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View Full Version : OpenGL vs. DirectX and the future of this conflict


serAph
09-17-03, 04:40 PM
Ah. We have a new home.... lets see... where did we leave off?

(original content here (http://www.nvnews.net/vbulletin/showthread.php?s=&threadid=18145&perpage=25&pagenumber=3) about half way down the page)

and we left off around the bottom of here (http://www.nvnews.net/vbulletin/showthread.php?s=&threadid=18145&perpage=25&pagenumber=5) with:

Originally posted by Skuzzy
Nutty, what version of OpenGL added PS/VS shaders? Which one added the fragment branching, or is that NVidia specific?

I can coorelate feature addtions if I know what revisions of OpenGL added things, as opposed to DX. Currently, my understanding is that ATI/NVidia are at version 1.5 or so of the ARB? Is that a fair assumption?

EDIT: We are getting very OT here. Maybe another discussion thread about this is in order. Sorry for the OT mods and thread starter.

Skuzzy
09-17-03, 04:48 PM
Thx. I didn't know you were a mod? How did I miss that?

I need to pull my head out of the compiler once in a while.

Nutty, ball's in your court. I can supply the DX side of when things happened and the limitations as well.

The Baron
09-17-03, 04:55 PM
Thx. I didn't know you were a mod? How did I miss that?
He's a mod? Over my dead body.

TheOneKEA
09-17-03, 04:56 PM
Speaking from a total OGL n00b, all I care about is good Linux OpenGL for Doom 3.

What is the specific status of the Linux ATi OpenGL driver support (if anyone knows)?

The Baron: Remind me never to upset you, sir.

Nutty
09-17-03, 05:01 PM
doh.. just finished replying in the other thread..

Nutty, what version of OpenGL added PS/VS shaders? Which one added the fragment branching, or is that NVidia specific?

I can coorelate feature addtions if I know what revisions of OpenGL added things, as opposed to DX. Currently, my understanding is that ATI/NVidia are at version 1.5 or so of the ARB? Is that a fair assumption?


Well NV introduced vertex shaders along time ago. About Detonator 7 they were available as emulation in the drivers. This was months before the GF3 emerged with them in hardware. This was NV_VertexProgram, which was the equivelent of DX8 Vertex Shaders, however DX8 wasn't out at this point.

DX8 class pixels shaders arrived with the GF3, in the form of NV_TextureShader, and NV_RegisterCombiners. Technically they could achieve more than DX8 pixel shaders, but were a bugger to code for.

Current drivers support opengl 1.4. Currently the ARB standards, ARB_VertexProgram (which come to think of it, is more akin to DX8 class Vertex Shaders) and ARB_FragmentProgam (DX9 class pixel shader) are only ARB extensions. They should be in the core of 1.5 though.

NV_VertexProgram2, is the GF-FX Vertex Shader, which has dynamic branching. NV_FragmentProgram is basically PS2.0, but slightly better. It has conditional statements, (not true branching) and much higher instruction counts.

Now, if we're talking about pure ARB only stuff. we currently have
ARB_VertexProgram = DX8+ Vertex shader
ARB_FragmentProgram = DX9 Pixel Shader.

Now, the new GLSlang language, introduces two new versions called

ARB_VertexShader, and ARB_FragmentShader. These are the two vertex and fragment shader implementations for the upcoming GLSlang high level shading language compiler.

I haven't looked at them much, but they're probably similar to DX9 equivelents. Perhaps with a few extra features, I dont know.

Anyone know if a new Vertex Shader was introduced in dx9, and what features it has over dx8 vertex shaders?

serAph
09-17-03, 05:14 PM
Originally posted by The Baron
He's a mod? Over my dead body.

haha - feelin' the love again ;) :D

Skuzzy
09-17-03, 06:08 PM
Oops. LOL! Nutty,..we gotta get on track. I'll snarf my post from the other thread.

Nutty, click here (http://test.hitechcreations.com/PSVersion.htm) to see the opcode listings and what versions of pixel shaders they are associated with. That should give you an idea of how pixel shaders have progressed in DX (sorry it ain't pretty, it was he best I could do in the few minutes I had).

I looked at Cg and the output, for DX anyways, was not very pretty at all. HLSL does do a better job, if you are looking to keep the shaders generic.

Skuzzy
09-17-03, 06:14 PM
Originally posted by TheOneKEA
Speaking from a total OGL n00b, all I care about is good Linux OpenGL for Doom 3.

What is the specific status of the Linux ATi OpenGL driver support (if anyone knows)?

The Baron: Remind me never to upset you, sir.

Catalyst Maker alluded to them working on better support for Linux, but I cannot remember when it was coming. Seems he was not in charge of it until recently, but dun't quote me on that. I have slept since then.

Skuzzy
09-17-03, 06:15 PM
Originally posted by The Baron
He's a mod? Over my dead body.

Heck, I'm just a programmer,..all this WEB shizz confuses me. :D

Nutty
09-17-03, 06:26 PM
Reporting for duty, Sir! :p

Skuzzy
09-17-03, 06:35 PM
ROFL! Did that link I posted help explain how DX shaders have evolved?

The Baron
09-17-03, 08:07 PM
Originally posted by Skuzzy
Catalyst Maker alluded to them working on better support for Linux, but I cannot remember when it was coming. Seems he was not in charge of it until recently, but dun't quote me on that. I have slept since then.
Linux drivers have been integrated into the Catalyst program thingy, so we'll probably see Linux Cats by November.

TheOneKEA
09-18-03, 04:29 AM
That is very good :D

Is that DX opcode page FUBARed? ALl I see is abunch of X's next to raw assembly language. Or is it just supposed to be a checklist, showing the progression of the shader assembly language from DX7 to DX9?

Skuzzy
09-18-03, 04:56 PM
It's a checklist to show what shader opcodes are available for each version of the pixel shaders.

Hey,..I'm a programmer, not a WEB site guru. HTML and me do not get a long. It was the best I could do in 10 minutes.

TheOneKEA
09-18-03, 05:33 PM
ACK.

I don't suppose anyone knows when the new Linux Catalysts will be madde available?

serAph
09-18-03, 05:41 PM
Originally posted by TheOneKEA
ACK.

I don't suppose anyone knows when the new Linux Catalysts will be madde available?

hmm..

*looks @ watch*

oh only a few years after nVidia officially supported it..


heheh - sorry. I love making fun of both companies ;)