CommonBoundarySetting.cs

    Vector2 initPos;
    Vector2 MinPos;
    Vector2 MaxPos;
    Vector2 targetPos;

    public float Speed = 2;
    public float thresholdStopDistance = .3f;

    void Start()
    {
        initPos = transform.position;
        targetPos = initPos;

        Vector2 Size = GetComponent<SpriteRenderer>().bounds.extents;
        MinPos = (Vector2)Camera.main.ViewportToWorldPoint(new Vector2(0, 0)) + Size;
        MaxPos = (Vector2)Camera.main.ViewportToWorldPoint(new Vector2(1, 1)) - Size;
    }