Show waypoint when holding a compass

init.lua

@@ -1,47 +1,99 @@
 local player_waypoints = {}
+local update_interval = 1.31415
+
+-- lua metatables? what is that? :P
+local function get_compass_meta_id(meta)
+    return meta:get_string("waypoint_compass:id") ~= "" or "default_id"
+end
+
+
+local function get_compass_meta_name(meta)
+    return meta:get_string("waypoint_compass:name") ~= "" or "destination"
+end
+
+local function get_compass_meta_pos(meta)
+    return {x=0, y=0, z=0}
+end
+
 
 minetest.register_tool("waypoint_compass:compass", {
                            description = "Waypoint compass",
+                           short_description = "Steel Axe",
                            inventory_image = "Waypoint_compass_inventory_image.png",
-                           -- Display HUD waypoint on use
                            on_use = function(itemstack, user, pointed_thing)
-                               if not itemstack then
+                               -- FIXME test code for checking how setting the description works
-                                   return nil
-                               end
-                               local meta = itemstack:get_meta()
-                               local waypoint_id = meta:get_string("waypoint_compass:id")
                                if user and user:is_player() then
                                    local player = user
-                                   local player_name = player:get_player_name()
+                                   local meta = itemstack:get_meta()
-                                   if (player_waypoints[player_name] and
+                                   local pos = get_compass_meta_pos(meta)
-                                       player_waypoints[player_name][waypoint_id]) then
+                                   local new_description = string.format("%f (%f,%f,%f)", math.random(), pos.x, pos.y, pos.z)
-                                       -- Waypoint is currently displayed, remove it
+                                   meta:set_string("description", new_description)
-                                       local hud_id = player_waypoints[player_name][waypoint_id]
+                                   meta:set_string("short_description", new_description)
-                                       print("hud_id remove", hud_id)
+                                   print("on use", new_description)
-                                       player_waypoints[player_name][waypoint_id] = nil
+                                   --player:set_wielded_item(nil)
+                                   --player:set_wielded_item(itemstack)
+                                   return itemstack
+                               end
+                           end
+})
+
+
+local function remove_hud_waypoint(player, player_name)
+    print("hud remove")
+    local hud_id = player_waypoints[player_name].hud_id
+    player_waypoints[player_name] = nil
     player:hud_remove(hud_id)
-                                   else
+end
+
+local function show_hud_waypoint(player, compass_item_meta)
+    local player_name = player:get_player_name()
     -- Show this waypoint
-                                       local waypoint_name = meta:get_string("waypoint_compass:name") ~= "" or "destination"
+    local waypoint_name = get_compass_meta_name(compass_item_meta)
     local hud_id = player:hud_add({
             hud_elem_type = "waypoint",
             name = waypoint_name,
             text = "m",
             precision=1,
             number = 0xFF, --0xFFFFFF,
-                                               world_pos = {x=0, y=0, z=0},
+            world_pos = get_compass_meta_pos(compass_item_meta),
     })
     -- store HUD elemnt id to remove it later
     if not player_waypoints[player_name] then
         player_waypoints[player_name] = {}
     end
     print("hud_id add", hud_id)
-                                       player_waypoints[player_name][waypoint_id] = hud_id
+    player_waypoints[player_name].id = get_compass_meta_id(compass_item_meta)
+    player_waypoints[player_name].hud_id = hud_id
+    print("id set", player_waypoints[player_name].id)
+end
+
+
+local timer = 0
+minetest.register_globalstep(function(dtime)
+        timer = timer + dtime
+        if timer > update_interval then
+            for _,player in pairs(minetest.get_connected_players()) do
+                local player_name = player:get_player_name()
+                local item = player:get_wielded_item()
+                -- player is holding compass
+                if (item and item:get_name() == "waypoint_compass:compass") then
+                    local meta = item:get_meta()
+                    local waypoint_id = get_compass_meta_id(meta)
+                    -- remove different waypoint if it exists
+                    print(player_waypoints[player_name] and player_waypoints[player_name].id)
+                    if player_waypoints[player_name] and (player_waypoints[player_name].id ~= waypoint_id) then
+                        remove_hud_waypoint(player, player_name)
                     end
-                                   
+                    -- show new waypoint
+                    if not player_waypoints[player_name] then
+                        show_hud_waypoint(player, meta)
                     end
-                               return nil
+                else
-                           end,
+                    if player_waypoints[player_name] then
-})
+                        remove_hud_waypoint(player, player_name)
-                           
+                    end
-
+                end
+            end
+            timer = 0
+        end
+end)