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  3. FEntityManager

FEntityManager

Top-level manager class that is responsible for all entity data and interaction/

API > API/Runtime > API/Runtime/MovieScene

Top-level manager class that is responsible for all entity data and interaction/

An entity is a stable index into the manager's EntityLocations, which defines the location for that entity's data. This allows the manager to relocate entity data at will without invalidating client held entity IDs. An entity may contain 0 or more components. Components are concrete pieces of data with a unique type identifier. Additionally, tags can be added to entities or whole batches of entities with zero memory overhead.

Entity Component data is stored in allocations organized by each unique combination of components. Each component type is stored as a contiguous array within each allocation, with each entity's component being a fixed offset from the start of each component array. This enables efficient read/write access into specific component arrays and makes issuing parallel tasks that require component data trivial. See FEntityAllocation for a more detailed explanation of entity component data layout.

   
Name FEntityManager
Type class
Header File /Engine/Source/Runtime/MovieScene/Public/EntitySystem/MovieSceneEntityManager.h
Include Path #include "EntitySystem/MovieSceneEntityManager.h"

Syntax

class FEntityManager : public FUObjectArray::FUObjectDeleteListener

Inheritance Hierarchy

Constructors

Name Remarks Include Path Unreal Specifiers
  EntitySystem/MovieSceneEntityManager.h  
  EntitySystem/MovieSceneEntityManager.h  
  EntitySystem/MovieSceneEntityManager.h  

Destructors

Name Remarks Include Path Unreal Specifiers

~FEntityManager()

   EntitySystem/MovieSceneEntityManager.h  

Structs

Name Remarks
FEntityLocation  

Variables

Protected

Name Type Remarks Include Path Unreal Specifiers
AccumulatedMask FComponentMask   EntitySystem/MovieSceneEntityManager.h  
AllocationsWithCapacity TBitArray Bit mask of allocations that currently have capacity EntitySystem/MovieSceneEntityManager.h  
bAccumulatedMaskStale bool   EntitySystem/MovieSceneEntityManager.h  
bHandleGenerationStale bool   EntitySystem/MovieSceneEntityManager.h  
ComponentRegistry FComponentRegistry *   EntitySystem/MovieSceneEntityManager.h  
CurrentHandleGeneration uint32 The current generation of entities - incremented any time an entity is destroyed EntitySystem/MovieSceneEntityManager.h  
DispatchThread ENamedThreads::Type   EntitySystem/MovieSceneEntityManager.h  
EntityAllocationMasks TSparseArray< FComponentMask > Sparse array of masks that define each index within EntityAllocations' component types EntitySystem/MovieSceneEntityManager.h  
EntityAllocations TSparseArray< FEntityAllocation * > Sparse array of entity allocation pointers. Allocations are heap allocated. EntitySystem/MovieSceneEntityManager.h  
EntityGenerationMap TMap< FMovieSceneEntityID, uint32 > Map of entity ID to the generation its handle was created in. EntitySystem/MovieSceneEntityManager.h  
EntityLocations TSparseArray< FEntityLocation > Sparse array of entity location information for each allocated entity ID. EntitySystem/MovieSceneEntityManager.h  
FFreeEntityOperation friend   EntitySystem/MovieSceneEntityManager.h  
GatherThread ENamedThreads::Type   EntitySystem/MovieSceneEntityManager.h  
GlobalIterationFilter FEntityComponentFilter   EntitySystem/MovieSceneEntityManager.h  
InstancedChildInitializers TSparseArray< TInlineValue< FChildEntityInitializer > >   EntitySystem/MovieSceneEntityManager.h  
IterationCount FEntitySystemMaybeAtomicInt32 Atomic counter that is incremented when an iteration begins, and decremented when it finishes EntitySystem/MovieSceneEntityManager.h  
LockdownState ELockdownState   EntitySystem/MovieSceneEntityManager.h  
ManagerDebugName FString Debug name for this entity manager EntitySystem/MovieSceneEntityManager.h  
NextAllocationID uint32 Serially incrementing unique identifier that is assigned to each new entity allocation that is created EntitySystem/MovieSceneEntityManager.h  
ParentToChild TMultiMap< FMovieSceneEntityID, FMovieSceneEntityID > Map of parent -> child entities EntitySystem/MovieSceneEntityManager.h  
RichComponentDebuggingPtr const bool * Debugging ptr for natvis EntitySystem/MovieSceneEntityManager.h  
StructureMutationSystemSerialNumber uint64 The value of this manager's SystemSerialNumber the last time any entities were allocated, freed, or mutated in some way (this does not include component values being written to) EntitySystem/MovieSceneEntityManager.h  
SystemSerialNumber uint64 System serial number incremented for every run of any system EntitySystem/MovieSceneEntityManager.h  
ThreadingModel EEntityThreadingModel   EntitySystem/MovieSceneEntityManager.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

void AccumulateMask ( const FEntityComponentFilter& InFilter,
FComponentMask& OutMask
) const

 Accumulate a mask from all entity types that match the specified filter EntitySystem/MovieSceneEntityManager.h  

void AddChild ( FMovieSceneEntityID ParentID,
FMovieSceneEntityID ChildID
)

 Set up an entity to be a child of another. EntitySystem/MovieSceneEntityManager.h  

void AddComponent ( FMovieSceneEntityID EntityID,
FComponentTypeID ComponentTypeID,
EEntityRecursion Recursion
)

   EntitySystem/MovieSceneEntityManager.h  

void AddComponent ( FMovieSceneEntityID EntityID,
TComponentTypeID< T > ComponentTypeID,
ValueType&& InValue
)

 Add the specified component value to an entity EntitySystem/MovieSceneEntityManager.h  

void AddComponent ( FMovieSceneEntityID EntityID,
FComponentTypeID ComponentTypeID
)

 Add the specified component type to an entity. The component value will be default-initialized. EntitySystem/MovieSceneEntityManager.h  

void AddComponents ( FMovieSceneEntityID EntityID,
const FComponentMask& EntityComponentMask
)

 Add the specified components to an entity. EntitySystem/MovieSceneEntityManager.h  

void AddComponents ( FMovieSceneEntityID EntityID,
const FComponentMask& EntityComponentMask,
EEntityRecursion Recursion
)

   EntitySystem/MovieSceneEntityManager.h  
Run through all entities in this entity manager, ensuring that all mutual components exist EntitySystem/MovieSceneEntityManager.h  

void AddMutualComponents ( const FEntityComponentFilter& InFilter
)

 Run through all entities in this entity manager, ensuring that all mutual components exist for any component types that match the specified filter EntitySystem/MovieSceneEntityManager.h  

void AddReferencedObjects ( FReferenceCollector& ReferenceCollector
)

 Explicitly add referenced objects from an external source. EntitySystem/MovieSceneEntityManager.h  

FEntityDataLocation AllocateContiguousEntities ( const FComponentMask& EntityComponentMask,
int32* InOutNum
)

 Attempt to allocate a number of entities of the same type contiguously in memory EntitySystem/MovieSceneEntityManager.h  
Allocate a new entity with no components EntitySystem/MovieSceneEntityManager.h  

FEntityInfo AllocateEntity ( const FComponentMask& EntityComponentMask
)

 Allocate a single entity with the specified components EntitySystem/MovieSceneEntityManager.h  

void ChangeEntityType ( FMovieSceneEntityID InEntity,
const FComponentMask& InNewMask
)

 Changes the components that exist on an entity to a new mask EntitySystem/MovieSceneEntityManager.h  

void CheckCanChangeStructure()

   EntitySystem/MovieSceneEntityManager.h  

void CombineComponents ( FMovieSceneEntityID DestinationEntityID,
FMovieSceneEntityID SourceEntityID,
const FComponentMask* OptionalMask
)

 Combine the components from one entity into another, overwriting any pre-existing component values. EntitySystem/MovieSceneEntityManager.h  

void Compact()

 Goes through all entity data and compacts like-for-like allocations into as few allocations as possible, resulting in the optimal data layout EntitySystem/MovieSceneEntityManager.h  
Compute and return this entity manager's threading model. EntitySystem/MovieSceneEntityManager.h  

bool Contains ( const FEntityComponentFilter& InFilter
) const

 Efficiently test whether this entity manager contains any allocations that match the specified filter EntitySystem/MovieSceneEntityManager.h  

bool ContainsAllComponents ( std::initializer_list< FComponentTypeID > ComponentTypeIDs
) const

 Check whether all of the specified components exist anywhere in this entity manager EntitySystem/MovieSceneEntityManager.h  

bool ContainsAnyComponent ( const FComponentMask& ComponentTypeIDs
) const

 Check whether any entity in this manager has any of the specified components EntitySystem/MovieSceneEntityManager.h  

bool ContainsAnyComponent ( std::initializer_list< FComponentTypeID > ComponentTypeIDs
) const

 Check whether any entity in this manager has any of the specified components EntitySystem/MovieSceneEntityManager.h  

bool ContainsComponent ( FComponentTypeID ComponentTypeID
) const

 Check whether any entity in this manager has the specified component EntitySystem/MovieSceneEntityManager.h  

bool CopyComponent ( FMovieSceneEntityID SrcEntityID,
FMovieSceneEntityID DstEntityID,
FComponentTypeID ComponentTypeID
)

 Copy the specified component type from an entity if it exists. EntitySystem/MovieSceneEntityManager.h  

void CopyComponents ( FMovieSceneEntityID SrcEntityID,
FMovieSceneEntityID DstEntityID,
const FComponentMask& ComponentsToCopy
)

 Copy any and all the specified component types from one entity onto another. EntitySystem/MovieSceneEntityManager.h  

void CountMemory ( FArchive& Ar,
FMovieSceneEntityID EntityID
)

 Run a serialization routine over the specified entity to approximate the memory it is using EntitySystem/MovieSceneEntityManager.h  

int32 DefineInstancedChildInitializer ( TInlineValue< FChildEntityInitializer >&& InInitializer
)

 Defines a new child initializer that applies only to entities factoried within this entity manager EntitySystem/MovieSceneEntityManager.h  

void Destroy()

 Destroy this entity manager and all the entities and components contained within it, resetting it back to its default state EntitySystem/MovieSceneEntityManager.h  

void DestroyInstancedChildInitializer ( int32 Index
)

 Destroy a previously registered instanced child initializer using its index EntitySystem/MovieSceneEntityManager.h  

FMovieSceneEntityID DuplicateEntity ( FMovieSceneEntityID InOther
)

 Duplicate an entity, by creating an exact copy with a new ID EntitySystem/MovieSceneEntityManager.h  

void EnterIteration()

 Efficiently test whether this entity manager contains any allocations that match the specified filter EntitySystem/MovieSceneEntityManager.h  

void ExitIteration()

   EntitySystem/MovieSceneEntityManager.h  

void FilterComponents ( FMovieSceneEntityID EntityID,
const FComponentMask& EntitiesToKeep
)

 Remove all but the specified components from an entity. EntitySystem/MovieSceneEntityManager.h  

int32 FreeEntities ( const FEntityComponentFilter& Filter,
TSet< FMovieSceneEntityID >* OutFreedEntities
)

 Free all entities that match the specified filter EntitySystem/MovieSceneEntityManager.h  

int32 FreeEntities ( const FFreeEntityOperation& Operation,
TSet< FMovieSceneEntityID >* OutFreedEntities
)

 Free all entities defined by the specified operation EntitySystem/MovieSceneEntityManager.h  

void FreeEntity ( FMovieSceneEntityID EntityID
)

 Free an entity and relinquish its entity ID EntitySystem/MovieSceneEntityManager.h  

const FComponentMask & GetAccumulatedMask()

 Retrieve an up-to-date accumulation of all components present on entities in this manager EntitySystem/MovieSceneEntityManager.h  

void GetChildren_ParentFirst ( FMovieSceneEntityID ParentID,
TArray< FMovieSceneEntityID >& OutChildren
) const

 Retrieve all children, grandchildren etc of the specified entity using a parent first traversal EntitySystem/MovieSceneEntityManager.h  

FComponentRegistry * GetComponents()

   EntitySystem/MovieSceneEntityManager.h  

ENamedThreads::Type GetDispatchThread()

   EntitySystem/MovieSceneEntityManager.h  

FEntityInfo GetEntity ( FMovieSceneEntityID EntityID
) const

 Retrieve an entity's allocation and component offset from its ID EntitySystem/MovieSceneEntityManager.h  

FEntityHandle GetEntityHandle ( FMovieSceneEntityID EntityID
)

 Retrieve a handle to an entity EntitySystem/MovieSceneEntityManager.h  

const FComponentMask & GetEntityType ( FMovieSceneEntityID InEntity
) const

 Retrieve the type mask for this component EntitySystem/MovieSceneEntityManager.h  

ENamedThreads::Type GetGatherThread()

   EntitySystem/MovieSceneEntityManager.h  
Retrieve the entity filter that should be used for any entity iteration. EntitySystem/MovieSceneEntityManager.h  

uint32 GetHandleGeneration()

   EntitySystem/MovieSceneEntityManager.h  

void GetImmediateChildren ( FMovieSceneEntityID ParentID,
TArray< FMovieSceneEntityID >& OutChildren
) const

 Retrieve the immediate children of the specified entity EntitySystem/MovieSceneEntityManager.h  

uint64 GetSystemSerial ()

 Get the current serial number for any system ovserving this entity manager. EntitySystem/MovieSceneEntityManager.h  

EEntityThreadingModel GetThreadingModel()

 Get this entitiy manager's current threading model based on the last time UpdateThreadingModel was called. EntitySystem/MovieSceneEntityManager.h  

bool HasComponent ( FMovieSceneEntityID EntityID,
FComponentTypeID ComponentTypeID
) const

 Check whether the specified component has a component of the specified type EntitySystem/MovieSceneEntityManager.h  

bool HasStructureChangedSince ( uint64 CachedSerial
) const

 Check whether the structure of this entity manager has changed at all since the specified serial number EntitySystem/MovieSceneEntityManager.h  

void IncrementSystemSerial ( uint64 IncAmount
)

 Increment the current serial number for systems observing this manager. EntitySystem/MovieSceneEntityManager.h  

void InitializeChildAllocation ( const FComponentMask& ParentType,
const FComponentMask& ChildType,
const FEntityAllocation* ParentAllocation,
TArrayView< const int32 > ParentAllocationOffsets,
const FEntityRange& InChildEntityRange
)

 Runs all initializers for the specified parent/child allocation EntitySystem/MovieSceneEntityManager.h  

bool IsAllocated ( FMovieSceneEntityID EntityID
) const

 Check whether an entity is allocated. EntitySystem/MovieSceneEntityManager.h  

bool IsHandleValid ( FEntityHandle EntityID
) const

 Check whether the specified entity handle is still valid EntitySystem/MovieSceneEntityManager.h  

bool IsLockedDown()

   EntitySystem/MovieSceneEntityManager.h  

FEntityAllocationIteratorProxy Iterate ( const FEntityComponentFilter* InFilter
) const

 Iterate through all the allocations that match the specified component filter EntitySystem/MovieSceneEntityManager.h  

void IterateChildren_ParentFirst ( FMovieSceneEntityID ParentID,
IteratorType&& Iterator
) const

 Iterate all children, grandchildren etc of the specified entity using a parent first traversal EntitySystem/MovieSceneEntityManager.h  

void IterateImmediateChildren ( FMovieSceneEntityID ParentID,
IteratorType&& Iterator
) const

 Itereate the immediate children of the specified entity EntitySystem/MovieSceneEntityManager.h  

void LockDown()

   EntitySystem/MovieSceneEntityManager.h  

void MimicStructureChanged()

 Called in order to mimic the entity structure changing, even if it has not EntitySystem/MovieSceneEntityManager.h  
Modify the entity filter that should be used for any entity iteration. EntitySystem/MovieSceneEntityManager.h  

int32 MutateAll ( const FEntityComponentFilter& Filter,
const IMovieSceneEntityMutation& Mutation,
EMutuallyInclusiveComponentType MutualTypes
)

 Efficiently mutate all entities that match a filter. EntitySystem/MovieSceneEntityManager.h  
Efficiently mutate all entities that match a filter. EntitySystem/MovieSceneEntityManager.h  

void OverwriteEntityWithDuplicate ( FMovieSceneEntityID& InOutEntity,
FMovieSceneEntityID InEntityToDuplicate
)

 Duplicate an entity over the top of an existing entity ID EntitySystem/MovieSceneEntityManager.h  

TComponentLock< TReadOptional< T > > ReadComponent ( FMovieSceneEntityID Entity,
TComponentTypeID< T > ComponentTypeID
) const

 Attempt to read a component from an entity. EntitySystem/MovieSceneEntityManager.h  

T ReadComponentChecked ( FMovieSceneEntityID Entity,
TComponentTypeID< T > ComponentTypeID
) const

 Read a component value from an entity that is known to exist. EntitySystem/MovieSceneEntityManager.h  

void ReleaseLockDown()

   EntitySystem/MovieSceneEntityManager.h  

void RemoveComponent ( FMovieSceneEntityID EntityID,
FComponentTypeID ComponentTypeID
)

 Remove the specified component type from an entity if it exists. EntitySystem/MovieSceneEntityManager.h  

void RemoveComponent ( FMovieSceneEntityID EntityID,
FComponentTypeID ComponentTypeID,
EEntityRecursion Recursion
)

   EntitySystem/MovieSceneEntityManager.h  

void RemoveComponents ( FMovieSceneEntityID EntityID,
const FComponentMask& ComponentsToRemove
)

 Remove the specified components from an entity, if they exist. EntitySystem/MovieSceneEntityManager.h  

void RemoveComponents ( FMovieSceneEntityID EntityID,
const FComponentMask& ComponentsToRemove,
EEntityRecursion Recursion
)

   EntitySystem/MovieSceneEntityManager.h  

void ReplaceEntityID ( FMovieSceneEntityID& InOutEntity,
FMovieSceneEntityID EntityToDiscard
)

 Replace an entity ID with the components from another, discarding the provided entity ID in the process EntitySystem/MovieSceneEntityManager.h  

void SetComponentRegistry ( FComponentRegistry* InComponents
)

   EntitySystem/MovieSceneEntityManager.h  

void SetDebugName ( FString&& InNewDebugName
)

 Set a debug name for this entity manager EntitySystem/MovieSceneEntityManager.h  

void SetDispatchThread ( ENamedThreads::Type InDispatchThread
)

   EntitySystem/MovieSceneEntityManager.h  

void SetGatherThread ( ENamedThreads::Type InGatherThread
)

   EntitySystem/MovieSceneEntityManager.h  

void TouchEntity ( FMovieSceneEntityID EntityID
)

 Touch the specified entity, cause the allocation and component serial numbers to be incremented. EntitySystem/MovieSceneEntityManager.h  

void UpdateThreadingModel()

 Compute and store the current threading model. EntitySystem/MovieSceneEntityManager.h  
Attempt to write to an entity's component. EntitySystem/MovieSceneEntityManager.h  

void WriteComponentChecked ( FMovieSceneEntityID Entity,
TComponentTypeID< T > ComponentTypeID,
ValueType&& Value
)

 Write a component value that is known to exist to an entity. EntitySystem/MovieSceneEntityManager.h  

Static

Name Remarks Include Path Unreal Specifiers

static IComponentTypeHandler * FindComponentTypeHandler ( const FGuid& ComponentGuid
)

 Find a component type hander from its registered GUID EntitySystem/MovieSceneEntityManager.h  

Operators

Name Remarks Include Path Unreal Specifiers

void operator= ( const FEntityManager&
)

   EntitySystem/MovieSceneEntityManager.h  
  EntitySystem/MovieSceneEntityManager.h  

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