Merge pull request #7220 from Citadel-Station-13/upstream-merge-38093

[MIRROR] Fixes and adds blast cannons to traitor science uplink items

code/modules/projectiles/guns/misc/blastcannon.dm

@@ -11,8 +11,21 @@
 	clumsy_check = FALSE
 	randomspread = FALSE
 
+	var/hugbox = TRUE
+	var/max_power = INFINITY
+	var/reaction_volume_mod = 0
+	var/reaction_cycles = 3				//How many times gases react() before calculation. Very finnicky value, do not mess with without good reason.
+	var/prereaction = TRUE
+
+	var/bombcheck = TRUE
+	var/debug_power = 0
+
 	var/obj/item/transfer_valve/bomb
 
+/obj/item/gun/blastcannon/debug
+	debug_power = 80
+	bombcheck = FALSE
+
 /obj/item/gun/blastcannon/Initialize()
 	. = ..()
 	if(!pin)
@@ -56,27 +69,33 @@
 		return TRUE
 	return ..()
 
+//returns the third value of a bomb blast
 /obj/item/gun/blastcannon/proc/calculate_bomb()
 	if(!istype(bomb) || !istype(bomb.tank_one) || !istype(bomb.tank_two))
 		return 0
-	var/datum/gas_mixture/temp = new(60)	//directional buff.
-	temp.merge(bomb.tank_one.air_contents.remove_ratio(1))
-	temp.merge(bomb.tank_two.air_contents.remove_ratio(2))
-	for(var/i in 1 to 6)
+	var/datum/gas_mixture/temp = new(max(reaction_volume_mod, 0))
+	bomb.merge_gases(temp)
+	if(prereaction)
+		temp.react(src)
+		var/prereaction_pressure = temp.return_pressure()
+		if(prereaction_pressure < TANK_FRAGMENT_PRESSURE)
+			return 0
+	for(var/i in 1 to reaction_cycles)
 		temp.react(src)
 	var/pressure = temp.return_pressure()
 	qdel(temp)
 	if(pressure < TANK_FRAGMENT_PRESSURE)
 		return 0
-	return (pressure / TANK_FRAGMENT_SCALE)
+	return ((pressure - TANK_FRAGMENT_PRESSURE) / TANK_FRAGMENT_SCALE)
 
 /obj/item/gun/blastcannon/afterattack(atom/target, mob/user, flag, params)
-	if((!bomb) || (!target) || (get_dist(get_turf(target), get_turf(user)) <= 2))
+	if((!bomb && bombcheck) || (!target) || (get_dist(get_turf(target), get_turf(user)) <= 2))
 		return ..()
-	var/power = calculate_bomb()
+	var/power = bomb? calculate_bomb() : debug_power
+	power = min(power, max_power)
 	QDEL_NULL(bomb)
 	update_icon()
-	var/heavy = power * 0.2
+	var/heavy = power * 0.25
 	var/medium = power * 0.5
 	var/light = power
 	user.visible_message("<span class='danger'>[user] opens [bomb] on [user.p_their()] [name] and fires a blast wave at [target]!</span>","<span class='danger'>You open [bomb] on your [name] and fire a blast wave at [target]!</span>")
@@ -87,7 +106,8 @@
 	message_admins(log_str)
 	log_game(log_str)
 	var/obj/item/projectile/blastwave/BW = new(loc, heavy, medium, light)
-	BW.preparePixelProjectile(target, get_turf(target), user, params, 0)
+	BW.hugbox = hugbox
+	BW.preparePixelProjectile(target, get_turf(src), params, 0)
 	BW.fire()
 
 /obj/item/projectile/blastwave
@@ -99,6 +119,7 @@
 	var/heavyr = 0
 	var/mediumr = 0
 	var/lightr = 0
+	var/hugbox = TRUE
 	range = 150
 
 /obj/item/projectile/blastwave/Initialize(mapload, _h, _m, _l)
@@ -110,14 +131,25 @@
 /obj/item/projectile/blastwave/Range()
 	..()
 	var/amount_destruction = EXPLODE_NONE
+	var/wallbreak_chance = 0
 	if(heavyr)
 		amount_destruction = EXPLODE_DEVASTATE
+		wallbreak_chance = 99
 	else if(mediumr)
 		amount_destruction = EXPLODE_HEAVY
+		wallbreak_chance = 66
 	else if(lightr)
 		amount_destruction = EXPLODE_LIGHT
+		wallbreak_chance = 33
 	if(amount_destruction)
-		loc.ex_act(amount_destruction)
+		if(hugbox)
+			loc.contents_explosion(EXPLODE_HEAVY, loc)
+			if(istype(loc, /turf/closed/wall))
+				var/turf/closed/wall/W = loc
+				if(prob(wallbreak_chance))
+					W.dismantle_wall(TRUE, TRUE)
+		else
+			loc.ex_act(amount_destruction)
 	else
 		qdel(src)
 

code/modules/uplink/uplink_items.dm

@@ -1412,6 +1412,16 @@ GLOBAL_LIST_INIT(uplink_items, subtypesof(/datum/uplink_item))
 	limited_stock = 2 //you can't use more than two!
 	restricted_roles = list("Shaft Miner")
 
+/datum/uplink_item/role_restricted/blastcannon
+	name = "Blast Cannon"
+	desc = "A highly specialized weapon, the Blast Cannon is actually relatively simple. It contains an attachment for a tank transfer valve mounted to an angled pipe specially constructed \
+			withstand extreme pressure and temperatures, and has a mechanical trigger for triggering the transfer valve. Essentially, it turns the explosive force of a bomb into a narrow-angle \
+			blast wave \"projectile\". Aspiring scientists may find this highly useful, as forcing the pressure shockwave into a narrow angle seems to be able to bypass whatever quirk of physics \
+			disallows explosive ranges above a certain distance, allowing for the device to use the theoretical yield of a transfer valve bomb, instead of the factual yield."
+	item = /obj/item/gun/blastcannon
+	cost = 14							//High cost because of the potential for extreme damage in the hands of a skilled scientist.
+	restricted_roles = list("Research Director", "Scientist")
+
 /datum/uplink_item/device_tools/clown_bomb
 	name = "Clown Bomb"
 	desc = "The Clown bomb is a hilarious device capable of massive pranks. It has an adjustable timer, \