Re: [Mesa3d-dev] Re: [Dri-devel] Mach64 flatshading

[Leif D. <lde...@re...>]

On Tue, 16 Jul 2002, Keith Whitwell wrote:

> > Well, it's not high on my list.  I don't think flat-shading is used that
> > often, and the changes don't have any effect on smooth shading.  Actually, 
> > it _eliminates_ some saves/restores necessary for unfilled polygons with 
> > hardware flat-shading.
> >  
> > Actually, I think the problem is larger than mach64.  Rage128 has the same
> > problem and it appears to have GL compliant flat-shading based on the
> > primitive.  The problem is that for clipped polygons, the primitive type
> > changes, so flat-shading breaks down in that case (like with unfilled
> > polygons).  I think the templates would have to be changed to copy the
> > provoking-vertex color of the polygon being clipped into the vertices of
> > the triangles generated by clipping, rather than interpolating the color.
> 
> I'm surprised that this isn't working.  Can you verify?  I tested on the i810 
> at the time & definitely got clipping working there...

Here's a couple screenshots with the r128 driver (20020629 build):

http://www.retinalburn.net/linux/r128-unclipped-flat.png
http://www.retinalburn.net/linux/r128-clipped-flat.png

Allen's test program is attached.  Maybe someone could check this on 
Radeon with software tcl as well?

-- 
Leif Delgass 
http://www.retinalburn.net