[Opensim-dev] build issues wrt native libs (redux)

[dan miller]

> Currently I'm looking for a good geometry library to use for that; my prim
> candidate is a lib named CGAL.

One thing this brings up is our increasing dependency on outside libraries,
with different licenses and mostly unmanaged code.  This is a separate
issue, but at some point we need to just face the fact that for this project
to move ahead at the fastest pace possible, we need to have an
infrastructure to easily incorporate native libs, deal with their build
idiosyncrasies, linkage/installation problems, licensing, versioning,
platform issues, custom modifications we may introduce, etc.  Just on the
physics side, we already have ODE, Physx, and a modified build of BulletX. 
I believe there are similar issues with SQL and JPEG components which I
don't know much about, but seem to be the same sorts of problems we have
with ODE.

As a use case, the BulletX library has been hacked into something
incompatible with the original project, and stuck in a folder called
/libraries (which I never noticed before!).  It has its own build system,
and you have to manually copy the .DLL's to /bin, where they get saved by
subversion, so most people don't think about it.  But this approach has
caused endless problems with ODE; I just finally figured out that the ODE
DLL's fail because they depend on certain Visual Studio redistributable
DLL's that aren't in subversion.

I guess opensim culture dictates that I stop complaining and just fix the
problem.  Issue is, I've always considered myself something of a build
idiot; I've never quite grokked makefiles, and I certainly know nothing of
autogen, configure, etc.  To top it off, we have a non-standard system
(nant) that seems pretty geared to C# (and yet doesn't satisfy VS users). I
know Sean D. has been thinking about this problem, and I've certainly had
enough C/C++ experience to contribute something to the process, but
apparently the usual suspects (GCC/'nix toolchain) is useless to Windows
developers unless it produces .sln files, and this has been a sticking
point.

The last suggestion that made any sense to me was to use Nant as the top
process (I assume it's a general scripting language in some sense), and have
it invoke everything else that needs to occur, including calling prebuild to
generate .sln files.  How to deal with all the 3rd party libs might be the
big sticking point.  To compile those things on windows often requires
cygwin, which ppl seem to dislike intensely in this crowd.

Perhaps there is simply another project, opensim-libs, which has *all* the
source code and a top-level, comprehensive build system (most likely GCC
config/make) that builds every dll needed, and copies them into bin?  
Eventually, there could be distribution-specific binary lib releases, ie
.rpm, .deb, and install-shield for windows.

I think we need to forge a consensus on this issue, agree on toolchains, and
get to work.  Otherwise we will descend into a deep world of pain, with
broken builds, frustrated users, and developers spending inordinate amounts
of time putting out fires.  Better to build a fireproof foundation now,
methinks.

-danx0r