Beispiel #1
0
        public virtual void Search(ref HashSet <SpaceTimeNode> reservationTable)
        {
            var startNode = new SpaceTimeNode(Start.X, Start.Y, 0);

            _gScore[startNode] = 0;
            _open.Enqueue(startNode, Heuristic(Start));

            SpaceTimeNode current;

            while (_open.Count > 0)
            {
                current = _open.Dequeue();
                _closed.Add(current);

                // current tile is reserved, we can't be here
                if (!current.Equals(Start) && (reservationTable.Contains(current) ||
                                               reservationTable.Contains(current.Next())))
                {
                    continue;
                }

                if (current.Equals(Target))
                {
                    Path.AddRange(ReconstructPath(current));

                    for (var t = 0; t < Path.Count; t++)
                    {
                        reservationTable.Add(new SpaceTimeNode(Path[t].X, Path[t].Y, t));
                    }

                    return;
                }

                foreach (var neighbor in _graph.GetNeighbours(current))
                {
                    if (_closed.Contains(neighbor) ||
                        reservationTable.Contains(neighbor) ||
                        reservationTable.Contains(neighbor.Next()))
                    {
                        continue;
                    }

                    var tentative_gScore = _gScore.GetValueOrDefault(current, double.PositiveInfinity) + Cost(current, neighbor);
                    if (tentative_gScore < _gScore.GetValueOrDefault(neighbor, double.PositiveInfinity))
                    {
                        _cameFrom[neighbor] = current;
                        _gScore[neighbor]   = tentative_gScore;

                        var fScore = tentative_gScore + Heuristic(_graph.GetTile(neighbor));
                        if (!_open.TryUpdatePriority(neighbor, fScore))
                        {
                            _open.Enqueue(neighbor, fScore);
                        }
                    }
                }
            }
        }
Beispiel #2
0
        private double Cost(SpaceTimeNode p, SpaceTimeNode q)
        {
            if (q == p.Next())
            {
                // wait node
                return(1);
            }

            return(Metrics.Octile(_graph.GetTile(p), _graph.GetTile(q)));
        }
Beispiel #3
0
        private List <AbstractTile> ReconstructPath(SpaceTimeNode current)
        {
            var path = new List <AbstractTile>()
            {
                _graph.GetTile(current)
            };

            while (_cameFrom.TryGetValue(current, out var prev))
            {
                current = prev;
                path.Add(_graph.GetTile(current));
            }

            path.Reverse();

            return(path);
        }
        private double Cost(SpaceTimeNode p, SpaceTimeNode q)
        {
            var pTile = _graph.GetTile(p);

            if (p.T == _w)
            {
                return(_rra.AbstractDist(pTile));
            }

            if (q == p.Next())
            {
                if (q.Equals(Target))
                {
                    return(0);
                }
                return(1);
            }

            var qTile = _graph.GetTile(q);

            return(Metrics.Octile(pTile, qTile));
        }
        private void Search(ref HashSet <SpaceTimeNode> reservationTable)
        {
            _cameFrom = new Dictionary <SpaceTimeNode, SpaceTimeNode>();
            _closed   = new HashSet <SpaceTimeNode>();
            _gScore   = new Dictionary <SpaceTimeNode, double>();
            _open     = new SimplePriorityQueue <SpaceTimeNode, double>();

            var pos = new SpaceTimeNode(Position.X, Position.Y, 0);

            _gScore[pos] = 0;
            _open.Enqueue(pos, _rra.AbstractDist(Position));

            SpaceTimeNode current;

            while (_open.Count > 0)
            {
                current = _open.Dequeue();
                _closed.Add(current);

                // current tile is reserved, we can't be here
                if (!current.Equals(Position) && (reservationTable.Contains(new SpaceTimeNode(current.X, current.Y, current.T + _pathIndex)) ||
                                                  reservationTable.Contains(new SpaceTimeNode(current.X, current.Y, current.T + _pathIndex + 1))))
                {
                    continue;
                }

                if (current.T == _w || current.Equals(Target))
                {
                    Path.AddRange(ReconstructPath(current));

                    for (var t = _pathIndex; t < Path.Count; t++)
                    {
                        reservationTable.Add(new SpaceTimeNode(Path[t].X, Path[t].Y, t));
                    }

                    return;
                }

                foreach (var neighbor in _graph.GetNeighbours(current))
                {
                    if (_closed.Contains(neighbor) ||
                        reservationTable.Contains(new SpaceTimeNode(neighbor.X, neighbor.Y, neighbor.T + _pathIndex)) ||
                        reservationTable.Contains(new SpaceTimeNode(neighbor.X, neighbor.Y, neighbor.T + _pathIndex + 1)))
                    {
                        continue;
                    }

                    var tentative_gScore = _gScore.GetValueOrDefault(current, double.PositiveInfinity) + Cost(current, neighbor);
                    if (tentative_gScore < _gScore.GetValueOrDefault(neighbor, double.PositiveInfinity))
                    {
                        _cameFrom[neighbor] = current;
                        _gScore[neighbor]   = tentative_gScore;

                        var fScore = tentative_gScore + _rra.AbstractDist(_graph.GetTile(neighbor));
                        if (!_open.TryUpdatePriority(neighbor, fScore))
                        {
                            _open.Enqueue(neighbor, fScore);
                        }
                    }
                }
            }
        }