Behavior Class Reference

Base class for defining logic that can be attached to Components, similar to Unity's MonoBehaviour. More...

#include <behavior.h>

Public Member Functions
	Behavior ()
virtual	~Behavior ()=default
void	attach (Component &component)
	Attaches this Behavior to a Component.
virtual void	on_awake ()
	Called when the Component is created. Runs before on_start().
virtual void	on_start ()
	Called before the first frame on_update().
virtual void	on_update (float dt)=0
	Called once per frame.
virtual void	on_destroy ()
	Called when the Behavior or associated GameObject is destroyed.
GameObject &	game_object () const
Transform &	transform () const
bool	enabled () const
Behavior &	enable ()
	Enables the behavior.
Behavior &	disable ()
	Disables the behavior.
virtual void	on_serialize (std::vector< uint8_t > &) const
	Serializes the behavior's state into a byte array.
virtual void	on_deserialize (const std::vector< uint8_t > &, size_t &)
	Deserializes the behavior's state from a byte array.
template<typename T >
std::optional< std::reference_wrapper< T > >	get_component ()
	Retrieves a component of type T attached to the same GameObject.
template<typename T >
std::vector< std::reference_wrapper< T > >	get_components ()
	Retrieves all components of type T attached to the same GameObject.
template<typename T >
std::optional< std::reference_wrapper< T > >	get_component_from_children ()
	Get a component of type T attached to this GameObject's children.
template<typename T >
std::vector< std::reference_wrapper< T > >	get_components_from_children ()
	Get all components of type T attached to this GameObject's children.
template<typename T >
std::optional< std::reference_wrapper< T > >	get_component_in_parent ()
	Get a component of type T attached to this GameObject's parents.
template<typename T >
std::vector< std::reference_wrapper< T > >	get_components_in_parent ()
	Get all components of type T attached to this GameObject's parents.
void	destroy ()
	Destroy the parent game object.
void	destroy (Component &component)
	Destroy a specific component on the parent game object.
void	destroy (GameObject &game_object)
	Destroy a specific game object in the scene.

Detailed Description

Base class for defining logic that can be attached to Components, similar to Unity's MonoBehaviour.

Behaviors provide a structured lifecycle for game logic:

• on_awake() : Called once when the Component is created.
• on_start() : Called once before the first update.
• on_update() : Called every frame.
• on_destroy() : Called when the Behavior or its GameObject is destroyed.

A Behavior operates on the Component it is attached to and provides utility methods for accessing the GameObject, Transform, and other Components. See it as a gateway to implement game logic that interacts with the engine's objects.

Note

Users should derive from this class to implement custom behavior.

Warning

on_update() must be overridden.

Usage:

• Create a class that inherits from Behavior.
• Override lifecycle methods (on_awake, on_start, on_update, on_destroy).
• Attach the Behavior to a Component via a BehaviorScript.

  See also

  BehaviorScript

Constructor & Destructor Documentation

Behavior()

Behavior::Behavior

(

)

~Behavior()

virtual Behavior::~Behavior ( )

virtualdefault

Member Function Documentation

attach()

void Behavior::attach

(

Component &

component

)

Attaches this Behavior to a Component.

Parameters

component

The component this behavior should operate on.

Exceptions

std::runtime_error

if already attached.

destroy() [1/3]

void Behavior::destroy

(

)

Destroy the parent game object.

destroy() [2/3]

void Behavior::destroy

(

Component &

component

)

Destroy a specific component on the parent game object.

destroy() [3/3]

void Behavior::destroy

(

GameObject &

game_object

)

Destroy a specific game object in the scene.

disable()

Behavior & Behavior::disable

(

)

Disables the behavior.

enable()

Behavior & Behavior::enable

(

)

Enables the behavior.

enabled()

bool Behavior::enabled

(

)

const

Returns

Whether the behavior is currently enabled.

game_object()

GameObject & Behavior::game_object

(

)

const

Returns

Reference to the GameObject this Behavior operates on.

Exceptions

std::runtime_error

if not attached.

get_component()

template<typename T >

std::optional< std::reference_wrapper< T > > Behavior::get_component ( )

inline

Retrieves a component of type T attached to the same GameObject.

Template Parameters

T	The type of the component to retrieve.

Returns

An optional reference to the component if found, std::nullopt otherwise.

Exceptions

std::runtime_error

if not attached.

get_component_from_children()

template<typename T >

std::optional< std::reference_wrapper< T > > Behavior::get_component_from_children ( )

inline

Get a component of type T attached to this GameObject's children.

Template Parameters

T	The type of the component to get.

Returns

An optional reference to the component if found, std::nullopt otherwise.

get_component_in_parent()

template<typename T >

std::optional< std::reference_wrapper< T > > Behavior::get_component_in_parent ( )

inline

Get a component of type T attached to this GameObject's parents.

Template Parameters

T	The type of the component to get.

Returns

An optional reference to the component if found, std::nullopt otherwise.

get_components()

template<typename T >

std::vector< std::reference_wrapper< T > > Behavior::get_components ( )

inline

Retrieves all components of type T attached to the same GameObject.

Template Parameters

T	The type of the components to retrieve.

Returns

A vector of references to the components found.

Exceptions

std::runtime_error

if not attached.

get_components_from_children()

template<typename T >

std::vector< std::reference_wrapper< T > > Behavior::get_components_from_children ( )

inline

Get all components of type T attached to this GameObject's children.

Template Parameters

T	The type of the component to get.

Returns

A vector of references to the components found.

get_components_in_parent()

template<typename T >

std::vector< std::reference_wrapper< T > > Behavior::get_components_in_parent ( )

inline

Get all components of type T attached to this GameObject's parents.

Template Parameters

T	The type of the component to get.

Returns

A vector of references to the components found.

on_awake()

virtual void Behavior::on_awake ( )

inlinevirtual

Called when the Component is created. Runs before on_start().

on_deserialize()

virtual void Behavior::on_deserialize ( const std::vector< uint8_t > &  , size_t &    )

inlinevirtual

Deserializes the behavior's state from a byte array.

Parameters

data	The byte array containing the serialized state.
offset	The current offset in the byte array from which to start reading. This offset will be updated as bytes are read.

Returns

void

on_destroy()

virtual void Behavior::on_destroy ( )

inlinevirtual

Called when the Behavior or associated GameObject is destroyed.

on_serialize()

virtual void Behavior::on_serialize ( std::vector< uint8_t > &  ) const

inlinevirtual

Serializes the behavior's state into a byte array.

Parameters

out	A vector to which the serialized bytes will be appended.

Returns

void

on_start()

virtual void Behavior::on_start ( )

inlinevirtual

Called before the first frame on_update().

on_update()

virtual void Behavior::on_update ( float  dt )

pure virtual

Called once per frame.

Parameters

dt	Time delta since last frame.

transform()

Transform & Behavior::transform

(

)

const

Returns

Reference to the Transform of the attached GameObject.

---

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

• include/engine/public/behavior.h