Struct TrackableChanges<T>

Holds arrays of changes (added, updated, and removed) to trackables. This is typically used by subsystems to report changes each frame.

Namespace: UnityEngine.XR.ARSubsystems

Syntax

public struct TrackableChanges<T> : IDisposable where T : struct, ITrackable

Type Parameters

Name	Description
T	The ITrackable that can be added and updated.

Constructors

TrackableChanges(Int32, Int32, Int32, Allocator)

Constructs a TrackableChanges<T> from the number of added, updated, and removed trackables. This creates the NativeArrays added, updated, and removed and should be disposed by calling Dispose() on this object.

Declaration

public TrackableChanges(int addedCount, int updatedCount, int removedCount, Allocator allocator)

Parameters

Type	Name	Description
Int32	addedCount	The number of added trackables.
Int32	updatedCount	The number of updated trackables.
Int32	removedCount	The number of removed trackables.
Allocator	allocator	An allocator to use for each of added, updated, and removed arrays.

TrackableChanges(Int32, Int32, Int32, Allocator, T)

Constructor which creates all three arrays and fills the added and updated arrays with repeated copies of defaultValue.

Declaration

public TrackableChanges(int addedCount, int updatedCount, int removedCount, Allocator allocator, T defaultValue)

Parameters

Type	Name	Description
Int32	addedCount	The number of added trackables.
Int32	updatedCount	The number of updated trackables.
Int32	removedCount	The number of removed trackables.
Allocator	allocator	The allocator to use for each of added, updated, and removed arrays.
T	defaultValue	The value with which to fill the added and updated arrays.

TrackableChanges(Void*, Int32, Void*, Int32, Void*, Int32, T, Int32, Allocator)

Constructs a TrackableChanges<T> from native memory.

Declaration

public TrackableChanges(void *addedPtr, int addedCount, void *updatedPtr, int updatedCount, void *removedPtr, int removedCount, T defaultT, int stride, Allocator allocator)

Parameters

Type	Name	Description
Void*	addedPtr	A pointer to a block of memory continaing addedCount elements each of size stride.
Int32	addedCount	The number of added elements.
Void*	updatedPtr	A pointer to a block of memory continaing updatedCount elements each of size stride.
Int32	updatedCount	The number of updated elements.
Void*	removedPtr	A pointer to a block of memory containing removedCount TrackableIds.
Int32	removedCount	The number of removed elements.
T	defaultT	A default T which should be used to fill the added and updated arrays before copying data from addedPtr and updatedPtr, respectively.
Int32	stride	The number of bytes for each element in the addedPtr and updatedPtr arrays.
Allocator	allocator	An allocator to use when creating the added, updated, and removed arrays.

Remarks

Because native code may be using an older version of T, this constructor first fills the added and updated arrays with copies of defaultT before copying the data from the addedPtr and updatedPtr pointers. This ensures that the addition of new fields to T will have appropriate default values.

Properties

added

An array of added trackables.

Declaration

public readonly NativeArray<T> added { get; }

Property Value

Type	Description
NativeArray<T>

isCreated

Whether the NativeArrays have been created.

Declaration

public bool isCreated { readonly get; }

Property Value

Type	Description
Boolean

removed

An array of TrackableIds that have been removed.

Declaration

public readonly NativeArray<TrackableId> removed { get; }

Property Value

Type	Description
NativeArray<TrackableId>

updated

An array of updated trackables.

Declaration

public readonly NativeArray<T> updated { get; }

Property Value

Type	Description
NativeArray<T>

Methods

CopyFrom(NativeArray<T>, NativeArray<T>, NativeArray<TrackableId>, Allocator)

Creates a new TrackableChanges<T> from existing NativeArrays.

Declaration

public static TrackableChanges<T> CopyFrom(NativeArray<T> added, NativeArray<T> updated, NativeArray<TrackableId> removed, Allocator allocator)

Parameters

Type	Name	Description
NativeArray<T>	added	An array of added elements.
NativeArray<T>	updated	An array of updated elements.
NativeArray<TrackableId>	removed	An array of removed elements.
Allocator	allocator	The allocator to use for each of the added, updated, and removed arrays.

Returns

Type	Description
TrackableChanges<T>	a new TrackableChanges<T> from existing NativeArrays. The caller must Dispose() the returned TrackableChanges<T> to avoid memory leaks.

Dispose()

Disposes the added, updated, and removed arrays. Safe to call on a default-constructed TrackableChanges<T>.

Declaration

public void Dispose()