#!/usr/bin/perl
      
   use strict;

   my @CHARS = split('', ' .,-+*$&#@');

   my ($XMIN, $XMAX) = qw(0 1);
   my ($YMIN, $YMAX) = qw(0 1);
   my ($ROWS, $COLS) = qw(40 80);
   my $POINTS        = 8;
   my $REPEAT        = 0;

   my $xfact = ($XMAX - $XMIN) / $COLS;
   my $yfact = ($YMAX - $YMIN) / $ROWS;

   my (@screen, @xs, @ys);

   # Pick some random points
   for (0..$POINTS-1) {
      my ($xrand, $yrand) = (rand(), rand());
      for my $xoffset (-1..1) {
         for my $yoffset (-1..1) {
            push (@xs, $xrand + $xoffset);
            push (@ys, $yrand + $yoffset);
         }
      }
   }

   # Calculate screen
   for my $yi (0..$ROWS-1) {
      my $y = $YMIN + $yi * $yfact;
      for my $xi (0..$COLS-1) {
         my $x = $XMIN + $xi * $xfact;
         my ($best, $good) = closest($x, $y, \@xs, \@ys);
         $screen[$xi][$yi] = $CHARS[int(10 * ($best / $good))];
      }
   }

   # Print screen
   for (0..$REPEAT) {
      for my $yi (0..$ROWS-1) {
         for my $xi (0..$COLS-1) {
            print "$screen[$xi][$yi]";
         }
         print "\n";
      }
   }

#-----------------------------------------------------------
sub closest {

   my ($x, $y, $xs, $ys) = @_;
   my ($dist, $best, $good);

   for (my $i = 0; $i < @$xs; $i++) {
      $dist = sqrt(($x - $xs->[$i])**2 + ($y - $ys->[$i])**2);

      if    ($i == 0 || $dist < $best) { ($good, $best) = ($best, $dist); }
      elsif ($i == 1 || $dist < $good) { $good = $dist; }
   }

   return ($best, $good);
}