Dreamora: In full-screen there is no delay(1) but some people (not very many at all) are getting jerks due to background tasks, it's the same in windowed mode. Watching the timer, you can see it make sudden jumps as the game loses CPU time to other tasks, some taking up to 200MS! My framework can do Flip 0 or 1 (or -1), VSync is on the options page and in the ini file. VSync on/off makes no difference to the jerks people are seeing because it's due to the timer skipping ahead a lot due to background tasks. Yes I used time difference based interpolation.
I still want to mess with OS priorities.
I still want to mess with OS priorities.