Struct bevy::ecs::entity::Entity

pub struct Entity { /* fields omitted */ }

Lightweight unique ID of an entity.

Obtained from World::spawn, typically via Commands::spawn. Can be stored to refer to an entity in the future.

Entity can be a part of a query, e.g. Query<(Entity, &MyComponent)>. Components of a specific entity can be accessed using Query::get and related methods.

Implementations

impl Entity

pub fn from_raw(id: u32) -> Entity

Creates a new entity reference with the specified id and a generation of 0.

Note

Spawning a specific entity value is rarely the right choice. Most apps should favor Commands::spawn. This method should generally only be used for sharing entities across apps, and only when they have a scheme worked out to share an ID space (which doesn’t happen by default).

In general, one should not try to synchronize the ECS by attempting to ensure that Entity lines up between instances, but instead insert a secondary identifier as a component.

There are still some use cases where it might be appropriate to use this function externally.

Examples

Initializing a collection (e.g. array or Vec) with a known size:

// Create a new array of size 10 and initialize it with (invalid) entities.
let mut entities: [Entity; 10] = [Entity::from_raw(0); 10];

// ... replace the entities with valid ones.

Deriving Reflect for a component that has an Entity field:

#[derive(Reflect, Component)]
#[reflect(Component)]
pub struct MyStruct {
    pub entity: Entity,
}

impl FromWorld for MyStruct {
    fn from_world(_world: &mut World) -> Self {
        Self {
            entity: Entity::from_raw(u32::MAX),
        }
    }
}

pub fn to_bits(self) -> u64

Convert to a form convenient for passing outside of rust.

Only useful for identifying entities within the same instance of an application. Do not use for serialization between runs.

No particular structure is guaranteed for the returned bits.

pub fn from_bits(bits: u64) -> Entity

Reconstruct an Entity previously destructured with Entity::to_bits.

Only useful when applied to results from to_bits in the same instance of an application.

pub fn id(self) -> u32

Return a transiently unique identifier.

No two simultaneously-live entities share the same ID, but dead entities’ IDs may collide with both live and dead entities. Useful for compactly representing entities within a specific snapshot of the world, such as when serializing.

pub fn generation(self) -> u32

Returns the generation of this Entity’s id. The generation is incremented each time an entity with a given id is despawned. This serves as a “count” of the number of times a given id has been reused (id, generation) pairs uniquely identify a given Entity.

Trait Implementations

impl Clone for Entity

pub fn clone(&self) -> Entity

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Entity

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Entity

pub fn deserialize<D>(
    deserializer: D
) -> Result<Entity, <D as Deserializer<'de>>::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl From<Entity> for SlotValue

pub fn from(value: Entity) -> SlotValue

Performs the conversion.

impl FromReflect for Entity

pub fn from_reflect(reflect: &(dyn Reflect + 'static)) -> Option<Entity>

Creates a clone of a reflected value, converting it to a concrete type if it was a dynamic types (e.g. DynamicStruct)

impl GetTypeRegistration for Entity

pub fn get_type_registration() -> TypeRegistration

impl Hash for Entity

pub fn hash<__H>(&self, state: &mut __H) where
    __H: Hasher, 

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl Ord for Entity

pub fn cmp(&self, other: &Entity) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Entity> for Entity

pub fn eq(&self, other: &Entity) -> bool

This method tests for self and other values to be equal, and is used by ==.

pub fn ne(&self, other: &Entity) -> bool

This method tests for !=.

impl PartialOrd<Entity> for Entity

pub fn partial_cmp(&self, other: &Entity) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Reflect for Entity

pub fn type_name(&self) -> &str

pub fn any(&self) -> &(dyn Any + 'static)

pub fn any_mut(&mut self) -> &mut (dyn Any + 'static)

pub fn clone_value(&self) -> Box<dyn Reflect + 'static, Global>

pub fn apply(&mut self, value: &(dyn Reflect + 'static))

pub fn set(
    &mut self,
    value: Box<dyn Reflect + 'static, Global>
) -> Result<(), Box<dyn Reflect + 'static, Global>>

pub fn reflect_ref(&self) -> ReflectRef<'_>

pub fn reflect_mut(&mut self) -> ReflectMut<'_>

pub fn reflect_hash(&self) -> Option<u64>

Returns a hash of the value (which includes the type) if hashing is supported. Otherwise None will be returned.

pub fn reflect_partial_eq(
    &self,
    value: &(dyn Reflect + 'static)
) -> Option<bool>

Returns a “partial equal” comparison result if comparison is supported. Otherwise None will be returned.

pub fn serializable(&self) -> Option<Serializable<'_>>

Returns a serializable value, if serialization is supported. Otherwise None will be returned.

impl Serialize for Entity

pub fn serialize<S>(
    &self,
    serializer: S
) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl SparseSetIndex for Entity

pub fn sparse_set_index(&self) -> usize

pub fn get_sparse_set_index(value: usize) -> Entity

impl WorldQuery for Entity

type Fetch = EntityFetch

type State = EntityState

type ReadOnlyFetch = EntityFetch

impl Copy for Entity

impl Eq for Entity

impl StructuralEq for Entity

impl StructuralPartialEq for Entity