP":
            surface.blit(pygame.image.load("ball_up.png"),(self.image_rect.x,self.image_rect.y))
        elif self.facing == "LEFT":
            surface.blit(self.image,(self.image_rect.x,self.image_rect.y))


pygame.init()
screen = pygame.display.set_mode((750, 422))

ball = Ball()
clock = pygame.time.Clock()

pygame.mixer.music.load("bg_music.mp3")
pygame.mixer.music.play(-1, 0.0)

running = True
while running:
    esc_key = pygame.key.get_pressed()
    for event in pygame.event.get():
        if esc_key[pygame.K_ESCAPE]:
            pygame.display.quit()
            pygame.quit()
            running = False

    ball.handle_keys()

    screen.blit(background_image, bg_image_rect)
    screen.blit(background_image, bg_image_rect.move(bg_image_rect.width, 0))
    bg_image_rect.move_ip(-2, 0)
    if bg_image_rect.right == 0:
        bg_image_rect.x == 0


    ball.draw(screen)
    pygame.display.update()

    clock.tick(60)

Answer 1

您的问题出在您检查背景的当前位置并重置它时：

if bg_image_rect.right == 0:
    bg_image_rect.x == 0

首先，if 语句假定您的 bg_image_rect.right 在滚动时将完全到达 0 位置。根据 window 大小和背景大小的组合，滚动可能看起来像： 13, 11, 9, 7, 5, 3, 1, -1, -3, -5。这意味着 right == 0 永远不会是 True.

其次，您在 x 的作业中有错字。 bg_image_rect.x == 0 是比较两个值。你需要 bg_image_rect.x = 0.

此部分需要更改为：

if bg_image_rect.right <= 0:
    bg_image_rect.x = 0

Ubuntu 18.04（Virtualbox）上的滑动背景问题

Issue with sliding background on Ubuntu18.04(Virtualbox)

python

virtualbox

pygame

python-3.x

ubuntu-18.04