Gun Safety PSA - Keep your gun safeties on to prevent accidental disc…

…harges! (shiptest-ss13#3312)

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## About The Pull Request

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documented or this can delay review and even discourage maintainers from
merging your PR! -->

Unsafetied guns have a small chance to go off and fire on their own
under select conditions, which are currently:
- Being thrown and hitting something.
- Being on a ship when it takes off or docks. (Having it stored in a
stable container eg. lockers/crates, protect it from going off)
- Falling down while carrying a gun (Shoves, slips, etc)
- Paralyzes while holding a gun
- Having your gun holstered lowers the chance of it going off from
falling down due to the aforementioned causes
- Being EMPed if it's an energy weapon.

Modifies fire_casing so it works without a user.

## Why It's Good For The Game

<!-- Please add a short description of why you think these changes would
benefit the game. If you can't justify it in words, it might not be
worth adding. -->

Makes guns a bit more dangerous (to yourself mainly), and reinforces the
fact guns are Dangerous Weapons and you should be careful with them by
adding a mechanical reason to have your safety on outside of combat and
properly securing your weapons.

~~adds more medical gameplay due to increased injuries~~

## Changelog

:cl:
add: Unsaftied guns can go off on their own.
code: Changes ammo casing firing code so it's able to work without a
user.
/:cl:

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the changes rather than a summary of the PR's contents. -->

code/__DEFINES/guns.dm

@@ -69,6 +69,11 @@
 #define MANUFACTURER_PGF "the Etherbor Industries emblem"
 #define MANUFACTURER_IMPORT "Lanchester Import Co."
 
+// Misfire chances if the gun's safety is off
+#define GUN_NO_SAFETY_MALFUNCTION_CHANCE_LOW 100
+#define GUN_NO_SAFETY_MALFUNCTION_CHANCE_MEDIUM 100
+#define GUN_NO_SAFETY_MALFUNCTION_CHANCE_HIGH 100
+
 /////////////////
 // ATTACHMENTS //
 /////////////////

code/datums/status_effects/debuffs.dm

@@ -49,6 +49,7 @@
 	. = ..()
 	if(!.)
 		return
+	owner.trip_with_gun("knockdown")
 	ADD_TRAIT(owner, TRAIT_FLOORED, TRAIT_STATUS_EFFECT(id))
 
 /datum/status_effect/incapacitating/knockdown/on_remove()
@@ -79,6 +80,7 @@
 	. = ..()
 	if(!.)
 		return
+	owner.trip_with_gun("paralyze")
 	ADD_TRAIT(owner, TRAIT_INCAPACITATED, TRAIT_STATUS_EFFECT(id))
 	ADD_TRAIT(owner, TRAIT_IMMOBILIZED, TRAIT_STATUS_EFFECT(id))
 	ADD_TRAIT(owner, TRAIT_FLOORED, TRAIT_STATUS_EFFECT(id))

code/game/objects/items/storage/storage.dm

@@ -28,6 +28,12 @@
 			if(EXPLODE_LIGHT)
 				SSexplosions.lowobj += A
 
+/obj/item/storage/throw_impact(atom/hit_atom, datum/thrownthing/throwingdatum)
+	. = ..()
+	for(var/obj/item/gun/at_risk in get_all_contents())
+		if(at_risk.safety == FALSE && prob(GUN_NO_SAFETY_MALFUNCTION_CHANCE_HIGH))
+			at_risk.discharge("is hits the ground hard")
+
 /obj/item/storage/canStrip(mob/who)
 	. = ..()
 	if(!. && rummage_if_nodrop)

code/modules/projectiles/ammunition/_firing.dm

@@ -1,7 +1,7 @@
-/obj/item/ammo_casing/proc/fire_casing(atom/target, mob/living/user, params, distro, quiet, zone_override, spread, atom/fired_from)
+/obj/item/ammo_casing/proc/fire_casing(atom/target, mob/living/user, params, distro, quiet, zone_override, spread, atom/fired_from, misfire = FALSE)
 	distro += variance
 	var/targloc = get_turf(target)
-	ready_proj(target, user, quiet, zone_override, fired_from)
+	ready_proj(target, user, quiet, zone_override, fired_from, misfire)
 	if(pellets == 1)
 		if(distro) //We have to spread a pixel-precision bullet. throw_proj was called before so angles should exist by now...
 			if(randomspread)
@@ -15,19 +15,20 @@
 			return FALSE
 		AddComponent(/datum/component/pellet_cloud, projectile_type, pellets)
 		SEND_SIGNAL(src, COMSIG_PELLET_CLOUD_INIT, target, user, fired_from, randomspread, spread, zone_override, params, distro)
+	if(user)
+		if(click_cooldown_override)
+			user.changeNext_move(click_cooldown_override)
 
-	if(click_cooldown_override)
-		user.changeNext_move(click_cooldown_override)
-
-	user.newtonian_move(get_dir(target, user))
+		user.newtonian_move(get_dir(target, user))
 	update_appearance()
 	return TRUE
 
-/obj/item/ammo_casing/proc/ready_proj(atom/target, mob/living/user, quiet, zone_override = "", atom/fired_from)
+/obj/item/ammo_casing/proc/ready_proj(atom/target, mob/living/user, quiet, zone_override = "", atom/fired_from, misfire = FALSE)
 	if (!BB)
 		return
 	BB.original = target
 	BB.firer = user
+	BB.misfire = misfire
 	BB.fired_from = fired_from
 	if (zone_override)
 		BB.def_zone = zone_override
@@ -45,7 +46,11 @@
 		qdel(reagents)
 
 /obj/item/ammo_casing/proc/throw_proj(atom/target, turf/targloc, mob/living/user, params, spread)
-	var/turf/curloc = get_turf(user)
+	var/turf/curloc
+	if(user)
+		curloc = get_turf(user)
+	else
+		curloc = get_turf(src)
 	if (!istype(targloc) || !istype(curloc) || !BB)
 		return FALSE
 
@@ -60,7 +65,10 @@
 		if(target) //if the target is right on our location we'll skip the travelling code in the proj's fire()
 			direct_target = target
 	if(!direct_target)
-		BB.preparePixelProjectile(target, user, params, spread)
+		if(user)
+			BB.preparePixelProjectile(target, user, params, spread)
+		else
+			BB.preparePixelProjectile(target, curloc, params, spread)
 	BB.fire(null, direct_target)
 	BB = null
 	return TRUE

code/modules/projectiles/gun.dm

@@ -728,6 +728,11 @@
 	if(zoomed)
 		zoom(user, user.dir)
 
+/obj/item/gun/throw_impact(atom/hit_atom, datum/thrownthing/throwingdatum)
+	. = ..()
+	if(prob(GUN_NO_SAFETY_MALFUNCTION_CHANCE_HIGH))
+		discharge("hits the ground hard")
+
 /obj/item/gun/update_overlays()
 	. = ..()
 	if(ismob(loc) && has_safety)
@@ -947,6 +952,49 @@
 		flash_loc.vis_contents -= muzzle_flash
 	muzzle_flash.applied = FALSE
 
+// for guns firing on their own without a user
+/obj/item/gun/proc/discharge(cause, seek_chance = 10)
+	var/target
+	if(!safety)
+		// someone is very unlucky and about to be shot
+		if(prob(seek_chance))
+			for(var/mob/living/target_mob in range(6, get_turf(src)))
+				if(!isInSight(src, target_mob))
+					continue
+				target = target_mob
+				break
+		if(!target)
+			var/fire_dir = pick(GLOB.alldirs)
+			target = get_ranged_target_turf(get_turf(src),fire_dir,6)
+		if(!chambered || !chambered.BB)
+			visible_message(span_danger("\The [src] [cause ? "[cause], suddenly going off" : "suddenly goes off"] without its safteies on! Luckily it wasn't live."))
+			playsound(src, dry_fire_sound, 30, TRUE)
+		else
+			visible_message(span_danger("\The [src] [cause ? "[cause], suddenly going off" : "suddenly goes off"] without its safeties on!"))
+			unsafe_shot(target)
+
+/obj/item/gun/proc/unsafe_shot(target)
+	if(chambered)
+		chambered.fire_casing(target,null, null, null, suppressed, ran_zone(BODY_ZONE_CHEST, 50), 0, src,TRUE)
+		playsound(src, fire_sound, 100, TRUE)
+
+/mob/living/proc/trip_with_gun(cause)
+	var/mob/living/carbon/human/human_holder
+	if(ishuman(src))
+		human_holder = src
+	for(var/obj/item/gun/at_risk in get_all_contents())
+		var/chance_to_fire = GUN_NO_SAFETY_MALFUNCTION_CHANCE_MEDIUM
+		var/did_fire = FALSE
+		if(human_holder)
+			// gun is less likely to go off in a holster
+			if(at_risk == human_holder.s_store)
+				chance_to_fire = GUN_NO_SAFETY_MALFUNCTION_CHANCE_LOW
+		if(at_risk.safety == FALSE && prob(chance_to_fire))
+			if(at_risk.process_fire(src,src,FALSE, null,  pick(BODY_ZONE_L_LEG,BODY_ZONE_R_LEG)) == TRUE)
+				log_combat(src,src,"misfired",at_risk,"caused by [cause]")
+				visible_message(span_danger("\The [at_risk.name]'s trigger gets caught as [src] falls, suddenly going off into [src]'s leg without its safties on!"), span_danger("\The [at_risk.name]'s trigger gets caught on something as you fall, suddenly going off into your leg without its safeties on!"))
+				emote("scream")
+
 //I need to refactor this into an attachment
 /datum/action/toggle_scope_zoom
 	name = "Toggle Scope"

code/modules/projectiles/guns/ballistic.dm

@@ -376,3 +376,8 @@ GLOBAL_LIST_INIT(gun_saw_types, typecacheof(list(
 		if(AC.BB)
 			process_fire(user, user, FALSE)
 			. = TRUE
+
+/obj/item/gun/ballistic/unsafe_shot(target, empty_chamber = TRUE)
+	. = ..()
+	process_chamber(empty_chamber,TRUE)
+

code/modules/projectiles/guns/energy.dm

@@ -39,6 +39,8 @@
 /obj/item/gun/energy/emp_act(severity)
 	. = ..()
 	if(!(. & EMP_PROTECT_CONTENTS))
+		if(prob(GUN_NO_SAFETY_MALFUNCTION_CHANCE_HIGH))
+			discharge("malfunctions from the EMP")
 		cell.use(round(cell.charge / severity))
 		chambered = null //we empty the chamber
 		recharge_newshot() //and try to charge a new shot
@@ -325,3 +327,7 @@
 		. += "\The [name] has [round(cell.charge/shot.e_cost)] shots remaining on <b>[shot.select_name]</b> mode."
 	else
 		. += span_notice("\The [name] doesn't seem to have a cell!")
+
+/obj/item/gun/energy/unsafe_shot(target)
+	. = ..()
+	process_chamber()

code/modules/projectiles/projectile.dm

@@ -24,6 +24,8 @@
 	resistance_flags = LAVA_PROOF | FIRE_PROOF | UNACIDABLE | ACID_PROOF
 	var/def_zone = ""	//Aiming at
 	var/atom/movable/firer = null//Who shot it
+	// if the projectile was the result of a misfire. For logging.
+	var/misfire = FALSE
 	var/atom/fired_from = null // the atom that the projectile was fired from (gun, turret)
 	var/suppressed = FALSE	//Attack message
 	var/yo = null
@@ -284,7 +286,9 @@
 		for(var/datum/reagent/R in reagents.reagent_list)
 			reagent_note += "[R.name] ([num2text(R.volume)])"
 
-	if(ismob(firer))
+	if(misfire)
+		L.log_message("has been hit by a misfired [src] from \a [fired_from] last touched by [fired_from.fingerprintslast]", LOG_ATTACK, color = "orange")
+	else if(ismob(firer))
 		log_combat(firer, L, "shot", src, reagent_note)
 	else
 		L.log_message("has been shot by [firer] with [src]", LOG_ATTACK, color="orange")

code/modules/shuttle/on_move.dm

@@ -291,6 +291,7 @@ All ShuttleMove procs go here
 
 /************************************Item move procs************************************/
 
+
 /obj/item/storage/pod/afterShuttleMove(turf/oldT, list/movement_force, shuttle_dir, shuttle_preferred_direction, move_dir, rotation)
 	. = ..()
 	// If the pod was launched, the storage will always open. The reserved_level check
@@ -299,6 +300,11 @@ All ShuttleMove procs go here
 	if (oldT && !is_reserved_level(oldT))
 		unlocked = TRUE
 
+/obj/item/gun/lateShuttleMove(turf/oldT, list/movement_force, move_dir)
+	. = ..()
+	if(prob(GUN_NO_SAFETY_MALFUNCTION_CHANCE_MEDIUM))
+		discharge("is thrown around by the force of the take off")
+
 /************************************Mob move procs************************************/
 
 /mob/onShuttleMove(turf/newT, turf/oldT, list/movement_force, move_dir, obj/docking_port/stationary/old_dock, obj/docking_port/mobile/moving_dock, list/obj/docking_port/mobile/towed_shuttles)