anchor.diff:                                     :descent (- (* (zpb-ttf:descender loader) units->pixels))))))
   	font))))
   
  -(defmethod print-object ((object zpb-ttf-face) stream)
  +(defmethod print-object ((object zpb-ttf-font) stream)
     (print-unreadable-object (object stream :type t :identity nil)
       (with-slots (font-loader filename size ascent descent) object      
         (format stream "~W size=~A ascent=~A descent=~A" 
  
positive.code: 	     (units->pixels (* pixel-size (/ units/em)))           
  	     (font (ensure-gethash
                      (list display loader size) font-cache
                      (make-instance 'zpb-ttf-face
                                     :display display
                                     :filename filename
                                     :size size
  
negative.code: 
  (defvar *zpb-font-lock* (climi::make-lock "zpb-font"))
  
  (defclass zpb-ttf-font (truetype-font)
    ((font-loader :reader zpb-ttf-font-loader :initarg :loader)
     (units->pixels :reader zpb-ttf-font-units->pixels :initarg :units->pixels)))
  
  