[Mesa-dev] S2TC - yet another attempt to solve the "S3TC issue"

[Rudolf Polzer]

On Wed, Aug 10, 2011 at 11:42:11AM +0200, Philipp Klaus Krause wrote:
> Am 10.08.2011 11:34, schrieb Rudolf Polzer:
> 
> > 
> >> The OpenGL ARB cannot incorporate S3TC into a core spec anyway.
> > 
> > But it already is core part of OpenGL 3.0.
> 
> No.
> 
> Making S3TC part of OpenGL was discussed, but rejected. OpenGL only
> requires RGTC (since OpenGL 3.0) and BPTC (since OpenGL 4.2).

Ah, okay then.

Speaking of BPTC - what is its patent situation? From a quick glance at the
extension spec, it does seem to use S3TC's interpolation method, so it likely
is not safe from S3's patents. But I may be wrong there, as BPTC is quite messy
and convoluted, and I may have misinterpreted that interpolation value
sequence.

Best regards,

Rudolf Polzer