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

Structs

• Entities
  A World’s internal metadata store on all of its entities.
• Entity
  Lightweight identifier of an entity.
• 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.

Traits

• EntityMapper
  An implementor of this trait knows how to map an Entity into another Entity.
• MapEntities
  Operation to map all contained Entity fields in a type to new values.
• VisitEntities
  Apply an operation to all entities in a container.
• VisitEntitiesMut
  Apply an operation to mutable references to all entities in a container.

Type Aliases

• EntityHashMap
  A HashMap pre-configured to use EntityHash hashing.
• EntityHashSet
  A HashSet pre-configured to use EntityHash hashing.

Derive Macros

• VisitEntities
• VisitEntitiesMut