1942379 - Pointer Lock API in Firefox for Android(version 132 or later) is causing high mouse sensitivity and mouse input lag

Status: UNCONFIRMED

(Fenix :: Browser Engine, defect)

Description

[hellodarkness2020]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:134.0) Gecko/20100101 Firefox/134.0

Steps to reproduce:

I was trying to use Firefox for Android to play a game on the cloud gaming service I use. I had connected an external mouse and keyboard to a Samsung tablet (Android 14) to do the same. I decided to choose Firefox for Android because very few android browsers support Pointer Lock API, Firefox being one of them. Up until I had started the game everything was fine, the cursor was working just as you would expect. But as soon the game started and mouse pointer lock started working, the cursor started behaving weirdly.

If you don't have access to a cloud gaming service you should be able to reproduce it using any of the below links:
http://media.tojicode.com/q3bsp/
https://mdn.github.io/dom-examples/pointer-lock/
Connect a mouse to any Android device and open these link on Firefox for Android.

I had first thought the issue was with the mouse I was using. So I bought another one. But the issue persisted. I then suspected that it had something to do with the cloud gaming service but then I tried to reproduce it on another platform (using the above links) and the issue persisted. I have reason to believe that the issue does not lie with my Android device itself because I tried this on my Android phone (Android 14, Motorola) and the issue still persisted.

I have been successful in replicating this on latest versions of both Firefox for Android and Firefox Nightly.

Actual results:

The moment the first person game started and Pointer Lock enabled, the mouse pointer started moving all over the screen. The touch sensitivity went really high. The pointer was reacting to the slightest movement of the mouse. I tried decreasing the mouse sensitivity from the game settings but it still remained pretty high.

At the same time, and now we come to the REAL problem, there was some sort of mouse input lag (if you would call it that). When I tried to move the mouse in one direction, the cursor followed with a small delay. But when I changed the direction of the mouse i.e. I started moving the mouse in the opposite direction, the cursor did not change course immediately but kept moving in the previous direction for some time while I was moving the mouse and ONLY while I was moving the mouse (this is important part) before changing course finally and moving in the right direction. This cycle repeated every time I tried to change the direction of the mouse.

Expected results:

Ideally, the mouse should have been working just fine, with the same sensitivity it was operating on before Pointer Lock enabled. And without any input lag whatsoever.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Fenix::Browser Engine' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:boek, could you have a look please?

For more information, please visit BugBot documentation.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:boek, could you have a look please?

For more information, please visit BugBot documentation.