prototype_roguelike_mapgen.lua

math.randomseed(os.time())

roguelike = {
	init_map = function(width, height, wall_probability)
		local map, x, y = {}, 0, 0
		-- Fill map with random splatter. It will be smoothed by roguelike.next_gen()
		for row = 1, height do
			map[row] = {}
			for column = 1, width do
				map[row][column] = math.floor(math.random() + wall_probability / 100)
			end
		end

		-- Paint a big X after random splatter to ensure the map is mostly connected.
		-- this is faster than any flood-fill function I could come up with, but we
		-- *may* generate small isolated sections since we're not checking connectivity.
		local max_offset = math.max(width, height)
		for offset = 1, max_offset do
			x = math.floor((height * offset / max_offset) + 0.5)
			y = math.floor((width  * offset / max_offset) + 0.5)
			for xc = math.max(1, x-1), math.min(height, x+1) do
				for yc = math.max(1, y-1), math.min(width, y+1) do
					map[xc][yc] = 0
					map[xc][width+1-yc] = 0
				end
			end
		end
		return map
	end,
	get_neighbors = function(map, x, y, radius)
		local neighbor_count, add_num = 0, 0
		for xn = x - radius, x + radius do
			for yn = y - radius, y + radius do
				if map[xn] and map[xn][yn] then
					add_num = map[xn][yn]
				else
					add_num = 0
				end
				neighbor_count = neighbor_count + add_num
			end
		end
		return neighbor_count
	end,
	next_gen = function(map, near_threshold, far_threshold)
		local new = {}
		for row = 1, #map do
			new[row] = {}
			for column = 1, #map[1] do
				local neighbors_near = roguelike.get_neighbors(map, row, column, 1)
				local neighbors_far  = roguelike.get_neighbors(map, row, column, 2)
				if neighbors_near >= near_threshold or neighbors_far <= far_threshold then
					new[row][column] = 1
				else
					new[row][column] = 0
				end
			end
		end
		return new
	end,
	make_map = function(width, height, wall_probability)
		local map = roguelike.init_map(width, height, wall_probability)
		for g = 1, 4 do map = roguelike.next_gen(map, 5, 2) end
		for g = 1, 3 do map = roguelike.next_gen(map, 5, 0) end
		for g = 1, 2 do map = roguelike.next_gen(map, 7, 0) end
		return map
	end,
	print_map = function(data)
		local line, char = "", ""
		for row = 1, #data do
			line = ""
			for column = 1, #data[1] do
				if data[row][column] == 1 then
					char = "#"
				else
					char = "."
				end
				line = line .. char
			end
			print(line)
		end
	end,
}

local test_map = roguelike.make_map(70, 50, 20)

if minetest then -- this check is here so we can still debug using the cli lua interpreter
	minetest.register_node("roguelike:stone", {
		description = "Roguelike Stone",
		tiles = {"default_stone.png"},
		is_ground_content = false,
		groups = {cracky = 3, stone = 1},
	})

	minetest.register_node("roguelike:air", {
		description = "Glowing Air (roguelike)",
		drawtype = "airlike",
		inventory_image = "air.png",
		wield_image = "air.png",
		paramtype = "light",
		light_source = 14,
		is_ground_content = false,
		air_equivalent = true,
		floodable = true,
		pointable = false,
		sunlight_propagates = true,
		walkable = false,
		diggable = false,
		buildable_to = true,
		groups = {not_in_creative_inventory = 1},
	})

	roguelike.place_map = function(data, pos)
		minetest.chat_send_all("Making map at pos " .. minetest.pos_to_string(pos))
		local line, char, node_name = "", "", ""
		for row = 0, #data+1 do
			for column = 0, #data[1]+1 do
				if data[row] and data[row][column] then
					if data[row][column] == 1 then
						node_name = "roguelike:stone"
					else
						node_name = "roguelike:air"
					end
					minetest.set_node({x = pos.x + row, y = pos.y - 1, z = pos.z + column}, {name="roguelike:stone"}) -- floor
					for height = 0, 2 do
						minetest.set_node({x = pos.x + row, y = pos.y + height, z = pos.z + column}, {name=node_name}) -- walls
					end
					minetest.set_node({x = pos.x + row, y = pos.y + 3, z = pos.z + column}, {name="roguelike:stone"}) -- ceiling
				else
					for height = -1, 3 do
						minetest.set_node({x = pos.x + row, y = pos.y + height, z = pos.z + column}, {name="roguelike:stone"}) -- outer walls
					end
				end
			end
		end
	end

	minetest.register_chatcommand("test", {
		params = "",
		description = "create a procedually generated roguelike map (using Cellular Automata)",
		func = function(name, param)
			local player = minetest.get_player_by_name(name)
			local pos = player:getpos()
			pos = {x = math.floor(pos.x - 2.5), y = math.floor(pos.y - 4.5), z = math.floor(pos.z - 2.5)}
			roguelike.place_map(test_map, pos)
			pos = player:getpos()
			pos = {x = math.floor(pos.x + 0.5), y = math.floor(pos.y - 4.5), z = math.floor(pos.z + 0.5)}
			for xoff = -1, 1 do
				for zoff = -1, 1 do
					for yoff = 0, 2 do
						minetest.set_node({x = pos.x + xoff, y = pos.y + yoff, z = pos.z + zoff}, {name="roguelike:air"})
					end
					for yoff = 3, 4 do
						minetest.set_node({x = pos.x + xoff, y = pos.y + yoff, z = pos.z + zoff}, {name="roguelike:stone"})
					end
				end
			end
			for yoff = 0, 4 do
				minetest.set_node({x = pos.x, y = pos.y + yoff, z = pos.z}, {name="default:ladder", param2 = 5})
				minetest.set_node({x = pos.x, y = pos.y + yoff, z = pos.z - 1}, {name="roguelike:stone"})
			end
		end,
	})
end

roguelike.print_map(test_map)