1. CLion Development Environment Setup

Note

This guide was written against CLion 2025.2

This page walks through the process of setting up a CLion development environment that’s suitable for developing OPynSim’s C++ and python code on Windows, Mac, and Linux.

This guide assumes the user isn’t particularly familar with large project development and strives to make things easier by doing everything via CLion, rather than (e.g.) asking the reader to use a mixture of applications and the terminal.

1.1. Download and Install Python

OPynSim is a hybrid C++ and python project. CLion includes C++, but not Python. Therefore, you need to install Python (at least version 3.12) and ensure that it is available on the system PATH.

• Windows: Download python from python.org, make sure to add it to the PATH when you install it. You can verify it’s installed by Shift+Right-clicking on your desktop, Open in Terminal, running python --version should work, as should running pip --version.

• Linux: Most major distributions already include python. Verify it by opening a terminal and running python3 --version and pip3 --version. Some distributions may require separately installing pip (google/ChatGPT it).

• MacOS: MacOS includes python and pip. Verify it by opening a terminal (Command+Space, “term”, Enter), and running python3 --version and pip3 --version.

1.2. Download and Install CLion

Download the install CLion from the offical jetbrains website (always works) or from your operating system’s app store (usually easier - the Ubuntu App Store has CLion). The default installation settings are usually fine.

You may need to create a JetBrains account in order to use CLion. CLion community edition is free and suitable for open-source development (e.g. developing OPynSim), but larger institutes/companies usually purchase a site license that permits commercial development (check with your IT department). Additionally, keep in mind that you may be entitled for a special status license (student, startup, etc.).

1.3. Use CLion to get OPynSim from GitHub

OPynSim’s source code is stored in the OPynSim Git Repository, which CLion is capable of cloning. The following screenshots describe how to clone the repository in CLion:

Fig. 1.1 When opening CLion for the first time, or when no projects are open, this screen is shown. Click the highlighted button.

Fig. 1.2 Enter the URL of the OPynSim git repository (https://github/opynsim/opynsim). Optionally, set the directory where the code should be downloaded to (I prefer the desktop). Press the Clone button to begin the download process.

1.4. Select Toolchain

This step depends on your operating system and the C/C++ toolchains you already have installed on the system. OPynSim’s C++ code should be portable enough to compile in all major compilers.

As a concrete example, on my Windows machine, which also has Visual Studio installed on it, I can select either MinGW (bundled with CLion) or Visual Studio’s MSVC compiler (bundled with Visual Studio). Either should work:

Fig. 1.3 When first opening a project in CLion, it will ask you which toolchain (i.e. build system + compiler) you want to use. OPynSim can be compiled with all major C++ compilers so, most of the time, you can just click Next.

1.5. Select Third-Party Development Build Profile

OPynSim includes a CMakePresets.json file, which tells IDEs like CLion and Visual Studio how to configure themselves when the (CLion) project is first opened.

OPynSim’s development environment setup is performed in two steps:

• Setup and build third-party code and a python virtual environment

• Setup OPynSim to use the built code and python virtual environment

This step does the first part.