-- This tables looks up nodes that aren't already stored.
local node = setmetatable({}, {
	__index = function(t, k)
		if not (t and k and type(t) == 'table') then
			return
		end

		t[k] = minetest.get_content_id(k)
		return t[k]
	end
})

loud_walking.node = node

local cloud_i = 0.5
local glass = {"loud_walking:sky_scrith", "loud_walking:cloud_scrith", "loud_walking:transparent_scrith"}


local data = {}
local p2data = {}  -- vm rotation data buffer
local lightmap = {}
local vm, emin, emax, a, csize, heightmap, biomemap
local div_sz_x, div_sz_z, minp, maxp, terrain, cave
local cloud

local terrain_noise = {offset = 0,
scale = 20, seed = 8829, spread = {x = 40, y = 40, z = 40},
octaves = 6, persist = 0.4, lacunarity = 2}

local cave_noise = {offset = 0, scale = 1,
seed = -3977, spread = {x = 30, y = 30, z = 30}, octaves = 3,
persist = 0.8, lacunarity = 2}

local cloud_noise = {offset = 0, scale = 1,
seed = -7874, spread = {x = 30, y = 30, z = 30}, octaves = 3,
persist = 0.8, lacunarity = 2}

loud_walking.biomes = {}
local biomes = loud_walking.biomes
local biome_names = {}
biome_names["common"] = {}
biome_names["uncommon"] = {}
do
	local biome_terrain_scale = {}
	biome_terrain_scale["coniferous_forest"] = 0.75
	biome_terrain_scale["rainforest"] = 0.33
	biome_terrain_scale["underground"] = 1.5

	local tree_biomes = {}
	tree_biomes["deciduous_forest"] = {"deciduous_trees"}
	tree_biomes["coniferous_forest"] = {"conifer_trees"}
	tree_biomes["taiga"] = {"conifer_trees"}
	tree_biomes["rainforest"] = {"jungle_trees"}
	tree_biomes["rainforest_swamp"] = {"jungle_trees"}
	tree_biomes["coniferous_forest"] = {"conifer_trees"}
	tree_biomes["savanna"] = {"acacia_trees"}

	for i, obiome in pairs(minetest.registered_biomes) do
		local biome = table.copy(obiome)
		biome.special_tree_prob = 2
		if biome.name == "savanna" then
			biome.special_tree_prob = 30
		end
		local rarity = "common"
		biome.terrain_scale = biome_terrain_scale[biome] or 0.5
		if string.find(biome.name, "ocean") then
			biome.terrain_scale = 1
			rarity = "uncommon"
		end
		if string.find(biome.name, "swamp") then
			biome.terrain_scale = 0.25
			rarity = "uncommon"
		end
		if string.find(biome.name, "beach") then
			biome.terrain_scale = 0.25
			rarity = "uncommon"
		end
		if string.find(biome.name, "^underground$") then
			biome.node_top = "default:stone"
			rarity = "uncommon"
		end
		biome.special_trees = tree_biomes[biome.name]
		biomes[biome.name] = biome
		biome_names[rarity][#biome_names[rarity]+1] = biome.name
	end
end
biomes["control"] = {}

local cave_stones = {
	"loud_walking:stone_with_moss",
	"loud_walking:stone_with_lichen",
	"loud_walking:stone_with_algae",
	"loud_walking:stone_with_salt",
}
local mushroom_stones = {}
mushroom_stones[node["default:stone"]] = true
mushroom_stones[node["loud_walking:stone_with_algae"]] = true
mushroom_stones[node["loud_walking:stone_with_lichen"]] = true

local function connection(x, y, z)
	local min_x = math.floor((x + 32) / csize.x)
	local min_y = math.floor((y + 32) / csize.y)
	local min_z = math.floor((z + 32) / csize.z)

	--local seed_noise = minetest.get_perlin({offset = 0, scale = 32768,
	--seed = 5202, spread = {x = 80, y = 80, z = 80}, octaves = 2,
	--persist = 0.4, lacunarity = 2})
	--math.randomseed(seed_noise:get2d({x=minp.x, y=minp.z}))

	local ct = min_x % 2 + min_y % 2 + min_z % 2
	local r = min_x % 2 + 2 * (min_y % 2) + 4 * (min_z % 2)
	if ct == 1 then
		return r
	end

	return nil
end

local function get_decoration(biome)
	if not loud_walking.decorations then
		return
	end

	for i, deco in pairs(loud_walking.decorations) do
		if not deco.biomes or deco.biomes[biome] then
			local range = 1000
			if deco.deco_type == "simple" then
				if deco.fill_ratio and math.random(range) - 1 < deco.fill_ratio * 1000 then
					return deco.decoration
				end
			else
				-- nop
			end
		end
	end
end


local pod_size = {x=300, y=100, z=200}
local half_pod = {x=math.floor(pod_size.x / 2), y=math.floor(pod_size.y / 2), z=math.floor(pod_size.z / 2)}
local bridge_size = 50
local fcsize = {x=pod_size.x + bridge_size, y=pod_size.y + bridge_size, z=pod_size.z + bridge_size}
local bevel = half_pod.y
local room_size = 20
local control_off = math.floor(room_size / 4)
local biome_look = {}
local cave_look = {}


local function place_schematic(pos, schem, center)
	local rot = math.random(4) - 1
	local yslice = {}
	if schem.yslice_prob then
		for _, ys in pairs(schem.yslice_prob) do
			yslice[ys.ypos] = ys.prob
		end
	end

	if center then
		pos.x = pos.x - math.floor(schem.size.x / 2)
		pos.z = pos.z - math.floor(schem.size.z / 2)
	end

	for z1 = 0, schem.size.z - 1 do
		for x1 = 0, schem.size.x - 1 do
			local x, z
			if rot == 0 then
				x, z = x1, z1
			elseif rot == 1 then
				x, z = schem.size.z - z1 - 1, x1
			elseif rot == 2 then
				x, z = schem.size.x - x1 - 1, schem.size.z - z1 - 1
			elseif rot == 3 then
				x, z = z1, schem.size.x - x1 - 1
			end
			local fdz = (pos.z + z) % fcsize.z
			local fdx = (pos.x + x) % fcsize.x
			if fdz < pod_size.z - 1 and fdz > 0 and fdx < pod_size.x - 1 and fdx > 0 then
				local ivm = a:index(pos.x + x, pos.y, pos.z + z)
				local isch = z1 * schem.size.y * schem.size.x + x1 + 1
				for y = 0, schem.size.y - 1 do
					local fdy = (pos.y + y) % fcsize.y
					if math.min(fdx, pod_size.x - fdx) + math.min(fdy, pod_size.y - fdy) + math.min(fdz, pod_size.z - fdz) > bevel then
						if yslice[y] or 255 >= math.random(255) then
							local prob = schem.data[isch].prob or schem.data[isch].param1 or 255
							if prob >= math.random(255) and schem.data[isch].name ~= "air" then
								data[ivm] = node[schem.data[isch].name]
							end
							local param2 = schem.data[isch].param2 or 0
							p2data[ivm] = param2
						end
					end

					ivm = ivm + a.ystride
					isch = isch + schem.size.x
				end
			end
		end
	end
end


local function get_biome(x, y, z)
	local px = math.floor(x / fcsize.x)
	local py = math.floor(y / fcsize.y)
	local pz = math.floor(z / fcsize.z)

	if px % 10 == 6 and pz % 10 == 6 then
		return "control"
	else
		local hash = px * 1000000 + py * 1000 + pz
		if not biome_look[hash] then
			-- use the same seed (based on perlin noise).
			local seed_noise = minetest.get_perlin({offset = 0, scale = 32768, seed = 5202, spread = {x = 80, y = 80, z = 80}, octaves = 2, persist = 0.4, lacunarity = 2})
			math.randomseed(seed_noise:get3d({x=px, y=py, z=pz}))

			local rarity = "common"
			if math.random(5) > 4 then
				rarity = "uncommon"
			end
			biome_look[hash] = biome_names[rarity][math.random(#biome_names[rarity])]

			local cave_lining
			if math.random(3) ~= 1 then
				cave_lining = cave_stones[math.random(#cave_stones)]
			end
			cave_look[hash] = cave_lining
		end

		return 'rainforest', cave_look[hash]
		--return biome_look[hash], cave_look[hash]
	end
end


local function get_height_old(dx, dz, terrain_scale, ocean, index)
	local terr
	local half = {x=math.floor(csize.x / 2 + 0.5), y=math.floor(csize.y / 2 + 0.5), z=math.floor(csize.z / 2 + 0.5)}
	terrain_scale = terrain_scale or 1

	--if index == true then
	--	terr = minetest.get_perlin(terrain_noise):get2d({x=dx, y=dz})
	--	-- Still need csize here...
	--	dx = (dx + 32) % 80
	--	dz = (dz + 32) % 80
	if not index then
		index = dz * csize.x + dx + 1
		terr = terrain[index]
	else
		terr = terrain[index]
	end

	terr = math.floor(terr * terrain_scale + 0.5)

	local d = half.y - 2 - math.abs(math.abs(dx - (half.x - 0.5)) - math.abs(dz - (half.z - 0.5)))
	if math.abs(terr) > d then
		if terr > 0 then
			terr = math.floor(d + 0.5)
		elseif not ocean then
			terr = math.floor(0.5 - d)
		end
	end

	return terr
end

local function get_height(fdx, fdz, y, index, heights, terrain_scale, ocean)
	local py = math.floor(y / fcsize.y)

	if not terrain_scale then
		return
	end

	if not heights[py] then
		heights[py] = minetest.get_perlin_map(terrain_noise, csize):get2dMap_flat({x=minp.x, y=minp.z})
	end

	local terr = math.floor(heights[py][index] * terrain_scale + 0.5)

	local d = - math.abs(math.abs(fdx - (half_pod.x - 0.5)) - math.abs(fdz - (half_pod.z - 0.5)))
	if math.abs(fdx - half_pod.x) > math.abs(fdz - half_pod.z) then
		d = d + half_pod.x - 2
	else
		d = d + half_pod.z - 2
	end

	if math.abs(terr) > d then
		if terr > 0 then
			terr = math.floor(d + 0.5)
		elseif not ocean then
			terr = math.floor(0.5 - d)
		end
	end

	return terr
end


local function generate(p_minp, p_maxp, seed)
	minp, maxp = p_minp, p_maxp
	vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
	vm:get_data(data)
	--p2data = vm:get_param2_data()
	a = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
	csize = vector.add(vector.subtract(maxp, minp), 1)

	vm:set_lighting({day = 15, night = 0}, minp, maxp)
	lightmap = vm:get_light_data()

	local ground = half_pod.y
	local heights = {}
	cloud = minetest.get_perlin_map(cloud_noise, csize):get2dMap_flat(minp)
	cave = minetest.get_perlin_map(cave_noise, csize):get3dMap_flat(minp)

	local index = 0
	local index3d = 0
	for z = minp.z, maxp.z do
		local dz = z - minp.z
		local fdz = z % fcsize.z
		for x = minp.x, maxp.x do
			index = index + 1
			local dx = x - minp.x
			local fdx = x % fcsize.x
			local in_cave = false
			index3d = dz * csize.y * csize.x + dx + 1
			local ivm = a:index(x, minp.y, z)
			local cave_height = 0
			for y = minp.y, maxp.y do
				local dy = y - minp.y
				local fdy = y % fcsize.y
				local biome, cave_lining = get_biome(x, y, z)
				local node_top = biomes[biome].node_top or "default:dirt_with_grass"
				local node_filler = biomes[biome].node_filler or "default:dirt"
				local node_water_top = biomes[biome].node_water_top or "default:water_source"
				local node_water = biomes[biome].node_water or "default:water_source"
				local depth_top = biomes[biome].depth_top or 1
				local depth_water_top = biomes[biome].node_water_top or 1
				local depth_filler = biomes[biome].depth_filler or 1
				local node_stone = biomes[biome].node_stone or "default:stone"
				local ocean = string.find(biome, "ocean") and true or false
				local swamp = string.find(biome, "swamp") and true or false
				local beach = string.find(biome, "beach") and true or false
				local dunes = string.find(biome, "dunes") and true or false
				local height = half_pod.y - 5
				if not (biome == "underground" or biome == 'control') then
					height = get_height(fdx, fdz, y, index, heights, biomes[biome].terrain_scale, ocean)
				end

				if not (data[ivm] == node['air'] or data[ivm] == node['ignore']) then
					-- nop
				elseif biome == "control" and math.abs(fdx - half_pod.x) < 3 and math.abs(fdz - half_pod.z) < 3 then
					data[ivm] = node["loud_walking:air_ladder"]
				elseif fdz >= pod_size.z or fdx >= pod_size.x or fdy >= pod_size.y then
					if (fdy == half_pod.y and fdx == half_pod.x) or (fdy == half_pod.y and fdz == half_pod.z) then
						data[ivm] = node['loud_walking:scrith']
					else
						data[ivm] = node['air']
					end
				elseif math.min(fdx, pod_size.x - fdx) + math.min(fdy, pod_size.y - fdy) + math.min(fdz, pod_size.z - fdz) < bevel then
					data[ivm] = node['air']
					lightmap[ivm] = 0
					in_cave = false
				elseif (fdx == 0 or fdx == pod_size.x - 1) or (fdz == 0 or fdz == pod_size.z - 1) or (fdy == 0 or fdy == pod_size.y - 1) or math.min(fdx, pod_size.x - fdx) + math.min(fdy, pod_size.y - fdy) + math.min(fdz, pod_size.z - fdz) < bevel + 1 then
					if math.abs(fdy - half_pod.y - 2) < 2 and (fdz == half_pod.z or fdx == half_pod.x) then
						data[ivm] = node["air"]
					else
						if biome == "control" then
							data[ivm] = node[glass[3]]
						elseif fdy < half_pod.y then
							data[ivm] = node["loud_walking:scrith"]
							lightmap[ivm] = 0
						elseif biome == "underground" then
							data[ivm] = node["loud_walking:scrith"]
							lightmap[ivm] = 0
						elseif fdy == pod_size.y - 1 then
							data[ivm] = node[glass[cloud[index] < cloud_i and 1 or 2]]
						else
							data[ivm] = node[glass[1]]
						end
					end
				elseif fdz == 0 and fdz == pod_size.z - 1 or fdx == 0 and fdx == pod_size.x - 1 or fdy == 0 and fdy == pod_size.y - 1 then
					data[ivm] = node['loud_walking:scrith']
				elseif biome == "control" and fdy % 5 == 0 then
					data[ivm] = node["loud_walking:control_floor"]
				elseif biome == "control" and (math.abs(fdx - half_pod.x) < 3 or math.abs(fdz - half_pod.z) < 3) then
					data[ivm] = node["air"]
				elseif biome == "control" and ((math.abs(fdx - half_pod.x) % room_size == 3 and (math.abs(fdz - half_pod.z) - 12) % room_size > 3) or (math.abs(fdz - half_pod.z) % room_size == 3 and (math.abs(fdx - half_pod.x) - 12) % room_size > 3)) then
					data[ivm] = node["loud_walking:control_wall"]
				elseif biome == "control" then
					--
				elseif (((fdx == (half_pod.x - control_off) or fdx == (half_pod.x + control_off)) and fdz >= (half_pod.z - control_off) and fdz <= (half_pod.z + control_off)) or ((fdz == (half_pod.z - control_off) or fdz == (half_pod.z + control_off)) and fdx >= (half_pod.x - control_off) and fdx <= (half_pod.x + control_off))) and fdx ~= half_pod.x and fdz ~= half_pod.z and fdy == pod_size.y - 2 then
					data[ivm] = node["loud_walking:controls"]
				elseif (((fdx == (half_pod.x - control_off) or fdx == (half_pod.x + control_off)) and fdz >= (half_pod.z - control_off) and fdz <= (half_pod.z + control_off)) or ((fdz == (half_pod.z - control_off) or fdz == (half_pod.z + control_off)) and fdx >= (half_pod.x - control_off) and fdx <= (half_pod.x + control_off))) and fdx ~= half_pod.x and fdz ~= half_pod.z and fdy > pod_size.y - control_off then
					data[ivm] = node[glass[3]]
				elseif fdz >= (half_pod.z - control_off) and fdz <= (half_pod.z + control_off) and fdx >= (half_pod.x - control_off) and fdx <= (half_pod.x + control_off) and fdy == pod_size.y - control_off then
					data[ivm] = node[glass[3]]
				elseif not in_cave and  (ocean or swamp or beach) and fdy > height + ground and fdy <= half_pod.y and fdy == height + ground + 1 then
					-- ** water decorations **
					--local deco = get_decoration(biome)
					--if deco then
					--	data[ivm] = node[deco]
					--end
				elseif not in_cave and fdy == height + ground + 1 then
					local deco = get_decoration(biome)
					if deco then
						data[ivm] = node[deco]
					end
				elseif (ocean or swamp or beach) and fdy > height + ground and fdy <= half_pod.y and fdy >= half_pod.y - depth_water_top then
					data[ivm] = node[node_water_top]
					in_cave = false
				elseif (ocean or swamp or beach) and fdy > height + ground and fdy <= half_pod.y then
					data[ivm] = node[node_water]
					in_cave = false
				elseif fdy > height + ground then
					data[ivm] = node["air"]
					in_cave = false
				elseif cave[index3d] ^ 2 > (biome == "underground" and 0.5 or 1.3 - math.sin(fdy / (half_pod.y * 0.2))) then
					cave_height = cave_height + 1
					if height + ground >= fdy and not in_cave and fdy > height + ground - 10 then
						data[ivm] = node[node_top]
					elseif fdy == 1 then
						if not cave_lining and not ocean and not swamp and not beach and biome ~= "glacier" and math.random(6) == 1 then
							data[ivm] = node["default:lava_source"]
						elseif ocean or swamp or beach then
							data[ivm] = node[node_filler]
						end
					elseif (ocean or swamp or beach) and not in_cave and node_stone == "default:stone" and fdy < half_pod.y and math.random(20) == 1 then
						data[ivm] = node["loud_walking:glowing_fungal_stone"]
					elseif (ocean or swamp or beach) and fdy < half_pod.y then
						data[ivm] = node[node_water]
					elseif cave_height == 3 and node_filler == "default:dirt" and mushroom_stones[data[ivm - 3 * a.ystride]] and math.random(40) == 1 then
						data[ivm] = node["loud_walking:giant_mushroom_cap"]
						data[ivm - a.ystride] = node["loud_walking:giant_mushroom_stem"]
						data[ivm - 2 * a.ystride] = node["loud_walking:giant_mushroom_stem"]
						data[ivm - 3 * a.ystride] = node[node_filler]
					elseif cave_height == 2 and node_filler == "default:dirt" and mushroom_stones[data[ivm - 2 * a.ystride]] and math.random(20) == 1 then
						data[ivm] = node["loud_walking:huge_mushroom_cap"]
						data[ivm - a.ystride] = node["loud_walking:giant_mushroom_stem"]
						data[ivm - 2 * a.ystride] = node[node_filler]
					elseif not in_cave and node_stone == "default:stone" and not cave_lining and math.random(10) == 1 then
						data[ivm] = node["loud_walking:stalagmite"]
					elseif not in_cave and node_stone == "default:ice" and math.random(10) == 1 then
						data[ivm] = node["loud_walking:icicle_up"]
					else
						data[ivm] = node["air"]
					end
					in_cave = true
					--lightmap[ivm] = 0
				elseif cave_lining and cave[index3d] ^ 2 > (biome == "underground" and 0.4 or 1.2 - math.sin(fdy / (half_pod.y * 0.2))) then
					data[ivm] = node[cave_lining]
					lightmap[ivm] = 0
				elseif fdy > height + ground - depth_top then
					data[ivm] = node[node_top]
					lightmap[ivm] = 0
					in_cave = false
				elseif fdy > height + ground - depth_filler - depth_top then
					data[ivm] = node[node_filler]
					lightmap[ivm] = 0
					in_cave = false
				else
					data[ivm] = node[node_stone]
					if in_cave and node_stone == "default:stone" and math.random(20) == 1 then
						data[ivm] = node["loud_walking:glowing_fungal_stone"]
					elseif in_cave and not (ocean or swamp or beach) and node_stone == "default:stone" and not cave_lining and math.random(10) == 1 then
						data[ivm - a.ystride] = node["loud_walking:stalactite"]
					elseif in_cave and not (ocean or swamp or beach) and node_stone == "default:ice" and math.random(10) == 1 then
						data[ivm - a.ystride] = node["loud_walking:icicle_down"]
					end
					lightmap[ivm] = 0
					in_cave = false
				end

				if not in_cave then
					cave_height = 0
				end

				ivm = ivm + a.ystride
				index3d = index3d + csize.x
			end
		end
	end

	local index = 0
	for z = minp.z, maxp.z do
		local fdz = z % fcsize.z
		for x = minp.x, maxp.x do
			local fdx = x % fcsize.x
			index = index + 1
			for y = minp.y, maxp.y do
				local fdy = y % fcsize.y
				if fdz % 5 == 0 and fdx % 5 == 0 then
					local fdy = y % fcsize.y
					local pod = fdz < pod_size.z and fdx < pod_size.x and fdy < pod_size.y
					local biome, cave_lining = get_biome(x, y, z)
					local ocean = string.find(biome, "ocean") and true or false
					local height = get_height(fdx, fdz, y, index, heights, biomes[biome].terrain_scale, ocean)

					if biome ~= 'control' and pod and fdy == height + ground and biomes[biome].special_tree_prob and math.random(biomes[biome].special_tree_prob) == 1 then
						local rx = x + math.random(5) - 1
						local rz = z + math.random(5) - 1
						local swamp = string.find(biome, "swamp") and true or false
						local node_top = biomes[biome].node_top or "default:dirt_with_grass"

						local ivm = a:index(rx, y, rz)
						if (swamp or data[ivm + a.ystride] ~= node["default:water_source"]) and (data[ivm] == node[node_top]) then
							if biomes[biome].special_trees then
								local tree_type = biomes[biome].special_trees[math.random(#biomes[biome].special_trees)]
								if tree_type and loud_walking.schematics then
									local schem = loud_walking.schematics[tree_type][math.random(#loud_walking.schematics[tree_type])]
									local pos = {x=rx, y=y, z=rz}
									-- The minetest schematic functions don't seem very accurate.
									place_schematic(pos, schem, true)
								end
							else
								-- regular schematics?
							end
						end
					end
				end
			end
		end
	end

	if false and pod and biome == "control" then
		for dy = 0, 15 do
			for dz = 0, 1 do
				for dx = 0, 1 do
					local x1 = minp.x + dx * 26 + 17
					local z1 = minp.z + dz * 26 + 17
					local y1 = minp.y + dy * 5

					local sr = math.random(6)
					for z = 0, 20 do
						local ivm = a:index(x1, y1, z1 + z)
						for x = 0, 20 do
							if sr == 1 then
								if dy > 0 then
									if data[ivm] == node["loud_walking:control_floor_alert_down"] then
										data[ivm] = node["loud_walking:control_floor_alert_both"]
									else
										data[ivm] = node["loud_walking:control_floor_alert_up"]
									end
								end
								if dy < 15 then
									data[ivm + a.ystride * 5] = node["loud_walking:control_floor_alert_down"]
								end
							elseif sr == 2 then
								if x > 1 and x < 19 and z > 1 and z < 19 and (z - 2) % 4 ~= 0 and (x - 2) % 4 ~= 0 then
									for y = 1, 4 do
										data[ivm + y * a.ystride] = node["loud_walking:air_ladder"]
									end
								end
							elseif sr == 3 then
								if dy > 0 and data[ivm] ~= node["loud_walking:control_floor_alert_down"] and x > 0 and z > 0 and x < 20 and z < 20 then
									data[ivm] = node["loud_walking:control_floor_growth"]
									local sr2 = math.random(20)
									if sr2 == 1 then
										data[ivm + a.ystride] = node["loud_walking:control_plant_1"]
									elseif sr2 == 2 then
										data[ivm + a.ystride] = node["loud_walking:control_plant_2"]
									end
								end
							elseif sr == 4 then
								if dy < 15 and (x > 0 and x < 20 and z > 0 and z < 20) and (((x == 1 or x == 19) and math.abs(z - 10) > 3) or ((z == 1 or z == 19) and math.abs(x - 10) > 3)) then
									data[ivm + 3 * a.ystride] = node["loud_walking:controls"]
								end
							end

							ivm = ivm + 1
						end
					end
				end
			end
		end
	end

	vm:set_data(data)
	minetest.generate_ores(vm, minp, maxp)
	--vm:set_param2_data(p2data)
	vm:set_light_data(lightmap)
	vm:update_liquids()
	vm:calc_lighting(minp, maxp, false)
	vm:write_to_map()
end


local function generate_old(p_minp, p_maxp, seed)
	minp, maxp = p_minp, p_maxp
	vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
	vm:get_data(data)
	--p2data = vm:get_param2_data()
	a = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
	csize = vector.add(vector.subtract(maxp, minp), 1)

	-- Deal with memory issues. This, of course, is supposed to be automatic.
	local mem = math.floor(collectgarbage("count")/1024)
	if mem > 300 then
		print("Loud Walking: Manually collecting garbage...")
		collectgarbage("collect")
	end

	-- use the same seed (based on perlin noise).
	local seed_noise = minetest.get_perlin({offset = 0, scale = 32768,
	seed = 5202, spread = {x = 80, y = 80, z = 80}, octaves = 2,
	persist = 0.4, lacunarity = 2})
	math.randomseed(seed_noise:get2d({x=minp.x, y=minp.z}))

	-- Keep this first after seeding!
	local px = math.floor((minp.x + 32) / csize.x)
	local pz = math.floor((minp.z + 32) / csize.z)
	local biome = get_biome(px, pz)
	local cave_lining = cave_stones[math.random(#cave_stones)]
	if math.random(3) == 1 then
		cave_lining = nil
	end

	vm:set_lighting({day = 15, night = (biome == "control" and 15 or 0)}, minp, maxp)
	lightmap = vm:get_light_data()

	local node_top = biomes[biome].node_top or "default:dirt_with_grass"
	local node_filler = biomes[biome].node_filler or "default:dirt"
	local node_water_top = biomes[biome].node_water_top or "default:water_source"
	local node_water = biomes[biome].node_water or "default:water_source"
	local depth_top = biomes[biome].depth_top or 1
	local depth_water_top = biomes[biome].node_water_top or 1
	local depth_filler = biomes[biome].depth_filler or 1
	local node_stone = biomes[biome].node_stone or "default:stone"
	local ocean = string.find(biome, "ocean") and true or false
	local swamp = string.find(biome, "swamp") and true or false
	local beach = string.find(biome, "beach") and true or false
	local dunes = string.find(biome, "dunes") and true or false
	local half = {x=math.floor(csize.x / 2 + 0.5), y=math.floor(csize.y / 2 + 0.5), z=math.floor(csize.z / 2 + 0.5)}
	local ground = half.y

	beach = beach or dunes
	if ocean then
		ground = ground - 15
	elseif swamp or beach then
		ground = ground - 3
	end

	terrain = minetest.get_perlin_map(terrain_noise, csize):get2dMap_flat(minp)
	cave = minetest.get_perlin_map(cave_noise, csize):get3dMap_flat(minp)
	cloud = minetest.get_perlin_map(cloud_noise, csize):get2dMap_flat(minp)

	local pod = is_pod(minp.x, minp.y, minp.z)
	local connection = connection(minp.x, minp.y, minp.z)

	local index = 0
	local index3d = 0
	for z = minp.z, maxp.z do
		local dz = z - minp.z
		for x = minp.x, maxp.x do
			index = index + 1
			local dx = x - minp.x
			index3d = dz * csize.y * csize.x + dx + 1
			local ivm = a:index(x, minp.y, z)

			local terr = get_height(dx, dz, biomes[biome].terrain_scale, ocean, index)
			local in_cave = false
			if biome == "underground" then
				terr = half.y - 5
			end

			local cave_height = 0
			for y = minp.y, maxp.y do
				local dy = y - minp.y
				if pod then
					if biome == "control" and math.abs(dx - half.x) < 3 and math.abs(dz - half.z) < 3 then
						data[ivm] = node["loud_walking:air_ladder"]
					elseif math.min(dx, csize.x - dx) + math.min(dy, csize.y - dy) + math.min(dz, csize.z - dz) < bevel then
						data[ivm] = node["air"]
						lightmap[ivm] = 0
						in_cave = false
					elseif (dx == 0 or dx == csize.x - 1) or (dz == 0 or dz == csize.z - 1) or (dy == 0 or dy == csize.y - 1) or math.min(dx, csize.x - dx) + math.min(dy, csize.y - dy) + math.min(dz, csize.z - dz) < bevel + 1 then
						if math.abs(dy - half.y - 2) < 2 and (dz == half.z or dx == half.x) then
							data[ivm] = node["air"]
						else
							if biome == "control" then
								data[ivm] = node[glass[3]]
							elseif dy < half.y then
								data[ivm] = node["loud_walking:scrith"]
								lightmap[ivm] = 0
							elseif biome == "underground" then
								data[ivm] = node["loud_walking:scrith"]
								lightmap[ivm] = 0
							elseif dy == csize.y - 1 then
								data[ivm] = node[glass[cloud[index] < cloud_i and 1 or 2]]
							else
								data[ivm] = node[glass[1]]
							end
						end
						in_cave = false
					elseif biome == "control" and dy % 5 == 0 then
						data[ivm] = node["loud_walking:control_floor"]
					elseif biome == "control" and (math.abs(dx - half.x) < 3 or math.abs(dz - half.z) < 3) then
						data[ivm] = node["air"]
					elseif biome == "control" and ((math.abs(dx - half.x) % 20 == 3 and (math.abs(dz - half.z) - 12) % 20 > 3) or (math.abs(dz - half.z) % 20 == 3 and (math.abs(dx - half.x) - 12) % 20 > 3)) then
						data[ivm] = node["loud_walking:control_wall"]
					elseif biome == "control" then
						--
					elseif (((dx == 35 or dx == 45) and dz >= 35 and dz <= 45) or ((dz == 35 or dz == 45) and dx >= 35 and dx <= 45)) and dx ~= 40 and dz ~= 40 and dy == csize.y - 2 then
						data[ivm] = node["loud_walking:controls"]
					elseif (((dx == 35 or dx == 45) and dz >= 35 and dz <= 45) or ((dz == 35 or dz == 45) and dx >= 35 and dx <= 45)) and dx ~= 40 and dz ~= 40 and dy > csize.y - 5 then
						data[ivm] = node[glass[3]]
					elseif dz >= 35 and dz <= 45 and dx >= 35 and dx <= 45 and dy == csize.y - 5 then
						data[ivm] = node[glass[3]]
					elseif not in_cave and  (ocean or swamp or beach) and dy > terr + ground and dy <= half.y and dy == terr + ground + 1 then
						-- ** water decorations **
						--local deco = get_decoration(biome)
						--if deco then
						--	data[ivm] = node[deco]
						--end
					elseif not in_cave and dy == terr + ground + 1 then
						local deco = get_decoration(biome)
						if deco then
							data[ivm] = node[deco]
						end
					elseif (ocean or swamp or beach) and dy > terr + ground and dy <= half.y and dy >= half.y - depth_water_top then
						data[ivm] = node[node_water_top]
						in_cave = false
					elseif (ocean or swamp or beach) and dy > terr + ground and dy <= half.y then
						data[ivm] = node[node_water]
						in_cave = false
					elseif dy > terr + ground then
						data[ivm] = node["air"]
						in_cave = false
					elseif cave[index3d] ^ 2 > (biome == "underground" and 0.5 or 1.3 - math.sin(dy / (half.y * 0.2))) then
						cave_height = cave_height + 1
						if terr + ground >= dy and not in_cave and dy > terr + ground - 10 then
							data[ivm] = node[node_top]
						elseif dy == 1 then
							if not cave_lining and not ocean and not swamp and not beach and biome ~= "glacier" and math.random(6) == 1 then
								data[ivm] = node["default:lava_source"]
							elseif ocean or swamp or beach then
								data[ivm] = node[node_filler]
							end
						elseif (ocean or swamp or beach) and not in_cave and node_stone == "default:stone" and dy < half.y and math.random(20) == 1 then
							data[ivm] = node["loud_walking:glowing_fungal_stone"]
						elseif (ocean or swamp or beach) and dy < half.y then
							data[ivm] = node[node_water]
						elseif cave_height == 3 and node_filler == "default:dirt" and mushroom_stones[data[ivm - 3 * a.ystride]] and math.random(40) == 1 then
							data[ivm] = node["loud_walking:giant_mushroom_cap"]
							data[ivm - a.ystride] = node["loud_walking:giant_mushroom_stem"]
							data[ivm - 2 * a.ystride] = node["loud_walking:giant_mushroom_stem"]
							data[ivm - 3 * a.ystride] = node[node_filler]
						elseif cave_height == 2 and node_filler == "default:dirt" and mushroom_stones[data[ivm - 2 * a.ystride]] and math.random(20) == 1 then
							data[ivm] = node["loud_walking:huge_mushroom_cap"]
							data[ivm - a.ystride] = node["loud_walking:giant_mushroom_stem"]
							data[ivm - 2 * a.ystride] = node[node_filler]
						elseif not in_cave and node_stone == "default:stone" and not cave_lining and math.random(10) == 1 then
							data[ivm] = node["loud_walking:stalagmite"]
						elseif not in_cave and node_stone == "default:ice" and math.random(10) == 1 then
							data[ivm] = node["loud_walking:icicle_up"]
						else
							data[ivm] = node["air"]
						end
						in_cave = true
						lightmap[ivm] = 0
					elseif cave_lining and cave[index3d] ^ 2 > (biome == "underground" and 0.4 or 1.2 - math.sin(dy / (half.y * 0.2))) then
						data[ivm] = node[cave_lining]
						lightmap[ivm] = 0
					elseif dy > terr + ground - depth_top then
						data[ivm] = node[node_top]
						lightmap[ivm] = 0
						in_cave = false
					elseif dy > terr + ground - depth_filler - depth_top then
						data[ivm] = node[node_filler]
						lightmap[ivm] = 0
						in_cave = false
					else
						data[ivm] = node[node_stone]
						if in_cave and node_stone == "default:stone" and math.random(20) == 1 then
							data[ivm] = node["loud_walking:glowing_fungal_stone"]
						elseif in_cave and not (ocean or swamp or beach) and node_stone == "default:stone" and not cave_lining and math.random(10) == 1 then
							data[ivm - a.ystride] = node["loud_walking:stalactite"]
						elseif in_cave and not (ocean or swamp or beach) and node_stone == "default:ice" and math.random(10) == 1 then
							data[ivm - a.ystride] = node["loud_walking:icicle_down"]
						end
						lightmap[ivm] = 0
						in_cave = false
					end
				elseif biome == "control" and math.abs(dx - half.x) < 3 and math.abs(dz - half.z) < 3 then
					data[ivm] = node["loud_walking:air_ladder"]
				elseif connection and dy == half.y and ((dx == half.x and connection % 4 == 0) or (dz == half.z and connection % 2 == 1)) then
					data[ivm] = node["loud_walking:scrith"]
					lightmap[ivm] = 0
				end

				if not in_cave then
					cave_height = 0
				end
				ivm = ivm + a.ystride
				index3d = index3d + csize.x
			end
		end
	end

	if pod then
		for dz = 0, 75, 5 do
			for dx = 0, 75, 5 do
				if biomes[biome].special_tree_prob and math.random(biomes[biome].special_tree_prob) == 1 then
					local x = minp.x + dx + math.random(5) - 1
					local z = minp.z + dz + math.random(5) - 1
					local y = minp.y + get_height(x - minp.x, z - minp.z, biomes[biome].terrain_scale, ocean) + ground

					local ivm = a:index(x, y, z)
					if y >= minp.y and y <= maxp.y and (swamp or data[ivm + a.ystride] ~= node["default:water_source"]) and (data[ivm] == node[node_top]) then
						if biomes[biome].special_trees then
							local tree_type = biomes[biome].special_trees[math.random(#biomes[biome].special_trees)]
							if tree_type and loud_walking.schematics then
								local schem = loud_walking.schematics[tree_type][math.random(#loud_walking.schematics[tree_type])]
								local pos = {x=x, y=y, z=z}
								-- The minetest schematic functions don't seem very accurate.
								place_schematic(pos, schem, true)
							end
						else
							-- regular schematics?
						end
					end
				end
			end
		end
	end

	if pod and biome == "control" then
		for dy = 0, 15 do
			for dz = 0, 1 do
				for dx = 0, 1 do
					local x1 = minp.x + dx * 26 + 17
					local z1 = minp.z + dz * 26 + 17
					local y1 = minp.y + dy * 5

					local sr = math.random(6)
					for z = 0, 20 do
						local ivm = a:index(x1, y1, z1 + z)
						for x = 0, 20 do
							if sr == 1 then
								if dy > 0 then
									if data[ivm] == node["loud_walking:control_floor_alert_down"] then
										data[ivm] = node["loud_walking:control_floor_alert_both"]
									else
										data[ivm] = node["loud_walking:control_floor_alert_up"]
									end
								end
								if dy < 15 then
									data[ivm + a.ystride * 5] = node["loud_walking:control_floor_alert_down"]
								end
							elseif sr == 2 then
								if x > 1 and x < 19 and z > 1 and z < 19 and (z - 2) % 4 ~= 0 and (x - 2) % 4 ~= 0 then
									for y = 1, 4 do
										data[ivm + y * a.ystride] = node["loud_walking:air_ladder"]
									end
								end
							elseif sr == 3 then
								if dy > 0 and data[ivm] ~= node["loud_walking:control_floor_alert_down"] and x > 0 and z > 0 and x < 20 and z < 20 then
									data[ivm] = node["loud_walking:control_floor_growth"]
									local sr2 = math.random(20)
									if sr2 == 1 then
										data[ivm + a.ystride] = node["loud_walking:control_plant_1"]
									elseif sr2 == 2 then
										data[ivm + a.ystride] = node["loud_walking:control_plant_2"]
									end
								end
							elseif sr == 4 then
								if dy < 15 and (x > 0 and x < 20 and z > 0 and z < 20) and (((x == 1 or x == 19) and math.abs(z - 10) > 3) or ((z == 1 or z == 19) and math.abs(x - 10) > 3)) then
									data[ivm + 3 * a.ystride] = node["loud_walking:controls"]
								end
							end

							ivm = ivm + 1
						end
					end
				end
			end
		end
	end

	vm:set_data(data)
	minetest.generate_ores(vm, minp, maxp)
	--minetest.generate_decorations(vm, minp, maxp)
	--vm:set_param2_data(p2data)
	--vm:set_lighting({day = 15, night = 0})
	if pod then
		vm:set_light_data(lightmap)
	end
	vm:update_liquids()
	vm:calc_lighting(minp, maxp, false)
	vm:write_to_map()

	vm, a, heightmap, biomemap = nil, nil, nil, nil
end


local function pgenerate(...)
	--local status, err = pcall(generate, ...)
	local status, err = true
	generate(...)
	if not status then
		print('Squaresville: Could not generate terrain:')
		print(dump(err))
		collectgarbage("collect")
	end
end


-- Inserting helps to ensure that squaresville operates first.
table.insert(minetest.registered_on_generateds, 1, pgenerate)


function loud_walking.respawn(player)
	while true do
		local px = math.random(-10, 10) * 2 - 1
		local pz = math.random(-10, 10) * 2
		local x = pod_size.x * px
		local z = pod_size.z * pz
		local y = half_pod.y + 1

		local pos = {x=x,y=y,z=z}
		local node = minetest.get_node(pos)
		if node.name ~= "air" then
			player:setpos(pos)
			return true
		end
	end
end

minetest.register_on_newplayer(loud_walking.respawn)
minetest.register_on_respawnplayer(loud_walking.respawn)