source/libr2c2/route.cpp

   1 #include <queue>
   2 #include <msp/core/maputils.h>
   3 #include <msp/strings/format.h>
   4 #include <msp/strings/utils.h>
   5 #include "layout.h"
   6 #include "route.h"
   7 #include "track.h"
   8 #include "trackiter.h"
   9 #include "tracktype.h"
  10 #include "zone.h"
  11
  12 using namespace std;
  13 using namespace Msp;
  14
  15 namespace {
  16
  17 using namespace R2C2;
  18
  19 typedef std::pair<Track *, unsigned> Key;
  20
  21 struct Node
  22 {
  23         TrackIter track;
  24         Node *prev;
  25         float dist;
  26
  27         Node():
  28                 prev(0), dist(0)
  29         { }
  30
  31         Node(const TrackIter &t):
  32                 track(t), prev(0), dist(0)
  33         { }
  34
  35         Node(const TrackIter &t, Node &r, float d):
  36                 track(t), prev(&r), dist(prev->dist+d)
  37         { }
  38
  39         bool operator<(const Node &other) const
  40         { return dist>other.dist; }
  41 };
  42
  43 struct TrackMatch
  44 {
  45         Track &track;
  46
  47         TrackMatch(Track &t): track(t) { }
  48
  49         bool operator()(Track &t) const { return &t==&track; }
  50 };
  51
  52 struct TrackInSet
  53 {
  54         const set<Track *> &tracks;
  55
  56         TrackInSet(const set<Track *> &t): tracks(t) { }
  57
  58         bool operator()(Track &t) const { return tracks.count(&t); }
  59 };
  60
  61 template<typename Pred>
  62 list<Track *> dijkstra(const TrackIter &from, const Pred &goal)
  63 {
  64         map<Key, Node> track_nodes;
  65         priority_queue<Node> nodes;
  66         Node *final = 0;
  67
  68         nodes.push(from);
  69
  70         while(!nodes.empty())
  71         {
  72                 Node lowest = nodes.top();
  73                 nodes.pop();
  74
  75                 Key key(lowest.track.track(), lowest.track.entry());
  76                 if(track_nodes.count(key))
  77                         continue;
  78
  79                 Node &ref = track_nodes[key] = lowest;
  80                 if(goal(*lowest.track))
  81                 {
  82                         final = &ref;
  83                         break;
  84                 }
  85
  86                 unsigned paths = lowest.track.endpoint().paths;
  87                 for(unsigned i=0; paths>>i; ++i)
  88                         if(paths&(1<<i))
  89                         {
  90                                 TrackIter next = lowest.track.next(i);
  91                                 if(!next)
  92                                         continue;
  93
  94                                 if(track_nodes.count(Key(next.track(), next.entry())))
  95                                         continue;
  96
  97                                 nodes.push(Node(next, ref, lowest.track->get_type().get_path_length(i)));
  98                         }
  99         }
 100
 101         list<Track *> result;
 102         for(Node *node=final; node; node=node->prev)
 103                 result.push_front(&*node->track);
 104
 105         return result;
 106 }
 107
 108 template<typename Pred>
 109 Route *create_route(const TrackIter &from, const Pred &goal)
 110 {
 111         list<Track *> tracks = dijkstra(from, goal);
 112
 113         if(tracks.empty())
 114                 return 0;
 115
 116         Route *route = new Route(from->get_layout());
 117         for(list<Track *>::iterator i=tracks.begin(); i!=tracks.end(); ++i)
 118                 route->add_track(**i);
 119
 120         route->set_name("Pathfinder");
 121         route->set_temporary(true);
 122
 123         return route;
 124 }
 125
 126 }
 127
 128
 129 namespace R2C2 {
 130
 131 string bad_route::get_message(RouteValidityMask valid)
 132 {
 133         const char *reasons[3];
 134         unsigned i = 0;
 135         if(!(valid&1))
 136                 reasons[i++] = "unlinked";
 137         else if(!(valid&2))
 138                 reasons[i++] = "branching";
 139         else if(!(valid&4))
 140                 reasons[i++] = "not smooth";
 141         return join(reasons, reasons+i, ", ");
 142 }
 143
 144
 145 Route::Route(Layout &l):
 146         layout(l),
 147         temporary(false)
 148 {
 149         layout.add_route(*this);
 150         layout.signal_track_removed.connect(sigc::mem_fun(this, &Route::track_removed));
 151 }
 152
 153 Route::~Route()
 154 {
 155         layout.remove_route(*this);
 156 }
 157
 158 void Route::set_name(const string &n)
 159 {
 160         name = n;
 161         signal_name_changed.emit(name);
 162 }
 163
 164 void Route::set_temporary(bool t)
 165 {
 166         temporary = t;
 167 }
 168
 169 void Route::set_turnout(unsigned addr, unsigned path)
 170 {
 171         if(!addr)
 172                 throw InvalidParameterValue("Invalid turnout address");
 173         int &state = get_item(turnouts, addr);
 174         if(state>=0 && path!=static_cast<unsigned>(state))
 175                 throw InvalidState("Setting conflicts with route");
 176         state = path;
 177 }
 178
 179 void Route::update_turnouts()
 180 {
 181         set<unsigned> found;
 182         for(set<Track *>::const_iterator i=tracks.begin(); i!=tracks.end(); ++i)
 183                 if(unsigned tid = (*i)->get_turnout_id())
 184                 {
 185                         found.insert(tid);
 186
 187                         const vector<TrackType::Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 188                         const vector<Track *> &links = (*i)->get_links();
 189
 190                         // Build a combined path mask from linked endpoints
 191                         unsigned mask = (*i)->get_type().get_paths();
 192                         for(unsigned j=0; j<endpoints.size(); ++j)
 193                         {
 194                                 if(!tracks.count(links[j]))
 195                                         continue;
 196
 197                                 if(unsigned tid2 = links[j]->get_turnout_id())
 198                                 {
 199                                         const TrackType::Endpoint &ep = links[j]->get_type().get_endpoint(links[j]->get_endpoint_by_link(**i));
 200                                         int p = get_turnout(tid2);
 201                                         if(p>=0 && !(ep.paths&(1<<p)))
 202                                         {
 203                                                 // The linked track is a turnout and has a path which is incompatible with this endpoint
 204                                                 mask &= ~endpoints[j].paths;
 205                                                 continue;
 206                                         }
 207                                 }
 208                                 mask &= endpoints[j].paths;
 209                         }
 210
 211                         if(mask && !(mask&(mask-1)))
 212                         {
 213                                 // Exactly one possible choice, set the path accordingly
 214                                 unsigned path = 0;
 215                                 for(; (mask && !(mask&1)); mask>>=1, ++path) ;
 216                                 turnouts[tid] = path;
 217                         }
 218                         else if(!turnouts.count(tid))
 219                                 // More than one possible choice, and no existing entry - set as undecided
 220                                 turnouts[tid] = -1;
 221                 }
 222
 223         // Remove any turnouts that do not exist in the route
 224         for(map<unsigned, int>::iterator i=turnouts.begin(); i!=turnouts.end();)
 225         {
 226                 if(!found.count(i->first))
 227                         turnouts.erase(i++);
 228                 else
 229                         ++i;
 230         }
 231 }
 232
 233 int Route::get_turnout(unsigned id) const
 234 {
 235         map<unsigned, int>::const_iterator i = turnouts.find(id);
 236         if(i!=turnouts.end())
 237                 return i->second;
 238         return -1;
 239 }
 240
 241 unsigned Route::get_path(Track &trk) const
 242 {
 243         if(unsigned tid = trk.get_turnout_id())
 244         {
 245                 map<unsigned, int>::const_iterator i = turnouts.find(tid);
 246                 if(i!=turnouts.end())
 247                         return i->second;
 248         }
 249         return trk.get_active_path();
 250 }
 251
 252 void Route::add_track(Track &trk)
 253 {
 254         if(tracks.count(&trk))
 255                 return;
 256
 257         if(!tracks.empty())
 258         {
 259                 RouteValidityMask valid = check_validity(trk);
 260                 if(valid!=ROUTE_VALID)
 261                         throw bad_route(valid);
 262         }
 263
 264         tracks.insert(&trk);
 265         update_turnouts();
 266 }
 267
 268 void Route::add_tracks(const set<Track *> &trks)
 269 {
 270         set<Track *> pending;
 271         for(set<Track *>::const_iterator i=trks.begin(); i!=trks.end(); ++i)
 272                 if(!tracks.count(*i))
 273                         pending.insert(*i);
 274
 275         while(!pending.empty())
 276         {
 277                 RouteValidityMask valid = ROUTE_INVALID;
 278                 for(set<Track *>::const_iterator i=pending.begin(); i!=pending.end(); ++i)
 279                         if(tracks.empty() || (valid=check_validity(**i))==ROUTE_VALID)
 280                         {
 281                                 tracks.insert(*i);
 282                                 pending.erase(*i);
 283                                 break;
 284                         }
 285
 286                 if(valid!=ROUTE_VALID)
 287                         throw bad_route(valid);
 288         }
 289
 290         update_turnouts();
 291 }
 292
 293 void Route::add_track_chain(Track &start, unsigned ep, const TurnoutMap &trnts)
 294 {
 295         TrackIter iter(&start, ep);
 296         while(iter)
 297         {
 298                 if(iter->get_type().is_dead_end())
 299                         break;
 300
 301                 if(has_track(*iter))
 302                         break;
 303
 304                 int path = 0;
 305                 if(iter->get_turnout_id())
 306                 {
 307                         TurnoutMap::const_iterator i = trnts.find(iter->get_turnout_id());
 308                         if(i==trnts.end())
 309                                 break;
 310
 311                         path = i->second;
 312                 }
 313
 314                 add_track(*iter);
 315
 316                 iter = iter.next(path);
 317         }
 318 }
 319
 320 bool Route::has_track(Track &t) const
 321 {
 322         return tracks.count(&t);
 323 }
 324
 325 void Route::save(list<DataFile::Statement> &st) const
 326 {
 327         st.push_back((DataFile::Statement("name"), name));
 328         for(map<unsigned, int>::const_iterator i=turnouts.begin(); i!=turnouts.end(); ++i)
 329                 st.push_back((DataFile::Statement("turnout"), i->first, i->second));
 330 }
 331
 332 RouteValidityMask Route::check_validity(Track &trk) const
 333 {
 334         unsigned result = ROUTE_SMOOTH;
 335         const vector<Track *> &links = trk.get_links();
 336         for(vector<Track *>::const_iterator i=links.begin(); i!=links.end(); ++i)
 337         {
 338                 if(!*i)
 339                         continue;
 340                 if(!tracks.count(*i))
 341                         continue;
 342
 343                 // Linked to an existing track - good
 344                 result |= ROUTE_LINKED;
 345
 346                 if(unsigned tid = (*i)->get_turnout_id())
 347                 {
 348                         const TrackType::Endpoint &ep = (*i)->get_type().get_endpoint((*i)->get_endpoint_by_link(trk));
 349                         int path = get_turnout(tid);
 350                         if(path>=0)
 351                         {
 352                                 // Linking to a turnout with path set is only good if we're continuing that path
 353                                 if(ep.paths&(1<<path))
 354                                         result |= ROUTE_LINEAR;
 355                         }
 356                         else
 357                         {
 358                                 // Linked to a turnout with no path set - check other linked tracks
 359                                 const vector<Track *> &tlinks = (*i)->get_links();
 360                                 unsigned count = 0;
 361                                 for(unsigned j=0; j<tlinks.size(); ++j)
 362                                         if(tracks.count(tlinks[j]))
 363                                         {
 364                                                 unsigned tid2 = tlinks[j]->get_turnout_id();
 365                                                 if(tid2)
 366                                                 {
 367                                                         const TrackType::Endpoint &ep2 = tlinks[j]->get_type().get_endpoint(tlinks[j]->get_endpoint_by_link(**i));
 368                                                         path = get_turnout(tid2);
 369                                                         // Ignore a linked turnout with some other path set
 370                                                         if(path>=0 && !(ep2.paths&(1<<path)))
 371                                                                 continue;
 372                                                 }
 373
 374                                                 ++count;
 375
 376                                                 const TrackType::Endpoint &ep2 = (*i)->get_type().get_endpoint(j);
 377                                                 if(!(ep.paths&ep2.paths))
 378                                                         // Impossible path through the turnout - not good
 379                                                         result &= ~ROUTE_SMOOTH;
 380                                         }
 381
 382                                 // Only good if at most one other track is linked to the turnout
 383                                 if(count<=1)
 384                                         result |= ROUTE_LINEAR;
 385                         }
 386                 }
 387                 else
 388                         // Linked to something linear - good
 389                         result |= ROUTE_LINEAR;
 390         }
 391
 392         return static_cast<RouteValidityMask>(result);
 393 }
 394
 395 void Route::track_removed(Track &t)
 396 {
 397         tracks.erase(&t);
 398 }
 399
 400 Route *Route::find(const TrackIter &from, Track &to)
 401 {
 402         return create_route(from, TrackMatch(to));
 403 }
 404
 405 Route *Route::find(const TrackIter &from, const Route &to)
 406 {
 407         return create_route(from, TrackInSet(to.get_tracks()));
 408 }
 409
 410 Route *Route::find(const TrackIter &from, const Zone &to)
 411 {
 412         return create_route(from, TrackInSet(to.get_tracks()));
 413 }
 414
 415 Route *Route::find(const TrackIter &from, const set<Track *> &to)
 416 {
 417         return create_route(from, TrackInSet(to));
 418 }
 419
 420
 421 Route::Loader::Loader(Route &r):
 422         DataFile::BasicLoader<Route>(r)
 423 {
 424         add("name",    &Route::name);
 425         add("turnout", &Loader::turnout);
 426 }
 427
 428 void Route::Loader::finish()
 429 {
 430         const set<Track *> &ltracks = obj.layout.get_tracks();
 431         for(set<Track *>::const_iterator i=ltracks.begin(); i!=ltracks.end(); ++i)
 432         {
 433                 unsigned tid = (*i)->get_turnout_id();
 434                 if(!tid)
 435                         continue;
 436
 437                 TurnoutMap::iterator j = turnouts.find(tid);
 438                 if(j==turnouts.end())
 439                         continue;
 440
 441                 unsigned path_mask = 1<<j->second;
 442                 const vector<TrackType::Endpoint> &eps = (*i)->get_type().get_endpoints();
 443                 for(unsigned k=0; k<eps.size(); ++k)
 444                         if(eps[k].paths&path_mask)
 445                         {
 446                                 Track *link = (*i)->get_link(k);
 447                                 if(!obj.tracks.count(link))
 448                                         obj.add_track_chain(*link, link->get_endpoint_by_link(**i), turnouts);
 449                                 if(!obj.tracks.count(*i))
 450                                         obj.add_track_chain(**i, k, turnouts);
 451                                 break;
 452                         }
 453
 454                 break;
 455         }
 456 }
 457
 458 void Route::Loader::turnout(unsigned id, unsigned path)
 459 {
 460         turnouts[id] = path;
 461 }
 462
 463 } // namespace R2C2