up ports the TG overlays subsystem update (#18945)

* up ports the TG overlays subsystem update

* .

* .

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* .

* for spell

* .

* cutting

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Co-authored-by: Cameron Lennox <killer65311@gmail.com>

code/modules/mob/living/living.dm

@@ -3,6 +3,7 @@
 
 	//Prime this list if we need it.
 	if(has_huds)
+		// Note, this should be refactored to drop priority overlays
 		add_overlay(backplane,TRUE) //Strap this on here, to block HUDs from appearing in rightclick menus: http://www.byond.com/forum/?post=2336679
 		hud_list = list()
 		hud_list.len = TOTAL_HUDS

code/modules/mob/living/simple_mob/subtypes/blob/spore.dm

@@ -94,7 +94,7 @@
 		if(overmind)
 			blob_head_overlay.color = overmind.blob_type.complementary_color
 		color = initial(color)//looks better.
-		add_overlay(blob_head_overlay, TRUE)
+		add_overlay(blob_head_overlay)
 
 /mob/living/simple_mob/blob/spore/handle_special()
 	..()

code/modules/multiz/turf.dm

@@ -67,7 +67,7 @@ GLOBAL_DATUM_INIT(openspace_backdrop_one_for_all, /atom/movable/openspace_backdr
 /turf/simulated/open/Initialize(mapload)
 	. = ..()
 	ASSERT(HasBelow(z))
-	add_overlay(GLOB.openspace_backdrop_one_for_all, TRUE) //Special grey square for projecting backdrop darkness filter on it.
+	add_overlay(GLOB.openspace_backdrop_one_for_all) //Special grey square for projecting backdrop darkness filter on it.
 	return INITIALIZE_HINT_LATELOAD
 
 /turf/simulated/open/LateInitialize()
@@ -99,6 +99,7 @@ GLOBAL_DATUM_INIT(openspace_backdrop_one_for_all, /atom/movable/openspace_backdr
 /turf/simulated/open/update_icon()
 	cut_overlays()
 	update_icon_edge()
+	add_overlay(GLOB.openspace_backdrop_one_for_all) //Special grey square for projecting backdrop darkness filter on it.
 
 // Straight copy from space.
 /turf/simulated/open/attackby(obj/item/C as obj, mob/user as mob)

code/modules/shieldgen/energy_shield.dm

@@ -32,8 +32,8 @@
 		overlays.Cut() // Snowflake handling, avoiding SSoverlays
 	else
 		icon_state = enabled_icon_state
-		flags |= OVERLAY_QUEUED //Trick SSoverlays
-		SSoverlays.queue += src
+		//flags |= OVERLAY_QUEUED //Trick SSoverlays
+		//SSoverlays.queue += src
 
 /obj/effect/shield/proc/update_color()
 	if(disabled_for || diffused_for)

code/modules/vore/eating/belly_obj_vr.dm

@@ -661,6 +661,7 @@
 			temp.filters += filter(type = "alpha", icon = icon(I.icon, I.icon_state))
 			I.d_stage_overlay = temp
 			for(var/count in I.d_mult to 1 step 0.25)
+				// Note, this should be refactored to drop priority overlays
 				I.add_overlay(I.d_stage_overlay, TRUE)
 
 // SEND_SIGNAL(COMSIG_BELLY_UPDATE_VORE_FX) is sometimes used when calling vore_fx() to send belly visuals