Enable feature to limit the GUI, console, and Log output to a single window in a multi-window setup

include/openspace/engine/wrapper/sgctwindowwrapper.h

@@ -49,6 +49,8 @@ public:
     int currentNumberOfAaSamples() const override;
 
     bool isRegularRendering() const override;
+    bool hasGuiWindow() const override;
+    bool isGuiWindow() const override;
     
     glm::mat4 viewProjectionMatrix() const override;
     glm::mat4 modelMatrix() const override;

include/openspace/engine/wrapper/windowwrapper.h

@@ -125,6 +125,22 @@ public:
      */
     virtual bool isRegularRendering() const;
 
+    /**
+     * Returns <code>true</code> if there is a dedicated GUI window. In these cases, the
+     * GUI elements will not be drawn on the non-GUI windows but only on the dedicated
+     * windows.
+     * \return Whether there are dedicated GUI windows
+     */
+    virtual bool hasGuiWindow() const;
+
+    /**
+     * Returns <code>true</code> if the current rendering window is a GUI-only window. In
+     * these cases, the regular rendering is suppressed, but input is still possible in
+     * the window
+     * \return Whether the current rendering window is GUI-only
+     */
+    virtual bool isGuiWindow() const;
+
     /**
      * Returns the currently employed view-projection matrix. On default, this method will
      * return the identity matrix.