Build for iOS

[L1onKing]

Hello everyone!

First of all, thank you for this amazing library!

I’m wondering if anyone has successfully used the Limbo library in an iOS project — either by building it as a static library or by integrating parts of the code directly into the project. If so, could you please share a guide or any tips on how to do it?

Any help would be greatly appreciated! 😊

[costashatz]

Hello @L1onKing! Very interesting question.

We've never tried, but I would imagine that everything boils down to 4 things:

1. Making Boost compile for iOS
2. Making Eigen compile for iOS
3. Compiling optional dependencies (mainly for optimizers, e.g. NLOpt, CMAES)
4. Adapting waf scripts for iOS

I have no experience with iOS development, how would you install Boost/Eigen there? If you cannot install them via a system package or something, you could build them (static libs) and then adapt the waf scripts to look for those libraries/includes.

Overall, I would start with compiling/installing the required Boost libraries (Eigen is header only, so it should be straightforward). We need the following libraries/components from Boost: serialization filesystem system unit_test_framework program_options thread.

Another important issue is with threading: does iOS support threading? If not, we might need to adapt some parts of the library (mainly from library dependencies). Which leads me to the final important point: compiling the optimizer dependencies. For this you should refer to the respective communities/documentations.

Hope this was helpful!

[L1onKing]

Hello @costashatz !

Well, boost and eigen are easy. I don't recall using boost on iOS, but I'm 99% confident there are out-of-box solutions that I can use. Eigen is a header-only as you mentioned, so I don't even build it, I just put the code with eigen folder inside my project and I can use it.

NLOpt and waf - that's what worries me. I want limbo to have optimizers, because the task for what I need the library is performance-sensitive. And waf.. well, I have no experience with waf.

Anyway, thanks for your thoughts on the subject, it is helpful! Then I know two areas where I need to focus on. I will share some updates as my progress goes in this thread 👍

[jbmouret]

Waf is to ease compilation and configuration on Linux, but Limbo is actually header-only (it only compiles examples). For IOS, the only use of WAF would be to setup the proper compilation flags (mostly standard ones: compile in C++-14, activate optimizations like -O3 and select if NLOPT and CMA-ES are activated)

For IOS, I would create an Xcode project and do the compilation of an example using the IOS tools. I would not try to use waf. You can link to NLopt and/or CMAES manually and set the flags the way you want (USE_NLOPT and USE_LIBCMAES). Last, I think Adam does not use any dependencies (no NLOPT or CMA-ES), so you could check if it works for you.

The easiest way would be to compile on Linux an example that works for you, and take inspiration from the compilation lines.

[L1onKing]

Hey guys!

A small update: I have managed to run limbo inside iOS project. At first I was using it without optimizers, but then I quickly realised the constraint of grid search for my use-case, so I also built NLOpt and successfully attached to it.

So your library works like a charm on iOS as well, just so you know :) If there is a request for it, I will write a comprehensive tutorial on how to use limbo + NLOpt on iOS (NLOpt doesn't provide building instructions for iOS, but it wasn't that hard to figure out) to this thread.

[jbmouret]

Thank you for the update and I am glad it works. If you have a few hints (maybe not a 'comprehensive tutorial'), I think this could be useful!