A* Pathfinding Project  3.8
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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
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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)
 Estimated cost from the specified node to the target.
 
bool CanTraverse (GraphNode node)
 Returns if the node can be traversed.
 
void Claim (System.Object o)
 Claim this path (pooling).
 
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 Release (System.Object o, bool silent=false)
 Releases a path claim (pooling).
 
void ReleaseSilent (System.Object o)
 Releases the path silently (pooling).
 
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
 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
 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< GraphNodepath
 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 list.
 

Protected Member Functions

override void CompletePathIfStartIsValidTarget ()
 The start node need to be special cased and checked here if it is a valid target.
 
- 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
void DebugStringPrefix (PathLog logMode, System.Text.StringBuilder text)
 Writes text shared for all overrides of DebugString to the string builder.
 
void DebugStringSuffix (PathLog logMode, System.Text.StringBuilder text)
 Writes text shared for all overrides of DebugString to the string builder.
 
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 Functions inherited from Path
void PrepareBase (PathHandler pathHandler)
 Prepares low level path variables for calculation.
 
- Package Attributes inherited from Path
Path next
 Internal linked list implementation.
 
bool pooled
 True if the path is currently pooled.
 
- Properties inherited from ABPath
virtual bool hasEndPoint [get]
 Determines if a search for an end node should be done.
 

Constructor & Destructor Documentation

XPath ( )

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 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.


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