Epic/mods/ingots/api.lua

--[[
   Ingots - allows the placemant of ingots in the world
   Copyright (C) 2018  Skamiz Kazzarch

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
]]--

-- takes an item name and a texture name and a boolean whether the ingots are big
function ingots.register_ingots(ingot_item, texture, is_big)
   --checks, whether the item name is a valid item (thanks 'puzzlecube')
   if not minetest.registered_items[ingot_item] then
      minetest.log("warning", ingot_item.." is not registered. Skipping ingot registration")
      return
   end

   -- de hardcoded modname, which allows the api to be properly used from within other mods (thanks 'argyle')
   local mod_name = minetest.get_current_modname()
   local mod_prefix = mod_name .. ":"

   local stack_size = 8
   local texture_prefix = "ingot_big_"
   --gets item name witout mod part, to be used in the deffinition of the new nodes
   local ingot_name = string.sub(ingot_item, string.find(ingot_item, ":", 1, true) +1, -1)

   --this way there is no need for a separate on_punch function for a stack of 1 ingot
   minetest.register_alias(mod_prefix .. ingot_name .."_0", "air")

   --gives the ingot_item the ability to be placed and increas already placed stacks of ingots
   minetest.override_item(ingot_item, {
      on_place = function (itemstack, placer, pointed_thing)
            local pos = minetest.get_pointed_thing_position(pointed_thing, true)
            if minetest.is_protected(pos, placer:get_player_name()) and not minetest.check_player_privs(placer, "protection_bypass") then
             return
          end
         if pointed_thing["type"] == "node" then
            local name = minetest.get_node(pointed_thing.under).name
            -- call on_rightclick function of pointed node if aplicable and not sneak
            -- might or might not break if item is placed by mod devices
            if minetest.registered_nodes[name].on_rightclick and
               not placer:get_player_control().sneak
            then
               minetest.registered_nodes[name].on_rightclick(pointed_thing.under,
                  minetest.get_node(pointed_thing.under),
                  placer,
                  itemstack)
            elseif string.find(name, mod_prefix .. ingot_name) then
               local count = string.gsub(name, "%D*", "")
               if stack_size > minetest.registered_nodes[minetest.get_node(pointed_thing.under).name]._ingot_count then
                  minetest.set_node(pointed_thing.under, {name = mod_prefix .. ingot_name .."_" .. count + 1, param2 = minetest.get_node(pointed_thing.under).param2})
                  if not (creative and creative.is_enabled_for and creative.is_enabled_for(placer:get_player_name())) then
                     itemstack:take_item()
                  end
               elseif minetest.get_node(pointed_thing.above).name == "air" then
                  minetest.set_node(pointed_thing.above, {name = mod_prefix .. ingot_name .."_1"})
                  if not (creative and creative.is_enabled_for and creative.is_enabled_for(placer:get_player_name())) then
                     itemstack:take_item()
                  end
               end

            elseif minetest.get_node(pointed_thing.above).name == "air" then
               minetest.set_node(pointed_thing.above, {name = mod_prefix .. ingot_name .."_1"})
               if not (creative and creative.is_enabled_for and creative.is_enabled_for(placer:get_player_name())) then
                  itemstack:take_item()
               end
            end

            return itemstack
         end
      end
   })

   --registers 'stack_size' number of nodes, each has one more ingot in it than the last
   for i = 1, stack_size do
      local box = {
               type = "fixed",
               fixed = {
                  --rectangular box which encompases all placed ingots
                  ingots.get_box(is_big, i),
               },
            }
      minetest.register_node(mod_prefix .. ingot_name .. "_" .. i,{
         _doc_items_create_entry = false,
         description = "ingots",
         drawtype = "mesh",
         tiles = {texture},
         mesh = texture_prefix .. i .. ".obj",
         selection_box = box,
         collision_box = box,
         paramtype = 'light',
         paramtype2 = "facedir",
         groups = {cracky = 3, level = 2, not_in_creative_inventory = 1},
         drop = ingot_item .. " " .. i,
         on_punch = function (pos, node, puncher, pointed_thing)
            if puncher then
               local wield = puncher:get_wielded_item()
               --checks, so that a stack can be taken appart only by hand or relevant ingot_item
               if wield:get_name() == ingot_item or
                  wield:get_count() == 0 then
                        if minetest.is_protected(pos, puncher:get_player_name()) and not minetest.check_player_privs(puncher, "protection_bypass") then
                         return
                      end
                  minetest.set_node(pos, {name = mod_prefix .. ingot_name .."_" .. i - 1, param2 = node.param2})
                  if not (creative and creative.is_enabled_for and creative.is_enabled_for(puncher:get_player_name())) then
                     local stack = ItemStack(ingot_item)
                     puncher:get_inventory():add_item("main", stack)
                  end
               end
            end
         end,
         _ingot_name = ingot_name,
         _ingot_count = i,
      })
   end
end

--returns an apropriate nodebox for a given number of ingots
function ingots.get_box(is_big, i)
   if is_big then return {-0.5, -0.5, -0.5, 0.5, (((i + 1 - ((i +1 )%2)) / 8) - 0.5), 0.5}
   else return {-0.5, -0.5, -0.5, 0.5, (((i - 1 - ((i-1)%8)) / 8) - 3) / 8, 0.5}
   end
end