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                         i->router->add_route(**j);
 112                 const TrainRoutingState *current_wait = 0;
 113                 for(list<const TrainRoutingState *>::const_iterator j=i->waits.begin(); j!=i->waits.end(); ++j)
 114                         if(!current_wait || (*j)->track.track()!=current_wait->track.track())
 115                         {
 116                                 Block &block = (*j)->track.next()->get_block();
 117                                 i->router->add_wait(block, 0);
 118                                 current_wait = *j;
 119                         }
 120         }
 121 }
 122
 123
 124 TrainRoutePlanner::TrainRoutingInfo::TrainRoutingInfo(Train &t):
 125         train(&t),
 126         speed(train->get_maximum_speed()),
 127         router(train->get_ai_of_type<TrainRouter>())
 128 {
 129         // If no maximum speed is specified, use a sensible default
 130         if(!speed)
 131                 speed = 20*train->get_layout().get_catalogue().get_scale();
 132 }
 133
 134
 135 TrainRoutePlanner::OccupiedTrack::OccupiedTrack(Track &t, unsigned p, OccupiedTrack *n):
 136         track(&t),
 137         path_length(track->get_type().get_path_length(p)),
 138         next(n),
 139         n_tracks(next ? next->n_tracks+1 : 1),
 140         refcount(1)
 141 {
 142         if(next)
 143                 ++next->refcount;
 144 }
 145
 146 TrainRoutePlanner::OccupiedTrack::OccupiedTrack(const OccupiedTrack &other):
 147         track(other.track),
 148         path_length(other.path_length),
 149         next(other.next),
 150         n_tracks(other.n_tracks),
 151         refcount(1)
 152 {
 153         if(next)
 154                 ++next->refcount;
 155 }
 156
 157 TrainRoutePlanner::OccupiedTrack::~OccupiedTrack()
 158 {
 159         if(next && !--next->refcount)
 160                 delete next;
 161 }
 162
 163
 164 TrainRoutePlanner::TrainRoutingState::TrainRoutingState(TrainRoutingInfo &inf):
 165         info(&inf),
 166         occupied_tracks(0),
 167         state(MOVING),
 168         delay(info->router->get_departure_delay()),
 169         waypoint(info->router->get_n_waypoints() ? 0 : -1),
 170         blocked_by(-1)
 171 {
 172         const Vehicle *veh = &info->train->get_vehicle(0);
 173         // TODO margins
 174         TrackOffsetIter track_and_offs = veh->get_placement().get_position(VehiclePlacement::FRONT_BUFFER);
 175         track = track_and_offs.track_iter();
 176         offset = track_and_offs.offset();
 177         path = track->get_active_path();
 178
 179         while(Vehicle *next = veh->get_link(1))
 180                 veh = next;
 181         track_and_offs = veh->get_placement().get_position(VehiclePlacement::BACK_BUFFER);
 182         back_offset = track_and_offs.offset();
 183
 184         TrackIter iter = track_and_offs.track_iter();
 185         while(1)
 186         {
 187                 occupied_tracks = new OccupiedTrack(*iter, iter->get_active_path(), occupied_tracks);
 188                 if(iter.track()==track.track())
 189                         break;
 190                 iter = iter.next();
 191         }
 192
 193         update_estimate();
 194 }
 195
 196 TrainRoutePlanner::TrainRoutingState::TrainRoutingState(const TrainRoutingState &other):
 197         info(other.info),
 198         track(other.track),
 199         path(other.path),
 200         occupied_tracks(other.occupied_tracks),
 201         offset(other.offset),
 202         back_offset(other.back_offset),
 203         state(other.state),
 204         delay(other.delay),
 205         waypoint(other.waypoint),
 206         remaining_estimate(other.remaining_estimate),
 207         blocked_by(other.blocked_by)
 208 {
 209         ++occupied_tracks->refcount;
 210 }
 211
 212 TrainRoutePlanner::TrainRoutingState::~TrainRoutingState()
 213 {
 214         if(occupied_tracks && !--occupied_tracks->refcount)
 215                 delete occupied_tracks;
 216 }
 217
 218 Time::TimeDelta TrainRoutePlanner::TrainRoutingState::get_time_to_next_track() const
 219 {
 220         return ((track->get_type().get_path_length(path)-offset)/info->speed)*Time::sec+delay;
 221 }
 222
 223 bool TrainRoutePlanner::TrainRoutingState::is_occupying(Track &trk) const
 224 {
 225         OccupiedTrack *occ = occupied_tracks;
 226         for(unsigned n=occ->n_tracks; n>0; --n, occ=occ->next)
 227                 if(occ->track==&trk)
 228                         return true;
 229         return false;
 230 }
 231
 232 bool TrainRoutePlanner::TrainRoutingState::check_arrival()
 233 {
 234         TrainRouter &router = *info->router;
 235         TrackIter next_track = track.next(path);
 236
 237         if(waypoint<0 && router.is_destination(*track) && !router.is_destination(*next_track))
 238         {
 239                 state = ARRIVED;
 240                 return true;
 241         }
 242         else if(waypoint>=0 && router.is_waypoint(waypoint, *track) && !router.is_waypoint(waypoint, *next_track))
 243         {
 244                 ++waypoint;
 245                 if(waypoint>=static_cast<int>(router.get_n_waypoints()))
 246                         waypoint = -1;
 247         }
 248
 249         return false;
 250 }
 251
 252 void TrainRoutePlanner::TrainRoutingState::advance(float distance)
 253 {
 254         offset += distance;
 255         back_offset += distance;
 256
 257         OccupiedTrack *last_occ = occupied_tracks;
 258         for(unsigned n=occupied_tracks->n_tracks; n>1; --n)
 259                 last_occ = last_occ->next;
 260
 261         // XXX What if there's multiple tracks to remove?
 262         if(back_offset>last_occ->path_length)
 263         {
 264                 back_offset -= last_occ->path_length;
 265                 if(occupied_tracks->refcount>1)
 266                 {
 267                         --occupied_tracks->refcount;
 268                         occupied_tracks = new OccupiedTrack(*occupied_tracks);
 269                 }
 270                 --occupied_tracks->n_tracks;
 271         }
 272
 273         remaining_estimate -= distance;
 274 }
 275
 276 void TrainRoutePlanner::TrainRoutingState::advance_track(unsigned next_path)
 277 {
 278         float distance = occupied_tracks->path_length-offset;
 279         track = track.next(path);
 280         path = next_path;
 281         occupied_tracks = new OccupiedTrack(*track, path, occupied_tracks);
 282         advance(distance);
 283         offset = 0;
 284 }
 285
 286 void TrainRoutePlanner::TrainRoutingState::update_estimate()
 287 {
 288         TrackIter iter = track.reverse(path);
 289         float distance = info->router->get_metric(waypoint).get_distance_from(*iter.track(), iter.entry());
 290         distance += track->get_type().get_path_length(path)-offset;
 291         remaining_estimate = distance;
 292 }
 293
 294
 295 TrainRoutePlanner::RoutingStep::RoutingStep():
 296         prev(0)
 297 { }
 298
 299 TrainRoutePlanner::RoutingStep::RoutingStep(const RoutingStep *p):
 300         time(p->time),
 301         total_estimate(p->total_estimate),
 302         trains(p->trains),
 303         prev(p)
 304 { }
 305
 306 void TrainRoutePlanner::RoutingStep::create_successors(list<RoutingStep> &new_steps) const
 307 {
 308         RoutingStep next(this);
 309         if(next.update_states())
 310         {
 311                 if(next.check_deadlocks())
 312                         return;
 313
 314                 new_steps.push_back(next);
 315                 return;
 316         }
 317
 318         int train_index = find_next_train();
 319         if(train_index<0)
 320                 return;
 321
 322         TrainRoutingState &train = next.trains[train_index];
 323
 324         Time::TimeDelta dt = train.get_time_to_next_track();
 325         next.advance(dt);
 326
 327         if(train.check_arrival())
 328         {
 329                 new_steps.push_back(next);
 330                 return;
 331         }
 332
 333         TrackIter next_track = train.track.next(train.path);
 334         train.advance_track(0);
 335
 336         const TrackType::Endpoint &next_entry_ep = next_track.endpoint();
 337         for(unsigned i=0; next_entry_ep.paths>>i; ++i)
 338                 if(next_entry_ep.has_path(i))
 339                 {
 340                         train.path = i;
 341                         train.update_estimate();
 342                         next.update_estimate();
 343                         if(next.is_viable())
 344                                 new_steps.push_back(next);
 345                 }
 346
 347         if(next_entry_ep.paths!=next_track->get_type().get_paths())
 348         {
 349                 RoutingStep wait(this);
 350                 wait.advance(dt);
 351                 wait.trains[train_index].state = WAITING;
 352                 if(wait.is_viable())
 353                         new_steps.push_back(wait);
 354         }
 355 }
 356
 357 bool TrainRoutePlanner::RoutingStep::update_states()
 358 {
 359         bool changes = false;
 360         for(vector<TrainRoutingState>::iterator i=trains.begin(); i!=trains.end(); ++i)
 361         {
 362                 if(i->state==ARRIVED)
 363                         continue;
 364
 365                 TrainState old_state = i->state;
 366
 367                 TrackIter next_track = i->track.next(i->path);
 368                 if(next_track)
 369                 {
 370                         i->blocked_by = get_occupant(*next_track);
 371                         if(i->blocked_by>=0)
 372                                 i->state = BLOCKED;
 373                         else if(i->state==BLOCKED)
 374                                 i->state = MOVING;
 375                 }
 376                 else
 377                         i->state = BLOCKED;
 378
 379                 if(i->state!=old_state)
 380                         changes = true;
 381         }
 382
 383         return changes;
 384 }
 385
 386 bool TrainRoutePlanner::RoutingStep::check_deadlocks() const
 387 {
 388         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 389         {
 390                 if(i->state!=BLOCKED)
 391                         continue;
 392
 393                 if(i->blocked_by<0)
 394                         return true;
 395
 396                 int slow = i->blocked_by;
 397                 int fast = trains[slow].blocked_by;
 398                 while(fast>=0 && trains[fast].blocked_by>=0)
 399                 {
 400                         if(fast==slow)
 401                                 return true;
 402
 403                         slow = trains[slow].blocked_by;
 404                         fast = trains[trains[fast].blocked_by].blocked_by;
 405                 }
 406         }
 407
 408         return false;
 409 }
 410
 411 int TrainRoutePlanner::RoutingStep::get_occupant(Track &track) const
 412 {
 413         for(unsigned i=0; i<trains.size(); ++i)
 414                 if(trains[i].is_occupying(track))
 415                         return i;
 416
 417         return -1;
 418 }
 419
 420 int TrainRoutePlanner::RoutingStep::find_next_train() const
 421 {
 422         Time::TimeDelta min_dt;
 423         int next_train = -1;
 424         for(unsigned i=0; i<trains.size(); ++i)
 425                 if(trains[i].state==MOVING)
 426                 {
 427                         Time::TimeDelta dt = trains[i].get_time_to_next_track();
 428                         if(dt<min_dt || next_train<0)
 429                         {
 430                                 min_dt = dt;
 431                                 next_train = i;
 432                         }
 433                 }
 434
 435         return next_train;
 436 }
 437
 438 void TrainRoutePlanner::RoutingStep::advance(const Time::TimeDelta &dt)
 439 {
 440         time += dt;
 441         for(vector<TrainRoutingState>::iterator i=trains.begin(); i!=trains.end(); ++i)
 442         {
 443                 if(i->delay)
 444                 {
 445                         i->delay -= dt;
 446                         if(i->delay>Time::zero)
 447                                 continue;
 448                         i->delay = Time::zero;
 449                 }
 450                 else if(i->state==MOVING)
 451                         i->advance(i->info->speed*(dt/Time::sec));
 452         }
 453 }
 454
 455 void TrainRoutePlanner::RoutingStep::update_estimate()
 456 {
 457         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 458         {
 459                 Time::TimeDelta t = time+(i->remaining_estimate/i->info->speed)*Time::sec+i->delay;
 460                 if(i==trains.begin() || t>total_estimate)
 461                         total_estimate = t;
 462         }
 463 }
 464
 465 bool TrainRoutePlanner::RoutingStep::is_viable() const
 466 {
 467         if(total_estimate<Time::zero)
 468                 return false;
 469
 470         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 471                 if(i->remaining_estimate<0)
 472                         return false;
 473
 474         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 475                 if(i->state==MOVING)
 476                         return true;
 477
 478         return false;
 479 }
 480
 481 bool TrainRoutePlanner::RoutingStep::is_goal() const
 482 {
 483         for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
 484                 if(i->state!=ARRIVED)
 485                         return false;
 486         return true;
 487 }
 488
 489 bool TrainRoutePlanner::RoutingStep::operator<(const RoutingStep &other) const
 490 {
 491         return total_estimate<other.total_estimate;
 492 }
 493
 494 } // namespace R2C2