anchor.diff:                                                          (font-scale font)))
             (slot-value font '%font-ascender) (round (* (zpb-ttf:ascender loader)
                                                         (font-scale font)))
  +          (slot-value font '%glyph-cache-lock) (mezzanine.supervisor:make-mutex (format nil "~S ~S lock" (name typeface) size))
             (slot-value font '%glyph-cache) (make-array 17 :initial-element nil))))
   
   (defun find-font (name &optional (errorp t))
  
positive.code: (defclass typeface ()
    ((%font-loader :initarg :font-loader :reader font-loader)
     (%name :initarg :name :reader name)
     (%refcount :initform 1)))
  
  (defclass font ()
    ((%typeface :initarg :typeface :reader typeface)
  
negative.code:    (%line-height :reader line-height)
     (%em-square-width :reader em-square-width)
     (%font-ascender :reader ascender)
     (%glyph-cache-lock :reader glyph-cache-lock)
     (%glyph-cache :reader glyph-cache)
     (%refcount :initform 1)))
  
  