Add node detector, which works like the player detector but detects a specific nodename (or any node except air) in front of it.

mesecons_detector/init.lua

@@ -108,3 +108,150 @@ minetest.register_abm(
 		end
 	end,
 })
+
+-- Node detector
+-- Detects the node in front of it
+
+local node_detector_make_formspec = function (pos)
+	local meta = minetest.get_meta(pos)
+	meta:set_string("formspec", "size[9,2.5]" ..
+		"field[0.3,  0;9,2;scanname;Name of node to scan for (empty for any):;${scanname}]"..
+		"field[0.3,1.5;4,2;digiline_channel;Digiline Channel (optional):;${digiline_channel}]"..
+		"button_exit[7,0.75;2,3;;Save]")
+end
+
+local node_detector_on_receive_fields = function(pos, formname, fields)
+	if not fields.scanname or not fields.digiline_channel then return end;
+
+	local meta = minetest.get_meta(pos)
+	meta:set_string("scanname", fields.scanname)
+	meta:set_string("digiline_channel", fields.digiline_channel)
+	node_detector_make_formspec(pos)
+end
+
+-- returns true if player was found, false if not
+local node_detector_scan = function (pos)
+	local node = minetest.get_node(pos)
+	local frontpos = vector.subtract(pos, minetest.facedir_to_dir(node.param2))
+	local frontnode = minetest.get_node(frontpos)
+	local meta = minetest.get_meta(pos)
+	return (frontnode.name == meta:get_string("scanname")) or
+		(frontnode.name ~= "air" and frontnode.name ~= "ignore" and meta:get_string("scanname") == "")
+end
+
+-- set player name when receiving a digiline signal on a specific channel
+node_detector_digiline = {
+	effector = {
+		action = function (pos, node, channel, msg)
+			local meta = minetest.get_meta(pos)
+			local active_channel = meta:get_string("digiline_channel")
+			if channel == active_channel then
+				meta:set_string("scanname", msg)
+				node_detector_make_formspec(pos)
+			end
+		end,
+	}
+}
+
+minetest.register_node("mesecons_detector:node_detector_off", {
+	tiles = {"default_steel_block.png", "default_steel_block.png", "default_steel_block.png", "default_steel_block.png", "default_steel_block.png", "jeija_node_detector_off.png"},
+	paramtype = "light",
+	paramtype2 = "facedir",
+	walkable = true,
+	groups = {cracky=3},
+	description="Node Detector",
+	mesecons = {receptor = {
+		state = mesecon.state.off
+	}},
+	on_construct = node_detector_make_formspec,
+	on_receive_fields = node_detector_on_receive_fields,
+	after_place_node = function (pos, placer)
+		local placer_pos = placer:getpos()
+		
+		--correct for the player's height
+		if placer:is_player() then placer_pos.y = placer_pos.y + 1.5 end
+		
+		--correct for 6d facedir
+		if placer_pos then
+			local dir = {
+				x = pos.x - placer_pos.x,
+				y = pos.y - placer_pos.y,
+				z = pos.z - placer_pos.z
+			}
+			local node = minetest.get_node(pos)
+			node.param2 = minetest.dir_to_facedir(dir, true)
+			minetest.set_node(pos, node)
+			minetest.log("action", "real (6d) facedir: " .. node.param2)
+		end
+	end,
+	sounds = default.node_sound_stone_defaults(),
+	digiline = node_detector_digiline
+})
+
+minetest.register_node("mesecons_detector:node_detector_on", {
+	tiles = {"default_steel_block.png", "default_steel_block.png", "default_steel_block.png", "default_steel_block.png", "default_steel_block.png", "jeija_node_detector_on.png"},
+	paramtype = "light",
+	paramtype2 = "facedir",
+	walkable = true,
+	groups = {cracky=3,not_in_creative_inventory=1},
+	drop = 'mesecons_detector:node_detector_off',
+	mesecons = {receptor = {
+		state = mesecon.state.on
+	}},
+	on_construct = node_detector_make_formspec,
+	on_receive_fields = node_detector_on_receive_fields,
+	after_place_node = function (pos, placer)
+		local placer_pos = placer:getpos()
+		
+		--correct for the player's height
+		if placer:is_player() then placer_pos.y = placer_pos.y + 1.5 end
+		
+		--correct for 6d facedir
+		if placer_pos then
+			local dir = {
+				x = pos.x - placer_pos.x,
+				y = pos.y - placer_pos.y,
+				z = pos.z - placer_pos.z
+			}
+			local node = minetest.get_node(pos)
+			node.param2 = minetest.dir_to_facedir(dir, true)
+			minetest.set_node(pos, node)
+			minetest.log("action", "real (6d) facedir: " .. node.param2)
+		end
+	end,
+	sounds = default.node_sound_stone_defaults(),
+	digiline = node_detector_digiline
+})
+
+minetest.register_craft({
+	output = 'mesecons_detector:node_detector_off',
+	recipe = {
+		{"default:steel_ingot", "group:mesecon_conductor_craftable", "default:steel_ingot"},
+		{"default:steel_ingot", "mesecons_luacontroller:luacontroller0000", "default:steel_ingot"},
+		{"default:steel_ingot", "default:steel_ingot", "default:steel_ingot"},
+	}
+})
+
+minetest.register_abm(
+	{nodenames = {"mesecons_detector:node_detector_off"},
+	interval = 1.0,
+	chance = 1,
+	action = function(pos, node)
+		if node_detector_scan(pos) then
+			minetest.swap_node(pos, {name = "mesecons_detector:node_detector_on", param2 = node.param2})
+			mesecon:receptor_on(pos)
+		end
+	end,
+})
+
+minetest.register_abm(
+	{nodenames = {"mesecons_detector:node_detector_on"},
+	interval = 1.0,
+	chance = 1,
+	action = function(pos, node)
+		if not node_detector_scan(pos) then
+			minetest.swap_node(pos, {name = "mesecons_detector:node_detector_off", param2 = node.param2})
+			mesecon:receptor_off(pos)
+		end
+	end,
+})