Im trying to create a dodgeball feature in my game and I need to repeatedly spawn a dodgeball and the current code I used (shown below) results in Thread 1: Exception: "Attemped to add a SKNode which already has a parent: name:'(null)' texture:[ 'dodgeball5' (500 x 500)] position:{-140.00019836425781, -55.124687194824219} scale:{1.00, 1.00} size:{30, 30} anchor:{0.5, 0.5} rotation:0.00". What am I doing incorrect?
class ClassicLevelScene: SKScene {
// Right Pointing Cannons
var rightPointingCannon: [SKReferenceNode] = []
// Dodgeball 5 Constants
var dodgeball5 = SKSpriteNode(imageNamed: "dodgeball5")
// Dodgeball SKActions
var dodgeballRepeat = SKAction()
let dodgeballMoveLeft = SKAction.moveBy(x: -400, y: 0, duration: 0.5)
let dodgeballMoveRight = SKAction.moveBy(x: 400, y: 0, duration: 0.5)
let dodgeballMoveDone = SKAction.removeFromParent()
let dodgeballWait = SKAction.wait(forDuration: 1)
var dodgeballLeftSequence = SKAction()
var dodgeballRightSequence = SKAction()
override func didMove(to view: SKView) {
// Cannon Setup
for child in self.children {
if child.name == "rightPointingCannon" {
if let child = child as? SKReferenceNode {
rightPointingCannon.append(child)
dodgeball5.position = child.position
run(SKAction.repeatForever(
SKAction.sequence([
SKAction.run(spawnDodgeball),
SKAction.wait(forDuration: 1.0)
])
))
}
}
}
// Dodgeball Right Sequence
dodgeballRightSequence = SKAction.sequence([dodgeballMoveRight, dodgeballMoveDone, dodgeballWait])
}
func spawnDodgeball() {
dodgeball5.zPosition = -1
dodgeball5.size = CGSize(width: 30, height: 30)
addChild(dodgeball5)
dodgeball5.run(dodgeballRightSequence)
}
}
Assuming single ball and ball can go off screen:
I would actually recommend against cloning the sprite.
Simply reuse it.
Once it's off the screen, you can reset it's position and speed and display it again. No need to create lots of objects, if you only need one.
One SKNode only can have 1 parent at time.
You need to create a new SKSpriteNode or clone the dodgeball5 before to add again on spawnDodgeball()
You can use
addChild(dodgeball5.copy())
instead of
addChild(dodgeball5)
But be make sure dodgeball5 have no parent before.
Your code seems to be unnecessarily complex.
all you need to do is copy() you ball and add it to your scene
Also all of your SKActions don't need to be declared at a class level
And it's not clear why you are creating an array of cannons when only one is instantiated
class ClassicLevelScene: SKScene {
// Dodgeball 5 Constants
var dodgeball5 = SKSpriteNode(imageNamed: "dodgeball5")
override func didMove(to view: SKView) {
setupCannonAndBall()
let dodgeballMoveRight = SKAction.moveBy(x: 400, y: 0, duration: 0.5)
let dodgeballMoveDone = SKAction.removeFromParent()
let dodgeballWait = SKAction.wait(forDuration: 1)
dodgeballRightSequence = SKAction.sequence([dodgeballMoveRight, dodgeballMoveDone, dodgeballWait])
//setup sequences ^ before spawning ball
let spawn = SKAction.run(spawnDodgeball)
let wait = SKAction.wait(forDuration: 1.0)
run(SKAction.repeatForever(SKAction.sequence([spawn, wait])))
}
func setupCannonAndBall() {
if let cannonRef = SKReferenceNode(fileNamed: "rightPointingCannon") {
dodgeball5.position = cannonRef.position
dodgeball5.isHidden = true
dodgeball5.size = CGSize(width: 30, height: 30)
dodgeball5.zPosition = -1
}
}
func spawnDodgeball() {
let dodgeball = dodgeball.copy()
dodgeball.isHidden = false
addChild(dodgeball)
dodgeball.run(dodgeballRightSequence)
}
}
To generate an image I have written the following function. However, I want that function to able to generate one of four possible images, instead of the same image every time. Right now it generates the "Top Side" image every time, but I want it to randomly choose one of the four images I have to generate.
func spawnBrick() {
let Brick = SKSpriteNode(imageNamed: "Top Side")
Brick.size = CGSize(width: 130, height: 100)
Brick.position = CGPoint(x: frame.midX, y: frame.maxY - Brick.size.width)
addChild(Brick)
}
enum brickType: UInt {
case brickTop = 1
case brickLeft = 2
case brickRight = 3
case brickBottom = 4
}
let brickTop = SKSpriteNode(imageNamed: "Top Side")
let brickLeft = SKSpriteNode(imageNamed: "Left Side")
let brickRight = SKSpriteNode(imageNamed: "Right Side")
let brickBottom = SKSpriteNode(imageNamed: "Bottom Side")
Swift array has a method called randomElement that will give you an optional element from the array (not its optional because the array could be empty)
https://developer.apple.com/documentation/swift/array/2994747-randomelement
func spawnBrick() {
let Brick = SKSpriteNode(imageNamed: ["Top Side","Left Side","Right Side","Bottom Side"].randomElement()!)
Brick.size = CGSize(width: 130, height: 100)
Brick.position = CGPoint(x: frame.midX, y: frame.maxY - Brick.size.width)
addChild(Brick)
}
The goal is to round the corners of an unconventional grid similar to the following:
https://s-media-cache-ak0.pinimg.com/564x/50/bc/e0/50bce0cb908913ebc2cf630d635331ef.jpg
https://s-media-cache-ak0.pinimg.com/564x/7e/29/ee/7e29ee80e957ec22bbba630ccefbfaa2.jpg
Instead of a grid with four corners like a conventional grid, these grids have multiple corners in need of rounding.
The brute force approach would be to identify tiles with corners exposed then round those corners either with a different background image or by clipping the corners in code.
Is there a cleaner approach?
The grid is rendered for an iOS app in a SpriteKit SKScene.
This is a really interesting question.You can build your matrix with different approaches but surely you must resolve everytime the changes about the 4 corners in background for each tiles.
Suppose you start with a GameViewController like this (without load SKS files and with anchorPoint equal to zero):
import UIKit
import SpriteKit
class GameViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
guard let view = self.view as! SKView? else { return }
view.ignoresSiblingOrder = true
view.showsFPS = true
view.showsNodeCount = true
let scene = GameScene(size:view.bounds.size)
scene.scaleMode = .resizeFill
scene.anchorPoint = CGPoint.zero
view.presentScene(scene)
}
}
My idea is to build a matrix like this:
import SpriteKit
class GameScene: SKScene {
private var sideTile:CGFloat = 40
private var gridWidthTiles:Int = 5
private var gridHeightTiles:Int = 6
override func didMove(to view: SKView) {
self.drawMatrix()
}
func drawMatrix(){
var index = 1
let matrixPos = CGPoint(x:50,y:150)
for i in 0..<gridHeightTiles {
for j in 0..<gridWidthTiles {
let tile = getTile()
tile.name = "tile\(index)"
addChild(tile)
tile.position = CGPoint(x:matrixPos.x+(sideTile*CGFloat(j)),y:matrixPos.y+(sideTile*CGFloat(i)))
let label = SKLabelNode.init(text: "\(index)")
label.fontSize = 12
label.fontColor = .white
tile.addChild(label)
label.position = CGPoint(x:tile.frame.size.width/2,y:tile.frame.size.height/2)
index += 1
}
}
}
func getTile()->SKShapeNode {
let tile = SKShapeNode(rect: CGRect(x: 0, y: 0, width: sideTile, height: sideTile), cornerRadius: 10)
tile.fillColor = .gray
tile.strokeColor = .gray
return tile
}
}
Output:
Now we can construct a background for each tile of our matrix.
We can made the same tile node but with a different color (maybe more clear than the tile color) and without corner radius. If we split this background in 4 parts we have:
left - bottom background tile
left - top background tile
right - bottom background tile
right - top background tile
Code for a typical background tile:
func getBgTileCorner()->SKShapeNode {
let bgTileCorner = SKShapeNode(rect: CGRect(x: 0, y: 0, width: sideTile/2, height: sideTile/2))
bgTileCorner.fillColor = .lightGray
bgTileCorner.strokeColor = .lightGray
bgTileCorner.lineJoin = .round
bgTileCorner.isAntialiased = false
return bgTileCorner
}
Now with the SKSCropNode we can obtain only the corner using the background tile and the tile:
func getCorner(at angle:String)->SKCropNode {
let cropNode = SKCropNode()
let tile = getTile()
let bgTile = getBgTileCorner()
cropNode.addChild(bgTile)
tile.position = CGPoint.zero
let tileFrame = CGRect(x: 0, y: 0, width: sideTile, height: sideTile)
switch angle {
case "leftBottom": bgTile.position = CGPoint(x:tile.position.x,y:tile.position.y)
case "rightBottom": bgTile.position = CGPoint(x:tile.position.x+tileFrame.size.width/2,y:tile.position.y)
case "leftTop": bgTile.position = CGPoint(x:tile.position.x,y:tile.position.y+tileFrame.size.height/2)
case "rightTop": bgTile.position = CGPoint(x:tile.position.x+tileFrame.size.width/2,y:tile.position.y+tileFrame.size.height/2)
default:break
}
tile.fillColor = self.backgroundColor
tile.strokeColor = self.backgroundColor
tile.lineWidth = 0.0
bgTile.lineWidth = 0.0
tile.blendMode = .replace
cropNode.position = CGPoint.zero
cropNode.addChild(tile)
cropNode.maskNode = bgTile
return cropNode
}
Output for a typical corner:
let corner = getCorner(at: "leftBottom")
addChild(corner)
corner.position = CGPoint(x:50,y:50)
Now we can rebuild the drawMatrix function with the corners for each tile:
func drawMatrix(){
var index = 1
let matrixPos = CGPoint(x:50,y:150)
for i in 0..<gridHeightTiles {
for j in 0..<gridWidthTiles {
let tile = getTile()
tile.name = "tile\(index)"
let bgTileLB = getCorner(at:"leftBottom")
let bgTileRB = getCorner(at:"rightBottom")
let bgTileLT = getCorner(at:"leftTop")
let bgTileRT = getCorner(at:"rightTop")
bgTileLB.name = "bgTileLB\(index)"
bgTileRB.name = "bgTileRB\(index)"
bgTileLT.name = "bgTileLT\(index)"
bgTileRT.name = "bgTileRT\(index)"
addChild(bgTileLB)
addChild(bgTileRB)
addChild(bgTileLT)
addChild(bgTileRT)
addChild(tile)
tile.position = CGPoint(x:matrixPos.x+(sideTile*CGFloat(j)),y:matrixPos.y+(sideTile*CGFloat(i)))
let label = SKLabelNode.init(text: "\(index)")
label.fontSize = 12
label.fontColor = .white
tile.addChild(label)
label.position = CGPoint(x:tile.frame.size.width/2,y:tile.frame.size.height/2)
bgTileLB.position = CGPoint(x:tile.position.x,y:tile.position.y)
bgTileRB.position = CGPoint(x:tile.position.x,y:tile.position.y)
bgTileLT.position = CGPoint(x:tile.position.x,y:tile.position.y)
bgTileRT.position = CGPoint(x:tile.position.x,y:tile.position.y)
index += 1
}
}
}
Output:
Very similar to your screenshots (these are two tile example:)
Now when you want to remove a tile, you can decide what corner you want to remove or leave because for each tile you have also the relative 4 corners :
Output:
Okay, the grid creation process isn't really relative to this. You just need some way of differentiating between a blank spot in the grid and a filled spot. In my example I have a Tile object with a type of .blank or .regular. You need to have all 15 images (you can change the style to whatever you like, although they have to be in the same order and they have to be prefixed with 1..15). It uses bit calculation to figure out which image to use as a background and offsets the background image by 1/2 tile size for x and y. Other than that it is pretty self explanitory. Those background images were my tester images I created when developing this, so feel free to use them.
struct GridPosition {
var col: Int = 0
var row: Int = 0
}
class GameScene: SKScene {
private var backgroundLayer = SKNode()
private var tileLayer = SKNode()
private var gridSize: CGSize = CGSize.zero
private var gridRows: Int = 0
private var gridCols: Int = 0
private var gridBlanks = [Int]()
private var tiles = [[Tile]]()
var tileSize: CGFloat = 150
override func didMove(to view: SKView) {
backgroundLayer.zPosition = 1
addChild(backgroundLayer)
tileLayer.zPosition = 2
addChild(tileLayer)
gridRows = 8
gridCols = 11
gridBlanks = [0,1,3,4,5,6,7,9,10,11,12,13,15,16,17,19,20,21,22,23,31,32,33,36,40,43,56,64,67,69,70,71,72,73,75,77,78,79,82,85,86,87]
createGrid()
createBackgroundTiles()
}
func createGrid() {
for row in 0 ..< gridRows {
var rowContent = [Tile]()
for col in 0 ..< gridCols {
let currentTileLocation: Int = row * gridCols + col
var tile: Tile
if gridBlanks.contains(currentTileLocation) {
tile = Tile(row: row, col: col, type: .blank, tileSize: tileSize)
}
else {
tile = Tile(row: row, col: col, type: .regular, tileSize: tileSize)
}
tile.position = positionInGrid(column: col, row: row)
tile.zPosition = CGFloat(100 + gridRows - row)
tileLayer.addChild(tile)
rowContent.append(tile)
}
tiles.append(rowContent)
}
}
func tileByGridPosition(_ gridPos: GridPosition) -> Tile {
return (tiles[Int(gridPos.row)][Int(gridPos.col)])
}
func positionInGrid(column: Int, row: Int) -> CGPoint {
let startX = 0 - CGFloat(gridCols / 2) * tileSize
let startY = 0 - CGFloat(gridRows / 2) * tileSize + tileSize / 2
return CGPoint(
x: startX + CGFloat(column) * tileSize,
y: startY + CGFloat(row) * tileSize)
}
func createBackgroundTiles() {
for row in 0...gridRows {
for col in 0...gridCols {
let topLeft = (col > 0) && (row < gridRows) && tileByGridPosition(GridPosition(col: col - 1, row: row)).type == .regular
let bottomLeft = (col > 0) && (row > 0) && tileByGridPosition(GridPosition(col: col - 1, row: row - 1)).type == .regular
let topRight = (col < gridCols) && (row < gridRows) && tileByGridPosition(GridPosition(col: col, row: row)).type == .regular
let bottomRight = (col < gridCols) && (row > 0) && tileByGridPosition(GridPosition(col: col, row: row - 1)).type == .regular
// The tiles are named from 0 to 15, according to the bitmask that is made by combining these four values.
let value = Int(NSNumber(value: topLeft)) | Int(NSNumber(value: topRight)) << 1 | Int(NSNumber(value: bottomLeft)) << 2 | Int(NSNumber(value: bottomRight)) << 3
// Values 0 (no tiles)
if value != 0 {
var gridPosition = positionInGrid(column: col, row: row)
gridPosition.x -= tileSize / 2
gridPosition.y -= tileSize / 2
let backgroundNode = SKSpriteNode(imageNamed: ("background_tile_\(value)"))
backgroundNode.size = CGSize(width: tileSize, height: tileSize)
backgroundNode.alpha = 0.8
backgroundNode.position = gridPosition
backgroundNode.zPosition = 1
backgroundLayer.addChild(backgroundNode)
}
}
}
}
}
class Tile: SKSpriteNode {
private var row = 0
private var col = 0
var type: TileType = .blank
init(row: Int, col: Int, type: TileType, tileSize: CGFloat) {
super.init(texture: nil ,color: .clear, size:CGSize(width: tileSize, height: tileSize))
self.type = type
size = self.size
let square = SKSpriteNode(color: type.color, size: size)
square.zPosition = 1
addChild(square)
}
}
Only thing that comes to mind is when one node touches another node, at that moment in time evaluate the display of said node, as well as change the neighbors that are affected by it.
What we did was lay out the tiles then call this function to round the nodes of exposed tiles.
// Rounds corners of exposed tiles. UIKit inverts coordinates so top is bottom and vice-versa.
fileprivate func roundTileCorners() {
// Get all tiles
var tiles = [TileClass]()
tileLayer.enumerateChildNodes(withName: ".//*") { node, stop in
if node is TileClass {
tiles.append(node as! TileClass)
}
}
// Round corners for each exposed tile
for t in tiles {
// Convert tile's position to root coordinates
let convertedPos = convert(t.position, from: t.parent!)
// Set neighbor positions
var leftNeighborPos = convertedPos
leftNeighborPos.x -= tileWidth
var rightNeighborPos = convertedPos
rightNeighborPos.x += tileWidth
var topNeighborPos = convertedPos
topNeighborPos.y += tileHeight
var bottomNeighborPos = convertedPos
bottomNeighborPos.y -= tileHeight
// Set default value for rounding
var cornersToRound : UIRectCorner?
// No neighbor below & to left? Round bottom left.
if !isTileAtPoint(point: bottomNeighborPos) && !isTileAtPoint(point: leftNeighborPos) {
cornersToRound = cornersToRound?.union(.topLeft) ?? .topLeft
}
// No neighbor below & to right? Round bottom right.
if !isTileAtPoint(point: bottomNeighborPos) && !isTileAtPoint(point: rightNeighborPos) {
cornersToRound = cornersToRound?.union(.topRight) ?? .topRight
}
// No neightbor above & to left? Round top left.
if !isTileAtPoint(point: topNeighborPos) && !isTileAtPoint(point: leftNeighborPos) {
cornersToRound = cornersToRound?.union(.bottomLeft) ?? .bottomLeft
}
// No neighbor above & to right? Round top right.
if !isTileAtPoint(point: topNeighborPos) && !isTileAtPoint(point: rightNeighborPos) {
cornersToRound = cornersToRound?.union(.bottomRight) ?? .bottomRight
}
// Any corners to round?
if cornersToRound != nil {
t.roundCorners(cornersToRound: cornersToRound!)
}
}
}
// Returns true if a tile exists at <point>. Assumes <point> is in root node's coordinates.
fileprivate func isTileAtPoint(point: CGPoint) -> Bool {
return nodes(at: point).contains(where: {$0 is BoardTileNode })
}
I'm trying to stop my nodes from falling just for a second or two at the start of my game. So my problem is when I push start the nodes are already halfway down the screen. I also tried changing how high the nodes start but it seems like a costly solution since I want to be careful not to let my FPS get too low. In my code I am trying to do this in the didMoveToView and I am using waitForDuration but it doesn't work.
Example Image of Nodes Falling Down
Any SpriteKit masters know what I should do? I'm using Swift.
Here is my code:
override func didMoveToView(view: SKView) {
let wait = SKAction.waitForDuration(2.5)
let run = SKAction.runBlock {
self.spawnNumbers()
}
numContainer.runAction(SKAction.sequence([wait, run]))
}
func spawnNumbers() {
let minValue = self.size.width / 8
let maxValue = self.size.width - 36
let spawnPoint = CGFloat(arc4random_uniform(UInt32(maxValue - minValue)))
let action = SKAction.moveToY(-300, duration: 2)
numContainer = SKSpriteNode(imageNamed: "Circle")
numContainer.name = "Circle"
numContainer.size = CGSize(width: 72, height: 72)
numContainer.anchorPoint = CGPointMake(0, 0)
numContainer.position = CGPoint(x: spawnPoint, y: self.size.height)
numContainer.runAction(SKAction.repeatActionForever(action))
numContainer.zPosition = 2
let numberLabel = SKLabelNode(fontNamed: "AvenirNext-Bold")
numberLabel.text = "\(numToTouch)"
numberLabel.name = "Label"
numberLabel.zPosition = -1
numberLabel.position = CGPointMake(CGRectGetMidX(numContainer.centerRect) + 36, CGRectGetMidY(numContainer.centerRect) + 36)
numberLabel.horizontalAlignmentMode = .Center
numberLabel.verticalAlignmentMode = .Center
numberLabel.fontColor = UIColor.whiteColor()
numberLabel.fontSize = 28
addChild(numContainer)
numContainer.addChild(numberLabel)
numContainerArray.append(numContainer)
numToTouch += 1
}
I think you have to cast the 2.5 seconds to an NSTimeInterval:
let wait = SKAction.waitForDuration(NSTimeInterval(2.5))
You could also try putting the actions in the init function for your scene:
override init (size: CGSize) {
super.init(size: size)
//your code from before
}
Also, not sure if it matters, but this is what I normally do and it works,
let wait = SKAction.waitForDuration(NSTimeInterval(2.5))
let action = SKAction.runBlock({() in self.spawnNumbers()})
let actionThenWait = SKAction.sequence([wait, action])
self.runAction(actionThenWait)
I'm new to Swift development and I'm trying to create a simple racing game. The road in the game has lane markers that animate from the top of the screen to the bottom then loop back up to the top. I am using SKShapeNodes for the lane line markers.
I have been able to get one lane marker to work and now I just need to create an array(I think?) of lane markers so that I can have 2 columns of lanes and enough to give the game the illusion of being a real road.
I'm able to create the array but I get a run-time error when I try to add a SKShapeNode to it. The error I get is:
Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP,subcode=0x0)
fatal error: Cannot index empty buffer
Here is the relevant source code:
class PlayScene: SKScene {
let road = SKSpriteNode(imageNamed: "road8")
let car = SKSpriteNode(imageNamed: "car")
let laneLineNode = SKShapeNode()
var laneLineNodeArray = [[SKShapeNode]]()
var groundSpeed = 25
}
override func didMoveToView(view: SKView) {
//draw a lane line
var path = CGPathCreateMutable();
var laneLineWidth = self.size.width / 85
var laneLineHeight = self.size.height / 11
var laneLine = CGRect(x: ((self.frame.size.width / 5) * 2), y:
(self.frame.size.height + laneLineHeight),
width: laneLineWidth, height: laneLineHeight)
laneLineNode.lineWidth = 0
laneLineNode.path = CGPathCreateWithRect(laneLine, nil)
laneLineNode.fillColor = SKColor.yellowColor()
laneLineNode.zPosition = 2
//THIS IS THE LINE I GET THE ERROR ON
laneLineNodeArray[0][0] = laneLineNode
self.addChild(self.road)
self.addChild(self.laneLineNode)
self.addChild(self.car)
}
override func update(currentTime: CFTimeInterval) {
//move the lane lines
scrollLaneLines(self.scene!)
}
}
Thanks for any help you can give me.
First of all... You are closing your class too soon with this code:
var groundSpeed = 25
} // <--
Second... Your are not initializing your array before using it. In my test, I got the error because of that.
You should use this syntax to initialize your Array or use append as #Arnab suggest.
let laneLineNode = SKShapeNode()
var laneLineNodeArray = [[laneLineNode]]
You have created an empty array so far. Use "append" to add data to the array before you access the elements by index.
Thank you! I was able to get it to work with this in Class PlayScene:
var laneLineNodeArray:[[SKShapeNode]] = []
and this in func didMoveToView:
//draw a lane line
var path = CGPathCreateMutable();
var laneLineWidth = self.size.width / 85
var laneLineHeight = self.size.height / 11
var laneLine = CGRect(x: 0, y: (self.frame.size.height + laneLineHeight),
width: laneLineWidth, height: laneLineHeight)
var laneLineRowNumber: Int
var laneLineY: CGFloat
for r in 0...6 {
var laneLineRow:[LaneLine] = []
laneLineRowNumber = r
for c in 0...1 {
let laneLineNode = LaneLine()
laneLineNode.lineWidth = 0
laneLineNode.path = CGPathCreateWithRect(laneLine, nil)
laneLineNode.fillColor = SKColor.yellowColor()
laneLineNode.zPosition = 2
//lanelineY determines the Y placement of the lane.
laneLineY = self.frame.size.height - (CGFloat((laneLineHeight) * 2)
* CGFloat(r))
if c == 0 {
laneLineNode.position = CGPointMake(laneWidth * 2, laneLineY)
}
else if c == 1 {
laneLineNode.position = CGPointMake(laneWidth * 3, laneLineY)
}
self.addChild(laneLineNode)
laneLineRow.append(laneLineNode)
}
laneLineNodeArray.append(laneLineRow)
}