FMI4cpp (work in progress)

FMI4cpp is a cross-platform FMI 2.0 implementation written in modern C++.

Influenced by it's spiritual brother FMI4j, it aims to be an easy to install, easy to use, object oriented and fast FMI implementation for C++.

Why should I use this over other C/C++ FMI Libraries

Because this library provides a clean API, is easy to install (through vcpkg) and is easy to use.

How do I use it in my own project?

When the library is stable it will be added to the vcpkg package manager.

Development dependencies

Install vcpkg and run:

./vcpkg install boost-property-tree libzip

On linux you might need to install some additional libraries:

./vcpkg install bzip2 openssl

These can probably also be installed through the native package handler.

API

#include <iostream>
#include <fmi4cpp/fmi2/fmi4cpp.hpp>

using namespace fmi4cpp::fmi2;

const double stop = 10.0;
const double stepSize = 1.0/100;

int main() {

    auto fmu = Fmu("path/to/fmu.fmu").asCoSimulationFmu();
    
    auto md = fmu->getModelDescription();
    std::cout << "modelIdentifier=" << md->modelIdentifier() << std::endl;
    
    auto var = md->getVariableByName("my_var").asRealVariable();
    cout << "Name=" << var.name() << ", start=" var.start().value_or(0) << endl;
    
    auto slave = fmu->newInstance();
    slave->init();
   
    double t;
    fmi2Real value;
    while ( (t = slave->getSimulationTime()) <= stop) {

        if (slave->doStep(stepSize) != fmi2OK) {
            //error handling
            break;
        }
        
        if (var.read(*slave, value) != fmi2OK) {
            //error handling
            break;
        }
        std::cout << "t=" << t << ", " << var.name() << "=" << value << std::endl;
     
    }
    
    slave->terminate();
    
}

Running examples/tests

In order to run the example/test code, a system variable named TEST_FMUs must be present on your system. This variable should point to the location of the content found here.

The examples are built by default. To change this pass -DFMI4CPP_BUILD_EXAMPLES=OFF to CMake. Test are on the other hand not built by default. To change this pass -DFMI4CPP_BUILD_TESTS=ON to CMake.

To run the tests you will need an additional dependency:

./vcpkg install boost-test