musttest_game/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 = 64
	local texture_prefix = "ingot_"
	-- 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)

	-- Some ingots do not have unique sub-names.
	-- For these ingots, use their whole name, replacing ':' with '_'.
	-- Ex: talinite:ingot and brass:ingot have the same sub-name, "ingot".
	if ingot_name == "ingot" then
		ingot_name = string.gsub(ingot_item, ":", "_")
	end

	if is_big then
		ingot_name = ingot_name .. "_big"
		stack_size = 8
		texture_prefix = "ingot_big_"
	end

	-- This is no longer used by the mod, but required for compatibility.
	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})

						itemstack:take_item()
					elseif minetest.get_node(pointed_thing.above).name == "air" then
						minetest.set_node(pointed_thing.above, {name = mod_prefix .. ingot_name .."_1"})

						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",
						param2 = math.random(0, 3),
					})

					itemstack:take_item()
				end

				return itemstack
			end
		end
	})

	-- Talinite ingots glow.
	local light_source = nil
	if ingot_item == "talinite:ingot" then
		light_source = 6
	end

	local function on_punch(pos, node_stale, puncher, pointed_thing)
		if not puncher then
			return
		end

		local wield = puncher:get_wielded_item()
		-- Checks that a stack can be taken apart by hand or relevant "ingot_item".
		if wield:get_name() == ingot_item or wield:get_count() == 0 then
			if minetest.test_protection(pos, puncher:get_player_name()) then
				return
			end

			-- Get actual node at this location. (Function call might be stale!)
			-- As a falling node, the falling code might (usually will) run first,
			-- which causes this function to misbehave if we don't check ....
			local node = minetest.get_node(pos)
			if node.name ~= node_stale.name then
				return
			end
			local ndef = minetest.registered_nodes[node.name]
			local count = ndef._ingot_count

			if count > 1 then
				minetest.set_node(pos, {
					name = mod_prefix .. ingot_name .."_" .. count - 1,
					param2 = node.param2,
				})
			else
				minetest.remove_node(pos)
				minetest.check_for_falling(pos)
			end

			local stack = ItemStack(ingot_item)
			puncher:get_inventory():add_item("main", stack)
		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,{
			description = "ingots",
			drawtype = "mesh",
			tiles = {texture},
			mesh = texture_prefix .. i .. ".obj",
			selection_box = box,
			collision_box = box,
			paramtype = 'light',
			paramtype2 = "facedir",
			light_source = light_source,

			-- Not quick to walk on top of ingot piles.
			movement_speed_multiplier = default.SLOW_SPEED,

			-- Horizontal rotation only!
			on_rotate = screwdriver.rotate_simple,

			groups = {
				cracky = 3,
				level = 2,
				not_in_creative_inventory = 1,
				falling_node = 1,
			},

			drop = ingot_item .. " " .. i,
			on_punch = on_punch,

			_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