Implement method to despawn sneekers that aren't near any players

TODO.txt

@@ -1,3 +1,2 @@
 
 TODO:
-- add option to remove mobs that aren't near any players

init.lua

@@ -114,8 +114,11 @@ def.on_activate = function(self, staticdata)
 	self.knockback = false
 	self.state = math.random(1, 2)
 	self.old_y = self.object:get_pos().y
+
+	-- despawning
 	self.lifetime = sneeker.lifetime
 	self.lifetimer = 0
+	self.check_despawn_player_distance = true
 
 	local data = core.deserialize(staticdata)
 	if data and type(data) == "table" then
@@ -154,6 +157,33 @@ def.on_step = function(self, dtime)
 	local ANIM_WALK  = 2
 
 	local pos = self.object:get_pos()
+
+	if sneeker.despawn_player_far then
+		-- run check about once per 60 seconds
+		local interval_reached = math.floor(self.lifetimer % 60) == 0
+		if not interval_reached and not self.check_despawn_player_distance then
+			self.check_despawn_player_distance = true
+		end
+
+		if interval_reached and self.check_despawn_player_distance then
+			local player_nearby = false
+			for _, entity in ipairs(core.get_objects_inside_radius(pos, sneeker.despawn_player_radius)) do
+				if entity:is_player() then
+					player_nearby = true
+					break
+				end
+			end
+
+			if not player_nearby then
+				self.object:remove()
+				return true
+			end
+
+			-- set flag to not check again until next interval
+			self.check_despawn_player_distance = false
+		end
+	end
+
 	local yaw = self.object:get_yaw()
 	local inside = core.get_objects_inside_radius(pos, 10)
 	local walk_speed = self.walk_speed

settings.lua

@@ -27,6 +27,18 @@ sneeker.spawn_require_player_nearby = core.settings:get_bool("sneeker.spawn_requ
 --  @setting sneeker.spawn_player_radius
 sneeker.spawn_player_radius = tonumber(core.settings:get("sneeker.spawn_player_radius") or 100)
 
+--- If enabled, mobs not near any players will despawn.
+--
+--  @setting sneeker.despawn_player_far
+sneeker.despawn_player_far = core.settings:get_bool("sneeker.despawn_player_far", true)
+
+--- Distance determining if a player is near enough to prevent despawn.
+--
+--  Only used if `sneeker.despawn_player_far` enabled.
+--
+--  @setting sneeker.despawn_player_radius
+sneeker.despawn_player_radius = tonumber(core.settings:get("sneeker.despawn_player_radius") or 500)
+
 --- Sets possibility for spawn.
 --
 --  Inverted value (e.g. 10000 = 1/10000).

settingtypes.txt

@@ -13,12 +13,20 @@ sneeker.lifetime (Sneeker lifetime) int 900
 sneeker.boom_gain (Boom volume) float 1.5
 
 # Determines whether or not a player must be close for spawn to occur.
-sneeker.spawn_require_player_nearby (Require player nearby) bool true
+sneeker.spawn_require_player_nearby (Require player nearby for spawn) bool true
 
 # Distance in nodes a player must be for spawn to occur.
 #
 # Only used if `sneeker.spawn_require_player_nearby` enabled.
-sneeker.spawn_player_radius (Player detect radius) int 100
+sneeker.spawn_player_radius (Player spawn detect radius) int 100
+
+# If enabled, mobs not near any players will despawn.
+sneeker.despawn_player_far (Despawn sneekers not near players) bool true
+
+# Distance determining if a player is near enough to prevent despawn.
+#
+# Only used if `sneeker.despawn_player_far` enabled.
+sneeker.despawn_player_radius (Player despawn detect radius) int 500
 
 # Sets possibility for spawn.
 #