Fix crash in mcl_mobs

[MineClone/MineClone2.git] / mods / ENTITIES / mcl_mobs / api.lua

-- API for Mobs Redo: MineClone 2 Edition (MRM)

mobs = {}
mobs.mod = "mrm"
mobs.version = "20180531" -- don't rely too much on this, rarely updated, if ever

local MAX_MOB_NAME_LENGTH = 30

-- Localize
local S = minetest.get_translator("mcl_mobs")

-- CMI support check
local use_cmi = minetest.global_exists("cmi")


-- Invisibility mod check
mobs.invis = {}
if minetest.global_exists("invisibility") then
        mobs.invis = invisibility
end


-- creative check
local creative_mode_cache = minetest.settings:get_bool("creative_mode")
function mobs.is_creative(name)
        return creative_mode_cache or minetest.check_player_privs(name, {creative = true})
end


-- localize math functions
local pi = math.pi
local sin = math.sin
local cos = math.cos
local abs = math.abs
local min = math.min
local max = math.max
local atann = math.atan
local random = math.random
local floor = math.floor
local atan = function(x)
        if not x or x ~= x then
                return 0
        else
                return atann(x)
        end
end


-- Load settings
local damage_enabled = minetest.settings:get_bool("enable_damage")
local mobs_spawn = minetest.settings:get_bool("mobs_spawn", true) ~= false

local disable_blood = minetest.settings:get_bool("mobs_disable_blood")
local mobs_drop_items = minetest.settings:get_bool("mobs_drop_items") ~= false
local mobs_griefing = minetest.settings:get_bool("mobs_griefing") ~= false
local creative = minetest.settings:get_bool("creative_mode")
local spawn_protected = minetest.settings:get_bool("mobs_spawn_protected") ~= false
local remove_far = false
local difficulty = tonumber(minetest.settings:get("mob_difficulty")) or 1.0
local show_health = false
local max_per_block = tonumber(minetest.settings:get("max_objects_per_block") or 99)
local mobs_spawn_chance = tonumber(minetest.settings:get("mobs_spawn_chance") or 2.5)

-- Peaceful mode message so players will know there are no monsters
if minetest.settings:get_bool("only_peaceful_mobs", false) then
        minetest.register_on_joinplayer(function(player)
                minetest.chat_send_player(player:get_player_name(),
                        S("Peaceful mode active! No monsters will spawn."))
        end)
end

-- calculate aoc range for mob count
local aosrb = tonumber(minetest.settings:get("active_object_send_range_blocks"))
local abr = tonumber(minetest.settings:get("active_block_range"))
local aoc_range = max(aosrb, abr) * 16

-- pathfinding settings
local enable_pathfinding = true
local stuck_timeout = 3 -- how long before mob gets stuck in place and starts searching
local stuck_path_timeout = 10 -- how long will mob follow path before giving up

-- default nodes
local node_ice = "mcl_core:ice"
local node_snowblock = "mcl_core:snowblock"
local node_snow = "mcl_core:snow"
mobs.fallback_node = minetest.registered_aliases["mapgen_dirt"] or "mcl_core:dirt"

local mod_weather = minetest.get_modpath("mcl_weather") ~= nil
local mod_tnt = minetest.get_modpath("mcl_tnt") ~= nil
local mod_mobspawners = minetest.get_modpath("mcl_mobspawners") ~= nil
local mod_hunger = minetest.get_modpath("mcl_hunger") ~= nil
local mod_worlds = minetest.get_modpath("mcl_worlds") ~= nil
local mod_armor = minetest.get_modpath("mcl_armor") ~= nil

-- play sound
local mob_sound = function(self, soundname, is_opinion, fixed_pitch)

        local soundinfo
        if self.sounds_child and self.child then
                soundinfo = self.sounds_child
        elseif self.sounds then
                soundinfo = self.sounds
        end
        if not soundinfo then
                return
        end
        local sound = soundinfo[soundname]
        if sound then
                if is_opinion and self.opinion_sound_cooloff > 0 then
                        return
                end
                local pitch
                if not fixed_pitch then
                        local base_pitch = soundinfo.base_pitch
                        if not base_pitch then
                                base_pitch = 1
                        end
                        if self.child and (not self.sounds_child) then
                                -- Children have higher pitch
                                pitch = base_pitch * 1.5
                        else
                                pitch = base_pitch
                        end
                        -- randomize the pitch a bit
                        pitch = pitch + math.random(-10, 10) * 0.005
                end
                minetest.sound_play(sound, {
                        object = self.object,
                        gain = 1.0,
                        max_hear_distance = self.sounds.distance,
                        pitch = pitch,
                })
                self.opinion_sound_cooloff = 1
        end
end

-- Reeturn true if object is in view_range
local function object_in_range(self, object)
        if not object then
                return false
        end
        local factor
        -- Apply view range reduction for special player armor
        if object:is_player() and mod_armor then
                factor = armor:get_mob_view_range_factor(object, self.name)
        end
        -- Distance check
        local dist
        if factor and factor == 0 then
                return false
        elseif factor then
                dist = self.view_range * factor
        else
                dist = self.view_range
        end
        if vector.distance(self.object:get_pos(), object:get_pos()) > dist then
                return false
        else
                return true
        end
end

-- attack player/mob
local do_attack = function(self, player)

        if self.state == "attack" then
                return
        end

        self.attack = player
        self.state = "attack"

        -- TODO: Implement war_cry sound without being annoying
        --if random(0, 100) < 90 then
                --mob_sound(self, "war_cry", true)
        --end
end


-- move mob in facing direction
local set_velocity = function(self, v)

        -- do not move if mob has been ordered to stay
        if self.order == "stand" then
                self.object:set_velocity({x = 0, y = 0, z = 0})
                return
        end

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

        self.object:set_velocity({
                x = sin(yaw) * -v,
                y = self.object:get_velocity().y,
                z = cos(yaw) * v
        })
end


-- calculate mob velocity
local get_velocity = function(self)

        local v = self.object:get_velocity()

        return (v.x * v.x + v.z * v.z) ^ 0.5
end


-- set and return valid yaw
local set_yaw = function(self, yaw, delay)

        if not yaw or yaw ~= yaw then
                yaw = 0
        end

        delay = delay or 0

        if delay == 0 then
                self.object:set_yaw(yaw)
                return yaw
        end

        self.target_yaw = yaw
        self.delay = delay

        return self.target_yaw
end

-- global function to set mob yaw
function mobs:yaw(self, yaw, delay)
        set_yaw(self, yaw, delay)
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

-- set defined animation
local set_animation = function(self, anim)

        if not self.animation
        or not anim then return end

        self.animation.current = self.animation.current or ""

        if anim == self.animation.current
        or not self.animation[anim .. "_start"]
        or not self.animation[anim .. "_end"] then
                return
        end

        self.animation.current = anim

        self.object:set_animation({
                x = self.animation[anim .. "_start"],
                y = self.animation[anim .. "_end"]},
                self.animation[anim .. "_speed"] or self.animation.speed_normal or 15,
                0, self.animation[anim .. "_loop"] ~= false)
end


-- above function exported for mount.lua
function mobs:set_animation(self, anim)
        set_animation(self, anim)
end

-- Returns true is node can deal damage to self
local is_node_dangerous = 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 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].drowning > 0 then
                if self.breath_max ~= -1 then
                        return true
                end
        end
        if minetest.registered_nodes[nn].damage_per_second > 0 then
                return true
        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


-- 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


-- 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

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

local update_tag = function(self)
        self.object:set_properties({
                nametag = self.nametag,
        })

end


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

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

        -- 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

                if random(1, self.drops[n].chance) == 1 then

                        num = random(self.drops[n].min or 1, self.drops[n].max or 1)
                        item = self.drops[n].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
                        obj = minetest.add_item(pos, ItemStack(item .. " " .. num))

                        if obj and obj:get_luaentity() then

                                obj:set_velocity({
                                        x = random(-10, 10) / 9,
                                        y = 6,
                                        z = 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)

        -- has health actually changed?
        if self.health == self.old_health and self.health > 0 then
                return
        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:#FF000040")
                        minetest.after(.2, function(self)
                                if self and self.object then
                                        remove_texture_mod(self, "^[colorize:#FF000040")
                                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

        -- dropped cooked item if mob died in lava
        if cause == "lava" then
                item_drop(self, true)
        else
                item_drop(self, nil)
        end

        mob_sound(self, "death")

        local pos = self.object:get_pos()

        -- execute custom death function
        if self.on_die then

                self.on_die(self, pos)

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

                self.object:remove()

                return true
        end

        -- default death function and die animation (if defined)
        if 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
                local length = max(frames / speed, 0)

                self.attack = nil
                self.v_start = false
                self.timer = 0
                self.blinktimer = 0
                self.passive = true
                self.state = "die"
                set_velocity(self, 0)
                set_animation(self, "die")

                minetest.after(length, function(self)
                        if not self.object:get_luaentity() then
                                return
                        end
                        if use_cmi  then
                                cmi.notify_die(self.object, cmi_cause)
                        end

                        self.object:remove()
                end, self)
        else

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

                self.object:remove()
        end

        effect(pos, 20, "tnt_smoke.png")

        return true
end


-- check if within physical map limits (-30911 to 30927)
local within_limits = function(pos, radius)

        if  (pos.x - radius) > -30913
        and (pos.x + radius) <  30928
        and (pos.y - radius) > -30913
        and (pos.y + radius) <  30928
        and (pos.z - radius) > -30913
        and (pos.z + radius) <  30928 then
                return true -- within limits
        end

        return false -- beyond limits
end


-- is mob facing a cliff or danger
local is_at_cliff_or_danger = function(self)

        if self.fear_height == 0 then -- 0 for no falling protection!
                return false
        end

        local yaw = self.object:get_yaw()
        local dir_x = -sin(yaw) * (self.collisionbox[4] + 0.5)
        local dir_z = 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 = is_node_dangerous(self, bnode.name)
                if danger then
                        return true
                else
                        local def = minetest.registered_nodes[bnode.name]
                        return (not def and def.walkable)
                end
        end

        return false
end


-- get node but use fallback for nil or unknown
local node_ok = function(pos, fallback)

        fallback = fallback or 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


-- environmental damage (water, lava, fire, light etc.)
local do_env_damage = function(self)

        -- feed/tame text timer (so mob 'full' messages dont spam chat)
        if self.htimer > 0 then
                self.htimer = self.htimer - 1
        end

        -- reset nametag after showing health stats
        if self.htimer < 1 and self.nametag2 then

                self.nametag = self.nametag2
                self.nametag2 = nil

                update_tag(self)
        end

        local pos = self.object:get_pos()

        self.time_of_day = minetest.get_timeofday()

        -- remove mob if beyond map limits
        if not within_limits(pos, 0) then
                self.object:remove()
                return
        end


        local deal_light_damage = function(self, pos, damage)
                if not (mod_weather and (mcl_weather.rain.raining or mcl_weather.state == "snow") and mcl_weather.is_outdoor(pos)) then
                        self.health = self.health - damage

                        effect(pos, 5, "tnt_smoke.png")

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

        -- bright light harms mob
        if self.light_damage ~= 0 and (minetest.get_node_light(pos) or 0) > 12 then
                deal_light_damage(self, pos, self.light_damage)
        end
        local _, dim = nil, "overworld"
        if mod_worlds then
                _, dim = mcl_worlds.y_to_layer(pos.y)
        end
        if self.sunlight_damage ~= 0 and (minetest.get_node_light(pos) or 0) >= minetest.LIGHT_MAX and dim == "overworld" then
                deal_light_damage(self, pos, self.sunlight_damage)
        end

        local y_level = self.collisionbox[2]

        if self.child then
                y_level = self.collisionbox[2] * 0.5
        end

        -- what is mob standing in?
        pos.y = pos.y + y_level + 0.25 -- foot level
        local pos2 = {x=pos.x, y=pos.y-1, z=pos.z}
        self.standing_in = node_ok(pos, "air").name
        self.standing_on = node_ok(pos2, "air").name

        -- don't fall when on ignore, just stand still
        if self.standing_in == "ignore" then
                self.object:set_velocity({x = 0, y = 0, z = 0})
        end

        local nodef = minetest.registered_nodes[self.standing_in]

        -- rain
        if self.rain_damage > 0 and mod_weather then
                if mcl_weather.rain.raining and mcl_weather.is_outdoor(pos) then

                        self.health = self.health - self.rain_damage

                        if check_for_death(self, "rain", {type = "environment",
                                        pos = pos, node = self.standing_in}) then return end
                end
        end

        pos.y = pos.y + 1 -- for particle effect position

        -- water damage
        if self.water_damage > 0
        and nodef.groups.water then

                if self.water_damage ~= 0 then

                        self.health = self.health - self.water_damage

                        effect(pos, 5, "tnt_smoke.png", nil, nil, 1, nil)

                        if check_for_death(self, "water", {type = "environment",
                                        pos = pos, node = self.standing_in}) then return end
                end

        -- lava damage
        elseif self.lava_damage > 0
        and (nodef.groups.lava) then

                if self.lava_damage ~= 0 then

                        self.health = self.health - self.lava_damage

                        effect(pos, 5, "fire_basic_flame.png", nil, nil, 1, nil)

                        if check_for_death(self, "lava", {type = "environment",
                                        pos = pos, node = self.standing_in}) then return end
                end

        -- fire damage
        elseif self.fire_damage > 0
        and (nodef.groups.fire) then

                if self.fire_damage ~= 0 then

                        self.health = self.health - self.fire_damage

                        effect(pos, 5, "fire_basic_flame.png", nil, nil, 1, nil)

                        if check_for_death(self, "fire", {type = "environment",
                                        pos = pos, node = self.standing_in}) then return end
                end

        -- damage_per_second node check
        elseif nodef.damage_per_second ~= 0 then

                self.health = self.health - nodef.damage_per_second

                effect(pos, 5, "tnt_smoke.png")

                if check_for_death(self, "dps", {type = "environment",
                                pos = pos, node = self.standing_in}) then return end
        end

        -- Drowning damage
        if self.breath_max ~= -1 then
                local drowning = false
                if self.breathes_in_water then
                        if minetest.get_item_group(self.standing_in, "water") == 0 then
                                drowning = true
                        end
                elseif nodef.drowning > 0 then
                        drowning = true
                end
                if drowning then

                        self.breath = math.max(0, self.breath - 1)

                        effect(pos, 2, "bubble.png", nil, nil, 1, nil)
                        if self.breath <= 0 then
                                local dmg
                                if nodef.drowning > 0 then
                                        dmg = nodef.drowning
                                else
                                        dmg = 4
                                end
                                damage_effect(self, dmg)
                                self.health = self.health - dmg
                        end
                        if check_for_death(self, "drowning", {type = "environment",
                                        pos = pos, node = self.standing_in}) then return end
                else
                        self.breath = math.min(self.breath_max, self.breath + 1)
                end
        end

        --- suffocation inside solid node
        -- FIXME: Redundant with mcl_playerplus
        if (self.suffocation == true)
        and (nodef.walkable == nil or nodef.walkable == true)
        and (nodef.collision_box == nil or nodef.collision_box.type == "regular")
        and (nodef.node_box == nil or nodef.node_box.type == "regular")
        and (nodef.groups.disable_suffocation ~= 1)
        and (nodef.groups.opaque == 1) then

                -- 2 damage per second
                -- TODO: Deal this damage once every 1/2 second
                self.health = self.health - 2

                if check_for_death(self, "suffocation", {type = "environment",
                                pos = pos, node = self.standing_in}) then return end
        end

        check_for_death(self, "", {type = "unknown"})
end


-- jump if facing a solid node (not fences or gates)
local do_jump = function(self)

        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 get_velocity(self) > 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

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

        -- 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] == true then
                return false
        end

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

        if self.walk_chance == 0
        or minetest.registered_items[nod.name].walkable 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

                        set_animation(self, "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() then
                                        return
                                end
                                self.object:set_acceleration({
                                        x = v.x * 2,
                                        y = 0,
                                        z = v.z * 2,
                                })
                        end, self, v)

                        if self.jump_sound_cooloff <= 0 then
                                mob_sound(self, "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 = set_yaw(self, yaw + 1.35, 8)

                                self.jump_count = 0
                        end
                end

                return true
        end

        return false
end


-- blast damage to entities nearby (modified from TNT mod)
local entity_physics = function(pos, radius)

        radius = radius * 2

        local objs = minetest.get_objects_inside_radius(pos, radius)
        local obj_pos, dist

        for n = 1, #objs do

                obj_pos = objs[n]:get_pos()

                dist = vector.distance(pos, obj_pos)
                if dist < 1 then dist = 1 end

                local damage = floor((4 / dist) * radius)
                local ent = objs[n]:get_luaentity()

                -- punches work on entities AND players
                objs[n]:punch(objs[n], 1.0, {
                        full_punch_interval = 1.0,
                        damage_groups = {fleshy = damage},
                }, pos)
        end
end


-- should mob follow what I'm holding ?
local follow_holding = function(self, clicker)

        if 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 two animals of same type and breed if nearby and horny
local breed = function(self)

        -- child takes 240 seconds before growing into adult
        if self.child == true then

                self.hornytimer = self.hornytimer + 1

                if self.hornytimer > 240 then

                        self.child = false
                        self.hornytimer = 0

                        self.object:set_properties({
                                textures = self.base_texture,
                                mesh = self.base_mesh,
                                visual_size = self.base_size,
                                collisionbox = self.base_colbox,
                                selectionbox = self.base_selbox,
                        })

                        -- custom function when child grows up
                        if self.on_grown then
                                self.on_grown(self)
                        else
                                -- jump when fully grown so as not to fall into ground
                                self.object:set_velocity({
                                        x = 0,
                                        y = self.jump_height,
                                        z = 0
                                })
                        end
                end

                return
        end

        -- horny animal can mate for 40 seconds,
        -- afterwards horny animal cannot mate again for 200 seconds
        if self.horny == true
        and self.hornytimer < 240 then

                self.hornytimer = self.hornytimer + 1

                if self.hornytimer >= 240 then
                        self.hornytimer = 0
                        self.horny = false
                end
        end

        -- find another same animal who is also horny and mate if nearby
        if self.horny == true
        and self.hornytimer <= 40 then

                local pos = self.object:get_pos()

                effect({x = pos.x, y = pos.y + 1, z = pos.z}, 8, "heart.png", 3, 4, 1, 0.1)

                local objs = minetest.get_objects_inside_radius(pos, 3)
                local num = 0
                local ent = nil

                for n = 1, #objs do

                        ent = objs[n]:get_luaentity()

                        -- check for same animal with different colour
                        local canmate = false

                        if ent then

                                if ent.name == self.name then
                                        canmate = true
                                else
                                        local entname = string.split(ent.name,":")
                                        local selfname = string.split(self.name,":")

                                        if entname[1] == selfname[1] then
                                                entname = string.split(entname[2],"_")
                                                selfname = string.split(selfname[2],"_")

                                                if entname[1] == selfname[1] then
                                                        canmate = true
                                                end
                                        end
                                end
                        end

                        if ent
                        and canmate == true
                        and ent.horny == true
                        and ent.hornytimer <= 40 then
                                num = num + 1
                        end

                        -- found your mate? then have a baby
                        if num > 1 then

                                self.hornytimer = 41
                                ent.hornytimer = 41

                                -- spawn baby
                                minetest.after(5, function(parent1, parent2, pos)
                                        if not parent1.object:get_luaentity() then
                                                return
                                        end
                                        if not parent2.object:get_luaentity() then
                                                return
                                        end

                                        -- custom breed function
                                        if parent1.on_breed then
                                                -- when false, skip going any further
                                                if parent1.on_breed(parent1, parent2) == false then
                                                        return
                                                end
                                        end

                                        local child = mobs:spawn_child(pos, parent1.name)

                                        local ent_c = child:get_luaentity()


                                        -- Use texture of one of the parents
                                        local p = math.random(1, 2)
                                        if p == 1 then
                                                ent_c.base_texture = parent1.base_texture
                                        else
                                                ent_c.base_texture = parent2.base_texture
                                        end
                                        child:set_properties({
                                                textures = ent_c.base_texture
                                        })

                                        -- tamed and owned by parents' owner
                                        ent_c.tamed = true
                                        ent_c.owner = parent1.owner
                                end, self, ent, pos)

                                num = 0

                                break
                        end
                end
        end
end


-- find and replace what mob is looking for (grass, wheat etc.)
local replace = function(self, pos)

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

        local what, with, y_offset

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

                local num = 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

        if #minetest.find_nodes_in_area(pos, pos, what) > 0 then

                local oldnode = {name = what}
                local newnode = {name = with}
                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, {name = with})
                        end

                end
        end
end


-- check if daytime and also if mob is docile during daylight hours
local day_docile = function(self)

        if self.docile_by_day == false then

                return false

        elseif self.docile_by_day == true
        and self.time_of_day > 0.2
        and self.time_of_day < 0.8 then

                return true
        end
end


local los_switcher = false
local height_switcher = false

-- 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 abs(s1.x - s.x) + 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 = floor(s.x + 0.5)
                s.z = 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 = floor(p1.x + 0.5)
                p1.y = floor(p1.y + 0.5)
                p1.z = 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() + pi / 2
                                        local p1 = {
                                                x = s.x + cos(yaw1),
                                                y = s.y,
                                                z = s.z + 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


-- 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

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

        if self.type ~= "monster"
        or not damage_enabled
        or creative
        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


-- 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


-- 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


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

        if not self.runaway_from 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 * pi / 2) - self.rotate

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

                yaw = set_yaw(self, 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
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.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.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
                if self.following
                and self.following:is_player()
                and follow_holding(self, self.following) == false 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) + pi / 2) - self.rotate

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

                                set_yaw(self, yaw, 6)

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

                                        set_velocity(self, self.walk_velocity)

                                        if self.walk_chance ~= 0 then
                                                set_animation(self, "walk")
                                        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_velocity({x = 0, y = -5, z = 0})

                        set_animation(self, "stand")

                        return
                elseif self.state == "flop" then
                        self.state = "stand"
                end
        end
end


-- dogshoot 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


-- execute current state (stand, walk, run, attacks)
local do_states = function(self, dtime)

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

        if self.state == "stand" then

                if random(1, 4) == 1 then

                        local lp = nil
                        local s = self.object:get_pos()
                        local objs = minetest.get_objects_inside_radius(s, 3)

                        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 then

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

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

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

                        yaw = set_yaw(self, yaw, 8)
                end

                set_velocity(self, 0)
                set_animation(self, "stand")

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

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

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

        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 (is_node_dangerous(self, self.standing_in) or
                                is_node_dangerous(self, self.standing_on)) then
                                is_in_danger = true

                                lp = minetest.find_node_near(s, 5, {"group:solid"})

                                -- 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) + pi / 2) - self.rotate

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

                                        -- look towards land and jump/move in that direction
                                        yaw = set_yaw(self, yaw, 6)
                                        do_jump(self)
                                        set_velocity(self, self.walk_velocity)
                                else
                                        yaw = yaw + random(-0.5, 0.5)
                                end

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

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

                        yaw = set_yaw(self, yaw, 8)

                -- otherwise randomly turn
                elseif random(1, 100) <= 30 then

                        yaw = yaw + random(-0.5, 0.5)
                        yaw = set_yaw(self, 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 = is_at_cliff_or_danger(self)
                end
                if self.facing_fence == true
                or cliff_or_danger
                or random(1, 100) <= 30 then

                        set_velocity(self, 0)
                        self.state = "stand"
                        set_animation(self, "stand")
                else

                        set_velocity(self, self.walk_velocity)

                        if flight_check(self)
                        and self.animation
                        and self.animation.fly_start
                        and self.animation.fly_end then
                                set_animation(self, "fly")
                        else
                                set_animation(self, "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 is_at_cliff_or_danger(self) then
                        self.runaway_timer = 0
                        set_velocity(self, 0)
                        self.state = "stand"
                        set_animation(self, "stand")
                else
                        set_velocity(self, self.run_velocity)
                        set_animation(self, "walk")
                end

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

                -- calculate distance from mob and enemy
                local s = self.object:get_pos()
                local p = self.attack:get_pos() or s
                local dist = vector.distance(p, s)

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

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

                        return
                end

                if self.attack_type == "explode" then

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

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

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

                        yaw = set_yaw(self, yaw)

                        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 line_of_sight(self, s, p, 2) then

                                self.v_start = true
                                self.timer = 0
                                self.blinktimer = 0
                                mob_sound(self, "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.reach
                                        or not line_of_sight(self, s, p, 2)) then
                                self.v_start = false
                                self.timer = 0
                                self.blinktimer = 0
                                self.blinkstatus = false
                                remove_texture_mod(self, "^[brighten")
                        end

                        -- walk right up to player unless the timer is active
                        if self.v_start and (self.stop_to_explode or dist < 1.5) then
                                set_velocity(self, 0)
                        else
                                set_velocity(self, self.run_velocity)
                        end

                        if self.animation and self.animation.run_start then
                                set_animation(self, "run")
                        else
                                set_animation(self, "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
                                                remove_texture_mod(self, "^[brighten")
                                        else
                                                add_texture_mod(self, "^[brighten")
                                        end

                                        self.blinkstatus = not self.blinkstatus
                                end

                                if self.timer > self.explosion_timer then

                                        local pos = self.object:get_pos()

                                        -- dont damage anything if area protected or next to water
                                        if minetest.find_node_near(pos, 1, {"group:water"})
                                        or minetest.is_protected(pos, "") then

                                                node_break_radius = 1
                                        end

                                        self.object:remove()

                                        if mobs_griefing and mod_tnt and tnt and tnt.boom
                                        and not minetest.is_protected(pos, "") then

                                                tnt.boom(pos, {
                                                        radius = node_break_radius,
                                                        damage_radius = entity_damage_radius,
                                                        sound = self.sounds.explode,
                                                        is_tnt = false,
                                                })
                                        else

                                                minetest.sound_play(self.sounds.explode, {
                                                        pos = pos,
                                                        gain = 1.0,
                                                        max_hear_distance = self.sounds.distance or 32
                                                })

                                                entity_physics(pos, entity_damage_radius)
                                                effect(pos, 32, "tnt_smoke.png", nil, nil, node_break_radius, 1, 0)
                                        end

                                        return
                                end
                        end

                elseif self.attack_type == "dogfight"
                or (self.attack_type == "dogshoot" and dogswitch(self, dtime) == 2)
                or (self.attack_type == "dogshoot" and dist <= self.reach and dogswitch(self) == 0) then

                        if self.fly
                        and dist > self.reach then

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

                                if flight_check(self, 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 abs(p1.x-s.x) + 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) + pi / 2) - self.rotate

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

                        yaw = set_yaw(self, yaw)

                        -- 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

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

                                if is_at_cliff_or_danger(self) then

                                        set_velocity(self, 0)
                                        set_animation(self, "stand")
                                else

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

                                        if self.animation and self.animation.run_start then
                                                set_animation(self, "run")
                                        else
                                                set_animation(self, "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

                                set_velocity(self, 0)

                                if not self.custom_attack then

                                        if self.timer > 1 then

                                                self.timer = 0

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

                                                local p2 = p
                                                local s2 = s

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

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

                                                        -- play attack sound
                                                        mob_sound(self, "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 dogswitch(self, dtime) == 1)
                or (self.attack_type == "dogshoot" and dist > self.reach and dogswitch(self) == 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) + pi / 2) - self.rotate

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

                        yaw = set_yaw(self, yaw)

                        set_velocity(self, 0)

                        if self.shoot_interval
                        and self.timer > self.shoot_interval
                        and random(1, 100) <= 60 then

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

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

                                local p = self.object:get_pos()

                                p.y = p.y + (self.collisionbox[2] + self.collisionbox[5]) / 2

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

                                        local arrow, ent
                                        local v = 1
                                        if not self.shoot_arrow then
                                                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
                                        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
                end
        end
end


-- falling and fall damage
local falling = function(self, pos)

        if self.fly then
                return
        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

        -- 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 / (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 = floor(damage)
                                if damage > 0 then
                                        self.health = self.health - damage

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

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

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


-- deal damage and effects when mob punched
local mob_punch = function(self, hitter, tflp, tool_capabilities, dir)

        -- custom punch function
        if self.do_punch then

                -- when false skip going any further
                if self.do_punch(self, hitter, tflp, tool_caps, dir) == false then
                        return
                end
        end

        -- error checking when mod profiling is enabled
        if not tool_capabilities then
                minetest.log("warning", "[mobs] Mod profiling enabled, damage not enabled")
                return
        end

        -- is mob protected?
        if self.protected and hitter:is_player()
        and minetest.is_protected(self.object:get_pos(), hitter:get_player_name()) then
                return
        end


        -- punch interval
        local weapon = hitter:get_wielded_item()
        local punch_interval = 1.4

        -- exhaust attacker
        if mod_hunger and hitter:is_player() then
                mcl_hunger.exhaust(hitter:get_player_name(), mcl_hunger.EXHAUST_ATTACK)
        end

        -- calculate mob damage
        local damage = 0
        local armor = self.object:get_armor_groups() or {}
        local tmp

        -- quick error check incase it ends up 0 (serialize.h check test)
        if tflp == 0 then
                tflp = 0.2
        end

        if use_cmi then
                damage = cmi.calculate_damage(self.object, hitter, tflp, tool_capabilities, dir)
        else

                for group,_ in pairs( (tool_capabilities.damage_groups or {}) ) do

                        tmp = tflp / (tool_capabilities.full_punch_interval or 1.4)

                        if tmp < 0 then
                                tmp = 0.0
                        elseif tmp > 1 then
                                tmp = 1.0
                        end

                        damage = damage + (tool_capabilities.damage_groups[group] or 0)
                                * tmp * ((armor[group] or 0) / 100.0)
                end
        end

        -- check for tool immunity or special damage
        for n = 1, #self.immune_to do

                if self.immune_to[n][1] == weapon:get_name() then

                        damage = self.immune_to[n][2] or 0
                        break
                end
        end

        -- healing
        if damage <= -1 then
                self.health = self.health - floor(damage)
                return
        end

        if use_cmi then

                local cancel =  cmi.notify_punch(self.object, hitter, tflp, tool_capabilities, dir, damage)

                if cancel then return end
        end

        if tool_capabilities then
                punch_interval = tool_capabilities.full_punch_interval or 1.4
        end

        -- add weapon wear manually
        -- Required because we have custom health handling ("health" property)
        if minetest.settings:get_bool("creative_mode") ~= true
        and tool_capabilities then
                if tool_capabilities.punch_attack_uses then
                        -- Without this delay, the wear does not work. Quite hacky ...
                        minetest.after(0, function(name)
                                local player = minetest.get_player_by_name(name)
                                if not player then return end
                                local weapon = hitter:get_wielded_item(player)
                                local def = weapon:get_definition()
                                if def.tool_capabilities and def.tool_capabilities.punch_attack_uses then
                                        local wear = floor(65535/tool_capabilities.punch_attack_uses)
                                        weapon:add_wear(wear)
                                        hitter:set_wielded_item(weapon)
                                end
                        end, hitter:get_player_name())
                end
        end

        local die = false

        -- only play hit sound and show blood effects if damage is 1 or over
        if damage >= 1 then

                -- weapon sounds
                if weapon:get_definition().sounds ~= nil then

                        local s = random(0, #weapon:get_definition().sounds)

                        minetest.sound_play(weapon:get_definition().sounds[s], {
                                object = self.object, --hitter,
                                max_hear_distance = 8
                        })
                else
                        minetest.sound_play("default_punch", {
                                object = self.object, --hitter,
                                max_hear_distance = 5
                        })
                end

                damage_effect(self, damage)

                -- do damage
                self.health = self.health - floor(damage)

                -- skip future functions if dead, except alerting others
                if check_for_death(self, "hit", {type = "punch", puncher = hitter}) then
                        die = true
                end

                -- knock back effect (only on full punch)
                if not die
                and self.knock_back
                and tflp >= punch_interval then

                        local v = self.object:get_velocity()
                        local r = 1.4 - min(punch_interval, 1.4)
                        local kb = r * 2.0
                        local up = 2

                        -- if already in air then dont go up anymore when hit
                        if v.y > 0
                        or self.fly then
                                up = 0
                        end

                        -- direction error check
                        dir = dir or {x = 0, y = 0, z = 0}

                        -- check if tool already has specific knockback value
                        if tool_capabilities.damage_groups["knockback"] then
                                kb = tool_capabilities.damage_groups["knockback"]
                        else
                                kb = kb * 1.5
                        end

                        self.object:set_velocity({
                                x = dir.x * kb,
                                y = up,
                                z = dir.z * kb
                        })

                        self.pause_timer = 0.25
                end
        end -- END if damage

        -- if skittish then run away
        if not die and self.runaway == true then

                local lp = hitter:get_pos()
                local s = self.object: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 * pi / 2) - self.rotate

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

                yaw = set_yaw(self, yaw, 6)
                self.state = "runaway"
                self.runaway_timer = 0
                self.following = nil
        end

        local name = hitter:get_player_name() or ""

        -- attack puncher and call other mobs for help
        if self.passive == false
        and self.state ~= "flop"
        and (self.child == false or self.type == "monster")
        and hitter:get_player_name() ~= self.owner
        and not mobs.invis[ name ] then

                if not die then
                        -- attack whoever punched mob
                        self.state = ""
                        do_attack(self, hitter)
                end

                -- alert others to the attack
                local objs = minetest.get_objects_inside_radius(hitter:get_pos(), self.view_range)
                local obj = nil

                for n = 1, #objs do

                        obj = objs[n]:get_luaentity()

                        if obj then

                                -- only alert members of same mob or friends
                                if obj.group_attack
                                and obj.state ~= "attack"
                                and obj.owner ~= name then
                                        if obj.name == self.name then
                                                do_attack(obj, hitter)
                                        elseif type(obj.group_attack) == "table" then
                                                for i=1, #obj.group_attack do
                                                        if obj.name == obj.group_attack[i] then
                                                                do_attack(obj, hitter)
                                                                break
                                                        end
                                                end
                                        end
                                end

                                -- have owned mobs attack player threat
                                if obj.owner == name and obj.owner_loyal then
                                        do_attack(obj, self.object)
                                end
                        end
                end
        end
end

local mob_detach_child = function(self, child)

        if self.driver == child then
                self.driver = nil
        end

end

-- get entity staticdata
local mob_staticdata = function(self)

        -- remove mob when out of range unless tamed
        if remove_far
        and self.can_despawn
        and self.remove_ok
        and ((not self.nametag) or (self.nametag == ""))
        and self.lifetimer <= 20 then

                minetest.log("action", "Mob "..name.." despawns in mob_staticdata at "..minetest.pos_to_string(self.object.get_pos()))
                self.object:remove()

                return ""-- nil
        end

        self.remove_ok = true
        self.attack = nil
        self.following = nil
        self.state = "stand"

        if use_cmi then
                self.serialized_cmi_components = cmi.serialize_components(self._cmi_components)
        end

        local tmp = {}

        for _,stat in pairs(self) do

                local t = type(stat)

                if  t ~= "function"
                and t ~= "nil"
                and t ~= "userdata"
                and _ ~= "_cmi_components" then
                        tmp[_] = self[_]
                end
        end

        return minetest.serialize(tmp)
end


-- activate mob and reload settings
local mob_activate = function(self, staticdata, def, dtime)

        -- remove monsters in peaceful mode
        if self.type == "monster"
        and minetest.settings:get_bool("only_peaceful_mobs", false) then

                self.object:remove()

                return
        end

        -- load entity variables
        local tmp = minetest.deserialize(staticdata)

        if tmp then
                for _,stat in pairs(tmp) do
                        self[_] = stat
                end
        end

        -- select random texture, set model and size
        if not self.base_texture then

                -- compatiblity with old simple mobs textures
                if type(def.textures[1]) == "string" then
                        def.textures = {def.textures}
                end

                self.base_texture = def.textures[random(1, #def.textures)]
                self.base_mesh = def.mesh
                self.base_size = self.visual_size
                self.base_colbox = self.collisionbox
                self.base_selbox = self.selectionbox
        end

        -- for current mobs that dont have this set
        if not self.base_selbox then
                self.base_selbox = self.selectionbox or self.base_colbox
        end

        -- set texture, model and size
        local textures = self.base_texture
        local mesh = self.base_mesh
        local vis_size = self.base_size
        local colbox = self.base_colbox
        local selbox = self.base_selbox

        -- specific texture if gotten
        if self.gotten == true
        and def.gotten_texture then
                textures = def.gotten_texture
        end

        -- specific mesh if gotten
        if self.gotten == true
        and def.gotten_mesh then
                mesh = def.gotten_mesh
        end

        -- set child objects to half size
        if self.child == true then

                vis_size = {
                        x = self.base_size.x * .5,
                        y = self.base_size.y * .5,
                }

                if def.child_texture then
                        textures = def.child_texture[1]
                end

                colbox = {
                        self.base_colbox[1] * .5,
                        self.base_colbox[2] * .5,
                        self.base_colbox[3] * .5,
                        self.base_colbox[4] * .5,
                        self.base_colbox[5] * .5,
                        self.base_colbox[6] * .5
                }
                selbox = {
                        self.base_selbox[1] * .5,
                        self.base_selbox[2] * .5,
                        self.base_selbox[3] * .5,
                        self.base_selbox[4] * .5,
                        self.base_selbox[5] * .5,
                        self.base_selbox[6] * .5
                }
        end

        if self.health == 0 then
                self.health = random (self.hp_min, self.hp_max)
        end
        if self.breath == nil then
                self.breath = self.breath_max
        end

        -- pathfinding init
        self.path = {}
        self.path.way = {} -- path to follow, table of positions
        self.path.lastpos = {x = 0, y = 0, z = 0}
        self.path.stuck = false
        self.path.following = false -- currently following path?
        self.path.stuck_timer = 0 -- if stuck for too long search for path

        -- Armor groups
        -- immortal=1 because we use custom health
        -- handling (using "health" property)
        local armor
        if type(self.armor) == "table" then
                armor = table.copy(self.armor)
                armor.immortal = 1
        else
                armor = {immortal=1, fleshy = self.armor}
        end
        self.object:set_armor_groups(armor)
        self.old_y = self.object:get_pos().y
        self.old_health = self.health
        self.sounds.distance = self.sounds.distance or 10
        self.textures = textures
        self.mesh = mesh
        self.collisionbox = colbox
        self.selectionbox = selbox
        self.visual_size = vis_size
        self.standing_in = "ignore"
        self.standing_on = "ignore"
        self.jump_sound_cooloff = 0 -- used to prevent jump sound from being played too often in short time
        self.opinion_sound_cooloff = 0 -- used to prevent sound spam of particular sound types

        self.texture_mods = {}
        self.object:set_texture_mod("")

        self.v_start = false
        self.timer = 0
        self.blinktimer = 0
        self.blinkstatus = false

        -- check existing nametag
        if not self.nametag then
                self.nametag = def.nametag
        end

        -- set anything changed above
        self.object:set_properties(self)
        set_yaw(self, (random(0, 360) - 180) / 180 * pi, 6)
        update_tag(self)
        set_animation(self, "stand")

        -- run on_spawn function if found
        if self.on_spawn and not self.on_spawn_run then
                if self.on_spawn(self) then
                        self.on_spawn_run = true --  if true, set flag to run once only
                end
        end

        -- run after_activate
        if def.after_activate then
                def.after_activate(self, staticdata, def, dtime)
        end

        if use_cmi then
                self._cmi_components = cmi.activate_components(self.serialized_cmi_components)
                cmi.notify_activate(self.object, dtime)
        end
end


-- main mob function
local mob_step = function(self, dtime)

        if use_cmi then
                cmi.notify_step(self.object, dtime)
        end

        local pos = self.object:get_pos()
        local yaw = 0

        -- Despawning: when lifetimer expires, remove mob
        if remove_far
        and self.can_despawn == true
        and ((not self.nametag) or (self.nametag == "")) then

                -- TODO: Finish up implementation of despawning rules

                self.lifetimer = self.lifetimer - dtime

                if self.lifetimer <= 0 then

                        -- only despawn away from player
                        local objs = minetest.get_objects_inside_radius(pos, 32)

                        for n = 1, #objs do

                                if objs[n]:is_player() then

                                        self.lifetimer = 20

                                        return
                                end
                        end

                        minetest.log("action", "Mob "..name.." despawns in mob_step at "..minetest.pos_to_string(pos))
                        self.object:remove()

                        return
                end
        end

        if self.jump_sound_cooloff > 0 then
                self.jump_sound_cooloff = self.jump_sound_cooloff - dtime
        end
        if self.opinion_sound_cooloff > 0 then
                self.opinion_sound_cooloff = self.opinion_sound_cooloff - dtime
        end
        falling(self, pos)

        -- smooth rotation by ThomasMonroe314

        if self.delay and self.delay > 0 then

                local yaw = self.object:get_yaw()

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

                        if yaw > self.target_yaw then

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

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

                self.delay = self.delay - 1
                self.object:set_yaw(yaw)
        end

        -- end rotation

        -- knockback timer
        if self.pause_timer > 0 then

                self.pause_timer = self.pause_timer - dtime

                return
        end

        -- run custom function (defined in mob lua file)
        if self.do_custom then

                -- when false skip going any further
                if self.do_custom(self, dtime) == false then
                        return
                end
        end

        -- attack timer
        self.timer = self.timer + dtime

        if self.state ~= "attack" then

                if self.timer < 1 then
                        return
                end

                self.timer = 0
        end

        -- never go over 100
        if self.timer > 100 then
                self.timer = 1
        end

        -- mob plays random sound at times
        if random(1, 100) == 1 then
                mob_sound(self, "random", true)
        end

        -- environmental damage timer (every 1 second)
        self.env_damage_timer = self.env_damage_timer + dtime

        if (self.state == "attack" and self.env_damage_timer > 1)
        or self.state ~= "attack" then

                self.env_damage_timer = 0

                -- check for environmental damage (water, fire, lava etc.)
                do_env_damage(self)

                -- node replace check (cow eats grass etc.)
                replace(self, pos)
        end

        monster_attack(self)

        npc_attack(self)

        breed(self)

        follow_flop(self)

        do_states(self, dtime)

        do_jump(self)

        runaway_from(self)

end


-- default function when mobs are blown up with TNT
local do_tnt = function(obj, damage)

        obj.object:punch(obj.object, 1.0, {
                full_punch_interval = 1.0,
                damage_groups = {fleshy = damage},
        }, nil)

        return false, true, {}
end


mobs.spawning_mobs = {}

-- Code to execute before custom on_rightclick handling
local on_rightclick_prefix = function(self, clicker)
        local item = clicker:get_wielded_item()

        -- Name mob with nametag
        if not self.ignores_nametag and item:get_name() == "mcl_mobs:nametag" then

                local tag = item:get_meta():get_string("name")
                if tag ~= "" then
                        if string.len(tag) > MAX_MOB_NAME_LENGTH then
                                tag = string.sub(tag, 1, MAX_MOB_NAME_LENGTH)
                        end
                        self.nametag = tag

                        update_tag(self)

                        if not mobs.is_creative(clicker:get_player_name()) then
                                item:take_item()
                                clicker:set_wielded_item(item)
                        end
                        return true
                end

        end
        return false
end

local create_mob_on_rightclick = function(on_rightclick)
        return function(self, clicker)
                local stop = on_rightclick_prefix(self, clicker)
                if (not stop) and (on_rightclick) then
                        on_rightclick(self, clicker)
                end
        end
end

-- register mob entity
function mobs:register_mob(name, def)

        mobs.spawning_mobs[name] = true

local can_despawn
if def.can_despawn ~= nil then
        can_despawn = def.can_despawn
else
        can_despawn = true
end

local function scale_difficulty(value, default, min, special)
        if (not value) or (value == default) or (value == special) then
                return default
        else
                return max(min, value * difficulty)
        end
end

local collisionbox = def.collisionbox or {-0.25, -0.25, -0.25, 0.25, 0.25, 0.25}
-- Workaround for <https://github.com/minetest/minetest/issues/5966>:
-- Increase upper Y limit to avoid mobs glitching through solid nodes.
-- FIXME: Remove workaround if it's no longer needed.
if collisionbox[5] < 0.79 then
        collisionbox[5] = 0.79
end

minetest.register_entity(name, {

        stepheight = def.stepheight or 0.6,
        name = name,
        type = def.type,
        attack_type = def.attack_type,
        fly = def.fly,
        fly_in = def.fly_in or {"air", "__airlike"},
        owner = def.owner or "",
        order = def.order or "",
        on_die = def.on_die,
        spawn_small_alternative = def.spawn_small_alternative,
        do_custom = def.do_custom,
        jump_height = def.jump_height or 4, -- was 6
        rotate = math.rad(def.rotate or 0), --  0=front, 90=side, 180=back, 270=side2
        lifetimer = def.lifetimer or 57.73,
        hp_min = scale_difficulty(def.hp_min, 5, 1),
        hp_max = scale_difficulty(def.hp_max, 10, 1),
        breath_max = def.breath_max or 15,
        breathes_in_water = def.breathes_in_water or false,
        physical = true,
        collisionbox = collisionbox,
        selectionbox = def.selectionbox or def.collisionbox,
        visual = def.visual,
        visual_size = def.visual_size or {x = 1, y = 1},
        mesh = def.mesh,
        makes_footstep_sound = def.makes_footstep_sound or false,
        view_range = def.view_range or 16,
        walk_velocity = def.walk_velocity or 1,
        run_velocity = def.run_velocity or 2,
        damage = scale_difficulty(def.damage, 0, 0),
        light_damage = def.light_damage or 0,
        sunlight_damage = def.sunlight_damage or 0,
        water_damage = def.water_damage or 0,
        lava_damage = def.lava_damage or 8,
        fire_damage = def.fire_damage or 1,
        suffocation = def.suffocation or true,
        fall_damage = def.fall_damage or 1,
        fall_speed = def.fall_speed or -10, -- must be lower than -2 (default: -10)
        drops = def.drops or {},
        armor = def.armor or 100,
        on_rightclick = create_mob_on_rightclick(def.on_rightclick),
        arrow = def.arrow,
        shoot_interval = def.shoot_interval,
        sounds = def.sounds or {},
        animation = def.animation,
        follow = def.follow,
        jump = def.jump ~= false,
        walk_chance = def.walk_chance or 50,
        attacks_monsters = def.attacks_monsters or false,
        group_attack = def.group_attack or false,
        passive = def.passive or false,
        knock_back = def.knock_back ~= false,
        shoot_offset = def.shoot_offset or 0,
        floats = def.floats or 1, -- floats in water by default
        replace_rate = def.replace_rate,
        replace_what = def.replace_what,
        replace_with = def.replace_with,
        replace_offset = def.replace_offset or 0,
        on_replace = def.on_replace,
        timer = 0,
        env_damage_timer = 0, -- only used when state = "attack"
        tamed = false,
        pause_timer = 0,
        horny = false,
        hornytimer = 0,
        gotten = false,
        health = 0,
        reach = def.reach or 3,
        htimer = 0,
        texture_list = def.textures,
        child_texture = def.child_texture,
        docile_by_day = def.docile_by_day or false,
        time_of_day = 0.5,
        fear_height = def.fear_height or 0,
        runaway = def.runaway,
        runaway_timer = 0,
        pathfinding = def.pathfinding,
        immune_to = def.immune_to or {},
        explosion_radius = def.explosion_radius,
        explosion_damage_radius = def.explosion_damage_radius,
        explosion_timer = def.explosion_timer or 3,
        allow_fuse_reset = def.allow_fuse_reset ~= false,
        stop_to_explode = def.stop_to_explode ~= false,
        custom_attack = def.custom_attack,
        double_melee_attack = def.double_melee_attack,
        dogshoot_switch = def.dogshoot_switch,
        dogshoot_count = 0,
        dogshoot_count_max = def.dogshoot_count_max or 5,
        dogshoot_count2_max = def.dogshoot_count2_max or (def.dogshoot_count_max or 5),
        attack_animals = def.attack_animals or false,
        specific_attack = def.specific_attack,
        runaway_from = def.runaway_from,
        owner_loyal = def.owner_loyal,
        facing_fence = false,
        _cmi_is_mob = true,

        -- MCL2 extensions
        ignores_nametag = def.ignores_nametag or false,
        rain_damage = def.rain_damage or 0,
        glow = def.glow,
        can_despawn = can_despawn,
        child = def.child or false,
        texture_mods = {},
        shoot_arrow = def.shoot_arrow,
        sounds_child = def.sounds_child,
        -- End of MCL2 extensions

        on_spawn = def.on_spawn,

        on_blast = def.on_blast or do_tnt,

        on_step = mob_step,

        do_punch = def.do_punch,

        on_punch = mob_punch,

        on_breed = def.on_breed,

        on_grown = def.on_grown,

        on_detach_child = mob_detach_child,

        on_activate = function(self, staticdata, dtime)
                return mob_activate(self, staticdata, def, dtime)
        end,

        get_staticdata = function(self)
                return mob_staticdata(self)
        end,

})

if minetest.get_modpath("doc_identifier") ~= nil then
        doc.sub.identifier.register_object(name, "basics", "mobs")
end

end -- END mobs:register_mob function


-- count how many mobs of one type are inside an area
local count_mobs = function(pos, type)

        local num_type = 0
        local num_total = 0
        local objs = minetest.get_objects_inside_radius(pos, aoc_range)

        for n = 1, #objs do

                if not objs[n]:is_player() then

                        local obj = objs[n]:get_luaentity()

                        -- count mob type and add to total also
                        if obj and obj.name and obj.name == type then

                                num_type = num_type + 1
                                num_total = num_total + 1

                        -- add to total mobs
                        elseif obj and obj.name and obj.health ~= nil then

                                num_total = num_total + 1
                        end
                end
        end

        return num_type, num_total
end


-- global functions

function mobs:spawn_abm_check(pos, node, name)
        -- global function to add additional spawn checks
        -- return true to stop spawning mob
end


function mobs:spawn_specific(name, nodes, neighbors, min_light, max_light,
        interval, chance, aoc, min_height, max_height, day_toggle, on_spawn)

        -- Do mobs spawn at all?
        if not mobs_spawn then
                return
        end

        -- chance/spawn number override in minetest.conf for registered mob
        local numbers = minetest.settings:get(name)

        if numbers then
                numbers = numbers:split(",")
                chance = tonumber(numbers[1]) or chance
                aoc = tonumber(numbers[2]) or aoc

                if chance == 0 then
                        minetest.log("warning", string.format("[mobs] %s has spawning disabled", name))
                        return
                end

                minetest.log("action",
                        string.format("[mobs] Chance setting for %s changed to %s (total: %s)", name, chance, aoc))

        end

        local spawn_action
        spawn_action = function(pos, node, active_object_count, active_object_count_wider, name)

                        local orig_pos = table.copy(pos)
                        -- is mob actually registered?
                        if not mobs.spawning_mobs[name]
                        or not minetest.registered_entities[name] then
                                minetest.log("warning", "Mob spawn of "..name.." failed, unknown entity or mob is not registered for spawning!")
                                return
                        end

                        -- additional custom checks for spawning mob
                        if mobs:spawn_abm_check(pos, node, name) == true then
                                minetest.log("info", "Mob spawn of "..name.." at "..minetest.pos_to_string(pos).." failed, ABM check rejected!")
                                return
                        end

                        -- do not spawn if too many of same mob in area
                        if active_object_count_wider >= max_per_block
                        or count_mobs(pos, name) >= aoc then
                                -- too many entities
                                minetest.log("info", "Mob spawn of "..name.." at "..minetest.pos_to_string(pos).." failed, too crowded!")
                                return
                        end

                        -- if toggle set to nil then ignore day/night check
                        if day_toggle ~= nil then

                                local tod = (minetest.get_timeofday() or 0) * 24000

                                if tod > 4500 and tod < 19500 then
                                        -- daylight, but mob wants night
                                        if day_toggle == false then
                                                -- mob needs night
                                                minetest.log("info", "Mob spawn of "..name.." at "..minetest.pos_to_string(pos).." failed, mob needs light!")
                                                return
                                        end
                                else
                                        -- night time but mob wants day
                                        if day_toggle == true then
                                                -- mob needs day
                                                minetest.log("info", "Mob spawn of "..name.." at "..minetest.pos_to_string(pos).." failed, mob needs daylight!")
                                                return
                                        end
                                end
                        end

                        -- spawn above node
                        pos.y = pos.y + 1

                        -- only spawn away from player
                        local objs = minetest.get_objects_inside_radius(pos, 10)

                        for n = 1, #objs do

                                if objs[n]:is_player() then
                                        -- player too close
                                        minetest.log("info", "Mob spawn of "..name.." at "..minetest.pos_to_string(pos).." failed, player too close!")
                                        return
                                end
                        end

                        -- mobs cannot spawn in protected areas when enabled
                        if not spawn_protected
                        and minetest.is_protected(pos, "") then
                                minetest.log("info", "Mob spawn of "..name.." at "..minetest.pos_to_string(pos).." failed, position is protected!")
                                return
                        end

                        -- are we spawning within height limits?
                        if pos.y > max_height
                        or pos.y < min_height then
                                minetest.log("info", "Mob spawn of "..name.." at "..minetest.pos_to_string(pos).." failed, out of height limit!")
                                return
                        end

                        -- are light levels ok?
                        local light = minetest.get_node_light(pos)
                        if not light
                        or light > max_light
                        or light < min_light then
                                minetest.log("info", "Mob spawn of "..name.." at "..minetest.pos_to_string(pos).." failed, bad light!")
                                return
                        end

                        -- do we have enough space to spawn mob?
                        local ent = minetest.registered_entities[name]
                        local width_x = max(1, math.ceil(ent.collisionbox[4] - ent.collisionbox[1]))
                        local min_x, max_x
                        if width_x % 2 == 0 then
                                max_x = math.floor(width_x/2)
                                min_x = -(max_x-1)
                        else
                                max_x = math.floor(width_x/2)
                                min_x = -max_x
                        end

                        local width_z = max(1, math.ceil(ent.collisionbox[6] - ent.collisionbox[3]))
                        local min_z, max_z
                        if width_z % 2 == 0 then
                                max_z = math.floor(width_z/2)
                                min_z = -(max_z-1)
                        else
                                max_z = math.floor(width_z/2)
                                min_z = -max_z
                        end

                        local max_y = max(0, math.ceil(ent.collisionbox[5] - ent.collisionbox[2]) - 1)

                        for y = 0, max_y do
                                for x = min_x, max_x do
                                        for z = min_z, max_z do
                                                local pos2 = {x = pos.x+x, y = pos.y+y, z = pos.z+z}
                                                if minetest.registered_nodes[node_ok(pos2).name].walkable == true then
                                                        -- inside block
                                                        minetest.log("info", "Mob spawn of "..name.." at "..minetest.pos_to_string(pos).." failed, too little space!")
                                                        if ent.spawn_small_alternative ~= nil and (not minetest.registered_nodes[node_ok(pos).name].walkable) then
                                                                minetest.log("info", "Trying to spawn smaller alternative mob: "..ent.spawn_small_alternative)
                                                                spawn_action(orig_pos, node, active_object_count, active_object_count_wider, ent.spawn_small_alternative)
                                                        end
                                                        return
                                                end
                                        end
                                end
                        end

                        -- spawn mob 1/2 node above ground
                        pos.y = pos.y + 0.5
                        -- tweak X/Z spawn pos
                        if width_x % 2 == 0 then
                                pos.x = pos.x + 0.5
                        end
                        if width_z % 2 == 0 then
                                pos.z = pos.z + 0.5
                        end

                        local mob = minetest.add_entity(pos, name)
                        minetest.log("action", "Mob spawned: "..name.." at "..minetest.pos_to_string(pos))

                        if on_spawn then

                                local ent = mob:get_luaentity()

                                on_spawn(ent, pos)
                        end
        end

        local function spawn_abm_action(pos, node, active_object_count, active_object_count_wider)
                spawn_action(pos, node, active_object_count, active_object_count_wider, name)
        end

        minetest.register_abm({
                label = name .. " spawning",
                nodenames = nodes,
                neighbors = neighbors,
                interval = interval,
                chance = floor(max(1, chance * mobs_spawn_chance)),
                catch_up = false,
                action = spawn_abm_action,
        })
end


-- compatibility with older mob registration
function mobs:register_spawn(name, nodes, max_light, min_light, chance, active_object_count, max_height, day_toggle)

        mobs:spawn_specific(name, nodes, {"air"}, min_light, max_light, 30,
                chance, active_object_count, -31000, max_height, day_toggle)
end


-- MarkBu's spawn function
function mobs:spawn(def)

        local name = def.name
        local nodes = def.nodes or {"group:soil", "group:stone"}
        local neighbors = def.neighbors or {"air"}
        local min_light = def.min_light or 0
        local max_light = def.max_light or 15
        local interval = def.interval or 30
        local chance = def.chance or 5000
        local active_object_count = def.active_object_count or 1
        local min_height = def.min_height or -31000
        local max_height = def.max_height or 31000
        local day_toggle = def.day_toggle
        local on_spawn = def.on_spawn

        mobs:spawn_specific(name, nodes, neighbors, min_light, max_light, interval,
                chance, active_object_count, min_height, max_height, day_toggle, on_spawn)
end


-- register arrow for shoot attack
function mobs:register_arrow(name, def)

        if not name or not def then return end -- errorcheck

        minetest.register_entity(name, {

                physical = false,
                visual = def.visual,
                visual_size = def.visual_size,
                textures = def.textures,
                velocity = def.velocity,
                hit_player = def.hit_player,
                hit_node = def.hit_node,
                hit_mob = def.hit_mob,
                hit_object = def.hit_object,
                drop = def.drop or false, -- drops arrow as registered item when true
                collisionbox = {0, 0, 0, 0, 0, 0}, -- remove box around arrows
                timer = 0,
                switch = 0,
                owner_id = def.owner_id,
                rotate = def.rotate,
                automatic_face_movement_dir = def.rotate
                        and (def.rotate - (pi / 180)) or false,

                on_activate = def.on_activate,

                on_step = def.on_step or function(self, dtime)

                        self.timer = self.timer + 1

                        local pos = self.object:get_pos()

                        if self.switch == 0
                        or self.timer > 150
                        or not within_limits(pos, 0) then

                                self.object:remove();

                                return
                        end

                        -- does arrow have a tail (fireball)
                        if def.tail
                        and def.tail == 1
                        and def.tail_texture then

                                minetest.add_particle({
                                        pos = pos,
                                        velocity = {x = 0, y = 0, z = 0},
                                        acceleration = {x = 0, y = 0, z = 0},
                                        expirationtime = def.expire or 0.25,
                                        collisiondetection = false,
                                        texture = def.tail_texture,
                                        size = def.tail_size or 5,
                                        glow = def.glow or 0,
                                })
                        end

                        if self.hit_node then

                                local node = node_ok(pos).name

                                if minetest.registered_nodes[node].walkable then

                                        self.hit_node(self, pos, node)

                                        if self.drop == true then

                                                pos.y = pos.y + 1

                                                self.lastpos = (self.lastpos or pos)

                                                minetest.add_item(self.lastpos, self.object:get_luaentity().name)
                                        end

                                        self.object:remove();

                                        return
                                end
                        end

                        if self.hit_player or self.hit_mob or self.hit_object then

                                for _,player in pairs(minetest.get_objects_inside_radius(pos, 1.0)) do

                                        if self.hit_player
                                        and player:is_player() then

                                                self.hit_player(self, player)
                                                self.object:remove();
                                                return
                                        end

                                        local entity = player:get_luaentity()

                                        if entity
                                        and self.hit_mob
                                        and entity._cmi_is_mob == true
                                        and tostring(player) ~= self.owner_id
                                        and entity.name ~= self.object:get_luaentity().name then
                                                self.hit_mob(self, player)
                                                self.object:remove();
                                                return
                                        end

                                        if entity
                                        and self.hit_object
                                        and (not entity._cmi_is_mob)
                                        and tostring(player) ~= self.owner_id
                                        and entity.name ~= self.object:get_luaentity().name then
                                                self.hit_object(self, player)
                                                self.object:remove();
                                                return
                                        end
                                end
                        end

                        self.lastpos = pos
                end
        })
end


-- no damage to nodes explosion
function mobs:safe_boom(self, pos, radius)

        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
        })

        entity_physics(pos, radius)
        effect(pos, 32, "tnt_smoke.png", radius * 3, radius * 5, radius, 1, 0)
end


-- make explosion with protection and tnt mod check
function mobs:boom(self, pos, radius)

        if mobs_griefing
        and mod_tnt and tnt and tnt.boom
        and not minetest.is_protected(pos, "") then

                tnt.boom(pos, {
                        radius = radius,
                        damage_radius = radius,
                        sound = self.sounds and self.sounds.explode,
                        explode_center = true,
                        is_tnt = false,
                })
        else
                mobs:safe_boom(self, pos, radius)
        end
end


-- Register spawn eggs

-- Note: This also introduces the “spawn_egg” group:
-- * spawn_egg=1: Spawn egg (generic mob, no metadata)
-- * spawn_egg=2: Spawn egg (captured/tamed mob, metadata)
function mobs:register_egg(mob, desc, background, addegg, no_creative)

        local grp = {spawn_egg = 1}

        -- do NOT add this egg to creative inventory (e.g. dungeon master)
        if creative and no_creative == true then
                grp.not_in_creative_inventory = 1
        end

        local invimg = background

        if addegg == 1 then
                invimg = "mobs_chicken_egg.png^(" .. invimg ..
                        "^[mask:mobs_chicken_egg_overlay.png)"
        end

        -- register old stackable mob egg
        minetest.register_craftitem(mob, {

                description = desc,
                inventory_image = invimg,
                groups = grp,

                _doc_items_longdesc = S("This allows you to place a single mob."),
                _doc_items_usagehelp = S("Just place it where you want the mob to appear. Animals will spawn tamed, unless you hold down the sneak key while placing. If you place this on a mob spawner, you change the mob it spawns."),

                on_place = function(itemstack, placer, pointed_thing)

                        local pos = pointed_thing.above

                        -- am I clicking on something with existing on_rightclick function?
                        local under = minetest.get_node(pointed_thing.under)
                        local def = minetest.registered_nodes[under.name]
                        if def and def.on_rightclick then
                                return def.on_rightclick(pointed_thing.under, under, placer, itemstack)
                        end

                        if pos
                        and within_limits(pos, 0)
                        and not minetest.is_protected(pos, placer:get_player_name()) then

                                local name = placer:get_player_name()
                                local privs = minetest.get_player_privs(name)
                                if mod_mobspawners and under.name == "mcl_mobspawners:spawner" then
                                        if minetest.is_protected(pointed_thing.under, name) then
                                                minetest.record_protection_violation(pointed_thing.under, name)
                                                return itemstack
                                        end
                                        if not privs.maphack then
                                                minetest.chat_send_player(name, S("You need the “maphack” privilege to change the mob spawner."))
                                                return itemstack
                                        end
                                        mcl_mobspawners.setup_spawner(pointed_thing.under, itemstack:get_name())
                                        if not minetest.settings:get_bool("creative_mode") then
                                                itemstack:take_item()
                                        end
                                        return itemstack
                                end

                                if not minetest.registered_entities[mob] then
                                        return itemstack
                                end

                                if minetest.settings:get_bool("only_peaceful_mobs", false)
                                                and minetest.registered_entities[mob].type == "monster" then
                                        minetest.chat_send_player(name, S("Only peaceful mobs allowed!"))
                                        return itemstack
                                end

                                pos.y = pos.y + 1

                                local mob = minetest.add_entity(pos, mob)
                                local ent = mob:get_luaentity()

                                -- don't set owner if monster or sneak pressed
                                if ent.type ~= "monster"
                                and not placer:get_player_control().sneak then
                                        ent.owner = placer:get_player_name()
                                        ent.tamed = true
                                end

                                -- set nametag
                                local nametag = itemstack:get_meta():get_string("name")
                                if nametag ~= "" then
                                        if string.len(nametag) > MAX_MOB_NAME_LENGTH then
                                                nametag = string.sub(nametag, 1, MAX_MOB_NAME_LENGTH)
                                        end
                                        ent.nametag = nametag
                                        update_tag(ent)
                                end

                                -- if not in creative then take item
                                if not mobs.is_creative(placer:get_player_name()) then
                                        itemstack:take_item()
                                end
                        end

                        return itemstack
                end,
        })

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

                -- 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

                        self.hornytimer = self.hornytimer + 20

                        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

-- 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, "tnt_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


-- 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