X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Flibmarklin%2Froute.cpp;fp=source%2Flibmarklin%2Froute.cpp;h=20017d240a429562a1e7e3907999eb40c2a2ebb6;hb=446fa7ad737b431621be53a23360ea3bbe417fe5;hp=40638d9683051fd3fa4581b14f3d6458d89d4880;hpb=45048d1eadafda8d956a074a730216cb74bffc51;p=r2c2.git

diff --git a/source/libmarklin/route.cpp b/source/libmarklin/route.cpp
index 40638d9..20017d2 100644
--- a/source/libmarklin/route.cpp
+++ b/source/libmarklin/route.cpp
@@ -92,17 +92,20 @@ void Route::update_turnouts()
 			const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 			const vector<Track *> &links = (*i)->get_links();
 
+			// Build a combined path mask from linked endpoints
 			unsigned mask = 15;
 			for(unsigned j=0; j<endpoints.size(); ++j)
 			{
 				if(!tracks.count(links[j]))
 					continue;
+
 				if(unsigned tid2=links[j]->get_turnout_id())
 				{
 					const Endpoint &ep = links[j]->get_type().get_endpoints()[links[j]->get_endpoint_by_link(**i)];
 					int p = get_turnout(tid2);
 					if(p>=0 && !(ep.paths&(1<<p)))
 					{
+						// The linked track is a turnout and has a path which is incompatible with this endpoint
 						mask &= ~endpoints[j].paths;
 						continue;
 					}
@@ -110,16 +113,19 @@ void Route::update_turnouts()
 				mask &= endpoints[j].paths;
 			}
 
-			if(!(mask&(mask-1)))
+			if(mask && !(mask&(mask-1)))
 			{
+				// Exactly one possible choice, set the path accordingly
 				unsigned path = 0;
 				for(; (mask && !(mask&1)); mask>>=1, ++path) ;
 				turnouts[tid] = path;
 			}
-			else
+			else if(!turnouts.count(tid))
+				// More than one possible choice, and no existing entry - set as undecided
 				turnouts[tid] = -1;
 		}
 
+	// Remove any turnouts that do not exist in the route
 	for(map<unsigned, int>::iterator i=turnouts.begin(); i!=turnouts.end();)
 	{
 		if(!found.count(i->first))
@@ -137,6 +143,7 @@ unsigned Route::check_validity(const Track &trk) const
 		int epi=(*i)->get_endpoint_by_link(trk);
 		if(epi>=0)
 		{
+			// Linked to an existing track - good
 			result |= 1;
 			const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 			if(unsigned tid=(*i)->get_turnout_id())
@@ -144,11 +151,13 @@ unsigned Route::check_validity(const Track &trk) const
 				int r = get_turnout(tid);
 				if(r>=0)
 				{
+					// Linking to a turnout with path set is only good if we're continuing that path
 					if(endpoints[epi].paths&(1<<r))
 						result |= 2;
 				}
 				else
 				{
+					// Linked to a turnout with no path set - find out other linked tracks 
 					unsigned count = 0;
 					const vector<Track *> &links = (*i)->get_links();
 					int epj = -1;
@@ -158,15 +167,19 @@ unsigned Route::check_validity(const Track &trk) const
 							++count;
 							epj = k;
 						}
+
+					// Only good if at most one other track is linked to the turnout
 					if(count<=1)
 					{
 						result |= 2;
 						if(epj>=0 && !(endpoints[epi].paths&endpoints[epj].paths))
+							// Impossible path through the turnout - not good
 							result &= 3;
 					}
 				}
 			}
 			else
+				// Linked to something linear - good
 				result |= 2;
 		}
 	}