Added fall checks for cliff edges (thanks cmdskp)

README.txt

@@ -28,6 +28,7 @@ This mod contains the following additions:
 
 Changelog:
 
+1.21- Added some more error checking to reduce serialize.h error and added height checks for falling off cliffs (thanks cmdskp)
 1.20- Error checking added to remove bad mobs, out of map limit mobs and stop serialize.h error
 1.19- Chickens now drop egg items instead of placing the egg, also throwing eggs result in 1/8 chance of spawning chick
 1.18- Added docile_by_day flag so that monsters will not attack automatically during daylight hours unless hit first

api.lua

@@ -1,4 +1,4 @@
--- Mobs Api (15th December 2015)
+-- Mobs Api (18th December 2015)
 mobs = {}
 mobs.mod = "redo"
 
@@ -234,6 +234,37 @@ function within_limits(pos, radius)
 	return false -- beyond limits
 end
 
+-- is mob facing a cliff
+local function is_at_cliff(self)
+
+	if self.fear_height == 0 then -- if 0, no falling protection!
+		return false
+	end
+
+	local yaw = self.object:getyaw()
+	local dir_x = -math.sin(yaw) * (self.collisionbox[4] + 0.5)
+	local dir_z = math.cos(yaw) * (self.collisionbox[4] + 0.5)
+	local pos = self.object:getpos()
+	local ypos = pos.y + self.collisionbox[2] -- just above floor
+
+	for height = self.fear_height, 0, -1 do
+
+		local nod = minetest.get_node_or_nil({
+			x = pos.x + dir_x,
+			y = ypos - height,
+			z = pos.z + dir_z
+		})
+
+		if nod
+		and nod.name
+		and nod.name ~= "air" then
+			return false
+		end
+	end
+
+	return true
+end
+
 -- environmental damage (water, lava, fire, light)
 do_env_damage = function(self)
 
@@ -306,9 +337,10 @@ do_jump = function(self)
 	end
 
 	local pos = self.object:getpos()
+	local temp_Y = pos.y
 
 	-- what is mob standing on?
-	pos.y = (pos.y + self.collisionbox[2]) - 0.2
+	pos.y = (temp_Y + self.collisionbox[2]) - 0.2
 
 	local nod = node_ok(pos)
 
@@ -339,6 +371,9 @@ do_jump = function(self)
 
 		local v = self.object:getvelocity()
 
+		-- move back a bit - allows jump velocity to carry it forward and succeed better
+		self.object:setpos({x=pos.x - self.direction.x/2, y=temp_Y, z=pos.z - self.direction.z/2})
+
 		v.y = self.jump_height + 1
 		v.x = v.x * 2.2
 		v.z = v.z * 2.2
@@ -600,6 +635,8 @@ minetest.register_entity(name, {
 
 	stepheight = def.stepheight or 0.6,
 	name = name,
+	type = def.type,
+	attack_type = def.attack_type,
 	fly = def.fly,
 	fly_in = def.fly_in or "air",
 	owner = def.owner or "",
@@ -631,8 +668,6 @@ minetest.register_entity(name, {
 	drops = def.drops or {},
 	armor = def.armor,
 	on_rightclick = def.on_rightclick,
-	type = def.type,
-	attack_type = def.attack_type,
 	arrow = def.arrow,
 	shoot_interval = def.shoot_interval,
 	sounds = def.sounds or {},
@@ -668,6 +703,7 @@ minetest.register_entity(name, {
 	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,
 
 	on_step = function(self, dtime)
 
@@ -1081,15 +1117,12 @@ minetest.register_entity(name, {
 			set_animation(self, "stand")
 
 			-- npc's ordered to stand stay standing
-			if self.type == "npc"
-			and self.order == "stand" then
+			if self.type ~= "npc"
+			or self.order ~= "stand" then
 
-				set_velocity(self, 0)
-				self.state = "stand"
-				set_animation(self, "stand")
-			else
 				if self.walk_chance ~= 0
-				and math.random(1, 100) <= self.walk_chance then
+				and math.random(1, 100) <= self.walk_chance
+				and is_at_cliff(self) == false then
 
 					set_velocity(self, self.walk_velocity)
 					self.state = "walk"
@@ -1147,8 +1180,13 @@ minetest.register_entity(name, {
 				self.object:setyaw(yaw)
 			end
 
+			-- stand for great fall in front
+			local temp_is_cliff = is_at_cliff(self)
+
 			-- jump when walking comes to a halt
-			if self.jump and get_velocity(self) <= 0.5
+			if temp_is_cliff == false
+			and self.jump
+			and get_velocity(self) <= 0.5
 			and self.object:getvelocity().y == 0 then
 
 				self.direction = {
@@ -1160,14 +1198,15 @@ minetest.register_entity(name, {
 				do_jump(self)
 			end
 
-			set_velocity(self, self.walk_velocity)
-			set_animation(self, "walk")
-
-			if math.random(1, 100) <= 30 then
+			if temp_is_cliff
+			or math.random(1, 100) <= 30 then
 
 				set_velocity(self, 0)
 				self.state = "stand"
 				set_animation(self, "stand")
+			else
+				set_velocity(self, self.walk_velocity)
+				set_animation(self, "walk")
 			end
 
 		-- attack routines (explode, dogfight, shoot, dogshoot)
@@ -1385,8 +1424,14 @@ minetest.register_entity(name, {
 					do_jump(self)
 				end
 
-				set_velocity(self, self.run_velocity)
-				set_animation(self, "run")
+				if is_at_cliff(self) then
+
+					set_velocity(self, 0)
+					set_animation(self, "stand")
+				else
+					set_velocity(self, self.run_velocity)
+					set_animation(self, "run")
+				end
 
 			else
 
@@ -2217,4 +2262,4 @@ function mobs:feed_tame(self, clicker, feed_count, breed, tame)
 	else
 		return false
 	end
-end
+end

bunny.lua

@@ -29,6 +29,7 @@ mobs:register_mob("mobs:bunny", {
 	water_damage = 1,
 	lava_damage = 4,
 	light_damage = 0,
+	fear_height = 2,
 	animation = {
 		speed_normal = 15,
 		stand_start = 1,

cow.lua

@@ -49,6 +49,7 @@ mobs:register_mob("mobs:cow", {
 	replace_rate = 10,
 	replace_what = {"default:grass_3", "default:grass_4", "default:grass_5", "farming:wheat_8"},
 	replace_with = "air",
+	fear_height = 2,
 	on_rightclick = function(self, clicker)
 		if not mobs:feed_tame(self, clicker, 8, true, true) then
 			local tool = clicker:get_wielded_item()

dirtmonster.lua

@@ -32,6 +32,7 @@ mobs:register_mob("mobs:dirt_monster", {
 	water_damage = 1,
 	lava_damage = 5,
 	light_damage = 2,
+	fear_height = 3,
 	animation = {
 		speed_normal = 15,
 		speed_run = 15,

dungeonmaster.lua

@@ -43,6 +43,7 @@ mobs:register_mob("mobs:dungeon_master", {
 	water_damage = 1,
 	lava_damage = 1,
 	light_damage = 0,
+	fear_height = 3,
 	animation = {
 		stand_start = 0,
 		stand_end = 19,

kitten.lua

@@ -29,6 +29,7 @@ mobs:register_mob("mobs:kitten", {
 	},
 	water_damage = 1,
 	lava_damage = 5,
+	fear_height = 3,
 	animation = {
 		speed_normal = 42,
 		stand_start = 97,

npc.lua

@@ -46,6 +46,7 @@ mobs:register_mob("mobs:npc", {
 	view_range = 15,
 	owner = "",
 	order = "follow",
+	fear_height = 3,
 	animation = {
 		speed_normal = 30,
 		speed_run = 30,

oerkki.lua

@@ -32,6 +32,7 @@ mobs:register_mob("mobs:oerkki", {
 	water_damage = 2,
 	lava_damage = 4,
 	light_damage = 1,
+	fear_height = 3,
 	animation = {
 		stand_start = 0,
 		stand_end = 23,

rat.lua

@@ -23,6 +23,7 @@ mobs:register_mob("mobs:rat", {
 	water_damage = 0,
 	lava_damage = 4,
 	light_damage = 0,
+	fear_height = 2,
 	on_rightclick = function(self, clicker)
 		mobs:capture_mob(self, clicker, 25, 80, 0, true, nil)
 	end,

sandmonster.lua

@@ -32,6 +32,7 @@ mobs:register_mob("mobs:sand_monster", {
 	water_damage = 3,
 	lava_damage = 4,
 	light_damage = 0,
+	fear_height = 3,
 	animation = {
 		speed_normal = 15,
 		speed_run = 15,

sheep.lua

@@ -14,7 +14,8 @@ for _, col in ipairs(all_colours) do
 		hp_min = 8,
 		hp_max = 10,
 		armor = 200,
-		collisionbox = {-0.4, -1, -0.4, 0.4, 0.3, 0.4},
+		--collisionbox = {-0.4, -1, -0.4, 0.4, 0.3, 0.4},
+		collisionbox = {-0.5, -1, -0.5, 0.5, 0.3, 0.5},
 		visual = "mesh",
 		mesh = "mobs_sheep.b3d",
 		textures = {
@@ -51,6 +52,7 @@ for _, col in ipairs(all_colours) do
 		replace_what = {"default:grass_3", "default:grass_4", "default:grass_5", "farming:wheat_8"},
 		replace_with = "air",
 		replace_offset = -1,
+		fear_height = 3,
 		on_rightclick = function(self, clicker)
 			local shpcolor = string.split(self.name,"_")[2]
 			if shpcolor =="dark" then
@@ -170,4 +172,4 @@ minetest.register_entity("mobs:sheep", {
 		end
 	end,
 
-})
+})

warthog.lua

@@ -34,6 +34,7 @@ mobs:register_mob("mobs:pumba", {
 	water_damage = 1,
 	lava_damage = 5,
 	light_damage = 0,
+	fear_height = 2,
 	animation = {
 		speed_normal = 15,
 		stand_start = 25,