nether/init.lua

--[[

  Nether mod for minetest

  Copyright (C) 2013 PilzAdam

  Permission to use, copy, modify, and/or distribute this software for
  any purpose with or without fee is hereby granted, provided that the
  above copyright notice and this permission notice appear in all copies.

  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
  WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
  WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR
  BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES
  OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  SOFTWARE.

]]--


-- Parameters

local NETHER_DEPTH = -5000
local TCAVE = 0.6
local BLEND = 128


-- 3D noise

local np_cave = {
	offset = 0,
	scale = 1,
	spread = {x = 384, y = 128, z = 384}, -- squashed 3:1
	seed = 59033,
	octaves = 5,
	persist = 0.7,
	lacunarity = 2.0,
	--flags = ""
}


-- Stuff

local yblmax = NETHER_DEPTH - BLEND * 2


-- Functions

local function build_portal(pos, target)
	local p1 = {x = pos.x - 1, y = pos.y - 1, z = pos.z}
	local p2 = {x = p1.x + 3, y = p1.y + 4, z = p1.z}

	local path = minetest.get_modpath("nether") .. "/schematics/nether_portal.mts"
	minetest.place_schematic({x = p1.x, y = p1.y, z = p1.z - 2}, path, 0, nil, true)

	for y = p1.y, p2.y do
	for x = p1.x, p2.x do
		local meta = minetest.get_meta({x = x, y = y, z = p1.z})
		meta:set_string("p1", minetest.pos_to_string(p1))
		meta:set_string("p2", minetest.pos_to_string(p2))
		meta:set_string("target", minetest.pos_to_string(target))
	end
	end
end


local function volume_is_natural(minp, maxp)
	local c_air = minetest.get_content_id("air")
	local c_ignore = minetest.get_content_id("ignore")

	local vm = minetest.get_voxel_manip()
	local pos1 = {x = minp.x, y = minp.y, z = minp.z}
	local pos2 = {x = maxp.x, y = maxp.y, z = maxp.z}
	local emin, emax = vm:read_from_map(pos1, pos2)
	local area = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
	local data = vm:get_data()

	for z = pos1.z, pos2.z do
	for y = pos1.y, pos2.y do
		local vi = area:index(pos1.x, y, z)
		for x = pos1.x, pos2.x do
			local id = data[vi] -- Existing node
			if id ~= c_air and id ~= c_ignore then -- These are natural
				local name = minetest.get_name_from_content_id(id)
				if not minetest.registered_nodes[name].is_ground_content then
					return false
				end
			end
			vi = vi + 1
		end
	end
	end

	return true
end


local function find_nether_target_y(target_x, target_z, start_y)
	local nobj_cave_point = minetest.get_perlin(np_cave)
	local air = 0 -- Consecutive air nodes found

	for y = start_y, start_y - 4096, -1 do
		local nval_cave = nobj_cave_point:get3d({x = target_x, y = y, z = target_z})

		if nval_cave > TCAVE then -- Cavern
			air = air + 1
		else -- Not cavern, check if 4 nodes of space above
			if air >= 4 then
				-- Check volume for non-natural nodes
				local minp = {x = target_x - 1, y = y - 1, z = target_z - 2}
				local maxp = {x = target_x + 2, y = y + 3, z = target_z + 2}
				if volume_is_natural(minp, maxp) then
					return y + 2
				else -- Restart search a little lower
					find_nether_target_y(target_x, target_z, y - 16)
				end
			else -- Not enough space, reset air to zero
				air = 0
			end
		end
	end

	return start_y -- Fallback
end


local function find_surface_target_y(target_x, target_z, start_y)
	for y = start_y, start_y - 256, -16 do
		-- Check volume for non-natural nodes
		local minp = {x = target_x - 1, y = y - 1, z = target_z - 2}
		local maxp = {x = target_x + 2, y = y + 3, z = target_z + 2}
		if volume_is_natural(minp, maxp) then
			return y
		end
	end

	return y -- Fallback
end


local function move_check(p1, max, dir)
	local p = {x = p1.x, y = p1.y, z = p1.z}
	local d = math.abs(max - p1[dir]) / (max - p1[dir])

	while p[dir] ~= max do
		p[dir] = p[dir] + d
		if minetest.get_node(p).name ~= "default:obsidian" then
			return false
		end
	end

	return true
end


local function check_portal(p1, p2)
	if p1.x ~= p2.x then
		if not move_check(p1, p2.x, "x") then
			return false
		end
		if not move_check(p2, p1.x, "x") then
			return false
		end
	elseif p1.z ~= p2.z then
		if not move_check(p1, p2.z, "z") then
			return false
		end
		if not move_check(p2, p1.z, "z") then
			return false
		end
	else
		return false
	end

	if not move_check(p1, p2.y, "y") then
		return false
	end
	if not move_check(p2, p1.y, "y") then
		return false
	end

	return true
end


local function is_portal(pos)
	for d = -3, 3 do
		for y = -4, 4 do
			local px = {x = pos.x + d, y = pos.y + y, z = pos.z}
			local pz = {x = pos.x, y = pos.y + y, z = pos.z + d}

			if check_portal(px, {x = px.x + 3, y = px.y + 4, z = px.z}) then
				return px, {x = px.x + 3, y = px.y + 4, z = px.z}
			end
			if check_portal(pz, {x = pz.x, y = pz.y + 4, z = pz.z + 3}) then
				return pz, {x = pz.x, y = pz.y + 4, z = pz.z + 3}
			end
		end
	end
end


local function make_portal(pos)
	local p1, p2 = is_portal(pos)
	if not p1 or not p2 then
		return false
	end

	for d = 1, 2 do
	for y = p1.y + 1, p2.y - 1 do
		local p
		if p1.z == p2.z then
			p = {x = p1.x + d, y = y, z = p1.z}
		else
			p = {x = p1.x, y = y, z = p1.z + d}
		end
		if minetest.get_node(p).name ~= "air" then
			return false
		end
	end
	end

	local param2
	if p1.z == p2.z then
		param2 = 0
	else
		param2 = 1
	end

	local target = {x = p1.x, y = p1.y, z = p1.z}
	target.x = target.x + 1
	if target.y < NETHER_DEPTH then
		target.y = find_surface_target_y(target.x, target.z, -16)
	else
		local start_y = NETHER_DEPTH - math.random(500, 1500) -- Search start
		target.y = find_nether_target_y(target.x, target.z, start_y)
	end

	for d = 0, 3 do
	for y = p1.y, p2.y do
		local p = {}
		if param2 == 0 then
			p = {x = p1.x + d, y = y, z = p1.z}
		else
			p = {x = p1.x, y = y, z = p1.z + d}
		end
		if minetest.get_node(p).name == "air" then
			minetest.set_node(p, {name = "nether:portal", param2 = param2})
		end
		local meta = minetest.get_meta(p)
		meta:set_string("p1", minetest.pos_to_string(p1))
		meta:set_string("p2", minetest.pos_to_string(p2))
		meta:set_string("target", minetest.pos_to_string(target))
	end
	end

	return true
end


-- ABMs

minetest.register_abm({
	nodenames = {"nether:portal"},
	interval = 1,
	chance = 2,
	action = function(pos, node)
		minetest.add_particlespawner(
			32, --amount
			4, --time
			{x = pos.x - 0.25, y = pos.y - 0.25, z = pos.z - 0.25}, --minpos
			{x = pos.x + 0.25, y = pos.y + 0.25, z = pos.z + 0.25}, --maxpos
			{x = -0.8, y = -0.8, z = -0.8}, --minvel
			{x = 0.8, y = 0.8, z = 0.8}, --maxvel
			{x = 0, y = 0, z = 0}, --minacc
			{x = 0, y = 0, z = 0}, --maxacc
			0.5, --minexptime
			1, --maxexptime
			1, --minsize
			2, --maxsize
			false, --collisiondetection
			"nether_particle.png" --texture
		)
		for _, obj in ipairs(minetest.get_objects_inside_radius(pos, 1)) do
			if obj:is_player() then
				local meta = minetest.get_meta(pos)
				local target = minetest.string_to_pos(meta:get_string("target"))
				if target then
					-- force emerge of target area
					minetest.get_voxel_manip():read_from_map(target, target)
					if not minetest.get_node_or_nil(target) then
						minetest.emerge_area(
							vector.subtract(target, 4), vector.add(target, 4))
					end
					-- teleport the player
					minetest.after(3, function(obj, pos, target)
						local objpos = obj:getpos()
						objpos.y = objpos.y + 0.1 -- Fix some glitches at -8000
						if minetest.get_node(objpos).name ~= "nether:portal" then
							return
						end

						obj:setpos(target)

						local function check_and_build_portal(pos, target)
							local n = minetest.get_node_or_nil(target)
							if n and n.name ~= "nether:portal" then
								build_portal(target, pos)
								minetest.after(2, check_and_build_portal, pos, target)
								minetest.after(4, check_and_build_portal, pos, target)
							elseif not n then
								minetest.after(1, check_and_build_portal, pos, target)
							end
						end

						minetest.after(1, check_and_build_portal, pos, target)

					end, obj, pos, target)
				end
			end
		end
	end,
})


-- Nodes

minetest.register_node("nether:portal", {
	description = "Nether Portal",
	tiles = {
		"nether_transparent.png",
		"nether_transparent.png",
		"nether_transparent.png",
		"nether_transparent.png",
		{
			name = "nether_portal.png",
			animation = {
				type = "vertical_frames",
				aspect_w = 16,
				aspect_h = 16,
				length = 0.5,
			},
		},
		{
			name = "nether_portal.png",
			animation = {
				type = "vertical_frames",
				aspect_w = 16,
				aspect_h = 16,
				length = 0.5,
			},
		},
	},
	drawtype = "nodebox",
	paramtype = "light",
	paramtype2 = "facedir",
	sunlight_propagates = true,
	use_texture_alpha = true,
	walkable = false,
	diggable = false,
	pointable = false,
	buildable_to = false,
	is_ground_content = false,
	drop = "",
	light_source = 5,
	post_effect_color = {a = 180, r = 128, g = 0, b = 128},
	alpha = 192,
	node_box = {
		type = "fixed",
		fixed = {
			{-0.5, -0.5, -0.1,  0.5, 0.5, 0.1},
		},
	},
	groups = {not_in_creative_inventory = 1}
})

minetest.register_node(":default:obsidian", {
	description = "Obsidian",
	tiles = {"default_obsidian.png"},
	is_ground_content = false,
	sounds = default.node_sound_stone_defaults(),
	groups = {cracky = 1, level = 2},

	on_destruct = function(pos)
		local meta = minetest.get_meta(pos)
		local p1 = minetest.string_to_pos(meta:get_string("p1"))
		local p2 = minetest.string_to_pos(meta:get_string("p2"))
		local target = minetest.string_to_pos(meta:get_string("target"))
		if not p1 or not p2 then
			return
		end

		for x = p1.x, p2.x do
		for y = p1.y, p2.y do
		for z = p1.z, p2.z do
			local nn = minetest.get_node({x = x, y = y, z = z}).name
			if nn == "default:obsidian" or nn == "nether:portal" then
				if nn == "nether:portal" then
					minetest.remove_node({x = x, y = y, z = z})
				end
				local m = minetest.get_meta({x = x, y = y, z = z})
				m:set_string("p1", "")
				m:set_string("p2", "")
				m:set_string("target", "")
			end
		end
		end
		end

		meta = minetest.get_meta(target)
		if not meta then
			return
		end
		p1 = minetest.string_to_pos(meta:get_string("p1"))
		p2 = minetest.string_to_pos(meta:get_string("p2"))
		if not p1 or not p2 then
			return
		end

		for x = p1.x, p2.x do
		for y = p1.y, p2.y do
		for z = p1.z, p2.z do
			local nn = minetest.get_node({x = x, y = y, z = z}).name
			if nn == "default:obsidian" or nn == "nether:portal" then
				if nn == "nether:portal" then
					minetest.remove_node({x = x, y = y, z = z})
				end
				local m = minetest.get_meta({x = x, y = y, z = z})
				m:set_string("p1", "")
				m:set_string("p2", "")
				m:set_string("target", "")
			end
		end
		end
		end
	end,
})

minetest.register_node("nether:rack", {
	description = "Netherrack",
	tiles = {"nether_rack.png"},
	is_ground_content = true,
	groups = {cracky = 3, level = 2},
	sounds = default.node_sound_stone_defaults(),
})

minetest.register_node("nether:sand", {
	description = "Nethersand",
	tiles = {"nether_sand.png"},
	is_ground_content = true,
	groups = {crumbly = 3, level = 2, falling_node = 1},
	sounds = default.node_sound_gravel_defaults({
		footstep = {name = "default_gravel_footstep", gain = 0.45},
	}),
})

minetest.register_node("nether:glowstone", {
	description = "Glowstone",
	tiles = {"nether_glowstone.png"},
	is_ground_content = true,
	light_source = 14,
	paramtype = "light",
	groups = {cracky = 3, oddly_breakable_by_hand = 3},
	sounds = default.node_sound_glass_defaults(),
})

minetest.register_node("nether:brick", {
	description = "Nether Brick",
	tiles = {"nether_brick.png"},
	is_ground_content = false,
	groups = {cracky = 2, level = 2},
	sounds = default.node_sound_stone_defaults(),
})

local fence_texture =
	"default_fence_overlay.png^nether_brick.png^default_fence_overlay.png^[makealpha:255,126,126"

minetest.register_node("nether:fence_nether_brick", {
	description = "Nether Brick Fence",
	drawtype = "fencelike",
	tiles = {"nether_brick.png"},
	inventory_image = fence_texture,
	wield_image = fence_texture,
	paramtype = "light",
	sunlight_propagates = true,
	is_ground_content = false,
	selection_box = {
		type = "fixed",
		fixed = {-1/7, -1/2, -1/7, 1/7, 1/2, 1/7},
	},
	groups = {cracky = 2, level = 2},
	sounds = default.node_sound_stone_defaults(),
})


-- Register stair and slab

stairs.register_stair_and_slab(
	"nether_brick",
	"nether:brick",
	{cracky = 2, level = 2},
	{"nether_brick.png"},
	"nether stair",
	"nether slab",
	default.node_sound_stone_defaults()
)

-- StairsPlus

if minetest.get_modpath("moreblocks") then
	stairsplus:register_all(
		"nether", "brick", "nether:brick", {
			description = "Nether Brick",
			groups = {cracky = 2, level = 2},
			tiles = {"nether_brick.png"},
			sounds = default.node_sound_stone_defaults(),
	})
end

stairs.register_stair_and_slab("brick", "nether:brick",
	{cracky=3, oddly_breakable_by_hand=1},
	{"nether_brick.png"},
	"nether stair",
	"nether slab",
	default.node_sound_stone_defaults())

local function replace(old, new)
	for i=1,8 do
		minetest.register_ore({
			ore_type       = "scatter",
			ore            = new,
			wherein        = old,
			clust_scarcity = 1,
			clust_num_ores = 1,
			clust_size     = 1,
			height_min     = -31000,
			height_max     = NETHER_DEPTH,
		})
	end
end

-- Craftitems

minetest.register_craftitem(":default:mese_crystal_fragment", {
	description = "Mese Crystal Fragment",
	inventory_image = "default_mese_crystal_fragment.png",
	on_place = function(stack, _, pt)
		if pt.under and minetest.get_node(pt.under).name == "default:obsidian" then
			local done = make_portal(pt.under)
			if done and not minetest.setting_getbool("creative_mode") then
				stack:take_item()
			end
		end

		return stack
	end,
})

-- Crafting

minetest.register_craft({
	output = "nether:brick 4",
	recipe = {
		{"nether:rack", "nether:rack"},
		{"nether:rack", "nether:rack"},
	}
})

minetest.register_craft({
	output = "nether:fence_nether_brick 6",
	recipe = {
		{"nether:brick", "nether:brick", "nether:brick"},
		{"nether:brick", "nether:brick", "nether:brick"},
	},
})


-- Mapgen

-- Initialize noise object, localise noise and data buffers

local nobj_cave = nil
local nbuf_cave
local dbuf


-- Content ids

local c_air = minetest.get_content_id("air")

local c_stone_with_coal = minetest.get_content_id("default:stone_with_coal")
local c_stone_with_iron = minetest.get_content_id("default:stone_with_iron")
local c_stone_with_mese = minetest.get_content_id("default:stone_with_mese")
local c_stone_with_diamond = minetest.get_content_id("default:stone_with_diamond")
local c_stone_with_gold = minetest.get_content_id("default:stone_with_gold")
local c_stone_with_copper = minetest.get_content_id("default:stone_with_copper")
local c_mese = minetest.get_content_id("default:mese")

local c_gravel = minetest.get_content_id("default:gravel")
local c_dirt = minetest.get_content_id("default:dirt")
local c_sand = minetest.get_content_id("default:sand")

local c_cobble = minetest.get_content_id("default:cobble")
local c_mossycobble = minetest.get_content_id("default:mossycobble")
local c_stair_cobble = minetest.get_content_id("stairs:stair_cobble")

local c_lava_source = minetest.get_content_id("default:lava_source")
local c_lava_flowing = minetest.get_content_id("default:lava_flowing")
local c_water_source = minetest.get_content_id("default:water_source")
local c_water_flowing = minetest.get_content_id("default:water_flowing")

local c_glowstone = minetest.get_content_id("nether:glowstone")
local c_nethersand = minetest.get_content_id("nether:sand")
local c_netherbrick = minetest.get_content_id("nether:brick")
local c_netherrack = minetest.get_content_id("nether:rack")


-- On-generated function

minetest.register_on_generated(function(minp, maxp, seed)
	if minp.y > NETHER_DEPTH then
		return
	end

	local x1 = maxp.x
	local y1 = maxp.y
	local z1 = maxp.z
	local x0 = minp.x
	local y0 = minp.y
	local z0 = minp.z

	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
	local area = VoxelArea:new{MinEdge = emin, MaxEdge = emax}
	local data = vm:get_data(dbuf)

	local x11 = emax.x -- Limits of mapchunk plus mapblock shell
	local y11 = emax.y
	local z11 = emax.z
	local x00 = emin.x
	local y00 = emin.y
	local z00 = emin.z

	local ystride = x1 - x0 + 1
	local zstride = ystride * ystride
	local chulens = {x = ystride, y = ystride, z = ystride}
	local minposxyz = {x = x0, y = y0, z = z0}

	nobj_cave = nobj_cave or minetest.get_perlin_map(np_cave, chulens)
	local nvals_cave = nobj_cave:get3dMap_flat(minposxyz, nbuf_cave)

	for y = y00, y11 do -- Y loop first to minimise tcave calculations
		local tcave
		local in_chunk_y = false
		if y >= y0 and y <= y1 then
			if y > yblmax then
				tcave = TCAVE + ((y - yblmax) / BLEND) ^ 2
			else
				tcave = TCAVE
			end
			in_chunk_y = true
		end

		for z = z00, z11 do
			local vi = area:index(x00, y, z) -- Initial voxelmanip index
			local ni
			local in_chunk_yz = in_chunk_y and z >= z0 and z <= z1

			for x = x00, x11 do
				if in_chunk_yz and x == x0 then
					-- Initial noisemap index
					ni = (z - z0) * zstride + (y - y0) * ystride + 1
				end
				local in_chunk_yzx = in_chunk_yz and x >= x0 and x <= x1 -- In mapchunk

				local id = data[vi] -- Existing node
				-- Cave air, cave liquids and dungeons are overgenerated,
				-- convert these throughout mapchunk plus shell
				if id == c_air or -- Air and liquids to air
						id == c_lava_source or
						id == c_lava_flowing or
						id == c_water_source or
						id == c_water_flowing then
					data[vi] = c_air
				-- Dungeons are preserved so we don't need
				-- to check for cavern in the shell
				elseif id == c_cobble or -- Dungeons (preserved) to netherbrick
						id == c_mossycobble or
						id == c_stair_cobble then
					data[vi] = c_netherbrick
				end

				if in_chunk_yzx then -- In mapchunk
					if nvals_cave[ni] > tcave then -- Only excavate cavern in mapchunk
						data[vi] = c_air
					elseif id == c_mese then -- Mese block to lava
						data[vi] = c_lava_source
					elseif id == c_stone_with_gold or -- Precious ores to glowstone
							id == c_stone_with_mese or
							id == c_stone_with_diamond then
						data[vi] = c_glowstone
					elseif id == c_gravel or -- Blob ore to nethersand
							id == c_dirt or
							id == c_sand then
						data[vi] = c_nethersand
					else -- All else to netherstone
						data[vi] = c_netherrack
					end

					ni = ni + 1 -- Only increment noise index in mapchunk
				end

				vi = vi + 1
			end
		end
	end

	vm:set_data(data)
	vm:set_lighting({day = 0, night = 0})
	vm:calc_lighting()
	vm:update_liquids()
	vm:write_to_map()
end)