#!/usr/bin/perl
# Convert a cip file back to a regular image

use strict;
use integer;
use IO::File;
use GD;

die "Usage: $0 <in file> <out file> <width> <height>\n"
    unless @ARGV == 4;

my ($file, $out, $width, $height) = @ARGV;

my $file = new IO::File $file;
my $data = <$file>;
$file->close;

# Convert back to bits
my @hex_data = split(//, $data);
my @data;
for (my $i = 0; $i < @hex_data; $i+=2)
{
    push @data, hex($hex_data[$i+1])%4;
    push @data, hex($hex_data[$i+1])/4;
    push @data, hex($hex_data[$i])%4;
    push @data, hex($hex_data[$i])/4;
}

my $img = new GD::Image($width, $height);
my @colors = ($img->colorAllocate(255, 255, 255),
	      $img->colorAllocate(170, 170, 170),
	      $img->colorAllocate(85, 85, 85),
	      $img->colorAllocate(0, 0, 0));
my $x;
my $y;
foreach (@data)
{
    $img->setPixel($x, $y, $colors[$_]);
    $x++;
    if ($x == $width)
    {
	$y++;
	$x = 0;
    }
}

$out =~ /\.([^\.]+)$/;
my $out = new IO::File ">$out";
eval("print \$out \$img->$1");
$out->close;