Improve the buffer pathfinding for carts not starting directly at a buffer

baselib.lua

@@ -75,7 +75,8 @@ function minecart.find_node_near_lvm(pos, radius, items)
 		for y = pos1.y, pos2.y do
 			for z = pos1.z, pos2.z do
 				local idx = area:indexp({x = x, y = y, z = z})
-				if minetest.get_name_from_content_id(data[idx]) then
+				local name = minetest.get_name_from_content_id(data[idx])
+				if name and tItems[name] then
 					return {x = x, y = y, z = z}
 				end
 			end
@@ -305,12 +306,12 @@ function minecart.add_entitycart(pos, node_name, entity_name, vel, cargo, owner,
 	end
 end
 
-function minecart.start_entitycart(self, pos)
+function minecart.start_entitycart(self, pos, facedir)
 	local route = {}
 	
 	self.is_running = true
 	self.arrival_time = 0
-	self.start_pos = minecart.get_buffer_pos(pos, self.owner)
+	self.start_pos = minecart.get_buffer_pos(pos, self.owner) or minecart.get_next_buffer(pos, facedir)
 	if self.start_pos then
 		-- Read buffer route for the junction info
 		route = minecart.get_route(self.start_pos) or {}

entitylib.lua

@@ -252,9 +252,11 @@ local function on_entitycard_punch(self, puncher, time_from_last_punch, tool_cap
 			local pos = vector.round(self.object:get_pos())
 			if puncher then
 				local yaw = puncher:get_look_horizontal()
+				dir = minetest.yaw_to_dir(yaw)
 				self.object:set_rotation({x = 0, y = yaw, z = 0})
 			end
-			minecart.start_entitycart(self, pos)
+			local facedir = minetest.dir_to_facedir(dir or {x=0, y=0, z=0})
+			minecart.start_entitycart(self, pos, facedir or 0)
 			minecart.start_recording(self, pos) 
 		end
 	end

nodelib.lua

@@ -47,14 +47,19 @@ function minecart.start_nodecart(pos, node_name, puncher, punch_dir)
 		local obj = minecart.node_to_entity(pos, node_name, entity_name)
 		if obj then
 			local entity = obj:get_luaentity()
+			local facedir
+			
 			if puncher then
 				local yaw = puncher:get_look_horizontal()
 				entity.object:set_rotation({x = 0, y = yaw, z = 0})
+				local dir = minetest.yaw_to_dir(yaw)
+				facedir = minetest.dir_to_facedir(dir)
 			elseif punch_dir then
 				local yaw = minetest.dir_to_yaw(punch_dir)
 				entity.object:set_rotation({x = 0, y = yaw, z = 0})
+				facedir = minetest.dir_to_facedir(punch_dir)
 			end
-			 minecart.start_entitycart(entity, pos)
+			minecart.start_entitycart(entity, pos, facedir or 0)
 		end
 	end
 end

rails.lua

@@ -424,6 +424,52 @@ function minecart.delete_waypoint(pos)
 	end
 end	
 
+-------------------------------------------------------------------------------
+-- find next buffer (needed as starting position)
+-------------------------------------------------------------------------------
+local function get_next_waypoints(pos)
+	local t = get_metadata(pos) 
+	if not t then
+		t = find_all_next_waypoints(pos)
+	end
+	return t
+end
+
+local function get_next_pos_and_facedir(waypoints, facedir)
+	local cnt = 0
+	local newpos, newfacedir
+	facedir = (facedir + 2) % 4  -- opposite dir
+	
+	for i = 0, 3 do
+		if waypoints[i] then
+			cnt = cnt + 1
+			if i ~= facedir then -- not the same way back
+				newpos = vector.new(waypoints[i].pos)
+				newfacedir = i
+			end
+		end
+	end
+	
+	-- no junction and valid facedir
+	if cnt < 3 and newfacedir then
+		return newpos, newfacedir
+	end
+end
+
+local function get_next_buffer(pos, facedir)
+	facedir = (facedir + 2) % 4  -- opposite dir
+	for i = 1,5 do  -- limit search depth
+		local waypoints = get_next_waypoints(pos) or {}
+		local pos1, facedir1 = get_next_pos_and_facedir(waypoints, facedir)
+		if pos1 then
+			pos, facedir = pos1, facedir1
+		else
+			return minecart.find_node_near_lvm(pos, 1, {"minecart:buffer"})
+		end
+	end
+end
+
+
 carts:register_rail("minecart:rail", {
 	description = "Rail",
 	tiles = {
@@ -536,13 +582,17 @@ function minecart.add_raillike_nodes(name)
 	lRailsExt[#lRailsExt + 1] = name
 end
 
+-- minecart.get_next_buffer(pos, facedir)
+minecart.get_next_buffer = get_next_buffer
+
 --minetest.register_lbm({
 --	label = "Delete waypoints",
 --	name = "minecart:del_meta",
---	nodenames = {"carts:brakerail"},
+--	nodenames = {"minecart:rail", "minecart:powerrail"},
 --	run_at_every_load = true,
 --	action = function(pos, node)
 --		del_metadata(pos)
 --	end,
 --})
 
+

tool.lua

@@ -29,6 +29,16 @@ end
 
 local old_pos
 
+local function test_get_buffer(pos, player)
+	local yaw = player:get_look_horizontal()
+	local dir = minetest.yaw_to_dir(yaw)
+	local facedir = minetest.dir_to_facedir(dir)
+	local pos1 = minecart.get_next_buffer(pos, facedir)
+	if pos1 then
+		minecart.set_marker(pos1, "buffer", 1.2, 10)
+	end
+end
+
 local function test_get_route(pos, node, player)
 	local yaw = player:get_look_horizontal()
 	local dir = minetest.yaw_to_dir(yaw)
@@ -67,9 +77,8 @@ end
 local function click_left(itemstack, placer, pointed_thing)
 	if pointed_thing.type == "node" then
 		local pos = pointed_thing.under
-		local node = minetest.get_node(pos)
-		if node.name == "carts:rail" or node.name == "carts:powerrail" then
-			test_get_route(pos, node, placer)
+		if minecart.is_rail(pos) then
+			test_get_buffer(pos, placer)
 		end
 	end
 end