QuadTreeNode <T> DeepChild(EQuadrant quad)
{
QuadTreeNode <T> current = this;
while (!current.IsLeaf())
{
current = current.Child(quad);
}
return(current);
}
QuadTreeNode <T> Neighbour(ESide direction, EQuadrant corner)
{
QuadTreeNode <T> quadnode = Neighbour(direction);
if (quadnode == null)
{
return(null);
}
while (!quadnode.IsLeaf())
{
quadnode = quadnode.Child(Reflect(direction, corner));
}
return(quadnode);
}
EQuadrant Quadrant()
{
if (_parent == null)
{
throw new InvalidOperationException("The root node's quadrant isn't defined.");
}
if (_parent.Child(EQuadrant.NORTHWEST) == this)
{
return(EQuadrant.NORTHWEST);
}
else if (_parent.Child(EQuadrant.SOUTHWEST) == this)
{
return(EQuadrant.SOUTHWEST);
}
else if (_parent.Child(EQuadrant.NORTHEAST) == this)
{
return(EQuadrant.NORTHEAST);
}
else
{
return(EQuadrant.SOUTHEAST);
}
}
QuadTreeNode <T> Neighbour(ESide direction)
{
QuadTreeNode <T> neighbor = null;
// Ascent the tree up to a common ancestor.
if (_parent != null && Adjacent(direction, Quadrant()))
{
neighbor = _parent.Neighbour(direction);
}
else
{
neighbor = _parent;
}
// Backtrack mirroring the ascending moves.
if (neighbor != null && !neighbor.IsLeaf())
{
return(neighbor.Child(Reflect(direction, Quadrant())));
}
else
{
return(neighbor);
}
}
