code: public function addGlyph($char, $path, $name = null, $width = null){
  
  		$glyph = $this->xmlDocument->defs[0]->font[0]->addChild('glyph');
  		$glyph->addAttribute('unicode', $char);
  		if($name !== null){
  			$glyph->addAttribute('glyph-name', $name);
  		}
  		if($width !== null){
  			$glyph->addAttribute('horiz-adv-x', $width);
  		}
  		$glyph->addAttribute('d', $path);
  
  	}
docs: add a glyph to the font
  
  @param string $char  character of the glyph
  @param string $path  SVG path definition
  @param string $name  name of the glyph
  @param float  $width glyph width (horiz-adv-x)