source/libr2c2/trainrouteplanner.cpp

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