From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 5 Feb 2015 08:48:48 +0000 (+0200)
Subject: Penalize steps other than the fastest one
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=9976acc82d98c8aecde0152a72be8cc8882e35ff;p=r2c2.git

Penalize steps other than the fastest one

This encourages the planner to follow a single chain of steps and avoids
exploding the state tree too much.  In the future this may be replaced by
different speed limits on diverging paths of turnouts (reducing the
ambiguity of fastest path) and an actual heuristic for potential wait time
(giving wait states an implicit penalty).
---

diff --git a/source/libr2c2/trainrouteplanner.cpp b/source/libr2c2/trainrouteplanner.cpp
index 163bb28..dbe6035 100644
--- a/source/libr2c2/trainrouteplanner.cpp
+++ b/source/libr2c2/trainrouteplanner.cpp
@@ -427,6 +427,7 @@ TrainRoutePlanner::RoutingStep::RoutingStep():
 
 TrainRoutePlanner::RoutingStep::RoutingStep(const RoutingStep *p):
 	time(p->time),
+	penalty(p->penalty),
 	cost_estimate(p->cost_estimate),
 	trains(p->trains),
 	prev(p)
@@ -473,11 +474,20 @@ void TrainRoutePlanner::RoutingStep::create_successors(list<RoutingStep> &new_st
 				new_steps.push_back(next);
 		}
 
+	new_steps.sort();
+	for(list<RoutingStep>::iterator i=new_steps.begin(); ++i!=new_steps.end(); )
+	{
+		i->penalty += 5*Time::sec;
+		i->update_estimate();
+	}
+
 	if(next_entry_ep.paths!=next_track->get_type().get_paths())
 	{
 		RoutingStep wait(this);
 		wait.advance(dt);
 		wait.trains[train_index].state = WAITING;
+		wait.penalty += 15*Time::sec;
+		wait.update_estimate();
 		if(wait.is_viable())
 			new_steps.push_back(wait);
 	}
@@ -573,7 +583,7 @@ void TrainRoutePlanner::RoutingStep::advance(const Time::TimeDelta &dt)
 
 void TrainRoutePlanner::RoutingStep::update_estimate()
 {
-	cost_estimate = Time::zero;
+	cost_estimate = penalty;
 	for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 		if(i->remaining_estimate>=0)
 			cost_estimate += i->wait_time+((i->distance_traveled+i->remaining_estimate)/i->info->speed)*Time::sec;
diff --git a/source/libr2c2/trainrouteplanner.h b/source/libr2c2/trainrouteplanner.h
index fa97920..85a748c 100644
--- a/source/libr2c2/trainrouteplanner.h
+++ b/source/libr2c2/trainrouteplanner.h
@@ -98,6 +98,7 @@ private:
 	struct RoutingStep
 	{
 		Msp::Time::TimeDelta time;
+		Msp::Time::TimeDelta penalty;
 		Msp::Time::TimeDelta cost_estimate;
 		std::vector<TrainRoutingState> trains;
 		const RoutingStep *prev;