Re: [Mesa3d-dev] EXT_fog_coord, EXT_secondary_color

[Michael V. <bri...@lo...>]

On Fri, Oct 27, 2000 at 12:46:32PM -0600, Keith Whitwell wrote:

> Not really.  The FX driver basically turns this code off as the hardware
> normally fogs from the z or 1/w values (I can't remember which).  I'm sure
> it's just a matter of setting up the fog table correctly for orthographic
> projections & making sure that some usable value gets into the vertex format.  

The w-value is always 1 (or 0, can't remember) for vertices in an
orthographic projection, and the 3Dfx card uses the w-value for
indexing into the fog table--thus everything is fogged with the fog
color from entry 1 (or 0).

In the past, Brian and Daryll mentioned using an alternatve fogging
method available in Glide3 (a z fogging method), but I don't believe
it was pursued.

m.

-- 
Programmer             "Ha ha." "Ha ha." "What are you laughing at?"
Loki Software                      "Just the horror of being alive."
http://lokigames.com/~briareos/                   - Tony Millionaire