TCPDFBarcode::barcode_msi PHP Method

    protected function barcode_msi($code, $checksum = false)
    {
        $chr['0'] = '100100100100';
        $chr['1'] = '100100100110';
        $chr['2'] = '100100110100';
        $chr['3'] = '100100110110';
        $chr['4'] = '100110100100';
        $chr['5'] = '100110100110';
        $chr['6'] = '100110110100';
        $chr['7'] = '100110110110';
        $chr['8'] = '110100100100';
        $chr['9'] = '110100100110';
        $chr['A'] = '110100110100';
        $chr['B'] = '110100110110';
        $chr['C'] = '110110100100';
        $chr['D'] = '110110100110';
        $chr['E'] = '110110110100';
        $chr['F'] = '110110110110';
        if ($checksum) {
            // add checksum
            $clen = strlen($code);
            $p = 2;
            $check = 0;
            for ($i = $clen - 1; $i >= 0; --$i) {
                $check += hexdec($code[$i]) * $p;
                ++$p;
                if ($p > 7) {
                    $p = 2;
                }
            }
            $check %= 11;
            if ($check > 0) {
                $check = 11 - $check;
            }
            $code .= $check;
        }
        $seq = '110';
        // left guard
        $clen = strlen($code);
        for ($i = 0; $i < $clen; ++$i) {
            $digit = $code[$i];
            if (!isset($chr[$digit])) {
                // invalid character
                return false;
            }
            $seq .= $chr[$digit];
        }
        $seq .= '1001';
        // right guard
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
        return $this->binseq_to_array($seq, $bararray);
    }