[Development] Move math3d from QtGui to QtCore

[Laszlo Papp]

> Qwt would also have interest interest in classes like QPointF3D

+1

> but this is not what QVector3D is ( or at least in Qt4 was ). As far as I
> understood QVector3D is designed as a helper class for drawing and IMHO
> should stay in QtGui as long as it is not implemented with a more common
> use case in mind.

The whole proposal is about "to implement with a more common use case
in mind"...

> But even with a different class design I agree with Thiago that it
> doesn't need to be QtCore where to move the class. Together with related
> algorithms ( often implemented, but not part of the API ) it could be
> indeed a valuable module.

So, instead of adding these few classes into QtCore, there would be a
need another module. Who supports the creation of such a math library
in Playground? Not that, I could work on that right now, just asking.

> What I would like to see in QtCore is what I had expected from a name
> like QVector2D: a template for 2-dimensional arrays ( or more ) like
> QVector.

Something like QVector<QPair> >. Not perfect, so I can understand your
calling for convenience.

BR,
Laszlo Papp