and again

include/td/simulation/RealTimeSimulation.h

@@ -17,9 +17,18 @@ class RealTimeSimulation {
 	std::size_t m_CurrentStep;
 
   public:
+	/**
+	 * \param a_StepTime in ms
+	 */
 	RealTimeSimulation(game::World& a_World, GameHistory&& a_History, std::uint64_t a_StepTime);
 
-	void Update();
+	/**
+	 * \return the progress [0-1] between two steps
+	 */
+	float Update();
+
+  private:
+	void Step();
 };
 
 }  // namespace sim