An accessor class that implements high-level access to an entity that has the given component. More...

#include <CeresEngine/Entity/Component.hpp>

Inheritance diagram for CeresEngine::Component< T >::Accessor:

Public Member Functions
	Accessor (const Entity &entity)

Public Attributes
const Entity &	entity

Protected Types
using	C = TC

Protected Member Functions
template<typename T >
auto	mutate (T C::*ptr)
	Accesses an element from an existing `Component`.

template<typename MutatorFunc , typename T > requires (CInvocable<MutatorFunc, T&>)
decltype(auto)	mutate (MutatorFunc &&func, T C::*ptr)
	Accesses an element from an existing `Component`.

template<typename T1 , typename T2 , typename... Ts>
Tuple< ComponentFieldMutator< T1, C >, ComponentFieldMutator< T2, C >, ComponentFieldMutator< Ts, C >... >	mutate (T1 C::ptr1, T2 C::ptr2, Ts C::*... ptrs)
	TODO Write docs.

template<typename MutatorFunc , typename T1 , typename T2 , typename... Ts>
Tuple< ComponentFieldMutator< T1, C >, ComponentFieldMutator< T2, C >, ComponentFieldMutator< Ts, C >... >	mutate (MutatorFunc &&func, T1 C::ptr1, T2 C::ptr2, Ts C::*... ptr)

template<typename T >
auto	get (T C::*ptr)
	Accesses an element from an existing `Component`.

template<typename T1 , typename T2 , typename... Ts>
Tuple< ComponentFieldMutator< T1, C >, ComponentFieldMutator< T2, C >, ComponentFieldMutator< Ts, C >... >	get (T1 C::ptr1, T2 C::ptr2, Ts C::*... ptrs)
	Accesses an element from an existing `Component`.

template<typename T >
const T &	read (const T C::*ptr) const
	Accesses an element from an existing `Component`.

template<typename T1 , typename T2 , typename... Ts>
Tuple< const T1 &, const T2 &, const Ts &... >	read (const T1 C::ptr1, const T2 C::ptr2, const Ts C::*... ptrs) const
	TODO Write docs.

template<typename T >
const T &	get (const T C::*ptr) const
	Accesses an element from an existing `Component`.

template<typename T1 , typename T2 , typename... Ts>
Tuple< const T1 &, const T2 &, const Ts &... >	get (const T1 C::ptr1, const T2 C::ptr2, const Ts C::*... ptrs) const
	Accesses an element from an existing `Component`.

Detailed Description

template<typename T>
struct CeresEngine::Component< T >::Accessor

An accessor class that implements high-level access to an entity that has the given component.

All components are encouraged to offer a TC::Accessor implementation that derives from this class that allows higher-level access to an entity.

Implementations can use the read() and mutate() methods to access data in the component. The C type is a type-alias to the component class the accessor is implemented for.

Use read() to access a value from a component. You can give it one or more pointers-to-member of the component type C. Data will be retrieved from the component and returned to you by const-reference.
Use mutate() to change a value from a component. You can give it one or more pointers-to-member of the component type C. Data will be retrieved from the component and returned to you by reference. mutate() automatically marks the entity as dirty.
Alternatively, you can use get() that will automatically deduce either read() if this is const or mutate() if it is non-const.

To use a custom Accessor you must use EntityObject or some of it's sub-classes.

struct MyComponent : public Component<MyComponent> {
    struct Accessor;
    String name;
};
 
struct MyComponent::Accessor : Component<MyComponent>::Accessor {
    using Component<MyComponent>::Accessor::Accessor;
    const String& getFullyQualifiedName() const { return read(&C::name); }
    void setName(String newName) {
        if(newName.empty()) throw std::invalid_argument("newName");
        if(newName == read(&C::name)) return;
        mutate(&C::name) = std::move(newName);
    }
};
 
using MyObject = EntityObject<MyComponent>;
EntityManager& entityManager = ...;
 
MyObject object = entityManager.create<MyObject>();
object->setName("Testing");

Template Parameters

TC	The component implementation type.

Member Typedef Documentation

◆ C

template<typename T >

using CeresEngine::Component< T >::Accessor::C = TC

protected

Constructor & Destructor Documentation

◆ Accessor()

template<typename T >

CeresEngine::Component< T >::Accessor::Accessor ( const Entity & entity )

inlineexplicit

Member Function Documentation

◆ get() [1/4]

template<typename T >

const T & CeresEngine::Component< T >::Accessor::get ( const T C::* ptr ) const

protected

Accesses an element from an existing Component.

If the component does not exists, it is undefined behavior.

Template Parameters

T	the component member type

Parameters

ptr	The component element pointer to member

Returns: A reference to the component element

◆ get() [2/4]

template<typename T >

template<typename T1 , typename T2 , typename... Ts>

Tuple< const T1 &, const T2 &, const Ts &... > CeresEngine::Component< T >::Accessor::get	(	const T1 C::*	ptr1,
		const T2 C::*	ptr2,
		const Ts C::*...	ptrs
	)		const

protected

Accesses an element from an existing Component.

If the component does not exists, it is undefined behavior.

Template Parameters

T	the component member type

Parameters

ptr	The component element pointer to member

Returns: A reference to the component element

◆ get() [3/4]

template<typename T >

auto CeresEngine::Component< T >::Accessor::get ( T C::* ptr )

protected

Accesses an element from an existing Component.

If the component does not exists, it is undefined behavior.

Template Parameters

T	the component member type

Parameters

ptr	The component element pointer to member

Returns: A reference to the component element

◆ get() [4/4]

template<typename T >

template<typename T1 , typename T2 , typename... Ts>

Tuple< ComponentFieldMutator< T1, C >, ComponentFieldMutator< T2, C >, ComponentFieldMutator< Ts, C >... > CeresEngine::Component< T >::Accessor::get	(	T1 C::*	ptr1,
		T2 C::*	ptr2,
		Ts C::*...	ptrs
	)

protected

Accesses an element from an existing Component.

If the component does not exists, it is undefined behavior.

Template Parameters

T	the component member type

Parameters

ptr	The component element pointer to member

Returns: A reference to the component element

◆ mutate() [1/4]

template<typename T >

template<typename MutatorFunc , typename T >
requires (CInvocable<MutatorFunc, T&>)

decltype(auto) CeresEngine::Component< T >::Accessor::mutate	(	MutatorFunc &&	func,
		T C::*	ptr
	)

protected

Accesses an element from an existing Component.

If the component does not exists, it is undefined behavior.

Template Parameters

T	The component member type

Parameters

ptr	The component element pointer to member
func	The function to be called with a reference to the property.

Returns: A reference to the component element

◆ mutate() [2/4]

template<typename T >

template<typename MutatorFunc , typename T1 , typename T2 , typename... Ts>

Tuple< ComponentFieldMutator< T1, C >, ComponentFieldMutator< T2, C >, ComponentFieldMutator< Ts, C >... > CeresEngine::Component< T >::Accessor::mutate	(	MutatorFunc &&	func,
		T1 C::*	ptr1,
		T2 C::*	ptr2,
		Ts C::*...	ptr
	)

protected

◆ mutate() [3/4]

template<typename T >

auto CeresEngine::Component< T >::Accessor::mutate ( T C::* ptr )

protected

Accesses an element from an existing Component.

If the component does not exists, it is undefined behavior.

Template Parameters

T	the component member type

Parameters

ptr	The component element pointer to member

Returns: A reference to the component element

◆ mutate() [4/4]

template<typename T >

template<typename T1 , typename T2 , typename... Ts>

Tuple< ComponentFieldMutator< T1, C >, ComponentFieldMutator< T2, C >, ComponentFieldMutator< Ts, C >... > CeresEngine::Component< T >::Accessor::mutate	(	T1 C::*	ptr1,
		T2 C::*	ptr2,
		Ts C::*...	ptrs
	)

protected

TODO Write docs.

◆ read() [1/2]

template<typename T >

const T & CeresEngine::Component< T >::Accessor::read ( const T C::* ptr ) const

protected

Accesses an element from an existing Component.

If the component does not exists, it is undefined behavior.

Template Parameters

T	the component member type

Parameters

ptr	The component element pointer to member

Returns: A reference to the component element

◆ read() [2/2]

template<typename T >

template<typename T1 , typename T2 , typename... Ts>

Tuple< const T1 &, const T2 &, const Ts &... > CeresEngine::Component< T >::Accessor::read	(	const T1 C::*	ptr1,
		const T2 C::*	ptr2,
		const Ts C::*...	ptrs
	)		const

protected

TODO Write docs.

Member Data Documentation

◆ entity

template<typename T >

const Entity& CeresEngine::Component< T >::Accessor::entity

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

/Users/Rogiel/Developer/CeresEngine/Engine/Sources/CeresEngine/Entity/Component.hpp

Public Member Functions

Public Attributes

Protected Types

Protected Member Functions

Detailed Description

Member Typedef Documentation

◆ C

Constructor & Destructor Documentation

◆ Accessor()

Member Function Documentation

◆ get() [1/4]

◆ get() [2/4]

◆ get() [3/4]

◆ get() [4/4]

◆ mutate() [1/4]

◆ mutate() [2/4]

◆ mutate() [3/4]

◆ mutate() [4/4]

◆ read() [1/2]

◆ read() [2/2]

Member Data Documentation

◆ entity