gods all seeing eye gazes down at me

code/__DEFINES/colors.dm

@@ -258,6 +258,7 @@
 #define DEFAULT_HEX_COLOR_LEN 6
 
 // Color filters
+#define CHECK_LIGHT_OCCLUSION(turf) (turf.directional_opacity || turf.opacity)
 /// Icon filter that creates ambient occlusion
 #define AMBIENT_OCCLUSION filter(type="drop_shadow", x=0, y=-2, size=4, color="#04080FAA")
 /// Icon filter that creates gaussian blur

code/__DEFINES/layers.dm

@@ -28,6 +28,7 @@
 #define FLOOR_PLANE -11
 
 #define WALL_PLANE -10
+#define WALL_RENDER_TARGET "*WALL_PLANE" //monkestation edit
 #define GAME_PLANE -9
 #define GAME_PLANE_FOV_HIDDEN -8
 #define GAME_PLANE_UPPER -7
@@ -85,6 +86,9 @@
 
 ///---------------- MISC -----------------------
 
+/// Shadowcasting
+#define SHADOWCASTING_PLANE 18 // monkestation edit
+
 ///Pipecrawling images
 #define PIPECRAWL_IMAGES_PLANE 20
 

code/__DEFINES/subsystems.dm

@@ -179,7 +179,8 @@
 #define INIT_ORDER_STICKY_BAN -10
 #define INIT_ORDER_LIGHTING -20
 #define INIT_ORDER_OUTDOOR_EFFECTS -21 //monkestation addition
-#define INIT_ORDER_SHUTTLE -22 //monkestation edit -21 > -22
+#define INIT_ORDER_SHADOWCASTING -22 // monkestation addition
+#define INIT_ORDER_SHUTTLE -23 //monkestation edit -21 > -23
 #define INIT_ORDER_MINOR_MAPPING -40
 #define INIT_ORDER_PATH -50
 #define INIT_ORDER_EXPLOSIONS -69

code/__HELPERS/~monkestation-helpers/triangles.dm

@@ -0,0 +1,23 @@
+/// A list that caches base appearances of triangles for later access.
+GLOBAL_LIST_EMPTY(triangle_appearances)
+
+/// Returns a mutable appearance of a triangle of the given points, and caches it for later use
+/proc/get_triangle_appearance(x1,y1, x2,y2, x3,y3, icon_size = 32, icon = 'monkestation/code/modules/shadowcasting/icons/geometric.dmi', icon_state = "triangle")
+	var/key = "[x1]_[y2]_[x2]_[y2]_[x3]_[y3]_[icon_size]_[icon]_[icon_state]"
+	if(GLOB.triangle_appearances[key])
+		return GLOB.triangle_appearances[key]
+	var/mutable_appearance/triangle_appearance = mutable_appearance(icon, icon_state)
+	triangle_appearance.transform = transform_triangle(x1,y1, x2,y2, x3,y3, icon_size)
+	GLOB.triangle_appearances[key] = triangle_appearance
+	return triangle_appearance
+
+/// Returns a matrix which when applied to a proper triangle image, creates an arbitrary triangle
+/proc/transform_triangle(x1, y1, x2, y2, x3, y3, icon_size = 32)
+	var/i = 1/icon_size
+	var/a = (x3*i)-(x2*i)
+	var/b = -(x2*i)+(x1*i)
+	var/c = (x3*0.5)+(x1*0.5)
+	var/d = (y1*i)-(y2*i)
+	var/e = -(y2*i)+(y3*i)
+	var/f = (y1*0.5)+(y3*0.5)
+	return matrix(a,b,c,e,d,f)

code/_onclick/hud/rendering/plane_master.dm

@@ -368,6 +368,7 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 	name = "Wall"
 	documentation = "Holds all walls. We render this onto the game world. Separate so we can use this + space and floor planes as a guide for where byond blackness is NOT."
 	plane = WALL_PLANE
+	render_target = WALL_RENDER_TARGET // monkestation edit
 	render_relay_planes = list(RENDER_PLANE_GAME_WORLD, LIGHT_MASK_PLANE)
 
 /atom/movable/screen/plane_master/wall/Initialize(mapload, datum/plane_master_group/home, offset)
@@ -660,3 +661,19 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 	appearance_flags = PLANE_MASTER|NO_CLIENT_COLOR
 	render_relay_planes = list(RENDER_PLANE_MASTER)
 	allows_offsetting = FALSE
+
+/atom/movable/screen/plane_master/shadowcasting
+	name = "Shadowcasting"
+	documentation = "Holds shadowcasting images so you can see fancy shadows where your vision can't reach."
+	plane = SHADOWCASTING_PLANE
+	appearance_flags = PLANE_MASTER|NO_CLIENT_COLOR
+	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	start_hidden = TRUE
+
+/atom/movable/screen/plane_master/shadowcasting/show_to(mob/mymob)
+	. = ..()
+	alpha = 96
+	add_filter("wall_mask", 1, alpha_mask_filter(render_source = OFFSET_RENDER_TARGET(WALL_RENDER_TARGET, offset), flags = MASK_INVERSE))
+	var/blurriness = 3
+	add_filter("blur", 2, gauss_blur_filter(size = blurriness))
+

code/datums/components/chasm.dm

@@ -8,6 +8,7 @@
 	/// List of refs to falling objects -> how many levels deep we've fallen
 	var/static/list/falling_atoms = list()
 	var/static/list/forbidden_types = typecacheof(list(
+		/atom/movable/shadowcasting_holder,
 		/obj/singularity,
 		/obj/energy_ball,
 		/obj/narsie,

code/game/turfs/change_turf.dm

@@ -6,7 +6,7 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 
 /turf/proc/empty(turf_type=/turf/open/space, baseturf_type, list/ignore_typecache, flags)
 	// Remove all atoms except observers, landmarks, docking ports
-	var/static/list/ignored_atoms = typecacheof(list(/mob/dead, /obj/effect/landmark, /obj/docking_port))
+	var/static/list/ignored_atoms = typecacheof(list(/atom/movable/shadowcasting_holder, /mob/dead, /obj/effect/landmark, /obj/docking_port))
 	var/list/allowed_contents = typecache_filter_list_reverse(get_all_contents_ignoring(ignore_typecache), ignored_atoms)
 	allowed_contents -= src
 	for(var/i in 1 to allowed_contents.len)

code/game/turfs/turf.dm

@@ -72,6 +72,9 @@ GLOBAL_LIST_EMPTY(station_turfs)
 	///Lazylist of movable atoms providing opacity sources.
 	var/list/atom/movable/opacity_sources
 
+	///Image used for shadowcasting
+	var/image/shadowcasting_image
+
 	///the holodeck can load onto this turf if TRUE
 	var/holodeck_compatible = FALSE
 

code/modules/lighting/lighting_turf.dm

@@ -129,6 +129,11 @@
 	if(!new_area.lighting_effects && old_area.lighting_effects && space_lit)
 		overlays += GLOB.fullbright_overlays[GET_TURF_PLANE_OFFSET(src) + 1]
 
+	//This, is also very expensive
+	for(var/turf/turf in range(world.view, src))
+		turf.check_shadowcasting_update()
+
+
 /turf/proc/generate_missing_corners()
 	if (!lighting_corner_NE)
 		lighting_corner_NE = new/datum/lighting_corner(src, NORTH|EAST)

code/modules/mob/living/living_defines.dm

@@ -3,6 +3,8 @@
 	hud_possible = list(HEALTH_HUD,STATUS_HUD,ANTAG_HUD,NANITE_HUD,DIAG_NANITE_FULL_HUD)
 	pressure_resistance = 10
 
+	shadow_caster = TRUE
+
 	hud_type = /datum/hud/living
 
 	///Badminnery resize

code/modules/mob/login.dm

@@ -124,6 +124,8 @@
 	SEND_SIGNAL(client, COMSIG_CLIENT_MOB_LOGIN, src)
 	client.init_verbs()
 
+	update_shadowcasting()
+
 	AddElement(/datum/element/weather_listener, /datum/weather/ash_storm, ZTRAIT_ASHSTORM, GLOB.ash_storm_sounds)
 
 	SEND_GLOBAL_SIGNAL(COMSIG_GLOB_MOB_LOGGED_IN, src)

code/modules/mob/mob.dm

@@ -102,6 +102,7 @@
 	initialize_actionspeed()
 	update_movespeed(TRUE)
 	become_hearing_sensitive()
+	update_shadowcasting()
 	log_mob_tag("CREATED: [key_name(src)] \[[type]\]")
 
 /**

monkestation/code/modules/shadowcasting/__shadow_vars.dm

@@ -0,0 +1,15 @@
+/mob
+	///Should the mob use the shadowcasting component when a client is logged to it?
+	var/shadow_caster = FALSE
+
+
+/mob/proc/update_shadowcasting()
+	if(!shadow_caster || !client)
+		return
+	for(var/atom/movable/screen/plane_master/plane_master as anything in hud_used.get_true_plane_masters(SHADOWCASTING_PLANE))
+		plane_master.alpha = 96
+	for(var/atom/movable/screen/plane_master/plane_master as anything in hud_used.get_true_plane_masters(SHADOWCASTING_PLANE))
+		plane_master.add_filter("blur", 2, gauss_blur_filter(size = 3))
+	var/datum/component/shadowcasting = GetComponent(/datum/component/shadowcasting)
+	if(!shadowcasting)
+		AddComponent(/datum/component/shadowcasting)

monkestation/code/modules/shadowcasting/_shadow_controller.dm

@@ -0,0 +1,42 @@
+/**
+ * This subsystem updates shadowcasting overlays for updates not caused by mob movement.
+ */
+SUBSYSTEM_DEF(shadowcasting)
+	name = "Shadowcasting"
+	wait = 2
+	init_order = INIT_ORDER_SHADOWCASTING
+	flags = SS_TICKER
+	var/static/list/turf/turf_queue = list()
+
+/datum/controller/subsystem/shadowcasting/stat_entry(msg)
+	msg = "T:[length(turf_queue)]|"
+	return ..()
+
+/datum/controller/subsystem/shadowcasting/Initialize()
+	fire(FALSE, TRUE)
+	initialized = TRUE
+
+	return SS_INIT_SUCCESS
+
+/datum/controller/subsystem/shadowcasting/fire(resumed, init_tick_checks)
+	MC_SPLIT_TICK_INIT(3)
+	if(!init_tick_checks)
+		MC_SPLIT_TICK
+
+	var/list/queue = turf_queue
+	var/i = 0
+	for (i in 1 to length(queue))
+		var/turf/shadow_source = queue[i]
+
+		shadow_source.update_shadowcasting()
+
+		if(init_tick_checks)
+			CHECK_TICK
+		else if (MC_TICK_CHECK)
+			break
+	if (i)
+		queue.Cut(1, i+1)
+
+/datum/controller/subsystem/shadowcasting/Recover()
+	initialized = SSshadowcasting.initialized
+	return ..()

monkestation/code/modules/shadowcasting/shadow_component.dm

@@ -0,0 +1,95 @@
+// lots of ctrl c ctrl v from fov component no fucks given
+/datum/component/shadowcasting
+	/// Whether we are applying the masks now or not
+	var/applied_shadow = FALSE
+	/// Atom that shows shadowcasting overlays
+	var/atom/movable/shadowcasting_holder/visual_shadow
+
+/datum/component/shadowcasting/Initialize()
+	. = ..()
+	if(!ismob(parent))
+		return COMPONENT_INCOMPATIBLE
+	var/mob/mob_parent = parent
+	var/client/parent_client = mob_parent.client
+	if(!parent_client) //Love client volatility!!
+		qdel(src) //no QDEL hint for components, and we dont want this to print a warning regarding bad component application
+		return
+
+	for(var/atom/movable/screen/plane_master/plane_master as anything in mob_parent.hud_used.get_true_plane_masters(SHADOWCASTING_PLANE))
+		plane_master.unhide_plane(mob_parent)
+
+	visual_shadow = new
+	update_shadow()
+
+/datum/component/shadowcasting/RegisterWithParent()
+	. = ..()
+	RegisterSignal(parent, COMSIG_MOVABLE_MOVED, PROC_REF(update_shadow))
+	RegisterSignal(parent, COMSIG_MOB_RESET_PERSPECTIVE, PROC_REF(update_shadow))
+	RegisterSignal(parent, COMSIG_MOB_SIGHT_CHANGE, PROC_REF(update_shadow))
+	RegisterSignal(parent, COMSIG_MOB_LOGOUT, PROC_REF(mob_logout))
+
+/datum/component/shadowcasting/UnregisterFromParent()
+	. = ..()
+	UnregisterSignal(parent, list(
+		COMSIG_MOVABLE_MOVED,
+		COMSIG_MOB_RESET_PERSPECTIVE,
+		COMSIG_MOB_SIGHT_CHANGE,
+		COMSIG_MOB_LOGOUT,
+	))
+
+/datum/component/shadowcasting/Destroy(force, silent)
+	var/mob/living/mob_parent = parent
+	for(var/atom/movable/screen/plane_master/plane_master as anything in mob_parent.hud_used.get_true_plane_masters(SHADOWCASTING_PLANE))
+		plane_master.hide_plane(mob_parent)
+
+	if(applied_shadow)
+		remove_shadow()
+	if(visual_shadow)
+		QDEL_NULL(visual_shadow)
+	return ..()
+
+/datum/component/shadowcasting/proc/update_shadow()
+	SIGNAL_HANDLER
+	var/mob/living/parent_mob = parent
+	var/client/parent_client = parent_mob.client
+	if(!parent_client) //Love client volatility!!
+		return
+
+	var/user_turf = get_turf(parent_mob)
+	var/atom/top_most_atom = get_atom_on_turf(parent_mob)
+	var/user_extends_eye = parent_client.eye != top_most_atom
+	var/user_sees_turfs = parent_mob.sight & SEE_TURFS
+	var/user_blind = parent_mob.sight & BLIND
+
+	var/should_apply_mask = user_turf && !user_extends_eye && !user_sees_turfs && !user_blind
+	if(should_apply_mask)
+		add_shadow(user_turf)
+	else
+		remove_shadow()
+
+/datum/component/shadowcasting/proc/add_shadow(turf/mob_turf)
+	var/mob/parent_mob = parent
+	var/client/parent_client = parent_mob.client
+	if(!parent_client) //Love client volatility!!
+		return
+	applied_shadow = TRUE
+	if(!mob_turf.shadowcasting_image)
+		mob_turf.update_shadowcasting_image()
+	visual_shadow.reflector.overlays = null
+	visual_shadow.reflector.overlays += mob_turf.shadowcasting_image
+	visual_shadow.loc = get_turf(parent_mob)
+	parent_client.images |= visual_shadow.reflector
+
+/datum/component/shadowcasting/proc/remove_shadow()
+	var/mob/parent_mob = parent
+	var/client/parent_client = parent_mob.client
+	if(!parent_client) //Love client volatility!!
+		return
+	applied_shadow = FALSE
+	visual_shadow.moveToNullspace()
+	parent_client.images -= visual_shadow.reflector
+
+/// When a mob logs out, delete the component
+/datum/component/shadowcasting/proc/mob_logout(mob/source)
+	SIGNAL_HANDLER
+	qdel(src)

monkestation/code/modules/shadowcasting/shadow_holder.dm

@@ -0,0 +1,18 @@
+/atom/movable/shadowcasting_holder
+	appearance_flags = KEEP_TOGETHER|TILE_BOUND|PIXEL_SCALE|LONG_GLIDE
+	plane = SHADOWCASTING_PLANE
+	animate_movement = NO_STEPS
+	invisibility = INVISIBILITY_LIGHTING
+	anchored = TRUE
+	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	var/image/reflector
+
+/atom/movable/shadowcasting_holder/Initialize(mapload)
+	. = ..()
+	reflector = new()
+	reflector.override = TRUE
+	reflector.loc = src
+
+/atom/movable/shadowcasting_holder/Destroy(force)
+	. = ..()
+	reflector = null