minetest_game/mods/default/functions.lua

-- mods/default/functions.lua

--
-- Sounds
--

function default.node_sound_defaults(table)
	table = table or {}
	table.footstep = table.footstep or
			{name = "", gain = 1.0}
	table.dug = table.dug or
			{name = "default_dug_node", gain = 0.25}
	table.place = table.place or
			{name = "default_place_node_hard", gain = 1.0}
	return table
end

function default.node_sound_stone_defaults(table)
	table = table or {}
	table.footstep = table.footstep or
			{name = "default_hard_footstep", gain = 0.5}
	table.dug = table.dug or
			{name = "default_hard_footstep", gain = 1.0}
	default.node_sound_defaults(table)
	return table
end

function default.node_sound_dirt_defaults(table)
	table = table or {}
	table.footstep = table.footstep or
			{name = "default_dirt_footstep", gain = 1.0}
	table.dug = table.dug or
			{name = "default_dirt_footstep", gain = 1.5}
	table.place = table.place or
			{name = "default_place_node", gain = 1.0}
	default.node_sound_defaults(table)
	return table
end

function default.node_sound_sand_defaults(table)
	table = table or {}
	table.footstep = table.footstep or
			{name = "default_sand_footstep", gain = 0.12}
	table.dug = table.dug or
			{name = "default_sand_footstep", gain = 0.24}
	table.place = table.place or
			{name = "default_place_node", gain = 1.0}
	default.node_sound_defaults(table)
	return table
end

function default.node_sound_wood_defaults(table)
	table = table or {}
	table.footstep = table.footstep or
			{name = "default_wood_footstep", gain = 0.5}
	table.dug = table.dug or
			{name = "default_wood_footstep", gain = 1.0}
	default.node_sound_defaults(table)
	return table
end

function default.node_sound_leaves_defaults(table)
	table = table or {}
	table.footstep = table.footstep or
			{name = "default_grass_footstep", gain = 0.35}
	table.dug = table.dug or
			{name = "default_grass_footstep", gain = 0.7}
	table.dig = table.dig or
			{name = "default_dig_crumbly", gain = 0.4}
	table.place = table.place or
			{name = "default_place_node", gain = 1.0}
	default.node_sound_defaults(table)
	return table
end

function default.node_sound_glass_defaults(table)
	table = table or {}
	table.footstep = table.footstep or
			{name = "default_glass_footstep", gain = 0.5}
	table.dug = table.dug or
			{name = "default_break_glass", gain = 1.0}
	default.node_sound_defaults(table)
	return table
end


--
-- Lavacooling
--

default.cool_lava = function(pos, node)
	if node.name == "default:lava_source" then
		minetest.set_node(pos, {name = "default:obsidian"})
	else -- Lava flowing
		minetest.set_node(pos, {name = "default:stone"})
	end
	minetest.sound_play("default_cool_lava",
		{pos = pos, max_hear_distance = 16, gain = 0.25})
end

minetest.register_abm({
	nodenames = {"default:lava_source", "default:lava_flowing"},
	neighbors = {"group:water"},
	interval = 1,
	chance = 1,
	catch_up = false,
	action = function(...)
		default.cool_lava(...)
	end,
})


--
-- Papyrus and cactus growing
--

-- wrapping the functions in abm action is necessary to make overriding them possible

function default.grow_cactus(pos, node)
	if node.param2 >= 4 then
		return
	end
	pos.y = pos.y - 1
	if minetest.get_item_group(minetest.get_node(pos).name, "sand") == 0 then
		return
	end
	pos.y = pos.y + 1
	local height = 0
	while node.name == "default:cactus" and height < 4 do
		height = height + 1
		pos.y = pos.y + 1
		node = minetest.get_node(pos)
	end
	if height == 4 or node.name ~= "air" then
		return
	end
	minetest.set_node(pos, {name = "default:cactus"})
	return true
end

function default.grow_papyrus(pos, node)
	pos.y = pos.y - 1
	local name = minetest.get_node(pos).name
	if name ~= "default:dirt_with_grass" and name ~= "default:dirt" then
		return
	end
	if not minetest.find_node_near(pos, 3, {"group:water"}) then
		return
	end
	pos.y = pos.y + 1
	local height = 0
	while node.name == "default:papyrus" and height < 4 do
		height = height + 1
		pos.y = pos.y + 1
		node = minetest.get_node(pos)
	end
	if height == 4 or node.name ~= "air" then
		return
	end
	minetest.set_node(pos, {name = "default:papyrus"})
	return true
end

minetest.register_abm({
	nodenames = {"default:cactus"},
	neighbors = {"group:sand"},
	interval = 12,
	chance = 83,
	action = function(...)
		default.grow_cactus(...)
	end
})

minetest.register_abm({
	nodenames = {"default:papyrus"},
	neighbors = {"default:dirt", "default:dirt_with_grass"},
	interval = 14,
	chance = 71,
	action = function(...)
		default.grow_papyrus(...)
	end
})


--
-- dig upwards
--

function default.dig_up(pos, node, digger)
	if digger == nil then return end
	local np = {x = pos.x, y = pos.y + 1, z = pos.z}
	local nn = minetest.get_node(np)
	if nn.name == node.name then
		minetest.node_dig(np, nn, digger)
	end
end


--
-- Fence registration helper
--
function default.register_fence(name, def)
	minetest.register_craft({
		output = name .. " 4",
		recipe = {
			{ def.material, 'group:stick', def.material },
			{ def.material, 'group:stick', def.material },
		}
	})

	local fence_texture = "default_fence_overlay.png^" .. def.texture ..
			"^default_fence_overlay.png^[makealpha:255,126,126"
	-- Allow almost everything to be overridden
	local default_fields = {
		paramtype = "light",
		drawtype = "nodebox",
		node_box = {
			type = "connected",
			fixed = {{-1/8, -1/2, -1/8, 1/8, 1/2, 1/8}},
			-- connect_top =
			-- connect_bottom =
			connect_front = {{-1/16,3/16,-1/2,1/16,5/16,-1/8},
				{-1/16,-5/16,-1/2,1/16,-3/16,-1/8}},
			connect_left = {{-1/2,3/16,-1/16,-1/8,5/16,1/16},
				{-1/2,-5/16,-1/16,-1/8,-3/16,1/16}},
			connect_back = {{-1/16,3/16,1/8,1/16,5/16,1/2},
				{-1/16,-5/16,1/8,1/16,-3/16,1/2}},
			connect_right = {{1/8,3/16,-1/16,1/2,5/16,1/16},
				{1/8,-5/16,-1/16,1/2,-3/16,1/16}},
		},
		connects_to = {"group:fence", "group:wood", "group:tree"},
		inventory_image = fence_texture,
		wield_image = fence_texture,
		tiles = {def.texture},
		sunlight_propagates = true,
		is_ground_content = false,
		groups = {},
	}
	for k, v in pairs(default_fields) do
		if not def[k] then
			def[k] = v
		end
	end

	-- Always add to the fence group, even if no group provided
	def.groups.fence = 1

	def.texture = nil
	def.material = nil

	minetest.register_node(name, def)
end


--
-- Leafdecay
--

default.leafdecay_trunk_cache = {}
default.leafdecay_enable_cache = true
-- Spread the load of finding trunks
default.leafdecay_trunk_find_allow_accumulator = 0

minetest.register_globalstep(function(dtime)
	local finds_per_second = 5000
	default.leafdecay_trunk_find_allow_accumulator =
			math.floor(dtime * finds_per_second)
end)

default.after_place_leaves = function(pos, placer, itemstack, pointed_thing)
	if placer and not placer:get_player_control().sneak then
		local node = minetest.get_node(pos)
		node.param2 = 1
		minetest.set_node(pos, node)
	end
end

minetest.register_abm({
	nodenames = {"group:leafdecay"},
	neighbors = {"air", "group:liquid"},
	-- A low interval and a high inverse chance spreads the load
	interval = 2,
	chance = 5,

	action = function(p0, node, _, _)
		--print("leafdecay ABM at "..p0.x..", "..p0.y..", "..p0.z..")")
		local do_preserve = false
		local d = minetest.registered_nodes[node.name].groups.leafdecay
		if not d or d == 0 then
			--print("not groups.leafdecay")
			return
		end
		local n0 = minetest.get_node(p0)
		if n0.param2 ~= 0 then
			--print("param2 ~= 0")
			return
		end
		local p0_hash = nil
		if default.leafdecay_enable_cache then
			p0_hash = minetest.hash_node_position(p0)
			local trunkp = default.leafdecay_trunk_cache[p0_hash]
			if trunkp then
				local n = minetest.get_node(trunkp)
				local reg = minetest.registered_nodes[n.name]
				-- Assume ignore is a trunk, to make the thing
				-- work at the border of the active area
				if n.name == "ignore" or (reg and reg.groups.tree and
						reg.groups.tree ~= 0) then
					--print("cached trunk still exists")
					return
				end
				--print("cached trunk is invalid")
				-- Cache is invalid
				table.remove(default.leafdecay_trunk_cache, p0_hash)
			end
		end
		if default.leafdecay_trunk_find_allow_accumulator <= 0 then
			return
		end
		default.leafdecay_trunk_find_allow_accumulator =
				default.leafdecay_trunk_find_allow_accumulator - 1
		-- Assume ignore is a trunk, to make the thing
		-- work at the border of the active area
		local p1 = minetest.find_node_near(p0, d, {"ignore", "group:tree"})
		if p1 then
			do_preserve = true
			if default.leafdecay_enable_cache then
				--print("caching trunk")
				-- Cache the trunk
				default.leafdecay_trunk_cache[p0_hash] = p1
			end
		end
		if not do_preserve then
			-- Drop stuff other than the node itself
			local itemstacks = minetest.get_node_drops(n0.name)
			for _, itemname in ipairs(itemstacks) do
				if minetest.get_item_group(n0.name, "leafdecay_drop") ~= 0 or
						itemname ~= n0.name then
					local p_drop = {
						x = p0.x - 0.5 + math.random(),
						y = p0.y - 0.5 + math.random(),
						z = p0.z - 0.5 + math.random(),
					}
					minetest.add_item(p_drop, itemname)
				end
			end
			-- Remove node
			minetest.remove_node(p0)
			nodeupdate(p0)
		end
	end
})


--
-- Convert dirt to something that fits the environment
--

minetest.register_abm({
	nodenames = {"default:dirt"},
	neighbors = {
		"default:dirt_with_grass",
		"default:dirt_with_dry_grass",
		"default:dirt_with_snow",
		"group:grass",
		"group:dry_grass",
		"default:snow",
	},
	interval = 6,
	chance = 67,
	catch_up = false,
	action = function(pos, node)
		-- Most likely case, half the time it's too dark for this.
		local above = {x = pos.x, y = pos.y + 1, z = pos.z}
		if (minetest.get_node_light(above) or 0) < 13 then
			return
		end

		-- Look for likely neighbors.
		local p2 = minetest.find_node_near(pos, 1, {"default:dirt_with_grass",
				"default:dirt_with_dry_grass", "default:dirt_with_snow"})
		if p2 then
			-- But the node needs to be under air in this case.
			local n2 = minetest.get_node(above)
			if n2 and n2.name == "air" then
				local n3 = minetest.get_node(p2)
				minetest.set_node(pos, {name = n3.name})
				return
			end
		end

		-- Anything on top?
		local n2 = minetest.get_node(above)
		if not n2 then
			return
		end

		local name = n2.name
		-- Snow check is cheapest, so comes first.
		if name == "default:snow" then
			minetest.set_node(pos, {name = "default:dirt_with_snow"})
		-- Most likely case first.
		elseif minetest.get_item_group(name, "grass") ~= 0 then
			minetest.set_node(pos, {name = "default:dirt_with_grass"})
		elseif minetest.get_item_group(name, "dry_grass") ~= 0 then
			minetest.set_node(pos, {name = "default:dirt_with_dry_grass"})
		end
	end
})

--
-- Grass and dry grass removed in darkness
--

minetest.register_abm({
	nodenames = {
		"default:dirt_with_grass",
		"default:dirt_with_dry_grass",
		"default:dirt_with_snow",
	},
	interval = 8,
	chance = 50,
	catch_up = false,
	action = function(pos, node)
		local above = {x = pos.x, y = pos.y + 1, z = pos.z}
		local name = minetest.get_node(above).name
		local nodedef = minetest.registered_nodes[name]
		if name ~= "ignore" and nodedef and not ((nodedef.sunlight_propagates or
				nodedef.paramtype == "light") and
				nodedef.liquidtype == "none") then
			minetest.set_node(pos, {name = "default:dirt"})
		end
	end
})


--
-- Moss growth on cobble near water
--

minetest.register_abm({
	nodenames = {"default:cobble"},
	neighbors = {"group:water"},
	interval = 16,
	chance = 200,
	catch_up = false,
	action = function(pos, node)
		minetest.set_node(pos, {name = "default:mossycobble"})
	end
})