CLAP Bindings for Mojo?

[RxndmForest]

I am interested in using CLAP, but am unfamiliar with Plug-in development. The part about CLAP that interest me is the following statement below:

The KISS (keep it simple, silly) mantra belongs to CLAP. From the C-only ABI, which allows binding to any programming language, to the transparent client-server model between host and plug-in, the robustness and clarity of the threading model, and the single event queue for all kinds of parameter changes, timing and MIDI. Despite being so comprehensive, everything in CLAP is easy to find and easy to implement.

At the bottom of the CLAP repo README, there is a project that utilizes rust. If I was interested in doing something similar in another programming language what are the things that I would need to implement? Specifically, I was interested in using Mojo as my language of choice. Mojo is a fairly new language so I'm not sure if this is feasible, but am interested in discussing its potential feasibility.

[baconpaul]

If your language can call and export a c signature function with c types and has enough memory control to make a c structure equivalent it will be able to interface with clap

to write a plugin it would also need to support threads since plugins have a two thread model

to make it appropriate to write the audio thread of a plugin it would need to be able to generate performant code without locks or allocations

I don’t know if mojo does any of that. But the mojo devs will!

[baconpaul]

those mean "it will be rather tricky to write a clap with a gui in mojo" - a separate process and shared memory IPC is difficult to engineer.

https://github.com/free-audio/clap/blob/main/include/clap/ext/thread-check.h this document explains the threading model in clap. To implement it you usually need your language to support things like lock free data structures and so forth.

But you can just implement a plugin without a gui and only have the audio thread. Then the questions come down to whether you can control things like memory allocation and so on to meet the various realtime constraints.

[baconpaul]

taking a 10 second look at the mojo website, it certainly looks like the ownership model is basically the rust ownership model so you can control ownership well enough to write audio. I think you could probably write the realtime thread from how they describe it.

I'd share the above threading doc with mojo devs and ask them what they think.

[RxndmForest]

Thanks! I'll share this with them and see what they have to say. I'd say at this point I can start working on implementing header files and see how far I make it. Does CLAP include anything to help me test the header files?

[baconpaul]

If you make a clap, the clap info project will tell you if it is loadable and show you config. And the clap validator will make sure it is used properly.

[RxndmForest]

Got it. Thanks for talking this through with me!