// Rosetta Code problem: http://rosettacode.org/wiki/Draw_a_rotating_cube
// adapted to Yabasic by Galileo, 05/2022

// GFA Punch (code from tigen.ti-fr.com/)
// Carré 3D en rotation

open window 50, 70
backcolor 0,0,0
clear window
color 255,255,255

do
  clear window
  x = COS(T) * 20
  y = SIN(T) * 18
  r = SIN(T + T)

  line (x + 40), (y + 40 - r), (-y + 40), (x + 40 - r)
  line (-y + 40), (x + 40 - r), (-x + 40), (-y + 40 - r)
  line (-x + 40), (-y + 40 - r), (y + 40), (-x + 40 - r)
  line (y + 40), (-x + 40 - r), (x + 40), (y + 40 - r)

  line (x + 40), (y + 20 + r), (-y + 40), (x + 20 + r)
  line (-y + 40), (x + 20 + r), (-x + 40), (-y + 20 + r)
  line (-x + 40), (-y + 20 + r), (y + 40), (-x + 20 + r)
  line (y + 40), (-x + 20 + r), (x + 40), (y + 20 + r)
  line (x + 40), (y + 40 - r), (x + 40), (y + 20 + r)
  line (-y + 40), (x + 40 - r), (-y + 40), (x + 20 + r)
  line (-x + 40), (-y + 40 - r), (-x + 40), (-y + 20 + r)
  line (y + 40), (-x + 40 - r), (y + 40), (-x + 20 + r)

  pause 0.02
  T = T + 0.15
loop