Module entity

Entity handling types.

An entity exclusively owns zero or more component instances, all of different types, and can dynamically acquire or lose them over its lifetime.

empty entity: Entity with zero components. pending entity: Entity reserved, but not flushed yet (see Entities::flush docs for reference). reserved entity: same as pending entity. invalid entity: pending entity flushed with invalid (see Entities::flush_as_invalid docs for reference).

See Entity to learn more.

Usage

Operations involving entities and their components are performed either from a system by submitting commands, or from the outside (or from an exclusive system) by directly using World methods:

Operation	Command	Method
Spawn an entity with components	Commands::spawn	World::spawn
Spawn an entity without components	Commands::spawn_empty	World::spawn_empty
Despawn an entity	EntityCommands::despawn	World::despawn
Insert a component, bundle, or tuple of components and bundles to an entity	EntityCommands::insert	EntityWorldMut::insert
Remove a component, bundle, or tuple of components and bundles from an entity	EntityCommands::remove	EntityWorldMut::remove

Re-exports

• pub use hash_map::EntityHashMap;
• pub use hash_set::EntityHashSet;
• pub use index_map::EntityIndexMap;
• pub use index_set::EntityIndexSet;
• pub use unique_array::UniqueEntityArray;
• pub use unique_array::UniqueEntityEquivalentArray;
• pub use unique_slice::UniqueEntityEquivalentSlice;
• pub use unique_slice::UniqueEntitySlice;
• pub use unique_vec::UniqueEntityEquivalentVec;
• pub use unique_vec::UniqueEntityVec;

Modules

• hash_map
  Contains the EntityHashMap type, a HashMap pre-configured to use EntityHash hashing.
• hash_set
  Contains the EntityHashSet type, a HashSet pre-configured to use EntityHash hashing.
• index_map
  Contains the EntityIndexMap type, an IndexMap pre-configured to use EntityHash hashing.
• index_set
  Contains the EntityIndexSet type, a IndexSet pre-configured to use EntityHash hashing.
• unique_array
  A wrapper around entity arrays with a uniqueness invariant.
• unique_slice
  A wrapper around entity slices with a uniqueness invariant.
• unique_vec
  A wrapper around entity Vecs with a uniqueness invariant.

Structs

• ComponentCloneCtx
  Context for component clone handlers.
• Entities
  A World’s internal metadata store on all of its entities.
• Entity
  Lightweight identifier of an entity.
• EntityCloner
  A configuration determining how to clone entities. This can be built using EntityCloner::build, which returns an EntityClonerBuilder.
• EntityClonerBuilder
  A builder for configuring EntityCloner. See EntityCloner for more information.
• EntityDoesNotExistDetails
  Helper struct that, when printed, will write the appropriate details regarding an entity that did not exist.
• EntityDoesNotExistError
  An error that occurs when a specified Entity does not exist.
• EntityHash
  A BuildHasher that results in a EntityHasher.
• EntityHasher
  A very fast hash that is only designed to work on generational indices like Entity. It will panic if attempting to hash a type containing non-u64 fields.
• EntityLocation
  A location of an entity in an archetype.
• ReserveEntitiesIterator
  An Iterator returning a sequence of Entity values from
• SceneEntityMapper
  A wrapper for EntityHashMap<Entity>, augmenting it with the ability to allocate new Entity references in a destination world. These newly allocated references are guaranteed to never point to any living entity in that world.
• SourceComponent
  Provides read access to the source component (the component being cloned) in a ComponentCloneFn.
• UniqueEntityIter
  An iterator that yields unique entities.

Traits

• ContainsEntity
  A trait for types that contain an Entity.
• EntityEquivalent
  A trait for types that represent an Entity.
• EntityMapper
  An implementor of this trait knows how to map an Entity into another Entity.
• EntitySet
  A set of unique entities.
• EntitySetIterator
  An iterator over a set of unique entities.
• FromEntitySetIterator
  Conversion from an EntitySetIterator.
• MapEntities
  Operation to map all contained Entity fields in a type to new values.

Derive Macros

• MapEntities