source/libr2c2/trainrouteplanner.cpp

   1 #include <msp/core/maputils.h>
   2 #include "catalogue.h"
   3 #include "layout.h"
   4 #include "route.h"
   5 #include "train.h"
   6 #include "trainroutemetric.h"
   7 #include "trainrouteplanner.h"
   8 #include "trainrouter.h"
   9 #include "vehicle.h"
  10
  11 using namespace std;
  12 using namespace Msp;
  13
  14 namespace R2C2 {
  15
  16 TrainRoutePlanner::TrainRoutePlanner(Layout &layout):
  17         result(PENDING)
  18 {
  19         const map<unsigned, Train *> &trains = layout.get_trains();
  20         for(map<unsigned, Train *>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
  21         {
  22                 TrainRoutingInfo info(*i->second);
  23                 if(info.router && info.router->get_destination())
  24                         routed_trains.push_back(info);
  25         }
  26 }
  27
  28 void TrainRoutePlanner::plan()
  29 {
  30         steps.clear();
  31         queue.clear();
  32         result = PENDING;
  33
  34         queue.push_back(RoutingStep());
  35         RoutingStep &start = queue.back();
  36         for(vector<TrainRoutingInfo>::iterator i=routed_trains.begin(); i!=routed_trains.end(); ++i)
  37                 start.trains.push_back(TrainRoutingState(*i));
  38         start.update_estimate();
  39
  40         const RoutingStep *goal = 0;
  41         while(!queue.empty())
  42         {
  43                 const RoutingStep &step = get_step();
  44                 if(step.is_goal())
  45                 {
  46                         goal = &step;
  47                         break;
  48                 }
  49
  50                 add_steps(step);
  51         }
  52
  53         if(goal)
  54         {
  55                 create_routes(*goal);
  56                 result = COMPLETE;
  57         }
  58         else
  59                 result = FAILED;
  60 }
  61
  62 const list<Route *> &TrainRoutePlanner::get_routes_for(const Train &train) const
  63 {
  64         return get_train_info(train).routes;
  65 }
  66
  67 const list<TrainRouter::SequencePoint> &TrainRoutePlanner::get_sequence_for(const Train &train) const
  68 {
  69         return get_train_info(train).sequence;
  70 }
  71
  72 const TrainRoutePlanner::TrainRoutingInfo &TrainRoutePlanner::get_train_info(const Train &train) const
  73 {
  74         for(vector<TrainRoutingInfo>::const_iterator i=routed_trains.begin(); i!=routed_trains.end(); ++i)
  75                 if(i->train==&train)
  76                         return *i;
  77
  78         throw key_error(train.get_name());
  79 }
  80
  81 const TrainRoutePlanner::RoutingStep &TrainRoutePlanner::get_step()
  82 {
  83         steps.splice(steps.end(), queue, queue.begin());
  84         return steps.back();
  85 }
  86
  87 void TrainRoutePlanner::add_steps(const RoutingStep &step)
  88 {
  89         list<RoutingStep> new_steps;
  90         step.create_successors(new_steps);
  91         new_steps.sort();
  92         queue.merge(new_steps);
  93 }
  94
  95 void TrainRoutePlanner::create_routes(const RoutingStep &goal)
  96 {
  97         for(vector<TrainRoutingInfo>::iterator i=routed_trains.begin(); i!=routed_trains.end(); ++i)
  98         {
  99                 i->routes.clear();
 100                 i->sequence.clear();
 101                 for(unsigned j=0; j<3; ++j)
 102                         i->track_history[j] = 0;
 103         }
 104
 105         map<Track *, TrainRouter::SequencePoint *> sequenced_tracks;
 106         unsigned sequence = steps.size();
 107         for(const RoutingStep *i=&goal; i; i=i->prev)
 108                 for(vector<TrainRoutingState>::const_iterator j=i->trains.begin(); j!=i->trains.end(); ++j)
 109                 {
 110                         Track **history = j->info->track_history;
 111                         if(j->track.track()==history[0])
 112                                 continue;
 113
 114                         Route *route = 0;
 115                         bool start_new_route = true;
 116                         if(!j->info->routes.empty())
 117                         {
 118                                 route = j->info->routes.front();
 119                                 start_new_route = route->has_track(*j->track);
 120                                 if(!start_new_route)
 121                                 {
 122                                         unsigned nls = j->track->get_n_link_slots();
 123                                         for(unsigned k=0; (!start_new_route && k<nls); ++k)
 124                                         {
 125                                                 Track *link = j->track->get_link(k);
 126                                                 start_new_route = (link && link!=history[0] && route->has_track(*link));
 127                                         }
 128                                 }
 129                         }
 130
 131                         if(start_new_route)
 132                         {
 133                                 route = new Route(j->info->train->get_layout());
 134                                 route->set_name("Router");
 135                                 route->set_temporary(true);
 136                                 for(unsigned k=2; k>0; --k)
 137                                         if(history[k])
 138                                                 route->add_track(*history[k]);
 139                                 j->info->routes.push_front(route);
 140                         }
 141
 142                         if(history[0])
 143                                 route->add_track(*history[0]);
 144                         for(unsigned k=2; k>0; --k)
 145                                 history[k] = history[k-1];
 146                         history[0] = j->track.track();
 147
 148                         bool waitable = j->track.endpoint().paths!=j->track->get_type().get_paths();
 149                         map<Track *, TrainRouter::SequencePoint *>::iterator k = sequenced_tracks.find(j->track.track());
 150                         if(k!=sequenced_tracks.end())
 151                         {
 152                                 if(!k->second->preceding_train)
 153                                 {
 154                                         k->second->preceding_train = j->info->train;
 155                                         k->second->sequence_in = sequence;
 156                                 }
 157                                 j->info->sequence.push_front(TrainRouter::SequencePoint(j->track->get_block(), sequence));
 158                                 if(waitable)
 159                                         k->second = &j->info->sequence.front();
 160                                 --sequence;
 161                         }
 162                         else if(waitable)
 163                         {
 164                                 j->info->sequence.push_front(TrainRouter::SequencePoint(j->track->get_block(), sequence));
 165                                 sequenced_tracks[j->track.track()] = &j->info->sequence.front();
 166                                 --sequence;
 167                         }
 168                 }
 169 }
 170
 171
 172 TrainRoutePlanner::TrainRoutingInfo::TrainRoutingInfo(Train &t):
 173         train(&t),
 174         speed(train->get_maximum_speed()),
 175         router(train->get_ai_of_type<TrainRouter>())
 176 {
 177         // If no maximum speed is specified, use a sensible default
 178         if(!speed)
 179                 speed = 20*train->get_layout().get_catalogue().get_scale();
 180 }
 181
 182
 183 TrainRoutePlanner::OccupiedTrack::OccupiedTrack(Track &t, unsigned p, OccupiedTrack *n):
 184         track(&t),
 185         path_length(track->get_type().get_path_length(p)),
 186         next(n),
 187         n_tracks(next ? next->n_tracks+1 : 1),
 188         refcount(1)
 189 {
 190         if(next)
 191                 ++next->refcount;
 192 }
 193
 194 TrainRoutePlanner::OccupiedTrack::OccupiedTrack(const OccupiedTrack &other):
 195         track(other.track),
 196         path_length(other.path_length),
 197         next(other.next),
 198         n_tracks(other.n_tracks),
 199         refcount(1)
 200 {
 201         if(next)
 202                 ++next->refcount;
 203 }
 204
 205 TrainRoutePlanner::OccupiedTrack::~OccupiedTrack()
 206 {
 207         if(next && !--next->refcount)
 208                 delete next;
 209 }
 210
 211
 212 TrainRoutePlanner::TrainRoutingState::TrainRoutingState(TrainRoutingInfo &inf):
 213         info(&inf),
 214         occupied_tracks(0),
 215         state(MOVING),
 216         delay(info->router->get_departure_delay()),
 217         waypoint(info->router->get_n_waypoints() ? 0 : -1),
 218         blocked_by(-1)
 219 {
 220         const Vehicle *veh = &info->train->get_vehicle(0);
 221         // TODO margins
 222         TrackOffsetIter track_and_offs = veh->get_placement().get_position(VehiclePlacement::FRONT_BUFFER);
 223         track = track_and_offs.track_iter();
 224         offset = track_and_offs.offset();
 225         path = track->get_active_path();
 226
 227         while(Vehicle *next = veh->get_link(1))
 228                 veh = next;
 229         track_and_offs = veh->get_placement().get_position(VehiclePlacement::BACK_BUFFER);
 230         back_offset = track_and_offs.offset();
 231
 232         TrackIter iter = track_and_offs.track_iter();
 233         while(1)
 234         {
 235                 occupied_tracks = new OccupiedTrack(*iter, iter->get_active_path(), occupied_tracks);
 236                 if(iter.track()==track.track())
 237                         break;
 238                 iter = iter.next();
 239         }
 240
 241         update_estimate();
 242 }
 243
 244 TrainRoutePlanner::TrainRoutingState::TrainRoutingState(const TrainRoutingState &other):
 245         info(other.info),
 246         track(other.track),
 247         path(other.path),
 248         occupied_tracks(other.occupied_tracks),
 249         offset(other.offset),
 250         back_offset(other.back_offset),
 251         state(other.state),
 252         delay(other.delay),
 253         waypoint(other.waypoint),
 254         distance_traveled(other.distance_traveled),
 255         remaining_estimate(other.remaining_estimate),
 256         wait_time(other.wait_time),
 257         blocked_by(other.blocked_by)
 258 {
 259         ++occupied_tracks->refcount;
 260 }
 261
 262 TrainRoutePlanner::TrainRoutingState::~TrainRoutingState()
 263 {
 264         if(occupied_tracks && !--occupied_tracks->refcount)
 265                 delete occupied_tracks;
 266 }
 267
 268 Time::TimeDelta TrainRoutePlanner::TrainRoutingState::get_time_to_next_track() const
 269 {
 270         return ((track->get_type().get_path_length(path)-offset)/info->speed)*Time::sec+delay;
 271 }
 272
 273 bool TrainRoutePlanner::TrainRoutingState::is_occupying(Track &trk) const
 274 {
 275         OccupiedTrack *occ = occupied_tracks;
 276         for(unsigned n=occ->n_tracks; n>0; --n, occ=occ->next)
 277                 if(occ->track==&trk)
 278                         return true;
 279         return false;
 280 }
 281
 282 bool TrainRoutePlanner::TrainRoutingState::check_arrival()
 283 {
 284         TrainRouter &router = *info->router;
 285         TrackIter next_track = track.next(path);
 286
 287         if(waypoint<0 && router.is_destination(*track) && !router.is_destination(*next_track))
 288         {
 289                 state = ARRIVED;
 290                 return true;
 291         }
 292         else if(waypoint>=0 && router.is_waypoint(waypoint, *track) && !router.is_waypoint(waypoint, *next_track))
 293         {
 294                 ++waypoint;
 295                 if(waypoint>=static_cast<int>(router.get_n_waypoints()))
 296                         waypoint = -1;
 297         }
 298
 299         return false;
 300 }
 301
 302 void TrainRoutePlanner::TrainRoutingState::advance(float distance)
 303 {
 304         offset += distance;
 305         back_offset += distance;
 306
 307         OccupiedTrack *last_occ = occupied_tracks;
 308         for(unsigned n=occupied_tracks->n_tracks; n>1; --n)
 309                 last_occ = last_occ->next;
 310
 311         // XXX What if there's multiple tracks to remove?
 312         if(back_offset>last_occ->path_length)
 313         {
 314                 back_offset -= last_occ->path_length;
 315                 if(occupied_tracks->refcount>1)
 316                 {
 317                         --occupied_tracks->refcount;
 318                         occupied_tracks = new OccupiedTrack(*occupied_tracks);
 319                 }
 320                 --occupied_tracks->n_tracks;
 321         }
 322
 323         distance_traveled += distance;
 324         remaining_estimate -= distance;
 325 }
 326
 327 void TrainRoutePlanner::TrainRoutingState::advance(const Time::TimeDelta &dt)
 328 {
 329         if(delay>=dt)
 330         {
 331                 delay -= dt;
 332                 return;
 333         }
 334
 335         float secs = dt/Time::sec;
 336         if(delay)
 337         {
 338                 secs -= delay/Time::sec;
 339                 delay = Time::zero;
 340         }
 341
 342         if(state==MOVING)
 343                 advance(info->speed*secs);
 344         else if(state!=ARRIVED)
 345                 wait_time += secs*Time::sec;
 346 }
 347
 348 void TrainRoutePlanner::TrainRoutingState::advance_track(unsigned next_path)
 349 {
 350         float distance = occupied_tracks->path_length-offset;
 351         track = track.next(path);
 352         path = next_path;
 353         occupied_tracks = new OccupiedTrack(*track, path, occupied_tracks);
 354         advance(distance);
 355         offset = 0;
 356 }
 357
 358 void TrainRoutePlanner::TrainRoutingState::update_estimate()
 359 {
 360         TrackIter iter = track.reverse(path);
 361         float distance = info->router->get_metric(waypoint).get_distance_from(*iter.track(), iter.entry());
 362         distance += track->get_type().get_path_length(path)-offset;
 363         remaining_estimate = distance;
 364 }
 365
 366
 367 TrainRoutePlanner::RoutingStep::RoutingStep():
 368         prev(0)
 369 { }
 370
 371 TrainRoutePlanner::RoutingStep::RoutingStep(const RoutingStep *p):
 372         time(p->time),
 373         cost_estimate(p->cost_estimate),
 374         trains(p->trains),
 375         prev(p)
 376 { }
 377
 378 void TrainRoutePlanner::RoutingStep::create_successors(list<RoutingStep> &new_steps) const
 379 {
 380         RoutingStep next(this);
 381         if(next.update_states())
 382         {
 383                 if(next.check_deadlocks())
 384                         return;
 385
 386                 new_steps.push_back(next);
 387                 return;
 388         }
 389
 390         int train_index = find_next_train();
 391         if(train_index<0)
 392                 return;
 393
 394         TrainRoutingState &train = next.trains[train_index];
 395
 396         Time::TimeDelta dt = train.get_time_to_next_track();
 397         next.advance(dt);
 398
 399         if(train.check_arrival())
 400         {
 401                 new_steps.push_back(next);
 402                 return;
 403         }
 404
 405         TrackIter next_track = train.track.next(train.path);
 406         train.advance_track(0);
 407
 408         const TrackType::Endpoint &next_entry_ep = next_track.endpoint();
 409         for(unsigned i=0; next_entry_ep.paths>>i; ++i)
 410                 if(next_entry_ep.has_path(i))
 411                 {
 412                         train.path = i;
 413                         train.update_estimate();
 414                         next.update_estimate();
 415                         if(next.is_viable())
 416                                 new_steps.push_back(next);
 417                 }
 418
 419         if(next_entry_ep.paths!=next_track->get_type().get_paths())
 420         {
 421                 RoutingStep wait(this);
 422                 wait.advance(dt);
 423                 wait.trains[train_index].state = WAITING;
 424                 if(wait.is_viable())
 425                         new_steps.push_back(wait);
 426         }
 427 }
 428
 429 bool TrainRoutePlanner::RoutingStep::update_states()
 430 {
 431         bool changes = false;
 432         for(vector<TrainRoutingState>::iterator i=trains.begin(); i!=trains.end(); ++i)
 433         {
 434                 if(i->state==ARRIVED)
 435                         continue;
 436
 437                 TrainState old_state = i->state;
 438
 439                 TrackIter next_track = i->track.next(i->path);
 440                 if(next_track)
 441                 {
 442                         i->blocked_by = get_occupant(*next_track);
 443                         if(i->blocked_by>=0)
 444                                 i->state = BLOCKED;
 445                         else if(i->state==BLOCKED)
 446                                 i->state = MOVING;
 447                 }
 448                 else
 449                         i->state = BLOCKED;
 450
 451                 if(i->state!=old_state)
 452                         changes = true;
 453         }
 454
 455         return changes;
 456 }
 457
 458 bool TrainRoutePlanner::RoutingStep::check_deadlocks() const
 459 {
 460         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 461         {
 462                 if(i->state!=BLOCKED)
 463                         continue;
 464
 465                 if(i->blocked_by<0)
 466                         return true;
 467
 468                 int slow = i->blocked_by;
 469                 int fast = trains[slow].blocked_by;
 470                 while(fast>=0 && trains[fast].blocked_by>=0)
 471                 {
 472                         if(fast==slow)
 473                                 return true;
 474
 475                         slow = trains[slow].blocked_by;
 476                         fast = trains[trains[fast].blocked_by].blocked_by;
 477                 }
 478         }
 479
 480         return false;
 481 }
 482
 483 int TrainRoutePlanner::RoutingStep::get_occupant(Track &track) const
 484 {
 485         for(unsigned i=0; i<trains.size(); ++i)
 486                 if(trains[i].is_occupying(track))
 487                         return i;
 488
 489         return -1;
 490 }
 491
 492 int TrainRoutePlanner::RoutingStep::find_next_train() const
 493 {
 494         Time::TimeDelta min_dt;
 495         int next_train = -1;
 496         for(unsigned i=0; i<trains.size(); ++i)
 497                 if(trains[i].state==MOVING)
 498                 {
 499                         Time::TimeDelta dt = trains[i].get_time_to_next_track();
 500                         if(dt<min_dt || next_train<0)
 501                         {
 502                                 min_dt = dt;
 503                                 next_train = i;
 504                         }
 505                 }
 506
 507         return next_train;
 508 }
 509
 510 void TrainRoutePlanner::RoutingStep::advance(const Time::TimeDelta &dt)
 511 {
 512         time += dt;
 513         for(vector<TrainRoutingState>::iterator i=trains.begin(); i!=trains.end(); ++i)
 514                 i->advance(dt);
 515 }
 516
 517 void TrainRoutePlanner::RoutingStep::update_estimate()
 518 {
 519         cost_estimate = Time::zero;
 520         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 521                 if(i->remaining_estimate>=0)
 522                         cost_estimate += i->wait_time+((i->distance_traveled+i->remaining_estimate)/i->info->speed)*Time::sec;
 523 }
 524
 525 bool TrainRoutePlanner::RoutingStep::is_viable() const
 526 {
 527         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 528                 if(i->remaining_estimate<0)
 529                         return false;
 530
 531         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 532                 if(i->state==MOVING)
 533                         return true;
 534
 535         return false;
 536 }
 537
 538 bool TrainRoutePlanner::RoutingStep::is_goal() const
 539 {
 540         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 541                 if(i->state!=ARRIVED)
 542                         return false;
 543         return true;
 544 }
 545
 546 bool TrainRoutePlanner::RoutingStep::operator<(const RoutingStep &other) const
 547 {
 548         return cost_estimate<other.cost_estimate;
 549 }
 550
 551 } // namespace R2C2