source/libr2c2/route.cpp

   1 #include <queue>
   2 #include <msp/core/maputils.h>
   3 #include <msp/strings/format.h>
   4 #include "layout.h"
   5 #include "route.h"
   6 #include "track.h"
   7 #include "trackiter.h"
   8 #include "tracktype.h"
   9 #include "zone.h"
  10
  11 using namespace std;
  12 using namespace Msp;
  13
  14 namespace {
  15
  16 using namespace R2C2;
  17
  18 typedef std::pair<Track *, unsigned> Key;
  19
  20 struct Node
  21 {
  22         TrackIter track;
  23         Node *prev;
  24         float dist;
  25
  26         Node():
  27                 prev(0), dist(0)
  28         { }
  29
  30         Node(const TrackIter &t):
  31                 track(t), prev(0), dist(0)
  32         { }
  33
  34         Node(const TrackIter &t, Node &r, float d):
  35                 track(t), prev(&r), dist(prev->dist+d)
  36         { }
  37
  38         bool operator<(const Node &other) const
  39         { return dist>other.dist; }
  40 };
  41
  42 struct TrackMatch
  43 {
  44         Track &track;
  45
  46         TrackMatch(Track &t): track(t) { }
  47
  48         bool operator()(Track &t) const { return &t==&track; }
  49 };
  50
  51 struct TrackInSet
  52 {
  53         const set<Track *> &tracks;
  54
  55         TrackInSet(const set<Track *> &t): tracks(t) { }
  56
  57         bool operator()(Track &t) const { return tracks.count(&t); }
  58 };
  59
  60 template<typename Pred>
  61 list<Track *> dijkstra(const TrackIter &from, const Pred &goal)
  62 {
  63         map<Key, Node> track_nodes;
  64         priority_queue<Node> nodes;
  65         Node *final = 0;
  66
  67         nodes.push(from);
  68
  69         while(!nodes.empty())
  70         {
  71                 Node lowest = nodes.top();
  72                 nodes.pop();
  73
  74                 Key key(lowest.track.track(), lowest.track.entry());
  75                 if(track_nodes.count(key))
  76                         continue;
  77
  78                 Node &ref = track_nodes[key] = lowest;
  79                 if(goal(*lowest.track))
  80                 {
  81                         final = &ref;
  82                         break;
  83                 }
  84
  85                 unsigned paths = lowest.track.endpoint().paths;
  86                 for(unsigned i=0; paths>>i; ++i)
  87                         if(paths&(1<<i))
  88                         {
  89                                 TrackIter next = lowest.track.next(i);
  90                                 if(!next)
  91                                         continue;
  92
  93                                 if(track_nodes.count(Key(next.track(), next.entry())))
  94                                         continue;
  95
  96                                 nodes.push(Node(next, ref, lowest.track->get_type().get_path_length(i)));
  97                         }
  98         }
  99
 100         list<Track *> result;
 101         for(Node *node=final; node; node=node->prev)
 102                 result.push_front(&*node->track);
 103
 104         return result;
 105 }
 106
 107 template<typename Pred>
 108 Route *create_route(const TrackIter &from, const Pred &goal)
 109 {
 110         list<Track *> tracks = dijkstra(from, goal);
 111
 112         if(tracks.empty())
 113                 return 0;
 114
 115         Route *route = new Route(from->get_layout());
 116         for(list<Track *>::iterator i=tracks.begin(); i!=tracks.end(); ++i)
 117                 route->add_track(**i);
 118
 119         route->set_name("Pathfinder");
 120         route->set_temporary(true);
 121
 122         return route;
 123 }
 124
 125 }
 126
 127
 128 namespace R2C2 {
 129
 130 Route::Route(Layout &l):
 131         layout(l),
 132         temporary(false)
 133 {
 134         layout.add_route(*this);
 135         layout.signal_track_removed.connect(sigc::mem_fun(this, &Route::track_removed));
 136 }
 137
 138 Route::~Route()
 139 {
 140         layout.remove_route(*this);
 141 }
 142
 143 void Route::set_name(const string &n)
 144 {
 145         name = n;
 146         signal_name_changed.emit(name);
 147 }
 148
 149 void Route::set_temporary(bool t)
 150 {
 151         temporary = t;
 152 }
 153
 154 void Route::set_turnout(unsigned addr, unsigned path)
 155 {
 156         if(!addr)
 157                 throw InvalidParameterValue("Invalid turnout address");
 158         int &state = get_item(turnouts, addr);
 159         if(state>=0 && path!=static_cast<unsigned>(state))
 160                 throw InvalidState("Setting conflicts with route");
 161         state = path;
 162 }
 163
 164 void Route::update_turnouts()
 165 {
 166         set<unsigned> found;
 167         for(set<Track *>::const_iterator i=tracks.begin(); i!=tracks.end(); ++i)
 168                 if(unsigned tid = (*i)->get_turnout_id())
 169                 {
 170                         found.insert(tid);
 171
 172                         const vector<TrackType::Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 173                         const vector<Track *> &links = (*i)->get_links();
 174
 175                         // Build a combined path mask from linked endpoints
 176                         unsigned mask = (*i)->get_type().get_paths();
 177                         for(unsigned j=0; j<endpoints.size(); ++j)
 178                         {
 179                                 if(!tracks.count(links[j]))
 180                                         continue;
 181
 182                                 if(unsigned tid2 = links[j]->get_turnout_id())
 183                                 {
 184                                         const TrackType::Endpoint &ep = links[j]->get_type().get_endpoint(links[j]->get_endpoint_by_link(**i));
 185                                         int p = get_turnout(tid2);
 186                                         if(p>=0 && !(ep.paths&(1<<p)))
 187                                         {
 188                                                 // The linked track is a turnout and has a path which is incompatible with this endpoint
 189                                                 mask &= ~endpoints[j].paths;
 190                                                 continue;
 191                                         }
 192                                 }
 193                                 mask &= endpoints[j].paths;
 194                         }
 195
 196                         if(mask && !(mask&(mask-1)))
 197                         {
 198                                 // Exactly one possible choice, set the path accordingly
 199                                 unsigned path = 0;
 200                                 for(; (mask && !(mask&1)); mask>>=1, ++path) ;
 201                                 turnouts[tid] = path;
 202                         }
 203                         else if(!turnouts.count(tid))
 204                                 // More than one possible choice, and no existing entry - set as undecided
 205                                 turnouts[tid] = -1;
 206                 }
 207
 208         // Remove any turnouts that do not exist in the route
 209         for(map<unsigned, int>::iterator i=turnouts.begin(); i!=turnouts.end();)
 210         {
 211                 if(!found.count(i->first))
 212                         turnouts.erase(i++);
 213                 else
 214                         ++i;
 215         }
 216 }
 217
 218 int Route::get_turnout(unsigned id) const
 219 {
 220         map<unsigned, int>::const_iterator i = turnouts.find(id);
 221         if(i!=turnouts.end())
 222                 return i->second;
 223         return -1;
 224 }
 225
 226 unsigned Route::get_path(Track &trk) const
 227 {
 228         if(unsigned tid = trk.get_turnout_id())
 229         {
 230                 map<unsigned, int>::const_iterator i = turnouts.find(tid);
 231                 if(i!=turnouts.end())
 232                         return i->second;
 233         }
 234         return trk.get_active_path();
 235 }
 236
 237 void Route::add_track(Track &trk)
 238 {
 239         if(tracks.count(&trk))
 240                 return;
 241
 242         if(!tracks.empty())
 243         {
 244                 unsigned valid = check_validity(trk);
 245                 if(!(valid&1))
 246                         throw Exception("Not linked to existing tracks");
 247                 else if(!(valid&2))
 248                         throw Exception("Branching routes not allowed");
 249                 else if(!(valid&4))
 250                         throw Exception("Route must be smooth");
 251         }
 252
 253         tracks.insert(&trk);
 254         update_turnouts();
 255 }
 256
 257 void Route::add_tracks(const set<Track *> &trks)
 258 {
 259         set<Track *> pending;
 260         for(set<Track *>::const_iterator i=trks.begin(); i!=trks.end(); ++i)
 261                 if(!tracks.count(*i))
 262                         pending.insert(*i);
 263
 264         while(!pending.empty())
 265         {
 266                 bool found = false;
 267                 for(set<Track *>::const_iterator i=pending.begin(); i!=pending.end(); ++i)
 268                         if(tracks.empty() || check_validity(**i)==7)
 269                         {
 270                                 tracks.insert(*i);
 271                                 pending.erase(*i);
 272                                 found = true;
 273                                 break;
 274                         }
 275
 276                 if(!found)
 277                         throw Exception("Could not add all tracks to route");
 278         }
 279
 280         update_turnouts();
 281 }
 282
 283 void Route::add_track_chain(Track &start, unsigned ep, const TurnoutMap &trnts)
 284 {
 285         TrackIter iter(&start, ep);
 286         while(iter)
 287         {
 288                 if(iter->get_type().is_dead_end())
 289                         break;
 290
 291                 if(has_track(*iter))
 292                         break;
 293
 294                 int path = 0;
 295                 if(iter->get_turnout_id())
 296                 {
 297                         TurnoutMap::const_iterator i = trnts.find(iter->get_turnout_id());
 298                         if(i==trnts.end())
 299                                 break;
 300
 301                         path = i->second;
 302                 }
 303
 304                 add_track(*iter);
 305
 306                 iter = iter.next(path);
 307         }
 308 }
 309
 310 bool Route::has_track(Track &t) const
 311 {
 312         return tracks.count(&t);
 313 }
 314
 315 void Route::save(list<DataFile::Statement> &st) const
 316 {
 317         st.push_back((DataFile::Statement("name"), name));
 318         for(map<unsigned, int>::const_iterator i=turnouts.begin(); i!=turnouts.end(); ++i)
 319                 st.push_back((DataFile::Statement("turnout"), i->first, i->second));
 320 }
 321
 322 unsigned Route::check_validity(Track &trk) const
 323 {
 324         unsigned result = 4;
 325         const vector<Track *> &links = trk.get_links();
 326         for(vector<Track *>::const_iterator i=links.begin(); i!=links.end(); ++i)
 327         {
 328                 if(!*i)
 329                         continue;
 330                 if(!tracks.count(*i))
 331                         continue;
 332
 333                 // Linked to an existing track - good
 334                 result |= 1;
 335
 336                 if(unsigned tid = (*i)->get_turnout_id())
 337                 {
 338                         const TrackType::Endpoint &ep = (*i)->get_type().get_endpoint((*i)->get_endpoint_by_link(trk));
 339                         int path = get_turnout(tid);
 340                         if(path>=0)
 341                         {
 342                                 // Linking to a turnout with path set is only good if we're continuing that path
 343                                 if(ep.paths&(1<<path))
 344                                         result |= 2;
 345                         }
 346                         else
 347                         {
 348                                 // Linked to a turnout with no path set - check other linked tracks
 349                                 const vector<Track *> &tlinks = (*i)->get_links();
 350                                 unsigned count = 0;
 351                                 for(unsigned j=0; j<tlinks.size(); ++j)
 352                                         if(tracks.count(tlinks[j]))
 353                                         {
 354                                                 unsigned tid2 = tlinks[j]->get_turnout_id();
 355                                                 if(tid2)
 356                                                 {
 357                                                         const TrackType::Endpoint &ep2 = tlinks[j]->get_type().get_endpoint(tlinks[j]->get_endpoint_by_link(**i));
 358                                                         path = get_turnout(tid2);
 359                                                         // Ignore a linked turnout with some other path set
 360                                                         if(path>=0 && !(ep2.paths&(1<<path)))
 361                                                                 continue;
 362                                                 }
 363
 364                                                 ++count;
 365
 366                                                 const TrackType::Endpoint &ep2 = (*i)->get_type().get_endpoint(j);
 367                                                 if(!(ep.paths&ep2.paths))
 368                                                         // Impossible path through the turnout - not good
 369                                                         result &= 3;
 370                                         }
 371
 372                                 // Only good if at most one other track is linked to the turnout
 373                                 if(count<=1)
 374                                         result |= 2;
 375                         }
 376                 }
 377                 else
 378                         // Linked to something linear - good
 379                         result |= 2;
 380         }
 381
 382         return result;
 383 }
 384
 385 void Route::track_removed(Track &t)
 386 {
 387         tracks.erase(&t);
 388 }
 389
 390 Route *Route::find(const TrackIter &from, Track &to)
 391 {
 392         return create_route(from, TrackMatch(to));
 393 }
 394
 395 Route *Route::find(const TrackIter &from, const Route &to)
 396 {
 397         return create_route(from, TrackInSet(to.get_tracks()));
 398 }
 399
 400 Route *Route::find(const TrackIter &from, const Zone &to)
 401 {
 402         return create_route(from, TrackInSet(to.get_tracks()));
 403 }
 404
 405 Route *Route::find(const TrackIter &from, const set<Track *> &to)
 406 {
 407         return create_route(from, TrackInSet(to));
 408 }
 409
 410
 411 Route::Loader::Loader(Route &r):
 412         DataFile::BasicLoader<Route>(r)
 413 {
 414         add("name",    &Route::name);
 415         add("turnout", &Loader::turnout);
 416 }
 417
 418 void Route::Loader::finish()
 419 {
 420         const set<Track *> &ltracks = obj.layout.get_tracks();
 421         for(set<Track *>::const_iterator i=ltracks.begin(); i!=ltracks.end(); ++i)
 422         {
 423                 unsigned tid = (*i)->get_turnout_id();
 424                 if(!tid)
 425                         continue;
 426
 427                 TurnoutMap::iterator j = turnouts.find(tid);
 428                 if(j==turnouts.end())
 429                         continue;
 430
 431                 unsigned path_mask = 1<<j->second;
 432                 const vector<TrackType::Endpoint> &eps = (*i)->get_type().get_endpoints();
 433                 for(unsigned k=0; k<eps.size(); ++k)
 434                         if(eps[k].paths&path_mask)
 435                         {
 436                                 Track *link = (*i)->get_link(k);
 437                                 if(!obj.tracks.count(link))
 438                                         obj.add_track_chain(*link, link->get_endpoint_by_link(**i), turnouts);
 439                                 if(!obj.tracks.count(*i))
 440                                         obj.add_track_chain(**i, k, turnouts);
 441                                 break;
 442                         }
 443
 444                 break;
 445         }
 446 }
 447
 448 void Route::Loader::turnout(unsigned id, unsigned path)
 449 {
 450         turnouts[id] = path;
 451 }
 452
 453 } // namespace R2C2