//maze: add path_length and path_width support

....now we jujst need to tackle //maze3d

README.md

@@ -14,7 +14,7 @@ If you can dream of it, it probably belongs here!
  - [`//hollowellipsoid <rx> <ry> <rz> <node_name>`](#hollowellipsoid-rx-ry-rz-node_name)
  - [`//torus <major_radius> <minor_radius> <node_name>`](#torus-major_radius-minor_radius-node_name)
  - [`//hollowtorus <major_radius> <minor_radius> <node_name>`](#hollowtorus-major_radius-minor_radius-node_name)
- - [`//maze <replace_node> [<seed>]`](#maze-replace_node-seed)
+ - [`//maze <replace_node> [<path_length> [<path_width> [<seed>]]]`](#maze-replace_node-seed)
  - [`//maze3d <replace_node> [<seed>]`](#maze3d-replace_node-seed)
  - [`//multi <command_a> <command_b> .....`](#multi-command_a-command_b-command_c-)
  - [`//yy`](#yy)
@@ -75,14 +75,23 @@ Creates a hollow torus at position 1 with the radius major and minor radii. Work
 //hollowtorus 21 11 stone
 ```
 
-### `//maze <replace_node> [<seed>]`
+### `//maze <replace_node> [<path_length> [<path_width> [<seed>]]]`
 Generates a maze using replace_node as the walls and air as the paths. Uses [an algorithm of my own devising](https://starbeamrainbowlabs.com/blog/article.php?article=posts/070-Language-Review-Lua.html). It is guaranteed that you can get from every point to every other point in generated mazes, and there are no loops.
 
 Requires the currently selected area to be at least 3x3x3.
 
+The optional `path_length` and `path_width` arguments require additional explanation. When generating a maze, a multi-headed random walk is performed. When the generator decides to move forwards from a point, it does so `path_length` nodes at a time.
+
+`path_width` is easier to explain. It's basically the number of nodes wide the path generated is.
+
+Note that `path_width` must always be at least 1 less than the `path_height` in order to operate normally.
+
+The last example below shows how to set the path length and width:
+
 ```
 //maze ice
 //maze stone 1234
+//maze dirt 56789 4 2
 ```
 
 ### `//maze3d <replace_node> [<seed>]`

worldeditadditions/init.lua

@@ -12,5 +12,5 @@ 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")
+dofile(minetest.get_modpath("worldeditadditions") .. "/maze2d.lua")
 dofile(minetest.get_modpath("worldeditadditions") .. "/maze3d.lua")

worldeditadditions/maze2d.lua

@@ -2,10 +2,11 @@
 -- 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)
+local function printspace(space, w, h)
 	for y = 0, h - 1, 1 do
 		local line = ""
 		for x = 0, w - 1, 1 do
@@ -15,7 +16,12 @@ function printspace(space, w, h)
 	end
 end
 
-function generate_maze(seed, width, height)
+local function generate_maze(seed, width, height, path_length, path_width)
+	start_time = os.clock()
+	
+    if not path_length then path_length = 2 end
+    if not path_width then path_width = 1 end
+    
 	-- minetest.log("action", "width: "..width..", height: "..height)
 	math.randomseed(seed) -- seed the random number generator with the system clock
 
@@ -37,21 +43,18 @@ function generate_maze(seed, width, height)
 	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
+		if cy - path_length > 0 and world[cy - path_length][cx] == "#" then
 			directions = directions .. "u"
 		end
-		if cy + 2 < height and world[cy + 2][cx] == "#" then
+		if cy + path_length < height-path_width and world[cy + path_length][cx] == "#" then
 			directions = directions .. "d"
 		end
-		if cx - 2 > 0 and world[cy][cx - 2] == "#" then
+		if cx - path_length > 0 and world[cy][cx - path_length] == "#" then
 			directions = directions .. "l"
 		end
-		if cx + 2 < width and world[cy][cx + 2] == "#" then
+		if cx + path_length < width-path_width and world[cy][cx + path_length] == "#" then
 			directions = directions .. "r"
 		end
 		
@@ -59,31 +62,44 @@ function generate_maze(seed, width, height)
 		
 		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(1, #directions)
 			local curdir = string.sub(directions, curdirnum, curdirnum)
 			if curdir == "u" then
-				world[cy - 1][cx] = " "
-				world[cy - 2][cx] = " "
-				cy = cy - 2
+                for ix = cx,cx+(path_width-1) do
+                    for iy = cy-path_length,cy do
+                        world[iy][ix] = " "
+                    end
+                end
+				cy = cy - path_length
 			elseif curdir == "d" then
-				world[cy + 1][cx] = " "
-				world[cy + 2][cx] = " "
-				cy = cy + 2
+                for ix = cx,cx+path_width-1 do
+                    for iy = cy,cy+path_length+(path_width-1) do
+                        world[iy][ix] = " "
+                    end
+                end
+				cy = cy + path_length
 			elseif curdir == "l" then
-				world[cy][cx - 1] = " "
-				world[cy][cx - 2] = " "
-				cx = cx - 2
+                for iy = cy,cy+path_width-1 do
+                    for ix = cx-path_length,cx do
+                        world[iy][ix] = " "
+                    end
+                end
+				cx = cx - path_length
 			elseif curdir == "r" then
-				world[cy][cx + 1] = " "
-				world[cy][cx + 2] = " "
-				cx = cx + 2
+                for iy = cy,cy+(path_width-1) do
+                    for ix = cx,cx+path_length+(path_width-1) do
+                        world[iy][ix] = " "
+                    end
+                end
+				cx = cx + path_length
 			end
 			
+			if #directions > 1 then
 				table.insert(nodes, { x = cx, y = cy })
+			end
 		else
-			--print("The node at " .. curnode .. " is a dead end.")
 			table.remove(nodes, curnode)
-			-- No need to do anything else here, since #directions == 0 will cause a teleport - see below
 		end
 		
 		if #directions == 0 or shift_attention <= 1 then
@@ -96,25 +112,26 @@ function generate_maze(seed, width, height)
 		end
 	end
     
-	return world
+	end_time = os.clock()
+	return world --, (end_time - start_time) * 1000
 end
 
 -- local world = maze(os.time(), width, height)
 
-function worldedit.maze(pos1, pos2, target_node, seed)
+function worldeditadditions.maze2d(pos1, pos2, target_node, seed, path_length, path_width)
 	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
+		x = (pos2.x - pos1.x) + 1, path_length, path_width,
+		y = (pos2.y - pos1.y) + 1, -- not a dimension passed to the maze generator itself
+		z = (pos2.z - pos1.z) + 1, path_length, path_width
 	}
 	-- minetest.log("action", "extent: ("..extent.x..", "..extent.y..", "..extent.z..")")
 	
-	if extent.x < 3 or extent.y < 3 or extent.z < 1 then
-		minetest.log("info", "[worldeditadditions/maze] error: either x, y of the extent were less than 3, or z of the extent was less than 1")
+	if extent.x < 3 or extent.y < 1 or extent.z < 3 then
+		minetest.log("error", "[worldeditadditions/maze] error: either x, y of the extent were less than 3, or z of the extent was less than 1")
 		return 0
 	end
 
@@ -125,20 +142,21 @@ function worldedit.maze(pos1, pos2, target_node, seed)
 	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))
+	-- print("pos1: ", worldeditadditions.vector.tostring(pos1))
+	-- print("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))
+	-- 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))
+	-- print("path_width: "..path_width..", path_length: "..path_length)
 
-	local maze = generate_maze(seed, extent.z, extent.x) -- x &   need to be the opposite way around to how we index it
+	local maze = generate_maze(seed, extent.z, extent.x, path_length, path_width) -- 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
+	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

worldeditadditions_commands/commands/maze.lua

@@ -8,43 +8,45 @@ local we_c = worldeditadditions_commands
 
 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
+		return nil, nil, nil, nil
 	end
 	
-	local seed = tonumber(seed_text)
+	local parts = we_c.split(params_text, "%s+", false)
+	
+	local replace_node = parts[1]
+	local seed = os.time()
+	local path_length = 2
+	local path_width = 1
+	
+	if #parts >= 2 then
+		path_length = tonumber(parts[2])
+	end
+	if #parts >= 3 then
+		path_width = tonumber(parts[3])
+	end
+	if #parts >= 4 then
+		seed = tonumber(parts[4])
+	end
 	
 	replace_node = worldedit.normalize_nodename(replace_node)
 	
-	return replace_node, seed, has_seed
+	return replace_node, seed, path_length, path_width
 end
 
 minetest.register_chatcommand("/maze", {
-	params = "<replace_node> [<seed>]",
-	description = "Generates a maze covering the currently selected area (must be at least 3x3 on the x,z axes) with replace_node as the walls. Optionally takes a (integer) seed.",
+	params = "<replace_node> [<path_length> [<path_width> [<seed>]]]",
+	description = "Generates a maze covering the currently selected area (must be at least 3x3 on the x,z axes) with replace_node as the walls. Optionally takes a (integer) seed and the path length and width (see the documentation in the worldeditadditions README for more information).",
 	privs = { worldedit = true },
 	func = we_c.safe_region(function(name, params_text)
-		local replace_node, seed, has_seed = parse_params_maze(params_text)
+		local replace_node, seed, path_length, path_width = 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 replaced = worldeditadditions.maze2d(worldedit.pos1[name], worldedit.pos2[name], replace_node, seed, path_length, path_width)
 		local time_taken = os.clock() - start_time
 		
 		worldedit.player_notify(name, replaced .. " nodes replaced in " .. time_taken .. "s")

worldeditadditions_commands/init.lua

@@ -15,6 +15,7 @@ dofile(we_c.modpath.."/multi.lua")
 we_c.safe_region, we_c.check_region, we_c.reset_pending
 	= dofile(we_c.modpath.."/safe.lua")
 
+dofile(we_c.modpath.."/utils/strings.lua")
 dofile(we_c.modpath.."/commands/floodfill.lua")
 dofile(we_c.modpath.."/commands/overlay.lua")
 dofile(we_c.modpath.."/commands/ellipsoid.lua")

worldeditadditions_commands/utils/strings.lua

@@ -0,0 +1,63 @@
+-- Licence: GPLv2 (MPL-2.0 is compatible, so we can use this here)
+-- Source: https://stackoverflow.com/a/43582076/1460422
+
+local we_c = worldeditadditions_commands
+
+
+-- gsplit: iterate over substrings in a string separated by a pattern
+--
+-- Parameters:
+-- text (string)    - the string to iterate over
+-- pattern (string) - the separator pattern
+-- plain (boolean)  - if true (or truthy), pattern is interpreted as a plain
+--                    string, not a Lua pattern
+--
+-- Returns: iterator
+--
+-- Usage:
+-- for substr in gsplit(text, pattern, plain) do
+--   doSomething(substr)
+-- end
+function we_c.gsplit(text, pattern, plain)
+	local splitStart, length = 1, #text
+	return function ()
+		if splitStart then
+			local sepStart, sepEnd = string.find(text, pattern, splitStart, plain)
+			local ret
+			if not sepStart then
+				ret = string.sub(text, splitStart)
+				splitStart = nil
+			elseif sepEnd < sepStart then
+				-- Empty separator!
+				ret = string.sub(text, splitStart, sepStart)
+				if sepStart < length then
+					splitStart = sepStart + 1
+				else
+					splitStart = nil
+				end
+			else
+				ret = sepStart > splitStart and string.sub(text, splitStart, sepStart - 1) or ''
+				splitStart = sepEnd + 1
+			end
+			return ret
+		end
+	end
+end
+
+
+-- split: split a string into substrings separated by a pattern.
+--
+-- Parameters:
+-- text (string)    - the string to iterate over
+-- pattern (string) - the separator pattern
+-- plain (boolean)  - if true (or truthy), pattern is interpreted as a plain
+--                    string, not a Lua pattern
+--
+-- Returns: table (a sequence table containing the substrings)
+function we_c.split(text, pattern, plain)
+	local ret = {}
+	for match in we_c.gsplit(text, pattern, plain) do
+		table.insert(ret, match)
+	end
+	return ret
+end