/**
* Sets all variables of the HelperNode.
*/
public void Initialize(int id, int state, int distance, HelperNodeController predecessor)
{
Id = id;
State = state;
Distance = distance;
Predecessor = predecessor;
}
// Checks whether to add the node to the queue or not
private bool DecideToAddNewNode(HelperNodeController nodeController)
{
if (nodeController.Distance < allDistances[nodeController.Id, nodeController.State])
{
// Update smallest known distance
allDistances[nodeController.Id, nodeController.State] = nodeController.Distance;
return(true);
}
return(false);
}
// Calculates the path between start and target
private void CalculatePathBetweenStartAndEndNode(HelperNodeController endHelperNode)
{
ShortestPath = new List <NodeController>();
List <NodeController> pathHelperList = new List <NodeController>();
HelperNodeController currentHelperNode = endHelperNode;
while (currentHelperNode != null)
{
pathHelperList.Add(MainScript.AllNodes[currentHelperNode.Id]);
currentHelperNode = currentHelperNode.Predecessor;
}
for (int i = pathHelperList.Count - 1; i >= 0; i--)
{
ShortestPath.Add(pathHelperList[i]);
}
}
// Performs the modified dijkstra algorithm and calls the method to fill the shortestPathBetweenStartAndEndNode list.
public void CalculateModifiedDijkstraAlgorithm()
{
HelperNodeController endHelperNode = null;
// Add the start node with state = 0 and distance = 0 to the SimplePriorityQueue
GameObject helpObject = Instantiate(helperNodePrefab);
HelperNodeController help = helpObject.GetComponent <HelperNodeController>();
help.Initialize(startNode.Id, initialState, 0, null);
prioQueue.Enqueue(help, 0);
garbage.Add(helpObject);
allDistances[startNode.Id, initialState] = 0;
while (prioQueue.Count != 0)
{
// Retrieve the node with the smallest distance
HelperNodeController currentHelperNode = prioQueue.Dequeue();
// Skip the node if it was treated yet
if (currentHelperNode.Distance != allDistances[currentHelperNode.Id, currentHelperNode.State])
{
continue;
}
NodeController currentNode = MainScript.AllNodes[currentHelperNode.Id];
// End node test
if (currentHelperNode.Id == endNode.Id)
{
endHelperNode = currentHelperNode;
break;
}
// Perform the state change of the current node
int newState = currentNode.ChangeState(currentHelperNode.State);
// Handle all outgoing edges of the current node
foreach (EdgeController edge in currentNode.OutgoingEdges)
{
// Calculate the new distance of the end node of the edge
int newDistance = currentHelperNode.Distance + edge.GetCostForState(newState);
// Create the new node and add it if allowed
GameObject newNodeObject = Instantiate(helperNodePrefab);
HelperNodeController newNode = newNodeObject.GetComponent <HelperNodeController>();
garbage.Add(newNodeObject);
// Check which node is the target node
if (edge.Node1.Id != currentNode.Id)
{
newNode.Initialize(edge.Node1.Id, newState, newDistance, currentHelperNode);
}
else
{
newNode.Initialize(edge.Node0.Id, newState, newDistance, currentHelperNode);
}
if (DecideToAddNewNode(newNode))
{
prioQueue.Enqueue(newNode, newDistance);
}
}
}
// Calculate the distance and path of the result
if (endHelperNode != null)
{
ShortestDistance = endHelperNode.Distance;
CalculatePathBetweenStartAndEndNode(endHelperNode);
}
// Destroy garbage
foreach (GameObject obj in garbage)
{
Destroy(obj);
}
}