]> git.tdb.fi Git - r2c2.git/blobdiff - source/libr2c2/trainrouteplanner.cpp
Consider train length when calculating wait time estimate
[r2c2.git] / source / libr2c2 / trainrouteplanner.cpp
index b6d2f07cb66203ded55f3471110f94a0270287c0..e42e61838d4fdc0c7dfa74fe2aa7b451211c8421 100644 (file)
@@ -167,6 +167,7 @@ void TrainRoutePlanner::finalize_plan()
                for(vector<TrainRoutingState>::const_iterator j=i->trains.begin(); j!=i->trains.end(); ++j)
                {
                        Track **history = j->info->track_history;
+                       // Don't process the same track again.
                        if(j->track.track()==history[0])
                                continue;
 
@@ -174,6 +175,8 @@ void TrainRoutePlanner::finalize_plan()
                        bool start_new_route = true;
                        if(!j->info->routes.empty())
                        {
+                               /* If we already have a route and this track or any linked track is
+                               in it, start a new one to avoid loops. */
                                route = j->info->routes.front();
                                start_new_route = route->has_track(*j->track);
                                if(!start_new_route)
@@ -192,6 +195,8 @@ void TrainRoutePlanner::finalize_plan()
                                route = new Route(j->info->train->get_layout());
                                route->set_name("Router");
                                route->set_temporary(true);
+                               /* Have the routes overlap by two tracks to ensure that turnout
+                               paths can be deduced. */
                                for(unsigned k=0; (k<2 && history[k]); ++k)
                                        route->add_track(*history[k]);
                                j->info->routes.push_front(route);
@@ -205,6 +210,7 @@ void TrainRoutePlanner::finalize_plan()
                        map<Track *, TrainRouter::SequencePoint *>::iterator k = sequenced_tracks.find(j->track.track());
                        if(k!=sequenced_tracks.end())
                        {
+                               // Add a sequence point if another train uses this track afterwards.
                                if(!k->second->preceding_train)
                                {
                                        k->second->preceding_train = j->info->train;
@@ -217,6 +223,8 @@ void TrainRoutePlanner::finalize_plan()
                        }
                        else if(waitable)
                        {
+                               /* Create a sequence point if it's possible to wait and let another
+                               train past. */
                                j->info->sequence.push_front(TrainRouter::SequencePoint(j->track->get_block(), sequence));
                                sequenced_tracks[j->track.track()] = &j->info->sequence.front();
                                --sequence;
@@ -229,6 +237,7 @@ void TrainRoutePlanner::finalize_plan()
 
 TrainRoutePlanner::TrainRoutingInfo::TrainRoutingInfo(Train &t):
        train(&t),
+       length(0),
        speed(train->get_maximum_speed()),
        first_noncritical(train->get_last_critical_block().next().block()),
        router(train->get_ai_of_type<TrainRouter>()),
@@ -246,6 +255,10 @@ TrainRoutePlanner::TrainRoutingInfo::TrainRoutingInfo(Train &t):
                has_duration = router->get_trip_duration();
        }
 
+       unsigned n_vehs = train->get_n_vehicles();
+       for(unsigned i=0; i<n_vehs; ++i)
+               length += train->get_vehicle(i).get_type().get_length();
+
        // If no maximum speed is specified, use a sensible default
        if(!speed)
                speed = 20*train->get_layout().get_catalogue().get_scale();
@@ -330,6 +343,7 @@ TrainRoutePlanner::TrainRoutingState::TrainRoutingState(const TrainRoutingState
        distance_traveled(other.distance_traveled),
        remaining_estimate(other.remaining_estimate),
        wait_time(other.wait_time),
+       estimated_wait(other.estimated_wait),
        blocked_by(other.blocked_by)
 {
        ++occupied_tracks->refcount;
@@ -346,6 +360,26 @@ Time::TimeDelta TrainRoutePlanner::TrainRoutingState::get_time_to_next_track() c
        return ((track->get_type().get_path_length(path)-offset)/info->speed)*Time::sec+delay;
 }
 
+Time::TimeDelta TrainRoutePlanner::TrainRoutingState::get_time_to_pass(Track &trk) const
+{
+       if(is_occupying(trk))
+       {
+               float passed_length = 0;
+               for(const OccupiedTrack *occ=occupied_tracks; (occ && occ->track!=&trk); occ=occ->next)
+                       passed_length += occ->path_length;
+               return (max(info->length-passed_length, 0.0f)/info->speed)*Time::sec+delay;
+       }
+
+       for(unsigned wp=waypoint; wp<info->waypoints.size(); ++wp)
+       {
+               float distance = info->metrics[wp]->get_distance_from(trk);
+               if(distance>=0 && distance<remaining_estimate)
+                       return ((remaining_estimate-distance+info->length)/info->speed)*Time::sec+delay;
+       }
+
+       return Time::day;
+}
+
 bool TrainRoutePlanner::TrainRoutingState::is_occupying(Track &trk) const
 {
        if(state==ARRIVED && !duration && info->has_duration)
@@ -362,6 +396,7 @@ bool TrainRoutePlanner::TrainRoutingState::check_arrival()
 {
        TrackIter next_track = track.next(path);
 
+       // Check if we're about the exit the current waypoint's tracks.
        const TrainRouter::Waypoint &wp = info->waypoints[waypoint];
        if(wp.chain->has_track(*track) && !wp.chain->has_track(*next_track))
                if(wp.direction==TrackChain::UNSPECIFIED || track==wp.chain->iter_for(*track, wp.direction))
@@ -375,7 +410,8 @@ bool TrainRoutePlanner::TrainRoutingState::check_arrival()
                        }
                }
 
-       if(info->first_noncritical->has_track(*track))
+       // If we're entering the first non-critical block, clear the critical flag.
+       if(info->first_noncritical->has_track(*next_track))
                critical = false;
 
        return false;
@@ -386,6 +422,7 @@ void TrainRoutePlanner::TrainRoutingState::advance(float distance)
        offset += distance;
        back_offset += distance;
 
+       // See if the tail end of the train has passed any sensors.
        unsigned count_to_free = 0;
        unsigned last_sensor_addr = 0;
        float distance_after_sensor = 0;
@@ -408,6 +445,7 @@ void TrainRoutePlanner::TrainRoutingState::advance(float distance)
                occ = occ->next;
        }
 
+       // Free the last passed sensor and any tracks behind it.
        if(count_to_free && back_offset>distance_after_sensor)
        {
                back_offset -= distance_after_sensor;
@@ -432,6 +470,7 @@ void TrainRoutePlanner::TrainRoutingState::advance(const Time::TimeDelta &dt)
        }
 
        float secs = dt/Time::sec;
+       // There may be negative delay remaining after previous step.
        if(delay)
        {
                secs -= delay/Time::sec;
@@ -441,6 +480,9 @@ void TrainRoutePlanner::TrainRoutingState::advance(const Time::TimeDelta &dt)
        if(duration)
                duration = max(duration-secs*Time::sec, Time::zero);
 
+       if(estimated_wait)
+               estimated_wait = max(estimated_wait-secs*Time::sec, Time::zero);
+
        if(state==MOVING)
                advance(info->speed*secs);
        else if(state!=ARRIVED)
@@ -490,14 +532,8 @@ TrainRoutePlanner::RoutingStep::RoutingStep(const RoutingStep *p):
 void TrainRoutePlanner::RoutingStep::create_successors(list<RoutingStep> &new_steps) const
 {
        RoutingStep next(this);
-       if(next.update_states())
-       {
-               if(next.check_deadlocks())
-                       return;
-
-               new_steps.push_back(next);
+       if(next.update_states() && next.check_deadlocks())
                return;
-       }
 
        int train_index = find_next_train();
        if(train_index<0)
@@ -508,6 +544,8 @@ void TrainRoutePlanner::RoutingStep::create_successors(list<RoutingStep> &new_st
        Time::TimeDelta dt = train.get_time_to_next_track();
        next.advance(dt);
 
+       /* Check arrival after the train has advanced to the end of its current track
+       so travel time and occupied tracks will be correct. */
        if(train.check_arrival())
        {
                new_steps.push_back(next);
@@ -519,11 +557,14 @@ void TrainRoutePlanner::RoutingStep::create_successors(list<RoutingStep> &new_st
        const TrackType::Endpoint &entry_ep = train.track.endpoint();
        if(train.critical)
        {
+               /* Only create a successor step matching the currently set path for a
+               critical track. */
                unsigned critical_path = train.track->get_type().coerce_path(train.track.entry(), train.track->get_active_path());
                create_successor(next, train_index, critical_path, new_steps);
        }
        else
        {
+               // Create successor steps for all possible paths through the new track.
                for(unsigned i=0; entry_ep.paths>>i; ++i)
                        if(entry_ep.has_path(i))
                                create_successor(next, train_index, i, new_steps);
@@ -538,10 +579,21 @@ void TrainRoutePlanner::RoutingStep::create_successors(list<RoutingStep> &new_st
 
        if(entry_ep.paths!=train.track->get_type().get_paths() && !train.critical)
        {
+               /* Create a waiting state before the track if there's at least one path
+               that doesn't pass through the entry endpoint. */
                RoutingStep wait(this);
                wait.advance(dt);
                wait.trains[train_index].state = WAITING;
-               wait.penalty += 15*Time::sec;
+
+               Time::TimeDelta estimated_wait = Time::day;
+               for(unsigned i=0; i<wait.trains.size(); ++i)
+                       if(i!=static_cast<unsigned>(train_index) && wait.trains[i].state!=ARRIVED)
+                       {
+                               Time::TimeDelta ttp = wait.trains[i].get_time_to_pass(*train.track);
+                               estimated_wait = min(estimated_wait, ttp);
+                       }
+               wait.trains[train_index].estimated_wait = estimated_wait;
+
                wait.update_estimate();
                if(wait.is_viable())
                        new_steps.push_back(wait);
@@ -575,12 +627,23 @@ bool TrainRoutePlanner::RoutingStep::update_states()
                        i->blocked_by = get_occupant(*next_track);
                        if(i->blocked_by>=0)
                        {
+                               /* If the train is still traversing its last critical track, the
+                               flag needs to be cleared here to pass viability test. */
                                if(i->info->first_noncritical->has_track(*next_track))
                                        i->critical = false;
+
+                               if(i->state!=BLOCKED)
+                                       i->estimated_wait = trains[i->blocked_by].get_time_to_pass(*next_track);
+
+                               /* Trains in the WAITING state will also transition to BLOCKED and
+                               then to MOVING when the other train has passed. */
                                i->state = BLOCKED;
                        }
                        else if(i->state==BLOCKED)
+                       {
+                               i->estimated_wait = Time::zero;
                                i->state = MOVING;
+                       }
                }
                else
                        i->state = BLOCKED;
@@ -599,9 +662,12 @@ bool TrainRoutePlanner::RoutingStep::check_deadlocks() const
                if(i->state!=BLOCKED)
                        continue;
 
+               // A train blocked by end of track is always considered a deadlock.
                if(i->blocked_by<0)
                        return true;
 
+               /* Use the tortoise and hare algorithm to check if trains are blocked
+               cyclically (A blocks B, which blocks ..., which blocks A). */
                int slow = i->blocked_by;
                int fast = trains[slow].blocked_by;
                while(fast>=0 && trains[fast].blocked_by>=0)
@@ -656,7 +722,7 @@ void TrainRoutePlanner::RoutingStep::update_estimate()
        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;
+                       cost_estimate += i->wait_time+i->estimated_wait+((i->distance_traveled+i->remaining_estimate)/i->info->speed)*Time::sec;
 }
 
 bool TrainRoutePlanner::RoutingStep::is_viable() const