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gavrilovmiroslav / svarog

A C#-only old-school modular game engine
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Svarog

An easy to use, old-school game engine for olden games. Think roguelikes, ultimas, etc. Currently only functional as a modular renderer and shader playground.

Quick Start

To start working with Svarog...

  1. have Visual Studio 2022 and .NET 8 (with C# 12) installed within it
  2. clone this repository to your machine
  3. open the solution in Visual Studio 2022 or equivalent
  4. build the svarog-bin project first
  5. build all the other plugin projects
  6. go to the top folder of the repository and run the run.bat batch file!

You're now set.

Svarog is modular: every piece of functionality is loaded as a separate DLL and can be reloaded: simply rebuild the project you changed while the editor is working and you should see the difference live.

Svarog has a plugin template that makes it very easy to setup a new plugin! Install it by copying the Svarog Engine Plugin.zip file from the root of the repo to where your VS templates are. After that, choose to make a new project in the svarog solution, and search for "Svarog". It should pop!

The playable version of the game lives in the svarog-game folder: it is a product of all the projects and needed a home of its own. The run.bat script just goes in and starts it from there.

Plugin 101s

For a plugin to be recognized by the engine, it needs to satisfy two simple conditions:

  1. It needs to be a class that has the [Plugin] attribute
  2. It needs to derive from either IPlugin or, more often, Plugin. The latter is a class that makes life a bit simpler than if you go with the interface.

Once you have this, simply override the functionalities from the interface/superclass and you're good to go. The [Plugin] attribute has a Priority field which sorts the plugins. The default value for priority is 100. Postprocessing currently starts at 1000.

Plugin lifetimes are straightforward:

  1. Load - called once either at engine start or when the plugin is loaded
  2. Render - called every frame during the rendering process
  3. Frame - called every frame at the end of frame
  4. Unload - called once either at engine shutdown or when the plugin is unloaded

Plugin reloads are simply Unload+Load cycles with no complications.

Each plugin can carry its own Data: make sure that the data is made to "Always Copy" on build. The build process will copy and unify the data with the one already present in the svarog-game folder.

Gotchas

When working with resources, make every plugin responsible for the data it brings in. Don't put all the resources in the svarog-bin data folder.

Don't make generic or smart loaders - make plugins to load the exact data you need if you don't need anything better than that.

Keep data unattached from the runtime (don't load a whole file and leave it open), so that it can be reloaded properly. This means using File.ReadAllBytes or File.ReadAllText, for example, instead of opening files.