#include <CUCompositeNode.h>

Inheritance diagram for cugl::ai::CompositeNode:

Public Member Functions
	CompositeNode ()

	~CompositeNode ()

virtual void	dispose () override

bool	isPreemptive () const

void	setPreemptive (bool preemptive)

const BehaviorNode *	getChildByPriorityIndex (Uint32 index) const

template<typename T >
const T *	getChildByPriorityIndex (Uint32 index) const

const BehaviorNode *	getActiveChild () const

template<typename T >
const T *	getActiveChild () const

virtual void	query (float dt) override

BehaviorNode::State	update (float dt) override

Public Member Functions inherited from cugl::ai::BehaviorNode
	BehaviorNode ()

	~BehaviorNode ()

bool	init (const std::string &name)

const std::string &	getName () const

float	getPriority () const

BehaviorNode::State	getState () const

virtual void	setState (BehaviorNode::State state)

std::function< float()>	getPrioritizer () const

void	setPrioritizer (const std::function< float()> &func)

virtual std::string	toString (bool verbose=false) const

	operator std::string () const

const BehaviorNode *	getParent () const

void	setParent (BehaviorNode *parent)

void	removeFromParent ()

int	getParentalOffset () const

size_t	getChildCount () const

std::vector< const BehaviorNode * >	getChildren () const

const BehaviorNode *	getChild (Uint32 pos) const

template<typename T >
const T *	getChild (Uint32 pos) const

const BehaviorNode *	getNodeByName (const std::string &name) const

const BehaviorNode *	getNodeByName (const char *name) const

template<typename T >
const T *	getNodeByName (const std::string &name) const

template<typename T >
const T *	getNodeByName (const char *name) const

virtual void	reset ()

virtual void	pause ()

virtual void	resume ()

virtual void	preempt ()

virtual void	start ()

void	setPriority (float priority)

std::shared_ptr< BehaviorNode >	removeChild (Uint32 pos)

void	addChild (const std::shared_ptr< BehaviorNode > child)

Protected Member Functions
virtual int	selectChild () const =0

Protected Attributes
bool	_preemptive

Protected Attributes inherited from cugl::ai::BehaviorNode
std::string	_name

std::string	_classname

BehaviorNode *	_parent

BehaviorNode::State	_state

float	_priority

std::function< float()>	_prioritizer

std::vector< std::shared_ptr< BehaviorNode > >	_children

int	_activeChild

int	_childOffset

Additional Inherited Members
Public Types inherited from cugl::ai::BehaviorNode
enum	State : unsigned int { State::INACTIVE = 0, State::RUNNING = 1, State::PAUSED = 2, State::FINISHED = 3 }

Static Public Member Functions inherited from cugl::ai::BehaviorNode
static bool	compareSiblings (const std::shared_ptr< BehaviorNode > &a, const std::shared_ptr< BehaviorNode > &b)

Detailed Description

A class representing a composite node for a behavior tree.

A composite node is a node that has one or more children. When a composite node starts, it chooses a child to run in some order specified by its subclasses. The composite node can be set to preempt its currently running child and choose a new child to run. If it is not set to preempt, the child will continue running until it has either finished running, or the composite node itself is interrupted by its parent. If a child successfully finishes running, the composite node will indicate this in the return status of update.

A composite node can be given a priority function to call when updating its own priority. If a function is not provided, the composite node will set its priority using a default algorithm, which is specified by its subclasses. Hence the priority function is a way of overriding the behavior of this node.

Constructor & Destructor Documentation

◆ CompositeNode()

cugl::ai::CompositeNode::CompositeNode ( )

Creates an uninitialized composite node.

You should never call this constructor directly. Instead, you should allocate a node with the BehaviorManager instance.

◆ ~CompositeNode()

cugl::ai::CompositeNode::~CompositeNode ( )

inline

Deletes this node, disposing all resources.

Member Function Documentation

◆ dispose()

virtual void cugl::ai::CompositeNode::dispose ( )

overridevirtual

Disposes all of the resources used by this node, including any descendants.

A disposed node can be safely reinitialized. Any children owned by this node will be released. They will be deleted if no other object owns them. This method should only be called by BehaviorManager.

Reimplemented from cugl::ai::BehaviorNode.

Reimplemented in cugl::ai::RandomNode.

◆ getActiveChild() [1/2]

const BehaviorNode* cugl::ai::CompositeNode::getActiveChild ( ) const

Returns a (weak) reference to the child currently running.

The purpose of this pointer is to allow access to the subtree of a behavior tree. It does not grant ownership, as ownership is confined to BehaviorManager.

Returns: a (weak) reference to the currently active child.

◆ getActiveChild() [2/2]

template<typename T >

const T* cugl::ai::CompositeNode::getActiveChild ( ) const

inline

Returns a (weak) reference to the child currently running.

The purpose of this pointer is to allow access to the subtree of a behavior tree. It does not grant ownership, as ownership is confined to BehaviorManager.

This version of the method performs a dynamic typecast to the correct type.

Returns: a (weak) reference to the currently active child.

◆ getChildByPriorityIndex() [1/2]

const BehaviorNode* cugl::ai::CompositeNode::getChildByPriorityIndex ( Uint32 index ) const

Returns a (weak) reference to the child with the given priority index.

A child with a specific priority index i is the child with the ith highest priority. Ties are broken by the position of the child in its parent's list.

The purpose of this pointer is to allow access to the subtree of a behavior tree. It does not grant ownership, as ownership is confined to BehaviorManager.

Parameters

index The child's priority index.

Returns: a (weak) reference the child with the given priority index.

◆ getChildByPriorityIndex() [2/2]

template<typename T >

const T* cugl::ai::CompositeNode::getChildByPriorityIndex ( Uint32 index ) const

inline

Returns a (weak) reference to the child with the given priority index.

A child with a specific priority index i is the child with the ith highest priority. Ties are broken by the position of the child in its parent's list.

The purpose of this pointer is to allow access to the subtree of a behavior tree. It does not grant ownership, as ownership is confined to BehaviorManager.

This version of the method performs a dynamic typecast to the correct type.

Parameters

index The child's priority index.

Returns: a (weak) reference the child with the given priority index.

◆ isPreemptive()

bool cugl::ai::CompositeNode::isPreemptive ( ) const

inline

Returns true this node allows preemption among its children.

If preemption is allowed, this node may choose a new child to run during an update, possibly interrupting an old child node. Otherwise, the composite node cannot interrupt its running child to select another child to run.

Returns: true this node allows preemption among its children.

◆ query()

virtual void cugl::ai::CompositeNode::query ( float dt )

overridevirtual

Updates the priority value(s) for this node.

This method recursively determines the priority of this node and all of its children. The priority may be determined by a user-provided priority function or by the default priority function of the class.

When this method is complete, it will chose a child node to run, but will not run it. Unlike update, this method is guaranteed to run every time step in BehaviorManager, provided that the root node is running.

Parameters

dt	The elapsed time since the last frame.

Implements cugl::ai::BehaviorNode.

Reimplemented in cugl::ai::RandomNode.

◆ selectChild()

virtual int cugl::ai::CompositeNode::selectChild ( ) const

protectedpure virtual

Returns a (possibly new) active child for this node.

This method is subclass dependent, and uses the rules of that subclass to select a child. If no child is selected, this method returns -1.

Returns: a (possibly new) active child for this node.

Implemented in cugl::ai::PriorityNode, cugl::ai::SelectorNode, and cugl::ai::RandomNode.

◆ setPreemptive()

void cugl::ai::CompositeNode::setPreemptive ( bool preemptive )

inline

Sets whether this node allows preemption among its children.

If preemption is allowed, this node may choose a new child to run during an update, possibly interrupting an old child node. Otherwise, the composite node cannot interrupt its running child to select another child to run.

Parameters

preemptive Whether this node allows preemption among its children.

◆ update()

BehaviorNode::State cugl::ai::CompositeNode::update ( float dt )

overridevirtual

Updates this node and any active children.

This method runs the update function, which executes to active child (if not a leaf) or the associated action (if a leaf). This method is not guaranteed to execute every time step; only if the node is the root of the tree or is selected as part of the active path.

If a node is not a leaf node and it has no active children, then the method will return INACTIVE.

Parameters

dt	The elapsed time since the last frame.

Returns: the state of this node after updating.

Implements cugl::ai::BehaviorNode.

Member Data Documentation

◆ _preemptive

bool cugl::ai::CompositeNode::_preemptive

protected

Whether to allow preemption among this node's children.

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

include/cugl/ai/behavior/CUCompositeNode.h

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ CompositeNode()

◆ ~CompositeNode()

Member Function Documentation

◆ dispose()

◆ getActiveChild() [1/2]

◆ getActiveChild() [2/2]

◆ getChildByPriorityIndex() [1/2]

◆ getChildByPriorityIndex() [2/2]

◆ isPreemptive()

◆ query()

◆ selectChild()

◆ setPreemptive()

◆ update()

Member Data Documentation

◆ _preemptive