Epic/mods/itemframes/init.lua

screwdriver = screwdriver or {}
local tmp = {}
local max_objs = tonumber(minetest.setting_get("max_objects_per_block")) or 49

-- item entity

minetest.register_entity("itemframes:item",{
   hp_max = 1,
   visual = "wielditem",
   visual_size = {x = 0.33, y = 0.33},
   collisionbox = {0, 0, 0, 0, 0, 0},
   physical = false,
   textures = {"air"},

   on_activate = function(self, staticdata)
      if not self then
         self.object:remove()
         return
      end
      if tmp.nodename ~= nil
      and tmp.texture ~= nil then
         self.nodename = tmp.nodename
         tmp.nodename = nil
         self.texture = tmp.texture
         tmp.texture = nil
         self.glow = tmp.glow
         tmp.glow = nil
      else
         if staticdata ~= nil
         and staticdata ~= "" then
            local data = staticdata:split(";")
            if data and data[1] and data[2] then
               self.nodename = data[1]
               self.texture = data[2]
               self.glow = data[3]
            end
         end
      end
      if self.texture ~= nil then
         self.object:set_properties({textures = {self.texture}})
      end
      if self.nodename == "itemframes:pedestal" then
         self.object:set_properties({automatic_rotate = 1})
      end
      if self.glow ~= nil then
         self.object:set_properties({glow = self.glow})
      end
   end,

   get_staticdata = function(self)
      if self.nodename ~= nil
      and self.texture ~= nil then
         return self.nodename .. ";" .. self.texture .. ";" .. (self.glow or "")
      end
      return ""
   end,
})

-- helper table

local facedir = {
   [0] = {x = 0, y = 0, z = 1},
   [1] = {x = 1, y = 0, z = 0},
   [2] = {x = 0, y = 0, z = -1},
   [3] = {x = -1, y = 0, z = 0}
}

-- remove entities

local remove_item = function(pos, nodename)
   local ypos = 0
   if nodename == "itemframes:pedestal" then
      ypos = 1
   end
   local objs = minetest.get_objects_inside_radius({
         x = pos.x, y = pos.y + ypos, z = pos.z}, 0.5)
   if objs then
      for _, obj in pairs(objs) do
         if obj and obj:get_luaentity()
         and obj:get_luaentity().name == "itemframes:item" then
            obj:remove()
         end
      end
   end
end

-- update entity

local update_item = function(pos, node)
   remove_item(pos, node.name)
   local meta = minetest.get_meta(pos)
   if not meta then return end
   local item = meta:get_string("item")
   if item ~= "" then
      if node.name == "itemframes:frame" then
         local posad = facedir[node.param2]
         if not posad then return end
         pos.x = pos.x + posad.x * 6.5 / 16
         pos.y = pos.y + posad.y * 6.5 / 16
         pos.z = pos.z + posad.z * 6.5 / 16
      elseif node.name == "itemframes:pedestal" then
         pos.y = pos.y + 12 / 16 + 0.33
      end
      tmp.nodename = node.name
      tmp.texture = ItemStack(item):get_name()
      local def = core.registered_nodes[item]
      tmp.glow = def and def.light_source
      local e = minetest.add_entity(pos,"itemframes:item")
      if node.name == "itemframes:frame" then
         --local yaw = math.pi * 2 - node.param2 * math.pi / 2
         local yaw = 6.28 - node.param2 * 1.57
         e:set_yaw(yaw)
      end
   end
end

-- remove entity and drop as item

local drop_item = function(pos, nodename, metadata)
   local meta = metadata or minetest.get_meta(pos)
   if not meta then return end
   local item = meta:get_string("item")
   meta:set_string("item", "")
   if item ~= "" then
      remove_item(pos, nodename)
      if nodename == "itemframes:pedestal" then
         pos.y = pos.y + 1
      end
      minetest.add_item(pos, item)
   end
end

-- pedestal node and recipe

minetest.register_node("itemframes:pedestal",{
   description = "Pedestal",
   drawtype = "nodebox",
   node_box = {
      type = "fixed", fixed = {
         {-7/16, -8/16, -7/16, 7/16, -7/16, 7/16}, -- bottom plate
         {-6/16, -7/16, -6/16, 6/16, -6/16, 6/16}, -- bottom plate (upper)
         {-0.25, -6/16, -0.25, 0.25, 11/16, 0.25}, -- pillar
         {-7/16, 11/16, -7/16, 7/16, 12/16, 7/16}, -- top plate
      }
   },
   selection_box = {
      type = "fixed",
      fixed = {-7/16, -0.5, -7/16, 7/16, 12/16, 7/16}
   },
   tiles = {"itemframes_pedestal.png"},
   paramtype = "light",
   groups = {cracky = 3},
   sounds = default.node_sound_defaults(),
   on_rotate = screwdriver.disallow,

   after_place_node = function(pos, placer, itemstack)
      local meta = minetest.get_meta(pos)
      meta:set_string("infotext","Pedestal (right-click to add or remove item)")
   end,

   on_rightclick = function(pos, node, clicker, itemstack)
      if not itemstack
      or minetest.is_protected(pos, clicker:get_player_name()) then
         return
      end
      local meta = minetest.get_meta(pos)
      if not meta then return end
      if meta:get_string("item") ~= "" then
         drop_item(pos, node.name, meta)
      else
         local s = itemstack:take_item()
         meta:set_string("item", s:to_string())
         update_item(pos, node)
         return itemstack
      end
   end,

   on_destruct = function(pos)
      drop_item(pos, "itemframes:pedestal")
   end,

   on_punch = function(pos, node, puncher)
      update_item(pos, node)
   end,

   on_blast = function(pos, intensity)
      drop_item(pos, "itemframes:pedestal")
      minetest.add_item(pos, {name = "itemframes:pedestal"})
      minetest.remove_node(pos)
   end
})

minetest.register_craft({
   output = "itemframes:pedestal",
   recipe = {
      {"default:stone", "default:stone", "default:stone"},
      {"", "default:stone", ""},
      {"default:stone", "default:stone", "default:stone"},
   }
})

-- automatically restore entities lost from frames/pedestals
-- due to /clearobjects or similar

minetest.register_abm({
   nodenames = {"itemframes:frame", "itemframes:pedestal"},
   interval = 25,
   chance = 1,
   catch_up = false,

   action = function(pos, node, active_object_count, active_object_count_wider)
      if active_object_count >= max_objs then
         return
      end
      local num
      if node.name == "itemframes:frame" then
         num = #minetest.get_objects_inside_radius(pos, 0.5)
      elseif node.name == "itemframes:pedestal" then
         pos.y = pos.y + 1
         num = #minetest.get_objects_inside_radius(pos, 0.5)
         pos.y = pos.y - 1
      end
      if num > 0 then
         return
      end
      update_item(pos, node)
   end
})