#!perl -w
use Imager;
use strict;

my $im = Imager->new(xsize=>200, ysize=>200);

thick_line($im, 10, 10, 100, 190, 5, color=>'#F00');
thick_line($im, 10, 100, 190, 40, 20, 
	   fill=>{ hatch=>'check2x2', fg=>'#0f0', bg=>'#088' });

$im->write(file=>'thickline.png');

sub thick_line {
  my ($im, $x1, $y1, $x2, $y2, $width, @extras) = @_;

  my $dx = $x2 - $x1;
  my $dy = $y2 - $y1;
  my $d = sqrt($dx * $dx + $dy * $dy);
  my $cos = $dx / $d;
  my $sin = $dy / $d;
  my $wcos = $width * $cos / 2;
  my $wsin = $width * $sin / 2;

  my @pts =
    (
     [ $x1 + $wsin, $y1 - $wcos ],
     [ $x1 - $wsin, $y1 + $wcos ],
     [ $x2 - $wsin, $y2 + $wcos ],
     [ $x2 + $wsin, $y2 - $wcos ],
    );
  $im->polygon(points=>\@pts, @extras)
    or die $im->errstr;
}