#!/usr/bin/perl

#
# convert (a subset) of fractint l-systems into
# lsys-lsystems
#
# version 1.0
#

while (<>) {
  chomp;
  my $comment=$1 if s/\s*;+\s*(.*)$//;
  my $o;
  s/"/%/g;
  if (/^\s*(\S+)\s+{\s*$/i) {
    $lsys=$1;
    $lsys=~s/[^A-Za-z_]/_/g;
    $lsys=~s/([_a-z])([A-Z])/$1_@{[lc($2)]}/g;
    $lsys=~s/__/_/g;
    $lsys=~s/^_//;
    $lsys=~s/_$//;
    $s=$lsys{$lsys};
    $lsys{$lsys}++;
    $lsys.=$s;
    $o="ruleset (";
  } elsif (/Angle (\d+)/i) {
    $angle=$1;
  } elsif (/Axiom (\S+)/i) {
    $o="	$lsys(n)	=> attr (delta, 360/$angle) ".mangle($1).", n;";
  } elsif (/^\s*(\S+)\s*=(.*)$/) {
    my($f,$g)=($1,$2);
    $f=~y/a-z/A-Z/;
    $f=~y/FGDM/FfFfFfFf/;
    $o="	$f	=> ".mangle($g).";";
  } elsif(/^\s*}\s*$/i) {
    undef $lsys;
    $o=")";
  }
  print $o,($comment ? "	// $comment" : ""),"\n";
}

sub mangle {
  $_=$_[0];
  s/([a-zA-Z])([a-z])/$1 $2/g;
  y/a-z/A-Z/;
  y/FGDM/FfFfFfFf/;
  s/\/([0-9.]+)/ +($1) /g;
  s/\\([0-9.]+)/ -($1) /g;
  s/\@q\s*i([0-9.]+)/ attr (distance, distance\/0$1^0.5) /ig;
  s/\@i\s*q([0-9.]+)/ attr (distance, distance\/0$1^0.5) /ig;
  s/\@q([0-9.]+)/ attr (distance, distance*0$1^0.5) /ig;
  s/\@i([0-9.]+)/ attr (distance, distance\/0$1) /ig;
  s/\@([0-9.]+)/ attr (distance, distance*0$1) /ig;
  s/c([0-9]+)//ig; # ignore all
  s/<([0-9]+)//g; # kinds of
  s/>([0-9]+)//g; # colours
  s/  / /g;
  s/^ //g;
  s/ $//g;
  $_;
}