add //maze command

worldeditadditions/init.lua

@@ -12,3 +12,4 @@ dofile(minetest.get_modpath("worldeditadditions") .. "/floodfill.lua")
 dofile(minetest.get_modpath("worldeditadditions") .. "/overlay.lua")
 dofile(minetest.get_modpath("worldeditadditions") .. "/ellipsoid.lua")
 dofile(minetest.get_modpath("worldeditadditions") .. "/torus.lua")
+dofile(minetest.get_modpath("worldeditadditions") .. "/maze.lua")

worldeditadditions/maze.lua

@@ -0,0 +1,164 @@
+--- Generates a maze.
+-- Algorithm origin: https://starbeamrainbowlabs.com/blog/article.php?article=posts/070-Language-Review-Lua.html
+-- @module worldeditadditions.maze
+
+----------------------------------
+-- function to print out the world
+----------------------------------
+function printspace(space, w, h)
+	for y = 0, h - 1, 1 do
+		local line = ""
+		for x = 0, w - 1, 1 do
+			line = line .. space[y][x]
+		end
+		minetest.log("action", line)
+	end
+end
+
+function generate_maze(seed, width, height)
+	minetest.log("action", "width: "..width..", height: "..height)
+	math.randomseed(seed) -- seed the random number generator with the system clock
+
+	width = width - 1
+	height = height - 1
+
+	local world = {}
+	for y = 0, height, 1 do
+		world[y] = {}
+		for x = 0, width, 1 do
+			world[y][x] = "#"
+		end
+	end
+
+	-- do a random walk to create pathways
+	local nodes = {} -- the nodes left that we haven't investigated
+	local curnode = 1 -- the node we are currently operating on
+	local cx, cy = 1, 1 -- our current position
+	table.insert(nodes, { x = cx, y = cy })
+	world[cy][cx] = " "
+	while #nodes > 0 do
+		-- io.write("Nodes left: " .. curnode .. "\r")
+		--print("Nodes left: " .. #nodes)
+		--print("Currently at (" .. cx .. ", " .. cy .. ")")
+
+		local directions = "" -- the different directions we can move
+		if cy - 2 > 0 and world[cy - 2][cx] == "#" then
+			directions = directions .. "u"
+		end
+		if cy + 2 < height and world[cy + 2][cx] == "#" then
+			directions = directions .. "d"
+		end
+		if cx - 2 > 0 and world[cy][cx - 2] == "#" then
+			directions = directions .. "l"
+		end
+		if cx + 2 < width and world[cy][cx + 2] == "#" then
+			directions = directions .. "r"
+		end
+		--print("radar output: '" .. directions .. "' (length: " .. #directions .. "), curnode: " .. curnode)
+		if #directions > 0 then
+			-- we still have somewhere that we can go
+			--print("This node is not a dead end yet.")
+			local curdirnum = math.random(0, #directions)
+			local curdir = string.sub(directions, curdirnum, curdirnum)
+			if curdir == "u" then
+				world[cy - 1][cx] = " "
+				world[cy - 2][cx] = " "
+				cy = cy - 2
+			elseif curdir == "d" then
+				world[cy + 1][cx] = " "
+				world[cy + 2][cx] = " "
+				cy = cy + 2
+			elseif curdir == "l" then
+				world[cy][cx - 1] = " "
+				world[cy][cx - 2] = " "
+				cx = cx - 2
+			elseif curdir == "r" then
+				world[cy][cx + 1] = " "
+				world[cy][cx + 2] = " "
+				cx = cx + 2
+			end
+
+			table.insert(nodes, { x = cx, y = cy })
+		else
+			--print("The node at " .. curnode .. " is a dead end.")
+			table.remove(nodes, curnode)
+			if #nodes > 0 then
+				--print("performing teleport.");
+				curnode = math.random(1, #nodes)
+				--print("New node: " .. curnode)
+				-- print("Nodes table: ")
+				-- print_r(nodes)
+				cx = nodes[curnode]["x"]
+				cy = nodes[curnode]["y"]
+			else
+				--print("Maze generation complete, no teleportation necessary.")
+			end
+		end
+		--printspace(world, width, height)
+	end
+
+	return world
+end
+
+-- local world = maze(os.time(), width, height)
+
+function worldedit.maze(pos1, pos2, target_node, seed)
+	pos1, pos2 = worldedit.sort_pos(pos1, pos2)
+	-- pos2 will always have the highest co-ordinates now
+	
+	-- getExtent() returns the number of nodes in the VoxelArea, which might be larger than we actually asked for
+	local extent = {
+		x = (pos2.x - pos1.x) + 1,
+		y = (pos2.y - pos1.y) + 1,
+		z = (pos2.z - pos1.z) + 1
+	}
+	minetest.log("action", "extent: ("..extent.x..", "..extent.y..", "..extent.z..")")
+	
+	if extent.x == 0 or extent.y == 0 or extent.z == 0 then
+		minetest.log("info", "[worldeditadditions/maze] error: either x, y, or z of the extent was zero")
+		return 0
+	end
+
+	-- Fetch the nodes in the specified area
+	local manip, area = worldedit.manip_helpers.init(pos1, pos2)
+	local data = manip:get_data()
+
+	local node_id_air = minetest.get_content_id("air")
+	local node_id_target = minetest.get_content_id(target_node)
+
+	-- minetest.log("action", "pos1: " .. worldeditadditions.vector.tostring(pos1))
+	-- minetest.log("action", "pos2: " .. worldeditadditions.vector.tostring(pos2))
+
+
+	minetest.log("action", "Generating "..extent.x.."x"..extent.z.." maze (depth "..extent.z..") from pos1 " .. worldeditadditions.vector.tostring(pos1).." to pos2 "..worldeditadditions.vector.tostring(pos2))
+
+	local maze = generate_maze(seed, extent.z, extent.x) -- x &   need to be the opposite way around to how we index it
+	printspace(maze, extent.z, extent.x)
+
+	-- z y x is the preferred loop order, but that isn't really possible here
+
+	for z = pos2.z, pos1.z, - 1 do
+		for x = pos2.x, pos1.x, - 1 do
+			for y = pos2.y, pos1.y, - 1 do
+				local maze_x = (x - pos1.x) -- - 1
+				local maze_z = (z - pos1.z) -- - 1
+				if maze_x < 0 then maze_x = 0 end
+				if maze_z < 0 then maze_z = 0 end
+				
+				minetest.log("action", "x: "..x..", y: "..y..", z: "..z..", pos x: "..maze_x..", pos z: "..maze_z)
+				minetest.log("action", "value: "..maze[maze_x][maze_z])
+				
+				if maze[maze_x][maze_z] == "#" then
+					data[area:index(x, y, z)] = node_id_target
+				else
+					data[area:index(x, y, z)] = node_id_air
+				end
+			end
+		end
+	end
+
+	-- Save the modified nodes back to disk & return
+	worldedit.manip_helpers.finish(manip, data)
+
+	return extent.x * extent.y * extent.z
+end

worldeditadditions_commands/init.lua

@@ -292,3 +292,76 @@ minetest.register_chatcommand("/hollowtorus", {
 		return math.ceil(2 * math.pi*math.pi * major_radius * minor_radius*minor_radius)
 	end)
 })
+
+
+-- ███    ███  █████  ███████ ███████
+-- ████  ████ ██   ██    ███  ██
+-- ██ ████ ██ ███████   ███   █████
+-- ██  ██  ██ ██   ██  ███    ██
+-- ██      ██ ██   ██ ███████ ███████
+
+local function parse_params_maze(params_text)
+	if not params_text then
+		return nil, nil, nil
+	end
+	local found, _, replace_node, seed_text = params_text:find("([a-z:_\\-]+)%s+([0-9]+)")
+	
+	local has_seed = true
+	
+	if found == nil then
+		has_seed = false 
+		replace_node = params_text
+	end
+	
+	local seed = tonumber(seed_text)
+	
+	replace_node = worldedit.normalize_nodename(replace_node)
+	
+	return replace_node, seed, has_seed
+end
+
+minetest.register_chatcommand("/maze", {
+	params = "<replace_node> [<seed>]",
+	description = "Generates a maze covering the currently selected area with replace_node as the walls. Optionally takes a (integer) seed.",
+	privs = { worldedit = true },
+	func = safe_region(function(name, params_text)
+		local replace_node, seed, has_seed = parse_params_maze(params_text)
+		
+		if not replace_node then
+			worldedit.player_notify(name, "Error: Invalid node name.")
+			return false
+		end
+		if not seed and has_seed then
+			worldedit.player_notify(name, "Error: Invalid seed.")
+			return false
+		end
+		
+		if not seed then
+			seed = os.time()
+		end
+		
+		local start_time = os.clock()
+		local replaced = worldedit.maze(worldedit.pos1[name], worldedit.pos2[name], replace_node, seed)
+		local time_taken = os.clock() - start_time
+		
+		worldedit.player_notify(name, replaced .. " nodes replaced in " .. time_taken .. "s")
+		minetest.log("action", name .. " used //maze at " .. worldeditadditions.vector.tostring(worldedit.pos1[name]) .. ", replacing " .. replaced .. " nodes in " .. time_taken .. "s")
+	end, function(name, params_text)
+		local replace_node, seed, has_seed = parse_params_maze(params_text)
+		if not params_text then params_text = "" end
+		
+		if not replace_node then
+			worldedit.player_notify(name, "Error: Invalid input '" .. params_text .. "' (specifically the replace node). Try '/help /maze' to learn how to use this command.")
+			return 0
+		end
+		if not seed and has_seed then
+			worldedit.player_notify(name, "Error: Invalid input '" .. params_text .. "' (specifically the seed). Try '/help /maze' to learn how to use this command.")
+			return 0
+		end
+		
+		local pos1 = worldedit.pos1[name]
+		local pos2 = worldedit.pos2[name]
+		
+		return (pos2.x - pos1.x) * (pos2.y - pos1.y) * (pos1.z - pos2.z)
+	end)
+})