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
* a very calming act
when the world is too much, too fast
* i'm tired
but i have to be efficient, infinite
* lick your lips at the sight of me
a fantasy made reality
* Adds brass, used to construct various brass objects
* brasshole
* give em the brass
* give em more brass
* DYNAMIC
* VAR MURDER SPREE
* brassy
* acceptaphil
* this is super against my general preferences but eeeeeh sure okay i guess
Fix carp knocking borg. 7394
Replace carp knockdown by stamina dmg (for human only) (now 5 bites instead of 7 to go from 100% to crit w/o armor) 7905
Fix being stunned as a borg causing temporary blindness, deafness and muteness. 9061
Change robot out of power: now only stunned, can talk but not move or interact. Adding feedback in examine. 6170
Robots now take damage in the hottest of inferno (35,000+ K) 8840
Nerfs uranium wall radiation: 6 times less radiation (just double the effect of urafloor), chain reaction range down to 1. 6841
Fixes putting braindead/notincorpse/ghosted brains in mmi, and same for mmi in borgs, the action fails and sends a message to the ghost. 4841 7447
Fixes brains taking eye damage and becoming blind. 6039
Fixes surviving suicide
Fixes suicide damage overlays.
Fixes ninja regen "clothes warm" spam message. (moving rad armor check outside of apply_effect)
Fixes ninja smoke bomb count.
Fixes dead shaved corgi
Fixes lipozine still being in code.
Fixes flattening boxes requiring them to have their window opened.
Fixes armor softening message from disarm attack.
Fixes player being forced to play spiders without choosing.
Broken walls now drop a multi-sheet metal stack instead of many 1-sheet stacks
Walls now have a builtin_sheet for performance. Also fixes bananium wall bugs with not dropping the mineral.
