working beacon and radar

radar.lua

@@ -0,0 +1,88 @@
+
+
+local update_formspec = function(meta)
+	local inv = meta:get_inventory()
+
+	meta:set_string("formspec", "size[8,3;]" ..
+		-- col 1
+		"button_exit[0,1;8,1;sweep;Radar sweep]" ..
+		"")
+end
+
+local hud = {} -- playername -> {}
+
+local clear_radar = function(playername)
+	local hud_data = hud[playername]
+	local player = minetest.get_player_by_name(playername)
+
+	if not hud_data or not player or not player:is_player() then
+		return
+	end
+
+	for _,id in pairs(hud_data) do
+		player:hud_remove(id)
+	end
+
+	hud[playername] = nil
+end
+
+local show_radar = function(pos, player)
+	local name = player:get_player_name()
+	local hud_data = hud[name]
+
+	if hud_data then
+		-- already active hud
+		return
+	end
+
+	hud_data = {}
+
+	for i,beacon in pairs(locator.beacons) do
+		local distance = vector.distance(pos, beacon.pos)
+		if distance < beacon.range then
+			-- in range
+			local id = player:hud_add({
+				hud_elem_type = "waypoint",
+				name = "Beacon: " .. beacon.name,
+				text = "m",
+				number = 0x00FF00,
+				world_pos = beacon.pos
+			})
+			
+			table.insert(hud_data, id)
+		end
+	end
+
+	hud[name] = hud_data;
+
+	minetest.after(10, function()
+		clear_radar(name)
+	end)
+
+end
+
+-- locator radar
+minetest.register_node("locator:radar", {
+	description = "Locator radar",
+	tiles = {
+		"locator_radar.png",
+		"locator_radar.png",
+		"locator_radar.png",
+		"locator_radar.png",
+		"locator_radar.png",
+		"locator_radar.png"
+	},
+	groups = {cracky=3,oddly_breakable_by_hand=3},
+	sounds = default.node_sound_glass_defaults(),
+
+	on_construct = function(pos)
+		local meta = minetest.get_meta(pos)
+		update_formspec(meta)
+	end,
+
+	on_receive_fields = function(pos, formname, fields, sender)
+		if fields.sweep then
+			show_radar(pos, sender)
+		end
+	end
+})