- Updated PresentSync to accurately measure present() block time, ensuring that the probe does not misclassify sync status due to FrameCap sleep artifacts.
- Enhanced FixedStep to implement a hard ceiling on catch-up debt, preventing input starvation during high-speed scenarios.
- Adjusted logic in Game and Game2 to utilize the new catchupLimit function for setting maxAccum, ensuring consistent behavior across speed multipliers.
- Improved test coverage for PresentProbe and PresentSync to validate the new logic and edge cases.
the display sync stuff i added was probing whether vsync was actually working, but it was measuring the wrong thing. during the probe we software-cap at 60 for safety, and the probe was looking at the gap between frames... which includes the sleep 😅 ..... so it always looked like sync was fine even when the driver was ignoring it. on something like the ally x on windows thats a real problem. vsync says on, probe says gated, we lift the cap and snap logic to the panel hz, then youre basically uncapped. at 2–4x that turns into hitching, dropped frames, dropped input, that weird half second freeze. speed swapping wasnt desyncing the driver, it was just making the bad path hurt more.
the solution is just we time present() itself now, not the gap after it, this way the warmup sleep cant fake a pass. if sync is unclear or broken we just stay on a capped 60 and dont snap logic. Also fixed fixedstep so it snaps wall clock dt before applying speed, so in general the 2-4x speed swaps dont screw the pacing math anymore
bryanthaboi