use raycast to find pointed object, add some config variables

init.lua

@@ -1,5 +1,11 @@
 local player_waypoints = {}
 local update_interval = 1.31415
+local compass_precision = 10 -- set to 1 to show whole number or 10 for 1 decimal
+local waypoint_color = 0xFC7D0A
+local target_above = false
+local point_to_objects = false -- unimplemented
+local point_to_liquids = true
+local compass_range = 96
 
 -- lua metatables? what is that? :P
 -- local function get_compass_meta_id(meta)
@@ -18,33 +24,16 @@ local function set_compass_meta_label(meta, label)
 end
 
 
-local function pos_serialize(pos)
-    -- strip "(" and ")"
-    return string.sub(minetest.pos_to_string(pos), 2, -2)
-end
-
-
-local function pos_deserialize(str)
-    -- numbers are separated by ","
-    local tmp = {}
-    for n in string.gmatch(str, "([^,]+)") do
-        table.insert(tmp, n)
-    end
-    tmp[1] = tonumber(tmp[1]) or 0
-    tmp[2] = tonumber(tmp[2]) or 0
-    tmp[3] = tonumber(tmp[3]) or 0
-    return {x = tmp[1], y = tmp[2], z = tmp[3]}
-end
 
 
 local function set_compass_meta_pos(meta, pos)
-    local pos_str = pos_serialize(pos)
+    local pos_str = minetest.serialize(pos)
     meta:set_string("waypoint_compass:position", pos_str)
 end
 
 
 local function get_compass_meta_pos(meta)
-    return pos_deserialize(meta:get_string("waypoint_compass:position"))
+    return minetest.deserialize(meta:get_string("waypoint_compass:position"))
 end
 
 -- local function set_compass_meta_pos(meta, pos)
@@ -57,23 +46,55 @@ end
 --     return minetest.get_position_from_hash(meta:get_int("waypoint_compass:position"))
 -- end
 
-minetest.register_tool("waypoint_compass:compass", {
+local function set_waypoint_at_pointed_place(itemstack, user, pointed_thing)
-                           description = "Waypoint compass",
+    if pointed_thing and pointed_thing.type == "node" then
-                           short_description = "Waypoint compass",
+        local pointed_pos = target_above and pointed_thing.above or pointed_thing.under
-                           inventory_image = "Waypoint_compass_inventory_image.png",
+        local meta = itemstack:get_meta()
-                           wield_scale = {x = 0.5, y = 0.5, z = 0.5},
+        meta:set_string("description", string.format("Waypoint compass %s", minetest.pos_to_string(pointed_pos)))
-                           range = 160, -- TODO what's the good range?
+        set_compass_meta_pos(meta, pointed_pos)
-                           on_place = function(itemstack, placer, pointed_thing)
+        set_compass_meta_label(meta, minetest.pos_to_string(pointed_pos))
-                               if pointed_thing and pointed_thing.type == "node" then
+        return itemstack
-                                   local pointed_pos =  pointed_thing.above
+    end
-                                   local meta = itemstack:get_meta()
+    -- TODO handle entities?
-                                   meta:set_string("description", string.format("Waypoint compass %s", minetest.pos_to_string(pointed_pos)))
+end
-                                   set_compass_meta_pos(meta, pointed_pos)
+
-                                   --set_compass_meta_label(meta, minetest.pos_to_string(pointed_pos))
+
-                                   --print("meta pos", minetest.pos_to_string(get_compass_meta_pos(meta)))
+-- return first thing player is pointing at
-                                   return itemstack
+local function raycast_crosshair(player, range)
-                               end
+    local p_pos = player:get_pos()
-                           end,
+    local p_eye_height = player:get_properties().eye_height
+    local p_eye_pos = { x = p_pos.x, y = p_pos.y + p_eye_height, z = p_pos.z }
+    local to = vector.add(p_eye_pos, vector.multiply(player:get_look_dir(), range))
+    local ray = minetest.raycast(p_eye_pos, to, point_to_objects, point_to_liquids)
+    local pointed_thing = ray:next()
+    return pointed_thing
+    -- while pointed_thing do
+    --     print(pointed_thing.type, minetest.pos_to_string(pointed_thing.under))
+    --     pointed_thing = ray:next()
+    -- end
+end
+
+
+minetest.register_tool(
+    "waypoint_compass:compass", {
+        description = "Waypoint compass",
+        short_description = "Waypoint compass",
+        inventory_image = "Waypoint_compass_inventory_image.png",
+        wield_scale = {x = 0.5, y = 0.5, z = 0.5},
+        range = 2.0, -- TODO what's the good range?
+        on_place = function(itemstack, placer, pointed_thing)
+            set_waypoint_at_pointed_place(itemstack, placer, pointed_thing)
+            return itemstack
+        end,
+        on_secondary_use = function(itemstack, user, pointed_thing)
+            if pointed_thing.type == "nothing" then
+                if user:is_player() then
+                    pointed_thing = raycast_crosshair(user, compass_range)
+                end
+            end
+            set_waypoint_at_pointed_place(itemstack, user, pointed_thing)
+            return itemstack
+        end,
 })
 
 
@@ -93,8 +114,8 @@ local function show_hud_waypoint(player, compass_item_meta)
             hud_elem_type = "waypoint",
             name = waypoint_name,
             text = "m",
-            precision=1,
+            precision= compass_precision,
-            number = 0xFC7D0A,
+            number = waypoint_color,
             world_pos = get_compass_meta_pos(compass_item_meta),
     })
     -- store HUD elemnt id to remove it later
@@ -120,7 +141,7 @@ minetest.register_globalstep(function(dtime)
                     local waypoint_pos = get_compass_meta_pos(meta)
                     -- remove different waypoint if it exists
                     if player_waypoints[player_name] and
-                        (pos_serialize(player_waypoints[player_name].pos) ~= pos_serialize(waypoint_pos)) then
+                        (player_waypoints[player_name].pos ~= waypoint_pos) then
                         remove_hud_waypoint(player, player_name)
                     end
                     -- show new waypoint