Re-implement point origin handling (replace old points_split hack by proper solution)

advtrains/init.lua

@@ -474,7 +474,7 @@ advtrains.avt_save = function(remove_players_from_wagons)
 				"atc_brake_target", "atc_wait_finish", "atc_command", "atc_delay", "door_open",
 				"text_outside", "text_inside", "line", "routingcode",
 				"il_sections", "speed_restriction", "speed_restrictions_t", "is_shunt",
-				"points_split", "autocouple", "atc_wait_autocouple", "ars_disable",
+				"path_ori_cp", "autocouple", "atc_wait_autocouple", "ars_disable",
 			})
 			--then save it
 			tmp_trains[id]=v

advtrains/nodedb.lua

@@ -264,7 +264,7 @@ end
 --get_node with pseudoload. now we only need track data, so we can use the trackdb as second fallback
 --nothing new will be saved inside the trackdb.
 --returns:
---true, conn1, conn2, rely1, rely2, railheight   in case everything's right.
+--true, conns, railheight, connmap   in case everything's right.
 --false  if it's not a rail or the train does not drive on this rail, but it is loaded or
 --nil    if the node is neither loaded nor in trackdb
 --the distraction between false and nil will be needed only in special cases.(train initpos)

advtrains/path.lua

@@ -217,9 +217,8 @@ function advtrains.path_get(train, index)
 			advtrains.occ.set_item(train.id, adj_pos, pef)
 			
 			local mconnid = advtrains.get_matching_conn(adj_connid, next_connmap)
-			-- If we have split points, notify accordingly
-			-- TODO readd support for split points (remember the cp and cn of points)
-		
+			-- NO split points handling here. It is only required for backwards path calculation
+			
 			adj_pos.y = adj_pos.y + nextrail_y
 			train.path_cp[pef] = adj_connid
 			train.path_cn[pef] = mconnid
@@ -253,9 +252,15 @@ function advtrains.path_get(train, index)
 			advtrains.occ.set_item(train.id, adj_pos, peb)
 			
 			local mconnid = advtrains.get_matching_conn(adj_connid, next_connmap)
-			-- If we have split points, notify accordingly
-			-- TODO readd support for split points (remember the cp and cn of points)
-			
+			-- If, for this position, we have remembered the origin conn, apply it here
+			if next_connmap then -- only needs to be done when this track is a turnout (>2 conns)
+				local origin_conn = train.path_ori_cp[advtrains.encode_pos(adj_pos)]
+				if origin_conn then
+					atdebug("Train",train.id,"at",adj_pos,"restoring turnout origin CP",origin_conn,"for path item",index)
+					mconnid = origin_conn
+				end
+			end
+						
 			adj_pos.y = adj_pos.y + nextrail_y
 			train.path_cn[peb] = adj_connid
 			train.path_cp[peb] = mconnid

advtrains/trainlogic.lua

@@ -280,8 +280,10 @@ function advtrains.train_ensure_init(id, train)
 	assertdef(train, "velocity", 0)
 	--assertdef(train, "tarvelocity", 0)
 	assertdef(train, "acceleration", 0)
-	assertdef(train, "id", id)
-	
+	if train.id ~= id then
+		train.id = id
+	end
+	assertdef(train, "path_ori_cp", {})
 	
 	if not train.max_speed then
 		--atprint("in ensure_init: missing properties, updating!")
@@ -861,13 +863,10 @@ local function tnc_call_enter_callback(pos, train_id, train, index)
 	run_callbacks_enter_node(pos, train_id, train, index)
 	
 	-- check for split points
-	if mregnode and mregnode.at_conns and #mregnode.at_conns == 3 and train.path_cp[index] == 3 then
-		-- train came from connection 3 of a switch, so it split points.
-		if not train.points_split then
-			train.points_split = {}
-		end
-		train.points_split[advtrains.encode_pos(pos)] = true
-		--atdebug(train_id,"split points at",pos)
+	if mregnode and mregnode.at_conn_map then
+		-- If this node has >2 conns (and a connmap), remember the connection where we came from to handle split points
+		atdebug("Train",train_id,"at",pos,"saving turnout origin CP",train.path_cp[index],"for path item",index)
+		train.path_ori_cp[advtrains.encode_pos(pos)] = train.path_cp[index]
 	end
 end
 local function tnc_call_leave_callback(pos, train_id, train, index)
@@ -882,18 +881,11 @@ local function tnc_call_leave_callback(pos, train_id, train, index)
 	run_callbacks_leave_node(pos, train_id, train, index)
 	
 	-- split points do not matter anymore. clear them
-	if train.points_split then
-		if train.points_split[advtrains.encode_pos(pos)] then
-			train.points_split[advtrains.encode_pos(pos)] = nil
-			--atdebug(train_id,"has passed split points at",pos)
-		end
-		-- any entries left?
-		for _,_ in pairs(train.points_split) do
-			return
-		end
-		train.points_split = nil
+	if mregnode and mregnode.at_conn_map then
+		-- If this node has >2 conns (and a connmap), remember the connection where we came from to handle split points
+		atdebug("Train",train_id,"at",pos,"removing turnout origin CP for path item",index," because train has left it")
+		train.path_ori_cp[advtrains.encode_pos(pos)] = nil
 	end
-	-- WARNING possibly unreachable place!
 end
 
 function advtrains.tnc_call_approach_callback(pos, train_id, train, index, lzbdata)
@@ -1189,8 +1181,24 @@ function advtrains.invert_train(train_id)
 		return
 	end
 	
+	-- Before flipping the train, we must check if there are any points on the path
+	-- which will become split on rotating, and store their cn (which will become the cp)
+	local ori_cp_after_flip = {}
+	for index = atround(train.end_index),atround(train.index) do
+		local pos = advtrains.path_get(train, index)
+		local ok, conns, railheight, connmap = advtrains.get_rail_info_at(pos)
+		if ok and connmap then
+			atdebug("Reversing Train",train.id," ori_cp Checks: at",pos,"saving turnout origin CP",train.path_cn[index],"for path item",index)
+			ori_cp_after_flip[advtrains.encode_pos(pos)] = train.path_cn[index]
+		end
+	end
+	
+	-- Actual rotation happens here! This sets the path restore position to the end of the train, inverting the connid.
 	advtrains.path_setrestore(train, true)
 	
+	-- clear the origin cp list because it is now invalid, and replace it by what we built prior.
+	train.path_ori_cp = ori_cp_after_flip
+	
 	-- rotate some other stuff
 	if train.door_open then
 		train.door_open = - train.door_open