Added functionality for two-handed gun use.

code/_onclick/telekinesis.dm

@@ -85,6 +85,7 @@ var/const/tk_maxrange = 15
 
 //stops TK grabs being equipped anywhere but into hands
 /obj/item/tk_grab/equipped(var/mob/user, var/slot)
+	..()
 	if( (slot == slot_l_hand) || (slot== slot_r_hand) )	return
 	qdel(src)
 	return

code/game/objects/items.dm

@@ -71,6 +71,16 @@
 	// Works similarly to worn sprite_sheets, except the alternate sprites are used when the clothing/refit_for_species() proc is called.
 	var/list/sprite_sheets_obj = list()
 
+/obj/item/equipped()
+	..()
+	var/mob/M = loc
+	if(!istype(M))
+		return
+	if(M.l_hand)
+		M.l_hand.update_held_icon()
+	if(M.r_hand)
+		M.r_hand.update_held_icon()
+
 /obj/item/Destroy()
 	if(ismob(loc))
 		var/mob/m = loc
@@ -89,7 +99,7 @@
 		var/mob/M = src.loc
 		if(M.l_hand == src)
 			M.update_inv_l_hand()
-		if(M.r_hand == src)
+		else if(M.r_hand == src)
 			M.update_inv_r_hand()
 
 /obj/item/ex_act(severity)

code/game/objects/items/devices/chameleonproj.dm

@@ -20,6 +20,7 @@
 	disrupt()
 
 /obj/item/device/chameleon/equipped()
+	..()
 	disrupt()
 
 /obj/item/device/chameleon/attack_self()

code/modules/mob/inventory.dm

@@ -216,7 +216,7 @@ var/list/slot_equipment_priority = list( \
 		wear_mask = null
 		update_inv_wear_mask(0)
 	return
-    
+
 /mob/proc/isEquipped(obj/item/I)
 	if(!I)
 		return 0

code/modules/mob/living/carbon/human/inventory.dm

@@ -171,9 +171,15 @@ This saves us from having to call add_fingerprint() any time something is put in
 		update_inv_legcuffed()
 	else if (W == r_hand)
 		r_hand = null
+		if(l_hand)
+			l_hand.update_held_icon()
+			update_inv_l_hand()
 		update_inv_r_hand()
 	else if (W == l_hand)
 		l_hand = null
+		if(r_hand)
+			r_hand.update_held_icon()
+			update_inv_l_hand()
 		update_inv_l_hand()
 	else
 		return 0

code/modules/mob/living/carbon/human/species/xenomorphs/alien_facehugger.dm

@@ -70,6 +70,7 @@ var/const/MAX_ACTIVE_TIME = 400
 	return
 
 /obj/item/clothing/mask/facehugger/equipped(mob/M)
+	..()
 	Attach(M)
 
 /obj/item/clothing/mask/facehugger/Crossed(atom/target)

code/modules/projectiles/gun.dm

@@ -64,6 +64,8 @@
 	var/list/burst_accuracy = list(0) //allows for different accuracies for each shot in a burst. Applied on top of accuracy
 	var/list/dispersion = list(0)
 	var/mode_name = null
+	var/requires_two_hands
+	var/wielded_icon = "gun_wielded"
 
 	var/next_fire_time = 0
 
@@ -87,17 +89,28 @@
 	if(isnull(scoped_accuracy))
 		scoped_accuracy = accuracy
 
+/obj/item/weapon/gun/update_held_icon()
+	if(requires_two_hands)
+		var/mob/living/M = loc
+		if(istype(M))
+			if((M.l_hand == src && !M.r_hand) || (M.r_hand == src && !M.l_hand))
+				item_state = wielded_icon
+			else
+				item_state = initial(item_state)
+				update_icon() // In case item_state is set somewhere else.
+	..()
+
 //Checks whether a given mob can use the gun
 //Any checks that shouldn't result in handle_click_empty() being called if they fail should go here.
 //Otherwise, if you want handle_click_empty() to be called, check in consume_next_projectile() and return null there.
 /obj/item/weapon/gun/proc/special_check(var/mob/user)
+
 	if(!istype(user, /mob/living))
 		return 0
 	if(!user.IsAdvancedToolUser())
 		return 0
 
 	var/mob/living/M = user
-
 	if(HULK in M.mutations)
 		M << "<span class='danger'>Your fingers are much too large for the trigger guard!</span>"
 		return 0
@@ -161,6 +174,14 @@
 	user.setMoveCooldown(shoot_time) //no moving while shooting either
 	next_fire_time = world.time + shoot_time
 
+	var/held_acc_mod = 0
+	var/held_disp_mod = 0
+	if(requires_two_hands)
+		update_held_icon()
+		if((user.l_hand == src && user.r_hand) || (user.r_hand == src && user.l_hand))
+			held_acc_mod = -3
+			held_disp_mod = 3
+
 	//actually attempt to shoot
 	var/turf/targloc = get_turf(target) //cache this in case target gets deleted during shooting, e.g. if it was a securitron that got destroyed.
 	for(var/i in 1 to burst)
@@ -169,8 +190,8 @@
 			handle_click_empty(user)
 			break
 
-		var/acc = burst_accuracy[min(i, burst_accuracy.len)]
+		var/acc = burst_accuracy[min(i, burst_accuracy.len)] + held_acc_mod
-		var/disp = dispersion[min(i, dispersion.len)]
+		var/disp = dispersion[min(i, dispersion.len)] + held_disp_mod
 		process_accuracy(projectile, user, target, acc, disp)
 
 		if(pointblank)