/// <summary>
/// Delink the given prim from this group. The delinked prim is established as
/// an independent SceneObjectGroup.
/// </summary>
/// <remarks>
/// FIXME: This method should not be called directly since it bypasses update locking, allowing a potential race
/// condition. But currently there is no
/// alternative method that does take a lock to delink a single prim.
/// </remarks>
/// <param name="partID"></param>
/// <param name="sendEvents"></param>
/// <returns>The object group of the newly delinked prim.</returns>
public SceneObjectGroup DelinkFromGroup(SceneObjectPart linkPart, bool sendEvents)
{
// m_log.DebugFormat(
// "[SCENE OBJECT GROUP]: Delinking part {0}, {1} from group with root part {2}, {3}",
// linkPart.Name, linkPart.UUID, RootPart.Name, RootPart.UUID);
linkPart.ClearUndoState();
Vector3 worldPos = linkPart.GetWorldPosition();
Quaternion worldRot = linkPart.GetWorldRotation();
// Remove the part from this object
lock (m_parts.SyncRoot)
{
m_parts.Remove(linkPart.UUID);
SceneObjectPart[] parts = m_parts.GetArray();
// Rejigger the linknum's of the remaining SOP's to fill any gap
if (parts.Length == 1 && RootPart != null)
{
// Single prim left
RootPart.LinkNum = 0;
}
else
{
for (int i = 0; i < parts.Length; i++)
{
SceneObjectPart part = parts[i];
if (part.LinkNum > linkPart.LinkNum)
part.LinkNum--;
}
}
}
linkPart.ParentID = 0;
linkPart.LinkNum = 0;
PhysicsActor linkPartPa = linkPart.PhysActor;
// Remove the SOP from the physical scene.
// If the new SOG is physical, it is re-created later.
// (There is a problem here in that we have not yet told the physics
// engine about the delink. Someday, linksets should be made first
// class objects in the physics engine interface).
if (linkPartPa != null)
m_scene.PhysicsScene.RemovePrim(linkPartPa);
// We need to reset the child part's position
// ready for life as a separate object after being a part of another object
/* This commented out code seems to recompute what GetWorldPosition already does.
* Replace with a call to GetWorldPosition (before unlinking)
Quaternion parentRot = m_rootPart.RotationOffset;
Vector3 axPos = linkPart.OffsetPosition;
axPos *= parentRot;
linkPart.OffsetPosition = new Vector3(axPos.X, axPos.Y, axPos.Z);
linkPart.GroupPosition = AbsolutePosition + linkPart.OffsetPosition;
linkPart.OffsetPosition = new Vector3(0, 0, 0);
*/
linkPart.GroupPosition = worldPos;
linkPart.OffsetPosition = Vector3.Zero;
linkPart.RotationOffset = worldRot;
// Create a new SOG to go around this unlinked and unattached SOP
SceneObjectGroup objectGroup = new SceneObjectGroup(linkPart);
m_scene.AddNewSceneObject(objectGroup, true);
if (sendEvents)
linkPart.TriggerScriptChangedEvent(Changed.LINK);
linkPart.Rezzed = RootPart.Rezzed;
// When we delete a group, we currently have to force persist to the database if the object id has changed
// (since delete works by deleting all rows which have a given object id)
objectGroup.HasGroupChangedDueToDelink = true;
return objectGroup;
}