/// <summary>
/// This function will "flux" the wood from path to path using connection points and list of sites in the paths until it meets an exit path.
/// </summary>
/// <param name="connectionToThisSite">The site from which we will beguin to flux on this current path. Has to be in the current path.</param>
/// <param name="woodFlux">The amount of wood to be fluxed along the paths to an exit point</param>
public void FluxPathFromSite(Site connectionToThisPath, double woodFlux)
{
FluxPath currentPath = this;
Site currentConnectionPoint = connectionToThisPath;
int connectionIndex;
List <Site> sitesTofFlux;
while (!currentPath.isAnEnd)
{
// Case of micro-paths (1 site), in order to avoid errors.
if (currentPath.sitesInPath.Count == 1)
{
SiteVars.RoadsInLandscape[currentPath.sitesInPath[0]].timestepWoodFlux += woodFlux;
}
else
{
connectionIndex = currentPath.sitesInPath.IndexOf(currentConnectionPoint);
if (connectionIndex == -1)
{
throw new Exception("FOREST ROADS SIMULATION ERROR : During the computing of the flux of wood, site " + currentConnectionPoint + " was not found in the corresponding path that contained " + currentPath.sitesInPath.Count + " sites. This is not normal." + PlugIn.errorToGithub);
}
sitesTofFlux = currentPath.sitesInPath.GetRange(connectionIndex, (currentPath.sitesInPath.Count - connectionIndex));
foreach (Site siteToFlux in sitesTofFlux)
{
SiteVars.RoadsInLandscape[siteToFlux].timestepWoodFlux += woodFlux;
}
}
currentConnectionPoint = currentPath.connectionToNext;
currentPath = currentPath.nextPath;
}
// Ending when we reached a currentPath that is an end
// Case of micro-paths (1 site), in order to avoid errors.
if (currentPath.sitesInPath.Count == 1)
{
SiteVars.RoadsInLandscape[currentPath.sitesInPath[0]].timestepWoodFlux += woodFlux;
}
else
{
connectionIndex = currentPath.sitesInPath.IndexOf(currentConnectionPoint);
if (connectionIndex == -1)
{
throw new Exception("FOREST ROADS SIMULATION ERROR : During the computing of the flux of wood, site " + currentConnectionPoint + " was not found in the corresponding path that contained " + currentPath.sitesInPath.Count + " sites. This is not normal." + PlugIn.errorToGithub);
}
sitesTofFlux = currentPath.sitesInPath.GetRange(connectionIndex, (currentPath.sitesInPath.Count - connectionIndex));
foreach (Site siteToFlux in sitesTofFlux)
{
SiteVars.RoadsInLandscape[siteToFlux].timestepWoodFlux += woodFlux;
}
}
}
// Constructor for the end of the dijkstra search, when we have found a connection to another path
public FluxPath(List <Site> sitesInPath, Site connectionToNext)
{
if (sitesInPath.Count == 0)
{
throw new Exception("FOREST ROADS SIMULATION ERROR : Tried to create a path with no sites in it." + PlugIn.errorToGithub);
}
// We create this path properly
this.sitesInPath = sitesInPath;
this.connectionToNext = connectionToNext;
this.nextPath = RoadNetwork.fluxPathDictionary[connectionToNext];
this.isAnEnd = false;
RoadNetwork.fluxPathCatalogue.Add(this);
foreach (Site site in sitesInPath)
{
RoadNetwork.fluxPathDictionary[site] = this;
}
}
/// <summary>
/// Finds the least cost path from roads to roads to a exit point for the wood in the landscape, and add the given wood flux to every road visited.
/// Warning : The starting site must not be inside an existing fluxpath.
/// </summary>
/// /// <param name="ModelCore">
/// The model's core framework.
/// </param>
/// /// <param name="startingSite">
/// The starting site of the search.
/// </param>
/// /// <param name="Woodflux">
/// The flux of wood that is going to flow to the exit point.
/// </param>
public static void DijkstraWoodFlux(ICore ModelCore, Site startingSite, double woodFlux)
{
// We initialize the frontier and everything else
Priority_Queue.SimplePriorityQueue <Site> frontier = new Priority_Queue.SimplePriorityQueue <Site>();
Dictionary <Site, Site> predecessors = new Dictionary <Site, Site>();
Dictionary <Site, double> costSoFar = new Dictionary <Site, Double>();
HashSet <Site> isClosed = new HashSet <Site>();
bool haveWeFoundARoadToConnectTo = false;
costSoFar[startingSite] = 0;
frontier.Enqueue(startingSite, 0);
Site siteToClose;
double newDistanceToStart;
// Useless assignement to please the gods of C#
Site arrivalSite = startingSite;
// First, we got to check the possibility that the starting site IS the arrival site. This is possible in very rare situations,
// as the given starting site can be an exit point...That is not surounded by roads. If that happens, the dijkstra will not be able to
// open any neighbors, and will fail. Again, very rare, but still important.
if (RoadNetwork.fluxPathDictionary.ContainsKey(startingSite) || SiteVars.RoadsInLandscape[startingSite].IsAPlaceForTheWoodToGo)
{
haveWeFoundARoadToConnectTo = true; goto End;
}
// We loop until the list is empty
while (frontier.Count > 0)
{
// We take the site with the lowest distance to start.
siteToClose = frontier.Dequeue();
// We look at each of its neighbours, but only those with roads on them.
foreach (Site neighbourToOpen in MapManager.GetNeighbouringSitesWithRoads(siteToClose))
{
// We don't consider the neighbour if it is closed
if (!isClosed.Contains(neighbourToOpen))
{
// We get the value of the distance to start by using the current node to close, which is just an addition of the distance to the start
// from the node to close + the cost between it and the neighbor.
newDistanceToStart = costSoFar[siteToClose] + MapManager.CostOfTransition(siteToClose, neighbourToOpen);
// If the node isn't opened yet, or if it is opened and going to start throught the current node to close is closer; then,
// this node to close will become its predecessor, and its distance to start will become this one.
if (!costSoFar.ContainsKey(neighbourToOpen) || newDistanceToStart < costSoFar[neighbourToOpen])
{
costSoFar[neighbourToOpen] = newDistanceToStart;
predecessors[neighbourToOpen] = siteToClose;
// Case of the node not being opened
if (!frontier.Contains(neighbourToOpen))
{
frontier.Enqueue(neighbourToOpen, (float)costSoFar[neighbourToOpen]);
}
// Case of the node being already open
else
{
frontier.UpdatePriority(neighbourToOpen, (float)costSoFar[neighbourToOpen]);
}
}
// We check if the neighbour is a exit node for the wood. If that's the case, search is other.
if (RoadNetwork.fluxPathDictionary.ContainsKey(neighbourToOpen) || SiteVars.RoadsInLandscape[neighbourToOpen].IsAPlaceForTheWoodToGo)
{
arrivalSite = neighbourToOpen; haveWeFoundARoadToConnectTo = true; goto End;
}
}
}
// Now that we have checked all of its neighbours, we can close the current node.
isClosed.Add(siteToClose);
}
End:
// ModelCore.UI.WriteLine("Dijkstra search for wood flux is over.");
// If we're out of the loop, that means that the search is over. If it was successfull before we ran out of neighbours to check,
// We can now retrieve the list of the sites that
// are the least cost path, and make sure that all of these site now have a road constructed on them, and that it is
// indicated as connected to a place where we can make wood go.
if (haveWeFoundARoadToConnectTo)
{
// If we found a fluxPath to connect to, we create a new one starting from the starting site, and stopping just before the arrival (which is our connection site to the fluxpath, and thus already belongs to a fluxpath)
if (RoadNetwork.fluxPathDictionary.ContainsKey(arrivalSite))
{
List <Site> listOfSitesInLeastCostPath = MapManager.FindPathToStart(startingSite, arrivalSite, predecessors);
// We have to reverse the list, because we want to go from the harvested zones to the connection point, and not the opposite.
listOfSitesInLeastCostPath.Reverse();
// We don't put the arrival site in the fluxpath, because it is part of another fluxpath.
listOfSitesInLeastCostPath.Remove(arrivalSite);
FluxPath newFluxPath = new FluxPath(listOfSitesInLeastCostPath, arrivalSite);
// Now that this new path is created, we flux the wood.
newFluxPath.FluxPathFromSite(startingSite, woodFlux);
}
// Else, if we didn't found a fluxPath to connect to but an exit point for the wood, we create a new "isAnEnd" path.
else
{
List <Site> listOfSitesInLeastCostPath = MapManager.FindPathToStart(startingSite, arrivalSite, predecessors);
// We have to reverse the list, because we want to go from the harvested zones to the exit point, and not the opposite.
listOfSitesInLeastCostPath.Reverse();
FluxPath newFluxPathIsAnEnd = new FluxPath(listOfSitesInLeastCostPath);
// Then, we flux the wood down this path.
newFluxPathIsAnEnd.FluxPathFromSite(startingSite, woodFlux);
}
}
else
{
throw new Exception("FOREST ROADS SIMULATION ERROR : A Dijkstra search wasn't able to flux the wood from site " + startingSite.Location + " to any exit point. This isn't supposed to happen. Please check the output raster containg the road network for the current timestep (" + ModelCore.CurrentTime + " years) and see if a road is interrupted somewhere." + PlugIn.errorToGithub);
}
}
