Bipod now gives you an option to switch to full auto when deploying (#…

…5638)

# About the pull request

Attaching the bipod to weapons with full auto capability or firearms
marked with the GUN_SUPPORT_PLATFORM flag will give the user a button
toggle to immediately switch to full auto when deploying the bipod.


![image](https://github.com/cmss13-devs/cmss13/assets/17518895/cea29ccc-5761-4a7b-99bd-cbdd035bc52b)



If the full auto switch is turned on, the weapon will simply switch to
full auto when the bipod is deployed. If you undeploy it, it will switch
back to whatever previous firemode the weapon was in, e.g:

1. You set your pulse rifle to semi auto. 
2. You deploy the bipod. 
3. The pulse rifle is set to full auto. 
4. You undeploy the bipod. 
5. The pulse rifle will switch back to semi auto.

In cases where you switch the weapon's firemode when it's already
switched to full auto, it won't revert back to whatever firemode was set
before it was deployed, e.g:

1. You set your pulse rifle to semi auto. 
2. You deploy the bipod. 
3. The pulse rifle is set to full auto. 
4. You set your pulse rifle to burst fire.
5. You undeploy the bipod. 
6. The pulse rifle will stay on burst fire.

Also renames a couple of one letter variables.

# Explain why it's good for the game

Quality of life. Less messing around with firemode selectors which is a
terrible headache, especially for the HPR, which you usually want to
have on full auto 90% of the time. Those who want to stick with the old
way don't have to change anything, as the full auto switch is entirely
optional.

# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>



https://github.com/cmss13-devs/cmss13/assets/17518895/35bcc6e7-947d-4f82-971f-ac22b723537b



</details>


# Changelog
:cl:
qol: Attaching the bipod to weapons that have full auto (HPR included)
will give you a button toggle for immediately switching to full auto
when deploying the bipod.
/:cl:

code/modules/projectiles/gun_attachables.dm

@@ -3301,6 +3301,10 @@ Defined in conflicts.dm of the #defines folder.
 	var/bipod_deployed = FALSE
 	/// If this should anchor the user while in use
 	var/heavy_bipod = FALSE
+	// Are switching to full auto when deploying the bipod
+	var/full_auto_switch = FALSE
+	// Store our old firemode so we can switch to it when undeploying the bipod
+	var/old_firemode = null
 
 /obj/item/attachable/bipod/New()
 	..()
@@ -3311,16 +3315,33 @@ Defined in conflicts.dm of the #defines folder.
 	scatter_mod = SCATTER_AMOUNT_TIER_9
 	recoil_mod = RECOIL_AMOUNT_TIER_5
 
-/obj/item/attachable/bipod/Attach(obj/item/weapon/gun/G)
+/obj/item/attachable/bipod/Attach(obj/item/weapon/gun/gun, mob/user)
 	..()
 
-	RegisterSignal(G, COMSIG_ITEM_DROPPED, PROC_REF(handle_drop))
+	if((GUN_FIREMODE_AUTOMATIC in gun.gun_firemode_list) || (gun.flags_gun_features & GUN_SUPPORT_PLATFORM))
+		var/given_action = FALSE
+		if(user && (gun == user.l_hand || gun == user.r_hand))
+			give_action(user, /datum/action/item_action/bipod/toggle_full_auto_switch, src, gun)
+			given_action = TRUE
+		if(!given_action)
+			new /datum/action/item_action/bipod/toggle_full_auto_switch(src, gun)
+
+	RegisterSignal(gun, COMSIG_ITEM_DROPPED, PROC_REF(handle_drop))
 
 /obj/item/attachable/bipod/Detach(mob/user, obj/item/weapon/gun/detaching_gub)
 	UnregisterSignal(detaching_gub, COMSIG_ITEM_DROPPED)
 
+	//clear out anything related to full auto switching
+	full_auto_switch = FALSE
+	old_firemode = null
+	for(var/item_action in detaching_gub.actions)
+		var/datum/action/item_action/bipod/toggle_full_auto_switch/target_action = item_action
+		if(target_action.target == src)
+			qdel(item_action)
+			break
+
 	if(bipod_deployed)
-		undeploy_bipod(detaching_gub)
+		undeploy_bipod(detaching_gub, user)
 	..()
 
 /obj/item/attachable/bipod/update_icon()
@@ -3334,86 +3355,92 @@ Defined in conflicts.dm of the #defines folder.
 	if(istype(loc, /obj/item/weapon/gun))
 		var/obj/item/weapon/gun/gun = loc
 		gun.update_attachable(slot)
-		for(var/datum/action/A as anything in gun.actions)
-			A.update_button_icon()
+		for(var/datum/action/item_action as anything in gun.actions)
+			if(!istype(item_action, /datum/action/item_action/bipod/toggle_full_auto_switch))
+				item_action.update_button_icon()
 
-/obj/item/attachable/bipod/proc/handle_drop(obj/item/weapon/gun/G, mob/living/carbon/human/user)
+/obj/item/attachable/bipod/proc/handle_drop(obj/item/weapon/gun/gun, mob/living/carbon/human/user)
 	SIGNAL_HANDLER
 
 	UnregisterSignal(user, COMSIG_MOB_MOVE_OR_LOOK)
 
 	if(bipod_deployed)
-		undeploy_bipod(G)
+		undeploy_bipod(gun, user)
 		user.apply_effect(1, SUPERSLOW)
 		user.apply_effect(2, SLOW)
 
-/obj/item/attachable/bipod/proc/undeploy_bipod(obj/item/weapon/gun/G)
-	REMOVE_TRAIT(G, TRAIT_GUN_BIPODDED, "attached_bipod")
+/obj/item/attachable/bipod/proc/undeploy_bipod(obj/item/weapon/gun/gun, mob/user)
+	REMOVE_TRAIT(gun, TRAIT_GUN_BIPODDED, "attached_bipod")
 	bipod_deployed = FALSE
 	accuracy_mod = -HIT_ACCURACY_MULT_TIER_5
 	scatter_mod = SCATTER_AMOUNT_TIER_9
 	recoil_mod = RECOIL_AMOUNT_TIER_5
 	burst_scatter_mod = 0
 	delay_mod = FIRE_DELAY_TIER_12
-	G.recalculate_attachment_bonuses()
-	G.stop_fire()
-	var/mob/living/user
-	if(isliving(G.loc))
-		user = G.loc
-		SEND_SIGNAL(user, COMSIG_MOB_UNDEPLOYED_BIPOD)
-		UnregisterSignal(user, COMSIG_MOB_MOVE_OR_LOOK)
+	//if we are no longer on full auto, don't bother switching back to the old firemode
+	if(full_auto_switch && gun.gun_firemode == GUN_FIREMODE_AUTOMATIC && gun.gun_firemode != old_firemode)
+		gun.do_toggle_firemode(user, null, old_firemode)
 
-	if(G.flags_gun_features & GUN_SUPPORT_PLATFORM)
-		G.remove_firemode(GUN_FIREMODE_AUTOMATIC)
+	gun.recalculate_attachment_bonuses()
+	gun.stop_fire()
+	SEND_SIGNAL(user, COMSIG_MOB_UNDEPLOYED_BIPOD)
+	UnregisterSignal(user, COMSIG_MOB_MOVE_OR_LOOK)
+
+	if(gun.flags_gun_features & GUN_SUPPORT_PLATFORM)
+		gun.remove_firemode(GUN_FIREMODE_AUTOMATIC)
 
 	if(heavy_bipod)
 		user.anchored = FALSE
 
-	if(!QDELETED(G))
+	if(!QDELETED(gun))
 		playsound(user,'sound/items/m56dauto_rotate.ogg', 55, 1)
 		update_icon()
 
-/obj/item/attachable/bipod/activate_attachment(obj/item/weapon/gun/G,mob/living/user, turn_off)
+/obj/item/attachable/bipod/activate_attachment(obj/item/weapon/gun/gun, mob/living/user, turn_off)
 	if(turn_off)
 		if(bipod_deployed)
-			undeploy_bipod(G)
+			undeploy_bipod(gun, user)
 	else
-		var/obj/support = check_bipod_support(G, user)
+		var/obj/support = check_bipod_support(gun, user)
 		if(!support&&!bipod_deployed)
 			to_chat(user, SPAN_NOTICE("You start deploying [src] on the ground."))
-			if(!do_after(user, 15, INTERRUPT_ALL, BUSY_ICON_HOSTILE, G,INTERRUPT_DIFF_LOC))
+			if(!do_after(user, 15, INTERRUPT_ALL, BUSY_ICON_HOSTILE, gun, INTERRUPT_DIFF_LOC))
 				return FALSE
 
 		bipod_deployed = !bipod_deployed
 		if(user)
 			if(bipod_deployed)
-				ADD_TRAIT(G, TRAIT_GUN_BIPODDED, "attached_bipod")
+				ADD_TRAIT(gun, TRAIT_GUN_BIPODDED, "attached_bipod")
 				to_chat(user, SPAN_NOTICE("You deploy [src] [support ? "on [support]" : "on the ground"]."))
 				SEND_SIGNAL(user, COMSIG_MOB_DEPLOYED_BIPOD)
 				playsound(user,'sound/items/m56dauto_rotate.ogg', 55, 1)
 				accuracy_mod = HIT_ACCURACY_MULT_TIER_5
 				scatter_mod = -SCATTER_AMOUNT_TIER_10
 				recoil_mod = -RECOIL_AMOUNT_TIER_4
 				burst_scatter_mod = -SCATTER_AMOUNT_TIER_8
-				if(istype(G,/obj/item/weapon/gun/rifle/sniper/M42A))
+				if(istype(gun, /obj/item/weapon/gun/rifle/sniper/M42A))
 					delay_mod = -FIRE_DELAY_TIER_7
 				else
 					delay_mod = -FIRE_DELAY_TIER_12
-				G.recalculate_attachment_bonuses()
-				G.stop_fire()
+				gun.recalculate_attachment_bonuses()
+				gun.stop_fire()
 
 				initial_mob_dir = user.dir
 				RegisterSignal(user, COMSIG_MOB_MOVE_OR_LOOK, PROC_REF(handle_mob_move_or_look))
 
-				if(G.flags_gun_features & GUN_SUPPORT_PLATFORM)
-					G.add_firemode(GUN_FIREMODE_AUTOMATIC)
+				if(gun.flags_gun_features & GUN_SUPPORT_PLATFORM)
+					gun.add_firemode(GUN_FIREMODE_AUTOMATIC)
 
 				if(heavy_bipod)
 					user.anchored = TRUE
 
+				old_firemode = gun.gun_firemode
+				if(full_auto_switch && gun.gun_firemode != GUN_FIREMODE_AUTOMATIC)
+					gun.do_toggle_firemode(user, null, GUN_FIREMODE_AUTOMATIC)
+
 			else
 				to_chat(user, SPAN_NOTICE("You retract [src]."))
-				undeploy_bipod(G)
+				undeploy_bipod(gun, user)
 
 	update_icon()
 
@@ -3430,10 +3457,10 @@ Defined in conflicts.dm of the #defines folder.
 
 
 //when user fires the gun, we check if they have something to support the gun's bipod.
-/obj/item/attachable/proc/check_bipod_support(obj/item/weapon/gun/G, mob/living/user)
+/obj/item/attachable/proc/check_bipod_support(obj/item/weapon/gun/gun, mob/living/user)
 	return 0
 
-/obj/item/attachable/bipod/check_bipod_support(obj/item/weapon/gun/G, mob/living/user)
+/obj/item/attachable/bipod/check_bipod_support(obj/item/weapon/gun/gun, mob/living/user)
 	var/turf/T = get_turf(user)
 	for(var/obj/O in T)
 		if(O.throwpass && O.density && O.dir == user.dir && O.flags_atom & ON_BORDER)
@@ -3445,6 +3472,31 @@ Defined in conflicts.dm of the #defines folder.
 			return O2
 	return 0
 
+//item actions for handling deployment to full auto.
+/datum/action/item_action/bipod/toggle_full_auto_switch/New(Target, obj/item/holder)
+	. = ..()
+	name = "Toggle Full Auto Switch"
+	action_icon_state = "full_auto_switch"
+	button.name = name
+	button.overlays.Cut()
+	button.overlays += image('icons/mob/hud/actions.dmi', button, action_icon_state)
+
+/datum/action/item_action/bipod/toggle_full_auto_switch/action_activate()
+	var/obj/item/weapon/gun/holder_gun = holder_item
+	var/obj/item/attachable/bipod/attached_bipod = holder_gun.attachments["under"]
+
+	attached_bipod.full_auto_switch = !attached_bipod.full_auto_switch
+	to_chat(owner, SPAN_NOTICE("[icon2html(holder_gun, owner)] You will [attached_bipod.full_auto_switch? "<B>start</b>" : "<B>stop</b>"] switching to full auto when deploying the bipod."))
+	playsound(owner, 'sound/weapons/handling/gun_burst_toggle.ogg', 15, 1)
+
+	if(attached_bipod.full_auto_switch)
+		button.icon_state = "template_on"
+	else
+		button.icon_state = "template"
+
+	button.overlays.Cut()
+	button.overlays += image('icons/mob/hud/actions.dmi', button, action_icon_state)
+
 
 /obj/item/attachable/bipod/m60
 	name = "bipod"

code/modules/projectiles/gun_helpers.dm

@@ -390,7 +390,7 @@ DEFINES in setup.dm, referenced here.
 			user.visible_message(SPAN_NOTICE("[user] attaches [attachment] to [src]."),
 			SPAN_NOTICE("You attach [attachment] to [src]."), null, 4)
 			user.temp_drop_inv_item(attachment)
-			attachment.Attach(src)
+			attachment.Attach(src, user)
 			update_attachable(attachment.slot)
 			playsound(user, 'sound/handling/attachment_add.ogg', 15, 1, 4)
 			return TRUE