#! /bin/awk
# TeX Sudoku Worksheet Generator
# The output is a TeX source file.
#
# Copyright (C) 2005 John D. Ramsdell
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details at
# http://www.gnu.org/copyleft/gpl.html.

BEGIN { n = 10;			# N is the number of pages printed
  print "\\nopagenumbers";
  print "\\font\\tl=cmr17";
  print "\\baselineskip=14pt";
  print "\\newdimen\\sudokuwidth";
  print "\\newdimen\\sudokuheight";
  print "\\sudokuwidth=.7em";
  print "\\sudokuheight=1.4ex";
  print "\\def\\sudokustrut{\\hbox{\\vrule height\\sudokuheight depth0ex width0ex}}";
  for (i = 0; i < n; i++)
    page();
  print "\\end";
}

function page() {
  print "\\sudokustrut\\vskip 2cm";
  print;
  print "\\centerline{\\tl Sudoku Worksheet}\\bigskip\\bigskip";
  print;
  print "\\centerline{\\offinterlineskip";
  table(2);
  print "}";
  print "\\vfil";
  print "\\eject";
}

function table(n, i) {
  if (n <= 0)
    tile();
  else {
    print "\\vbox{\\hrule";
    print "\\halign{\\vrule#\\tabskip=\\sudokuwidth&\\hfil#\\hfil&\\hfil#\\hfil&\\hfil#\\hfil&\\vrule#\\tabskip=0em\\cr";
    for (i = 0; i < 3; i++) {
      print "&\\sudokustrut&\\sudokustrut&\\sudokustrut&\\cr";
      printf("&");
      table(n - 1);
      printf("&");
      table(n - 1);
      printf("&");
      table(n - 1);
      print "&\\cr";
    }
    print "&\\sudokustrut&\\sudokustrut&\\sudokustrut&\\cr";
    print "}\\hrule}\\relax";
  }
}

function tile() {
  print "\\vbox{\\hrule";
  print "\\halign{\\vrule#\\tabskip=\\sudokuwidth&\\hfil#\\hfil&\\hfil#\\hfil&\\hfil#\\hfil&\\vrule#\\tabskip=0em\\cr";
  print "&\\sudokustrut&\\sudokustrut&\\sudokustrut&\\cr";
  print "&1&2&3&\\cr";
  print "&\\sudokustrut&\\sudokustrut&\\sudokustrut&\\cr";
  print "&4&5&6&\\cr";
  print "&\\sudokustrut&\\sudokustrut&\\sudokustrut&\\cr";
  print "&7&8&9&\\cr";
  print "&\\sudokustrut&\\sudokustrut&\\sudokustrut&\\cr";
  print "}\\hrule}\\relax";
}