public List<Node> Astar(Node start, Node goal)
{
if (start == null || goal == null){
return null;
}
if (start == goal)
{
return new List<Node> {start};
}
foreach(Node node in objectManager.NodeManager.nodes)
{
node.Reset();
}
MinHeap openSet = new MinHeap(start);
start.IsInOpenSet = true;
start.gScore = 0;
start.fScore = start.gScore + Heuristic_cost_estimate (goal, start);
Node current = null;
while (openSet.Count() > 0) {
current = openSet.GetRoot ();
current.IsInOpenSet = false;
current.IsInClosedSet = true;
if (current == goal)
{
return Reconstruct_path (start, goal);
}
foreach (Node neighbor in current.BorderTiles) {
if(neighbor == null || !neighbor.IsWalkable || neighbor.IsInClosedSet)
continue;
// if the new gscore is lower replace it
int tentativeGscore = current.gScore + Heuristic_cost_estimate (current, neighbor);
if (!neighbor.IsInOpenSet || tentativeGscore < neighbor.gScore) {
neighbor.parent = current;
neighbor.gScore = tentativeGscore;
neighbor.fScore = neighbor.gScore + Heuristic_cost_estimate (goal, neighbor);
if (!neighbor.IsInOpenSet){
openSet.Add (neighbor);
neighbor.IsInOpenSet = true;
}
else
{
openSet.Reevaluate(neighbor);
}
}
}
}
// Fail
return null;
}
public void Astar()
{
if (start == null || goal == null)
{
done = true;
return;
}
if (start == goal)
{
done = true;
return;
}
MinHeap openSet = new MinHeap(start);
start.isInOpenSet = true;
start.gScore = 0;
start.fScore = start.gScore + Heuristic_cost_estimate(goal, start);
int numSteps = 0;
Node current = null;
while (openSet.Count() > 0)
{
current = openSet.GetRoot();
current.isCurrent = true;
current.isInOpenSet = false;
current.isInClosedSet = true;
ControlLogic(current, numSteps);
numSteps++;
current.isCurrent = false;
if (current == goal)
{
pathToDestination = Reconstruct_path(start, goal);
done = true;
return;
}
foreach (Node neighbor in current.getNeighbors())
{
if (neighbor == null || !neighbor.isWalkable || neighbor.isInClosedSet)
{
continue;
}
// if the new gscore is lower replace it
int tentativeGscore = current.gScore + Heuristic_cost_estimate(current, neighbor);
if (!neighbor.isInOpenSet || tentativeGscore < neighbor.gScore)
{
neighbor.parent = current;
neighbor.gScore = tentativeGscore;
neighbor.fScore = neighbor.gScore + Heuristic_cost_estimate(goal, neighbor);
if (!neighbor.isInOpenSet)
{
openSet.Add(neighbor);
neighbor.isInOpenSet = true;
}
else
{
openSet.Reevaluate(neighbor);
}
}
}
}
// Fail
done = true;
return;
}
private void Astar()
{
start.isInOpenSetOfThread[id] = true;
MinHeap openSet = new MinHeap(start, id);
openSet.Add(start);
start.gScores[id] = 0;
start.fScores[id] = start.gScores[id] + Heuristic_cost_estimate(goal, start);
int numSteps = 0;
while (!finished)
{
Node current = openSet.GetRoot();
current.isInOpenSetOfThread[id] = false;
current.isInClosedSet = true;
current.isCurrent = true;
ControlLogic(current, numSteps);
numSteps++;
current.isCurrent = false;
if (current.checkedByThread == 0)
{
if (current.fScores[id] < (int)L && current.gScores[id] + brotherThread.F - brotherThread.Heuristic_cost_estimate(start, current) < (int)L)
{
foreach (Node neighbor in current.getNeighbors())
{
if (neighbor != null && neighbor.isWalkable)
{
int cost = Heuristic_cost_estimate(current, neighbor);
if (neighbor.checkedByThread == 0 && neighbor.gScores[id] > current.gScores[id] + cost)
{
neighbor.gScores[id] = current.gScores[id] + cost;
neighbor.fScores[id] = neighbor.gScores[id] + Heuristic_cost_estimate(goal, neighbor);
neighbor.parents[id] = current;
if (!neighbor.isInOpenSetOfThread[id])
{
neighbor.isInOpenSetOfThread[id] = true;
openSet.Add(neighbor);
}
else
{
openSet.Reevaluate(neighbor);
}
if (neighbor.gScores[brotherThread.id] != int.MaxValue && neighbor.gScores[brotherThread.id] + neighbor.gScores[id] < (int)L)
{
lock (L)
{
if (neighbor.gScores[brotherThread.id] + neighbor.gScores[id] < (int)L)
{
L = neighbor.gScores[brotherThread.id] + neighbor.gScores[id];
endNode = current;
brotherThread.endNode = neighbor;
}
}
}
}
}
}
}
current.checkedByThread = id;
}
if (openSet.Count() > 0)
{
F = openSet.Peek().fScores[id];
}
else
{
finished = true;
}
}
}