Minetest-WorldEditAdditions/worldeditadditions/maze2d.lua
2020-05-10 22:24:33 +01:00

182 lines
5.9 KiB
Lua

--- 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
----------------------------------
local 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
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
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
local directions = "" -- the different directions we can move
if cy - path_length > 0 and world[cy - path_length][cx] == "#" then
directions = directions .. "u"
end
if cy + path_length < height-path_width and world[cy + path_length][cx] == "#" then
directions = directions .. "d"
end
if cx - path_length > 0 and world[cy][cx - path_length] == "#" then
directions = directions .. "l"
end
if cx + path_length < width-path_width and world[cy][cx + path_length] == "#" then
directions = directions .. "r"
end
local shift_attention = math.random(0, 9)
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
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
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
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
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
table.remove(nodes, curnode)
end
if #directions == 0 or shift_attention <= 1 then
if #nodes > 0 then
--print("performing teleport.");
curnode = math.random(1, #nodes)
cx = nodes[curnode]["x"]
cy = nodes[curnode]["y"]
end
end
end
local end_time = os.clock()
return world, (end_time - start_time) * 1000
end
-- local world = maze(os.time(), width, height)
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, 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 < 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
-- 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)
-- 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))
-- print("path_width: "..path_width..", path_length: "..path_length)
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
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