This specific issue was already addressed by https://github.com/dolphin-emu/dolphin/pull/11635
though I felt like there was something more we could do, and wasn't too happy with the
likelihood of devices update calls being skipped (due to `m_devices_population_mutex` being locked).
A comment removed by this commit gives two reasons for listening to
slave devices, both of which no longer apply:
- "Only slaves emit raw motion events": perhaps this was true when the
comment was written, but now master devices provide raw motion events
along with the other raw events.
- "Selecting slave keyboards avoids dealing with key focus": we get raw
key events regardless of the focus.
Listening to both master and slave devices results in duplicate raw
events. For button and key events, that's a tiny waste of time setting
the update flag a second time, but for raw mouse events the raw motion
will be processed twice. That makes this commit a user-facing change.
SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
The SDL backend crashes when you close a joystick after SDL_Quit has
been called. Some backends don't need to be shutdown and
re-initialized everytime, we can just ask to enumerate devices again.
This makes the device ID assigning code common to all backends, by
moving it to AddDevice() instead of copy-pasting or replicating
the logic in the backends.
Also, to prepare for hotplugging, instead of relying on a name usage
count, the new ID assigning system always starts from ID 0 and tries
to assign the first ID that is not used.
Previously, the devices vector would be passed to all backends. They
would then manually push_back to it to add new devices. This was fine
but caused issues when trying to add synchronisation.
Instead, backends now call AddDevice() to fill m_devices so that it is
not accessible from the outside.
Jordan Woyak