source/libmarklin/route.cpp

   1 /* $Id$
   2
   3 This file is part of the MSP Märklin suite
   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 "tracktype.h"
  14
  15 using namespace std;
  16 using namespace Msp;
  17
  18 namespace {
  19
  20 using namespace Marklin;
  21
  22 typedef std::pair<const Track *, unsigned> Key;
  23
  24 struct Node
  25 {
  26         const Track *track;
  27         unsigned ep;
  28         Node *prev;
  29         float dist;
  30
  31         Node():
  32                 track(0), ep(0), prev(0), dist(0)
  33         { }
  34
  35         Node(const Track &t, unsigned e):
  36                 track(&t), ep(e), prev(0), dist(0)
  37         { }
  38
  39         Node(const Track &t, unsigned e, Node &r, float d):
  40                 track(&t), ep(e), 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         const Track &track;
  50
  51         TrackMatch(const Track &t): track(t) { }
  52
  53         bool operator()(const Track &t) const { return &t==&track; }
  54 };
  55
  56 struct TrackInRoute
  57 {
  58         const Route &route;
  59
  60         TrackInRoute(const Route &r): route(r) { }
  61
  62         bool operator()(const Track &t) const { return route.get_tracks().count(&t); }
  63 };
  64
  65 template<typename Pred>
  66 list<const Track *> dijkstra(const Track &from, unsigned ep, const Pred &goal)
  67 {
  68         map<Key, Node> track_nodes;
  69         priority_queue<Node> nodes;
  70         Node *final = 0;
  71
  72         nodes.push(Node(from, ep));
  73
  74         while(!nodes.empty())
  75         {
  76                 Node lowest = nodes.top();
  77                 nodes.pop();
  78
  79                 Key key(lowest.track, lowest.ep);
  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                 const TrackType &type = lowest.track->get_type();
  91                 const vector<Endpoint> &eps = type.get_endpoints();
  92                 const vector<Track *> &links = lowest.track->get_links();
  93                 for(unsigned i=0; i<eps.size(); ++i)
  94                 {
  95                         if(i==lowest.ep || !links[i])
  96                                 continue;
  97
  98                         unsigned link_ep = links[i]->get_endpoint_by_link(*lowest.track);
  99                         if(track_nodes.count(Key(links[i], link_ep)))
 100                                 continue;
 101
 102                         unsigned mask = eps[i].paths&eps[lowest.ep].paths;
 103                         if(!mask)
 104                                 continue;
 105
 106                         unsigned path=0;
 107                         for(; !(mask&1); ++path, mask>>=1) ;
 108                         nodes.push(Node(*links[i], links[i]->get_endpoint_by_link(*lowest.track), ref, type.get_path_length(path)));
 109                 }
 110         }
 111
 112         if(!final)
 113                 throw InvalidParameterValue("Could not find a route");
 114
 115         list<const Track *> result;
 116         for(Node *node=final; node; node=node->prev)
 117                 result.push_front(node->track);
 118
 119         return result;
 120 }
 121
 122 unsigned count = 0;
 123
 124 template<typename Pred>
 125 Route *create_route(const Track &from, unsigned ep, const Pred &goal)
 126 {
 127         list<const Track *> tracks = dijkstra(from, ep, goal);
 128
 129         Route *route = new Route(from.get_layout(), format("-%d-", ++count));
 130         for(list<const Track *>::iterator i=tracks.begin(); i!=tracks.end(); ++i)
 131                 route->add_track(**i);
 132
 133         return route;
 134 }
 135
 136 }
 137
 138
 139 namespace Marklin {
 140
 141 Route::Route(Layout &l, const string &n):
 142         layout(l),
 143         name(n)
 144 {
 145         layout.add_route(*this);
 146         layout.signal_track_removed.connect(sigc::mem_fun(this, &Route::track_removed));
 147 }
 148
 149 Route::~Route()
 150 {
 151         layout.remove_route(*this);
 152 }
 153
 154 int Route::get_turnout(unsigned id) const
 155 {
 156         map<unsigned, int>::const_iterator i = turnouts.find(id);
 157         if(i!=turnouts.end())
 158                 return i->second;
 159         return -1;
 160 }
 161
 162 void Route::add_track(const Track &trk)
 163 {
 164         if(tracks.count(&trk))
 165                 return;
 166
 167         if(!tracks.empty())
 168         {
 169                 unsigned valid = check_validity(trk);
 170                 if(!(valid&1))
 171                         throw Exception("Not linked to existing tracks");
 172                 else if(!(valid&2))
 173                         throw Exception("Branching routes not allowed");
 174                 else if(!(valid&4))
 175                         throw Exception("Route must be smooth");
 176         }
 177
 178         tracks.insert(&trk);
 179         update_turnouts();
 180 }
 181
 182 void Route::add_tracks(const set<const Track *> &trks)
 183 {
 184         set<const Track *> pending;
 185         for(set<const Track *>::const_iterator i=trks.begin(); i!=trks.end(); ++i)
 186                 if(!tracks.count(*i))
 187                         pending.insert(*i);
 188
 189         while(!pending.empty())
 190         {
 191                 bool found = false;
 192                 for(set<const Track *>::const_iterator i=pending.begin(); i!=pending.end(); ++i)
 193                         if(tracks.empty() || check_validity(**i)==7)
 194                         {
 195                                 tracks.insert(*i);
 196                                 pending.erase(*i);
 197                                 found = true;
 198                                 break;
 199                         }
 200
 201                 if(!found)
 202                         throw Exception("Could not add all tracks to route");
 203         }
 204
 205         update_turnouts();
 206 }
 207
 208 void Route::save(list<DataFile::Statement> &st) const
 209 {
 210         for(map<unsigned, int>::const_iterator i=turnouts.begin(); i!=turnouts.end(); ++i)
 211                 st.push_back((DataFile::Statement("turnout"), i->first, i->second));
 212 }
 213
 214 void Route::update_turnouts()
 215 {
 216         set<unsigned> found;
 217         for(set<const Track *>::const_iterator i=tracks.begin(); i!=tracks.end(); ++i)
 218                 if(unsigned tid=(*i)->get_turnout_id())
 219                 {
 220                         found.insert(tid);
 221
 222                         const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 223                         const vector<Track *> &links = (*i)->get_links();
 224
 225                         // Build a combined path mask from linked endpoints
 226                         unsigned mask = 15;
 227                         for(unsigned j=0; j<endpoints.size(); ++j)
 228                         {
 229                                 if(!tracks.count(links[j]))
 230                                         continue;
 231
 232                                 if(unsigned tid2=links[j]->get_turnout_id())
 233                                 {
 234                                         const Endpoint &ep = links[j]->get_type().get_endpoints()[links[j]->get_endpoint_by_link(**i)];
 235                                         int p = get_turnout(tid2);
 236                                         if(p>=0 && !(ep.paths&(1<<p)))
 237                                         {
 238                                                 // The linked track is a turnout and has a path which is incompatible with this endpoint
 239                                                 mask &= ~endpoints[j].paths;
 240                                                 continue;
 241                                         }
 242                                 }
 243                                 mask &= endpoints[j].paths;
 244                         }
 245
 246                         if(mask && !(mask&(mask-1)))
 247                         {
 248                                 // Exactly one possible choice, set the path accordingly
 249                                 unsigned path = 0;
 250                                 for(; (mask && !(mask&1)); mask>>=1, ++path) ;
 251                                 turnouts[tid] = path;
 252                         }
 253                         else if(!turnouts.count(tid))
 254                                 // More than one possible choice, and no existing entry - set as undecided
 255                                 turnouts[tid] = -1;
 256                 }
 257
 258         // Remove any turnouts that do not exist in the route
 259         for(map<unsigned, int>::iterator i=turnouts.begin(); i!=turnouts.end();)
 260         {
 261                 if(!found.count(i->first))
 262                         turnouts.erase(i++);
 263                 else
 264                         ++i;
 265         }
 266 }
 267
 268 unsigned Route::check_validity(const Track &trk) const
 269 {
 270         unsigned result = 4;
 271         for(set<const Track *>::const_iterator i=tracks.begin(); i!=tracks.end(); ++i)
 272         {
 273                 int epi=(*i)->get_endpoint_by_link(trk);
 274                 if(epi>=0)
 275                 {
 276                         // Linked to an existing track - good
 277                         result |= 1;
 278                         const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 279                         if(unsigned tid=(*i)->get_turnout_id())
 280                         {
 281                                 int r = get_turnout(tid);
 282                                 if(r>=0)
 283                                 {
 284                                         // Linking to a turnout with path set is only good if we're continuing that path
 285                                         if(endpoints[epi].paths&(1<<r))
 286                                                 result |= 2;
 287                                 }
 288                                 else
 289                                 {
 290                                         // Linked to a turnout with no path set - find out other linked tracks
 291                                         unsigned count = 0;
 292                                         const vector<Track *> &links = (*i)->get_links();
 293                                         int epj = -1;
 294                                         for(unsigned k=0; k<endpoints.size(); ++k)
 295                                                 if(tracks.count(links[k]))
 296                                                 {
 297                                                         ++count;
 298                                                         epj = k;
 299                                                 }
 300
 301                                         // Only good if at most one other track is linked to the turnout
 302                                         if(count<=1)
 303                                         {
 304                                                 result |= 2;
 305                                                 if(epj>=0 && !(endpoints[epi].paths&endpoints[epj].paths))
 306                                                         // Impossible path through the turnout - not good
 307                                                         result &= 3;
 308                                         }
 309                                 }
 310                         }
 311                         else
 312                                 // Linked to something linear - good
 313                                 result |= 2;
 314                 }
 315         }
 316
 317         return result;
 318 }
 319
 320 void Route::track_removed(Track &t)
 321 {
 322         tracks.erase(&t);
 323 }
 324
 325 Route *Route::find(const Track &from, unsigned ep, const Track &to)
 326 {
 327         return create_route(from, ep, TrackMatch(to));
 328 }
 329
 330 Route *Route::find(const Track &from, unsigned ep, const Route &to)
 331 {
 332         return create_route(from, ep, TrackInRoute(to));
 333 }
 334
 335
 336 Route::Loader::Loader(Route &r):
 337         DataFile::BasicLoader<Route>(r)
 338 {
 339         add("turnout", &Loader::turnout);
 340 }
 341
 342 void Route::Loader::turnout(unsigned id, unsigned path)
 343 {
 344         obj.turnouts[id] = path;
 345 }
 346
 347 } // namespace Marklin