Run mapgen in MT mapgen environment (MT 5.9.0)

mods/lzr_globals/init.lua

@@ -25,10 +25,6 @@ lzr_globals.MENU_SHIP_EDITOR_OFFSET = vector.new(13, 10, 31)
 lzr_globals.MENU_SHIP_SPEAKER_OFFSET = vector.new(6, 9, 25)
 lzr_globals.MENU_SHIP_TELEVISION_OFFSET = vector.new(5, 9, 25)
 lzr_globals.MENU_PLAYER_SPAWN_POS = vector.add(lzr_globals.MENU_SHIP_POS, lzr_globals.MENU_SHIP_PLAYER_SPAWN_OFFSET)
-lzr_globals.WATER_LEVEL = 1
-lzr_globals.SEABED_LEVEL = -1000
-lzr_globals.SEASTONE_LEVEL = -1002
-lzr_globals.DEEP_OCEAN_Z = -20000
 lzr_globals.GRAVITY = tonumber(minetest.settings:get("movement_gravity")) or 9.81
 lzr_globals.LASER_GLOW = 3
 lzr_globals.LASER_ALPHA = 0x8E
@@ -38,6 +34,10 @@ lzr_globals.PARROT_SPAWN_OFFSET = vector.new(0, 0.01, 0)
 
 lzr_globals.MAX_RECEIVER_RECALLS = 5
 
+-- WARNING: This value is duplicated in lzr_mapgen.
+-- Only change this value when also changing lzr_mapgen!
+lzr_globals.DEEP_OCEAN_Z = -20000
+
 -- Maximum number of nodes the player can see. We do this because
 -- the map is segmented in multiple zones (e.g. islands, deep ocean)
 -- with visible seams. By making sure the player is always far enough

mods/lzr_levels/init.lua

@@ -370,7 +370,7 @@ function lzr_levels.reset_area(clear, start_pos, size, start_pos_protected, size
 			aprot_min, aprot_max)
 	else
 		lzr_mapgen.generate_piece(start_pos, vector.add(start_pos, size),
-			false, aprot_min, aprot_max)
+			nil, aprot_min, aprot_max)
 	end
 
 	-- Also clear objects

mods/lzr_mapgen/init.lua

@@ -20,6 +20,11 @@ lzr_mapgen.get_backdrop_description = function(id)
 	return backdrop_descriptions[id]
 end
 
+dofile(minetest.get_modpath("lzr_mapgen").."/settings.lua")
 dofile(minetest.get_modpath("lzr_mapgen").."/aliases.lua")
-dofile(minetest.get_modpath("lzr_mapgen").."/islands.lua")
-dofile(minetest.get_modpath("lzr_mapgen").."/islands_decorations.lua")
+dofile(minetest.get_modpath("lzr_mapgen").."/decorations.lua")
+
+-- The mapgen script will both run in the global environment
+-- and the mapgen environment. See mapgen.lua to learn why.
+dofile(minetest.get_modpath("lzr_mapgen").."/mapgen.lua")
+minetest.register_mapgen_script(minetest.get_modpath("lzr_mapgen").."/mapgen.lua")

mods/lzr_mapgen/mapgen.lua

@@ -1,3 +1,68 @@
+-- The main mapgen code.
+
+--[[ THIS FILE WILL BE RUN TWICE!
+1) In the global Minetest environment,
+2) In the heavily-restricted threaded mapgen environment
+
+This means this file is very restricted and only has
+access to functions that are available in both the
+global and the mapgen environment. Refer to Minetest's
+Lua API documentation for details.
+
+In the global environment, this file runs to expose the
+function lzr_mapgen.generate_piece, but it does not call
+minetest.register_on_generated.
+
+In the mapgen environment, it uses
+minetest.register_on_generated, but it does not modify
+the global environment.
+
+The reason this file is called twice is to avoid code
+duplication.
+]]
+
+-- This variable will be true when we're in the mapgen
+-- environment. The mapgen environment does not have
+-- access to global variables, so if lzr_mapgen does
+-- not exist, we can decude we must be the mapgen
+-- environment.
+local IS_IN_MAPGEN_ENVIRONMENT = not minetest.global_exists("lzr_mapgen")
+
+
+--[[ MAPGEN OVERVIEW:
+The mapgen has two main zones:
+
+Deep Ocean: The Deep Ocean is a very simple zone and very fast
+to generate, it's just a flat layer of water with a flat seabed
+way below the surface. Perfect to spawn the ship in.
+
+Islands: Islands is a beautiful zone using 2D Perlin
+noise, featuring tropical islands, palms, plants, hills, and
+a “hilly” ocean floor. It is derived from the [islands] mod
+by TheTermos, released under the MIT License in 2019.
+
+Both zones are separated on the Z axis by DEEP_OCEAN_Z.
+
+There is a hard ugly seam between both zones, so it is
+important the game action happens far away from this
+seam.
+]]
+
+
+-- Some basic values for mapgen coordinates
+
+-- Water will be at this Y level, all the way down to SEABED_LEVEL+1
+local WATER_LEVEL = 1
+-- The seabed will be at this Y level, all the way down to SEASTONE_LEVEL+1 (deep ocean only)
+local SEABED_LEVEL = -1000
+-- The seastone will be at and below this Y level, all the way down to the bottom of the world (deep ocean only)
+local SEASTONE_LEVEL = -1002
+
+-- The deep ocean will begin when the Z coordinate is this value or lower.
+-- WARNING: This value is duplicated in lzr_globals.
+-- When you change it, you MUST also change it in lzr_globals!
+local DEEP_OCEAN_Z = -20000
+
 local floor = math.floor
 local ceil = math.ceil
 local min = math.min
@@ -94,22 +159,6 @@ local base_heightmap = {}
 local result_heightmap = {}
 
 
--- Set singlenode mapgen (air nodes only).
--- Disable the engine lighting calculation since that will be done for a
--- mapchunk of air nodes and will be incorrect after we place nodes.
-
-minetest.set_mapgen_setting('mg_name', 'singlenode', true)
-minetest.set_mapgen_setting('flags', 'nolight', true)
-minetest.set_mapgen_setting('seed', '5436146057422610855', true)
-
-minetest.set_mapgen_setting("mg_biome_np_heat", 
-	"90,0,(1000,1000,1000),5349,3,0.5,2",
-	true)
-
-minetest.set_mapgen_setting("mg_biome_np_humidity", 
-	"54,10,(1000,1000,1000),5349,3,0.5,2",
-	true)
-
 -- Get the content IDs for the nodes used.
 
 local c_stone = minetest.get_content_id("lzr_core:stone")
@@ -147,29 +196,33 @@ local function get_terrain_height(theight,hheight,cheight)
 	return theight
 end
  
-lzr_mapgen.generate_piece = function(minp, maxp, is_on_generated, prot_min, prot_max)
+-- Generate a piece of the map and set nodes in the specified area.
+-- * minp: Minimum position of the area
+-- * maxp: Maximum position of the area
+-- * vm: VoxelManip object (only required when calling this function in the mapgen environment. Set to nil otherwise)
+-- * prot_min: Minimum position of protected area. The protected area will NOT be overwritten by this function
+-- * prot_min: Maximum position of protected area
+local generate_piece = function(minp, maxp, vm, prot_min, prot_max)
 
 	local sidelen_x = maxp.x - minp.x + 1
 	local sidelen_z = maxp.z - minp.z + 1
 	local permapdims3d = {x = sidelen_x, y = sidelen_z}
 
-	local clear = is_on_generated ~= true
+	local clear = IS_IN_MAPGEN_ENVIRONMENT ~= true
 
 	-- voxelmanip stuff
-	local vm, emin, emax
-	if is_on_generated then
-		vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
-	else
+	if not vm then
 		vm = minetest.get_voxel_manip(minp, maxp)
-		emin, emax = vm:get_emerged_area()
 	end
+	local emin, emax = vm:get_emerged_area()
+
 	local area = VoxelArea:new{MinEdge = emin, MaxEdge = emax}
 	vm:get_data(data)
 
 	-- If we are fully outside the islands area,
 	-- we can switch to the ultra-fast deep ocean
 	-- algorithm.
-	local generate_islands = maxp.z > lzr_globals.DEEP_OCEAN_Z
+	local generate_islands = maxp.z > DEEP_OCEAN_Z
 	local isln_terrain = nil
 	local isln_var = nil
 	local isln_hills = nil
@@ -238,12 +291,12 @@ lzr_mapgen.generate_piece = function(minp, maxp, is_on_generated, prot_min, prot
 				if not prot_min or not vector.in_area(mpos, prot_min, prot_max) then
 					local vi = area:index(x, y, z)
 					-- Deep ocean
-					if z <= lzr_globals.DEEP_OCEAN_Z then
-						if y <= lzr_globals.SEASTONE_LEVEL then
+					if z <= DEEP_OCEAN_Z then
+						if y <= SEASTONE_LEVEL then
 							data[vi] = c_stone
-						elseif y <= lzr_globals.SEABED_LEVEL then
+						elseif y <= SEABED_LEVEL then
 							data[vi] = c_seabed
-						elseif y <= lzr_globals.WATER_LEVEL then
+						elseif y <= WATER_LEVEL then
 							data[vi] = c_water
 						elseif clear then
 							data[vi] = minetest.CONTENT_AIR
@@ -271,37 +324,36 @@ lzr_mapgen.generate_piece = function(minp, maxp, is_on_generated, prot_min, prot
 	end
 
 	vm:set_data(data)
+
 	if generate_islands then
 		minetest.generate_decorations(vm)
 		minetest.generate_ores(vm)
-		if is_on_generated then
+		if IS_IN_MAPGEN_ENVIRONMENT then
 			vm:calc_lighting()
-		end
-		vm:write_to_map(true)
-		minetest.after(0,function()
-			minetest.fix_light(minp, maxp)
-		end)
 		else
 			vm:write_to_map(true)
 		end
-
-
+	elseif not IS_IN_MAPGEN_ENVIRONMENT then
+		vm:write_to_map(true)
+	end
 end
 
 
--- On generated function.
+if IS_IN_MAPGEN_ENVIRONMENT then
+	minetest.log("action", "[lzr_mapgen] mapgen script successfully run in mapgen environment")
+	-- On generated function for the mapgen environment
 
--- 'minp' and 'maxp' are the minimum and maximum positions of the mapchunk that
--- define the 3D volume.
-
-minetest.register_on_generated(function(minp, maxp, seed)
+	minetest.register_on_generated(function(vmanip, minp, maxp)
 		-- Start time of mapchunk generation.
 		local t0 = os.clock()
-	lzr_mapgen.generate_piece(minp, maxp, true)
+		generate_piece(minp, maxp, vmanip)
 		-- Print generation time of this mapchunk.
 		local chugent = ceil((os.clock() - t0) * 1000)
 		minetest.log("action", "[lzr_mapgen] Mapchunk generation time for piece at " .. minetest.pos_to_string(minp)..": " .. chugent .. " ms")
 	end)
-
-
-
+else
+	minetest.log("action", "[lzr_mapgen] mapgen script successfully run in global environment")
+	-- Expose generate_piece to the global environment when this file does not
+	-- run as mapgen thrad
+	lzr_mapgen.generate_piece = generate_piece
+end

mods/lzr_mapgen/settings.lua

@@ -0,0 +1,23 @@
+-- Mapgen settings
+
+
+-- Set singlenode mapgen
+minetest.set_mapgen_setting('mg_name', 'singlenode', true)
+
+-- Disable the engine lighting calculation since that will be done for a
+-- mapchunk of air nodes and will be incorrect after we place nodes.
+minetest.set_mapgen_setting('flags', 'nolight', true)
+
+-- Set a fixed seed so the islands backdrop used by levels
+-- will stay consistent for all players
+minetest.set_mapgen_setting('seed', '5436146057422610855', true)
+
+minetest.set_mapgen_setting("mg_biome_np_heat", 
+	"90,0,(1000,1000,1000),5349,3,0.5,2",
+	true)
+
+minetest.set_mapgen_setting("mg_biome_np_humidity", 
+	"54,10,(1000,1000,1000),5349,3,0.5,2",
+	true)
+
+