如何在pymunk和pyglet中让相机跟踪汽车

import pymunk
import pyglet

window = pyglet.window.Window(width=800, height=600)

space = pymunk.Space()
space.gravity = (0, -1000)  # 设置重力，可以根据需要调整数值

car_mass = 1
car_size = (50, 30)
car_moment = pymunk.moment_for_box(car_mass, car_size)
car_body = pymunk.Body(car_mass, car_moment)
car_shape = pymunk.Poly.create_box(car_body, car_size)
car_body.position = (400, 300)  # 设置汽车初始位置，可以根据需要调整坐标
space.add(car_body, car_shape)

camera_mass = 0  # 相机不受重力影响，所以质量为0
camera_size = (800, 600)  # 相机大小与窗口大小一致
camera_moment = pymunk.moment_for_box(camera_mass, camera_size)
camera_body = pymunk.Body(camera_mass, camera_moment)
camera_shape = pymunk.Poly.create_box(camera_body, camera_size)
space.add(camera_body, camera_shape)

pivot = pymunk.constraint.PivotJoint(car_body, camera_body, (0, 0), (0, 0))
space.add(pivot)

@window.event
def update(dt):
    space.step(dt)  # 更新pymunk空间

    # 设置相机位置为汽车位置的负偏移量
    camera_body.position = (-car_body.position.x + window.width / 2, -car_body.position.y + window.height / 2)

@window.event
def on_draw():
    window.clear()
    car_shape.draw()
    camera_shape.draw()

pyglet.clock.schedule_interval(update, 1 / 60)  # 设置更新频率为60帧/秒
pyglet.app.run()