anchor.diff:  (defparameter +grazing-field-spawn-cooldown-max+ 14.0)
   (defparameter +max-simultaneous-food+ 20)
   
  -(defparameter +sheep-house-color+ (p2dg:make-color-4 0.5 0.25 0 1))
  -
  -(defparameter +wolf-color+ (p2dg:make-color-4 1.0 0.2 0.2 1))
  +(defparameter +sheep-house-color+ (p2dg:make-color-4 0.7 0.5 0 1))
  +
  +(defparameter +wolf-color+ (p2dg:make-color-4 0.0 0.0 0.0 1))
   (defparameter +wolf-size+ 3.0)
   (defparameter +wolf-eating-cooldown+ 3.0)
   (defparameter +wolf-eating-speed+ 1.0)
  
positive.code: 
  (defparameter +boid-perception-range+ 50)
  
  (defparameter +player-base-speed+ 50)
  (defparameter +player-running-speed+ 90)
  (defparameter +player-slow-speed+ 10)
  (defparameter +player-angular-speed+ p2dm:+pi+)
  
  (defparameter +sheep-hungry-color+ (p2dg:make-color-4 0.2 0.2 0.2 1))
  (defparameter +sheep-full-color+ (p2dg:make-color-4 0.9 0.9 0.9 1))
  
  (defparameter +sheep-size+ 2.5)
  
negative.code: (defun make-default-player ()
    (make-instance 'player
                   :position (p2dm:make-vector-2d (/ p2d:*canvas-width* 2.0) (/ p2d:*canvas-height* 2.0))
                   :color +player-color+))
  
  
  