anchor.diff:    ;; compute-perf-stats
     ;; show-log
     )
  +|#
   
   (defclass nbody-window (glut:window)
     ((new-pos :initform nil)
  
positive.code:         (delta-time 0.016)
          (damping 1.0)
          (p 256))
      (with-cuda-context (dev-id)
        (with-memory-blocks ((new-pos 'float4 num-bodies)
                             (old-pos 'float4 num-bodies)
                             (vel 'float4 num-bodies))
          (reset old-pos vel cluster-scale velocity-scale num-bodies)
          (memcpy-host-to-device old-pos vel)
          (let ((window (make-instance 'nbody-window)))
            (setf (slot-value window 'new-pos) new-pos)
            (setf (slot-value window 'old-pos) old-pos)
            (setf (slot-value window 'vel) vel)
            (setf (slot-value window 'delta-time) delta-time)
            (setf (slot-value window 'damping) damping)
            (setf (slot-value window 'num-bodies) num-bodies)
            (setf (slot-value window 'p) p)
            (glut:display-window window))))))
  
negative.code: (defun update (new-pos old-pos vel delta-time damping num-bodies p)
    (integrate-nbody-system new-pos old-pos vel delta-time damping num-bodies p))
  
  #|
  (defun run-benchmark (new-pos old-pos vel delta-time damping num-bodies p iterations)
    (update new-pos old-pos vel delta-time damping num-bodies p)
    ;; create-timer
  