#  Copyright (c) 1997-2018
#  Ewgenij Gawrilow, Michael Joswig (Technische Universitaet Berlin, Germany)
#  http://www.polymake.org
#
#  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, or (at your option) any
#  later version: http://www.gnu.org/licenses/gpl.txt.
#
#  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.
#-------------------------------------------------------------------------------

CREDIT tplib
  TPLib: Tropical Polyhedra Library
  Copyright by Xavier Allamigeon
  https://gforge.inria.fr/projects/tplib/

# path to the tplib executable
custom $tplib_compute_halfspaces;

CONFIGURE {
   find_program($tplib_compute_halfspaces, "compute_halfspaces") or return;

   # check the version
   open TPLIB_OUT, "$tplib_compute_halfspaces -help |"
       or die "can't run $tplib_compute_halfspaces: $!";
   local $/;
   my $version=<TPLIB_OUT>;
   close TPLIB_OUT;
   $version =~ /Version of TPLib:\s+([\d\.]+)/ and $version=$1;
   eval("v$version") ge v1.1.1
      or die <<'.';
polymake requires TPLib v1.1.1 or newer;
Please download the current version
and repeat the auto-configuration.
.
}

object TropicalPolytope {

# Tropical double description method.
label tplib

# Allamigeon, Xavier
#   Static analysis of memory manipulations by abstract interpretation,
#   PhD thesis, Ecole Polytechnique, 2009.

rule tplib.half_spaces : HALF_SPACES : POINTS, AMBIENT_DIM {
  my $d=$this->AMBIENT_DIM+1;
  my @points=@{$this->POINTS};
  my $n_points=scalar(@points);

  my $tempname=new Tempfile;
  open TPLIB_FILE, ">$tempname"
    or die "can't create temporary file $tempname: $!";
  for (my $i=0; $i<$n_points; ++$i) {
    my $p=$this->POINTS->[$i];
    my $single_point="$p"; $single_point =~ s/ +/,/g;
    print TPLIB_FILE "[$single_point]\n";
  }
  close TPLIB_FILE;

  my @halfspaces;
  open TPLIB_OUT, "$tplib_compute_halfspaces -min-plus -numerical-data ocaml_big_rat $d < $tempname |"
    or die "can't read TPLib output: $!";
  foreach my $line (<TPLIB_OUT>) {
    my ($apex,$sectors) = ($line =~ /\(\[(.*)\],\[(.*)\]\)/);
    $apex =~ s/,/ /g; $sectors =~ s/,/ /g; $sectors="{$sectors}";
    my $apex_as_vector=new Vector<Rational>($apex);
    my $sectors_as_set=new Set<Int>($sectors);
    push @halfspaces, [$apex_as_vector,$sectors_as_set];
  }
  close TPLIB_OUT;

  $this->HALF_SPACES=\@halfspaces;
}

}

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