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Re: The great DX vs GL debate

Posted: Sat Aug 04, 2012 7:46 pm
by BobbinThreadbare
Jason181 wrote:
Game_boy wrote:
Most games are developed for consoles first. Since PS3 can't use Direct3D, why don't they already have a GL port of everything anyway?


I could be mistaken, but I don't think PS3 supports OGL calls? PS3 does support OpenGL ES, evidently. PS3's hardware is a pretty far removed from x86 PCs though. Some of the programming is bare to metal to eek out all the performance possible.

On the CPU side, the GPU is an Nvidia 7800 (I think, I might have the wrong model number).

Most games these days are Unreal 3 engine anyways. So if Epic ports their engine to Linux, then it should be trivial to get the games to work on it.

Re: The great DX vs GL debate

Posted: Sat Aug 04, 2012 8:00 pm
by cheesyking
I think something this whole debate is missing is that a vast amount of the effort that goes into 3d games is not related to whether you use opengl or dx. Models, textures, level design, sound, AI, story, cut scenes etc. I don't actually work in the gaming industry but I'd have thought with all the other stuff that goes into games the cost savings of only doing one code path Vs doing two is relatively small, even when you allow for having to do extra testing.

There's not really any need for an either / or choice about dx and opengl so the tiny advantages one system might have over another don't really matter that much.

Re: The great DX vs GL debate

Posted: Sat Aug 04, 2012 8:29 pm
by Madman
cheesyking wrote:
I think something this whole debate is missing is that a vast amount of the effort that goes into 3d games is not related to whether you use opengl or dx. Models, textures, level design, sound, AI, story, cut scenes etc. I don't actually work in the gaming industry but I'd have thought with all the other stuff that goes into games the cost savings of only doing one code path Vs doing two is relatively small, even when you allow for having to do extra testing.

There's not really any need for an either / or choice about dx and opengl so the tiny advantages one system might have over another don't really matter that much.

I agree, maintaining setups for different platforms is probably tougher than supporting DX and OGL.

Re: The great DX vs GL debate

Posted: Sun Aug 05, 2012 9:20 pm
by Jason181
BobbinThreadbare wrote:
On the CPU side, the GPU is an Nvidia 7800 (I think, I might have the wrong model number).


The different CPU and the paltry amount of shared memory is what I was referring to, but I'd imagine they'd also need to make changes from OGL ES to OGL. Those are such huge differences, that I doubt they'd take anything from the PS3 and attempt to adapt it to PC.

As the article states, they started out at 6 fps on Linux. I suspect that even if the engine was ported, there would be considerable work to get each game working and performing properly. Most developers probably aren't going to do that.

Re: The great DX vs GL debate

Posted: Sun Aug 05, 2012 9:34 pm
by codedivine
Jason181 wrote:
PS3 does support OpenGL ES, evidently. PS3's hardware is a pretty far removed from x86 PCs though. Some of the programming is bare to metal to eek out all the performance possible.


PS3 does support OpenGL ES, but my understanding is that very few games actually utilize OpenGL on the PS3. It is more there for prototyping. There is a separate low-level graphics library, and that is what most engines build on top of for the PS3.

Re: The great DX vs GL debate

Posted: Mon Aug 06, 2012 6:16 am
by cheesyking
Jason181 wrote:
As the article states, they started out at 6 fps on Linux. I suspect that even if the engine was ported, there would be considerable work to get each game working and performing properly. Most developers probably aren't going to do that.


Porting to a different OS is very different from porting between OGL and DX.

Without wanting to derail this thread too much what I see most in the Valve linux blog you're quoting is that writing your code to run on multiple platforms helps you write better code. It's has to better segmented into reusable blocks and gives you an opportunity to see whether a bug is in to your code or in the platform you're running on.

Re: The great DX vs GL debate

Posted: Mon Aug 06, 2012 3:06 pm
by Jason181
cheesyking wrote:
Porting to a different OS is very different from porting between OGL and DX.


What made you think I don't know that? In this case though, they did both. In pretty much every game that's going to be the case with porting, since they use DirectX.

The part that's probably confusing is that I only quoted part of his post, but the portion you're reading is referring to this comment:

BobbinThreadbare wrote:
Most games these days are Unreal 3 engine anyways. So if Epic ports their engine to Linux, then it should be trivial to get the games to work on it.

Re: The great DX vs GL debate

Posted: Mon Aug 06, 2012 4:42 pm
by cheesyking
Jason181 wrote:
cheesyking wrote:
Porting to a different OS is very different from porting between OGL and DX.


What made you think I don't know that? In this case though, they did both. In pretty much every game that's going to be the case with porting, since they use DirectX.


Sorry, it's just that as I read it you were bringing up figures about porting windows to linux in a thread about DX and OGL.

Also technically in this L4D2 linux case the engine already had support for OGL they just hadn't exposed it to windows users before so that 6fps for the initial port probably had far more to do with them needing to rewrite their memory allocation stuff than problems with supporting OGL. Source engine needs OGL support to work on macs anyway.