From 4f158857ff60c674c6143c50ba93e56e0f9aced6 Mon Sep 17 00:00:00 2001
From: Shariff Faleel <shariff.mfa@outlook.com>
Date: Thu, 18 Jul 2024 17:32:19 -0700
Subject: [PATCH] Adding hover update event

---
 Runtime/Interaction/HPUIEvents.cs      | 44 ++++++++++++++++++++++++++
 Runtime/Interaction/HPUIInteractor.cs  | 35 +++++++++++++++++---
 Runtime/Interaction/IHPUIInteractor.cs |  5 +++
 3 files changed, 79 insertions(+), 5 deletions(-)

diff --git a/Runtime/Interaction/HPUIEvents.cs b/Runtime/Interaction/HPUIEvents.cs
index 558538a..acaae8f 100644
--- a/Runtime/Interaction/HPUIEvents.cs
+++ b/Runtime/Interaction/HPUIEvents.cs
@@ -19,6 +19,50 @@ public enum HPUIGestureState
     }
 
     #region events classes
+    /// <summary>
+    /// Event class that reports hover events
+    /// </summary>
+    public class HPUIHoverUpdateEvent : UnityEvent<HPUIHoverUpdateEventArgs>
+    {}
+
+    // NOTE: This is used instead of the IXRHoverStrength* interfaces as those
+    // interfaces don't report the data being exposed here.
+    /// <summary>
+    /// Event data associated with a Hover update on HPUI
+    /// </summary>
+    public class HPUIHoverUpdateEventArgs
+    {
+        /// <summary>
+        /// Instantiate hover event.
+        /// </summary>
+        public HPUIHoverUpdateEventArgs(IHPUIInteractor interactorObject, Vector3 hoverPoint, Vector3 attachPoint)
+        {
+            this.interactorObject = interactorObject;
+            this.hoverPoint = hoverPoint;
+            this.attachPoint = attachPoint;
+        }
+
+        /// <summary>
+        /// The Interactor associated with the interaction event.
+        /// </summary>
+        public IHPUIInteractor interactorObject { get; set; }
+
+        /// <summary>
+        /// The endpoint of the hover. This is generally the centroid when
+        /// the interactor is hovering on targets.
+        /// </summary>
+        public Vector3 hoverPoint { get; set; }
+
+        /// <summary>
+        /// The location of the attach transform.
+        /// <seealso cref="XRBaseInteractor.GetAttachTransform"/>
+        /// </summary>
+        public Vector3 attachPoint { get; set; }
+    }
+
+    /// <summary>
+    /// Base event class for tap/gesture events
+    /// </summary>
     public class HPUIInteractionEvent<T>: UnityEvent<T> where T: HPUIInteractionEventArgs
     {
         protected int eventsCount = 0;
diff --git a/Runtime/Interaction/HPUIInteractor.cs b/Runtime/Interaction/HPUIInteractor.cs
index 0831228..baa74b0 100644
--- a/Runtime/Interaction/HPUIInteractor.cs
+++ b/Runtime/Interaction/HPUIInteractor.cs
@@ -148,6 +148,13 @@ public RayCastTechniqueEnum RayCastTechnique {
         /// <inheritdoc />
         public HPUIGestureEvent GestureEvent { get => gestureEvent; set => gestureEvent = value; }
 
+        [SerializeField]
+        [Tooltip("Event triggered on hover update.")]
+        private HPUIHoverUpdateEvent hoverUpdateEvent = new HPUIHoverUpdateEvent();
+
+        /// <inheritdoc />
+        public HPUIHoverUpdateEvent HoverUpdateEvent { get => hoverUpdateEvent; set => hoverUpdateEvent = value; }
+
         [SerializeField]
         [Tooltip("Interation hover radius.")]
         private float interactionHoverRadius = 0.015f;
@@ -395,7 +402,6 @@ protected override void OnEnable()
 
         //FIXME: debug code
         public Transform o1, o2, o3;
-        public LineRenderer lineRenderer;
 
         /// <inheritdoc />
         public override void PreprocessInteractor(XRInteractionUpdateOrder.UpdatePhase updatePhase)
@@ -561,10 +567,12 @@ interactable is IHPUIInteractable hpuiInteractable &&
                         ListPool<InteractionInfo>.Release(kvp.Value);
                     }
 
-                    if (lineRenderer != null)
+                    if (validTargets.Count > 0)
                     {
-                        lineRenderer.SetPosition(0, attachTransform.position);
-                        lineRenderer.SetPosition(1, new Vector3(xEndPoint, yEndPoint, zEndPoint) / count);
+                        HoverUpdateEvent?.Invoke(new HPUIHoverUpdateEventArgs(
+                                                     this,
+                                                     new Vector3(xEndPoint, yEndPoint, zEndPoint) / count,
+                                                     attachTransform.position));
                     }
 
                     tempValidTargets.Clear();
@@ -580,6 +588,9 @@ interactable is IHPUIInteractable hpuiInteractable &&
                         // FIXME: QueryTriggerInteraction should be allowed to be set in inpsector
                         QueryTriggerInteraction.Ignore);
 
+                    Vector3 hoverPoint = attachTransform.position;
+                    float shortestInteractableDist = float.MaxValue;
+
                     for (var i = 0; i < numberOfOverlaps; ++i)
                     {
                         Collider collider = overlapSphereHits[i];
@@ -589,9 +600,23 @@ interactable is IHPUIInteractable hpuiInteractable &&
                             hpuiInteractable.IsHoverableBy(this))
                         {
                             XRInteractableUtility.TryGetClosestPointOnCollider(interactable, interactionPoint, out DistanceInfo info);
-                            validTargets.Add(hpuiInteractable, new InteractionInfo(Mathf.Sqrt(info.distanceSqr), info.point));
+                            float dist = Mathf.Sqrt(info.distanceSqr);
+                            validTargets.Add(hpuiInteractable, new InteractionInfo(dist, info.point));
+                            if (dist < shortestInteractableDist)
+                            {
+                                hoverPoint = info.point;
+                            }
                         }
                     }
+
+                    if (validTargets.Count > 0)
+                    {
+                        HoverUpdateEvent?.Invoke(new HPUIHoverUpdateEventArgs(
+                                                     this,
+                                                     hoverPoint,
+                                                     attachTransform.position));
+                    }
+
                 }
             }
             gestureLogic.Update(validTargets.ToDictionary(kvp => kvp.Key, kvp => new HPUIInteractionData(kvp.Value.distance, kvp.Value.huristic)));
diff --git a/Runtime/Interaction/IHPUIInteractor.cs b/Runtime/Interaction/IHPUIInteractor.cs
index 7926093..592cb4a 100644
--- a/Runtime/Interaction/IHPUIInteractor.cs
+++ b/Runtime/Interaction/IHPUIInteractor.cs
@@ -15,6 +15,11 @@ public interface IHPUIInteractor: IXRSelectInteractor, IXRHoverInteractor
         /// </summary>
         public HPUIGestureEvent GestureEvent { get; }
 
+        /// <summary>
+        /// Event that triggers with hover strength data
+        /// </summary>
+        public HPUIHoverUpdateEvent HoverUpdateEvent { get; }
+
         /// <summary>
         /// This is called when a tap event occurs on the interactable.
         /// </summary>