Merge branch 'master' into feature/FastVolume

include/openspace/engine/windowdelegate.h

@@ -118,6 +118,10 @@ struct WindowDelegate {
     double (*getHorizFieldOfView)() = []() { return 0.0; };
 
     void (*setHorizFieldOfView)(float hFovDeg) = [](float) { };
+    
+    void* (*getNativeWindowHandle)(size_t windowIndex) = [](size_t) -> void* { 
+        return nullptr; 
+    };
 
     using GLProcAddress = void(*)(void);