Refactor area and turf lighting (#60954)

code/modules/lighting/lighting_area.dm

@@ -1,32 +1,59 @@
 /area
-	luminosity = TRUE
-	var/dynamic_lighting = DYNAMIC_LIGHTING_ENABLED
+	luminosity = 1
+	///The mutable appearance we underlay to show light
+	var/mutable_appearance/lighting_effect = null
+	///Whether this area has a currently active base lighting, bool
+	var/area_has_base_lighting = FALSE
+	///alpha 0-255 of lighting_effect and thus baselighting intensity
+	var/base_lighting_alpha = 0
+	///The colour of the light acting on this area
+	var/base_lighting_color = null
 
-/area/proc/set_dynamic_lighting(new_dynamic_lighting = DYNAMIC_LIGHTING_ENABLED)
-	if (new_dynamic_lighting == dynamic_lighting)
+/area/proc/set_base_lighting(new_base_lighting_color = -1, new_alpha = -1)
+	if(base_lighting_alpha == new_alpha && base_lighting_color == new_base_lighting_color)
 		return FALSE
-
-	dynamic_lighting = new_dynamic_lighting
-
-	if (IS_DYNAMIC_LIGHTING(src))
-		cut_overlay(/obj/effect/fullbright)
-		blend_mode = BLEND_DEFAULT
-		for (var/turf/T in src)
-			if (IS_DYNAMIC_LIGHTING(T))
-				T.lighting_build_overlay()
-
-	else
-		add_overlay(/obj/effect/fullbright)
-		blend_mode = BLEND_MULTIPLY
-		for (var/turf/T in src)
-			if (T.lighting_object)
-				T.lighting_clear_overlay()
-
+	if(new_alpha != -1)
+		base_lighting_alpha = new_alpha
+	if(new_base_lighting_color != -1)
+		base_lighting_color = new_base_lighting_color
+	update_base_lighting()
 	return TRUE
 
 /area/vv_edit_var(var_name, var_value)
 	switch(var_name)
-		if(NAMEOF(src, dynamic_lighting))
-			set_dynamic_lighting(var_value)
+		if("base_lighting_color")
+			set_base_lighting(new_base_lighting_color = var_value)
+			return TRUE
+		if("base_lighting_alpha")
+			set_base_lighting(new_alpha = var_value)
 			return TRUE
 	return ..()
+
+/area/proc/update_base_lighting()
+	if(!area_has_base_lighting && (!base_lighting_alpha || !base_lighting_color))
+		return
+
+	if(!area_has_base_lighting)
+		add_base_lighting()
+		return
+	remove_base_lighting()
+	if(base_lighting_alpha && base_lighting_color)
+		add_base_lighting()
+
+/area/proc/remove_base_lighting()
+	for(var/turf/T in src)
+		T.cut_overlay(lighting_effect)
+	QDEL_NULL(lighting_effect)
+	area_has_base_lighting = FALSE
+
+/area/proc/add_base_lighting()
+	lighting_effect = mutable_appearance('icons/effects/alphacolors.dmi', "white")
+	lighting_effect.plane = LIGHTING_PLANE
+	lighting_effect.layer = LIGHTING_PRIMARY_LAYER
+	lighting_effect.blend_mode = BLEND_ADD
+	lighting_effect.alpha = base_lighting_alpha
+	lighting_effect.color = base_lighting_color
+	for(var/turf/T in src)
+		T.add_overlay(lighting_effect)
+		T.luminosity = 1
+	area_has_base_lighting = TRUE

code/modules/lighting/lighting_setup.dm

@@ -1,14 +1,12 @@
 
 /proc/create_all_lighting_objects()
 	for(var/area/A in world)
-		if(!IS_DYNAMIC_LIGHTING(A))
+		if(!A.static_lighting)
 			continue
 
 		for(var/turf/T in A)
-
-			if(!IS_DYNAMIC_LIGHTING(T))
+			if(T.always_lit)
 				continue
-
 			new/datum/lighting_object(T)
 			CHECK_TICK
 		CHECK_TICK

code/modules/lighting/lighting_turf.dm

@@ -15,7 +15,7 @@
 		qdel(lighting_object, force=TRUE) //Shitty fix for lighting objects persisting after death
 
 	var/area/our_area = loc
-	if (!IS_DYNAMIC_LIGHTING(our_area) && !light_sources)
+	if (!our_area.static_lighting && !light_sources)
 		return
 
 	new/datum/lighting_object(src)
@@ -97,11 +97,16 @@
 
 /turf/proc/change_area(area/old_area, area/new_area)
 	if(SSlighting.initialized)
-		if (new_area.dynamic_lighting != old_area.dynamic_lighting)
-			if (new_area.dynamic_lighting)
+		if (new_area.static_lighting != old_area.static_lighting)
+			if (new_area.static_lighting)
 				lighting_build_overlay()
 			else
 				lighting_clear_overlay()
+	//Inherit overlay of new area
+	if(old_area.lighting_effect)
+		cut_overlay(old_area.lighting_effect)
+	if(new_area.lighting_effect)
+		add_overlay(new_area.lighting_effect)
 
 /turf/proc/generate_missing_corners()
 	if (!lighting_corner_NE)

code/modules/lighting/static_lighting_area.dm

@@ -0,0 +1,17 @@
+
+GLOBAL_DATUM_INIT(fullbright_overlay, /mutable_appearance, create_fullbright_overlay())
+
+/proc/create_fullbright_overlay()
+	var/mutable_appearance/lighting_effect = mutable_appearance('icons/effects/alphacolors.dmi', "white")
+	lighting_effect.plane = LIGHTING_PLANE
+	lighting_effect.layer = LIGHTING_PRIMARY_LAYER
+	lighting_effect.blend_mode = BLEND_ADD
+	return lighting_effect
+
+/area
+	///Whether this area allows static lighting and thus loads the lighting objects
+	var/static_lighting = TRUE
+
+//Non static lighting areas.
+//Any lighting area that wont support static lights.
+//These areas will NOT have corners generated.