Add in dynamic pitch in flying/swimming mobs

mods/ENTITIES/mcl_mobs/api/api.lua

@@ -313,6 +313,7 @@ function mobs:register_mob(name, def)
 		gravity = GRAVITY,
 		swim = def.swim,
 		swim_in = def.swim_in or {mobs_mc.items.water_source, "mcl_core:water_flowing", mobs_mc.items.river_water_source},
+		pitch_switch = "static",
 		--set_animation = mobs.set_animation,
 		--end j4i stuff
 

mods/ENTITIES/mcl_mobs/api/mob_functions/ai.lua

@@ -1,4 +1,5 @@
 local math_random = math.random
+local math_pi     = math.pi
 
 local vector_multiply = vector.multiply
 local vector_add      = vector.add
@@ -273,6 +274,8 @@ local swim_state_execution = function(self,dtime)
 
 			mobs.set_swim_velocity(self,0)
 
+			mobs.set_static_pitch(self)
+
 		elseif self.state == "swim" then
 
 			self.walk_timer = self.walk_timer - dtime
@@ -300,6 +303,8 @@ local swim_state_execution = function(self,dtime)
 			end
 
 			mobs.set_swim_velocity(self,self.walk_velocity)
+
+			mobs.set_dynamic_pitch(self)
 		end
 	--flop around if not inside swim node
 	else
@@ -307,6 +312,8 @@ local swim_state_execution = function(self,dtime)
 		mobs.set_mob_animation(self, "stand")
 
 		mobs.flop(self)
+
+		mobs.set_static_pitch(self)
 	end
 
 end
@@ -394,6 +401,8 @@ local fly_state_execution = function(self,dtime)
 
 			mobs.set_fly_velocity(self,0)
 
+			mobs.set_static_pitch(self)
+
 		elseif self.state == "fly" then
 
 			self.walk_timer = self.walk_timer - dtime
@@ -420,12 +429,18 @@ local fly_state_execution = function(self,dtime)
 				quick_rotate(self,dtime)
 			end
 
+			mobs.set_dynamic_pitch(self)
+
 			mobs.set_fly_velocity(self,self.walk_velocity)
 		end
 	else
 		--make the mob float
 		if self.floats and float_now then
+			mobs.set_velocity(self, 0)
+
 			mobs.float(self)
+
+			mobs.set_static_pitch(self)
 		end
 	end
 end
@@ -476,4 +491,5 @@ mobs.mob_step = function(self, dtime)
 	end
 
     self.old_velocity = self.object:get_velocity()
+	self.old_pos = self.object:get_pos()
 end

mods/ENTITIES/mcl_mobs/api/mob_functions/animation.lua

@@ -1,4 +1,19 @@
 local math_pi     = math.pi
+local math_floor  = math.floor
+local HALF_PI     = math_pi/2
+
+
+
+local vector_distance = vector.distance
+local vector_new      = vector.new
+
+local minetest_dir_to_yaw = minetest.dir_to_yaw
+
+
+-- simple degrees calculation
+local degrees = function(yaw)
+    return(yaw*180.0/math_pi)
+end
 
 -- set defined animation
 mobs.set_mob_animation = function(self, anim, fixed_frame)
@@ -67,8 +82,8 @@ mobs.death_effect = function(pos, yaw, collisionbox, rotate)
 		time = 0.001,
 		minpos = vector.add(pos, min),
 		maxpos = vector.add(pos, max),
-		minvel = vector.new(-5,-5,-5),
-		maxvel = vector.new(5,5,5),
+		minvel = vector_new(-5,-5,-5),
+		maxvel = vector_new(5,5,5),
 		minexptime = 1.1,
 		maxexptime = 1.5,
 		minsize = 1,
@@ -102,4 +117,49 @@ mobs.movement_rotation_lock = function(self)
 	elseif math.abs(current_engine_yaw - current_lua_yaw) > 0.05 and self.object:get_properties().automatic_face_movement_dir == false then
 		self.object:set_properties{automatic_face_movement_dir = self.rotate}
 	end
+end
+
+
+local calculate_pitch = function(self)
+	local pos  = self.object:get_pos()
+	local pos2 = self.old_pos
+
+	if pos == nil or pos2 == nil then
+		return false
+	end
+
+    return(minetest_dir_to_yaw(vector_new(vector_distance(vector_new(pos.x,0,pos.z),vector_new(pos2.x,0,pos2.z)),0,pos.y - pos2.y)) + HALF_PI)
+end
+
+--this is a helper function used to make mobs pitch rotation dynamically flow when flying/swimming
+mobs.set_dynamic_pitch = function(self)
+	local pitch = calculate_pitch(self)
+
+	if not pitch then
+		return
+	end
+
+	local current_rotation = self.object:get_rotation()
+
+	current_rotation.x = pitch
+
+	self.object:set_rotation(current_rotation)
+
+	self.pitch_switch = "dynamic"
+end
+
+--this is a helper function used to make mobs pitch rotation reset when flying/swimming
+mobs.set_static_pitch = function(self)
+
+	if self.pitch_switch == "static" then
+		return
+	end
+
+	local current_rotation = self.object:get_rotation()
+
+	current_rotation.x = 0
+	current_rotation.z = 0
+
+	self.object:set_rotation(current_rotation)
+	self.pitch_switchfdas = "static"
 end