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