VoxeLibre/mods/ENTITIES/mcl_mobs/backup_code_api.lua

local disable_physics = function(object, luaentity, ignore_check, reset_movement)
	if luaentity.physical_state == true or ignore_check == true then
		luaentity.physical_state = false
		object:set_properties({
			physical = false
		})
		if reset_movement ~= false then
			object:set_velocity({x=0,y=0,z=0})
			object:set_acceleration({x=0,y=0,z=0})
		end
	end
end

----For Water Flowing:
local enable_physics = function(object, luaentity, ignore_check)
	if luaentity.physical_state == false or ignore_check == true then
		luaentity.physical_state = true
		object:set_properties({
			physical = true
		})
		object:set_velocity({x=0,y=0,z=0})
		object:set_acceleration({x=0,y=-9.81,z=0})
	end
end

--[[
local timer = 0
minetest.register_globalstep(function(dtime)
	timer = timer + dtime
	if timer < 1 then return end
	for _, player in pairs(minetest.get_connected_players()) do
		local pos = player:get_pos()
		for _, obj in pairs(minetest_get_objects_inside_radius(pos, 47)) do
			local lua = obj:get_luaentity()
			if lua and lua._cmi_is_mob then
				lua.lifetimer = math.max(20, lua.lifetimer)
				lua.despawn_immediately = false
			end
		end
	end
	timer = 0
end)
]]--

-- compatibility function for old entities to new modpack entities
function mobs:alias_mob(old_name, new_name)

	-- spawn egg
	minetest.register_alias(old_name, new_name)

	-- entity
	minetest.register_entity(":" .. old_name, {

		physical = false,

		on_step = function(self)

			if minetest_registered_entities[new_name] then
				minetest_add_entity(self.object:get_pos(), new_name)
			end

			self.object:remove()
		end
	})
end


-- Spawn a child
function mobs:spawn_child(pos, mob_type)
	local child = minetest_add_entity(pos, mob_type)
	if not child then
		return
	end

	local ent = child:get_luaentity()
	effect(pos, 15, "mcl_particles_smoke.png", 1, 2, 2, 15, 5)

	ent.child = true

	local textures
	-- using specific child texture (if found)
	if ent.child_texture then
		textures = ent.child_texture[1]
	end

	-- and resize to half height
	child:set_properties({
		textures = textures,
		visual_size = {
			x = ent.base_size.x * .5,
			y = ent.base_size.y * .5,
		},
		collisionbox = {
			ent.base_colbox[1] * .5,
			ent.base_colbox[2] * .5,
			ent.base_colbox[3] * .5,
			ent.base_colbox[4] * .5,
			ent.base_colbox[5] * .5,
			ent.base_colbox[6] * .5,
		},
		selectionbox = {
			ent.base_selbox[1] * .5,
			ent.base_selbox[2] * .5,
			ent.base_selbox[3] * .5,
			ent.base_selbox[4] * .5,
			ent.base_selbox[5] * .5,
			ent.base_selbox[6] * .5,
		},
	})

	return child
end


-- No-op in MCL2 (capturing mobs is not possible).
-- Provided for compability with Mobs Redo
function mobs:capture_mob(self, clicker, chance_hand, chance_net, chance_lasso, force_take, replacewith)
	return false
end


-- No-op in MCL2 (protecting mobs is not possible).
function mobs:protect(self, clicker)
	return false
end


-- feeding, taming and breeding (thanks blert2112)
function mobs:feed_tame(self, clicker, feed_count, breed, tame)
	if not self.follow then
		return false
	end

	-- can eat/tame with item in hand
	if follow_holding(self, clicker) then

		-- if not in creative then take item
		if not mobs.is_creative(clicker:get_player_name()) then

			local item = clicker:get_wielded_item()

			item:take_item()

			clicker:set_wielded_item(item)
		end

		mob_sound(self, "eat", nil, true)

		-- increase health
		self.health = self.health + 4

		if self.health >= self.hp_max then

			self.health = self.hp_max

			if self.htimer < 1 then
				self.htimer = 5
			end
		end

		self.object:set_hp(self.health)

		update_tag(self)

		-- make children grow quicker
		if self.child == true then

			-- deduct 10% of the time to adulthood
			self.hornytimer = self.hornytimer + ((CHILD_GROW_TIME - self.hornytimer) * 0.1)

			return true
		end

		-- feed and tame
		self.food = (self.food or 0) + 1
		if self.food >= feed_count then

			self.food = 0

			if breed and self.hornytimer == 0 then
				self.horny = true
			end

			if tame then

				self.tamed = true

				if not self.owner or self.owner == "" then
					self.owner = clicker:get_player_name()
				end
			end

			-- make sound when fed so many times
			mob_sound(self, "random", true)
		end

		return true
	end

	return false
end

-- no damage to nodes explosion
function mobs:safe_boom(self, pos, strength)
	minetest_sound_play(self.sounds and self.sounds.explode or "tnt_explode", {
		pos = pos,
		gain = 1.0,
		max_hear_distance = self.sounds and self.sounds.distance or 32
	}, true)
	local radius = strength
	entity_physics(pos, radius)
	effect(pos, 32, "mcl_particles_smoke.png", radius * 3, radius * 5, radius, 1, 0)
end


-- make explosion with protection and tnt mod check
function mobs:boom(self, pos, strength, fire)
	self.object:remove()
	if mod_explosions then
		if mobs_griefing and not minetest_is_protected(pos, "") then
			mcl_explosions.explode(pos, strength, { drop_chance = 1.0, fire = fire }, self.object)
		else
			mobs:safe_boom(self, pos, strength)
		end
	else
		mobs:safe_boom(self, pos, strength)
	end
end

-- falling and fall damage
-- returns true if mob died
local falling = function(self, pos)

	if self.fly and self.state ~= "die" then
		return
	end

	if mcl_portals ~= nil then
		if mcl_portals.nether_portal_cooloff(self.object) then
			return false -- mob has teleported through Nether portal - it's 99% not falling
		end
	end

	-- floating in water (or falling)
	local v = self.object:get_velocity()

	if v.y > 0 then

		-- apply gravity when moving up
		self.object:set_acceleration({
			x = 0,
			y = -10,
			z = 0
		})

	elseif v.y <= 0 and v.y > self.fall_speed then

		-- fall downwards at set speed
		self.object:set_acceleration({
			x = 0,
			y = self.fall_speed,
			z = 0
		})
	else
		-- stop accelerating once max fall speed hit
		self.object:set_acceleration({x = 0, y = 0, z = 0})
	end

	if minetest_registered_nodes[node_ok(pos).name].groups.lava then

		if self.floats_on_lava == 1 then

			self.object:set_acceleration({
				x = 0,
				y = -self.fall_speed / (max(1, v.y) ^ 2),
				z = 0
			})
		end
	end

	-- in water then float up
	if minetest_registered_nodes[node_ok(pos).name].groups.water then

		if self.floats == 1 then

			self.object:set_acceleration({
				x = 0,
				y = -self.fall_speed / (math_max(1, v.y) ^ 2),
				z = 0
			})
		end
	else

		-- fall damage onto solid ground
		if self.fall_damage == 1
		and self.object:get_velocity().y == 0 then

			local d = (self.old_y or 0) - self.object:get_pos().y

			if d > 5 then

				local add = minetest_get_item_group(self.standing_on, "fall_damage_add_percent")
				local damage = d - 5
				if add ~= 0 then
					damage = damage + damage * (add/100)
				end
				damage = math_floor(damage)
				if damage > 0 then
					self.health = self.health - damage

					effect(pos, 5, "mcl_particles_smoke.png", 1, 2, 2, nil)

					if check_for_death(self, "fall", {type = "fall"}) then
						return true
					end
				end
			end

			self.old_y = self.object:get_pos().y
		end
	end
end

local teleport = function(self, target)
	if self.do_teleport then
		if self.do_teleport(self, target) == false then
			return
		end
	end
end


-- find someone to runaway from
local runaway_from = function(self)

	if not self.runaway_from and self.state ~= "flop" then
		return
	end

	local s = self.object:get_pos()
	local p, sp, dist
	local player, obj, min_player
	local type, name = "", ""
	local min_dist = self.view_range + 1
	local objs = minetest_get_objects_inside_radius(s, self.view_range)

	for n = 1, #objs do

		if objs[n]:is_player() then

			if mobs.invis[ objs[n]:get_player_name() ]
			or self.owner == objs[n]:get_player_name()
			or (not object_in_range(self, objs[n])) then
				type = ""
			else
				player = objs[n]
				type = "player"
				name = "player"
			end
		else
			obj = objs[n]:get_luaentity()

			if obj then
				player = obj.object
				type = obj.type
				name = obj.name or ""
			end
		end

		-- find specific mob to runaway from
		if name ~= "" and name ~= self.name
		and specific_runaway(self.runaway_from, name) then

			p = player:get_pos()
			sp = s

			-- aim higher to make looking up hills more realistic
			p.y = p.y + 1
			sp.y = sp.y + 1

			dist = vector.distance(p, s)


			-- choose closest player/mpb to runaway from
			if dist < min_dist
			and line_of_sight(self, sp, p, 2) == true then
				min_dist = dist
				min_player = player
			end
		end
	end

	if min_player then

		local lp = player:get_pos()
		local vec = {
			x = lp.x - s.x,
			y = lp.y - s.y,
			z = lp.z - s.z
		}

		local yaw = (atan(vec.z / vec.x) + 3 * math_pi / 2) - self.rotate

		if lp.x > s.x then
			yaw = yaw + math_pi
		end

		yaw = set_yaw(self, yaw, 4)
		self.state = "runaway"
		self.runaway_timer = 3
		self.following = nil
	end
end


-- specific runaway
local specific_runaway = function(list, what)

	-- no list so do not run
	if list == nil then
		return false
	end

	-- found entity on list to attack?
	for no = 1, #list do

		if list[no] == what then
			return true
		end
	end

	return false
end


-- follow player if owner or holding item, if fish outta water then flop
local follow_flop = function(self)

	-- find player to follow
	if (self.follow ~= ""
	or self.order == "follow")
	and not self.following
	and self.state ~= "attack"
	and self.order ~= "sit"
	and self.state ~= "runaway" then

		local s = self.object:get_pos()
		local players = minetest.get_connected_players()

		for n = 1, #players do

			if (object_in_range(self, players[n]))
			and not mobs.invis[ players[n]:get_player_name() ] then

				self.following = players[n]

				break
			end
		end
	end

	if self.type == "npc"
	and self.order == "follow"
	and self.state ~= "attack"
	and self.order ~= "sit"
	and self.owner ~= "" then

		-- npc stop following player if not owner
		if self.following
		and self.owner
		and self.owner ~= self.following:get_player_name() then
			self.following = nil
		end
	else
		-- stop following player if not holding specific item,
		-- mob is horny, fleeing or attacking
		if self.following
		and self.following:is_player()
		and (follow_holding(self, self.following) == false or
		self.horny or self.state == "runaway") then
			self.following = nil
		end

	end

	-- follow that thing
	if self.following then

		local s = self.object:get_pos()
		local p

		if self.following:is_player() then

			p = self.following:get_pos()

		elseif self.following.object then

			p = self.following.object:get_pos()
		end

		if p then

			local dist = vector.distance(p, s)

			-- dont follow if out of range
			if (not object_in_range(self, self.following)) then
				self.following = nil
			else
				local vec = {
					x = p.x - s.x,
					z = p.z - s.z
				}

				local yaw = (atan(vec.z / vec.x) + math_pi / 2) - self.rotate

				if p.x > s.x then yaw = yaw + math_pi end

				set_yaw(self, yaw, 2.35)

				-- anyone but standing npc's can move along
				if dist > 3
				and self.order ~= "stand" then

 					set_velocity(self, self.follow_velocity)

					if self.walk_chance ~= 0 then
						set_animation(self, "run")
					end
				else
					set_velocity(self, 0)
					set_animation(self, "stand")
				end

				return
			end
		end
	end

	-- swimmers flop when out of their element, and swim again when back in
	if self.fly then
		local s = self.object:get_pos()
		if not flight_check(self, s) then

			self.state = "flop"
			self.object:set_acceleration({x = 0, y = DEFAULT_FALL_SPEED, z = 0})

			local sdef = minetest_registered_nodes[self.standing_on]
			-- Flop on ground
			if sdef and sdef.walkable then
				mob_sound(self, "flop")
				self.object:set_velocity({
					x = math_random(-FLOP_HOR_SPEED, FLOP_HOR_SPEED),
					y = FLOP_HEIGHT,
					z = math_random(-FLOP_HOR_SPEED, FLOP_HOR_SPEED),
				})
			end

			set_animation(self, "stand", true)

			return
		elseif self.state == "flop" then
			self.state = "stand"
			self.object:set_acceleration({x = 0, y = 0, z = 0})
			set_velocity(self, 0)
		end
	end
end


-- npc, find closest monster to attack
local npc_attack = function(self)

	if self.type ~= "npc"
	or not self.attacks_monsters
	or self.state == "attack" then
		return
	end

	local p, sp, obj, min_player
	local s = self.object:get_pos()
	local min_dist = self.view_range + 1
	local objs = minetest_get_objects_inside_radius(s, self.view_range)

	for n = 1, #objs do

		obj = objs[n]:get_luaentity()

		if obj and obj.type == "monster" then

			p = obj.object:get_pos()
			sp = s

			local dist = vector.distance(p, s)

			-- aim higher to make looking up hills more realistic
			p.y = p.y + 1
			sp.y = sp.y + 1

			if dist < min_dist
			and line_of_sight(self, sp, p, 2) == true then
				min_dist = dist
				min_player = obj.object
			end
		end
	end

	if min_player then
		do_attack(self, min_player)
	end
end


-- monster find someone to attack
local monster_attack = function(self)

	if self.type ~= "monster"
	or not damage_enabled
	or minetest_is_creative_enabled("")
	or self.passive
	or self.state == "attack"
	or day_docile(self) then
		return
	end

	local s = self.object:get_pos()
	local p, sp, dist
	local player, obj, min_player
	local type, name = "", ""
	local min_dist = self.view_range + 1
	local objs = minetest_get_objects_inside_radius(s, self.view_range)

	for n = 1, #objs do

		if objs[n]:is_player() then

			if mobs.invis[ objs[n]:get_player_name() ] or (not object_in_range(self, objs[n])) then
				type = ""
			else
				player = objs[n]
				type = "player"
				name = "player"
			end
		else
			obj = objs[n]:get_luaentity()

			if obj then
				player = obj.object
				type = obj.type
				name = obj.name or ""
			end
		end

		-- find specific mob to attack, failing that attack player/npc/animal
		if specific_attack(self.specific_attack, name)
		and (type == "player" or type == "npc"
			or (type == "animal" and self.attack_animals == true)) then

			p = player:get_pos()
			sp = s

			dist = vector.distance(p, s)

			-- aim higher to make looking up hills more realistic
			p.y = p.y + 1
			sp.y = sp.y + 1


			-- choose closest player to attack
			if dist < min_dist
			and line_of_sight(self, sp, p, 2) == true then
				min_dist = dist
				min_player = player
			end
		end
	end

	-- attack player
	if min_player then
		do_attack(self, min_player)
	end
end


-- specific attacks
local specific_attack = function(list, what)

	-- no list so attack default (player, animals etc.)
	if list == nil then
		return true
	end

	-- found entity on list to attack?
	for no = 1, #list do

		if list[no] == what then
			return true
		end
	end

	return false
end


-- dogfight attack switch and counter function
local dogswitch = function(self, dtime)

	-- switch mode not activated
	if not self.dogshoot_switch
	or not dtime then
		return 0
	end

	self.dogshoot_count = self.dogshoot_count + dtime

	if (self.dogshoot_switch == 1
	and self.dogshoot_count > self.dogshoot_count_max)
	or (self.dogshoot_switch == 2
	and self.dogshoot_count > self.dogshoot_count2_max) then

		self.dogshoot_count = 0

		if self.dogshoot_switch == 1 then
			self.dogshoot_switch = 2
		else
			self.dogshoot_switch = 1
		end
	end

	return self.dogshoot_switch
end

-- path finding and smart mob routine by rnd, line_of_sight and other edits by Elkien3
local smart_mobs = function(self, s, p, dist, dtime)

	local s1 = self.path.lastpos

	local target_pos = self.attack:get_pos()

	-- is it becoming stuck?
	if math_abs(s1.x - s.x) + math_abs(s1.z - s.z) < .5 then
		self.path.stuck_timer = self.path.stuck_timer + dtime
	else
		self.path.stuck_timer = 0
	end

	self.path.lastpos = {x = s.x, y = s.y, z = s.z}

	local use_pathfind = false
	local has_lineofsight = minetest_line_of_sight(
		{x = s.x, y = (s.y) + .5, z = s.z},
		{x = target_pos.x, y = (target_pos.y) + 1.5, z = target_pos.z}, .2)

	-- im stuck, search for path
	if not has_lineofsight then

		if los_switcher == true then
			use_pathfind = true
			los_switcher = false
		end -- cannot see target!
	else
		if los_switcher == false then

			los_switcher = true
			use_pathfind = false

			minetest_after(1, function(self)
				if not self.object:get_luaentity() then
					return
				end
				if has_lineofsight then self.path.following = false end
			end, self)
		end -- can see target!
	end

	if (self.path.stuck_timer > stuck_timeout and not self.path.following) then

		use_pathfind = true
		self.path.stuck_timer = 0

		minetest_after(1, function(self)
			if not self.object:get_luaentity() then
				return
			end
			if has_lineofsight then self.path.following = false end
		end, self)
	end

	if (self.path.stuck_timer > stuck_path_timeout and self.path.following) then

		use_pathfind = true
		self.path.stuck_timer = 0

		minetest_after(1, function(self)
			if not self.object:get_luaentity() then
				return
			end
			if has_lineofsight then self.path.following = false end
		end, self)
	end

	if math_abs(vector.subtract(s,target_pos).y) > self.stepheight then

		if height_switcher then
			use_pathfind = true
			height_switcher = false
		end
	else
		if not height_switcher then
			use_pathfind = false
			height_switcher = true
		end
	end

	if use_pathfind then
		-- lets try find a path, first take care of positions
		-- since pathfinder is very sensitive
		local sheight = self.collisionbox[5] - self.collisionbox[2]

		-- round position to center of node to avoid stuck in walls
		-- also adjust height for player models!
		s.x = math_floor(s.x + 0.5)
		s.z = math_floor(s.z + 0.5)

		local ssight, sground = minetest_line_of_sight(s, {
			x = s.x, y = s.y - 4, z = s.z}, 1)

		-- determine node above ground
		if not ssight then
			s.y = sground.y + 1
		end

		local p1 = self.attack:get_pos()

		p1.x = math_floor(p1.x + 0.5)
		p1.y = math_floor(p1.y + 0.5)
		p1.z = math_floor(p1.z + 0.5)

		local dropheight = 12
		if self.fear_height ~= 0 then dropheight = self.fear_height end
		local jumpheight = 0
		if self.jump and self.jump_height >= 4 then
			jumpheight = math.min(math.ceil(self.jump_height / 4), 4)
		elseif self.stepheight > 0.5 then
			jumpheight = 1
		end
		self.path.way = minetest_find_path(s, p1, 16, jumpheight, dropheight, "A*_noprefetch")

		self.state = ""
		do_attack(self, self.attack)

		-- no path found, try something else
		if not self.path.way then

			self.path.following = false

			 -- lets make way by digging/building if not accessible
			if self.pathfinding == 2 and mobs_griefing then

				-- is player higher than mob?
				if s.y < p1.y then

					-- build upwards
					if not minetest_is_protected(s, "") then

						local ndef1 = minetest_registered_nodes[self.standing_in]

						if ndef1 and (ndef1.buildable_to or ndef1.groups.liquid) then

								minetest_set_node(s, {name = mobs.fallback_node})
						end
					end

					local sheight = math.ceil(self.collisionbox[5]) + 1

					-- assume mob is 2 blocks high so it digs above its head
					s.y = s.y + sheight

					-- remove one block above to make room to jump
					if not minetest_is_protected(s, "") then

						local node1 = node_ok(s, "air").name
						local ndef1 = minetest_registered_nodes[node1]

						if node1 ~= "air"
						and node1 ~= "ignore"
						and ndef1
						and not ndef1.groups.level
						and not ndef1.groups.unbreakable
						and not ndef1.groups.liquid then

							minetest_set_node(s, {name = "air"})
							minetest_add_item(s, ItemStack(node1))

						end
					end

					s.y = s.y - sheight
					self.object:set_pos({x = s.x, y = s.y + 2, z = s.z})

				else -- dig 2 blocks to make door toward player direction

					local yaw1 = self.object:get_yaw() + math_pi / 2
					local p1 = {
						x = s.x + math_cos(yaw1),
						y = s.y,
						z = s.z + math_sin(yaw1)
					}

					if not minetest_is_protected(p1, "") then

						local node1 = node_ok(p1, "air").name
						local ndef1 = minetest_registered_nodes[node1]

						if node1 ~= "air"
							and node1 ~= "ignore"
							and ndef1
							and not ndef1.groups.level
							and not ndef1.groups.unbreakable
							and not ndef1.groups.liquid then

							minetest_add_item(p1, ItemStack(node1))
							minetest_set_node(p1, {name = "air"})
						end

						p1.y = p1.y + 1
						node1 = node_ok(p1, "air").name
						ndef1 = minetest_registered_nodes[node1]

						if node1 ~= "air"
						and node1 ~= "ignore"
						and ndef1
						and not ndef1.groups.level
						and not ndef1.groups.unbreakable
						and not ndef1.groups.liquid then

							minetest_add_item(p1, ItemStack(node1))
							minetest_set_node(p1, {name = "air"})
						end

					end
				end
			end

			-- will try again in 2 seconds
			self.path.stuck_timer = stuck_timeout - 2
		elseif s.y < p1.y and (not self.fly) then
			do_jump(self) --add jump to pathfinding
			self.path.following = true
			-- Yay, I found path!
			-- TODO: Implement war_cry sound without being annoying
			--mob_sound(self, "war_cry", true)
		else
			set_velocity(self, self.walk_velocity)

			-- follow path now that it has it
			self.path.following = true
		end
	end
end

local update_tag = function(self)
	local tag
	if mobs_debug then
		tag = "nametag = '"..tostring(self.nametag).."'\n"..
		"state = '"..tostring(self.state).."'\n"..
		"order = '"..tostring(self.order).."'\n"..
		"attack = "..tostring(self.attack).."\n"..
		"health = "..tostring(self.health).."\n"..
		"breath = "..tostring(self.breath).."\n"..
		"gotten = "..tostring(self.gotten).."\n"..
		"tamed = "..tostring(self.tamed).."\n"..
		"horny = "..tostring(self.horny).."\n"..
		"hornytimer = "..tostring(self.hornytimer).."\n"..
		"runaway_timer = "..tostring(self.runaway_timer).."\n"..
		"following = "..tostring(self.following)
	else
		tag = self.nametag
	end
	self.object:set_properties({
		nametag = tag,
	})

	update_roll(self)
end

-- drop items
local item_drop = function(self, cooked, looting_level)

	-- no drops if disabled by setting
	if not mobs_drop_items then return end

	looting_level = looting_level or 0

	-- no drops for child mobs (except monster)
	if (self.child and self.type ~= "monster") then
		return
	end

	local obj, item, num
	local pos = self.object:get_pos()

	self.drops = self.drops or {} -- nil check

	for n = 1, #self.drops do
		local dropdef = self.drops[n]
		local chance = 1 / dropdef.chance
		local looting_type = dropdef.looting

		if looting_level > 0 then
			local chance_function = dropdef.looting_chance_function
			if chance_function then
				chance = chance_function(looting_level)
			elseif looting_type == "rare" then
				chance = chance + (dropdef.looting_factor or 0.01) * looting_level
			end
		end

		local num = 0
		local do_common_looting = (looting_level > 0 and looting_type == "common")
		if math_random() < chance then
			num = math_random(dropdef.min or 1, dropdef.max or 1)
		elseif not dropdef.looting_ignore_chance then
			do_common_looting = false
		end

		if do_common_looting then
			num = num + math_floor(math_random(0, looting_level) + 0.5)
		end

		if num > 0 then
			item = dropdef.name

			-- cook items when true
			if cooked then

				local output = minetest_get_craft_result({
					method = "cooking", width = 1, items = {item}})

				if output and output.item and not output.item:is_empty() then
					item = output.item:get_name()
				end
			end

			-- add item if it exists
			for x = 1, num do
				obj = minetest_add_item(pos, ItemStack(item .. " " .. 1))
			end

			if obj and obj:get_luaentity() then

				obj:set_velocity({
					x = math_random(-10, 10) / 9,
					y = 6,
					z = math_random(-10, 10) / 9,
				})
			elseif obj then
				obj:remove() -- item does not exist
			end
		end
	end

	self.drops = {}
end


-- check if mob is dead or only hurt
local check_for_death = function(self, cause, cmi_cause)

	if self.state == "die" then
		return true
	end

	-- has health actually changed?
	if self.health == self.old_health and self.health > 0 then
		return false
	end

	local damaged = self.health < self.old_health
	self.old_health = self.health

	-- still got some health?
	if self.health > 0 then

		-- make sure health isn't higher than max
		if self.health > self.hp_max then
			self.health = self.hp_max
		end

		-- play damage sound if health was reduced and make mob flash red.
		if damaged then
			add_texture_mod(self, "^[colorize:red:130")
			minetest_after(.2, function(self)
				if self and self.object then
					remove_texture_mod(self, "^[colorize:red:130")
				end
			end, self)
			mob_sound(self, "damage")
		end

		-- backup nametag so we can show health stats
		if not self.nametag2 then
			self.nametag2 = self.nametag or ""
		end

		if show_health
		and (cmi_cause and cmi_cause.type == "punch") then

			self.htimer = 2
			self.nametag = "♥ " .. self.health .. " / " .. self.hp_max

			update_tag(self)
		end

		return false
	end

	mob_sound(self, "death")

	local function death_handle(self)
		-- dropped cooked item if mob died in fire or lava
		if cause == "lava" or cause == "fire" then
			item_drop(self, true, 0)
		else
			local wielditem = ItemStack()
			if cause == "hit" then
				local puncher = cmi_cause.puncher
				if puncher then
					wielditem = puncher:get_wielded_item()
				end
			end
			local cooked = mcl_burning.is_burning(self.object) or mcl_enchanting.has_enchantment(wielditem, "fire_aspect")
			local looting = mcl_enchanting.get_enchantment(wielditem, "looting")
			item_drop(self, cooked, looting)

			if mod_experience and ((not self.child) or self.type ~= "animal") and (minetest_get_us_time() - self.xp_timestamp <= 5000000) then
				mcl_experience.throw_experience(self.object:get_pos(), math_random(self.xp_min, self.xp_max))
			end
		end
	end

	-- execute custom death function
	if self.on_die then

		local pos = self.object:get_pos()
		local on_die_exit = self.on_die(self, pos, cmi_cause)
		if on_die_exit ~= true then
			death_handle(self)
		end

		if use_cmi then
			cmi.notify_die(self.object, cmi_cause)
		end

		if on_die_exit == true then
			self.state = "die"
			mcl_burning.extinguish(self.object)
			self.object:remove()
			return true
		end
	end

	local collisionbox
	if self.collisionbox then
		collisionbox = table.copy(self.collisionbox)
	end

	self.state = "die"
	self.attack = nil
	self.v_start = false
	self.fall_speed = DEFAULT_FALL_SPEED
	self.timer = 0
	self.blinktimer = 0
	remove_texture_mod(self, "^[colorize:#FF000040")
	remove_texture_mod(self, "^[brighten")
	self.passive = true

	self.object:set_properties({
		pointable = false,
		collide_with_objects = false,
	})

	set_velocity(self, 0)
	local acc = self.object:get_acceleration()
	acc.x, acc.y, acc.z = 0, DEFAULT_FALL_SPEED, 0
	self.object:set_acceleration(acc)

	local length
	-- default death function and die animation (if defined)
	if self.instant_death then
		length = 0
	elseif self.animation
	and self.animation.die_start
	and self.animation.die_end then

		local frames = self.animation.die_end - self.animation.die_start
		local speed = self.animation.die_speed or 15
		length = max(frames / speed, 0) + DEATH_DELAY
		set_animation(self, "die")
	else
		local rot = self.object:get_rotation()
		rot.z = math_pi/2
		self.object:set_rotation(rot)
		length = 1 + DEATH_DELAY
		set_animation(self, "stand", true)
	end


	-- Remove body after a few seconds and drop stuff
	local kill = function(self)
		if not self.object:get_luaentity() then
			return
		end
		if use_cmi  then
			cmi.notify_die(self.object, cmi_cause)
		end

		death_handle(self)
		local dpos = self.object:get_pos()
		local cbox = self.collisionbox
		local yaw = self.object:get_rotation().y
		mcl_burning.extinguish(self.object)
		self.object:remove()
		mobs.death_effect(dpos, yaw, cbox, not self.instant_death)
	end
	if length <= 0 then
		kill(self)
	else
		minetest_after(length, kill, self)
	end

	return true
end

local damage_effect = function(self, damage)
	-- damage particles
	if (not disable_blood) and damage > 0 then

		local amount_large = math_floor(damage / 2)
		local amount_small = damage % 2

		local pos = self.object:get_pos()

		pos.y = pos.y + (self.collisionbox[5] - self.collisionbox[2]) * .5

		local texture = "mobs_blood.png"
		-- full heart damage (one particle for each 2 HP damage)
		if amount_large > 0 then
			effect(pos, amount_large, texture, 2, 2, 1.75, 0, nil, true)
		end
		-- half heart damage (one additional particle if damage is an odd number)
		if amount_small > 0 then
			-- TODO: Use "half heart"
			effect(pos, amount_small, texture, 1, 1, 1.75, 0, nil, true)
		end
	end
end


-- custom particle effects
local effect = function(pos, amount, texture, min_size, max_size, radius, gravity, glow, go_down)

	radius = radius or 2
	min_size = min_size or 0.5
	max_size = max_size or 1
	gravity = gravity or -10
	glow = glow or 0
	go_down = go_down or false

	local ym
	if go_down then
		ym = 0
	else
		ym = -radius
	end

	minetest_add_particlespawner({
		amount = amount,
		time = 0.25,
		minpos = pos,
		maxpos = pos,
		minvel = {x = -radius, y = ym, z = -radius},
		maxvel = {x = radius, y = radius, z = radius},
		minacc = {x = 0, y = gravity, z = 0},
		maxacc = {x = 0, y = gravity, z = 0},
		minexptime = 0.1,
		maxexptime = 1,
		minsize = min_size,
		maxsize = max_size,
		texture = texture,
		glow = glow,
	})
end


-- are we flying in what we are suppose to? (taikedz)
local flight_check = function(self)

	local nod = self.standing_in
	local def = minetest_registered_nodes[nod]

	if not def then return false end -- nil check

	local fly_in
	if type(self.fly_in) == "string" then
		fly_in = { self.fly_in }
	elseif type(self.fly_in) == "table" then
		fly_in = self.fly_in
	else
		return false
	end

	for _,checknode in pairs(fly_in) do
		if nod == checknode then
			return true
		elseif checknode == "__airlike" and def.walkable == false and
				(def.liquidtype == "none" or minetest_get_item_group(nod, "fake_liquid") == 1) then
			return true
		end
	end

	return false
end


-- check line of sight (BrunoMine)
local line_of_sight = function(self, pos1, pos2, stepsize)

	stepsize = stepsize or 1

	local s, pos = minetest_line_of_sight(pos1, pos2, stepsize)

	-- normal walking and flying mobs can see you through air
	if s == true then
		return true
	end

	-- New pos1 to be analyzed
	local npos1 = {x = pos1.x, y = pos1.y, z = pos1.z}

	local r, pos = minetest_line_of_sight(npos1, pos2, stepsize)

	-- Checks the return
	if r == true then return true end

	-- Nodename found
	local nn = minetest_get_node(pos).name

	-- Target Distance (td) to travel
	local td = vector.distance(pos1, pos2)

	-- Actual Distance (ad) traveled
	local ad = 0

	-- It continues to advance in the line of sight in search of a real
	-- obstruction which counts as 'normal' nodebox.
	while minetest_registered_nodes[nn]
	and minetest_registered_nodes[nn].walkable == false do

		-- Check if you can still move forward
		if td < ad + stepsize then
			return true -- Reached the target
		end

		-- Moves the analyzed pos
		local d = vector.distance(pos1, pos2)

		npos1.x = ((pos2.x - pos1.x) / d * stepsize) + pos1.x
		npos1.y = ((pos2.y - pos1.y) / d * stepsize) + pos1.y
		npos1.z = ((pos2.z - pos1.z) / d * stepsize) + pos1.z

		-- NaN checks
		if d == 0
		or npos1.x ~= npos1.x
		or npos1.y ~= npos1.y
		or npos1.z ~= npos1.z then
			return false
		end

		ad = ad + stepsize

		-- scan again
		r, pos = minetest_line_of_sight(npos1, pos2, stepsize)

		if r == true then return true end

		-- New Nodename found
		nn = minetest_get_node(pos).name

	end

	return false
end

-- Returns true if node is a water hazard
local is_node_waterhazard = function(self, nodename)
	local nn = nodename
	if self.water_damage > 0 then
		if minetest_get_item_group(nn, "water") ~= 0 then
			return true
		end
	end
	if minetest_registered_nodes[nn] and minetest_registered_nodes[nn].drowning and minetest_registered_nodes[nn].drowning > 0 then
		if self.breath_max ~= -1 then
			-- check if the mob is water-breathing _and_ the block is water; only return true if neither is the case
			-- this will prevent water-breathing mobs to classify water or e.g. sand below them as dangerous
			if not self.breathes_in_water and minetest_get_item_group(nn, "water") ~= 0 then
				return true
			end
		end
	end
	return false
end


-- Returns true is node can deal damage to self
local is_node_dangerous = function(self, nodename)
	local nn = nodename
	if self.lava_damage > 0 then
		if minetest_get_item_group(nn, "lava") ~= 0 then
			return true
		end
	end
	if self.fire_damage > 0 then
		if minetest_get_item_group(nn, "fire") ~= 0 then
			return true
		end
	end
	if minetest_registered_nodes[nn] and minetest_registered_nodes[nn].damage_per_second and minetest_registered_nodes[nn].damage_per_second > 0 then
		return true
	end
	return false
end


local add_texture_mod = function(self, mod)
	local full_mod = ""
	local already_added = false
	for i=1, #self.texture_mods do
		if mod == self.texture_mods[i] then
			already_added = true
		end
		full_mod = full_mod .. self.texture_mods[i]
	end
	if not already_added then
		full_mod = full_mod .. mod
		table.insert(self.texture_mods, mod)
	end
	self.object:set_texture_mod(full_mod)
end


local remove_texture_mod = function(self, mod)
	local full_mod = ""
	local remove = {}
	for i=1, #self.texture_mods do
		if self.texture_mods[i] ~= mod then
			full_mod = full_mod .. self.texture_mods[i]
		else
			table.insert(remove, i)
		end
	end
	for i=#remove, 1 do
		table.remove(self.texture_mods, remove[i])
	end
	self.object:set_texture_mod(full_mod)
end