draw_cell = function(n, x,y, draw_cursor, fixed)
	local s = tostring(n)
	local w = App.width(s)
	local px = (Square_side-w)/2
	if fixed then
		App.color{r=0, g=0, b=0}
	else
		App.color{r=0.4, g=0.4, b=0.4}
	end
	love.graphics.print(s, x+px, y+Padding)
	if draw_cursor then
		if math.floor(Cursor_time)%2 == 0 then  -- blink
			App.color(Cursor_color)
			love.graphics.rectangle('fill', x+px+w, y+15, 3, Square_side-20)
		end
	end
end