essentials.action.Pathing.Engines.AStarEngine Class Reference

The AStar implementation of 3D path-finding More...

Inheritance diagram for essentials.action.Pathing.Engines.AStarEngine:

Public Member Functions
	AStarEngine (Vector3i start, Vector3i end, IPathCostEngine costEngine, Vector3i[] neighborSet)
Path	GetResult ()
	Returns the full resulting path. Throws if incomplete More...
Path	GetIncrementalPath ()
	Gets the currently known best-path to the result. Depending on the implementation, may be called to get the best-path in the case where the overall search has failed. More...
void	Iterate ()
	Iterate the engine (Call this in a loop until finished) More...
Path	Compute ()
	Full path compute (Iterate until done). Returns Path or null More...

Properties
static readonly	Vector3i
	All neighbors More...
Vector3i	Start [get]
Vector3i	End [get]
PathEngineState	State [get]
Properties inherited from essentials.action.Pathing.IPathingEngine
Vector3i	Start [get]
	Starting position More...
Vector3i	End [get]
	Ending position More...
PathEngineState	State [get]
	The current state of the path resolution More...

Detailed Description

The AStar implementation of 3D path-finding

Constructor & Destructor Documentation

AStarEngine()

essentials.action.Pathing.Engines.AStarEngine.AStarEngine	(	Vector3i	start,
		Vector3i	end,
		IPathCostEngine	costEngine,
		Vector3i []	neighborSet
	)

Attribute: _start

= new CostNode(_start, _startingHeuristic, 0, null);

        {
            _start = start;
            _end = end;
            _costEngine = costEngine;
            _neighbors = neighborSet;
            _state = PathEngineState.Working;

            _startingHeuristic = _costEngine.GetHeuristic(_start, _end);
            _openNodes[_start] = new CostNode(_start, _startingHeuristic, 0, null);
        }

Member Function Documentation

Compute()

Path essentials.action.Pathing.Engines.AStarEngine.Compute

(

)

Full path compute (Iterate until done). Returns Path or null

Returns

The compute.

Implements essentials.action.Pathing.IPathingEngine.

        {
            while(_state == PathEngineState.Working)
            {
                Iterate();
            }

            if (_state == PathEngineState.Complete)
            {
                return GetResult();
            }
            return null;
        }

GetIncrementalPath()

Path essentials.action.Pathing.Engines.AStarEngine.GetIncrementalPath

(

)

Gets the currently known best-path to the result. Depending on the implementation, may be called to get the best-path in the case where the overall search has failed.

Returns

The incremental path.

Implements essentials.action.Pathing.IPathingEngine.

        {
            var path = new List<Vector3i>();
            var current = GetCurrentNode();
            do
            {
                path.Add(current.Point);
                current = current.Parent;
            } while(current != null);
            path.Reverse();
            return new Path(path);
        }

GetResult()

Path essentials.action.Pathing.Engines.AStarEngine.GetResult

(

)

Returns the full resulting path. Throws if incomplete

Exceptions

PathEngineException

Returns

The result.

Implements essentials.action.Pathing.IPathingEngine.

        {
            if (_state != PathEngineState.Complete)
            {
                throw new PathEngineException("Uncomplete pathing");
            }

            return GetIncrementalPath();
        }

Iterate()

void essentials.action.Pathing.Engines.AStarEngine.Iterate

(

)

Iterate the engine (Call this in a loop until finished)

Attribute: newPoint

.ActualCost)

Attribute: newPoint

= new CostNode(newPoint, heuristicCost, newCost, current);

Implements essentials.action.Pathing.IPathingEngine.

        {
            if (_state != PathEngineState.Working)
                return;

            if (_openNodes.Count == 0)
            {
                _state = PathEngineState.Failed;
                return;
            }

            var current = GetCurrentNode();
            if (current.Point == _end)
            {
                _state = PathEngineState.Complete;
                return;
            }

            if (current.HeuristicCost >= _startingHeuristic * 2 && _iterationCount > 50)
            {
                _state = PathEngineState.Failed;
                return;
            }

            _openNodes.Remove(current.Point);
            _closedPoints.Add(current.Point);

            foreach(var offset in _neighbors)
            {
                var newPoint = current.Point + offset;
                if (_closedPoints.Contains(newPoint))
                    continue;

                int moveCost = _costEngine.GetActualCost(current.Point, newPoint);
                if (moveCost < 0)
                {
                    _closedPoints.Add(newPoint);
                    continue;
                }

                int newCost = current.ActualCost + moveCost;
                if (!_openNodes.ContainsKey(newPoint) || newCost < _openNodes[newPoint].ActualCost)
                {
                    int heuristicCost = newCost + _costEngine.GetHeuristic(newPoint, _end);
                    _openNodes[newPoint] = new CostNode(newPoint, heuristicCost, newCost, current);
                }
            }

            _iterationCount++;
        }

Property Documentation

End

Vector3i essentials.action.Pathing.Engines.AStarEngine.End

get

Start

Vector3i essentials.action.Pathing.Engines.AStarEngine.Start

get

State

PathEngineState essentials.action.Pathing.Engines.AStarEngine.State

get

Vector3i

static readonly essentials.action.Pathing.Engines.AStarEngine.Vector3i

static

All neighbors

Only neighbors that are not on the diagnol (Except Z axis, since step-up and step-down)

Attribute: ] NEIGHBORS_ALL = new Vector3i[

Attribute: ] NEIGHBORS_AXIS_ALIGNED = new Vector3i[

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The documentation for this class was generated from the following file:

• essentials.action/Pathing/Engines/AStarEngine.cs