Flying mobs now clip past non flying mobs, various flightsuit/iontrail/movement tweaks/code improvements/bugfixes

code/game/area/areas.dm

@@ -460,14 +460,14 @@ GLOBAL_LIST_EMPTY(teleportlocs)
 		T = get_turf(src)
 	var/area/A = get_area(T)
 	if(isspaceturf(T)) // Turf never has gravity
-		return 0
+		return FALSE
 	else if(A && A.has_gravity) // Areas which always has gravity
-		return 1
+		return TRUE
 	else
 		// There's a gravity generator on our z level
 		if(T && GLOB.gravity_generators["[T.z]"] && length(GLOB.gravity_generators["[T.z]"]))
-			return 1
-	return 0
+			return TRUE
+	return FALSE
 
 /area/proc/setup(a_name)
 	name = a_name

code/game/atoms_movable.dm

@@ -115,8 +115,8 @@
 		. = 0
 
 //Called after a successful Move(). By this point, we've already moved
-/atom/movable/proc/Moved(atom/OldLoc, Dir)
-	SendSignal(COMSIG_MOVABLE_MOVED, OldLoc, Dir)
+/atom/movable/proc/Moved(atom/OldLoc, Dir, Forced = FALSE)
+	SendSignal(COMSIG_MOVABLE_MOVED, OldLoc, Dir, Forced)
 	if (!inertia_moving)
 		inertia_next_move = world.time + inertia_move_delay
 		newtonian_move(Dir)
@@ -219,7 +219,7 @@
 	if(A)
 		if(throwing)
 			throwing.hit_atom(A)
-			. = 1
+			. = TRUE
 			if(!A || QDELETED(A))
 				return
 		A.CollidedWith(src)
@@ -260,8 +260,7 @@
 				if(AM == src)
 					continue
 				AM.Crossed(src, oldloc)
-
-		Moved(oldloc, 0)
+		Moved(oldloc, NONE, TRUE)
 		. = TRUE
 
 	//If no destination, move the atom into nullspace (don't do this unless you know what you're doing)
@@ -277,9 +276,9 @@
 /mob/living/forceMove(atom/destination)
 	stop_pulling()
 	if(buckled)
-		buckled.unbuckle_mob(src,force=1)
+		buckled.unbuckle_mob(src, force = TRUE)
 	if(has_buckled_mobs())
-		unbuckle_all_mobs(force=1)
+		unbuckle_all_mobs(force = TRUE)
 	. = ..()
 	if(.)
 		if(client)
@@ -534,6 +533,7 @@
 	acted_explosions += ex_id
 	return TRUE
 
+//TODO: Better floating
 /atom/movable/proc/float(on)
 	if(throwing)
 		return

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

@@ -8,8 +8,13 @@
 
 /datum/effect_system/trail_follow
 	var/turf/oldposition
-	var/processing = TRUE
-	var/on = TRUE
+	var/active = FALSE
+	var/allow_overlap = FALSE
+	var/auto_process = TRUE
+	var/qdel_in_time = 10
+	var/fadetype = "ion_fade"
+	var/fade = TRUE
+	var/nograv_required = FALSE
 
 /datum/effect_system/trail_follow/set_up(atom/atom)
 	attach(atom)
@@ -17,37 +22,49 @@
 
 /datum/effect_system/trail_follow/Destroy()
 	oldposition = null
+	stop()
 	return ..()
 
 /datum/effect_system/trail_follow/proc/stop()
-	processing = FALSE
-	on = FALSE
 	oldposition = null
+	STOP_PROCESSING(SSfastprocess, src)
+	active = FALSE
+	return TRUE
+
+/datum/effect_system/trail_follow/start()
+	oldposition = get_turf(holder)
+	if(!check_conditions())
+		return FALSE
+	if(auto_process)
+		START_PROCESSING(SSfastprocess, src)
+	active = TRUE
+	return TRUE
+
+/datum/effect_system/trail_follow/process()
+	generate_effect()
+
+/datum/effect_system/trail_follow/generate_effect()
+	if(!check_conditions())
+		return stop()
+	if(oldposition && !(oldposition == get_turf(holder)))
+		if(!oldposition.has_gravity() || !nograv_required)
+			var/obj/effect/E = new effect_type(oldposition)
+			set_dir(E)
+			if(fade)
+				flick(fadetype, E)
+				E.icon_state = ""
+			if(qdel_in_time)
+				QDEL_IN(E, qdel_in_time)
+	oldposition = get_turf(holder)
+
+/datum/effect_system/trail_follow/proc/check_conditions()
+	if(!get_turf(holder))
+		return FALSE
+	return TRUE
 
 /datum/effect_system/trail_follow/steam
 	effect_type = /obj/effect/particle_effect/steam
 
-/datum/effect_system/trail_follow/steam/start()
-	if(!on)
-		on = TRUE
-		processing = TRUE
-		if(!oldposition)
-			oldposition = get_turf(holder)
-	if(processing)
-		processing = FALSE
-		if(number < 3)
-			var/obj/effect/particle_effect/steam/I = new /obj/effect/particle_effect/steam(oldposition)
-			number++
-			I.setDir(holder.dir)
-			oldposition = get_turf(holder)
-			spawn(10)
-				qdel(I)
-				number--
-		spawn(2)
-			if(on)
-				processing = TRUE
-				start()
-
 /obj/effect/particle_effect/ion_trails
 	name = "ion trails"
 	icon_state = "ion_trails"
@@ -58,47 +75,23 @@
 
 /datum/effect_system/trail_follow/ion
 	effect_type = /obj/effect/particle_effect/ion_trails
-	var/fadetype = "ion_fade"
-	var/fade = 1
-	var/nograv_required = 1
+	nograv_required = TRUE
+	qdel_in_time = 20
 
-/datum/effect_system/trail_follow/ion/start() //Whoever is responsible for this abomination of code should become an hero
-	if(!on)
-		on = TRUE
-		processing = TRUE
-		if(!oldposition)
-			oldposition = get_turf(holder)
-	if(processing)
-		processing = FALSE
-		var/turf/T = get_turf(holder)
-		if(T != oldposition)
-			if(!T.has_gravity() || !nograv_required)
-				var/obj/effect/particle_effect/ion_trails/I = new effect_type(oldposition)
-				set_dir(I)
-				if(fade)
-					flick(fadetype, I)
-					I.icon_state = ""
-				spawn(20)
-					qdel(I)
-			oldposition = T
-		spawn(2)
-			if(on)
-				processing = TRUE
-				start()
-
-/datum/effect_system/trail_follow/ion/proc/set_dir(obj/effect/particle_effect/ion_trails/I)
+/datum/effect_system/trail_follow/proc/set_dir(obj/effect/particle_effect/ion_trails/I)
 	I.setDir(holder.dir)
 
 /datum/effect_system/trail_follow/ion/flight
 	effect_type = /obj/effect/particle_effect/ion_trails/flight
 	fadetype = "ion_fade_flight"
-	nograv_required = 0
+	nograv_required = FALSE
+	auto_process = FALSE
 
 /datum/effect_system/trail_follow/ion/flight/set_dir(obj/effect/particle_effect/ion_trails/I)
 	if(istype(holder, /obj/item/device/flightpack))
 		var/obj/item/device/flightpack/F = holder
-		I.setDir(F.suit.user.dir)
-
+		if(istype(F.wearer))
+			I.setDir(F.wearer.dir)
 
 //Reagent-based explosion effect
 

code/game/objects/objs.dm

@@ -189,7 +189,7 @@
 /obj/proc/check_uplink_validity()
 	return 1
 
-/obj/proc/on_mob_move(dir, mob, oldLoc)
+/obj/proc/on_mob_move(dir, mob, oldLoc, forced)
 	return
 
 /obj/proc/on_mob_turn(dir, mob)