Re: TGeoElementTable::Instance (fwd)

Hi Sue,

I have implemented the necessary changes such that it is now possible to draw different geometries in the same pad. (now in CVS).
Let us know if everything works in your case.

Rene Brun

On Sun, 24 Apr
2005, Sue Kasahara wrote:

> Hi Andrei & Rene,
> Thanks! I've tested the fix and I seem to be able to build two
> geometries now in memory and switch between them.
> I'm wondering if you can expand a little bit on this restriction:
> > - do not try to draw in the same time 2 geometries
> I can see that it would be a problem to draw two geometries
> on the same canvas simultaneously, but I'm wondering if I should
> expect that it's possible to draw 2 geometries sequentially in the same
> root
> session after switching gGeoManager to point to the current geometry?
> In my own experiment this fails: the first geometry draws okay, the
> second does
> not.
> Thanks again,
> -Sue
>
> Andrei Gheata wrote:
>
> > Hi Sue,
> >
> > I will fix the problem with TGeoElementTable and let you know.
> > Hopefully you should not run into other problems - different
> > geometries can reside in the same time in memory - however you will be
> > the first testing this in detail. The only cautions you should take are:
> > - set gGeoManager pointer to 0 before adding a new geometry in memory
> > (by whatever method)- if you have already one.
> > - switch gGeoManager to the active geometry before starting to use it.
> > - do not try to draw in the same time 2 geometries
> >
> > I will let you know,
> > Regards,
> > Andrei
> >
> >> Hi root team,
> >> I'm making use of the TGeo associated classes to build
> >> our detector geometries. We need to be able to build more
> >> than one geometry in the course of a job, and we store these multiple
> >> geometries in a loan pool of geometries available for use. These
> >> geometries are to be used within a vmc application, but also for other
> >> purposes.
> >> In order to manage multiple geometries in memory, I realize
> >> I need to manage the gGeoManager global pointer so
> >> that it points to the geometry in use and I've attempted to do this.
> >> I've run into my first problem however, in that I find that I receive
> >> a complaint when building a second geometry after the first is built
> >> which is:
> >>
> >> Error in <TGeoElementTable::ctor>: Element table already instantiated
> >>
> >> Investigating a bit, I see that TGeoElementTable is a singleton to
> >> hold the default list of elements, but it's not really treated like a
> >> singleton.
> >> For example, the TGeoManager destructor will delete the Instance.
> >> This is of course a problem when one has multiple geometry in memory,
> >> one of which may go out of use before another. Can this behavior be
> >> changed?
> >> A more general question: will I run into other problems trying to
> >> manage
> >> multiple geometries in memory in this way? How do you recommend
> >> handling
> >> this problem?
> >> Thanks,
> >> -Sue
> >>
> >>
> >>
> >
>
Received on Mon Apr 25 2005 - 09:58:00 MEST