From aa558fa42bb61feb1f77002061d9d6a3927e5149 Mon Sep 17 00:00:00 2001
From: teknomunk <teknomunk@protonmail.com>
Date: Wed, 10 Apr 2024 07:40:25 +0000
Subject: [PATCH] Implement movement thru tee rails

---
 mods/ENTITIES/mcl_minecarts/movement.lua |  2 +-
 mods/ENTITIES/mcl_minecarts/rails.lua    | 65 ++++++++++++++++++++++--
 2 files changed, 61 insertions(+), 6 deletions(-)

diff --git a/mods/ENTITIES/mcl_minecarts/movement.lua b/mods/ENTITIES/mcl_minecarts/movement.lua
index b7b389102..61a3b9629 100644
--- a/mods/ENTITIES/mcl_minecarts/movement.lua
+++ b/mods/ENTITIES/mcl_minecarts/movement.lua
@@ -32,7 +32,7 @@ mod.detach_minecart = detach_minecart
 local function try_detach_minecart(staticdata)
 	if not staticdata or not staticdata.connected_at then return end
 	if not mod:is_rail(staticdata.connected_at) then
-		print("Detaching minecart"..tostring(staticdata.uuid))
+		print("Detaching minecart #"..tostring(staticdata.uuid))
 		detach_minecart(staticdata)
 	end
 end
diff --git a/mods/ENTITIES/mcl_minecarts/rails.lua b/mods/ENTITIES/mcl_minecarts/rails.lua
index b3d304b9b..835b30b06 100644
--- a/mods/ENTITIES/mcl_minecarts/rails.lua
+++ b/mods/ENTITIES/mcl_minecarts/rails.lua
@@ -89,11 +89,65 @@ local function rail_dir_curve(pos, dir, node)
 		if vector.equals(dir, east) then return east end
 	end
 end
-local function rail_dir_tee(pos, dir, node)
+
+
+local function rail_dir_tee_off(pos, dir, node)
 	dir = vector.new(dir.x, 0, dir.z)
 
-	minetest.log("warning","TODO: implement rail_dir_tee()")
-	return north
+	if node.param2 == 0 then -- north
+		-- South and East
+		if vector.equals(dir, south) then return south end
+		if vector.equals(dir, north) then return east end
+		if vector.equals(dir, west) then return south end
+		if vector.equals(dir, east) then return east end
+	elseif node.param2 == 1 then -- east
+		-- South and West
+		if vector.equals(dir, south) then return south end
+		if vector.equals(dir, north) then return west end
+		if vector.equals(dir, west) then return west end
+		if vector.equals(dir, east) then return south end
+	elseif node.param2 == 2 then
+		-- North and West
+		if vector.equals(dir, south) then return west end
+		if vector.equals(dir, north) then return north end
+		if vector.equals(dir, west) then return west end
+		if vector.equals(dir, east) then return north end
+	elseif node.param2 == 3 then
+		-- North and East
+		if vector.equals(dir, south) then return east end
+		if vector.equals(dir, north) then return north end
+		if vector.equals(dir, west) then return north end
+		if vector.equals(dir, east) then return east end
+	end
+end
+local function rail_dir_tee_on(pos, dir, node)
+	dir = vector.new(dir.x, 0, dir.z)
+
+	if node.param2 == 0 then -- north
+		-- South and East
+		if vector.equals(dir, south) then return east end
+		if vector.equals(dir, north) then return north end
+		if vector.equals(dir, west) then return north end
+		if vector.equals(dir, east) then return east end
+	elseif node.param2 == 1 then -- east
+		-- South and West
+		if vector.equals(dir, south) then return south end
+		if vector.equals(dir, north) then return east end
+		if vector.equals(dir, west) then return south end
+		if vector.equals(dir, east) then return east end
+	elseif node.param2 == 2 then
+		-- North and West
+		if vector.equals(dir, south) then return south end
+		if vector.equals(dir, north) then return west end
+		if vector.equals(dir, west) then return west end
+		if vector.equals(dir, east) then return south end
+	elseif node.param2 == 3 then
+		-- North and East
+		if vector.equals(dir, south) then return west end
+		if vector.equals(dir, north) then return north end
+		if vector.equals(dir, west) then return west end
+		if vector.equals(dir, east) then return north end
+	end
 end
 local function rail_dir_cross(pos, dir, node)
 	dir = vector.new(dir.x, 0, dir.z)
@@ -292,13 +346,14 @@ function mod.register_curves_rail(base_name, tiles, def)
 			}
 		},
 		_mcl_minecarts = {
-			railtype = "corner",
+			get_next_dir = rail_dir_tee_off,
+			railtype = "tee",
 		},
 	}))
 	mod.register_rail(base_name.."_tee_on", table_merge(table.copy(base_def),{
 		tiles = { tiles[4] },
 		_mcl_minecarts = {
-			get_next_dir = rail_dir_tee,
+			get_next_dir = rail_dir_tee_on,
 			railtype = "tee",
 		},
 		mesecons = {