Overlay lighting component (#52413)

Sparks no longer lag, projectile beams move super smoothly, same with mobs and whatnot. This also allows for easy expansion into directional lights, field-of-view, wee-woo rotating lights or whatever.

It does have a downside: things right-clicked or checked through the alt+click tab will show the light overlay:


This is a BYOND limitation, very well worth it IMO.

🆑
add: Smooth movable lighting system implemented. Projectiles, sparks, thrown flashlights or moving mobs with lights should be much smoother and less laggy.
balance: Light sources no longer stack in range, though they still do in intensity.
/🆑

code/__DEFINES/dcs/signals.dm

@@ -173,6 +173,8 @@
 #define COMSIG_ATOM_SET_LIGHT_COLOR "atom_set_light_color"
 ///Called right before the atom changes the value of light_on to a different one, from base atom/set_light_on(): (new_value)
 #define COMSIG_ATOM_SET_LIGHT_ON "atom_set_light_on"
+///Called right before the atom changes the value of light_flags to a different one, from base atom/set_light_flags(): (new_value)
+#define COMSIG_ATOM_SET_LIGHT_FLAGS "atom_set_light_flags"
 ///called for each movable in a turf contents on /turf/zImpact(): (atom/movable/A, levels)
 #define COMSIG_ATOM_INTERCEPT_Z_FALL "movable_intercept_z_impact"
 ///called on a movable (NOT living) when someone starts pulling it (atom/movable/puller, state, force)
@@ -274,6 +276,14 @@
 #define COMSIG_MOVABLE_SET_ANCHORED "movable_set_anchored"
 ///from base of atom/movable/setGrabState(): (newstate)
 #define COMSIG_MOVABLE_SET_GRAB_STATE "living_set_grab_state"
+///Called when the movable tries to change its dynamic light color setting, from base atom/movable/lighting_overlay_set_color(): (color)
+#define COMSIG_MOVABLE_LIGHT_OVERLAY_SET_RANGE "movable_light_overlay_set_color"
+///Called when the movable tries to change its dynamic light power setting, from base atom/movable/lighting_overlay_set_power(): (power)
+#define COMSIG_MOVABLE_LIGHT_OVERLAY_SET_POWER "movable_light_overlay_set_power"
+///Called when the movable tries to change its dynamic light range setting, from base atom/movable/lighting_overlay_set_range(): (range)
+#define COMSIG_MOVABLE_LIGHT_OVERLAY_SET_COLOR "movable_light_overlay_set_range"
+///Called when the movable tries to toggle its dynamic light LIGHTING_ON status, from base atom/movable/lighting_overlay_toggle_on(): (new_state)
+#define COMSIG_MOVABLE_LIGHT_OVERLAY_TOGGLE_ON "movable_light_overlay_toggle_on"
 
 // /mob signals
 

code/__DEFINES/layers.dm

@@ -110,8 +110,12 @@
 
 #define RAD_TEXT_LAYER 15.1
 
-#define ABOVE_LIGHTING_PLANE 16
-#define ABOVE_LIGHTING_LAYER 16
+#define O_LIGHTING_VISUAL_PLANE 16
+#define O_LIGHTING_VISUAL_LAYER 16
+#define O_LIGHTING_VISUAL_RENDER_TARGET "O_LIGHT_VISUAL_PLANE"
+
+#define ABOVE_LIGHTING_PLANE 17
+#define ABOVE_LIGHTING_LAYER 17
 #define ABOVE_LIGHTING_RENDER_TARGET "ABOVE_LIGHTING_PLANE"
 
 #define BYOND_LIGHTING_PLANE 18

code/__DEFINES/lighting.dm

@@ -1,3 +1,13 @@
+///Object doesn't use any of the light systems. Should be changed to add a light source to the object.
+#define NO_LIGHT_SUPPORT 0
+///Light made with the lighting datums, applying a matrix.
+#define STATIC_LIGHT 1
+///Light made by masking the lighting darkness plane.
+#define MOVABLE_LIGHT 2
+
+///Is a movable light source attached to another movable (its loc), meaning that the lighting component should go one level deeper.
+#define LIGHT_ATTACHED (1<<0)
+
 //Bay lighting engine shit, not in /code/modules/lighting because BYOND is being shit about it
 /// frequency, in 1/10ths of a second, of the lighting process
 #define LIGHTING_INTERVAL       5

code/__DEFINES/mobs.dm

@@ -373,3 +373,6 @@
 #define EYE_CONTACT_RANGE	5
 
 #define SILENCE_RANGED_MESSAGE (1<<0)
+
+///Swarmer flags
+#define SWARMER_LIGHT_ON (1<<0)

code/_onclick/hud/plane_master.dm

@@ -79,8 +79,9 @@
 
 /obj/screen/plane_master/lighting/Initialize()
 	. = ..()
-	filters += filter(type="alpha", render_source=EMISSIVE_RENDER_TARGET, flags=MASK_INVERSE)
-	filters += filter(type="alpha", render_source=EMISSIVE_UNBLOCKABLE_RENDER_TARGET, flags=MASK_INVERSE)
+	filters += filter(type="alpha", render_source = EMISSIVE_RENDER_TARGET, flags = MASK_INVERSE)
+	filters += filter(type="alpha", render_source = EMISSIVE_UNBLOCKABLE_RENDER_TARGET, flags = MASK_INVERSE)
+	filters += filter(type="alpha", render_source = O_LIGHTING_VISUAL_RENDER_TARGET, flags = MASK_INVERSE)
 
 /**
   * Things placed on this mask the lighting plane. Doesn't render directly.
@@ -104,7 +105,6 @@
   * Always masks the light plane, isn't blocked by anything. Use for on mob glows,
   * magic stuff, etc.
   */
-
 /obj/screen/plane_master/emissive_unblockable
 	name = "unblockable emissive plane master"
 	plane = EMISSIVE_UNBLOCKABLE_PLANE
@@ -145,3 +145,11 @@
 	appearance_flags = PLANE_MASTER
 	blend_mode = BLEND_OVERLAY
 	alpha = 0
+
+/obj/screen/plane_master/o_light_visual
+	name = "overlight light visual plane master"
+	layer = O_LIGHTING_VISUAL_LAYER
+	plane = O_LIGHTING_VISUAL_PLANE
+	render_target = O_LIGHTING_VISUAL_RENDER_TARGET
+	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	blend_mode = BLEND_MULTIPLY

code/datums/components/overlay_lighting.dm

@@ -0,0 +1,362 @@
+///For switchable lights, is it on and currently emitting light?
+#define LIGHTING_ON (1<<0)
+///Is the parent attached to something else, its loc? Then we need to keep an eye of this.
+#define LIGHTING_ATTACHED (1<<1)
+
+#define GET_PARENT (parent_attached_to || parent)
+
+/**
+  * Movable atom overlay-based lighting component.
+  *
+  * * Component works by applying a visual object to the parent target.
+  *
+  * * The component tracks the parent's loc to determine the current_holder.
+  * * The current_holder is either the parent or its loc, whichever is on a turf. If none, then the current_holder is null and the light is not visible.
+  *
+  * * Lighting works at its base by applying a dark overlay and "cutting" said darkness with light, adding (possibly colored) transparency.
+  * * This component uses the visible_mask visual object to apply said light mask on the darkness.
+  *
+  * * The main limitation of this system is that it uses a limited number of pre-baked geometrical shapes, but for most uses it does the job.
+  *
+  * * Another limitation is for big lights: you only see the light if you see the object emiting it.
+  * * For small objects this is good (you can't see them behind a wall), but for big ones this quickly becomes prety clumsy.
+*/
+/datum/component/overlay_lighting
+	///How far the light reaches, float.
+	var/range = 1
+	///Ceiling of range, integer without decimal entries.
+	var/lumcount_range = 0
+	///How much this light affects the dynamic_lumcount of turfs.
+	var/lum_power = 0.5
+	///Transparency value.
+	var/set_alpha = 0
+	///For light sources that can be turned on and off.
+	var/overlay_lighting_flags = NONE
+
+	///Cache of the possible light overlays, according to size.
+	var/static/list/light_overlays = list(
+		"32" = 'icons/effects/light_overlays/light_32.dmi',
+		"64" = 'icons/effects/light_overlays/light_64.dmi',
+		"96" = 'icons/effects/light_overlays/light_96.dmi',
+		"128" = 'icons/effects/light_overlays/light_128.dmi',
+		"160" = 'icons/effects/light_overlays/light_160.dmi',
+		"192" = 'icons/effects/light_overlays/light_192.dmi',
+		"224" = 'icons/effects/light_overlays/light_224.dmi',
+		"256" = 'icons/effects/light_overlays/light_256.dmi',
+		"288" = 'icons/effects/light_overlays/light_288.dmi',
+		"320" = 'icons/effects/light_overlays/light_320.dmi',
+		"352" = 'icons/effects/light_overlays/light_352.dmi',
+		)
+
+	///Overlay effect to cut into the darkness and provide light.
+	var/obj/effect/overlay/light_visible/visible_mask
+	///Lazy list to track the turfs being affected by our light, to determine their visibility.
+	var/list/turf/affected_turfs
+	///Movable atom currently holding the light. Parent might be a flashlight, for example, but that might be held by a mob or something else.
+	var/atom/movable/current_holder
+	///Movable atom the parent is attached to. For example, a flashlight into a helmet or gun. We'll need to track the thing the parent is attached to as if it were the parent itself.
+	var/atom/movable/parent_attached_to
+
+
+/datum/component/overlay_lighting/Initialize(_range, _power, _color, starts_on)
+	if(!ismovable(parent))
+		return COMPONENT_INCOMPATIBLE
+
+	var/atom/movable/movable_parent = parent
+	if(movable_parent.light_system != MOVABLE_LIGHT)
+		stack_trace("[type] added to [parent], with [movable_parent.light_system] value for the light_system var. Use [MOVABLE_LIGHT] instead.")
+		return COMPONENT_INCOMPATIBLE
+
+	. = ..()
+
+	visible_mask = new()
+	if(!isnull(_range))
+		movable_parent.set_light_range(_range)
+	set_range(parent, movable_parent.light_range)
+	if(!isnull(_power))
+		movable_parent.set_light_power(_power)
+	set_power(parent, movable_parent.light_power)
+	if(!isnull(_color))
+		movable_parent.set_light_color(_color)
+	set_color(parent, movable_parent.light_color)
+	if(!isnull(starts_on))
+		movable_parent.set_light_on(starts_on)
+
+
+/datum/component/overlay_lighting/RegisterWithParent()
+	. = ..()
+	RegisterSignal(parent, COMSIG_MOVABLE_MOVED, .proc/on_parent_moved)
+	RegisterSignal(parent, COMSIG_ATOM_SET_LIGHT_RANGE, .proc/set_range)
+	RegisterSignal(parent, COMSIG_ATOM_SET_LIGHT_POWER, .proc/set_power)
+	RegisterSignal(parent, COMSIG_ATOM_SET_LIGHT_COLOR, .proc/set_color)
+	RegisterSignal(parent, COMSIG_ATOM_SET_LIGHT_ON, .proc/on_toggle)
+	RegisterSignal(parent, COMSIG_ATOM_SET_LIGHT_FLAGS, .proc/on_light_flags_change)
+	var/atom/movable/movable_parent = parent
+	if(movable_parent.light_flags & LIGHT_ATTACHED)
+		overlay_lighting_flags |= LIGHTING_ATTACHED
+		set_parent_attached_to(ismovable(movable_parent.loc) ? movable_parent.loc : null)
+	check_holder()
+	if(movable_parent.light_on)
+		turn_on()
+
+
+/datum/component/overlay_lighting/UnregisterFromParent()
+	overlay_lighting_flags &= ~LIGHTING_ATTACHED
+	set_parent_attached_to(null)
+	set_holder(null)
+	clean_old_turfs()
+	UnregisterSignal(parent, list(
+		COMSIG_MOVABLE_MOVED,
+		COMSIG_ATOM_SET_LIGHT_RANGE,
+		COMSIG_ATOM_SET_LIGHT_POWER,
+		COMSIG_ATOM_SET_LIGHT_COLOR,
+		COMSIG_ATOM_SET_LIGHT_ON,
+		COMSIG_ATOM_SET_LIGHT_FLAGS,
+		))
+	if(overlay_lighting_flags & LIGHTING_ON)
+		turn_off()
+	return ..()
+
+
+/datum/component/overlay_lighting/Destroy()
+	set_parent_attached_to(null)
+	set_holder(null)
+	clean_old_turfs()
+	QDEL_NULL(visible_mask)
+	return ..()
+
+
+///Clears the affected_turfs lazylist, removing from its contents the effects of being near the light.
+/datum/component/overlay_lighting/proc/clean_old_turfs()
+	for(var/t in affected_turfs)
+		var/turf/lit_turf = t
+		lit_turf.dynamic_lumcount -= lum_power
+	affected_turfs = null
+
+
+///Populates the affected_turfs lazylist, adding to its contents the effects of being near the light.
+/datum/component/overlay_lighting/proc/get_new_turfs()
+	if(!current_holder)
+		return
+	for(var/turf/lit_turf in view(lumcount_range, get_turf(current_holder)))
+		lit_turf.dynamic_lumcount += lum_power
+		LAZYADD(affected_turfs, lit_turf)
+
+
+///Clears the old affected turfs and populates the new ones.
+/datum/component/overlay_lighting/proc/make_luminosity_update()
+	clean_old_turfs()
+	if(!isturf(current_holder?.loc))
+		return
+	get_new_turfs()
+
+
+///Adds the luminosity and source for the afected movable atoms to keep track of their visibility.
+/datum/component/overlay_lighting/proc/add_dynamic_lumi(atom/movable/affected_movable)
+	LAZYSET(affected_movable.affected_dynamic_lights, src, lumcount_range + 1)
+	affected_movable.vis_contents += visible_mask
+	affected_movable.update_dynamic_luminosity()
+
+
+///Removes the luminosity and source for the afected movable atoms to keep track of their visibility.
+/datum/component/overlay_lighting/proc/remove_dynamic_lumi(atom/movable/affected_movable)
+	LAZYREMOVE(affected_movable.affected_dynamic_lights, src)
+	affected_movable.vis_contents -= visible_mask
+	affected_movable.update_dynamic_luminosity()
+
+
+///Called to change the value of parent_attached_to.
+/datum/component/overlay_lighting/proc/set_parent_attached_to(atom/movable/new_parent_attached_to)
+	if(new_parent_attached_to == parent_attached_to)
+		return
+	. = parent_attached_to
+	parent_attached_to = new_parent_attached_to
+	if(.)
+		var/atom/movable/old_parent_attached_to = .
+		UnregisterSignal(old_parent_attached_to, list(COMSIG_PARENT_QDELETING, COMSIG_MOVABLE_MOVED))
+		if(old_parent_attached_to == current_holder)
+			RegisterSignal(old_parent_attached_to, COMSIG_PARENT_QDELETING, .proc/on_holder_qdel)
+			RegisterSignal(old_parent_attached_to, COMSIG_MOVABLE_MOVED, .proc/on_holder_moved)
+	if(parent_attached_to)
+		if(parent_attached_to == current_holder)
+			UnregisterSignal(current_holder, list(COMSIG_PARENT_QDELETING, COMSIG_MOVABLE_MOVED))
+		RegisterSignal(parent_attached_to, COMSIG_PARENT_QDELETING, .proc/on_parent_attached_to_qdel)
+		RegisterSignal(parent_attached_to, COMSIG_MOVABLE_MOVED, .proc/on_parent_attached_to_moved)
+	check_holder()
+
+
+///Called to change the value of current_holder.
+/datum/component/overlay_lighting/proc/set_holder(atom/movable/new_holder)
+	if(new_holder == current_holder)
+		return
+	if(current_holder)
+		if(current_holder != parent && current_holder != parent_attached_to)
+			UnregisterSignal(current_holder, list(COMSIG_PARENT_QDELETING, COMSIG_MOVABLE_MOVED))
+		if(overlay_lighting_flags & LIGHTING_ON)
+			remove_dynamic_lumi(current_holder)
+	current_holder = new_holder
+	if(new_holder == null)
+		clean_old_turfs()
+		return
+	if(overlay_lighting_flags & LIGHTING_ON)
+		add_dynamic_lumi(new_holder)
+	if(new_holder != parent && new_holder != parent_attached_to)
+		RegisterSignal(new_holder, COMSIG_PARENT_QDELETING, .proc/on_holder_qdel)
+		RegisterSignal(new_holder, COMSIG_MOVABLE_MOVED, .proc/on_holder_moved)
+
+
+///Used to determine the new valid current_holder from the parent's loc.
+/datum/component/overlay_lighting/proc/check_holder()
+	var/atom/movable/movable_parent = GET_PARENT
+	if(isturf(movable_parent.loc))
+		set_holder(movable_parent)
+		return
+	var/atom/inside = movable_parent.loc //Parent's loc
+	if(isnull(inside))
+		set_holder(null)
+		return
+	if(isturf(inside.loc))
+		set_holder(inside)
+		return
+	set_holder(null)
+
+
+///Called when the current_holder is qdeleted, to remove the light effect.
+/datum/component/overlay_lighting/proc/on_holder_qdel(atom/movable/source, force)
+	SIGNAL_HANDLER
+	UnregisterSignal(current_holder, list(COMSIG_PARENT_QDELETING, COMSIG_MOVABLE_MOVED))
+	set_holder(null)
+
+
+///Called when current_holder changes loc.
+/datum/component/overlay_lighting/proc/on_holder_moved(atom/movable/source, OldLoc, Dir, Forced)
+	SIGNAL_HANDLER
+	if(!(overlay_lighting_flags & LIGHTING_ON))
+		return
+	make_luminosity_update()
+
+
+///Called when parent changes loc.
+/datum/component/overlay_lighting/proc/on_parent_moved(atom/movable/source, OldLoc, Dir, Forced)
+	SIGNAL_HANDLER
+	var/atom/movable/movable_parent = parent
+	if(overlay_lighting_flags & LIGHTING_ATTACHED)
+		set_parent_attached_to(ismovable(movable_parent.loc) ? movable_parent.loc : null)
+	check_holder()
+	if(!(overlay_lighting_flags & LIGHTING_ON) || !current_holder)
+		return
+	make_luminosity_update()
+
+
+///Called when the current_holder is qdeleted, to remove the light effect.
+/datum/component/overlay_lighting/proc/on_parent_attached_to_qdel(atom/movable/source, force)
+	SIGNAL_HANDLER
+	UnregisterSignal(parent_attached_to, list(COMSIG_PARENT_QDELETING, COMSIG_MOVABLE_MOVED))
+	if(parent_attached_to == current_holder)
+		set_holder(null)
+	set_parent_attached_to(null)
+
+
+///Called when parent_attached_to changes loc.
+/datum/component/overlay_lighting/proc/on_parent_attached_to_moved(atom/movable/source, OldLoc, Dir, Forced)
+	SIGNAL_HANDLER
+	check_holder()
+	if(!(overlay_lighting_flags & LIGHTING_ON) || !current_holder)
+		return
+	make_luminosity_update()
+
+
+///Changes the range which the light reaches. 0 means no light, 6 is the maximum value.
+/datum/component/overlay_lighting/proc/set_range(atom/source, new_range)
+	SIGNAL_HANDLER
+	if(range == new_range)
+		return
+	if(range == 0)
+		turn_off()
+	range = clamp(CEILING(new_range, 0.5), 1, 6)
+	var/pixel_bounds = ((range - 1) * 64) + 32
+	lumcount_range = CEILING(range, 1)
+	visible_mask.icon = light_overlays["[pixel_bounds]"]
+	if(pixel_bounds == 32)
+		visible_mask.transform = null
+		return
+	var/offset = (pixel_bounds - 32) * 0.5
+	var/matrix/transform = new
+	transform.Translate(-offset, -offset)
+	visible_mask.transform = transform
+	if(overlay_lighting_flags & LIGHTING_ON)
+		make_luminosity_update()
+
+
+///Changes the intensity/brightness of the light by altering the visual object's alpha.
+/datum/component/overlay_lighting/proc/set_power(atom/source, new_power)
+	SIGNAL_HANDLER
+	set_lum_power(new_power >= 0 ? 0.5 : -0.5)
+	set_alpha = min(230, (abs(new_power) * 120) + 30)
+	visible_mask.alpha = set_alpha
+
+
+///Changes the light's color, pretty straightforward.
+/datum/component/overlay_lighting/proc/set_color(atom/source, new_color)
+	SIGNAL_HANDLER
+	visible_mask.color = new_color
+
+
+///Toggles the light on and off.
+/datum/component/overlay_lighting/proc/on_toggle(atom/source, new_value)
+	SIGNAL_HANDLER
+	if(new_value) //Truthy value input, turn on.
+		turn_on()
+		return
+	turn_off() //Falsey value, turn off.
+
+
+///Triggered right before the parent light flags change.
+/datum/component/overlay_lighting/proc/on_light_flags_change(atom/source, new_value)
+	SIGNAL_HANDLER
+	var/atom/movable/movable_parent = parent
+	if(new_value & LIGHT_ATTACHED)
+		if(!(movable_parent.light_flags & LIGHT_ATTACHED)) //Gained the LIGHT_ATTACHED property.
+			overlay_lighting_flags |= LIGHTING_ATTACHED
+			if(ismovable(movable_parent.loc))
+				set_parent_attached_to(movable_parent.loc)
+	else if(movable_parent.light_flags & LIGHT_ATTACHED) //Lost the LIGHT_ATTACHED property.
+		overlay_lighting_flags &= ~LIGHTING_ATTACHED
+		set_parent_attached_to(null)
+
+
+///Toggles the light on.
+/datum/component/overlay_lighting/proc/turn_on()
+	if(overlay_lighting_flags & LIGHTING_ON)
+		return
+	if(current_holder)
+		add_dynamic_lumi(current_holder)
+	overlay_lighting_flags |= LIGHTING_ON
+	get_new_turfs()
+
+
+///Toggles the light off.
+/datum/component/overlay_lighting/proc/turn_off()
+	if(!(overlay_lighting_flags & LIGHTING_ON))
+		return
+	if(current_holder)
+		remove_dynamic_lumi(current_holder)
+	overlay_lighting_flags &= ~LIGHTING_ON
+	clean_old_turfs()
+
+
+///Here we append the behavior associated to changing lum_power.
+/datum/component/overlay_lighting/proc/set_lum_power(new_lum_power)
+	if(lum_power == new_lum_power)
+		return
+	. = lum_power
+	lum_power = new_lum_power
+	var/difference = . - lum_power
+	for(var/t in affected_turfs)
+		var/turf/lit_turf = t
+		lit_turf.dynamic_lumcount -= difference
+
+
+#undef LIGHTING_ON
+#undef LIGHTING_ATTACHED
+#undef GET_PARENT

code/datums/mutations/body.dm

@@ -209,7 +209,8 @@
 		return
 	var/power = GET_MUTATION_POWER(src)
 
-	glowth.set_light(range * power, glow, glow_color)
+	glowth.set_light_range_power_color(range * power, glow, glow_color)
+
 
 /// Returns the color for the glow effect
 /datum/mutation/human/glow/proc/glow_color()

code/game/atoms.dm

@@ -92,6 +92,8 @@
 	/// Last appearance of the atom for demo saving purposes
 	var/image/demo_last_appearance
 
+	///Light systems, both shouldn't be active at the same time.
+	var/light_system = STATIC_LIGHT
 	///Range of the light in tiles. Zero means no light.
 	var/light_range = 0
 	///Intensity of the light. The stronger, the less shadows you will see on the lit area.
@@ -100,6 +102,8 @@
 	var/light_color = COLOR_WHITE
 	///Boolean variable for toggleable lights. Has no effect without the proper light_system, light_range and light_power values.
 	var/light_on = TRUE
+	///Bitflags to determine lighting-related atom properties.
+	var/light_flags = NONE
 	///Our light source. Don't fuck with this directly unless you have a good reason!
 	var/tmp/datum/light_source/light
 	///Any light sources that are "inside" of us, for example, if src here was a mob that's carrying a flashlight, that flashlight's light source would be part of this list.
@@ -204,7 +208,7 @@
 	if(color)
 		add_atom_colour(color, FIXED_COLOUR_PRIORITY)
 
-	if (light_power && light_range)
+	if (light_system == STATIC_LIGHT && light_power && light_range)
 		update_light()
 
 	if (length(smoothing_groups))

code/game/atoms_movable.dm

@@ -54,6 +54,11 @@
 	///Used for the calculate_adjacencies proc for icon smoothing.
 	var/can_be_unanchored = FALSE
 
+	///Lazylist to keep track on the sources of illumination.
+	var/list/affected_dynamic_lights
+	///Highest-intensity light affecting us, which determines our visibility.
+	var/affecting_dynamic_lumi = 0
+
 
 /atom/movable/Initialize(mapload)
 	. = ..()
@@ -66,6 +71,8 @@
 			vis_contents += em_block
 	if(opacity)
 		AddElement(/datum/element/light_blocking)
+	if(light_system == MOVABLE_LIGHT)
+		AddComponent(/datum/component/overlay_lighting)
 
 
 /atom/movable/Destroy(force)

code/game/machinery/dance_machine.dm

@@ -185,60 +185,28 @@
 	var/turf/cen = get_turf(src)
 	FOR_DVIEW(var/turf/t, 3, get_turf(src),INVISIBILITY_LIGHTING)
 		if(t.x == cen.x && t.y > cen.y)
-			var/obj/item/flashlight/spotlight/L = new /obj/item/flashlight/spotlight(t)
-			L.set_light_color(COLOR_SOFT_RED)
-			L.set_light_power(30-(get_dist(src,L)*8))
-			L.range = 1+get_dist(src, L)
-			spotlights+=L
+			spotlights += new /obj/item/flashlight/spotlight(t, 1 + get_dist(src, t), 30 - (get_dist(src, t) * 8), COLOR_SOFT_RED)
 			continue
 		if(t.x == cen.x && t.y < cen.y)
-			var/obj/item/flashlight/spotlight/L = new /obj/item/flashlight/spotlight(t)
-			L.set_light_color(LIGHT_COLOR_PURPLE)
-			L.set_light_power(30-(get_dist(src,L)*8))
-			L.range = 1+get_dist(src, L)
-			spotlights+=L
+			spotlights += new /obj/item/flashlight/spotlight(t, 1 + get_dist(src, t), 30 - (get_dist(src, t) * 8), LIGHT_COLOR_PURPLE)
 			continue
 		if(t.x > cen.x && t.y == cen.y)
-			var/obj/item/flashlight/spotlight/L = new /obj/item/flashlight/spotlight(t)
-			L.set_light_color(LIGHT_COLOR_YELLOW)
-			L.set_light_power(30-(get_dist(src,L)*8))
-			L.range = 1+get_dist(src, L)
-			spotlights+=L
+			spotlights += new /obj/item/flashlight/spotlight(t, 1 + get_dist(src, t), 30 - (get_dist(src, t) * 8), LIGHT_COLOR_YELLOW)
 			continue
 		if(t.x < cen.x && t.y == cen.y)
-			var/obj/item/flashlight/spotlight/L = new /obj/item/flashlight/spotlight(t)
-			L.set_light_color(LIGHT_COLOR_GREEN)
-			L.set_light_power(30-(get_dist(src,L)*8))
-			L.range = 1+get_dist(src, L)
-			spotlights+=L
+			spotlights += new /obj/item/flashlight/spotlight(t, 1 + get_dist(src, t), 30 - (get_dist(src, t) * 8), LIGHT_COLOR_GREEN)
 			continue
 		if((t.x+1 == cen.x && t.y+1 == cen.y) || (t.x+2==cen.x && t.y+2 == cen.y))
-			var/obj/item/flashlight/spotlight/L = new /obj/item/flashlight/spotlight(t)
-			L.set_light_color(LIGHT_COLOR_ORANGE)
-			L.set_light_power(30-(get_dist(src,L)*8))
-			L.range = 1.4+get_dist(src, L)
-			spotlights+=L
+			spotlights += new /obj/item/flashlight/spotlight(t, 1.4 + get_dist(src, t), 30 - (get_dist(src, t) * 8), LIGHT_COLOR_ORANGE)
 			continue
 		if((t.x-1 == cen.x && t.y-1 == cen.y) || (t.x-2==cen.x && t.y-2 == cen.y))
-			var/obj/item/flashlight/spotlight/L = new /obj/item/flashlight/spotlight(t)
-			L.set_light_color(LIGHT_COLOR_CYAN)
-			L.set_light_power(30-(get_dist(src,L)*8))
-			L.range = 1.4+get_dist(src, L)
-			spotlights+=L
+			spotlights += new /obj/item/flashlight/spotlight(t, 1.4 + get_dist(src, t), 30 - (get_dist(src, t) * 8), LIGHT_COLOR_CYAN)
 			continue
 		if((t.x-1 == cen.x && t.y+1 == cen.y) || (t.x-2==cen.x && t.y+2 == cen.y))
-			var/obj/item/flashlight/spotlight/L = new /obj/item/flashlight/spotlight(t)
-			L.set_light_color(LIGHT_COLOR_BLUEGREEN)
-			L.set_light_power(30-(get_dist(src,L)*8))
-			L.range = 1.4+get_dist(src, L)
-			spotlights+=L
+			spotlights += new /obj/item/flashlight/spotlight(t, 1.4 + get_dist(src, t), 30 - (get_dist(src, t) * 8), LIGHT_COLOR_BLUEGREEN)
 			continue
 		if((t.x+1 == cen.x && t.y-1 == cen.y) || (t.x+2==cen.x && t.y-2 == cen.y))
-			var/obj/item/flashlight/spotlight/L = new /obj/item/flashlight/spotlight(t)
-			L.set_light_color(LIGHT_COLOR_BLUE)
-			L.set_light_power(30-(get_dist(src,L)*8))
-			L.range = 1.4+get_dist(src, L)
-			spotlights+=L
+			spotlights += new /obj/item/flashlight/spotlight(t, 1.4 + get_dist(src, t), 30 - (get_dist(src, t) * 8), LIGHT_COLOR_BLUE)
 			continue
 		continue
 	FOR_DVIEW_END
@@ -270,61 +238,80 @@
 		sleep(7)
 	if(selection.song_name == "Engineering's Ultimate High-Energy Hustle")
 		sleep(280)
-	for(var/obj/reveal in sparkles)
+	for(var/s in sparkles)
+		var/obj/effect/overlay/sparkles/reveal = s
 		reveal.alpha = 255
 	while(active)
-		for(var/obj/item/flashlight/spotlight/glow in spotlights) // The multiples reflects custom adjustments to each colors after dozens of tests
-			if(QDELETED(src) || !active || QDELETED(glow))
+		for(var/g in spotlights) // The multiples reflects custom adjustments to each colors after dozens of tests
+			var/obj/item/flashlight/spotlight/glow = g
+			if(QDELETED(glow))
+				stack_trace("[glow?.gc_destroyed ? "Qdeleting glow" : "null entry"] found in [src].[gc_destroyed ? " Source qdeleting at the time." : ""]")
 				return
-			if(glow.light_color == COLOR_SOFT_RED)
-				glow.set_light_color(LIGHT_COLOR_BLUE)
-				glow.set_light_power(glow.light_power * 1.48)
-				glow.set_light_range(0)
-				glow.update_light()
-				continue
-			if(glow.light_color == LIGHT_COLOR_BLUE)
-				glow.set_light_color(LIGHT_COLOR_GREEN)
-				glow.set_light_range(glow.range * DISCO_INFENO_RANGE)
-				glow.set_light_power(glow.light_power * 2) // Any changes to power must come in pairs to neutralize it for other colors
-				glow.update_light()
-				continue
-			if(glow.light_color == LIGHT_COLOR_GREEN)
-				glow.set_light_color(LIGHT_COLOR_ORANGE)
-				glow.set_light_power(glow.light_power * 0.5)
-				glow.set_light_range(0)
-				glow.update_light()
-				continue
-			if(glow.light_color == LIGHT_COLOR_ORANGE)
-				glow.set_light_color(LIGHT_COLOR_PURPLE)
-				glow.set_light_power(glow.light_power * 2.27)
-				glow.set_light_range(glow.range * DISCO_INFENO_RANGE)
-				glow.update_light()
-				continue
-			if(glow.light_color == LIGHT_COLOR_PURPLE)
-				glow.set_light_color(LIGHT_COLOR_BLUEGREEN)
-				glow.set_light_power(glow.light_power * 0.44)
-				glow.set_light_range(0)
-				glow.update_light()
-				continue
-			if(glow.light_color == LIGHT_COLOR_BLUEGREEN)
-				glow.set_light_color(LIGHT_COLOR_YELLOW)
-				glow.set_light_range(glow.range * DISCO_INFENO_RANGE)
-				glow.update_light()
-				continue
-			if(glow.light_color == LIGHT_COLOR_YELLOW)
-				glow.set_light_color(LIGHT_COLOR_CYAN)
-				glow.set_light_range(0)
-				glow.update_light()
-				continue
-			if(glow.light_color == LIGHT_COLOR_CYAN)
-				glow.set_light_color(COLOR_SOFT_RED)
-				glow.set_light_power(glow.light_power * 0.68)
-				glow.set_light_range(glow.range * DISCO_INFENO_RANGE)
-				glow.update_light()
-				continue
+			switch(glow.light_color)
+				if(COLOR_SOFT_RED)
+					if(glow.even_cycle)
+						glow.set_light_on(FALSE)
+						glow.set_light_color(LIGHT_COLOR_BLUE)
+					else
+						glow.set_light_range_power_color(glow.base_light_range * DISCO_INFENO_RANGE, glow.light_power * 1.48, LIGHT_COLOR_BLUE)
+						glow.set_light_on(TRUE)
+				if(LIGHT_COLOR_BLUE)
+					if(glow.even_cycle)
+						glow.set_light_range_power_color(glow.base_light_range * DISCO_INFENO_RANGE, glow.light_power * 2, LIGHT_COLOR_GREEN)
+						glow.set_light_on(TRUE)
+					else
+						glow.set_light_on(FALSE)
+						glow.set_light_color(LIGHT_COLOR_GREEN)
+				if(LIGHT_COLOR_GREEN)
+					if(glow.even_cycle)
+						glow.set_light_on(FALSE)
+						glow.set_light_color(LIGHT_COLOR_ORANGE)
+					else
+						glow.set_light_range_power_color(glow.base_light_range * DISCO_INFENO_RANGE, glow.light_power * 0.5, LIGHT_COLOR_ORANGE)
+						glow.set_light_on(TRUE)
+				if(LIGHT_COLOR_ORANGE)
+					if(glow.even_cycle)
+						glow.set_light_range_power_color(glow.base_light_range * DISCO_INFENO_RANGE, glow.light_power * 2.27, LIGHT_COLOR_PURPLE)
+						glow.set_light_on(TRUE)
+					else
+						glow.set_light_on(FALSE)
+						glow.set_light_color(LIGHT_COLOR_PURPLE)
+				if(LIGHT_COLOR_PURPLE)
+					if(glow.even_cycle)
+						glow.set_light_on(FALSE)
+						glow.set_light_color(LIGHT_COLOR_BLUEGREEN)
+					else
+						glow.set_light_range_power_color(glow.base_light_range * DISCO_INFENO_RANGE, glow.light_power * 0.44, LIGHT_COLOR_BLUEGREEN)
+						glow.set_light_on(TRUE)
+				if(LIGHT_COLOR_BLUEGREEN)
+					if(glow.even_cycle)
+						glow.set_light_range(glow.base_light_range * DISCO_INFENO_RANGE)
+						glow.set_light_color(LIGHT_COLOR_YELLOW)
+						glow.set_light_on(TRUE)
+					else
+						glow.set_light_on(FALSE)
+						glow.set_light_color(LIGHT_COLOR_YELLOW)
+				if(LIGHT_COLOR_YELLOW)
+					if(glow.even_cycle)
+						glow.set_light_on(FALSE)
+						glow.set_light_color(LIGHT_COLOR_CYAN)
+					else
+						glow.set_light_range(glow.base_light_range * DISCO_INFENO_RANGE)
+						glow.set_light_color(LIGHT_COLOR_CYAN)
+						glow.set_light_on(TRUE)
+				if(LIGHT_COLOR_CYAN)
+					if(glow.even_cycle)
+						glow.set_light_range_power_color(glow.base_light_range * DISCO_INFENO_RANGE, glow.light_power * 0.68, COLOR_SOFT_RED)
+						glow.set_light_on(TRUE)
+					else
+						glow.set_light_on(FALSE)
+						glow.set_light_color(COLOR_SOFT_RED)
+					glow.even_cycle = !glow.even_cycle
 		if(prob(2))  // Unique effects for the dance floor that show up randomly to mix things up
 			INVOKE_ASYNC(src, .proc/hierofunk)
 		sleep(selection.song_beat)
+		if(QDELETED(src))
+			return
 
 #undef DISCO_INFENO_RANGE
 

code/game/machinery/flasher.dm

@@ -25,6 +25,9 @@
 	anchored = FALSE
 	base_state = "pflash"
 	density = TRUE
+	light_system = MOVABLE_LIGHT //Used as a flash here.
+	light_range = FLASH_LIGHT_RANGE
+	light_on = FALSE
 
 /obj/machinery/flasher/Initialize(mapload, ndir = 0, built = 0)
 	. = ..() // ..() is EXTREMELY IMPORTANT, never forget to add it
@@ -35,6 +38,7 @@
 	else
 		bulb = new(src)
 
+
 /obj/machinery/flasher/connect_to_shuttle(obj/docking_port/mobile/port, obj/docking_port/stationary/dock, idnum, override=FALSE)
 	id = "[idnum][id]"
 
@@ -107,7 +111,9 @@
 
 	playsound(src.loc, 'sound/weapons/flash.ogg', 100, TRUE)
 	flick("[base_state]_flash", src)
-	flash_lighting_fx(FLASH_LIGHT_RANGE, light_power, light_color)
+	set_light_on(TRUE)
+	addtimer(CALLBACK(src, .proc/flash_end), FLASH_LIGHT_DURATION, TIMER_OVERRIDE|TIMER_UNIQUE)
+
 	last_flash = world.time
 	use_power(1000)
 
@@ -126,6 +132,10 @@
 	return 1
 
 
+/obj/machinery/flasher/proc/flash_end()
+	set_light_on(FALSE)
+
+
 /obj/machinery/flasher/emp_act(severity)
 	. = ..()
 	if(!(machine_stat & (BROKEN|NOPOWER)) && !(. & EMP_PROTECT_SELF))

code/game/mecha/combat/durand.dm

@@ -13,18 +13,19 @@
 	wreckage = /obj/structure/mecha_wreckage/durand
 	var/obj/durand_shield/shield
 
+
 /obj/mecha/combat/durand/Initialize()
-	shield = new/obj/durand_shield
-	shield.chassis = src
-	shield.layer = layer
+	. = ..()
+	shield = new /obj/durand_shield(loc, src, layer, dir)
 	RegisterSignal(src, COMSIG_MECHA_ACTION_ACTIVATE, .proc/relay)
 	RegisterSignal(src, COMSIG_PROJECTILE_PREHIT, .proc/prehit)
-	. = ..()
+
 
 /obj/mecha/combat/durand/Destroy()
 	if(shield)
-		qdel(shield)
-	. = ..()
+		QDEL_NULL(shield)
+	return ..()
+
 
 /obj/mecha/combat/durand/GrantActions(mob/living/user, human_occupant = 0)
 	..()
@@ -43,7 +44,7 @@
 	. = ..()
 	if(shield)
 		shield.forceMove(loc)
-		shield.dir = dir
+		shield.setDir(dir)
 
 /obj/mecha/combat/durand/forceMove(turf/T)
 	. = ..()
@@ -59,11 +60,9 @@
 	SIGNAL_HANDLER
 
 	if(!shield) //if the shield somehow got deleted
-		shield = new/obj/durand_shield
-		shield.chassis = src
-		shield.layer = layer
-		shield.forceMove(loc)
-	shield.dir = dir
+		stack_trace("Durand triggered relay without a shield")
+		shield = new /obj/durand_shield(loc, src, layer)
+	shield.setDir(dir)
 	SEND_SIGNAL(shield, COMSIG_MECHA_ACTION_ACTIVATE, source, signal_args)
 
 //Redirects projectiles to the shield if defense_check decides they should be blocked and returns true.
@@ -143,17 +142,28 @@ own integrity back to max. Shield is automatically dropped if we run out of powe
 	max_integrity = 10000
 	obj_integrity = 10000
 	anchored = TRUE
+	light_system = MOVABLE_LIGHT
+	light_range = MINIMUM_USEFUL_LIGHT_RANGE
+	light_power = 5
+	light_color = LIGHT_COLOR_ELECTRIC_CYAN
+	light_on = FALSE
 	var/obj/mecha/combat/durand/chassis ///Our link back to the durand
 	var/switching = FALSE ///To keep track of things during the animation
 
-/obj/durand_shield/Initialize()
+
+/obj/durand_shield/Initialize(mapload, _chassis, _layer, _dir)
 	. = ..()
+	chassis = _chassis
+	layer = _layer
+	setDir(_dir)
 	RegisterSignal(src, COMSIG_MECHA_ACTION_ACTIVATE, .proc/activate)
 
+
 /obj/durand_shield/Destroy()
 	if(chassis)
 		chassis.shield = null
-	. = ..()
+		chassis = null
+	return ..()
 
 /**Handles activating and deactivating the shield. This proc is called by a signal sent from the mech's action button
 and relayed by the mech itself. The "forced" variabe, signal_args[1], will skip the to-pilot text and is meant for when
@@ -179,11 +189,12 @@ the shield is disabled by means other than the action button (like running out o
 		chassis.log_message("defense mode state changed -- now [chassis.defense_mode?"enabled":"disabled"].", LOG_MECHA)
 	chassis.defense_action.UpdateButtonIcon()
 
+	set_light_on(chassis.defense_mode)
+
 	if(chassis.defense_mode)
 		invisibility = 0
 		flick("shield_raise", src)
 		playsound(src, 'sound/mecha/mech_shield_raise.ogg', 50, FALSE)
-		set_light(l_range = MINIMUM_USEFUL_LIGHT_RANGE	, l_power = 5, l_color = "#00FFFF")
 		addtimer(CALLBACK(src, .proc/shield_icon_enable), 3)
 	else
 		flick("shield_drop", src)
@@ -195,7 +206,6 @@ the shield is disabled by means other than the action button (like running out o
 	icon_state = "shield"
 
 /obj/durand_shield/proc/shield_icon_reset()
-	set_light(0)
 	icon_state = "shield_null"
 	invisibility = INVISIBILITY_MAXIMUM //no showing on right-click
 

code/game/mecha/mecha.dm

@@ -10,6 +10,8 @@
 	infra_luminosity = 15 //byond implementation is bugged.
 	force = 5
 	flags_1 = HEAR_1
+	light_system = MOVABLE_LIGHT
+	light_on = FALSE
 	var/ruin_mecha = FALSE //if the mecha starts on a ruin, don't automatically give it a tracking beacon to prevent metagaming.
 	var/can_move = 0 //time of next allowed movement
 	var/mob/living/carbon/occupant = null

code/game/mecha/mecha_actions.dm

@@ -112,11 +112,10 @@
 		return
 	chassis.lights = !chassis.lights
 	if(chassis.lights)
-		chassis.set_light(chassis.lights_power)
 		button_icon_state = "mech_lights_on"
 	else
-		chassis.set_light(-chassis.lights_power)
 		button_icon_state = "mech_lights_off"
+	chassis.set_light_on(chassis.lights)
 	chassis.occupant_message("<span class='notice'>Toggled lights [chassis.lights?"on":"off"].</span>")
 	chassis.log_message("Toggled lights [chassis.lights?"on":"off"].", LOG_MECHA)
 	UpdateButtonIcon()

code/game/movable_luminosity.dm

@@ -0,0 +1,19 @@
+///Keeps track of the sources of dynamic luminosity and updates our visibility with the highest.
+/atom/movable/proc/update_dynamic_luminosity()
+	var/highest = 0
+	for(var/i in affected_dynamic_lights)
+		if(affected_dynamic_lights[i] <= highest)
+			continue
+		highest = affected_dynamic_lights[i]
+	if(highest == affecting_dynamic_lumi)
+		return
+	luminosity -= affecting_dynamic_lumi
+	affecting_dynamic_lumi = highest
+	luminosity += affecting_dynamic_lumi
+
+
+///Helper to change several lighting overlay settings.
+/atom/movable/proc/set_light_range_power_color(range, power, color)
+	set_light_range(range)
+	set_light_power(power)
+	set_light_color(color)

code/game/objects/effects/effect_system/effects_sparks.dm

@@ -20,8 +20,9 @@
 	name = "sparks"
 	icon_state = "sparks"
 	anchored = TRUE
-	light_power = 1.3
-	light_range = MINIMUM_USEFUL_LIGHT_RANGE
+	light_system = MOVABLE_LIGHT
+	light_range = 2
+	light_power = 0.5
 	light_color = LIGHT_COLOR_FIRE
 
 /obj/effect/particle_effect/sparks/Initialize()

code/game/objects/effects/misc.dm

@@ -75,13 +75,19 @@
 	name = "lighting fx obj"
 	desc = "Tell a coder if you're seeing this."
 	icon_state = "nothing"
+	light_system = MOVABLE_LIGHT
 	light_range = MINIMUM_USEFUL_LIGHT_RANGE
 	light_color = COLOR_WHITE
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
 
-/obj/effect/dummy/lighting_obj/Initialize(mapload, _color, _range, _power, _duration)
+/obj/effect/dummy/lighting_obj/Initialize(mapload, _range, _power, _color, _duration)
 	. = ..()
-	set_light(_range ? _range : light_range, _power ? _power : light_power, _color ? _color : light_color)
+	if(!isnull(_range))
+		set_light_range(_range)
+	if(!isnull(_power))
+		set_light_power(_power)
+	if(!isnull(_color))
+		set_light_color(_color)
 	if(_duration)
 		QDEL_IN(src, _duration)
 

code/game/objects/effects/overlays.dm

@@ -64,3 +64,14 @@
 
 	layer = ATMOS_GROUP_LAYER
 	plane = ATMOS_GROUP_PLANE
+
+/obj/effect/overlay/light_visible
+	name = ""
+	icon = 'icons/effects/light_overlays/light_32.dmi'
+	icon_state = "light"
+	layer = O_LIGHTING_VISUAL_LAYER
+	plane = O_LIGHTING_VISUAL_PLANE
+	appearance_flags = RESET_COLOR | RESET_ALPHA | RESET_TRANSFORM
+	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	alpha = 0
+	vis_flags = NONE

code/game/objects/items/cigs_lighters.dm

@@ -621,7 +621,11 @@ CIGARETTE PACKETS ARE IN FANCY.DM
 	resistance_flags = FIRE_PROOF
 	grind_results = list(/datum/reagent/iron = 1, /datum/reagent/fuel = 5, /datum/reagent/fuel/oil = 5)
 	custom_price = 55
+	light_system = MOVABLE_LIGHT
+	light_range = 2
+	light_power = 0.6
 	light_color = LIGHT_COLOR_FIRE
+	light_on = FALSE
 	var/lit = 0
 	var/fancy = TRUE
 	var/overlay_state
@@ -667,6 +671,8 @@ CIGARETTE PACKETS ARE IN FANCY.DM
 		. = "<span class='rose'>With a single flick of [user.p_their()] wrist, [user] smoothly lights [A] with [src]. Damn [user.p_theyre()] cool.</span>"
 
 /obj/item/lighter/proc/set_lit(new_lit)
+	if(lit == new_lit)
+		return
 	lit = new_lit
 	if(lit)
 		force = 5
@@ -674,15 +680,14 @@ CIGARETTE PACKETS ARE IN FANCY.DM
 		hitsound = 'sound/items/welder.ogg'
 		attack_verb_continuous = list("burns", "sings")
 		attack_verb_simple = list("burn", "sing")
-		set_light(1)
 		START_PROCESSING(SSobj, src)
 	else
 		hitsound = "swing_hit"
 		force = 0
 		attack_verb_continuous = null //human_defense.dm takes care of it
 		attack_verb_simple = null
-		set_light(0)
 		STOP_PROCESSING(SSobj, src)
+	set_light_on(lit)
 	update_icon()
 
 /obj/item/lighter/extinguish()

code/game/objects/items/devices/PDA/PDA.dm

@@ -26,7 +26,11 @@ GLOBAL_LIST_EMPTY(PDAs)
 	actions_types = list(/datum/action/item_action/toggle_light)
 	armor = list("melee" = 0, "bullet" = 0, "laser" = 0, "energy" = 0, "bomb" = 0, "bio" = 0, "rad" = 0, "fire" = 100, "acid" = 100)
 	resistance_flags = FIRE_PROOF | ACID_PROOF
-
+	light_system = MOVABLE_LIGHT
+	light_range = 2.3
+	light_power = 0.6
+	light_color = "#FFCC66"
+	light_on = FALSE
 
 	//Main variables
 	var/owner = null // String name of owner
@@ -49,8 +53,6 @@ GLOBAL_LIST_EMPTY(PDAs)
 
 	//Secondary variables
 	var/scanmode = PDA_SCANNER_NONE
-	var/fon = FALSE //Is the flashlight function on?
-	var/f_lum = 2.3 //Luminosity for the flashlight function
 	var/silent = FALSE //To beep or not to beep, that is the question
 	var/toff = FALSE //If TRUE, messenger disabled
 	var/tnote = null //Current Texts
@@ -106,8 +108,6 @@ GLOBAL_LIST_EMPTY(PDAs)
 
 /obj/item/pda/Initialize()
 	. = ..()
-	if(fon)
-		set_light(f_lum)
 
 	GLOB.PDAs += src
 	if(default_cartridge)
@@ -175,7 +175,7 @@ GLOBAL_LIST_EMPTY(PDAs)
 	if(inserted_item)
 		overlay.icon_state = "insert_overlay"
 		. += new /mutable_appearance(overlay)
-	if(fon)
+	if(light_on)
 		overlay.icon_state = "light_overlay"
 		. += new /mutable_appearance(overlay)
 	if(pai)
@@ -311,7 +311,7 @@ GLOBAL_LIST_EMPTY(PDAs)
 					if (cartridge.access & CART_DRONEPHONE)
 						dat += "<li><a href='byond://?src=[REF(src)];choice=Drone Phone'>[PDAIMG(dronephone)]Drone Phone</a></li>"
 				dat += "<li><a href='byond://?src=[REF(src)];choice=3'>[PDAIMG(atmos)]Atmospheric Scan</a></li>"
-				dat += "<li><a href='byond://?src=[REF(src)];choice=Light'>[PDAIMG(flashlight)][fon ? "Disable" : "Enable"] Flashlight</a></li>"
+				dat += "<li><a href='byond://?src=[REF(src)];choice=Light'>[PDAIMG(flashlight)][light_on ? "Disable" : "Enable"] Flashlight</a></li>"
 				if (pai)
 					if(pai.loc != src)
 						pai = null
@@ -835,12 +835,10 @@ GLOBAL_LIST_EMPTY(PDAs)
 /obj/item/pda/proc/toggle_light(mob/user)
 	if(issilicon(user) || !user.canUseTopic(src, BE_CLOSE))
 		return
-	if(fon)
-		fon = FALSE
-		set_light(0)
-	else if(f_lum)
-		fon = TRUE
-		set_light(f_lum)
+	if(light_on)
+		set_light_on(FALSE)
+	else if(light_range)
+		set_light_on(TRUE)
 	update_icon()
 	for(var/X in actions)
 		var/datum/action/A = X

code/game/objects/items/devices/PDA/PDA_types.dm

@@ -43,7 +43,7 @@
 /obj/item/pda/ai
 	icon = null
 	ttone = "data"
-	fon = FALSE
+
 
 /obj/item/pda/ai/attack_self(mob/user)
 	if ((honkamt > 0) && (prob(60)))//For clown virus.

code/game/objects/items/devices/flashlight.dm

@@ -13,9 +13,12 @@
 	slot_flags = ITEM_SLOT_BELT
 	custom_materials = list(/datum/material/iron=50, /datum/material/glass=20)
 	actions_types = list(/datum/action/item_action/toggle_light)
+	light_system = MOVABLE_LIGHT
+	light_range = 4
+	light_power = 1
+	light_on = FALSE
 	var/on = FALSE
-	var/brightness_on = 4 //range of light when on
-	var/flashlight_power = 1 //strength of the light when on
+
 
 /obj/item/flashlight/Initialize()
 	. = ..()
@@ -23,16 +26,13 @@
 		on = TRUE
 	update_brightness()
 
-/obj/item/flashlight/proc/update_brightness(mob/user = null)
+/obj/item/flashlight/proc/update_brightness(mob/user)
 	if(on)
 		icon_state = "[initial(icon_state)]-on"
-		if(flashlight_power)
-			set_light(l_range = brightness_on, l_power = flashlight_power)
-		else
-			set_light(brightness_on)
 	else
 		icon_state = initial(icon_state)
-		set_light(0)
+	set_light_on(on)
+
 
 /obj/item/flashlight/attack_self(mob/user)
 	on = !on
@@ -64,7 +64,7 @@
 			to_chat(user, "<span class='warning'>[M] doesn't have a head!</span>")
 			return
 
-		if(flashlight_power < 1)
+		if(light_power < 1)
 			to_chat(user, "<span class='warning'>\The [src] isn't bright enough to see anything!</span> ")
 			return
 
@@ -169,7 +169,7 @@
 	inhand_icon_state = ""
 	worn_icon_state = "pen"
 	flags_1 = CONDUCT_1
-	brightness_on = 2
+	light_range = 2
 	var/holo_cooldown = 0
 
 /obj/item/flashlight/pen/afterattack(atom/target, mob/user, proximity_flag)
@@ -217,7 +217,7 @@
 	lefthand_file = 'icons/mob/inhands/equipment/security_lefthand.dmi'
 	righthand_file = 'icons/mob/inhands/equipment/security_righthand.dmi'
 	force = 9 // Not as good as a stun baton.
-	brightness_on = 5 // A little better than the standard flashlight.
+	light_range = 5 // A little better than the standard flashlight.
 	hitsound = 'sound/weapons/genhit1.ogg'
 
 // the desk lamps are a bit special
@@ -229,7 +229,7 @@
 	lefthand_file = 'icons/mob/inhands/items_lefthand.dmi'
 	righthand_file = 'icons/mob/inhands/items_righthand.dmi'
 	force = 10
-	brightness_on = 5
+	light_range = 5
 	w_class = WEIGHT_CLASS_BULKY
 	flags_1 = CONDUCT_1
 	custom_materials = null
@@ -265,7 +265,7 @@
 	name = "flare"
 	desc = "A red Nanotrasen issued flare. There are instructions on the side, it reads 'pull cord, make light'."
 	w_class = WEIGHT_CLASS_SMALL
-	brightness_on = 7 // Pretty bright.
+	light_range = 7 // Pretty bright.
 	icon_state = "flare"
 	inhand_icon_state = "flare"
 	worn_icon_state = "flare"
@@ -335,7 +335,7 @@
 	name = "torch"
 	desc = "A torch fashioned from some leaves and a log."
 	w_class = WEIGHT_CLASS_BULKY
-	brightness_on = 4
+	light_range = 4
 	icon_state = "torch"
 	inhand_icon_state = "torch"
 	lefthand_file = 'icons/mob/inhands/items_lefthand.dmi'
@@ -351,19 +351,19 @@
 	lefthand_file = 'icons/mob/inhands/equipment/mining_lefthand.dmi'
 	righthand_file = 'icons/mob/inhands/equipment/mining_righthand.dmi'
 	desc = "A mining lantern."
-	brightness_on = 6			// luminosity when on
+	light_range = 6			// luminosity when on
 
 /obj/item/flashlight/lantern/heirloom_moth
 	name = "old lantern"
 	desc = "An old lantern that has seen plenty of use."
-	brightness_on = 4
+	light_range = 4
 
 /obj/item/flashlight/lantern/syndicate
 	name = "suspicious lantern"
 	desc = "A suspicious looking lantern."
 	icon_state = "syndilantern"
 	inhand_icon_state = "syndilantern"
-	brightness_on = 10
+	light_range = 10
 
 /obj/item/flashlight/lantern/jade
 	name = "jade lantern"
@@ -381,7 +381,7 @@
 	w_class = WEIGHT_CLASS_SMALL
 	slot_flags = ITEM_SLOT_BELT
 	custom_materials = null
-	brightness_on = 6 //luminosity when on
+	light_range = 6 //luminosity when on
 
 /obj/item/flashlight/emp
 	var/emp_max_charges = 4
@@ -442,7 +442,7 @@
 	desc = "A military-grade glowstick."
 	custom_price = 50
 	w_class = WEIGHT_CLASS_SMALL
-	brightness_on = 4
+	light_range = 4
 	color = LIGHT_COLOR_GREEN
 	icon_state = "glowstick"
 	inhand_icon_state = "glowstick"
@@ -450,14 +450,17 @@
 	grind_results = list(/datum/reagent/phenol = 15, /datum/reagent/hydrogen = 10, /datum/reagent/oxygen = 5) //Meth-in-a-stick
 	var/fuel = 0
 
+
 /obj/item/flashlight/glowstick/Initialize()
 	fuel = rand(1600, 2000)
 	set_light_color(color)
-	. = ..()
+	return ..()
+
 
 /obj/item/flashlight/glowstick/Destroy()
 	STOP_PROCESSING(SSobj, src)
-	. = ..()
+	return ..()
+
 
 /obj/item/flashlight/glowstick/process()
 	fuel = max(fuel - 1, 0)
@@ -476,13 +479,13 @@
 	if(!fuel)
 		icon_state = "glowstick-empty"
 		cut_overlays()
-		set_light(0)
+		set_light_on(FALSE)
 	else if(on)
 		var/mutable_appearance/glowstick_overlay = mutable_appearance(icon, "glowstick-glow")
 		glowstick_overlay.color = color
 		add_overlay(glowstick_overlay)
 		inhand_icon_state = "glowstick-on"
-		set_light(brightness_on)
+		set_light_on(TRUE)
 	else
 		icon_state = "glowstick"
 		cut_overlays()
@@ -549,30 +552,56 @@
 	name = "disco light"
 	desc = "Groovy..."
 	icon_state = null
-	light_color = COLOR_WHITE
-	brightness_on = 0
-	light_range = 0
+	light_range = 4
 	light_power = 10
 	alpha = 0
 	layer = 0
 	on = TRUE
 	anchored = TRUE
-	var/range = null
 	resistance_flags = INDESTRUCTIBLE | LAVA_PROOF | FIRE_PROOF | UNACIDABLE | ACID_PROOF
+	///Boolean that switches when a full color flip ends, so the light can appear in all colors.
+	var/even_cycle = FALSE
+	///Base light_range that can be set on Initialize to use in smooth light range expansions and contractions.
+	var/base_light_range = 4
+
+
+/obj/item/flashlight/spotlight/Initialize(mapload, _light_range, _light_power, _light_color)
+	. = ..()
+	if(!isnull(_light_range))
+		base_light_range = _light_range
+		set_light_range(_light_range)
+	if(!isnull(_light_power))
+		set_light_power(_light_power)
+	if(!isnull(_light_color))
+		set_light_color(_light_color)
+
 
 /obj/item/flashlight/flashdark
 	name = "flashdark"
 	desc = "A strange device manufactured with mysterious elements that somehow emits darkness. Or maybe it just sucks in light? Nobody knows for sure."
 	icon_state = "flashdark"
 	inhand_icon_state = "flashdark"
-	brightness_on = 2.5
-	flashlight_power = -3
+	light_system = STATIC_LIGHT //The overlay light component is not yet ready to produce darkness.
+	light_range = 0
+	///Variable to preserve old lighting behavior in flashlights, to handle darkness.
+	var/dark_light_range = 2.5
+	///Variable to preserve old lighting behavior in flashlights, to handle darkness.
+	var/dark_light_power = -3
+
+
+/obj/item/flashlight/flashdark/update_brightness(mob/user)
+	. = ..()
+	if(on)
+		set_light(dark_light_range, dark_light_power)
+	else
+		set_light(0)
+
 
 /obj/item/flashlight/eyelight
 	name = "eyelight"
 	desc = "This shouldn't exist outside of someone's head, how are you seeing this?"
-	brightness_on = 15
-	flashlight_power = 1
+	light_range = 15
+	light_power = 1
 	flags_1 = CONDUCT_1
 	item_flags = DROPDEL
 	actions_types = list()

code/game/objects/items/dualsaber.dm

@@ -16,7 +16,10 @@
 	w_class = WEIGHT_CLASS_SMALL
 	hitsound = "swing_hit"
 	armour_penetration = 35
+	light_system = MOVABLE_LIGHT
+	light_range = 6 //TWICE AS BRIGHT AS A REGULAR ESWORD
 	light_color = LIGHT_COLOR_ELECTRIC_GREEN
+	light_on = FALSE
 	attack_verb_continuous = list("attacks", "slashes", "stabs", "slices", "tears", "lacerates", "rips", "dices", "cuts")
 	attack_verb_simple = list("attack", "slash", "stab", "slice", "tear", "lacerate", "rip", "dice", "cut")
 	block_chance = 75
@@ -29,7 +32,6 @@
 	var/saber_color = "green"
 	var/two_hand_force = 34
 	var/hacked = FALSE
-	var/brightness_on = 6 //TWICE AS BRIGHT AS A REGULAR ESWORD
 	var/list/possible_colors = list("red", "blue", "green", "purple")
 	var/wielded = FALSE // track wielded status on item
 
@@ -50,7 +52,8 @@
 	w_class = w_class_on
 	hitsound = 'sound/weapons/blade1.ogg'
 	START_PROCESSING(SSobj, src)
-	set_light(brightness_on)
+	set_light_on(TRUE)
+
 
 /// Triggered on unwield of two handed item
 /// switch hitsounds
@@ -61,7 +64,8 @@
 	w_class = initial(w_class)
 	hitsound = "swing_hit"
 	STOP_PROCESSING(SSobj, src)
-	set_light(0)
+	set_light_on(FALSE)
+
 
 /obj/item/dualsaber/get_sharpness()
 	return wielded * sharpness

code/game/objects/items/flamethrower.dm

@@ -15,6 +15,8 @@
 	custom_materials = list(/datum/material/iron=500)
 	resistance_flags = FIRE_PROOF
 	trigger_guard = TRIGGER_GUARD_NORMAL
+	light_system = MOVABLE_LIGHT
+	light_on = FALSE
 	var/status = FALSE
 	var/lit = FALSE	//on or off
 	var/operating = FALSE//cooldown
@@ -165,16 +167,15 @@
 	to_chat(user, "<span class='notice'>You [lit ? "extinguish" : "ignite"] [src]!</span>")
 	lit = !lit
 	if(lit)
-		set_light(1)
 		playsound(loc, acti_sound, 50, TRUE)
 		START_PROCESSING(SSobj, src)
 		if(!warned_admins)
 			message_admins("[ADMIN_LOOKUPFLW(user)] has lit a flamethrower.")
 			warned_admins = TRUE
 	else
-		set_light(0)
 		playsound(loc, deac_sound, 50, TRUE)
 		STOP_PROCESSING(SSobj,src)
+	set_light_on(lit)
 	update_icon()
 
 /obj/item/flamethrower/CheckParts(list/parts_list)

code/game/objects/items/grenades/flashbang.dm

@@ -14,7 +14,7 @@
 		return
 	do_sparks(rand(5, 9), FALSE, src)
 	playsound(flashbang_turf, 'sound/weapons/flashbang.ogg', 100, TRUE, 8, 0.9)
-	new /obj/effect/dummy/lighting_obj (flashbang_turf, COLOR_WHITE, (flashbang_range + 2), 4, 2)
+	new /obj/effect/dummy/lighting_obj (flashbang_turf, flashbang_range + 2, 4, COLOR_WHITE, 2)
 	for(var/mob/living/M in get_hearers_in_view(flashbang_range, flashbang_turf))
 		bang(get_turf(M), M)
 	qdel(src)
@@ -82,7 +82,7 @@
 		return
 	do_sparks(rand(5, 9), FALSE, src)
 	playsound(flashbang_turf, 'sound/weapons/flashbang.ogg', 50, TRUE, 8, 0.9)
-	new /obj/effect/dummy/lighting_obj (flashbang_turf, COLOR_WHITE, (flashbang_range + 2), 2, 1)
+	new /obj/effect/dummy/lighting_obj (flashbang_turf, flashbang_range + 2, 2, COLOR_WHITE, 1)
 	for(var/mob/living/M in get_hearers_in_view(flashbang_range, flashbang_turf))
 		pop(get_turf(M), M)
 	qdel(src)

code/game/objects/items/grenades/hypno.dm

@@ -15,7 +15,7 @@
 		return
 	do_sparks(rand(5, 9), FALSE, src)
 	playsound(flashbang_turf, 'sound/effects/screech.ogg', 100, TRUE, 8, 0.9)
-	new /obj/effect/dummy/lighting_obj (flashbang_turf, LIGHT_COLOR_PURPLE, (flashbang_range + 2), 4, 2)
+	new /obj/effect/dummy/lighting_obj (flashbang_turf, flashbang_range + 2, 4, LIGHT_COLOR_PURPLE, 2)
 	for(var/mob/living/M in get_hearers_in_view(flashbang_range, flashbang_turf))
 		bang(get_turf(M), M)
 	qdel(src)

code/game/objects/items/melee/energy.dm

@@ -5,13 +5,15 @@
 	max_integrity = 200
 	armor = list("melee" = 0, "bullet" = 0, "laser" = 0, "energy" = 0, "bomb" = 0, "bio" = 0, "rad" = 0, "fire" = 100, "acid" = 30)
 	resistance_flags = FIRE_PROOF
-	var/brightness_on = 3
+	light_system = MOVABLE_LIGHT
+	light_range = 3
+	light_power = 1
+	light_on = FALSE
 	var/sword_color
 
 /obj/item/melee/transforming/energy/Initialize()
 	. = ..()
 	if(active)
-		set_light(brightness_on)
 		START_PROCESSING(SSobj, src)
 
 /obj/item/melee/transforming/energy/Destroy()
@@ -40,10 +42,10 @@
 			if(sword_color)
 				icon_state = "sword[sword_color]"
 			START_PROCESSING(SSobj, src)
-			set_light(brightness_on)
 		else
 			STOP_PROCESSING(SSobj, src)
-			set_light(0)
+		set_light_on(active)
+
 
 /obj/item/melee/transforming/energy/get_temperature()
 	return active * heat
@@ -167,7 +169,6 @@
 	if(hacked)
 		var/set_color = pick(possible_colors)
 		set_light_color(possible_colors[set_color])
-		update_light()
 
 /obj/item/melee/transforming/energy/sword/saber/red
 	possible_colors = list("red" = COLOR_SOFT_RED)

code/game/objects/items/pitchfork.dm

@@ -45,10 +45,11 @@
 	desc = "A red pitchfork, it looks like the work of the devil."
 	force = 19
 	throwforce = 24
+	light_system = MOVABLE_LIGHT
+	light_range = 3
+	light_power = 6
+	light_color = COLOR_SOFT_RED
 
-/obj/item/pitchfork/demonic/Initialize()
-	. = ..()
-	set_light(3,6,COLOR_SOFT_RED)
 
 /obj/item/pitchfork/demonic/ComponentInitialize()
 	. = ..()

code/game/objects/items/tools/weldingtool.dm

@@ -16,7 +16,11 @@
 	usesound = list('sound/items/welder.ogg', 'sound/items/welder2.ogg')
 	drop_sound = 'sound/items/handling/weldingtool_drop.ogg'
 	pickup_sound =  'sound/items/handling/weldingtool_pickup.ogg'
+	light_system = MOVABLE_LIGHT
+	light_range = 2
+	light_power = 0.75
 	light_color = LIGHT_COLOR_FIRE
+	light_on = FALSE
 	throw_speed = 3
 	throw_range = 5
 	w_class = WEIGHT_CLASS_SMALL
@@ -28,12 +32,12 @@
 	wound_bonus = 10
 	bare_wound_bonus = 15
 	custom_materials = list(/datum/material/iron=70, /datum/material/glass=30)
-	var/welding = 0 	//Whether or not the welding tool is off(0), on(1) or currently welding(2)
+	///Whether the welding tool is on or off.
+	var/welding = FALSE
 	var/status = TRUE 		//Whether the welder is secured or unsecured (able to attach rods to it to make a flamethrower)
 	var/max_fuel = 20 	//The max amount of fuel the welder can hold
 	var/change_icons = 1
 	var/can_off_process = 0
-	var/light_intensity = 2 //how powerful the emitted light is when used.
 	var/burned_fuel_for = 0	//when fuel was last removed
 	var/acti_sound = 'sound/items/welderactivate.ogg'
 	var/deac_sound = 'sound/items/welderdeactivate.ogg'
@@ -47,7 +51,7 @@
 /obj/item/weldingtool/ComponentInitialize()
 	. = ..()
 	AddElement(/datum/element/update_icon_updates_onmob)
-	AddElement(/datum/element/tool_flash, light_intensity)
+	AddElement(/datum/element/tool_flash, light_range)
 
 /obj/item/weldingtool/update_icon_state()
 	if(welding)
@@ -158,16 +162,16 @@
 				message_admins("[ADMIN_LOOKUPFLW(user)] set [key_name_admin(L)] on fire with [src] at [AREACOORD(user)]")
 				log_game("[key_name(user)] set [key_name(L)] on fire with [src] at [AREACOORD(user)]")
 
+
 /obj/item/weldingtool/attack_self(mob/user)
 	if(src.reagents.has_reagent(/datum/reagent/toxin/plasma))
 		message_admins("[ADMIN_LOOKUPFLW(user)] activated a rigged welder at [AREACOORD(user)].")
 		explode()
 	switched_on(user)
-	if(welding)
-		set_light(light_intensity)
 
 	update_icon()
 
+
 // Ah fuck, I can't believe you've done this
 /obj/item/weldingtool/proc/handle_fuel_and_temps(used = 0, mob/living/user)
 	use(used)
@@ -194,10 +198,19 @@
 		return FALSE
 
 
+//Toggles the welding value.
+/obj/item/weldingtool/proc/set_welding(new_value)
+	if(welding == new_value)
+		return
+	. = welding
+	welding = new_value
+	set_light_on(welding)
+
+
 //Turns off the welder if there is no more fuel (does this really need to be its own proc?)
 /obj/item/weldingtool/proc/check_fuel(mob/user)
 	if(get_fuel() <= 0 && welding)
-		set_light(0)
+		set_light_on(FALSE)
 		switched_on(user)
 		update_icon()
 		return 0
@@ -208,7 +221,7 @@
 	if(!status)
 		to_chat(user, "<span class='warning'>[src] can't be turned on while unsecured!</span>")
 		return
-	welding = !welding
+	set_welding(!welding)
 	if(welding)
 		if(get_fuel() >= 1)
 			to_chat(user, "<span class='notice'>You switch [src] on.</span>")
@@ -228,8 +241,7 @@
 
 //Switches the welder off
 /obj/item/weldingtool/proc/switched_off(mob/user)
-	welding = 0
-	set_light(0)
+	set_welding(FALSE)
 
 	force = 3
 	damtype = "brute"
@@ -335,7 +347,8 @@
 	icon = 'icons/obj/abductor.dmi'
 	icon_state = "welder"
 	toolspeed = 0.1
-	light_intensity = 0
+	light_system = NO_LIGHT_SUPPORT
+	light_range = 0
 	change_icons = 0
 
 /obj/item/weldingtool/abductor/process()
@@ -360,7 +373,7 @@
 	custom_materials = list(/datum/material/iron=70, /datum/material/glass=120)
 	change_icons = 0
 	can_off_process = 1
-	light_intensity = 1
+	light_range = 1
 	toolspeed = 0.5
 	var/last_gen = 0
 	var/nextrefueltick = 0

code/game/turfs/open/space/space.dm

@@ -57,7 +57,7 @@
 	if(requires_activation)
 		SSair.add_to_active(src)
 
-	if (light_power && light_range)
+	if (light_system == STATIC_LIGHT && light_power && light_range)
 		update_light()
 
 	if (opacity)

code/game/turfs/turf.dm

@@ -38,6 +38,9 @@ GLOBAL_LIST_EMPTY(station_turfs)
 	///Icon-smoothing variable to map a diagonal wall corner with a fixed underlay.
 	var/list/fixed_underlay = null
 
+	///Lumcount added by sources other than lighting datum objects, such as the overlay lighting component.
+	var/dynamic_lumcount = 0
+
 	var/dynamic_lighting = TRUE
 
 	var/tmp/lighting_corners_initialised = FALSE

code/modules/antagonists/cult/blood_magic.dm

@@ -421,12 +421,12 @@
 		user.visible_message("<span class='warning'>[user] holds up [user.p_their()] hand, which explodes in a flash of red light!</span>", \
 							"<span class='cultitalic'>You attempt to stun [L] with the spell!</span>")
 
-		user.mob_light(_color = LIGHT_COLOR_BLOOD_MAGIC, _range = 3, _duration = 2)
+		user.mob_light(_range = 3, _color = LIGHT_COLOR_BLOOD_MAGIC, _duration = 0.2 SECONDS)
 
 		var/anti_magic_source = L.anti_magic_check()
 		if(anti_magic_source)