Re: Large textures getting soft

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Dirk Reiners (reiners++at++ecrc.de)
Fri, 30 May 1997 15:11:02 -0600


On May 29, 6:35pm, Dewey Anderson wrote:
> Subject: Re: Large textures getting soft
>
> Say Hallelujah! When I do this, it comes back with 512. That certainly
seems
> like the problem.

Well, now it gets more complicated... ;)

> Now the question is, what sets that limit? Is this something I can change to
> 1024? And can anybody verify that this would cause filtering?

There's no way you can change it, it's a restriction of the implementation.

> (I guess I'm still puzzled, because when I do this in my little test program,
> it ALSO says 512, but there is no softening.)

The restriction is worst case, i.e. if you turn on all the bells and whistles
the implementation will give you 512x512 max. If you don't use every feature it
can support bigger textures. The real way to test it is the texture proxy.

But this hints at not using the exact same texture paramters in both test
cases. Try to run the test with 1 texture only using ogldebug and take a look
at all the texture-relevant calls, especially glTexParameter*. If they aren't
the same this might be the problem.

> BTW, I do have the MINFILTER set to MIPMAP_TRILINEAR but since the pixels and
> texels are the same size, I wouldn't think this would come into play.

So you're only using a 720x486 part of the texture by giving restricted texture
coordinates? Just try to turn the MipMapping off and see what happens. Mipmaps
take more texture mem and you might exceed the capabilities of your machine
(althoguh usually in that case the texture doesn't show up at all). It's a shot
into the dark, but it's easy to do.

>-- End of excerpt from Dewey Anderson

Hope it helps

        Dirk

-- 
-- Dirk Reiners     reiners++at++ecrc.de   True straightness seems crooked.
-- ZGDV - AR Group                          True wisdom seems foolish.
-- Arabellastr. 17 (ECRC)                      True art seems artless.
-- D-81925 Muenchen  All standard disclaimers apply. 
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