anchor.diff:    (x :float)
     (y :float))
   
  -(cffi:defcenum ai-return
  +(cffi:defcenum (ai-return :int)
     (:ai-return-success 0)
     (:ai-return-failure -1)
  -  (:ai-return-outofmemory -3)
  -  (:_ai-enforce-enum-size 2147483647))
  +  (:ai-return-outofmemory -3))
   
   (cffi:defcstruct ai-vector-key
     (m-time :double)
  
positive.code:   (m-time :double)
    (m-value ai-quaternion))
  
  (cffi:defcenum ai-anim-behaviour
    (:ai-anim-behaviour-default 0)
    (:ai-anim-behaviour-constant 1)
    (:ai-anim-behaviour-linear 2)
    (:ai-anim-behaviour-repeat 3)
    (:_ai-anim-behaviour-force-32-bit -1879048193))
  
  (cffi:defcstruct ai-node-anim
    (m-node-name ai-string)
  
negative.code:   (:ai-component-lights 256)
    (:ai-component-cameras 512)
    (:ai-component-meshes 1024)
    (:ai-component-materials 2048))
  
  (cffi::defctype ai-file-open-proc :pointer)
  
  