Screen flicker when my app is closed

Hi all, so I’m in the last legs of my update to Mighty Mower. The previous version was portrait and this one is now landscape. What I’ve found is that when I quit the app, the area where the fence was hurtling past leaves a flicker in the screen that takes a while to die down. Is this normal? Or is there something I can do to stop this happening?

Thanks The Major


Is this in Codea itself, or have you exported it?


@Codeanoob it’s not something I can take a screencaps of and a photo of the screen doesn’t show it either as its a screen thing.

@Ignatz, it happens in both the codea app and in the export.

As I’m redrawing the same two fence positions 25 times a second each (alternating) I think the screen starts to retain a residual pixel flicker.

It’s happened on both the iPad 2 and the iPad mini 2.

The way round it is to switch off the motion to the fence so that it actually stays still. The rest of the objects and where your eye looks makes you believe it’s moving.


Are you sure it’s not leaving an after image in your eyes? (If you look at something else immediately after closing the app, do you see the flicker?)

@Ignatz It’s not an after image in the eyes. I see it sometimes when I exit a project. There will be part of an image still on the screen for an instant before the project completly closes. I don’t see it every time so I’m not sure the exact cause.

Maybe, but not a flicker that lasts “a while”, as reported above, surely?

I’ve had a weird bug with Codea where I have Codea running for a few hours then when I close Codea I can still see very faint images on my home screen of the assets button, etc.

It used to happen all the time with my iPad 2, but haven’t noticed it with the iPad mini retina.

Not sure if it’s the same type of bug you describe.

It might well be @Crumble

Hey @Ignatz it’s not an eye image, it’s defanately in the hardware screen. It’s either the iPad graphics card still thinks it’s receiving pixel instructions to redraw or it’s (more worryingly) a power/voltage problem where the power has been switched so fast in the rgb values of those pixels and for so long that the screen pixels are taking on that behaviour in a hardware way. Think screen burn when you had to have a screen saver on monitors to stop the pixels permanently becoming set to that colour.

The thing is when you stop playing the game and let the screen ‘cool down’ and display something else for a while it goes back to normal. But it takes about 10 mins or so…