tc-1.1.tar.gz is a working codec for FXT1 and DXTn texture compression. It has a balanced speed/quality ratio, and is very tweakable.
Both FXT1 and DXTn use vector quantization for lossy encoding. The decoder is rather trivial, at the expense of the encoder complexity. This means that applications heavily relying on texture compression should provide precompressed textures, for several obvious reasons:
The FXT1 and DXTn codecs were written using documentation freely
available on the world-wide-web, including, but not limited to:
3DFX_texture_compression_FXT1 and EXT_texture_compression_s3tc
from http://oss.sgi.com/projects/ogl-sample/registry/
I just translated the human readable spec into ANSI C. There are
NO binaries available, as I am NOT using this code! Therefore,
THE RESPONSIBILITY OF USING THE CODE IS ENTIRELY WITH YOU!
The implementation per-se is made available under GPL, which does not necessarily apply to the abstract content (texture compression algorithms):
FXT1 is subject to "3DFX FXT1 Source Code General Public License"
DXTn is basically the S3TC texture compression, a license to the "S3TC Intellectual Property" may be required prior to any use.
There is significant IP associated with the S3TC format. Existing users probably have executed licenses directly with S3 or its successors (Sonic Blue, S3 Graphics).
The current ownership of the S3TC IP is unknown to me. It is known that when S3 exited the graphics hardware business, part of their operations were sold to ATI and part were spun off to a joint Taiwanese venture with Via Technologies, called S3 Graphics.
I, DANIEL BORCA, AM NOT AWARE OF ANY LEGAL ISSUE CAUSED BY RELEASING THIS CODE. Prior to commencement of legal action, the Plaintiff should make an informal demand to Cease and Desist. In deference to the regulations of the Federal Communications Commission, which requires notice prior to filing an action, and in the spirit of cooperation, all complaints, issues and concerns should first be directed to me in an effort to resolve them amicably and promptly. FCC s2250.
Daniel Borca