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public static Backtrace ( |
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| iNode | ||
| return | List |
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public static List <GridPos> FindPath(JumpPointParam iParam)
{
try
{
List <Node> tOpenList = iParam.openList;
Node tStartNode = iParam.StartNode;
Node tEndNode = iParam.EndNode;
bool revertEndNodeWalkable = false;
// set the `g` and `f` value of the start node to be 0
tStartNode.startToCurNodeLen = 0;
tStartNode.heuristicStartToEndLen = 0;
// push the start node into the open list
tOpenList.Add(tStartNode);
tStartNode.isOpened = true;
if (iParam.AllowEndNodeUnWalkable && !iParam.SearchGrid.IsWalkableAt(tEndNode.x, tEndNode.y))
{
iParam.SearchGrid.SetWalkableAt(tEndNode.x, tEndNode.y, 0);
revertEndNodeWalkable = true;
}
// while the open list is not empty
while (tOpenList.Any())
{
// pop the position of node which has the minimum `f` value.
Node tNode = tOpenList.Last();
tOpenList.RemoveAt(tOpenList.Count - 1);
tNode.isClosed = true;
if (tNode.Equals(tEndNode))
{
if (revertEndNodeWalkable)
{
iParam.SearchGrid.SetWalkableAt(tEndNode.x, tEndNode.y, 1);
}
return(Node.Backtrace(tNode)); // rebuilding path
}
identifySuccessors(iParam, tNode);
}
if (revertEndNodeWalkable)
{
iParam.SearchGrid.SetWalkableAt(tEndNode.x, tEndNode.y, 1);
}
// fail to find the path
return(new List <GridPos>());
}
catch
{
return(new List <GridPos>());
}
}
public static List <GridPos> FindPath(JumpPointParam iParam)
{
var tOpenList = iParam.openList;
var tStartNode = iParam.StartNode;
var tEndNode = iParam.EndNode;
var revertEndNodeWalkable = false;
// set the `g` and `f` value of the start node to be 0
tStartNode.startToCurNodeLen = 0;
tStartNode.heuristicStartToEndLen = 0;
// push the start node into the open list
tOpenList.Add(tStartNode);
tStartNode.isOpened = true;
if (iParam.CurEndNodeUnWalkableTreatment == EndNodeUnWalkableTreatment.Allow && !iParam.SearchGrid.IsWalkableAt(tEndNode.x, tEndNode.y))
{
iParam.SearchGrid.SetWalkableAt(tEndNode.x, tEndNode.y, true);
revertEndNodeWalkable = true;
}
// while the open list is not empty
while (tOpenList.Count > 0)
{
// pop the position of node which has the minimum `f` value.
var tNode = tOpenList.DeleteMin();
tNode.isClosed = true;
if (tNode.Equals(tEndNode))
{
if (revertEndNodeWalkable)
{
iParam.SearchGrid.SetWalkableAt(tEndNode.x, tEndNode.y, false);
}
return(Node.Backtrace(tNode)); // rebuilding path
}
IdentifySuccessors(iParam, tNode);
}
if (revertEndNodeWalkable)
{
iParam.SearchGrid.SetWalkableAt(tEndNode.x, tEndNode.y, false);
}
// Failed to find path
return(new List <GridPos>());
}
public static List <GridPos> FindPath(AStarParam parameters)
{
object lo = new object();
var openList = new IntervalHeap <Node>();
var startNode = parameters.StartNode;
var endNode = parameters.EndNode;
var heuristic = parameters.HeuristicFunc;
var grid = parameters.SearchGrid;
var diagonalMovement = parameters.DiagonalMovement;
var weight = parameters.Weight;
startNode.startToCurNodeLen = 0;
startNode.heuristicStartToEndLen = 0;
openList.Add(startNode);
startNode.isOpened = true;
while (openList.Count != 0)
{
var node = openList.DeleteMin();
node.isClosed = true;
if (node == endNode)
{
return(Node.Backtrace(endNode));
}
var neighbors = grid.GetNeighbors(node, diagonalMovement);
Parallel.ForEach(neighbors, neighbor =>
{
if (neighbor.isClosed)
{
return;
}
var x = neighbor.x;
var y = neighbor.y;
float ng = node.startToCurNodeLen + (float)((x - node.x == 0 || y - node.y == 0) ? 1 : Math.Sqrt(2));
if (!neighbor.isOpened || ng < neighbor.startToCurNodeLen)
{
neighbor.startToCurNodeLen = ng;
if (neighbor.heuristicCurNodeToEndLen == null)
{
neighbor.heuristicCurNodeToEndLen = weight * heuristic(Math.Abs(x - endNode.x), Math.Abs(y - endNode.y));
}
neighbor.heuristicStartToEndLen = neighbor.startToCurNodeLen + neighbor.heuristicCurNodeToEndLen.Value;
neighbor.parent = node;
if (!neighbor.isOpened)
{
lock (lo)
{
openList.Add(neighbor);
}
neighbor.isOpened = true;
}
}
});
}
return(new List <GridPos>());
}