Valve's L4D2 Is Faster On Linux Than Windows

[ownagefool]

A DX to GL wrapper? Isn't that how Wine handles D3D games and software? What would be the point with another one?

I think its probably somewhat different actually. I'm certaintly no expert, but I in WINE imagine theres some hackage where black box calls are intercpeted and coverted, whilst putting an abstraction in your engine is probably a bit more straight forward and sensible. Its probably not VERY different, but different enough. It depends on specifics though, something that'd take someone with actual knowledge to answer.

More importantly though, WINE does a hell of a lot more than translating D3D to OpenGL and it tackles a wide base not a specific engine. Personally, I honestly don't care how its done, as long as its on par with the Windows version.

[Kristian Joensen]

A DX to GL wrapper? Isn't that how Wine handles D3D games and software? What would be the point with another one?

[entropy]

Good question. AFAIK they will be at the OpenGL Birds of a Feather Wednesday, 8 August 6:00 pm - 7:00 pm | JW Marriott Los Angeles L.A. Live - Gold Ballroom Salon 3 . Any additional info? Slides, video, live streaming?

They answered a similar question on their blog.

peter_2 says:
August 2, 2012 at 10:29 am

Will a video of the SIGGRAPH presentation be made available on this blog?
I would really like to watch it, because I cannot attend it in person.

Valve Linux team says:
August 2, 2012 at 3:11 pm

Great idea. We?ll make our information available in whatever form we can.

[kwahoo]

I couldn't find the date on the siggraph site.

Good question. AFAIK they will be at the OpenGL Birds of a Feather Wednesday, 8 August 6:00 pm - 7:00 pm | JW Marriott Los Angeles L.A. Live - Gold Ballroom Salon 3 . Any additional info? Slides, video, live streaming?

[ownagefool]

Well, its doable. All you'd really need is a 1:1 function equivalent for every OGL call. Problem is, so many DX functions rely on various Windows calls, you need to emulate those too to a certain extent. Plus, the overhead cost of running an interpreter.

Also remember its not just the graphics part of the game you need to rip out to make a port, you also need to remove all those windows specific API calls, and I can assure you theres a LOT of them. So making a OGL to DX wrapper won't magically make everything ported to linux.

Given the OS X port, its probably OK to assume those specific Win API calls are going to some sort of abstraction layer. They'll still need to write the functionality, but I imagine its a lot simpler when you're not playing hunt the platform specific code.

[curaga]

When is the siggraph talk? I couldn't find the date on the siggraph site.

[kwahoo]

Some interesting comments (Q&A) from blog:

Durandle says:
I?m interested to read that the rendering is achieved via a D3D > OpenGL abstraction layer, especially as it appears to be faster to do that than native D3D usage, that seems somewhat counter intuitive!

I?d be interested to know though if your abstraction layer is generic enough that it could be applied with the same success to non-source-engine games, since that would be a nice big door to open, unless that?s something you don?t wish to discuss right now! The prospect of an almost no-effort-needed wrapper that achieves native performance is a good one.

Valve Linux team says:
Although the abstraction layer is currently quite powerful don?t think of it as an ?almost no-effort-needed? layer. A lot of time and effort was spent to get the layer (and L4D2) to the point it is today and we still aren?t finished.

Durandle says:
Is it overly simplistic to think of it as a library that exposes a DirectX API that converts to OpenGL on the fly?
(...) Would it be valid to compare what you are doing to be similar to what Transgaming?s Cider does?

Valve Linux team says:
It?s too early to answer those questions as we?re still learning a lot about Linux porting but it is our hope that this work will be useful for porting games besides L4D2.

[gamerk2]

Is there anyone with interest in replacing OpenGL(Linux or not)?? In case there is such a big demand for D3D on Linux they can write a State tracker and be done with it. Can't they??

Well, its doable. All you'd really need is a 1:1 function equivalent for every OGL call. Problem is, so many DX functions rely on various Windows calls, you need to emulate those too to a certain extent. Plus, the overhead cost of running an interpreter.

Also remember its not just the graphics part of the game you need to rip out to make a port, you also need to remove all those windows specific API calls, and I can assure you theres a LOT of them. So making a OGL to DX wrapper won't magically make everything ported to linux.

[SolidSteel144]

I'm heading over to Valve HQ at the end of this month.
Can't wait to visit their Linux dev cabal (I already got the okay for that).

[RussianNeuroMancer]

Source 2 engine references have been found in Source Filmmaker.

I hope this one will have OpenGL 4 support.