From 462a04be004ab4b0ff3ce14c51a19b50271b17c7 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 5 Feb 2015 15:58:45 +0200
Subject: [PATCH] Restructure lead route generation

All of the relevant logic is now in one place.
---
 source/libr2c2/trainrouter.cpp | 81 ++++++++++++++--------------------
 source/libr2c2/trainrouter.h   |  2 +-
 2 files changed, 33 insertions(+), 50 deletions(-)

diff --git a/source/libr2c2/trainrouter.cpp b/source/libr2c2/trainrouter.cpp
index ff3c664..13b2970 100644
--- a/source/libr2c2/trainrouter.cpp
+++ b/source/libr2c2/trainrouter.cpp
@@ -40,31 +40,12 @@ void TrainRouter::set_priority(int p)
 
 bool TrainRouter::set_route(const Route *r)
 {
-	BlockIter fncb = train.get_first_noncritical_block();
-
-	Route *lead = 0;
-	if(r && train.is_placed())
-	{
-		const BlockAllocator &allocator = train.get_block_allocator();
-		TrackIter first = allocator.first().track_iter();
-		TrackIter next = fncb.track_iter();
-		if(!r->has_track(*next))
-		{
-			lead = Route::find(next, *r);
-			if(!lead)
-				return false;
-			create_lead_route(lead, lead);
-		}
-		else if(!r->has_track(*first))
-			lead = create_lead_route(0, r);
-	}
-
 	routes.clear();
-	if(lead)
-		routes.push_back(lead);
-	// TODO Check if eclipsed by lead route
 	if(r)
+	{
 		routes.push_back(r);
+		create_lead_route();
+	}
 
 	destination = 0;
 	waypoints.clear();
@@ -234,20 +215,8 @@ void TrainRouter::tick(const Time::TimeDelta &dt)
 			const list<Route *> &planned_routes = planner->get_routes_for(train);
 
 			routes.clear();
-			Route *lead = create_lead_route(0, planned_routes.front());
-			routes.push_back(lead);
-
-			list<Route *>::const_iterator begin = planned_routes.begin();
-			for(; begin!=planned_routes.end(); ++begin)
-			{
-				const Route::TrackSet &tracks = (*begin)->get_tracks();
-				bool eclipsed = true;
-				for(Route::TrackSet::const_iterator i=tracks.begin(); (eclipsed && i!=tracks.end()); ++i)
-					eclipsed = lead->has_track(**i);
-				if(!eclipsed)
-					break;
-			}
-			routes.insert(routes.end(), begin, planned_routes.end());
+			routes.insert(routes.end(), planned_routes.begin(), planned_routes.end());
+			create_lead_route();
 
 			sequence_points = planner->get_sequence_for(train);
 			current_sequence = 0;
@@ -434,31 +403,45 @@ void TrainRouter::create_metrics()
 	metrics_stale = false;
 }
 
-Route *TrainRouter::create_lead_route(Route *lead, const Route *target)
+bool TrainRouter::create_lead_route()
 {
-	if(!lead)
+	if(routes.empty() || !train.is_placed())
+		return false;
+
+	BlockIter fncb = train.get_first_noncritical_block();
+	TrackIter next_track = fncb.track_iter();
+	if(!routes.front()->has_track(*next_track.flip()))
 	{
-		lead = new Route(train.get_layout());
-		lead->set_name("Lead");
-		lead->set_temporary(true);
+		Route *pf = Route::find(next_track, *routes.front());
+		if(!pf)
+			return false;
+
+		routes.push_front(pf);
 	}
 
-	unsigned target_tracks = 0;
-	for(TrackIter i=train.get_block_allocator().first().track_iter(); (target_tracks<2 && i); i=i.next())
+	TrackIter first_track = train.get_block_allocator().first().track_iter();
+	if(!routes.front()->has_track(*first_track))
 	{
-		if(i->get_block().get_train()!=&train)
-			break;
-		if(target)
+		Route *lead = new Route(train.get_layout());
+		lead->set_name("Lead");
+		lead->set_temporary(true);
+
+		unsigned target_tracks = 0;
+		for(TrackIter i=first_track; (target_tracks<2 && i); i=i.next())
 		{
-			if(target->has_track(*i))
+			if(i->get_block().get_train()!=&train)
+				break;
+			if(routes.front()->has_track(*i))
 				++target_tracks;
 			else if(target_tracks>0)
 				break;
+			lead->add_track(*i);
 		}
-		lead->add_track(*i);
+
+		routes.push_front(lead);
 	}
 
-	return lead;
+	return true;
 }
 
 bool TrainRouter::is_valid_for_track(const Route &route, Track &track) const
diff --git a/source/libr2c2/trainrouter.h b/source/libr2c2/trainrouter.h
index 2b59603..7a560a1 100644
--- a/source/libr2c2/trainrouter.h
+++ b/source/libr2c2/trainrouter.h
@@ -105,7 +105,7 @@ private:
 	void train_rear_advanced(Block &);
 
 	void create_metrics();
-	Route *create_lead_route(Route *, const Route *);
+	bool create_lead_route();
 	bool is_valid_for_track(const Route &, Track &) const;
 	bool advance_to_track(RouteList::iterator &, Track &);
 
-- 
2.43.0