Module prelude

The ECS prelude.

This includes the most common types in this crate, re-exported for your convenience.

Macros

• children
  Returns a SpawnRelatedBundle that will insert the Children component, spawn a SpawnableList of entities with given bundles that relate to the Children entity via the ChildOf component, and reserve space in the Children for each spawned entity.
• related
  Returns a SpawnRelatedBundle that will insert the given RelationshipTarget, spawn a SpawnableList of entities with given bundles that relate to the RelationshipTarget entity via the RelationshipTarget::Relationship component, and reserve space in the RelationshipTarget for each spawned entity.

Structs

• Added
  A filter on a component that only retains results the first time after they have been added.
• AnyOf
  The AnyOf query parameter fetches entities with any of the component types included in T.
• AppTypeRegistry
  A Resource storing TypeRegistry for type registrations relevant to a whole app.
• ApplyDeferred
  A special System that instructs the executor to call System::apply_deferred on the systems that have run but not applied their Deferred system parameters (like Commands) or other system buffers.
• BevyError
  The built in “universal” Bevy error type. This has a blanket From impl for any type that implements Rust’s Error, meaning it can be used as a “catch all” error.
• Changed
  A filter on a component that only retains results the first time after they have been added or mutably dereferenced.
• ChildOf
  Stores the parent entity of this child entity with this component.
• Children
  Tracks which entities are children of this parent entity.
• Commands
  A Command queue to perform structural changes to the World.
• Deferred
  A SystemParam that stores a buffer which gets applied to the World during ApplyDeferred. This is used internally by Commands to defer World mutations.
• Entity
  Lightweight identifier of an entity.
• EntityCommands
  A list of commands that will be run to modify an Entity.
• EntityMut
  Provides mutable access to a single entity and all of its components.
• EntityRef
  A read-only reference to a particular Entity and all of its components.
• EntityWorldMut
  A mutable reference to a particular Entity, and the entire world.
• EventMutator
  Mutably reads events of type T keeping track of which events have already been read by each system allowing multiple systems to read the same events. Ideal for chains of systems that all want to modify the same events.
• EventReader
  Reads events of type T in order and tracks which events have already been read.
• EventWriter
  Sends events of type T.
• Events
  An event collection that represents the events that occurred within the last two Events::update calls. Events can be written to using an EventWriter and are typically cheaply read using an EventReader.
• FilteredResources
  Provides read-only access to a set of Resources defined by the contained Access.
• FilteredResourcesMut
  Provides mutable access to a set of Resources defined by the contained Access.
• Has
  Returns a bool that describes if an entity has the component T.
• In
  A SystemInput type which denotes that a System receives an input value of type T from its caller.
• InMut
  A SystemInput type which denotes that a System receives a mutable reference to a value of type T from its caller.
• InRef
  A SystemInput type which denotes that a System receives a read-only reference to a value of type T from its caller.
• Local
  A system local SystemParam.
• Mut
  Unique mutable borrow of an entity’s component or of a resource.
• Name
  Component used to identify an entity. Stores a hash for faster comparisons.
• NameOrEntity
  Convenient query for giving a human friendly name to an entity.
• NonSend
  Shared borrow of a non-Send resource.
• NonSendMut
  Unique borrow of a non-Send resource.
• Observer
  An Observer system. Add this Component to an Entity to turn it into an “observer”.
• OnAdd
  Trigger emitted when a component is inserted onto an entity that does not already have that component. Runs before OnInsert. See crate::component::ComponentHooks::on_add for more information.
• OnInsert
  Trigger emitted when a component is inserted, regardless of whether or not the entity already had that component. Runs after OnAdd, if it ran. See crate::component::ComponentHooks::on_insert for more information.
• OnRemove
  Trigger emitted when a component is removed from an entity, and runs before the component is removed, so you can still access the component data. See crate::component::ComponentHooks::on_remove for more information.
• OnReplace
  Trigger emitted when a component is inserted onto an entity that already has that component. Runs before the value is replaced, so you can still access the original component data. See crate::component::ComponentHooks::on_replace for more information.
• Or
  A filter that tests if any of the given filters apply.
• ParallelCommands
  An alternative to Commands that can be used in parallel contexts, such as those in Query::par_iter.
• ParamSet
  A collection of potentially conflicting SystemParams allowed by disjoint access.
• Populated
  System parameter that works very much like Query except it always contains at least one matching entity.
• Query
  A system parameter that provides selective access to the Component data stored in a World.
• QueryBuilder
  Builder struct to create QueryState instances at runtime.
• QueryState
  Provides scoped access to a World state according to a given QueryData and QueryFilter.
• Ref
  Shared borrow of an entity’s component with access to change detection. Similar to Mut but is immutable and so doesn’t require unique access.
• ReflectComponent
  A struct used to operate on reflected Component trait of a type.
• ReflectFromWorld
  A struct used to operate on the reflected FromWorld trait of a type.
• ReflectResource
  A struct used to operate on reflected Resource of a type.
• RemovedComponents
  A SystemParam that yields entities that had their T Component removed or have been despawned with it.
• Res
  Shared borrow of a Resource.
• ResMut
  Unique mutable borrow of a Resource.
• Schedule
  A collection of systems, and the metadata and executor needed to run them in a certain order under certain conditions.
• Schedules
  Resource that stores Schedules mapped to ScheduleLabels excluding the current running Schedule.
• Single
  System parameter that provides access to single entity’s components, much like Query::single/Query::single_mut.
• Spawn
  A wrapper over a Bundle indicating that an entity should be spawned with that Bundle. This is intended to be used for hierarchical spawning via traits like SpawnableList and SpawnRelated.
• Trigger
  Type containing triggered Event information for a given run of an Observer. This contains the Event data itself. If it was triggered for a specific Entity, it includes that as well. It also contains event propagation information. See Trigger::propagate for more information.
• With
  Filter that selects entities with a component T.
• Without
  Filter that selects entities without a component T.
• World
  Stores and exposes operations on entities, components, resources, and their associated metadata.

Constants

• apply_deferredDeprecated
  See ApplyDeferred.

Traits

• Bundle
  The Bundle trait enables insertion and removal of Components from an entity.
• Command
  A World mutation.
• Component
  A data type that can be used to store data for an entity.
• Condition
  A system that determines if one or more scheduled systems should run.
• ContainsEntity
  A trait for types that contain an Entity.
• DetectChanges
  Types that can read change detection information. This change detection is controlled by DetectChangesMut types such as ResMut.
• DetectChangesMut
  Types that implement reliable change detection.
• EntityCommand
  A command which gets executed for a given Entity.
• EntityMapper
  An implementor of this trait knows how to map an Entity into another Entity.
• Event
  Something that “happens” and might be read / observed by app logic.
• FromWorld
  Creates an instance of the type this trait is implemented for using data from the supplied World.
• IntoScheduleConfigs
  Types that can convert into a ScheduleConfigs.
• IntoSystem
  Conversion trait to turn something into a System.
• IntoSystemSet
  Types that can be converted into a SystemSet.
• ReadOnlySystem
  System types that do not modify the World when run. This is implemented for any systems whose parameters all implement ReadOnlySystemParam.
• RelationshipTarget
  A Component containing the collection of entities that relate to this Entity via the associated Relationship type. See the Relationship documentation for more information.
• Resource
  A type that can be inserted into a World as a singleton.
• SpawnRelated
  RelationshipTarget methods that create a Bundle with a DynamicBundle::Effect that:
• System
  An ECS system that can be added to a Schedule
• SystemInput
  Trait for types that can be used as input to Systems.
• SystemParamBuilder
  A builder that can create a SystemParam.
• SystemParamFunction
  A trait implemented for all functions that can be used as Systems.
• SystemSet
  Types that identify logical groups of systems.

Functions

• any_component_removed
  A Condition-satisfying system that returns true if there are any entity with a component of the given type removed.
• any_match_filter
  A Condition-satisfying system that returns true if there are any entities that match the given QueryFilter.
• any_with_component
  A Condition-satisfying system that returns true if there are any entities with the given component type.
• condition_changed
  Generates a Condition that returns true when the passed one changes.
• condition_changed_to
  Generates a Condition that returns true when the result of the passed one went from false to true since the last time this was called.
• not
  Generates a Condition that inverses the result of passed one.
• on_event
  A Condition-satisfying system that returns true if there are any new events of the given type since it was last called.
• resource_added
  A Condition-satisfying system that returns true if the resource of the given type has been added since the condition was last checked.
• resource_changed
  A Condition-satisfying system that returns true if the resource of the given type has had its value changed since the condition was last checked.
• resource_changed_or_removed
  A Condition-satisfying system that returns true if the resource of the given type has had its value changed since the condition was last checked.
• resource_equals
  Generates a Condition-satisfying closure that returns true if the resource is equal to value.
• resource_exists
  A Condition-satisfying system that returns true if the resource exists.
• resource_exists_and_changed
  A Condition-satisfying system that returns true if the resource of the given type has had its value changed since the condition was last checked.
• resource_exists_and_equals
  Generates a Condition-satisfying closure that returns true if the resource exists and is equal to value.
• resource_removed
  A Condition-satisfying system that returns true if the resource of the given type has been removed since the condition was last checked.
• run_once
  A Condition-satisfying system that returns true on the first time the condition is run and false every time after.

Type Aliases

• ChildSpawner
  A type alias over RelatedSpawner used to spawn child entities containing a ChildOf relationship.
• ChildSpawnerCommands
  A type alias over RelatedSpawnerCommands used to spawn child entities containing a ChildOf relationship.
• Result
  A result type for use in fallible systems, commands and observers.
• SystemIn
  Shorthand way to get the System::In for a System as a SystemInput::Inner.

Derive Macros

• Bundle
• Component
• Event
• FromWorld
• Resource
• SystemSet
  Derive macro generating an impl of the trait SystemSet.