[RFC] Prototyping speed improvements

[AnneKitsune]

Problem

Prototyping in amethyst is slow.

100 lines of code seems to be the minimum to make the smallest of game. While its not a lot, it definitely is more than necessary.

Source

I'm taking https://github.com/amethyst/amethyst/blob/develop/examples/sphere/main.rs as a model Lack of good defaults for generic types. Imports Lack of handle_event utils for simple cases -> Quit on any key, quit on some key, is key pressed.

Propositions

Lack of good defaults for generic types.

Adding sensible defaults as type alias for generics. 1) Add a default.rs file. 2) Make a DefaultSomething type alias with a default consistent with the others. 3) Export the module default.

Example: amethyst_input/src/default.rs

type DefaultInputHandler = InputHandler<String,String>

Imports

Expand the prelude to include as many common types as possible. I'm not too sure how much this slows down compile time when using the prelude, but I do have performance degradation in one of my project where I was using only preludes.

Lack of handle_event utils for simple cases -> Quit on any key, quit on some key, is key pressed.

I already implemented it inside of a custom project, currently debating if this should be inside of the engine.

[AnneKitsune]

first!

[majstudio]

Bump !

[Rhuagh]

I'm fine with this, but please don't use external libraries which are unreleased (and not even close to complete) as the main example.

[Rhuagh]

Oops, wrong button.

[Rhuagh]

I mean, when is a normal user going to use something else, except in an extremely low amount of edge cases?

Just a personal opinion on this, but I would never use String.

[AnneKitsune]

Not even for your prototypes?

[Rhuagh]

Not even for my prototypes.

[torkleyy]

MaterialDefaults is a resource, I think it should be a constant.

No, it should not. It's a fallback for when a texture handle is invalid and the user may provide it. Also, a constant would need late initialization (and yeah involve global state, probably not work with multithreaded tests, ..).

[AnneKitsune]

Lack of handle_event utils for simple cases -> Quit on any key, quit on some key, is key pressed. I already implemented it inside of a custom project, currently debating if this should be inside of the engine.

Thinking of adding it in amethyst_input/src/utils.rs instead of amethyst_utils. Would that make sense @torkleyy ?

ps: I removed the material defaults part.

[Rhuagh]

Sounds like an excellent location.

[torkleyy]

Hmm I'm not sure, creating a convenience function for everything might obscure things too much.

[AnneKitsune]

So, who wants to have this: https://github.com/jojolepro/amethyst-extra/blob/master/src/lib.rs#L193 (lines 193 to 257 included into the engine, and who doesn't? I don't mind keeping it external, but integrating it would make the examples cleaner.

[Xaeroxe]

I agree there shouldn't be a function for everything, but this qualifies as extremely common. I say we should add it.

[MrMinimal]

Generating a quad and handling basic events should be part of the engine, I'd agree it's okay to add it. As long as we keep @torkleyy's concerns in mind for other (less integral) features.

[torkleyy]

Well, I think it would be nice to have a more concise Event type. It should just be

match event {
    Event::KeyPressed(KeyCode::Escapce) => blah,
}

That would make things a lot nicer.

[torkleyy]

That's why I'm still in favor of exposing our own event type instead of winit::Event.

[Xaeroxe]

Why not expose both?

[torkleyy]

Exposing just our own type allows us to upgrade winit without breakage. Additionally, if we convert winit events into our own type, I don't see any need to interface with the winit version.

[torkleyy]

Having two ways of dealing with the problem would be confusing IMO.

[Xaeroxe]

That's fair. I was mostly thinking of people who might want to use winit events to interface with other winit compatible crates, but I'm not sure I have any good examples at this time.

[Rhuagh]

I do that, I convert winit events myself into other events.

[Rhuagh]

I do think we can add a system event for the things that are hard events

[torkleyy]

for the things that are hard events

What do you understand by that?

[Rhuagh]

Window close, resize etc, things that you usually don't rebind.

[torkleyy]

I'm not sure I understand what you're suggesting, sorry.

[Rhuagh]

I'm not even sure I do myself :P

My current gripe with the current handle_event function calls are that there's absolutely no control from the users perspective what events get propagated there. For the most part if you want input in a usable manner today you'd request access to an EventChannel manually, and just ignore what comes to handle_event. Somehow I guess to basic use case for it was the ability to get easy access to input events.

The problem however is that input events can roughly be divided into two groups of events:

• What I call hard events - Close, Resize, Focus etc - Things that are never rebound, just acted upon
• Rebindable events - Mouse, Keyboard, Touchpad etc, i.e. actual input events, which are most likely passed through some kind of rebinding and transformed into an event structure specific to each game.

I'm not sure I even have a proposal right now, just some gripes.

[raskyld]

Is this issue up-to-date ? Are all listed problems still there?

[torkleyy]

@AlmightyScientist Yes, this issue did not change a lot. I'll go through all the RFCs soon and make sure they're all discussed properly.

[raskyld]

Should we use the <T=ConcreteType> notation or use a typedef (type Default... = ...<ConcreteType>) ?

[AnneKitsune]

<T=ConcreteType> where it makes sense to have a default type. For example, draw Passes shouldn't have a default for the data because there's no good default (PosTex, PosNormTex, PosNormTangTex, etc)

Those that don't should have a type Default..

[fhaynes]

Transferring to RFC repo