source/libr2c2/route.cpp

   1 /* $Id$
   2
   3 This file is part of R²C²
   4 Copyright © 2007-2010  Mikkosoft Productions, Mikko Rasa
   5 Distributed under the GPL
   6 */
   7
   8 #include <queue>
   9 #include <msp/strings/formatter.h>
  10 #include "layout.h"
  11 #include "route.h"
  12 #include "track.h"
  13 #include "trackiter.h"
  14 #include "tracktype.h"
  15 #include "zone.h"
  16
  17 using namespace std;
  18 using namespace Msp;
  19
  20 namespace {
  21
  22 using namespace R2C2;
  23
  24 typedef std::pair<Track *, unsigned> Key;
  25
  26 struct Node
  27 {
  28         TrackIter track;
  29         Node *prev;
  30         float dist;
  31
  32         Node():
  33                 prev(0), dist(0)
  34         { }
  35
  36         Node(const TrackIter &t):
  37                 track(t), prev(0), dist(0)
  38         { }
  39
  40         Node(const TrackIter &t, Node &r, float d):
  41                 track(t), prev(&r), dist(prev->dist+d)
  42         { }
  43
  44         bool operator<(const Node &other) const
  45         { return dist>other.dist; }
  46 };
  47
  48 struct TrackMatch
  49 {
  50         Track &track;
  51
  52         TrackMatch(Track &t): track(t) { }
  53
  54         bool operator()(Track &t) const { return &t==&track; }
  55 };
  56
  57 struct TrackInSet
  58 {
  59         const set<Track *> &tracks;
  60
  61         TrackInSet(const set<Track *> &t): tracks(t) { }
  62
  63         bool operator()(Track &t) const { return tracks.count(&t); }
  64 };
  65
  66 template<typename Pred>
  67 list<Track *> dijkstra(const TrackIter &from, const Pred &goal)
  68 {
  69         map<Key, Node> track_nodes;
  70         priority_queue<Node> nodes;
  71         Node *final = 0;
  72
  73         nodes.push(from);
  74
  75         while(!nodes.empty())
  76         {
  77                 Node lowest = nodes.top();
  78                 nodes.pop();
  79
  80                 Key key(lowest.track.track(), lowest.track.entry());
  81                 if(track_nodes.count(key))
  82                         continue;
  83
  84                 Node &ref = track_nodes[key] = lowest;
  85                 if(goal(*lowest.track))
  86                 {
  87                         final = &ref;
  88                         break;
  89                 }
  90
  91                 unsigned paths = lowest.track.endpoint().paths;
  92                 for(unsigned i=0; paths>>i; ++i)
  93                         if(paths&(1<<i))
  94                         {
  95                                 TrackIter next = lowest.track.next(i);
  96                                 if(!next)
  97                                         continue;
  98
  99                                 if(track_nodes.count(Key(next.track(), next.entry())))
 100                                         continue;
 101
 102                                 nodes.push(Node(next, ref, lowest.track->get_type().get_path_length(i)));
 103                         }
 104         }
 105
 106         list<Track *> result;
 107         for(Node *node=final; node; node=node->prev)
 108                 result.push_front(&*node->track);
 109
 110         return result;
 111 }
 112
 113 template<typename Pred>
 114 Route *create_route(const TrackIter &from, const Pred &goal)
 115 {
 116         list<Track *> tracks = dijkstra(from, goal);
 117
 118         if(tracks.empty())
 119                 return 0;
 120
 121         Route *route = new Route(from->get_layout());
 122         for(list<Track *>::iterator i=tracks.begin(); i!=tracks.end(); ++i)
 123                 route->add_track(**i);
 124
 125         route->set_name("Pathfinder");
 126         route->set_temporary(true);
 127
 128         return route;
 129 }
 130
 131 }
 132
 133
 134 namespace R2C2 {
 135
 136 Route::Route(Layout &l):
 137         layout(l),
 138         temporary(false)
 139 {
 140         layout.add_route(*this);
 141         layout.signal_track_removed.connect(sigc::mem_fun(this, &Route::track_removed));
 142 }
 143
 144 Route::~Route()
 145 {
 146         layout.remove_route(*this);
 147 }
 148
 149 void Route::set_name(const string &n)
 150 {
 151         name = n;
 152         signal_name_changed.emit(name);
 153 }
 154
 155 void Route::set_temporary(bool t)
 156 {
 157         temporary = t;
 158 }
 159
 160 void Route::set_turnout(unsigned addr, unsigned path)
 161 {
 162         if(!addr)
 163                 throw InvalidParameterValue("Invalid turnout address");
 164         map<unsigned, int>::iterator i = turnouts.find(addr);
 165         if(i==turnouts.end())
 166                 throw KeyError("Turnout is not in this route");
 167         if(i->second>=0 && path!=static_cast<unsigned>(i->second))
 168                 throw InvalidState("Setting conflicts with route");
 169         i->second = path;
 170 }
 171
 172 void Route::update_turnouts()
 173 {
 174         set<unsigned> found;
 175         for(set<Track *>::const_iterator i=tracks.begin(); i!=tracks.end(); ++i)
 176                 if(unsigned tid = (*i)->get_turnout_id())
 177                 {
 178                         found.insert(tid);
 179
 180                         const vector<TrackType::Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 181                         const vector<Track *> &links = (*i)->get_links();
 182
 183                         // Build a combined path mask from linked endpoints
 184                         unsigned mask = (*i)->get_type().get_paths();
 185                         for(unsigned j=0; j<endpoints.size(); ++j)
 186                         {
 187                                 if(!tracks.count(links[j]))
 188                                         continue;
 189
 190                                 if(unsigned tid2 = links[j]->get_turnout_id())
 191                                 {
 192                                         const TrackType::Endpoint &ep = links[j]->get_type().get_endpoint(links[j]->get_endpoint_by_link(**i));
 193                                         int p = get_turnout(tid2);
 194                                         if(p>=0 && !(ep.paths&(1<<p)))
 195                                         {
 196                                                 // The linked track is a turnout and has a path which is incompatible with this endpoint
 197                                                 mask &= ~endpoints[j].paths;
 198                                                 continue;
 199                                         }
 200                                 }
 201                                 mask &= endpoints[j].paths;
 202                         }
 203
 204                         if(mask && !(mask&(mask-1)))
 205                         {
 206                                 // Exactly one possible choice, set the path accordingly
 207                                 unsigned path = 0;
 208                                 for(; (mask && !(mask&1)); mask>>=1, ++path) ;
 209                                 turnouts[tid] = path;
 210                         }
 211                         else if(!turnouts.count(tid))
 212                                 // More than one possible choice, and no existing entry - set as undecided
 213                                 turnouts[tid] = -1;
 214                 }
 215
 216         // Remove any turnouts that do not exist in the route
 217         for(map<unsigned, int>::iterator i=turnouts.begin(); i!=turnouts.end();)
 218         {
 219                 if(!found.count(i->first))
 220                         turnouts.erase(i++);
 221                 else
 222                         ++i;
 223         }
 224 }
 225
 226 int Route::get_turnout(unsigned id) const
 227 {
 228         map<unsigned, int>::const_iterator i = turnouts.find(id);
 229         if(i!=turnouts.end())
 230                 return i->second;
 231         return -1;
 232 }
 233
 234 unsigned Route::get_path(Track &trk) const
 235 {
 236         if(unsigned tid = trk.get_turnout_id())
 237         {
 238                 map<unsigned, int>::const_iterator i = turnouts.find(tid);
 239                 if(i!=turnouts.end())
 240                         return i->second;
 241         }
 242         return trk.get_active_path();
 243 }
 244
 245 void Route::add_track(Track &trk)
 246 {
 247         if(tracks.count(&trk))
 248                 return;
 249
 250         if(!tracks.empty())
 251         {
 252                 unsigned valid = check_validity(trk);
 253                 if(!(valid&1))
 254                         throw Exception("Not linked to existing tracks");
 255                 else if(!(valid&2))
 256                         throw Exception("Branching routes not allowed");
 257                 else if(!(valid&4))
 258                         throw Exception("Route must be smooth");
 259         }
 260
 261         tracks.insert(&trk);
 262         update_turnouts();
 263 }
 264
 265 void Route::add_tracks(const set<Track *> &trks)
 266 {
 267         set<Track *> pending;
 268         for(set<Track *>::const_iterator i=trks.begin(); i!=trks.end(); ++i)
 269                 if(!tracks.count(*i))
 270                         pending.insert(*i);
 271
 272         while(!pending.empty())
 273         {
 274                 bool found = false;
 275                 for(set<Track *>::const_iterator i=pending.begin(); i!=pending.end(); ++i)
 276                         if(tracks.empty() || check_validity(**i)==7)
 277                         {
 278                                 tracks.insert(*i);
 279                                 pending.erase(*i);
 280                                 found = true;
 281                                 break;
 282                         }
 283
 284                 if(!found)
 285                         throw Exception("Could not add all tracks to route");
 286         }
 287
 288         update_turnouts();
 289 }
 290
 291 void Route::add_track_chain(Track &start, unsigned ep, const TurnoutMap &trnts)
 292 {
 293         TrackIter iter(&start, ep);
 294         while(iter)
 295         {
 296                 if(iter->get_type().is_dead_end())
 297                         break;
 298
 299                 if(has_track(*iter))
 300                         break;
 301
 302                 int path = 0;
 303                 if(iter->get_turnout_id())
 304                 {
 305                         TurnoutMap::const_iterator i = trnts.find(iter->get_turnout_id());
 306                         if(i==trnts.end())
 307                                 break;
 308
 309                         path = i->second;
 310                 }
 311
 312                 add_track(*iter);
 313
 314                 iter = iter.next(path);
 315         }
 316 }
 317
 318 bool Route::has_track(Track &t) const
 319 {
 320         return tracks.count(&t);
 321 }
 322
 323 void Route::save(list<DataFile::Statement> &st) const
 324 {
 325         st.push_back((DataFile::Statement("name"), name));
 326         for(map<unsigned, int>::const_iterator i=turnouts.begin(); i!=turnouts.end(); ++i)
 327                 st.push_back((DataFile::Statement("turnout"), i->first, i->second));
 328 }
 329
 330 unsigned Route::check_validity(Track &trk) const
 331 {
 332         unsigned result = 4;
 333         const vector<Track *> &links = trk.get_links();
 334         for(vector<Track *>::const_iterator i=links.begin(); i!=links.end(); ++i)
 335         {
 336                 if(!*i)
 337                         continue;
 338                 if(!tracks.count(*i))
 339                         continue;
 340
 341                 // Linked to an existing track - good
 342                 result |= 1;
 343
 344                 if(unsigned tid = (*i)->get_turnout_id())
 345                 {
 346                         const TrackType::Endpoint &ep = (*i)->get_type().get_endpoint((*i)->get_endpoint_by_link(trk));
 347                         int path = get_turnout(tid);
 348                         if(path>=0)
 349                         {
 350                                 // Linking to a turnout with path set is only good if we're continuing that path
 351                                 if(ep.paths&(1<<path))
 352                                         result |= 2;
 353                         }
 354                         else
 355                         {
 356                                 // Linked to a turnout with no path set - check other linked tracks
 357                                 const vector<Track *> &tlinks = (*i)->get_links();
 358                                 unsigned count = 0;
 359                                 for(unsigned j=0; j<tlinks.size(); ++j)
 360                                         if(tracks.count(tlinks[j]))
 361                                         {
 362                                                 unsigned tid2 = tlinks[j]->get_turnout_id();
 363                                                 if(tid2)
 364                                                 {
 365                                                         const TrackType::Endpoint &ep2 = tlinks[j]->get_type().get_endpoint(tlinks[j]->get_endpoint_by_link(**i));
 366                                                         path = get_turnout(tid2);
 367                                                         // Ignore a linked turnout with some other path set
 368                                                         if(path>0 && !(ep2.paths&(1<<path)))
 369                                                                 continue;
 370                                                 }
 371
 372                                                 ++count;
 373
 374                                                 const TrackType::Endpoint &ep2 = (*i)->get_type().get_endpoint(j);
 375                                                 if(!(ep.paths&ep2.paths))
 376                                                         // Impossible path through the turnout - not good
 377                                                         result &= 3;
 378                                         }
 379
 380                                 // Only good if at most one other track is linked to the turnout
 381                                 if(count<=1)
 382                                         result |= 2;
 383                         }
 384                 }
 385                 else
 386                         // Linked to something linear - good
 387                         result |= 2;
 388         }
 389
 390         return result;
 391 }
 392
 393 void Route::track_removed(Track &t)
 394 {
 395         tracks.erase(&t);
 396 }
 397
 398 Route *Route::find(const TrackIter &from, Track &to)
 399 {
 400         return create_route(from, TrackMatch(to));
 401 }
 402
 403 Route *Route::find(const TrackIter &from, const Route &to)
 404 {
 405         return create_route(from, TrackInSet(to.get_tracks()));
 406 }
 407
 408 Route *Route::find(const TrackIter &from, const Zone &to)
 409 {
 410         return create_route(from, TrackInSet(to.get_tracks()));
 411 }
 412
 413 Route *Route::find(const TrackIter &from, const set<Track *> &to)
 414 {
 415         return create_route(from, TrackInSet(to));
 416 }
 417
 418
 419 Route::Loader::Loader(Route &r):
 420         DataFile::BasicLoader<Route>(r)
 421 {
 422         add("name",    &Route::name);
 423         add("turnout", &Loader::turnout);
 424 }
 425
 426 void Route::Loader::finish()
 427 {
 428         const set<Track *> &ltracks = obj.layout.get_tracks();
 429         for(set<Track *>::const_iterator i=ltracks.begin(); i!=ltracks.end(); ++i)
 430         {
 431                 unsigned tid = (*i)->get_turnout_id();
 432                 if(!tid)
 433                         continue;
 434
 435                 TurnoutMap::iterator j = turnouts.find(tid);
 436                 if(j==turnouts.end())
 437                         continue;
 438
 439                 unsigned path_mask = 1<<j->second;
 440                 const vector<TrackType::Endpoint> &eps = (*i)->get_type().get_endpoints();
 441                 for(unsigned k=0; k<eps.size(); ++k)
 442                         if(eps[k].paths&path_mask)
 443                         {
 444                                 Track *link = (*i)->get_link(k);
 445                                 if(!obj.tracks.count(link))
 446                                         obj.add_track_chain(*link, link->get_endpoint_by_link(**i), turnouts);
 447                                 if(!obj.tracks.count(*i))
 448                                         obj.add_track_chain(**i, k, turnouts);
 449                                 break;
 450                         }
 451
 452                 break;
 453         }
 454 }
 455
 456 void Route::Loader::turnout(unsigned id, unsigned path)
 457 {
 458         turnouts[id] = path;
 459 }
 460
 461 } // namespace R2C2