Struct EntityCommandBuffer

A thread-safe command buffer that can buffer commands that affect entities and components for later playback.

Namespace: Unity.Entities
Syntax
[NativeContainer]
[GenerateBurstMonoInterop("EntityCommandBuffer")]
public struct EntityCommandBuffer : IDisposable

Constructors

EntityCommandBuffer(Allocator)

Creates a new command buffer.

Declaration
public EntityCommandBuffer(Allocator label)
Parameters
Type Name Description
Allocator label

Memory allocator to use for chunks and data

EntityCommandBuffer(Allocator, PlaybackPolicy)

Creates a new command buffer.

Declaration
public EntityCommandBuffer(Allocator label, PlaybackPolicy playbackPolicy)
Parameters
Type Name Description
Allocator label

Memory allocator to use for chunks and data
PlaybackPolicy playbackPolicy

Specifies if the EntityCommandBuffer can be played a single time or more than once.

Properties

IsCreated

Declaration
public bool IsCreated { get; }
Property Value
Type Description
Boolean

MinimumChunkSize

Allows controlling the size of chunks allocated from the temp job allocator to back the command buffer.

Declaration
public int MinimumChunkSize { get; set; }
Property Value
Type Description
Int32

ShouldPlayback

Controls whether this command buffer should play back.

Declaration
public bool ShouldPlayback { get; set; }
Property Value
Type Description
Boolean

Methods

AddBuffer<T>(Entity)

Declaration
public DynamicBuffer<T> AddBuffer<T>(Entity e)
    where T : struct, IBufferElementData
Parameters
Type Name Description
Entity e
Returns
Type Description
DynamicBuffer<T>
Type Parameters
Name Description
T

AddComponent(Entity, ComponentType)

Declaration
public void AddComponent(Entity e, ComponentType componentType)
Parameters
Type Name Description
Entity e
ComponentType componentType

AddComponent(Entity, ComponentTypes)

Records a command to add one or more components to an entity.

Declaration
public void AddComponent(Entity e, ComponentTypes componentTypes)
Parameters
Type Name Description
Entity e

The entity to get additional components.

ComponentTypes componentTypes

The types of components to add.

AddComponent(EntityQuery, ComponentType)

Records a command to add a component to all entities matching a query.

Declaration
public void AddComponent(EntityQuery entityQuery, ComponentType componentType)
Parameters
Type Name Description
EntityQuery entityQuery

The query specifying which entities to add the component to.

ComponentType componentType

The type of component to add.
Remarks

The query is performed at playback time, not when the method is called.

AddComponent(EntityQuery, ComponentTypes)

Records a command to add one or more components to all entities matching a query.

Declaration
public void AddComponent(EntityQuery entityQuery, ComponentTypes types)
Parameters
Type Name Description
EntityQuery entityQuery

The query specifying which entities get the added components.

ComponentTypes types
Remarks

The query is performed at playback time, not when the method is called.

AddComponent<T>(Entity)

Declaration
public void AddComponent<T>(Entity e)
    where T : struct, IComponentData
Parameters
Type Name Description
Entity e
Type Parameters
Name Description
T

AddComponent<T>(Entity, T)

Declaration
public void AddComponent<T>(Entity e, T component)
    where T : struct, IComponentData
Parameters
Type Name Description
Entity e
T component
Type Parameters
Name Description
T

AddComponent<T>(EntityQuery)

Records a command to add a component to all entities matching a query.

Declaration
public void AddComponent<T>(EntityQuery entityQuery)
Parameters
Type Name Description
EntityQuery entityQuery

The query specifying which entities get the added component.

Type Parameters
Name Description
T

The type of component to add.

Remarks

The query is performed at playback time, not when the method is called.

AddSharedComponent<T>(Entity, T)

Declaration
public void AddSharedComponent<T>(Entity e, T component)
    where T : struct, ISharedComponentData
Parameters
Type Name Description
Entity e
T component
Type Parameters
Name Description
T

AddSharedComponent<T>(EntityQuery, T)

Records a command to add a shared component to all entities matching a query.

Declaration
public void AddSharedComponent<T>(EntityQuery entityQuery, T component)
    where T : struct, ISharedComponentData
Parameters
Type Name Description
EntityQuery entityQuery

The query specifying which entities to add the component value to.

T component

The component value to add.

Type Parameters
Name Description
T
Remarks

The query is performed at playback time, not when the method is called. For entities matching the query which already have this component type, the value is updated.

AppendToBuffer<T>(Entity, T)

Appends a single element to the end of a dynamic buffer component.

Declaration
public void AppendToBuffer<T>(Entity e, T element)
    where T : struct, IBufferElementData
Parameters
Type Name Description
Entity e

The entity to which the dynamic buffer belongs.
T element

The new element to add to the DynamicBuffer<T> component.
Type Parameters
Name Description
T

The IBufferElementData type stored by the DynamicBuffer<T>.
Remarks

At Playback(EntityManager), this command throws an InvalidOperationException if the entity doesn't have a DynamicBuffer<T> component storing elements of type T.

Exceptions
Type Condition
InvalidOperationException

Thrown if the entity does not have a DynamicBuffer<T> component storing elements of type T at the time the entity command buffer executes this append-to-buffer command.

AsParallelWriter()

Declaration
public EntityCommandBuffer.ParallelWriter AsParallelWriter()
Returns
Type Description
EntityCommandBuffer.ParallelWriter

CreateEntity()

Create an entity with no components.

Declaration
public Entity CreateEntity()
Returns
Type Description
Entity

CreateEntity(EntityArchetype)

Create an entity with specified archetype.

Declaration
public Entity CreateEntity(EntityArchetype archetype)
Parameters
Type Name Description
EntityArchetype archetype

The archetype of the new entity.
Returns
Type Description
Entity

DestroyEntity(Entity)

Declaration
public void DestroyEntity(Entity e)
Parameters
Type Name Description
Entity e

DestroyEntity(EntityQuery)

Records a command to destroy all entities matching a query.

Declaration
public void DestroyEntity(EntityQuery entityQuery)
Parameters
Type Name Description
EntityQuery entityQuery

The query specifying which entities from which the component is removed.

Remarks

The query is performed at playback time, not when the method is called.

Dispose()

Declaration
public void Dispose()

Instantiate(Entity)

Declaration
public Entity Instantiate(Entity e)
Parameters
Type Name Description
Entity e
Returns
Type Description
Entity

Playback(EntityManager)

Play back all recorded operations against an entity manager.

Declaration
public void Playback(EntityManager mgr)
Parameters
Type Name Description
EntityManager mgr

The entity manager that will receive the operations

Playback(ExclusiveEntityTransaction)

Play back all recorded operations with an exclusive entity transaction. BeginExclusiveEntityTransaction().

Declaration
public void Playback(ExclusiveEntityTransaction mgr)
Parameters
Type Name Description
ExclusiveEntityTransaction mgr

The exclusive entity transaction that will process the operations

RemoveComponent(Entity, ComponentType)

Declaration
public void RemoveComponent(Entity e, ComponentType componentType)
Parameters
Type Name Description
Entity e
ComponentType componentType

RemoveComponent(Entity, ComponentTypes)

Records a command to remove one or more components from an entity.

Declaration
public void RemoveComponent(Entity e, ComponentTypes componentTypes)
Parameters
Type Name Description
Entity e

The entity to have components removed.

ComponentTypes componentTypes

The types of components to remove.

RemoveComponent(EntityQuery, ComponentType)

Records a command to remove a component from all entities matching a query.

Declaration
public void RemoveComponent(EntityQuery entityQuery, ComponentType componentType)
Parameters
Type Name Description
EntityQuery entityQuery

The query specifying which entities from which the component is removed.

ComponentType componentType
Remarks

The query is performed at playback time, not when the method is called.

RemoveComponent(EntityQuery, ComponentTypes)

Records a command to remove one or more components from all entities matching a query.

Declaration
public void RemoveComponent(EntityQuery entityQuery, ComponentTypes componentTypes)
Parameters
Type Name Description
EntityQuery entityQuery

The query specifying which entities to remove the components from.

ComponentTypes componentTypes

The types of components to remove.

Remarks

The query is performed at playback time, not when the method is called.

RemoveComponent<T>(Entity)

Declaration
public void RemoveComponent<T>(Entity e)
Parameters
Type Name Description
Entity e
Type Parameters
Name Description
T

RemoveComponent<T>(EntityQuery)

Records a command to remove a component from all entities matching a query.

Declaration
public void RemoveComponent<T>(EntityQuery entityQuery)
Parameters
Type Name Description
EntityQuery entityQuery

The query specifying which entities from which the component is removed.

Type Parameters
Name Description
T

The type of component to remove.

Remarks

The query is performed at playback time, not when the method is called.

SetBuffer<T>(Entity)

Declaration
public DynamicBuffer<T> SetBuffer<T>(Entity e)
    where T : struct, IBufferElementData
Parameters
Type Name Description
Entity e
Returns
Type Description
DynamicBuffer<T>
Type Parameters
Name Description
T

SetComponent<T>(Entity, T)

Declaration
public void SetComponent<T>(Entity e, T component)
    where T : struct, IComponentData
Parameters
Type Name Description
Entity e
T component
Type Parameters
Name Description
T

SetSharedComponent<T>(Entity, T)

Declaration
public void SetSharedComponent<T>(Entity e, T component)
    where T : struct, ISharedComponentData
Parameters
Type Name Description
Entity e
T component
Type Parameters
Name Description
T

Extension Methods