The tree node data structure. Nodes points to the actual memory allocated for the internal nodes, but is shifted such that Nodes[Sp.MaxPart] gives the first allocated node. Note that node numbers less than Sp.MaxPart are the leaf nodes that contain a single particle, and node numbers >= MaxPart+MaxNodes are "pseudo
particles" that hang off the toplevel leaf nodes belonging to other tasks. These are not represented by this structure. Instead, the tree traversal for these are saved in the Nextnode, Prevnode and Father arrays, indexed with the node number in the case of real particles and by nodenumber-MaxNodes for pseudo particles.

Definition at line 47 of file tree.h.