Pollus Game Engine

What is Pollus?

A small endevour into the possibilities of a "pure" C# game engine that can compile to both native and web platforms. It aims to create a smaller 2D engine as a complete package, but still supporting selecting the underlying core modules to create other types of engines.

You can find the Breakout clone example running here

Features

• ECS with some inspiration from bevy
• Plugin based features
• WGPU rendering backend
  • WebGPU on web
  • Other WGPU supported backends on native
• Simple audio plugin
• Simple input plugin
• Build to Windows and Browser (WASM)
• Dear ImGui renderer, which is the only form of UI right now

Currently requires net9.0 and net8.0-browser targets and the wasm-tools workload.
net9.0-browser is currently not working, likely an issue with the browser-wasm target in the emcc compilation step. Status of the different areas of the project is currently tracked in TODO.

WARNING

This project is still very early in development and any api surface and underlying features might change at any point.
There are still a lot of important features missing and most of the WASM and browser support is still a prototype.

Getting Started

Pollus.Engine is the glue project and contains all the required Plugins and systems to get up and running.

Building WASM for web

Browser is built with dotnet publish --framework net8.0-browser -c Release and can be hosted locally with dotnet serve -S -p <port>.
Install the wasm-tools and wasm-experimental workloads with dotnet workload install <tool> WebGPU is currently only working in Chromium-based browsers.

Example folder

The /examples/ folder in the root directory contains a few different examples for each aspect of the engine.
A lot of the contents in Pollus.Examples.csproj file is required to build for web and will be templated to be more usable in the future.

Minimal example

Application.Builder
    .AddPlugins([
        new AssetPlugin { RootPath = "assets" },
        new InputPlugin(),
    ])
    .AddSystems(CoreStage.PostInit, FnSystem.Create("SetupEntities",
    static (Commands commands) => 
    {
        commands.Spawn(Entity.With(Transform2D.Default, new Player()));
    }))
    .AddSystems(CoreStage.Update, FnSystem.Create("UpdateEntities",
    static (Query<Transform2D>.Filter<All<Player>> query, ButtonInput<Key> keys) => 
    {
        query.ForEach((ref Transform2D transform) =>
        {
            if (keys.Pressed(Key.ArrowLeft))
            {
                transform.Position += Vec2f.Left;
            }
            if (keys.Pressed(Key.ArrowRight))
            {
                transform.Position += Vec2f.Right;
            }
        });
    }))
    .Run()

Known Issues

• ImGui has some function signature mismatch between Silk.NET generated bindings and the wasm native library file.
  • ImGui.Text might have to be replace with ImGui.TextUnformatted
• Fullscreen mode in browser is broken

Libraries

The aim is to have as few dependencies as possible. This will allow the project to more easily adjust to any differing requirements between web and native. Most pure dotnet projects will work with WASM out of the box, but anything that is built on top of native libraries will not.

• Silk.NET.SDL (for SDL bindings)
• Silk.NET.WebGPU (for native WebGPU bindings)
• Silk.NET.OpenAL (for native OpenAL bindings)
• SixLabors.ImageSharp (image assets)
• ImGui.NET (Dear ImGui bindings)
• cimgui/imgui (for wasm builds)

License

This project is licensed under 'MIT License' except where noted. Parts of the project with a different license is either notified in the file itself or in the directory of the file.