Fix steam engine sound playing forever (H#121)

1 files changed, 16 insertions, 7 deletions

diff --git a/advtrains_train_steam/init.lua b/advtrains_train_steam/init.lua
index db2d087..5d6955c 100755
--- a/advtrains_train_steam/init.lua
+++ b/advtrains_train_steam/init.lua
@@ -5,6 +5,9 @@ else
     S = function(s,a,...)a={a,...}return s:gsub("@(%d+)",function(n)return a[tonumber(n)]end)end
 end
 
+-- length of the steam engine loop sound
+local SND_LOOP_LEN = 5
+
 advtrains.register_wagon("newlocomotive", {
 	mesh="advtrains_engine_steam.b3d",
 	textures = {"advtrains_engine_steam.png"},
@@ -111,14 +114,20 @@ advtrains.register_wagon("detailed_steam_engine", {
 			self.object:set_animation({x=1,y=80}, advtrains.abs_ceil(velocity)*15, 0, true)
 			self.old_anim_velocity=advtrains.abs_ceil(velocity)
 		end
-        if velocity > 0 and not self.sound_loop_handle then
-			self.sound_loop_handle = minetest.sound_play({name="advtrains_steam_loop", gain=2}, {object = self.object, loop=true})
-		elseif velocity==0 then
-			if self.sound_loop_handle then
-				minetest.sound_stop(self.sound_loop_handle)
-				self.sound_loop_handle = nil
+	end,
+	custom_on_step=function(self, dtime)
+		if self:train().velocity > 0 then -- First make sure that the train isn't standing
+			if not self.sound_loop_tmr or self.sound_loop_tmr <= 0 then
+				-- start the sound if it was never started or has expired
+				self.sound_loop_handle = minetest.sound_play({name="advtrains_steam_loop", gain=2}, {object=self.object})
+				self.sound_loop_tmr = SND_LOOP_LEN
 			end
-		end 
+			--decrease the sound timer
+			self.sound_loop_tmr = self.sound_loop_tmr - dtime
+		else
+			-- If the train is standing, the sound will be stopped in some time. We do not need to interfere with it.
+			self.sound_loop_tmr = nil
+		end
 	end,
 	custom_on_activate = function(self, staticdata_table, dtime_s)
 		minetest.add_particlespawner({