#!/usr/bin/perl

# Scan files for -0.0 in normals.
# Replace the -0.0 with 0.0.

foreach $stl (<*/*.stl>) {
  open(INPUT, $stl) || die "$stl: $!";
  $hdr = <INPUT>;
  die "$stl: STL not ASCII" unless $hdr =~ /^solid /;

  $new = "$stl.new";
# if (-f $new) {
#   warn "$stl.new exists\n";
#   next;
# }
  open(OUTPUT, ">$new") || die "$new: $!";
  print OUTPUT $hdr;

  while (<INPUT>) {
    s/-0[.]0 /0.0 /g;
    s/-0[.]0$/0.0/g;
    print OUTPUT $_;
  }

  # Now, if $new is identical to $stl, delete it.
  close(OUTPUT);
  $s1 = -s $stl;
  $s2 = -s $new;
  next unless $s1 == $s2;
  warn "$stl is the same as $new\n" if $s1 == $s2;
  system("rm $new");
}