666.ngc

o666 sub

o667 if[ #1 EQ 10 ]
 (big circle)
 g91g21f200
 g1x[#3]z[#4]
 g2i[0-[#3]]
 g1x[0-[#3]]z[0-[#4]]

o667 else
 o668 if[ #1 EQ 20 ]
  (rect)
  #<width>=#2
  #<halfwidth>=[#2/2]
  #<height>=#3
  #<halfheight>=[#3/2]
  #<reldepth>=#4
  g91g21f200
  g1x[#<halfwidth>]y[#<halfheight>]z[#<reldepth>]
  g1x[0-[#<width>]]
  g1y[0-[#<height>]]
  g1x[#<width>]
  g1y[#<height>]
  g1x[0-[#<halfwidth>]]y[0-[#<halfheight>]]z[0-[#<reldepth>]]
  (call local diamond)
  #<dmdwidth>=#<halfwidth>
  #<dmdheight>=#<halfheight>
  o30 call [#<dmdwidth>] [#<dmdheight>] [-3]
 o668 endif

o667 endif

o666 endsub

( guess: local subs to this file must be after the filename endsub ^^^ right up there )
o30 sub
 (diamond)
 g91g21f200
 g1x[#1/2]z[#3]
 g1x[0-[#1/2]]y[#2/2]
 g1x[0-[#1/2]]y[0-[#2/2]]
 g1x[#1/2]y[0-[#2/2]]
 g1x[#1/2]y[#2/2]
 g1x[0-[#1/2]]z[0-[#3]]
o30 endsub

M2