regionchange

#!/usr/bin/env perl

use strict;
use warnings;

unless(@ARGV == 3){
  die "Usage: regionchange <elem file> <points file> <new region #>\n";
}

my $tetfile   = $ARGV[0];
my $ptsfile   = $ARGV[1];
my $newregion = $ARGV[2];

my %elemtypes;

$elemtypes{'Tt'} = 4;
$elemtypes{'Hx'} = 8;

# First get list of points
open(PTS, "<" . $ptsfile) || die "Failed to open points file $ptsfile for read: $!\n";
chomp(my @pts = <PTS>);
close(PTS) || die "Failed to close points file $ptsfile after read: $!\n";

# convert to a hash for speed
my %ptshash;

foreach my $point (@pts){
  $ptshash{$point} = 1;
}

undef @pts;

# Read in elems file
open(ELEMS, "<" . $tetfile) || die "Failed to open elems file $tetfile for read: $!\n";
chomp(my @elems = <ELEMS>);
close(ELEMS) || die "Failed to close elems file $tetfile after read: $!\n";

# re-print header
print shift(@elems) . "\n";

# start processing
foreach my $line (@elems){
  my @tmp = split(/\s+/, $line);
  my $elemtype = shift(@tmp);
  my $elempts;
  if(defined($elemtypes{$elemtype})){
      $elempts = $elemtypes{$elemtype}
  }else{
      die "Failed to find elem type or definition of elem type in .elem file: ".$line."\n";
  }

  die "Wrong number of points in this line of $tetfile: $line -- expected $elempts points.\n" unless (@tmp == $elempts + 1);

  my @found;
  my $foundcount = 0;

  print $elemtype . " ";

  for(my $point = 0; $point < $elempts; $point++){
#    @found = grep(/^$tmp[$point]$/, @pts);
#    if(@found == 1){
    if(defined($ptshash{$tmp[$point]})){
      $foundcount++;
    }
    print $tmp[$point] . " ";
  }
  if($foundcount == $elempts){
#    print STDERR "Found elem -- changing region to $newregion.\n";
    print $newregion . "\n";
  }else{
    print $tmp[$elempts] . "\n";
  }
}