Struct Entities 

pub struct Entities { /* private fields */ }

Entities tracks all known EntityIndexs and their metadata. This is like a base table of information all entities have.

Implementations

impl Entities

pub fn clear(&mut self)

Clears all entity information

pub fn get_spawned( &self, entity: Entity, ) -> Result<EntityLocation, EntityNotSpawnedError>

Returns the EntityLocation of an Entity if it is valid and spawned. This will return an error if the EntityGeneration of this entity has passed or if the EntityIndex is not spawned.

See the module docs for a full explanation of these ids, entity life cycles, and the meaning of this result.

pub fn get( &self, entity: Entity, ) -> Result<Option<EntityLocation>, InvalidEntityError>

Returns the EntityLocation of an Entity if it is valid. The location will be None if the entity is not spawned. If you expect the entity to be spawned, use get_spawned.

This will fail if the Entity is not valid (ex: the generation is mismatched).

See the module docs for a full explanation of these ids, entity life cycles, and the meaning of this result.

pub fn resolve_from_index(&self, index: EntityIndex) -> Entity

Get the Entity for the given EntityIndex. Note that this entity may not be spawned yet.

See the module docs for a full explanation of these ids, entity life cycles, and the meaning of this result.

pub fn is_index_spawned(&self, index: EntityIndex) -> bool

Returns whether the entity at this index is spawned or not.

See the module docs for a full explanation of these ids, entity life cycles, and the meaning of this result.

pub fn contains(&self, entity: Entity) -> bool

Returns true if the entity is valid. This will return true for entities that are valid but have not been spawned.

See the module docs for a full explanation of these ids, entity life cycles, and the meaning of this result.

pub fn contains_spawned(&self, entity: Entity) -> bool

Returns true if the entity is valid and is spawned.

See the module docs for a full explanation of these ids, entity life cycles, and the meaning of this result.

pub fn check_can_spawn_at(&self, entity: Entity) -> Result<(), SpawnError>

Provides information regarding if entity may be safely spawned. This can error if the entity is invalid or is already spawned.

See the module docs for a full explanation of these ids, entity life cycles, and the meaning of this result.

pub fn entity_get_spawned_or_despawned_by( &self, entity: Entity, ) -> MaybeLocation<Option<&'static Location<'static>>>

Try to get the source code location from which this entity has last been spawned or despawned.

Returns None if the entity does not exist or has never been construced/despawned.

pub fn entity_get_spawn_or_despawn_tick(&self, entity: Entity) -> Option<Tick>

Try to get the Tick at which this entity has last been spawned or despawned.

Returns None if the entity does not exist or has never been construced/despawned.

pub fn len(&self) -> u32

The count of currently allocated entity indices. For information on active entities, see Self::count_spawned.

pub fn is_empty(&self) -> bool

Checks if any entity has been declared. For information on active entities, see Self::any_spawned.

pub fn count_spawned(&self) -> u32

Counts the number of entity indices currently spawned. See the module docs for a more precise explanation of what spawning means. Be aware that this is O(n) and is intended only to be used as a diagnostic for tests.

pub fn any_spawned(&self) -> bool

Returns true if there are any entity indices currently spawned. See the module docs for a more precise explanation of what spawning means.

Trait Implementations

impl Clone for Entities

fn clone(&self) -> Entities

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Entities

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'a> SystemParam for &'a Entities

type State = ()

Used to store data which persists across invocations of a system.

type Item<'w, 's> = &'w Entities

The item type returned when constructing this system param. The value of this associated type should be Self, instantiated with new lifetimes.

fn init_state(_world: &mut World) -> <&'a Entities as SystemParam>::State

Creates a new instance of this param’s State.

fn init_access( _state: &<&'a Entities as SystemParam>::State, _system_meta: &mut SystemMeta, _component_access_set: &mut FilteredAccessSet, _world: &mut World, )

Registers any World access used by this SystemParam

unsafe fn get_param<'w, 's>( _state: &'s mut <&'a Entities as SystemParam>::State, _system_meta: &SystemMeta, world: UnsafeWorldCell<'w>, _change_tick: Tick, ) -> <&'a Entities as SystemParam>::Item<'w, 's>

Creates a parameter to be passed into a SystemParamFunction.

fn apply(state: &mut Self::State, system_meta: &SystemMeta, world: &mut World)

Applies any deferred mutations stored in this SystemParam’s state. This is used to apply Commands during ApplyDeferred.

fn queue( state: &mut Self::State, system_meta: &SystemMeta, world: DeferredWorld<'_>, )

Queues any deferred mutations to be applied at the next ApplyDeferred.

unsafe fn validate_param( state: &mut Self::State, system_meta: &SystemMeta, world: UnsafeWorldCell<'_>, ) -> Result<(), SystemParamValidationError>

Validates that the param can be acquired by the get_param.

impl<'a> ReadOnlySystemParam for &'a Entities