Reduce number of laser nodes from 63 to 7

mods/lzr_laser/laser.lua

@@ -6,9 +6,9 @@ local LASER_RADIUS = -1/16
 -- Returns a nodebox for the given dirs table
 local function dirs_to_nodebox(dirs)
 	local boxes = {}
-	local x = dirs[1] == 1 or dirs[4] == 1
-	local y = dirs[2] == 1 or dirs[5] == 1
-	local z = dirs[3] == 1 or dirs[6] == 1
+	local x = dirs[1] == 1
+	local y = dirs[2] == 1
+	local z = dirs[3] == 1
 
 	-- True if 2 or more axes are used
 	local multidir = (x and y) or (x and z) or (y and z)
@@ -47,9 +47,9 @@ local function dirs_to_nodebox(dirs)
 end
 
 -- Register laser nodes
--- 64 nodes because 2^6 (6 directions with on/off state)
-for i=1, 64 do
-	local dirstring = lzr_laser.dec2bin(i, 6)
+-- 7 nodes because (2^3)-1 (2 states for each of 3 axes, minus the state when there's no laser (=air))
+for i=1, 7 do
+	local dirstring = lzr_laser.dec2bin(i, 3)
 	local dirs = lzr_laser.dirstring_to_dirs(dirstring)
 
 	-- Check which textures to render.
@@ -59,7 +59,7 @@ for i=1, 64 do
 	local axes = 0
 	local axes_active = {x=false,y=false,z=false}
 	for a=1,3 do
-		if dirs[a] ~= 0 or dirs[a+3] ~= 0 then
+		if dirs[a] ~= 0 then
 			axes = axes + 1
 			if a == 1 then
 				axes_active.x = true

mods/lzr_laser/physics.lua

@@ -15,7 +15,7 @@ function lzr_laser.add_laser(pos, dir)
 	-- Laser through laser (laser intersection)
 	elseif minetest.get_item_group(node.name, "laser") > 0 then
 		local dirnum = minetest.get_item_group(node.name, "laser")
-		local dirstring_old = lzr_laser.dec2bin(dirnum, 6)
+		local dirstring_old = lzr_laser.dec2bin(dirnum, 3)
 
 		local dirs_new = lzr_laser.vector_to_dirs(dir)
 		local dirstring_new = lzr_laser.dirs_to_dirstring(dirs_new)

mods/lzr_laser/util.lua

@@ -2,22 +2,22 @@
 local LASER_RADIUS = -1/16
 
 -- DATA FORMATS:
---[[ dirstring: A representation of 6 cardinal directions which are either
+--[[ dirstring: A representation of 3 axes (XYZ) which are either
 'active' (1) or 'inactive' (0)
 Each direction has the character "1" or "0".
-The characters stand for these directions, in order: -X, -Y, -Z, +X, +Y, +Z
-Example: "101010"
+The characters stand for these directions, in order: X, Y, Z
+Example: "101"
 ]]
 --[[ dirs table: Like dirstring, but in table format. It's a table
-with 6 numbers, each of them being either 1 or 0. The same order of
-directions is used like for dirstring.
-Example: { 1, 0, 1, 0, 1, 0 }
+with 3 numbers, each of them being either 1 or 0. The same order of
+axes is used like for dirstring.
+Example: { 1, 0, 1 }
 ]]
 
 -- Converts a dirstring to a dirs table
 function lzr_laser.dirstring_to_dirs(dirstring)
 	local dirs = {}
-	for d=1, 6 do
+	for d=1, 3 do
 		if string.sub(dirstring, d, d) == "1" then
 			dirs[d] = 1
 		elseif string.sub(dirstring, d, d) == "0" then
@@ -32,7 +32,7 @@ end
 -- Converts a dirs table to a dirstring
 function lzr_laser.dirs_to_dirstring(dirs)
 	local dirstring = ""
-	for d=1, 6 do
+	for d=1, 3 do
 		if dirs[d] == 0 then
 			dirstring = dirstring .. "0"
 		elseif dirs[d] == 1 then
@@ -45,23 +45,14 @@ function lzr_laser.dirs_to_dirstring(dirs)
 end
 
 function lzr_laser.vector_to_dirs(dir_vector)
-	local dirs = {0,0,0,0,0,0}
-	if dir_vector.x > 0 then
-		dirs[4] = 1
-	end
-	if dir_vector.x < 0 then
+	local dirs = {0,0,0}
+	if dir_vector.x ~= 0 then
 		dirs[1] = 1
 	end
-	if dir_vector.y > 0 then
-		dirs[5] = 1
-	end
-	if dir_vector.y < 0 then
+	if dir_vector.y ~= 0 then
 		dirs[2] = 1
 	end
-	if dir_vector.z > 0 then
-		dirs[6] = 1
-	end
-	if dir_vector.z < 0 then
+	if dir_vector.z ~= 0 then
 		dirs[3] = 1
 	end
 	return dirs