The Fling Engine aims to be a cross platform Vulkan game engine that will experiment with the following:

• Low-level engine systems such as render API abstraction, file systems, and custom allocators.
• Multithreaded engine architecture
• The Vulkan graphics API for real time rendering

Getting Started

There are a few basic steps to compiling Fling on your platform.

CMake 3.21 or higher!

This project requires CMake 3.21 or higher, you can install it here.

A C++20 compiler

GCC 13 or newer, Clang 16 or newer, or Visual Studio 2022. Older GCC and Clang are rejected at configure time (see Skills/building.md for why). On Ubuntu 22.04, install g++-13 and configure with CC=gcc-13 CXX=g++-13.

For Linux

This project uses GLFW, so you will need to install those libraries to your machine.

Ubuntu:

sudo apt-get update
sudo apt-get install -y libglm-dev libxcb-dri3-0 libxcb-present0
sudo apt-get install -y libpciaccess0 libpng-dev libxcb-keysyms1-dev
sudo apt-get install -y libxcb-dri3-dev libx11-dev
sudo apt-get install -y libwayland-dev libxkbcommon-dev libxrandr-dev
sudo apt-get install -y libglfw3-dev
sudo apt-get install -y xorg-dev

Vulkan SDK

Obviously this project is build using Vulkan, so you will need to install it before compiling or running the program.

You can download the SDK from the LunarG website here.

On Ubuntu/Debian you can alternatively install the headers, loader, and validation layers from the system package manager instead of the LunarG SDK — this is enough for find_package(Vulkan) in CMake to succeed:

sudo apt-get install -y libvulkan-dev vulkan-tools vulkan-validationlayers spirv-tools glslang-tools

If you are having trouble with the Vulkan SDK then check out some of these resources:

• Vulkan Verify Install
• Vulkan Tutorial FAQ

Init.bat and Init.sh

After installing the SDK, you can simply run one of the provided scripts.

Both scripts run the same thing, scripts/init.cmake: they get all submodules and external libraries that the engine uses, install Catch2 locally for the tests, and create a folder called build. The build folder will have your platform specific build files (Visual Studio, Makefiles, etc). Any arguments are passed through to the build configure, e.g. ./Init.sh -G Ninja -DCMAKE_BUILD_TYPE=Debug.

Quick start: clone, build, and run the Sandbox

Once the system dependencies and Vulkan SDK above are installed, here's the full path from a fresh clone to a running game, on Linux/macOS:

# 1. Pull submodules, install Catch2 locally, and configure CMake into `build/`
./Init.sh

# 2. Build the Sandbox target
# --parallel $(nproc) tells the build to use all of your CPU cores at once
cmake --build build --target Sandbox --parallel $(nproc)

# 3. Run it
./build/Sandbox/bin/Sandbox

On Windows, the equivalent is:

:: 1. Pull submodules, install Catch2 locally, and configure CMake into `build/`
Init.bat

:: 2. Build the Sandbox target
cmake --build build --target Sandbox --config Debug

:: 3. Run it (path includes the build config)
build\Sandbox\bin\Debug\Sandbox.exe

See Skills/building.md for switching build types (Debug/Release/ shipping) and other day-to-day build details.

Building and debugging in VS Code

After running Init.bat/Init.sh, open FlingEngine.code-workspace in VS Code (install the recommended CMake Tools and C/C++ extensions if prompted). The Run and Debug panel has ready-made configurations — Debug Sandbox and Debug CoreTests, Debug ResourcesTests, Debug EngineTests, Debug PhysicsTests, and Debug ApplicationTests — that build the right target and launch it under the debugger. Ctrl+Shift+B runs Build All (the engine, Sandbox, and the test executables). The Run CTest task runs every Catch2 case and the isolation tests; per-target build tasks are also available via Tasks: Run Task. Click the build-type entry in the bottom status bar (or run CMake: Select Variant) to switch between Debug, Release, RelWithDebInfo, and MinSizeRel — no need to re-run Init.bat/Init.sh; the extension reconfigures automatically.

Packaging a project

For ease of development and iteration the file paths to Assets (shaders, textures, models, etc) are all absolute paths generated by CMake. If you want to have a copy of your executeable with asset paths relative to the program, then generate your project files with CMake with this flag:

cmake -DDEFINE_SHIPPING=ON -B build .

Notice the -DDEFINE_SHIPPING option is set to ON. This sets a definiton that you can use in C++:

#ifdef FLING_SHIPPING
// Do some nice stuff
#else
// Do non-shipping code, perhaps with a lot of log messages
#endif

See Skills/coding-style.md for documentation-comment conventions and how to run the comment-style check / clang-format.

AI coding assistants

If you're using Claude Code, Cursor, Copilot, or another AI coding assistant on this project, start at AGENTS.md — it covers build/test commands, coding style, and architecture, and links into Skills/ for topic-specific detail.

Branching Strategy

We use a pretty basic branching strategy. Make a feature branch off of Main for something like "add-support-for-x", and then that feature is done and tested create a pull request to get it into Main.

We will create stable "Release" branches and tag them accordingly with stable versions of the build.

Thanks and third-party notices

Fling Engine uses many open source libraries, and the community game controller database SDL_GameControllerDB. THIRD_PARTY_NOTICES.md lists each one, with its license.

Cool Resources

Some great resources are the Vulkan Tutorial and SaschaWillems's repo with different Vulkan examples