Cursor stuck top left when leaving game when it's fullscreen & raw input

[LittleEndu]

https://youtu.be/CX7_A6Ylyaw (first part is fullscreen, second is borderless)

DxDiag.txt

[bdach]

What pointing device is this? Mouse, tablet? dxdiag lists multiple.

[LittleEndu]

Both are stuck. Tablet does move the cursor freely but any cycle where there is no input from the tablet it goes back to top left.

[bdach]

Does unplugging either one help? Asking to ascertain whether it's crosstalk between the two, not as a suggested solution.

[LittleEndu]

It doesn't seem to. Unplugging the mouse didn't fix, unplugging the tablet didn't fix. Worth noting (and I think this might even invalidate the issue) is that I'm not on vendor software, I'm using hawku drivers. But the issue persist when I uninstall the driver and let windows grab generic driver after plugging the tablet back in.

[bdach]

I can't say I tested SDL on windows but it really ought to be working with some device...

[nbvdkamp]

I encountered this too on Windows with only mouse (don't own a tablet), upon following an external URL so it seems to be unrelated to tablets. It can get stuck in the corner of either monitor in multi monitor setups.

[peppy]

Just to confirm, this only occurs until you alt-tab cycle once, after which point it's fixed?

[Joehuu]

Okay, first off the PR doesn't fix the issue.

From my findings on Windows 10, I can now reproduce on framework by a different method. It needs to be windowed, and raw input needs to be on. Then, you need to move the cursor really fast inside and press WIN-D. The cursor will then teleport to the top left, but it won't get stuck.

On lazer, I can also reproduce on windowed with raw input by pressing WIN-D. Cursor still gets stuck though.

Just to confirm, this only occurs until you alt-tab cycle once, after which point it's fixed?

Nope, for the fullscreen reproduction, you just need to minimize fullscreen in any way (alt-tab, win-d, etc.) and it'll never recover.

[peppy]

This looks to be an internal bug in SDL2, specific to the use of winkey+D. I'm guessing they are using similar logic to what we were prior to #4056.

I guess I'll report this over their way, but there's not much we can seemingly do to fix this (i've tried a few different methods of fixing locally, but the grab commands seem to have no effect after a winkey+D cycle until next focus loss).

[peppy]

For the record, I've tried:

• Applying the grab change inside WINDOW_EXPOSE or MOUSE_ENTERED
• Applying the grab change in the main loop, every loop (with a preceding false to ensure SDL isn't keeping some internal state)

Based on both of these failing it seems like something internal to SDL is tracking window active state incorrectly, as I suggest above.