TCPDFBarcode::barcode_eanupc PHP Method

    protected function barcode_eanupc($code, $len = 13)
    {
        $upce = false;
        if ($len == 6) {
            $len = 12;
            // UPC-A
            $upce = true;
            // UPC-E mode
        }
        $data_len = $len - 1;
        //Padding
        $code = str_pad($code, $data_len, '0', STR_PAD_LEFT);
        $code_len = strlen($code);
        // calculate check digit
        $sum_a = 0;
        for ($i = 1; $i < $data_len; $i += 2) {
            $sum_a += $code[$i];
        }
        if ($len > 12) {
            $sum_a *= 3;
        }
        $sum_b = 0;
        for ($i = 0; $i < $data_len; $i += 2) {
            $sum_b += $code[$i];
        }
        if ($len < 13) {
            $sum_b *= 3;
        }
        $r = ($sum_a + $sum_b) % 10;
        if ($r > 0) {
            $r = 10 - $r;
        }
        if ($code_len == $data_len) {
            // add check digit
            $code .= $r;
        } elseif ($r !== intval($code[$data_len])) {
            // wrong checkdigit
            return false;
        }
        if ($len == 12) {
            // UPC-A
            $code = '0' . $code;
            ++$len;
        }
        if ($upce) {
            // convert UPC-A to UPC-E
            $tmp = substr($code, 4, 3);
            if ($tmp == '000' or $tmp == '100' or $tmp == '200') {
                // manufacturer code ends in 000, 100, or 200
                $upce_code = substr($code, 2, 2) . substr($code, 9, 3) . substr($code, 4, 1);
            } else {
                $tmp = substr($code, 5, 2);
                if ($tmp == '00') {
                    // manufacturer code ends in 00
                    $upce_code = substr($code, 2, 3) . substr($code, 10, 2) . '3';
                } else {
                    $tmp = substr($code, 6, 1);
                    if ($tmp == '0') {
                        // manufacturer code ends in 0
                        $upce_code = substr($code, 2, 4) . substr($code, 11, 1) . '4';
                    } else {
                        // manufacturer code does not end in zero
                        $upce_code = substr($code, 2, 5) . substr($code, 11, 1);
                    }
                }
            }
        }
        //Convert digits to bars
        $codes = array('A' => array('0' => '0001101', '1' => '0011001', '2' => '0010011', '3' => '0111101', '4' => '0100011', '5' => '0110001', '6' => '0101111', '7' => '0111011', '8' => '0110111', '9' => '0001011'), 'B' => array('0' => '0100111', '1' => '0110011', '2' => '0011011', '3' => '0100001', '4' => '0011101', '5' => '0111001', '6' => '0000101', '7' => '0010001', '8' => '0001001', '9' => '0010111'), 'C' => array('0' => '1110010', '1' => '1100110', '2' => '1101100', '3' => '1000010', '4' => '1011100', '5' => '1001110', '6' => '1010000', '7' => '1000100', '8' => '1001000', '9' => '1110100'));
        $parities = array('0' => array('A', 'A', 'A', 'A', 'A', 'A'), '1' => array('A', 'A', 'B', 'A', 'B', 'B'), '2' => array('A', 'A', 'B', 'B', 'A', 'B'), '3' => array('A', 'A', 'B', 'B', 'B', 'A'), '4' => array('A', 'B', 'A', 'A', 'B', 'B'), '5' => array('A', 'B', 'B', 'A', 'A', 'B'), '6' => array('A', 'B', 'B', 'B', 'A', 'A'), '7' => array('A', 'B', 'A', 'B', 'A', 'B'), '8' => array('A', 'B', 'A', 'B', 'B', 'A'), '9' => array('A', 'B', 'B', 'A', 'B', 'A'));
        $upce_parities = array();
        $upce_parities[0] = array('0' => array('B', 'B', 'B', 'A', 'A', 'A'), '1' => array('B', 'B', 'A', 'B', 'A', 'A'), '2' => array('B', 'B', 'A', 'A', 'B', 'A'), '3' => array('B', 'B', 'A', 'A', 'A', 'B'), '4' => array('B', 'A', 'B', 'B', 'A', 'A'), '5' => array('B', 'A', 'A', 'B', 'B', 'A'), '6' => array('B', 'A', 'A', 'A', 'B', 'B'), '7' => array('B', 'A', 'B', 'A', 'B', 'A'), '8' => array('B', 'A', 'B', 'A', 'A', 'B'), '9' => array('B', 'A', 'A', 'B', 'A', 'B'));
        $upce_parities[1] = array('0' => array('A', 'A', 'A', 'B', 'B', 'B'), '1' => array('A', 'A', 'B', 'A', 'B', 'B'), '2' => array('A', 'A', 'B', 'B', 'A', 'B'), '3' => array('A', 'A', 'B', 'B', 'B', 'A'), '4' => array('A', 'B', 'A', 'A', 'B', 'B'), '5' => array('A', 'B', 'B', 'A', 'A', 'B'), '6' => array('A', 'B', 'B', 'B', 'A', 'A'), '7' => array('A', 'B', 'A', 'B', 'A', 'B'), '8' => array('A', 'B', 'A', 'B', 'B', 'A'), '9' => array('A', 'B', 'B', 'A', 'B', 'A'));
        $k = 0;
        $seq = '101';
        // left guard bar
        if ($upce) {
            $bararray = array('code' => $upce_code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
            $p = $upce_parities[$code[1]][$r];
            for ($i = 0; $i < 6; ++$i) {
                $seq .= $codes[$p[$i]][$upce_code[$i]];
            }
            $seq .= '010101';
            // right guard bar
        } else {
            $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
            $half_len = ceil($len / 2);
            if ($len == 8) {
                for ($i = 0; $i < $half_len; ++$i) {
                    $seq .= $codes['A'][$code[$i]];
                }
            } else {
                $p = $parities[$code[0]];
                for ($i = 1; $i < $half_len; ++$i) {
                    $seq .= $codes[$p[$i - 1]][$code[$i]];
                }
            }
            $seq .= '01010';
            // center guard bar
            for ($i = $half_len; $i < $len; ++$i) {
                $seq .= $codes['C'][$code[$i]];
            }
            $seq .= '101';
            // right guard bar
        }
        $clen = strlen($seq);
        $w = 0;
        for ($i = 0; $i < $clen; ++$i) {
            $w += 1;
            if ($i == $clen - 1 or $i < $clen - 1 and $seq[$i] != $seq[$i + 1]) {
                if ($seq[$i] == '1') {
                    $t = true;
                    // bar
                } else {
                    $t = false;
                    // space
                }
                $bararray['bcode'][$k] = array('t' => $t, 'w' => $w, 'h' => 1, 'p' => 0);
                $bararray['maxw'] += $w;
                ++$k;
                $w = 0;
            }
        }
        return $bararray;
    }