[Bug 20626] r200 texgen with glVertex4f(x, y, z, w) error

[<bug...@fr...>]

http://bugs.freedesktop.org/show_bug.cgi?id=20626





--- Comment #12 from raoxianhong <rao...@16...>  2009-03-17 18:06:53 PST ---
(In reply to comment #11)
> (In reply to comment #10)
> > (In reply to comment #8)
> > > R200 is correct, and you. The real world is 3D world, we can only use three 
> > > indenpendent parameters talk with it.
> > > 
> > > But can I set q coordinate to 1.0f when I disable texgen Q?
> > As said the chip might have problem with disabling only some texgen coords,
> > though in this case if you don't need a texture matrix it might be fine.
> > You can play with R200_TEXGEN_FORCE_W_TO_ONE but this setting doesn't seem
> > useful to generate OpenGL-compliant results.
> Yes, I do the same operation under ATI's windows driver, and no problem with
> disabling texgen R or Q, (and when enable all of texgen STRQ, they looks like
> not set R200_TEXGEN_FORCE_W_TO_ONE), so I guess they maybe have another way to
> set q to 1.0 when disable texgen Q. To play with R200_TEXGEN_FORCE_W_TO_ONE is
> not a right way but a useful way sometimes.
> And sometimes when we disable some of the texgen coords, the r200 produce
> unexperted results, this maybe we have no right way to generate q coord(for
> examples, q is zero), but ATI can do it!

An acceptable way maybe when user disable texgen Q, driver can enable it on
R200, and set q1 = q2 = q3 = 0.0f, and q4 = 1.0f, and set the
R200_TEXGEN_FORCE_W_TO_ONE, thus we can get q to 1.0f. it is OpenGL-compliant!


-- 
Configure bugmail: http://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.