Revert "emissive blockers are now just an overlay (with kickass fucki…

…ng graphs). FUCK YOU MAPTICK (tgstation#57934)"

This reverts commit 0992c09.

code/game/atoms_movable.dm

@@ -77,15 +77,11 @@
 	. = ..()
 	switch(blocks_emissive)
 		if(EMISSIVE_BLOCK_GENERIC)
-			var/mutable_appearance/gen_emissive_blocker = mutable_appearance(icon, icon_state, EMISSIVE_BLOCKER_LAYER, EMISSIVE_BLOCKER_PLANE)
-			gen_emissive_blocker.dir = dir
-			gen_emissive_blocker.alpha = alpha
-			gen_emissive_blocker.appearance_flags |= appearance_flags
-			add_overlay(list(gen_emissive_blocker))
+			update_emissive_block()
 		if(EMISSIVE_BLOCK_UNIQUE)
 			render_target = ref(src)
 			em_block = new(src, render_target)
-			add_overlay(list(em_block))
+			vis_contents += em_block
 	if(opacity)
 		AddElement(/datum/element/light_blocking)
 	switch(light_system)
@@ -135,24 +131,17 @@
 
 	vis_contents.Cut()
 
+
 /atom/movable/proc/update_emissive_block()
-	if(!blocks_emissive)
+	if(blocks_emissive != EMISSIVE_BLOCK_GENERIC)
 		return
-	else if (blocks_emissive == EMISSIVE_BLOCK_GENERIC)
-		var/mutable_appearance/gen_emissive_blocker = mutable_appearance(icon, icon_state, EMISSIVE_BLOCKER_LAYER, EMISSIVE_BLOCKER_PLANE)
-		gen_emissive_blocker.dir = dir
-		gen_emissive_blocker.alpha = alpha
-		gen_emissive_blocker.appearance_flags |= appearance_flags
-		return gen_emissive_blocker
-	else if(blocks_emissive == EMISSIVE_BLOCK_UNIQUE)
-		if(!em_block)
-			render_target = ref(src)
-			em_block = new(src, render_target)
-		return em_block
-
-/atom/movable/update_overlays()
-	. = ..()
-	. += update_emissive_block()
+	if(length(managed_vis_overlays))
+		for(var/a in managed_vis_overlays)
+			var/obj/effect/overlay/vis/vs
+			if(vs.plane == EMISSIVE_BLOCKER_PLANE)
+				SSvis_overlays.remove_vis_overlay(src, list(vs))
+				break
+	SSvis_overlays.add_vis_overlay(src, icon, icon_state, EMISSIVE_BLOCKER_LAYER, EMISSIVE_BLOCKER_PLANE, dir)
 
 /atom/movable/proc/can_zFall(turf/source, levels = 1, turf/target, direction)
 	if(!direction)