Added kelp API and additional refactorings.

WIP: register nodetimers for kelp

mods/ITEMS/mcl_ocean/kelp.lua

@@ -1,94 +1,163 @@
-local S = minetest.get_translator("mcl_ocean")
-local mod_doc = minetest.get_modpath("doc") ~= nil
 -- NOTE: whenever it becomes possible to fully implement kelp without the
 -- plantlike_rooted limitation, please adapt the code accordingly.
 -- TODO: In MC, you can't actually destroy kelp by bucket'ing water in the middle.
 -- However, because of the plantlike_rooted hack, we'll just allow it for now.
 
--- List of supported surfaces for seagrass and kelp.
+local S = minetest.get_translator("mcl_ocean")
-local surfaces = {
+local mod_doc = minetest.get_modpath("doc") ~= nil
-	{ "dirt", "mcl_core:dirt" },
+
-	{ "sand", "mcl_core:sand", 1 },
+--------------------------------------------------------------------------------
-	{ "redsand", "mcl_core:redsand", 1 },
+-- local-ify runtime functions
-	{ "gravel", "mcl_core:gravel", 1 },
+--------------------------------------------------------------------------------
-}
+-- objects
+local registered_items = minetest.registered_items
+local registered_nodes = minetest.registered_nodes
+
+-- functions
+local mt_get_item_group = minetest.get_item_group
+local mt_get_node = minetest.get_node
+local mt_set_node = minetest.set_node
+local mt_add_item = minetest.add_item
+local mt_sound_play = minetest.sound_play
+local mt_is_creative_enabled = minetest.is_creative_enabled
+local mt_is_protected = minetest.is_protected
+local mt_hash_node_position = minetest.hash_node_position
+local mt_get_node_timer = minetest.get_node_timer
+
+-- DEBUG: functions
+local chatlog = minetest.chat_send_all
+
+--------------------------------------------------------------------------------
+-- Kelp API
+--------------------------------------------------------------------------------
+
+kelp = {}
 
 -- Is this water?
+-- Returns the liquidtype, if indeed water.
 local function is_submerged(node, nodedef)
-	if minetest.get_item_group(node.name, "water") ~= 0 then
+	if mt_get_item_group(node.name, "water") ~= 0 then
 		return nodedef.liquidtype -- Expected only "source" and "flowing" from water liquids
 	end
 	return false
 end
+kelp.is_submerged = is_submerged
+
 
 -- Is the water downward flowing?
 -- (kelp can grow/be placed inside downward flowing water)
 local function is_downward_flowing(pos, node, nodedef, is_above)
-
+	local result = (math.floor(node.param2 / 8) % 2) == 1
-	result = (math.floor(node.param2 / 8) % 2) == 1
 	if not (result or is_above) then
-		-- If not, also check node above
+		-- If not, also check node above.
 		-- (this is needed due a weird quirk in the definition of "downwards flowing"
 		-- liquids in Minetest)
-		local node_above = minetest.get_node({x=pos.x,y=pos.y+1,z=pos.z})
+		local node_above = mt_get_node({x=pos.x,y=pos.y+1,z=pos.z})
-		local nodedef_above = minetest.registered_nodes[node_above.name]
+		local nodedef_above = registered_nodes[node_above.name]
 		result = is_submerged(node_above, nodedef_above)
 			or is_downward_flowing(pos, node_above, nodedef_above, true)
 	end
 	return result
 end
+kelp.is_downward_flowing = is_downward_flowing
+
 
 -- Converts param2 to kelp height.
-local function get_kelp_height(param2)
+local function get_height(param2)
 	return math.floor(param2 / 16)
 end
+kelp.get_height = get_height
+
 
 -- Obtain pos and node of the top of kelp.
-local function get_kelp_top(pos, node)
+local function get_tip(pos, node)
 	local size = math.ceil(node.param2 / 16)
 	local pos_top = table.copy(pos)
 	pos_top.y = pos_top.y + size
-	return pos_top, minetest.get_node(pos_top)
+	return pos_top, mt_get_node(pos_top)
 end
+kelp.get_tip = get_tip
+
 
 -- Obtain position of the first kelp unsubmerged.
-local function get_kelp_unsubmerged(pos, node)
+local function find_unsubmerged(pos, node)
 	local x,y,z = pos.x, pos.y, pos.z
-	local height = get_kelp_height(node.param2)
+	local height = get_height(node.param2)
 	for i=1,height do
 		local walk_pos = {x=x, y=y + i, z=z}
-		if minetest.get_item_group(minetest.get_node(walk_pos).name, "water") == 0 then
+		if mt_get_item_group(mt_get_node(walk_pos).name, "water") == 0 then
 			return walk_pos
 		end
 	end
 	return nil
 end
+kelp.find_unsubmerged = find_unsubmerged
 
--- Obtain next param2 if grown
-local function grow_param2_step(param2)
-	-- TODO: allow kelp to grow bypass this limit according to MC rules.
-	-- https://minecraft.gamepedia.com/Kelp
 
+-- Obtain next param2.
+local function next_param2(param2)
 	local old_param2 = param2
 	param2 = param2+16 - param2 % 16
-	if param2 > 240 then
-		param2 = 240
-	end
 	return param2, param2 ~= old_param2
 end
+kelp.next_param2 = next_param2
 
-local function kelp_place(pos, node, pos_top, def_top, is_downward_flowing)
-	-- Liquid source: Grow normally
-	minetest.set_node(pos, node)
 
-	-- Flowing liquid: Grow 1 step, but also turn the top node into a liquid source
+-- Grow next kelp.
+local function next_grow(pos, node, pos_top, def_top, is_downward_flowing)
+	-- Liquid source: Grow normally.
+	mt_set_node(pos, node)
+
+	-- Flowing liquid: Grow 1 step, but also turn the top node into a liquid source.
 	if is_downward_flowing then
 		local alt_liq = def_top.liquid_alternative_source
 		if alt_liq then
-			minetest.set_node(pos_top, {name=alt_liq})
+			mt_set_node(pos_top, {name=alt_liq})
 		end
 	end
 end
+kelp.next_grow = next_grow
+
+
+-- Drops the items for detached kelps.
+local function detach_drop(pos, height)
+	local x,y,z = pos.x,pos.y,pos.z
+	for i=1,height do
+		mt_add_item({x=x, y=y+i, z=z}, "mcl_ocean:kelp")
+	end
+end
+kelp.detach_drop = detach_drop
+
+
+-- Detach the kelp at dig_pos, and drop their items.
+-- Synonyous to digging the kelp
+local function detach_dig(dig_pos, pos, node, is_drop)
+	local param2 = node.param2
+	-- pos.y points to the surface, offset needed to point to the first kelp.
+	local new_height = dig_pos.y - (pos.y+1)
+
+	-- Digs the entire kelp: invoke after_dig_node to mt_set_node.
+	if new_height <= 0 then
+		if is_drop then
+			detach_drop(dig_pos, get_height(param2))
+		end
+		mt_set_node(pos, {
+			name=registered_nodes[node.name].node_dig_prediction,
+			param=node.param, param2=0 })
+
+	-- Digs the kelp beginning at a height
+	else
+		if is_drop then
+			detach_drop(dig_pos, get_height(param2) - new_height)
+		end
+		mt_set_node(pos, {name=node.name, param=node.param, param2=16*new_height})
+	end
+end
+kelp.detach_dig = detach_dig
+
+--------------------------------------------------------------------------------
+-- Kelp callback functions
+--------------------------------------------------------------------------------
 
 local function kelp_on_place(itemstack, placer, pointed_thing)
 	if pointed_thing.type ~= "node" or not placer then
@@ -98,17 +167,17 @@ local function kelp_on_place(itemstack, placer, pointed_thing)
 	local player_name = placer:get_player_name()
 	local pos_under = pointed_thing.under
 	local pos_above = pointed_thing.above
-	local node_under = minetest.get_node(pos_under)
+	local node_under = mt_get_node(pos_under)
 	local nu_name = node_under.name
-	local def_under = minetest.registered_nodes[nu_name]
+	local def_under = registered_nodes[nu_name]
 
 	if def_under and def_under.on_rightclick and not placer:get_player_control().sneak then
 		return def_under.on_rightclick(pos_under, node_under,
 				placer, itemstack, pointed_thing) or itemstack
 	end
 
-	if minetest.is_protected(pos_under, player_name) or
+	if mt_is_protected(pos_under, player_name) or
-			minetest.is_protected(pos_above, player_name) then
+			mt_is_protected(pos_above, player_name) then
 		minetest.log("action", player_name
 			.. " tried to place " .. itemstack:get_name()
 			.. " at protected position "
@@ -122,23 +191,24 @@ local function kelp_on_place(itemstack, placer, pointed_thing)
 	local pos_top, node_top, def_top
 
 	-- When placed on kelp.
-	if minetest.get_item_group(nu_name, "kelp") == 1 then
+	if mt_get_item_group(nu_name, "kelp") == 1 then
-		node_under.param2, new_kelp = grow_param2_step(node_under.param2)
+		node_under.param2, new_kelp = next_param2(node_under.param2)
 		-- Kelp must not reach the height limit.
 		-- Kelp must also be placed on top of kelp to add kelp.
 		if not new_kelp or pos_under.y >= pos_above.y then
 			return itemstack
 		end
-		pos_top, node_top = get_kelp_top(pos_under, node_under)
+		pos_top, node_top = get_tip(pos_under, node_under)
-		def_top = minetest.registered_nodes[node_top.name]
+		def_top = registered_nodes[node_top.name]
 
 	-- When placed on surface.
 	else
+		local surfaces = kelp.surfaces or surfaces
 		for _,surface in pairs(surfaces) do
 			-- Surface must support kelp
-			if nu_name == surface[2] then
+			if nu_name == surface.nodename then
-				node_under.name = "mcl_ocean:kelp_" ..surface[1]
+				node_under.name = "mcl_ocean:kelp_" ..surface.name
-				node_under.param2 = minetest.registered_items[nu_name].place_param2 or 16
+				node_under.param2 = registered_items[nu_name].place_param2 or 16
 				new_kelp = true
 				break
 			end
@@ -150,8 +220,8 @@ local function kelp_on_place(itemstack, placer, pointed_thing)
 		end
 
 		pos_top = pos_above
-		node_top = minetest.get_node(pos_above)
+		node_top = mt_get_node(pos_above)
-		def_top = minetest.registered_nodes[node_top.name]
+		def_top = registered_nodes[node_top.name]
 	end
 
 	-- New kelp must also be submerged in water.
@@ -161,49 +231,194 @@ local function kelp_on_place(itemstack, placer, pointed_thing)
 	end
 
 	-- Play sound, place surface/kelp and take away an item
-	local def_node = minetest.registered_items[nu_name]
+	local def_node = registered_items[nu_name]
 	if def_node.sounds then
-		minetest.sound_play(def_node.sounds.place, { gain = 0.5, pos = pos_under }, true)
+		mt_sound_play(def_node.sounds.place, { gain = 0.5, pos = pos_under }, true)
 	end
-	kelp_place(pos_under, node_under, pos_top, def_top, downward_flowing)
+	next_grow(pos_under, node_under, pos_top, def_top, downward_flowing)
-	if not minetest.is_creative_enabled(player_name) then
+	if not mt_is_creative_enabled(player_name) then
 		itemstack:take_item()
 	end
 
 	return itemstack
 end
+kelp.kelp_on_place = kelp_on_place
 
--- From kelp at pos, drop kelp until reaching its height.
+
-local function kelp_drop(pos, height)
+local function surface_on_dig(pos, node, digger)
-	local x,y,z = pos.x,pos.y,pos.z
+	-- TODO: poll on whether if players like dropping kelp in creative
-	for i=1,height do
+	-- detach_dig(pos, pos, node,
-		minetest.add_item({x=x, y=y+i, z=z}, "mcl_ocean:kelp")
+	-- 	not (digger and mt_is_creative_enabled(digger:get_player_name())))
+	detach_dig(pos, pos, node, true)
 end
+kelp.surface_on_dig = surface_on_dig
+
+
+local function surface_after_dig_node(pos, node)
+	return mt_set_node(pos, {name=registred_nodes[node.name].node_dig_prediction})
+end
+kelp.surface_after_dig_node = surface_after_dig_node
+
+
+local function grow_kelp(pos, node)
+	local grow
+	-- Grow kelp by 1 node length if it would grow inside water
+	node.param2, grow = next_param2(node.param2)
+	local pos_top, node_top = get_tip(pos, node)
+	local def_top = registered_nodes[node_top.name]
+	if grow and is_submerged(node_top, def_top) then
+		next_grow(pos, node, pos_top, def_top,
+			is_downward_flowing(pos_top, node_top, def_top))
+	end
+end
+kelp.grow_kelp = grow_kelp
+
+
+local kelp_timers_idx = {}
+local kelp_timers = {}
+local function surface_register_nodetimer(pos, node)
+	local pos_hash = mt_hash_node_position(pos)
+	if kelp_timers_idx[pos_hash] then
+		return
+	end
+	local timer = mt_get_node_timer(pos)
+	table.insert(kelp_timers, timer)
+	kelp_timers_idx[pos_hash] = #kelp_timers
+	chatlog("added a timer. Currently " ..tostring(#kelp_timers) .." timers")
+end
+kelp.surface_register_nodetiemr = surface_register_nodetimer
+
+--------------------------------------------------------------------------------
+-- Kelp registration API
+--------------------------------------------------------------------------------
+
+-- List of supported surfaces for seagrass and kelp.
+local surfaces = {
+	{ name="dirt",    nodename="mcl_core:dirt",    },
+	{ name="sand",    nodename="mcl_core:sand",    },
+	{ name="redsand", nodename="mcl_core:redsand", },
+	{ name="gravel",  nodename="mcl_core:gravel",  },
+}
+kelp.surfaces = surfaces
+local registered_surfaces = {}
+kelp.registered_surfaces = registered_surfaces
+
+-- Commented keys are the ones obtained using register_kelp_surface.
+-- If you define your own keys, that keys will be used instead.
+local surface_deftemplate = {
+	drawtype = "plantlike_rooted",
+	paramtype = "light",
+	paramtype2 = "leveled",
+	place_param2 = 16,
+	--tiles = def.tiles,
+	special_tiles = {
+		{
+		image = "mcl_ocean_kelp_plant.png",
+		animation = {type="vertical_frames", aspect_w=16, aspect_h=16, length=2.0},
+		tileable_vertical = true,
+		}
+	},
+	--inventory_image = "("..def.tiles[1]..")^mcl_ocean_kelp_item.png",
+	wield_image = "mcl_ocean_kelp_item.png",
+	selection_box = {
+		type = "fixed",
+		fixed = {
+			{ -0.5, -0.5, -0.5, 0.5, 0.5, 0.5 },
+			{ -0.5, 0.5, -0.5, 0.5, 1.5, 0.5 },
+		},
+	},
+	-- groups.falling_node = is_falling,
+	groups = { dig_immediate = 3, deco_block = 1, plant = 1, kelp = 1, },
+	--sounds = sounds,
+	--node_dig_prediction = nodename,
+	after_dig_node = surface_after_dig_node,
+	on_dig = surface_on_dig,
+	drop = "", -- drops are handled in on_dig
+	--_mcl_falling_node_alternative = is_falling and nodename or nil,
+	_mcl_hardness = 0,
+	_mcl_blast_resistance = 0,
+}
+kelp.surface_deftemplate = surface_deftemplate
+
+-- Commented keys are the ones obtained using register_kelp_surface.
+local surface_docs = {
+	-- entry_id_orig = nodename,
+	_doc_items_entry_name = S("Kelp"),
+	_doc_items_longdesc = S("Kelp grows inside water on top of dirt, sand or gravel."),
+	--_doc_items_create_entry = doc_create,
+	_doc_items_image = "mcl_ocean_kelp_item.png",
+}
+kelp.surface_docs = surface_docs
+
+--[==[--
+register_kelp_surface(surface[, surface_deftemplate[, surface_docs]])
+
+surface: table with the specifications below. See also kelp.surface.
+	{
+		name="dirt",
+		The name of the surface. This will appended to the surface's nodedef name
+
+		nodename="mcl_core:dirt"
+		The nodename of the surface kelp can be planted on.
+	}
+
+surface_deftemplate: modifiable nodedef template. See also kelp.surface_deftempate.
+DO NOT RE-USE THE SAME DEFTEMPLATE. create copies.
+
+surface_docs: table with keys related to docs. See also kelp.surface_docs.
+--]==]--
+local leaf_sounds = mcl_sounds.node_sound_leaves_defaults()
+local function register_kelp_surface(surface, surface_deftemplate, surface_docs)
+	local name = surface.name
+	local nodename = surface.nodename
+	local def = registered_nodes[nodename]
+	local def_tiles = def.tiles
+
+	local surfacename = "mcl_ocean:kelp_"..name
+	local surface_deftemplate = surface_deftemplate or kelp.surface_deftemplate -- optional param
+
+	local doc_create = surface.doc_create or false
+	local surface_docs = surface_docs or kelp.surface_docs
+
+	if doc_create then
+		surface_deftemplate._doc_items_entry_name = surface_docs._doc_items_entry_name
+		surface_deftemplate._doc_items_longdesc = surface_docs._doc_items_longdesc
+		surface_deftemplate._doc_items_create_entry = true
+		surface_deftemplate._doc_items_image = surface_docs._doc_items_image
+		-- Takes the first surface with docs
+		if not surface_docs.entry_id_orig then
+			surface_docs.entry_id_orig = nodename
+		end
+	elseif mod_doc then
+		doc.add_entry_alias("nodes", surface_docs.entry_id_orig, "nodes", surfacename)
 	end
 
-local function kelp_dig(dig_pos, pos, node, is_drop)
+	local sounds = table.copy(def.sounds)
-	local param2 = node.param2
+	sounds.dig = leaf_sounds.dig
-	-- pos.y points to the surface, offset needed to point to the first kelp
+	sounds.dug = leaf_sounds.dug
-	local new_height = dig_pos.y - (pos.y+1)
+	sounds.place = leaf_sounds.place
 
-	-- Digs the entire kelp: invoke after_dig_node to set_node
+	surface_deftemplate.tiles = surface_deftemplate.tiles or def_tiles
-	if new_height <= 0 then
+	surface_deftemplate.inventory_image = surface_deftemplate.inventory_image or "("..def_tiles[1]..")^mcl_ocean_kelp_item.png"
-		if is_drop then
+	surface_deftemplate.sounds = surface_deftemplate.sound or sounds
-			kelp_drop(dig_pos, get_kelp_height(param2))
+	local falling_node = mt_get_item_group(nodename, "falling_node")
-		end
+	surface_deftemplate.node_dig_prediction = surface_deftemplate.node_dig_prediction or nodename
-		minetest.set_node(pos, {
+	surface_deftemplate.groups.faling_node = surface_deftemplate.groups.faling_node or falling_node
-			name=minetest.registered_nodes[node.name].node_dig_prediction,
+	surface_deftemplate._mcl_falling_node_alternative = surface_deftemplate._mcl_falling_node_alternative or (falling_node and nodename or nil)
-			param=node.param, param2=0 })
 
-	-- Digs the kelp beginning at a height
+	minetest.register_node(surfacename, surface_deftemplate)
-	else
-		if is_drop then
-			kelp_drop(dig_pos, get_kelp_height(param2) - new_height)
-		end
-		minetest.set_node(pos, {name=node.name, param=node.param, param2=16*new_height})
 end
+
+-- Kelp surfaces nodes ---------------------------------------------------------
+
+-- Dirt must be registered first, for the docs
+register_kelp_surface(surfaces[1], table.copy(surface_deftemplate), surface_docs)
+for i=2, #surfaces do
+	register_kelp_surface(surfaces[i], table.copy(surface_deftemplate), surface_docs)
 end
 
+-- Kelp item -------------------------------------------------------------------
+
 minetest.register_craftitem("mcl_ocean:kelp", {
 	description = S("Kelp"),
 	_tt_help = S("Grows in water on dirt, sand, gravel"),
@@ -214,86 +429,11 @@ minetest.register_craftitem("mcl_ocean:kelp", {
 	groups = { deco_block = 1 },
 })
 
--- Kelp nodes: kelp on a surface node
-
-for s=1, #surfaces do
-	local def = minetest.registered_nodes[surfaces[s][2]]
-	local alt
-	if surfaces[s][3] == 1 then
-		alt = surfaces[s][2]
-	end
-	local sounds = table.copy(def.sounds)
-	local leaf_sounds = mcl_sounds.node_sound_leaves_defaults()
-	sounds.dig = leaf_sounds.dig
-	sounds.dug = leaf_sounds.dug
-	sounds.place = leaf_sounds.place
-	local tt_help, doc_longdesc, doc_img, desc
-	if surfaces[s][1] == "dirt" then
-		doc_longdesc = S("Kelp grows inside water on top of dirt, sand or gravel.")
-		desc = S("Kelp")
-		doc_create = true
-		doc_img = "mcl_ocean_kelp_item.png"
-	else
-		doc_create = false
-	end
-	minetest.register_node("mcl_ocean:kelp_"..surfaces[s][1], {
-		_doc_items_entry_name = desc,
-		_doc_items_longdesc = doc_longdesc,
-		_doc_items_create_entry = doc_create,
-		_doc_items_image = doc_img,
-		drawtype = "plantlike_rooted",
-		paramtype = "light",
-		paramtype2 = "leveled",
-		place_param2 = 16,
-		tiles = def.tiles,
-		special_tiles = {
-			{
-			image = "mcl_ocean_kelp_plant.png",
-			animation = {type="vertical_frames", aspect_w=16, aspect_h=16, length=2.0},
-			tileable_vertical = true,
-			}
-		},
-		inventory_image = "("..def.tiles[1]..")^mcl_ocean_kelp_item.png",
-		wield_image = "mcl_ocean_kelp_item.png",
-		selection_box = {
-			type = "fixed",
-			fixed = {
-				{ -0.5, -0.5, -0.5, 0.5, 0.5, 0.5 },
-				{ -0.5, 0.5, -0.5, 0.5, 1.5, 0.5 },
-			},
-		},
-		groups = { dig_immediate = 3, deco_block = 1, plant = 1, kelp = 1, falling_node = surfaces[s][3] },
-		sounds = sounds,
-		node_dig_prediction = surfaces[s][2],
-		after_dig_node = function(pos)
-			minetest.set_node(pos, {name=surface[s][2]})
-		end,
-		-- TODO: add ability to detect whether the kelp or the surface is dug.
-		-- Currently, digging the surface gives sand, which isn't ideal.
-		on_dig = function(pos, node, digger)
-			minetest.chat_send_all("mo2")
-			local is_drop = true
-			if digger and minetest.is_creative_enabled(digger:get_player_name()) then
-				is_drop = false
-			end
-			kelp_dig(pos, pos, node, is_drop)
-		end,
-		drop = "", -- drops are handled in on_dig
-		_mcl_falling_node_alternative = alt,
-		_mcl_hardness = 0,
-		_mcl_blast_resistance = 0,
-	})
-
-	if mod_doc and surfaces[s][1] ~= "dirt" then
-		doc.add_entry_alias("nodes", "mcl_ocean:kelp_dirt", "nodes", "mcl_ocean:kelp_"..surfaces[s][1])
-	end
-end
-
 if mod_doc then
-	doc.add_entry_alias("nodes", "mcl_ocean:kelp_dirt", "craftitems", "mcl_ocean:kelp")
+	doc.add_entry_alias("nodes", surface_docs.entry_id_orig, "craftitems", "mcl_ocean:kelp")
 end
 
--- Dried kelp stuff
+-- Dried kelp ------------------------------------------------------------------
 
 -- TODO: This is supposed to be eaten very fast
 minetest.register_craftitem("mcl_ocean:dried_kelp", {
@@ -308,13 +448,13 @@ minetest.register_craftitem("mcl_ocean:dried_kelp", {
 	_mcl_saturation = 0.6,
 })
 
+
 local mod_screwdriver = minetest.get_modpath("screwdriver") ~= nil
 local on_rotate
 if mod_screwdriver then
 	on_rotate = screwdriver.rotate_3way
 end
 
-
 minetest.register_node("mcl_ocean:dried_kelp_block", {
 	description = S("Dried Kelp Block"),
 	_doc_items_longdesc = S("A decorative block that serves as a great furnace fuel."),
@@ -354,39 +494,36 @@ minetest.register_craft({
 	burntime = 200,
 })
 
--- Grow kelp
+-- ABMs ------------------------------------------------------------------------
 minetest.register_abm({
-	label = "Kelp growth",
+	label = "mcl_ocean:Kelp growth",
 	nodenames = { "group:kelp" },
-	-- interval = 45,
+	interval = 45,
-	-- chance = 12,
+	chance = 12,
-	interval = 1,
-	chance = 1,
 	catch_up = false,
-	action = function(pos, node, active_object_count, active_object_count_wider)
+	action = grow_kelp,
-		local grow
-		-- Grow kelp by 1 node length if it would grow inside water
-		node.param2, grow = grow_param2_step(node.param2)
-		local pos_top, node_top = get_kelp_top(pos, node)
-		local def_top = minetest.registered_nodes[node_top.name]
-		if grow and is_submerged(node_top, def_top) then
-			kelp_place(pos, node, pos_top, def_top,
-				is_downward_flowing(pos_top, node_top, def_top))
-		end
-	end,
 })
 
--- Break kelp not underwater.
+minetest.register_lbm({
-minetest.register_abm({
+	label = "Kelp timer registration",
-	label = "Kelp drops",
+	name = "mcl_ocean:kelp_timer_registration",
 	nodenames = { "group:kelp" },
-	interval = 0.25,
+	run_at_every_load = true,
-	chance = 1,
+	action = surface_register_nodetimer,
-	catch_up = false,
-	action = function(pos, node)
-		local dig_pos = get_kelp_unsubmerged(pos, node)
-		if dig_pos then
-			kelp_dig(dig_pos, pos, node, true)
-		end
-	end
 })
+
+-- TODO: test if nodetimers are more efficient than ABM
+-- -- Break kelp not underwater.
+-- minetest.register_abm({
+-- 	label = "Kelp drops",
+-- 	nodenames = { "group:kelp" },
+-- 	interval = 0.5,
+-- 	chance = 1,
+-- 	catch_up = false,
+-- 	action = function(pos, node)
+-- 		local dig_pos = find_unsubmerged(pos, node)
+-- 		if dig_pos then
+-- 			detach_dig(dig_pos, pos, node, true)
+-- 		end
+-- 	end
+-- })