C++ N-Body Simulation

This N-Body Simulation is compiled in C++ and Raylib.

Feel free to use this repo for your own use.

Features

• Barnes-Hut model
• Adjustable simulation bounds by modifying minX, maxX, minY, and maxY variables in the source code.
• Dynamic visuals with color-coded particles representing energy levels (blue to red), grid overlays, and a contrasting UI.
• Inelastic collisions (modifiable via code)
• Spawn particles in-game with velocities and directions of your choosing
• Hold mouse down to select what mass of particle you would like to spawn
• Adjustable number of particles to spawn on start
• In-game gravity manipulation
• Multi-threading capabilities

Compatibility

The project was compiled with -Ofast flags, significantly increasing performance, but this means that your system must have AVX instructions. Most CPUs made in the last decade have AVX instructions.

Controls

Particle Interaction

• Left click anywhere to spawn a particle.
• Left click and drag to spawn a particle with a direction and velocity.
• Hold down Left click in order to select your particle's mass.

Camera Controls

• Hold right click to pan the camera.
• You can also use the arrow keys to pan the camera.
• Use the scroll wheel to zoom in and out with the camera.

Simulation Adjustments

• The '[' button halves Gravity while ']' doubles it.
• Press C to toggle collisions.
• Press P to toggle whether or not you want to automatically spawn particles on start/restart.
• Press R to restart the simulation.

Exit

• Esc button to leave the game.

Important notes

• This is an amateur project.
• This project is EXTREMELY terribly made.
• Particles in the center of large^[1] clumps may exhibit instability due to unoptimized handling of extreme interactions. This is a known limitation and may be addressed in future updates.

^[1] Smaller clumps collide perfectly correctly.

Future Improvements

This is a todo list of improvements I am planning on implementing as the project grows.

• Barnes-Hut model (Allowing for millions of particles)
• Better parameter adjustment UI
• Coloured controls in UI for readability and accessibility
• Multi-threading support (currently it has a very basic implementation)
• Sound effects on collision
• Individual particle manipulation
• MacOS/Linux export

Not planned

• Web export (Extremely difficult to do, decreases performance significantly, limitations and issues with multithreading)

How to compile

For VSCode

This project contains a .vscode folder with configurations. Just make sure that you have Raylib and g++ (a C++ compiler) properly installed. Also, add this code to your .vscode/c_cpp_properties.json file, create it if it doesn't exist:

{
    "configurations": [
        {
            "name": "Win32",
            "includePath": [
                "${workspaceFolder}/**",
                "C://raylib/raylib/src"
            ],
            "defines": [
                "_DEBUG",
                "UNICODE",
                "_UNICODE"
            ],
            "windowsSdkVersion": "10.0.22000.0",
            "compilerPath": "cl.exe",
            "cStandard": "c17",
            "cppStandard": "c++17",
            "intelliSenseMode": "windows-msvc-x64"
        }
    ],
    "version": 4
}

Also, these directions assume you have everything installed in the default location.

For Notepad++

If you use Raylib's given Notepad++

You can find Raylib's Notepad++ inside of the raylib installation directory. Then you can find notepad++.exe under the npp folder.

Steps

1. Open main.cpp (with Raylib's version of NP++)
2. Press f6
3. You'll see a list of commands. One of them should be SET CC=gcc. Replace gcc with g++. If it's already like that, continue to the next step.
4. Click on 'OK'.
5. You're done!

Notes

• gcc must be replaced with g++ because the project does not work with a C compiler (gcc), and thus you must compile it with a C++ compiler (g++) instead.

If you use any other edition of Notepad++

I have not compiled this project under any other version of NP++, so I suggest that you either use Raylib's NP++, or you search for help elsewhere online.

For any other IDE/Text editor

Unfortunately, if your IDE or text editor is not mentioned here, that means I have not compiled my project with it. You can find articles online detailing how to compile it on your system or IDE.