Please refer to #20867 and #20870 for a easier view of the changes. Those two PRs show all meaningful changes (hopefully) and doesn't show the files changed with just 3 lines changed.
This PR does three things:
It makes all children of /obj/ use the same damage system.
Previously to make your new machine/structure be destroyable you needed to give it a var/health, and its own version of many damage related proc such as bullet_act(), take_damage(), attacked_by(), attack_animal(), attack_hulk(), ex_act(), etc... But now, all /obj/ use the same version of those procs at the /obj/ level in code/game/obj_defense.dm. All these obj share the same necessary vars: obj_integrity (health), max_integrity, integrity_failure (optional, below that health level failure happens), and the armor list var which was previously only for items, as well as the resistance_flags bitfield. When you want your new object to be destroyable, you only have to give it a value for those vars and maybe override one proc if you want a special behavior but that's it. This reorganization removes a lot of copypasta (most bullet_act() version for each obj were nearly identical). Two new elements are added to the armor list var: fire and acid armor values.
How much damage an obj take depends on the armor value for each damage category. But some objects are INDESTRUCTIBLE and simply never take any damage no matter the type.
The armor categories are:
-melee(punches, item attacks, xeno/animal/hulk attacks, blob attacks, thrown weapons)
-bullet
-laser
-energy (used by projectiles like ionrifle, taser, and also by EMPs)
-bio (unused for this, only here because clothes use them when worn)
-rad (same)
-bomb (self-explanatory)
-fire (for fire damage, not for heat damage though)
-acid
For machines and structures, when their health reaches zero the object is not just deleted but gets somewhat forcedeconstructed (the proc used is shared with the actual deconstruction system) which can drops things. To not frustrates players most of these objects drop most of the elements necessary to rebuild them (think window dropping shards). Machines drop a machine frame and all components for example (but the frame can then be itself smashed to pieces).
For clothes, when they are damaged, they get a "damaged" overlay, which can also be seen when worn, similar to the "bloody" overlay.
It refactors acid. See #20537.
Some objects are ACID_PROOF and take no damage from acid, while others take varying amounts
of damage depending on their acid armor value. Some objects are even UNACIDABLE, no acid effect can even land on them. Acid on objects can be washed off using water.
It changes some aspect of damage from fires.
All /obj/ can now take fire damage and be flammable, instead of just items. And instead of having just FLAMMABLE objs that become ON_FIRE as soon as some fire touch them (paper), we now have objects that are non flammable but do take damage from fire and become ashes if their health reaches zero (only for items). The damage taken varies depending on the obj's fire armor value and total health. There's also still obj and items that are FIRE_PROOF (although some might still be melted by lava if they're not LAVA_PROOF).
When a mob is on fire, its clothes now take fire damage and can turn to ashes. Similarly, when a mob takes melee damages, its clothes gets damaged a bit and can turn to shreds. You can repair clothes with cloth that is produceable by botany's biogenerator.
It also does many minor things:
Clicking a structure/machine with an item on help intent never results in an attack (so you don't destroy a structure while trying to figure out which tool to use).
I moved a lot of objects away from /obj/effect, it should only be used for visual effects, decals and stuff, not for things you can hit and destroy.
I tweaked a bit how clothes shredding from bombs work.
I made a machine or structure un/anchorable with the wrench, I don't remember which object...
Since I changed the meaning of the FIRE_PROOF bitflag to actually mean fire immune, I'm buffing the slime extract that you apply on items to make them fire proof. well now they're really 100% fire proof!
animals with environment_smash = 1 no longer one-hit destroy tables and stuff, we give them a decent obj_damage value so they can destroy most obj relatively fast depending on the animal.
Probably a million things I forgot.
If you want to know how the damage system works all you need is the three obj vars "obj_integrity", "max_integrity", "integrity_failure", as well as the armor list var and the resistance_flags bitfield, and read the file obj_defense.dm
Adds a large ash and large molten item decal (for future use)
simplifies decal/cleanable/replace_decal() code a bit.
Changes construction() proc to on_construction() for consistency, same for deconstruction().
Made a deconstruct() proc for machinery and computer (also for future use).
Added priority overlays to atoms, which will not be removed when overlays are cut and will always remain on top when new overlays are added. This requires everyone to use add_overlay() and cut_overlays() instead of overlays += and overlays.Cut(). These procs are found in __HELPERS/icons.dm, and the priority overlay list is found in game/atoms.dm. Everything else is replacing deprecated overlay manipulation.
This contains the changes to item_attack.dm
Obj/attackby() now follows a similar structure as mob/living/attackby. It calls attack_obj() (like attack() but for obj) which calls attacked_by (just like attack() does)
The use of the NOBLUDGEON flag changes a bit, it is now used to signify the item cannot be used as a melee weapon at all. No attack animation, no attack message. I've given this bitflag to many items that have an afterattack() so as to not both attack and do the special action (among those items: the rcd)
There's also the code changes to attacking machines: attacking any machine now give a proper message and a sound. And with this, I made more machines breakable (using a health var and the very little used BROKEN stat). Most notably, tables can now be attacked when on harm intent and be destroyed.
The newly destroyable machines have a take_damage() proc used by all sorts of attack (weapon, xeno, animal, hulk, mech melee, gun projectile, thrown items).
There's some more stuff in there, see the PR's description and comments.
Adding missing "target=src" to a couple do_after() calls.
You can now close a fire axe cabinet by clicking it with a full hand (if it's not broken/locked)
Misc:
+Fixes unreported issue with initializing lighting on a specific zlevel
+Fixes two similar issues with moveElement and moveRange. Where fromIndex or toIndex could be adjusted incorrectly in certain conditions. Potentially causing bad-sorts, or out of bound errors.
+Rewrites listclearnulls(list/L) to no longer iterate through L.len elements for every null in the list (plus 1). i.e. went from L.len*(number_of_nulls+1) list-element reads (best-case), to L.len list-element reads (worst-case)
+New proc/getElementByVar(list/L, varname, value) which finds the first datum in a list, with a variable named varname, which equals value. You can also feed it atoms instead of lists due to the way the in operator functions.
+Fixes an unreported issue with Yota's list2text rewrite. Under certain conditions, the first element would not be converted into a string. Causing type-mismatch runtimes.
+New global map_ready variable. This is not fully implemented yet, but will be used to avoid duplicate calls to initialize() for map objects.
+All turfs now maintain references to all lights currently illuminating them. This will mean higher memory use unfortunately, due to the huge number of turfs. However, it will speed up updateAffectingLights significantly. I've used list husbandry to reduce baseline memory usage, so it shouldn't be any worse than some past atmos modifications memory-wise.
-Removed 'quadratic lighting', can add this back at some point. Sorry.
+modified the way lum() works slightly, to allow turfs to have overridden delta-lumen. i.e. space cannot be illuminated more than its default ambiance. This allowed removal of some iffy special-snowflake lighting areas implemented by somebody else.
+Lighting images in the dmi can now use arbitrary naming schemes. It is reliant on order now. This allows the dmi to be replaced by simply dropping in a new dmi.
-Removed all subtypes of /area/shuttle. Shuttles now create duplicate 'rooms' of /area/shuttle. (More on this later). This will conflict with most maps. Guide on how to fix to follow.
+All verbs/tools relating to world.tick_lag were refactored to use world.fps. However old config text for setting tick_lag will still work (it converts the value to fps for you)
+MC stats improved using smoothing. They now have their own tab so they dont get in the way when you're playing as an admin.
-removed the push_mob_back stuff due to conflicting changes. Sorry Giacom.
_OK, NOW THE ACTUAL INTERESTING STUFF_
Following systems moved over to subsystem datums:
air_master
garbage_manager
lighting_controller
process_mobs (aka Life())
nanomanager
power
sun
pipenets
AFK kick loops
shuttle_controller (aka emergency shuttle/pods), supply_shuttle and other shuttles
voting
bots
radio
diseases
events
jobs
objects
ticker
Subsystems hooks and variables should be commented fairly in-depth. If anything isn't particularly clear, please make an issue.
Many system-specific global variables have been refactored into
All tickers which previously used world.timeofday now use world.time
some subsystems can iterate before round start. this resolves the issue with votes not working pregame
