[BUG]: Final Fantasy X Tidus Falls Through Lift

[vcx33]

Describe the Bug

When using the lift in the omega ruins, tidus falls through during his jump animation

Bug:
https://user-images.githubusercontent.com/118646244/220760903-795ecea1-f77a-4269-9f35-7e42954485bd.mp4

Correct behavior:
https://youtu.be/x5cI9PNjMUQ?t=919

GS dump:
Final Fantasy X International_SLPS-25088_20230222210329.gs.zip

Changing FPU values (rounding/clamping) does nothing

Reproduction Steps

go to the omega ruins and step on the lift

Expected Behavior

No response

PCSX2 Revision

1.7.4126

Operating System

Linux (64bit) - Specify distro below

If Linux - Specify Distro

No response

[BParks21]

I'm having an issue in FF X-2 when flying enemies are killed they fall upward to their death instead of falling to the ground. Wonder if it's related? I'll probably open an issue for that as well.

[Mrlinkwii]

Can this be rechecked on latest release

[bigol83]

Still the same issue. Tried with every single advanced setting in EE and VU, it always has this issue. Tested with master 1.7.5460.

[refractionpcsx2]

Can we get a modern savestate from before she falls through the floor? No guarantees of fixing it, but would like to see it

[bigol83]

This one should work for FF X PAL UK

final-fantasy-x.10053.zip

Use the teleport sphere to Omega Ruins, put a no Encounter armor, and reach the elevator. That's how i tested it.

[refractionpcsx2]

Teleport sphere? You'll have to instruct me like I've never played it :P

[bigol83]

I didn't know you already played it. 😜

[refractionpcsx2]

ffx.zip

here's that save on a memcard, you go to the airship, talk to cid on the left, then choose to go to the Omega Ruins, go immediately down the left/west path, follow it round, then I think you go right at the fork, and there's a little floating platform thing you stand on as you go around, that's it.

I messed with game fixes, tried poking some of the code, didn't get anywhere though :(

[refractionpcsx2]

okay so this is fixed by setting EE Division Rounding to Negative makes the animations work in both directions! (Take that, Play! and Dobie lol). Be aware that you will need to go via memcard, a savestate will have already stored a bad state for it.

However I don't know what affect it has on the rest of the game, it may make things explode, it'll need testing throughout.

[vcx33]

This fixes the lift bug, but not when EE rounding mode is set to positive which is required to fix another FPU bug (cid running in place during the airship cutscene liftoff).
After testing a bit i found an FPU config that fixes pretty much every known FPU related bug, like characters and enemies facing the wrong way in battle, characters turning invisible during cutscenes, characters running into walls as well as the lift bug.

EE Rounding Mode: Negative
EE Division Rounding Mode: Chop/Zero
EE Clamping Mode: Full

VU options are set to the default ones

[refractionpcsx2]

I believe EE division chop zero doesn't work going back down the lift, which is why I did negative.

[vcx33]

settting EE division to chop/zero fixed the lift bug on my end
along with the other EE FPU settings i posted

[refractionpcsx2]

settting EE division to chop/zero fixed the lift bug on my end along with the other EE FPU settings i posted

Going up AND back down on the lift? Keep in mind you need to reload the level (transport from your ship) for it to take effect. If you don't reload it'll use the old settings, so savestates do not work here.

[vcx33]

yes up and down, you also dont need to reset the level you can just move forward a bit step on the warp pad and then come back. I also restarted the game several times to test every single bug

[refractionpcsx2]

alright, I just tried it, can confirm it seems be okay

[vcx33]

this EE FPU config still needs thorough testing to see if it breaks something else.

[vcx33]

Setting EE Division Rounding Mode to negative or chop/zero breaks a number of cutscenes, like the one where tidus washes up in besaid beach, and one in the kilika docks with wakka where he faces the wrong way, the latter only has this issue if playing the game for some time, if reloading a save right before it the bug doesn't happen similar to this: #8595
I guess FFX will always have FPU glitches one way or another.

[bigol83]

Ignore this, i retested it and disabling EE recompiler doesn't really fix it