Implement sound api and some sounds

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

5 files changed, 37 insertions, 1 deletions

diff --git a/advtrains/api_doc.txt b/advtrains/api_doc.txt
index e86f16b..c944e30 100644
--- a/advtrains/api_doc.txt
+++ b/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
diff --git a/advtrains/nodedb.lua b/advtrains/nodedb.lua
index 45a51fe..2f014f8 100644
--- a/advtrains/nodedb.lua
+++ b/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
diff --git a/advtrains/signals.lua b/advtrains/signals.lua
index 62b9f03..a42f5e7 100644
--- a/advtrains/signals.lua
+++ b/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,
+    }
+)
diff --git a/advtrains/sounds/advtrains_crossing_bell.ogg b/advtrains/sounds/advtrains_crossing_bell.ogg
new file mode 100644
index 0000000..74df669
--- /dev/null
+++ b/advtrains/sounds/advtrains_crossing_bell.ogg
diff --git a/advtrains/wagons.lua b/advtrains/wagons.lua
index 4306b50..b30d3d4 100644
--- a/advtrains/wagons.lua
+++ b/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