Class entity_handle¶

Defined in File entity_handle.hpp

Class Documentation¶

class legion::core::ecs::entity_handle¶

Serializable handle for executing operations on entities. This class only stores a reference to the registry and the id of the entity.

Public Functions

inline entity_handle(id_type id) noexcept¶: Main constructor for constructing a valid entity handle.

inline entity_handle() noexcept¶

Constructor for constructing an invalid entity handle.

Note: Should only be used to create temporary handles. Allows use of entity handle in containers together with copy constructor.

inline entity_handle(const entity_handle &other) noexcept¶

Copy constructor (DOES NOT CREATE NEW ENTITY, both handles will reference the same entity).

Note: Allows use of entity handle in containers together with default invalid entity constructor.

entity_handle &operator=(const entity_handle &other) noexcept¶: Copy assignment. Exists for the same reasons as the copy constructor. legion::core::ecs::entity_handle::entity_handle(const legion::core::ecs::entity& other)

std::string get_name() const noexcept¶

void set_name(const std::string &name)¶

entity_handle clone(bool keep_parent = true, bool clone_children = true, bool clone_components = true) const¶

Clones an entity.

Return

entity_handle A handle to the copied entity.

Parameters

keep_parent: If true sets the parent of the cloned entity to the same parent as the source [default: true]
clone_children: If true copies all the children of the entity as well. [default: true]
clone_components: If true copies all the components of the entity. [default: true]

hashed_sparse_set<id_type> component_composition() const¶

Returns the type id’s of the components this entity contains.

Return

hashed_sparse_set<id_type>& Sparse map with component type id as both the key as well as the value. (behaves as sparse_set with hash table)

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

inline operator id_type() const¶

Cast to id_type returns the id of the entity this handle references.

Return: id_type If the handle is valid it will return the entity id, otherwise invalid_id.

inline bool operator==(const entity_handle &other) const¶

inline bool operator!=(const entity_handle &other) const¶

inline operator bool() const¶

id_type get_id() const¶

Returns the id of the entity this handle references.

Return: id_type If the handle is valid it will return the entity id, otherwise invalid_id.

entity_set children() const¶: Returns hashed sparse set with all children of this entity.

entity_handle get_parent() const¶

Returns entity handle to parent entity.

Return

entity_handle Entity handle that either points to the parent entity or is invalid if the entity doesn’t have a parent.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

void set_parent(id_type newParent, bool addHierarchyIfAbsent = true)¶

Set parent of entity.

Note

Will remove as child from parent.

Parameters

newParent: Id of the entity you wish to set as the parent. (invalid_id if you wish to remove parent)

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

void serialize(cereal::JSONOutputArchive &oarchive)¶

serializes the entity depending on its archive

Note

Will only be called when said entity is serializes through an archive.

Parameters

oarchive: template<typename Archive>

void serialize(cereal::BinaryOutputArchive &oarchive)¶

void serialize(cereal::JSONInputArchive &oarchive)¶

void serialize(cereal::BinaryInputArchive &oarchive)¶

entity_handle operator[](index_type index) const¶

Get child of the entity at a certain index.

Exceptions

std::out_of_range: Thrown when index is more than or equal to the child count.
legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

entity_handle get_child(index_type index) const¶

Get child of the entity at a certain index.

Exceptions

std::out_of_range: Thrown when index is more than or equal to the child count.
legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

size_type child_count() const¶

Get amount of children the referenced entity has.

Return

size_type

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

void add_child(id_type childId)¶

Add child to entity.

Note

Will change parent of the entity to add as child.

Parameters

childId: Id of the entity you wish to add as a child.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

void remove_child(id_type childId)¶

Remove child from entity.

Note

Will remove parent of the entity to remove as child.

Parameters

childId: Id of the entity you wish to remove as a child.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

template<typename component_type> inline bool has_component() const¶

Check if entity contains a certain component.

Template Parameters

component_type: Type of component to check for.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

template<typename component_type, typename ...component_types, typename = doesnt_inherit_from<component_type, archetype_base>> bool has_components() const¶

Check if entity contains a certain components.

Template Parameters

component_type: First type of component to check for.
component_types: The rest of the types of components to check for.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

template<typename archetype_type, typename = inherits_from<archetype_type, archetype_base>> bool has_components() const¶

Check if entity contains the components of a certain archetype.

Template Parameters

archetype_type: The type of archetype to check for.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

bool has_component(id_type componentTypeId) const¶

Check if entity contains a certain component.

Parameters

componentTypeId: Type id of component to check for.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

component_handle_base get_component_handle(id_type componentTypeId)¶

Get component handle of a certain component.

Return

component_handle_base Valid component handle if the entity has the component, invalid handle if the entity doesn’t have the component.

Note

component_handle_base needs to be force_cast to component_handle<T> in order to be usable.

Parameters

componentTypeId: Type id of component to fetch.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

const component_handle_base get_component_handle(id_type componentTypeId) const¶

template<typename component_type> inline component_handle<component_type> get_component_handle()¶

Get component handle of a certain component.

Return

component_handle<component_type> Valid component handle if the entity has the component, invalid handle if the entity doesn’t have the component.

Template Parameters

component_type: Type of component to fetch.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

template<typename component_type> inline const component_handle<component_type> get_component_handle() const¶

template<typename component_type, typename ...component_types, typename = doesnt_inherit_from<component_type, archetype_base>> auto get_component_handles() const¶

Get component handles of certain components.

Return

Tuple with all the handles.

Template Parameters

component_type: First type of component to fetch.
component_types: The rest of the types of components to fetch.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

template<typename archetype_type, typename = inherits_from<archetype_type, archetype_base>> auto get_component_handles() const¶

Get component handles of all components of a certain archetype.

Return

Tuple with all the handles.

Template Parameters

archetype_type: The type of archetype to fetch the components of.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.

template<typename component_type> inline component_type read_component() const¶: Shortcut to component_handle::read.

template<typename component_type> inline void write_component(component_type &&value)¶: Shortcut to component_handle::write.

template<typename component_type> inline void write_component(const component_type &value)¶: Shortcut to component_handle::write.

component_handle_base add_component(id_type componentTypeId)¶

Add component to the entity.

Return

component_handle_base Valid component handle base for the newly created component.

Note

component_handle_base needs to be force_cast to component_handle<T> in order to be usable.

Parameters

componentTypeId: Type id of component to add.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

component_handle_base add_component(id_type componentTypeId, void *value)¶

Add component to the entity.

Return

component_handle_base Valid component handle base for the newly created component.

Note

component_handle_base needs to be force_cast to component_handle<T> in order to be usable.

Parameters

componentTypeId: Type id of component to add.
value: Pointer to component_type that has the starting value you require.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename component_type> inline component_handle<component_type> add_component()¶

Add component to the entity.

Return

component_handle<component_type> Valid component handle for the newly created component.

Template Parameters

component_type: Type of component to add.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename component_type> inline component_handle<std::remove_reference_t<component_type>> add_component(component_type &&value)¶

Add component to the entity.

Return

component_handle<component_type> Valid component handle for the newly created component.

Parameters

value: Starting value of the component.

Template Parameters

component_type: Type of component to add.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename component_type> inline component_handle<std::remove_reference_t<component_type>> add_component(const component_type &value)¶

Add component to the entity.

Return

component_handle<component_type> Valid component handle for the newly created component.

Parameters

value: Starting value of the component.

Template Parameters

component_type: Type of component to add.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename component_type, typename ...component_types, typename = doesnt_inherit_from<component_type, archetype_base>> auto add_components()¶

Add multiple components to the entity.

Return

Tuple with all the handles.

Template Parameters

component_type: First type of component to add.
component_types: The rest of the types of components to add.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename archetype_type, typename = inherits_from<archetype_type, archetype_base>> auto add_components()¶

Add multiple components to the entity through the use of an archetype.

Return

Tuple with all the handles.

Template Parameters

archetype_type: The type of archetype to add the components of.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename component_type, typename ...component_types, typename = doesnt_inherit_from<component_type, archetype_base>> auto add_components(component_type &&value, component_types&&... values)¶

Add multiple components to the entity.

Return

Tuple with all the handles.

Template Parameters

component_type: First type of component to add.
component_types: The rest of the types of components to add.

Parameters

value: Starting value of the first component.
values...: Starting values of the other components.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename component_type, typename ...component_types, typename = doesnt_inherit_from<component_type, archetype_base>> auto add_components(component_type &value, component_types&... values)¶

Add multiple components to the entity.

Return

Tuple with all the handles.

Template Parameters

component_type: First type of component to add.
component_types: The rest of the types of components to add.

Parameters

value: Starting value of the first component.
values...: Starting values of the other components.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename archetype_type, typename ...component_types, typename = inherits_from<archetype_type, archetype_base>> auto add_components(component_types&&... values)¶

Add multiple components to the entity through the use of an archetype.

Return

Tuple with all the handles.

Template Parameters

archetype_type: The type of archetype to add the components of.

Parameters

values...: Starting values of the components.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

void remove_component(id_type componentTypeId)¶

Remove component from entity.

Note

Nothing will happen if the entity doesn’t have this component.

Parameters

componentTypeId: Type id of component to remove.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename component_type> inline void remove_component()¶

Remove component from entity.

Note

Nothing will happen if the entity doesn’t have this component.

Template Parameters

component_type: Type of component to remove.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename component_type, typename ...component_types, typename = doesnt_inherit_from<component_type, archetype_base>> void remove_components()¶

Remove multiple components from entity.

Note

Nothing will happen if the entity doesn’t have a component.

Template Parameters

component_type: Type of the first component to remove.
component_types: Types of the other components to remove.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<typename archetype_type, typename = inherits_from<archetype_type, archetype_base>> void remove_components()¶

Remove multiple components from entity through an archetype.

Note

Nothing will happen if the entity doesn’t have a component.

Template Parameters

archetype_type: Type of the archetype with the components to remove.

Exceptions

legion_invalid_entity_error: Thrown when handle’s registry reference is invalid.
legion_entity_not_found_error: Thrown when handle’s id is invalid.
legion_unknown_component_error: Thrown when the component type is unknown.

template<class component_type, class Func, typename = doesnt_inherit_from<component_type, archetype_base>> void modify_component(Func &&f)¶

void destroy(bool recurse = true)¶

Destroy this entity. Destroys entity and invalidates handle. (also destroys all of it’s components)

Parameters

recurse: Destroy all children and children of children as well? Default value is true.

bool valid() const¶

Check whether this entity handle is valid or not.

Return: bool True if the handle is pointing to valid entity and the registry reference is also valid.

Class entity_handle¶

Class Documentation¶

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