From fd9cbaf813a20297132a4bc14ab1cc0ba45c0f38 Mon Sep 17 00:00:00 2001
From: teknomunk <teknomunk@protonmail.com>
Date: Sun, 28 Apr 2024 06:21:46 +0000
Subject: [PATCH] Rework rail_dir_curve to significantly reduce code size

---
 mods/ENTITIES/mcl_minecarts/rails.lua | 44 +++++----------------------
 1 file changed, 8 insertions(+), 36 deletions(-)

diff --git a/mods/ENTITIES/mcl_minecarts/rails.lua b/mods/ENTITIES/mcl_minecarts/rails.lua
index f54ccadf4..f4d14f867 100644
--- a/mods/ENTITIES/mcl_minecarts/rails.lua
+++ b/mods/ENTITIES/mcl_minecarts/rails.lua
@@ -45,47 +45,19 @@ local function rail_dir_sloped(pos, dir, node)
 		return downhill
 	end
 end
+-- Fourdir
+-- 0 = north
+-- 1 = east
+-- 2 = south
+-- 3 = west
+local CURVE_RAIL_DIRS = { [0] = 1, 1, 2, 2, }
 local function rail_dir_curve(pos, dir, node)
 	dir = vector.new(dir.x, 0, dir.z)
-	local dir_fourdir = minetest.dir_to_fourdir(dir)
-
-	-- Fourdir
-	-- 0 = north
-	-- 1 = east
-	-- 2 = south
-	-- 3 = west
-
-	local new_fourdir = 0
-	if node.param2 == 0 then -- north
-		-- South and East
-		if dir_fourdir == 0 then new_fourdir = 1 end
-		if dir_fourdir == 1 then new_fourdir = 1 end
-		if dir_fourdir == 2 then new_fourdir = 2 end
-		if dir_fourdir == 3 then new_fourdir = 2 end
-	elseif node.param2 == 1 then -- east
-		-- South and West
-		if dir_fourdir == 1 then new_fourdir = 2 end
-		if dir_fourdir == 2 then new_fourdir = 2 end
-		if dir_fourdir == 3 then new_fourdir = 3 end
-		if dir_fourdir == 0 then new_fourdir = 3 end
-	elseif node.param2 == 2 then -- south
-		-- North and West
-		if dir_fourdir == 2 then new_fourdir = 3 end
-		if dir_fourdir == 3 then new_fourdir = 3 end
-		if dir_fourdir == 0 then new_fourdir = 0 end
-		if dir_fourdir == 1 then new_fourdir = 0 end
-	elseif node.param2 == 3 then -- west
-		-- North and East
-		if dir_fourdir == 3 then new_fourdir = 0 end
-		if dir_fourdir == 0 then new_fourdir = 0 end
-		if dir_fourdir == 1 then new_fourdir = 1 end
-		if dir_fourdir == 2 then new_fourdir = 1 end
-	end
-
+	local dir_fourdir = (minetest.dir_to_fourdir(dir) - node.param2 + 4) % 4
+	local new_fourdir = (CURVE_RAIL_DIRS[dir_fourdir] + node.param2) % 4
 	return minetest.fourdir_to_dir(new_fourdir)
 end
 
-
 local function rail_dir_tee_off(pos, dir, node)
 	dir = vector.new(dir.x, 0, dir.z)