split off physics functions into separate file + use metatable

mods/ENTITIES/mcl_mobs/effects.lua

@@ -0,0 +1,43 @@
+local math, vector, minetest, mcl_mobs = math, vector, minetest, mcl_mobs
+local mob_class = mcl_mobs.mob_class
+-- play sound
+function mob_class:mob_sound(soundname, is_opinion, fixed_pitch)
+
+	local soundinfo
+	if self.sounds_child and self.child then
+		soundinfo = self.sounds_child
+	elseif self.sounds then
+		soundinfo = self.sounds
+	end
+	if not soundinfo then
+		return
+	end
+	local sound = soundinfo[soundname]
+	if sound then
+		if is_opinion and self.opinion_sound_cooloff > 0 then
+			return
+		end
+		local pitch
+		if not fixed_pitch then
+			local base_pitch = soundinfo.base_pitch
+			if not base_pitch then
+				base_pitch = 1
+			end
+			if self.child and (not self.sounds_child) then
+				-- Children have higher pitch
+				pitch = base_pitch * 1.5
+			else
+				pitch = base_pitch
+			end
+			-- randomize the pitch a bit
+			pitch = pitch + math.random(-10, 10) * 0.005
+		end
+		minetest.sound_play(sound, {
+			object = self.object,
+			gain = 1.0,
+			max_hear_distance = self.sounds.distance,
+			pitch = pitch,
+		}, true)
+		self.opinion_sound_cooloff = 1
+	end
+end

mods/ENTITIES/mcl_mobs/init.lua

@@ -1,6 +1,11 @@
-
+mcl_mobs = {}
+mcl_mobs.mob_class = {}
+mcl_mobs.mob_class_meta = {__index = mcl_mobs.mob_class}
 local path = minetest.get_modpath(minetest.get_current_modname())
 
+dofile(path .. "/effects.lua")
+dofile(path .. "/physics.lua")
+
 -- Mob API
 dofile(path .. "/api.lua")
 
@@ -11,4 +16,4 @@ dofile(path .. "/spawning.lua")
 dofile(path .. "/mount.lua")
 
 -- Mob Items
-dofile(path .. "/crafts.lua")
+dofile(path .. "/crafts.lua")

mods/ENTITIES/mcl_mobs/physics.lua

@@ -0,0 +1,799 @@
+local math, vector, minetest, mcl_mobs = math, vector, minetest, mcl_mobs
+local mob_class = mcl_mobs.mob_class
+
+local ENTITY_CRAMMING_MAX = 24
+local CRAMMING_DAMAGE = 3
+local DEFAULT_FALL_SPEED = -9.81*1.5
+
+
+-- get node but use fallback for nil or unknown
+local node_ok = function(pos, fallback)
+
+	fallback = fallback or mcl_mobs.fallback_node
+
+	local node = minetest.get_node_or_nil(pos)
+
+	if node and minetest.registered_nodes[node.name] then
+		return node
+	end
+
+	return minetest.registered_nodes[fallback]
+end
+
+-- check if within physical map limits (-30911 to 30927)
+local function within_limits(pos, radius)
+	local wmin, wmax = -30912, 30928
+	if mcl_vars then
+		if mcl_vars.mapgen_edge_min and mcl_vars.mapgen_edge_max then
+			wmin, wmax = mcl_vars.mapgen_edge_min, mcl_vars.mapgen_edge_max
+		end
+	end
+	if radius then
+		wmin = wmin - radius
+		wmax = wmax + radius
+	end
+	for _,v in pairs(pos) do
+		if v < wmin or v > wmax then return false end
+	end
+	return true
+end
+
+-- collision function borrowed amended from jordan4ibanez open_ai mod
+function mob_class:collision()
+	local pos = self.object:get_pos()
+	if not pos then return {0,0} end
+	local vel = self.object:get_velocity()
+	local x = 0
+	local z = 0
+	local width = -self.collisionbox[1] + self.collisionbox[4] + 0.5
+	for _,object in pairs(minetest.get_objects_inside_radius(pos, width)) do
+
+		local ent = object:get_luaentity()
+		if object:is_player() or (ent and ent.is_mob and object ~= self.object) then
+
+			if object:is_player() and mcl_burning.is_burning(self.object) then
+				mcl_burning.set_on_fire(object, 4)
+			end
+
+			local pos2 = object:get_pos()
+			local vec  = {x = pos.x - pos2.x, z = pos.z - pos2.z}
+			local force = (width + 0.5) - vector.distance(
+				{x = pos.x, y = 0, z = pos.z},
+				{x = pos2.x, y = 0, z = pos2.z})
+
+			x = x + (vec.x * force)
+			z = z + (vec.z * force)
+		end
+	end
+
+	return({x,z})
+end
+
+-- move mob in facing direction
+function mob_class:set_velocity( v)
+
+	local c_x, c_y = 0, 0
+
+	-- can mob be pushed, if so calculate direction
+	if self.pushable then
+		c_x, c_y = unpack(self:collision())
+	end
+
+	-- halt mob if it has been ordered to stay
+	if self.order == "stand" or self.order == "sit" then
+	  self.acc=vector.new(0,0,0)
+	  return
+	end
+
+	local yaw = (self.object:get_yaw() or 0) + self.rotate
+	local vv = self.object:get_velocity()
+	if vv then
+		self.acc={
+		  x = ((math.sin(yaw) * -v) + c_x)*.27,
+		  y = 0,
+		  z = ((math.cos(yaw) * v) + c_y)*.27,
+		}
+	end
+end
+
+-- calculate mob velocity
+function mob_class:get_velocity()
+
+	local v = self.object:get_velocity()
+	if v then
+		return (v.x * v.x + v.z * v.z) ^ 0.5
+	end
+
+	return 0
+end
+
+function mob_class:update_roll()
+	local is_Fleckenstein = self.nametag == "Fleckenstein"
+	local was_Fleckenstein = false
+
+	local rot = self.object:get_rotation()
+	rot.z = is_Fleckenstein and pi or 0
+	self.object:set_rotation(rot)
+
+	local cbox = table.copy(self.collisionbox)
+	local acbox = self.object:get_properties().collisionbox
+
+	if math.abs(cbox[2] - acbox[2]) > 0.1 then
+		was_Fleckenstein = true
+	end
+
+	if is_Fleckenstein ~= was_Fleckenstein then
+		local pos = self.object:get_pos()
+		pos.y = pos.y + (acbox[2] + acbox[5])
+		self.object:set_pos(pos)
+	end
+
+	if is_Fleckenstein then
+		cbox[2], cbox[5] = -cbox[5], -cbox[2]
+		self.object:set_properties({collisionbox = cbox})
+	-- This leads to child mobs having the wrong collisionbox
+	-- and seeing as it seems to be nothing but an easter egg
+	-- i've put it inside the if. Which just makes it be upside
+	-- down lol.
+	end
+
+end
+
+function mob_class:update_tag()
+	local tag
+	if mobs_debug then
+		tag = "nametag = '"..tostring(self.nametag).."'\n"..
+		"state = '"..tostring(self.state).."'\n"..
+		"order = '"..tostring(self.order).."'\n"..
+		"attack = "..tostring(self.attack).."\n"..
+		"health = "..tostring(self.health).."\n"..
+		"breath = "..tostring(self.breath).."\n"..
+		"gotten = "..tostring(self.gotten).."\n"..
+		"tamed = "..tostring(self.tamed).."\n"..
+		"horny = "..tostring(self.horny).."\n"..
+		"hornytimer = "..tostring(self.hornytimer).."\n"..
+		"runaway_timer = "..tostring(self.runaway_timer).."\n"..
+		"following = "..tostring(self.following)
+	else
+		tag = self.nametag
+	end
+	self.object:set_properties({
+		nametag = tag,
+	})
+
+	self:update_roll()
+end
+
+local function shortest_term_of_yaw_rotatoin(self, rot_origin, rot_target, nums)
+	if not rot_origin or not rot_target then
+		return
+	end
+
+	rot_origin = math.deg(rot_origin)
+	rot_target = math.deg(rot_target)
+
+	if math.abs(rot_target - rot_origin) < 180 then
+		return rot_target - rot_origin
+	else
+		if (rot_target - rot_origin) > 0 then
+			return 360-(rot_target - rot_origin)
+		else
+			return (rot_target - rot_origin)+360
+		end
+	end
+end
+
+
+-- set and return valid yaw
+function mob_class:set_yaw(yaw, delay, dtime)
+	if self.noyaw then return end
+
+	if self.state ~= PATHFINDING then
+		self._turn_to = yaw
+	end
+
+	--mcl_log("Yaw is: \t\t" .. tostring(math.deg(yaw)))
+	--mcl_log("self.object:get_yaw() is: \t" .. tostring(math.deg(self.object:get_yaw())))
+
+	--clamp our yaw to a 360 range
+	if math.deg(self.object:get_yaw()) > 360 then
+		self.object:set_yaw(math.rad(1))
+	elseif math.deg(self.object:get_yaw()) < 0 then
+		self.object:set_yaw(math.rad(359))
+	end
+
+	--calculate the shortest way to turn to find our target
+	local target_shortest_path = shortest_term_of_yaw_rotatoin(self, self.object:get_yaw(), yaw, true)
+
+	--turn in the shortest path possible toward our target. if we are attacking, don't dance.
+	if (math.abs(target_shortest_path) > 50 and not self._kb_turn) and (self.attack and self.attack:get_pos() or self.following and self.following:get_pos()) then
+		if self.following then
+			target_shortest_path = shortest_term_of_yaw_rotatoin(self, self.object:get_yaw(), minetest.dir_to_yaw(vector.direction(self.object:get_pos(), self.following:get_pos())), true)
+		else
+			target_shortest_path = shortest_term_of_yaw_rotatoin(self, self.object:get_yaw(), minetest.dir_to_yaw(vector.direction(self.object:get_pos(), self.attack:get_pos())), true)
+		end
+	end
+
+	local ddtime = 0.05 --set_tick_rate
+
+	if dtime then
+		ddtime = dtime
+	end
+
+	if math.abs(target_shortest_path) > 280*ddtime then
+		if target_shortest_path > 0 then
+			self.object:set_yaw(self.object:get_yaw()+3.6*ddtime)
+			if self.acc then
+				self.acc=vector.rotate_around_axis(self.acc,vector.new(0,1,0), 3.6*ddtime)
+			end
+		else
+			self.object:set_yaw(self.object:get_yaw()-3.6*ddtime)
+			if self.acc then
+				self.acc=vector.rotate_around_axis(self.acc,vector.new(0,1,0), -3.6*ddtime)
+			end
+		end
+	end
+
+	delay = delay or 0
+
+	yaw = self.object:get_yaw()
+
+	if delay == 0 then
+		if self.shaking and dtime then
+			yaw = yaw + (random() * 2 - 1) * 5 * dtime
+		end
+		self:update_roll()
+		return yaw
+	end
+
+	self.target_yaw = yaw
+	self.delay = delay
+
+	return self.target_yaw
+end
+
+-- global function to set mob yaw
+function mcl_mobs.yaw(self, yaw, delay, dtime)
+	return mob_class.set_yaw(self, yaw, delay, dtime)
+end
+
+-- are we flying in what we are suppose to? (taikedz)
+function mob_class:flight_check()
+
+	local nod = self.standing_in
+	local def = minetest.registered_nodes[nod]
+
+	if not def then return false end -- nil check
+
+	local fly_in
+	if type(self.fly_in) == "string" then
+		fly_in = { self.fly_in }
+	elseif type(self.fly_in) == "table" then
+		fly_in = self.fly_in
+	else
+		return false
+	end
+
+	for _,checknode in pairs(fly_in) do
+		if nod == checknode or nod == "ignore" then
+			return true
+		end
+	end
+
+	return false
+end
+
+-- check if mob is dead or only hurt
+function mob_class:check_for_death(cause, cmi_cause)
+
+	if self.state == "die" then
+		return true
+	end
+
+	-- has health actually changed?
+	if self.health == self.old_health and self.health > 0 then
+		return false
+	end
+
+	local damaged = self.health < self.old_health
+	self.old_health = self.health
+
+	-- still got some health?
+	if self.health > 0 then
+
+		-- make sure health isn't higher than max
+		if self.health > self.hp_max then
+			self.health = self.hp_max
+		end
+
+		-- play damage sound if health was reduced and make mob flash red.
+		if damaged then
+			add_texture_mod(self, "^[colorize:#d42222:175")
+			minetest.after(1, function(self)
+				if self and self.object then
+					remove_texture_mod(self, "^[colorize:#d42222:175")
+				end
+			end, self)
+			self:mob_sound("damage")
+		end
+
+		-- backup nametag so we can show health stats
+		if not self.nametag2 then
+			self.nametag2 = self.nametag or ""
+		end
+
+		if show_health
+		and (cmi_cause and cmi_cause.type == "punch") then
+
+			self.htimer = 2
+			self.nametag = "♥ " .. self.health .. " / " .. self.hp_max
+
+			self:update_tag()
+		end
+
+		return false
+	end
+
+	self:mob_sound("death")
+
+	local function death_handle(self)
+		-- dropped cooked item if mob died in fire or lava
+		if cause == "lava" or cause == "fire" then
+			item_drop(self, true, 0)
+		else
+			local wielditem = ItemStack()
+			if cause == "hit" then
+				local puncher = cmi_cause.puncher
+				if puncher then
+					wielditem = puncher:get_wielded_item()
+				end
+			end
+			local cooked = mcl_burning.is_burning(self.object) or mcl_enchanting.has_enchantment(wielditem, "fire_aspect")
+			local looting = mcl_enchanting.get_enchantment(wielditem, "looting")
+			item_drop(self, cooked, looting)
+
+			if ((not self.child) or self.type ~= "animal") and (minetest.get_us_time() - self.xp_timestamp <= 5000000) then
+				mcl_experience.throw_xp(self.object:get_pos(), random(self.xp_min, self.xp_max))
+			end
+		end
+	end
+
+	-- execute custom death function
+	if self.on_die then
+
+		local pos = self.object:get_pos()
+		local on_die_exit = self.on_die(self, pos, cmi_cause)
+		if on_die_exit ~= true then
+			death_handle(self)
+		end
+
+		if on_die_exit == true then
+			self.state = "die"
+			mcl_burning.extinguish(self.object)
+			self.object:remove()
+			return true
+		end
+	end
+
+	local collisionbox
+	if self.collisionbox then
+		collisionbox = table.copy(self.collisionbox)
+	end
+
+	self.state = "die"
+	self.attack = nil
+	self.v_start = false
+	self.fall_speed = DEFAULT_FALL_SPEED
+	self.timer = 0
+	self.blinktimer = 0
+	remove_texture_mod(self, "^[colorize:#FF000040")
+	remove_texture_mod(self, "^[brighten")
+	self.passive = true
+
+	self.object:set_properties({
+		pointable = false,
+		collide_with_objects = false,
+	})
+
+	set_velocity(self, 0)
+	local acc = self.object:get_acceleration()
+	acc.x, acc.y, acc.z = 0, DEFAULT_FALL_SPEED, 0
+	self.object:set_acceleration(acc)
+
+	local length
+	-- default death function and die animation (if defined)
+	if self.instant_death then
+		length = 0
+	elseif self.animation
+	and self.animation.die_start
+	and self.animation.die_end then
+
+		local frames = self.animation.die_end - self.animation.die_start
+		local speed = self.animation.die_speed or 15
+		length = math.max(frames / speed, 0) + DEATH_DELAY
+		set_animation(self, "die")
+	else
+		length = 1 + DEATH_DELAY
+		set_animation(self, "stand", true)
+	end
+
+
+	-- Remove body after a few seconds and drop stuff
+	local kill = function(self)
+		if not self.object:get_luaentity() then
+			return
+		end
+
+		death_handle(self)
+		local dpos = self.object:get_pos()
+		local cbox = self.collisionbox
+		local yaw = self.object:get_rotation().y
+		mcl_burning.extinguish(self.object)
+		self.object:remove()
+		mcl_mobs.death_effect(dpos, yaw, cbox, not self.instant_death)
+	end
+	if length <= 0 then
+		kill(self)
+	else
+		minetest.after(length, kill, self)
+	end
+
+	return true
+end
+
+-- environmental damage (water, lava, fire, light etc.)
+function mob_class:do_env_damage()
+
+	-- 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
+
+		self:update_tag()
+	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
+		mcl_burning.extinguish(self.object)
+		self.object:remove()
+		return true
+	end
+
+	-- Deal light damage to mob, returns true if mob died
+	local function deal_light_damage(self, pos, damage)
+		if not ((mcl_weather.rain.raining or mcl_weather.state == "snow") and mcl_weather.is_outdoor(pos)) then
+			self.health = self.health - damage
+
+			effect(pos, 5, "mcl_particles_smoke.png")
+
+			if self:check_for_death("light", {type = "light"}) then
+				return true
+			end
+		end
+	end
+
+	local sunlight = 10
+	if within_limits(pos,0) then
+		sunlight = minetest.get_natural_light(pos, self.time_of_day)
+	end
+
+	-- bright light harms mob
+	if self.light_damage ~= 0 and (sunlight or 0) > 12 then
+		if deal_light_damage(self, pos, self.light_damage) then
+			return true
+		end
+	end
+	local _, dim = mcl_worlds.y_to_layer(pos.y)
+	if (self.sunlight_damage ~= 0 or self.ignited_by_sunlight) and (sunlight or 0) >= minetest.LIGHT_MAX and dim == "overworld" then
+		if self.armor_list and not self.armor_list.helmet or not self.armor_list or self.armor_list and self.armor_list.helmet and self.armor_list.helmet == "" then
+			if self.ignited_by_sunlight then
+				mcl_burning.set_on_fire(self.object, 10)
+			else
+				deal_light_damage(self, pos, self.sunlight_damage)
+				return true
+			end
+		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
+	local pos2 = {x=pos.x, y=pos.y-1, z=pos.z}
+	self.standing_in = node_ok(pos, "air").name
+	self.standing_on = node_ok(pos2, "air").name
+
+	-- don't fall when on ignore, just stand still
+	if self.standing_in == "ignore" then
+		self.object:set_velocity({x = 0, y = 0, z = 0})
+	end
+
+	local nodef = minetest.registered_nodes[self.standing_in]
+
+	-- rain
+	if self.rain_damage > 0 then
+		if mcl_weather.rain.raining and mcl_weather.is_outdoor(pos) then
+
+			self.health = self.health - self.rain_damage
+
+			if self:check_for_death("rain", {type = "environment",
+					pos = pos, node = self.standing_in}) then
+				return true
+			end
+		end
+	end
+
+	pos.y = pos.y + 1 -- for particle effect position
+
+	-- water damage
+	if self.water_damage > 0
+	and nodef.groups.water then
+
+		if self.water_damage ~= 0 then
+
+			self.health = self.health - self.water_damage
+
+			effect(pos, 5, "mcl_particles_smoke.png", nil, nil, 1, nil)
+
+			if self:check_for_death("water", {type = "environment",
+					pos = pos, node = self.standing_in}) then
+				return true
+			end
+		end
+
+	-- lava damage
+	elseif self.lava_damage > 0
+	and (nodef.groups.lava) then
+
+		if self.lava_damage ~= 0 then
+
+			self.health = self.health - self.lava_damage
+
+			effect(pos, 5, "fire_basic_flame.png", nil, nil, 1, nil)
+			mcl_burning.set_on_fire(self.object, 10)
+
+			if self:check_for_death("lava", {type = "environment",
+					pos = pos, node = self.standing_in}) then
+				return true
+			end
+		end
+
+	-- fire damage
+	elseif self.fire_damage > 0
+	and (nodef.groups.fire) then
+
+		if self.fire_damage ~= 0 then
+
+			self.health = self.health - self.fire_damage
+
+			effect(pos, 5, "fire_basic_flame.png", nil, nil, 1, nil)
+			mcl_burning.set_on_fire(self.object, 5)
+
+			if self:check_for_death("fire", {type = "environment",
+					pos = pos, node = self.standing_in}) then
+				return true
+			end
+		end
+
+	-- damage_per_second node check
+	elseif nodef.damage_per_second ~= 0 and not nodef.groups.lava and not nodef.groups.fire then
+
+		self.health = self.health - nodef.damage_per_second
+
+		effect(pos, 5, "mcl_particles_smoke.png")
+
+		if self:check_for_death("dps", {type = "environment",
+				pos = pos, node = self.standing_in}) then
+			return true
+		end
+	end
+
+	-- Drowning damage
+	if self.breath_max ~= -1 then
+		local drowning = false
+		if self.breathes_in_water then
+			if minetest.get_item_group(self.standing_in, "water") == 0 then
+				drowning = true
+			end
+		elseif nodef.drowning > 0 then
+			drowning = true
+		end
+		if drowning then
+
+			self.breath = math.max(0, self.breath - 1)
+
+			effect(pos, 2, "bubble.png", nil, nil, 1, nil)
+			if self.breath <= 0 then
+				local dmg
+				if nodef.drowning > 0 then
+					dmg = nodef.drowning
+				else
+					dmg = 4
+				end
+				damage_effect(self, dmg)
+				self.health = self.health - dmg
+			end
+			if self:check_for_death("drowning", {type = "environment",
+					pos = pos, node = self.standing_in}) then
+				return true
+			end
+		else
+			self.breath = math.min(self.breath_max, self.breath + 1)
+		end
+	end
+
+	--- suffocation inside solid node
+	-- FIXME: Redundant with mcl_playerplus
+	if (self.suffocation == true)
+	and (nodef.walkable == nil or nodef.walkable == true)
+	and (nodef.collision_box == nil or nodef.collision_box.type == "regular")
+	and (nodef.node_box == nil or nodef.node_box.type == "regular")
+	and (nodef.groups.disable_suffocation ~= 1)
+	and (nodef.groups.opaque == 1) then
+
+		-- Short grace period before starting to take suffocation damage.
+		-- This is different from players, who take damage instantly.
+		-- This has been done because mobs might briefly be inside solid nodes
+		-- when e.g. climbing up stairs.
+		-- This is a bit hacky because it assumes that do_env_damage
+		-- is called roughly every second only.
+		self.suffocation_timer = self.suffocation_timer + 1
+		if self.suffocation_timer >= 3 then
+			-- 2 damage per second
+			-- TODO: Deal this damage once every 1/2 second
+			self.health = self.health - 2
+
+			if self:check_for_death("suffocation", {type = "environment",
+					pos = pos, node = self.standing_in}) then
+				return true
+			end
+		end
+	else
+		self.suffocation_timer = 0
+	end
+
+	return self:check_for_death("", {type = "unknown"})
+end
+
+function mob_class:damage_mob(reason,damage)
+	if not self.health then return end
+	damage = floor(damage)
+	if damage > 0 then
+		self.health = self.health - damage
+
+		effect(self.object:get_pos(), 5, "mcl_particles_smoke.png", 1, 2, 2, nil)
+
+		if self:check_for_death(reason, {type = reason}) then
+			return true
+		end
+	end
+end
+
+function mob_class:check_entity_cramming()
+	local p = self.object:get_pos()
+	if not p then return end
+	local oo = minetest.get_objects_inside_radius(p,1)
+	local mobs = {}
+	for _,o in pairs(oo) do
+		local l = o:get_luaentity()
+		if l and l.is_mob and l.health > 0 then table.insert(mobs,l) end
+	end
+	local clear = #mobs < ENTITY_CRAMMING_MAX
+	local ncram = {}
+	for _,l in pairs(mobs) do
+		if l then
+			if clear then
+				l.cram = nil
+			elseif l.cram == nil and not self.child then
+				table.insert(ncram,l)
+			elseif l.cram then
+				l:damage_mob("cramming",CRAMMING_DAMAGE)
+			end
+		end
+	end
+	for i,l in pairs(ncram) do
+		if i > ENTITY_CRAMMING_MAX then
+			l.cram = true
+		else
+			l.cram = nil
+		end
+	end
+end
+
+-- falling and fall damage
+-- returns true if mob died
+function mob_class:falling(pos)
+
+	if self.fly and self.state ~= "die" then
+		return
+	end
+
+	if mcl_portals ~= nil then
+		if mcl_portals.nether_portal_cooloff(self.object) then
+			return false -- mob has teleported through Nether portal - it's 99% not falling
+		end
+	end
+
+	-- floating in water (or falling)
+	local v = self.object:get_velocity()
+
+	if v.y > 0 then
+
+		-- apply gravity when moving up
+		self.object:set_acceleration({
+			x = 0,
+			y = DEFAULT_FALL_SPEED,
+			z = 0
+		})
+
+	elseif v.y <= 0 and v.y > self.fall_speed then
+
+		-- fall downwards at set speed
+		self.object:set_acceleration({
+			x = 0,
+			y = self.fall_speed,
+			z = 0
+		})
+	else
+		-- stop accelerating once max fall speed hit
+		self.object:set_acceleration({x = 0, y = 0, z = 0})
+	end
+
+	if minetest.registered_nodes[node_ok(pos).name].groups.lava then
+
+		if self.floats_on_lava == 1 then
+
+			self.object:set_acceleration({
+				x = 0,
+				y = -self.fall_speed / (math.max(1, v.y) ^ 2),
+				z = 0
+			})
+		end
+	end
+
+	-- in water then float up
+	if minetest.registered_nodes[node_ok(pos).name].groups.water then
+
+		if self.floats == 1 then
+
+			self.object:set_acceleration({
+				x = 0,
+				y = -self.fall_speed / (math.max(1, v.y) ^ 2),
+				z = 0
+			})
+		end
+	else
+
+		-- fall damage onto solid ground
+		if self.fall_damage == 1
+		and self.object:get_velocity().y == 0 then
+			local n = node_ok(vector.offset(pos,0,-1,0)).name
+			local d = (self.old_y or 0) - self.object:get_pos().y
+
+			if d > 5 and n ~= "air" and n ~= "ignore" then
+				local add = minetest.get_item_group(self.standing_on, "fall_damage_add_percent")
+				local damage = d - 5
+				if add ~= 0 then
+					damage = damage + damage * (add/100)
+				end
+				self:damage_mob("fall",damage)
+			end
+
+			self.old_y = self.object:get_pos().y
+		end
+	end
+end