I'm the creator of Easel, a game programming language with automatic multiplayer. I've been trying to figure out what to do with the feedback that people have been finding it difficult, and this has been my analysis and my response to the situation. Maybe some of you might find this interesting?
I once had a C# server with a TypeScript frontend (this was for work, so I didn't choose the tech stack). We had one part of the code which had a lot of calculations. We wrote the code in a C# library, then used Roslyn to analyse the C# code and generate TypeScript code that matched it identically. This way the client could visualise the results on the client with zero latency, no server roundtrip, but ultimately the server would be in charge of the final calculations. It was a great solution, I would do it again.
We could have potentially used Fusion for this had it existed, but I don't know if we would. We didn't have to support 12 different languages, only 2.
Still working on my programming language which makes your game multiplayer automatically. Currently working on improving the tutorials. When writing the tutorials I followed the "focus on the action" principle from Diataxis (https://diataxis.fr/tutorials/) perhaps too much. Easel is a unique language in a number of ways and it really does actually have to be taught, so I'm trying to make it do a better job of that.
A reactive programming language for games! Properties signal when they change and you can register blocks that tell the engine how to use that property, not just once but every time it changes. It’s a more declarative way of making games which I think is lots more productive.
I’ve been working on this for four years, it’s been a big project!
I would LOVE to one day make a source-available standalone license for Easel that you can run on your own server! I just have a bunch of problems to solve to get there before it’s ready.
1. The people who really love Easel right now are teenagers who have mastered Scratch and are looking for more. Expert game devs who come from Unity or other programming languages find it’s missing some capability they really want and tend to get frustrated right now. I’ve been solving so many issues every month, like we got multiple cameras the other month for example, but there’s so much left. If I made a standalone version now, no one would buy it because it doesn’t yet do what they need, and if you did I would probably be refunding you quite soon. We might need another 6-12 months to be ready for experts. Sign up to the mailing list and we can keep you updated.
2. I would be willing to go as far as source available to licensees but there’s are some practical issues with fully open source. First, it makes it easier to cheat at all Easel games. Easel is client authoritative for certain things. Why? So I can keep the server costs within what I can actually afford because I am one person. Maybe once I can afford 30 servers we can make it all server authoritative and I won’t worry about this anymore. Second, I expect a net decrease in my productivity if I have to argue and defend my code, and become the BDFL to the open internet all the time in an open source environment. I’ve been really really productive just working by myself.
I would love to make a license where you could export and then you can run it forever yourself on your own server! It’s not because I don’t want to do these things, it’s just I’m one person and I never get the time to do everything I would like to do.
Wow, I’m amazed someone noticed this. I’d be interested to know more about your background and interests. How much have you been looking at programming language design vs just designing for complex systems in general?
I ask because yes, I have put in a great deal of time and effort into the programming language design, and to me, I think that is the greater achievement, more than the automatic multiplayer. But the benefits of automatic multiplayer are easy for the general population to understand and the improvements programming language design is hard to convey and so people don’t normally get it. The fact that you can see what I’ve been trying to do so quickly shows you must be coming from a place which has developed that discernment for you.
While there are many inspirations, like I love coding using React for example, my primary inspiration is the last game I made, I released all the modding tools along with them and lots of non-coders loved it. The modding was JSON, which might sound primitive, but it was actually a hierarchical declarative domain specific language and it seemed to really work for people intuitively.
Easel was born from me spending 2 years trying to make an imperative programming language in a similar shape as that declarative one. I wanted it to be just as easy, but infinitely more powerful. It took a lot of iteration to merge the declarative and imperative styles into one language. There is so much to it - lexical lifetimes and ownership, reactivity like you noticed, but also weaving in concurrency and asynchronous programming seamlessly took time as well.
I really wish this is more the part of Easel that would stand out and be talked about more because I think it’s the coolest part.
Okay, in that case you can upload a stub with a transclusion of the game. If there is enough demand I would definitely work on a standalone export system!
Yes, sounds like you get it, Giant Wall changed so it gets rolled back to point A, then it resimulates, which might mean Giant Wall might push some other things this time around that it didn't before during the predicted simulation. It kind of uses a transaction log copy-on-write kind of mechanism, so there will be a log entry for previous value of the Giant Wall slot and it will restore that into its old slot. It's a bit more advanced than that but that's the gist.
This physics engine is a deterministic physics engine. It has to be to make sure that when it rolls back and resimulates forward, it gets the same answer on all machines.
The determinism is partly possible because WebAssembly is deterministic (except for a few known cases https://github.com/WebAssembly/design/blob/main/Nondetermini...), and partly because I’m making sure to use my own trigonometric functions, and the entire game simulation is executed single threaded with a known order of execution.
If you meant to ask how does it compare to non deterministic physics engines, I’m sure they might be faster on the physics but would be slower on the rollback, and I think on most reasonably-sized games the slow rollback would dominate and so they would be slower overall. But, you wouldn’t make a rollback netcode game with that size of world anyway, at least maybe not until now, so it’s a bit of a false comparison. They’re good at their different use cases.
Actually, it doesn’t roll back the entire game state. Everything is stored in slot maps, and if there are 1000 slots and only 10 changed, it really does only rollback those 10 only and it does not touch anything else. Slot maps are great!