[Kstars-devel] HTMesh Perl module?

[Akarsh Simha]

Hi James

Nice to hear from you!

> I made an HTMesh.pm Perl module 7 or 8 years ago when I was adding
> HTMesh to KStars.  IIRC, it was only for my own testing during early
> development.  I am surprised that anything would depend upon it but
> I suppose it would make sense to use something like it for creating
> binary data files since you need to know about the HTMesh for binning
> the stars.

This is precisely what we want it for. If you remember, you wrote a
bunch of Perl scripts to read ASCII star data files and use DBI to put
them into a database. I modified some of those during my GSoC. These
are still shipped along with KStars source, although they are not used
to create the KStars binary. Jasem wants to try and resurrect the
system for generation of star data.

> For kicks, I tried to rebuild the module but it failed at the linker
> stage due to a problem with -fPIC.
>
> This was back in the KDE-3.x days.  It used the dcop interface to draw
> HTMesh elements in KStars which was pretty cool.  AFAIK, none of that
> interface survived the switch to dbus.  But that is independent of the
> HTMesh.pm module which was just a wrapper to let Perl programs use the
> HTMesh library.

I thought we had some of that code commented out, which was later
removed -- but git knows about it, so we can resurrect the trixel
plotting stuff any time we need to.

> I can send you the code and the code for creating the htmesh library
> but that code does not compile now either.  If KStars still uses
> HTMesh then you should have a working version of the htmesh library
> around somewhere.

KStars still uses HTMesh. It seems like the C++ version of the library
is unmaintained. A search for Hierarchical Triangular Mesh library
leads me to the SDSS website, where I can only find C# versions of the
library. So I'm not sure if there are newer C++ versions.

We seem to ship a HTMesh library with KStars. This builds fine and
works fine. This was stripped down quite a bit in the recent past
because KStars does not use all the functionality of HTMesh. I don't
know whether stripping down the HTMesh.xs perl module is a better
solution, or whether reintroducing the removed methods into the HTMesh
library shipped with KStars is a better solution. I'm somewhat leaning
to the latter because in case we need a certain functionality that was
removed, a new developer might not know that it was indeed present and
might go on to reinvent the wheel.

Regards
Akarsh