[Mesa-dev] glean pointSprite test

[Pauli Nieminen]

On Wed, Apr 14, 2010 at 8:01 PM, Keith Whitwell <keithw at vmware.com> wrote:
> On Tue, 2010-04-13 at 23:27 -0700, Dave Airlie wrote:
>> So I've finished the r300g point sprite code and this test fails,
>> fglrx fails the exact same way.
>>
>> http://people.freedesktop.org/~airlied/piglit/fglrx/fglrxr500/test_glean__pointSprite.html
>>
>> It appears the point size where the texture sampler decides to use the
>> next mipmap is different than the swrast/softpipe.
>>
>> Any GL experts tell me if this is actually well specified or hw specific?
>
> I think it's pretty well specified.  See the calculations of lambda in
> section 3.8 of the GL spec.  I don't know if hardware is as uniform as
> that makes out though.
>

I did fix similar mipmap selection problem in r200 with minor
correction value to LOD bias. There was already small correction to
LOD bias in driver code but ti wasn't enough to pass piglit.