//this will store the initial posityion of the joystick, so it returns to its position when we dont click the screen
    private Vector3 initPosOfJoystick;
    //this will store the transform of joystick
    public RectTransform joystick;

    //this will store the canvas 
    Canvas canvas;

    //this will store the limit of the movement of the joystick
    float limitOfJoystick;

    //this will be true if we are dragging the joystick, we need this, so that we only start moving the joystick when we have clicked it, and not outside of it
    bool amIDragging = false;

    private void Start()
        //get the initial position of the joystick
        initPosOfJoystick = joystick.position;

    // Update is called once per frame
    void Update()
        //if the mouse is clicking
            //this will store the movepos of the mouse
            Vector2 movePos;
            //get the mouse position on the canvas
                canvas.transform as RectTransform,
                Input.mousePosition, canvas.worldCamera,
                out movePos);


            //if the distance between the mouse and the 
            if (Vector3.Distance(canvas.transform.TransformPoint(movePos), initPosOfJoystick) < limitOfJoystick)
                //move the joystick to where the mouse is 
                joystick.position = canvas.transform.TransformPoint(movePos);
                amIDragging = true;
            //if we are not inside the joystick space, we need to move the joystick to where the mouse is pointing within the limit of the joystick movement
            //and we have started dragging this joystick, we can move him even tho the mouse pos is outside the joystick
            else if(amIDragging==true)
                //this will get the offset from the mouse position and the initial joystick position
                Vector3 offset = canvas.transform.TransformPoint(movePos) - initPosOfJoystick;
                //this will move the mouse within the limitis of the joystick space
                joystick.position = initPosOfJoystick + Vector3.ClampMagnitude(offset, limitOfJoystick);
        //if we are not clicking the mouse / touchscreen e move the joystick to its initial position
            //move the joystick to its init pos
            joystick.position = initPosOfJoystick;
            //tell the code that we are no longer dragging
            amIDragging = false;
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