[Mesa-dev] EXT_texture_compression_RGTC support

[Dave Airlie]

Hi guys,

I've pushed a branch to my personal repo with support for mesa core +
swrast + gallium (enough for r600g to work) for this extension.

I've just ported the alpha compression from Roland's DXTn work and as
far as I can ascertain from reading the EXT_texture_compression_rgtc
specification there is no IP issues declared.

I'm sure the compression code could do with a cleanup (and it had to
be duplicated, once for unsigned and once for signed conversion).

There are couple of tests in piglit rgtc-teximage-01 and
rgtc-teximage-02 which I've tested against fglrx but measuring failure
is difficult due to possible compression artifacts.

In theory for softpipe/llvmpipe to work I think I need to add
u_format_rgtc.c with copies of the code again I suppose.

Dave.