EinsDreiDreiSieben/mods/atl_path/init.lua

--[[
    This program allow to create paths with shovel
    Copyright (C) 2024  Atlante and contributors

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
]]

local S = minetest.get_translator("atl_path")

minetest.register_node("atl_path:path_dirt", {
    description = S("Dirt Path"),
    drawtype = "nodebox",
    tiles = {
        "atl_dirt_path_top.png",
        "atl_dirt_path_top.png",
        "default_dirt.png^atl_dirt_path_side.png"
    },
    use_texture_alpha = "clip",
    is_ground_content = false,
    paramtype = "light",
    node_box = {
        type = "fixed",
        fixed = { -1 / 2, -1 / 2, -1 / 2, 1 / 2, 1 / 2 - 1 / 16, 1 / 2 },
    },
    drop = "default:dirt",
    groups = { no_silktouch = 1, crumbly = 3, not_in_creative_inventory = 1 },
    sounds = default.node_sound_dirt_defaults()
})

local function is_attached_bottom(pos)
    local node = minetest.get_node(pos)
    local def = minetest.registered_nodes[pos]
    local paramtype2 = def and def.paramtype2 or "none"
    local attach_group = minetest.get_item_group(node.name, "attached_node")

    if attach_group == 3 then
        return true
    elseif attach_group == 1 then
        if paramtype2 == "wallmounted" then
            return minetest.wallmounted_to_dir(node.param2).y == -1
        end
        return true
    elseif attach_group == 2
        and paramtype2 == "facedir" -- 4dir won't attach to bottom
        and minetest.facedir_to_dir(node.param2).y == -1 then
        return true
    end
    return false
end

-- For some reason MT engine does not expose this function
-- Found in builtin/game/faling.lua
local function drop_attached_node(pos)
	local n = minetest.get_node(pos)
	local drops = minetest.get_node_drops(n, "")
	local def = minetest.registered_items[n.name]
	if def and def.preserve_metadata then
		local oldmeta = minetest.get_meta(pos):to_table().fields
		-- Copy pos and node because the callback can modify them.
		local pos_copy = vector.copy(pos)
		local node_copy = {name=n.name, param1=n.param1, param2=n.param2}
		local drop_stacks = {}
		for k, v in pairs(drops) do
			drop_stacks[k] = ItemStack(v)
		end
		drops = drop_stacks
		def.preserve_metadata(pos_copy, node_copy, oldmeta, drops)
	end
	if def and def.sounds and def.sounds.fall then
		minetest.sound_play(def.sounds.fall, {pos = pos}, true)
	end
	minetest.remove_node(pos)
	for _, item in pairs(drops) do
		minetest.add_item({
			x = pos.x + math.random()/2 - 0.25,
			y = pos.y + math.random()/2 - 0.25,
			z = pos.z + math.random()/2 - 0.25,
		}, item)
	end
end

local function shovel_on_place(itemstack, user, pointed_thing)
    if pointed_thing.type ~= "node" then
        return itemstack
    end
    local pos = pointed_thing.under
    if vector.subtract(pointed_thing.above, pos).y ~= 1 then
        -- only allow from top
        return itemstack
    end

    local tool_def = minetest.registered_tools[itemstack:get_name()]
    local uses = 100
    if tool_def.tool_capabilities
        and tool_def.tool_capabilities.groupcaps
        and tool_def.tool_capabilities.groupcaps.crumbly then
        uses = tool_def.tool_capabilities.groupcaps.crumbly.uses or 100
    end
    local wear = minetest.get_tool_wear_after_use(uses)

    local node = minetest.get_node(pos)
    local node_def = minetest.registered_nodes[node.name]
    local name = user:get_player_name()

    if node_def and node_def.groups and node_def.groups.soil == 1 then
        if minetest.is_protected(pos, name) then
            minetest.record_protection_violation(pos, name)
            return itemstack
        end
        local pos_above = {x = pos.x, y = pos.y + 1, z = pos.z}
        local node_above = minetest.get_node(pos_above)
        if is_attached_bottom(pos_above) then
            if minetest.is_protected(pos_above, name) then
                minetest.record_protection_violation(pos_above, name)
                return itemstack
            end
            drop_attached_node(pos_above)
        elseif node_above.name ~= "air" then
            return itemstack
        end
        minetest.set_node(pos, {name = "atl_path:path_dirt"})
        if not minetest.is_creative_enabled(name) then
            itemstack:add_wear(wear)
        end
    end
    return itemstack
end

minetest.register_on_mods_loaded(function()
    for name, def in pairs(minetest.registered_tools) do
        if def.groups and def.groups.shovel == 1 then
            minetest.override_item(name, {
                on_place = shovel_on_place
            })
        end
    end
end)