hopper/nodes/hoppers.lua

local S = minetest.get_translator("hopper")
local FS = hopper.translator_escaped
local ALPHA_CLIP = minetest.features.use_texture_alpha_string_modes and "clip" or true

-- formspec
local function get_hopper_formspec(pos)
	local spos = hopper.get_string_pos(pos)
	local formspec =
		"size[8,9]"
		.. hopper.formspec_bg
		.. "label[3.5,-0.1;" .. FS("Hopper") .."]"
		.. "list[nodemeta:" .. spos .. ";main;2,0.4;4,4;]"
		.. hopper.get_eject_button_texts(pos, 6.5, 2)
		.. "list[current_player;main;0,4.85;8,1;]"
		.. "list[current_player;main;0,6.08;8,3;8]"
		.. "listring[nodemeta:" .. spos .. ";main]"
		.. "listring[current_player;main]"
	return formspec
end

-- unfortunately param2 overrides are needed for side hoppers even in the non-single-craftable-item case
-- because they are literally *side* hoppers - their spouts point to the side rather than to the front, so
-- the default item_place_node orientation code will not orient them pointing toward the selected surface.
local hopper_on_place = function(itemstack, placer, pointed_thing, node_name)
	local returned_stack, success, _

	if not (hopper.config.single_craftable_item or node_name == "hopper:hopper_side") then
		returned_stack, _ = minetest.item_place_node(itemstack, placer, pointed_thing)
		return returned_stack
	end

	local pointed_pos = pointed_thing.under
	local hopper_pos  = pointed_thing.above

	local param2
	local pointed_registered = hopper.get_registered(minetest.get_node(pointed_pos).name)
	if pointed_registered and pointed_registered.extra.set_hopper_param2 then
		param2 = pointed_registered.extra.set_hopper_param2(hopper_pos, pointed_pos)
	else
		local param2_by_offset = {
			[vector.new(-1, 0, 0):to_string()] = 0,
			[vector.new( 0, 0, 1):to_string()] = 1,
			[vector.new( 1, 0, 0):to_string()] = 2,
			[vector.new( 0, 0,-1):to_string()] = 3,
		}
		param2 = param2_by_offset[(pointed_pos - hopper_pos):to_string()]
	end

	if param2 then
		_, success = minetest.item_place_node(ItemStack("hopper:hopper_side"), placer, pointed_thing, param2)
	else
		if hopper.config.single_craftable_item then
			node_name = "hopper:hopper" -- For cases where single_craftable_item was set on an existing world and there are still side hoppers in player inventories
		end
		_, success = minetest.item_place_node(ItemStack(node_name), placer, pointed_thing)
	end

	if success then
		local meta = minetest.get_meta(hopper_pos)
		meta:set_string("placer", placer:get_player_name())
		if not minetest.settings:get_bool("creative_mode") then
			itemstack:take_item()
		end
	end
	return itemstack
end

-------------------------------------------------------------------------------------------
-- Hoppers

minetest.register_node("hopper:hopper", {
	drop = "hopper:hopper",
	description = S("Hopper"),
	_doc_items_longdesc = hopper.doc.hopper_long_desc,
    _doc_items_usagehelp = hopper.doc.hopper_usage,
	groups = {cracky = 3},
	sounds = hopper.metal_sounds,
	drawtype = "nodebox",
	paramtype = "light",
	paramtype2 = "facedir",
	tiles = {
		"hopper_top_" .. hopper.config.texture_resolution .. ".png",
		"hopper_top_" .. hopper.config.texture_resolution .. ".png",
		"hopper_front_" .. hopper.config.texture_resolution .. ".png"
	},
	use_texture_alpha = ALPHA_CLIP,
	node_box = {
		type = "fixed",
		fixed = {
			--funnel walls
			{-0.5, 0.0, 0.4, 0.5, 0.5, 0.5},
			{0.4, 0.0, -0.5, 0.5, 0.5, 0.5},
			{-0.5, 0.0, -0.5, -0.4, 0.5, 0.5},
			{-0.5, 0.0, -0.5, 0.5, 0.5, -0.4},
			--funnel base
			{-0.5, 0.0, -0.5, 0.5, 0.1, 0.5},
			--spout
			{-0.3, -0.3, -0.3, 0.3, 0.0, 0.3},
			{-0.15, -0.3, -0.15, 0.15, -0.7, 0.15},
		},
	},
	selection_box = {
		type = "fixed",
		fixed = {
			--funnel
			{-0.5, 0.0, -0.5, 0.5, 0.5, 0.5},
			--spout
			{-0.3, -0.3, -0.3, 0.3, 0.0, 0.3},
			{-0.15, -0.3, -0.15, 0.15, -0.7, 0.15},
		},
	},

	on_construct = function(pos)
		local inv = minetest.get_meta(pos):get_inventory()
		inv:set_size("main", 4*4)
	end,

	on_place = function(itemstack, placer, pointed_thing)
		return hopper_on_place(itemstack, placer, pointed_thing, "hopper:hopper")
	end,

	can_dig = function(pos, player)
		local inv = minetest.get_meta(pos):get_inventory()
		return inv:is_empty("main")
	end,

	on_rightclick = function(pos, node, clicker, itemstack)
		if minetest.is_protected(pos, clicker:get_player_name()) and not minetest.check_player_privs(clicker, "protection_bypass") then
			return
		end
		minetest.show_formspec(clicker:get_player_name(),
			"hopper_formspec:"..minetest.pos_to_string(pos), get_hopper_formspec(pos))
	end,

	on_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
		minetest.log("action", ("%s moves stuff in hopper at %s"):format(
			player:get_player_name(), minetest.pos_to_string(pos)))
	end,

	on_metadata_inventory_put = function(pos, listname, index, stack, player)
		hopper.log_inventory(("%s moves stuff to hopper at %s"):format(
			player:get_player_name(), minetest.pos_to_string(pos)))
	end,

	on_metadata_inventory_take = function(pos, listname, index, stack, player)
		hopper.log_inventory(("%s moves stuff from hopper at %s"):format(
			player:get_player_name(), minetest.pos_to_string(pos)))
	end,
})

local hopper_side_drop
local hopper_groups
if hopper.config.single_craftable_item then
	hopper_side_drop = "hopper:hopper"
	hopper_groups = {cracky=3, not_in_creative_inventory = 1}
else
	hopper_side_drop = "hopper:hopper_side"
	hopper_groups = {cracky=3}
end

minetest.register_node("hopper:hopper_side", {
	description = S("Side Hopper"),
	_doc_items_longdesc = hopper.doc.hopper_long_desc,
    _doc_items_usagehelp = hopper.doc.hopper_usage,
	drop = hopper_side_drop,
	groups = hopper_groups,
	sounds = hopper.metal_sounds,
	drawtype = "nodebox",
	paramtype = "light",
	paramtype2 = "facedir",
	tiles = {
		"hopper_top_" .. hopper.config.texture_resolution .. ".png",
		"hopper_bottom_" .. hopper.config.texture_resolution .. ".png",
		"hopper_back_" .. hopper.config.texture_resolution .. ".png",
		"hopper_side_" .. hopper.config.texture_resolution .. ".png",
		"hopper_back_" .. hopper.config.texture_resolution .. ".png",
		"hopper_back_" .. hopper.config.texture_resolution .. ".png"
	},
	use_texture_alpha = ALPHA_CLIP,
	node_box = {
		type = "fixed",
		fixed = {
			--funnel walls
			{-0.5, 0.0, 0.4, 0.5, 0.5, 0.5},
			{0.4, 0.0, -0.5, 0.5, 0.5, 0.5},
			{-0.5, 0.0, -0.5, -0.4, 0.5, 0.5},
			{-0.5, 0.0, -0.5, 0.5, 0.5, -0.4},
			--funnel base
			{-0.5, 0.0, -0.5, 0.5, 0.1, 0.5},
			--spout
			{-0.3, -0.3, -0.3, 0.3, 0.0, 0.3},
			{-0.7, -0.3, -0.15, 0.15, 0.0, 0.15},
		},
	},
	selection_box = {
		type = "fixed",
		fixed = {
			--funnel
			{-0.5, 0.0, -0.5, 0.5, 0.5, 0.5},
			--spout
			{-0.3, -0.3, -0.3, 0.3, 0.0, 0.3},
			{-0.7, -0.3, -0.15, 0.15, 0.0, 0.15},
		},
	},

	on_construct = function(pos)
		local inv = minetest.get_meta(pos):get_inventory()
		inv:set_size("main", 4*4)
	end,

	on_place = function(itemstack, placer, pointed_thing)
		return hopper_on_place(itemstack, placer, pointed_thing, "hopper:hopper_side")
	end,

	can_dig = function(pos,player)
		local inv = minetest.get_meta(pos):get_inventory()
		return inv:is_empty("main")
	end,

	on_rightclick = function(pos, node, clicker, itemstack)
		if minetest.is_protected(pos, clicker:get_player_name()) and not minetest.check_player_privs(clicker, "protection_bypass") then
			return
		end
		minetest.show_formspec(clicker:get_player_name(),
			"hopper_formspec:"..minetest.pos_to_string(pos), get_hopper_formspec(pos))
	end,

	on_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
		-- Only players move items. "action" is generally okay here.
		minetest.log("action", ("%s moves stuff in hopper at %s"):format(
			player:get_player_name(), minetest.pos_to_string(pos)))
	end,

	on_metadata_inventory_put = function(pos, listname, index, stack, player)
		hopper.log_inventory(("%s moves stuff to hopper at%s"):format(
			player:get_player_name(), minetest.pos_to_string(pos)))
	end,

	on_metadata_inventory_take = function(pos, listname, index, stack, player)
		hopper.log_inventory(("%s moves stuff from hopper at %s"):format(
			player:get_player_name(), minetest.pos_to_string(pos)))
	end,
})