/// <summary>
/// Finds a path on the current thread and returns.
/// task.CompletedCallBack is ignored.
/// </summary>
/// <param name="state"></param>
public void FindPathSync(AStarState <T> state)
{
try
{
state.SearchingPath = true;
FindPathExec(state);
}
finally
{
state.SearchingPath = false;
}
}
public async Task FindPath(AStarState <T> state)
{
try
{
state.SearchingPath = true;
await Task.Run(() => FindPathExec(state)).ConfigureAwait(false);
}
finally
{
state.SearchingPath = false;
}
state.Complete = true;
}
void FindPathExec(AStarState <T> state)
{
var openNodes = state.openNodes;
var closedNodes = state.closedNodes;
openNodes.Clear();
closedNodes.Clear();
state.Path.Clear();
state.AbortOperation = false;
var node = new AStarNode <T>
{
Location = state.Start,
Parent = null,
Heuristic = mMap.CalculateHeuristic(state.Start, state.EndPoints),
PaidCost = 0
};
state.openNodes.Add(node);
bool found = false;
int steps = 0;
do
{
SortOpenNodes(openNodes);
//sMap.ReportProgress(openNodes, closedNodes, end);
node = openNodes[0];
openNodes.RemoveAt(0);
closedNodes.Add(node);
if (state.EndPoints.Contains(node.Location))
{
found = true;
break;
}
steps++;
if (steps > maxSteps)
{
break;
}
foreach (T test in mMap.GetAvailableSteps(state, node.Location))
{
if (state.AbortOperation)
{
return;
}
if (LocationIn(closedNodes, test))
{
continue;
}
int deltaCost = mMap.GetStepCost(test, node.Location);
int index = FindPointInOpenNodes(openNodes, test);
if (index >= 0)
{
if (node.PaidCost + deltaCost < openNodes[index].PaidCost)
{
var target = openNodes[index];
target.Parent = node;
target.PaidCost = node.PaidCost + deltaCost;
openNodes[index] = target;
}
}
else
{
var newtarget = new AStarNode <T>
{
Location = test,
Parent = node,
PaidCost = node.PaidCost + deltaCost,
Heuristic = mMap.CalculateHeuristic(test, state.EndPoints)
};
if (newtarget.Heuristic < 0)
{
continue;
}
openNodes.Add(newtarget);
if (newtarget.Heuristic == 0)
{
node = newtarget;
found = true;
}
}
if (found)
{
break;
}
}
} while (openNodes.Count > 0 && found == false);
if (!found)
{
state.FoundPath = false;
return;
}
var path = new List <T>();
path.Add(node.Location);
while (node.Parent != null && node.Parent != node)
{
node = node.Parent;
path.Add(node.Location);
}
state.Path.AddRange(path);
state.FoundPath = true;
}