Blinking sprites

Questions
1

Hello everyone! (sorry for my english)

I have a little problem. When I am trying draw more sprites someones start blinking. You can try it on this simply program. When you touch somewhere, it will drawcodea icon. But if you will touching faster, with more fingers some icon will blinking… any solution? Bye

2 
function setup()
    displayMode(FULLSCREEN)
    
x=10
y=10
end

function touched(touch)
    if touch.state==BEGAN then
   x=CurrentTouch.x
        y=CurrentTouch.y
        end
    end

-- This function gets called once every frame
function draw()
    -- This sets a dark background color
 sprite("Cargo Bot:Codea Icon",x,y,30,30)
end
3

As you aren’t setting the background, each call to draw() draws its screen on top of the previous one. The problem is that there isn’t a single screen to be drawn on but rather a set of three. So each draw() statement draws its stuff on top of what was shown on the screen three frames ago. When setting a background, this doesn’t matter, but when not doing so then it does.

You can get round this by using backingMode(RETAINED) in your setup() function. this forces Codea to copy each frame to the next one to ensure that what was on the screen last frame is still on it in the next frame.