Glass Floor Transparency Fix

code/__DEFINES/dcs/signals/signals.dm

@@ -302,6 +302,8 @@
 #define COMSIG_TURF_MULTIZ_DEL "turf_multiz_del"
 ///from base of turf/multiz_turf_new: (turf/source, direction)
 #define COMSIG_TURF_MULTIZ_NEW "turf_multiz_new"
+///from base of turf/initilize_turf_transparency: (turf/source, direction)
+#define COMSIG_TURF_INITIALIZE_TRANSPARENCY "initilize_turf_transparency"
 //! from base of turf/proc/afterShuttleMove: (turf/new_turf)
 #define COMSIG_TURF_AFTER_SHUTTLE_MOVE "turf_after_shuttle_move"
 

code/__DEFINES/traits.dm

@@ -444,6 +444,8 @@ Remember to update _globalvars/traits.dm if you're adding/removing/renaming trai
 #define WARPWHISTLE_TRAIT "warpwhistle"
 ///Turf trait for when a turf is transparent
 #define TURF_Z_TRANSPARENT_TRAIT "turf_z_transparent"
+///Turf trait for when a transparent turf should display the bottom.
+#define TURF_Z_SHOW_BOTTOM_TRAIT "turf_z_show_bottom"
 /// Trait applied to slimes by low temperature
 #define SLIME_COLD "slime-cold"
 /// Trait applied to bots by being tipped over

code/datums/elements/turf_transparency.dm

@@ -1,35 +1,32 @@
 /datum/element/turf_z_transparency
-	var/show_bottom_level = FALSE
-	var/turf/our_turf
+	element_flags = ELEMENT_DETACH //Important so it is properly cleared out on turf qdel.
 
 ///This proc sets up the signals to handle updating viscontents when turfs above/below update. Handle plane and layer here too so that they don't cover other obs/turfs in Dream Maker
-/datum/element/turf_z_transparency/Attach(datum/target, show_bottom_level = TRUE)
+/datum/element/turf_z_transparency/Attach(turf/our_turf, show_bottom_level = TRUE)
 	. = ..()
-	if(!isturf(target))
+	if(!isturf(our_turf))
 		return ELEMENT_INCOMPATIBLE
 
-	our_turf = target
-
-	src.show_bottom_level = show_bottom_level
-
 	our_turf.plane = OPENSPACE_PLANE
 	our_turf.layer = OPENSPACE_LAYER
 
-	RegisterSignal(target, COMSIG_TURF_MULTIZ_DEL, PROC_REF(on_multiz_turf_del), TRUE)
-	RegisterSignal(target, COMSIG_TURF_MULTIZ_NEW, PROC_REF(on_multiz_turf_new), TRUE)
+	RegisterSignal(our_turf, COMSIG_TURF_MULTIZ_DEL, PROC_REF(on_multiz_turf_del), TRUE)
+	RegisterSignal(our_turf, COMSIG_TURF_MULTIZ_NEW, PROC_REF(on_multiz_turf_new), TRUE)
+	RegisterSignal(our_turf, COMSIG_TURF_INITIALIZE_TRANSPARENCY, PROC_REF(initilize_turf_transparency), TRUE)
 
 	ADD_TRAIT(our_turf, TURF_Z_TRANSPARENT_TRAIT, TURF_TRAIT)
-
-
-	update_multiz(our_turf, TRUE, TRUE)
+	if(show_bottom_level) //Sets up the trait to check when initializing the turf elsewhere.
+		ADD_TRAIT(our_turf, TURF_Z_SHOW_BOTTOM_TRAIT, TURF_TRAIT)
 
 /datum/element/turf_z_transparency/Detach(datum/source, force)
 	. = ..()
 	var/turf/our_turf = source
-	our_turf.vis_contents.len = 0
+	our_turf.vis_contents.len = 0 //vis_contents are handled by Destroy() when a turf is qdel'd, but you could also call Detach from elsewhere.
 	UnregisterSignal(our_turf, COMSIG_TURF_MULTIZ_DEL)
 	UnregisterSignal(our_turf, COMSIG_TURF_MULTIZ_NEW)
+	UnregisterSignal(our_turf, COMSIG_TURF_INITIALIZE_TRANSPARENCY)
 	REMOVE_TRAIT(our_turf, TURF_Z_TRANSPARENT_TRAIT, TURF_TRAIT)
+	REMOVE_TRAIT(our_turf, TURF_Z_SHOW_BOTTOM_TRAIT, TURF_TRAIT)
 
 ///Updates the viscontents or underlays below this tile.
 /datum/element/turf_z_transparency/proc/update_multiz(turf/our_turf, prune_on_fail = FALSE, init = FALSE)
@@ -39,15 +36,16 @@
 		if(!show_bottom_level(our_turf) && prune_on_fail) //If we cant show whats below, and we prune on fail, change the turf to plating as a fallback
 			our_turf.ChangeTurf(/turf/open/floor/plating, flags = CHANGETURF_INHERIT_AIR)
 			return FALSE
-	if(init)
-		our_turf.vis_contents += below_turf
-	if(isclosedturf(our_turf)) //Show girders below closed turfs
-		var/mutable_appearance/girder_underlay = mutable_appearance('icons/obj/structures.dmi', "girder", layer = TURF_LAYER-0.01)
-		girder_underlay.appearance_flags = RESET_ALPHA | RESET_COLOR
-		our_turf.underlays += girder_underlay
-		var/mutable_appearance/plating_underlay = mutable_appearance('icons/turf/floors.dmi', "plating", layer = TURF_LAYER-0.02)
-		plating_underlay = RESET_ALPHA | RESET_COLOR
-		our_turf.underlays += plating_underlay
+	else
+		if(init)
+			our_turf.vis_contents += below_turf
+		if(isclosedturf(our_turf)) //Show girders below closed turfs
+			var/mutable_appearance/girder_underlay = mutable_appearance('icons/obj/structures.dmi', "girder", layer = TURF_LAYER-0.01)
+			girder_underlay.appearance_flags = RESET_ALPHA | RESET_COLOR
+			our_turf.underlays += girder_underlay
+			var/mutable_appearance/plating_underlay = mutable_appearance('icons/turf/floors.dmi', "plating", layer = TURF_LAYER-0.02)
+			plating_underlay = RESET_ALPHA | RESET_COLOR
+			our_turf.underlays += plating_underlay
 	return TRUE
 
 /datum/element/turf_z_transparency/proc/on_multiz_turf_del(turf/our_turf, turf/T, dir)
@@ -62,17 +60,47 @@
 		return
 	update_multiz(our_turf)
 
+/**
+ * Initializes, or actually gives appearance to, transparent tiles.
+ *
+ * Called via COMSIG_TURF_INITIALIZE_TRANSPARENCY from:
+ * ChangeTurf() - generic case for glass floors, initialized when plating turns into glass floor.
+ * on_applied_turf() - material application, special case. You can make transparent tiled floor, so it's initialized here as the proc calls are different.
+ * onShuttleMove() is a case for both glass and material floors, as it's called only when the shuttle moves.
+ *
+ * We do these calls as late as possible to get a full baseturfs list to later pass to show_bottom_level().
+ * This should have no effect on multi-z performance, but I have not tested it.
+ *
+ * Arguments:
+ * * our_turf - turf being passed to initialize transparency. Only tested on open turfs.
+ */
+/datum/element/turf_z_transparency/proc/initilize_turf_transparency(turf/our_turf)
+	SIGNAL_HANDLER
+	update_multiz(our_turf, TRUE, TRUE)
+
 ///Called when there is no real turf below this turf
 /datum/element/turf_z_transparency/proc/show_bottom_level(turf/our_turf)
-	if(!show_bottom_level)
+	if(!HAS_TRAIT(our_turf, TURF_Z_SHOW_BOTTOM_TRAIT))
 		return FALSE
-	var/turf/path = our_turf.virtual_level_trait(ZTRAIT_BASETURF) || /turf/open/space
-	if(!ispath(path))
-		path = text2path(path)
+
+	var/turf/path
+	if(our_turf.baseturfs && length(our_turf.baseturfs) > 1)
+		path = our_turf.baseturfs[2] //Why 2? It's usually a better indicator of what we landed on.
+		if(ispath(path, /turf/closed)) //Do not want to show walls, looks strange.
+			path = our_turf.baseturfs[1] //The first element is going to be a floor of some kind.
+
+	if(!path) //Fallback to the regular, bland, method of determining a level baseturf.
+		//linters fix, change to this in the future:
+		//path = our_turf.get_z_base_turf()
+		path = our_turf.virtual_level_trait(ZTRAIT_BASETURF) || /turf/open/space
 		if(!ispath(path))
-			warning("Z-level [our_turf.z] has invalid baseturf '[our_turf.virtual_level_trait(ZTRAIT_BASETURF)]'")
-			path = /turf/open/space
-	var/mutable_appearance/underlay_appearance = mutable_appearance(initial(path.icon), initial(path.icon_state), layer = TURF_LAYER-0.02, plane = PLANE_SPACE)
+			path = text2path(path)
+			if(!ispath(path))
+				warning("Z-level [our_turf.z] has invalid baseturf '[our_turf.virtual_level_trait(ZTRAIT_BASETURF)]'")
+				path = /turf/open/space
+
+	//PLANE_SPACE to show the parallax if it's a space tile.
+	var/mutable_appearance/underlay_appearance = mutable_appearance(initial(path.icon), initial(path.icon_state), layer = TURF_LAYER-0.02, plane = (ispath(path, /turf/open/space) ? PLANE_SPACE : null))
 	underlay_appearance.appearance_flags = RESET_ALPHA | RESET_COLOR
 	our_turf.underlays += underlay_appearance
 	return TRUE

code/datums/materials/_material.dm

@@ -128,6 +128,7 @@ Simple datum which is instanced once per type and is used for every object of sa
 			O.heavyfootstep = turf_sound_override
 	if(alpha < 255)
 		T.AddElement(/datum/element/turf_z_transparency, TRUE)
+		SEND_SIGNAL(T, COMSIG_TURF_INITIALIZE_TRANSPARENCY)
 	return
 
 ///This proc is called when the material is removed from an object.
@@ -161,8 +162,7 @@ Simple datum which is instanced once per type and is used for every object of sa
 		o.throwforce = initial(o.throwforce)
 
 /datum/material/proc/on_removed_turf(turf/T, amount, material_flags)
-	if(alpha != 255)
-		RemoveElement(/datum/element/turf_z_transparency, FALSE)
+	return
 
 /** Returns the composition of this material.
  *

code/game/turfs/change_turf.dm

@@ -16,15 +16,10 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 	if(turf_type)
 		ChangeTurf(turf_type, baseturf_type, flags)
 
+//This proc is actually evil. Needs a rewrite.
 /turf/proc/copyTurf(turf/T, copy_air, flags)
 	if(T.type != type)
-		var/obj/O
-		if(underlays.len)	//we have underlays, which implies some sort of transparency, so we want to a snapshot of the previous turf as an underlay
-			O = new()
-			O.underlays.Add(T)
 		T.ChangeTurf(type, null, flags)
-		if(underlays.len)
-			T.underlays = O.underlays
 	if(T.icon_state != icon_state)
 		T.icon_state = icon_state
 	if(T.icon != icon)
@@ -36,14 +31,28 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 		T.setDir(dir)
 	if(T.smoothing_flags != smoothing_flags)
 		T.smoothing_flags = smoothing_flags
+	if(T.alpha != alpha)
+		T.alpha = alpha
+//PENTEST ADDITION - GLASS TRANSPARENCY FIX - START
+	if(custom_materials)
+		//If it's not a glass floor, it's a material floor with transparency (glass floors are initialized in ChangeTurf()).
+		if(HAS_TRAIT(src, TURF_Z_TRANSPARENT_TRAIT))
+			T.AddElement(/datum/element/turf_z_transparency, TRUE)
+		T.custom_materials = custom_materials
+//PENTEST ADDITION - GLASS TRANSPARENCY FIX - END
 	return T
 
-/turf/open/copyTurf(turf/T, copy_air = FALSE)
+/turf/open/copyTurf(turf/open/T, copy_air = FALSE)
 	. = ..()
 	if(isopenturf(T))
 		if(copy_air)
 			var/turf/open/openTurf = T
 			openTurf.air.copy_from(air)
+		if(custom_materials) //For custom material floor overrides on footsteps.
+			T.footstep = footstep
+			T.barefootstep = barefootstep
+			T.clawfootstep = clawfootstep
+			T.heavyfootstep = heavyfootstep
 
 //wrapper for ChangeTurf()s that you want to prevent/affect without overriding ChangeTurf() itself
 /turf/proc/TerraformTurf(path, new_baseturf, flags)
@@ -129,6 +138,10 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 
 	W.virtual_z = old_virtual_z
 
+	//We need baseturfs and virtual_z to be set before sending this signal.
+	if(!(flags & CHANGETURF_DEFER_CHANGE)) //Travel transparency initialization is handled in onShuttleMove().
+		SEND_SIGNAL(W, COMSIG_TURF_INITIALIZE_TRANSPARENCY)
+
 	lighting_corner_NE = old_lighting_corner_NE
 	lighting_corner_SE = old_lighting_corner_SE
 	lighting_corner_SW = old_lighting_corner_SW

code/game/turfs/open/glass.dm

@@ -1,5 +1,5 @@
 /turf/open/floor/glass
-	name = "Glass floor"
+	name = "glass floor"
 	desc = "While it at first appears to be a dangerous glass floor over space, closer inspection reveals it to simply be a screen behind a layer of glass."
 	icon = 'icons/turf/floors/glass.dmi'
 	icon_state = "glass-0"
@@ -16,15 +16,11 @@
 
 /turf/open/floor/glass/Initialize(mapload, inherited_virtual_z)
 	icon_state = "" //Prevent the normal icon from appearing behind the smooth overlays
-	..()
-	return INITIALIZE_HINT_LATELOAD
-
-/turf/open/floor/glass/LateInitialize()
-	. = ..()
 	AddElement(/datum/element/turf_z_transparency, TRUE)
+	. = ..()
 
 /turf/open/floor/glass/reinforced
-	name = "Reinforced glass floor"
+	name = "reinforced glass floor"
 	desc = "While it at first appears to be a dangerous glass floor over space, closer inspection reveals it to simply be a screen behind a reinforced protective layer of glass."
 	icon = 'icons/turf/floors/reinf_glass.dmi'
 	icon_state = "reinf_glass-0"

code/modules/shuttle/on_move.dm

@@ -76,6 +76,8 @@ All ShuttleMove procs go here
 		for(var/i in 0 to new_loc.get_missing_shuttles(newT)) //Start at 0 because get_missing_shuttles() will report 1 less missing shuttle because of the CopyOnTop()
 			newT.baseturfs.Insert(inject_index, /turf/baseturf_skipover/shuttle)
 
+	SEND_SIGNAL(newT, COMSIG_TURF_INITIALIZE_TRANSPARENCY) //After baseturfs ares established, we send this signal. Deferred to here on travel, otherwise usually performed in ChangeTurf().
+
 	return TRUE
 
 // Called on the new turf after everything has been moved