X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Flibr2c2%2Ftrainroutemetric.cpp;h=469fc9494715dfea68be9517b7a71f1b783d8b89;hb=279f10b0dffc4b207b7998ac2761514b80d57780;hp=7e4d4856fe91a484f794470ce8a2e66a03151b96;hpb=3dd660ffad729fbd6e75e6401f5c7f27b9013faf;p=r2c2.git

diff --git a/source/libr2c2/trainroutemetric.cpp b/source/libr2c2/trainroutemetric.cpp
index 7e4d485..469fc94 100644
--- a/source/libr2c2/trainroutemetric.cpp
+++ b/source/libr2c2/trainroutemetric.cpp
@@ -9,6 +9,9 @@ namespace R2C2 {
 
 TrainRouteMetric::TrainRouteMetric(const TrackChain &tc, TrackChain::Direction dir)
 {
+	/* Initialize goals for tracks in the target chain.  We travel outwards from
+	the target in the search phase so the iters appear to point the wrong way. */
+	TrackChain::Direction reverse_dir = (dir==TrackChain::DOWN ? TrackChain::UP : TrackChain::DOWN);
 	const TrackChain::TrackSet &ctracks = tc.get_tracks();
 	for(TrackChain::TrackSet::const_iterator i=ctracks.begin(); i!=ctracks.end(); ++i)
 	{
@@ -31,6 +34,9 @@ TrainRouteMetric::TrainRouteMetric(const TrackChain &tc, TrackChain::Direction d
 		queue.push_back(i->track);
 	}
 
+	/* Use Dijkstra's algorithm to find the shortest distance from the goal to
+	every reachable track in the layout.  Entry points here become exit points
+	when looking up distances to the goal. */
 	while(!queue.empty())
 	{
 		TrackIter track = queue.front();