add receiver stations

craft.lua

@@ -40,6 +40,15 @@ minetest.register_craft({
   }
 })
 
+minetest.register_craft({
+  output = "ham_radio:receiver",
+  recipe = {
+    {body, antenna, body},
+    {glass,'ham_radio:circuit', glass},
+    {body, body, body}
+  }
+})
+
 minetest.register_craft({
   output = "ham_radio:transmitter",
   recipe = {

init.lua

@@ -6,6 +6,7 @@ ham_radio = rawget(_G, "ham_radio") or {}
 ham_radio = {
   playerhuds = {},
   player_rds = {},
+  receiver_rds = {},
   is_receiver_wielded = {},
   transmitters = {},
 }
@@ -53,6 +54,7 @@ dofile(modpath.."/transmitter.lua")
 dofile(modpath.."/receiver.lua")
 dofile(modpath.."/beacon.lua")
 dofile(modpath.."/rds.lua")
+dofile(modpath.."/receiver_station.lua")
 dofile(modpath.."/hud.lua")
 
 -- globals

rds.lua

@@ -1,4 +1,4 @@
-function ham_radio.get_rds_messages(frequency)
+function ham_radio.get_rds_messages(frequency, is_receiver_station)
   local transmitters = ham_radio.find_transmitters(frequency)
   local rds_messages = {}
   for position, transmitter in pairs(transmitters) do
@@ -10,6 +10,15 @@ function ham_radio.get_rds_messages(frequency)
         ' ] ',
         transmitter.rds_message,
       }, "")
+      if is_receiver_station then
+        message = table.concat({
+          '[ ',
+          transmitter.operated_by,
+          ' ] ',
+          transmitter.rds_message
+        }, "")
+      end
+
       table.insert(rds_messages, message)
     end
   end

receiver_station.lua

@@ -0,0 +1,111 @@
+ham_radio.receiver_update_infotext = function(meta)
+  local rds_message = meta:get_string("rds_message")
+  local infotext = 'Radio Receiver'
+  if rds_message ~= "" then
+    infotext = rds_message
+  end
+  meta:set_string("infotext", infotext)
+end
+
+minetest.register_node("ham_radio:receiver", {
+  description = "Ham Radio Receiver",
+  tiles = {
+	  "ham_radio_receiver_top.png",
+	  "ham_radio_receiver_top.png",
+	  "ham_radio_receiver_side.png",
+	  "ham_radio_receiver_side.png",
+	  "ham_radio_receiver_side.png",
+	  "ham_radio_receiver_front.png"
+  },
+  groups = {cracky=2,oddly_breakable_by_hand=2},
+  sounds = default.node_sound_metal_defaults(),
+  paramtype2 = "facedir",
+  drawtype = "nodebox",
+  paramtype = "light",
+  node_box = {
+    type = "fixed",
+    fixed = {-0.5, -0.5, -0.5, 0.5, 0, 0.5},
+  },
+  light_source = 3,
+  after_place_node = function(pos, placer)
+    local meta = minetest.get_meta(pos);
+    local name = placer:get_player_name()
+    meta:set_string("formspec",
+      table.concat({
+        "size[7,4]",
+        "image[0,0;1,1;ham_radio_receiver_front.png]",
+        "field[0.25,2;7,1;frequency;Frequency;${frequency}]",
+        "tooltip[frequency;Integer number ",
+          ham_radio.settings.frequency.min,"-",
+          ham_radio.settings.frequency.max, "]",
+        "button_exit[2,3.5;3,1;;Done]"
+      },'')
+    )
+    meta:set_string("infotext", 'Radio Receiver')
+  end,
+  on_receive_fields = function(pos, formname, fields, sender)
+    if not minetest.is_player(sender) then
+      return
+    end
+
+    if (
+      fields.quit ~= "true"
+      or minetest.is_protected(pos, sender:get_player_name()) 
+      or not ham_radio.validate_frequency(fields.frequency)
+    ) then
+      return
+    end
+
+    local meta = minetest.get_meta(pos)
+    meta:set_string("frequency", fields.frequency)
+    ham_radio.receiver_update_infotext(meta)
+  end,
+  can_dig = function(pos,player)
+    local meta = minetest.get_meta(pos);
+    local inv = meta:get_inventory()
+    local name = player:get_player_name()
+    return inv:is_empty("main") and not minetest.is_protected(pos, name)
+  end,
+  -- digiline
+  digiline = {
+    receptor = {action = function() end},
+    effector = {
+      action = ham_radio.digiline_effector
+    },
+  },
+});
+
+minetest.register_abm(
+  {
+    label = "Listen Ham Radion Broadcast",
+    nodenames = {"ham_radio:receiver"},
+    interval = 10,
+    chance = 1,
+    catch_up = false,
+    action = function(pos, node)
+      local meta = minetest.get_meta(pos)
+      local frequency = meta:get_string("frequency")
+    
+      if frequency == "" then
+        return
+      end
+      
+      local poshash = minetest.pos_to_string(pos, 0)
+        
+      if ham_radio.receiver_rds[poshash] == nil then
+        ham_radio.receiver_rds[poshash] = ham_radio.get_rds_messages(frequency, true)
+      end
+      
+      local message = table.remove(ham_radio.receiver_rds[poshash])
+      if message ~= nil then
+        meta:set_string('rds_message', message)
+        ham_radio.receiver_update_infotext(meta)
+
+        -- when all RDS messages are shown, reload them again
+        if not next(ham_radio.receiver_rds[poshash]) then    
+          ham_radio.receiver_rds[poshash] = ham_radio.get_rds_messages(frequency, true)
+        end
+      end
+    end
+  }
+);