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View Full Version : Is OGL 1.4 == D3D9 ???



nomad516
10-10-2003, 03:13 AM
Hi,

I'd like to ask if OpenGL 1.4 has everything that Direct3D9 has? like pixel shaders and stuffs?

what does OpenGL1.4 has (functionality) that Direct3D9 doesn't?

what does Direct3D9 has (functionality) that OpenGL1.4 doesn't?

Thanks.

mdog1234
10-10-2003, 04:42 AM
This is just my opinion and others may not agree. DX9 is better than openGL and no 1.4 != DX9. if opengl 2.0 ever came out that may be more like DX9. However, I havent ever had a problem in openGL that would be easily solvable in DX9. Its really up to you. I think openGL is easier to learn but I think most game companies use DX9 because it is higher performance

nomad516
10-10-2003, 07:25 AM
thanks.

well, how about opengl1.4 + Cg...

is ((OGL1.4 + Cg) == Direct3D9) ???

what would direct3d9 have that (OGL1.4 + Cg) doesn't have?

thanks.

vincoof
10-10-2003, 07:50 AM
Cg can be run on OpenGL as well as Direct3D, so you can't comppare (GL+Cg) and (DX).

Direct3D in DX9 is more recent that OpenGL1.4, so it mainly have more features like pixelshading. With that said, OpenGL still can perform stuff like pixelshading but you need extensions.
It is really unclear how to compare D3D and a certain version of OpenGL because OpenGL extensions do apply on top of the core specification, and it is undefined that a range of hardware will support extension regardless of the OpenGL core support.

If I'm not clear, that's fine. DirectX vs OpenGL topic is considered a troll, and if this board was moderated I bet that the topic would already be closed.

Tom78
10-10-2003, 08:33 AM
OpenGL 1.5 will be more like DX9, with an integrated high level shading language.

cu
Tom

zeckensack
10-10-2003, 08:51 AM
*sigh*

PS2.0 ~= ARB_fragment_program
VS2.0 ~= ARB_vertex_program

What OpenGL lacks is a unified interface for 'smaller' shader hardware, like Geforce 3 and Radeon 8500.

Regarding performance, DirectX Graphics by design can't be faster than OpenGL. It performs more switches to kernel mode and is a layered model involving more function call overhead and command forwarding.

That doesn't mean that it's slower. DXG is simply more sensitive to batch size/number of batches per frame than OpenGL.

OpenGL drivers - warning: generalization - are somewhat inefficient when it comes to direct surface operations like blits. That's however implementation dependant and doesn't really have anything to do with API design.

vincoof
10-10-2003, 09:34 AM
Originally posted by zeckensack:
VS2.0 ~= ARB_vertex_program

Doesn't VS2.0 integrate branching ?
If so, VS2.0 is merely a NV_vp2 more than ARB_vp

nomad516
10-11-2003, 01:08 AM
Oh, there's Opengl 1.5 already? didn't know that...


so pixel shaders in direct3d9 is ARB_fragment_program in OGL?

and vertex shaders in direct3d9 is ARB_vertex_program in OGL?


thanks.

al_bob
10-12-2003, 09:08 PM
so pixel shaders in direct3d9 is ARB_fragment_program in OGL?

and vertex shaders in direct3d9 is ARB_vertex_program in OGL?
More or less. The different versions of pixel shaders and vertex shaders correspond to different fragment and vertex program extensions in OGL.

There isn't really anything (meaningful) that you can only do in one API and not in the other.

vincoof
10-13-2003, 03:14 AM
Originally posted by nomad516:
Oh, there's Opengl 1.5 already? didn't know that...
Not yet, but very soon it will be.
The ARB majorly discussed about upgrades, and now it's just a matter of time before the final specification comes out.

nomad516
10-13-2003, 07:40 AM
i see now.

this means that anything i can do with direct3d can be done with opengl.

ok, thanks guys. http://www.opengl.org/discussion_boards/ubb/smile.gif.

10-14-2003, 09:47 AM
Originally posted by nomad516:
i see now.

this means that anything i can do with direct3d can be done with opengl.

ok, thanks guys. http://www.opengl.org/discussion_boards/ubb/smile.gif.

Thanks a lot for the info!