I'm working on an app that will be used to control a theater show. At first I hardcoded in C++ all the steps of the show, corresponding to all the events that can occur on stage (light changes, video starts, and so on).
It was pretty tedious to stop the app, change source code, recompile, wait, and launch, rince, repeat.
So, I interfaced my app with Lua. At first I searched for a readymade solution, but they were all too complicated for me (I'll talk about ofxLUA later), Lua binding with C++ being a real pain in the ass (Lua can't natively call C++ member methods, only c methods or C++ static ones). I simply coded a central dispatcher (static method), that calls a private non static dispatcher. The static dispatcher is declared as global "c" function is lua (might be any other name), I call it in Lua with result = c(oneaction_code, param1, param2, paramN). Then the c++ dispatcher case switches from the action_code and for each case pops Lua stack and calls c++ methods.
So I get some classes like
myApp which owns a sceneManager instance
sceneManager instance owns several classes instances like oscQLCPlus, oscMillumin, oscAbletonLive, midiAbletonLive, lifxClient
sceneManager owns one instance of LUAScript (the Lua init and dispatcher), and LUAScript which is threaded communicates with the sceneManager with atomic states. LUAScript is friend class of sceneManager and so have access to all of its ressources. And the most important point : LUAScript is interruptible.
I coded the whole LUAScript mechanism in 2 days. It's not Lua C++ binding state of art, but it works pretty well, it's very fast and easy to extend. I added a fileWatcher system to detect Lua script changes, who reloads and relaunches the current scene, if any.
Now I have my app running, my global Lua script open with an editor, and as soon as I save it I get it running in 1 second. So it's quite live coding in OF.
Now, about ofxLUA. Last year I coded a small experimental app on raspberry Pi and used ofxLUA. Combined with the fileWatcher mechanism I was able to have quite instant result. I adapted the OF graphicsExample in LUA and it was running pretty well, even on a PI2. I did not investigated advanced OpenGL stuff or video manipulations or videograbbing but it was ok and running at 20/30 fps. Could have been used for some sort of VJing for 2D effects. Might give better result on a machine with more horsepower.