|| :@include: lib/math.nv

||	:entity.slab.id: 1
	:entity.slab.free: (1 2 3 4 5)
	:entity.slab.pool:
		. 1 0 0 0
		. 2 0 0 0
		. 3 0 0 0
		. 4 0 0 0
		. 5 0 0 0

|:: create entity at $x $y|
	:entity.slab.x: $x
	:entity.slab.y: $y
	:: allocate entity

|:: allocate entity
		:entity.slab.free: $ptr
		:entity.slab.id: $id
		:entity.slab.x: $x
		:entity.slab.y: $y
		:entity.slab.pool: $ptr $oldId $oldX $oldY|
	:entity.slab.pool: $ptr $id $x $y
	:: restore entity pool
	:: next entity id from $id

|:: allocate entity?
		:entity.slab.free: $ptr?
		:entity.slab.pool: $0 $1 $2 $3|
	:entity.slab.pool.retained: $0 $1 $2 $3

|:: allocate entity
		:entity.slab.x: $0
		:entity.slab.y: $1|
	:failed: create entity at $0 $1
	:: entity allocator out of space

|:: restore entity pool? :entity.slab.pool.retained: $0 $1 $2 $3|
	:entity.slab.pool: $0 $1 $2 $3

|:: restore entity pool|

|:: free entity $ptr|
	:entity.slab.free: $ptr

|:: next entity id from $id|
	:@math: add $id 1
	:: set entity id

|:: set entity id :@math: $id|
	:entity.slab.id: $id

|| :: 
	. create entity at 10 20
	. create entity at 45 30
	. create entity at 50 12
	. create entity at 23 43
	. create entity at 49 87
	. free entity 3
	. free entity 5
	. create entity at 31 33