Backtrace() публичный статический Метод

public static Backtrace ( Node iNode ) : List
iNode Node
Результат List
Пример #1
0
        public static List <GridPos> FindPath(JumpPointParam iParam)
        {
            List <Node> tOpenList  = iParam.openList;
            Node        tStartNode = iParam.StartNode;
            Node        tEndNode   = iParam.EndNode;
            Node        tNode;
            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, 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.
                tOpenList.Sort();
                tNode = (Node)tOpenList[tOpenList.Count - 1];
                tOpenList.RemoveAt(tOpenList.Count - 1);
                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);
            }

            // fail to find the path
            return(new List <GridPos>());
        }
Пример #2
0
        public static List <GridPos> FindPath(JumpPointParam jpParam)
        {
            var  tOpenList  = jpParam.OpenList;
            var  tStartNode = jpParam.StartNode;
            var  tEndNode   = jpParam.EndNode;
            Node tNode;
            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 (jpParam.CurEndNodeUnWalkableTreatment == EndNodeUnWalkableTreatment.Allow && !jpParam.SearchGrid.IsWalkableAt(tEndNode.X, tEndNode.Y))
            {
                _ = jpParam.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.
                tNode          = tOpenList.DeleteMin();
                tNode.IsClosed = true;

                if (tNode.Equals(tEndNode))
                {
                    if (revertEndNodeWalkable)
                    {
                        _ = jpParam.SearchGrid.SetWalkableAt(tEndNode.X, tEndNode.Y, false);
                    }
                    return(Node.Backtrace(tNode));                    // rebuilding path
                }

                IdentifySuccessors(jpParam, tNode);
            }

            if (revertEndNodeWalkable)
            {
                _ = jpParam.SearchGrid.SetWalkableAt(tEndNode.X, tEndNode.Y, false);
            }

            // fail to find the path
            return(new List <GridPos>());
        }
Пример #3
0
        /*
        private class NodeComparer : IComparer<Node>
        {
            public int Compare(Node x, Node y)
            {
                var result = (x.heuristicStartToEndLen - y.heuristicStartToEndLen);
                if (result < 0) return -1;
                else
                if (result > 0) return 1;
                else
                {
                    return 0;
                }
            }
        }
        */
        public static List<GridPos> FindPath(AStarParam iParam)
        {
            object lo = new object();
            //var openList = new IntervalHeap<Node>(new NodeComparer());
            var openList = new IntervalHeap<Node>();
            var startNode = iParam.StartNode;
            var endNode = iParam.EndNode;
            var heuristic = iParam.HeuristicFunc;
            var grid = iParam.SearchGrid;
            var diagonalMovement = iParam.DiagonalMovement;
            var weight = iParam.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);

#if (UNITY)
                foreach(var neighbor in neighbors)
#else
                Parallel.ForEach(neighbors, neighbor =>
#endif
                {
#if (UNITY)
                    if (neighbor.isClosed) continue;
#else
                    if (neighbor.isClosed) return;
#endif
                    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;
                        }
                        else
                        {

                        }
                    }
                }
#if (!UNITY)
                );
#endif
            }
            return new List<GridPos>();

        }