Deceptus Engine

A C++23/lua-based platformer game engine
It utilizes Box2D for game physics, SFML for rendering, and SDL for game controller support.

It builds for Windows, Linux and macOS, it compiles to WebAssembly so it runs in the browser without a plugin, and it runs on the Nintendo Switch as unsigned homebrew.

▶ Play it in your browser on itch.io

The clip above is also available as an MP4 at full resolution.

Documentation

The complete documentation lives in doc/readme.md. The most travelled paths:

Topic	Where
Designing a level	designing_a_level.md
Mechanisms, all 39 of them	mechanisms.md
Enemies	enemies.md
Visual effects, lighting and weather	visual_effects.md
Writing your own enemies in Lua	lua_interface/readme.md
Cutscenes	cutscene.md
Development hotkeys	development_hotkeys.md

Credits

What	Who
Artwork	dstar
Code	mueslee (Matthias Varnholt)

Get a Build

Every push to master is built for all five targets. These links always give you the newest successful build and need no GitHub account:

Platform	Download
Windows	deceptus-windows.zip
Linux	deceptus-linux.zip
macOS	deceptus-macos.zip
Web	deceptus-wasm.zip
Nintendo Switch	deceptus-switch.zip

The desktop archives contain the executable next to the data/ directory. On Linux and macOS the shared libraries come along in lib/ with a run.sh that points the loader at them, so start those through run.sh. The web archive holds the Emscripten output and needs a server that sends the COOP/COEP headers described under Web (WebAssembly). The Switch archive is a single self-contained deceptus.nro with the assets embedded as romfs — it needs a console running custom firmware, and it has to be started in title takeover mode, as described under Nintendo Switch (homebrew).

The links resolve through nightly.link, which hands out the artifact of the latest successful workflow run. That indirection exists because GitHub only serves Actions artifacts to signed-in users. If you are signed in you can equally take them straight from the workflow runs.

How to Build

Only a compiler, CMake and the platform's development headers are needed. SFML 3, SDL 3, Lua 5.4 and GLEW are downloaded and built by CMake via FetchContent; Box2D, ImGui, tinyxml2 and glm are vendored in the source tree.

The engine uses C++23, so the compiler has to be recent. CI builds with gcc 14, MSVC 2022, Homebrew LLVM and the latest Emscripten. Anything older than gcc 13 or Clang 15 will not do.

Windows

cmake -B build -A x64 -DCMAKE_BUILD_TYPE=Release
cmake --build build --config Release --parallel

Linux

sudo apt-get install -y \
    gcc-14 g++-14 cmake ninja-build \
    libglm-dev \
    libx11-dev libxrandr-dev libxinerama-dev libxcursor-dev libxi-dev \
    libxkbcommon-dev \
    mesa-common-dev libgl-dev libglvnd-dev \
    libasound2-dev libpulse-dev \
    libogg-dev libvorbis-dev libflac-dev libopenal-dev \
    libfreetype-dev libpng-dev \
    libudev-dev

cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_C_COMPILER=gcc-14 -DCMAKE_CXX_COMPILER=g++-14
cmake --build build --parallel

macOS

brew install llvm glm ninja

cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build --parallel

Running

The game reads data/ relative to the working directory, so run it from the repository root:

./build/deceptus            # Linux, macOS
build\Release\deceptus.exe  # Windows

Web (WebAssembly)

The web build swaps vanilla SFML for VRSFML and renders through WebGL 2. It uses pthreads for audio worklets, which means the page has to be cross-origin isolated — opening the generated .html from file:// will not work.

With the Emscripten SDK on PATH:

emcmake cmake -B build_wasm -DCMAKE_BUILD_TYPE=Release
cmake --build build_wasm --parallel

On Windows, build_wasm.bat does the same inside the official emscripten/emsdk Docker image, so no local SDK is needed.

The link step produces deceptus.html, deceptus.js, deceptus.wasm and deceptus.data, the last of which is the whole data/ directory preloaded into the virtual file system. To play it locally, server_wasm.bat starts a small server on localhost:9080 that sends the required COOP/COEP headers.

emscripten/ holds the hosting shell for the published build: itch_index.html is a player-facing page that shows only the canvas, and coi-serviceworker.js establishes cross-origin isolation on hosts that do not send the headers themselves, itch.io among them.

Nintendo Switch (homebrew)

The Switch build is an unsigned .nro for a console running custom firmware. It reuses the web build's rendering stack — VRSFML over SDL 3 — because vanilla SFML 3 renders through the fixed-function pipeline and the Switch's mesa/nouveau driver is core profile only. The SDL video, joystick and audio backends for the platform are carried as patches under patches/.

build_switch.bat

Everything runs in the official devkitpro/devkita64 Docker image, so no local devkitPro install is needed. The result is a self-contained deceptus.nro with the whole data/ directory embedded as romfs.

It boots and plays, on a console as well as in an emulator, and audio is silent so far. On hardware it has to be launched in title takeover mode — hold R while starting a game from the HOME menu — or it runs out of memory during asset loading. doc/switch_build.md has the full setup, how to run and script it in Ryujinx, and how to work on the port itself.

Contribute and Talk to Us!

If you're a musician, graphic artist, level designer or programmer, or just want to hang out and chat, please join us on Discord!

License

The engine and its assets are released under Creative Commons Attribution-NonCommercial 4.0 International.