The author has one major issue with Rust in gamedev: they can't easily try out new game feature ideas or gameplay tweaks by writing quick and dirty code.
Such unfinished code can be obviously buggy and unsafe, but in game dev it matters more to have short feedback loop to try how things feel, than to have a perfectly correct code all the time.
Rust doesn't do quick and dirty, and will complain about code quality even when game devs don't even plan to keep the code.
This is a substantially different situation from other domains like application and services development, where it's easier to plan what you're going to implement, correctness is more important, and you don't need to try out 20 different JSON parsers to see which one has the most satisfying feel.
C++ doesn't do quick and dirty either. That's why experienced game developers combine a core engine written in a high-performance language (C++, Rust, C#), with a scripting language (Lua, Python, hand-rolled).
That approach gives you the best of both worlds: high-performance core with high-velocity iterations for gameplay. Don't use Rust or C++ for scripting... madness lies that way.
C++ will easily let you write non-thread-safe code anywhere, won't complain about multiple mutable pointers to the same object, will let you leave pointers dangling and resources leaked.
Such code is of course crappy, but the OP wants to test if things are fun before committing to implementing them properly. Rust wants things done properly on the first try (which usually is a good thing, except throw-away prototypes).
"CHR is very new and experimental feature of the engine, it is based on wildly unsafe functionality which could result in memory corruption, subtle bugs, etc."
I also think that doc page is a little old. The feature is over 2 years old now and hot reloading is inherently "unsafe" in any compiled language. It's just letting you know that Rust's safety guarantees might go out the window if there are bugs in the code that handles hot-reloading.
Funnily enough, Mojang is on that list, and I remember recently watching a video[1] of Notch hot-reloading code while developing Minecraft, except it was with Java and I'm sure he didn't pay a dime for the ability to do that.
> Rust doesn't do quick and dirty, and will complain about code quality even when game devs don't even plan to keep the code.
The problem might just be an aversion to using quick and dirty solutions. Rust does a good job of making it feel wrong to write code that's not production ready, but there's nothing stopping you from using unsafe wherever you want.
I've worked with Bevy, and there's it's incredibly easy to write "quick and dirty" to test stuff. I guess the major "downside" you need to account for is that the type system will try to prote you from crashes. Which can be a bit of a chore since youknow it won't crash with the values you've given it. But if you're comfortable with .unwrap and the occasional unsafe while prototyping, it's honestly fine (at least within Bevy).
Alternatively, they could try "scripting" behaviour first before implementing it in Rust, although from what I understand bevy's scripting support (I don't think it's explicitly supported, but bevy is very extensible) is still very early in development
1. You dynamically add components to any entity, so entities don't have a static type. Semantically they're comparable to a JavaScript Object where you can add and remove properties at will, rather than being structs or class instances with a closed set of fields.
2. Bevy's entity references are generational IDs, without static lifetime guarantees (and restrictions) of Rust's references.
I don't think this is true for either `Component` or `Entity` in Bevy. You set what fields a `Component` has when writing the code, then it remains so during the runtime. There is no dynamically adding/removing fields at runtime, at least yet.
What you do tend to do in Bevy is adding/removing `Component`s to `Entity`s at runtime, is that maybe where the confusion comes in?
> Yes, technically, but in how they're used - no. They're a dynamic type.
No, they're really not. Are you talking about Archetypes or something else? Because an Entity is just a ID + a generation, that's it. Nothing more and nothing less. You don't define them as more/less, nor do you use them are more/less either.
> Yes, this is dynamic typing. Or, at least, one way to look at it - and what allows games to be iterated on quick.
I guess a `Vec<u8>` is also then dynamic typing in your mind as you can add/remove elements to the vector? Doesn't really compute for me personally, but whatever floats your boat.
But that's not really true either, is it? You don't query properties in JavaScript, at best you query for Objects of a certain shape/name. You don't encapsulate data in properties so one object has many different behavior based on those, you either split the Object into many different ones and have one parent, or you mix the behavior into the same Object.
Such unfinished code can be obviously buggy and unsafe, but in game dev it matters more to have short feedback loop to try how things feel, than to have a perfectly correct code all the time.
Rust doesn't do quick and dirty, and will complain about code quality even when game devs don't even plan to keep the code.
This is a substantially different situation from other domains like application and services development, where it's easier to plan what you're going to implement, correctness is more important, and you don't need to try out 20 different JSON parsers to see which one has the most satisfying feel.