/**
  * set the asceneder value
  * @param numeric $ascender
  **/
 public function setAscender($ascender)
 {
     if ($this->direction == -1) {
         foreach ($this->directions as $direction) {
             $this->font_metrics[$direction]->setAscender($ascender);
         }
         parent::setAscender($ascender);
     } else {
         $this->font_metrics[$this->direction]->setAscender($ascender);
     }
 }