Build 14

- Closes #10
- Closes #16
- Closes #20

README.txt

@@ -27,11 +27,11 @@ Here are some of the other highlights of the Mobs Lite engine:
  * Animals will attempt to flee to safety when a player that previously punched them 
    returns to the field of view.
 
- * Creatures avoid running into most obstacles by analyzing the surroundings and steadily
+ * Animals can be programmed to follow players that are wielding food and to eat directly
-   adjusting their course.
+   from the player's hand.
 
- * Mobs can be randomly spawned in the vicinity of players, thus relieving the overhead of 
+ * Seamless integration with Axon allows Mobs to react to various environmental stimulii
-   costly ABM-based spawners.
+   like smells, sounds, etc.
 
  * Timekeeper helper class ensures efficient dispatching of mob-related callbacks at the
    appropriate server step.
@@ -39,6 +39,12 @@ Here are some of the other highlights of the Mobs Lite engine:
  * Builtin lookup table allows for efficiently iterating over multiple classes of objects
    within a specific radius.
 
+ * Mobs can be randomly spawned in the vicinity of players, thus relieving the overhead of 
+   costly ABM-based spawners.
+
+ * Mobs will avoid running into most obstacles by analyzing the surroundings and steadily
+   adjusting their course.
+
  * And of course, much much more!
 
 Since Mobs Lite is still in early beta, there is the likelihood of lingering bugs. The API
@@ -70,6 +76,9 @@ TNT Mod (required)
 Default Mod (required)
   https://github.com/minetest-game-mods/default
 
+Axon Mod (optional)
+  https://bitbucket.org/sorcerykid/axon
+
 Installation
 ----------------------
 

animals.lua

@@ -34,21 +34,32 @@ mobs.register_mob( "mobs:kitten", {
 	hunger_params = { offset = -0.5, spread = 2.5 },
 	alertness_states = {
 		ignore = { view_offset = 2, view_radius = 4, view_height = 4, view_acuity = 3 },
+		search = { view_offset = 2, view_radius = 10, view_height = 4, view_acuity = 3, view_filter = function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "follow"
+                end },
 		follow = { view_offset = 2, view_radius = 10, view_height = 4, view_acuity = 3 },
 		escape = { view_offset = 2, view_radius = 10, view_height = 4, view_acuity = 3 },
 	},
+        awareness_stages = {
+                search = { decay = 12.0, abort_state = "ignore" },
+                follow = { decay = 0.0, abort_state = "search" },
+                escape = { decay = 12.0, abort_state = "ignore" },
+        },
+
 	certainty = 1.0,
 	sensitivity = 0.6,
 
-	fear_factor = 0,
+	fear_factor = 6,
 	flee_factor = 10,
+	sneak_velocity = 0.8,
 	walk_velocity = 0.8,
 	stray_velocity = 1.0,
 	recoil_velocity = 1.0,
 	run_velocity = 1.2,
-	escape_range = 3.0,
+	search_range = 3.0,
 	follow_range = 2.0,
 	pickup_range = 2.0,
+	escape_range = 3.0,
 	can_jump = false,
 	can_walk = true,
 	enable_fall_damage = true,
@@ -129,21 +140,32 @@ mobs.register_mob( "mobs:rat", {
 	hunger_params = { offset = 0.0, spread = 2.5 },
 	alertness_states = {
 		ignore = { view_offset = 0, view_radius = 3, view_height = 3, view_acuity = 4 },
+		search = { view_offset = 0, view_radius = 6, view_height = 3, view_acuity = 6, view_filter = function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "follow"
+                end },
 		follow = { view_offset = 0, view_radius = 6, view_height = 3, view_acuity = 6 },
 		escape = { view_offset = 0, view_radius = 6, view_height = 3, view_acuity = 6 },
 	},
+        awareness_stages = {
+                search = { decay = 12.0, abort_state = "ignore" },
+                follow = { decay = 0.0, abort_state = "search" },
+                escape = { decay = 12.0, abort_state = "ignore" },
+        },
+
 	certainty = 1.0,
 	sensitivity = 0.0,
 
 	fear_factor = 8,
 	flee_factor = 10,
+	sneak_velocity = 0.5,
 	walk_velocity = 0.5,
 	stray_velocity = 0.5,
 	recoil_velocity = 0.5,
 	run_velocity = 1.2,
-	escape_range = 0.0,
+	search_range = 2.0,
 	follow_range = 2.0,
 	pickup_range = 2.0,
+	escape_range = 0.0,
 	can_jump = false,
 	can_walk = true,
 	enable_fall_damage = true,
@@ -212,21 +234,32 @@ mobs.register_mob( "mobs:hare", {
 	hunger_params = { offset = 0.0, spread = 2.0 },
 	alertness_states = {
 		ignore = { view_offset = 0, view_radius = 2, view_height = 6, view_acuity = 0 },
+		search = { view_offset = 0, view_radius = 12, view_height = 6, view_acuity = 3, view_filter = function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "follow"
+                end },
 		follow = { view_offset = 0, view_radius = 12, view_height = 6, view_acuity = 3 },
 		escape = { view_offset = 0, view_radius = 12, view_height = 6, view_acuity = 3 },
 	},
+        awareness_stages = {
+                search = { decay = 12.0, abort_state = "ignore" },
+                follow = { decay = 0.0, abort_state = "search" },
+                escape = { decay = 12.0, abort_state = "ignore" },
+        },
+
 	certainty = 1.0,
 	sensitivity = 0.5,
 
 	fear_factor = 6,
 	flee_factor = 10,
+	sneak_velocity = 2.0,
 	walk_velocity = 3.0,
 	stray_velocity = 1.0,
 	recoil_velocity = 2.0,
 	run_velocity = 3.5,
-	escape_range = 3.0,
+	search_range = 3.0,
 	follow_range = 3.0,
 	pickup_range = 2.0,
+	escape_range = 3.0,
 	can_jump = true,
 	can_walk = true,
 	enable_fall_damage = true,
@@ -306,18 +339,29 @@ mobs.register_mob( "mobs:chicken", {
 	hunger_params = { offset = 0.0, spread = 2.0 },
 	alertness_states = {
 		ignore = { view_offset = 2, view_radius = 4, view_height = 4, view_acuity = 0 },
+		search = { view_offset = 2, view_radius = 6, view_height = 4, view_acuity = 2, view_filter = function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "follow"
+                end },
 		follow = { view_offset = 2, view_radius = 6, view_height = 4, view_acuity = 2 },
 		escape = { view_offset = 2, view_radius = 6, view_height = 4, view_acuity = 2 },
 	},
+        awareness_stages = {
+                search = { decay = 12.0, abort_state = "ignore" },
+                follow = { decay = 0.0, abort_state = "search" },
+                escape = { decay = 12.0, abort_state = "ignore" },
+        },
+
 	certainty = 1.0,
 	sensitivity = 0.3,
 
 	fear_factor = 2,
 	flee_factor = 10,
+	sneak_velocity = 1.5,
 	walk_velocity = 1.5,
 	stray_velocity = 1.0,
 	recoil_velocity = 2.0,
 	run_velocity = 2.0,
+	search_range = 3.0,
 	follow_range = 3.0,
 	pickup_range = 2.0,
 	escape_range = 3.0,

init.lua

@@ -20,6 +20,8 @@ local world_gravity = -10
 local liquid_density = 0.5
 local liquid_viscosity = 0.6
 
+local next_noise_id = 1
+
 --------------------
 
 local random = math.random
@@ -66,7 +68,7 @@ function Timekeeper( this )
 	end
 
 	self.start_now = function ( period, name, func )
-		if func( this, 0, period, 0.0, 0.0 ) then
+		if not func( this, 0, period, 0.0, 0.0 ) then
 			timer_defs[ name ] = { cycles = 0, period = period, expiry = clock + period, started = clock, func = func }
 		end
 	end
@@ -256,8 +258,9 @@ minetest.register_on_leaveplayer( function( player, is_timeout )
 
 	-- delete all target references (if applicable)
 	for id, obj in pairs( registry.avatars ) do
-		if obj:get_luaentity( ).target == player then
+		local this = obj:get_luaentity( )
-			this:reset_target( )
+		if this.target and this.target.obj == player then
+			this:reset_alertness( "ignore" )
 		end
 	end
 	registry.players[ name ] = nil
@@ -287,8 +290,9 @@ end
 
 builtin_item.on_deactivate = function ( self, id )
 	for id, obj in pairs( registry.avatars ) do
-		if obj:get_luaentity( ).target == self.object then
+		local this = obj:get_luaentity( )
-			this:reset_target( )
+		if this.target and this.target.obj == self.object then
+			this:reset_alertness( "ignore" )
 		end
 	end
 	registry.spawnitems[ id ] = nil
@@ -324,11 +328,13 @@ mobs.register_mob = function ( name, def )
 		receptrons = def.receptrons,
 		death_message = def.death_message,
 		alertness_states = def.alertness_states,
+		awareness_stages = def.awareness_stages,
 		sensitivity = def.sensitivity or 0.0,
 		certainty = def.certainty or 1.0,
 		attack_range = def.attack_range,
 		escape_range = def.escape_range,
 		follow_range = def.follow_range,
+		search_range = def.search_range,
 		pickup_range = def.pickup_range,
 		sneak_velocity = def.sneak_velocity,
 		walk_velocity = def.walk_velocity,
@@ -351,9 +357,9 @@ mobs.register_mob = function ( name, def )
 		shoot_period = def.shoot_period,
 		shoot_chance = def.shoot_chance,
 		weapon_params = def.weapon_params,
-		watch_wielditems = def.watch_wielditems,
+		watch_wielditems = def.watch_wielditems or { },
-		watch_spawnitems = def.watch_spawnitems,
+		watch_spawnitems = def.watch_spawnitems or { },
-		watch_players = def.watch_players,
+		watch_players = def.watch_players or { },
 		sounds = def.sounds,
 		animation = def.animation,
 		fear_factor = def.fear_factor,
@@ -365,11 +371,13 @@ mobs.register_mob = function ( name, def )
 		enable_swimming = true,
 		shoot_count = 0,
 		timeout = def.timeout,
+		neutral_state = "ignore",
+		defense_state = def.type == "monster" and "attack" or "ignore",	
 		is_tamed = false,
 		description = def.description,
 		after_activate = def.after_activate,
 		before_deactivate = def.before_deactivate,
-		after_state_change = def.after_state_change,
+		before_state_change = def.before_state_change,
 		before_punch = def.before_punch,
 
 		-- prepare noise generator with seed, octaves, persistence, spread
@@ -426,14 +434,14 @@ mobs.register_mob = function ( name, def )
 		get_direct_yaw_delta = function ( self, pos )
 			local yaw = self:get_direct_yaw( pos )
 			return abs( normalize_angle( yaw - self.yaw ) )
-		end
-
-		get_target_yaw = function ( self, pos, r_limit, r_ratio )
-			return self:get_direct_yaw( pos ) + upper_random( r_limit, r_ratio or 1 )
 		end,
 
-		get_target_yaw_delta = function ( self, pos )
+		get_target_yaw = function ( self, r_limit, r_ratio )
-			local yaw = self:get_direct_yaw( pos )
+			return self:get_direct_yaw( self.target.pos ) + upper_random( r_limit, r_ratio or 1 )
+		end,
+
+		get_target_yaw_delta = function ( self )
+			local yaw = self:get_direct_yaw( self.target.pos )
 			return abs( normalize_angle( yaw - self.yaw ) )
 		end,
 
@@ -482,7 +490,7 @@ mobs.register_mob = function ( name, def )
 		end,
 
 		play_sound = function ( self, name )
-			minetest.sound_play( name, { object = self.object } )
+			minetest.sound_play( name, { object = self.object, loop = false } )
 		end,
 
 		play_sound_repeat = function ( self, name )
@@ -504,31 +512,34 @@ mobs.register_mob = function ( name, def )
 
 		-- sensory processing --
 
-		check_suspect = function ( self, target, elapsed )
+		check_suspect = function ( self, target_obj, clarity, elapsed )
-			local entity = target:get_luaentity( )
+			-- default to defense or neutral state if not in any watch list
-			local suspect
+			local suspect = random( 10 ) <= self.fear_factor and self.defense_state or self.neutral_state
+			local entity = target_obj:get_luaentity( )
 
 			if not entity then
-				local player_name = target:get_player_name( )
+				local player_name = target_obj:get_player_name( )
-				local item_name = target:get_wielded_item( ):get_name( )
+				local item_name = target_obj:get_wielded_item( ):get_name( )
-				suspect = self.watch_players[ player_name ] or self.watch_wielditems[ item_name ]
+				suspect = self.watch_players[ player_name ] or self.watch_wielditems[ item_name ] or suspect
 			elseif entity.name == "__builtin:item" then
-				suspect = self.watch_spawnitems[ entity.item_name ]
+				suspect = self.watch_spawnitems[ entity.item_name ] or suspect
 			end
 
 			if type( suspect ) == "function" then
-				return suspect( self, target, elapsed or 0.0 )
+				return suspect( self, target_obj, clarity, elapsed or 0.0 )  -- must always return a valid state
 			else
 				return suspect
 			end
 		end,
 
-		is_paranoid = function ( self, target_pos )
+		get_visibility = function ( self, target_pos )
 			local length = get_vector_length( self.pos, target_pos )
+			local height = get_vector_height( self.pos, target_pos )
 			local this = self.alertness
 
-			if not this or length > 48 then
+			if not this or length > 48 or height > 48 then  -- immediately eliminate far objects
-				return false
+				return 0.0, false, false
+
 			else
 				local view_range = this.view_radius + this.view_offset
 				local view_pos = this.view_offset == 0.0 and self.pos or vector.new(
@@ -538,93 +549,123 @@ mobs.register_mob = function ( name, def )
 				)
 
 				local radius = get_vector_length( view_pos, target_pos )
-				local height = get_vector_height( view_pos, target_pos )
 				local clarity = get_power_decrease( 1.0, this.view_acuity, length / view_range )
 
 				-- certainty factor ranges from 0 (target never evident) to 1 (target always evident)
 				-- sensitivity threshold ranges from 0 (full perception) to 1 (no perception)
 
 				--node_locator( vector.offset_y( view_pos ), 4.5, 1.0, "yellow" )
-				--printf( "is_paranoid(%s):\n[%s] radius <= view_radius\n[%s] height <= view_height\n%0.2f = clarity (%0.2f = sensitivity, %0.2f = certainty)", self.name, radius <= this.view_radius and "x" or " ", height <= this.view_height and "x" or " ", clarity, self.sensitivity, self.certainty )
+				--printf( "is_paranoid(%s):\n[%s] radius <= view_radius\n[%s] height <= view_height\n%0.2f = clarity (%0.2f = sensitivity, %$
 
-				return radius <= this.view_radius and height <= this.view_height and
+				local is_visible = radius <= this.view_radius and height <= this.view_height
-					clarity > self.sensitivity and clarity * self.certainty > random( )
+				local is_evident = clarity > self.sensitivity and clarity * self.certainty > random( )
+
+				return clarity, is_visible, is_evident
 			end
 		end,
 
-		-- state-change handlers --
+		-- target functions --
 
-		reset_target = function ( self )
+		create_target = function ( self, obj )
-			if self.target then
+			local pos = obj:get_pos( )
-				self:set_ignore_state( )
+			local clarity, is_visible, is_evident = self:get_visibility( pos )
+			local alertness = self.alertness_states[ self.state ]
+
+			-- when creating target it must be visible and evident!
+			if is_visible and is_evident then
+				if alertness and alertness.view_filter then
+					return alertness.view_filter( self, obj, clarity ), { obj = obj, pos = pos }
+				elseif clarity > 0.0 then
+					return self:check_suspect( obj, clarity ), { obj = obj, pos = pos }
+				end
+			else
+				return self.state, self.target
 			end
 		end,
 
-		set_ignore_state = function ( self )
+		verify_target = function ( self, elapsed )
-			if self.state == "ignore" then return end
+			if self.target.obj then
+				local target_pos = self.target.obj:get_pos( )  -- check target's new position
+				local clarity, is_visible, is_evident = self:get_visibility( target_pos )
+				local alertness = self.alertness_states[ self.state ]
 
-			self.state = "ignore"
+				-- update last-known target position only if visible and evident
-			self.target = nil
+				if is_visible and is_evident then
-			self.alertness = self.alertness_states.ignore
+					self.target.pos = target_pos
-			self.is_tamed = false
+				else
+					clarity = 0.0
+				end
 
-			if self.custom.after_state_change then
+				if alertness and alertness.view_filter then
-				self.custom.after_state_change( self )
+					return alertness.view_filter( self, self.target.obj, clarity )
+				elseif clarity > 0.0 then
+					return self:check_suspect( self.target.obj, clarity, elapsed )
+				else
+					return self.abort_state or self.neutral_state
+				end
 			end
 
-			self:start_ignore_action( )
+			return self.state
 		end,
 
-		set_escape_state = function ( self, target )
+		locate_target = function ( self )
-			if self.state == "escape" then return end
+			if self.sounds and self.sounds.random and random( 35 ) == 1 then
-			self.state = "escape"
+				minetest.sound_play( self.sounds.random, { object = self.object } )
+			end
+
+			-- when not upset, seek out food or prey at random intervals
+			for obj in mobs.iterate_registry( self.pos, 30, 30, { players = true, spawnitems = true } ) do
+
+				if random( 10 ) <= self.fear_factor and obj:is_player( ) and not obj:get_attach( ) then
+					local state, target = self:create_target( obj )
+					if state ~= self.state then
+						self:reset_alertness( state, target )
+						return
+					end
+				end
+			end
+		end,
+
+		-- alertness and awareness functions --
+
+		start_awareness = function ( self, target )
+			local awareness = self.awareness_stages[ self.state ]
+
+			if awareness then
+				self.abort_state = awareness.abort_state
+				if awareness.decay > 0 then
+					self.timekeeper.start( awareness.decay, "awareness", function ( )
+						self:reset_alertness( self.abort_state, self.target )
+					end )
+				else
+					self.timekeeper.clear( "awareness" )
+				end
+			else
+				self.abort_state = nil
+				self.timekeeper.clear( "awareness" )
+			end
+		end,
+
+		reset_alertness = function ( self, state, target )
+			if state == self.state then return end
+
+			if self.before_state_change then
+				self:before_state_change( self.state, state )
+			end
+
+			self.state = state
 			self.target = target
-			self.alertness = self.alertness_states.escape
+			self.alertness = self.alertness_states[ state ]
-			self.is_tamed = false
 
-			if random( 2 ) == 1 then
+			self:start_awareness( )
-				-- this is a bad player, so keep watch
+			self.action_funcs[ state ]( self )
-				self.watch_players[ target:get_player_name( ) ] = "escape"
-			end
-
-			if self.custom.after_state_change then
-				self.custom.after_state_change( self )
-			end
-
-			self:start_escape_action( )
-		end,
-
-		set_follow_state = function ( self, target )
-			if self.state == "follow" then return end
-			self.state = "follow"
-			self.target = target
-			self.alertness = self.alertness_states.follow
-			self.is_tamed = true
-
-			if self.custom.after_state_change then
-				self.custom.after_state_change( self )
-			end
-
-			self:start_follow_action( )
-		end,
-
-		set_attack_state = function ( self, target )
-			if self.state == "attack" then return end
-			self.state = "attack"
-			self.target = target
-			self.alertness = self.alertness_states.attack
-			self.is_tamed = false
-
-			if self.custom.after_state_change then
-				self.custom.after_state_change( self )
-			end
-
-			self:start_attack_action( )
 		end,
 
 		-- action hooks --
 
 		start_ignore_action = function ( self )
+			self.target = nil  -- forget any target
+
 			if not self.move_result.is_standing then
 				-- always stand when in mid-air
 				self:set_speed( 0 )
@@ -637,7 +678,7 @@ mobs.register_mob = function ( name, def )
 				self:set_animation( "stand" )
 			end
 
-			self.timekeeper.start( 1.0, "hunger", self.handle_hunger )
+			self.timekeeper.start( 1.0, "hunger", self.locate_target )
 			self.timekeeper.start( 1.0, "action", self.on_ignore_action )
 		end,
 
@@ -727,6 +768,8 @@ mobs.register_mob = function ( name, def )
 		end,
 
 		start_follow_action = function ( self )
+			assert( self.target.pos )  -- sanity check
+
 			self:turn_to( self:get_target_yaw( rad_20 ), 10 )
 			self:set_speed( self.recoil_velocity )
 			self:set_animation( "walk" )
@@ -736,13 +779,10 @@ mobs.register_mob = function ( name, def )
 		end,
 
 		on_follow_action = function ( self, cycles, period, elapsed )
-			local target_pos = self:get_target_pos( 0.5 )
+			if cycles % 2 == 0 then  -- validate target every 1.0 seconds
-			local dist = vector.distance( self.pos, target_pos )
+				local goal_state = self:verify_target( )
-
+				if goal_state ~= self.state then
-			if cycles % 2 == 0 then
+					self:reset_alertness( goal_state, self.target )
-				local next_state = validate_target( )
-				if next_state ~= self.state then
-					self:reset_state( next_state, self.target )
 					return
 				end
 			end
@@ -753,6 +793,9 @@ mobs.register_mob = function ( name, def )
 				end
 			end
 
+			local target_pos = self.target.pos
+			local dist = vector.distance( self.pos, target_pos )
+
 			if dist <= self.follow_range then
 				if self.speed > 0 then
 					self:set_speed( 0 )
@@ -786,10 +829,71 @@ mobs.register_mob = function ( name, def )
 			end
 		end,
 
-		start_escape_action = function ( self )
+		start_search_action = function ( self )
-			local target_pos = vector.offset_y( self.target:get_pos( ) )
+			assert( self.target.pos )  -- sanity check
-			local dist = vector.distance( self.pos, self.target.pos )
 
+			self:turn_to( self:get_target_yaw( rad_5 ), 10 )
+			self:set_speed( self.walk_velocity )
+			self:set_animation( "walk" )
+
+			self.timekeeper.clear( "hunger" )
+			self.timekeeper.start( 0.5, "action", self.on_search_action )
+		end,
+
+		on_search_action = function ( self, cycles, period, elapsed )
+			if cycles % 2 == 0 then  -- validate target every 1.0 seconds
+				local goal_state = self:verify_target( )
+				if goal_state ~= self.state then
+					self:reset_alertness( goal_state, self.target )
+					return
+				end
+			end
+
+			local target_pos = self.target.pos
+			local dist = vector.distance( self.pos, target_pos )
+
+			-- go to last known position of target and look around
+			if dist <= self.search_range then
+				if self.speed > 0 then
+					self:set_speed( 0 )
+					self:set_animation( "stand" )
+				end
+
+				if random( 4 ) == 1 then
+					self:turn_to( self:get_random_yaw( rad_180 ), 20 )
+				end
+			else
+				if self.speed == 0 then
+					self:set_speed( self.walk_velocity )
+					self:set_animation( "walk" )
+
+				else
+					if self.can_fly then
+						-- descend or ascend to slightly above player altitude, but prevent incessant bobbing
+						local v = 0
+						if target_pos.y + 2.5 > self.pos.y then
+							v = self.walk_velocity
+						elseif target_pos.y + 0.5 < self.pos.y then
+							v = -self.walk_velocity
+						end
+						self:set_velocity_vert( v )
+
+					elseif self.can_jump and self.move_result.is_standing then
+						if self.yield_level < 3 and self.move_result.collides_xz then
+							self.yield_level = self.yield_level + 1
+							self.object:set_velocity_vert( 5 )
+						elseif random( 2 ) == 1 then
+							self.object:set_velocity_vert( 5 )
+						end
+					end
+				end
+			end
+		end,
+
+		start_escape_action = function ( self )
+			assert( self.target.pos )  -- sanity check
+
+			local dist = vector.distance( self.pos, self.target.pos )
 			if self:get_target_yaw_delta( ) < rad_60 and dist <= self.escape_range then
 				-- recoil if facing intruder
 				self:set_speed( -self.recoil_velocity )
@@ -804,6 +908,11 @@ mobs.register_mob = function ( name, def )
 				self:set_animation( "walk" )
 			end
 
+			if self.target.obj and self.target.obj:is_player( ) then
+				-- this is a bad player, so keep watch
+				self.watch_players[ self.target.obj:get_player_name( ) ] = "escape"
+			end
+
 			if self.sounds and self.sounds.escape and random( 2 ) == 1  then
 				minetest.sound_play( self.sounds.escape, { object = self.object } )
 			end
@@ -813,16 +922,17 @@ mobs.register_mob = function ( name, def )
 		end,
 
 		on_escape_action = function ( self, cycles, period, elapsed )
-			local target_pos = self:get_target_pos( 0.5 )
-			local dist = vector.distance( self.pos, target_pos )
-
 			if cycles % 2 == 0 then
-				if not self:is_paranoid( elapsed ) or random( 10 ) > self.flee_factor then
+				local goal_state = self:verify_target( )
-					self:lower_awareness( )
+				if goal_state ~= self.state or random( 10 ) > self.flee_factor then
+					self:reset_alertness( goal_state, self.target )
 					return
 				end
 			end
 
+			local target_pos = self.target.pos
+			local dist = vector.distance( self.pos, target_pos )
+
 			if dist <= self.escape_range then
 				-- if close, keep backtracking
 				if cycles % 2 == 0 then
@@ -867,6 +977,8 @@ mobs.register_mob = function ( name, def )
 		end,
 
 		start_attack_action = function ( self )
+			assert( self.target.pos and self.target.obj )  -- sanity check
+
 			self:set_speed( self.run_velocity )
 			self:set_animation( "run" )
 			self:turn_to( self:get_target_yaw( rad_90 ), 10 )
@@ -880,23 +992,24 @@ mobs.register_mob = function ( name, def )
 		end,
 
 		on_attack_action = function ( self, cycles, period, elapsed )
-			if self.target:get_hp( ) == 0 or self.target:get_attach( ) then
+			if self.target.obj:get_hp( ) == 0 or self.target.obj:get_attach( ) then
-				self:set_ignore_state( )
+				self:reset_alertness( "ignore" )
 				return
 			end
 
 			if cycles % 5 == 0 then  -- validate target once per second
-				if not self:is_paranoid( elapsed ) then
+				local goal_state = self:verify_target( )
-					self:lower_awareness( )
+				if goal_state ~= self.state then
+					self:reset_alertness( goal_state, self.target )
 					return
 				end
 			end
 
-			self:turn_to( self:get_target_yaw( rad_0 ), 5 )
+			local target_pos = self.target.pos
-
-			local target_pos = vector.offset_y( self.target.pos, 0.5 )
 			local dist = vector.distance( self.pos, target_pos )
 
+			self:turn_to( self:get_target_yaw( rad_0 ), 5 )
+
 			if dist <= self.attack_range then
 				if self.attack_type == "shoot" and self.fire_weapon then
 					if cycles % ( self.shoot_period * 5 ) == 0 and random( self.shoot_chance ) == 1 then
@@ -915,7 +1028,7 @@ mobs.register_mob = function ( name, def )
 							minetest.sound_play( self.sounds.attack, { object = self.object } )
 						end
 					--      if minetest.line_of_sight( pos, target_pos, 0.5 ) then  -- do not hit player through walls!
-							self.target:punch( self.object, 1.0,  {
+							self.target.obj:punch( self.object, 1.0,  {
 								full_punch_interval = 1.0,
 								damage_groups = { fleshy=self.damage }
 							}, vector.direction( self.pos, target_pos ) )
@@ -1027,7 +1140,7 @@ mobs.register_mob = function ( name, def )
 			self.cur_animation = type
 		end,
 
-		-- damage and hunger routines --
+		-- damage handler --
 
 		handle_damage = function ( self )
 			-- handle environmental damage (light, water, and lava)
@@ -1066,24 +1179,6 @@ mobs.register_mob = function ( name, def )
 			end
 		end,
 
-		locate_target = function ( self )
-			if self.sounds and self.sounds.random and random( 35 ) == 1 then
-				minetest.sound_play( self.sounds.random, { object = self.object } )
-			end
-
-			-- when not upset, seek out food or prey at random intervals
-			for obj in mobs.iterate_registry( self.pos, 30, 30, { players = true, spawnitems = true } ) do
-
-				if random( 10 ) <= self.fear_factor and obj:is_player( ) and not obj:get_attach( ) then
-					local state, target = self:create_target( obj )
-					if state ~= self.state then
-						self:reset_state( state, target )
-						return
-					end
-				end
-			end
-		end,
-
 		-- generic callbacks --
 		
 		on_step = function( self, dtime, pos, rot, new_vel, old_vel, move_result )
@@ -1153,19 +1248,13 @@ mobs.register_mob = function ( name, def )
 			self.move_result = { collides_xz = false, collides_y = true, is_standing = true }
 			self.pos = self.object:get_pos( )
 
-			if self.type == "monster" then
+			self.action_funcs = {
-				self.on_create_target = function ( obj, clarity )
+				ignore = self.start_ignore_action,
-					return clarity < 0.5 and "search" or "attack"
+				remark = self.start_remark_action,
-				end
+				search = self.start_search_action,
-			else
+				follow = self.start_follow_action,
-				self:set_escape_state( obj )
+				escape = self.start_escape_action,
-				return
+				attack = self.start_attack_action,
-			end
-
-			self.reset_funcs = {
-				ignore = self.set_ignore_state,
-				remark = self.set_remark_state,
-				search = self.set_search_state,
 			}
 
 			if staticdata then
@@ -1191,7 +1280,7 @@ mobs.register_mob = function ( name, def )
 				self.after_activate( self, id )
 			end
 
-			self:set_ignore_state( )
+			self:reset_alertness( self.neutral_state )
 		end,
 
 		on_deactivate = function ( self, id )
@@ -1238,9 +1327,9 @@ mobs.register_mob = function ( name, def )
 				end
 
 				if hp - damage <= self.hp_low then
-					self:set_escape_state( hitter )
+					self:reset_alertness( "escape", { obj = hitter, pos = hitter:get_pos( ) } )
 				elseif self.type == "monster" then
-					self:set_attack_state( hitter )
+					self:reset_alertness( "attack", { obj = hitter, pos = hitter:get_pos( ) } )
 				end
 			end
 		end,
@@ -1373,18 +1462,18 @@ end
 
 --------------------
 
-mobs.play_sound = function ( obj, name )
+mobs.play_sound = function ( pos, name )
-        minetest.sound_play( name, { loop = false }, true )
+	minetest.sound_play( name, { loop = false }, true )
 end
 
 mobs.make_noise = function ( pos, radius, group, intensity )
-	axon.generate_radial_stimulus( pos, radius, 0.0, 0.0, 1, { [group] = intensity }, { avatars = true } )
+	axon.generate_radial_stimulus( pos, radius, 0.0, 0.0, { [group] = intensity }, { avatars = true } )
 end
 
 mobs.make_noise_repeat = function ( pos, radius, interval, duration, group, intensity )
 	globaltimer.start_now( interval, "noise" .. next_noise_id, function ( this, cycles, period, elapsed )
 		if elapsed >= duration then return true end  -- we're finished, so cancel timer
-		axon.generate_radial_stimulus( pos, radius, 0.0, 0.0, 1, { [group] = intensity }, { avatars = true } )
+		axon.generate_radial_stimulus( pos, radius, 0.0, 0.0, { [group] = intensity }, { avatars = true } )
 	end )
 	next_noise_id = next_noise_id + 1
 end
@@ -1412,11 +1501,11 @@ mobs.presets = {
 				local dist = vector.distance( self.pos, target_pos )
 
 				if self:get_direct_yaw_delta( target_pos ) < rad_30 and dist <= self.pickup_range then
-					if target:is_player( ) then
+					if target_obj:is_player( ) then
-						target:get_wielded_item( ):take_item( )
+						target_obj:get_wielded_item( ):take_item( )
-						target:set_wielded_item( "" )
+						target_obj:set_wielded_item( "" )
-					elseif target:get_entity_name( ) == "__builtin:item" then
+					elseif target_obj:get_entity_name( ) == "__builtin:item" then
-						target:remove( )
+						target_obj:remove( )
 					end
 					if can_eat then
 					--	minetest.sound_play( "hbhunger_eat_generic", {

monsters.lua

@@ -35,9 +35,19 @@ mobs.register_mob( "mobs:ghost", {
 	hunger_params = { offset = -0.1, spread = 3.0 },
 	alertness_states = {
 		ignore = { view_offset = 2, view_radius = 8, view_height = 8, view_acuity = 0 },
-		attack = { view_offset = 2, view_radius = 14, view_height = 8, view_acuity = 3 },
+		search = { view_offset = 2, view_radius = 14, view_height = 8, view_acuity = 3, view_filter =  function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "attack"
+                end },
+		attack = { view_offset = 2, view_radius = 14, view_height = 8, view_acuity = 3 , view_filter =  function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "attack"
+                end },
 		escape = { view_offset = 2, view_radius = 14, view_height = 8, view_acuity = 3 },
 	},
+	awareness_stages = {
+		attack = { decay = 15.0, abort_state = "ignore" },
+		escape = { decay = 10.0, abort_state = "ignore" },
+	},
+
 	certainty = 1.0,
 	sensitivity = 0.2,
 
@@ -46,8 +56,9 @@ mobs.register_mob( "mobs:ghost", {
 	attack_type = "melee",
 	standoff = 4.0,
 	attack_range = 6.0,
+	search_range = 2.5,
 	escape_range = 2.5,
-	sneak_velocity = 0.2,
+	sneak_velocity = 0.5,
 	walk_velocity = 0.5,
 	recoil_velocity = 1.5,
 	run_velocity = 1.5,
@@ -126,9 +137,20 @@ mobs.register_mob( "mobs:spider", {
 	hunger_params = { offset = 0.3, spread = 4.0 },
 	alertness_states = {
 		ignore = { view_offset = 6, view_radius = 6, view_height = 6, view_acuity = 3 },
-		attack = { view_offset = 6, view_radius = 12, view_height = 6, view_acuity = 5 },
+		search = { view_offset = 6, view_radius = 12, view_height = 6, view_acuity = 5, view_filter =  function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "attack"
+                end },
+		attack = { view_offset = 6, view_radius = 12, view_height = 6, view_acuity = 5, view_filter =  function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "attack"
+                end },
 		escape = { view_offset = 6, view_radius = 12, view_height = 6, view_acuity = 5 },
 	},
+	awareness_stages = {
+		search = { decay = 18.0, abort_state = "ignore" },
+		attack = { decay = 0.0, abort_state = "search" },
+		escape = { decay = 18.0, abort_state = "ignore" },
+	},
+
 	certainty = 1.0,
 	sensitivity = 0.2,
 
@@ -136,7 +158,9 @@ mobs.register_mob( "mobs:spider", {
 	flee_factor = 8,
 	attack_type = "melee",
 	attack_range = 3.0,
+	search_range = 3.0,
 	escape_range = 3.0,
+	sneak_velocity = 0.5,
 	walk_velocity = 1.0,
 	stray_velocity = 1.0,
 	recoil_velocity = 0.5,
@@ -174,10 +198,7 @@ mobs.register_mob( "mobs:spider", {
 		damage_hand = "mobs_damage_hand",
 	},
 	drops = {
-		{ name = "farming:blueberries", chance = 6, min = 1, max = 2 },
-		{ name = "farming:raspberries", chance = 6, min = 1, max = 2 },
 		{ name = "default:grass_1", chance = 8, min = 1, max = 2 },
-		{ name = "default:shrub", chance = 8, min = 1, max = 2 },
 	},
 	on_rightclick = nil,
 } ) 
@@ -220,9 +241,20 @@ mobs.register_mob( "mobs:bat", {
 	hunger_params = { offset = 1.0, spread = 1.0 },
 	alertness_states = {
 		ignore = { view_offset = 10, view_radius = 15, view_height = 15, view_acuity = 3 },
-		attack = { view_offset = 10, view_radius = 20, view_height = 15, view_acuity = 5 },
+		search = { view_offset = 10, view_radius = 20, view_height = 15, view_acuity = 5, view_filter =  function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "attack"
+                end },
+		attack = { view_offset = 10, view_radius = 20, view_height = 15, view_acuity = 5, view_filter =  function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "attack"
+                end },
 		escape = { view_offset = 10, view_radius = 20, view_height = 15, view_acuity = 3 },
 	},
+	awareness_stages = {
+		search = { decay = 14.0, abort_state = "ignore" },
+		attack = { decay = 0.0, abort_state = "search" },
+		escape = { decay = 14.0, abort_state = "ignore" },
+	},
+
 	certainty = 1.0,
 	sensitivity = 0.3,
 
@@ -230,6 +262,7 @@ mobs.register_mob( "mobs:bat", {
 	flee_factor = 6,
 	attack_type = "melee",
 	attack_range = 3.0,
+	search_range = 5.0,
 	escape_range = 5.0,
 	sneak_velocity = 1.0,
 	walk_velocity = 1.0,
@@ -271,7 +304,6 @@ mobs.register_mob( "mobs:bat", {
 	},
 	drops = {
 		{ name = "default:apple", chance = 4, min = 1, max = 2 },
-		{ name = "default:orange", chance = 4, min = 1, max = 2 },
 	},
 } )
 
@@ -313,9 +345,20 @@ mobs.register_mob( "mobs:griefer_ghost", {
 	hunger_params = { offset = 0.3, spread = 6.0 },
 	alertness_states = {
 		ignore = { view_offset = 5, view_radius = 10, view_height = 8, view_acuity = 2 },
-		attack = { view_offset = 5, view_radius = 20, view_height = 8, view_acuity = 2 },
+		search = { view_offset = 5, view_radius = 20, view_height = 8, view_acuity = 2, view_filter =  function ( self, obj, clarity )
+        	        return clarity == 0.0 and "search" or "attack"
+	        end },
+		attack = { view_offset = 5, view_radius = 20, view_height = 8, view_acuity = 2, view_filter =  function ( self, obj, clarity )
+                        return clarity == 0.0 and "search" or "attack"
+                end },
 		escape = { view_offset = 5, view_radius = 20, view_height = 8, view_acuity = 2 },
 	},
+	awareness_stages = {
+		search = { decay = 8.0, abort_state = "ignore" },
+		attack = { decay = 25.0, abort_state = "search" },
+		escape = { decay = 8.0, abort_state = "ignore" },
+	},
+
 	certainty = 1.0,
 	sensitivity = 0.6,
 
@@ -323,7 +366,9 @@ mobs.register_mob( "mobs:griefer_ghost", {
 	flee_factor = 10,
 	attack_type = "melee",
 	attack_range = 3.0,
+	search_range = 4.0,
 	escape_range = 4.0,
+	sneak_velocity = 0.5,
 	walk_velocity = 1.0,
 	stray_velocity = 1.0,
 	recoil_velocity = 0.5,
@@ -360,9 +405,6 @@ mobs.register_mob( "mobs:griefer_ghost", {
 	},
 	drops = {
 		{ name = "default:papyrus", chance = 6, min = 1, max = 2 },
-		{ name = "default:cactus", chance = 6, min = 1, max = 2 },
-		{ name = "farming:pumpkin_slice", chance = 8, min = 1, max = 2 },
-		{ name = "farming:melon_slice", chance = 8, min = 1, max = 2 },
 	},
 } )