BRUTAL

BRUTAL Framework

A free, open source C# framework for making games, or your own game engine.

BRUTAL is a framework. You can make a game directly with it, or use it as the foundation for a separate engine. We made Kitten Space Agency directly on BRUTAL. Ludeon built their Waylith engine on it to move RimWorld off Unity.

At its core is a custom interop layer giving C# direct access to native APIs and libraries. Around that we've built mathematics, memory management, strings, collections, job scheduling, logging, localization, and bindings for Vulkan, GLFW, Dear ImGui, FMOD, RakNet, Jolt and Box2D. BRUTAL doesn't make the architectural decisions for you. You write your own stack. You can use whatever NuGet packages you want, including third-party ones.

It's called BRUTAL for a reason. In some ways it's much harder to use than Unity, Unreal or Godot. In other ways, particularly if you're doing something unusual, it's considerably easier. You actually have to know what you want to do first.

Why

You are only as independent as your tools are.

Developers have surrendered an extraordinary amount of control over their work to companies whose interests are not necessarily aligned with their own. We're not suggesting everyone should make their own game engine. We're suggesting every developer should have the option to, without having to spend four years building the foundations first.

What that means in practice:

• Free, including for commercial games. No royalties. We don't want a percentage of your game's revenue. We ask for credit.
• Open source. The source is here under an MIT-based licence. If one day we stop being accountable to developers, you can fork it and go your own way.
• Deliberately small. We do a few low-level things well: interop, memory, concurrency, maths, strings, and bindings to native libraries, on the latest C# and Vulkan. We avoid allocations and unnecessary overhead and use unmanaged memory and unsafe code where it makes sense.
• A foundation, like a kernel. Think of the Linux kernel and something like Ubuntu. It's not an exact comparison, but it gets the idea across. We provide the foundation and you build your own systems on top.

What BRUTAL is not

BRUTAL is not trying to be a general-purpose engine. There is no editor, no scene graph and no renderer, and we're not adding them. We push back on efforts to add more, because adding everything is how the industry ended up with the kind of engines we don't want to use. Pull requests that drift away from a clear purpose will be rejected.

Projects using BRUTAL

Product	Studio	Engine (if any)
RimWorld	Ludeon Studios	Waylith
Kitten Space Agency	RocketWerkz	Direct on BRUTAL
Torpedia	RocketWerkz	Direct on BRUTAL
Art of the Rail	RocketWerkz	Direct on BRUTAL
Gruntz	RocketWerkz	Direct on BRUTAL
Afterskies	Floating Origin Interactive	Direct on BRUTAL

Ludeon report 2 to 4 times the performance of the Unity build in their own tests, with the vast majority of existing mods still compatible. See their Steam announcement.

Kitten Space Agency is a free pre-alpha spaceflight simulation. It runs a solar system at real scale, and is the first major project built directly on BRUTAL. Download it on Ahwoo and see the technology yourself.

What is in the box

Each top-level folder in this repository is one library, published as a NuGet package. Reference only the ones you need.

Library	What it is
Brutal.Core	Base types, attributes, platform detection, pointer helpers, Roslyn analyzers
Brutal.Interop	The custom interop layer that gives C# direct access to native APIs
Brutal.Memory	Unmanaged memory management and allocators
Brutal.Collections	Collections that don't allocate
Brutal.Strings	String building and handling without allocation
Brutal.Maths, Brutal.Numerics	Vector, matrix and numeric types
Brutal.Concurrency	Job system and threading
Brutal.Logging	Logging
Brutal.Localization	Localization
Brutal.Vulkan, Brutal.Vulkan.Abstractions, Brutal.Vulkan.Vma	Vulkan bindings, abstractions and the Vulkan Memory Allocator
Brutal.OpenGl	OpenGL bindings
Brutal.ShaderC, Brutal.Slang	Shader compilation
Brutal.Glfw, Brutal.Sdl, Brutal.Sdl.Image, Brutal.Sdl.Mixer, Brutal.Sdl.Ttf	Windowing and input, with SDL's image, audio mixing and font add-ons
Brutal.ImGui, Brutal.ImGui.*, Brutal.ImPlot	Dear ImGui and ImPlot bindings, docking branch
Brutal.Render.Mesh	Mesh utilities
Brutal.Texture, Brutal.Texture.Abstractions, Brutal.Ktx, Brutal.Gli, Brutal.Stb	Texture loading, KTX and compressed formats, image decoding
Brutal.Gltf, Brutal.MeshOptimizer	glTF loading and mesh optimisation
Brutal.FreeType	Font rasterisation
Brutal.Fmod, Brutal.OpenAl	Audio
Brutal.RakNet	Networking
Brutal.Jolt, Brutal.Box2D	3D and 2D physics
Brutal.Monitor.Common, Brutal.Monitor.Host, Brutal.RenderDoc, Brutal.RenderDoc.ImGui	Runtime monitoring and RenderDoc capture integration
Brutal.NativeFileDialog, Brutal.NotCurses, Brutal.ZLib	Native file dialogs, terminal UI, compression

Third-party notices for each library live in its LICENSES folder, Brutal.ImGui/LICENSES say.

Getting started

Prerequisites

• .NET 10 SDK
• A Vulkan 1.3 capable GPU with current drivers (if you render)
• The Vulkan SDK if you want validation layers while developing
• Windows or Linux

Your first window

Create a project and add Core and Glfw:

dotnet new console -n HelloBrutal
cd HelloBrutal
dotnet add package Ahwoo.Brutal.Core
dotnet add package Ahwoo.Brutal.Glfw

Replace Program.cs:

using Brutal.GlfwApi;
using Brutal.Numerics;

if (!Glfw.Init())
    throw new Exception("Failed to initialize GLFW");

Glfw.WindowHint(GlfwWindowHint.ClientApi, 0);
var window = Glfw.CreateWindow(new GlfwWindow.CreateInfo
{
    Title = "Hello BRUTAL",
    Size = new int2(1280, 720),
});

while (!window.ShouldClose)
    Glfw.PollEvents();

Glfw.Terminate();

dotnet run

That opens a window with no graphics API. For a minimal sample of every package, see samples.

What you add next is up to you:

• Rendering: Ahwoo.Brutal.Vulkan.Abstractions and Ahwoo.Brutal.Vulkan.Vma for a Vulkan renderer, Ahwoo.Brutal.ShaderC to compile shaders at runtime.
• Debug UI: Ahwoo.Brutal.ImGui and Ahwoo.Brutal.ImPlot.
• Parallelism: Ahwoo.Brutal.Concurrency for the job system.
• Audio and networking: Ahwoo.Brutal.Fmod, Ahwoo.Brutal.RakNet.

Questions and "how do I" threads go on the Guides and Help forum.

Building from source

This is the source for every published package. Project files, a solution and build scripts are coming. Until then use the NuGet packages, and use this repository to read and fork the code.

git clone https://github.com/ahwootech/BRUTAL.git

Licence

BRUTAL is free to use, modify and distribute, including in commercial games. There are no royalties and we don't want a percentage of your game's revenue.

The licence is based on MIT with an added attribution requirement. A game or product built with BRUTAL:

1. includes the BRUTAL copyright notice in its credits screen, or equivalent (section 2.1)
2. shows the BRUTAL logo before gameplay starts (section 2.2)
3. ships NOTICE.txt alongside the product (section 2.3)

If you don't want to do that, we can arrange a separate commercial licence. We also waive the logo requirement for non-profit projects and where displaying it would be detrimental to the application's purpose.

BRUTAL is open source. There are already OSI-approved licences that allow graphical attribution. Ours is not yet OSI approved because we have not submitted it yet. We intend to, and to develop the licence with community feedback. See LICENSE.txt for the full text.

Third-party components keep their own licences. Section 4.0 points at the LICENSES folder at the root of each NuGet package; in this repository, those notices are in the LICENSES folder of each library that redistributes them.

Contributing

You can submit PRs and issues. We are a small team and maintaining a public framework is going to be a lot of work, so please be patient with us. We'll see what happens, assess the problems, and change our workflows as necessary. What won't change is BRUTAL's scope.

Before opening a PR, read CONTRIBUTING.md. It covers scope, what we expect from AI-assisted contributions, the contribution grant in section 5.0 of the licence, and the sign-off every commit needs. Small changes you understand and have tested, with a clear purpose, are the ones that will get merged.

• Security issues: report them privately, see SECURITY.md. Don't open a public issue.
• Conduct: CODE_OF_CONDUCT.md.

Community

• Source: https://github.com/ahwootech/BRUTAL
• NuGet packages: https://www.nuget.org/profiles/Ahwoo
• Forums: https://forums.ahwoo.com/forums/brutal/
• Discord: https://discord.gg/MEuNTYbAh8

Credits

BRUTAL was made by the RocketWerkz Enterprise team and others, named in CONTRIBUTORS.md. When we talk about wanting credit for BRUTAL, these are the people we are talking about.

BRUTAL is Copyright (c) 2024 Ahwoo Limited.