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