[131] 64 bit Major slowdowns in ACSrcade.wad in GL mode

Agent ME · Post by **Agent ME** » Sat Jul 19, 2008 17:54

Wad link - http://www.doomworld.com/idgames/index.php?id=15090

For some time after the map starts, there is heavy slowdown, and looking away from the duck hunt minigame seems to stop the slowdown. It would seem that it has something to do with the camera texture, but if you go into the area where the camera is and see the minigame objects first-hand, slowdown also happens there. Maybe it has something to do with how the scoreboard is rendered?

Oh and the slowdown only happens in the GL renderer.
I'm going to look at this again soon, but I posted it here so (mainly I won't forget about it but also so) someone might be able to give me some tips on what the problem could be and where I should look.

Post by **Graf Zahl** » Sat Jul 19, 2008 18:41

There's absolutely nothing special in that part of the map that could explain a slowdown - unless it's something that doesn't compile right in 64 bit mode. Good luck finding it.

Agent ME · Post by **Agent ME** » Sat Jul 19, 2008 22:59

I've figured out it's not the ACS, and it's not the sky textures.

I'm going to try to figure this out a bit more later (in an hour or a few days...). I've figured out how to compile and run gzdoom under a profiling application (gprof) and I've linked to the output at the bottom of this post.
Two profiles are gzdoom being run through in doom2 map01 with no slowdowns exhibited, the other two are from playing acsrcade with frequent full-slowdowns. The second one from acsrcade was run from gzdoom compiled with calls to SkyVertex() commented out, as I thought that might stop the slowdowns judging from the first profile - it didn't.

If anyone can find anything meaningful out of the profiles or suggest some other method, tell me so I can take a look. Otherwise I'll attempt again later to figure this out myself.

Profiling output

The_Funktasm · Post by **The_Funktasm** » Tue Aug 05, 2008 21:14

The camera/rendertarget screens cause it. I know this because Skulltag, which is a modified GZdoom port, has the same problem and it's always around camera screens.

Agent ME · Post by **Agent ME** » Wed Aug 06, 2008 1:19

Skulltag slows down with cameras in 64 bit mode, on linux, or overall? (They're finally making a 64 bit version maybe?) And on systems where there is slowdown, does it happen with all camera textures or specific ones? (It could be useful to see other cameras in wads this happens with.) Any idea why the game would also slow to a crawl even when the player wasn't looking at the rendered camera texture, but at the camera's viewpoint?

The_Funktasm · Post by **The_Funktasm** » Wed Aug 06, 2008 10:01

EDIT: What I said made no sense at all...

Alright, I'm certain it's because of a camera render, and not dependent on whether it's 32 bit or 64, Gzdoom or Skulltag.