Add z order for HPUI Interactables

Author: ahmed-shariff

Editor/HPUIBaseInteractableEditor.cs

@@ -54,5 +54,9 @@ protected override List<string> GetDerivedSerializedPropertyNames()
             props.AddRange(EventPropertyNames);
             return props;
         }
+
+        /// <inheritdoc />
+        protected override void DrawSelectionConfiguration()
+        {}
     }
 }

Runtime/Interaction/HPUIBaseInteractable.cs

@@ -24,6 +24,12 @@ public Handedness Handedness
 
         public Collider boundsCollider;
 
+        [SerializeField]
+        private int _zOrder;
+
+        /// <inheritdoc />
+        public int zOrder { get => _zOrder; set => _zOrder = value; }
+
         [SerializeField]
         private HPUITapEvent tapEvent = new HPUITapEvent();
 
@@ -48,6 +54,7 @@ protected override void Awake()
         {
             base.Awake();
             getDistanceOverride = GetDistanceOverride;
+            selectMode = InteractableSelectMode.Single;
         }
 
         /// <inheritdoc />

Runtime/Interaction/HPUIInteractor.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using UnityEngine;
 using UnityEngine.Pool;
 using UnityEngine.XR.Hands;
@@ -14,7 +15,7 @@ namespace ubco.ovilab.HPUI.Interaction
     [DisallowMultipleComponent]
     public class HPUIInteractor: XRPokeInteractor, IHPUIInteractor
     {
-        public Handedness handedness;
+        public new Handedness handedness;
 
         // TODO move these to an asset?
         [SerializeField]
@@ -87,16 +88,21 @@ public override void GetValidTargets(List<IXRInteractable> targets)
             List<IXRInteractable> recievedTargets = ListPool<IXRInteractable>.Get();
             recievedTargets.AddRange(targets);
 
-            foreach(IXRInteractable target in recievedTargets)
+            targets.Clear();
+            foreach(IXRInteractable target in recievedTargets.Select(t => t as IHPUIInteractable).Where(ht => ht != null).OrderBy(ht => ht.zOrder))
             {
-                if (!(target is HPUIBaseInteractable hpuiTarget) || hpuiTarget.Handedness != handedness)
-                {
-                    targets.Remove(target);
-                }
+                targets.Add(target);
             }
             ListPool<IXRInteractable>.Release(recievedTargets);
         }
 
+        /// <inheritdoc />
+        public override bool CanSelect(IXRSelectInteractable interactable)
+        {
+            return ProcessSelectFilters(interactable);
+        }
+
+
         #region IHPUIInteractor interface
         /// <inheritdoc />
         public void OnTap(HPUITapEventArgs args)

Runtime/Interaction/IHPUIInteractable.cs

@@ -5,6 +5,11 @@ namespace ubco.ovilab.HPUI.Interaction
 {
     public interface IHPUIInteractable : IXRInteractable, IXRSelectInteractable
     {
+        /// <summary>
+        /// Lower z order will get higher priority.
+        /// </summary>
+        int zOrder { get; set; }
+
         /// <summary>
         /// Get the projection of the interactors position on the xz plane of this interactable, normalized.
         /// the returned Vector2 - (x, z) on the xz-plane.