S3TC => r600{c,g}

[nanonyme]

And more importantly, do the same patents still cover it even though it was invented and implemented by ATi...

[whizse]

I agree, but I wonder why it doesn't work like that.

If AMD is developing a driver for AMD hardware, and this driver only runs on AMD hardware (obviously), then why is it not covered by the AMD patent license?

I mean, the patent is not a trade secret -- everybody knows how it works, and can look it up at the patent office. Using the license for their drivers should therefore not be a problem even if the source is open.

Another reason why software patents are an evil pile of crap.

No idea how a patent license is written, but I think it would be hard to comply with it, and at the same time license the code under an MIT license.

[whizse]

The bad news is that S3TC isn't the only patented stuff in GL3:

http://www.x.org/wiki/Events/XDC2009/Notes#idr.3AOpenGL3andMesa

[adamk]

Gallium can load an external s3tc library on demand if it's available. The major legal issues are hopefully on user's end. r600g will assumably sooner or later have a similar stance to s3tc as r300g. Of these I'm fairly sure. I'd give it a whack myself if I a bit less vague idea of how it works.

Unless I'm mistaken, it doesn't even work (properly) on r300g with multitextured apps.

Adam

[pingufunkybeat]

No idea how a patent license is written, but I think it would be hard to comply with it, and at the same time license the code under an MIT license.

So licence the s3tc part (and only that) under the GPL.

Best of all, abolish the nonsense already, most of the planet does not even allow such silly patents.

[nanonyme]

Unless I'm mistaken, it doesn't even work (properly) on r300g with multitextured apps.

Oh, right. How many of real texture compression programs does that rule out?

[adamk]

I've only tried a few apps that use S3TC on r300... Neverwinter Nights, doom3, ut2004, and quake4 come to mind. Of those four, S3TC only works properly with NWN (last I tried).

Q4 won't even start without S3TC, and using the external lib on r300 with Q4 screws up the textures so bad the game is unplayable (as is the case with ut2004 and doom3). At least UT2004 and Doom3 will run without S3TC as it's not a hard requirement on those games.

So, here, s3tc works on r300g with one out of four apps. Not exactly impressive, and something that desperately needs to be addressed by someone.

Adam

[Nille]

in germany software patents are against the law but microsoft win on the highest Court with there FAT software patents.

But not in Germany.

do you really think there are only 2 countries?

USA and Japan.

[Nille]

Gallium can load an external s3tc library on demand if it's available.

The Mesa Classic driver do the same and if you install the Library the Driver advertise the Extension but in the Application you see only broken Textures.

I have postet an Link to the Bug Report. In this bug are some Screenshots.

[RavFX]

You don't need to do anything to decompress DXT textures as the card can handle them directly. However, the card needs to be told it is getting compressed textures. Unfortunately, the register documentation released by AMD doesn't give the format codes for DXT textures (for IP reasons). The r300 driver has support because the format codes were guessed.

Can it be the reason why it's not implemented?

I did notfind the DXT* register number in the AMD documentation. Or I may have searched wrong.