feat(server_openvr): ✨ Add "Enforce server frame pacing"

[zmerp]

This is exactly the same as the old "Optimize game render latency" but with a different name to make it more clear that you don't want to touch it unless you know what you are doing

[shinyquagsire23]

actually I realized a bit too late, that 8ms fallback suould probably have been 1ms because now if a game runs at ie 6ms per frame, it'll get saddled with an 8ms wait every time and get worse performance. And 16ms turns to 24ms.

[zmerp]

actually I realized a bit too late, that 8ms fallback suould probably have been 1ms because now if a game runs at ie 6ms per frame, it'll get saddled with an 8ms wait every time and get worse performance. And 16ms turns to 24ms.

I don't understand you reasoning. 8 ms is like 125hz. But now that I think about it, we should have left som room for the game render. so 1ms is probably the right thing to do

[shinyquagsire23]

Yeah the current enforced system rounds up to display Hz increments so that if game render is 8ms on a 100Hz HMD, it waits 2ms, so 1ms is technically a perf penalty but a very small one comparatively. Arguably the wait could be dropped to a yield if the game render is more than the display vsync interval.

[zmerp]

I don't understand you reasoning. 8 ms is like 125hz. But now that I think about it, we should have left som room for the game render. so 1ms is probably the right thing to do

No wait, I pull that back. we do fall back to 8ms per frame only when the StatisticsManager is not initialized. so in those moments there is no load in the rendering loop.

[shinyquagsire23]

I think my original PR had an unwrap_or(Duration::from_millis(50)); for that condition specifically, so that None only applied to framepace-less settings and not no StatisticsManager. So here it'd be unwrap_or(Duration::from_millis(8)); and then 1ms in the else

[zmerp]

Ah. I think it's better if you make another PR with the final fix

[shinyquagsire23]

Yeah sure

[shinyquagsire23]

Oh, lol I guess I didn't have the 50ms thing separate