# Request an update on the CPU
	#
	# This is called automatically on modification of any value of `Sprite`.
	# However, it can still be set manually if a modification can't be
	# detected or by subclasses.
	fun needs_update
	do
		var c = context
		if c == null then return
		if c.last_sprite_to_update == self then return
		c.sprites_to_update.add self
		c.last_sprite_to_update = self
	end