[Mesa-dev] Another Take on the S3TC issue

[Uwe Schmidt]

Hi,

I have read about the issue of implementing the S3TC Extension in Mesa:
http://dri.freedesktop.org/wiki/S3TC/

As I understood, the problem is, that encoding and decoding S3TC in
software is covered by patents, while passing S3TC compressed data to the
GPU is still ok.

AS NOW:

If "force_s3tc_enable" is enabled in Mesa3D, uploading a S3TC encoded
texture works if format==internalFormat is true. If format!=internalFormat
is true, it would fail (as i know).

SO MY PROPOSAL:

If 'format' is one of the S3TC types, and format!=internalFormat is true,
then set internalFormat:=format.

Else, if 'internalFormat' is one of the S3TC types, but the 'format' isn't,
set internalFormat:=format (or any other format, Mesa3D can encode).