After talking for quite a bit to Nach, here's the problem he has with not limiting framerates at all:
19:10:16 <Nach> making the game rely on OS function time, and then also screwing with that time to allow range max (resolution max?) is extremely questionable
19:35:52 <Nach> it's questionable because you're screwing with the functions the game use and using it in situations it wasn't designed for. The entire topic also begins off with a false premise, which I absolutely not apologize for, nor will I even remotely try to operate in.
So yeah, I'm not a tech guru, and when brainstorming in order to create this thread, the internal technical aspects of this problem weren't known to me. After having learned about it, here's the summary of our talk:
For a very long time, the standard the games strive to work well under has been vsync. It's the primary mode to use during play, since it helps with a lot of issues, one of them being inconsistency of hardware specs which only gets worse over time.
18:23:00 <Nach> PC specs games are designed for are typically around a 6 year window surrounding the game design/release period
18:23:27 <Nach> shoving a PC game onto a PC with specs 20 years later, and running it natively that way is crazy
18:24:33 <Nach> even consider the PCs from 3x86 to Pentium era, they all had a "Turbo" button which you could turn off to make the CPU speed more like what you saw on an x86 or 2x86, so you could run old software as they were intended
18:26:50 <Nach> since everyone saw games from the x86 and 2x86 era were misdesigned based on actual clock count, forcing later x86 CPUs to have that turbo option, practically every game since started limiting time based on video and sound output speeds. Games in the last ~15 years even go for a combo due to various differences in hardware and to allow the most precise measurement of time. This is why vsync exists. If you're going to use 20+ year future CPUs and you want it to work right, use vsync (assuming vsync isn't nuts either). Turning off vsync and using 20+ year CPU? Come on...
19:01:26 <Nach> the only reason why games generally even allow turning off vsync is so you can play them on older hardware, which isn't capable of hitting 60 FPS or whatever, or for cases where you have some exotic hardware which doesn't report vsync properly, although in that latter case, there's no telling without vsync will work either
So for games that allow to disable vsync and still run at the same speed regardless, they rely on OS time functions among other things to work properly time-wise. When the game runs at high framerate without vsync, the actual rate it runs at isn't consistent. Hourglass and libTAS replace time-related OS functions and can force the game to run at certain framerate
consistently without vsync.
While consistency sounds like something good, we're not just modifying OS functionality to make the game TASable and then replay the movie without OS hacks. We're hacking OS functions to affect the way the game works. Even though some time functions report proper time, allowing the game to be aware of real world time and work at consistent speed gameplay-wise regardless, other time functions are replaced and report false time altogether.
The suggested solution is limiting all this to vsync and internal options for game speed, since neither involves hacking OS functions and both allow the games to run in the frameworks they target. I can add that this
unifies the competition conditions too.
