iOS Player Input

Simulate Player Input With Mouse

If you don’t have access to a phone you can simulate a touch screen inside the Unity Editor with the mouse by going to Window > Analysis > Input Debugger. This will bring up an Input Debug window. Inside window click the Options dropdown and select Simulate Touch Input from Mouse or Pen. Now clicking the mouse in play mode will simulate touching the screen. Unfortunately you cannot simulate multi touch using the mouse so to do that you must use Unity Remote or build the project to your phone (Unity iOS Build).

Touch Utilities

The script below provided the following functionalities:

  • Project a ray from the camera through the touch point and gets the location of where the ray intersects a plane specified by the user.

TouchUtilities.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public static class TouchUtilities
{
    public static Vector3 GetTouchPositionOnPlane(Plane plane, Vector2 touchPosition)
    {
        Ray ray = Camera.main.ScreenPointToRay(touchPosition);
        // Plane.Raycast stores the distance from ray.origin to the hit point in this variable:
        float distance = 0;
        // if the ray hits the plane...
        if (plane.Raycast(ray, out distance))
        {
            // get the hit point:
            return ray.GetPoint(distance);
        }
        else
        {
            // Return Zero if no intersection occurs
            return Vector3.zero;
        }
    }
}

Get Touch Data Using Input Action Assets

Using Unity’s Input System (See: Using the Unity Input System Package), we can listen into touch events that allow us to detect when a touch begins and ends while also reading data from the input system to determine more information about the touche’s starting point, ending point, delta, etc.

Key Takeaways:

  • We create an Action Map containing Touch Actions.

  • We connect Touch actions to Input Events (See Scriptable Object Input Events V2) that trigger when touches begin and end (when the finger is placed on the screen, and released from the screen)

  • TouchVisualizer.cs connects activates / deactivates the touch visualization assets when detecting the touches happening. Additionally it reads in the TouchState property (touchAction.ReadValue<TouchState>()) from a Touch Action to get current and start position data.

TouchVisualizer.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;
using UnityEngine.InputSystem;
using UnityEngine.InputSystem.LowLevel;

public class TouchVisualizer : MonoBehaviour
{
    [SerializeField] private TextMeshProUGUI startPositionText;
    [SerializeField] private TextMeshProUGUI currentPositionText;
    [SerializeField] private InputActionReference touchActionReference;
    [SerializeField] private GameObject startSprite;
    [SerializeField] private GameObject endSprite;
    [SerializeField] private GameObject lineRendererObject;

    private LineRenderer lineRenderer;
    private InputAction touchAction;
    private bool isTouching;
    private Plane xyPlane;

    void Start()
    {
        // Save the action to a variable so we don't have to keep referring to the '.action' property
        touchAction = touchActionReference.action;
        // We need to make sure the touch action is enabled otherwise the input will not be processed.
        touchAction.Enable();

        xyPlane = new Plane(Vector3.forward, Vector3.zero);
        lineRenderer = lineRendererObject.GetComponent<LineRenderer>();

        // We assume the user is not touching the screen at the start
        OnTouchEnd();
    }

    public void OnTouchStart()
    {
        isTouching = true;
        EnableVisuals();
    }

    public void OnTouchEnd()
    {
        isTouching = false;
        DisableVisuals();
    }

    private void EnableVisuals()
    {
        startSprite.SetActive(true);
        endSprite.SetActive(true);
        lineRendererObject.SetActive(true);
    }

    private void DisableVisuals()
    {
        startPositionText.text = "Touch The Screen";
        currentPositionText.text = "Touch The Screen";
        startSprite.SetActive(false);
        endSprite.SetActive(false);
        lineRendererObject.SetActive(false);
    }

    void Update()
    {
        if (isTouching)
        {
            // Gather touch data from touch action
            TouchState touchState = touchAction.ReadValue<TouchState>();
            Vector2 startPosition = touchState.position;
            Vector2 currentPosition = touchState.startPosition;

            // Set text
            startPositionText.text = $"Start Position: {startPosition}";
            currentPositionText.text = $"Current Position: {currentPosition}";

            // Update positions of sprites and lines
            Vector3 startWorldPosition = TouchUtilities.GetTouchPositionOnPlane(xyPlane, startPosition);
            Vector3 currentWorldPosition = TouchUtilities.GetTouchPositionOnPlane(xyPlane, currentPosition);
            startSprite.transform.position = startWorldPosition;
            endSprite.transform.position = currentWorldPosition;
            lineRenderer.SetPosition(0, startWorldPosition);
            lineRenderer.SetPosition(1, currentWorldPosition);
        }
    }
}

Example

Important

This example requires the following packages to be installed:

  • TextMeshPro Essentials

  • Input System

Warning

This example also includes the following packages:

Note

This example also includes utilities for processing touch inputs as seen in Touch Utilities

Click to download InputActionTouchDataExample.unitypackage.

Get Touch Data Using EnhancedTouch

Unity’s Input System (See: Using the Unity Input System Package) comes with support for a class called EnhancedTouch.Touch. With this class we can detect how many fingers are touching the screen as well as the touch information associated with each finger.

Key Takeaways:

  • We enable Enhanced Touch features by calling EnhancedTouchSupport.Enable();

  • We connect Touch events to functions when enabling the TouchVisualizer (Touch.onFingerDown += OnFingerDown;).

  • We store a reference to a target “Finger” and then extract touch information from the finger (Touch touch = currentFinger.currentTouch;) to get current and start position data.

TouchVisualizer.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;
using UnityEngine.InputSystem.EnhancedTouch;
using Touch = UnityEngine.InputSystem.EnhancedTouch.Touch;

public class TouchVisualizer : MonoBehaviour
{
    [SerializeField] private TextMeshProUGUI startPositionText;
    [SerializeField] private TextMeshProUGUI currentPositionText;
    [SerializeField] private GameObject startSprite;
    [SerializeField] private GameObject endSprite;
    [SerializeField] private GameObject lineRendererObject;
    [SerializeField] private int fingerIndex;

    private LineRenderer lineRenderer;
    private bool isTouching;
    private Plane xyPlane;
    private Finger currentFinger;

    private void Awake()
    {
        // We need to call EnhancedTouchSupport.Enable() to use the EnhancedTouch.Touch API.
        EnhancedTouchSupport.Enable();
    }

    void Start()
    {
        xyPlane = new Plane(Vector3.forward, Vector3.zero);
        lineRenderer = lineRendererObject.GetComponent<LineRenderer>();

        // We assume the user is not touching the screen at the start
        isTouching = false;
        DisableVisuals();
    }

    // Connect Touch events to functions inside this class
    private void OnEnable()
    {
        Touch.onFingerDown += OnFingerDown;
        Touch.onFingerUp += OnFingerUp;
    }

    // Remove links to Touch events when this class is disabled
    private void OnDisable()
    {
        Touch.onFingerDown -= OnFingerDown;
        Touch.onFingerUp -= OnFingerUp;
    }

    public void OnFingerDown(Finger finger)
    {
        if (finger.index == fingerIndex)
        {
            currentFinger = finger;
            isTouching = true;
            EnableVisuals();
        }
    }

    public void OnFingerUp(Finger finger)
    {
        if (finger.index == fingerIndex)
        {
            isTouching = false;
            DisableVisuals();
        }
    }

    private void EnableVisuals()
    {
        startSprite.SetActive(true);
        endSprite.SetActive(true);
        lineRendererObject.SetActive(true);
    }

    private void DisableVisuals()
    {
        startPositionText.text = "Touch The Screen";
        currentPositionText.text = "Touch The Screen";
        startSprite.SetActive(false);
        endSprite.SetActive(false);
        lineRendererObject.SetActive(false);
    }

    void Update()
    {
        if (isTouching)
        {
            // Gather touch data from the current finger
            Touch touch = currentFinger.currentTouch;
            Vector2 startPosition = touch.startScreenPosition;
            Vector2 currentPosition = touch.screenPosition;

            // Set text
            startPositionText.text = $"Start Position: {startPosition}";
            currentPositionText.text = $"Current Position: {currentPosition}";

            // Update positions of sprites and lines
            Vector3 startWorldPosition = TouchUtilities.GetTouchPositionOnPlane(xyPlane, startPosition);
            Vector3 currentWorldPosition = TouchUtilities.GetTouchPositionOnPlane(xyPlane, currentPosition);
            startSprite.transform.position = startWorldPosition;
            endSprite.transform.position = currentWorldPosition;
            lineRenderer.SetPosition(0, startWorldPosition);
            lineRenderer.SetPosition(1, currentWorldPosition);
        }
    }
}

Example

Important

This example requires the following packages to be installed:

  • TextMeshPro Essentials

  • Input System

Note

This example also includes utilities for processing touch inputs as seen in Touch Utilities

Click to download EnhancedTouchDataExample.unitypackage.

Processing Touch Data Example

In the following code we are able to do more with processing touch input from the EnhancedTouch.Touch class. We have different behaviors for handling a single vs multiple touches.

Key Takeaways:

  • We enable Enhanced Touch features by calling EnhancedTouchSupport.Enable();

  • We connect Touch events to functions when enabling the TouchVisualizer (Touch.onFingerDown += OnFingerDown;).

  • We detect how many touches are occuring using Touch.activeTouches.Count and execute different behaviors depending on the amount of touches detected.

  • We extract touch data from individual touches using Touch.activeTouches[n].

Note

In this example we gather touch data from Touch.activeTouches instead of Touch.activeFingers since, at the time, touch data from fingers behaved in an odd way. For example, when the user’s finger stopped moving, the TouchPhase property of the touch data from Touch.activeFingers still registered as being Moved instead of stationary. Additionally the delta property would never reach 0. This was in contrast to touch data gathered from Touch.activeTouches which had phases and deltas that behaved as expected when a user’s finger stopped moving.

MultiTouchController.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.InputSystem.EnhancedTouch;
using Touch = UnityEngine.InputSystem.EnhancedTouch.Touch;
using TouchPhase = UnityEngine.InputSystem.TouchPhase;

public class MultiTouchController : MonoBehaviour
{
    [SerializeField] private GameObject targetObject;
    [SerializeField] private Camera mainCamera;
    [SerializeField] private float rotationScaling;
    [SerializeField] private float zoomScaling;
    [SerializeField] private float maxFov;
    [SerializeField] private float minFov;

    private bool isTouching;
    private Plane xyPlane;

    private void Awake()
    {
        // We need to call EnhancedTouchSupport.Enable() to use the EnhancedTouch.Touch API.
        EnhancedTouchSupport.Enable();
    }

    void Start()
    {
        // We assume the user is not touching the screen at the start
        isTouching = false;

        xyPlane = new Plane(Vector3.forward, Vector3.zero);
    }

    // Connect Touch events to functions inside this class
    private void OnEnable()
    {
        Touch.onFingerDown += OnFingerDown;
        Touch.onFingerUp += OnFingerUp;
    }

    // Remove links to Touch events when this class is disabled
    private void OnDisable()
    {
        Touch.onFingerDown -= OnFingerDown;
        Touch.onFingerUp -= OnFingerUp;
    }

    public void OnFingerDown(Finger finger)
    {
        isTouching = true;
    }

    public void OnFingerUp(Finger finger)
    {
        if (Touch.activeFingers.Count == 0)
        {
            isTouching = false;
        }
    }

    private void Handle2ActiveTouches()
    {
        Touch touch0 = Touch.activeTouches[0];
        Touch touch1 = Touch.activeTouches[1];
        if (touch0.phase == TouchPhase.Moved || touch1.phase == TouchPhase.Moved)
        {
            // handle position
            Vector2 currentPosition = (touch1.screenPosition + touch0.screenPosition) / 2;
            Vector2 previousPosition = (touch1.screenPosition - touch1.delta + touch0.screenPosition - touch0.delta) / 2;
            Vector3 currentWorldPosition = TouchUtilities.GetTouchPositionOnPlane(xyPlane, currentPosition);
            Vector3 previousWorldPosition = TouchUtilities.GetTouchPositionOnPlane(xyPlane, previousPosition);
            Vector3 delta = currentWorldPosition - previousWorldPosition;
            targetObject.transform.position += new Vector3(delta.x, delta.y, 0);

            // handle rotation
            Vector2 currentDirection = touch1.screenPosition - touch0.screenPosition;
            Vector2 previousDirection = (touch1.screenPosition - touch1.delta) - (touch0.screenPosition - touch0.delta);
            float angle = Vector2.SignedAngle(previousDirection, currentDirection);
            targetObject.transform.Rotate(new Vector3(0, 0, angle), Space.World);

            // handle zoom
            float currentDistance = currentDirection.magnitude;
            float previousDistance = previousDirection.magnitude;
            float zoomMagnitude = (currentDistance - previousDistance) * zoomScaling;
            float newFov = mainCamera.fieldOfView / (1+zoomMagnitude);
            if (zoomMagnitude < 0)
            {
                newFov = mainCamera.fieldOfView * (1-zoomMagnitude);
            }
            mainCamera.fieldOfView = Mathf.Clamp(newFov, minFov, maxFov);
        }
    }

    private void Handle1ActiveTouch()
    {
        Touch touch0 = Touch.activeTouches[0];
        if (touch0.phase == TouchPhase.Moved)
        {
            // handle position
            Vector3 currentWorldPosition = TouchUtilities.GetTouchPositionOnPlane(xyPlane, touch0.screenPosition);
            Vector3 previousWorldPosition = TouchUtilities.GetTouchPositionOnPlane(xyPlane, touch0.screenPosition - touch0.delta);
            Vector3 delta = currentWorldPosition - previousWorldPosition;
            targetObject.transform.position += new Vector3(delta.x, delta.y, 0);
        }
    }

    void Update()
    {
        if (isTouching)
        {
            int activeTouches = Touch.activeTouches.Count;
            if (activeTouches >= 2)
            {
                Handle2ActiveTouches();
            }
            else if (activeTouches == 1)
            {
                Handle1ActiveTouch();
            }
        }
    }
}

Important

This example requires the following packages to be installed:

  • Input System

Note

This example also includes utilities for processing touch inputs as seen in Touch Utilities

Click to download EnhancedMultiTouchExample.unitypackage.