#!/usr/bin/perl

$|=1;

use Term::ReadKey;

($w, $h) = GetTerminalSize;

ReadMode 3;

$x1 = 3; $y1 = 3;
$dx = 0.05; $dy = 0.05;

print "\e[H";
print "\n" x ($h-2); print " " x ($w/2-5);
print "##########\r";
$x=($w/2-5);


while (1) {

  $key = ReadKey -1;

  if ($key eq "d") {$x++; if ($x>($w-10)) {$x=($w-10)};
                    print "\e[H"; print "\n" x ($h-2); print "\r"; print "\e[K"; print " " x $x; print "##########\r";}
  if ($key eq "a") {$x--; if ($x<0) {$x=0};
                    print "\e[H"; print "\n" x ($h-2); print "\r"; print "\e[K"; print " " x $x; print "##########\r"; }

print "\e[H";
for (0..($h-3)) {print " " x ($w); print "\n"}
print "\e[H\n\n\n"; print "\n" x $y1; print "\r\e[K"; print " " x $x1; print "O\r";

$x1 = ($x1 + $dx);
$y1 = ($y1 + $dy);

if ( ($y1)>=($h-5) || $y1<=0) {$dy *= -1}
if ( ($x1)>=($w-1) || $x1<=0) {$dx *= -1}

}

ReadMode 0;