void Update()
    {
        mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);

        if (Input.GetMouseButtonDown(0))
        {
            Vector2 reach = new Vector2(mousePos.x - transform.position.x, mousePos.y - transform.position.y);

            if (reach.magnitude < maxReachDistance)
            {
                var go = tilemap.GetTileGameObject(mousePos.x, mousePos.y);
                go.GetComponent <Renderer>().material.color = Color.grey;
                go.GetComponent <Collider2D>().enabled      = true;
            }
        }

        if (Input.GetMouseButton(1))
        {
            Vector2 reach = new Vector2(mousePos.x - transform.position.x, mousePos.y - transform.position.y);

            if (reach.magnitude < maxReachDistance)
            {
                var go   = tilemap.GetTileGameObject(mousePos.x, mousePos.y);
                var tile = tilemap.GetTile(mousePos.x, mousePos.y);

                go.GetComponent <Renderer>().material.color = perlinGenerator.BiomeToColor(tile);
                go.GetComponent <Collider2D>().enabled      = false;
            }
        }
    }