GraphNode Class Reference

Base class for all nodes. More...

Detailed Description

Base class for all nodes.

Public Member Functions
abstract void	AddConnection (GraphNode node, uint cost)
abstract void	ClearConnections (bool alsoReverse)
	Remove all connections from this node.
virtual bool	ContainsConnection (GraphNode node)
	Checks if this node has a connection to the specified node.
virtual void	DeserializeNode (GraphSerializationContext ctx)
virtual void	DeserializeReferences (GraphSerializationContext ctx)
	Used to deserialize references to other nodes e.g connections.
virtual void	FloodFill (Stack< GraphNode > stack, uint region)
abstract void	GetConnections (System.Action< GraphNode > action)
	Calls the delegate with all connections from this node.
virtual int	GetGizmoHashCode ()
	Hash code used for checking if the gizmos need to be updated.
virtual bool	GetPortal (GraphNode other, List< Vector3 > left, List< Vector3 > right, bool backwards)
	Add a portal from this node to the specified node.
abstract void	Open (Path path, PathNode pathNode, PathHandler handler)
	Open the node.
virtual Vector3	RandomPointOnSurface ()
	A random point on the surface of the node.
virtual void	RecalculateConnectionCosts ()
	Recalculates all connection costs from this node.
abstract void	RemoveConnection (GraphNode node)
virtual void	SerializeNode (GraphSerializationContext ctx)
virtual void	SerializeReferences (GraphSerializationContext ctx)
	Used to serialize references to other nodes e.g connections.
virtual float	SurfaceArea ()
	The surface area of the node in square world units.
void	UpdateG (Path path, PathNode pathNode)
virtual void	UpdateRecursiveG (Path path, PathNode pathNode, PathHandler handler)

Public Attributes
const uint	MaxAreaIndex = FlagsAreaMask >> FlagsAreaOffset
const uint	MaxGraphIndex = FlagsGraphMask >> FlagsGraphOffset
	Max number of graphs-1.
Int3	position
	Position of the node in world space.

Protected Member Functions
	GraphNode (AstarPath astar)
	Constructor for a graph node.

Protected Attributes
uint	flags
	Bitpacked field holding several pieces of data.

Package Functions
void	Destroy ()
	Destroys the node.

Properties
uint	Area [get, set]
	Connected component that contains the node.
bool	Destroyed [get]
uint	Flags [get, set]
	Holds various bitpacked variables.
uint	GraphIndex [get, set]
	Graph which contains this node.
int	NodeIndex [get]
	Internal unique index.
uint	Penalty [get, set]
	Penalty cost for walking on this node.
uint	Tag [get, set]
	Node tag.
bool	Walkable [get, set]
	True if the node is traversable.

Private Attributes
const uint	FlagsAreaMask = (131072-1) << FlagsAreaOffset
	Mask of area bits.
const int	FlagsAreaOffset = 1
	Start of area bits.
const uint	FlagsGraphMask = (256u-1) << FlagsGraphOffset
	Mask of graph index bits.
const int	FlagsGraphOffset = 24
	Start of graph index bits.
const uint	FlagsTagMask = (32-1) << FlagsTagOffset
	Mask of tag bits.
const int	FlagsTagOffset = 19
	Start of tag bits.
const uint	FlagsWalkableMask = 1 << FlagsWalkableOffset
	Mask of the walkable bit.
const int	FlagsWalkableOffset = 0
	Position of the walkable bit.
int	nodeIndex
	Internal unique index.
uint	penalty
	Penalty cost for walking on this node.

Constructor & Destructor Documentation

GraphNode ( AstarPath  astar )

protected

Constructor for a graph node.

Member Function Documentation

abstract void AddConnection ( GraphNode  node, uint  cost  )

pure virtual

Implemented in MeshNode, GridNodeBase, and PointNode.

abstract void ClearConnections ( bool  alsoReverse )

pure virtual

Remove all connections from this node.

Parameters

alsoReverse

if true, neighbours will be requested to remove connections to this node.

Implemented in LevelGridNode, MeshNode, GridNodeBase, GridNode, and PointNode.

virtual bool ContainsConnection ( GraphNode  node )

virtual

Checks if this node has a connection to the specified node.

Reimplemented in MeshNode, GridNodeBase, and PointNode.

virtual void DeserializeNode ( GraphSerializationContext  ctx )

virtual

Reimplemented in LevelGridNode, GridNode, TriangleMeshNode, and PointNode.

virtual void DeserializeReferences ( GraphSerializationContext  ctx )

virtual

Used to deserialize references to other nodes e.g connections.

Use the GraphSerializationContext.GetNodeIdentifier and GraphSerializationContext.GetNodeFromIdentifier methods for serialization and deserialization respectively.

Nodes must override this method and serialize their connections. Graph generators do not need to call this method, it will be called automatically on all nodes at the correct time by the serializer.

Reimplemented in MeshNode, GridNodeBase, and PointNode.

void Destroy ( )

package

Destroys the node.

Cleans up any temporary pathfinding data used for this node. The graph is responsible for calling this method on nodes when they are destroyed, including when the whole graph is destoyed. Otherwise memory leaks might present themselves.

Once called the Destroyed property will return true and subsequent calls to this method will not do anything.

Note

Assumes the current active AstarPath instance is the same one that created this node.

Warning

Should only be called by graph classes on their own nodes

virtual void FloodFill ( Stack< GraphNode >  stack, uint  region  )

virtual

Reimplemented in LevelGridNode, MeshNode, and GridNode.

abstract void GetConnections ( System.Action< GraphNode >  action )

pure virtual

Calls the delegate with all connections from this node.

node.GetConnections(connectedTo => {
   Debug.DrawLine((Vector3)node.position, (Vector3)connectedTo.position, Color.red);
});

You can add all connected nodes to a list like this

List<GraphNode> connections = new List<GraphNode>();
node.GetConnections(connections.Add);

Implemented in LevelGridNode, MeshNode, GridNodeBase, GridNode, and PointNode.

virtual int GetGizmoHashCode ( )

virtual

Hash code used for checking if the gizmos need to be updated.

Will change when the gizmos for the node might change.

Reimplemented in LevelGridNode, MeshNode, PointNode, and GridNodeBase.

virtual bool GetPortal ( GraphNode  other, List< Vector3 >  left, List< Vector3 >  right, bool  backwards  )

virtual

Add a portal from this node to the specified node.

This function should add a portal to the left and right lists which is connecting the two nodes (this and other).

Parameters

other	The node which is on the other side of the portal (strictly speaking it does not actually have to be on the other side of the portal though).
left	List of portal points on the left side of the funnel
right	List of portal points on the right side of the funnel
backwards	If this is true, the call was made on a node with the other node as the node before this one in the path. In this case you may choose to do nothing since a similar call will be made to the other node with this node referenced as other (but then with backwards = true). You do not have to care about switching the left and right lists, that is done for you already.

Returns

True if the call was deemed successful. False if some unknown case was encountered and no portal could be added. If both calls to node1.GetPortal (node2,...) and node2.GetPortal (node1,...) return false, the funnel modifier will fall back to adding to the path the positions of the node.

The default implementation simply returns false.

This function may add more than one portal if necessary.

See Also

http://digestingduck.blogspot.se/2010/03/simple-stupid-funnel-algorithm.html

Reimplemented in LevelGridNode, GridNode, and NodeLink3Node.

abstract void Open ( Path  path, PathNode  pathNode, PathHandler  handler  )

pure virtual

Open the node.

Implemented in LevelGridNode, GridNode, GridNodeBase, TriangleMeshNode, and PointNode.

virtual Vector3 RandomPointOnSurface ( )

virtual

A random point on the surface of the node.

For point nodes and other nodes which do not have a surface, this will always return the position of the node.

Reimplemented in TriangleMeshNode, and GridNodeBase.

virtual void RecalculateConnectionCosts ( )

virtual

Recalculates all connection costs from this node.

Depending on the node type, this may or may not be supported. Nothing will be done if the operation is not supported

Todo:

Use interface?

abstract void RemoveConnection ( GraphNode  node )

pure virtual

Implemented in MeshNode, GridNodeBase, and PointNode.

virtual void SerializeNode ( GraphSerializationContext  ctx )

virtual

Reimplemented in LevelGridNode, GridNode, TriangleMeshNode, and PointNode.

virtual void SerializeReferences ( GraphSerializationContext  ctx )

virtual

Used to serialize references to other nodes e.g connections.

Use the GraphSerializationContext.GetNodeIdentifier and GraphSerializationContext.GetNodeFromIdentifier methods for serialization and deserialization respectively.

Nodes must override this method and serialize their connections. Graph generators do not need to call this method, it will be called automatically on all nodes at the correct time by the serializer.

Reimplemented in MeshNode, GridNodeBase, and PointNode.

virtual float SurfaceArea ( )

virtual

The surface area of the node in square world units.

Reimplemented in TriangleMeshNode, and GridNodeBase.

void UpdateG	(	Path	path,
		PathNode	pathNode
	)

virtual void UpdateRecursiveG ( Path  path, PathNode  pathNode, PathHandler  handler  )

virtual

Reimplemented in LevelGridNode, MeshNode, GridNode, GridNodeBase, TriangleMeshNode, and PointNode.

Member Data Documentation

uint flags

protected

Bitpacked field holding several pieces of data.

See Also

Walkable

Area

GraphIndex

Tag

const uint FlagsAreaMask = (131072-1) << FlagsAreaOffset

private

Mask of area bits.

See Also

Area

const int FlagsAreaOffset = 1

private

Start of area bits.

See Also

Area

const uint FlagsGraphMask = (256u-1) << FlagsGraphOffset

private

Mask of graph index bits.

See Also

GraphIndex

const int FlagsGraphOffset = 24

private

Start of graph index bits.

See Also

GraphIndex

const uint FlagsTagMask = (32-1) << FlagsTagOffset

private

Mask of tag bits.

See Also

Tag

const int FlagsTagOffset = 19

private

Start of tag bits.

See Also

Tag

const uint FlagsWalkableMask = 1 << FlagsWalkableOffset

private

Mask of the walkable bit.

See Also

Walkable

const int FlagsWalkableOffset = 0

private

Position of the walkable bit.

See Also

Walkable

const uint MaxAreaIndex = FlagsAreaMask >> FlagsAreaOffset

const uint MaxGraphIndex = FlagsGraphMask >> FlagsGraphOffset

Max number of graphs-1.

int nodeIndex

private

Internal unique index.

uint penalty

private

Penalty cost for walking on this node.

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

A penalty of 1000 (Int3.Precision) corresponds to the cost of walking one world unit.

Int3 position

Position of the node in world space.

Note

The position is stored as an Int3, not a Vector3. You can convert an Int3 to a Vector3 using an explicit conversion.

var v3 = (Vector3)node.position; 

Property Documentation

uint Area

getset

Connected component that contains the node.

This is visualized in the scene view as differently colored nodes (if the graph coloring mode is set to 'Areas'). Each area represents a set of nodes such that there is no valid path between nodes of different colors.

See Also

https://en.wikipedia.org/wiki/Connected_component_(graph_theory)

AstarPath.FloodFill

bool Destroyed

get

uint Flags

getset

Holds various bitpacked variables.

uint GraphIndex

getset

Graph which contains this node.

See Also

Pathfinding.AstarData.graphs

int NodeIndex

get

Internal unique index.

Every node will get a unique index. This index is not necessarily correlated with e.g the position of the node in the graph.

uint Penalty

getset

Penalty cost for walking on this node.

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

uint Tag

getset

Node tag.

See Also

Working with tags

bool Walkable

getset

True if the node is traversable.

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

• /Users/arong/Unity/a-pathfinding-project/Assets/AstarPathfindingProject/Core/Nodes/GraphNode.cs