on.update = function(dt)
	if Global_next_save and Global_next_save < Current_time then
		save_graph_to_disk()
		Global_next_save = nil
	end
	if Pan then
		Viewport.x = Pan.sx - App.mouse_x()/Viewport.zoom
		Viewport.y = Pan.sy - App.mouse_y()/Viewport.zoom
		B()
		return
	end
	local sx = sx(App.mouse_x())
	local sy = sy(App.mouse_y())
	if Edge then
		Edge.s = intersect_with_centroid(Edge.source, sx,sy)
		Edge.e = {sx=sx, sy=sy}
	elseif Move_node then
		Move_node.x = sx - Move.sx
		Move_node.y = sy - Move.sy
		A1(Move_node.id)
	elseif Resize_node then
		Resize_node.width = math.max(30, sx - Resize.sx)
		A1(Resize_node.id)
	elseif on_move_bar(sx, sy) then
		set_mouse_cursor('crosshair')
	elseif on_resize(sx, sy) then
		set_mouse_cursor('sizewe')
	elseif on_edge(sx,sy) then
		set_mouse_cursor('no')
	else
		set_mouse_cursor('arrow')
	end
end