keyloop microopt (#16710)

code/modules/client/client_defines.dm

@@ -121,5 +121,9 @@
 	/// Messages currently seen by this client
 	var/list/seen_messages
 
+	/// The direction we WANT to move, based off our keybinds
+	/// Will be udpated to be the actual direction later on
+	var/intended_direction = NONE
+
 	show_popup_menus = TRUE // right click menu no longer shows up
 	control_freak = CONTROL_FREAK_MACROS

code/modules/client/client_procs.dm

@@ -867,6 +867,7 @@
 						winset(src, "default-[REF(key)]", "parent=default;name=[key];command=[msay]")
 					else
 						winset(src, "default-[REF(key)]", "parent=default;name=[key];command=")
+	calculate_move_dir()
 
 /client/proc/change_view(new_size)
 	if(isnull(new_size))

code/modules/keybindings/bindings_atom.dm

@@ -1,18 +1,32 @@
 // You might be wondering why this isn't client level. If focus is null, we don't want you to move.
 // Only way to do that is to tie the behavior into the focus's keyLoop().
 /atom/movable/keyLoop(client/user)
-	if(user?.keys_held["Ctrl"])
+	// Clients don't go null randomly. They do go null unexpectedly though, when they're poked in particular ways
+	// keyLoop is called by a for loop over mobs. We're guarenteed that all the mobs have clients at the START
+	// But the move of one mob might poke the client of another, so we do this
+	if(!user)
+		return FALSE
+	if(user.keys_held["Ctrl"])
 		return
-	var/movement_dir = NONE
-	for(var/_key in user.keys_held)
-		movement_dir = movement_dir | user.movement_keys[_key]
-	if(user?.next_move_dir_add)
-		movement_dir |= user.next_move_dir_add
-	if(user?.next_move_dir_sub)
+	var/movement_dir = user.intended_direction | user.next_move_dir_add
+	// If we're not movin anywhere, we aren't movin anywhere
+	// Safe because nothing adds to movement_dir after this moment
+	if(!movement_dir)
+		// No input == our removal would have done nothing
+		// So we can safely forget about it
+		user.next_move_dir_sub = NONE
+		return FALSE
+	if(user.next_move_dir_sub)
 		movement_dir &= ~user.next_move_dir_sub
 	// Sanity checks in case you hold left and right and up to make sure you only go up
 	if((movement_dir & NORTH) && (movement_dir & SOUTH))
 		movement_dir &= ~(NORTH|SOUTH)
 	if((movement_dir & EAST) && (movement_dir & WEST))
 		movement_dir &= ~(EAST|WEST)
-	user?.Move(get_step(src, movement_dir), movement_dir)
+	user.Move(get_step(src, movement_dir), movement_dir)
+
+/client/proc/calculate_move_dir()
+	var/movement_dir = NONE
+	for(var/_key in keys_held)
+		movement_dir |= movement_keys[_key]
+	intended_direction = movement_dir

code/modules/keybindings/bindings_client.dm

@@ -43,8 +43,10 @@
 	//the time a key was pressed isn't actually used anywhere (as of 2019-9-10) but this allows easier access usage/checking
 	keys_held[_key] = world.time
 	var/movement = movement_keys[_key]
-	if(!(next_move_dir_sub & movement) && !keys_held["Ctrl"])
-		next_move_dir_add |= movement
+	if(movement)
+		calculate_move_dir()
+		if(!keys_held["Ctrl"] && !(next_move_dir_sub & movement))
+			next_move_dir_add |= movement
 
 	// Client-level keybindings are ones anyone should be able to do at any time
 	// Things like taking screenshots, hitting tab, and adminhelps.
@@ -86,8 +88,10 @@
 
 	keys_held -= _key
 	var/movement = movement_keys[_key]
-	if(!(next_move_dir_add & movement))
-		next_move_dir_sub |= movement
+	if(movement)
+		calculate_move_dir()
+		if(!keys_held["Ctrl"] && !(next_move_dir_add & movement))
+			next_move_dir_sub |= movement
 
 	// We don't do full key for release, because for mod keys you
 	// can hold different keys and releasing any should be handled by the key binding specifically

code/modules/mob/mob_movement.dm

@@ -65,8 +65,8 @@
 /client/Move(atom/newloc, direction, glide_size_override)
 	if(world.time < move_delay) //do not move anything ahead of this check please
 		return FALSE
-	next_move_dir_add = 0
-	next_move_dir_sub = 0
+	next_move_dir_add = NONE
+	next_move_dir_sub = NONE
 	var/old_move_delay = move_delay
 	move_delay = world.time + world.tick_lag //this is here because Move() can now be called mutiple times per tick
 	if(!mob?.loc)