add limiter, simplify filter code

limiter.lua

@@ -0,0 +1,58 @@
+
+minetest.register_node("digicontrol:limiter", {
+	description = "Digilines Limiter",
+	inventory_image = "digicontrol_limiter.png",
+	tiles = {
+		"digicontrol_limiter.png",
+		"digicontrol_bottom.png",
+		"digicontrol_side_port.png",
+		"digicontrol_side_port.png",
+		"digicontrol_side.png",
+		"digicontrol_side.png"
+	},
+	drawtype = "nodebox",
+	node_box = digicontrol.node_box,
+	selection_box = digicontrol.selection_box,
+	paramtype = "light",
+	paramtype2 = "facedir",
+	is_ground_content = false,
+	groups = {digicontrol = 1, dig_immediate = 2},
+	on_construct = function(pos)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("formspec", "field[limit;Message Limit (messages/second);${limit}]")
+		meta:set_string("limit", "1")
+	end,
+	on_receive_fields = function(pos, _, fields, sender)
+		if minetest.is_protected(pos, sender:get_player_name()) then return end
+		if fields.limit then
+			local limit = tonumber(fields.limit)
+			if limit then
+				minetest.get_meta(pos):set_string("limit", math.min(limit, 10))
+			end
+		end
+	end,
+	digiline = {
+		semiconductor = {
+			rules = function(node, pos)
+				local timer = minetest.get_node_timer(pos)
+				local limit = tonumber(minetest.get_meta(pos):get_string("limit"))
+				if not limit or limit == 0 or timer:is_started() then return {} end
+				if limit > 0 then
+					timer:start(1 / limit)
+				end
+				return {
+					digicontrol.get_rule(1, node.param2),
+					digicontrol.get_rule(3, node.param2)
+				}
+			end
+		},
+		wire = {
+			rules = function(node)
+				return {
+					digicontrol.get_rule(1, node.param2),
+					digicontrol.get_rule(3, node.param2)
+				}
+			end
+		}
+	}
+})