xy::System Class Reference

Base class for systems. Systems should all derive from this base class, and instanciated before any entities are created. Concrete system types should declare a list component types via requireComponent() on construction, so that only entities with the relevant components are added to the system. More...

#include <System.hpp>

Inheritance diagram for xy::System:

Public Types
using	Ptr = std::unique_ptr< System >

Public Member Functions
	System (MessageBus &mb, UniqueType t)
	Constructor. Pass in a reference to the concrete implementation to generate a unique type ID for this system.
UniqueType	getType () const
	Returns the unique type ID of the system.
const std::vector< Entity > &	getEntities () const
	Returns a list of entities that this system is currently interested in.
void	addEntity (Entity)
	Adds an entity to the list to process.
void	removeEntity (Entity)
	Removes an entity from the list to process.
const ComponentMask &	getComponentMask () const
	Returns the component mask used to mask entities with corresponding components for this system to process.
virtual void	handleMessage (const Message &)
	Used to process any incoming system messages.
virtual void	process (float)
	Implement this for system specific processing to entities.
bool	isActive () const
	Returns true if the system is currently active. Systems can be activeated and deactivated with Scene::setSystemActive()
template<typename T >
void	requireComponent ()
template<typename T >
T *	postMessage (Message::ID id)

Protected Member Functions
template<typename T >
void	requireComponent ()
	Adds a component type to the list of components required by the system for it to be interested in a particular entity. This should only be used in the constructor of the System else types will not be registered.
std::vector< Entity > &	getEntities ()
virtual void	onEntityAdded (Entity)
	Optional callback performed when an entity is added.
virtual void	onEntityRemoved (Entity)
	Optional callback performed when an entity is removed.
template<typename T >
T *	postMessage (Message::ID id)
	Posts a message on the system wide message bus.
MessageBus &	getMessageBus ()
	Returns a reference to the MessageBus.
void	setScene (Scene &)
Scene *	getScene ()
	Returns a pointer to the scene to which this system belongs.

Friends
class	SystemManager

Detailed Description

Base class for systems. Systems should all derive from this base class, and instanciated before any entities are created. Concrete system types should declare a list component types via requireComponent() on construction, so that only entities with the relevant components are added to the system.