#!/usr/bin/tclsh

set outputFile [lindex $argv 0]
set units [lindex $argv 2]
set grid [lindex $argv 1]
puts "output=$outputFile grid=$grid$units"
set gs [open "|gs -sDEVICE=ljet4 -sOutputFile=$outputFile -dNOPAUSE" w]

puts $gs \
"%!PS-Adobe-2.0
% there are some -d switches needed for gs to make this work
% -dGridSize=number
% -dUnits=units (in, mm, pt, pc)

/GridSize $grid def
/Units {$units} def
/Weight {0.1} def

gsave
initclip clippath pathbbox
/PageHeight exch def
/PageWidth exch def
pop pop
grestore

/in { 72 mul } def
/pt { 1 mul } def
/pc { 12 mul } def
/mm { 2.8346 mul } def

/gridDistance GridSize Units def
/nGridsWide PageWidth gridDistance div floor cvi def
/nGridsHigh PageHeight gridDistance div floor cvi def

/d gridDistance def
/dx d 4 div def
/dy d 2 div 60 sin mul def

/hexPath {
  dx dy rlineto
  d 0 rlineto
  dx dy neg rlineto
  dx neg dy neg rlineto
  d neg 0 rlineto
  dx neg dy rlineto
  } def

/toStart {
  PageWidth useWide sub 2 div
  PageHeight useHeight sub 2 div
  moveto
  } def

Weight setlinewidth
toStart
0 1 nGridsHigh {
  pop
  0 1 nGridsWide {
    pop
    hexPath exec stroke
    gridDistance 0 rmoveto
    } for
  useWide neg
  dy 2 mul
    rmoveto
  } for

showpage
quit
"