refactor: Movement cross/uncross implementation.

[warriorstar-orion]

What Does This PR Do

This PR refactors several aspects of movement code. It provides a replacement implementation for /atom/movable/Move which does not call the native implementation nor the various /Cross//Uncross native procs, instead relegating this behavior to signal handlers. It introduces the connect_loc component, which handles crossing-style signals for objects by reregistering the specified signals onto locations that the parent moves to, and connect_loc_behalf, which does the same thing as connect_loc except on behalf of another listener.

This PR is an amalgamation of several /tg/ PRs, including but not limited to:

• Converts collide back to bump and fixes double bumping in another way tgstation/tgstation#38938
• Remove Uncross() and CheckExit(), add connect_loc element to cover the cases we used it for tgstation/tgstation#58188
• (code bounty) refactors all uses of Crossed() and Uncrossed() into signals sent to loc, tracked by connect_loc tgstation/tgstation#58340
• Makes turfs persist their signals, uses this to optimize connect_loc  tgstation/tgstation#59608
• CanPass refactor tgstation/tgstation#59804

Why It's Good For The Game

This implementation clears the way for #26637, another important refactor.

Many native BYOND procs are called millions of times a round for no reason. This implementation shortcircuits millions of these calls.

Overall this is a much cleaner implementation and easier to reason about, surprisingly.

Testing

In progorororereressss.

• Test crossing terror spider webs.
• Test bumps into doors/airlocks.
• Test bumps into gravgen tiles.
• Test crossover/crossing organics and exposed pulse demons.
• Test crossing over mice for squeak noise.
• Test crossing over peels.
• Test passing flipped tables in correct directions.
• Test projectiles passing shieldwalls and flipped tables.
• Test mobs passing under tesla balls.
• Test treadmill.
• Test assemblies.
• Test walking barefoot on syringes.
• Test meteor gun.
• Test necropolis doors.
• Test bloody decals.
• Test flamethrowers.
• Test beartraps.
• Test crossing over bluespace lockers.
• Test railings.
• Test teleport hubs.
• Test border firedoors.
• Test bonfires.
• Test acid.
• Test windoors.
• Test mines.
• Test snap-pops.
• Test tar.
• Test proximity sensors in assemblies, as well as assemblies placed in crates.
• Test proximity detector for energy projectiles shot near a singulo.

---

Declaration

• I confirm that I either do not require pre-approval for this PR, or I have obtained such approval and have included a screenshot to demonstrate this below.

---

Changelog

NPFC

[lewcc]

The performance implications of this look sick. I gave some of it a quick look, but there is a LOT. I'll probably try to come back to this down the line.

The one thing that strikes me is that this does feel much less intuitive than simply overriding Crossed() as before. Do you think you could create some kind of developer documentation for this change that explains the difference between the old and new way of doing this? Maybe on the new documentation site.
I think it'd be worth listing out things like

• which procs are now off limits (partially or entirely)
• which signals should be used to replace them (possibly with their arguments), and in particular, how to interact with them, especially with the return types.
• A good example or two of how you might now use it, maybe with a comparison of the old way and the new way in order to show how the concepts have transferred.

The more I look at the changes, the more straightforward it feels, but I also say this as someone who has a reasonable understanding of our ECS. I also really appreciate that you've put a lot into this work and don't want to put too much more onto your plate, but I think having this would do dividends.

[lewcc]

Document these, please

[warriorstar-orion]

Whoops, don't need these in this PR. Removed.

[warriorstar-orion]

The performance implications of this look sick. I gave some of it a quick look, but there is a LOT. I'll probably try to come back to this down the line.

The one thing that strikes me is that this does feel much less intuitive than simply overriding Crossed() as before. Do you think you could create some kind of developer documentation for this change that explains the difference between the old and new way of doing this? Maybe on the new documentation site. I think it'd be worth listing out things like

• which procs are now off limits (partially or entirely)
• which signals should be used to replace them (possibly with their arguments), and in particular, how to interact with them, especially with the return types.
• A good example or two of how you might now use it, maybe with a comparison of the old way and the new way in order to show how the concepts have transferred.

The more I look at the changes, the more straightforward it feels, but I also say this as someone who has a reasonable understanding of our ECS. I also really appreciate that you've put a lot into this work and don't want to put too much more onto your plate, but I think having this would do dividends.

I've added a new page of documentation on the relevant signals and what to use when. PTAL and let me know it it needs any improvements.

[lewcc]

This doesn't change its behavior, right? Was this original variable in seconds, ds, or processing ticks?

[warriorstar-orion]

I just did some extra testing. As far as I can tell, the original sensor cooldown is 10 ticks. I'm almost positive I ported the behavior correctly, both for the sensor cooldown and the arming timer. There's also "cooldown", which is not related to the timing countdown, meant to prevent spamming the sensor, which is part of the parent proc /obj/item/assembly/proc/process_cooldown(), and was already on a timer so the behavior there shouldn't have changed either.