Not about ECS, but speaking of components: I’m developing an unreal engine game and component based programming has been a dream. You end up with the opportunity to create so many pieces of code that are able to be dumb and that don’t need to know about the rest of the system. Then you add come control code that is also as dumb and blind (in a good, decoupled sense) as possible and the whole application comes together in 1/10th the effort of a more coupled and fragile inheritance heavy approach. You can actually change things without breaking everything and you can actually understand what something does by reading 1-2 source files instead of 40.
I'm curious about emergent problems that are difficult to diagnose with many systems operating seemingly independently. Systems interacting in odd ways, and ordering of systems (dependency ie one system MUST run before another). Do these come up?
You’re right, they do. You add a layer on top that is in charge of worrying about those interactions, and it works pretty smoothly in my experience, but even then there can be some challenges from multiple pieces of code trying to use that controller code to do contradictory things. But I think you end up in the same situation with all big apps, and in this setup at least some of your code is still easy to reason about. It’s still several layers of abstractions. Command pattern with a good entry-in-progress-exit lifecycle is another system to add on top that helps things stay flexible and easy to work with later on
Not to sound rude but IMO I find components really hard to organize and structure data. Components are probably really nice for storytelling games and games with simple logic: they really shine when you can just take some effect like a particle system and attach it to some object like a Sci-Fi weapon. But it's really hard to separate model, view, and controller from your game when they're all separate components on the same object.
MVC is good for user interfaces, but there is some inherent coupling between model and view in most games. Eg, animations. I didn’t have much luck using mvc outside of the ui. IMHO, single responsibility is the more fundamental principle and components are helpful for that
