unity 2d camera 跟踪角色 加上背景大小限制移动

public Vector2 margin, Smoothing;
public BoxCollider2D bounds;//2d背景物理box
Vector3 min, max;
public Transform player;

Camera camera;

void Start () {

    min = bounds.bounds.min;
    max = bounds.bounds.max;
    camera = GetComponent<Camera>();

}

// Update is called once per frame
void Update () {

    var x = transform.position.x;
    var y = transform.position.y;

    if (Mathf.Abs(x-player.position.x)>margin.x)
    {
        x = Mathf.Lerp(x, player.position.x, Smoothing.x * Time.deltaTime);

    }

    if (Mathf.Abs(y-player.position.y)>margin.y)
    {
        y = Mathf.Lerp(y, player.position.y, Smoothing.y * Time.deltaTime);

    }


    var halfwidth = camera.orthographicSize * ((float) Screen.width / Screen.height);
    x = Mathf.Clamp(x, min.x + halfwidth, max.x - halfwidth);
    y = Mathf.Clamp(y, min.y + camera.orthographicSize, max.y - camera.orthographicSize);
    transform.position = new Vector3(x, y, transform.position.z);




}