Engine::Core Class Reference

The core is the place where all the data of the engine is stored. It contains the registry (entities), the resources and the schedulers(+systems). It allows to manage entities so to create, delete them. It also allows to manage dependencies between schedulers. It also allows to aggregate plugins to it, and then plugins will be able to add resources and systems to the core. More...

#include <Core.hpp>

Public Types
using	Registry = entt::basic_registry<Id>
	The type of the registry used by the core. It is an alias for entt::basic_registry with Id as entity identifier.

Public Member Functions
	Core ()
	Default constructor of the core. It will initialize the registry and the scheduler container. Some schedulers will be automatically registered like Startup, Update and Shutdown.
	~Core ()
	Destructor of the core. It will clear the registry and the scheduler container.
Registry &	GetRegistry ()
	Get the entt::registry that contains all components. It should be used to update component through systems.
const Registry &	GetRegistry () const
	Get the entt::registry that contains all components. It should be used to update component through systems.
Entity	CreateEntity ()
	Create an entity in the context of the registry.
void	KillEntity (Id entity)
	Kill an entity. It will remove all components from the entity.
template<typename TResource>
TResource &	RegisterResource (TResource &&resource)
	Store a resource instance.
template<typename TResource>
TResource &	GetResource ()
	Get a reference of a resource.
template<typename TResource>
const TResource &	GetResource () const
	Get a const reference of a resource.
template<typename TResource>
bool	HasResource () const
	Check if a resource is registered in the core.
template<typename TResource>
void	DeleteResource ()
	Delete a resource from the core.
template<CScheduler TScheduler, typename... Args>
TScheduler &	RegisterScheduler (Args &&...args)
	Add a new scheduler to the registry.
template<CScheduler TScheduler>
TScheduler &	GetScheduler ()
	Get a scheduler from the registry by its type.
Scheduler::AScheduler &	GetScheduler (std::type_index id)
	Get a scheduler from the registry by its type index.
template<typename TSchedulerA, typename TSchedulerB>
void	SetSchedulerBefore ()
	Sets the execution order of two schedulers, ensuring that TSchedulerA is executed before TSchedulerB.
template<typename TSchedulerA, typename TSchedulerB>
void	SetSchedulerAfter ()
	Sets the execution order of two schedulers by specifying that one scheduler should execute after another.
template<typename TSchedulerA, typename TSchedulerB>
void	RemoveDependencyAfter ()
	Removes a dependency between two schedulers, ensuring that TSchedulerB is no longer dependent on TSchedulerA.
template<typename TSchedulerA, typename TSchedulerB>
void	RemoveDependencyBefore ()
	Removes a dependency between two schedulers, ensuring that TSchedulerA is no longer dependent on TSchedulerB.
bool	IsRunning ()
	Get the running state of the core.
void	Stop ()
	Stop the core execution. It will finish the current loop, call shutdown systems if any and stop.
void	RunCore ()
	Execute the core loop, which will run all the schedulers.
template<CScheduler TScheduler, typename... Systems>
decltype(auto)	RegisterSystem (Systems... systems)
	Add one or multiple systems associated with a specific scheduler.
template<typename... Systems>
decltype(auto)	RegisterSystem (Systems... systems)
	Add one or multiple systems associated to the default scheduler.
template<CScheduler TScheduler, typename System, typename ErrorCallback>
decltype(auto)	RegisterSystemWithErrorHandler (System system, ErrorCallback callback)
	Add a system to a specific scheduler, associated with a callback that should run if the system fails (throw).
template<typename System, typename ErrorCallback>
decltype(auto)	RegisterSystemWithErrorHandler (System system, ErrorCallback callback)
	Add a system to the default scheduler, associated with a callback that should run if the system fails (throw).
template<CScheduler TScheduler>
void	DeleteScheduler ()
	Deletes a scheduler.
void	RunSystems ()
	Run all the systems once by calling each scheduler.
bool	IsEntityValid (Id entity) const
	Check if entity is valid in the context of the registry. It check if the id of the entity exist.
template<CPlugin... TPlugins>
void	AddPlugins ()
	Adds multiple plugins that will be call instantly through the Bind method to agregate their systems and resources to the core.
template<CPlugin TPlugin>
bool	HasPlugin () const
	Checks if a plugin is present.
bool	HasPlugin (std::type_index type) const
	Checks if a plugin of the specified type is present.
void	ClearEntities ()
	Clear all entities and components from the registry.
template<CScheduler TScheduler>
void	SetDefaultScheduler ()
	Sets the default scheduler.
void	SetDefaultScheduler (std::type_index scheduler)
	Sets the default scheduler.
void	SetErrorPolicyForAllSchedulers (Scheduler::SchedulerErrorPolicy policy)
	Sets the error policy for all schedulers.

Private Member Functions
template<CPlugin TPlugin>
void	AddPlugin ()
	Adds a plugin.

Private Attributes
std::unique_ptr< Registry >	_registry
	The registry that contains all components (and by definition, the entities).
Engine::SchedulerContainer	_schedulers
	The container that contains all the schedulers.
std::type_index	_defaultScheduler = typeid(Engine::Scheduler::Update)
	The default scheduler type index. It is used when adding systems without specifying a scheduler.
std::vector< std::type_index >	_schedulersToDelete
	The list of schedulers to delete at the end of the current loop.
std::unordered_map< std::type_index, std::unique_ptr< IPlugin > >	_plugins
	The plugins added to the core.
bool	_running = false
	The running state of the core. It is true if the core is running, false otherwise. It is used to stop the core loop.

Detailed Description

The core is the place where all the data of the engine is stored. It contains the registry (entities), the resources and the schedulers(+systems). It allows to manage entities so to create, delete them. It also allows to manage dependencies between schedulers. It also allows to aggregate plugins to it, and then plugins will be able to add resources and systems to the core.

Examples

/home/runner/work/EngineSquared/EngineSquared/src/plugin/physics/src/system/ConstraintSystem.hpp, and /home/runner/work/EngineSquared/EngineSquared/src/plugin/sound/src/resource/SoundManager.hpp.

Member Typedef Documentation

Registry

using Engine::Core::Registry = entt::basic_registry<Id>

The type of the registry used by the core. It is an alias for entt::basic_registry with Id as entity identifier.

Constructor & Destructor Documentation

Core()

Engine::Core::Core

(

)

Default constructor of the core. It will initialize the registry and the scheduler container. Some schedulers will be automatically registered like Startup, Update and Shutdown.

~Core()

Engine::Core::~Core

(

)

Destructor of the core. It will clear the registry and the scheduler container.

Member Function Documentation

AddPlugin()

template<CPlugin TPlugin>

void Engine::Core::AddPlugin ( )

private

Adds a plugin.

Template Parameters

TPlugin

The type of the plugin to add. See Engine::CPlugin.

AddPlugins()

template<CPlugin... TPlugins>

void Engine::Core::AddPlugins

(

)

Adds multiple plugins that will be call instantly through the Bind method to agregate their systems and resources to the core.

Note

2 same plugins can't be added.

Template Parameters

TPlugins

Types of the plugins to add. See Engine::CPlugin.

ClearEntities()

void Engine::Core::ClearEntities

(

)

Clear all entities and components from the registry.

CreateEntity()

Engine::Entity Engine::Core::CreateEntity

(

)

Create an entity in the context of the registry.

Returns

The entity created.

DeleteResource()

template<typename TResource>

void Engine::Core::DeleteResource ( )

inline

Delete a resource from the core.

Template Parameters

TResource

type of the resource to delete

DeleteScheduler()

template<CScheduler TScheduler>

void Engine::Core::DeleteScheduler

(

)

Deletes a scheduler.

Template Parameters

TScheduler

The type of scheduler to delete. See Engine::CScheduler.

Note

This function will not delete the scheduler immediately, but it will mark it for deletion. The scheduler will be deleted at the end of the current loop, after all systems have been executed.

GetRegistry() [1/2]

Registry & Engine::Core::GetRegistry ( )

inline

Get the entt::registry that contains all components. It should be used to update component through systems.

Returns

registry that contains all components.

Todo

put the implementation in the cpp file, (remove inline)

GetRegistry() [2/2]

const Registry & Engine::Core::GetRegistry ( ) const

inline

Get the entt::registry that contains all components. It should be used to update component through systems.

Returns

registry that contains all components.

Todo

put the implementation in the cpp file, (remove inline)

GetResource() [1/2]

template<typename TResource>

TResource & Engine::Core::GetResource ( )

inline

Get a reference of a resource.

Template Parameters

TResource

type of the resource to get

Returns

reference of the resource

Examples

/home/runner/work/EngineSquared/EngineSquared/src/plugin/sound/src/resource/SoundManager.hpp.

GetResource() [2/2]

template<typename TResource>

const TResource & Engine::Core::GetResource ( ) const

inline

Get a const reference of a resource.

Template Parameters

TResource

type of the resource to get

Returns

const reference of the resource

GetScheduler() [1/2]

template<CScheduler TScheduler>

TScheduler & Engine::Core::GetScheduler ( )

inline

Get a scheduler from the registry by its type.

Template Parameters

TScheduler

The type of scheduler to get.

Returns

The scheduler.

GetScheduler() [2/2]

Scheduler::AScheduler & Engine::Core::GetScheduler ( std::type_index id )

inline

Get a scheduler from the registry by its type index.

Parameters

id	The type index of the scheduler to get.

Returns

The scheduler.

HasPlugin() [1/2]

template<CPlugin TPlugin>

bool Engine::Core::HasPlugin

(

)

const

Checks if a plugin is present.

Template Parameters

TPlugin

The type of the plugin to check for. See Engine::CPlugin.

Returns

true if the plugin is present, false otherwise.

HasPlugin() [2/2]

bool Engine::Core::HasPlugin

(

std::type_index

type

)

const

Checks if a plugin of the specified type is present.

Parameters

type	The type of the plugin to check for.

Returns

true if the plugin is present, false otherwise.

HasResource()

template<typename TResource>

bool Engine::Core::HasResource ( ) const

inline

Check if a resource is registered in the core.

Template Parameters

TResource

type of the resource to check

Returns

Return true if the resource is registered, false otherwise

IsEntityValid()

bool Engine::Core::IsEntityValid

(

Engine::Id

entity

)

const

Check if entity is valid in the context of the registry. It check if the id of the entity exist.

Returns

true if the entity is valid, false otherwise.

IsRunning()

bool Engine::Core::IsRunning

(

)

Get the running state of the core.

Returns

The running state.

KillEntity()

void Engine::Core::KillEntity

(

Engine::Id

entity

)

Kill an entity. It will remove all components from the entity.

Parameters

entity

The entity to kill.

RegisterResource()

template<typename TResource>

TResource & Engine::Core::RegisterResource ( TResource && resource )

inline

Store a resource instance.

Template Parameters

TResource

type of the resource to add

Parameters

resource

rvalue of the resource to add

Returns

reference of the added resource

RegisterScheduler()

template<CScheduler TScheduler, typename... Args>

TScheduler & Engine::Core::RegisterScheduler ( Args &&... args )

inline

Add a new scheduler to the registry.

Template Parameters

TScheduler

The type of scheduler to use.

Parameters

args	The scheduler to add.

RegisterSystem() [1/2]

template<typename... Systems>

decltype(auto) Engine::Core::RegisterSystem ( Systems... systems )

inline

Add one or multiple systems associated to the default scheduler.

Template Parameters

Systems

The types of the systems to add. This is not a mandatory template parameter, you can add only the system variable and it will be deduced by the compiler. You can add as many systems as you want, they will be called in the order they were added.

Parameters

systems

The systems to add.

Returns

Return the identifiers of the systems added, in the same order as the systems were added.

See also

FunctionUtils::FunctionID.

RegisterSystem() [2/2]

template<CScheduler TScheduler, typename... Systems>

decltype(auto) Engine::Core::RegisterSystem ( Systems... systems )

inline

Add one or multiple systems associated with a specific scheduler.

Template Parameters

TScheduler	The type of the scheduler to use. It must be derived from AScheduler. You can look at CScheduler
Systems	The types of the systems to add. This is not a mandatory template parameter, you can add only the system variable and it will be deduced by the compiler. You can add as many systems as you want, they will be called in the order they were added.

Parameters

systems

The systems to add.

Returns

Return the identifiers of the systems added, in the same order as the systems were added.

See also

FunctionUtils::FunctionID.

RegisterSystemWithErrorHandler() [1/2]

template<typename System, typename ErrorCallback>

decltype(auto) Engine::Core::RegisterSystemWithErrorHandler ( System system, ErrorCallback callback )

inline

Add a system to the default scheduler, associated with a callback that should run if the system fails (throw).

Template Parameters

TScheduler

The type of scheduler to use.

See also

Engine::CScheduler.

Parameters

system	The system to add.
callback	The callback to run if the system fails (throw).

Returns

Return the identifier of the system added. See FunctionUtils::FunctionID.

RegisterSystemWithErrorHandler() [2/2]

template<CScheduler TScheduler, typename System, typename ErrorCallback>

decltype(auto) Engine::Core::RegisterSystemWithErrorHandler ( System system, ErrorCallback callback )

inline

Add a system to a specific scheduler, associated with a callback that should run if the system fails (throw).

Template Parameters

TScheduler

The type of scheduler to use. It must be derived from AScheduler. See Engine::CScheduler.

Parameters

system	The system to add.
callback	The callback to run if the system fails (throw).

Returns

Return the identifier of the system added. See FunctionUtils::FunctionID.

RemoveDependencyAfter()

template<typename TSchedulerA, typename TSchedulerB>

void Engine::Core::RemoveDependencyAfter ( )

inline

Removes a dependency between two schedulers, ensuring that TSchedulerB is no longer dependent on TSchedulerA.

Template Parameters

TSchedulerA	The type of the first scheduler (the one being depended on).
TSchedulerB	The type of the second scheduler (the one depending on TSchedulerA).

Todo

Move the implementation of this function in the .inl file

RemoveDependencyBefore()

template<typename TSchedulerA, typename TSchedulerB>

void Engine::Core::RemoveDependencyBefore ( )

inline

Removes a dependency between two schedulers, ensuring that TSchedulerA is no longer dependent on TSchedulerB.

Template Parameters

TSchedulerA	The type of the first scheduler (the one depending on TSchedulerB).
TSchedulerB	The type of the second scheduler (the one being depended on).

Todo

Move the implementation of this function in the .inl file

RunCore()

void Engine::Core::RunCore

(

)

Execute the core loop, which will run all the schedulers.

RunSystems()

void Engine::Core::RunSystems

(

)

Run all the systems once by calling each scheduler.

SetDefaultScheduler() [1/2]

template<CScheduler TScheduler>

void Engine::Core::SetDefaultScheduler ( )

inline

Sets the default scheduler.

Template Parameters

TScheduler

The type of the scheduler to be set as default. See Engine::CScheduler.

Todo

Move the implementation of this function in the .inl file.

SetDefaultScheduler() [2/2]

void Engine::Core::SetDefaultScheduler ( std::type_index scheduler )

inline

Sets the default scheduler.

Parameters

scheduler

The type index of the scheduler to be set as default.

Note

The scheduler must be present in the core.

SetErrorPolicyForAllSchedulers()

void Engine::Core::SetErrorPolicyForAllSchedulers

(

Scheduler::SchedulerErrorPolicy

policy

)

Sets the error policy for all schedulers.

Parameters

policy

The error policy to set for all schedulers. See Engine::Scheduler::SchedulerErrorPolicy.

SetSchedulerAfter()

template<typename TSchedulerA, typename TSchedulerB>

void Engine::Core::SetSchedulerAfter ( )

inline

Sets the execution order of two schedulers by specifying that one scheduler should execute after another.

Template Parameters

TSchedulerA	The type of the scheduler that should execute first.
TSchedulerB	The type of the scheduler that should execute after TSchedulerA.

Todo

Move the implementation of this function in the .inl file

SetSchedulerBefore()

template<typename TSchedulerA, typename TSchedulerB>

void Engine::Core::SetSchedulerBefore ( )

inline

Sets the execution order of two schedulers, ensuring that TSchedulerA is executed before TSchedulerB.

Template Parameters

TSchedulerA	The type of the scheduler that should execute first.
TSchedulerB	The type of the scheduler that should execute after TSchedulerA.

Todo

Move the implementation of this function in the .inl file

Stop()

void Engine::Core::Stop

(

)

Stop the core execution. It will finish the current loop, call shutdown systems if any and stop.

Member Data Documentation

_defaultScheduler

std::type_index Engine::Core::_defaultScheduler = typeid(Engine::Scheduler::Update)

private

The default scheduler type index. It is used when adding systems without specifying a scheduler.

_plugins

std::unordered_map<std::type_index, std::unique_ptr<IPlugin> > Engine::Core::_plugins

private

The plugins added to the core.

_registry

std::unique_ptr<Registry> Engine::Core::_registry

private

The registry that contains all components (and by definition, the entities).

_running

bool Engine::Core::_running = false

private

The running state of the core. It is true if the core is running, false otherwise. It is used to stop the core loop.

_schedulers

Engine::SchedulerContainer Engine::Core::_schedulers

private

The container that contains all the schedulers.

_schedulersToDelete

std::vector<std::type_index> Engine::Core::_schedulersToDelete

private

The list of schedulers to delete at the end of the current loop.

---

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

• src/engine/src/core/Core.hpp
• src/engine/src/core/Core.cpp
• src/engine/src/core/Core.inl