[Julian Bäume <julian@sv...>]

On Sunday 03 January 2010 12:42:42 Axel Jäger wrote:
> > Concerning the float/double question:
> > on most (all?) of our target platforms, float will have single-precision,
> > where double offers double-precision. Of course, size differs and float
> > might be faster on embedded platforms, like arm. I think, as long as we
> > don't encounter any performance issues, because of matrices with really
> > large dimensions, we should use double.
> 
> If your main concern is bad performance on ARM, use qreal. It is a double
> on all plattforms except ARM. It is used in QGraphicsView for nearly
> everything.
That was just an example ;) I'm aware of qreal and what it does (that is 
actually, why I choose this example here). I just wanted to make clear, that 
double might be a better choice, since float has only some limitations on a 
few (one for those Qt is running on) platforms. I don't see arm as a target 
platform for KTechLab (or do we expect widely deployment of arm-based netbooks 
any time and want to use KTechLab on them? May be, we should think about 
that.. ;)). The point is: float has limitations, most of our target platforms 
support double precision (and even long double) in hardware, so we should just 
use double, IMHO.

bye then
julian