Split monolithic physics class files

[smix8]

Splits monolithic physics class files.

This PR moves things around a lot, but what this PR primarly does is to split the monolithic physics class files into subfiles. Something that was imo overdue for a very long time. E.g. physics body was harboring all the rigid, static, character, and what-not bodies. This made the file already lag in editors and resulted in all kind of functionality that only needed a single physics base class to include near everything physics has to offer.

All the main physics classes are now in their own file in a scene/2d_or_3d/physics subfolder.
Same with bone joints, each bone joint now has its own file in a joints subfolder.
Main means the class is primarily or exclusively used with or for physics.
E.g. raycast, shape cast, physics bones, collision shapes, objects and bodies.

A few random includes that were discovered as no longer needed are also removed.
E.g. the NavigationObstacle no longer uses physics so no need to include physics classes.

[fire]

It is very hard to review these changes. Especially when the github web interface freezes on my computer. The typical strategy is make sure the tests pass and let the testing go to the wider community.

[fire]

Aha. I switched from Firefox to Safari and it loaded. See previous comment. Assuming that there is no functionality change.

[akien-mga]

You'll need to add the new folders to generate_scu_files in scu_builders.py for the SCU builds, as it's currently a manual listing of suitable folders.

@lawnjelly Is this something we could worth towards automating? Are there any reasons not to process all folders recursively (at least within specific top level folders) for SCU?

[lawnjelly]

@lawnjelly Is this something we could worth towards automating? Are there any reasons not to process all folders recursively (at least within specific top level folders) for SCU?

We could potentially have the option to process_folder_recursive(). 🤔

I think I erred on the side of caution here, and also control. (It's likely I tried it during development and wasn't convinced by the benefits at the time.)

There's folders such as editor/icons, translations, __pycache__ etc, which make no sense to process every time you hit compile, just in case they contain cpps. There also may be some folders that are not included currently because they pollute the global namespace and aren't worth it in terms of costs / benefits of fixing the source code (especially third party stuff which we want to be able to update easily).

Currently it doesn't break when you add new folders, it just doesn't accelerate them until they are added manually to scu_builders.py. So accelerating them would be fine for a followup PR too.

[smix8]

Added the physics and joints folders to the scu script and fixed the gltf includes.

[akien-mga]

Looks good to me, and compiles fine. A quick test shows the GDQuest TPS demo with 3D physics seems to work.

[akien-mga]

Thanks!