Raster Line txt decoder

raster-decoder.pl

# CC0 Public Domain (唐鳳)
use Imager;
my $img = Imager->new( xsize => 512, ysize => 512, channels=>1 );
my $color = Imager::Color->new( 255, 255, 255 );
my $dir = 0;
die "Usage: $0 input.txt" unless @ARGV;
while (<>) {
    if (/^(\d+),\d+\s*$/) {
        $dir = $1;
        next;
    }
    /(\d+),(\d+),(\d+)/ or next;
    if ($dir == 1) {
        my ($x, $y1, $y2) = ($1, $2, $3);
        $img->line(x1 => $x, x2 => $x, y1 => $y1, y2 => $y2, color => $color);
    }
    else {
        my ($y, $x1, $x2) = ($1, $2, $3);
        $img->line(x1 => $x1, x2 => $x2, y1 => $y, y2 => $y, color => $color);
    }
}
$img->write(file=>'output.png');