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using UnityEngine; |
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using UnityEngine.InputSystem; |
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public class InputManager : MonoBehaviour |
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{ |
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// the class generates from the InputActions asset (your name can vary) |
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private TouchInputs touchInputs; |
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// tracks which object is currently actively receiving touch input |
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private InputReceiver currentReceiver; |
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// the last touch position that was recorded |
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private Vector2 lastTouchPosition; |
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private void Awake() { |
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touchInputs = new(); |
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} |
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private void Start() { |
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// we subscribe to the start/cancel events of the Button action |
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touchInputs.CoreActions.PrimaryTouch.started += OnPrimaryTouchStarted; |
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touchInputs.CoreActions.PrimaryTouch.canceled += OnPrimaryTouchCancelled; |
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// and the performed event of the position tracking PassThrough Value action |
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touchInputs.CoreActions.PrimaryTouchPosition.performed += OnPrimaryTouchPositionChanged; |
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// NOTE: The PassThrough action will not raise the started/cancelled events |
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} |
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private void OnEnable() => touchInputs.Enable(); |
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private void OnDisable() => touchInputs.Disable(); |
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// Here we check if we have a current reciever, and if not ray-cast the touch position in screen-space to locate |
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// which object should be notified it is recieving touch inputs. Since we use Physics.Raycast() the object MUST |
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// have a collider. We also return whether this is the first touch of the new object or not. |
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private InputReceiver FindTouchReceiver(Vector2 touchPosition, Camera raycastCamera, out bool isFirstTouch) { |
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// if we already have a receiver, return it |
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// NOTE: We may need to reset this in some cases if the receiver is destroyed or |
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// if there was a focus change in the game (or the app was minimized/suspended). |
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if (currentReceiver) { |
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// TODO: Correctly handle focus loss and re-acquisition and destroyed objects |
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isFirstTouch = false; |
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return currentReceiver; |
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} |
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isFirstTouch = true; |
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if (raycastCamera) { |
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Ray ray = raycastCamera.ScreenPointToRay(touchPosition); |
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if (Physics.Raycast(ray, out var hit)) { |
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return hit.transform.GetComponent<InputReceiver>(); |
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} |
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} else { |
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Debug.Log("No camera provided found to raycast from."); |
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} |
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return null; |
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} |
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private void OnPrimaryTouchPositionChanged(InputAction.CallbackContext context) { |
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// we can read the Vector2 value from the event state and use it to maintain the last touch position |
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lastTouchPosition = context.ReadValue<Vector2>(); |
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if (currentReceiver) { |
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currentReceiver.OnTouchPositionUpdated(lastTouchPosition); |
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} |
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} |
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private void OnPrimaryTouchStarted(InputAction.CallbackContext context) { |
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// we can read the initial position of the touch event (this works because we use a Modifier in the action binding) |
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lastTouchPosition = context.ReadValue<Vector2>(); |
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var receiver = FindTouchReceiver(lastTouchPosition, Camera.main, out var isFirstTouch); |
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if (receiver) { |
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if(isFirstTouch) { // dispatch touch even as either an first touch, or touch position update |
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currentReceiver = receiver; |
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receiver.OnTouchStarted(lastTouchPosition); |
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} else { |
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currentReceiver.OnTouchPositionUpdated(lastTouchPosition); |
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} |
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} |
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} |
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// When the touch input ends, this even will be raised. NOTABLY, we don't try to read the touch input position |
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// from the context, as it will always be (0,0) here. Instead, we rely on the lastTouchPosition to notify the |
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// receiver of the last location of the touch input. |
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private void OnPrimaryTouchCancelled(InputAction.CallbackContext context) { |
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if (currentReceiver) { |
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currentReceiver.OnTouchStopped(lastTouchPosition); |
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} |
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currentReceiver = null; |
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} |
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} |
