/// <summary>Creates a populated <see cref="Collection{T}"/> of <see cref="Landmark"/>
/// instances.</summary>
/// <param name="board">The board on which the collection of landmarks is to be instantiated.</param>
/// <param name="landmarkCoords">Board coordinates of the desired landmarks</param>
public static ILandmarkCollection CreateLandmarks(
IHexBoard <IHex> board,
IFastList <HexCoords> landmarkCoords
)
{
if (landmarkCoords == null)
{
throw new ArgumentNullException("landmarkCoords");
}
ILandmarkCollection tempLandmarks = null, landmarks = null;
try {
tempLandmarks = new LandmarkCollection((
from coords in landmarkCoords.AsParallel().AsOrdered()
where board.IsOnboard(coords)
select new Landmark(coords, board)
).ToList <ILandmark>());
landmarks = tempLandmarks;
tempLandmarks = null;
} finally { if (tempLandmarks != null)
{
tempLandmarks.Dispose();
}
}
return(landmarks);
}
public static LandmarkCollection CreateLandmarks(
IBoard <IHex> board,
IList <HexCoords> landmarkCoords
)
{
if (landmarkCoords == null)
{
throw new ArgumentNullException("landmarkCoords");
}
var list = new List <Landmark>(landmarkCoords.Count);
for (var i = 0; i < landmarkCoords.Count; i++)
{
list.Add(new Landmark(landmarkCoords[i], null));
}
var landmarks = new LandmarkCollection(list);
if (board != null)
{
landmarks.ResetLandmarks(board);
}
return(landmarks);
}
/// <summary>(Re)calculates distances for all landmarks using the provided IBoard<IHex> definition.</summary>
/// <param name="this">The </param>
/// <param name="board">The </param>
public static void ResetLandmarks(this LandmarkCollection @this, IBoard <IHex> board)
{
if (board == null)
{
throw new ArgumentNullException("board");
}
Parallel.For(0, @this.Count, i => @this[i].FillLandmark(board));
}
/// <summary>Create a new instance of <see cref="PathfinderRev"/>.</summary>
/// <param name="start"></param>
/// <param name="goal"></param>
/// <param name="stepCost"></param>
/// <param name="landmarks"></param>
/// <param name="closed"></param>
/// <param name="setBestSoFar"></param>
/// <param name="getBestSoFar"></param>
public PathfinderRev(IHex start, IHex goal, Func <IHex, Hexside, int> stepCost,
LandmarkCollection landmarks, HashSet <HexCoords> closed,
Action <DirectedPath, DirectedPath> setBestSoFar, Func <int> getBestSoFar
) : base(goal, start, landmarks, closed, getBestSoFar)
{
_addStep = (path, there, hexside, cost) => path.AddStep(there, hexside.Reversed(), cost);
_setBestSoFar = (self, partner) => setBestSoFar(partner, self);
_stepCost = (here, hexside, there) => stepCost(here, hexside);
_search = "Rev";
TraceFlags.FindPathDetail.Trace(" {0} Search uses: vectorGoal = {1}; and landmark at {2}",
_search, _vectorGoal, _landmark.Coords);
}
/// <summary>Returns an <c>IPath</c> for the optimal path from coordinates <c>start</c> to <c>goal</c>.</summary>
/// <param name="start">Coordinates for the <c>last</c> step on the desired path.</param>
/// <param name="goal">Coordinates for the <c>first</c> step on the desired path.</param>
/// <param name="stepCost">Cost to extend path by hex at <c>coords</c> from hex at direction <c>hexside</c>.</param>
/// <param name="landmarks"><c>LandmarkCollection</c> of landmarks available for heuristic calculation.</param>
static PathHalves FindDirectedPath(
IHex start, IHex goal,
Func <IHex, Hexside, int> stepCost,
LandmarkCollection landmarks
)
{
if (start == null)
{
throw new ArgumentNullException("start");
}
if (goal == null)
{
throw new ArgumentNullException("goal");
}
if (stepCost == null)
{
throw new ArgumentNullException("stepCost");
}
if (landmarks == null)
{
throw new ArgumentNullException("landmarks");
}
TraceFlags.FindPathDetail.Trace(true,
"Fwd: Find path from {0} to {1}:", start.Coords, goal.Coords);
var closed = new HashSet <HexCoords>();
var pathHalves = new PathHalves();
var pathfinderFwd = new PathfinderFwd(start, goal, stepCost, landmarks,
closed, pathHalves.SetBestSoFar, () => pathHalves.BestSoFar);
var pathfinderRev = new PathfinderRev(start, goal, stepCost, landmarks,
closed, pathHalves.SetBestSoFar, () => pathHalves.BestSoFar);
pathfinderFwd.Partner = pathfinderRev;
var pathfinder = pathfinderRev.Partner
= pathfinderFwd;
while (!pathfinder.IsFinished())
{
pathfinder = pathfinder.Partner;
}
return(pathHalves);
}
BidirectionalPathfinder(IHex start, IHex goal,
LandmarkCollection landmarks, HashSet <HexCoords> closed, Func <int> getBestSoFar
)
{
_start = start;
_goal = goal;
_getBestSoFar = getBestSoFar;
_vectorGoal = goal.Coords.Canon - start.Coords.Canon;
_open = new Dictionary <HexCoords, DirectedPath>();
_closed = closed;
_queue = new HotPriorityQueue <DirectedPath>(16);
_landmark = landmarks
.OrderByDescending(l => l.HexDistance(goal.Coords) - l.HexDistance(start.Coords))
.FirstOrDefault();
_heuristic = c => _landmark.HexDistance(c) - _landmark.HexDistance(start.Coords);
var path = new DirectedPath(goal);
_open.Add(goal.Coords, path);
_queue.Enqueue(0, path);
}
