XPath Class Reference

Extended Path. More...

Detailed Description

Extended Path.

This is the same as a standard path but it is possible to customize when the target should be considered reached. Can be used to for example signal a path as complete when it is within a specific distance from the target.

Note

More customizations does make it slower to calculate than an ABPath but not by very much.

A* Pro Feature:

This is an A* Pathfinding Project Pro feature only. This function/class/variable might not exist in the Free version of the A* Pathfinding Project or the functionality might be limited
The Pro version can be bought here

See Also

Pathfinding.PathEndingCondition

Public Member Functions
	XPath ()
override void	CalculateStep (long targetTick)
	Calculates the path until completed or until the time has passed targetTick.
override void	Reset ()
	Reset all values to their default values.
Public Member Functions inherited from ABPath
override void	Cleanup ()
	Always called after the path has been calculated.
override string	DebugString (PathLog logMode)
	Returns a debug string for this path.
override uint	GetConnectionSpecialCost (GraphNode a, GraphNode b, uint currentCost)
	May be called by graph nodes to get a special cost for some connections.
Vector3	GetMovementVector (Vector3 point)
	Returns in which direction to move from a point on the path.
override void	Initialize ()
	Initializes the path.
override void	Prepare ()
	Prepares the path.
void	ResetCosts (Path p)
	Resets End Node Costs.
	ABPath ()
	Default constructor.
Public Member Functions inherited from Path
void	AdvanceState (PathState s)
	Threadsafe increment of the state.
uint	CalculateHScore (GraphNode node)
bool	CanTraverse (GraphNode node)
	Returns if the node can be traversed.
void	Claim (System.Object o)
	Claim this path.
void	Error ()
	Aborts the path because of an error.
void	ForceLogError (string msg)
	Logs an error and calls Error().
Int3	GetHTarget ()
PathState	GetState ()
	Returns the state of the path in the pathfinding pipeline.
uint	GetTagPenalty (int tag)
	Returns penalty for the given tag.
float	GetTotalLength ()
	Total Length of the path.
uint	GetTraversalCost (GraphNode node)
bool	IsDone ()
	Returns if this path is done calculating.
void	Log (string msg)
	Appends a message to the errorLog.
void	LogError (string msg)
	Appends msg to errorLog and logs msg to the console.
virtual void	OnEnterPool ()
	Called when the path enters the pool.
void	PrepareBase (PathHandler pathHandler)
	Prepares low level path variables for calculation.
void	Release (System.Object o)
	Releases a path claim.
void	ReleaseSilent (System.Object o)
	Releases the path silently.
virtual void	ReturnPath ()
	Calls callback to return the calculated path.
IEnumerator	WaitForPath ()
	Waits until this path has been calculated and returned.

Static Public Member Functions
static new XPath	Construct (Vector3 start, Vector3 end, OnPathDelegate callback=null)
Static Public Member Functions inherited from ABPath
static ABPath	Construct (Vector3 start, Vector3 end, OnPathDelegate callback=null)
	Construct a path with a start and end point.

Public Attributes
PathEndingCondition	endingCondition
	Ending Condition for the path.
Public Attributes inherited from ABPath
bool	calculatePartial
	Calculate partial path if the target node cannot be reached.
GraphNode	endHint
	Hints can be set to enable faster Get Nearest Node queries.
GraphNode	endNode
	End node of the path.
Vector3	endPoint
	Exact end point of the path.
Vector3	originalEndPoint
	End Point exactly as in the path request.
Vector3	originalStartPoint
	Start Point exactly as in the path request.
bool	recalcStartEndCosts = true
	Defines if start and end nodes will have their connection costs recalculated for this path.
GraphNode	startHint
	Hints can be set to enable faster Get Nearest Node queries.
Int3	startIntPoint
	Start point in integer coordinates.
GraphNode	startNode
	Start node of the path.
Vector3	startPoint
	Exact start point of the path.
Public Attributes inherited from Path
OnPathDelegate	callback
	Callback to call when the path is complete.
float	duration
	The duration of this path in ms.
int	enabledTags = -1
	Which graph tags are traversable.
Heuristic	heuristic
	Determines which heuristic to use.
float	heuristicScale = 1F
	Scale of the heuristic values.
OnPathDelegate	immediateCallback
	Immediate callback to call when the path is complete.
NNConstraint	nnConstraint = PathNNConstraint.Default
	Constraint for how to search for nodes.
List< GraphNode >	path
	Holds the path as a Node array.
int	searchedNodes
	Number of nodes this path has searched.
int	searchIterations
	The number of frames/iterations this path has executed.
List< Vector3 >	vectorPath
	Holds the (perhaps post processed) path as a Vector3 array.

Protected Member Functions
override void	CompletePathIfStartIsValidTarget ()
	The start node need to be special cased and checked here if it is a valid target.
override void	Recycle ()
	Internal method to recycle the path.
Protected Member Functions inherited from ABPath
void	UpdateStartEnd (Vector3 start, Vector3 end)
	Sets the start and end points.
void	Setup (Vector3 start, Vector3 end, OnPathDelegate callbackDelegate)
Protected Member Functions inherited from Path
bool	HasExceededTime (int searchedNodes, long targetTime)
virtual void	Trace (PathNode from)
	Traces the calculated path from the end node to the start.

Additional Inherited Members
Protected Attributes inherited from ABPath
int[]	endNodeCosts
	Saved original costs for the end node.
PathNode	partialBestTarget
	Current best target for the partial path.
Package Attributes inherited from Path
Path	next
	Internal linked list implementation.
bool	recycled
	True if the path is currently recycled (i.e in the path pool).
Properties inherited from ABPath
virtual bool	hasEndPoint [get]
	Determines if a search for an end node should be done.

Constructor & Destructor Documentation

XPath

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Member Function Documentation

override void CalculateStep ( long  targetTick )

virtual

Calculates the path until completed or until the time has passed targetTick.

Usually a check is only done every 500 nodes if the time has passed targetTick. Time/Ticks are got from System.DateTime.UtcNow.Ticks.

Basic outline of what the function does for the standard path (Pathfinding.ABPath).

while the end has not been found and no error has ocurred
    check if we have reached the end
        if so, exit and return the path

    open the current node, i.e loop through its neighbours, mark them as visited and put them on a heap

    check if there are still nodes left to process (or have we searched the whole graph)
        if there are none, flag error and exit

    pop the next node of the heap and set it as current

    check if the function has exceeded the time limit
        if so, return and wait for the function to get called again

Reimplemented from ABPath.

override void CompletePathIfStartIsValidTarget ( )

protectedvirtual

The start node need to be special cased and checked here if it is a valid target.

Reimplemented from ABPath.

static new XPath Construct ( Vector3  start, Vector3  end, OnPathDelegate  callback = null  )

static

override void Recycle ( )

protectedvirtual

Internal method to recycle the path.

Calling this means that the path and any variables on it are not needed anymore and the path can be pooled. All path data will be reset. Implement this in inheriting path types to support recycling of paths.

public override void Recycle () {
    //Recycle the Path (<Path> should be replaced by the path type it is implemented in)
    PathPool<Path>.Recycle (this);
}

Warning

Do not call this function directly, instead use the Claim and Release functions.

See Also

Pathfinding.PathPool

Reset

Claim

Release

Reimplemented from ABPath.

override void Reset ( )

virtual

Reset all values to their default values.

All inheriting path types must implement this function, resetting ALL their variables to enable recycling of paths. Call this base function in inheriting types with base.Reset ();

Reimplemented from ABPath.

Member Data Documentation

PathEndingCondition endingCondition

Ending Condition for the path.

The ending condition determines when the path has been completed. Can be used to for example signal a path as complete when it is within a specific distance from the target.

If ending conditions are used that are not centered around the endpoint of the path you should also switch the heuristic to None to make sure that optimal paths are still found. This has quite a large performance impact so you might want to try to run it with the default heuristic and see if the path is optimal in enough cases.

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

• /Users/arong/Unity/a-pathfinding-project/Assets/AstarPathfindingProject/Pathfinders/XPath.cs