first experimental version

depends.txt

@@ -0,0 +1 @@
+areas

init.lua

@@ -0,0 +1,591 @@
+
+-- markers are useful for measuring distances and for marking areas
+-- markers are protected from digging by other players for one day
+-- (the protection for the *marker* auto-expires then, and it can be digged)
+
+markers = {}
+
+-- stores up to 4 marker positions for each player
+markers.positions = {}
+
+-- store the positions of that many markers for each player (until server restart)
+markers.MAX_MARKERS  = 10;
+ 
+-- the protection against digging of the marker by other players expires after this time
+markers.EXPIRE_AFTER = 60*60*24;
+
+-- self-protected areas can not get higher than 100 blocks
+markers.MAX_HEIGHT   = 100;
+
+-- only areas up to this size (in square meters) can be protected
+markers.MAX_SIZE     = 1024; -- 32m * 32m = 1024 m^2
+
+
+dofile(minetest.get_modpath("markers").."/marker_stone.lua");
+
+-- TODO: dofile land_title_register.lua
+--dofile(minetest.get_modpath("markers").."/land_title_register.lua");
+
+
+-- returns the first area found
+markers.get_area_by_pos1_pos2 = function(pos1, pos2)
+   for id, area in pairs(areas.areas) do
+
+      if( ((area.pos1.x == pos1.x and area.pos1.z == pos1.z )
+        or (area.pos1.x == pos1.x and area.pos1.z == pos2.z )
+        or (area.pos1.x == pos2.x and area.pos1.z == pos1.z )
+        or (area.pos1.x == pos2.x and area.pos1.z == pos2.z ))
+
+       and((area.pos2.x == pos1.x and area.pos2.z == pos1.z )
+        or (area.pos2.x == pos1.x and area.pos2.z == pos2.z )
+        or (area.pos2.x == pos2.x and area.pos2.z == pos1.z )
+        or (area.pos2.x == pos2.x and area.pos2.z == pos2.z ))) then
+
+          -- at least pos1 needs to have a hight value that fits in
+          if(  (area.pos1.y <= pos1.y and area.pos2.y >= pos1.y)
+            or (area.pos1.y >= pos1.y and area.pos2.y <= pos1.y)) then
+
+             local found = area;
+             found[ 'id' ] = id;
+             return found;
+
+          end
+      end
+   end
+   return nil;
+end
+
+
+
+
+
+
+-- this function is supposed to return a text string describing the price of the land between po1 and pos2
+-- You can return somethiing like "for free" or "the promise to build anything good" as well as any
+-- real prices in credits or materials - it's really just a text here.
+-- Make sure you do not charge the player more than what you ask here.
+markers.calculate_area_price_text = function( pos1, pos2, playername )
+
+   local price = ( math.abs( pos1.x - pos2.x )+1 )
+               * ( math.abs( pos1.z - pos2.z )+1 );
+
+--               * math.ceil( ( math.abs( pos1.y - pos2.y )+1 )/10);
+
+   return tostring( price )..' credits';
+end
+
+
+
+
+markers.marker_placed = function( pos, placer, itemstack )
+ 
+   if( not( pos ) or not( placer )) then
+      return;
+   end
+ 
+   local meta = minetest.env:get_meta( pos );
+   local name = placer:get_player_name();
+
+   meta:set_string( 'infotext', 'Marker at '..minetest.pos_to_string( pos )..
+				' (placed by '..tostring( name )..'). '..
+				'Right-click to update.');
+   meta:set_string( 'owner',    name );
+   -- this allows protection of this particular marker to expire
+   meta:set_string( 'time',     tostring( os.time()) );
+
+   local txt = '';
+
+   if( not( markers.positions[ name ] ) or #markers.positions[name]<1) then
+      markers.positions[ name ] = {};
+      markers.positions[ name ][ 1 ] = pos;
+ 
+      minetest.chat_send_player( name,
+		'First marker set to position '..
+		minetest.pos_to_string( markers.positions[ name ][ 1 ] )..
+		'. Please place a second marker to measure distance. '..
+		'Place four markers in a square to define an area.');
+   else
+      table.insert( markers.positions[ name ], pos );
+
+      local n = #markers.positions[ name ];
+
+      local dx = markers.positions[ name ][ n ].x - markers.positions[ name ][ n-1 ].x;
+      local dy = markers.positions[ name ][ n ].y - markers.positions[ name ][ n-1 ].y;
+      local dz = markers.positions[ name ][ n ].z - markers.positions[ name ][ n-1 ].z;
+
+      local dir_name = "unknown";
+      local d = 0;
+      if(     dx == 0 and dz > 0 )             then dir_name = "north"; d = math.abs(dz);
+      elseif( dx == 0 and dz < 0 )             then dir_name = "south"; d = math.abs(dz);
+      elseif( dz == 0 and dx > 0 )             then dir_name = "east";  d = math.abs(dx);
+      elseif( dz == 0 and dx < 0 )             then dir_name = "west";  d = math.abs(dx);
+      elseif( dx == 0 and dz == 0 and dy > 0 ) then dir_name = "above"; d = math.abs(dy);
+      elseif( dx == 0 and dz == 0 and dy < 0 ) then dir_name = "below"; d = math.abs(dy);
+      else
+
+         local area   =        (math.abs( dx )+1)
+                             * (math.abs( dz )+1);
+         local volume = area * (math.abs( dy )+1);
+
+         minetest.chat_send_player( name, 'This marker is at '..
+               minetest.pos_to_string( markers.positions[ name ][ n ] )..', while the last one is at '..
+               minetest.pos_to_string( markers.positions[ name ][ n-1 ] )..'. Distance (x/y/z): '..
+               tostring(math.abs(dx))..'/'..
+               tostring(math.abs(dy))..'/'..
+               tostring(math.abs(dz))..
+              '. Area: '..tostring( area )..' m^2. Volume: '..tostring( volume )..' m^3.');
+      end
+     
+      -- this marker is aligned to the last one
+      if( d > 0 ) then
+         minetest.chat_send_player( name, 'Marker placed at '..minetest.pos_to_string( pos )..
+				'. Relative to the marker you placed before, this one is '..
+ 				tostring( d )..' m '..dir_name..'.');
+      end
+
+      -- do the last 4 markers placed form an area?
+      if( #markers.positions[ name ] > 3 ) then
+         local count_x_coord = {};
+         local count_z_coord = {};
+         local anz_x_coord   = 0;
+         local anz_z_coord   = 0;
+         local check_failed  = 0;
+         for i=0,3 do
+
+            local v = markers.positions[ name ][ n-i ].x;
+
+            if( not( count_x_coord[ v ] )) then
+               count_x_coord[       v ] = 1;
+               anz_x_coord = anz_x_coord + 1;
+            elseif(  count_x_coord[ v ] == 2 ) then               
+               check_failed = 1;
+            else
+               count_x_coord[       v ] = count_x_coord[ v ] + 1;
+            end
+
+            v = markers.positions[ name ][ n-i ].z;
+            if( not( count_z_coord[ v ] )) then
+               count_z_coord[       v ] = 1;
+               anz_z_coord = anz_z_coord + 1;
+            elseif(  count_z_coord[ v ] == 2 ) then               
+               check_failed = 1;
+            else
+               count_z_coord[       v ] = count_z_coord[ v ] + 1;
+            end
+         end
+
+         if(     anz_x_coord == 2 
+            and  anz_z_coord == 2
+            and check_failed == 0 ) then
+               
+            minetest.chat_send_player( name, 'The last four markers you placed form a rectangle. '..
+                   'Right-click on this marker here in order to protect the area.');
+         end
+      end
+
+      -- make sure the list does not grow too large
+      if( n > markers.MAX_MARKERS ) then
+         table.remove( markers.positions[ name ], 1 );
+      end
+   end
+end
+
+
+
+markers.marker_can_dig = function(pos,player) 
+
+   if( not( pos ) or not( player )) then
+      return true;
+   end
+
+   local meta  = minetest.env:get_meta( pos );
+   local owner = meta:get_string( 'owner' );
+   local time  = meta:get_string( 'time' ); 
+
+   -- can the marker be removed?
+   if( not( owner ) 
+       or owner==''
+       or not( time ) 
+       or time==''
+       or (os.time() - tonumber( time )) > markers.EXPIRE_AFTER ) then
+
+      return true;
+
+   -- marker whose data got lost anyway
+   elseif( not( markers.positions[ owner ] )
+            or #markers.positions[ owner ] < 1 ) then
+   
+     return true;
+
+   -- marker owned by someone else and still in use
+   elseif( owner ~= player:get_player_name()) then
+
+      minetest.chat_send_player( player:get_player_name(),
+		'Sorry, this marker belongs to '..tostring( owner )..
+		'. If you still want to remove it, try again in '..
+		( tostring( markers.EXPIRE_AFTER + tonumber( time ) - os.time()))..' seconds.');
+      return false;
+
+   end
+  
+   return true;
+end
+
+
+
+
+markers.marker_after_dig_node = function(pos, oldnode, oldmetadata, digger)
+
+   if( not(oldmetadata ) or not(oldmetadata['fields'])) then
+      return;
+   end
+
+   local owner = oldmetadata['fields']['owner'];
+   if( not( owner ) 
+       or owner==''
+       or not( markers.positions[ owner ] )
+       or     #markers.positions[ owner ] < 1 ) then
+
+      return;
+   end
+
+   -- remove the markers position from our table of stored positions
+   local found = 0;
+   for i,v in ipairs( markers.positions[ owner ] ) do
+      if(   v.x == pos.x 
+        and v.y == pos.y
+        and v.z == pos.z ) then
+         found = i;
+      end
+   end
+   if( found ~= 0 ) then
+      table.remove( markers.positions[ owner ], found );
+   end
+   return true;
+end
+
+
+
+
+
+
+markers.get_marker_formspec = function(player, pos, error_msg)
+   local formspec = "";
+
+   local meta  = minetest.env:get_meta( pos );
+   local owner = meta:get_string( 'owner' );
+
+   local name  = player:get_player_name();
+
+   local formspec_info = "size[6,4]"..
+             "button_exit[2,2.5;1,0.5;abort;OK]"..
+             "textarea[1,1;4,2;info;Information;";
+   if( owner ~= nil and owner ~= '' and owner ~= name ) then
+      return formspec_info.."This marker\ncan only be used by\n"..tostring( owner )..", who\nplaced the markers.]";
+   end
+
+   if( not( markers.positions[ name ]) or #markers.positions[name]<1) then
+      return formspec_info.."Information about the positions\nof your other markers\ngot lost.\nPlease dig and place\nyour markers again!]";
+   end
+
+   local n = #markers.positions[ name ];
+
+   if(    markers.positions[ name ][ n ].x ~= pos.x
+      or  markers.positions[ name ][ n ].y ~= pos.y
+      or  markers.positions[ name ][ n ].z ~= pos.z ) then
+
+      return formspec_info.."Please use the marker\nyou placed last\n"..
+                 "for accessing this menu.\nYou can find said marker at\n"..
+                 minetest.pos_to_string( markers.positions[ name ][ n ] )..'.]';
+   end
+
+   if( n < 4 ) then
+      return formspec_info.."Please place 4 markers\n - one in each corner\n of your area - first.]";
+   end
+
+
+   local coords_raw = meta:get_string( 'coords' );
+   local coords      = {};
+   if( coords_raw ~= nil and coords_raw ~= '' ) then
+      coords = minetest.deserialize( coords_raw );
+   end
+   
+
+   local opposite = n;
+   -- the last 4 markers placed ought to form the area
+   if( true or #coords ~= 2 ) then -- TODO
+  
+
+      for i=1,3 do
+
+         -- if both coordinates are diffrent, then this may be the opposite marker
+         if(   ( markers.positions[ name ][ n-i ].x ~=  
+                 markers.positions[ name ][ n   ].x )
+           and ( markers.positions[ name ][ n-i ].z ~=  
+                 markers.positions[ name ][ n   ].z )) then 
+
+             opposite = n-i;
+             coords = { markers.positions[ name ][ n   ],
+                        markers.positions[ name ][ n-i ] };
+         end
+      end
+
+      -- check if they fit
+      for i=1,3 do
+
+         if(not( ((n-i) == opposite )
+             or  ( markers.positions[ name ][ n-i ].x == coords[ 1 ].x
+               and markers.positions[ name ][ n-i ].z == coords[ 2 ].z )
+             or  ( markers.positions[ name ][ n-i ].x == coords[ 2 ].x
+               and markers.positions[ name ][ n-i ].z == coords[ 1 ].z ))) then
+
+            return formspec_info.."Error: The last 4 markers\nyou placed do not form\na rectangle.]";
+         end
+
+      end
+
+      -- save data     
+      meta:set_string( 'coords', minetest.serialize( coords ) );
+   end
+
+   -- the coordinates are set; we may present an input form now
+
+    -- has the area already been defined?
+    local area = markers.get_area_by_pos1_pos2( coords[1], coords[2] );
+
+
+    local size = (math.abs( coords[1].x - coords[2].x )+1) 
+               * (math.abs( coords[1].z - coords[2].z )+1);
+
+    -- check if area is too large
+    if( markers.MAX_SIZE < size ) then
+       return formspec_info.."Error: You can only protect\nareas of up to "..tostring( markers.MAX_SIZE ).."m^2.\n"..
+                             "Your marked area is "..tostring( size ).." m^2 large.]";
+    end
+
+    local formspec = 'size[10,7]'..
+               'label[0.5,1;The area you marked extends from]'..
+               'label[4.7,1;'..minetest.pos_to_string( coords[ 1 ] )..' to '..minetest.pos_to_string( coords[ 2 ] )..'.]'..
+               'label[4.7,1.5;It spans '..tostring( math.abs( coords[1].x - coords[2].x )+1 )..
+                               ' x '..tostring( math.abs( coords[1].z - coords[2].z )+1 )..
+                               ' = '..tostring( size )..' m^2.]';
+
+    -- display the error message (if there is any)
+    if( error_msg ~= nil ) then
+       formspec = formspec..
+                    'label[0.5,0.0;Error: ]'..
+                    'textarea[5.0,0;4,1.5;info;;'..error_msg..']';
+    end
+      
+    if( area and area['id'] ) then
+       formspec =   formspec..
+                    'label[0.5,2.0;This is area number ]'..
+                    'label[4.7,2.0;'..tostring( area['id'] )..'.]'..
+                    'label[0.5,2.5;It is owned by ]'..
+                    'label[4.7,2.5;'..tostring( area['owner'] )..'.]'..
+                    'label[0.5,3.0;The area is called ]'..
+                    'label[4.7,3.0;'..tostring( area['name'] )..'.]'..
+                    "button_exit[2,6.0;2,0.5;abort;OK]";
+    else
+       formspec =   formspec..
+                    'label[0.5,2.0;Buying this area will cost you ]'..
+                    'label[4.7,2.0;'..markers.calculate_area_price_text( coords[1], coords[2], name )..'.]'..
+
+                    'label[0.5,3.0;Your area ought to go..]'..
+                    'label[0.5,3.5;this many blocks up:]'..
+                    'field[5.0,4.0;1,0.5;add_height;;40]'..
+                    'label[6.0,3.5;(relative to this marker)]'..
+
+                    'label[0.5,4.0;and this many blocks down:]'..
+                    'field[5.0,4.5;1,0.5;add_depth;;10]'..
+                    'label[6.0,4.0;(relative to this marker)]'..
+
+                    'label[0.5,4.5;The area shall be named]'..
+                    'field[5.0,5.0;6,0.5;set_area_name;;please enter a name]'..
+     
+                    "button_exit[2,6.0;2,0.5;abort;Abort]"..
+                    -- code the position in the "Buy area" field
+                    "button_exit[6,6.0;2,0.5;"..minetest.pos_to_string(pos)..";Buy area]";
+    end
+
+   return formspec;
+end
+
+
+
+-- protect/buy an area
+markers.marker_on_receive_fields = function(pos, formname, fields, sender)
+
+   if( not( pos )) then
+      minetest.chat_send_player( name, 'Sorry, could not find the marker you where using to access this formspec.' );
+      return;
+   end
+
+
+   local meta  = minetest.env:get_meta( pos );
+
+   local name  = sender:get_player_name();
+
+   local coords_string = meta:get_string( 'coords' );
+   if( not( coords_string ) or coords_string == '' ) then
+      minetest.chat_send_player( name, 'Could not find marked area. Please dig and place your markers again!');
+      return;
+   end
+   local coords = minetest.deserialize( coords_string );
+
+
+   -- do not protect areas twice
+   local area = markers.get_area_by_pos1_pos2( coords[1], coords[2] );
+   if( area ) then
+
+      minetest.chat_send_player( name, 'This area is already protected.');
+      return;
+   end
+
+
+   -- check input
+   local add_height = tonumber( fields['add_height'] );
+   local add_depth  = tonumber( fields['add_depth']  );
+
+   local error_msg = '';
+   if(     not( add_height ) or add_height < 0 or add_height > markers.MAX_HEIGHT ) then
+      minetest.chat_send_player( name, 'Please enter a number between 0 and '..tostring( markers.MAX_HEIGHT )..
+		' in the field where the height of your area is requested. Your area will stretch that many blocks '..
+		'up into the sky from the position of this marker onward.');
+      error_msg = 'The height value\nhas to be larger than 0\nand smaller than '..tostring( markers.MAX_HEIGHT );
+     
+   elseif( not( add_depth  ) or add_depth  < 0 or add_depth  > markers.MAX_HEIGHT ) then
+      minetest.chat_send_player( name, 'Please enter a number between 0 and '..tostring( markers.MAX_HEIGHT )..
+		' in the field where the depth of your area is requested. Your area will stretch that many blocks '..
+		'into the ground from the position of this marker onward.');
+      error_msg = 'The depth value\nhas to be larger than 0\nand smaller than '..tostring( markers.MAX_HEIGHT );
+
+   elseif( add_height + add_depth > markers.MAX_HEIGHT ) then
+      minetest.chat_send_player( name,  'Sorry, your area exceeds the height limit. Height and depth added have to '..
+		'be smaller than '..tostring( markers.MAX_HEIGHT )..'.');
+      error_msg = 'height + depth has to\nbe smaller than '..tostring( markers.MAX_HEIGHT )..'.'
+
+   elseif( not( fields[ 'set_area_name' ] ) or fields['set_area_name'] == 'please enter a name' ) then
+      minetest.chat_send_player( name, 'Please provide a name for your area, i.e. \"'..
+		tostring( name )..'s first house\" The name ought to describe what you intend to build here.');
+      error_msg = 'Please provide a\nname for your area!';
+
+   else
+      error_msg = nil;
+   end
+ 
+
+   if( error_msg ~= nil ) then
+      minetest.show_formspec( name, "markers:mark", markers.get_marker_formspec(sender, pos, error_msg));
+      return;
+   end
+
+
+   -- those coords lack the height component
+   local pos1 = coords[1];
+   local pos2 = coords[2];
+   -- apply height values from the formspeck
+   pos1.y = pos.y + add_height;
+   pos2.y = pos.y - add_depth;
+
+   pos1, pos2 = areas:sortPos( pos1, pos2 );
+
+   --minetest.chat_send_player('singleplayer','INPUT: '..minetest.serialize( pos1  )..' pos2: '..minetest.serialize( pos2 ));
+   minetest.log("action", "[markers] /protect invoked, owner="..name..
+                                " areaname="..fields['set_area_name']..
+                                " startpos="..minetest.pos_to_string(pos1)..
+                                " endpos="  ..minetest.pos_to_string(pos2));
+
+   local canAdd, errMsg = areas:canPlayerAddArea(pos1, pos2, name)
+   if not canAdd then
+      minetest.chat_send_player(name, "You can't protect that area: "..errMsg)
+      return
+   end
+
+   local id = areas:add(name, fields['set_area_name'], pos1, pos2, nil)
+   areas:save()
+
+   minetest.chat_send_player(name, "Area protected. ID: "..id)
+
+   minetest.show_formspec( name, "markers:mark", markers.get_marker_formspec(sender, pos, nil));
+end
+
+
+
+-- formspec input needs to be handled diffrently
+markers.form_input_handler = function( player, formname, fields)
+
+   if( formname == "markers:mark" ) then
+
+
+      if( not(fields) or fields['abort']) then
+         return true;
+      end
+
+      --- decode the position of the marker (which is hidden in the Buy-buttons name
+      local pos = {};
+      for k, v in pairs( fields ) do
+         if( v == 'Buy area' ) then
+            pos = minetest.string_to_pos( k );
+         end
+      end
+      if( pos and pos.x and pos.y and pos.z ) then
+         markers.marker_on_receive_fields(pos, formname, fields, player);
+      end
+      return true;
+   end
+   
+   return false;
+
+end
+
+minetest.register_on_player_receive_fields( markers.form_input_handler)
+
+
+
+
+minetest.register_node("markers:mark", {
+	description = "Marker",
+	tiles = {"markers_mark.png"},
+	drawtype = "nodebox",
+	paramtype = "light",
+	paramtype2 = "facedir",
+	groups = {snappy=2,choppy=2,dig_immediate=3},
+	light_source = 1,
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -0.1, -0.5, -0.1, 0.1, 1.5, 0.1 },
+			},
+		},
+
+        after_place_node = function(pos, placer, itemstack)
+           markers.marker_placed( pos, placer, itemstack );
+        end,
+  
+        -- the node is digged immediately, so we may as well do all the work in can_dig (any wrong digs are not that critical)
+        can_dig = function(pos,player) 
+           return markers.marker_can_dig( pos, player );
+        end,
+
+        after_dig_node = function(pos, oldnode, oldmetadata, digger)
+           return markers.marker_after_dig_node( pos, oldnode, oldmetadata, digger );
+        end,
+
+	on_rightclick = function(pos, node, clicker)
+
+           minetest.show_formspec( clicker:get_player_name(),
+				   "markers:mark",
+				   markers.get_marker_formspec(clicker, pos, nil)
+			);
+	end,
+})
+
+
+minetest.register_craft({
+   output = "markers:mark 4",
+   recipe = { { "group:stick" },
+              { "default:apple" },
+              { "group:stick" },
+             } });
+

land_title_register.lua

@@ -0,0 +1,139 @@
+
+
+
+
+markers.get_area_info = function(pos)
+   local found = {}
+   for nr, area in pairs(areas.areas) do
+      if pos.x >= area.pos1.x and pos.x <= area.pos2.x and
+         pos.y >= area.pos1.y and pos.y <= area.pos2.y and
+         pos.z >= area.pos1.z and pos.z <= area.pos2.z then
+              area[ 'id' ] = nr;
+              table.insert( found, area )
+      end
+   end
+   return found;
+end
+
+
+
+markers.get_area_info_as_text = function(pos, name)
+
+   local text = 'Checking '..minetest.pos_to_string( pos )..'. Owned by: ';
+
+   local found_areas = markers.get_area_info( pos );
+--minetest.chat_send_player('singleplayer', 'Areas FOUND: '..minetest.serialize( found_areas ));
+
+   if( not( found_areas ) or #found_areas < 1 ) then
+      minetest.chat_send_player( name, text..'-nobody- (unprotected)');
+      return;
+   end
+
+   local parent = {};
+   for _, area in pairs( found_areas ) do
+      if( not( area[ 'parent' ] )) then 
+         parent = area;
+         minetest.chat_send_player(name, '  '..areas:toString( area['id']))
+      end
+   end
+
+   if( #found_areas > 1 ) then
+      minetest.chat_send_player(name, '  Sub-owners of entire area:');
+   
+      for _, area in pairs( found_areas ) do
+         if( area[ 'parent' ]==parent['nr'] ) then
+            if(  parent.pos1.x == area.pos1.x
+             and parent.pos1.y == area.pos1.y
+             and parent.pos1.z == area.pos1.z
+             and parent.pos2.x == area.pos2.x
+             and parent.pos2.y == area.pos2.y
+             and parent.pos2.z == area.pos2.z) then 
+
+               minetest.chat_send_player(name, '    '..areas:toString( area['id']))
+            end    
+         end
+      end
+   end
+
+
+   if( #found_areas > 1 ) then
+      minetest.chat_send_player(name, '  Sub-owners:');
+   
+      for _, area in pairs( found_areas ) do
+         if( area[ 'parent' ] ) then 
+            minetest.chat_send_player(name, '    '..areas:toString( area['id']))
+         end
+      end
+   end
+
+    minetest.chat_send_player(name, 'ALL owners:');
+   for _, area in pairs( found_areas ) do
+      minetest.chat_send_player(name, '    '..areas:toString( area['id']))
+   end
+end
+
+
+minetest.register_tool( "markers:land_title_register",
+{
+    description = "Land title register. Left-click with it to get information about the land owner or to protect your own ground.",
+    groups = {}, 
+    inventory_image = "default_book.png", -- TODO
+    wield_image = "",
+    wield_scale = {x=1,y=1,z=1},
+    stack_max = 1, -- there is no need to have more than one
+    liquids_pointable = true, -- ground with only water on can be owned as well
+    -- the tool_capabilities are completely irrelevant here - no need to dig
+    tool_capabilities = {
+        full_punch_interval = 1.0,
+        max_drop_level=0,
+        groupcaps={
+            fleshy={times={[2]=0.80, [3]=0.40}, maxwear=0.05, maxlevel=1},
+            snappy={times={[2]=0.80, [3]=0.40}, maxwear=0.05, maxlevel=1},
+            choppy={times={[3]=0.90}, maxwear=0.05, maxlevel=0}
+        }
+    },
+    node_placement_prediction = nil,
+
+    on_place = function(itemstack, placer, pointed_thing)
+
+       if( placer == nil or pointed_thing == nil) then
+          return itemstack; -- nothing consumed
+       end
+       local name = placer:get_player_name();
+
+       -- the position is what we're actually looking for
+       local pos  = minetest.get_pointed_thing_position( pointed_thing, 0 ); --under );
+       
+       if( not( pos ) or not( pos.x )) then
+          minetest.chat_send_player( name, "Position not found.");
+          return;
+       end
+
+       local found_areas = markers.get_area_info_as_text( pos, placer:get_player_name() );
+-- TODO
+--       inspector.search_node( pos.x, pos.y, pos.z, name );
+       return itemstack; -- nothing consumed, nothing changed
+    end,
+     
+
+    on_use = function(itemstack, placer, pointed_thing)
+
+       if( placer == nil or pointed_thing == nil) then
+          return itemstack; -- nothing consumed
+       end
+       local name = placer:get_player_name();
+
+       local pos  = minetest.get_pointed_thing_position( pointed_thing, under );
+       
+       if( not( pos ) or not( pos.x )) then
+          minetest.chat_send_player( name, "Position not found.");
+          return;
+       end
+-- TODO
+--       inspector.search_node( pos.x, pos.y, pos.z, name );
+       local found_areas = markers.get_area_info_as_text( pos, placer:get_player_name() );
+
+       return itemstack; -- nothing consumed, nothing changed
+    end,
+})
+

marker_stone.lua

@@ -0,0 +1,18 @@
+
+minetest.register_node("markers:stone", {
+	description = "Boundary marker for land administration",
+	tiles = {"markers_stone.png", "markers_stone.png", "markers_stone_side.png",
+                "markers_stone_side.png", "markers_stone_side.png", "markers_stone_side.png" },
+	paramtype2 = "facedir",
+	groups = {cracky=2},
+	legacy_facedir_simple = true,
+	is_ground_content = false,
+})
+
+
+minetest.register_craft({
+   output = "markers:stone",
+   recipe = { { "markers:mark" },
+              { "default:cobble" },
+             } });
+