--- Flood-fill command for complex lakes etc. -- @module worldeditadditions.floodfill ------------------------------------------------------------------------------- --- A Queue implementation, taken & adapted from https://www.lua.org/pil/11.4.html -- @submodule worldeditadditions.utils.queue local Queue = {} function Queue.new() return { first = 0, last = -1 } end function Queue.enqueue(queue, value) local new_last = queue.last + 1 queue.last = new_last queue[new_last] = value end function Queue.contains(queue, value) for i=queue.first,queue.last do if queue[i] == value then return true end end return false end function Queue.is_empty(queue) return queue.first > queue.last end function Queue.dequeue(queue) local first = queue.first if Queue.is_empty(queue) then error("Error: The queue is empty!") end local value = queue[first] queue[first] = nil -- Help the garbage collector out queue.first = first + 1 return value end ------------------------------------------------------------------------------- function worldeditadditions.floodfill(start_pos, radius, replace_node) -- Calculate the area we want to modify local pos1 = vector.add(start_pos, { x = radius, y = 0, z = radius }) local pos2 = vector.subtract(start_pos, { x = radius, y = radius, z = radius }) pos1, pos2 = worldedit.sort_pos(pos1, pos2) -- pos2 will always have the highest co-ordinates now -- Fetch the nodes in the specified area local manip, area = worldedit.manip_helpers.init(pos1, pos2) local data = manip:get_data() -- Setup for the floodfill operation itself local start_pos_index = area:index(start_pos.x, start_pos.y, start_pos.z) local search_id = data[start_pos_index] local replace_id = minetest.get_content_id(replace_node) local radius_sq = radius*radius if search_id == replace_id then return false end local count = 0 local remaining_nodes = Queue.new() Queue.enqueue(remaining_nodes, start_pos_index) -- Do the floodfill while Queue.is_empty(remaining_nodes) == false do local cur = Queue.dequeue(remaining_nodes) -- Replace this node data[cur] = replace_id count = count + 1 -- Check all the nearby nodes -- We don't need to go upwards here, since we're filling in lake-style local xplus = cur + 1 -- +X if data[xplus] == search_id and worldeditadditions.vector.lengthsquared(vector.subtract(area:position(xplus), start_pos)) < radius_sq and not Queue.contains(remaining_nodes, xplus) then -- minetest.log("action", "[floodfill] [+X] index " .. xplus .. " is a " .. data[xplus] .. ", searching for a " .. search_id) Queue.enqueue(remaining_nodes, xplus) end local xminus = cur - 1 -- -X if data[xminus] == search_id and worldeditadditions.vector.lengthsquared(vector.subtract(area:position(xminus), start_pos)) < radius_sq and not Queue.contains(remaining_nodes, xminus) then -- minetest.log("action", "[floodfill] [-X] index " .. xminus .. " is a " .. data[xminus] .. ", searching for a " .. search_id) Queue.enqueue(remaining_nodes, xminus) end local zplus = cur + area.zstride -- +Z if data[zplus] == search_id and worldeditadditions.vector.lengthsquared(vector.subtract(area:position(zplus), start_pos)) < radius_sq and not Queue.contains(remaining_nodes, zplus) then -- minetest.log("action", "[floodfill] [+Z] index " .. zplus .. " is a " .. data[zplus] .. ", searching for a " .. search_id) Queue.enqueue(remaining_nodes, zplus) end local zminus = cur - area.zstride -- -Z if data[zminus] == search_id and worldeditadditions.vector.lengthsquared(vector.subtract(area:position(zminus), start_pos)) < radius_sq and not Queue.contains(remaining_nodes, zminus) then -- minetest.log("action", "[floodfill] [-Z] index " .. zminus .. " is a " .. data[zminus] .. ", searching for a " .. search_id) Queue.enqueue(remaining_nodes, zminus) end local yminus = cur - area.ystride -- -Y if data[yminus] == search_id and worldeditadditions.vector.lengthsquared(vector.subtract(area:position(yminus), start_pos)) < radius_sq and not Queue.contains(remaining_nodes, yminus) then -- minetest.log("action", "[floodfill] [-Y] index " .. yminus .. " is a " .. data[yminus] .. ", searching for a " .. search_id) Queue.enqueue(remaining_nodes, yminus) end count = count + 1 end -- Save the modified nodes back to disk & return worldedit.manip_helpers.finish(manip, data) return count end