[Axe] Face sorting routine

:Lbl SortFaces
:...
:r1→pointer on table of rotated 2-bytes Z of each vertices in the faces
:r2→pointer on faces array
:r3→output area,which contains at least 1 byte for each face
:returns the sorted order in outputArea
:...
:.Z-average of each face
:For(r4,0,{r2-1}-1)
:0→{r4*2+L4→r6}^r
:‾1
:For(4)
:+1→r5
:{{r4*4+r5+r2}*2+r1}^r+{r6}^r→{r6}^r
:r5
:End
:End
:
:.Init sorting
:For(r4,0,{r2-1}-1)
:r4→{r4+r3}
:End
:
:
:.Sort
:While 1
:0→r6
:For(r4,0,4)
:If {{r4+r3}*2+L4}^r<<{{r4+r3+1}*2+L4}^r
:1→r6
:{r4+r3}^r→{r4+r3}^r^r
:End
:End
:End!If r6
:Return