Adds an universal object health system. (#21266)

https://www.youtube.com/watch?v=ZpUYjpKg9KY

As per title. The goal is to add health to most objects in the game and
thus allow them to be dynamically destructible, while also avoiding
shitcode like each structure having its own snowflake health update
proc.

---------

Signed-off-by: Matt Atlas <mattiathebest2000@hotmail.it>
Co-authored-by: Matt Atlas <liermattia@gmail.com>
Co-authored-by: SleepyGemmy <99297919+SleepyGemmy@users.noreply.github.com>

code/modules/modular_computers/computers/modular_computer/core.dm

@@ -5,7 +5,7 @@
 		last_power_usage = 0
 		return FALSE
 
-	if(damage > broken_damage)
+	if(health <= broken_damage)
 		shutdown_computer()
 		return FALSE
 
@@ -41,7 +41,7 @@
 			else
 				enabled_services -= service
 
-	working = hard_drive && processor_unit && damage < broken_damage && computer_use_power()
+	working = hard_drive && processor_unit && health >= broken_damage && computer_use_power()
 	check_update_ui_need()
 
 	if(looping_sound && working && enabled && world.time > ambience_last_played_time + 30 SECONDS && prob(3))
@@ -168,7 +168,7 @@
 	icon_state = icon_state_unpowered
 
 	ClearOverlays()
-	if(damage >= broken_damage)
+	if(health <= broken_damage)
 		icon_state = icon_state_broken
 		AddOverlays("broken")
 		return
@@ -264,7 +264,7 @@
 	if(tesla_link)
 		tesla_link.enabled = TRUE
 	var/issynth = issilicon(user) // Robots and AIs get different activation messages.
-	if(damage > broken_damage)
+	if(health <= broken_damage)
 		if(issynth)
 			to_chat(user, SPAN_WARNING("You send an activation signal to \the [src], but it responds with an error code. It must be damaged."))
 		else

code/modules/modular_computers/computers/modular_computer/damage.dm

@@ -4,50 +4,47 @@
 		. += FONT_SMALL(SPAN_NOTICE("It contains the following hardware:"))
 		for(var/obj/CH in get_all_components())
 			. += FONT_SMALL(SPAN_NOTICE(" - [capitalize_first_letters(CH.name)]"))
-	if(damage > broken_damage)
+	if(health <= broken_damage)
 		. += SPAN_DANGER("It is heavily damaged!")
-	else if(damage)
+	else if(health <= maxhealth)
 		. += SPAN_WARNING("It is damaged.")
 
-/obj/item/modular_computer/proc/break_apart(msg = TRUE)
-	if(msg)
-		visible_message(SPAN_WARNING("\The [src] breaks apart!"))
+/obj/item/modular_computer/add_damage(damage, damage_flags, damage_type, armor_penetration, obj/weapon)
+	. = ..()
+	var/component_probability = 0
+	switch(damage_type)
+		if(DAMAGE_BRUTE)
+			component_probability = damage / 2
+		if(DAMAGE_BURN)
+			component_probability = damage / 1.5
+
+	if(component_probability)
+		for(var/obj/item/computer_hardware/H in get_all_components())
+			if(prob(component_probability))
+				H.take_damage(round(damage / 2))
+
+	update_icon()
+
+/obj/item/modular_computer/on_death()
+	visible_message(SPAN_WARNING("\The [src] breaks apart!"))
 	new /obj/item/stack/material/steel(get_turf(src), round(steel_sheet_cost/2))
 	for(var/obj/item/computer_hardware/H in get_all_components())
 		uninstall_component(null, H)
 		H.forceMove(get_turf(src))
 		if(prob(25))
 			H.take_damage(rand(10, 30))
-	qdel(src)
-
-/obj/item/modular_computer/proc/take_damage(var/amount, var/component_probability, var/damage_casing = TRUE, var/randomize = TRUE, msg=TRUE)
-	if(randomize)
-		// 75%-125%, rand() works with integers, apparently.
-		amount *= (rand(75, 125) / 100.0)
-	amount = round(amount)
-	if(damage_casing)
-		damage += amount
-		damage = between(0, damage, max_damage)
-
-	if(component_probability)
-		for(var/obj/item/computer_hardware/H in get_all_components())
-			if(prob(component_probability))
-				H.take_damage(round(amount / 2))
-
-	if(damage >= max_damage)
-		break_apart(msg)
-	update_icon()
+	. = ..()
 
 // Stronger explosions cause serious damage to internal components
 // Minor explosions are mostly mitigitated by casing.
 /obj/item/modular_computer/ex_act(var/severity)
-	take_damage(rand(125, 200) / severity, 30 / severity, msg = FALSE)
+	add_damage(rand(125, 200) / severity, 30 / severity)
 
 // EMPs are similar to explosions, but don't cause physical damage to the casing. Instead they screw up the components
 /obj/item/modular_computer/emp_act(severity)
 	. = ..()
 
-	take_damage(rand(100, 200) / severity, 50 / severity, FALSE)
+	add_damage(rand(100, 200) / severity, 50 / severity)
 
 // "Stun" weapons can cause minor damage to components (short-circuits?)
 // "Burn" damage is equally strong against internal components and exterior casing
@@ -57,10 +54,4 @@
 	if(. != BULLET_ACT_HIT)
 		return .
 
-	switch(hitting_projectile.damage_type)
-		if(DAMAGE_BRUTE)
-			take_damage(hitting_projectile.damage, hitting_projectile.damage / 2)
-		if(DAMAGE_PAIN)
-			take_damage(hitting_projectile.damage, hitting_projectile.damage / 3, 0)
-		if(DAMAGE_BURN)
-			take_damage(hitting_projectile.damage, hitting_projectile.damage / 1.5)
+	add_damage(hitting_projectile, hitting_projectile.damage_flags(), hitting_projectile.damage_type, hitting_projectile.armor_penetration)

code/modules/modular_computers/computers/modular_computer/interaction.dm

@@ -311,14 +311,15 @@
 			to_chat(user, SPAN_WARNING("\The [attacking_item] is off."))
 			return TRUE
 
-		if(!damage)
+		if(health >= maxhealth)
 			to_chat(user, SPAN_WARNING("\The [src] does not require repairs."))
 			return TRUE
 
 		to_chat(user, SPAN_NOTICE("You begin repairing the damage to \the [src]..."))
 		playsound(get_turf(src), 'sound/items/Welder.ogg', 100, 1)
+		var/damage = maxhealth - health
 		if(WT.use(round(damage / 75)) && do_after(user, damage / 10, src, DO_REPAIR_CONSTRUCT))
-			damage = 0
+			health = maxhealth
 			to_chat(user, SPAN_NOTICE("You fully repair \the [src]."))
 		update_icon()
 		return TRUE
@@ -354,6 +355,15 @@
 		if(do_after(user, 1 SECONDS))
 			visible_message(SPAN_NOTICE("[user] slots \the [access_cable] into \the [src]."))
 			universal_port.insert_cable(access_cable, user)
+
+	if(user?.a_intent == I_HURT && maxhealth)
+		user.do_attack_animation(src)
+		user.setClickCooldown(DEFAULT_ATTACK_COOLDOWN)
+		visible_message(SPAN_DANGER("[user] [pick(attacking_item.attack_verb)] \the [src]!"))
+		add_damage(attacking_item.force, attacking_item.damage_flags(), attacking_item.damtype, attacking_item.armor_penetration, attacking_item)
+		playsound(user, 'sound/effects/metalhit.ogg', attacking_item.get_clamped_volume())
+		return TRUE
+
 	return ..()
 
 /obj/item/modular_computer/mouse_drop_dragged(atom/over, mob/user, src_location, over_location, params)

code/modules/modular_computers/computers/modular_computer/variables.dm

@@ -3,6 +3,8 @@
 /obj/item/modular_computer
 	name = "Modular Computer"
 	desc = DESC_PARENT
+	maxhealth = OBJECT_HEALTH_MEDIUM
+	should_use_health = TRUE
 
 	var/lexical_name = "computer"
 	/// Whether the computer is turned on.
@@ -94,13 +96,8 @@
 	var/power_has_failed = FALSE
 	var/is_holographic = FALSE
 
-	/// Damage of the chassis. If the chassis takes too much damage it will break apart.
-	/// Current damage level
-	var/damage = 0
 	/// Damage level at which the computer ceases to operate
 	var/broken_damage = 50
-	/// Damage level at which the computer breaks apart.
-	var/max_damage = 100
 
 	/// Important hardware (must be installed for computer to work)
 	/// CPU. Without it the computer won't run. Better CPUs can run more programs at once.

code/modules/modular_computers/computers/subtypes/dev_laptop.dm

@@ -16,7 +16,7 @@
 	message_output_range = 1
 	max_hardware_size = 2
 	light_range = 3
-	max_damage = 50
+	maxhealth = OBJECT_HEALTH_VERY_LOW
 	broken_damage = 25
 	var/icon_state_closed = "laptop-closed"
 
@@ -43,7 +43,7 @@
 		..()
 	else
 		ClearOverlays()
-		if(damage >= broken_damage)
+		if(health <= broken_damage)
 			icon_state = icon_state_broken + "-closed"
 		else
 			icon_state = icon_state_closed

code/modules/modular_computers/computers/subtypes/dev_silicon.dm

@@ -9,7 +9,7 @@
 	base_idle_power_usage = 5
 	base_active_power_usage = 25
 	max_hardware_size = 3
-	max_damage = 50
+	maxhealth = OBJECT_HEALTH_LOW
 	w_class = WEIGHT_CLASS_NORMAL
 	enrolled = DEVICE_PRIVATE
 	/// Thing that contains this computer. Used for silicon computers