#  Copyright (c) 1997-2015
#  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.
#-------------------------------------------------------------------------------


package Postscript;

# a postscript file viewer, e.g. ghostscript
custom $viewer;

CONFIGURE_OPT {
   find_program($viewer, qw( gv evince kghostview ggv okular ghostview ), { prompt => "a PostScript viewer program" });
}

# @topic custom
# All numeric constants defined here are in postscript points (1/72")

# height of DIN A4 sheet
custom $Hpaper=841;

# width of DIN A4 sheet
custom $Wpaper=595;

# vertical margin
custom $Hmargin=50;

# horizontal margin
custom $Wmargin=30;

# text labels
custom $fontname="Times-Roman";

# text labels
custom $fontsize=10;

# for circles representing single geometric points
custom $point_radius=4;

# normal line width
custom $line_width=1;

# spacing between points (lines) and labels
custom $text_spacing=3;

use Postscript;

# @category Visualization
# Create a PostScript (tm) drawing and show it with your favorite viewer.
label postscript

###########################################################################################
#
#  Basic class implementing the required back-end interface.
#

package Postscript::Viewer;
use BackgroundViewer;

use Polymake::Struct [ '@ISA' => 'Background::Viewer' ];

sub file_suffix { ".ps" }

sub new {
   unless (defined $viewer) {
      die <<'.';
no Postscript viewer configured: please specify the output File option
or call  reconfigure("common::postscript.rules");
.
   }
   my $self=&_new;
   $self->graphics=new Postscript::File;
   $self;
}

sub command {
   my ($self, $filename)=@_;
   "$viewer $filename";
}

sub new_drawing {
   my $self=shift;
   $self->graphics->new_page(@_);
   $self;
}

sub current_page {
   shift->graphics->pages->[-1];
}

global_method postscript.geometry: draw(Visual::PointSet, @) {
   my ($self, $P)=@_;
   $self->current_page->addPointSet(new Postscript::PointSet($P));
}

global_method postscript.geometry: draw(Visual::Polygon, @) {
   my ($self, $P)=@_;
   $self->current_page->addPointSet(new Postscript::Polygon($P));
}

global_method postscript.geometry: draw(Visual::Polygons, @) {
   my ($self, $P)=@_;
   $self->current_page->addPointSet(new Postscript::Polygons($P));
}


###########################################################################################
#
#  Writes a PS file without rendering
#

package Postscript::File::Writer;
import Visual::FileWriter(multiple => 1);

###########################################################################################

package application;

# @category Visualization
# Create a Postscript (tm) drawing with the given visual objects.
#
# @param Visual::Object vis_obj ... objects to draw
#
# @option String File "filename" or "AUTO"
#  Store the drawing in a file without starting the viewer.
#  The ''.ps'' suffix is automatically added to the file name.
#
#  Specify //AUTO// if you want the filename be automatically derived
#  from the drawing title.
#
#  You can also use any expression allowed for the ''open'' function,
#  including "-" for terminal output, "&HANDLE" for an already opened file handle,
#  or "| program" for a pipe.

user_function postscript(Visual::Object+, { File => undef }) {
   visualize_explicit(@_, "Postscript");
}


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