[Development] Move math3d from QtGui to QtCore

[Laszlo Papp]

> We've long stopped discussing your project. The moment you suggested making
> this a Qt feature, we stopped talking about your needs and we started talking
> about everyone's needs. I expect you to come up with and consider a reasonable
> set of use-cases when proposing Qt classes or a Qt module.

OpenGL, Audio 3D, QtSensors, Qwt, and others are not really just "my
project" who spoke up to have something common.

> Yes, it might be a sad conclusion for your project, but it is probably a happy
> conclusion overall.

As far as I see, way more people wanted to have more in common as a
collaborative way than not.

> You only proposed moving, with no plan going forward. I'd like to see such a
> plan, how you plan on making changes (and when, considering that 5.0 should be
> close now and that sets binary compatibility requirements). You have not done
> that. So I simply cannot accept moving anything now and I think Gunnar feels
> the same.

Well, I did say my use cases, and what I would need (float and
integers), so I do not understand this comment. Not to mention, I did
say in my first email, what I should change during the porting effort
about getting this UI free.

> Instead, I recommend you start a new module doing mathematical stuff. In doing
> that, you may need to address a lot more use-cases, like those Charles
> mentioned in this thread. You might end up with something very close to Eigen
> in that case.

No, that is the whole point. I would *not* like to depend on such a
difficult mathematical library or unnecessarily Qt UI library when I
only need position tracking. Depending on A-Z, if you only need A is
weird. Especially, if A is already almost in place.

Best Regards,
Laszlo Papp