/// <summary>
/// Get the mesh data associated with the face with <paramref name="faceId"/>. The <paramref name="faceMesh"/>
/// is reused if it is the correct size, otherwise, it is disposed and reallocated using <paramref name="allocator"/>.
/// </summary>
/// <param name="faceId">The <see cref="TrackableId"/> for a <see cref="XRFace"/>.</param>
/// <param name="allocator">The allocator to use for the returned data if a resize is necessary. Must be <c>Allocator.TempJob</c> or <c>Allocator.Persistent</c>.</param>
/// <param name="faceMesh">The container for the mesh data to either re-use or re-allocate.</param>
/// <exception cref="System.InvalidOperationException">Thrown if <paramref name="allocator"> is <c>Allocator.Temp</c></exception>
/// <exception cref="System.InvalidOperationException">Thrown if <paramref name="allocator"> is <c>Allocator.None</c></exception>
public virtual void GetFaceMesh(TrackableId faceId, Allocator allocator, ref XRFaceMesh faceMesh)
{
if (allocator == Allocator.Temp)
throw new InvalidOperationException("Allocator.Temp is not supported. Use Allocator.TempJob if you wish to use a temporary allocator.");
if (allocator == Allocator.None)
throw new InvalidOperationException("Allocator.None is not a valid allocator.");
m_Provider.GetFaceMesh(faceId, allocator, ref faceMesh);
}
/// <summary>
/// Get the mesh data associated with the face with <paramref name="faceId"/>. The <paramref name="faceMesh"/>
/// should be reused if it is the correct size, otherwise, its arrays should be reallocated with <paramref name="allocator"/>.
/// Use <see cref="XRFaceMesh.Assign(XRFaceMesh)"/> to ensure unused <c>NativeArray</c>s are disposed properly and
/// <see cref="CreateOrResizeNativeArrayIfNecessary"/> to resize individual arrays.
/// </summary>
/// <param name="faceId">The <see cref="TrackableId"/> for a <see cref="XRFace"/>.</param>
/// <param name="allocator">The allocator to use for the returned data if a resize is necessary.</param>
/// <param name="faceMesh">The container for the mesh data to either re-use or re-allocate.</param>
/// <example>
/// <code>
/// var vertices = faceMesh.vertices;
/// CreateOrResizeNativeArrayIfNecessary(numVertices, allocator, ref vertices);
///
/// ...
///
/// faceMesh.Assign(new XRFaceMesh
/// {
/// vertices = vertices,
/// indices = ...
/// });
/// </code>
/// </example>
public virtual void GetFaceMesh(TrackableId faceId, Allocator allocator, ref XRFaceMesh faceMesh)
{
faceMesh.Dispose();
faceMesh = default(XRFaceMesh);
}