From 4c787ea0227ee891b3f7dac3d071e607fbf8d109 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 21 Oct 2010 10:55:35 +0000
Subject: [PATCH] Better lead route generation

---
 source/libmarklin/train.cpp | 42 ++++++++++++++++++++++++-------------
 source/libmarklin/train.h   |  2 +-
 2 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/source/libmarklin/train.cpp b/source/libmarklin/train.cpp
index baa58db..ccb7cc2 100644
--- a/source/libmarklin/train.cpp
+++ b/source/libmarklin/train.cpp
@@ -214,15 +214,19 @@ void Train::set_route(const Route *r)
 
 	if(r && !cur_blocks.empty())
 	{
+		BlockRef &first = cur_blocks.front();
 		BlockRef &last = (rsv_blocks.empty() ? cur_blocks.back() : rsv_blocks.back());
 		BlockRef next = last.next();
-		const Block::Endpoint &ep = next.block->get_endpoints()[next.entry];
-		if(!r->get_tracks().count(ep.track))
-			routes.push_front(Route::find(*ep.track, ep.track_ep, *r));
-
-		/* XXX This is sort of a hack, but it keeps divert() happy.  Need to come
-		up with a better solution when there is time. */
-		routes.push_front(create_lead_route());
+		const Block::Endpoint &first_ep = first.block->get_endpoints()[first.entry];
+		const Block::Endpoint &next_ep = next.block->get_endpoints()[next.entry];
+		if(!r->get_tracks().count(next_ep.track))
+		{
+			Route *lead = Route::find(*next_ep.track, next_ep.track_ep, *r);
+			create_lead_route(lead, lead);
+			routes.push_front(lead);
+		}
+		else if(!r->get_tracks().count(first_ep.track))
+			routes.push_front(create_lead_route(0, r));
 	}
 
 	reserve_more();
@@ -246,7 +250,9 @@ void Train::go_to(const Track &to)
 	BlockRef next = last.next();
 	const Block::Endpoint &ep = next.block->get_endpoints()[next.entry];
 
-	set_route(Route::find(*ep.track, ep.track_ep, to));
+	Route *route = Route::find(*ep.track, ep.track_ep, to);
+	create_lead_route(route, route);
+	set_route(route);
 }
 
 bool Train::divert(Track &from)
@@ -1283,23 +1289,29 @@ bool Train::advance_route(list<RouteRef>::iterator &iter, const Track &track)
 	return true;
 }
 
-Route *Train::create_lead_route()
+Route *Train::create_lead_route(Route *lead, const Route *target)
 {
-	Route *lead = new Route(layout);
-	lead->set_name("Lead");
-	lead->set_temporary(true);
+	if(!lead)
+	{
+		lead = new Route(layout);
+		lead->set_name("Lead");
+		lead->set_temporary(true);
+	}
 
+	set<const Track *> tracks;
 	for(list<BlockRef>::iterator i=cur_blocks.begin(); i!=rsv_blocks.end(); )
 	{
-		// XXX Make Route eat non-const tracks to get rid of this idiocy and various const_casts
 		const set<Track *> &btracks = i->block->get_tracks();
-		set<const Track *> tracks(btracks.begin(), btracks.end());
-		lead->add_tracks(tracks);
+		for(set<Track *>::const_iterator j=btracks.begin(); j!=btracks.end(); ++j)
+			if(!target || !target->get_tracks().count(*j))
+				tracks.insert(*j);
 
 		if(++i==cur_blocks.end())
 			i = rsv_blocks.begin();
 	}
 
+	lead->add_tracks(tracks);
+
 	return lead;
 }
 
diff --git a/source/libmarklin/train.h b/source/libmarklin/train.h
index e675c4b..d9026c7 100644
--- a/source/libmarklin/train.h
+++ b/source/libmarklin/train.h
@@ -175,7 +175,7 @@ private:
 	void release_blocks(std::list<BlockRef> &, std::list<BlockRef>::iterator, std::list<BlockRef>::iterator);
 	void reverse_blocks(std::list<BlockRef> &) const;
 	bool advance_route(std::list<RouteRef>::iterator &, const Track &);
-	Route *create_lead_route();
+	Route *create_lead_route(Route *, const Route *);
 	bool is_valid_diversion(const Route &, const Track &, unsigned);
 };
 
-- 
2.45.2