Indicating runtime location on the system

[rpavlik]

cc @JeroMiya

Would be good to indicate runtime locations on the system. The simple way is to set an environment variable, to say "I am the OSVR install.". The more complete way would be to essentially add itself to a list of OSVR installs, to permit choosing between installs. (These are not mutually exclusive: a new install might add itself to the list of installs, and may set itself as a system-wide default)

I've seen two models for this:

• Unreal engine - they've got a few tools to work with it, but it was a real pain and took some serious powershell scripting juju to just iterate through the available engine installs and find one of the right version with a desired tool: https://github.com/OSVR/OSVR-Unreal/blob/master/generate-project-files.ps1 Might not be super long, but it was very painful.
• CMake exported packages (package database/registration): https://cmake.org/cmake/help/v3.0/manual/cmake-packages.7.html#user-package-registry This, in addition to being neatly documented and cross-platform, is pretty easy to script - much quicker than the Unreal stuff was. Sample script that is actually included with every OSVR snapshot, to let you register it and its included packages - note that this is a totally generic script that traverses a tree looking for anything resembling a CMake package and registering it, which makes it longer: https://github.com/OSVR/OSVR-Core/blob/master/devtools/add_sdk_to_registry.ps1

Obviously, if we decide that keeping track of multiple locations of OSVR on the system is something we want to do, you know which general technique has my vote ;)

[JeroMiya]

cc: https://github.com/OSVR/OSVR-Core/pull/380

The current implementation uses the OSVR_SERVER_ROOT environment variable. If the installer set that environment variable (preferably user level environment variable) on Windows, then the auto-launch functionality would work.

[gfrolov]

First step with indicating runtime location is done - https://github.com/OSVR/OSVR-win-installer/commit/40257ee8c3ee7965a2714220e66199bd4913203b It adds (and removes on uninstall) user lever environment variable - OSVR_SERVER_ROOT which points to bin folder with all "exes", when you install runtime or sdk. @rpavlik , not sure if I understood completely the adding to a list of OSVR installs? Do you mean maintaining an environment variable like "OSVR_ROOT" and append install locations when you install SDK and Runtime?

[gfrolov]

@rpavlik, @JeroMiya Which direction do we want to go here. Appending multiple locations to OSVR_SERVER_ROOT will break things for OSVR-Config and auto launch. I recently fixed issue #17 where it appended multiple values and I think it was causing some problems. We can of course setup a new variable OSVR_INSTALL_LOCATIONS, if needed?