Ports new zmimic changes/bugfixes/etc from Bay/Nebula. (#14495)

code/controllers/subsystems/zcopy.dm

@@ -2,6 +2,7 @@
 #define OPENTURF_CAP_PLANE -70      // The multiplier goes here so it'll be on top of every other overlay.
 #define OPENTURF_MAX_DEPTH 10		// The maxiumum number of planes deep we'll go before we just dump everything on the same plane.
 #define SHADOWER_DARKENING_FACTOR 0.85	// The multiplication factor for openturf shadower darkness. Lighting will be multiplied by this.
+#define SHADOWER_DARKENING_COLOR "#999999"	// The above, but as an RGB string for lighting-less turfs.
 
 /var/datum/controller/subsystem/zcopy/SSzcopy
 
@@ -17,80 +18,118 @@
 	var/list/queued_overlays = list()
 	var/qo_idex = 1
 
-	var/list/openspace_overlays = list()
-	var/list/openspace_turfs = list()
+	var/openspace_overlays = 0
+	var/openspace_turfs = 0
 
-	var/starlight_enabled = FALSE
+	var/multiqueue_skips_turf = 0
+	var/multiqueue_skips_object = 0
+
+	// Highest Z level in a given Z-group for absolute layering.
+	// zstm[zlev] = group_max
+	var/list/zlev_maximums = list()
 
 /datum/controller/subsystem/zcopy/New()
 	NEW_SS_GLOBAL(SSzcopy)
 
+// for admin proc-call
 /datum/controller/subsystem/zcopy/proc/update_all()
 	disable()
-	for (var/thing in openspace_overlays)
-		var/atom/movable/AM = thing
+	log_debug("SSzcopy: update_all() invoked.")
 
-		var/turf/T = get_turf(AM)
-		if (TURF_IS_MIMICING(T))
-			if (!(T.flags & MIMIC_QUEUED))
+	var/turf/T 	// putting the declaration up here totally speeds it up, right?
+	var/num_upd = 0
+	var/num_del = 0
+	var/num_amupd = 0
+	for (var/atom/A in world)
+		if (isturf(A))
+			T = A
+			if (T.z_flags & ZM_MIMIC_BELOW)
 				T.update_mimic()
-		else
-			qdel(AM)
+				num_upd += 1
+
+		else if (istype(A, /atom/movable/openspace/mimic))
+			var/turf/Tloc = A.loc
+			if (TURF_IS_MIMICING(Tloc))
+				Tloc.update_mimic()
+				num_amupd += 1
+			else
+				qdel(A)
+				num_del += 1
 
 		CHECK_TICK
 
-	for (var/thing in openspace_turfs)
-		var/turf/T = thing
-		T.update_mimic()
+	log_debug("SSzcopy: [num_upd + num_amupd] turf updates queued ([num_upd] direct, [num_amupd] indirect), [num_del] orphans destroyed.")
 
 	enable()
 
+// for admin proc-call
 /datum/controller/subsystem/zcopy/proc/hard_reset()
 	disable()
 	log_debug("SSzcopy: hard_reset() invoked.")
 	var/num_deleted = 0
-	var/thing
-	for (thing in openspace_overlays)
-		qdel(thing)
-		num_deleted++
-		CHECK_TICK
-
-	log_debug("SSzcopy: deleted [num_deleted] overlays.")
-
 	var/num_turfs = 0
-	for (thing in turfs)
-		var/turf/T = thing
-		if (T.flags & MIMIC_BELOW)
-			T.update_mimic()
-			num_turfs++
+
+	var/turf/T
+	for (var/atom/A in world)
+		if (isturf(A))
+			T = A
+			if (T.z_flags & ZM_MIMIC_BELOW)
+				T.update_mimic()
+				num_turfs += 1
+
+		else if (istype(A, /atom/movable/openspace/mimic))
+			qdel(A)
+			num_deleted += 1
 
 		CHECK_TICK
 
-	log_debug("SSzcopy: queued [num_turfs] turfs for update. hard_reset() complete.")
+	log_debug("SSzcopy: deleted [num_deleted] overlays, and queued [num_turfs] turfs for update.")
+
 	enable()
 
-/datum/controller/subsystem/zcopy/stat_entry()
-	..("Q:{T:[queued_turfs.len - (qt_idex - 1)]|O:[queued_overlays.len - (qo_idex - 1)]} T:{T:[openspace_turfs.len]|O:[openspace_overlays.len]}")
+/datum/controller/subsystem/zcopy/stat_entry(text, force)
+		..("\
+			[text]\n\
+			Mx: [json_encode(zlev_maximums)]\n\
+			Queues: \
+			Turfs [queued_turfs.len - (qt_idex - 1)] \
+			Overlays [queued_overlays.len - (qo_idex - 1)]\n\
+			Open Turfs: \
+			Turfs [openspace_turfs] \
+			Overlays [openspace_overlays]\n\
+			Skips: \
+			Turfs [multiqueue_skips_turf] \
+			Objects [multiqueue_skips_object]\
+		")
 
 /datum/controller/subsystem/zcopy/Initialize(timeofday)
-	starlight_enabled = config.starlight && config.openturf_starlight_permitted
+	calculate_zstack_limits()
 	// Flush the queue.
 	fire(FALSE, TRUE)
-	if (starlight_enabled)
-		var/t = REALTIMEOFDAY
-		admin_notice("<span class='danger'>[src] setup completed in [(t - timeofday)/10] seconds!</span>", R_DEBUG)
 
-		SSlighting.fire(FALSE, TRUE)
-		admin_notice("<span class='danger'>Secondary [SSlighting] flush completed in [(REALTIMEOFDAY - t)/10] seconds!</span>", R_DEBUG)
+// If you add a new Zlevel or change Z-connections, call this.
+/datum/controller/subsystem/zcopy/proc/calculate_zstack_limits()
+	zlev_maximums = new(world.maxz)
+	var/start_zlev = 1
+	for (var/z in 1 to world.maxz)
+		if (!HasAbove(z))
+			for (var/member_zlev in start_zlev to z)
+				zlev_maximums[member_zlev] = z
+			if (z - start_zlev > OPENTURF_MAX_DEPTH)
+				log_ss("zcopy", "WARNING: Z-levels [start_zlev] through [z] exceed maximum depth of [OPENTURF_MAX_DEPTH]; layering may behave strangely in this Z-stack.")
+			else if (z - start_zlev > 1)
+				log_ss("zcopy", "Found Z-Stack: [start_zlev] -> [z] = [z - start_zlev + 1] zl")
+			start_zlev = z + 1
 
-		t = REALTIMEOFDAY
+	log_ss("zcopy", "Z-Level maximums: [json_encode(zlev_maximums)]")
 
-		fire(FALSE, TRUE)	// Fire /again/ to flush updates caused by the above.
-		admin_notice("<span class='danger'>Secondary [src] flush completed in [(REALTIMEOFDAY - t)/10] seconds!</span>", R_DEBUG)
+/datum/controller/subsystem/zcopy/StartLoadingMap()
+	suspend()
 
-	..()
+/datum/controller/subsystem/zcopy/StopLoadingMap()
+	wake()
 
-/datum/controller/subsystem/zcopy/fire(resumed = FALSE, no_mc_tick = FALSE)
+/datum/controller/subsystem/zcopy/fire(resumed, no_mc_tick)
 	if (!resumed)
 		qt_idex = 1
 		qo_idex = 1
@@ -105,98 +144,178 @@
 	while (qt_idex <= curr_turfs.len)
 		var/turf/T = curr_turfs[qt_idex]
 		curr_turfs[qt_idex] = null
-		qt_idex++
+		qt_idex += 1
 
-		if (!istype(T) || !T.below)
+		if (!isturf(T) || !(T.z_flags & ZM_MIMIC_BELOW) || !T.z_queued)
 			if (no_mc_tick)
 				CHECK_TICK
 			else if (MC_TICK_CHECK)
 				break
 			continue
 
-		if (!T.shadower)	// If we don't have our shadower yet, create it.
-			T.shadower = new(T)
+		// If we're not at our most recent queue position, don't bother -- we're updating again later anyways.
+		if (T.z_queued > 1)
+			T.z_queued -= 1
+			multiqueue_skips_turf += 1
+			if (no_mc_tick)
+				CHECK_TICK
+			else if (MC_TICK_CHECK)
+				break
+			continue
 
-		// Figure out how many z-levels down we are.
-		var/depth = 0
+		// Z-Turf on the bottom-most level, just fake-copy space.
+		// If this is ever true, that turf should always pass this condition, so don't bother cleaning up beyond the Destroy() hook.
+		if (!T.below)	// Z-turf on the bottom-most level, just fake-copy space.
+			if (T.z_flags & ZM_MIMIC_OVERWRITE)
+				T.appearance = SSskybox.space_appearance_cache[(((T.x + T.y) ^ ~(T.x * T.y) + T.z) % 25) + 1]
+				T.name = initial(T.name)
+				T.desc = initial(T.desc)
+				T.gender = initial(T.gender)
+			else
+				// Some openturfs have icons, so we can't overwrite their appearance.
+				if (!T.mimic_underlay)
+					T.mimic_underlay = new(T)
+				var/atom/movable/openspace/turf_proxy/TO = T.mimic_underlay
+				TO.appearance = SSskybox.space_appearance_cache[(((T.x + T.y) ^ ~(T.x * T.y) + T.z) % 25) + 1]
+				TO.name = T.name
+				TO.gender = T.gender	// Need to grab this too so PLURAL works properly in examine.
+				TO.mouse_opacity = initial(TO.mouse_opacity)
+
+			if (no_mc_tick)
+				CHECK_TICK
+			else if (MC_TICK_CHECK)
+				break
+			continue
+
+		if (!T.shadower)	// If we don't have a shadower yet, something has gone horribly wrong.
+			WARNING("Turf [T] at [T.x],[T.y],[T.z] was queued, but had no shadower.")
+			continue
+
+		T.z_generation += 1
+
+		// Get the bottom-most turf, the one we want to mimic.
 		var/turf/Td = T
-		while (Td && TURF_IS_MIMICING(Td.below))
+		while (Td.below)
 			Td = Td.below
-			depth++
-		if (depth > OPENTURF_MAX_DEPTH)
-			depth = OPENTURF_MAX_DEPTH
 
-		var/oo_target = OPENTURF_MAX_PLANE - depth
-		var/t_target
+		// Depth must be the depth of the *visible* turf, not self.
+		var/turf_depth
+		turf_depth = T.z_depth = zlev_maximums[Td.z] - Td.z
+
+		var/t_target = OPENTURF_MAX_PLANE - turf_depth	// This is where the turf (but not the copied atoms) gets put.
 
 		// Handle space parallax & starlight.
-		if (T.is_above_space())
+		if (T.below.z_eventually_space)
+			T.z_eventually_space = TRUE
 			t_target = PLANE_SPACE_BACKGROUND
-			if (starlight_enabled && !T.light_range)
-				T.set_light(config.starlight, 0.5)
-		else
-			t_target = oo_target
-			if (starlight_enabled && T.light_range)
-				T.set_light(0)
 
-		if (!(T.flags & MIMIC_OVERWRITE))
-			// Some openturfs have icons, so we can't overwrite their appearance.
-			if (!T.below.bound_overlay)
-				T.below.bound_overlay = new(T)
-			var/atom/movable/openspace/turf_overlay/TO = T.below.bound_overlay
-			TO.appearance = T.below
-			TO.name = T.name
-			TO.opacity = FALSE
-			T.desc = TO.desc = "Below seems to be \a [T.below]."
-			TO.plane = t_target
-			TO.mouse_opacity = FALSE
-		else
+		if (T.z_flags & ZM_MIMIC_OVERWRITE)
 			// This openturf doesn't care about its icon, so we can just overwrite it.
-			if (T.below.bound_overlay)
-				QDEL_NULL(T.below.bound_overlay)
+			if (T.below.mimic_proxy)
+				QDEL_NULL(T.below.mimic_proxy)
 			T.appearance = T.below
 			T.name = initial(T.name)
-			T.gender = NEUTER
+			T.desc = initial(T.desc)
+			T.gender = initial(T.gender)
 			T.opacity = FALSE
 			T.plane = t_target
+		else
+			// Some openturfs have icons, so we can't overwrite their appearance.
+			if (!T.below.mimic_proxy)
+				T.below.mimic_proxy = new(T)
+			var/atom/movable/openspace/turf_proxy/TO = T.below.mimic_proxy
+			TO.appearance = Td
+			TO.name = T.name
+			TO.gender = T.gender	// Need to grab this too so PLURAL works properly in examine.
+			TO.opacity = FALSE
+			TO.plane = t_target
+			TO.mouse_opacity = initial(TO.mouse_opacity)
 
-		T.desc = "Below seems to be \a [T.below]."
-		T.queue_ao()	// No need to recalculate ajacencies, shouldn't have changed.
+		T.queue_ao(T.ao_neighbors_mimic == null)	// If ao_neighbors hasn't been set yet, we need to do a rebuild
+
+		// Explicitly copy turf delegates so they show up properly on below levels.
+		//   I think it's possible to get this to work without discrete delegate copy objects, but I'd rather this just work.
+		if ((T.below.z_flags & (ZM_MIMIC_BELOW|ZM_MIMIC_OVERWRITE)) == ZM_MIMIC_BELOW)
+			// Below is a delegate, gotta explicitly copy it for recursive copy.
+			if (!T.below.mimic_above_copy)
+				T.below.mimic_above_copy = new(T)
+			var/atom/movable/openspace/turf_mimic/DC = T.below.mimic_above_copy
+			DC.appearance = T.below
+			DC.mouse_opacity = initial(DC.mouse_opacity)
+			DC.plane = OPENTURF_MAX_PLANE
+
+		else if (T.below.mimic_above_copy)
+			QDEL_NULL(T.below.mimic_above_copy)
+
+		// Handle below atoms.
 
 		// Add everything below us to the update queue.
 		for (var/thing in T.below)
 			var/atom/movable/object = thing
-			if (QDELETED(object) || object.no_z_overlay || object.loc != T.below)
-				// Don't queue deleted stuff or stuff that doesn't need an overlay.
+			if (QDELETED(object) || object.no_z_overlay || object.loc != T.below || object.invisibility == INVISIBILITY_ABSTRACT)
+				// Don't queue deleted stuff, stuff that's not visible, blacklisted stuff, or stuff that's centered on another tile but intersects ours.
 				continue
 
-			if (object.type == /atom/movable/lighting_overlay)	// Special case.
-				T.shadower.copy_lighting(object)
-			else
-				if (!object.bound_overlay)	// Generate a new overlay if the atom doesn't already have one.
-					object.bound_overlay = new(T)
-					object.bound_overlay.associated_atom = object
+			// Special case: these are merged into the shadower to reduce memory usage.
+			if (object.type == /atom/movable/lighting_overlay)
+				//T.shadower.copy_lighting(object)
+				continue
 
-				var/atom/movable/openspace/overlay/OO = object.bound_overlay
+			if (!object.bound_overlay)	// Generate a new overlay if the atom doesn't already have one.
+				object.bound_overlay = new(T)
+				object.bound_overlay.associated_atom = object
 
-				// If the OO was queued for destruction but was claimed by another OT, stop the destruction timer.
-				if (OO.destruction_timer)
-					deltimer(OO.destruction_timer)
-					OO.destruction_timer = null
+			var/override_depth
+			var/original_type = object.type
+			var/original_z = object.z
+			switch (object.type)
+				if (/atom/movable/openspace/mimic)
+					var/atom/movable/openspace/mimic/OOO = object
+					original_type = OOO.mimiced_type
+					override_depth = OOO.override_depth
+					original_z = OOO.original_z
 
-				// Cache our already-calculated depth so we don't need to re-calculate it a bunch of times.
-				OO.depth = oo_target
+				if (/atom/movable/openspace/turf_proxy, /atom/movable/openspace/turf_mimic)
+					// If we're a turf overlay (the mimic for a non-OVERWRITE turf), we need to make sure copies of us respect space parallax too
+					if (T.z_eventually_space)
+						// Yes, this is an awful hack; I don't want to add yet another override_* var.
+						override_depth = OPENTURF_MAX_PLANE - PLANE_SPACE_BACKGROUND
 
-				queued_overlays += OO
+			var/atom/movable/openspace/mimic/OO = object.bound_overlay
 
-		T.flags &= ~MIMIC_QUEUED
+			// If the OO was queued for destruction but was claimed by another OT, stop the destruction timer.
+			if (OO.destruction_timer)
+				deltimer(OO.destruction_timer)
+				OO.destruction_timer = null
+
+			OO.depth = override_depth || min(zlev_maximums[T.z] - original_z, OPENTURF_MAX_DEPTH)
+
+			// These types need to be pushed a layer down for bigturfs to function correctly.
+			switch (original_type)
+				if (/atom/movable/openspace/multiplier, /atom/movable/openspace/turf_mimic, /atom/movable/openspace/turf_proxy)
+					if (OO.depth < OPENTURF_MAX_DEPTH)
+						OO.depth += 1
+
+			OO.mimiced_type = original_type
+			OO.override_depth = override_depth
+			OO.original_z = original_z
+
+			// Multi-queue to maintain ordering of updates to these
+			//   queueing it multiple times will result in only the most recent
+			//   actually processing.
+			OO.queued += 1
+			queued_overlays += OO
+
+		T.z_queued -= 1
+		if (T.above)
+			T.above.update_mimic()
 
 		if (no_mc_tick)
 			CHECK_TICK
 		else if (MC_TICK_CHECK)
 			break
 
-	if (qt_idex > 1 && qt_idex <= curr_turfs.len)
+	if (qt_idex > 1)
 		curr_turfs.Cut(1, qt_idex)
 		qt_idex = 1
 
@@ -204,11 +323,11 @@
 		MC_SPLIT_TICK
 
 	while (qo_idex <= curr_ov.len)
-		var/atom/movable/openspace/overlay/OO = curr_ov[qo_idex]
+		var/atom/movable/openspace/mimic/OO = curr_ov[qo_idex]
 		curr_ov[qo_idex] = null
-		qo_idex++
+		qo_idex += 1
 
-		if (QDELETED(OO))
+		if (QDELETED(OO) || !OO.queued)
 			if (no_mc_tick)
 				CHECK_TICK
 			else if (MC_TICK_CHECK)
@@ -224,12 +343,25 @@
 				break
 			continue
 
+		// Don't update unless we're at the most recent queue occurrence.
+		if (OO.queued > 1)
+			OO.queued -= 1
+			multiqueue_skips_object += 1
+			if (no_mc_tick)
+				CHECK_TICK
+			else if (MC_TICK_CHECK)
+				break
+			continue
+
 		// Actually update the overlay.
-		OO.dir = OO.associated_atom.dir
+		if (OO.dir != OO.associated_atom.dir)
+			OO.set_dir(OO.associated_atom.dir)
+
 		OO.appearance = OO.associated_atom
-		OO.plane = OO.depth
+		OO.plane = OPENTURF_MAX_PLANE - OO.depth
+
 		OO.opacity = FALSE
-		OO.queued = FALSE
+		OO.queued = 0
 
 		if (OO.bound_overlay)	// If we have a bound overlay, queue it too.
 			OO.update_above()
@@ -239,47 +371,125 @@
 		else if (MC_TICK_CHECK)
 			break
 
-		if (qo_idex > 1 && qo_idex <= curr_ov.len)
-			curr_ov.Cut(1, qo_idex)
-			qo_idex = 1
+	if (qo_idex > 1)
+		curr_ov.Cut(1, qo_idex)
+		qo_idex = 1
 
+#define FMT_DEPTH(X) (X == null ? "(null)" : X)
+
+// This is a dummy object used so overlays can be shown in the analyzer.
+/atom/movable/openspace/debug
 
 /client/proc/analyze_openturf(turf/T)
 	set name = "Analyze Openturf"
 	set desc = "Show the layering of an openturf and everything it's mimicking."
 	set category = "Debug"
 
-	if (!check_rights(R_DEBUG|R_DEV))
+	if (!check_rights(R_DEBUG))
 		return
 
+	var/is_above_space = T.is_above_space()
 	var/list/out = list(
+		"<head><meta charset='utf-8'/></head><body>",
 		"<h1>Analysis of [T] at [T.x],[T.y],[T.z]</h1>",
-		"<b>Z Flags</b>: [english_list(bitfield2list(T.flags, list("NOJAUNT", "MIMIC_BELOW", "MIMIC_OVERWRITE", "MIMIC_QUEUED", "MIMIC_NO_AO")), "(none)")]",
+		"<b>Queue occurrences:</b> [T.z_queued]",
+		"<b>Above space:</b> Apparent [T.z_eventually_space ? "Yes" : "No"], Actual [is_above_space ? "Yes" : "No"] - [T.z_eventually_space == is_above_space ? "<font color='green'>OK</font>" : "<font color='red'>MISMATCH</font>"]",
+		"<b>Z Flags</b>: [english_list(bitfield2list(T.z_flags, global.mimic_defines), "(none)")]",
 		"<b>Has Shadower:</b> [T.shadower ? "Yes" : "No"]",
+		"<b>Has turf proxy:</b> [T.mimic_proxy ? "Yes" : "No"]",
+		"<b>Has above copy:</b> [T.mimic_above_copy ? "Yes" : "No"]",
+		"<b>Has mimic underlay:</b> [T.mimic_underlay ? "Yes" : "No"]",
 		"<b>Below:</b> [!T.below ? "(nothing)" : "[T.below] at [T.below.x],[T.below.y],[T.below.z]"]",
+		"<b>Depth:</b> [FMT_DEPTH(T.z_depth)] [T.z_depth == OPENTURF_MAX_DEPTH ? "(max)" : ""]",
+		"<b>Generation:</b> [T.z_generation]",
 		"<ul>"
 	)
 
 	var/list/found_oo = list(T)
-	for (var/thing in T)
-		if (istype(thing, /atom/movable/openspace))
-			found_oo += thing
+	for (var/atom/movable/openspace/O in T)
+		found_oo += O
+
+	if (T.shadower.overlays.len)
+		for (var/overlay in T.shadower.overlays)
+			var/atom/movable/openspace/debug/D = new
+			D.appearance = overlay
+			if (D.plane < -10000)	// FLOAT_PLANE
+				D.plane = T.shadower.plane
+			found_oo += D
 
 	sortTim(found_oo, /proc/cmp_planelayer)
+
+	var/list/atoms_list_list = list()
 	for (var/thing in found_oo)
 		var/atom/A = thing
-		if (istype(A, /atom/movable/openspace/overlay))
-			var/atom/movable/openspace/overlay/OO = A
-			var/atom/movable/AA = OO.associated_atom
-			out += "<li>[icon2html(A, usr)] plane [A.plane], layer [A.layer], depth [OO.depth], associated Z-level [AA.z] - [OO.type] copying [AA] ([AA.type])</li>"
-		else if (isturf(A))
-			if (A == T)
-				out += "<li>[icon2html(A, usr)] plane [A.plane], layer [A.layer], Z-level [A.z] - [A] ([A.type]) - <span class='good'>SELF</span></li>"
-			else    // foreign turfs - not visible here, but good for figuring out layering
-				out += "<li>[icon2html(A, usr)] plane [A.plane], layer [A.layer], Z-level [A.z] - [A] ([A.type]) - <span class='warning'>FOREIGN</span></li>"
-		else
-			out += "<li>[icon2html(A, usr)] plane [A.plane], layer [A.layer], Z-level [A.z] - [A] ([A.type])</li>"
+		var/pl = "[A.plane]"
+		LAZYINITLIST(atoms_list_list[pl])
+		atoms_list_list[pl] += A
 
-	out += "</ul>"
+	if (atoms_list_list["0"])
+		out += "<strong>Non-Z</strong>"
+		SSzcopy.debug_fmt_planelist(atoms_list_list["0"], out, T)
 
-	usr << browse(out.Join("<br>"), "window=openturfanalysis-\ref[T]")
+		atoms_list_list -= "0"
+
+	for (var/d in 0 to OPENTURF_MAX_DEPTH)
+		var/pl = OPENTURF_MAX_PLANE - d
+		if (!atoms_list_list["[pl]"])
+			out += "<strong>Depth [d], plane [pl] - empty</strong>"
+			continue
+
+		out += "<strong>Depth [d], plane [pl]</strong>"
+		SSzcopy.debug_fmt_planelist(atoms_list_list["[pl]"], out, T)
+
+		// Flush the list so we can find orphans.
+		atoms_list_list -= "[pl]"
+
+	if (atoms_list_list["[PLANE_SPACE_BACKGROUND]"])	// Space parallax plane
+		out += "<strong>Space parallax plane</strong> ([PLANE_SPACE_BACKGROUND])"
+		SSzcopy.debug_fmt_planelist(atoms_list_list["[PLANE_SPACE_BACKGROUND]"], out, T)
+		atoms_list_list -= "[PLANE_SPACE_BACKGROUND]"
+
+	for (var/key in atoms_list_list)
+		out += "<strong style='color: red;'>Unknown plane: [key]</strong>"
+		SSzcopy.debug_fmt_planelist(atoms_list_list[key], out, T)
+
+		out += "<hr/>"
+
+	out += "</body>"
+
+	show_browser(usr, out.Join("<br>"), "size=980x580;window=openturfanalysis-\ref[T]")
+
+// Yes, I know this proc is a bit of a mess. Feel free to clean it up.
+/datum/controller/subsystem/zcopy/proc/debug_fmt_thing(atom/A, list/out, turf/original)
+	if (istype(A, /atom/movable/openspace/mimic))
+		var/atom/movable/openspace/mimic/OO = A
+		var/atom/movable/AA = OO.associated_atom
+		var/copied_type = AA.type == OO.mimiced_type ? "[AA.type] \[direct\]" : "[AA.type], eventually [OO.mimiced_type]"
+		return "<li>\icon[A] <b>\[Mimic\]</b> plane [A.plane], layer [A.layer], depth [FMT_DEPTH(OO.depth)], associated Z-level [AA.z] - [OO.type] copying [AA] ([copied_type])</li>"
+	else if (istype(A, /atom/movable/openspace/turf_mimic))
+		var/atom/movable/openspace/turf_mimic/DC = A
+		return "<li>\icon[A] <b>\[Turf Mimic\]</b> plane [A.plane], layer [A.layer], Z-level [A.z], delegate of \icon[DC.delegate] [DC.delegate] ([DC.delegate.type])</li>"
+	else if (isturf(A))
+		if (A == original)
+			return "<li>\icon[A] <b>\[Turf\]</b> plane [A.plane], layer [A.layer], depth [FMT_DEPTH(A:z_depth)], Z-level [A.z] - [A] ([A.type]) - <font color='green'>SELF</font></li>"
+		else	// foreign turfs - not visible here, but sometimes good for figuring out layering -- showing these is currently not enabled
+			return "<li>\icon[A] <b>\[Turf\]</b> <em><font color='#646464'>plane [A.plane], layer [A.layer], depth [FMT_DEPTH(A:z_depth)], Z-level [A.z] - [A] ([A.type])</font></em> - <font color='red'>FOREIGN</font></em></li>"
+	else if (A.type == /atom/movable/openspace/multiplier)
+		return "<li>\icon[A] <b>\[Shadower\]</b> plane [A.plane], layer [A.layer], Z-level [A.z] - [A] ([A.type])</li>"
+	else if (A.type == /atom/movable/openspace/debug)	// These are fake objects that exist just to show the shadower's overlays in this list.
+		return "<li>\icon[A] <b>\[Shadower True Overlay\]</b> plane [A.plane], layer [A.layer] - <font color='grey'>VIRTUAL</font></li>"
+	else if (A.type == /atom/movable/openspace/turf_proxy)
+		return "<li>\icon[A] <b>\[Turf Proxy\]</b> plane [A.plane], layer [A.layer], Z-level [A.z] - [A] ([A.type])</li>"
+	else
+		return "<li>\icon[A] <b>\[?\]</b>  plane [A.plane], layer [A.layer], Z-level [A.z] - [A] ([A.type])</li>"
+
+/datum/controller/subsystem/zcopy/proc/debug_fmt_planelist(list/things, list/out, turf/original)
+	if (things)
+		out += "<ul>"
+		for (var/thing in things)
+			out += debug_fmt_thing(thing, out, original)
+		out += "</ul>"
+	else
+		out += "<em>No atoms.</em>"
+
+#undef FMT_DEPTH