nodecore-cd2025/mods/nc_api_visinv/init.lua

-- LUALOCALS < ---------------------------------------------------------
local minetest, nodecore, pairs, vector
    = minetest, nodecore, pairs, vector
-- LUALOCALS > ---------------------------------------------------------

nodecore.amcoremod()

--[[
Helpers for visible inventory. Use "visinv" node group.
Sets up on_construct, after_destruct and an ABM to manage
the visual entities.
--]]

local modname = minetest.get_current_modname()

------------------------------------------------------------------------
-- VISIBLE STACK ENTITY

minetest.register_entity(modname .. ":stackent", {
		initial_properties = nodecore.stackentprops(),
		is_stack = true,
		itemcheck = function(self)
			local pos = self.object:get_pos()
			local stack = nodecore.stack_get(pos)
			if not stack or stack:is_empty() then return self.object:remove() end

			local rp = vector.round(pos)
			local props, scale, yaw = nodecore.stackentprops(stack,
				rp.x * 3 + rp.y * 5 + rp.z * 7)
			rp.y = rp.y + scale - 31/64

			local obj = self.object
			obj:set_properties(props)
			obj:set_yaw(yaw)
			obj:set_pos(rp)
		end,
		on_activate = function(self)
			self.cktime = 0.00001
		end,
		on_step = function(self, dtime)
			self.cktime = (self.cktime or 0) - dtime
			if self.cktime > 0 then return end
			self.cktime = 1
			return self:itemcheck()
		end
	})

function nodecore.visinv_update_ents(pos, node)
	node = node or minetest.get_node(pos)
	local def = minetest.registered_items[node.name] or {}
	local max = def.groups and def.groups.visinv and 1 or 0

	local found = {}
	for _, v in pairs(minetest.get_objects_inside_radius(pos, 0.5)) do
		if v and v.get_luaentity and v:get_luaentity()
		and v:get_luaentity().is_stack then
			found[#found + 1] = v
		end
	end

	if #found < max then
		minetest.add_entity(pos, modname .. ":stackent")
	else
		while #found > max do
			found[#found]:remove()
			found[#found] = nil
		end
	end

	return found
end

------------------------------------------------------------------------
-- NODE REGISTRATION HELPERS

function nodecore.visinv_on_construct(pos)
	local meta = minetest.get_meta(pos)
	local inv = meta:get_inventory()
	inv:set_size("solo", 1)
	nodecore.visinv_update_ents(pos)
end

function nodecore.visinv_after_destruct(pos)
	nodecore.visinv_update_ents(pos)
	nodecore.fallcheck(pos)
end

nodecore.register_on_register_item(function(_, def)
		if def.type ~= "node" then return end

		def.groups = def.groups or {}

		if def.groups.visinv then
			def.on_construct = def.on_construct or nodecore.visinv_on_construct
			def.after_destruct = def.after_destruct or nodecore.visinv_after_destruct
		end
	end)

nodecore.register_limited_abm({
		label = "VisInv Check",
		nodenames = {"group:visinv"},
		interval = 1,
		chance = 1,
		ignore_stasis = true,
		action = function(...) return nodecore.visinv_update_ents(...) end
	})

------------------------------------------------------------------------
-- DIG INVENTORY

local digpos
local old_node_dig = minetest.node_dig
minetest.node_dig = function(pos, ...)
	nodecore.stack_sounds(pos, "dug")
	local function helper(...)
		digpos = nil
		return ...
	end
	digpos = pos
	return helper(old_node_dig(pos, ...))
end
local old_get_node_drops = minetest.get_node_drops
minetest.get_node_drops = function(...)
	local drops = old_get_node_drops(...)
	if not digpos then return drops end
	drops = drops or {}
	local stack = nodecore.stack_get(digpos)
	if stack and not stack:is_empty() then
		drops[#drops + 1] = stack
	end
	return drops
end