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

(require :cl-opengl)

(load "math.lisp")

(defun draw-triangle (x1 y1 x2 y2 x3 y3 r g b)
  (gl:begin :triangles)
  (gl:color r g b)
  (gl:vertex x1 y1)
  (gl:vertex x2 y2)
  (gl:vertex x3 y3)
  (gl:end) )

(defun draw-triangle-test (&optional (num 3) (limit 2.0))
  (dotimes (_ num)
    (draw-triangle
     (random-limit limit) ; x1 y1
     (random-limit limit)
     (random-limit limit) ; x2 y2
     (random-limit limit)
     (random-limit limit) ; x3 y3
     (random-limit limit)
     (random-color-channel) ; r g b
     (random-color-channel)
     (random-color-channel) )))