Merge branch 'master' of github.com:OpenSpace/OpenSpace into feature/data-management

include/openspace/engine/wrapper/sgctwindowwrapper.h

@@ -81,6 +81,9 @@ public:
 
     void swapBuffer() const override;
 
+    int nWindows() const override;
+    int currentWindowId() const override;
+
 private:
     properties::FloatProperty _eyeSeparation;
     properties::BoolProperty _showStatsGraph;

include/openspace/engine/wrapper/windowwrapper.h

@@ -271,8 +271,21 @@ public:
      */
     virtual void takeScreenshot(bool applyWarping = false) const;
 
+    /**
+     * Encourages the windowing system to swap the back- and front buffers
+     */
     virtual void swapBuffer() const;
 
+    /**
+     * Returns the number of windows that are currently instantiated
+     */
+    virtual int nWindows() const;
+
+    /**
+     * Returns the id of the current window (in the range [0, nWindows -1])
+     */
+    virtual int currentWindowId() const;
+
     struct WindowWrapperException : public ghoul::RuntimeError {
         explicit WindowWrapperException(const std::string& msg);
     };