allow building without vendored libraries

[baikiet]

The documented way to build psmoveapi relies on vendored libraries PS3EYEDriver, glm, hidapi and libusb-1.0. They are stored in external/. Three of them are git submodules. One is fully embedded in the psmoveapi repo. This makes it difficult to use distribution-provided version of these packages and is an obstacle to having psmoveapi properly packaged into most GNU/Linux distribution. See for example Debian's policy on this matter.

Would you be open to an update of your build system such that vendoring is optional. For example, to allow something like cmake -DVENDORING=OFF which would ignore external/?

Some preliminary tests suggest this is entirely feasible. I mostly would like whether it's worth for me to clean up my patch and send it for your consideration.

[thp]

Sure. We probably need to document more clearly what the minimum and maximum supported versions of the non-vendored components are. In case of hidapi (iirc, would have to check) we also have some PS Move API-specific patches that are required and would otherwise break the build. I'm not sure if we have submitted them upstream.

Also note that currently we don't really provide a stable ABI for code in Git, and the latest ABI-stable version currently is 4.0.12. See this blog post from early 2023 for details.

But in any case, even if there's no commitment to a stable API and ABI, users might still benefit from having the option to use distribution-supplied development packages for dependencies. The development pace is also "slow enough" these days that there probably won't be breakages every few weeks, but also not really "official" releases as such.

[baikiet]

Thank you for the quick reply and for the details.

In my experience, it builds fine with upstream hidapi but I have not performed extended testing. I'll try to send a PR later.