;; this file:
;;   https://dataswamp.org/~incal/cl/general-base/polygon.lisp

(require :cl-opengl)

(load "math.lisp")

(defun draw-polygon (ps r g b)
  (gl:begin :polygon)
  (gl:color r g b)
  (loop for (x y z) in ps do
    (gl:vertex x y z) )
  (gl:end) )

(defun draw-polygon-test (&optional (num 3) (limit 2.0))
  (dotimes (_ num)
    (let*((max    20)
          (offset  4)
          (num-verts (+ offset (random (- max offset)))) )
      (dotimes (_ num-verts)
        (draw-polygon
          (list `(,(random-limit limit)
                  ,(random-limit limit)
                  ,(random-limit limit) ))
          (random-color-channel)
          (random-color-channel)
          (random-color-channel) )))))