import pygame

from pygame.locals import *

width = 800

height = 260

FPS = 30

class MyMap():

    def __init__(self,x,y):

        self.bg = pygame.image.load("image/bg.png")

        self.x = x

        self.y = y

    def map_rolling(self):

        if self.x < -790:

            self.x = 800

        else:

            self.x -= 5

    def map_update(self):

        SCREEN.blit(self.bg,(self.x,self.y))

def mainGame():

    score = 0

    over = False

    pygame.init()

    global SCREEN,FPSCLOCK

    SCREEN = pygame.display.set_mode((width,height))

    pygame.display.set_caption("小恐龙")

    FPSCLOCK = pygame.time.Clock()

    bg1 = MyMap(0,0)

    bg2 = MyMap(800,0)

    while True:

        for event in pygame.event.get():

            if event.type == QUIT:

                over = True

                exit()

            if over == False:

                bg1.map_update()

                bg1.map_rolling()

                bg2.map_update()

                bg2.map_rolling()

        pygame.display.flip()

        FPSCLOCK.tick(FPS)

if __name__ == '__main__':

    mainGame()