text: import pygame
  pygame.init()
  window = pygame.display.set_mode((1200, 400))
  track = pygame.image.load('t6.png')
  car = pygame.image.load('car.png')
  car = pygame.transform.scale(car, (30, 60))
  car_x = 155
  car_y = 300
  focal_dis = 25
  cam_x_offset = 0
  cam_y_offset = 0
  direction = 'up'
  drive = True
  clock = pygame.time.Clock()
  while drive:
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              drive = False
      clock.tick(60)
      cam_x = car_x + cam_x_offset + 15
      cam_y = car_y + cam_y_offset + 15
      up_px = window.get_at((cam_x, cam_y - focal_dis))[0]
      down_px = window.get_at((cam_x, cam_y + focal_dis))[0]
      right_px = window.get_at((cam_x + focal_dis, cam_y))[0]
      print(up_px, right_px, down_px)
  
      # change direction (take turn)
      if direction == 'up' and up_px != 255 and right_px == 255:
          direction = 'right'
          cam_x_offset = 30
          car = pygame.transform.rotate(car, -90)
      elif direction == 'right' and right_px != 255 and down_px == 255:
          direction = 'down'
          car_x = car_x + 30
          cam_x_offset = 0
          cam_y_offset = 30
          car = pygame.transform.rotate(car, -90)
      elif direction == 'down' and down_px != 255 and right_px == 255:
          direction = 'right'
          car_y = car_y + 30
          cam_x_offset = 30
          cam_y_offset = 0
          car = pygame.transform.rotate(car, 90)
      elif direction == 'right' and right_px != 255 and up_px == 255:
          direction = 'up'
          car_x = car_x + 30
          cam_x_offset = 0
          car = pygame.transform.rotate(car, 90)
      # drive
      if direction == 'up' and up_px == 255:
          car_y = car_y - 2
      elif direction == 'right' and right_px == 255:
          car_x = car_x + 2
      elif direction == 'down' and down_px == 255:
          car_y = car_y + 2
      window.blit(track, (0, 0))
      window.blit(car, (car_x, car_y))
      pygame.draw.circle(window, (0, 255, 0), (cam_x, cam_y), 5, 5)
      pygame.display.update()