Base class for all path types. More...

Detailed Description

Base class for all path types.

Public Member Functions
void	BlockUntilCalculated ()
	Blocks until this path has been calculated and returned. More...

void	Claim (System.Object o)
	Claim this path (pooling). More...

void	Error ()
	Aborts the path because of an error. More...

PathState	GetState ()
	Returns the state of the path in the pathfinding pipeline. More...

float	GetTotalLength ()
	Total Length of the path. More...

bool	IsDone ()
	Returns if this path is done calculating. More...

void	Release (System.Object o, bool silent=false)
	Releases a path claim (pooling). More...

IEnumerator	WaitForPath ()
	Waits until this path has been calculated and returned. More...

Public Attributes
OnPathDelegate	callback
	Callback to call when the path is complete. More...

float	duration
	How long it took to calculate this path in milliseconds. More...

int	enabledTags = -1
	Which graph tags are traversable. More...

Heuristic	heuristic
	Determines which heuristic to use. More...

float	heuristicScale = 1F
	Scale of the heuristic values. More...

OnPathDelegate	immediateCallback
	Immediate callback to call when the path is complete. More...

NNConstraint	nnConstraint = PathNNConstraint.Default
	Constraint for how to search for nodes. More...

List< GraphNode >	path
	Holds the path as a Node array. More...

ITraversalProvider	traversalProvider
	Provides additional traversal information to a path request. More...

List< Vector3 >	vectorPath
	Holds the (possibly post processed) path as a Vector3 list. More...

Protected Member Functions
abstract void	CalculateStep (long targetTick)
	Calculates the until it is complete or the time has progressed past targetTick. More...

virtual void	Cleanup ()
	Always called after the path has been calculated. More...

void	DebugStringPrefix (PathLog logMode, System.Text.StringBuilder text)
	Writes text shared for all overrides of DebugString to the string builder. More...

void	DebugStringSuffix (PathLog logMode, System.Text.StringBuilder text)
	Writes text shared for all overrides of DebugString to the string builder. More...

abstract void	Initialize ()
	Initializes the path. More...

virtual void	OnEnterPool ()
	Called when the path enters the pool. More...

abstract void	Prepare ()
	Called before the path is started. More...

void	PrepareBase (PathHandler pathHandler)
	Prepares low level path variables for calculation. More...

virtual void	Reset ()
	Reset all values to their default values. More...

virtual void	ReturnPath ()
	Calls callback to return the calculated path. More...

virtual void	Trace (PathNode from)
	Traces the calculated path from the end node to the start. More...

Protected Attributes
PathCompleteState	completeState
	Backing field for CompleteState. More...

PathNode	currentR
	The node currently being processed. More...

bool	hasBeenReset
	True if the Reset function has been called. More...

Int3	hTarget
	Target to use for H score calculations. More...

GraphNode	hTargetNode
	Target to use for H score calculation. More...

int []	internalTagPenalties
	The tag penalties that are actually used. More...

int []	manualTagPenalties
	Tag penalties set by other scripts. More...

PathHandler	pathHandler
	Data for the thread calculating this path. More...

Package Functions
uint	CalculateHScore (GraphNode node)
	Estimated cost from the specified node to the target. More...

bool	CanTraverse (GraphNode node)
	Returns if the node can be traversed. More...

virtual string	DebugString (PathLog logMode)
	Returns a string with information about it. More...

void	FailWithError (string msg)
	Causes the path to fail and sets errorLog to msg. More...

virtual uint	GetConnectionSpecialCost (GraphNode a, GraphNode b, uint currentCost)
	May be called by graph nodes to get a special cost for some connections. More...

Int3	GetHTarget ()

uint	GetTagPenalty (int tag)
	Returns penalty for the given tag. More...

uint	GetTraversalCost (GraphNode node)

void	Log (string msg)
	Appends a message to the errorLog. More...

void	LogError (string msg)
	Logs an error. More...

void	ReleaseSilent (System.Object o)
	Releases the path silently (pooling). More...

Package Attributes
Path	next
	Internal linked list implementation. More...

int	searchedNodes
	Number of nodes this path has searched. More...

Properties
PathCompleteState	CompleteState `[get, protected set]`
	Current state of the path. More...

bool	error `[get]`
	If the path failed, this is true. More...

string	errorLog `[get, private set]`
	Additional info on why a path failed. More...

virtual bool	FloodingPath `[get]`
	True for paths that want to search all nodes and not jump over nodes as optimizations. More...

PathHandler IPathInternals.	PathHandler `[get]`

ushort	pathID `[get, private set]`
	ID of this path. More...

PathState	PipelineState `[get, private set]`
	Returns the state of the path in the pathfinding pipeline. More...

bool IPathInternals.	Pooled `[get, set]`
	True if the path is currently pooled. More...

bool	recycled `[get]`
	True if the path is currently recycled (i.e in the path pool). More...

int []	tagPenalties `[get, set]`
	Penalties for each tag. More...

Properties inherited from IPathInternals
PathHandler	PathHandler `[get]`

bool	Pooled `[get, set]`

Private Member Functions
void IPathInternals.	AdvanceState (PathState s)
	Threadsafe increment of the state. More...

void IPathInternals.	CalculateStep (long targetTick)

void IPathInternals.	Cleanup ()

void	ErrorCheck ()
	Performs some error checking. More...

void IPathInternals.	Initialize ()

void IPathInternals.	OnEnterPool ()

void IPathInternals.	Prepare ()

void IPathInternals.	PrepareBase (PathHandler handler)

void IPathInternals.	Reset ()

void IPathInternals.	ReturnPath ()

Private Attributes
List< System.Object >	claimed = new List<System.Object>()
	List of claims on this path with reference objects. More...

bool	releasedNotSilent
	True if the path has been released with a non-silent call yet. More...

System.Object	stateLock = new object ()

Static Private Attributes
static readonly int []	ZeroTagPenalties = new int[32]
	List of zeroes to use as default tag penalties. More...

Member Function Documentation

◆ AdvanceState()

void IPathInternals. AdvanceState ( PathState s )

private

Threadsafe increment of the state.

Implements IPathInternals.

◆ BlockUntilCalculated()

void BlockUntilCalculated ( )

Blocks until this path has been calculated and returned.

Normally it takes a few frames for a path to be calculated and returned. This function will ensure that the path will be calculated when this function returns and that the callback for that path has been called.

Use this function only if you really need to. There is a point to spreading path calculations out over several frames. It smoothes out the framerate and makes sure requesting a large number of paths at the same time does not cause lag.

Note: Graph updates and other callbacks might get called during the execution of this function.

Path p = seeker.StartPath (transform.position, transform.position + Vector3.forward * 10);
p.BlockUntilCalculated();
// The path is calculated now

See also: This is equivalent to calling AstarPath.BlockUntilCalculated(Path); WaitForPath

◆ CalculateHScore()

uint CalculateHScore ( GraphNode node )

package

Estimated cost from the specified node to the target.

See also: https://en.wikipedia.org/wiki/A*_search_algorithm

◆ CalculateStep() [1/2]

abstract void CalculateStep ( long targetTick )

protectedpure virtual

Calculates the until it is complete or the time has progressed past targetTick.

Implements IPathInternals.

Implemented in MultiTargetPath, ABPath, RandomPath, FloodPath, ConstantPath, FloodPathTracer, and XPath.

◆ CalculateStep() [2/2]

void IPathInternals. CalculateStep ( long targetTick )

private

Implements IPathInternals.

◆ CanTraverse()

bool CanTraverse ( GraphNode node )

package

Returns if the node can be traversed.

This per default equals to if the node is walkable and if the node's tag is included in enabledTags

◆ Claim()

void Claim ( System.Object o )

Claim this path (pooling).

A claim on a path will ensure that it is not pooled. If you are using a path, you will want to claim it when you first get it and then release it when you will not use it anymore. When there are no claims on the path, it will be reset and put in a pool.

This is essentially just reference counting.

The object passed to this method is merely used as a way to more easily detect when pooling is not done correctly. It can be any object, when used from a movement script you can just pass "this". This class will throw an exception if you try to call Claim on the same path twice with the same object (which is usually not what you want) or if you try to call Release with an object that has not been used in a Claim call for that path. The object passed to the Claim method needs to be the same as the one you pass to this method.

See also: Release; Pool; Pooling; https://en.wikipedia.org/wiki/Reference_counting

◆ Cleanup() [1/2]

virtual void Cleanup ( )

protectedvirtual

Always called after the path has been calculated.

Guaranteed to be called before other paths have been calculated on the same thread. Use for cleaning up things like node tagging and similar.

Implements IPathInternals.

Reimplemented in MultiTargetPath, ABPath, and ConstantPath.

◆ Cleanup() [2/2]

void IPathInternals. Cleanup ( )

private

Implements IPathInternals.

◆ DebugString()

virtual string DebugString ( PathLog logMode )

packagevirtual

Returns a string with information about it.

More information is emitted when logMode == Heavy. An empty string is returned if logMode == None or logMode == OnlyErrors and this path did not fail.

Reimplemented in MultiTargetPath, and ABPath.

◆ DebugStringPrefix()

void DebugStringPrefix	(	PathLog	logMode,
		System.Text.StringBuilder	text
	)

protected

Writes text shared for all overrides of DebugString to the string builder.

See also: DebugString

◆ DebugStringSuffix()

void DebugStringSuffix	(	PathLog	logMode,
		System.Text.StringBuilder	text
	)

protected

Writes text shared for all overrides of DebugString to the string builder.

See also: DebugString

◆ Error()

void Error ( )

Aborts the path because of an error.

Sets error to true. This function is called when an error has occurred (e.g a valid path could not be found).

See also: FailWithError

◆ ErrorCheck()

void ErrorCheck ( )

private

Performs some error checking.

Makes sure the user isn't using old code paths and that no major errors have been made.

Causes the path to fail if any errors are found.

◆ FailWithError()

void FailWithError ( string msg )

package

Causes the path to fail and sets errorLog to msg.

◆ GetConnectionSpecialCost()

virtual uint GetConnectionSpecialCost	(	GraphNode	a,
		GraphNode	b,
		uint	currentCost
	)

packagevirtual

May be called by graph nodes to get a special cost for some connections.

Nodes may call it when PathNode.flag2 is set to true, for example mesh nodes, which have a very large area can be marked on the start and end nodes, this method will be called to get the actual cost for moving from the start position to its neighbours instead of as would otherwise be the case, from the start node's position to its neighbours. The position of a node and the actual start point on the node can vary quite a lot.

The default behaviour of this method is to return the previous cost of the connection, essentiall making no change at all.

This method should return the same regardless of the order of a and b. That is f(a,b) == f(b,a) should hold.

Parameters

a	Moving from this node
b	Moving to this node
currentCost	The cost of moving between the nodes. Return this value if there is no meaningful special cost to return.

Reimplemented in ABPath.

◆ GetHTarget()

Int3 GetHTarget ( )

package

◆ GetState()

PathState GetState ( )

Returns the state of the path in the pathfinding pipeline.

Deprecated:: Use the Pathfinding.Path.PipelineState property instead

◆ GetTagPenalty()

uint GetTagPenalty ( int tag )

package

Returns penalty for the given tag.

Parameters

tag	A value between 0 (inclusive) and 32 (exclusive).

◆ GetTotalLength()

float GetTotalLength ( )

Total Length of the path.

Calculates the total length of the vectorPath. Cache this rather than call this function every time since it will calculate the length every time, not just return a cached value.

Returns: Total length of vectorPath, if vectorPath is null positive infinity is returned.

◆ GetTraversalCost()

uint GetTraversalCost ( GraphNode node )

package

◆ Initialize() [1/2]

abstract void Initialize ( )

protectedpure virtual

Initializes the path.

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

Implements IPathInternals.

Implemented in MultiTargetPath, ABPath, RandomPath, FloodPath, ConstantPath, and FloodPathTracer.

◆ Initialize() [2/2]

void IPathInternals. Initialize ( )

private

Implements IPathInternals.

◆ IsDone()

bool IsDone ( )

Returns if this path is done calculating.

Note: The callback for the path might not have been called yet.

Since: Added in 3.0.8

See also: #Seeker.IsDone which also takes into account if the path callback has been called and had Modifiers applied.

◆ Log()

void Log ( string msg )

package

Appends a message to the errorLog.

Nothing is logged to the console.

Note: If AstarPath.logPathResults is PathLog.None and this is a standalone player, nothing will be logged as an optimization.

Deprecated:: Use FailWithError instead

◆ LogError()

void LogError ( string msg )

package

Logs an error.

Deprecated:: Use FailWithError instead

◆ OnEnterPool() [1/2]

virtual void OnEnterPool ( )

protectedvirtual

Called when the path enters the pool.

This method should release e.g pooled lists and other pooled resources The base version of this method releases vectorPath and path lists. Reset() will be called after this function, not before.

Warning: Do not call this function manually.

Implements IPathInternals.

Reimplemented in MultiTargetPath, and ConstantPath.

◆ OnEnterPool() [2/2]

void IPathInternals. OnEnterPool ( )

private

Implements IPathInternals.

◆ Prepare() [1/2]

abstract void Prepare ( )

protectedpure virtual

Called before the path is started.

Called right before Initialize

Implements IPathInternals.

Implemented in ABPath, MultiTargetPath, RandomPath, FloodPath, and ConstantPath.

◆ Prepare() [2/2]

void IPathInternals. Prepare ( )

private

Implements IPathInternals.

◆ PrepareBase() [1/2]

void PrepareBase ( PathHandler pathHandler )

protected

Prepares low level path variables for calculation.

Called before a path search will take place. Always called before the Prepare, Initialize and CalculateStep functions

Implements IPathInternals.

◆ PrepareBase() [2/2]

void IPathInternals. PrepareBase ( PathHandler handler )

private

Implements IPathInternals.

◆ Release()

void Release	(	System.Object	o,
		bool	silent = `false`
	)

Releases a path claim (pooling).

Removes the claim of the path by the specified object. When the claim count reaches zero, the path will be pooled, all variables will be cleared and the path will be put in a pool to be used again. This is great for performance since fewer allocations are made.

If the silent parameter is true, this method will remove the claim by the specified object but the path will not be pooled if the claim count reches zero unless a Release call (not silent) has been made earlier. This is used by the internal pathfinding components such as Seeker and AstarPath so that they will not cause paths to be pooled. This enables users to skip the claim/release calls if they want without the path being pooled by the Seeker or AstarPath and thus causing strange bugs.

See also: Claim; PathPool

◆ ReleaseSilent()

void ReleaseSilent ( System.Object o )

package

Releases the path silently (pooling).

Deprecated:: Use Release(o, true) instead

◆ Reset() [1/2]

virtual void Reset ( )

protectedvirtual

Reset all values to their default values.

Note: All inheriting path types (e.g ConstantPath, RandomPath, etc.) which declare their own variables need to override this function, resetting ALL their variables to enable pooling of paths. If this is not done, trying to use that path type for pooling could result in weird behaviour. The best way is to reset to default values the variables declared in the extended path type and then call the base function in inheriting types with base.Reset().

Implements IPathInternals.

Reimplemented in ABPath, MultiTargetPath, FloodPath, ConstantPath, RandomPath, FloodPathTracer, and XPath.

◆ Reset() [2/2]

void IPathInternals. Reset ( )

private

Implements IPathInternals.

◆ ReturnPath() [1/2]

virtual void ReturnPath ( )

protectedvirtual

Calls callback to return the calculated path.

See also: callback

Implements IPathInternals.

Reimplemented in MultiTargetPath, and RandomPath.

◆ ReturnPath() [2/2]

void IPathInternals. ReturnPath ( )

private

Implements IPathInternals.

◆ Trace()

virtual void Trace ( PathNode from )

protectedvirtual

Traces the calculated path from the end node to the start.

This will build an array (path) of the nodes this path will pass through and also set the vectorPath array to the path arrays positions. Assumes the vectorPath and path are empty and not null (which will be the case for a correctly initialized path).

Reimplemented in MultiTargetPath.

◆ WaitForPath()

IEnumerator WaitForPath ( )

Waits until this path has been calculated and returned.

Allows for very easy scripting.

IEnumerator Start () {
 var path = seeker.StartPath(transform.position, transform.position + transform.forward*10, null);
 yield return StartCoroutine(path.WaitForPath());
 // The path is calculated now
}

Note: Do not confuse this with AstarPath.WaitForPath. This one will wait using yield until it has been calculated while AstarPath.WaitForPath will halt all operations until the path has been calculated.

Exceptions

System.InvalidOperationException if the path is not started. Send the path to Seeker.StartPath or AstarPath.StartPath before calling this function.

See also: BlockUntilCalculated; https://docs.unity3d.com/Manual/Coroutines.html

Member Data Documentation

◆ callback

OnPathDelegate callback

Callback to call when the path is complete.

This is usually sent to the Seeker component which post processes the path and then calls a callback to the script which requested the path

◆ claimed

List<System.Object> claimed = new List<System.Object>()

private

List of claims on this path with reference objects.

◆ completeState

PathCompleteState completeState

protected

Backing field for CompleteState.

◆ currentR

PathNode currentR

protected

The node currently being processed.

◆ duration

float duration

How long it took to calculate this path in milliseconds.

◆ enabledTags

int enabledTags = -1

Which graph tags are traversable.

This is a bitmask so -1 = all bits set = all tags traversable. For example, to set bit 5 to true, you would do

myPath.enabledTags |= 1 << 5;

To set it to false, you would do

myPath.enabledTags &= ~(1 << 5);

The Seeker has a popup field where you can set which tags to use.

Note: If you are using a Seeker. The Seeker will set this value to what is set in the inspector field on StartPath. So you need to change the Seeker value via script, not set this value if you want to change it via script.

See also: CanTraverse

◆ hasBeenReset

bool hasBeenReset

protected

True if the Reset function has been called.

Used to alert users when they are doing something wrong.

◆ heuristic

Heuristic heuristic

Determines which heuristic to use.

◆ heuristicScale

float heuristicScale = 1F

Scale of the heuristic values.

See also: AstarPath.heuristicScale

◆ hTarget

Int3 hTarget

protected

Target to use for H score calculations.

See also: Pathfinding.Node.H

◆ hTargetNode

GraphNode hTargetNode

protected

Target to use for H score calculation.

Used alongside hTarget.

◆ immediateCallback

OnPathDelegate immediateCallback

Immediate callback to call when the path is complete.

Warning: This may be called from a separate thread. Usually you do not want to use this one.

See also: callback

◆ internalTagPenalties

int [] internalTagPenalties

protected

The tag penalties that are actually used.

If manualTagPenalties is null, this will be ZeroTagPenalties

See also: tagPenalties

◆ manualTagPenalties

int [] manualTagPenalties

protected

Tag penalties set by other scripts.

See also: tagPenalties

◆ next

Path next

package

Internal linked list implementation.

Warning: This is used internally by the system. You should never change this.

◆ nnConstraint

NNConstraint nnConstraint = PathNNConstraint.Default

Constraint for how to search for nodes.

◆ path

List<GraphNode> path

Holds the path as a Node array.

All nodes the path traverses. This may not be the same nodes as the post processed path traverses.

◆ pathHandler

PathHandler pathHandler

protected

Data for the thread calculating this path.

◆ releasedNotSilent

bool releasedNotSilent

private

True if the path has been released with a non-silent call yet.

See also: Release; Claim

◆ searchedNodes

int searchedNodes

package

Number of nodes this path has searched.

◆ stateLock

System.Object stateLock = new object ()

private

◆ traversalProvider

ITraversalProvider traversalProvider

Provides additional traversal information to a path request.

See also: Utilities for turn-based games

◆ vectorPath

List<Vector3> vectorPath

Holds the (possibly post processed) path as a Vector3 list.

◆ ZeroTagPenalties

readonly int [] ZeroTagPenalties = new int[32]

staticprivate

List of zeroes to use as default tag penalties.

Property Documentation

◆ CompleteState

PathCompleteState CompleteState

getprotected set

Current state of the path.

Bug:: This may currently be set to Complete before the path has actually been fully calculated. In particular the vectorPath and path lists may not have been fully constructed. This can lead to race conditions when using multithreading. Try to avoid using this method to check for if the path is calculated right now, use IsDone instead.

◆ error

bool error

get

If the path failed, this is true.

See also: errorLog; This is equivalent to checking path.CompleteState == PathCompleteState.Error

◆ errorLog

string errorLog

getprivate set

Additional info on why a path failed.

See also: AstarPath.logPathResults

◆ FloodingPath

virtual bool FloodingPath

getpackage

True for paths that want to search all nodes and not jump over nodes as optimizations.

This disables Jump Point Search when that is enabled to prevent e.g ConstantPath and FloodPath to become completely useless.

◆ PathHandler

PathHandler IPathInternals. PathHandler

getprivate

◆ pathID

ushort pathID

getprivate set

ID of this path.

Used to distinguish between different paths

◆ PipelineState

PathState PipelineState

getprivate set

Returns the state of the path in the pathfinding pipeline.

◆ Pooled

bool IPathInternals. Pooled

getsetprivate

True if the path is currently pooled.

Do not set this value. Only read. It is used internally.

See also: PathPool

Version: Was named 'recycled' in 3.7.5 and earlier.

◆ recycled

bool recycled

getpackage

True if the path is currently recycled (i.e in the path pool).

Do not set this value. Only read. It is used internally.

Deprecated:: Has been renamed to 'pooled' to use more widely underestood terminology

◆ tagPenalties

int [] tagPenalties

getset

Penalties for each tag.

Tag 0 which is the default tag, will have added a penalty of tagPenalties[0]. These should only be positive values since the A* algorithm cannot handle negative penalties.

Note: This array will never be null. If you try to set it to null or with a length which is not 32. It will be set to "new int[0]".; If you are using a Seeker. The Seeker will set this value to what is set in the inspector field on StartPath. So you need to change the Seeker value via script, not set this value if you want to change it via script.

See also: Seeker.tagPenalties

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

/Users/arong/Unity/a-pathfinding-project/Assets/AstarPathfindingProject/Core/Path.cs

Detailed Description

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Package Functions

Package Attributes

Properties

Private Member Functions

Private Attributes

Static Private Attributes

Member Function Documentation

◆ AdvanceState()

◆ BlockUntilCalculated()

◆ CalculateHScore()

◆ CalculateStep() [1/2]

◆ CalculateStep() [2/2]

◆ CanTraverse()

◆ Claim()

◆ Cleanup() [1/2]

◆ Cleanup() [2/2]

◆ DebugString()

◆ DebugStringPrefix()

◆ DebugStringSuffix()

◆ Error()

◆ ErrorCheck()

◆ FailWithError()

◆ GetConnectionSpecialCost()

◆ GetHTarget()

◆ GetState()

◆ GetTagPenalty()

◆ GetTotalLength()

◆ GetTraversalCost()

◆ Initialize() [1/2]

◆ Initialize() [2/2]

◆ IsDone()

◆ Log()

◆ LogError()

◆ OnEnterPool() [1/2]

◆ OnEnterPool() [2/2]

◆ Prepare() [1/2]

◆ Prepare() [2/2]

◆ PrepareBase() [1/2]

◆ PrepareBase() [2/2]

◆ Release()

◆ ReleaseSilent()

◆ Reset() [1/2]

◆ Reset() [2/2]

◆ ReturnPath() [1/2]

◆ ReturnPath() [2/2]

◆ Trace()

◆ WaitForPath()

Member Data Documentation

◆ callback

◆ claimed

◆ completeState

◆ currentR

◆ duration

◆ enabledTags

◆ hasBeenReset

◆ heuristic

◆ heuristicScale

◆ hTarget

◆ hTargetNode

◆ immediateCallback

◆ internalTagPenalties

◆ manualTagPenalties

◆ next

◆ nnConstraint

◆ path

◆ pathHandler

◆ releasedNotSilent

◆ searchedNodes

◆ stateLock

◆ traversalProvider

◆ vectorPath

◆ ZeroTagPenalties

Property Documentation

◆ CompleteState

◆ error