X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Flibmarklin%2Froute.cpp;h=ace8d0b950812c56a22e23a0ba381f4d389b9f7b;hb=f06c2b89a2601981aae84d0f971c07816dc1bab4;hp=40638d9683051fd3fa4581b14f3d6458d89d4880;hpb=6dc18b0e518407bd2a86602bae1e9bbae05da7c8;p=r2c2.git

diff --git a/source/libmarklin/route.cpp b/source/libmarklin/route.cpp
index 40638d9..ace8d0b 100644
--- a/source/libmarklin/route.cpp
+++ b/source/libmarklin/route.cpp
@@ -1,10 +1,12 @@
 /* $Id$
 
 This file is part of the MSP Märklin suite
-Copyright © 2007-2009  Mikkosoft Productions, Mikko Rasa
+Copyright © 2007-2010  Mikkosoft Productions, Mikko Rasa
 Distributed under the GPL
 */
 
+#include <queue>
+#include <msp/strings/formatter.h>
 #include "layout.h"
 #include "route.h"
 #include "track.h"
@@ -13,14 +15,142 @@ Distributed under the GPL
 using namespace std;
 using namespace Msp;
 
+namespace {
+
+using namespace Marklin;
+
+typedef std::pair<const Track *, unsigned> Key;
+
+struct Node
+{
+	const Track *track;
+	unsigned ep;
+	Node *prev;
+	float dist;
+
+	Node():
+		track(0), ep(0), prev(0), dist(0)
+	{ }
+
+	Node(const Track &t, unsigned e):
+		track(&t), ep(e), prev(0), dist(0)
+	{ }
+
+	Node(const Track &t, unsigned e, Node &r, float d):
+		track(&t), ep(e), prev(&r), dist(prev->dist+d)
+	{ }
+
+	bool operator<(const Node &other) const
+	{ return dist>other.dist; }
+};
+
+struct TrackMatch
+{
+	const Track &track;
+
+	TrackMatch(const Track &t): track(t) { }
+
+	bool operator()(const Track &t) const { return &t==&track; }
+};
+
+struct TrackInRoute
+{
+	const Route &route;
+
+	TrackInRoute(const Route &r): route(r) { }
+
+	bool operator()(const Track &t) const { return route.get_tracks().count(&t); }
+};
+
+template<typename Pred>
+list<const Track *> dijkstra(const Track &from, unsigned ep, const Pred &goal)
+{
+	map<Key, Node> track_nodes;
+	priority_queue<Node> nodes;
+	Node *final = 0;
+
+	nodes.push(Node(from, ep));
+
+	while(!nodes.empty())
+	{
+		Node lowest = nodes.top();
+		nodes.pop();
+
+		Key key(lowest.track, lowest.ep);
+		if(track_nodes.count(key))
+			continue;
+
+		Node &ref = track_nodes[key] = lowest;
+		if(goal(*lowest.track))
+		{
+			final = &ref;
+			break;
+		}
+
+		const TrackType &type = lowest.track->get_type();
+		const vector<Endpoint> &eps = type.get_endpoints();
+		const vector<Track *> &links = lowest.track->get_links();
+		for(unsigned i=0; i<eps.size(); ++i)
+		{
+			if(i==lowest.ep || !links[i])
+				continue;
+
+			unsigned link_ep = links[i]->get_endpoint_by_link(*lowest.track);
+			if(track_nodes.count(Key(links[i], link_ep)))
+				continue;
+
+			unsigned mask = eps[i].paths&eps[lowest.ep].paths;
+			if(!mask)
+				continue;
+
+			unsigned path=0;
+			for(; !(mask&1); ++path, mask>>=1) ;
+			nodes.push(Node(*links[i], links[i]->get_endpoint_by_link(*lowest.track), ref, type.get_path_length(path)));
+		}
+	}
+
+	if(!final)
+		throw InvalidParameterValue("Could not find a route");
+
+	list<const Track *> result;
+	for(Node *node=final; node; node=node->prev)
+		result.push_front(node->track);
+
+	return result;
+}
+
+unsigned count = 0;
+
+template<typename Pred>
+Route *create_route(const Track &from, unsigned ep, const Pred &goal)
+{
+	list<const Track *> tracks = dijkstra(from, ep, goal);
+
+	Route *route = new Route(from.get_layout(), format("-%d-", ++count));
+	for(list<const Track *>::iterator i=tracks.begin(); i!=tracks.end(); ++i)
+		route->add_track(**i);
+
+	return route;
+}
+
+}
+
+
 namespace Marklin {
 
-Route::Route(Layout &layout, const string &n):
+Route::Route(Layout &l, const string &n):
+	layout(l),
 	name(n)
 {
+	layout.add_route(*this);
 	layout.signal_track_removed.connect(sigc::mem_fun(this, &Route::track_removed));
 }
 
+Route::~Route()
+{
+	layout.remove_route(*this);
+}
+
 int Route::get_turnout(unsigned id) const
 {
 	map<unsigned, int>::const_iterator i = turnouts.find(id);
@@ -92,17 +222,20 @@ void Route::update_turnouts()
 			const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 			const vector<Track *> &links = (*i)->get_links();
 
+			// Build a combined path mask from linked endpoints
 			unsigned mask = 15;
 			for(unsigned j=0; j<endpoints.size(); ++j)
 			{
 				if(!tracks.count(links[j]))
 					continue;
+
 				if(unsigned tid2=links[j]->get_turnout_id())
 				{
 					const Endpoint &ep = links[j]->get_type().get_endpoints()[links[j]->get_endpoint_by_link(**i)];
 					int p = get_turnout(tid2);
 					if(p>=0 && !(ep.paths&(1<<p)))
 					{
+						// The linked track is a turnout and has a path which is incompatible with this endpoint
 						mask &= ~endpoints[j].paths;
 						continue;
 					}
@@ -110,16 +243,19 @@ void Route::update_turnouts()
 				mask &= endpoints[j].paths;
 			}
 
-			if(!(mask&(mask-1)))
+			if(mask && !(mask&(mask-1)))
 			{
+				// Exactly one possible choice, set the path accordingly
 				unsigned path = 0;
 				for(; (mask && !(mask&1)); mask>>=1, ++path) ;
 				turnouts[tid] = path;
 			}
-			else
+			else if(!turnouts.count(tid))
+				// More than one possible choice, and no existing entry - set as undecided
 				turnouts[tid] = -1;
 		}
 
+	// Remove any turnouts that do not exist in the route
 	for(map<unsigned, int>::iterator i=turnouts.begin(); i!=turnouts.end();)
 	{
 		if(!found.count(i->first))
@@ -137,6 +273,7 @@ unsigned Route::check_validity(const Track &trk) const
 		int epi=(*i)->get_endpoint_by_link(trk);
 		if(epi>=0)
 		{
+			// Linked to an existing track - good
 			result |= 1;
 			const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
 			if(unsigned tid=(*i)->get_turnout_id())
@@ -144,11 +281,13 @@ unsigned Route::check_validity(const Track &trk) const
 				int r = get_turnout(tid);
 				if(r>=0)
 				{
+					// Linking to a turnout with path set is only good if we're continuing that path
 					if(endpoints[epi].paths&(1<<r))
 						result |= 2;
 				}
 				else
 				{
+					// Linked to a turnout with no path set - find out other linked tracks 
 					unsigned count = 0;
 					const vector<Track *> &links = (*i)->get_links();
 					int epj = -1;
@@ -158,15 +297,19 @@ unsigned Route::check_validity(const Track &trk) const
 							++count;
 							epj = k;
 						}
+
+					// Only good if at most one other track is linked to the turnout
 					if(count<=1)
 					{
 						result |= 2;
 						if(epj>=0 && !(endpoints[epi].paths&endpoints[epj].paths))
+							// Impossible path through the turnout - not good
 							result &= 3;
 					}
 				}
 			}
 			else
+				// Linked to something linear - good
 				result |= 2;
 		}
 	}
@@ -179,6 +322,16 @@ void Route::track_removed(Track &t)
 	tracks.erase(&t);
 }
 
+Route *Route::find(const Track &from, unsigned ep, const Track &to)
+{
+	return create_route(from, ep, TrackMatch(to));
+}
+
+Route *Route::find(const Track &from, unsigned ep, const Route &to)
+{
+	return create_route(from, ep, TrackInRoute(to));
+}
+
 
 Route::Loader::Loader(Route &r):
 	DataFile::BasicLoader<Route>(r)