Introduction
About Me
Hi, my name is Peter, and I'm a game engine developer from Sweden, I'm also the author of this guide. I've been working on a game engine called Hazel for over a year, and one of the things I've worked on is a C# scripting engine, using the Mono library.
Hazel is not my own personal engine, and it was originally created by Yan Chernikov. I joined the project in September of 2020 as a volunteer, and now I'm lucky enough to be able to work on it as an actual job.
The goal of this guide
The goal of this guide is to help you embed the Mono library into your game engine. For the past few months I've been working on rewriting the C# scripting engine in Hazel, and I kept getting frustrated because there's very little in terms of useful documentation on how to use Mono in the scope of a game engine.
Yes, Mono does have a documentation site for embedding: http://docs.go-mono.com/, but in my experience it's all but useless. There are a few open source (or at least source available) projects out there that have embedded Mono, but there's no real documentation available.
So, that's why I decided to create this guide. I've been through the pain of googling for hours to figure out how to do something in Mono, and I figured I could help spare others from that pain.
Before we get started I just wanted to say that this guide is not a guide on building a complete scripting engine, it's just meant to give you the knowledge you need to write a scripting engine.
I will also mention that the "First Steps" section only covers the very basics, I'll go into way more depth and show more complex code in a more advanced section later on.
Credits
I'm not the only person who has contributed to this. I've had some help with certain parts of it, so I wanted to make sure to mention anyone that has helped out.
- Marca, provided build instructions for Mac OSX
The Game Engine Series
As I've mentioned this guide isn't meant to teach you how to write a fully fledged scripting engine. But there is a series on YouTube that does cover writing a scripting engine in C++, the Game Engine Series from The Cherno.
The scripting engine that he's writing is based on the scripting engine that I wrote for Hazel, and he does reference this guide as well. I highly recommend watching the C# scripting related episodes if you're interested in how you can design an actual scripting API.
Understandably there's a lot of different ways of writing a scripting engine, and there's no "correct" way of doing so, although there are worse ways and better ways, as with everything.