While working on low latency canvas on Nocturne, and investigating why we were getting a really high latency when drawing, we noticed that if a pen was used instead of touch, latency was pretty good.

We also tried to move Windows around and interact with the UI and noticed that touch latency was generally significantly worse than the pen: https://drive.google.com/a/google.com/file/d/102AbEQUNYy4_wXKtBnq7qzajno-RcUIG/view?usp=drivesdk

Surprisingly, touch latency is not always that bad though. Sometimes touch latency seems acceptable, sometimes it seems to enter a state where everything seems to be delayed of a bunch of frames, dragging a window almost feels like the window is attached to an elastic and the window itself has a high drag coefficient.

We're not quite sure what triggers that state.

adlr suggested it might be that noisy input results in averaging many frames of input to compensate. He also suggested to try to reproduce the issue and use WALT, that should help pinpoint where the problem is happening in the stack.