#!/usr/bin/perl -w
use strict;
use Tk;

my($o, $s) = (250, 20);
my($pi, $x, $y) = (3.1415926, 0);

my $mw = MainWindow->new;

my $c = $mw->Canvas(-width => 500, 
                   -height => 500,
                   -bg => 'white',
                   )->pack;

# make minimal axis set                   
$c->createLine(50, 250, 450, 250);
$c->createText(10, 250, -fill => 'blue', -text => 'X');
$c->createLine(250, 50, 250, 450);
$c->createText(250, 10, -fill => 'blue', -text => 'Y');

# add some data
for ($x = -(3*$pi); $x <= +(3*$pi); $x += 0.1) {
    $y = sin($x);
    $c->createText( $x*$s+$o, $y*$s+$o, -fill => 'red', -text => ':');
    $y = cos($x);
    $c->createText( $x*$s+$o, $y*$s+$o, -fill => 'green', -text => '|');
}


$mw->Button(
    -text    => "Save Postscript",
    -command => sub {
         $c->update;
         my @capture=();
         my ($x0,$y0,$x1,$y1)=$c->bbox('all');
         @capture=('-x'=>$x0,'-y'=>$y0,-height=>$y1-$y0,-width=>$x1-$x0);
         $c -> postscript(-colormode=>'color',
                               -file=>$0.'.ps',
			       -rotate=>0,
			       @capture);
         print "saved\n";                        
	  } 
   
    )->pack;
 

MainLoop;