Add workaround to unload wagons that are too far away from players

4 files changed, 39 insertions, 4 deletions

diff --git a/advtrains/init.lua b/advtrains/init.lua
index 28e104e..84cfa38 100644
--- a/advtrains/init.lua
+++ b/advtrains/init.lua
@@ -39,6 +39,12 @@ AT_CMAX = 16
 
 advtrains = {trains={}, player_to_train_mapping={}}
 
+-- get wagon loading range
+advtrains.wagon_load_range = tonumber(minetest.settings:get("advtrains_wagon_load_range"))
+if not advtrains.wagon_load_range then
+	advtrains.wagon_load_range = tonumber(minetest.settings:get("active_block_range"))*16
+end
+
 --pcall
 local no_action=false
 
diff --git a/advtrains/settingtypes.txt b/advtrains/settingtypes.txt
index 26c6d5a..d8eb44a 100644
--- a/advtrains/settingtypes.txt
+++ b/advtrains/settingtypes.txt
@@ -38,4 +38,10 @@ advtrains_prot_range_down (Track protection range [down]) int 1 0 10
 #    none: No damage is dealt at all.
 #    drop: Player is killed, all items are dropped as items on the tracks.
 #    normal: Player is killed, game-defined behavior is applied as if the player died by other means.
-advtrains_overrun_mode (Overrun mode) enum drop none,drop,normal
\ No newline at end of file
+advtrains_overrun_mode (Overrun mode) enum drop none,drop,normal
+
+#    Wagon entity loading/unloading range, in nodes
+#    When a wagon is within this range to a player, it is loaded
+#    When a wagon leaves this range + 32 nodes, it is unloaded
+#    If unset, defaults to active_block_range*16
+advtrains_wagon_load_range (Wagon Entity Load/Unload Range) int 96 32 512
diff --git a/advtrains/trainlogic.lua b/advtrains/trainlogic.lua
index 6155768..3e57db2 100644
--- a/advtrains/trainlogic.lua
+++ b/advtrains/trainlogic.lua
@@ -851,7 +851,7 @@ function advtrains.update_trainpart_properties(train_id, invert_flipstate)
 end
 
 
-local ablkrng = minetest.settings:get("active_block_range")*16
+local ablkrng = advtrains.wagon_load_range
 -- This function checks whether entities need to be spawned for certain wagons, and spawns them.
 -- Called from train_step_*(), not required to check init.
 function advtrains.spawn_wagons(train_id)
@@ -862,7 +862,7 @@ function advtrains.spawn_wagons(train_id)
 		local data = advtrains.wagons[w_id]
 		if data then
 			if data.train_id ~= train_id then
-				atwarn("Train",train_id,"Wagon #",1,": Saved train ID",data.train_id,"did not match!")
+				atwarn("Train",train_id,"Wagon #",i,": Saved train ID",data.train_id,"did not match!")
 				data.train_id = train_id
 			end
 			if not advtrains.wagon_objects[w_id] or not advtrains.wagon_objects[w_id]:getyaw() then
@@ -878,6 +878,7 @@ function advtrains.spawn_wagons(train_id)
 				end
 				
 				if spawn then
+					--atdebug("wagon",w_id,"spawning")
 					local wt = advtrains.get_wagon_prototype(data)
 					local wagon = minetest.add_entity(pos, wt):get_luaentity()
 					wagon:set_id(w_id)
diff --git a/advtrains/wagons.lua b/advtrains/wagons.lua
index 2b0833d..28a471a 100644
--- a/advtrains/wagons.lua
+++ b/advtrains/wagons.lua
@@ -14,6 +14,8 @@ advtrains.wagons = {}
 advtrains.wagon_prototypes = {}

 advtrains.wagon_objects = {}

 

+local unload_wgn_range = advtrains.wagon_load_range + 32

+

 local setting_show_ids = minetest.settings:get_bool("advtrains_show_ids")

 

 --

@@ -473,8 +475,29 @@ function wagon:on_step(dtime)
 			yaw=yaw+math.pi

 		end

 		

+		-- this timer runs off every 2 seconds.

 		self.updatepct_timer=(self.updatepct_timer or 0)-dtime

 		local updatepct_timer_elapsed = self.updatepct_timer<=0

+		

+		if updatepct_timer_elapsed then

+			--restart timer

+			self.updatepct_timer=2

+			-- perform checks that are not frequently needed

+			

+			-- unload entity if out of range (because relevant pr won't be merged in engine)

+			-- This is a WORKAROUND!

+			local outofrange = false

+			for _,p in pairs(minetest.get_connected_players()) do

+				if vector.distance(p:get_pos(),pos)>=unload_wgn_range then

+					outofrange = true

+				end

+			end

+			if outofrange then

+				--atdebug("wagon",self.id,"unloading (too far away)")

+				self.object:remove()

+			end

+		end

+		

 		if not self.old_velocity_vector 

 				or not vector.equals(velocityvec, self.old_velocity_vector)

 				or not self.old_acceleration_vector 

@@ -520,7 +543,6 @@ function wagon:on_step(dtime)
                 self.object:setyaw(yaw)

             end

 			

-			self.updatepct_timer=2

 			if self.update_animation then

 				self:update_animation(train.velocity, self.old_velocity)

 			end