Implement movement with the mouse.

src/fmri/RenderingState.hpp

@@ -68,6 +68,8 @@ namespace fmri
             float layerAlpha;
             float interactionAlpha;
             Color pathColor;
+            bool mouse_1_pressed = false;
+            bool mouse_2_pressed = false;
         } options;
         std::array<float, 3> pos;
         std::array<float, 2> angle;
@@ -83,6 +85,7 @@ namespace fmri
 
         void move(unsigned char key, bool sprint);
         void updateVisualisers();
+        void idleFunc();
 
         std::string debugInfo() const;
         void renderOverlayText() const;