YerbEngine

YerbEngine is a work-in-progress game engine featuring a hybrid architecture, built with SDL2 and C++. The core engine now lives in lib/ (public headers in lib/includes, implementations in lib/src) and powers the playable shoot-demo sample game.

Features

• Cross-platform – Supports builds on MacOS, Linux (tested on Fedora), and the Web via Emscripten/WebAssembly.
• Core library + demo – Engine code is packaged as a static library (yerb_engine_core) and consumed by the shoot-demo reference game.
• Modular ECS design – Independent systems for input, rendering, and more, enabling scalability.
• JSON configuration – Loads game settings using nlohmann/json.
• Modern C++ – Written in C++23, with code quality enforced by clang-format and clang-tidy.
• Asset Management – Built-in managers for textures, fonts, audio samples, and music tracks.
• Docker Support – Containerized build environment for consistent development experience.

Project Structure

lib/                          # Core engine library
├── includes/                 # Public headers (AssetManagement, Configuration, EntityManagement, GameEngine, GameScenes, Helpers, SystemManagement)
└── src/                      # Engine implementations mirroring the include layout
shoot-demo/                   # Playable reference game using the engine
├── includes/                 # Demo-specific scenes and helpers
├── src/                      # Demo gameplay code
└── assets/                   # Audio, fonts, and images bundled into builds
config/                       # JSON configuration consumed at runtime
template/                     # HTML/CSS/JS for Emscripten builds
tests/                        # Boost.Test-based unit tests for engine modules
diagrams/                     # Supporting diagrams (buildable with the Makefile in this folder)

Building from Source

Prerequisites

Native builds:

• CMake 3.21 or higher
• C++23 compatible compiler (Clang, GCC)
• SDL2, SDL2_image, SDL2_ttf, SDL2_mixer

Web builds:

• Emscripten SDK

Native Build (macOS/Linux)

mkdir -p build
cd build
cmake ..
cmake --build .

Run the demo:

./shoot-demo   # assets and config are copied into the build directory automatically

Web Build (Emscripten)

mkdir -p dist-web
cd dist-web
emcmake cmake ..
cmake --build .

Serve locally:

emrun --no_browser --port 3333 bin/index.html

Open http://localhost:3333 in your browser.

Docker Build

docker-compose up --build

Formatting

./format.sh

Formats all code in lib/ and shoot-demo/ using clang-format.

Audio Conversion

Convert audio files to the correct formats:

./convert-audio.sh

• Samples → WAV format (for sound effects)
• Tracks → OGG format (for music)

Tests (native)

After configuring the native build (Boost.Test required):

cd build
ctest --output-on-failure

Usage

Run ./shoot-demo from the build directory. On launch, the menu scene appears; follow on-screen instructions to navigate through the demo.

Contributions

Contributions are welcome! Submit issues or pull requests to help improve the engine.

License

Licensed under GNU GPL v3.0. See LICENSE.md for details.