Update Mobs Redo, fix crash

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

-- Mobs Api

mobs = {}
mobs.mod = "redo"
mobs.version = "20180126"


-- Intllib
local MP = minetest.get_modpath(minetest.get_current_modname())
local S, NS = dofile(MP .. "/intllib.lua")
mobs.intllib = S


-- 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 square = math.sqrt
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
                --error("atan bassed NaN")
                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") ~= false
local peaceful_only = minetest.settings:get_bool("only_peaceful_mobs")
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 = minetest.settings:get_bool("remove_far_mobs")
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 mob_chance_multiplier = tonumber(minetest.settings:get("mob_chance_multiplier") or 1)

-- Peaceful mode message so players will know there are no monsters
if peaceful_only 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_fire = "mcl_fire:fire"
local node_permanent_flame = "mcl_fire:eternal_fire"
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"


-- play sound
local mob_sound = function(self, sound)

        if sound then
                minetest.sound_play(sound, {
                        object = self.object,
                        gain = 1.0,
                        max_hear_distance = self.sounds.distance
                })
        end
end


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

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

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

        if random(0, 100) < 90 then
                mob_sound(self, self.sounds.war_cry)
        end
end


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

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

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


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

        local v = self.object:getvelocity()

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


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

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

        self:setyaw(yaw)

        return yaw
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


-- calculate distance
local get_distance = function(a, b)

        local x, y, z = a.x - b.x, a.y - b.y, a.z - b.z

        return square(x * x + y * y + z * z)
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 = get_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
        or minetest.registered_nodes[nn].drawtype == "nodebox") 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 = get_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, pos_w)

        local nod = self.standing_in
        local def = minetest.registered_nodes[nod]

        if not def then return false end -- nil check

        if type(self.fly_in) == "string"
        and nod == self.fly_in then

                return true

        elseif type(self.fly_in) == "table" then

                for _,fly_in in pairs(self.fly_in) do

                        if nod == fly_in then

                                return true
                        end
                end
        end

        -- stops mobs getting stuck inside stairs and plantlike nodes
        if def.drawtype ~= "airlike"
        and def.drawtype ~= "liquid"
        and def.drawtype ~= "flowingliquid" then
                return true
        end

        return false
end


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

        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

        minetest.add_particlespawner({
                amount = amount,
                time = 0.25,
                minpos = pos,
                maxpos = pos,
                minvel = {x = -radius, y = -radius, 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


-- update nametag colour
local update_tag = function(self)

        local col = "#00FF00"
        local qua = self.hp_max / 4

        if self.health <= floor(qua * 3) then
                col = "#FFFF00"
        end

        if self.health <= floor(qua * 2) then
                col = "#FF6600"
        end

        if self.health <= floor(qua) then
                col = "#FF0000"
        end

        self.object:set_properties({
                nametag = self.nametag,
                nametag_color = col
        })

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
        if self.child 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:setvelocity({
                                        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

        self.old_health = self.health

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

                mob_sound(self, self.sounds.damage)

                -- make sure health isn't higher than max
                if self.health > self.hp_max then
                        self.health = self.hp_max
                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, self.sounds.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 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
local is_at_cliff = 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

        if 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}
        , 1) then

                return true
        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] -- {name = 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

        -- bright light harms mob
        if self.light_damage ~= 0
--      and pos.y > 0
--      and self.time_of_day > 0.2
--      and self.time_of_day < 0.8
        and (minetest.get_node_light(pos) or 0) > 12 then

                self.health = self.health - self.light_damage

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

                if check_for_death(self, "light", {type = "light"}) then return end
        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
        self.standing_in = node_ok(pos, "air").name
--      print ("standing in " .. self.standing_in)

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

        local nodef = minetest.registered_nodes[self.standing_in]

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

        -- water
        if self.water_damage
        and nodef.groups.water then

                if self.water_damage ~= 0 then

                        self.health = self.health - self.water_damage

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

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

        -- lava or fire
        elseif self.lava_damage
        and (nodef.groups.lava
        or self.standing_in == node_fire
        or self.standing_in == node_permanent_flame) 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

        -- 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
--[[
        --- suffocation inside solid node
        if self.suffocation ~= 0
        and nodef.walkable == true
        and nodef.groups.disable_suffocation ~= 1
        and nodef.drawtype == "normal" then

                self.health = self.health - self.suffocation

                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 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:getvelocity().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)

--print ("standing on:", nod.name, pos.y)

        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?
        local nod = node_ok({
                x = pos.x + dir_x,
                y = pos.y + 0.5,
                z = pos.z + dir_z
        })

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

--print ("in front:", nod.name, pos.y + 0.5)

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

                if not nod.name:find("fence")
                and not nod.name:find("gate") then

                        local v = self.object:getvelocity()

                        v.y = self.jump_height

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

                        self.object:setvelocity(v)

if get_velocity(self) > 0 then
                        mob_sound(self, self.sounds.jump)
end
                else
                        self.facing_fence = true
                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 = get_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:setvelocity({
                                        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()

                                        -- custom breed function
                                        if self.on_breed then

                                                -- when false skip going any further
                                                if self.on_breed(self, ent) == false then
                                                                return
                                                end
                                        else
                                                effect(pos, 15, "tnt_smoke.png", 1, 2, 2, 15, 5)
                                        end

                                        local mob = minetest.add_entity(pos, self.name)
                                        local ent2 = mob:get_luaentity()
                                        local textures = self.base_texture

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

                                        -- and resize to half height
                                        mob:set_properties({
                                                textures = textures,
                                                visual_size = {
                                                        x = self.base_size.x * .5,
                                                        y = self.base_size.y * .5,
                                                },
                                                collisionbox = {
                                                        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,
                                                },
                                                selectionbox = {
                                                        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,
                                                },
                                        })
                                        -- tamed and owned by parents' owner
                                        ent2.child = true
                                        ent2.tamed = true
                                        ent2.owner = self.owner
                                end)

                                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 mobs_griefing
        or not self.replace_rate
        or not self.replace_what
        or self.child == true
        or self.object:getvelocity().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

-- print ("replace node = ".. minetest.get_node(pos).name, pos.y)

                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

                        minetest.set_node(pos, {name = with})

                        -- when cow/sheep eats grass, replace wool and milk
                        if self.gotten == true then
                                self.gotten = false
                                self.object:set_properties(self)
                        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


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

        local s1 = self.path.lastpos

        -- is it becoming stuck?
        if abs(s1.x - s.x) + abs(s1.z - s.z) < 1.5 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}

        -- im stuck, search for path
        if (self.path.stuck_timer > stuck_timeout and not self.path.following)
        or (self.path.stuck_timer > stuck_path_timeout and self.path.following) then

                self.path.stuck_timer = 0

                -- 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.y = floor(s.y + 0.5) - sheight
                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 = 6
                if self.fear_height ~= 0 then dropheight = self.fear_height end

--              self.path.way = minetest.find_path(s, p1, 16, 2, 6, "Dijkstra")
                self.path.way = minetest.find_path(s, p1, 16, self.stepheight, dropheight, "A*_noprefetch")

                -- attempt to unstick mob that is "daydreaming"
                self.object:setpos({
                        x = s.x + 0.1 * (random() * 2 - 1),
                        y = s.y + 1,
                        z = s.z + 0.1 * (random() * 2 - 1)
                })

                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:setpos({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 second
                        self.path.stuck_timer = stuck_timeout - 2

                        -- frustration! cant find the damn path :(
                        mob_sound(self, self.sounds.random)
                else
                        -- yay i found path
                        mob_sound(self, self.sounds.attack)

                        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() ] 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

                        s = self.object:get_pos()
                        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 = get_distance(p, s)

                        if dist < self.view_range then
                        -- field of view check goes here

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

                        dist = get_distance(p, s)

                        if dist < min_dist 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 or list[no] == "player" 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() ] 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

                        s = self.object:get_pos()
                        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 = get_distance(p, s)

                        if dist < self.view_range then
                        -- field of view check goes here

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

        -- attack player
        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.object, yaw)
                self.state = "runaway"
                self.runaway_timer = 0
                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 get_distance(players[n]:get_pos(), s) < self.view_range
                        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 = get_distance(p, s)

                        -- dont follow if out of range
                        if dist > self.view_range 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

                                yaw = set_yaw(self.object, yaw)

                                -- 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:setvelocity({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.object, yaw)
                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(self) == false then

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

                                -- fly up/down randomly for flying mobs
                                if self.fly and random(1, 100) <= self.walk_chance then

                                        local v = self.object:getvelocity()
                                        local ud = random(-1, 2) / 9

                                        self.object:setvelocity({x = v.x, y = ud, z = v.z})
                                end
                        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 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"})
                end

                if lp then

                        -- if mob in water or lava then look for land
                        if (self.lava_damage
                                and minetest.registered_nodes[self.standing_in].groups.lava)
                        or (self.water_damage
                                and minetest.registered_nodes[self.standing_in].groups.water) then

                                lp = minetest.find_node_near(s, 5, {"group:soil", "group:stone",
                                        "group:sand", node_ice, node_snowblock})

                                -- 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.object, yaw)
                                        do_jump(self)
                                        set_velocity(self, self.walk_velocity)
                                else
                                        yaw = yaw + random(-0.5, 0.5)
                                end

                        else

                                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
                        end

                        yaw = set_yaw(self.object, yaw)

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

                        yaw = yaw + random(-0.5, 0.5)

                        yaw = set_yaw(self.object, yaw)
                end

                -- stand for great fall in front
                local temp_is_cliff = is_at_cliff(self)

                if self.facing_fence == true
                or temp_is_cliff
                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(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 = get_distance(p, s)

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

--                      print(" ** stop attacking **", dist, self.view_range)
                        self.state = "stand"
                        set_velocity(self, 0)
                        set_animation(self, "stand")
                        self.attack = nil
                        self.v_start = false
                        self.timer = 0
                        self.blinktimer = 0

                        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.object, yaw)

                        -- start timer when inside reach
                        if dist < self.reach and not self.v_start then
                                self.v_start = true
                                self.timer = 0
                                self.blinktimer = 0
--                              print ("=== explosion timer started", self.explosion_timer)
                        end

                        -- walk right up to player when timer active
                        if dist < 1.5 and self.v_start 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
                                                self.object:settexturemod("")
                                        else
                                                self.object:settexturemod("^[brighten")
                                        end

                                        self.blinkstatus = not self.blinkstatus
                                end

--                              print ("=== explosion timer", self.timer)

                                if self.timer > self.explosion_timer then

                                        local pos = self.object:get_pos()
                                        local radius = self.explosion_radius or 1
                                        local damage_radius = radius

                                        -- 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

                                                damage_radius = 0
                                        end

                                        self.object:remove()

                                        if minetest.get_modpath("mcl_tnt") and tnt and tnt.boom
                                        and not minetest.is_protected(pos, "") then

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

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

                                                entity_physics(pos, damage_radius)
                                                effect(pos, 32, "tnt_smoke.png", radius * 3, radius * 5, 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:getvelocity()

                                if flight_check(self, s) then

                                        if me_y < p_y then

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

                                        elseif me_y > p_y then

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

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

                                        elseif me_y > p_y then

                                                self.object:setvelocity({
                                                        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.object, 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(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, self.sounds.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 = get_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.object, 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, self.sounds.shoot_attack)

                                local p = self.object:get_pos()

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

                                if minetest.registered_entities[self.arrow] then

                                        local obj = minetest.add_entity(p, self.arrow)
                                        local ent = obj:get_luaentity()
                                        local amount = (vec.x * vec.x + vec.y * vec.y + vec.z * vec.z) ^ 0.5
                                        local v = ent.velocity or 1 -- or set to default

                                        ent.switch = 1
                                        ent.owner_id = tostring(self.object) -- add unique owner id to arrow

                                         -- 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)

                                        obj:setvelocity(vec)
                                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:getvelocity()

        if v.y > 0 then

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

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

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

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

                if self.floats == 1 then

                        self.object:setacceleration({
                                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:getvelocity().y == 0 then

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

                        if d > 5 then

                                self.health = self.health - floor(d - 5)

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

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

        -- mob health check
--      if self.health <= 0 then
--              return
--      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
                minetest.chat_send_player(hitter:get_player_name(), S("Mob has been protected!"))
                return
        end


        -- weapon wear
        local weapon = hitter:get_wielded_item()
        local punch_interval = 1.4

        -- 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

--      print ("Mob Damage is", damage)

        if use_cmi then

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

                if cancel then return end
        end

        -- add weapon wear
        if tool_capabilities then
                punch_interval = tool_capabilities.full_punch_interval or 1.4
        end

        if weapon:get_definition()
        and weapon:get_definition().tool_capabilities then

                weapon:add_wear(floor((punch_interval / 75) * 9000))
                hitter:set_wielded_item(weapon)
        end

        -- 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

                -- blood_particles
                if self.blood_amount > 0
                and not disable_blood then

                        local pos = self.object:get_pos()

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

                        -- do we have a single blood texture or multiple?
                        if type(self.blood_texture) == "table" then

                                local blood = self.blood_texture[random(1, #self.blood_texture)]

                                effect(pos, self.blood_amount, blood, nil, nil, 1, nil)
                        else
                                effect(pos, self.blood_amount, self.blood_texture, nil, nil, 1, nil)
                        end
                end

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

                -- exit here if dead, special item check
                if weapon:get_name() == "mobs:pick_lava" then
                        if check_for_death(self, "lava", {type = "punch",
                                        puncher = hitter}) then
                                return
                        end
                else
                        if check_for_death(self, "hit", {type = "punch",
                                        puncher = hitter}) then
                                return
                        end
                end

                --[[ add healthy afterglow when hit (can cause hit lag with larger textures)
                core.after(0.1, function()
                        self.object:settexturemod("^[colorize:#c9900070")

                        core.after(0.3, function()
                                self.object:settexturemod("")
                        end)
                end) ]]

                -- knock back effect (only on full punch)
                if self.knock_back > 0
                and tflp >= punch_interval then

                        local v = self.object:getvelocity()
                        local r = 1.4 - min(punch_interval, 1.4)
                        local kb = r * 5
                        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:setvelocity({
                                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 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.object, yaw)
                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
        and hitter:get_player_name() ~= self.owner
        and not mobs.invis[ name ] then

                -- attack whoever punched mob
                self.state = ""
                do_attack(self, hitter)

                -- 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
                                if obj.group_attack == true
                                and obj.state ~= "attack"
                                and obj.owner ~= name
                                and obj.name == self.name then
                                        do_attack(obj, hitter)
                                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


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

        -- remove mob when out of range unless tamed
        if remove_far
        and self.remove_ok
        and self.type ~= "npc"
        and self.state ~= "attack"
        and not self.tamed
        and self.lifetimer < 20000 then

                --print ("REMOVED " .. self.name)

                self.object:remove()

                return ""-- nil
        end

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

        -- used to rotate older mobs
        if self.drawtype
        and self.drawtype == "side" then
                self.rotate = math.rad(90)
        end

        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

        --print('===== '..self.name..'\n'.. dump(tmp)..'\n=====\n')
        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 peaceful_only 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

        -- 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

        -- mob defaults
        self.object:set_armor_groups({immortal = 1, fleshy = self.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 = ""

        -- 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.object, (random(0, 360) - 180) / 180 * pi)
        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

        -- when lifetimer expires remove mob (except npc and tamed)
        if self.type ~= "npc"
        and not self.tamed
        and self.state ~= "attack"
        and remove_far ~= true
        and self.lifetimer < 20000 then

                self.lifetimer = self.lifetimer - dtime

                if self.lifetimer <= 0 then

                        -- only despawn away from player
                        local objs = minetest.get_objects_inside_radius(pos, 15)

                        for n = 1, #objs do

                                if objs[n]:is_player() then

                                        self.lifetimer = 20

                                        return
                                end
                        end

--                      minetest.log("action",
--                              S("lifetimer expired, removed @1", self.name))

                        effect(pos, 15, "tnt_smoke.png", 2, 4, 2, 0)

                        self.object:remove()

                        return
                end
        end

        falling(self, pos)

        -- 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

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

        -- mob plays random sound at times
        if random(1, 100) == 1 then
                mob_sound(self, self.sounds.random)
        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

                do_env_damage(self)
        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)

        --print ("----- Damage", 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 = {}

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

        mobs.spawning_mobs[name] = true

minetest.register_entity(name, {

        stepheight = def.stepheight or 1.1, -- was 0.6
        name = name,
        type = def.type,
        attack_type = def.attack_type,
        fly = def.fly,
        fly_in = def.fly_in or "air",
        owner = def.owner or "",
        order = def.order or "",
        on_die = def.on_die,
        do_custom = def.do_custom,
        jump_height = def.jump_height or 4, -- was 6
        drawtype = def.drawtype, -- DEPRECATED, use rotate instead
        rotate = math.rad(def.rotate or 0), --  0=front, 90=side, 180=back, 270=side2
        lifetimer = def.lifetimer or 180, -- 3 minutes
        hp_min = max(1, (def.hp_min or 5) * difficulty),
        hp_max = max(1, (def.hp_max or 10) * difficulty),
        physical = true,
        collisionbox = def.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 5,
        walk_velocity = def.walk_velocity or 1,
        run_velocity = def.run_velocity or 2,
        damage = max(0, (def.damage or 0) * difficulty),
        light_damage = def.light_damage or 0,
        water_damage = def.water_damage or 0,
        lava_damage = def.lava_damage or 0,
        suffocation = def.suffocation or 2,
        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 = 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 or 3,
        blood_amount = def.blood_amount or 5,
        blood_texture = def.blood_texture or "mobs_blood.png",
        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,
        child = false,
        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_timer = def.explosion_timer or 3,
        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,

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

        get_staticdata = function(self)
                return mob_staticdata(self)
        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_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

        minetest.register_abm({

                label = name .. " spawning",
                nodenames = nodes,
                neighbors = neighbors,
                interval = interval,
                chance = max(1, (chance * mob_chance_multiplier)),
                catch_up = false,

                action = function(pos, node, active_object_count, active_object_count_wider)

                        -- is mob actually registered?
                        if not mobs.spawning_mobs[name]
                        or not minetest.registered_entities[name] then
--print ("--- mob doesn't exist", name)
                                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
--print ("--- too many entities", name, aoc, active_object_count_wider)
                                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
--print ("--- mob needs night", name)
                                                return
                                        end
                                else
                                        -- night time but mob wants day
                                        if day_toggle == true then
--print ("--- mob needs day", name)
                                                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
--print ("--- player too close", name)
                                        return
                                end
                        end

                        -- mobs cannot spawn in protected areas when enabled
                        if not spawn_protected
                        and minetest.is_protected(pos, "") then
--print ("--- inside protected area", name)
                                return
                        end

                        -- are we spawning within height limits?
                        if pos.y > max_height
                        or pos.y < min_height then
--print ("--- height limits not met", name, pos.y)
                                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
--print ("--- light limits not met", name, light)
                                return
                        end

                        -- do we have enough height clearance to spawn mob?
                        local ent = minetest.registered_entities[name]
                        local height = max(0, math.ceil(ent.collisionbox[5] - ent.collisionbox[2]) - 1)

                        for n = 0, height do

                                local pos2 = {x = pos.x, y = pos.y + n, z = pos.z}

                                if minetest.registered_nodes[node_ok(pos2).name].walkable == true then
--print ("--- inside block", name, node_ok(pos2).name)
                                        return
                                end
                        end

                        -- spawn mob half block higher than ground
                        pos.y = pos.y + 0.5

                        local mob = minetest.add_entity(pos, name)
--[[
                        print ("[mobs] Spawned " .. name .. " at "
                        .. minetest.pos_to_string(pos) .. " on "
                        .. node.name .. " near " .. neighbors[1])
]]
                        if on_spawn then

                                local ent = mob:get_luaentity()

                                on_spawn(ent, pos)
                        end
                end
        })
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,
                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() ; -- print ("removed arrow")

                                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() ; -- print ("hit node")

                                        return
                                end
                        end

                        if self.hit_player or self.hit_mob 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() ; -- print ("hit player")
                                                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() ;  --print ("hit mob")

                                                return
                                        end
                                end
                        end

                        self.lastpos = pos
                end
        })
end


-- compatibility function
function mobs:explosion(pos, radius)
        local self = {sounds = {}}
        self.sounds.explode = "tnt_explode"
        mobs:boom(self, pos, radius)
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 minetest.get_modpath("mcl_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,
                })
        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 = "This allows you to place a single mob.",
                _doc_items_usagehelp = "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 not privs.maphack then
                                        minetest.chat_send_player(name, "You need the “maphack” privilege to change the mob spawner.")
                                        return itemstack
                                end
                                if minetest.get_modpath("mcl_mobspawners") and under.name == "mcl_mobspawners:spawner" then
                                        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
                                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

                                -- 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


-- capture critter (thanks to blert2112 for idea)
function mobs:capture_mob(self, clicker, chance_hand, chance_net, chance_lasso, force_take, replacewith)

        if self.child
        or not clicker:is_player()
        or not clicker:get_inventory() then
                return false
        end

        -- get name of clicked mob
        local mobname = self.name

        -- if not nil change what will be added to inventory
        if replacewith then
                mobname = replacewith
        end

        local name = clicker:get_player_name()
        local tool = clicker:get_wielded_item()

        -- are we using hand, net or lasso to pick up mob?
        if tool:get_name() ~= ""
        and tool:get_name() ~= "mobs:net"
        and tool:get_name() ~= "mobs:lasso" then
                return false
        end

        -- is mob tamed?
        if self.tamed == false
        and force_take == false then

                minetest.chat_send_player(name, S("Not tamed!"))

                return true -- false
        end

        -- cannot pick up if not owner
        if self.owner ~= name
        and force_take == false then

                minetest.chat_send_player(name, S("@1 is owner!", self.owner))

                return true -- false
        end

        if clicker:get_inventory():room_for_item("main", mobname) then

                -- was mob clicked with hand, net, or lasso?
                local chance = 0

                if tool:get_name() == "" then
                        chance = chance_hand

                elseif tool:get_name() == "mobs:net" then

                        chance = chance_net

                        tool:add_wear(4000) -- 17 uses

                        clicker:set_wielded_item(tool)

                elseif tool:get_name() == "mobs:lasso" then

                        chance = chance_lasso

                        tool:add_wear(650) -- 100 uses

                        clicker:set_wielded_item(tool)

                end

                -- calculate chance.. add to inventory if successful?
                if chance > 0 and random(1, 100) <= chance then

                        -- default mob egg
                        local new_stack = ItemStack(mobname)

                        -- add special mob egg with all mob information
                        -- unless 'replacewith' contains new item to use
                        if not replacewith then

                                new_stack = ItemStack(mobname .. "_set")

                                local tmp = {}

                                for _,stat in pairs(self) do
                                        local t = type(stat)
                                        if  t ~= "function"
                                        and t ~= "nil"
                                        and t ~= "userdata" then
                                                tmp[_] = self[_]
                                        end
                                end

                                local data_str = minetest.serialize(tmp)

                                new_stack:set_metadata(data_str)
                        end

                        local inv = clicker:get_inventory()

                        if inv:room_for_item("main", new_stack) then
                                inv:add_item("main", new_stack)
                        else
                                minetest.add_item(clicker:get_pos(), new_stack)
                        end

                        self.object:remove()

                        mob_sound(self, "default_place_node_hard")


                else
                        minetest.chat_send_player(name, S("Missed!"))

                        mob_sound(self, "mobs_swing")
                end
        end

        return true
end


-- protect tamed mob with rune item
function mobs:protect(self, clicker)

        local name = clicker:get_player_name()
        local tool = clicker:get_wielded_item()

        if tool:get_name() ~= "mobs:protector" then
                return false
        end

        if self.tamed == false then
                minetest.chat_send_player(name, S("Not tamed!"))
                return true -- false
        end

        if self.protected == true then
                minetest.chat_send_player(name, S("Already protected!"))
                return true -- false
        end

        if not mobs.is_creative(clicker:get_player_name()) then
                tool:take_item() -- take 1 protection rune
                clicker:set_wielded_item(tool)
        end

        self.protected = true

        local pos = self.object:get_pos()
        pos.y = pos.y + self.collisionbox[2] + 0.5

        effect(self.object:get_pos(), 25, "mobs_protect_particle.png", 0.5, 4, 2, 15)

        mob_sound(self, "mobs_spell")

        return true
end


local mob_obj = {}
local mob_sta = {}

-- 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

                        self.gotten = false

                        if tame then

                                if self.tamed == false then
                                        minetest.chat_send_player(clicker:get_player_name(),
                                                S("@1 has been tamed!",
                                                self.name:split(":")[2]))
                                end

                                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, self.sounds.random)
                end

                return true
        end

        local item = clicker:get_wielded_item()

        -- if mob has been tamed you can name it with a nametag
        if item:get_name() == "mobs:nametag"
        and clicker:get_player_name() == self.owner then

                local name = clicker:get_player_name()

                -- store mob and nametag stack in external variables
                mob_obj[name] = self
                mob_sta[name] = item

                local tag = self.nametag or ""

                minetest.show_formspec(name, "mobs_nametag", "size[8,4]"
                        .. mcl_vars.gui_bg
                        .. mcl_vars.gui_bg_img
                        .. "field[0.5,1;7.5,0;name;" .. minetest.formspec_escape(S("Enter name:")) .. ";" .. tag .. "]"
                        .. "button_exit[2.5,3.5;3,1;mob_rename;" .. minetest.formspec_escape(S("Rename")) .. "]")

        end

        return false

end


-- inspired by blockmen's nametag mod
minetest.register_on_player_receive_fields(function(player, formname, fields)

        -- right-clicked with nametag and name entered?
        if formname == "mobs_nametag"
        and fields.name
        and fields.name ~= "" then

                local name = player:get_player_name()

                if not mob_obj[name]
                or not mob_obj[name].object then
                        return
                end

                -- limit name entered to 64 characters long
                if string.len(fields.name) > 64 then
                        fields.name = string.sub(fields.name, 1, 64)
                end

                -- update nametag
                mob_obj[name].nametag = fields.name

                update_tag(mob_obj[name])

                -- if not in creative then take item
                if not mobs.is_creative(name) then

                        mob_sta[name]:take_item()

                        player:set_wielded_item(mob_sta[name])
                end

                -- reset external variables
                mob_obj[name] = nil
                mob_sta[name] = nil

        end
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)

                        local pos = self.object:get_pos()

                        if minetest.registered_entities[new_name] then
                                minetest.add_entity(pos, new_name)
                        end

                        self.object:remove()
                end
        })
end