#!/usr/bin/perl -w

$width = 320;
$height = 200;

$c0 = 0;
$c1 = 1;

$usage = "$0 input.bmp output.prg";
$bmp = shift || die $usage;
unless ($prg = shift) {
  $prg = $bmp;
  die $usage unless ($prg =~ s/\.bmp$/\.prg/i);
}
shift && die $usage;


open(BMP, $bmp) || die;
binmode(BMP);
while (<BMP>) {
  $bmp .= $_;
}
close(BMP);

$bitmap = substr($bmp, -$width * $height);

foreach $yy (0 .. $height - 1) {
  $y = $height - $yy - 1;
  $line = substr($bitmap, $width * $yy);
  for ($x = 0; $x < $width; $x += 1) {
    $c = ord(substr($line, $x));
    if ($c == $c0) {
      $out[$y] .= "0";
    } elsif ($c == $c1) {
      $out[$y] .= "1";
    } else {
      $out[$y] .= "1";
    }
  }
}

for ($y = 0; $y < $height; $y++) {
  print substr($out[$y], 0, 79) . "\n";
}

for ($y = 0; $y < $height / 8; $y++) {
  print $y . "\n";
  for ($x = 0; $x < $width / 8; $x++) {
    foreach $i (0 .. 7) {
      $line = substr($out[$y*8 + $i], $x*8, 8);
      $charset .= pack("B8", $line);
    }
  }
}


print "Writing " . length($charset) . " bytes, plus 2\n";

open(PRG, ">$prg") || die;
binmode(PRG);
print PRG "\x00\x20";
print PRG $charset;
close(PRG);