Implement sound api and some sounds

- Level crossing bell
- Horns
- Subway train driving and door sounds
...to be continued...

advtrains/api_doc.txt

@@ -57,10 +57,14 @@ advtrains.register_wagon(name, prototype, description, inventory_image)
 		open={
 			[-1]={frames={x=0, y=20}, time=1}, -- open left doors
 			[1]={frames={x=40, y=60}, time=1}  -- open right doors
+			sound = <simpleSoundSpec>
+			^- The sound file of the doors opening. If none is specified, nothing is played.
 		},
 		close={
 			[-1]={frames={x=20, y=40}, time=1}, -- close left doors
 			[1]={frames={x=60, y=80}, time=1} -- close right doors
+			sound = <simpleSoundSpec>
+			^- The sound file of the doors closing. If none is specified, nothing is played.
 		}
 	},
 	door_entry={ 1.5, -1.5 }
@@ -77,6 +81,8 @@ advtrains.register_wagon(name, prototype, description, inventory_image)
 	extent_v = 2,
 	^- Determines the collision box extent in y direction. Defaults to 2 (=3).
 	^- The actual bounding box size is extent_v+1, so 0 means 1, 1 means 2, 2 means 3 a.s.o.
+	horn_sound = <simpleSoundSpec>,
+	^- The sound file of the horn. If none is specified, this wagon can't sound a horn. The specified sound file will be looped.
 	
 	drops = {"default:steelblock 3"}
 	^- List of itemstrings what to drop when the wagon is destroyed

advtrains/nodedb.lua

@@ -262,7 +262,7 @@ ndb.restore_all = function()
 						end
 					else
 						ndb.clear(pos)
-						atwarn("Found ghost node (former",ndbnode.name,") @",pos,"deleting")
+						atwarn("Found ghost node (former",ndbnode and ndbnode.name,") @",pos,"deleting")
 					end
 				end
 			end

advtrains/signals.lua

@@ -225,3 +225,19 @@ minetest.register_node("advtrains:across_on", {
 		end
 	end,
 })
+
+minetest.register_abm(
+	{
+        label = "Sound for Level Crossing",
+        nodenames = {"advtrains:across_on"},
+        interval = 3,
+        chance = 1,
+        action = function(pos, node, active_object_count, active_object_count_wider)
+			minetest.sound_play("advtrains_crossing_bell", {
+				pos = pos,
+				gain = 1.0, -- default
+				max_hear_distance = 16, -- default, uses an euclidean metric
+			})
+        end,
+    }
+)

advtrains/wagons.lua

@@ -270,6 +270,18 @@ function wagon:on_step(dtime)
 				if has_driverstand then
 					--regular driver stand controls
 					advtrains.on_control_change(pc, self:train(), self.wagon_flipped)
+					--sound horn when required
+					if self.horn_sound and pc.aux1 and not pc.sneak and not self.horn_handle then
+						self.horn_handle = minetest.sound_play(self.horn_sound, {
+							object = self.object,
+							gain = 1.0, -- default
+							max_hear_distance = 128, -- default, uses an euclidean metric
+							loop = true,
+						})
+					elseif not pc.aux1 and self.horn_handle then
+						minetest.sound_stop(self.horn_handle)
+						self.horn_handle = nil
+					end
 				else
 					-- If on a passenger seat and doors are open, get off when W or D pressed.
 					local pass = self.seatp[seatno] and minetest.get_player_by_name(self.seatp[seatno])
@@ -322,10 +334,12 @@ function wagon:on_step(dtime)
 					-- if changed from 0 to +-1, play open anim. if changed from +-1 to 0, play close.
 					-- if changed from +-1 to -+1, first close and set 0, then it will detect state change again and run open.
 					if self.door_state == 0 then
+						if self.doors.open.sound then minetest.sound_play(self.doors.open.sound, {object = self.object}) end
 						at=self.doors.open[dstate]
 						self.object:set_animation(at.frames, at.speed or 15, at.blend or 0, false)
 						self.door_state = dstate
 					else
+						if self.doors.close.sound then minetest.sound_play(self.doors.close.sound, {object = self.object}) end
 						at=self.doors.close[self.door_state or 1]--in case it has not been set yet
 						self.object:set_animation(at.frames, at.speed or 15, at.blend or 0, false)
 						self.door_state = 0

advtrains_train_industrial/init.lua

@@ -39,6 +39,7 @@ advtrains.register_wagon("engine_industrial", {
 	is_locomotive=true,
 	collisionbox = {-1.0,-0.5,-1.0, 1.0,2.5,1.0},
 	drops={"default:steelblock 4"},
+	horn_sound = "advtrains_industrial_horn",
 }, S("Industrial Train Engine"), "advtrains_engine_industrial_inv.png")
 advtrains.register_wagon("wagon_tank", {
 	mesh="advtrains_wagon_tank.b3d",

advtrains_train_japan/init.lua

@@ -72,6 +72,7 @@ advtrains.register_wagon("engine_japan", {
 	is_locomotive=true,
 	collisionbox = {-1.0,-0.5,-1.0, 1.0,2.5,1.0},
 	drops={"default:steelblock 4"},
+	horn_sound = "advtrains_japan_horn",
 }, S("Japanese Train Engine"), "advtrains_engine_japan_inv.png")
 
 advtrains.register_wagon("wagon_japan", {

advtrains_train_steam/init.lua

@@ -71,6 +71,7 @@ advtrains.register_wagon("newlocomotive", {
 		})
 	end,
 	drops={"default:steelblock 4"},
+	horn_sound = "advtrains_steam_whistle",
 }, S("Steam Engine"), "advtrains_engine_steam_inv.png")
 
 advtrains.register_wagon("detailed_steam_engine", {
@@ -139,6 +140,7 @@ advtrains.register_wagon("detailed_steam_engine", {
 		})
 	end,
 	drops={"default:steelblock 4"},
+	horn_sound = "advtrains_steam_whistle",
 }, S("Detailed Steam Engine"), "advtrains_detailed_engine_steam_inv.png")
 
 advtrains.register_wagon("wagon_default", {

advtrains_train_subway/init.lua

@@ -59,11 +59,13 @@ advtrains.register_wagon("subway_wagon", {
 	doors={
 		open={
 			[-1]={frames={x=0, y=20}, time=1},
-			[1]={frames={x=40, y=60}, time=1}
+			[1]={frames={x=40, y=60}, time=1},
+			sound = "advtrains_subway_dopen",
 		},
 		close={
 			[-1]={frames={x=20, y=40}, time=1},
-			[1]={frames={x=60, y=80}, time=1}
+			[1]={frames={x=60, y=80}, time=1},
+			sound = "advtrains_subway_dclose",
 		}
 	},
 	door_entry={-1, 1},
@@ -73,10 +75,26 @@ advtrains.register_wagon("subway_wagon", {
 	collisionbox = {-1.0,-0.5,-1.0, 1.0,2.5,1.0},
 	is_locomotive=true,
 	drops={"default:steelblock 4"},
-	--custom_on_activate = function(self, dtime_s)
-	--	atprint("subway custom_on_activate")
-	--	self.object:set_animation({x=1,y=80}, 15, 0, true)
-	--end,
+	horn_sound = "advtrains_subway_horn",
+	custom_on_velocity_change = function(self, velocity, old_velocity)
+		if old_velocity == 0 and velocity > 0 then
+			minetest.sound_play("advtrains_subway_depart", {object = self.object})
+		end
+		if velocity < 2 and (old_velocity >= 2 or old_velocity == velocity) and not self.sound_arrive_handle then
+			self.sound_arrive_handle = minetest.sound_play("advtrains_subway_arrive", {object = self.object})
+		elseif (velocity > old_velocity) and self.sound_arrive_handle then
+			minetest.sound_stop(self.sound_arrive_handle)
+			self.sound_arrive_handle = nil
+		end
+		if velocity > 0 and not self.sound_loop_handle then
+			self.sound_loop_handle = minetest.sound_play({name="advtrains_subway_loop", gain=0.3}, {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
+		end
+	end,
 }, S("Subway Passenger Wagon"), "advtrains_subway_wagon_inv.png")
 
 --wagons

readme.txt

@@ -24,6 +24,13 @@ Inventory images            : mbb
 Small code contributions    : NaruTrey
 Major code contributions    : gpcf
 Mod Description             : hajo
+Sounds:
+advtrains_crossing_bell     : Codesound
+advtrains_japan_horn        : Codesound
+advtrains_steam_whistle     : googol 
+advtrains_subway_horn       : https://freesound.org/people/Mullumbimby/sounds/385283/
+advtrains_subway_*          : Gabriel (gpcf, gbl08ma)
+
 If I forgot someone please punish me for that.
 
 You can see this mod in action on Linuxworks Next Generation server.