PHP5 class written by Carlo Perassi based on the EAN13 functions of SVG barcode for PHP Application written by Trần Ngọc Quân

Barcode.php

<?php
/*

PHP5 class written by Carlo Perassi [0]
based on the EAN13 functions of SVG barcode for PHP Application [1]
written by Trần Ngọc Quân [2].
Same license.

[0] http://perassi.org/2013/05/28/php5-svg-ean13-barcode-class/
[1] http://sourceforge.net/projects/phpsvgbarcode/
[2] http://vnwildman.users.sourceforge.net/

*/

class Barcode {

    private $_prity;
    private $_bartable;
    private $_guard;
    private $_center;
    private $_unit;
    private $_bw;
    private $_width;
    private $_height;
    private $_fs;
    private $_dx;
    private $_x;
    private $_yt;
    private $_sb;
    private $_lb;

    public function __construct() {
        $this->_prity = array(
            array(1, 1, 1, 1, 1, 1),
            array(1, 1, 0, 1, 0, 0),
            array(1, 1, 0, 0, 1, 0),
            array(1, 1, 0, 0, 0, 1),
            array(1, 0, 1, 1, 0, 0),
            array(1, 0, 0, 1, 1, 0),
            array(1, 0, 0, 0, 1, 1),
            array(1, 0, 1, 0, 1, 0),
            array(1, 0, 1, 0, 0, 1),
            array(1, 0, 0, 1, 0, 1)
        );

        // left has white bar at 1st.
        // right has black bar at 1st (event only).
        $this->_bartable = array(
            array('3211', '1123'),
            array('2221', '1222'),
            array('2122', '2212'),
            array('1411', '1141'),
            array('1132', '2311'),
            array('1231', '1321'),
            array('1114', '4111'),
            array('1312', '2131'),
            array('1213', '3121'),
            array('3112', '2113')
        );

        $this->_guard = '101';
        $this->_center = '01010';

        //configure
        $this->_unit = 'px';
        $this->_bw = 3; // bar width
        $this->_width = $this->_bw * 106;
        $this->_height = $this->_bw * 50;
        $this->_fs = 8 * $this->_bw; // font size
        $this->_yta = 45 * $this->_bw;
        $this->_ytb = 2.5 * $this->_bw;
        $this->_dx = 2 * $this->_bw; // lenght between bar and text
        $this->_x = 7 * $this->_bw;
        $this->_sb = 35 * $this->_bw;
        $this->_lb = 45 * $this->_bw;
    }

    public function check($str) {
        $code = str_split($str);

        return 10 - ((3 * ($code[1] + $code[3] + $code[5] + $code[7] + $code[9] + $code[11]) + ($code[0] + $code[2] + $code[4] + $code[6] + $code[8] + $code[10])) % 10);
    }

    public function draw($num) {
        $num = preg_replace('/\D/', '', $num);
        $char = $num . $this->check($num);
        $first = (int) substr($num, 0, 1);
        $oe = $this->_prity[$first]; // old event array for first number
        $char = str_split($char);

        $img = '';
        $img.= '<?xml version="1.0" encoding="UTF-8" standalone="no"?>' . "\n";
        $img .= '<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">' . "\n";
        $img.= "<svg width='" . $this->_width . $this->_unit . "' height='" . $this->_height . $this->_unit . "' version='1.1' xmlns='http://www.w3.org/2000/svg'>" . "\n";
        $this->_xt = $this->_x + $this->_dx - 8 * $this->_bw; // start point of text drawing
        $img.= "<text x='" . $this->_xt . $this->_unit . "' y='" . $this->_yta . $this->_unit . "' font-family='Arial' font-size='" . $this->_fs . "'>" . $char[0] . '</text>' . "\n";

        $img.= "<desc>First guard</desc>\n";
        $val = str_split($this->_guard);
        foreach ($val as $bar) {
            if ((int) $bar === 1) {
                $img.= "<rect x='" . $this->_x . $this->_unit . "' y='" . $this->_ytb . $this->_unit . "' width='" . $this->_bw . $this->_unit . "' height='" . $this->_lb . $this->_unit . "' fill='black' stroke-width='0' />" . "\n";
            }
            $this->_x = $this->_x + $this->_bw;
        }

        // draw Left Bar.
        for ($i = 1; $i < 7; $i++) {
            $id = $i - 1; // id for Old-event array
            $oev = !$oe[$id]; // old-event value
            $val = $this->_bartable[$char[$i]][$oev];
            $img.= '<desc>' . htmlspecialchars($char[$i]) . "</desc>\n";
            $this->_xt = $this->_x + $this->_dx;
            $img.= "<text x='" . $this->_xt . $this->_unit . "' y='" . $this->_yta . $this->_unit . "' font-family='Arial' font-size='" . $this->_fs . "'>" . $char[$i] . "</text>\n";
            $val = str_split($val);
            for ($j = 0; $j < 4; $j++) {
                $num = (int) $val[$j];
                $w = $this->_bw * $num;
                if ($j % 2) {
                    $img.= "<rect x='" . $this->_x . $this->_unit . "' y='" . $this->_ytb . $this->_unit . "' width='" . $w . $this->_unit . "' height='" . $this->_sb . $this->_unit . "' fill='black' stroke-width='0' />" . "\n";
                }
                $this->_x = $this->_x + $w;
            }
        }

        // draw Center Bar.
        $val = $this->_center;
        $img .= "<desc>Center</desc>\n";
        $val = str_split($val);
        foreach ($val as $bar) {
            if ((int) $bar === 1) {
                $img .= "<rect x='" . $this->_x . $this->_unit . "' y='" . $this->_ytb . $this->_unit . "' width='" . $this->_bw . $this->_unit . "' height='" . $this->_lb . $this->_unit . "' fill='black' stroke-width='0' />" . "\n";
            }
            $this->_x = $this->_x + $this->_bw;
        }

        // draw Right Bar always in first column.
        for ($i = 7; $i < 13; $i++) {
            $val = $this->_bartable[$char[$i]][0];
            $img .= '<desc>' . htmlspecialchars($char[$i]) . "</desc>\n";
            $this->_xt = $this->_x + $this->_dx;
            $img .= "<text x='" . $this->_xt . $this->_unit . "' y='" . $this->_yta . $this->_unit . "' font-family='Arial' font-size='" . $this->_fs . "'>" . $char[$i] . "</text>\n";
            $val = str_split($val);
            for ($j = 0; $j < 4; $j++) {
                $num = (int) $val[$j];
                $w = $this->_bw * $num;
                if (!($j % 2)) {
                    $img.= "<rect x='" . $this->_x . $this->_unit . "' y='" . $this->_ytb . $this->_unit . "' width='" . $w . $this->_unit . "' height='" . $this->_sb . $this->_unit . "' fill='black' stroke-width='0' />" . "\n";
                }
                $this->_x = $this->_x + $w;
            }
        }

        // draw End guard Bar.
        $val = $this->_guard;
        $img .= "<desc>End guard</desc>\n";
        $val = str_split($val);
        foreach ($val as $bar) {
            if ((int) $bar === 1) {
                $img.= "<rect x='" . $this->_x . $this->_unit . "' y='" . $this->_ytb . $this->_unit . "' width='" . $this->_bw . $this->_unit . "' height='" . $this->_lb . $this->_unit . "' fill='black' stroke-width='0' />" . "\n";
            }
            $this->_x = $this->_x + $this->_bw;
        }
        $img.= '</svg>';

        return $img;
    }

}