Calling methods of C++ class in MEX from MATLAB

Question

I have a DLP kit which I need to control via MATLAB using a C++ API.

Say, I have functions/methods using C/C++ for {load_data, load_settings,display_data}

Answer 1

The easiest is to design a MEX wrapper that keeps an instance of the class object, and dispatch a call to that MEX binary. I have made a library for those trying to develop a MEX wrapper in C++.

https://github.com/kyamagu/mexplus

Here is a quick snippet.

// C++ class to be wrapped.
class Database;
// Instance session storage.
template class mexplus::Session;
// Constructor.
MEX_DEFINE(new) (int nlhs, mxArray* plhs[],
                 int nrhs, const mxArray* prhs[]) {
  InputArguments input(nrhs, prhs, 1);
  OutputArguments output(nlhs, plhs, 1);
  output.set(0, Session::create(
      new Database(input.get(0))));
}
// Destructor.
MEX_DEFINE(delete) (int nlhs, mxArray* plhs[],
                    int nrhs, const mxArray* prhs[]) {
  InputArguments input(nrhs, prhs, 1);
  OutputArguments output(nlhs, plhs, 0);
  Session::destroy(input.get(0));
}
// Member method.
MEX_DEFINE(query) (int nlhs, mxArray* plhs[],
                   int nrhs, const mxArray* prhs[]) {
  InputArguments input(nrhs, prhs, 2);
  OutputArguments output(nlhs, plhs, 1);
  const Database& database = Session::getConst(input.get(0));
  output.set(0, database.query(input.get(1)));
}
// And so on...
MEX_DISPATCH