Moving the player on the y-axis

Question

I am working on a Pong-Clone for Android right now and have watched a tutorial about it. It works perfectly with the keyboard, but how do I get a similar control on the mobile phone. My current code looks like this:

    private void Start()
    {
        ball = GameObject.FindGameObjectWithTag("Ball").GetComponent<Ball>();
        col = GetComponent<BoxCollider2D>();
        if (side == Side.Left)
            forwardDirection = Vector2.right;
        else if (side == Side.Right)
            forwardDirection = Vector2.left;
    }

    private void Update()
    {
        if (!overridePosition)
            MovePaddle();
    }

    private void MovePaddle()
    {
        float targetYPosition = GetNewYPosition();
        ClampPosition(ref targetYPosition);
        transform.position = new Vector3(transform.position.x, targetYPosition, transform.position.z);
    }

    private void ClampPosition(ref float yPosition)
    {
        float minY = Camera.main.ScreenToWorldPoint(new Vector3(0, 0)).y;
        float maxY = Camera.main.ScreenToWorldPoint(new Vector3(0, Screen.height)).y;
        yPosition = Mathf.Clamp(yPosition, minY, maxY);
    }

    private float GetNewYPosition()
    {
        float result = transform.position.y;
        if (isAI)
        {
            if (BallIncoming())
            {
                if (firstIncoming)
                {
                    firstIncoming = false;
                    randomYOffset = GetRandomOffset();
                }
                result = Mathf.MoveTowards(transform.position.y, ball.transform.position.y + randomYOffset, moveSpeed * Time.deltaTime);
            }
            else
            {
                firstIncoming = true;
            }
        }
        else
        {
            float movement = Input.GetAxisRaw("Vertical " + side.ToString()) * moveSpeed * Time.deltaTime;
            result = transform.position.y + movement;
        }
        return result;
    }

I want the player to move on the y Axis, but I have no idea how I can do it with touch controls (I am new to games). I would really appreciate any help, so I can continue programming :)

Answer 1

I'm going to assume what you want isove the padel by touch and drag up or down.

I would keep your code for debugging and add a switch to only use touch if touch is supported and your code otherwise.

// Adjust via the Inspector how much the user has to drag in order to move the padel
[SerializeField] private float touchDragSensitivity = 1;
private float lastTouchPosY;

// Make sure to store the camera
// Using Camera.main is quite expensive!
[SerializeField] private Camera _mainCamera;

private void Awake()
{
    if(!_mainCamera) _mainCamera = GetComponent<Camera>();

    ...
}

private float GetNewPosition()
{
    ...

    else
    {
        var movement = 0f;
        if(!Input.touchSupported)
        {
            // For non-touch device keep your current code
            movement = Input.GetAxisRaw("Vertical " + side.ToString()) * moveSpeed * Time.deltaTime;
        }
        else
        {
            if(Input.touchCount > 0)
            {
                var touch = Input.GetTouch(0);
                var touchPositionY = _mainCamera.ScreenToWorldPoint(touch.position).y;
                if(touch.phase = TouchPhase.Moved)
                {
                    var delta = touchPositionY - lastTouchPosY;
                    movement = delta * touchDragSensitivity;
                }

                lastTouchPosY = touchPositionY;
            }
        }
        result = transform.position.y + movement;
    }
}

---

Or alternatively if you rather wanted a similar experience as for the button input you could also only check whether the touch is on the bottom or top half of the screen and move the padel constantly like with your original code before:

private void Update()
{
    ...

    else
    {
        var movement = 0f;
        if(!Input.touchSupported)
        {
            // For non-touch device keep your current code
            movement = Input.GetAxisRaw("Vertical " + side.ToString()) * moveSpeed * Time.deltaTime;
        }
        else
        {
            if(Input.touchCount > 0)
            {
                var touch = Input.GetTouch(0);
                var touchPositionY = touch.position.y;
                movement = (touchPositionY >= Screen.height / 2f ? 1 : -1) * moveSpeed * Time.deltaTime;
            }
        }
        result = transform.position.y + movement;
    }
}

---

Update

As to your question

is there some way to split the screen so two players can play on the same screen

Yes: You can add a check on which side a touch is using touch.position.x >= screen.width / 2f => right side.

You could e.g. filter for valid touches like

if(Input.touchCount > 0)
{
    if(side == Side.Right)
    {
        var validTouches = Input.touches.Where(t => t.position >= Screen.width / 2f).ToArray();
        if(validTouches.Length > 0)
        {
            var touchPositionY = validTouches[0].position.y;
       
            movement = (touchPositionY >= Screen.height / 2f ? 1 : -1) * moveSpeed * Time.deltaTime;
        }
    }
    else
    {
        var validTouches = Input.touches.Where(t => t.position < Screen.width / 2f).ToArray();
        if(validTouches.Length > 0)
        {
            var touchPositionY = validTouches[0].position.y;
       
            movement = (touchPositionY >= Screen.height / 2f ? 1 : -1) * moveSpeed * Time.deltaTime;
        }
    }
}