# Seconds since the last call to `lapse`
	fun lapse: Float
	do
		var time_at_last_lapse = time_at_last_lapse
		var now = temp
		now.update
		time_at_last_lapse.minus(now, time_at_last_lapse)
		var r = time_at_last_lapse.to_f

		self.temp = time_at_last_lapse
		self.time_at_last_lapse = now

		return r
	end