Merge pull request #52 from OSVR/persistentSingleton

Made ClientKit a persistent singleton

Author: rpavlik

OSVR-Unity/Assets/OSVRUnity/src/ClientKit.cs

@@ -31,6 +31,9 @@ public class ClientKit : MonoBehaviour
 
             private OSVR.ClientKit.ClientContext contextObject;
 
+            /// Uses the Unity "Persistent Singleton" pattern, see http://unitypatterns.com/singletons/
+            private static ClientKit _instance;
+
             /// <summary>
             /// Use to access the single instance of this object/script in your game.
             /// </summary>
@@ -39,13 +42,19 @@ public static ClientKit instance
             {
                 get
                 {
-                    ClientKit candidate = GameObject.FindObjectOfType<ClientKit>();
-                    if (null == candidate)
+                    if(_instance == null)
                     {
-                        Debug.LogError("OSVR Error: You need the ClientKit prefab in your game!!");
+                        _instance = GameObject.FindObjectOfType<ClientKit>();
+                        if (_instance == null)
+                        {
+                            Debug.LogError("OSVR Error: You need the ClientKit prefab in your game!!");
+                        }
+                        else
+                        {
+                            DontDestroyOnLoad(_instance.gameObject);
+                        }
                     }
-                    return candidate;
-
+                    return _instance;
                 }
             }
 
@@ -78,7 +87,20 @@ private void EnsureStarted()
             void Awake()
             {
                 DLLSearchPathFixer.fix();
-                DontDestroyOnLoad(gameObject);
+                //if an instance of this singleton does not exist, set the instance to this object and make it persist
+                if(_instance == null)
+                {
+                    _instance = this;
+                    DontDestroyOnLoad(this);
+                }
+                else
+                {
+                    //if an instance of this singleton already exists, destroy this one
+                    if(_instance != this)
+                    {
+                        Destroy(this.gameObject);
+                    }
+                }
             }
             void Start()
             {

OSVR-Unity/Assets/OSVRUnity/src/VRHead.cs

@@ -54,6 +54,7 @@ public class VRHead : MonoBehaviour
             private Camera _camera;
             private DeviceDescriptor _deviceDescriptor;
             private OsvrDistortion _distortionEffect;
+            private DisplayInterface _displayInterface;
             private bool _initDisplayInterface = false;
             #endregion
 
@@ -68,27 +69,30 @@ void Start()
                     _distortionEffect.enabled = (viewMode == ViewMode.mono);
                 }
 
+                _displayInterface = GetComponent<DisplayInterface>();
+
                 //update VRHead with info from the display interface if it has been initialized
                 //it might not be initialized if it is still parsing a display json file
                 //in that case, we will try to initialize asap in the update function
-                if (GetComponent<DisplayInterface>().Initialized)
+                if (_displayInterface != null && _displayInterface.Initialized)
                 {
                     UpdateDisplayInterface();                  
-                }              
+                }
+                //else initialize in Update() 
             }         
             #endregion
 
             #region Loop
             void Update()
             {
-                
-                if(!_initDisplayInterface && !GetComponent<DisplayInterface>().Initialized)
+
+                if (!_initDisplayInterface && !_displayInterface.Initialized)
                 {
                     //if the display configuration hasn't initialized, ping the DisplayInterface to retrieve it from the ClientKit
                     //this would mean DisplayInterface was unable to retrieve that data in its Start() function.
-                    GetComponent<DisplayInterface>().ReadDisplayPath();
+                    _displayInterface.ReadDisplayPath();
                 }
-                else if (!_initDisplayInterface && GetComponent<DisplayInterface>().Initialized)
+                else if (!_initDisplayInterface && _displayInterface.Initialized)
                 {
                     //once the DisplayInterface has initialized, meaning it has read data from the /display path which contains
                     //display configuration, update the Camera and other settings with properties from the display configuration.
@@ -207,7 +211,7 @@ void Init()
             /// </summary>
             private void GetDeviceDescription()
             {
-                _deviceDescriptor = GetComponent<DisplayInterface>().GetDeviceDescription();
+                _deviceDescriptor = _displayInterface.GetDeviceDescription();
                 if (_deviceDescriptor != null)
                 {
                     switch (_deviceDescriptor.DisplayMode)