fix typo

to give old, deferrred blocks a chance to time-out.  Needed
because if players aren't currently creating new terrain,
old blocks would never get processed, causing the block log
to only grow rather than eventually run dry (which could result
in very long shutdown times).

API.txt

@@ -72,6 +72,7 @@ biome = {
 	---- most likely want to use at least some of these to limit how and
 	---- where your objects are spawned.
 
+	label = string,		-- set this to identify the ABM for Minetest's profiler
 	avoid_nodes = {table},	-- same meaning as savoid, above
 	avoid_radius = num,	-- same as sradius
 	seed_diff = num,	-- The Perlin seed difference value passed to the
@@ -342,14 +343,18 @@ into something else over time.  This function has no return value, and accepts
 a biome definition table as the only parameter.  These are defined like so:
 
 options = {
-	grow_plant = "string", -- Name of the node to be grown into something
-						-- else.  This value is passed to the ABM as the
-						-- "nodenames" parameter, so it is the plants
-						-- themselves that are the ABM trigger, rather than
+	label = string,		-- set this to identify the ABM for Minetest's
+						-- profiler.  If not set, biome_lib will set it to 
+						-- "biome_lib grow_plants(): " appended with the node
+						-- in grow_plant (or the first item if it's a table)
+	grow_plant = "string" or {table}, -- Name(s) of the node(s) to be grown
+						-- into something else.  This value is passed to the
+						-- ABM as the "nodenames" parameter, so the plants
+						-- themselves are the ABM trigger, rather than
 						-- the ground they spawned on.  A plant will only grow
-						-- if the node above it is air.  Can also be a table,
-						-- but note that all nodes referenced therein will be
-						-- grown into the same object.
+						-- if the node above it is air.  If you use a table,
+						-- note that all nodes referenced therein will be
+						-- grown into the same final object.
 	grow_delay = num,	-- Passed as the ABM "interval" parameter, as with
 						-- spawning.
 	grow_chance = num,	-- Passed as the ABM "chance" parameter.
@@ -441,12 +446,22 @@ question is already loaded, or false if not.
 
 
 =====
-dbg(string)
+dbg(string, level)
 
 This is a simple debug output function which takes one string parameter.  It
 just checks if DEBUG is true and outputs the phrase "[Plantlife] " followed by
 the supplied string, via the print() function, if so.
 
+'level' is a number that, if supplied, dictates the lowest 'biome_lib_debug'
+can be set to in minetest.conf for this message to be displayed.  Both the
+default log level and the default message level are 0, thus always showing the
+supplied message.
+
+Although it's not set in stone, a good practice is to use a level of 0 (or
+just omit the value) for anything that generally important enough that it
+ought always be shown, 1 for errors, 2 for warnings, 3 for info, 4 for verbose
+spammy stuff.
+
 =====
 biome_lib:generate_tree(pos, treemodel)
 biome_lib:grow_tree(pos, treemodel)
@@ -583,3 +598,43 @@ And this particular one is mapped slightly differently from the others:
 
 (Note the +150 and +50 offsets)
 
+
+==================
+Default game nodes
+==================
+
+Although this project was intended to be used with minetest_game, it can be
+configured to work with something else instead.  All you need to do is provide
+the names of the nodes in your game you want biome_lib's internals to use.
+
+Put these settings in your game's minetest.conf (or your client's own config,
+if desired).  You'll need to set all of them.
+
+biome_lib_default_grow_through_nodes
+	Comma-separated list of things that a spawned node is allowed to grow
+	through.  Air is always added to whatever you specify.
+	Default:  air, default:snow
+
+biome_lib_default_water_nodes
+	Comma-separated list of nodes that should be treated as water for the sake
+	of looking for neighboring "wet" ground.
+	Default: default:water_source, default:water_flowing,
+		default:river_water_source, default:river_water_flowing
+
+biome_lib_default_wet_surfaces
+	Comma-separated list of nodes that should be considered "wet" if one of
+	the aforementioned water nodes is nearby.
+	Default: default:dirt, default:dirt_with_grass, default:sand
+
+biome_lib_default_grow_nodes
+	Comma-separated list of nodes that something must be sitting on to be
+	able to actively change from one thing to another (such as a sapling
+	growing into a tree), to be used for ALL growable nodes, if the calling
+	mod doesn't provide its own lists.
+	Default: "default:dirt_with_grass"
+
+biome_lib_default_ground_nodes
+	Comma-separated list of nodes to use as the "root" of something that can
+	gradually climb up a wall, to be used for ALL such nodes, if the calling
+	mod doesn't provide its own lists.
+	Default: "default:dirt_with_grass"

README.md

@@ -12,7 +12,7 @@ Both mapgen-based spawning and ABM-based spawning is supported. Growing code is
 
 It is primarily intended for mapgen v6, but it should work fine when used with mapgen v7.
 
-**Dependencies**: default from minetest_game
+**Dependencies:** nothing, but if you don't use `minetest_game`, you'll need to supply some settings (see API.txt).
 
 **Recommends**: [Plantlife Modpack](https://github.com/minetest-mods/plantlife_modpack), 
 [More Trees](https://github.com/minetest-mods/moretrees)

depends.txt

@@ -1,3 +0,0 @@
-default
-intllib?
-

growth.lua

@@ -0,0 +1,90 @@
+local time_scale = ...
+
+-- The growing ABM
+
+function biome_lib.check_surface(name, nodes)
+	if not nodes then return true end
+	if type(nodes) == "string" then return nodes == name end
+	if nodes.set and nodes[name] then
+		return true
+	else
+		for _, n in ipairs(nodes) do
+			if name == n then return true end
+		end
+	end
+	return false
+end
+
+function biome_lib:grow_plants(opts)
+
+	local options = opts
+
+	options.height_limit = options.height_limit or 5
+	options.ground_nodes = options.ground_nodes or biome_lib.default_ground_nodes
+	options.grow_nodes = options.grow_nodes or biome_lib.default_grow_nodes
+	options.seed_diff = options.seed_diff or 0
+
+	local n
+
+	if type(options.grow_plant) == "table" then
+		n = "multi: "..options.grow_plant[1]..", ..."
+	else
+		n = options.grow_plant
+	end
+
+	options.label = options.label or "biome_lib grow_plants(): "..n
+
+	if options.grow_delay*time_scale >= 1 then
+		options.interval = options.grow_delay*time_scale
+	else
+		options.interval = 1
+	end
+
+	minetest.register_abm({
+		nodenames = { options.grow_plant },
+		interval = options.interval,
+		chance = options.grow_chance,
+		label = options.label,
+		action = function(pos, node, active_object_count, active_object_count_wider)
+			local p_top = {x=pos.x, y=pos.y+1, z=pos.z}
+			local p_bot = {x=pos.x, y=pos.y-1, z=pos.z}
+			local n_top = minetest.get_node(p_top)
+			local n_bot = minetest.get_node(p_bot)
+			local root_node = minetest.get_node({x=pos.x, y=pos.y-options.height_limit, z=pos.z})
+			local walldir = nil
+			if options.need_wall and options.verticals_list then
+				walldir = biome_lib:find_adjacent_wall(p_top, options.verticals_list, options.choose_random_wall)
+			end
+			if biome_lib.default_grow_through_nodes[n_top.name]
+			  and (not options.need_wall or (options.need_wall and walldir)) then
+				if options.grow_vertically and walldir then
+					if biome_lib:search_downward(pos, options.height_limit, options.ground_nodes) then
+						minetest.swap_node(p_top, { name = options.grow_plant, param2 = walldir})
+					end
+
+				elseif biome_lib.check_surface(n_bot.name, options.grow_nodes) then
+					if not options.grow_result and not options.grow_function then
+						minetest.swap_node(pos, biome_lib.air)
+
+					else
+						biome_lib:replace_object(pos, options.grow_result, options.grow_function, options.facedir, options.seed_diff)
+					end
+				end
+			end
+		end
+	})
+end
+
+
+-- spawn_tree() on generate is routed through here so that other mods can hook
+-- into it.
+
+function biome_lib:generate_tree(pos, nodes_or_function_or_model)
+	minetest.spawn_tree(pos, nodes_or_function_or_model)
+end
+
+-- and this one's for the call used in the growing code
+
+function biome_lib:grow_tree(pos, nodes_or_function_or_model)
+	minetest.spawn_tree(pos, nodes_or_function_or_model)
+end

init.lua

@@ -1,54 +1,91 @@
--- Biome library mod by Vanessa Ezekowitz
+-- Biome library mod by VanessaE
 --
 -- I got the temperature map idea from "hmmmm", values used for it came from
 -- Splizard's snow mod.
 --
 
--- Various settings - most of these probably won't need to be changed
-
 biome_lib = {}
-biome_lib.air = {name = "air"}
-
-plantslib = setmetatable({}, { __index=function(t,k) print("Use of deprecated function:", k) return biome_lib[k] end })
-
-biome_lib.blocklist_aircheck = {}
-biome_lib.blocklist_no_aircheck = {}
-
-biome_lib.surface_nodes_aircheck = {}
-biome_lib.surface_nodes_no_aircheck = {}
-
-biome_lib.surfaceslist_aircheck = {}
-biome_lib.surfaceslist_no_aircheck = {}
-
-biome_lib.actioncount_aircheck = {}
-biome_lib.actioncount_no_aircheck = {}
-
-biome_lib.actionslist_aircheck = {}
-biome_lib.actionslist_no_aircheck = {}
-
-biome_lib.modpath = minetest.get_modpath("biome_lib")
-
-biome_lib.total_no_aircheck_calls = 0
-
-biome_lib.queue_run_ratio = tonumber(minetest.settings:get("biome_lib_queue_run_ratio")) or 100
 
 -- Boilerplate to support localized strings if intllib mod is installed.
 local S
-if minetest.get_modpath("intllib") then
+if minetest.global_exists("intllib") then
+	if intllib.make_gettext_pair then
+		S = intllib.make_gettext_pair()
+	else
 		S = intllib.Getter()
+	end
 else
 	S = function(s) return s end
 end
 biome_lib.intllib = S
 
-local DEBUG = false --... except if you want to spam the console with debugging info :-)
+-- Various settings - most of these probably won't need to be changed
 
-function biome_lib:dbg(msg)
-	if DEBUG then
-		print("[Plantlife] "..msg)
-		minetest.log("verbose", "[Plantlife] "..msg)
+biome_lib.air = {name = "air"}
+
+biome_lib.block_log = {}
+biome_lib.block_recheck_list = {}
+biome_lib.run_block_recheck_list = false
+
+biome_lib.actionslist_aircheck = {}
+biome_lib.actionslist_no_aircheck = {}
+
+biome_lib.surfaceslist_aircheck = {}
+biome_lib.surfaceslist_no_aircheck = {}
+
+biome_lib.modpath = minetest.get_modpath("biome_lib")
+
+local function tableize(s)
+	return string.split(string.trim(string.gsub(s, " ", "")))
 end
+
+local c1 = minetest.settings:get("biome_lib_default_grow_through_nodes")
+biome_lib.default_grow_through_nodes = {["air"] = true}
+if c1 then
+	for _, i in ipairs(tableize(c1)) do
+		biome_lib.default_grow_through_nodes[i] = true
 	end
+else
+	biome_lib.default_grow_through_nodes["default:snow"] = true
+end
+
+local c2 = minetest.settings:get("biome_lib_default_water_nodes")
+biome_lib.default_water_nodes = {}
+if c2 then
+	for _, i in ipairs(tableize(c2)) do
+		biome_lib.default_water_nodes[i] = true
+	end
+else
+	biome_lib.default_water_nodes["default:water_source"] = true
+	biome_lib.default_water_nodes["default:water_flowing"] = true
+	biome_lib.default_water_nodes["default:river_water_source"] = true
+	biome_lib.default_water_nodes["default:river_water_flowing"] = true
+end
+
+local c3 = minetest.settings:get("biome_lib_default_wet_surfaces")
+local c4 = minetest.settings:get("biome_lib_default_ground_nodes")
+local c5 = minetest.settings:get("biome_lib_default_grow_nodes")
+
+biome_lib.default_wet_surfaces = c3 and tableize(c3) or {"default:dirt", "default:dirt_with_grass", "default:sand"}
+biome_lib.default_ground_nodes = c4 and tableize(c4) or {"default:dirt_with_grass"}
+biome_lib.default_grow_nodes =   c5 and tableize(c5) or {"default:dirt_with_grass"}
+
+biome_lib.debug_log_level = tonumber(minetest.settings:get("biome_lib_debug_log_level")) or 0
+
+local rr = tonumber(minetest.settings:get("biome_lib_queue_run_ratio")) or -100
+biome_lib.queue_run_ratio = 100 - rr
+biome_lib.entries_per_step = math.max(-rr, 1)
+
+-- the timer that manages the block timeout is in microseconds, but the timer
+-- that manages the queue wakeup call has to be in seconds, and works best if
+-- it takes a little longer than the block timeout interval.
+
+local t = tonumber(minetest.settings:get("biome_lib_block_timeout")) or 300
+
+biome_lib.block_timeout = t * 1000000
+biome_lib.block_queue_wakeup_time = t * 1.1
+
+local time_speed = tonumber(minetest.settings:get("time_speed"))
 
 biome_lib.plantlife_seed_diff = 329 -- needs to be global so other mods can see it
 
@@ -67,7 +104,6 @@ local humidity_persistence = 0.5
 local humidity_scale = 250
 
 local time_scale = 1
-local time_speed = tonumber(minetest.settings:get("time_speed"))
 
 if time_speed and time_speed > 0 then
 	time_scale = 72 / time_speed
@@ -80,6 +116,30 @@ biome_lib.perlin_humidity = PerlinNoise(humidity_seeddiff, humidity_octaves, hum
 
 -- Local functions
 
+function biome_lib.dbg(msg, level)
+	local l = tonumber(level) or 0
+	if biome_lib.debug_log_level >= l then
+		print("[Biome Lib] "..msg)
+		minetest.log("verbose", "[Biome Lib] "..msg)
+	end
+end
+
+local function get_biome_data(pos, perlin_fertile)
+	local fertility = perlin_fertile:get_2d({x=pos.x, y=pos.z})
+
+	if type(minetest.get_biome_data) == "function" then
+		local data = minetest.get_biome_data(pos)
+		if data then
+			return fertility, data.heat / 100, data.humidity / 100
+		end
+	end
+
+	local temperature = biome_lib.perlin_temperature:get2d({x=pos.x, y=pos.z})
+	local humidity = biome_lib.perlin_humidity:get2d({x=pos.x+150, y=pos.z+50})
+
+	return fertility, temperature, humidity
+end
+
 function biome_lib:is_node_loaded(node_pos)
 	local n = minetest.get_node_or_nil(node_pos)
 	if (not n) or (n.name == "ignore") then
@@ -105,7 +165,7 @@ function biome_lib:set_defaults(biome)
 	biome.near_nodes_size = biome.near_nodes_size or 0
 	biome.near_nodes_count = biome.near_nodes_count or 1
 	biome.rarity = biome.rarity or 50
-	biome.max_count = biome.max_count or 5
+	biome.max_count = biome.max_count or 125
 	if biome.check_air ~= false then biome.check_air = true end
 
 -- specific to abm spawner
@@ -134,17 +194,17 @@ function biome_lib:register_generate_plant(biomedef, nodes_or_function_or_model)
 	if type(nodes_or_function_or_model) == "string"
 	  and string.find(nodes_or_function_or_model, ":")
 	  and not minetest.registered_nodes[nodes_or_function_or_model] then
-		biome_lib:dbg("Warning: Ignored registration for undefined spawn node: "..dump(nodes_or_function_or_model))
+		biome_lib.dbg("Warning: Ignored registration for undefined spawn node: "..dump(nodes_or_function_or_model), 2)
 		return
 	end
 
 	if type(nodes_or_function_or_model) == "string"
 	  and not string.find(nodes_or_function_or_model, ":") then
-		biome_lib:dbg("Warning: Registered function call using deprecated string method: "..dump(nodes_or_function_or_model))
+		biome_lib.dbg("Warning: Registered function call using deprecated string method: "..dump(nodes_or_function_or_model), 2)
 	end
 
 	if biomedef.check_air == false then 
-		biome_lib:dbg("Register no-air-check mapgen hook: "..dump(nodes_or_function_or_model))
+		biome_lib.dbg("Register no-air-check mapgen hook: "..dump(nodes_or_function_or_model), 3)
 		biome_lib.actionslist_no_aircheck[#biome_lib.actionslist_no_aircheck + 1] = { biomedef, nodes_or_function_or_model }
 		local s = biomedef.surface
 		if type(s) == "string" then
@@ -153,7 +213,7 @@ function biome_lib:register_generate_plant(biomedef, nodes_or_function_or_model)
 					biome_lib.surfaceslist_no_aircheck[#biome_lib.surfaceslist_no_aircheck + 1] = s
 				end
 			else
-				biome_lib:dbg("Warning: Ignored no-air-check registration for undefined surface node: "..dump(s))
+				biome_lib.dbg("Warning: Ignored no-air-check registration for undefined surface node: "..dump(s), 2)
 			end
 		else
 			for i = 1, #biomedef.surface do
@@ -163,12 +223,12 @@ function biome_lib:register_generate_plant(biomedef, nodes_or_function_or_model)
 						biome_lib.surfaceslist_no_aircheck[#biome_lib.surfaceslist_no_aircheck + 1] = s
 					end
 				else
-					biome_lib:dbg("Warning: Ignored no-air-check registration for undefined surface node: "..dump(s))
+					biome_lib.dbg("Warning: Ignored no-air-check registration for undefined surface node: "..dump(s), 2)
 				end
 			end
 		end
 	else
-		biome_lib:dbg("Register with-air-checking mapgen hook: "..dump(nodes_or_function_or_model))
+		biome_lib.dbg("Register with-air-checking mapgen hook: "..dump(nodes_or_function_or_model), 3)
 		biome_lib.actionslist_aircheck[#biome_lib.actionslist_aircheck + 1] = { biomedef, nodes_or_function_or_model }
 		local s = biomedef.surface
 		if type(s) == "string" then
@@ -177,7 +237,7 @@ function biome_lib:register_generate_plant(biomedef, nodes_or_function_or_model)
 					biome_lib.surfaceslist_aircheck[#biome_lib.surfaceslist_aircheck + 1] = s
 				end
 			else
-				biome_lib:dbg("Warning: Ignored with-air-checking registration for undefined surface node: "..dump(s))
+				biome_lib.dbg("Warning: Ignored with-air-checking registration for undefined surface node: "..dump(s), 2)
 			end
 		else
 			for i = 1, #biomedef.surface do
@@ -187,28 +247,34 @@ function biome_lib:register_generate_plant(biomedef, nodes_or_function_or_model)
 						biome_lib.surfaceslist_aircheck[#biome_lib.surfaceslist_aircheck + 1] = s
 					end
 				else
-					biome_lib:dbg("Warning: Ignored with-air-checking registration for undefined surface node: "..dump(s))
+					biome_lib.dbg("Warning: Ignored with-air-checking registration for undefined surface node: "..dump(s), 2)
 				end
 			end
 		end
 	end
 end
 
-function biome_lib:populate_surfaces(biome, nodes_or_function_or_model, snodes, checkair)
+-- Function to check whether a position matches the given biome definition
+-- Returns true when the surface can be populated
 
-	biome_lib:set_defaults(biome)
-
-	-- filter stage 1 - find nodes from the supplied surfaces that are within the current biome.
-
-	local in_biome_nodes = {}
-	local perlin_fertile_area = minetest.get_perlin(biome.seed_diff, perlin_octaves, perlin_persistence, perlin_scale)
-
-	for i = 1, #snodes do
-		local pos = snodes[i]
+local function populate_single_surface(biome, pos, perlin_fertile_area, checkair)
 	local p_top = { x = pos.x, y = pos.y + 1, z = pos.z }
-		local noise1 = perlin_fertile_area:get2d({x=pos.x, y=pos.z})
-		local noise2 = biome_lib.perlin_temperature:get2d({x=pos.x, y=pos.z})
-		local noise3 = biome_lib.perlin_humidity:get2d({x=pos.x+150, y=pos.z+50})
+
+	if math.random(1, 100) <= biome.rarity then
+		return
+	end
+
+	local fertility, temperature, humidity = get_biome_data(pos, perlin_fertile_area)
+
+	local pos_biome_ok = pos.y >= biome.min_elevation and pos.y <= biome.max_elevation
+		and fertility > biome.plantlife_limit
+		and temperature <= biome.temp_min and temperature >= biome.temp_max
+		and humidity <= biome.humidity_min and humidity >= biome.humidity_max
+	
+	if not pos_biome_ok then
+		return -- Y position mismatch, outside of biome
+	end
+
 	local biome_surfaces_string = dump(biome.surface)
 	local surface_ok = false
 
@@ -227,24 +293,61 @@ function biome_lib:populate_surfaces(biome, nodes_or_function_or_model, snodes,
 				end
 			end
 		end
-		elseif not string.find(biome_surfaces_string, minetest.get_node({ x = pos.x, y = pos.y-biome.depth-1, z = pos.z }).name) then
+	elseif not string.find(biome_surfaces_string,
+			minetest.get_node({ x = pos.x, y = pos.y-biome.depth-1, z = pos.z }).name) then
 		surface_ok = true
 	end
 	
-		if surface_ok
-		  and pos.y >= biome.min_elevation
-		  and pos.y <= biome.max_elevation
-		  and noise1 > biome.plantlife_limit
-		  and noise2 <= biome.temp_min
-		  and noise2 >= biome.temp_max
-		  and noise3 <= biome.humidity_min
-		  and noise3 >= biome.humidity_max
-		  and (not checkair or minetest.get_node(p_top).name == "air")
-		  and (not biome.ncount or #(minetest.find_nodes_in_area({x=pos.x-1, y=pos.y, z=pos.z-1}, {x=pos.x+1, y=pos.y, z=pos.z+1}, biome.neighbors)) > biome.ncount)
-		  and (not biome.near_nodes or #(minetest.find_nodes_in_area({x=pos.x-biome.near_nodes_size, y=pos.y-biome.near_nodes_vertical, z=pos.z-biome.near_nodes_size}, {x=pos.x+biome.near_nodes_size, y=pos.y+biome.near_nodes_vertical, z=pos.z+biome.near_nodes_size}, biome.near_nodes)) >= biome.near_nodes_count)
-		  and math.random(1,100) > biome.rarity
-		  and (not biome.below_nodes or string.find(dump(biome.below_nodes), minetest.get_node({x=pos.x, y=pos.y-1, z=pos.z}).name) )
-		  then
+	if not surface_ok then
+		return -- Surface does not match the given node group/name
+	end
+
+	if checkair and minetest.get_node(p_top).name ~= "air" then
+		return
+	end
+
+	if biome.below_nodes and
+			not string.find(dump(biome.below_nodes),
+				minetest.get_node({x=pos.x, y=pos.y-1, z=pos.z}).name
+			) then
+		return -- Node below does not match
+	end
+
+	if biome.ncount and
+			#minetest.find_nodes_in_area(
+				{x=pos.x-1, y=pos.y, z=pos.z-1},
+				{x=pos.x+1, y=pos.y, z=pos.z+1},
+				biome.neighbors
+			) <= biome.ncount then
+		return -- Not enough similar biome nodes around
+	end
+
+	if biome.near_nodes and
+			#minetest.find_nodes_in_area(
+				{x=pos.x-biome.near_nodes_size, y=pos.y-biome.near_nodes_vertical, z=pos.z-biome.near_nodes_size},
+				{x=pos.x+biome.near_nodes_size, y=pos.y+biome.near_nodes_vertical, z=pos.z+biome.near_nodes_size}, 
+				biome.near_nodes
+			) < biome.near_nodes_count then
+		return -- Long distance neighbours do not match
+	end
+
+	-- Position fits into given biome
+	return true
+end
+
+function biome_lib.populate_surfaces(biome, nodes_or_function_or_model, snodes, checkair)
+	local items_added = 0
+
+	biome_lib:set_defaults(biome)
+
+	-- filter stage 1 - find nodes from the supplied surfaces that are within the current biome.
+
+	local in_biome_nodes = {}
+	local perlin_fertile_area = minetest.get_perlin(biome.seed_diff, perlin_octaves, perlin_persistence, perlin_scale)
+
+	for i = 1, #snodes do
+		local pos = vector.new(snodes[i])
+		if populate_single_surface(biome, pos, perlin_fertile_area, checkair) then
 			in_biome_nodes[#in_biome_nodes + 1] = pos
 		end
 	end
@@ -253,8 +356,11 @@ function biome_lib:populate_surfaces(biome, nodes_or_function_or_model, snodes,
 
 	local num_in_biome_nodes = #in_biome_nodes
 
-	if num_in_biome_nodes > 0 then
-		for i = 1, math.min(biome.max_count, num_in_biome_nodes) do
+	if num_in_biome_nodes == 0 then
+		return 0
+	end
+
+	for i = 1, math.min(math.ceil(biome.max_count/25), num_in_biome_nodes) do
 		local tries = 0
 		local spawned = false
 		while tries < 2 and not spawned do
@@ -264,7 +370,9 @@ function biome_lib:populate_surfaces(biome, nodes_or_function_or_model, snodes,
 			end
 			local p_top = { x = pos.x, y = pos.y + 1, z = pos.z }
 
-				if not (biome.avoid_nodes and biome.avoid_radius and minetest.find_node_near(p_top, biome.avoid_radius + math.random(-1.5,2), biome.avoid_nodes)) then
+			if not (biome.avoid_nodes and biome.avoid_radius
+					and minetest.find_node_near(p_top, biome.avoid_radius
+					+ math.random(-1.5,2), biome.avoid_nodes)) then
 				if biome.delete_above then
 					minetest.swap_node(p_top, biome_lib.air)
 					minetest.swap_node({x=p_top.x, y=p_top.y+1, z=p_top.z}, biome_lib.air)
@@ -291,13 +399,16 @@ function biome_lib:populate_surfaces(biome, nodes_or_function_or_model, snodes,
 				if objtype == "table" then
 					if nodes_or_function_or_model.axiom then
 						biome_lib:generate_tree(p_top, nodes_or_function_or_model)
+						biome_lib.dbg("An L-tree was spawned at "..minetest.pos_to_string(p_top), 4)
 						spawned = true
 					else
 						local fdir = nil
 						if biome.random_facedir then
 							fdir = math.random(biome.random_facedir[1], biome.random_facedir[2])
 						end
-							minetest.swap_node(p_top, { name = nodes_or_function_or_model[math.random(#nodes_or_function_or_model)], param2 = fdir })
+						local n=nodes_or_function_or_model[math.random(#nodes_or_function_or_model)]
+						minetest.swap_node(p_top, { name = n, param2 = fdir })
+						biome_lib.dbg("Node \""..n.."\" was randomly picked from a list and placed at "..minetest.pos_to_string(p_top), 4)
 						spawned = true
 					end
 				elseif objtype == "string" and
@@ -307,166 +418,187 @@ function biome_lib:populate_surfaces(biome, nodes_or_function_or_model, snodes,
 						fdir = math.random(biome.random_facedir[1], biome.random_facedir[2])
 					end
 					minetest.swap_node(p_top, { name = nodes_or_function_or_model, param2 = fdir })
+					biome_lib.dbg("Node \""..nodes_or_function_or_model.."\" was placed at "..minetest.pos_to_string(p_top), 4)
 					spawned = true
 				elseif objtype == "function" then
 					nodes_or_function_or_model(pos)
+					biome_lib.dbg("A function was run on surface node at "..minetest.pos_to_string(pos), 4)
 					spawned = true
 				elseif objtype == "string" and pcall(loadstring(("return %s(...)"):
 					format(nodes_or_function_or_model)),pos) then
 					spawned = true
+					biome_lib.dbg("An obsolete string-specified function was run on surface node at "..minetest.pos_to_string(p_top), 4)
 				else
-						biome_lib:dbg("Warning: Ignored invalid definition for object "..dump(nodes_or_function_or_model).." that was pointed at {"..dump(pos).."}")
+					biome_lib.dbg("Warning: Ignored invalid definition for object "..dump(nodes_or_function_or_model).." that was pointed at {"..dump(pos).."}", 2)
 				end
 			else
 				tries = tries + 1
 			end
 		end
+		if spawned then items_added = items_added + 1 end
+	end
+	return items_added
+end
+
+-- Primary log read-out/mapgen spawner
+
+local function confirm_block_surroundings(p)
+	local n=minetest.get_node_or_nil(p)
+	if not n or n.name == "ignore" then return false end
+
+	for x = -32,32,64 do -- step of 64 causes it to only check the 8 corner blocks
+		for y = -32,32,64 do
+			for z = -32,32,64 do
+				local n=minetest.get_node_or_nil({x=p.x + x, y=p.y + y, z=p.z + z})
+				if not n or n.name == "ignore" then return false end
 			end
 		end
 	end
+	return true
+end
 
--- Primary mapgen spawner, for mods that can work with air checking enabled on
--- a surface during the initial map read stage.
+function biome_lib.generate_block(shutting_down)
 
-function biome_lib:generate_block_with_air_checking()
-	if #biome_lib.blocklist_aircheck > 0 then
-
-		local minp =		biome_lib.blocklist_aircheck[1][1]
-		local maxp =		biome_lib.blocklist_aircheck[1][2]
-
-		-- use the block hash as a unique key into the surface nodes
-		-- tables, so that we can write the tables thread-safely.
-
-		local blockhash =	minetest.hash_node_position(minp)
-
-		if not biome_lib.surface_nodes_aircheck.blockhash then
-
-			if type(minetest.find_nodes_in_area_under_air) == "function" then -- use newer API call
-				biome_lib.surface_nodes_aircheck.blockhash =
-					minetest.find_nodes_in_area_under_air(minp, maxp, biome_lib.surfaceslist_aircheck)
+	if shutting_down then
+		if #biome_lib.block_recheck_list > 0 then
+			for i = 1, #biome_lib.block_recheck_list do
+				biome_lib.block_log[#biome_lib.block_log + 1] = biome_lib.block_recheck_list[i]
+			end
+			biome_lib.block_recheck_list = {}
+		end
+		biome_lib.run_block_recheck_list = false
 	else
-				local search_area = minetest.find_nodes_in_area(minp, maxp, biome_lib.surfaceslist_aircheck)
-
-				-- search the generated block for air-bounded surfaces the slow way.
-
-				biome_lib.surface_nodes_aircheck.blockhash = {}
-
-				for i = 1, #search_area do
-				local pos = search_area[i]
-					local p_top = { x=pos.x, y=pos.y+1, z=pos.z }
-					if minetest.get_node(p_top).name == "air" then
-						biome_lib.surface_nodes_aircheck.blockhash[#biome_lib.surface_nodes_aircheck.blockhash + 1] = pos
+		if biome_lib.run_block_recheck_list
+		  and not biome_lib.block_recheck_list[1] then
+				biome_lib.run_block_recheck_list = false
 		end
 	end
-			end
-			biome_lib.actioncount_aircheck.blockhash = 1
 
+	local blocklog = biome_lib.run_block_recheck_list
+	  and biome_lib.block_recheck_list
+	  or biome_lib.block_log
+
+	if not blocklog[1] then return end
+
+	local minp =		blocklog[1][1]
+	local maxp =		blocklog[1][2]
+	local airflag = 	blocklog[1][3]
+	local pos_hash = 	minetest.hash_node_position(minp)
+
+	if not biome_lib.pos_hash then -- we need to read the maplock and get the surfaces list
+		local now = minetest.get_us_time()
+		biome_lib.pos_hash = {}
+		minetest.load_area(minp)
+		if not confirm_block_surroundings(minp)
+		  and not shutting_down
+		  and (blocklog[1][4] + biome_lib.block_timeout) > now then -- if any neighbors appear not to be loaded and the block hasn't expired yet, defer it
+			blocklog[1][4] = now -- reset the timer, give this block more time to "cook"
+			if biome_lib.run_block_recheck_list then
+				biome_lib.block_log[#biome_lib.block_log + 1] = table.copy(biome_lib.block_recheck_list[1])
+				table.remove(biome_lib.block_recheck_list, 1)
 			else
-			if biome_lib.actioncount_aircheck.blockhash <= #biome_lib.actionslist_aircheck then
-				-- [1] is biome, [2] is node/function/model
-				biome_lib:populate_surfaces(
-					biome_lib.actionslist_aircheck[biome_lib.actioncount_aircheck.blockhash][1],
-					biome_lib.actionslist_aircheck[biome_lib.actioncount_aircheck.blockhash][2],
-					biome_lib.surface_nodes_aircheck.blockhash, true)
-				biome_lib.actioncount_aircheck.blockhash = biome_lib.actioncount_aircheck.blockhash + 1
+				biome_lib.block_recheck_list[#biome_lib.block_recheck_list + 1] = table.copy(biome_lib.block_log[1])
+				table.remove(biome_lib.block_log, 1)
+			end
+			biome_lib.pos_hash = nil
+				biome_lib.dbg("Mapblock at "..minetest.pos_to_string(minp)..
+					" had a neighbor not fully emerged, skipped it for now.", 4)
+			return
 		else
-				if biome_lib.surface_nodes_aircheck.blockhash then
-					table.remove(biome_lib.blocklist_aircheck, 1)
-					biome_lib.surface_nodes_aircheck.blockhash = nil
+			biome_lib.pos_hash.surface_node_list = airflag
+				and minetest.find_nodes_in_area_under_air(minp, maxp, biome_lib.surfaceslist_aircheck)
+				or minetest.find_nodes_in_area(minp, maxp, biome_lib.surfaceslist_no_aircheck)
+			biome_lib.pos_hash.action_index = 1
+			if #biome_lib.pos_hash.surface_node_list > 0 then
+				biome_lib.dbg("Mapblock at "..minetest.pos_to_string(minp)..
+					" has "..#biome_lib.pos_hash.surface_node_list..
+					" surface nodes to work on (airflag="..dump(airflag)..")", 4)
 			end
 		end
+	elseif not (airflag and biome_lib.actionslist_aircheck[biome_lib.pos_hash.action_index])
+	  and not (not airflag and biome_lib.actionslist_no_aircheck[biome_lib.pos_hash.action_index]) then
+		-- the block is finished, remove it
+		if #biome_lib.pos_hash.surface_node_list > 0 then
+			biome_lib.dbg("Deleted mapblock "..minetest.pos_to_string(minp).." from the block log", 4)
 		end
-	end
-end
-
--- Secondary mapgen spawner, for mods that require disabling of
--- checking for air during the initial map read stage.
-
-function biome_lib:generate_block_no_aircheck()
-	if #biome_lib.blocklist_no_aircheck > 0 then
-
-		local minp =		biome_lib.blocklist_no_aircheck[1][1]
-		local maxp =		biome_lib.blocklist_no_aircheck[1][2]
-
-		local blockhash =	minetest.hash_node_position(minp)
-
-		if not biome_lib.surface_nodes_no_aircheck.blockhash then
-
-			-- directly read the block to be searched into the chunk cache
-
-			biome_lib.surface_nodes_no_aircheck.blockhash =
-				minetest.find_nodes_in_area(minp, maxp, biome_lib.surfaceslist_no_aircheck)
-			biome_lib.actioncount_no_aircheck.blockhash = 1
-
+		table.remove(blocklog, 1)
+		biome_lib.pos_hash = nil
 	else
-			if biome_lib.actioncount_no_aircheck.blockhash <= #biome_lib.actionslist_no_aircheck then
-				biome_lib:populate_surfaces(
-					biome_lib.actionslist_no_aircheck[biome_lib.actioncount_no_aircheck.blockhash][1],
-					biome_lib.actionslist_no_aircheck[biome_lib.actioncount_no_aircheck.blockhash][2],
-					biome_lib.surface_nodes_no_aircheck.blockhash, false)
-				biome_lib.actioncount_no_aircheck.blockhash = biome_lib.actioncount_no_aircheck.blockhash + 1
+		-- below, [1] is biome, [2] is the thing to be added
+		local added = 0
+		if airflag then
+			if biome_lib.actionslist_aircheck[biome_lib.pos_hash.action_index] then
+				added = biome_lib.populate_surfaces(
+							biome_lib.actionslist_aircheck[biome_lib.pos_hash.action_index][1],
+							biome_lib.actionslist_aircheck[biome_lib.pos_hash.action_index][2],
+							biome_lib.pos_hash.surface_node_list, true)
+				biome_lib.pos_hash.action_index = biome_lib.pos_hash.action_index + 1
+			end
 		else
-				if biome_lib.surface_nodes_no_aircheck.blockhash then
-					table.remove(biome_lib.blocklist_no_aircheck, 1)
-					biome_lib.surface_nodes_no_aircheck.blockhash = nil
+			if biome_lib.actionslist_no_aircheck[biome_lib.pos_hash.action_index] then
+				added = biome_lib.populate_surfaces(
+							biome_lib.actionslist_no_aircheck[biome_lib.pos_hash.action_index][1],
+							biome_lib.actionslist_no_aircheck[biome_lib.pos_hash.action_index][2],
+							biome_lib.pos_hash.surface_node_list, false)
+				biome_lib.pos_hash.action_index = biome_lib.pos_hash.action_index + 1
+			end
+		end
+		if added > 0 then
+			biome_lib.dbg("biome_lib.populate_surfaces ran on mapblock at "..
+				minetest.pos_to_string(minp)..".  Entry #"..
+				(biome_lib.pos_hash.action_index-1).." added "..added.." items.", 4)
 		end
 	end
 end
-	end
-end
-
--- "Record" the chunks being generated by the core mapgen
-
-minetest.register_on_generated(function(minp, maxp, blockseed)
-	biome_lib.blocklist_aircheck[#biome_lib.blocklist_aircheck + 1] = { minp, maxp }
-end)
-
-minetest.register_on_generated(function(minp, maxp, blockseed)
-	biome_lib.blocklist_no_aircheck[#biome_lib.blocklist_no_aircheck + 1] = { minp, maxp }
-end)
 
 -- "Play" them back, populating them with new stuff in the process
 
 minetest.register_globalstep(function(dtime)
-	if dtime < 0.2    -- don't attempt to populate if lag is already too high
-	  and math.random(100) <= biome_lib.queue_run_ratio
-	  and (#biome_lib.blocklist_aircheck > 0 or #biome_lib.blocklist_no_aircheck > 0) then
-		biome_lib.globalstep_start_time = minetest.get_us_time()
-		biome_lib.globalstep_runtime = 0
-		while (#biome_lib.blocklist_aircheck > 0 or #biome_lib.blocklist_no_aircheck > 0)
-		  and biome_lib.globalstep_runtime < 200000 do  -- 0.2 seconds, in uS.
-			if #biome_lib.blocklist_aircheck > 0 then
-				biome_lib:generate_block_with_air_checking()
-			end
-			if #biome_lib.blocklist_no_aircheck > 0 then
-				biome_lib:generate_block_no_aircheck()
-			end
-			biome_lib.globalstep_runtime = minetest.get_us_time() - biome_lib.globalstep_start_time
-		end
+	if not biome_lib.block_log[1] then return end -- the block log is empty
+
+	if math.random(100) > biome_lib.queue_run_ratio then return end
+	for s = 1, biome_lib.entries_per_step do
+		biome_lib.generate_block()
 	end
 end)
 
+-- Periodically wake-up the queue to give old blocks a chance to time-out
+-- if the player isn't currently exploring (i.e. they're just playing in one area)
+
+function biome_lib.wake_up_queue()
+	if #biome_lib.block_recheck_list > 0
+	  and #biome_lib.block_log == 0 then
+		-- we move the second element and not the first because we can't be
+		-- sure if the recheck list's first item is the one currently acted upon
+		-- (else it'd be the first item in the main block log)
+		biome_lib.block_log = table.copy(biome_lib.block_recheck_list)
+		biome_lib.block_recheck_list = {}
+		biome_lib.queue_idle_flag = false
+		biome_lib.dbg("Woke-up the map queue to give old blocks a chance to time-out.", 3)
+	end
+	minetest.after(biome_lib.block_queue_wakeup_time, biome_lib.wake_up_queue)
+end
+
+biome_lib.wake_up_queue()
+
 -- Play out the entire log all at once on shutdown
 -- to prevent unpopulated map areas
 
 minetest.register_on_shutdown(function()
-	if #biome_lib.blocklist_aircheck > 0 then
-		print("[biome_lib] Stand by, playing out the rest of the aircheck mapblock log")
-		print("(there are "..#biome_lib.blocklist_aircheck.." entries)...")
-		while true do
-			biome_lib:generate_block_with_air_checking(0.1)
-			if #biome_lib.blocklist_aircheck == 0 then return end
+	if #biome_lib.block_log + #biome_lib.block_recheck_list == 0 then
+		return
 	end
-	end
-end)
 
-minetest.register_on_shutdown(function()
-	if #biome_lib.blocklist_no_aircheck > 0 then
-		print("[biome_lib] Stand by, playing out the rest of the no-aircheck mapblock log")
-		print("(there are "..#biome_lib.blocklist_no_aircheck.." entries)...")
-		while true do
-			biome_lib:generate_block_no_aircheck(0.1)
-			if #biome_lib.blocklist_no_aircheck == 0 then return end
+	biome_lib.dbg("[biome_lib] Stand by, playing out the rest of the mapblock log", 0)
+	biome_lib.dbg("(there are "..(#biome_lib.block_log + #biome_lib.block_recheck_list).." entries)...", 0)
+	while #biome_lib.block_log > 0 do
+		biome_lib.generate_block(true)
+	end
+
+	if #biome_lib.block_recheck_list > 0 then
+		biome_lib.block_log = table.copy(biome_lib.block_recheck_list)
+		while #biome_lib.block_log > 0 do
+			biome_lib.generate_block(true)
 		end
 	end
 end)
@@ -497,44 +629,94 @@ function biome_lib:spawn_on_surfaces(sd,sp,sr,sc,ss,sa)
 	biome_lib:set_defaults(biome)
 	biome.spawn_plants_count = #(biome.spawn_plants)
 
+	local n
+	if type(biome.spawn_plants) == "table" then
+		n = "random: "..biome.spawn_plants[1]..", ..."
+	else
+		n = biome.spawn_plants
+	end
+	biome.label = biome.label or "biome_lib spawn_on_surfaces(): "..n
+
 	minetest.register_abm({
 		nodenames = biome.spawn_surfaces,
 		interval = biome.interval,
 		chance = biome.spawn_chance,
 		neighbors = biome.neighbors,
+		label = biome.label,
 		action = function(pos, node, active_object_count, active_object_count_wider)
 			local p_top = { x = pos.x, y = pos.y + 1, z = pos.z }	
 			local n_top = minetest.get_node(p_top)
 			local perlin_fertile_area = minetest.get_perlin(biome.seed_diff, perlin_octaves, perlin_persistence, perlin_scale)
-			local noise1 = perlin_fertile_area:get2d({x=p_top.x, y=p_top.z})
-			local noise2 = biome_lib.perlin_temperature:get2d({x=p_top.x, y=p_top.z})
-			local noise3 = biome_lib.perlin_humidity:get2d({x=p_top.x+150, y=p_top.z+50})
-			if noise1 > biome.plantlife_limit 
-			  and noise2 <= biome.temp_min
-			  and noise2 >= biome.temp_max
-			  and noise3 <= biome.humidity_min
-			  and noise3 >= biome.humidity_max
-			  and biome_lib:is_node_loaded(p_top) then
+
+			local fertility, temperature, humidity = get_biome_data(pos, perlin_fertile_area)
+
+			local pos_biome_ok = pos.y >= biome.min_elevation and pos.y <= biome.max_elevation
+				and fertility > biome.plantlife_limit
+				and temperature <= biome.temp_min and temperature >= biome.temp_max
+				and humidity <= biome.humidity_min and humidity >= biome.humidity_max
+				and biome_lib:is_node_loaded(p_top)
+
+			if not pos_biome_ok then
+				return -- Outside of biome
+			end
+
 			local n_light = minetest.get_node_light(p_top, nil)
-				if not (biome.avoid_nodes and biome.avoid_radius and minetest.find_node_near(p_top, biome.avoid_radius + math.random(-1.5,2), biome.avoid_nodes))
-				  and n_light >= biome.light_min
-				  and n_light <= biome.light_max
-				  and (not(biome.neighbors and biome.ncount) or #(minetest.find_nodes_in_area({x=pos.x-1, y=pos.y, z=pos.z-1}, {x=pos.x+1, y=pos.y, z=pos.z+1}, biome.neighbors)) > biome.ncount )
-				  and (not(biome.near_nodes and biome.near_nodes_count and biome.near_nodes_size) or #(minetest.find_nodes_in_area({x=pos.x-biome.near_nodes_size, y=pos.y-biome.near_nodes_vertical, z=pos.z-biome.near_nodes_size}, {x=pos.x+biome.near_nodes_size, y=pos.y+biome.near_nodes_vertical, z=pos.z+biome.near_nodes_size}, biome.near_nodes)) >= biome.near_nodes_count)
-				  and (not(biome.air_count and biome.air_size) or #(minetest.find_nodes_in_area({x=p_top.x-biome.air_size, y=p_top.y, z=p_top.z-biome.air_size}, {x=p_top.x+biome.air_size, y=p_top.y, z=p_top.z+biome.air_size}, "air")) >= biome.air_count)
-				  and pos.y >= biome.min_elevation
-				  and pos.y <= biome.max_elevation
-				  then
+			if n_light < biome.light_min or n_light > biome.light_max then
+				return -- Too dark or too bright
+			end
+
+			if biome.avoid_nodes and biome.avoid_radius and minetest.find_node_near(
+					p_top, biome.avoid_radius + math.random(-1.5,2), biome.avoid_nodes) then
+				return -- Nodes to avoid are nearby
+			end
+
+			if biome.neighbors and biome.ncount and
+					#minetest.find_nodes_in_area(
+						{x=pos.x-1, y=pos.y, z=pos.z-1},
+						{x=pos.x+1, y=pos.y, z=pos.z+1},
+						biome.neighbors
+					) <= biome.ncount then
+				return -- Near neighbour nodes are not present
+			end
+
+			local NEAR_DST = biome.near_nodes_size
+			if biome.near_nodes and biome.near_nodes_count and biome.near_nodes_size and
+					#minetest.find_nodes_in_area(
+						{x=pos.x-NEAR_DST, y=pos.y-biome.near_nodes_vertical, z=pos.z-NEAR_DST},
+						{x=pos.x+NEAR_DST, y=pos.y+biome.near_nodes_vertical, z=pos.z+NEAR_DST},
+						biome.near_nodes
+					) < biome.near_nodes_count then
+				return -- Far neighbour nodes are not present
+			end
+
+			if (biome.air_count and biome.air_size) and
+					#minetest.find_nodes_in_area(
+						{x=p_top.x-biome.air_size, y=p_top.y, z=p_top.z-biome.air_size},
+						{x=p_top.x+biome.air_size, y=p_top.y, z=p_top.z+biome.air_size},
+						"air"
+					) < biome.air_count then
+				return -- Not enough air
+			end
+
 			local walldir = biome_lib:find_adjacent_wall(p_top, biome.verticals_list, biome.choose_random_wall)
 			if biome.alt_wallnode and walldir then
 				if n_top.name == "air" then
 					minetest.swap_node(p_top, { name = biome.alt_wallnode, param2 = walldir })
 				end
-					else
+				return
+			end
+
 			local currentsurface = minetest.get_node(pos).name
-						if currentsurface ~= "default:water_source"
-						  or (currentsurface == "default:water_source" and #(minetest.find_nodes_in_area({x=pos.x, y=pos.y-biome.depth_max-1, z=pos.z}, {x=pos.x, y=pos.y, z=pos.z}, {"default:dirt", "default:dirt_with_grass", "default:sand"})) > 0 )
-						  then
+
+			if biome_lib.default_water_nodes[currentsurface] and
+					#minetest.find_nodes_in_area(
+						{x=pos.x, y=pos.y-biome.depth_max-1, z=pos.z},
+						vector.new(pos),
+						biome_lib.default_wet_surfaces
+					) == 0 then
+				return -- On water but no ground nearby
+			end
+
 			local rnd = math.random(1, biome.spawn_plants_count)
 			local plant_to_spawn = biome.spawn_plants[rnd]
 			local fdir = biome.facedir
@@ -561,64 +743,6 @@ function biome_lib:spawn_on_surfaces(sd,sp,sr,sc,ss,sa)
 				end
 			end
 		end
-					end
-				end
-			end
-		end
-	})
-end
-
--- The growing ABM
-
-function biome_lib:grow_plants(opts)
-
-	local options = opts
-
-	options.height_limit = options.height_limit or 5
-	options.ground_nodes = options.ground_nodes or { "default:dirt_with_grass" }
-	options.grow_nodes = options.grow_nodes or { "default:dirt_with_grass" }
-	options.seed_diff = options.seed_diff or 0
-
-	if options.grow_delay*time_scale >= 1 then
-		options.interval = options.grow_delay*time_scale
-	else
-		options.interval = 1
-	end
-
-	minetest.register_abm({
-		nodenames = { options.grow_plant },
-		interval = options.interval,
-		chance = options.grow_chance,
-		action = function(pos, node, active_object_count, active_object_count_wider)
-			local p_top = {x=pos.x, y=pos.y+1, z=pos.z}
-			local p_bot = {x=pos.x, y=pos.y-1, z=pos.z}
-			local n_top = minetest.get_node(p_top)
-			local n_bot = minetest.get_node(p_bot)
-			local root_node = minetest.get_node({x=pos.x, y=pos.y-options.height_limit, z=pos.z})
-			local walldir = nil
-			if options.need_wall and options.verticals_list then
-				walldir = biome_lib:find_adjacent_wall(p_top, options.verticals_list, options.choose_random_wall)
-			end
-			if (n_top.name == "air" or n_top.name == "default:snow")
-			  and (not options.need_wall or (options.need_wall and walldir)) then
-				-- corner case for changing short junglegrass
-				-- to dry shrub in desert
-				if n_bot.name == options.dry_early_node and options.grow_plant == "junglegrass:short" then
-					minetest.swap_node(pos, { name = "default:dry_shrub" })
-
-				elseif options.grow_vertically and walldir then
-					if biome_lib:search_downward(pos, options.height_limit, options.ground_nodes) then
-						minetest.swap_node(p_top, { name = options.grow_plant, param2 = walldir})
-					end
-
-				elseif not options.grow_result and not options.grow_function then
-					minetest.swap_node(pos, biome_lib.air)
-
-				else
-					biome_lib:replace_object(pos, options.grow_result, options.grow_function, options.facedir, options.seed_diff)
-				end
-			end
-		end
 	})
 end
 
@@ -633,15 +757,13 @@ function biome_lib:replace_object(pos, replacement, grow_function, walldir, seed
 		return
 	elseif growtype == "function" then
 		local perlin_fertile_area = minetest.get_perlin(seeddiff, perlin_octaves, perlin_persistence, perlin_scale)
-		local noise1 = perlin_fertile_area:get2d({x=pos.x, y=pos.z})
-		local noise2 = biome_lib.perlin_temperature:get2d({x=pos.x, y=pos.z})
-		grow_function(pos,noise1,noise2,walldir)
+		local fertility, temperature, _ = get_biome_data(pos, perlin_fertile_area)
+		grow_function(pos, fertility, temperature, walldir)
 		return
 	elseif growtype == "string" then
 		local perlin_fertile_area = minetest.get_perlin(seeddiff, perlin_octaves, perlin_persistence, perlin_scale)
-		local noise1 = perlin_fertile_area:get2d({x=pos.x, y=pos.z})
-		local noise2 = biome_lib.perlin_temperature:get2d({x=pos.x, y=pos.z})
-		assert(loadstring(grow_function.."(...)"))(pos,noise1,noise2,walldir)
+		local fertility, temperature, _ = get_biome_data(pos, perlin_fertile_area)
+		assert(loadstring(grow_function.."(...)"))(pos, fertility, temperature, walldir)
 		return
 	elseif growtype == "nil" then
 		minetest.swap_node(pos, { name = replacement, param2 = walldir})
@@ -651,71 +773,8 @@ function biome_lib:replace_object(pos, replacement, grow_function, walldir, seed
 	end
 end
 
--- function to decide if a node has a wall that's in verticals_list{}
--- returns wall direction of valid node, or nil if invalid.
-
-function biome_lib:find_adjacent_wall(pos, verticals, randomflag)
-	local verts = dump(verticals)
-	if randomflag then
-		local walltab = {}
-		
-		if string.find(verts, minetest.get_node({ x=pos.x-1, y=pos.y, z=pos.z   }).name) then walltab[#walltab + 1] = 3 end
-		if string.find(verts, minetest.get_node({ x=pos.x+1, y=pos.y, z=pos.z   }).name) then walltab[#walltab + 1] = 2 end
-		if string.find(verts, minetest.get_node({ x=pos.x  , y=pos.y, z=pos.z-1 }).name) then walltab[#walltab + 1] = 5 end
-		if string.find(verts, minetest.get_node({ x=pos.x  , y=pos.y, z=pos.z+1 }).name) then walltab[#walltab + 1] = 4 end
-
-		if #walltab > 0 then return walltab[math.random(1, #walltab)] end
-
-	else
-		if string.find(verts, minetest.get_node({ x=pos.x-1, y=pos.y, z=pos.z   }).name) then return 3 end
-		if string.find(verts, minetest.get_node({ x=pos.x+1, y=pos.y, z=pos.z   }).name) then return 2 end
-		if string.find(verts, minetest.get_node({ x=pos.x  , y=pos.y, z=pos.z-1 }).name) then return 5 end
-		if string.find(verts, minetest.get_node({ x=pos.x  , y=pos.y, z=pos.z+1 }).name) then return 4 end
-	end
-	return nil
-end
-
--- Function to search downward from the given position, looking for the first
--- node that matches the ground table.  Returns the new position, or nil if
--- height limit is exceeded before finding it.
-
-function biome_lib:search_downward(pos, heightlimit, ground)
-	for i = 0, heightlimit do
-		if string.find(dump(ground), minetest.get_node({x=pos.x, y=pos.y-i, z = pos.z}).name) then
-			return {x=pos.x, y=pos.y-i, z = pos.z}
-		end
-	end
-	return false
-end
-
-function biome_lib:find_open_side(pos)
-	if minetest.get_node({ x=pos.x-1, y=pos.y, z=pos.z }).name == "air" then
-		return {newpos = { x=pos.x-1, y=pos.y, z=pos.z }, facedir = 2}
-	end
-	if minetest.get_node({ x=pos.x+1, y=pos.y, z=pos.z }).name == "air" then
-		return {newpos = { x=pos.x+1, y=pos.y, z=pos.z }, facedir = 3}
-	end
-	if minetest.get_node({ x=pos.x, y=pos.y, z=pos.z-1 }).name == "air" then
-		return {newpos = { x=pos.x, y=pos.y, z=pos.z-1 }, facedir = 4}
-	end
-	if minetest.get_node({ x=pos.x, y=pos.y, z=pos.z+1 }).name == "air" then
-		return {newpos = { x=pos.x, y=pos.y, z=pos.z+1 }, facedir = 5}
-	end
-	return nil
-end
-
--- spawn_tree() on generate is routed through here so that other mods can hook
--- into it.
-
-function biome_lib:generate_tree(pos, nodes_or_function_or_model)
-	minetest.spawn_tree(pos, nodes_or_function_or_model)
-end
-
--- and this one's for the call used in the growing code
-
-function biome_lib:grow_tree(pos, nodes_or_function_or_model)
-	minetest.spawn_tree(pos, nodes_or_function_or_model)
-end
+dofile(biome_lib.modpath .. "/search_functions.lua")
+assert(loadfile(biome_lib.modpath .. "/growth.lua"))(time_scale)
 
 -- Check for infinite stacks
 
@@ -734,10 +793,34 @@ function biome_lib:get_nodedef_field(nodename, fieldname)
 	return minetest.registered_nodes[nodename][fieldname]
 end
 
-print("[Biome Lib] Loaded")
+if biome_lib.debug_log_level >= 3 then
+	biome_lib.last_count = 0
+
+	function biome_lib.show_pending_block_count()
+		if biome_lib.last_count ~= #biome_lib.block_log then
+			biome_lib.dbg(string.format("Pending block counts - ready to process: %-8icurrently deferred: %i",
+				#biome_lib.block_log, #biome_lib.block_recheck_list), 3)
+			biome_lib.last_count = #biome_lib.block_log
+			biome_lib.queue_idle_flag = false
+		elseif not biome_lib.queue_idle_flag then
+			if #biome_lib.block_recheck_list > 0 then
+				biome_lib.dbg("Mapblock queue only contains blocks that can't yet be processed.",  3)
+				biome_lib.dbg("Idling the queue until new blocks arrive or the next wake-up call occurs.",  3)
+			else
+				biome_lib.dbg("Mapblock queue has run dry.",  3)
+				biome_lib.dbg("Idling the queue until new blocks arrive.",  3)
+			end
+			biome_lib.queue_idle_flag = true
+		end
+		minetest.after(1, biome_lib.show_pending_block_count)
+	end
+
+	biome_lib.show_pending_block_count()
+end
 
 minetest.after(0, function()
-	print("[Biome Lib] Registered a total of "..(#biome_lib.surfaceslist_aircheck)+(#biome_lib.surfaceslist_no_aircheck).." surface types to be evaluated, spread")
-	print("[Biome Lib] across "..#biome_lib.actionslist_aircheck.." actions with air-checking and "..#biome_lib.actionslist_no_aircheck.." actions without.")
+	biome_lib.dbg("Registered a total of "..(#biome_lib.surfaceslist_aircheck)+(#biome_lib.surfaceslist_no_aircheck).." surface types to be evaluated, spread", 0)
+	biome_lib.dbg("across "..#biome_lib.actionslist_aircheck.." actions with air-checking and "..#biome_lib.actionslist_no_aircheck.." actions without.", 0)
 end)
 
+biome_lib.dbg("[Biome Lib] Loaded", 0)

mod.conf

@@ -1 +1,3 @@
 name = biome_lib
+min_minetest_version = 5.2.0
+optional_depends = default, intllib

search_functions.lua

@@ -0,0 +1,75 @@
+
+-- function to decide if a node has a wall that's in verticals_list{}
+-- returns wall direction of valid node, or nil if invalid.
+
+function biome_lib:find_adjacent_wall(pos, verticals, randomflag)
+	local verts = dump(verticals)
+	if randomflag then
+		local walltab = {}
+		
+		if string.find(verts, minetest.get_node({ x=pos.x-1, y=pos.y, z=pos.z   }).name) then walltab[#walltab + 1] = 3 end
+		if string.find(verts, minetest.get_node({ x=pos.x+1, y=pos.y, z=pos.z   }).name) then walltab[#walltab + 1] = 2 end
+		if string.find(verts, minetest.get_node({ x=pos.x  , y=pos.y, z=pos.z-1 }).name) then walltab[#walltab + 1] = 5 end
+		if string.find(verts, minetest.get_node({ x=pos.x  , y=pos.y, z=pos.z+1 }).name) then walltab[#walltab + 1] = 4 end
+
+		if #walltab > 0 then return walltab[math.random(1, #walltab)] end
+
+	else
+		if string.find(verts, minetest.get_node({ x=pos.x-1, y=pos.y, z=pos.z   }).name) then return 3 end
+		if string.find(verts, minetest.get_node({ x=pos.x+1, y=pos.y, z=pos.z   }).name) then return 2 end
+		if string.find(verts, minetest.get_node({ x=pos.x  , y=pos.y, z=pos.z-1 }).name) then return 5 end
+		if string.find(verts, minetest.get_node({ x=pos.x  , y=pos.y, z=pos.z+1 }).name) then return 4 end
+	end
+	return nil
+end
+
+-- Function to search downward from the given position, looking for the first
+-- node that matches the ground table.  Returns the new position, or nil if
+-- height limit is exceeded before finding it.
+
+function biome_lib:search_downward(pos, heightlimit, ground)
+	for i = 0, heightlimit do
+		if string.find(dump(ground), minetest.get_node({x=pos.x, y=pos.y-i, z = pos.z}).name) then
+			return {x=pos.x, y=pos.y-i, z = pos.z}
+		end
+	end
+	return false
+end
+
+function biome_lib:find_open_side(pos)
+	if minetest.get_node({ x=pos.x-1, y=pos.y, z=pos.z }).name == "air" then
+		return {newpos = { x=pos.x-1, y=pos.y, z=pos.z }, facedir = 2}
+	end
+	if minetest.get_node({ x=pos.x+1, y=pos.y, z=pos.z }).name == "air" then
+		return {newpos = { x=pos.x+1, y=pos.y, z=pos.z }, facedir = 3}
+	end
+	if minetest.get_node({ x=pos.x, y=pos.y, z=pos.z-1 }).name == "air" then
+		return {newpos = { x=pos.x, y=pos.y, z=pos.z-1 }, facedir = 4}
+	end
+	if minetest.get_node({ x=pos.x, y=pos.y, z=pos.z+1 }).name == "air" then
+		return {newpos = { x=pos.x, y=pos.y, z=pos.z+1 }, facedir = 5}
+	end
+	return nil
+end
+
+-- "Record" the map chunks being generated by the core mapgen,
+-- split into individual mapblocks to reduce lag
+
+minetest.register_on_generated(function(minp, maxp, blockseed)
+	local timestamp = minetest.get_us_time()
+	for x = 0, 4 do
+		local minx = minp.x + x*16
+		for y = 0, 4 do
+			local miny = minp.y + y*16
+			for z = 0, 4 do
+				local minz = minp.z + z*16
+
+				local bmin = {x=minx, y=miny, z=minz}
+				local bmax = {x=minx + 15, y=miny + 15, z=minz + 15}
+				biome_lib.block_log[#biome_lib.block_log + 1] = { bmin, bmax, true, timestamp }
+				biome_lib.block_log[#biome_lib.block_log + 1] = { bmin, bmax, false, timestamp }
+			end
+		end
+	end
+	biome_lib.run_block_recheck_list = true
+end)