public class Joystick : MonoBehaviour {
         private Ray ray;
         private RaycastHit hit;
         private Transform myTransform;
         private Touch myTouch;
         public float speed = 0.1f;
         public Vector3 center;
         public float radius;

         void Start(){
                 myTransform = transform;
         }

         void Update(){
                 Vector3 movement = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
                 Vector3 newPos = transform.position + movement;
                 Vector3 offset = newPos - center;
                 transform.position = center + Vector3.ClampMagnitude(offset, radius);

                 if(Input.touchCount == 1){
                         myTouch = Input.GetTouch(0);
                         if(myTouch.phase == TouchPhase.Began){
                    ray = Camera.main.ScreenPointToRay(myTouch.position);
                         }
                         if(Physics.Raycast (ray, out hit)){
                    if(hit.collider.tag == "GameController"){
                    if(Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Moved){
                    Vector2 touchDeltaPosition = Input.GetTouch(0).deltaPosition;
                    transform.Translate(touchDeltaPosition.x * speed * Time.deltaTime, touchDeltaPosition.y * speed * Time.deltaTime, 0);
                    }
                    }
                         }
                 }

                 if(Input.touchCount <= 0){
                         transform.position = new Vector2(0, 0);
                 }
         }
}