anchor.diff:         (glVertex2f WIDTH i))
         (iota 0 1 HEIGHT))
      (glEnd)
  -   (glEnd))
   
      
      
  
positive.code:    (glClear GL_COLOR_BUFFER_BIT)
     (glDisable GL_TEXTURE_2D)
  
     (let* ((my (get-mouse-pos)) ;(my (get userdata 'mouse (cons 0 0)))
            (x (car my))
            (y (cdr my)))
     ; поле
     (glColor3f 1.0 1.0 1.0)
     (glEnable GL_TEXTURE_2D)
  
negative.code:    
     ; осмотр себя любимого на N клеток вокруг
     ;#|
     (let ((ms (get userdata 'mouse #f)))
     (if ms (begin
        (glPointSize 4.0)
        (glColor3f 0 0 1)
        (glBegin GL_POINTS)
        (glVertex2f (car ms) (cdr ms))
        (glEnd)
     )))
     (let ((me (get-mouse-pos))
           (N 2))
     (glColor3f 0 1 0)
     (glBegin GL_LINES)
     (let lookout ((n 0)  (x (+ (floor (car me)) 0.5)) (y (+ (floor (cdr me)) 0.5)))
        (if (= n N)
           #t
  