Anisotropic extension, why not in core?


i’m really wondering why the extension for anisotropic texture filtering is still not in the core of gl 3.

I think it’s one of the most useful extensions at all. Does anyone know why it’s not in the core, although this extension is nearly one decade old?


Yeah, we had that discussion quite often over the last few years. I mean to remember that the extension is covered by a patent and thus by licensing fees and the ARB does not want to put something into core, that forces vendors to pay a fee to a third party.

On the other hand it is so widely supported, that it doesn’t matter whether it is in core or not, it will always be there.

Also, it only changes the very final output. So if you enable it, you get nicer graphics, that’s it. It does not change how you program your renderer. That means, in the rare case that it is not supported, your code does not need to change, at all.
So, even if it were missing on some hardware, it wouldn’t be an issue, at all.


What about a non-licensed implementation which support this extension, but with max aniso = 1 ?

EDIT: damn, they though about it on the spec :

What should the minimum value for MAX_TEXTURE_MAX_ANISTROPY_EXT be?
  RESOLUTION:  2.0.  To support this extension, at least 2 to 1
  anisotropy should be supported.