ABPath Class Reference

Basic path, finds the shortest path from A to B. More...

Inheritance diagram for ABPath:

Collaboration diagram for ABPath:

Public Member Functions
	ABPath (Vector3 start, Vector3 end, OnPathDelegate callbackDelegate)
	Create a new path with a start and end point.
override void	CalculateStep (long targetTick)
	Calculates the path until completed or until the time has passed targetTick.
override string	DebugString (PathLog logMode)
	Returns a debug string for this path.
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.
override void	Reset ()
	Reset all values to their default values.
void	ResetCosts (Path p)
	Resets End Node Costs.
Public Member Functions inherited from Path
void	AdvanceState (PathState s)
	Threadsafe increment of the state.
bool	CanTraverse (Node 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() to true.
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.
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 (NodeRunData runData)
	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.
virtual void	Trace (NodeRun from)
	Traces the calculated path from the end node to the start.

Public Attributes
bool	calculatePartial = false
	Calculate partial path if the target node cannot be reached.
Node	endHint
	Hints can be set to enable faster Get Nearest Node queries.
Node	endNode
	End node of the path.
Vector3	endPoint
	Exact end point of the path.
Int3	hTarget
	Target to use for H score calculations.
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.
Node	startHint
	Hints can be set to enable faster Get Nearest Node queries.
Int3	startIntPoint
	Start point in integer coordinates.
Node	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.
System.DateTime	callTime
	When the call was made to start the pathfinding for this path.
float	duration
	The duration of this path in ms.
int	enabledTags = -1
	Which graph tags are traversable.
int	height
	Height of the character.
Heuristic	heuristic
	Determines which heuristic to use.
float	heuristicScale = 1F
	Scale of the heuristic values.
Path	next
	The next path to be searched.
NNConstraint	nnConstraint = PathNNConstraint.Default
	Constraint for how to search for nodes.
List< Node >	path
	Holds the path as a Node array.
ushort	pathID
	ID of this path.
int	radius
	Radius for the unit searching for the path.
bool	recycled = false
	True if the path is currently recycled (i.e in the path pool).
NodeRunData	runData
int	searchedNodes
	Number of nodes this path has searched.
int	searchIterations = 0
int	speed
	Speed of the character.
int	turnRadius
	Turning radius of the character.
List< Vector3 >	vectorPath
	Holds the (perhaps post processed) path as a Vector3 array.
int	walkabilityMask = -1
	A mask for defining what type of ground a unit can traverse, not used in any default standard graph.

Protected Member Functions
override void	Recycle ()
	Recycle the path.
void	UpdateStartEnd (Vector3 start, Vector3 end)
	Sets the start and end points.
Protected Member Functions inherited from Path
bool	HasExceededTime (int searchedNodes, long targetTime)

Protected Attributes
int[]	endNodeCosts
	Saved original costs for the end node.
bool	hasEndPoint = true
	Determines if a search for an end node should be done.
NodeRun	partialBestTarget = null
	Current best target for the partial path.
Protected Attributes inherited from Path
int[]	_tagPenalties = new int[0]
	Penalties for each tag.
NodeRun	currentR
	The node currently being processed.
bool	hasBeenReset = false
	True if the Reset function has been called.
float	maxFrameTime
	The max number of milliseconds per iteration (frame, in case of non-multithreading)

Constructors
	ABPath ()
	Default constructor.
static ABPath	Construct (Vector3 start, Vector3 end, OnPathDelegate callback=null)
	Construct a path with a start and end point.
void	Setup (Vector3 start, Vector3 end, OnPathDelegate callbackDelegate)

Additional Inherited Members
Properties inherited from Path
PathCompleteState	CompleteState [get, set]
bool	error [get]
	If the path failed, this is true.
string	errorLog [get]
	Log messages with info about eventual errors.
int[]	tagPenalties [get, set]
	Penalties for each tag.

Detailed Description

Basic path, finds the shortest path from A to B.

This is the most basic path object it will try to find the shortest path from A to B.
Many other path types inherit from this type.

See Also

Seeker::StartPath

Constructor & Destructor Documentation

ABPath	(	Vector3	start,
		Vector3	end,
		OnPathDelegate	callbackDelegate
	)

Create a new path with a start and end point.

The delegate will be called when the path has been calculated. Do not confuse it with the Seeker callback as they are sent at different times. If you are using a Seeker to start the path you can set callbackDelegate to null

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ABPath

(

)

Default constructor.

Do not use this. Instead use Pathfinding.PathPool<Pathfinding.Path>.GetPath()
If you want to use the constructor, use this:

ABPath p = new ABPath();
p.Reset();

And then use a Setup() method.

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

Implements Path.

Reimplemented in MultiTargetPath, RandomPath, FloodPathTracer, and XPath.

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

static

Construct a path with a start and end point.

The delegate will be called when the path has been calculated. Do not confuse it with the Seeker callback as they are sent at different times. If you are using a Seeker to start the path you can set callback to null.

Returns

The constructed path object

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Vector3 GetMovementVector

(

Vector3

point

)

Returns in which direction to move from a point on the path.

A simple and quite slow (well, compared to more optimized algorithms) algorithm first finds the closest path segment (from vectorPath) and then returns the direction to the next point from there. The direction is not normalized.

Returns

Direction to move from a point, returns Vector3::zero if vectorPath is null or has a length of 0

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override void Initialize ( )

virtual

Initializes the path.

Sets up the open list and adds the first node to it

Implements Path.

Reimplemented in MultiTargetPath, RandomPath, FloodPathTracer, and XPath.

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override void Prepare ( )

virtual

Prepares the path.

Searches for start and end nodes and does some simple checking if a path is at all possible

Implements Path.

Reimplemented in MultiTargetPath, and RandomPath.

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override void Recycle ( )

protectedvirtual

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);
}

Note

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

See Also

Pathfinding.PathPool

Reset

Claim

Release

Implements Path.

Reimplemented in MultiTargetPath, RandomPath, and XPath.

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 Path.

Reimplemented in FloodPathTracer, RandomPath, and XPath.

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void ResetCosts

(

Path

p

)

Resets End Node Costs.

Costs are updated on the end node at the start of the search to better reflect the end point passed to the path, the previous ones are saved in endNodeCosts and are reset in this function which is called after the path search is complete

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void UpdateStartEnd ( Vector3  start, Vector3  end  )

protected

Sets the start and end points.

Sets originalStartPoint, originalEndPoint, startPoint, endPoint, startIntPoint and hTarget (to end )

Member Data Documentation

bool calculatePartial = false

Calculate partial path if the target node cannot be reached.

If the target node cannot be reached, the node which was closest (given by heuristic) will be chosen as target node and a partial path will be returned. This only works if a heuristic is used (which is the default). If a partial path is found, CompleteState is set to Partial.

Note

It is not required by other path types to respect this setting

Node endHint

Hints can be set to enable faster Get Nearest Node queries.

Only applies to some graph types

int [] endNodeCosts

protected

Saved original costs for the end node.

See Also

ResetCosts

bool hasEndPoint = true

protected

Determines if a search for an end node should be done.

Set by different path types.

Since

Added in 3.0.8.3

Int3 hTarget

Target to use for H score calculations.

See Also

Pathfinding::Node::h

NodeRun partialBestTarget = null

protected

Current best target for the partial path.

This is the node with the lowest H score

bool recalcStartEndCosts = true

Defines if start and end nodes will have their connection costs recalculated for this path.

These connection costs will be more accurate and based on the exact start point and target point, however it should not be used when connection costs are not the default ones (all build in graph generators currently generate default connection costs).

See Also

Int3.costMagnitude

Since

Added in 3.0.8.3

Bug:

Does not do anything in 3.2 and up due to incompabilities with multithreading. Will be enabled again in later versions.

Node startHint

Hints can be set to enable faster Get Nearest Node queries.

Only applies to some graph types

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

• /Users/aron/Unity/AstarPathfindingGIT/Assets/AstarPathfindingProject/Pathfinders/ABPath.cs