add sound to motorbike

LICENSE

@@ -15,3 +15,6 @@ All other colours are edits of motorbike_blue.png by Melkor
 motorbike_wheel_inv.png
 motorbike_(colour)_imv.png (Render of Melkors bike)
 motorbike_biker.b3d (Edited version of minetest player model from 3d_armor)
+
+Alexander (CC BY-NC 4.0) <http://www.orangefreesounds.com/author/alexander/>
+Harley Davidson Motorcycle Slow Pass By > motoengine.ogg

functions.lua

@@ -391,6 +391,49 @@ function biker.drive(entity, dtime)
 	entity.object:setvelocity(new_velo)
 	entity.object:setacceleration(new_acce)
 	entity.lastv = entity.object:getvelocity()
+	
+	--sound
+	if entity.v > 0 and entity.driver ~= nil then
+		entity.timer1 = entity.timer1 + dtime
+		if entity.timer1 > .1 then
+				local rpm = 1
+				if entity.v > 7 then
+					rpm = entity.v/7+.4
+				elseif entity.v > 3 then
+					rpm = entity.v/3+.3
+				else
+					rpm = entity.v/3+.2
+				end
+				minetest.sound_play("motoengine", {
+					max_hear_distance = 48,
+					pitch = rpm+.1,
+					object = entity.object
+				})
+		entity.timer1 = 0
+		end
+	end
+	entity.timer2 = entity.timer2 + dtime
+	if entity.timer2 > 1.5-entity.v/max_spd*1.1 then
+		if math.abs(entity.v) > .2 then
+			if math.abs(velo.y) < .1 then 
+				entity.wheelsound = minetest.sound_play("tyresound", {
+					max_hear_distance = 48,
+					object = entity.object,
+					pitch = 1.1 + (entity.v/max_spd)*.6,
+					gain = .5 + (entity.v/max_spd)*2
+				})
+			elseif entity.windsound then
+				minetest.sound_fade(entity.windsound, 30, 0)
+			end
+			entity.windsound = minetest.sound_play("wind", {
+				max_hear_distance = 10,
+				object = entity.object,
+				pitch = 1 + (entity.v/max_spd)*.6,
+				gain = 0 + (entity.v/max_spd)*4
+			})
+		end
+		entity.timer2 = 0
+	end
 end
 
 minetest.register_on_leaveplayer(function(player)