check euslisp jsk rbrain

draw-cube-edge-direction.l

(defun draw-cube-edge-direction
  ()
  (setq *obj* (make-cube 200 200 200))
  (objects (list *obj*))
  (dotimes (i (length (send *obj* :edges)))
    (with-set-color-line-width
     *viewer* #f(1 1 1) 5
     (send *viewer* :draw-arrow
           (send (elt (send *obj* :edges) i) :point 0)
           (send (elt (send *obj* :edges) i) :point 1)))
    (send *viewer* :flush)
    (read-line)
    )
  )

(defmacro with-set-color-line-width ;; just for coloring
  (vw color line-width &rest bodies)
  (with-gensyms
   (prev-color prev-width)
   `(let* ((,prev-color (send ,vw :viewsurface :color))
           (,prev-width (send ,vw :viewsurface :line-width)))
      (unwind-protect
          (progn
            (send ,vw :viewsurface :color ,color)
            (send ,vw :viewsurface :line-width ,line-width)
            ,@bodies)
        (send ,vw :viewsurface :color ,prev-color)
        (send ,vw :viewsurface :line-width ,prev-width)
        ))))

(draw-cube-edge-direction)