Filter works.

filter.lua

@@ -0,0 +1,147 @@
+-- © 2017 numberZero
+-- License: GNU Lesser General Public License, version 2 (or any later version)
+
+local OVERLOAD_THRESHOLD = 50.0
+local FILTER_FORMSPEC = "field[channel;Channel;${channel}]"
+local FILTER_INFOTEXT = "Digiline Filter (channel \"%s\")"
+local FILTER_INFOTEXT_DEFAULT = FILTER_INFOTEXT:format("")
+
+local function filter_rules_in(node)
+	return {
+		digiline_routing.get_base_rule(3, node.param2),
+	}
+end
+
+local function filter_rules_out(node)
+	return {
+		digiline_routing.get_base_rule(1, node.param2),
+	}
+end
+
+local function filter_init(pos)
+	local meta = minetest.get_meta(pos)
+	meta:set_string("formspec", FILTER_FORMSPEC)
+	meta:set_string("infotext", FILTER_INFOTEXT_DEFAULT)
+	meta:set_string("channel", "")
+end
+
+local function filter_receive_fields(pos, formname, fields, sender)
+	if minetest.is_protected(pos, sender) and not minetest.check_player_privs(sender, "protection_bypass") then
+		minetest.record_protection_violation(pos, sender)
+		return
+	end
+	if not fields.channel then
+		return
+	end
+	local meta = minetest.get_meta(pos)
+	meta:set_string("channel", fields.channel)
+	meta:set_string("infotext", FILTER_INFOTEXT:format(fields.channel))
+end
+
+local function filter_place(...)
+	return (digiline_routing.multiblock.build2("digiline_routing:filter", "digiline_routing:filter_b", ...)) -- adjust to 1 value
+end
+
+local function filter_cleanup(pos, node)
+	digiline_routing.overheat.forget(pos)
+	digiline_routing.multiblock.dig2(pos, node)
+end
+
+local function filter_test(master, channel)
+	if digiline_routing.overheat.heat(master) > OVERLOAD_THRESHOLD then
+		minetest.dig_node(master)
+		minetest.add_item(master, "digiline_routing:filter")
+		return false
+	end
+	return channel == minetest.get_meta(master):get_string("channel")
+end
+
+local function filter_in_action(pos, node, channel, msg)
+	if filter_test(pos, channel) then
+		local off = minetest.facedir_to_dir(node.param2)
+		local slave = vector.add(pos, off)
+		digiline:receptor_send(slave, filter_rules_out(node), channel, msg)
+	end
+end
+
+local function filter_out_action(pos, node, channel, msg)
+	local off = minetest.facedir_to_dir(node.param2)
+	local master = vector.subtract(pos, off)
+	if filter_test(master, channel) then
+		digiline:receptor_send(master, filter_rules_in(node), channel, msg)
+	end
+end
+
+minetest.register_node("digiline_routing:filter", {
+	description = "Digiline Filter",
+	drawtype = "nodebox",
+	tiles = {
+		"digiline_routing_metal.png"
+	},
+	paramtype = "light",
+	paramtype2 = "facedir",
+	is_ground_content = false,
+	groups = {dig_immediate=2},
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -1/16, -8/16, -8/16, 1/16, -7/16, 24/16 },
+			{ -2/16, -8/16, -4/16, 2/16, -6/16, 20/16 },
+
+			{ -3/16, -8/16, -3/16, 3/16, -5/16, 4/16 },
+			{ -4/16, -8/16, -2/16, 4/16, -5/16, 3/16 },
+			{ -5/16, -8/16, -1/16, 5/16, -5/16, 2/16 },
+
+			{ -5/16, -8/16, 7/16, 5/16, -6/16, 9/16 },
+			{ -7/16, -8/16, 5/16, -5/16, -5/16, 11/16 },
+			{ 5/16, -8/16, 5/16, 7/16, -5/16, 11/16 },
+
+			{ -3/16, -8/16, 12/16, 3/16, -5/16, 19/16 },
+			{ -4/16, -8/16, 13/16, 4/16, -5/16, 18/16 },
+			{ -5/16, -8/16, 14/16, 5/16, -5/16, 17/16 },
+		},
+	},
+	on_construct = filter_init,
+	on_place = filter_place,
+	after_destruct = filter_cleanup,
+	on_receive_fields = filter_receive_fields,
+	on_rotate = digiline_routing.multiblock.rotate2,
+	digiline = {
+		effector = {
+                        action = filter_in_action,
+			rules = filter_rules_in,
+		},
+		receptor = {
+			rules = filter_rules_in,
+		},
+	},
+})
+
+minetest.register_node("digiline_routing:filter_b", {
+	description = "<<INTERNAL>> Digiline Filter (Part B)",
+	drawtype = "nodebox",
+	tiles = {
+		"digiline_routing_metal.png"
+	},
+	paramtype = "light",
+	paramtype2 = "facedir",
+	is_ground_content = false,
+	pointable = false,
+	groups = {dig_immediate=2, not_in_creative_inventory=1},
+	node_box = {
+		type = "fixed",
+		fixed = {},
+	},
+	drop = "",
+	after_destruct = digiline_routing.multiblock.dig2b,
+	on_rotate = digiline_routing.multiblock.rotate2b,
+	digiline = {
+		effector = {
+                        action = filter_out_action,
+			rules = filter_rules_out,
+		},
+		receptor = {
+			rules = filter_rules_out,
+		},
+	},
+})

init.lua

@@ -12,3 +12,4 @@ dofile(MODPATH.."/overheating.lua")
 dofile(MODPATH.."/multiblock.lua")
 dofile(MODPATH.."/diode.lua")
 dofile(MODPATH.."/splitter.lua")
+dofile(MODPATH.."/filter.lua")