onPrePointerObservable sometimes runs twice for same pointer event?

Bugs
1

Hey team…
I notised issues with the GUI in latest preview, clicking a GUI button will randomly run the pointer observables twice sometimes.

Sometimes you can make 10-20 clicks with no problems, and sometimes it can run twice 3-4 clicks in a row.

I haven’t found the exact root of the problem, but it appears to exist already on the scene.onPrePointerObservable

It’s a bit tough to give a good repro :slight_smile:
This PG makes 4 log messages per pointer click (2 per down & 2 per up)
Switching between left & right clicks seems to reproduce the error often.

2

cc @PolygonalSun and @carolhmj in case it rings a bell.

3

If it helps, the extra observables always happens after the pointer up has run.
Primarily on right clicks.
I managed to replicate on v5.71.1 too.

Just never had issues with it until now.

4

As a temporary fix, you could add your own debounce wrapper:

function debounce(func, timeout = 300){
let timer;
let ready = true;

return (...args) => {
  clearTimeout(timer);
  if (ready) {
      func.apply(this, args); 
  }
  ready = false;
  timer = setTimeout(() => { ready = true}, timeout);
};

}

Usage:
let myClickAction = debounce(myClickAction);

Then when you run myClickAction, it doesn’t allow it to fire more than once every 300 ms.

5

From what I’m seeing, it looks like the extra prepointer log is coming from a move event with a non -1 value for button. Lemme take a closer look.

6

@PolygonalSun
I digged a bit further, seeing the erorr already at scene._inputManager._deviceSourceManager._onInputChanged

At which point the code gets pretty convoluted and hard to follow further, in the PG at least.

7

@PolygonalSun
Okay… It’s actually not babylonjs.

its… windows or V8 ??
Test latest Chrome, lastest Opera, lastest Edge

Edit;
Downloaded Firefox, it happens in SpiderMonkey too, so it’s assumeably not V8 ?