var time = 0.0
var fps = 0
var fpsIt = 0

while true:
  var frameTime = cpuTime()

  # Do stuff that takes time

  let wait = (1.0/ X ) - (cpuTime()-frameTime)
  echo wait
  if wait > 0.0:
    os.sleep(toInt(wait*1000))

  if fpsIt == 10:
    fpsIt = 0
    fps = toInt(1.0/((cpuTime()-time)/10.0))
    time = cpuTime()
  else:
    fpsIt += 1