Question

我正在尝试复制那些背景不断向左（或向上或向下）滑动的旧式街机游戏，但我正在寻找一些简单的代码行来实现该目标。会使背景图像向左移动，然后重置以添加同一图像的另一个副本的操作。您能建议我一个简单的方法将此功能添加到我的代码中吗？

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()

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, [0, 0])
    ball.draw(screen)
    pygame.display.update()

    clock.tick(40)

Answer 1

这是一个简单的例子。

请注意注释以得到解释。

import pygame

pygame.init()

screen = pygame.display.set_mode((640, 480))

clock = pygame.time.Clock()

# this is the background image
# we need to blit it two times, let's call them "left" and "right"
back_image = pygame.image.load('background.png')

# this rect will store the position of the "left"-part of the background
back_rect = back_image.get_rect()

while True:
    if pygame.event.get(pygame.QUIT):
        break

    for e in pygame.event.get():
        # your event handling here
        pass

    # this is the "left" image
    screen.blit(back_image, back_rect)
    # this is the "right" image, next to the left one
    # we calculate the "right" position by simply moving the rect by the width of the image
    screen.blit(back_image, back_rect.move(back_rect.width, 0))

    # we want a scrolling background, so we just move the position rect
    back_rect.move_ip(-2, 0)

    # it the right edge of the "left" image is zero, that means it's fully out of view
    if back_rect.right == 0:
        # so we reset the rect and start over
        back_rect.x = 0

    clock.tick(60)
    pygame.display.flip()

这是示例图片（另存为background.png）

最终结果将如下所示：

横向滚动背景

1 个答案: