<?php
/**************************************************
 *            Kody kreskowe - Code 11             *
 **************************************************
 * Wersja: 1.0                                    *
 * Autor: Jacek Kowalski (http://jacekk.info)     *
 *                                                *
 * Utwór rozprowadzany na licencji                *
 * http://creativecommons.org/licenses/by-nc/2.5/ *
 **************************************************/

if(trim($_GET['kod'], '0123456789-')!='') {
	echo 'Znaki inne niż cyfry i pauza';
	die();
}


function checksum($kod) {
	$chk = array_reverse(str_split($kod));

	foreach($chk as $key => $val) {
		if($val=='-') {
			$val = 10;
		}

		$check += (1+$key)*$val;
	}

	$check = $check%11;

	if($check==10) {
		$check = '-';
	}

	return $kod.$check;
}


$_GET['kod'] = checksum($_GET['kod']);
if(strlen($_GET['kod'])>10) {
	$_GET['kod'] = checksum($_GET['kod']);
}


$code = array(
	'SS' => '1011001',
	'BT' => '0',
	'0' => '1010111',
	'1' => '1101011',
	'2' => '1001011',
	'3' => '1100101',
	'4' => '1011011',
	'5' => '1101101',
	'6' => '1001101',
	'7' => '1010011',
	'8' => '1101001',
	'9' => '1110101',
	'-' => '1011101'
);


function gen_binary($kod) {
	global $code, $kol;

	$kod = str_split($kod);
	$ret = '';
	foreach($kod as $key => $val) {
		$ret .= $code[$val].$code['BT'];
	}

	return $ret;
}
function print_code($kod, $img) {
	global $b, $w, $now;

	$kod = str_split($kod);
	foreach($kod as $val) {
		if($val==1) {
			imageline($img, $now, 0, $now, 40, $b);
			$now++;
		}
		elseif($val==0) {
			$now++;
		}
	}
}

$_GET['kod'] = $code['SS'].$code['BT'].gen_binary($_GET['kod']).$code['SS'];

$i = imagecreate(strlen($_GET['kod']), 40);
$w = imagecolorallocate($i, 255, 255, 255);
$b = imagecolorallocate($i, 0, 0, 0);

print_code($_GET['kod'], $i);

header('Content-type: image/gif');
imagegif($i);
?>