Allow quake class registration across files

[janhohenheim]

This is needed for ergonomic splitting of TB entities across files.

Option 1: The precedent here is to have an extension method on App. See bevy_enhanced_input for a recent example. This is very simple and guarantees that this happens before the config is written or the level is spawned. My vote goes here!

Option 2: Read quake classes automatically from the type registry. Sounds neat, as that reuses existing API, but also sounds annoying to set up.

Option 3: Allow changing the BTB config after the plugin is created. Imo even if we already had this, I would still prefer to have a way to do the registration directly on the App instead of having multiple setup systems on startup

[Noxmore]

This is a big part of what the auto_register feature sought to solve, if only inventory worked on wasm!

This is my personal preference as it has zero boilerplate, but it's been 2 months and the maintainer hasn't looked into the issue.
I could also try the ctor crate, which to my knowledge is just a more general version of inventory. I'll let you know how this goes.

[janhohenheim]

@Noxmore I doubt you will find a satisfactory Wasm compatible solution. The Bevy devs have found nothing suitable so far either, otherwise .register_type would be automatic as well IIRC.
If you do find something, make sure to ping the reflection people on Discord, they would love this :)
And bevy_enhanced_input also wants this.

Edit: would you look at that, some people are working on it right now! bevyengine/bevy#15030 implements bevyengine/bevy#3936

[Noxmore]

Just went down this whole rabbit hole, including finding that PR, and here's what's i'm considering:
Remove the auto_register feature and TrenchBroomConfig::register_entity_class_types entirely, instead going with your option 2, and have the user use a crate like bevy_registration or Bevy's own implementation if that PR merges if they want that functionality.