Procedural Level Generation With Cellular Automaton In Swift - swift

Question

Is there a easy way to create a procedural level with a cellular automaton in swift/SpriteKit(library?)? I want to create a 'cave' with 11 fields in the height and 22 width. These should be randomly created and every field without a wall should be reached.
I just found a documentation using Objective-C, which I am not familiar with. I spend quite some time trying to understand the code and follow the example without success.
PS: If there is an easier way I appreciate some algorithms

Answer 1

I made a Playground where you can experiment
//: Playground - noun: a place where people can play
import UIKit
import SpriteKit
import XCPlayground
class Cave {
var cellmap:[[Bool]]
let chanceToStartAlive = 35
let deathLimit = 3
let birthLimit = 4
var xCell = 40 // number of cell in x axes
var yCell = 20 // number of cell in y axes
var wCell = 20 // cell width
var hCell = 20 // cell height
init(){
cellmap = Array(count:yCell, repeatedValue:
Array(count:xCell, repeatedValue:false))
cellmap = self.initialiseMap(xCell, yIndex:yCell)
}
func initialiseMap(xIndex:Int, yIndex:Int) -> [[Bool]]{
var map:[[Bool]] = Array(count:yIndex, repeatedValue:
Array(count:xIndex, repeatedValue:false))
for y in 0...(yIndex - 1) {
for x in 0...(xIndex - 1) {
let diceRoll = Int(arc4random_uniform(100))
if diceRoll < chanceToStartAlive {
map[y][x] = true
} else {
map[y][x] = false
}
}
}
return map
}
func addSprite(scene:SKScene){
for (indexY, row) in cellmap.enumerate(){
for (indexX, isWall) in row.enumerate(){
if isWall {
let wall = SKSpriteNode(color: UIColor.redColor(), size: CGSize(width: wCell, height: hCell))
wall.position = CGPoint(x: (indexX * wCell) + (wCell / 2) , y: (indexY * hCell) + (hCell / 2) )
scene.addChild(wall)
}
}
}
}
func countAliveNeighbours(x:Int, y:Int) -> Int{
var count = 0
var neighbour_x = 0
var neighbour_y = 0
for i in -1...1 {
for j in -1...1 {
neighbour_x = x + j
neighbour_y = y + i
if(i == 0 && j == 0){
} else if(neighbour_x < 0 || neighbour_y < 0 || neighbour_y >= cellmap.count || neighbour_x >= cellmap[0].count){
count = count + 1
} else if(cellmap[neighbour_y][neighbour_x]){
count = count + 1
}
}
}
return count
}
func applyRules(){
var newMap:[[Bool]] = Array(count:yCell, repeatedValue:
Array(count:xCell, repeatedValue:false))
for y in 0...(cellmap.count - 1) {
for x in 0...(cellmap[0].count - 1) {
let nbs = countAliveNeighbours( x, y: y);
if(cellmap[y][x]){
if(nbs < deathLimit){
newMap[y][x] = false;
}
else{
newMap[y][x] = true;
}
} else{
if(nbs > birthLimit){
newMap[y][x] = true;
}
else{
newMap[y][x] = false;
}
}
}
}
cellmap = newMap
}
}
let view:SKView = SKView(frame: CGRectMake(0, 0, 1024, 768))
XCPShowView("Live View", view: view)
let scene:SKScene = SKScene(size: CGSizeMake(1024, 768))
scene.scaleMode = SKSceneScaleMode.AspectFit
let aCave = Cave()
aCave.applyRules()
aCave.applyRules()
aCave.addSprite(scene)
view.presentScene(scene)

Answer 2

Updated the playground code for Xcode 8 and Swift 3. I swapped the X and Y cell count since you will likely see the view in a "portrait" orientation.
Remember to open the Assistant Editor to view the results. It also takes a little while to execute, so give it a couple of minutes to run the algorithm.
//: Playground - noun: a place where people can play
import UIKit
import SpriteKit
import XCPlayground
import PlaygroundSupport
class Cave {
var cellmap:[[Bool]]
let chanceToStartAlive = 35
let deathLimit = 3
let birthLimit = 4
var xCell = 20 // number of cell in x axes
var yCell = 40 // number of cell in y axes
var wCell = 20 // cell width
var hCell = 20 // cell height
init(){
cellmap = Array(repeating:
Array(repeating:false, count:xCell), count:yCell)
cellmap = self.initialiseMap(xIndex: xCell, yIndex:yCell)
}
func initialiseMap(xIndex:Int, yIndex:Int) -> [[Bool]]{
var map:[[Bool]] = Array(repeating:
Array(repeating:false, count:xIndex), count:yIndex)
for y in 0...(yIndex - 1) {
for x in 0...(xIndex - 1) {
let diceRoll = Int(arc4random_uniform(100))
if diceRoll < chanceToStartAlive {
map[y][x] = true
} else {
map[y][x] = false
}
}
}
return map
}
func addSprite(scene:SKScene){
for (indexY, row) in cellmap.enumerated(){
for (indexX, isWall) in row.enumerated(){
if isWall {
let wall = SKSpriteNode(color: UIColor.red, size: CGSize(width: wCell, height: hCell))
wall.position = CGPoint(x: (indexX * wCell) + (wCell / 2) , y: (indexY * hCell) + (hCell / 2) )
scene.addChild(wall)
}
}
}
}
func countAliveNeighbours(x:Int, y:Int) -> Int{
var count = 0
var neighbour_x = 0
var neighbour_y = 0
for i in -1...1 {
for j in -1...1 {
neighbour_x = x + j
neighbour_y = y + i
if(i == 0 && j == 0){
} else if(neighbour_x < 0 || neighbour_y < 0 || neighbour_y >= cellmap.count || neighbour_x >= cellmap[0].count){
count = count + 1
} else if(cellmap[neighbour_y][neighbour_x]){
count = count + 1
}
}
}
return count
}
func applyRules(){
var newMap:[[Bool]] = Array(repeating:
Array(repeating:false, count:xCell), count:yCell)
for y in 0...(cellmap.count - 1) {
for x in 0...(cellmap[0].count - 1) {
let nbs = countAliveNeighbours( x: x, y: y);
if(cellmap[y][x]){
if(nbs < deathLimit){
newMap[y][x] = false;
}
else{
newMap[y][x] = true;
}
} else{
if(nbs > birthLimit){
newMap[y][x] = true;
}
else{
newMap[y][x] = false;
}
}
}
}
cellmap = newMap
}
}
let view:SKView = SKView(frame: CGRect(x: 0, y: 0, width: 768, height: 1024))
let scene:SKScene = SKScene(size: CGSize(width: 768, height: 1024))
scene.scaleMode = SKSceneScaleMode.aspectFit
PlaygroundPage.current.needsIndefiniteExecution = true
PlaygroundPage.current.liveView = view
let aCave = Cave()
aCave.applyRules()
aCave.applyRules()
aCave.addSprite(scene: scene)
view.presentScene(scene)