Fixed UWP Lag issue, changed from Event Based updates to polling.

Issue seems related to the way Unity is exposing the InteractionManager and access to the data within which seems UI / polling bound.

Author: SimonDarksideJ

Assets/MixedRealityToolkit/_Core/Devices/MixedReality/WindowsMixedRealityDeviceManager.cs

@@ -35,6 +35,16 @@ public WindowsMixedRealityDeviceManager(string name, uint priority) : base(name,
         /// </summary>
         private readonly Dictionary<uint, IMixedRealityController> activeControllers = new Dictionary<uint, IMixedRealityController>();
 
+        /// <summary>
+        /// Cache of the states captured from the Unity InteractionManager for UWP
+        /// </summary>
+        InteractionSourceState[] interactionmanagerStates;
+
+        /// <summary>
+        /// The current source state reading for the Unity InteractionManager for UWP
+        /// </summary>
+        public InteractionSourceState[] LastInteractionManagerStateReading { get; protected set; }
+
         /// <inheritdoc/>
         public override IMixedRealityController[] GetActiveControllers()
         {
@@ -243,21 +253,18 @@ public override void Enable()
             }
 
             InteractionManager.InteractionSourceDetected += InteractionManager_InteractionSourceDetected;
-            InteractionManager.InteractionSourceUpdated += InteractionManager_InteractionSourceUpdated;
-            InteractionManager.InteractionSourcePressed += InteractionManager_InteractionSourcePressed;
-            InteractionManager.InteractionSourceReleased += InteractionManager_InteractionSourceReleased;
             InteractionManager.InteractionSourceLost += InteractionManager_InteractionSourceLost;
 
-            InteractionSourceState[] states = InteractionManager.GetCurrentReading();
+            interactionmanagerStates = InteractionManager.GetCurrentReading();
 
             // NOTE: We update the source state data, in case an app wants to query it on source detected.
-            for (var i = 0; i < states.Length; i++)
+            for (var i = 0; i < interactionmanagerStates?.Length; i++)
             {
-                var controller = GetController(states[i].source);
+                var controller = GetController(interactionmanagerStates[i].source);
 
                 if (controller != null)
                 {
-                    controller.UpdateController(states[i]);
+                    controller.UpdateController(interactionmanagerStates[i]);
                     MixedRealityManager.InputSystem?.RaiseSourceDetected(controller.InputSource, controller);
                 }
             }
@@ -270,6 +277,26 @@ public override void Enable()
             }
         }
 
+        /// <inheritdoc/>
+        public override void Update()
+        {
+            base.Update();
+
+            interactionmanagerStates = InteractionManager.GetCurrentReading();
+
+            for (var i = 0; i < interactionmanagerStates?.Length; i++)
+            {
+                var controller = GetController(interactionmanagerStates[i].source);
+
+                if (controller != null)
+                {
+                    controller.UpdateController(interactionmanagerStates[i]);
+                }
+            }
+
+            LastInteractionManagerStateReading = interactionmanagerStates;
+        }
+
         private void RegisterGestureEvents()
         {
             if (gestureRecognizer == null)
@@ -333,9 +360,6 @@ public override void Disable()
             navigationGestureRecognizer?.Dispose();
 
             InteractionManager.InteractionSourceDetected -= InteractionManager_InteractionSourceDetected;
-            InteractionManager.InteractionSourcePressed -= InteractionManager_InteractionSourcePressed;
-            InteractionManager.InteractionSourceUpdated -= InteractionManager_InteractionSourceUpdated;
-            InteractionManager.InteractionSourceReleased -= InteractionManager_InteractionSourceReleased;
             InteractionManager.InteractionSourceLost -= InteractionManager_InteractionSourceLost;
 
             InteractionSourceState[] states = InteractionManager.GetCurrentReading();
@@ -438,33 +462,6 @@ private void InteractionManager_InteractionSourceDetected(InteractionSourceDetec
             controller?.UpdateController(args.state);
         }
 
-        /// <summary>
-        /// SDK Interaction Source Updated Event handler
-        /// </summary>
-        /// <param name="args">SDK source updated event arguments</param>
-        private void InteractionManager_InteractionSourceUpdated(InteractionSourceUpdatedEventArgs args)
-        {
-            GetController(args.state.source)?.UpdateController(args.state);
-        }
-
-        /// <summary>
-        /// SDK Interaction Source Pressed Event handler
-        /// </summary>
-        /// <param name="args">SDK source pressed event arguments</param>
-        private void InteractionManager_InteractionSourcePressed(InteractionSourcePressedEventArgs args)
-        {
-            GetController(args.state.source)?.UpdateController(args.state);
-        }
-
-        /// <summary>
-        /// SDK Interaction Source Released Event handler
-        /// </summary>
-        /// <param name="args">SDK source released event arguments</param>
-        private void InteractionManager_InteractionSourceReleased(InteractionSourceReleasedEventArgs args)
-        {
-            GetController(args.state.source)?.UpdateController(args.state);
-        }
-
         /// <summary>
         /// SDK Interaction Source Lost Event handler
         /// </summary>