VoxeLibre/mods/ENTITIES/mcl_mobs/movement.lua

local math, vector, minetest, mcl_mobs = math, vector, minetest, mcl_mobs
local mob_class = mcl_mobs.mob_class
local DEFAULT_FALL_SPEED = -9.81*1.5
local FLOP_HEIGHT = 6
local FLOP_HOR_SPEED = 1.5
local PATHFINDING = "gowp"
local enable_pathfinding = true

local node_ice = "mcl_core:ice"
local node_snowblock = "mcl_core:snowblock"
local node_snow = "mcl_core:snow"


local mobs_griefing = minetest.settings:get_bool("mobs_griefing") ~= false

local atann = math.atan
local function atan(x)
	if not x or x ~= x then
		return 0
	else
		return atann(x)
	end
end

-- get node but use fallback for nil or unknown
local node_ok = function(pos, fallback)
	fallback = fallback or mcl_mobs.fallback_node
	local node = minetest.get_node_or_nil(pos)
	if node and minetest.registered_nodes[node.name] then
		return node
	end
	return minetest.registered_nodes[fallback]
end

-- Returns true is node can deal damage to self
function mob_class:is_node_dangerous(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


-- Returns true if node is a water hazard
function mob_class:is_node_waterhazard(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

-- check line of sight (BrunoMine)
function mob_class:line_of_sight(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

function mob_class:can_jump_cliff()
	local yaw = self.object:get_yaw()
	local pos = self.object:get_pos()
	local v = self.object:get_velocity()

	local v2 = math.abs(v.x)+math.abs(v.z)*.833
	local jump_c_multiplier = 1
	if v2/self.walk_velocity/2>1 then
		jump_c_multiplier = v2/self.walk_velocity/2
	end

	-- where is front
	local dir_x = -math.sin(yaw) * (self.collisionbox[4] + 0.5)*jump_c_multiplier+0.6
	local dir_z = math.cos(yaw) * (self.collisionbox[4] + 0.5)*jump_c_multiplier+0.6

	--is there nothing under the block in front? if so jump the gap.
	local nodLow = node_ok({
		x = pos.x + dir_x-0.6,
		y = pos.y - 0.5,
		z = pos.z + dir_z-0.6
	}, "air")

	local nodFar = node_ok({
		x = pos.x + dir_x*2,
		y = pos.y - 0.5,
		z = pos.z + dir_z*2
	}, "air")

	local nodFar2 = node_ok({
		x = pos.x + dir_x*2.5,
		y = pos.y - 0.5,
		z = pos.z + dir_z*2.5
	}, "air")


	if minetest.registered_nodes[nodLow.name]
	and minetest.registered_nodes[nodLow.name].walkable ~= true


	and (minetest.registered_nodes[nodFar.name]
	and minetest.registered_nodes[nodFar.name].walkable == true

	or minetest.registered_nodes[nodFar2.name]
	and minetest.registered_nodes[nodFar2.name].walkable == true)

	then
		--disable fear heigh while we make our jump
		self._jumping_cliff = true
		minetest.after(1, function()
			if self and self.object then
				self._jumping_cliff = false
			end
		end)
		return true
	else
		return false
	end
end

-- is mob facing a cliff or danger
function mob_class:is_at_cliff_or_danger()
	if self.fear_height == 0 or self:can_jump_cliff() or self._jumping_cliff or not self.object:get_luaentity() then -- 0 for no falling protection!
		return false
	end

	local yaw = self.object:get_yaw()
	local dir_x = -math.sin(yaw) * (self.collisionbox[4] + 0.5)
	local dir_z = math.cos(yaw) * (self.collisionbox[4] + 0.5)
	local pos = self.object:get_pos()
	local ypos = pos.y + self.collisionbox[2] -- just above floor

	local free_fall, blocker = minetest.line_of_sight(
		{x = pos.x + dir_x, y = ypos, z = pos.z + dir_z},
		{x = pos.x + dir_x, y = ypos - self.fear_height, z = pos.z + dir_z})
	if free_fall then
		return true
	else
		local bnode = minetest.get_node(blocker)
		local danger = self:is_node_dangerous(bnode.name)
		if danger then
			return true
		else
			local def = minetest.registered_nodes[bnode.name]
			if def and def.walkable then
				return false
			end
		end
	end

	return false
end


-- copy the 'mob facing cliff_or_danger check' from above, and rework to avoid water
function mob_class:is_at_water_danger()
	if not self.object:get_luaentity() or self:can_jump_cliff() or self._jumping_cliff then
		return false
	end
	local yaw = self.object:get_yaw()
	local dir_x = -math.sin(yaw) * (self.collisionbox[4] + 0.5)
	local dir_z = math.cos(yaw) * (self.collisionbox[4] + 0.5)
	local pos = self.object:get_pos()
	local ypos = pos.y + self.collisionbox[2] -- just above floor

	local free_fall, blocker = minetest.line_of_sight(
		{x = pos.x + dir_x, y = ypos, z = pos.z + dir_z},
		{x = pos.x + dir_x, y = ypos - 3, z = pos.z + dir_z})
	if free_fall then
		return true
	else
		local bnode = minetest.get_node(blocker)
		local waterdanger = self:is_node_waterhazard(bnode.name)
		if
			waterdanger and (self:is_node_waterhazard(self.standing_in) or self:is_node_waterhazard( self.standing_on)) then
			return false
		elseif waterdanger and (self:is_node_waterhazard(self.standing_in) or self:is_node_waterhazard(self.standing_on)) == false then
			return true
		else
			local def = minetest.registered_nodes[bnode.name]
			if def and def.walkable then
				return false
			end
		end
	end

	return false
end

-- jump if facing a solid node (not fences or gates)
function mob_class:do_jump()
	if not self.jump
	or self.jump_height == 0
	or self.fly
	or (self.child and self.type ~= "monster")
	or self.order == "stand" then
		return false
	end

	self.facing_fence = false

	-- something stopping us while moving?
	if self.state ~= "stand"
	and self:get_velocity() > 0.5
	and self.object:get_velocity().y ~= 0 then
		return false
	end

	local pos = self.object:get_pos()
	local yaw = self.object:get_yaw()

	-- what is mob standing on?
	pos.y = pos.y + self.collisionbox[2] - 0.2

	local nod = node_ok(pos)

	if minetest.registered_nodes[nod.name].walkable == false then
		return false
	end

	local v = self.object:get_velocity()
	local v2 = math.abs(v.x)+math.abs(v.z)*.833
	local jump_c_multiplier = 1
	if v2/self.walk_velocity/2>1 then
		jump_c_multiplier = v2/self.walk_velocity/2
	end

	-- where is front
	local dir_x = -math.sin(yaw) * (self.collisionbox[4] + 0.5)*jump_c_multiplier+0.6
	local dir_z = math.cos(yaw) * (self.collisionbox[4] + 0.5)*jump_c_multiplier+0.6

	-- what is in front of mob?
	nod = node_ok({
		x = pos.x + dir_x,
		y = pos.y + 0.5,
		z = pos.z + dir_z
	})

	-- this is used to detect if there's a block on top of the block in front of the mob.
	-- If there is, there is no point in jumping as we won't manage.
	local nodTop = node_ok({
		x = pos.x + dir_x,
		y = pos.y + 1.5,
		z = pos.z + dir_z
	}, "air")


	-- we don't attempt to jump if there's a stack of blocks blocking
	if minetest.registered_nodes[nodTop.name].walkable == true and not (self.attack and self.state == "attack") then
		return false
	end

	-- thin blocks that do not need to be jumped
	if nod.name == node_snow then
		return false
	end

	local ndef = minetest.registered_nodes[nod.name]
	if self.walk_chance == 0 or ndef and ndef.walkable or self:can_jump_cliff() then

		if minetest.get_item_group(nod.name, "fence") == 0
		and minetest.get_item_group(nod.name, "fence_gate") == 0
		and minetest.get_item_group(nod.name, "wall") == 0 then

			local v = self.object:get_velocity()

			v.y = self.jump_height + 0.1 * 3

			if self:can_jump_cliff() then
				v=vector.multiply(v, vector.new(2.8,1,2.8))
			end

			self:set_animation( "jump") -- only when defined

			self.object:set_velocity(v)

			-- when in air move forward
			minetest.after(0.3, function(self, v)
				if (not self.object) or (not self.object:get_luaentity()) or (self.state == "die") then
					return
				end
				self.object:set_acceleration({
					x = v.x * 2,
					y = DEFAULT_FALL_SPEED,
					z = v.z * 2,
				})
			end, self, v)

			if self.jump_sound_cooloff <= 0 then
				self:mob_sound("jump")
				self.jump_sound_cooloff = 0.5
			end
		else
			self.facing_fence = true
		end

		-- if we jumped against a block/wall 4 times then turn
		if self.object:get_velocity().x ~= 0
		and self.object:get_velocity().z ~= 0 then

			self.jump_count = (self.jump_count or 0) + 1

			if self.jump_count == 4 then

				local yaw = self.object:get_yaw() or 0

				yaw = self:set_yaw( yaw + 1.35, 8)

				self.jump_count = 0
			end
		end

		return true
	end

	return false
end

-- should mob follow what I'm holding ?
function mob_class:follow_holding(clicker)
	if self.nofollow then return false end

	if mcl_mobs.invis[clicker:get_player_name()] then
		return false
	end

	local item = clicker:get_wielded_item()
	local t = type(self.follow)

	-- single item
	if t == "string"
	and item:get_name() == self.follow then
		return true

	-- multiple items
	elseif t == "table" then

		for no = 1, #self.follow do

			if self.follow[no] == item:get_name() then
				return true
			end
		end
	end

	return false
end


-- find and replace what mob is looking for (grass, wheat etc.)
function mob_class:replace(pos)

	if not self.replace_rate
	or not self.replace_what
	or self.child == true
	or self.object:get_velocity().y ~= 0
	or math.random(1, self.replace_rate) > 1 then
		return
	end

	local what, with, y_offset

	if type(self.replace_what[1]) == "table" then

		local num = math.random(#self.replace_what)

		what = self.replace_what[num][1] or ""
		with = self.replace_what[num][2] or ""
		y_offset = self.replace_what[num][3] or 0
	else
		what = self.replace_what
		with = self.replace_with or ""
		y_offset = self.replace_offset or 0
	end

	pos.y = pos.y + y_offset

	local node = minetest.get_node(pos)
	if node.name == what then

		local oldnode = {name = what, param2 = node.param2}
		local newnode = {name = with, param2 = node.param2}
		local on_replace_return

		if self.on_replace then
			on_replace_return = self.on_replace(self, pos, oldnode, newnode)
		end

		if on_replace_return ~= false then

			if mobs_griefing then
				minetest.set_node(pos, newnode)
			end

		end
	end
end

-- specific runaway
local specific_runaway = function(list, what)
	if type(list) ~= "table" then
		list = {}
	end

	-- 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


-- find someone to runaway from
function mob_class:check_runaway_from()
	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 mcl_mobs.invis[ objs[n]:get_player_name() ]
			or self.owner == objs[n]:get_player_name()
			or (not self:object_in_range(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 self:line_of_sight(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 = self:set_yaw( yaw, 4)
		self.state = "runaway"
		self.runaway_timer = 3
		self.following = nil
	end
end


-- follow player if owner or holding item, if fish outta water then flop
function mob_class:follow_flop()

	-- 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 (self:object_in_range(players[n]))
			and not mcl_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 (self:follow_holding(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 self:object_in_range(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

				self:set_yaw( yaw, 2.35)

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

 					self:set_velocity(self.follow_velocity)

					if self.walk_chance ~= 0 then
						self:set_animation( "run")
					end
				else
					self:set_velocity(0)
					self:set_animation( "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 self:flight_check( s) == false then

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

			local p = self.object:get_pos()
			local sdef = minetest.registered_nodes[node_ok(vector.add(p, vector.new(0,self.collisionbox[2]-0.2,0))).name]
			-- Flop on ground
			if sdef and sdef.walkable then
				if self.object:get_velocity().y < 0.1 then
					self:mob_sound("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
			end

			self:set_animation( "stand", true)

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

function mob_class:go_to_pos(b)
	if not self then return end
	local s=self.object:get_pos()
	if not b then
		--self.state = "stand"
		return end
	if vector.distance(b,s) < 1 then
		--self:set_velocity(0)
		return true
	end
	local v = { x = b.x - s.x, z = b.z - s.z }
	local yaw = (atann(v.z / v.x) +math.pi/ 2) - self.rotate
	if b.x > s.x then yaw = yaw +math.pi end
	self.object:set_yaw(yaw)
	self:set_velocity(self.follow_velocity)
	self:set_animation("walk")
end

local check_herd_timer = 0
function mob_class:check_herd(dtime)
	local pos = self.object:get_pos()
	if not pos then return end
	check_herd_timer = check_herd_timer + dtime
	if check_herd_timer < 4 then return end
	check_herd_timer = 0
	for _,o in pairs(minetest.get_objects_inside_radius(pos,self.view_range)) do
		local l = o:get_luaentity()
		local p,y
		if l and l.is_mob and l.name == self.name then
			if self.horny and l.horny then
				p = l.object:get_pos()
			else
				y = o:get_yaw()
			end
			if p then
				go_to_pos(self,p)
			elseif y then
				self:set_yaw(y)
			end
		end
	end
end

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

-- execute current state (stand, walk, run, attacks)
-- returns true if mob has died
function mob_class:do_states(dtime)
	--if self.can_open_doors then check_doors(self) end

	local yaw = self.object:get_yaw() or 0

	if self.state == "stand" then
		if math.random(1, 4) == 1 then

			local s = self.object:get_pos()
			local objs = minetest.get_objects_inside_radius(s, 3)
			local lp
			for n = 1, #objs do
				if objs[n]:is_player() then
					lp = objs[n]:get_pos()
					break
				end
			end

			-- look at any players nearby, otherwise turn randomly
			if lp and self.look_at_players then

				local vec = {
					x = lp.x - s.x,
					z = lp.z - s.z
				}

				yaw = (atan(vec.z / vec.x) +math.pi/ 2) - self.rotate

				if lp.x > s.x then yaw = yaw +math.pi end
			else
				yaw = yaw + math.random(-0.5, 0.5)
			end

			yaw = self:set_yaw( yaw, 8)
		end
		if self.order == "sit" then
			self:set_animation( "sit")
			self:set_velocity(0)
		else
			self:set_animation( "stand")
			self:set_velocity(0)
		end

		-- npc's ordered to stand stay standing
		if self.order == "stand" or self.order == "sleep" or self.order == "work" then

		else
			if self.walk_chance ~= 0
			and self.facing_fence ~= true
			and math.random(1, 100) <= self.walk_chance
			and self:is_at_cliff_or_danger() == false then

				self:set_velocity(self.walk_velocity)
				self.state = "walk"
				self:set_animation( "walk")
			end
		end

	elseif self.state == PATHFINDING then
		self:check_gowp(dtime)

	elseif self.state == "walk" then
		local s = self.object:get_pos()
		local lp = nil

		-- is there something I need to avoid?
		if (self.water_damage > 0
		and self.lava_damage > 0)
		or self.breath_max ~= -1 then

			lp = minetest.find_node_near(s, 1, {"group:water", "group:lava"})

		elseif self.water_damage > 0 then

			lp = minetest.find_node_near(s, 1, {"group:water"})

		elseif self.lava_damage > 0 then

			lp = minetest.find_node_near(s, 1, {"group:lava"})

		elseif self.fire_damage > 0 then

			lp = minetest.find_node_near(s, 1, {"group:fire"})

		end

		local is_in_danger = false
		if lp then
			-- If mob in or on dangerous block, look for land
			if (self:is_node_dangerous(self.standing_in) or
				self:is_node_dangerous(self.standing_on)) or (self:is_node_waterhazard(self.standing_in) or self:is_node_waterhazard(self.standing_on)) and (not self.fly) then
				is_in_danger = true

					-- If mob in or on dangerous block, look for land
					if is_in_danger then
					-- Better way to find shore - copied from upstream
						lp = minetest.find_nodes_in_area_under_air(
							{x = s.x - 5, y = s.y - 0.5, z = s.z - 5},
							{x = s.x + 5, y = s.y + 1, z = s.z + 5},
							{"group:solid"})

						lp = #lp > 0 and lp[math.random(#lp)]

						-- did we find land?
						if lp then

							local vec = {
								x = lp.x - s.x,
								z = lp.z - s.z
							}

							yaw = (atan(vec.z / vec.x) +math.pi/ 2) - self.rotate


							if lp.x > s.x  then yaw = yaw +math.pi end

							-- look towards land and move in that direction
							yaw = self:set_yaw( yaw, 6)
							self:set_velocity(self.walk_velocity)

						end
					end

			-- A danger is near but mob is not inside
			else

				-- Randomly turn
				if math.random(1, 100) <= 30 then
					yaw = yaw + math.random(-0.5, 0.5)
					yaw = self:set_yaw( yaw, 8)
				end
			end

			yaw = self:set_yaw( yaw, 8)

		-- otherwise randomly turn
		elseif math.random(1, 100) <= 30 then
			yaw = yaw + math.random(-0.5, 0.5)
			yaw = self:set_yaw( yaw, 8)
		end

		-- stand for great fall or danger or fence in front
		local cliff_or_danger = false
		if is_in_danger then
			cliff_or_danger = self:is_at_cliff_or_danger()
		end
		if self.facing_fence == true
		or cliff_or_danger
		or math.random(1, 100) <= 30 then

			self:set_velocity(0)
			self.state = "stand"
			self:set_animation( "stand")
			local yaw = self.object:get_yaw() or 0
			yaw = self:set_yaw( yaw + 0.78, 8)
		else

			self:set_velocity(self.walk_velocity)

			if self:flight_check()
			and self.animation
			and self.animation.fly_start
			and self.animation.fly_end then
				self:set_animation( "fly")
			else
				self:set_animation( "walk")
			end
		end

	-- runaway when punched
	elseif self.state == "runaway" then

		self.runaway_timer = self.runaway_timer + 1

		-- stop after 5 seconds or when at cliff
		if self.runaway_timer > 5
		or self:is_at_cliff_or_danger() then
			self.runaway_timer = 0
			self:set_velocity(0)
			self.state = "stand"
			self:set_animation( "stand")
			local yaw = self.object:get_yaw() or 0
			yaw = self:set_yaw( yaw + 0.78, 8)
		else
			self:set_velocity( self.run_velocity)
			self:set_animation( "run")
		end

	-- attack routines (explode, dogfight, shoot, dogshoot)
	elseif self.state == "attack" then

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

		-- stop attacking if player invisible or out of range
		if not self.attack
		or not self.attack:get_pos()
		or not self:object_in_range(self.attack)
		or self.attack:get_hp() <= 0
		or (self.attack:is_player() and mcl_mobs.invis[ self.attack:get_player_name() ]) then

			self.state = "stand"
			self:set_velocity( 0)
			self:set_animation( "stand")
			self.attack = nil
			self.v_start = false
			self.timer = 0
			self.blinktimer = 0
			self.path.way = nil

			return
		end

		-- calculate distance from mob and enemy
		local dist = vector.distance(p, s)

		if self.attack_type == "explode" then

			local vec = {
				x = p.x - s.x,
				z = p.z - s.z
			}

			yaw = (atan(vec.z / vec.x) +math.pi/ 2) - self.rotate

			if p.x > s.x then yaw = yaw +math.pi end

			yaw = self:set_yaw( yaw, 0, dtime)

			local node_break_radius = self.explosion_radius or 1
			local entity_damage_radius = self.explosion_damage_radius
					or (node_break_radius * 2)

			-- start timer when in reach and line of sight
			if not self.v_start
			and dist <= self.reach
			and self:line_of_sight( s, p, 2) then

				self.v_start = true
				self.timer = 0
				self.blinktimer = 0
				self:mob_sound("fuse", nil, false)

			-- stop timer if out of reach or direct line of sight
			elseif self.allow_fuse_reset
			and self.v_start
			and (dist >= self.explosiontimer_reset_radius
					or not self:line_of_sight( s, p, 2)) then
				self.v_start = false
				self.timer = 0
				self.blinktimer = 0
				self.blinkstatus = false
				self:remove_texture_mod("^[brighten")
			end

			-- walk right up to player unless the timer is active
			if self.v_start and (self.stop_to_explode or dist < self.reach) then
				self:set_velocity( 0)
			else
				self:set_velocity( self.run_velocity)
			end

			if self.animation and self.animation.run_start then
				self:set_animation( "run")
			else
				self:set_animation( "walk")
			end

			if self.v_start then

				self.timer = self.timer + dtime
				self.blinktimer = (self.blinktimer or 0) + dtime

				if self.blinktimer > 0.2 then

					self.blinktimer = 0

					if self.blinkstatus then
						self:remove_texture_mod("^[brighten")
					else
						self:add_texture_mod("^[brighten")
					end

					self.blinkstatus = not self.blinkstatus
				end

				if self.timer > self.explosion_timer then

					local pos = self.object:get_pos()

					if mobs_griefing and not minetest.is_protected(pos, "") then
						mcl_explosions.explode(mcl_util.get_object_center(self.object), self.explosion_strength, { drop_chance = 1.0 }, self.object)
					else
						minetest.sound_play(self.sounds.explode, {
							pos = pos,
							gain = 1.0,
							max_hear_distance = self.sounds.distance or 32
						}, true)
						self:entity_physics(pos,entity_damage_radius)
						mcl_mobs.effect(pos, 32, "mcl_particles_smoke.png", nil, nil, node_break_radius, 1, 0)
					end
					mcl_burning.extinguish(self.object)
					self.object:remove()

					return true
				end
			end

		elseif self.attack_type == "dogfight"
		or (self.attack_type == "dogshoot" and self:dogswitch(dtime) == 2) and (dist >= self.avoid_distance or not self.shooter_avoid_enemy)
		or (self.attack_type == "dogshoot" and dist <= self.reach and self:dogswitch() == 0) then

			if self.fly
			and dist > self.reach then

				local p1 = s
				local me_y = math.floor(p1.y)
				local p2 = p
				local p_y = math.floor(p2.y + 1)
				local v = self.object:get_velocity()

				if self:flight_check( s) then

					if me_y < p_y then

						self.object:set_velocity({
							x = v.x,
							y = 1 * self.walk_velocity,
							z = v.z
						})

					elseif me_y > p_y then

						self.object:set_velocity({
							x = v.x,
							y = -1 * self.walk_velocity,
							z = v.z
						})
					end
				else
					if me_y < p_y then

						self.object:set_velocity({
							x = v.x,
							y = 0.01,
							z = v.z
						})

					elseif me_y > p_y then

						self.object:set_velocity({
							x = v.x,
							y = -0.01,
							z = v.z
						})
					end
				end

			end

			-- rnd: new movement direction
			if self.path.following
			and self.path.way
			and self.attack_type ~= "dogshoot" then

				-- no paths longer than 50
				if #self.path.way > 50
				or dist < self.reach then
					self.path.following = false
					return
				end

				local p1 = self.path.way[1]

				if not p1 then
					self.path.following = false
					return
				end

				if math.abs(p1.x-s.x) + math.abs(p1.z - s.z) < 0.6 then
					-- reached waypoint, remove it from queue
					table.remove(self.path.way, 1)
				end

				-- set new temporary target
				p = {x = p1.x, y = p1.y, z = p1.z}
			end

			local vec = {
				x = p.x - s.x,
				z = p.z - s.z
			}

			yaw = (atan(vec.z / vec.x) + math.pi / 2) - self.rotate

			if p.x > s.x then yaw = yaw + math.pi end

			yaw = self:set_yaw( yaw, 0, dtime)

			-- move towards enemy if beyond mob reach
			if dist > self.reach then

				-- path finding by rnd
				if self.pathfinding -- only if mob has pathfinding enabled
				and enable_pathfinding then

					self:smart_mobs(s, p, dist, dtime)
				end

				if self:is_at_cliff_or_danger() then

					self:set_velocity( 0)
					self:set_animation( "stand")
					local yaw = self.object:get_yaw() or 0
					yaw = self:set_yaw( yaw + 0.78, 8)
				else

					if self.path.stuck then
						self:set_velocity( self.walk_velocity)
					else
						self:set_velocity( self.run_velocity)
					end

					if self.animation and self.animation.run_start then
						self:set_animation( "run")
					else
						self:set_animation( "walk")
					end
				end

			else -- rnd: if inside reach range

				self.path.stuck = false
				self.path.stuck_timer = 0
				self.path.following = false -- not stuck anymore

				self:set_velocity( 0)

				if not self.custom_attack then

					if self.timer > 1 then

						self.timer = 0

						if self.double_melee_attack
						and math.random(1, 2) == 1 then
							self:set_animation( "punch2")
						else
							self:set_animation( "punch")
						end

						local p2 = p
						local s2 = s

						p2.y = p2.y + .5
						s2.y = s2.y + .5

						if self:line_of_sight( p2, s2) == true then

							-- play attack sound
							self:mob_sound("attack")

							-- punch player (or what player is attached to)
							local attached = self.attack:get_attach()
							if attached then
								self.attack = attached
							end
							self.attack:punch(self.object, 1.0, {
								full_punch_interval = 1.0,
								damage_groups = {fleshy = self.damage}
							}, nil)
						end
					end
				else	-- call custom attack every second
					if self.custom_attack
					and self.timer > 1 then

						self.timer = 0

						self.custom_attack(self, p)
					end
				end
			end

		elseif self.attack_type == "shoot"
		or (self.attack_type == "dogshoot" and self:dogswitch(dtime) == 1)
		or (self.attack_type == "dogshoot" and (dist > self.reach or dist < self.avoid_distance and self.shooter_avoid_enemy) and self:dogswitch() == 0) then

			p.y = p.y - .5
			s.y = s.y + .5

			local dist = vector.distance(p, s)
			local vec = {
				x = p.x - s.x,
				y = p.y - s.y,
				z = p.z - s.z
			}

			yaw = (atan(vec.z / vec.x) +math.pi/ 2) - self.rotate

			if p.x > s.x then yaw = yaw +math.pi end

			yaw = self:set_yaw( yaw, 0, dtime)

			local stay_away_from_player = vector.new(0,0,0)

			--strafe back and fourth

			--stay away from player so as to shoot them
			if dist < self.avoid_distance and self.shooter_avoid_enemy then
				self:set_animation( "shoot")
				stay_away_from_player=vector.multiply(vector.direction(p, s), 0.33)
			end

			if self.strafes then
				if not self.strafe_direction then
					self.strafe_direction = 1.57
				end
				if math.random(40) == 1 then
					self.strafe_direction = self.strafe_direction*-1
				end
				self.acc = vector.add(vector.multiply(vector.rotate_around_axis(vector.direction(s, p), vector.new(0,1,0), self.strafe_direction), 0.3*self.walk_velocity), stay_away_from_player)
			else
				self:set_velocity( 0)
			end

			local p = self.object:get_pos()
			p.y = p.y + (self.collisionbox[2] + self.collisionbox[5]) / 2

			if self.shoot_interval
			and self.timer > self.shoot_interval
			and not minetest.raycast(vector.add(p, vector.new(0,self.shoot_offset,0)), vector.add(self.attack:get_pos(), vector.new(0,1.5,0)), false, false):next()
			and math.random(1, 100) <= 60 then

				self.timer = 0
				self:set_animation( "shoot")

				-- play shoot attack sound
				self:mob_sound("shoot_attack")

				-- Shoot arrow
				if minetest.registered_entities[self.arrow] then

					local arrow, ent
					local v = 1
					if not self.shoot_arrow then
						self.firing = true
						minetest.after(1, function()
							self.firing = false
						end)
						arrow = minetest.add_entity(p, self.arrow)
						ent = arrow:get_luaentity()
						if ent.velocity then
							v = ent.velocity
						end
						ent.switch = 1
						ent.owner_id = tostring(self.object) -- add unique owner id to arrow

						-- important for mcl_shields
						ent._shooter = self.object
						ent._saved_shooter_pos = self.object:get_pos()
					end

					local amount = (vec.x * vec.x + vec.y * vec.y + vec.z * vec.z) ^ 0.5
					-- offset makes shoot aim accurate
					vec.y = vec.y + self.shoot_offset
					vec.x = vec.x * (v / amount)
					vec.y = vec.y * (v / amount)
					vec.z = vec.z * (v / amount)
					if self.shoot_arrow then
						vec = vector.normalize(vec)
						self:shoot_arrow(p, vec)
					else
						arrow:set_velocity(vec)
					end
				end
			end
		else

		end
	end
end

function mob_class:check_smooth_rotation()
	-- smooth rotation by ThomasMonroe314
	if self._turn_to then
		self:set_yaw( self._turn_to, .1)
	end

	if self.delay and self.delay > 0 then

		local yaw = self.object:get_yaw() or 0

		if self.delay == 1 then
			yaw = self.target_yaw
		else
			local dif = math.abs(yaw - self.target_yaw)

			if yaw > self.target_yaw then

				if dif > math.pi then
					dif = 2 * math.pi - dif -- need to add
					yaw = yaw + dif / self.delay
				else
					yaw = yaw - dif / self.delay -- need to subtract
				end

			elseif yaw < self.target_yaw then

				if dif >math.pi then
					dif = 2 * math.pi - dif
					yaw = yaw - dif / self.delay -- need to subtract
				else
					yaw = yaw + dif / self.delay -- need to add
				end
			end

			if yaw > (math.pi * 2) then yaw = yaw - (math.pi * 2) end
			if yaw < 0 then yaw = yaw + (math.pi * 2) end
		end

		self.delay = self.delay - 1
		if self.shaking then
			yaw = yaw + (math.random() * 2 - 1) * 5 * dtime
		end
		self.object:set_yaw(yaw)
		self:update_roll()
	end
	-- end rotation
end