SolarSystemGL

A real-time 3D Newtonian N-body solar-system simulator — runs natively (OpenGL 3.3) and in the browser (WebGL2 / WebAssembly).

▶ Live demo: https://solar-system-gl.vercel.app 📖 API docs: Doxygen reference (served at /docs on the live site)

‍Tip: use docs/assets/hero.png as the repo's social preview image (Settings → Social preview).

What it does

• Newtonian N-body gravity in double precision (Velocity Verlet, fixed-timestep accumulator), rendered in single precision via a 1 WU = 10⁹ m unit conversion.
• Nine-body solar system out of the box (Sun + 8 planets) with real masses, distances, and orbital velocities — plus bundled presets (asteroid belt, binary stars, TRAPPIST-1, blank slate).
• Interactive editing: click a body to inspect/edit mass, density, position, velocity; add bodies on the fly (drag-to-place or a form) and watch orbits respond from the next physics step.
• Visualisation: spacetime-curvature grid, orbit trails, path prediction, Lagrange points, procedural rings & atmospheres, emissive bloom, MSAA, procedural starfield.
• Save / load simulations to a human-readable text format. On the web build, saves persist in the browser (IndexedDB via IDBFS) and can be exported / imported as files.
• Runs on phones: touch gestures (drag to orbit, pinch to zoom), a responsive UI that reflows into a More… overflow menu on small screens, and a quality toggle (MSAA) for weaker GPUs.
• Screenshots: F12 saves a BMP (downloaded in the browser, written to screenshots/ natively).

Try it

The fastest way to play is the live demo link above — no install. To run locally, build either target below.

Build — desktop (Windows / MSVC 2022)

cmake -S . -B build
cmake --build build --config Release
build\Release\SolarSystemGL.exe

Requirements: Visual Studio 2022 (links a vendored glfw3.lib built for VC2022), CMake ≥ 3.16, a GPU with OpenGL 3.3. Linux/macOS use the find_package(glfw3) fallback path (see `docs/build.md`).

Build — web (WebAssembly)

Needs the Emscripten SDK + Ninja. See `BUILDING-WEB.md` for setup.

emcmake cmake -S . -B build-web -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build-web
python -m http.server -d build-web 8080   # then open http://localhost:8080/SolarSystemGL.html

Controls

Input	Action
W A S D	Move (free camera)
Right-click + drag · one-finger drag	Look around / orbit
Scroll wheel · two-finger pinch	Zoom (orbital) / change speed (free)
Left-click / tap a body	Smooth-focus / set orbital target
Space R F 1 2 F1–F3 F5–F8 F11 F12	Pause · reset · focus · camera modes · view presets · bookmarks · demo · screenshot
Top action bar	System picker, time scale, camera, save/load, settings (overflow ⋯ on mobile)

Project layout

src/
├── core/      Application, Camera, Window, Shader, Grid, Framebuffer,
│              Screenshot, SaveLoad, WebPersistence (IDBFS), Platform
├── objects/   CelestialBody (physics + identity), PlanetMesh (GL state)
├── physics/   PhysicsSystem (integrator), PathPredictor, Lagrange
├── ui/        UIManager, Actionbar, modals, Toast, Tutorial, UI (responsive helpers)
└── main.cpp   Entry point
 
shaders/        GLSL sources (embedded at build time; rewritten to ES 3.00 on web)
web/            Emscripten HTML shell
third_party/    glad, GLFW, glm, ImGui (vendored)
docs/           Architecture, build, physics, render, user guide, API refs, ADRs

Documentation

• Hand-written guides: docs/ — architecture, physics, rendering, user guide, ADRs.
• Generated API reference: Doxygen, served at /docs on the live site (doxygen Doxyfile locally).

License

MIT — see [LICENSE](LICENSE). Contributions welcome: `CONTRIBUTING.md`.