Height and minor bodypart overlay refactor (#96570)

## About The Pull Request

### Main changes

Height is no longer applied in `apply_overlay`

There is now a proc titled `apply_height()` which is passed an
appearance and a body area, and handles either applying a filter or
adjusting the offset of the appearance up or down

`apply_height` is now called directly when applying item appearances
(ie, `update_worn_x`)
`apply_height` is also called directly in `get_limb_icon` (as height is
included in limb render keys).

### Other changes

Bodypart overlays were cleaned up a bit. You can now apply and remove
bodypart overlays directly with just the typepath, which is a bit more
convenient.

Bodypart textures were split into a separate type. Previously, textures
relied on insertion order to be "correctly" added (any bodypart overlays
added later would not be modified by the bodypart texture). Now

Fixed a bug with cybernetics while I was there. They reskin by changing
DMI so they needed to have their DMI included in their render keys.

## Why It's Good For The Game

This allows us to be more specific and less wasteful about applying
height filters and whatnot - We can now specify whether certain overlays
are offset or given a filter.

For example: In the past, horns and frills were filtered solely because
they were attached to the head and the head was filtered.
We couldn't independently say "Offsets the horns and frills, they don't
need filters".
But now, not only are we able to say "rather than filter the head, just
apply an offset", we can also say "horns and frills should be offset
rather than filtered".

TL;DR fixes the issue where horns or cat ears are cut off by height
filters, yippee.

## Changelog

🆑 Melbert
fix: Cybernetic reskinning should break less. 
fix: Horns and cat ears should be cut off less by height.
fix: Bodypart textures should apply more consistently. 
refactor: Mutant parts like moth wings, lizard tails, cat eats, etc.
have been refactored a tiny bit, report any oddities.
refactor: Bodypart textures were refactored a tiny bit, report any
oddities.
refactor: Refactored the way height works, report anything weird looking
things involving that.
/🆑

code/modules/surgery/organs/external/_visual_organs.dm

@@ -94,9 +94,9 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 		return
 
 	//Build the mob sprite and use it as our overlay
-	for(var/external_layer in bodypart_overlay.all_layers)
+	for(var/external_layer, actual_layer in bodypart_overlay.all_layers)
 		if(bodypart_overlay.layers & external_layer)
-			. += bodypart_overlay.get_overlay(external_layer, bodypart_owner, bodypart_owner?.is_husked)
+			. += bodypart_overlay.get_overlay(actual_layer, bodypart_owner)
 
 ///The horns of a lizard!
 /obj/item/organ/horns
@@ -119,8 +119,9 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	feature_key = FEATURE_HORNS
 	dyable = TRUE
 	draw_on_husks = HUSK_OVERLAY_NORMAL
+	offset_location = UPPER_BODY
 
-/datum/bodypart_overlay/mutant/horns/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/horns/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & HIDEHAIR)
 
 ///The frills of a lizard (like weird fin ears)
@@ -142,11 +143,12 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 /datum/bodypart_overlay/mutant/frills
 	layers = EXTERNAL_ADJACENT
 	feature_key = FEATURE_FRILLS
+	offset_location = UPPER_BODY
 
-/datum/bodypart_overlay/mutant/frills/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/frills/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & HIDEHAIR)
 
-/datum/bodypart_overlay/mutant/frills/generate_icon_cache(obj/item/bodypart/limb)
+/datum/bodypart_overlay/mutant/frills/icon_render_key(obj/item/bodypart/limb)
 	. = ..()
 	if(LAZYLEN(limb?.owner?.hair_masks))
 		. += jointext(limb.owner.hair_masks, ",")
@@ -211,8 +213,9 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	layers = EXTERNAL_ADJACENT
 	feature_key = FEATURE_SNOUT
 	draw_on_husks = HUSK_OVERLAY_GRAYSCALE
+	offset_location = UPPER_BODY
 
-/datum/bodypart_overlay/mutant/snout/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/snout/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & HIDESNOUT)
 
 ///A moth's antennae
@@ -280,6 +283,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	layers = EXTERNAL_FRONT | EXTERNAL_BEHIND
 	feature_key = FEATURE_MOTH_ANTENNAE
 	dyable = TRUE
+	offset_location = UPPER_BODY
 	///Accessory datum of the burn sprite
 	var/datum/sprite_accessory/burn_datum = /datum/sprite_accessory/moth_antennae/burnt_off
 	///Are we burned? If so we draw differently
@@ -293,7 +297,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 /datum/bodypart_overlay/mutant/antennae/get_base_icon_state()
 	return burnt ? burn_datum.icon_state : sprite_datum.icon_state
 
-/datum/bodypart_overlay/mutant/antennae/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/antennae/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & HIDEANTENNAE)
 
 ///The leafy hair of a podperson
@@ -318,6 +322,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	layers = EXTERNAL_FRONT|EXTERNAL_ADJACENT
 	feature_key = FEATURE_POD_HAIR
 	dyable = TRUE
+	offset_location = UPPER_BODY
 
 	///This layer will be colored differently than the rest of the organ. So we can get differently colored flowers or something
 	var/color_swapped_layer = EXTERNAL_FRONT
@@ -325,7 +330,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	var/color_inverse_base = 255
 
 /datum/bodypart_overlay/mutant/pod_hair/color_image(image/overlay, draw_layer, obj/item/bodypart/limb)
-	if(draw_layer != bitflag_to_layer(color_swapped_layer))
+	if(draw_layer != all_layers[color_swapped_layer])
 		return ..()
 
 	var/color_to_use = dye_color || draw_color
@@ -335,5 +340,5 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	else
 		overlay.color = null
 
-/datum/bodypart_overlay/mutant/pod_hair/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/pod_hair/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & HIDEHAIR)

code/modules/surgery/organs/external/spines.dm

@@ -32,8 +32,9 @@
 	feature_key = FEATURE_SPINES
 	dyable = TRUE
 	draw_on_husks = HUSK_OVERLAY_GRAYSCALE
+	offset_location = ENTIRE_BODY
 
-/datum/bodypart_overlay/mutant/spines/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/spines/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & HIDEJUMPSUIT)
 
 /datum/bodypart_overlay/mutant/spines/set_dye_color(new_color, obj/item/organ/tail/organ)

code/modules/surgery/organs/external/tails.dm

@@ -142,12 +142,13 @@
 /datum/bodypart_overlay/mutant/tail
 	layers = EXTERNAL_FRONT|EXTERNAL_BEHIND
 	dyable = TRUE
+	offset_location = ENTIRE_BODY
 	var/wagging = FALSE
 
 /datum/bodypart_overlay/mutant/tail/get_base_icon_state()
 	return "[wagging ? "wagging_" : ""][sprite_datum.icon_state]" //add the wagging tag if we be wagging
 
-/datum/bodypart_overlay/mutant/tail/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/tail/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & HIDEJUMPSUIT)
 
 /obj/item/organ/tail/cat
@@ -254,6 +255,7 @@
 	layers = EXTERNAL_ADJACENT|EXTERNAL_BEHIND
 	feature_key = FEATURE_TAILSPINES
 	draw_on_husks = HUSK_OVERLAY_GRAYSCALE
+	offset_location = ENTIRE_BODY
 	///Spines wag when the tail does
 	var/wagging = FALSE
 	/// Key for tail spine states, depends on the shape of the tail. Defined in the tail sprite datum.
@@ -262,7 +264,7 @@
 /datum/bodypart_overlay/mutant/tail_spines/get_base_icon_state()
 	return (!isnull(tail_spine_key) ? "[tail_spine_key]_" : "") + (wagging ? "wagging_" : "") + sprite_datum.icon_state // Select the wagging state if appropriate
 
-/datum/bodypart_overlay/mutant/tail_spines/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/tail_spines/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & HIDEJUMPSUIT)
 
 /datum/bodypart_overlay/mutant/tail_spines/set_dye_color(new_color, obj/item/organ/organ)

code/modules/surgery/organs/external/wings/functional_wings.dm

@@ -183,7 +183,7 @@
 	feature_key = initial(feature_key)
 	set_appearance_from_name(sprite_datum.name)
 
-/datum/bodypart_overlay/mutant/wings/functional/generate_icon_cache(obj/item/bodypart/limb)
+/datum/bodypart_overlay/mutant/wings/functional/icon_render_key(obj/item/bodypart/limb)
 	. = ..()
 	. += wings_open ? "open" : "closed"
 

code/modules/surgery/organs/external/wings/wings.dm

@@ -22,10 +22,11 @@
 
 ///Bodypart overlay of default wings. Does not have any wing functionality
 /datum/bodypart_overlay/mutant/wings
-	layers = ALL_EXTERNAL_OVERLAYS
+	layers = EXTERNAL_FRONT | EXTERNAL_ADJACENT | EXTERNAL_BEHIND
 	feature_key = FEATURE_WINGS
+	offset_location = ENTIRE_BODY
 	/// Slot we check against
 	var/slot_blocker = HIDEJUMPSUIT
 
-/datum/bodypart_overlay/mutant/wings/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/wings/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & slot_blocker)

code/modules/surgery/organs/internal/cyberimp/augments_internal.dm

@@ -47,6 +47,7 @@
 /datum/bodypart_overlay/augment
 	layers = EXTERNAL_ADJACENT
 	draw_on_husks = HUSK_OVERLAY_NORMAL
+	offset_location = ENTIRE_BODY
 	/// Implant that owns this overlay
 	var/obj/item/organ/cyberimp/implant
 
@@ -58,12 +59,11 @@
 	implant = null
 	return ..()
 
-/datum/bodypart_overlay/augment/generate_icon_cache(obj/item/bodypart/limb)
+/datum/bodypart_overlay/augment/icon_render_key(obj/item/bodypart/limb)
 	. = ..()
 	. += implant.get_overlay_state()
 
 /datum/bodypart_overlay/augment/get_overlay(layer, obj/item/bodypart/limb)
-	layer = bitflag_to_layer(layer)
 	var/list/imageset = implant.get_overlay(layer, limb)
 	if(blocks_emissive == EMISSIVE_BLOCK_NONE || !limb)
 		return imageset

code/modules/surgery/organs/internal/ears/_ears.dm

@@ -162,11 +162,12 @@
 	color_source = ORGAN_COLOR_HAIR
 	feature_key = FEATURE_EARS
 	dyable = TRUE
+	offset_location = UPPER_BODY
 
 	/// Layer upon which we add the inner ears overlay
 	var/inner_layer = EXTERNAL_FRONT
 
-/datum/bodypart_overlay/mutant/cat_ears/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner, is_husked = FALSE)
+/datum/bodypart_overlay/mutant/cat_ears/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner, mob/living/carbon/owner)
 	return ..() && !(bodypart_owner.owner?.obscured_slots & HIDEHAIR)
 
 /datum/bodypart_overlay/mutant/cat_ears/get_image(image_layer, obj/item/bodypart/limb)
@@ -174,7 +175,7 @@
 	base_ears.color = (dye_color || draw_color)
 
 	// Only add inner ears on the inner layer
-	if(image_layer != bitflag_to_layer(inner_layer))
+	if(image_layer != all_layers[inner_layer])
 		return base_ears
 
 	// Construct image of inner ears, apply to base ears as an overlay
@@ -237,7 +238,7 @@
 	var/inner_color = "#F0004A"
 
 /datum/bodypart_overlay/mutant/cat_ears/cybernetic/get_image(image_layer, obj/item/bodypart/limb)
-	if (image_layer != bitflag_to_layer(inner_layer))
+	if (image_layer != all_layers[inner_layer])
 		return ..()
 	var/mutable_appearance/ear_holder = ..()
 	var/mutable_appearance/inner = ear_holder.overlays[2]
@@ -245,7 +246,7 @@
 	return ear_holder
 
 /datum/bodypart_overlay/mutant/cat_ears/cybernetic/get_overlay(layer, obj/item/bodypart/limb)
-	if (layer != inner_layer)
+	if (layer != all_layers[inner_layer])
 		return ..()
 	var/list/all_images = ..()
 	var/mutable_appearance/ear_holder = all_images[1]