feat(client): ✨ Expose server version from client_core

[zmerp]

The new C API is alvr_get_server_version which works similarly to alvr_get_settings_json. The value can be obtained only after server connection, and the string length can be obtained by passing a null buffer.

[shinyquagsire23]

Tested it on visionOS and it seems to work fine, defaults to "20.11.0" on older versions but it seems like client_core works fine for those versions anyhow

[zmerp]

@shinyquagsire23 What do you mean "defaults to "20.11.0" on older versions"? What did you try?

[shinyquagsire23]

@zarik5 I tested streamer 20.9 and 20.10 from Releases with the patched client_core and it always returned the string "20.11.0"

[zmerp]

Now I remember why. This is actually caused by sloppy session extrapolation. Thankfully i can implement a fix and this will work retroactively for previous server builds.

[The-personified-devil]

Thankfully i can implement a fix and this will work retroactively for previous server builds.

Do you mean knowing that the version is <= 20.11 is good enough and the fix in the server will be implemented later?

[zmerp]

No, i mean that the server version is already passed correctly but the client mistakenly overwrites and loses the value, because of faulty session extrapolation

[The-personified-devil]

that's what I was wondering, odd choice to not directly add the fix to the pr then

[zmerp]

I was thinking about that. You may be right. Anyway I'll make another PR tomorrow

[shinyquagsire23]

honestly for visionOS it kinda works out anyhow, because the issue I thought I needed the versions to patch over (controllers being rotated) was fixed with the client_core update anyhow. Though I might disable the hand skeleton hysteresis on older versions where SteamVR input 2.0 gets set true by default w/o the streamer having those settings present