Merge branch 'master' of https://github.com/tgstation/-tg-station into revert_revert_revert_come_on_revert_please_rever_please_shit_REVERT_JESUS_TAPDANCING_CHRIST_REVERT_YOU_FUCKING_PIECE_OF_GODDAMN_PISS

Conflicts:
	code/_onclick/hud/plane_master.dm
	code/modules/lighting/lighting_object.dm

code/modules/lighting/lighting_object.dm

@@ -0,0 +1,114 @@
+/var/list/all_lighting_objects = list() // Global list of lighting objects.
+
+/atom/movable/lighting_object
+	name          = ""
+
+	anchored      = TRUE
+
+	icon             = LIGHTING_ICON
+	color            = LIGHTING_BASE_MATRIX
+	plane            = LIGHTING_PLANE
+	mouse_opacity    = 0
+	layer            = LIGHTING_LAYER
+	invisibility     = INVISIBILITY_LIGHTING
+
+	blend_mode       = BLEND_ADD
+
+	var/needs_update = FALSE
+
+/atom/movable/lighting_object/Initialize(mapload, var/no_update = FALSE)
+	. = ..()
+	verbs.Cut()
+	global.all_lighting_objects += src
+
+	var/turf/T         = loc // If this runtimes atleast we'll know what's creating overlays in things that aren't turfs.
+	T.lighting_object = src
+	T.luminosity       = 0
+
+	for(var/turf/open/space/S in RANGE_TURFS(1, src)) //RANGE_TURFS is in code\__HELPERS\game.dm
+		S.update_starlight()
+
+	if (no_update)
+		return
+
+	update()
+
+/atom/movable/lighting_object/Destroy(var/force)
+	if (force)
+		global.all_lighting_objects        -= src
+		global.lighting_update_objects     -= src
+
+		var/turf/T   = loc
+		if (istype(T))
+			T.lighting_object = null
+			T.luminosity = 1
+
+		return ..()
+	else
+		return QDEL_HINT_LETMELIVE
+
+/atom/movable/lighting_object/proc/update()
+	var/turf/T = loc
+	if (!istype(T)) // Erm...
+		if (loc)
+			warning("A lighting object realised its loc was NOT a turf (actual loc: [loc], [loc.type]) in update()!")
+
+		else
+			warning("A lighting object realised it was in nullspace in update()!")
+
+		qdel(src, TRUE)
+		return
+
+	// To the future coder who sees this and thinks
+	// "Why didn't he just use a loop?"
+	// Well my man, it's because the loop performed like shit.
+	// And there's no way to improve it because
+	// without a loop you can make the list all at once which is the fastest you're gonna get.
+	// Oh it's also shorter line wise.
+	// Including with these comments.
+
+	// See LIGHTING_CORNER_DIAGONAL in lighting_corner.dm for why these values are what they are.
+	var/datum/lighting_corner/cr  = T.corners[3] || dummy_lighting_corner
+	var/datum/lighting_corner/cg  = T.corners[2] || dummy_lighting_corner
+	var/datum/lighting_corner/cb  = T.corners[4] || dummy_lighting_corner
+	var/datum/lighting_corner/ca  = T.corners[1] || dummy_lighting_corner
+
+	var/max = max(cr.cache_mx, cg.cache_mx, cb.cache_mx, ca.cache_mx)
+
+	color  = list(
+		cr.cache_r, cr.cache_g, cr.cache_b, 0,
+		cg.cache_r, cg.cache_g, cg.cache_b, 0,
+		cb.cache_r, cb.cache_g, cb.cache_b, 0,
+		ca.cache_r, ca.cache_g, ca.cache_b, 0,
+		0, 0, 0, 1
+	)
+	#if LIGHTING_SOFT_THRESHOLD != 0
+	luminosity = max > LIGHTING_SOFT_THRESHOLD
+	#else
+	// Because of floating points™️, it won't even be a flat 0.
+	// This number is mostly arbitrary.
+	luminosity = max > 1e-6
+	#endif
+
+// Variety of overrides so the overlays don't get affected by weird things.
+
+/atom/movable/lighting_object/ex_act(severity)
+	return 0
+
+/atom/movable/lighting_object/singularity_act()
+	return
+
+/atom/movable/lighting_object/singularity_pull()
+	return
+
+/atom/movable/lighting_object/blob_act()
+	return
+
+// Nope nope nope!
+/atom/movable/lighting_object/onShuttleMove(turf/T1, rotation)
+	return FALSE
+
+// Override here to prevent things accidentally moving around overlays.
+/atom/movable/lighting_object/forceMove(atom/destination, var/no_tp=FALSE, var/harderforce = FALSE)
+	if(harderforce)
+		. = ..()