protected List <Node> GetNeighbours(AlgorithmData data, Node current)
{
List <Node> neighbours = new List <Node>();
foreach (var edge in data.allEdges)
{
if (edge.nodeFrom == current)
{
neighbours.Add(edge.nodeTo);
}
else if (edge.nodeTo == current)
{
neighbours.Add(edge.nodeFrom);
}
}
return(neighbours);
}
public AlgorithmData ConvertVisualsToData()
{
AlgorithmData data = new AlgorithmData();
var visualNodes = FindObjectsOfType <VisualNode>();
data.allNodes = new List <Node>();
foreach (var visualNode in visualNodes)
{
Node newNode = new Node();
data.allNodes.Add(newNode);
if (visualNode.isStartNode)
{
data.startNode = newNode;
}
if (visualNode.isEndNode)
{
data.endNode = newNode;
}
visualNodeToNodeDict[visualNode] = newNode;
nodeToVisualNodeDict[newNode] = visualNode;
}
var visualEdges = FindObjectOfType <EdgeMaker>().visualEdges;
data.allEdges = new List <Edge>();
foreach (var visualEdge in visualEdges)
{
Edge newEdge = new Edge();
data.allEdges.Add(newEdge);
newEdge.nodeFrom = visualNodeToNodeDict[visualEdge.nodeFrom];
newEdge.nodeTo = visualNodeToNodeDict[visualEdge.nodeTo];
visualEdgeToEdgeDict[visualEdge] = newEdge;
edgeToVisualEdgeDict[newEdge] = visualEdge;
}
return(data);
}
protected override IEnumerator PerformAlgorithmCO(AlgorithmData data)
{
bool result = false;
Queue <Node> queue = new Queue <Node>();
List <Node> visitedNodes = new List <Node>();
queue.Enqueue(data.startNode);
visitedNodes.Add(data.startNode);
while (queue.Count > 0)
{
Node current = queue.Dequeue();
converter.SelectNode(current);
yield return(new WaitForSeconds(0.05f));
if (current == data.endNode)
{
Debug.Log("WE FOUND THE END NODE!");
result = true;
break;
}
List <Node> neighbours = GetNeighbours(data, current);
foreach (var neighbour in neighbours)
{
if (!visitedNodes.Contains(neighbour))
{
queue.Enqueue(neighbour);
visitedNodes.Add(neighbour);
}
}
}
if (result == false)
{
Debug.Log("We could not find a path to the end node.");
}
}
protected override IEnumerator PerformAlgorithmCO(AlgorithmData data)
{
List <Node> unvisitedNodes = new List <Node>(); // nodes we need to check
// Initialise all nodes to infinity and put them in the unvisited list
foreach (var node in data.allNodes)
{
unvisitedNodes.Add(node);
node.pathWeight = Mathf.Infinity;
}
// Initialise the start node
Node current = data.startNode;
data.startNode.pathWeight = 0;
converter.SelectNode(current);
while (true)
{
List <Node> neighbours = GetNeighbours(data, current);
foreach (var neighbour in neighbours)
{
if (unvisitedNodes.Contains(neighbour))
{
float tentativeWeight = current.pathWeight + 1; // 1 is the weight of the segment connecting the two nodes
// we compare the tentative weight with the one we already set for that neighbour
if (tentativeWeight < neighbour.pathWeight)
{
neighbour.pathWeight = tentativeWeight;
}
}
}
// we remove the visited node
unvisitedNodes.Remove(current);
// let's check whether we finished the path
if (current == data.endNode)
{
Debug.Log("WE FOUND THE SHORTEST PATH " + current.pathWeight);
break;
}
// let's choose the node with the minimum weight
float minWeight = Mathf.Infinity;
foreach (var node in unvisitedNodes)
{
if (node.pathWeight < minWeight)
{
minWeight = node.pathWeight;
current = node;
}
}
converter.SelectNode(current, new Color(current.pathWeight / 15f, 1 - current.pathWeight / 15f, 0));
yield return(new WaitForSeconds(0.05f));
}
// Find the shortest path
List <Node> shortestPath = new List <Node>();
shortestPath.Add(data.endNode);
current = data.endNode;
converter.SelectNode(current, new Color(0f, 0f, 1f));
while (true)
{
// Find the lowest weight neighbour (which is the one that will take me to the start node at minimum cost)
float minWeight = Mathf.Infinity;
Node minNeighbour = null;
foreach (var neighbour in GetNeighbours(data, current))
{
if (neighbour.pathWeight < minWeight)
{
minWeight = neighbour.pathWeight;
minNeighbour = neighbour;
}
}
shortestPath.Add(minNeighbour);
current = minNeighbour;
converter.SelectNode(current, new Color(0f, 0f, 1f));
yield return(new WaitForSeconds(0.05f));
if (current == data.startNode)
{
break;
}
}
}
protected abstract IEnumerator PerformAlgorithmCO(AlgorithmData data);
protected override IEnumerator PerformAlgorithmCO(AlgorithmData data)
{
List <Node> unvisitedNodes = new List <Node>(); // nodes we need to check
// Initialise all nodes to infinity and put them in the unvisited list
foreach (var node in data.allNodes)
{
unvisitedNodes.Add(node);
node.pathWeight = Mathf.Infinity;
node.tentativeWeight = Mathf.Infinity;
}
// Initialise the start node
Node current = data.startNode;
data.startNode.pathWeight = 0;
converter.SelectNode(current);
while (true)
{
List <Node> neighbours = GetNeighbours(data, current);
foreach (var neighbour in neighbours)
{
if (unvisitedNodes.Contains(neighbour))
{
float pathWeight = current.pathWeight + segmentWeight; // segmentWeight is the weight of the segment connecting the two nodes
// A* magic here!
// we also add a heuristic "h" estimate of the remaining cost
// we use distance as an heuristic
float distance = (converter.nodeToVisualNodeDict[neighbour].transform.position
- converter.nodeToVisualNodeDict[data.endNode].transform.position).sqrMagnitude;
float heuristicWeight = distance * heuristicFactor;
float tentativeWeight = pathWeight + heuristicWeight;
Debug.Log("Tot: " + tentativeWeight + " Path: " + pathWeight + " Heur: " + heuristicWeight);
// we compare the tentative weight with the one we already set for that neighbour
if (tentativeWeight < neighbour.tentativeWeight)
{
neighbour.tentativeWeight = tentativeWeight;
}
if (pathWeight < neighbour.pathWeight)
{
neighbour.pathWeight = pathWeight;
}
}
}
// we remove the visited node
unvisitedNodes.Remove(current);
// let's check whether we finished the path
if (current == data.endNode)
{
Debug.Log("WE FOUND THE SHORTEST PATH " + current.pathWeight);
break;
}
// let's choose the node with the minimum weight
float minWeight = Mathf.Infinity;
foreach (var node in unvisitedNodes)
{
if (node.tentativeWeight < minWeight)
{
minWeight = node.tentativeWeight;
current = node;
}
}
converter.SelectNode(current, new Color(current.tentativeWeight / 15f, 1 - current.tentativeWeight / 15f, 0));
yield return(new WaitForSeconds(0.05f));
}
// Find the shortest path
List <Node> shortestPath = new List <Node>();
shortestPath.Add(data.endNode);
current = data.endNode;
converter.SelectNode(current, new Color(0f, 0f, 1f));
while (true)
{
// Find the lowest weight neighbour (which is the one that will take me to the start node at minimum cost)
float minWeight = Mathf.Infinity;
Node minNeighbour = null;
foreach (var neighbour in GetNeighbours(data, current))
{
if (neighbour.pathWeight < minWeight)
{
minWeight = neighbour.pathWeight;
minNeighbour = neighbour;
}
}
shortestPath.Add(minNeighbour);
current = minNeighbour;
converter.SelectNode(current, new Color(0f, 0f, 1f));
yield return(new WaitForSeconds(0.05f));
if (current == data.startNode)
{
break;
}
}
}