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 struct Node
  23 {
  24         const Track *track;
  25         unsigned ep;
  26         Node *prev;
  27         float dist;
  28
  29         Node():
  30                 track(0), ep(0), prev(0), dist(0)
  31         { }
  32
  33         Node(const Track &t, unsigned e):
  34                 track(&t), ep(e), prev(0), dist(0)
  35         { }
  36
  37         Node(const Track &t, unsigned e, Node &r, float d):
  38                 track(&t), ep(e), prev(&r), dist(prev->dist+d)
  39         { }
  40
  41         bool operator<(const Node &other) const
  42         { return dist>other.dist; }
  43 };
  44
  45 struct TrackMatch
  46 {
  47         const Track &track;
  48
  49         TrackMatch(const Track &t): track(t) { }
  50
  51         bool operator()(const Track &t) const { return &t==&track; }
  52 };
  53
  54 struct TrackInRoute
  55 {
  56         const Route &route;
  57
  58         TrackInRoute(const Route &r): route(r) { }
  59
  60         bool operator()(const Track &t) const { return route.get_tracks().count(&t); }
  61 };
  62
  63 template<typename Pred>
  64 list<const Track *> dijkstra(const Track &from, unsigned ep, const Pred &goal)
  65 {
  66         // XXX Fails to find some routes - should use track+ep as key
  67         map<const Track *, Node> track_nodes;
  68         priority_queue<Node> nodes;
  69         Node *final = 0;
  70
  71         nodes.push(Node(from, ep));
  72
  73         while(!nodes.empty())
  74         {
  75                 Node lowest = nodes.top();
  76                 nodes.pop();
  77
  78                 if(track_nodes.count(lowest.track))
  79                         continue;
  80
  81                 Node &ref = track_nodes[lowest.track] = lowest;
  82                 if(goal(*lowest.track))
  83                 {
  84                         final = &ref;
  85                         break;
  86                 }
  87
  88                 const TrackType &type = lowest.track->get_type();
  89                 const vector<Endpoint> &eps = type.get_endpoints();
  90                 const vector<Track *> &links = lowest.track->get_links();
  91                 for(unsigned i=0; i<eps.size(); ++i)
  92                 {
  93                         if(i==lowest.ep || !links[i] || track_nodes.count(links[i]))
  94                                 continue;
  95
  96                         unsigned mask = eps[i].paths&eps[lowest.ep].paths;
  97                         if(!mask)
  98                                 continue;
  99
 100                         unsigned path=0;
 101                         for(; !(mask&1); ++path, mask>>=1) ;
 102                         nodes.push(Node(*links[i], links[i]->get_endpoint_by_link(*lowest.track), ref, type.get_path_length(path)));
 103                 }
 104         }
 105
 106         if(!final)
 107                 throw InvalidParameterValue("Could not find a route");
 108
 109         list<const Track *> result;
 110         for(Node *node=final; node; node=node->prev)
 111                 result.push_front(node->track);
 112
 113         return result;
 114 }
 115
 116 unsigned count = 0;
 117
 118 template<typename Pred>
 119 Route *create_route(const Track &from, unsigned ep, const Pred &goal)
 120 {
 121         list<const Track *> tracks = dijkstra(from, ep, goal);
 122
 123         Route *route = new Route(from.get_layout(), format("-%d-", ++count));
 124         for(list<const Track *>::iterator i=tracks.begin(); i!=tracks.end(); ++i)
 125                 route->add_track(**i);
 126
 127         return route;
 128 }
 129
 130 }
 131
 132
 133 namespace Marklin {
 134
 135 Route::Route(Layout &l, const string &n):
 136         layout(l),
 137         name(n)
 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 int Route::get_turnout(unsigned id) const
 149 {
 150         map<unsigned, int>::const_iterator i = turnouts.find(id);
 151         if(i!=turnouts.end())
 152                 return i->second;
 153         return -1;
 154 }
 155
 156 void Route::add_track(const Track &trk)
 157 {
 158         if(tracks.count(&trk))
 159                 return;
 160
 161         if(!tracks.empty())
 162         {
 163                 unsigned valid = check_validity(trk);
 164                 if(!(valid&1))
 165                         throw Exception("Not linked to existing tracks");
 166                 else if(!(valid&2))
 167                         throw Exception("Branching routes not allowed");
 168                 else if(!(valid&4))
 169                         throw Exception("Route must be smooth");
 170         }
 171
 172         tracks.insert(&trk);
 173         update_turnouts();
 174 }
 175
 176 void Route::add_tracks(const set<const Track *> &trks)
 177 {
 178         set<const Track *> pending;
 179         for(set<const Track *>::const_iterator i=trks.begin(); i!=trks.end(); ++i)
 180                 if(!tracks.count(*i))
 181                         pending.insert(*i);
 182
 183         while(!pending.empty())
 184         {
 185                 bool found = false;
 186                 for(set<const Track *>::const_iterator i=pending.begin(); i!=pending.end(); ++i)
 187                         if(tracks.empty() || check_validity(**i)==7)
 188                         {
 189                                 tracks.insert(*i);
 190                                 pending.erase(*i);
 191                                 found = true;
 192                                 break;
 193                         }
 194
 195                 if(!found)
 196                         throw Exception("Could not add all tracks to route");
 197         }
 198
 199         update_turnouts();
 200 }
 201
 202 void Route::save(list<DataFile::Statement> &st) const
 203 {
 204         for(map<unsigned, int>::const_iterator i=turnouts.begin(); i!=turnouts.end(); ++i)
 205                 st.push_back((DataFile::Statement("turnout"), i->first, i->second));
 206 }
 207
 208 void Route::update_turnouts()
 209 {
 210         set<unsigned> found;
 211         for(set<const Track *>::const_iterator i=tracks.begin(); i!=tracks.end(); ++i)
 212                 if(unsigned tid=(*i)->get_turnout_id())
 213                 {
 214                         found.insert(tid);
 215
 216                         const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 217                         const vector<Track *> &links = (*i)->get_links();
 218
 219                         // Build a combined path mask from linked endpoints
 220                         unsigned mask = 15;
 221                         for(unsigned j=0; j<endpoints.size(); ++j)
 222                         {
 223                                 if(!tracks.count(links[j]))
 224                                         continue;
 225
 226                                 if(unsigned tid2=links[j]->get_turnout_id())
 227                                 {
 228                                         const Endpoint &ep = links[j]->get_type().get_endpoints()[links[j]->get_endpoint_by_link(**i)];
 229                                         int p = get_turnout(tid2);
 230                                         if(p>=0 && !(ep.paths&(1<<p)))
 231                                         {
 232                                                 // The linked track is a turnout and has a path which is incompatible with this endpoint
 233                                                 mask &= ~endpoints[j].paths;
 234                                                 continue;
 235                                         }
 236                                 }
 237                                 mask &= endpoints[j].paths;
 238                         }
 239
 240                         if(mask && !(mask&(mask-1)))
 241                         {
 242                                 // Exactly one possible choice, set the path accordingly
 243                                 unsigned path = 0;
 244                                 for(; (mask && !(mask&1)); mask>>=1, ++path) ;
 245                                 turnouts[tid] = path;
 246                         }
 247                         else if(!turnouts.count(tid))
 248                                 // More than one possible choice, and no existing entry - set as undecided
 249                                 turnouts[tid] = -1;
 250                 }
 251
 252         // Remove any turnouts that do not exist in the route
 253         for(map<unsigned, int>::iterator i=turnouts.begin(); i!=turnouts.end();)
 254         {
 255                 if(!found.count(i->first))
 256                         turnouts.erase(i++);
 257                 else
 258                         ++i;
 259         }
 260 }
 261
 262 unsigned Route::check_validity(const Track &trk) const
 263 {
 264         unsigned result = 4;
 265         for(set<const Track *>::const_iterator i=tracks.begin(); i!=tracks.end(); ++i)
 266         {
 267                 int epi=(*i)->get_endpoint_by_link(trk);
 268                 if(epi>=0)
 269                 {
 270                         // Linked to an existing track - good
 271                         result |= 1;
 272                         const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 273                         if(unsigned tid=(*i)->get_turnout_id())
 274                         {
 275                                 int r = get_turnout(tid);
 276                                 if(r>=0)
 277                                 {
 278                                         // Linking to a turnout with path set is only good if we're continuing that path
 279                                         if(endpoints[epi].paths&(1<<r))
 280                                                 result |= 2;
 281                                 }
 282                                 else
 283                                 {
 284                                         // Linked to a turnout with no path set - find out other linked tracks
 285                                         unsigned count = 0;
 286                                         const vector<Track *> &links = (*i)->get_links();
 287                                         int epj = -1;
 288                                         for(unsigned k=0; k<endpoints.size(); ++k)
 289                                                 if(tracks.count(links[k]))
 290                                                 {
 291                                                         ++count;
 292                                                         epj = k;
 293                                                 }
 294
 295                                         // Only good if at most one other track is linked to the turnout
 296                                         if(count<=1)
 297                                         {
 298                                                 result |= 2;
 299                                                 if(epj>=0 && !(endpoints[epi].paths&endpoints[epj].paths))
 300                                                         // Impossible path through the turnout - not good
 301                                                         result &= 3;
 302                                         }
 303                                 }
 304                         }
 305                         else
 306                                 // Linked to something linear - good
 307                                 result |= 2;
 308                 }
 309         }
 310
 311         return result;
 312 }
 313
 314 void Route::track_removed(Track &t)
 315 {
 316         tracks.erase(&t);
 317 }
 318
 319 Route *Route::find(const Track &from, unsigned ep, const Track &to)
 320 {
 321         return create_route(from, ep, TrackMatch(to));
 322 }
 323
 324 Route *Route::find(const Track &from, unsigned ep, const Route &to)
 325 {
 326         return create_route(from, ep, TrackInRoute(to));
 327 }
 328
 329
 330 Route::Loader::Loader(Route &r):
 331         DataFile::BasicLoader<Route>(r)
 332 {
 333         add("turnout", &Loader::turnout);
 334 }
 335
 336 void Route::Loader::turnout(unsigned id, unsigned path)
 337 {
 338         obj.turnouts[id] = path;
 339 }
 340
 341 } // namespace Marklin