From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 6 Feb 2015 14:32:18 +0000 (+0200)
Subject: Consider block deallocation when planning routes
X-Git-Url: http://git.tdb.fi/?p=r2c2.git;a=commitdiff_plain;h=ace4d2175dce7364ff094b8dd44c53e47ba395b1

Consider block deallocation when planning routes

Blocks are not released until a sensor is detriggered.  Not taking that
into account could cause situations where the planner tries to drive
trains through a balloon loop which is actually too small for them.
---

diff --git a/source/libr2c2/trainrouteplanner.cpp b/source/libr2c2/trainrouteplanner.cpp
index a05e97e..5bffec1 100644
--- a/source/libr2c2/trainrouteplanner.cpp
+++ b/source/libr2c2/trainrouteplanner.cpp
@@ -375,20 +375,37 @@ void TrainRoutePlanner::TrainRoutingState::advance(float distance)
 	offset += distance;
 	back_offset += distance;
 
-	OccupiedTrack *last_occ = occupied_tracks;
-	for(unsigned n=occupied_tracks->n_tracks; n>1; --n)
-		last_occ = last_occ->next;
+	unsigned count_to_free = 0;
+	unsigned last_sensor_addr = 0;
+	float distance_after_sensor = 0;
+	OccupiedTrack *occ = occupied_tracks;
+	for(unsigned n=occupied_tracks->n_tracks; n>0; --n)
+	{
+		if(unsigned saddr = occ->track->get_sensor_address())
+		{
+			if(saddr!=last_sensor_addr)
+			{
+				count_to_free = 0;
+				distance_after_sensor = 0;
+			}
+			last_sensor_addr = saddr;
+		}
+
+		++count_to_free;
+		distance_after_sensor += occ->path_length;
+
+		occ = occ->next;
+	}
 
-	// XXX What if there's multiple tracks to remove?
-	if(back_offset>last_occ->path_length)
+	if(count_to_free && back_offset>distance_after_sensor)
 	{
-		back_offset -= last_occ->path_length;
+		back_offset -= distance_after_sensor;
 		if(occupied_tracks->refcount>1)
 		{
 			--occupied_tracks->refcount;
 			occupied_tracks = new OccupiedTrack(*occupied_tracks);
 		}
-		--occupied_tracks->n_tracks;
+		occupied_tracks->n_tracks -= count_to_free;
 	}
 
 	distance_traveled += distance;