Iterate visualizers

Author: keveleigh

org.mixedrealitytoolkit.input/Visualizers/HandMeshVisualizer.cs

@@ -78,7 +78,7 @@ public XRInputButtonReader SelectInput
         /// </summary>
         /// <seealso cref="XRInputButtonReader.EnableDirectActionIfModeUsed"/>
         /// <seealso cref="XRInputButtonReader.DisableDirectActionIfModeUsed"/>
-        protected List<XRInputButtonReader> buttonReaders { get; } = new List<XRInputButtonReader>();
+        private readonly List<XRInputButtonReader> buttonReaders = new List<XRInputButtonReader>();
 
         /// <summary>
         /// Whether this visualizer currently has a loaded and visible hand mesh or not.

org.mixedrealitytoolkit.input/Visualizers/PlatformHandVisualizer/PlatformHandMeshVisualizer.cs

@@ -50,6 +50,9 @@ protected override void OnEnable()
 #if UNITY_OPENXR_PRESENT
             if (UnityEngine.XR.OpenXR.OpenXRRuntime.IsExtensionEnabled("XR_ANDROID_hand_mesh"))
             {
+                // If we already found our subsystem, just return
+                if (meshSubsystem != null && meshSubsystem.running) { return; }
+
                 List<XRMeshSubsystem> meshSubsystems = new List<XRMeshSubsystem>();
                 SubsystemManager.GetSubsystems(meshSubsystems);
                 foreach (XRMeshSubsystem subsystem in meshSubsystems)