public Path ComputeInternalPathFromTo(Tile _StartTile, Tile _EndTile)
{
List <PathLinkHeuristic> openList = new List <PathLinkHeuristic>();
HashSet <Tile> closeSet = new HashSet <Tile>();
openList.Add(new PathLinkHeuristic(_StartTile, Tile.GetManhattanDistance(_StartTile, _EndTile)));
CustomComparer <PathLinkHeuristic> comparer = new CustomComparer <PathLinkHeuristic>(false);
while (openList.Count > 0)
{
PathLinkHeuristic linkToExtend = openList.Last();
if (linkToExtend.Tile == _EndTile)
{
return(Path.CreatePath(linkToExtend));
}
openList.RemoveAt(openList.Count - 1);
Tile tileToExtend = linkToExtend.Tile;
if (closeSet.Contains(tileToExtend))
{
continue;
}
closeSet.Add(tileToExtend);
for (int i = 0; i < tileToExtend.Neighbors.Count; i++)
{
Tile neighbor = tileToExtend.Neighbors[i];
if (!neighbor.IsAccessible || !IsTileInside(neighbor) || closeSet.Contains(neighbor))
{
continue;
}
//PathLinkHeuristic extension = new PathLinkHeuristic(linkToExtend, neighbor, Tile.GetManhattanDistance(neighbor, _EndTile));
PathLinkHeuristic extension = linkToExtend.MakeExtensionWith(neighbor, Tile.GetManhattanDistance(neighbor, _EndTile));
int indexInsertion = openList.BinarySearch(extension, comparer);
if (indexInsertion < 0)
{
indexInsertion = ~indexInsertion;
}
openList.Insert(indexInsertion, extension);
}
}
return(null);
}
/// <summary>
/// Search a path with custom AStar algorithm
/// (PathLink is use to explore the grid. this way, there's no duplicate of tile array when we extend open list)
/// </summary>
/// <param name="_Start">Tile to start from</param>
/// <param name="_End">Tile to reach</param>
/// <param name="_ChronoInfos">Struct with times value to evaluate performance</param>
/// <param name="_MaxSeconds">Max time allowed to search a solution. If value is negative, no time limit applied</param>
/// <returns>the shortest path from start tile to end tile if it exists, null otherwise</returns>
public static Path AStar_LinkOpti(Tile _Start, Tile _End, out ChronoInfos _ChronoInfos, float _MaxSeconds)
{
StartChrono();
if (_Start == null || !_Start.IsAccessible || _End == null || !_End.IsAccessible)
{
_ChronoInfos = ChronoInfos.InfosNone;
return(null);
}
List <PathLinkHeuristic> openList = new List <PathLinkHeuristic>(100)
{
new PathLinkHeuristic(_Start, Tile.GetManhattanDistance(_Start, _End))
};
HashSet <Tile> closeHashSet = new HashSet <Tile>();
CustomComparer <PathLinkHeuristic> customComparer = new CustomComparer <PathLinkHeuristic>(true);
while (openList.Count > 0)
{
if (_MaxSeconds > 0 && chrono.Elapsed.TotalSeconds > _MaxSeconds)
{
_ChronoInfos = StopChrono(_Start, _End, false);
return(null);
}
PathLinkHeuristic linkToExtend = openList.First();
if (linkToExtend.Tile == _End)
{
_ChronoInfos = StopChrono(_Start, _End, true);
createSolutionChrono -= chrono.ElapsedMilliseconds;
Path solution = Path.CreatePath(linkToExtend);
createSolutionChrono += chrono.ElapsedMilliseconds;
return(solution);
}
removeFromOpenChrono -= chrono.ElapsedMilliseconds;
openList.RemoveAt(0);
removeFromOpenChrono += chrono.ElapsedMilliseconds;
if (closeHashSet.Contains(linkToExtend.Tile))
{
continue;
}
closeHashSet.Add(linkToExtend.Tile);
Tile tileToExtend = linkToExtend.Tile;
foreachNeighborsChrono -= chrono.ElapsedMilliseconds;
for (int i = 0; i < tileToExtend.Neighbors.Count; i++)
{
Tile neighbor = tileToExtend.Neighbors[i];
searchInCloseListChrono -= chrono.ElapsedMilliseconds;
bool existInCloseList = closeHashSet.Contains(neighbor);
searchInCloseListChrono += chrono.ElapsedMilliseconds;
if (!neighbor.IsAccessible || existInCloseList)
{
continue;
}
extendPathChrono -= chrono.ElapsedMilliseconds;
//PathLinkHeuristic extendedLink = new PathLinkHeuristic(linkToExtend, neighbor, Tile.GetManhattanDistance(neighbor, _End));
PathLinkHeuristic extendedLink = linkToExtend.MakeExtensionWith(neighbor, Tile.GetManhattanDistance(neighbor, _End));
extendPathChrono += chrono.ElapsedMilliseconds;
searchInsertionChrono -= chrono.ElapsedMilliseconds;
int indexInsertion = openList.BinarySearch(extendedLink, customComparer);
if (indexInsertion < 0)
{
indexInsertion = ~indexInsertion;
}
searchInsertionChrono += chrono.ElapsedMilliseconds;
insertToOpenListChrono -= chrono.ElapsedMilliseconds;
openList.Insert(indexInsertion, extendedLink);
insertToOpenListChrono += chrono.ElapsedMilliseconds;
}
foreachNeighborsChrono += chrono.ElapsedMilliseconds;
}
_ChronoInfos = StopChrono(_Start, _End, false);
return(null);
}
