Better define default behaviour

include/ITA/simulation_scheduler/audibility_filter/audibility_filter_interface.h

@@ -55,11 +55,10 @@ namespace ITA
 				/// A filter might have a condition that has to be fulfilled to be actually useful.
 				/// Another filter might just be a conditional filter.
 				/// This function should handle both of these cases.
-				/// \note Default behaviour it to return true;
+				/// \note Default behaviour it to return true if \p previousState was created before \p newUpdate.
 				/// \param previousState the previous state of the scene to check against.
 				/// \param newUpdate the CUpdateScene to check.
 				/// \return true if the condition is fulfilled, else false.
-				/// \todo Check time stamps that this function was used correctly.
 				/// 
 				virtual bool conditionFulfilled(const CUpdateScene& previousState, const CUpdateScene& newUpdate);
 
@@ -68,11 +67,10 @@ namespace ITA
 				/// \brief Check if the change between \p previousState and \p newUpdate is audible.
 				///
 				///	This function might call ::conditionFulfilled to check if the condition for its test is fulfilled.
-				/// \note Default behaviour it to return true;
+				/// \note Default behaviour it to return the result of conditionFulfilled.
 				/// \param previousState the previous state of the scene to check against.
 				/// \param newUpdate the CUpdateScene to check for audibility.
 				/// \return true if the change between \p previousState and \p newUpdate is audible, else false.
-				/// \todo Check time stamps that this function was used correctly.
 				/// 
 				virtual bool changeIsAudible(const CUpdateScene& previousState, const CUpdateScene& newUpdate);
 			};

src/ITA/simulation_scheduler/audibility_filter/audibility_filter_interface.cpp

 #include <ITA/simulation_scheduler/audibility_filter/audibility_filter_interface.h>
 
+// simulation scheduler includes
+#include <ITA/simulation_scheduler/update_scene.h>
+
 namespace ITA
 {
 	namespace simulation_scheduler
@@ -9,18 +12,17 @@ namespace ITA
 			std::map<std::string, CAudibilityFilterFactory::CreateCallback> CAudibilityFilterFactory::m_mFilters;
 
 			// Definition of the pure virtual destructor.
-			IAudibilityFilter::~IAudibilityFilter()
-			{
-			}
+			IAudibilityFilter::~IAudibilityFilter ( )
+			{ }
 
-			bool IAudibilityFilter::conditionFulfilled(const CUpdateScene& previousState, const CUpdateScene& newUpdate)
+			bool IAudibilityFilter::conditionFulfilled ( const CUpdateScene& previousState, const CUpdateScene& newUpdate )
 			{
-				return true;
+				return previousState.getTimeStamp ( ) < newUpdate.getTimeStamp ( );
 			}
 
-			bool IAudibilityFilter::changeIsAudible(const CUpdateScene& previousState, const CUpdateScene& newUpdate)
+			bool IAudibilityFilter::changeIsAudible ( const CUpdateScene& previousState, const CUpdateScene& newUpdate )
 			{
-				return true;
+				return conditionFulfilled ( previousState, newUpdate );
 			}
 
 			void CAudibilityFilterFactory::registerFilter ( const std::string& type, CreateCallback createFunction )