Neckties can be worn below suits and accessories (#83131) (#491)

code/__DEFINES/mobs.dm

@@ -693,39 +693,41 @@ GLOBAL_LIST_INIT(human_heights_to_offsets, list(
 /// Total number of layers for mob overlays
 /// KEEP THIS UP-TO-DATE OR SHIT WILL BREAK
 /// Also consider updating layers_to_offset
-#define TOTAL_LAYERS 34
+#define TOTAL_LAYERS 35
 /// Mutations layer - Tk headglows, cold resistance glow, etc
-#define MUTATIONS_LAYER 34
+#define MUTATIONS_LAYER 35
 /// Mutantrace features (tail when looking south) that must appear behind the body parts
-#define BODY_BEHIND_LAYER 33
+#define BODY_BEHIND_LAYER 34
 /// Layer for bodyparts that should appear behind every other bodypart - Mostly, legs when facing WEST or EAST
-#define BODYPARTS_LOW_LAYER 32
+#define BODYPARTS_LOW_LAYER 33
 /// Layer for most bodyparts, appears above BODYPARTS_LOW_LAYER and below BODYPARTS_HIGH_LAYER
-#define BODYPARTS_LAYER 31
+#define BODYPARTS_LAYER 32
 /// Mutantrace features (snout, body markings) that must appear above the body parts
-#define BODY_ADJ_LAYER 30
+#define BODY_ADJ_LAYER 31
 /// Underwear, undershirts, socks, eyes, lips(makeup)
-#define BODY_LAYER 29
+#define BODY_LAYER 30
 /// Mutations that should appear above body, body_adj and bodyparts layer (e.g. laser eyes)
-#define FRONT_MUTATIONS_LAYER 28
+#define FRONT_MUTATIONS_LAYER 29
 /// Damage indicators (cuts and burns)
-#define DAMAGE_LAYER 27
+#define DAMAGE_LAYER 28
 /// Jumpsuit clothing layer
-#define UNIFORM_LAYER 26
+#define UNIFORM_LAYER 27
 /// ID card layer
-#define ID_LAYER 25
+#define ID_LAYER 26
 /// ID card layer (might be deprecated)
-#define ID_CARD_LAYER 24
+#define ID_CARD_LAYER 25
 /// Layer for bodyparts that should appear above every other bodypart - Currently only used for hands
-#define BODYPARTS_HIGH_LAYER 23
+#define BODYPARTS_HIGH_LAYER 24
 /// Gloves layer
-#define GLOVES_LAYER 22
+#define GLOVES_LAYER 23
 /// Shoes layer
-#define SHOES_LAYER 21
+#define SHOES_LAYER 22
 /// Layer for masks that are worn below ears and eyes (like Balaclavas) (layers below hair, use flagsinv=HIDEHAIR as needed)
-#define LOW_FACEMASK_LAYER 20
+#define LOW_FACEMASK_LAYER 21
 /// Ears layer (Spessmen have ears? Wow)
-#define EARS_LAYER 19
+#define EARS_LAYER 20
+/// Layer for neck apperal that should appear below the suit slot (like neckties)
+#define LOW_NECK_LAYER 19
 /// Suit layer (armor, coats, etc.)
 #define SUIT_LAYER 18
 /// Glasses layer
@@ -734,7 +736,7 @@ GLOBAL_LIST_INIT(human_heights_to_offsets, list(
 #define BELT_LAYER 16 //Possible make this an overlay of somethign required to wear a belt?
 /// Suit storage layer (tucking a gun or baton underneath your armor)
 #define SUIT_STORE_LAYER 15
-/// Neck layer (for wearing ties and bedsheets)
+/// Neck layer (for wearing capes and bedsheets)
 #define NECK_LAYER 14
 /// Back layer (for backpacks and equipment on your back)
 #define BACK_LAYER 13
@@ -781,7 +783,9 @@ GLOBAL_LIST_INIT(layers_to_offset, list(
 	"[BELT_LAYER]" = LOWER_BODY,
 	// Everything below looks fine with or without a filter, so we can skip it and just offset
 	// (In practice they'd be fine if they got a filter but we can optimize a bit by not.)
+	"[NECK_LAYER]" = UPPER_BODY,
 	"[GLASSES_LAYER]" = UPPER_BODY,
+	"[LOW_NECK_LAYER]" = UPPER_BODY,
 	"[ABOVE_BODY_FRONT_GLASSES_LAYER]" = UPPER_BODY, // currently unused
 	"[ABOVE_BODY_FRONT_HEAD_LAYER]" = UPPER_BODY, // only used for head stuff
 	"[GLOVES_LAYER]" = LOWER_BODY,

code/modules/clothing/neck/_neck.dm

@@ -48,6 +48,7 @@
 	icon = 'icons/obj/clothing/neck.dmi'
 	icon_state = "tie_greyscale_tied"
 	inhand_icon_state = "" //no inhands
+	alternate_worn_layer = LOW_NECK_LAYER // So that it renders below suit jackets, MODsuits, etc
 	w_class = WEIGHT_CLASS_SMALL
 	custom_price = PAYCHECK_CREW
 	greyscale_config = /datum/greyscale_config/ties
@@ -70,6 +71,7 @@
 
 /obj/item/clothing/neck/tie/examine(mob/user)
 	. = ..()
+	. += span_notice("The tie can be worn above or below your suit. Alt-Right-click to toggle.")
 	if(clip_on)
 		. += span_notice("Looking closely, you can see that it's actually a cleverly disguised clip-on.")
 	else if(!is_tied)
@@ -106,6 +108,14 @@
 	update_appearance(UPDATE_ICON)
 	user.update_clothing(ITEM_SLOT_NECK)
 
+/obj/item/clothing/neck/tie/alt_click_secondary(mob/user)
+	. = ..()
+	if(!user.can_perform_action(src, NEED_DEXTERITY))
+		return	
+	alternate_worn_layer = alternate_worn_layer == initial(alternate_worn_layer) ? NONE : initial(alternate_worn_layer)
+	user.update_clothing(ITEM_SLOT_NECK)
+	balloon_alert(user, "wearing [alternate_worn_layer == initial(alternate_worn_layer) ? "below" : "above"] suits")
+
 /obj/item/clothing/neck/tie/update_icon()
 	. = ..()
 	if(clip_on)
@@ -124,6 +134,7 @@
 
 /obj/item/clothing/neck/tie/add_context(atom/source, list/context, obj/item/held_item, mob/user)
 	. = ..()
+	context[SCREENTIP_CONTEXT_ALT_RMB] = "Wear [alternate_worn_layer == initial(alternate_worn_layer) ? "above" : "below"] suit"
 	if(clip_on)
 		return
 	if(is_tied)
@@ -132,6 +143,17 @@
 		context[SCREENTIP_CONTEXT_ALT_LMB] = "Tie"
 	return CONTEXTUAL_SCREENTIP_SET
 
+/obj/item/clothing/neck/tie/worn_overlays(mutable_appearance/standing, isinhands)
+	. = ..()
+	var/mob/living/carbon/human/wearer = loc
+	if(!ishuman(wearer) || !wearer.w_uniform)
+		return
+	var/obj/item/clothing/under/undershirt = wearer.w_uniform
+	if(!istype(undershirt) || !LAZYLEN(undershirt.attached_accessories))
+		return
+	if(alternate_worn_layer)
+		. += undershirt.accessory_overlay
+
 /obj/item/clothing/neck/tie/blue
 	name = "blue tie"
 	icon_state = "tie_greyscale_untied"

code/modules/clothing/under/_under.dm

@@ -54,7 +54,7 @@
 		//make the sensor mode favor higher levels, except coords.
 		sensor_mode = pick(SENSOR_VITALS, SENSOR_VITALS, SENSOR_VITALS, SENSOR_LIVING, SENSOR_LIVING, SENSOR_COORDS, SENSOR_COORDS, SENSOR_OFF)
 	register_context()
-	AddElement(/datum/element/update_icon_updates_onmob, flags = ITEM_SLOT_ICLOTHING|ITEM_SLOT_OCLOTHING, body = TRUE)
+	AddElement(/datum/element/update_icon_updates_onmob, flags = ITEM_SLOT_ICLOTHING|ITEM_SLOT_OCLOTHING|ITEM_SLOT_NECK, body = TRUE)
 
 /obj/item/clothing/under/add_context(atom/source, list/context, obj/item/held_item, mob/living/user)
 	. = NONE

code/modules/clothing/under/accessories/_accessories.dm

@@ -157,11 +157,12 @@
 	SIGNAL_HANDLER
 
 	accessory_dropped(source, user)
-	user.update_clothing(ITEM_SLOT_ICLOTHING|ITEM_SLOT_OCLOTHING)
+	user.update_clothing(ITEM_SLOT_ICLOTHING|ITEM_SLOT_OCLOTHING|ITEM_SLOT_NECK)
 
 /// Called when the uniform this accessory is pinned to is equipped in a valid slot
 /obj/item/clothing/accessory/proc/accessory_equipped(obj/item/clothing/under/clothes, mob/living/user)
 	equipped(user, user.get_slot_by_item(clothes)) // so we get any actions, item_flags get set, etc
+	user.update_clothing(ITEM_SLOT_OCLOTHING|ITEM_SLOT_NECK)
 	return
 
 /// Called when the uniform this accessory is pinned to is dropped