The OpenGL Pipeline 004

[CouldntResist]

Yes, particularly the rendering to a one-component render target (you could probably do that in DX8.1 even, but definitely in DX9).

Oh come on, I've been doing that in GL since GeForce FX...

AFAIK, there is currently no way in OGL to perform a programmable MSAA resolve. My version of DX 10 SDK is missing any information about Texture2DMS and alike, so all I believe about this feature, is derived from the recent Epic comment about D3D10 enhancements in UT3 engine. If my understanding of the technique is correct, there is no equivalent GL extension yet.

 

[Andrew Lauritzen]

Oh come on, I've been doing that in GL since GeForce FX...

Using FBOs (see the OP)?

AFAIK, there is currently no way in OGL to perform a programmable MSAA resolve. My version of DX 10 SDK is missing any information about Texture2DMS and alike, so all I believe about this feature, is derived from the recent Epic comment about D3D10 enhancements in UT3 engine. If my understanding of the technique is correct, there is no equivalent GL extension yet.

There's some good information (and code samples) in a recent ATI presentation (the one that discuses "Frostbite" and so forth).

Regarding DX10/Vista adoption rates I don't think it's unreasonable to assume that it will be a good chunk of the AAA game user base in ~3 years (normal game development cycle length) based on similar results with DX9. Sure you didn't need to upgrade your OS to use DX9 but honestly I don't think that's much an issue since *all* new computes are shipping with Vista, and you can't really expect to play AAA titles on computes >3 years old. Anyways I'm sure everyone won't have switched over, but I suspect a significant enough percentage will have for it to be a reasonable target for a high-end game. Considering that incredibly inexpensive DX10-capable hardware is now available I think it's even more reasonable.

Of course I'm not the one who makes such decisions, and rightfully so

 

[GLX]

A subtle distinction when comparing DX9 and DX10 is that DX9 supports hardware many years older than its intro date (and still does). DX10 doesn't provide that kind of reach. NV7950 ? nope.. 1900XTX? nope. These aren't old or lame cards.

 

[Andrew Lauritzen]

A subtle distinction when comparing DX9 and DX10 is that DX9 supports hardware many years older than its intro date (and still does).

Not if you use DX9 features... IIRC R300 came out around the same time as DX9. And I don't really consider apps that link to the DX9 libs but use only SM1.4 (for example) to be "true" DX9 apps. I'm talking about real programs that *require* a fully DX9 card.

And remember while the 7950 and X1900 aren't old cards now, G80 already makes them look positively dated; in 3 years they'll be very "old" looking.

 

[BRiT]

IIRC R300 came out around the same time as DX9.

The R300 hit 3 to 4 months ahead of the DX9 release.

 

[Andrew Lauritzen]

The R300 hit 3 to 4 months ahead of the DX9 release.

Even more similar to G80 then

 

[GLX]

Nonetheless, given the DX9 API, an application writer *can choose* to develop an app that supports *their choice* of older hardware. With DX10, these choices are removed, and these choices include cards such as teh ones I mentioned.