Intermittent touch input on iPhone 11 Pro


My game has had one bug reported for over a month that I’ve been unable to fix. It’s to do with input on iPhone 11 Pro. I now have just such a device to test on, and can conclude:

  1. Touch input suddenly stops working for a couple of seconds, then returns to normal.
  2. It’s rare.
  3. When it happens all Defold input goes silent.

I have a couple of videos of this behaviour, but because there is no (simple) way to record that the screen is actually touched on iOS it’s difficult to say for certain it’s something to do with Defold. I have found this library, which would help, but I don’t know how to include it in a Defold project.

Has anyone here experienced this issue? Please say yes, it’s driving me mad.



I haven’t heard of this before. Which iOS version?




iOS 13.3.1



And you can reproduce this on your own as well? Can you create a test app that spawns a game object or particle effect on touch? Does everything pause? Sounds? Animations? Is it multi touch?

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Questions, questions!

Yes, I can reproduce it, but it’s not easy because it happens so rarely. It’s just the input that pauses, so, in the case of my game, the player is likely to die because the rest of the game continues normally. Unreleased, but I’ll send a pm with a couple of videos.



One thing that comes to mind is that touch input might not be detected outside the safe area (I can’t remember). Could it be that you are actually tapping outside the safe area when it doesn’t work?



I’ve thought of that, but when I was able to replicate it I tapped with one finger well within the safe area. Another theory of mine was that some input might be blocked because of multitouch, but that doesn’t seem to be the case.



I would appreciate if you could try to reproduce the problem in a minimal example. That would make it a lot easier for us to investigate.



Sent PM.



After a lot of testing and hair pulling it looks like this is an issue with iOS, rather than Defold. Thanks @britzl and @JCash for your patience and help trying to track it down.

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that is what still is happening with me too! … but on android … it almost looks to me as if it can have something to do with the long-touch interval …



@kakerlaka please tell us more. We can provide an engine with additional input logging.



just as in this post: Simultaneous tapping Virtual gamepad example (SOLVED)

sometimes the app on the device starts with that bug, that the buttons or stick release although one never took the finger(s) off the screen. then i close the app, kill the task (activity), restart the app and it works. when it happens, it is always the same timespan that passes 'till the button or stick releases. it feels like its around 1 to 1.5 seconds, just like a long tap would feel.