Big Fat Emission PR (#18124)

* amogus

* Revert "amogus"

This reverts commit ebaa99c77b.

* Part 1

* rest of the airlocks

holy shit that took a long time

* part 2

* part 3

finale

* conflict resolution

* fixes warnings

* fixes paneloen airlock emissives

* adds back changes from #18145

* #18085 sprites

* SteelSlayer Review

readded process in status_display, idk why I removed it, it broke some functionality

* future proofing firedoors

Talked with the contributor who added emissive appearances to the codebase. As of now they wont block them unless they spawn as closed, but with future PR merges this code will work.

* solar panel PR conflict resolve

* pain

* small fix

* farie82 suggestions

Co-authored-by: Farie82 <farie82@users.noreply.github.com>

* farie82 suggestions part 2

* farie82 suggestions part 3

* finalle

pog champ ers 2000

* farie82 suggestions the sequel

Co-authored-by: Farie82 <farie82@users.noreply.github.com>

* SteelSlayer Suggestions

Co-authored-by: SteelSlayer <42044220+SteelSlayer@users.noreply.github.com>

Co-authored-by: Farie82 <farie82@users.noreply.github.com>
Co-authored-by: SteelSlayer <42044220+SteelSlayer@users.noreply.github.com>

code/game/objects/items/devices/radio/intercom.dm

@@ -7,6 +7,7 @@
 	w_class = WEIGHT_CLASS_BULKY
 	canhear_range = 2
 	flags = CONDUCT
+	blocks_emissive = FALSE
 	var/circuitry_installed = 1
 	var/buildstage = 0
 	var/custom_name
@@ -64,7 +65,7 @@
 		b_stat = TRUE
 		on = FALSE
 	GLOB.global_intercoms.Add(src)
-	update_icon(UPDATE_ICON_STATE)
+	update_icon(UPDATE_ICON_STATE | UPDATE_OVERLAYS)
 
 /obj/item/radio/intercom/Initialize()
 	. = ..()
@@ -205,7 +206,7 @@
 	on = FALSE
 	b_stat = TRUE
 	buildstage = 1
-	update_icon(UPDATE_ICON_STATE)
+	update_icon(UPDATE_ICON_STATE | UPDATE_OVERLAYS)
 	update_operating_status(FALSE)
 
 /obj/item/radio/intercom/welder_act(mob/user, obj/item/I)
@@ -226,6 +227,13 @@
 	else
 		icon_state = "intercom[!on?"-p":""][b_stat ? "-open":""]"
 
+/obj/item/radio/intercom/update_overlays()
+	. = ..()
+	underlays.Cut()
+
+	if(on && buildstage == 3)
+		underlays += emissive_appearance(icon, "intercom_lightmask")
+
 /obj/item/radio/intercom/proc/update_operating_status(on = TRUE)
 	var/area/current_area = get_area(src)
 	if(!current_area)
@@ -247,9 +255,11 @@
 	var/area/current_area = get_area(src)
 	if(!current_area)
 		on = FALSE
+		set_light(0)
 	else
 		on = current_area.powered(EQUIP) // set "on" to the equipment power status of our area.
-	update_icon(UPDATE_ICON_STATE)
+		set_light(1, LIGHTING_MINIMUM_POWER)
+	update_icon(UPDATE_ICON_STATE | UPDATE_OVERLAYS)
 
 /obj/item/intercom_electronics
 	name = "intercom electronics"