Node Class Reference

Holds one node in a navgraph. More...

Inheritance diagram for Node:

Collaboration diagram for Node:

Public Member Functions
void	AddConnection (Node node, int cost)
	Add a connection to the node with the specified cost.
void	BaseFloodFill (Stack< Node > stack, int area)
	Adds all connecting nodes to the stack and sets the area variable to area.
int[]	BaseInitialOpen (BinaryHeapM open, Int3 targetPosition, Int3 position, Path path, bool doOpen)
void	BaseOpen (NodeRunData nodeRunData, NodeRun nodeR, Int3 targetPosition, Path path)
	Opens the nodes connected to this node.
void	BaseResetCosts (int[] costs)
	Resets the costs modified by the InitialOpen function when 'doOpen' was false (for the end node).
virtual bool	ContainsConnection (Node node)
	Returns true if this node has a connection to the node.
virtual void	FloodFill (Stack< Node > stack, int area)
	Adds all connecting nodes to the stack and sets the area variable to area.
virtual void	GetConnections (NodeDelegate callback)
	Get all connections for a node.
void	GetConnectionsBase (NodeDelegate callback)
	Get all connections for a node.
int	GetNodeIndex ()
	Returns the global node index.
virtual int[]	InitialOpen (BinaryHeapM open, Int3 targetPosition, Int3 position, Path path, bool doOpen)
virtual void	Open (NodeRunData nodeRunData, NodeRun nodeR, Int3 targetPosition, Path path)
void	RecalculateConnectionCosts (bool neighbours)
	Recalculate costs for each connection.
virtual bool	RemoveConnection (Node node)
	Removes the connection to the node if it exists.
virtual void	ResetCosts (int[] costs)
	Resets the costs modified by the InitialOpen function when 'doOpen' was false (for the end node).
void	SetNodeIndex (int index)
virtual void	UpdateAllG (NodeRun nodeR, NodeRunData nodeRunData)
virtual void	UpdateConnections ()
	Remove connections to unwalkable nodes.
void	UpdateG (NodeRun nodeR, NodeRunData nodeRunData)
void	UpdateH (Int3 targetPosition, Heuristic heuristic, float scale, NodeRun nodeR)
	Calculates and updates the H score.
virtual void	UpdateNeighbourConnections ()
	Calls UpdateConnections on all neighbours.

Static Public Member Functions
static int	Abs (int x)
	Implementation of the Absolute function.

Public Attributes
int[]	connectionCosts
	Cost for the connections to other nodes.
Node[]	connections
	List of all connections from this node.
int	flags
	Bit packed values for different fields.
Int3	position
	Position in world space of the node.

Protected Member Functions
void	BaseUpdateAllG (NodeRun nodeR, NodeRunData nodeRunData)

Properties
int	area [get, set]
	Area ID of the node.
bool	Bit15 [get, set]
	Returns bit 15 from flags.
bool	Bit16 [get, set]
	Returns bit 16 from flags.
bool	Bit8 [get, set]
	Returns bit 8 from flags.
int	graphIndex [get, set]
	The index of the graph this node is in.
uint	penalty [get, set]
int	tags [get, set]
	Tags for walkability.
bool	walkable [get, set]
	Is the node walkable.

Private Attributes
uint	_penalty
	Penlty cost for walking on this node.
const int	AreaBitNumber = 24
	1 << WalkableBitNumber
const int	AreaBitsSize = 0xFF
	Size of the area bits.
const int	GraphIndexBitNumber = 18
const int	GraphIndexBitsSize = 0x1F
int	nodeIndex
	Global node index.
const int	NotAreaBits = ~(AreaBitsSize << AreaBitNumber)
	The bits in flags which are NOT area bits.
const int	NotGraphIndexBits = ~(GraphIndexBitsSize << GraphIndexBitNumber)
	Bits which are NOT graphIndex bits.
const int	WalkableBit = 1 << WalkableBitNumber
const int	WalkableBitNumber = 23
	Bit number for the walkable bool.

Detailed Description

Holds one node in a navgraph.

A node is a simple object in the shape of a square (GridNode), triangle (NavMeshNode), or point (the rest).
A node has a position and a list of neighbour nodes which are the nodes this node can form a straight path to
Size: (4*3)+4+4+4+4+4+4+8+8*n = 44+8*n bytes where n is the number of connections (estimate)

Member Function Documentation

void AddConnection	(	Node	node,
		int	cost
	)

Add a connection to the node with the specified cost.

If a connection to the node already exists, this function will only change the cost of it.

Note

This will create a one-way connection, consider calling the same function on the other node too.

GridGraphs use custom connections and has a fixed cost for connections to neighbour nodes. So you will not be able to modify costs to neighbour nodes on grid graphs with this function.

See Also

RemoveConnection

Pathfinding::Int3::costMagnitude

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void BaseFloodFill	(	Stack< Node >	stack,
		int	area
	)

Adds all connecting nodes to the stack and sets the area variable to area.

This is a base function and can be called by node classes overriding the FloodFill function to add the connections in the connections array

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void BaseOpen	(	NodeRunData	nodeRunData,
		NodeRun	nodeR,
		Int3	targetPosition,
		Path	path
	)

Opens the nodes connected to this node.

This is a base call and can be called by node classes overriding the Open function to open all connections in the connections array.

See Also

connections

Open

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void BaseResetCosts

(

int[]

costs

)

Resets the costs modified by the InitialOpen function when 'doOpen' was false (for the end node).

This is called at the end of a pathfinding search

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virtual bool ContainsConnection ( Node  node )

virtual

Returns true if this node has a connection to the node.

Note

this might not return true for node classes using their own connection system (like GridNode)

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virtual void GetConnections ( NodeDelegate  callback )

virtual

Get all connections for a node.

This function will call the callback with every node this node is connected to. In contrast to the connections array this function also includes custom connections which for example grid graphs use.

Since

Added in version 3.2

Reimplemented in GridNode.

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void GetConnectionsBase

(

NodeDelegate

callback

)

Get all connections for a node.

This function will call the callback with every node this node is connected to. This is a base function and will simply loop through the connections array.

See Also

GetConnections

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int GetNodeIndex

(

)

Returns the global node index.

Used for internal pathfinding purposes

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void RecalculateConnectionCosts

(

bool

neighbours

)

Recalculate costs for each connection.

All standard connections, which means those stored in the connections array will have their costs recalculated. Non-standard connections such as most grid graph connections will not be recalculated (mostly because they are constant and cannot be recalculated).

Parameters

neighbours

If true, recalculates connection costs on this node's neighbours as well. This makes sure costs are calculated correctly (the same) in both directions.

Note

Assumes the correct cost is simply the distance between the nodes (in Int3 space). This is what the built-in graphs (e.g Point Graph) use, so it should be fine.

virtual bool RemoveConnection ( Node  node )

virtual

Removes the connection to the node if it exists.

Returns true if a connection was removed, returns false if no connection to the node was found

Note

This will only remove the connection from this node to node, but it will still exist in the other direction consider calling the same function on the other node too

See Also

AddConnection

Reimplemented in GridNode.

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virtual void ResetCosts ( int[]  costs )

virtual

Resets the costs modified by the InitialOpen function when 'doOpen' was false (for the end node).

This is called at the end of a pathfinding search

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virtual void UpdateConnections ( )

virtual

Remove connections to unwalkable nodes.

This function loops through all connections and removes the ones which lead to unwalkable nodes.
This can speed up performance if a lot of nodes have connections to unwalkable nodes, they usually don't though

Note

This function does not add connections which might have been removed previously

Reimplemented in GridNode.

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void UpdateH	(	Int3	targetPosition,
		Heuristic	heuristic,
		float	scale,
		NodeRun	nodeR
	)

Calculates and updates the H score.

Calculates the H score with respect to the target position and chosen heuristic.

Parameters

targetPosition	The position to calculate the distance to.
heuristic	Heuristic to use. The heuristic can also be hard coded using pre processor directives (check sourcecode)
scale	Scale of the heuristic
nodeR	NodeRun object associated with this node.

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virtual void UpdateNeighbourConnections ( )

virtual

Calls UpdateConnections on all neighbours.

Neighbours are all nodes in the connections array. Good to use if the node has been set to unwalkable-

See Also

UpdateConnections

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Member Data Documentation

uint _penalty

private

Penlty cost for walking on this node.

This can be used to make it harder/slower to walk over certain areas.

const int AreaBitNumber = 24

private

1 << WalkableBitNumber

Bit number at which area starts

int [] connectionCosts

Cost for the connections to other nodes.

The cost of moving from this node to connections[x] is stored in connectionCosts[x].

See Also

connections

Node [] connections

List of all connections from this node.

This node's neighbour nodes are stored in this array.

Note

Not all connections are stored in this array, some node types (such as Pathfinding::GridNode) use custom connection systems which they store somewhere else.

See Also

connectionCosts

int flags

Bit packed values for different fields.

It's amazing how much information you can store in an integer! Below you can see a table showing how the different bits are used:

	Area								Walkability	Graph Index						Graph Specific Values		Tags (tag)						Bit 8 - Path specific value	Graph specific values
																	Walkable before erosion (Grid Graph and derived only)							Used as a tag by some path types	(GridGraph only) Connections
Bit	31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0

Do not get or set this variable directly, instead, get or set the appropriate properties.

See Also

walkable

area

graphIndex

Bit8

tags

Int3 position

Position in world space of the node.

The position is stored as integer coordinates to avoid precision loss when the node is far away from the world origin. The default precision is 0.001 (one millimeter).

See Also

Pathfinding.Int3

Property Documentation

int area

getset

Area ID of the node.

Nodes which there are no valid path between have different area values.

Note

Small areas can have have the same area ID since only 256 ID values are available

See Also

AstarPath::minAreaSize

bool Bit15

getset

Returns bit 15 from flags.

In the GridGraph (and derived) it is used to store if walkable before erosion.

See Also

GridNode::WalkableErosion

bool Bit16

getset

Returns bit 16 from flags.

Graphs can use this value for any kind of data storage. Grid Graphs use it as a temporary variable when updating graphs using erosion.

See Also

GridNode::WalkableErosion

bool Bit8

getset

Returns bit 8 from flags.

Used to flag special nodes with special pathfinders

int graphIndex

getset

The index of the graph this node is in.

See Also

AstarData.graphs

int tags

getset

Tags for walkability.

Determines which tag is set for this node. 0...31.

Warning

Do NOT pass a value larger than 31 to this variable, that could affect other parameters since it's bit-packed.

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

• /Users/aron/Unity/AstarPathfindingGIT/Assets/AstarPathfindingProject/Core/Node.cs