This is useful to investigate any TAS desync/reproducibility issues
relating to RNG, because even though I specifically separated the
Gravitron RNG away from other RNG and made it not dependent on the
system libc rand() function, there's still apparently some differences
in RNG execution between systems, resulting in TASVideos submission 7575
( https://tasvideos.org/7575S ) not syncing for everyone except the
author.
It seems that SDL_GetTicks(), which is used to seed the xoshiro RNG, is
not reliably consistent between systems, so in the future I will
probably replace it with a counter that is incremented each frame
starting from game startup, which is probably better.
This is to make it so RNG is deterministic when played back with the
same inputs in a libTAS movie even if screen effects or backgrounds are
disabled.
That way, Gravitron RNG is on its own system (seeded in hardreset()),
separate from the constant fRandom() calls that go to visual systems and
don't do anything of actual consequence.
The seed is based off of SDL_GetTicks(), so RTA runners don't get the
same Gravitron RNG every time. This also paves the way for a future
in-built input-based recording system, which now only has to save the
seed for a given recording in order for it to play back
deterministically.
