public function getSVG($width, $height)
    {
        if($this->svgEnvelope === null)
        {
            return null;
        }
        $min_max = explode(" ",
                           preg_replace('/M\s?|\sL|\sZ/', "", $this->svgEnvelope));
        $min_x = floatval($min_max[0]);
        $min_y = floatval($min_max[1]);
        $max_x = floatval($min_max[0]);
        $max_y = floatval($min_max[1]);
        for($i = 1; $i < count($min_max); $i = $i + 2)
        {
            $min_x = min($min_x, floatval($min_max[$i - 1]));
            $max_x = max($max_x, floatval($min_max[$i - 1]));
            $min_y = min($min_y, floatval($min_max[$i]));
            $max_y = max($max_y, floatval($min_max[$i]));
        }
        $vb = $min_x . " " . $min_y . " " . ($max_x - $min_x) . " " . ($max_y - $min_y);

        return '<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="' . $width . 'px" height="' . $height . 'px" viewBox="' . $vb . '" version="1.1" xmlns="http://www.w3.org/2000/svg">
	<path d="' . ($this->svgGeometry === null
                            ? '' : $this->svgGeometry) . '" fill="black" />
</svg>';
    }