private bool CanUnify()
{
if (_children != null && _children.Any(c => c != null && c.Active))
{
for (int i = 0; i < 4; i++)
{
EdgeType edge = (EdgeType)i;
Quad neighbor = GetNeighbor(edge);
if (neighbor != null)
{
if (!neighbor.Active && neighbor.HasChildren)
{
EdgeType neighborEdge = neighbor.GetEdgeSharedWith(this);
var children = neighbor.GetChildrenSharingEdge(neighborEdge);
if (children.Any(c => c != null && !c.Active && c.HasChildren))
{
return(false); // unable to Unify due to neighbor subdivision
}
}
}
}
}
return(true);
}