From 5232d1a3af343e20b035fbb402edb990209c1dd4 Mon Sep 17 00:00:00 2001
From: Cam B <camabyss@gmail.com>
Date: Wed, 20 Jan 2021 20:48:18 +0000
Subject: [PATCH] Implemented new method of defining valid faces through the
 secondary node registration

---
 internal2.lua | 10 +++++-----
 tube_api.lua  | 35 +++++++++++++++++++++++++++++++++--
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/internal2.lua b/internal2.lua
index 646dd62..821c408 100644
--- a/internal2.lua
+++ b/internal2.lua
@@ -121,12 +121,12 @@ function Tube:get_secondary_node(pos, dir)
 	local npos = vector.add(pos, Dir6dToVector[dir or 0])
 	local node = self:get_node_lvm(npos)
 	if self.secondary_node_names[node.name] then
-		local valid_dir_string = minetest.get_meta(npos):get_string('valid_dirs')
-		local valid_dirs = self.valid_dirs
-		if valid_dir_string and valid_dir_string ~= "" then
-			valid_dirs = minetest.deserialize(valid_dir_string)
+		local is_valid_dir = nil
+		if dir ~= nil then
+			local side = tubelib2.dir_to_side(Turn180Deg[dir], node.param2)
+			is_valid_dir = self.secondary_node_names[node.name][side] or false
 		end
-		return node, npos, valid_dirs[Turn180Deg[dir]] or false
+		return node, npos, is_valid_dir
 	end
 end
 
diff --git a/tube_api.lua b/tube_api.lua
index 9f1cfc4..e74910b 100644
--- a/tube_api.lua
+++ b/tube_api.lua
@@ -23,12 +23,34 @@ local M = minetest.get_meta
 local MP = minetest.get_modpath("tubelib2")
 local I,_ = dofile(MP.."/intllib.lua")
 
+-- Cardinal directions, regardless of orientation
 local Dir2Str = {"north", "east", "south", "west", "down", "up"}
 
 function tubelib2.dir_to_string(dir)
 	return Dir2Str[dir]
 end
 
+-- Relative directions, dependant on orientation (param2)
+local DirToSide = {"B", "R", "F", "L", "D", "U"}
+
+function tubelib2.dir_to_side(dir, param2)
+	if dir < 5 then
+		dir = (((dir - 1) - (param2 % 4)) % 4) + 1
+	end
+	return DirToSide[dir]
+end
+
+local SideToDir = {B=1, R=2, F=3, L=4, D=5, U=6}
+
+function tubelib2.side_to_dir(side, param2)
+	local dir = SideToDir[side]
+	if dir < 5 then
+		dir = (((dir - 1) + (param2 % 4)) % 4) + 1
+	end
+	return dir
+end
+
+
 local function Tbl(list)
 	local tbl = {}
 	for _,item in ipairs(list) do
@@ -193,10 +215,19 @@ function Tube:new(attr)
 	return o
 end
 
+
+
 -- Register (foreign) tubelib compatible nodes.
-function Tube:add_secondary_node_names(names)
+local valid_sides_default = {B=true, R=true, F=true, L=true, D=true, U=true}
+function Tube:add_secondary_node_names(names, valid_sides)
+	local valid_sides_complete = valid_sides or {}
+	for side, defaultValue in pairs(valid_sides_default) do
+		if valid_sides_complete[side] == nil then
+			valid_sides_complete[side] = defaultValue
+		end
+	end
 	for _,name in ipairs(names) do
-		self.secondary_node_names[name] = true
+		self.secondary_node_names[name] = valid_sides_complete
 	end
 end