#pragma once

entityclass(Sort);
// .float(entity,entity) sort_cmp;
classfield(Sort).entity chain, sort_next, sort_prev;

entity Sort_Spawn();

/**
 * Swap two neighbours in a sortlist.
 * @param a FIRST entity
 * @param b entity after a
 */
#define SORT_SWAP(a, b)                                  \
	b.sort_prev = a.sort_prev;                          \
	a.sort_next = b.sort_next;                          \
	if (b.sort_next) b.sort_next.sort_prev = a;          \
	if (a.sort_prev) a.sort_prev.sort_next = b;          \
	a.sort_prev = b;                                    \
	b.sort_next = a