public override IEnumerator Search(List <Node> nodes, int size, Node start, Node goal, int framesPerSecond)
{
IsSearching = true;
Debug.LogFormat("Searching path using A* algorythm");
bool hasPath = false;
bool[,] visited = new bool[size, size];
cameFrom = new Dictionary <Node, Node> ();
List <NodeDistance> frontier = new List <NodeDistance> ();
Node current = new Node();
float pathLength;
frontier.Add(new NodeDistance(start, 0 + Mathf.Abs(Vector2.Distance(start.pos, goal.pos))));
cameFrom[start] = null;
visited[(int)start.pos.x, (int)start.pos.y] = true;
while (frontier.Count > 0)
{
current = frontier[0].node;
pathLength = frontier[0].distance - Mathf.Abs(Vector2.Distance(current.pos, goal.pos));
frontier.RemoveAt(0);
UIUpdate(frontier.Count, pathLength, Mathf.Abs(Vector2.Distance(current.pos, goal.pos)) + pathLength);
//visualize path to current
GraphSearcher.VisualizePath(cameFrom, current, start);
yield return(new WaitForSeconds(1f / framesPerSecond));
if (current == goal)
{
hasPath = true;
break;
}
//get the maxNodes nodes closest to the objective and keep them.
for (int i = 0; i < current.links.Count; i++)
{
Node neighbour = current.links[i];
if (!visited[(int)neighbour.pos.x, (int)neighbour.pos.y])
{
visited[(int)neighbour.pos.x, (int)neighbour.pos.y] = true;
cameFrom[neighbour] = current;
float totalDistance = pathLength + Mathf.Abs(Vector2.Distance(neighbour.pos, current.pos)) + Mathf.Abs(Vector2.Distance(neighbour.pos, goal.pos));
frontier.Add(new NodeDistance(neighbour, totalDistance));
UIIncrementEnqueuings();
}
frontier.Sort();
}
}
SearchComplete(hasPath);
yield break;
}
public override IEnumerator Search(List <Node> nodes, int size, Node start, Node goal, int framesPerSecond)
{
IsSearching = true;
Debug.Log("Searching path using Breadth First Search algorythm.");
bool hasPath = false;
bool[,] visited = new bool[size, size];
cameFrom = new Dictionary <Node, Node> ();
Queue <Node> frontier = new Queue <Node> ();
Node current = new Node();
frontier.Enqueue(start);
cameFrom[start] = null;
visited[(int)start.pos.x, (int)start.pos.y] = true;
while (frontier.Count > 0)
{
current = frontier.Dequeue();
UIUpdate(frontier.Count, CalculatePathLength(start, current));
//visualize path to current
GraphSearcher.VisualizePath(cameFrom, current, start);
yield return(new WaitForSeconds(1f / framesPerSecond));
if (current == goal)
{
hasPath = true;
break;
}
for (int i = 0; i < current.links.Count; i++)
{
Node neighbour = current.links[i];
if (neighbour == current)
{
Debug.LogErrorFormat("node {0} has link to itself.", current);
}
if (!visited[(int)neighbour.pos.x, (int)neighbour.pos.y])
{
visited[(int)neighbour.pos.x, (int)neighbour.pos.y] = true;
cameFrom[neighbour] = current;
frontier.Enqueue(neighbour);
UIIncrementEnqueuings();
}
}
}
SearchComplete(hasPath);
yield break;
}
public override IEnumerator Search(List <Node> nodes, int size, Node start, Node goal, int framesPerSecond)
{
IsSearching = true;
Debug.Log("Searching path using Hill Climbing algorythm.");
bool hasPath = false;
bool[,] visited = new bool[size, size];
cameFrom = new Dictionary <Node, Node> ();
Stack <Node> frontier = new Stack <Node> ();
Node current = new Node();
frontier.Push(start);
cameFrom[start] = null;
while (frontier.Count > 0)
{
current = frontier.Pop();
UIUpdate(frontier.Count, CalculatePathLength(start, current));
//visualize path to current
GraphSearcher.VisualizePath(cameFrom, current, start);
yield return(new WaitForSeconds(1f / framesPerSecond));
if (current == goal)
{
hasPath = true;
break;
}
float closestDistance = Vector2.Distance(current.pos, goal.pos);
Node closestNeighbour = null;
for (int i = 0; i < current.links.Count; i++)
{
Node neighbour = current.links[i];
// test shortest path
float neighbourDist = Vector2.Distance(neighbour.pos, goal.pos);
if (neighbourDist < closestDistance || closestDistance == float.MaxValue)
{
closestNeighbour = neighbour;
closestDistance = neighbourDist;
}
}
// extend path
if (closestNeighbour != null)
{
if (!visited[(int)closestNeighbour.pos.x, (int)closestNeighbour.pos.y])
{
visited[(int)closestNeighbour.pos.x, (int)closestNeighbour.pos.y] = true;
cameFrom[closestNeighbour] = current;
frontier.Push(closestNeighbour);
UIIncrementEnqueuings();
}
}
else
{
Debug.LogFormat("Stuck in local maxima. node {0}", current.ID);
}
}
SearchComplete(hasPath);
yield break;
}
