[Mesa-dev] gl_NormalMatrix issue on Intel driver

[tom fogal]

Hi Ian, Kenneth,

Ian Romanick <idr at freedesktop.org> writes:
> On 10/10/2011 03:30 PM, tom fogal wrote:
> > One of our programs which relies on shaders heavily is having
> > issues, and I have tracked it down to unexpected values in
> > gl_NormalMatrix within the fragment shader.
>
> I think we could make a more general piglit test the reproduce this
> sort of failure.

Attached is a new patch against piglit master.  I took the approach of
generating the shader instead of uniforms, because I perceived it to be
easier to specify .x, .y, and .z as the gl_NormalMatrix vector element.

> > Is this a known issue?  Any workarounds available?  Anything else I
> > could do to help debug?
>
> Yikes!  A *lot* has changed in the fragment shader back-end for i965
> since 7.10.2.  Have you at least tried 7.10.3?  7.11?

I've compiled Mesa master (983fa4) and enabled it (thanks for the help,
Kenneth!) and I can reproduce it there.

The attached piglit test succeeds with: the nvidia binary blob,
and with both versions of Mesa (7.10.2 and master-983fa4) when
LIBGL_ALWAYS_SOFTWARE is set to 1.  It fails on both versions of Mesa
when software mode is disabled.

What else can I do to help?

Thanks,

-tom

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