source/libr2c2/route.cpp

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