anchor.diff:  	(setf normal (normal sail)
   	      reflectv (reflectv incident normal)
   	      reflection (reflection corners reflectv)
  -	      reflect-arrow (new (3fn *arrow-helper ((@ ((@ reflectv clone)) negate)) origin 10 0xff0000))
  +	      reflect-arrow (new (3fn *arrow-helper reflectv origin 10 0xffff00))
   	      visibility
   	      (let ((visibility-super ((@ app superior) "visibility")))
   		(lambda (bool)
   		  (funcall visibility-super bool)
  -		  (setf (@ reflection visible) bool)
  -		  (@ reflect-arrow visible) bool))
  +		  (setf (@ reflection visible) bool
  +			(@ reflect-arrow visible) bool)))
   	      update-tilt
   	      (let ((tilt-super ((@ app superior) "updateTilt"))) 
   		(lambda ()
  
positive.code:       (add-absorb-force (add-animation (absorb))))
  
      (defun add-reflect-force (app)
        (with-slots (sail camera reflectv reflect-arrow incidence accelfn timefactor sail-position init) app
  	(setf
  	 accelfn
  	 (lambda ()
  	   (let ((accel (* 5d-5 (abs (cos (* incidence (/ pi 180)))))))
  
negative.code: 		  ((@ scene remove) reflection)
  		  (setf reflection (reflection corners reflectv))
  		  ((@ scene add) reflection)
  		  ((@ reflect-arrow set-direction) reflectv)
  		  ((@ reflect-arrow set-length) (* 10 (/ absorbed 100))))))
  	((@ scene add) reflection)
  	((@ scene add) reflect-arrow))
  