I am making a word game. For this I am using SceneKit and adding a SpriteNodes to represent letter tiles.
The idea is that when a user clicks on a letter tile, some extra tiles appear around it with different letter options. My issue is regarding the touch gestures for various interactions.
When a user taps on a letter tile, additional tiles are shown. I have achieved this using the following method in my tile SpriteNode class:
override func touchesBegan(_ touches:Set<UITouch> , with event: UIEvent?) {
guard let touch = touches.first else {
return
}
delegate?.updateLetter(row: row, column: column, x:xcoord, y:ycoord, useCase: 1)
}
This triggers the delegate correctly which shows another sprite node.
What I would like to achieve is for a long press to remove the sprite node from parent. I have found the .removeFromParent() method, however I cannot get this to detect a long press gesture.
My understanding is that this type of gesture must be added using UIGestureRecognizer. I can add the following method to my Scene class:
override func didMove(to view: SKView) {
let longPress = UILongPressGestureRecognizer(target: self,
action: #selector(GameScene.longPress(sender:)))
view.addGestureRecognizer(longPress)
}
#objc func longPress(sender: UILongPressGestureRecognizer) {
print("Long Press")
This will detect a long press anywhere on the scene. However I need to be able to handle the pressed nodes properties before removing it. I have tried adding the below to the longPress function:
let location = sender.location(in: self)
let touchedNodes = nodes(at: location)
let firstTouchedNode = atPoint(location).name
touchedNodes[0].removeFromParent()
but I get the following error: Cannot convert value of type 'GameScene' to expected argument type 'UIView?'
This seems a little bit of a messy way of doing things, as I have touch methods in different places.
So my question is, how can I keep the current touchesBegan method that is in the tile class, and add a long press gesture to be able to reference and delete the spriteNode?
Long press gestures are continuous gestures that may be called multiple times as you are seeing. Have you tried Recognizer.State.began, .changed, .ended? I solved a similar problem doing things this way.
EDIT - I think one way to get there is to get your object on handleTap and hang on to the object. Then when LongPress happens, you already have your node. If something changes before longPress, obviously you need to reset. Sorry, this is some extra code on here, but look at hitTest.
#objc func handleTap(recognizer: UITapGestureRecognizer)
{
let location: CGPoint = recognizer.location(in: gameScene)
if(data.isAirStrikeModeOn == true)
{
let projectedPoint = gameScene.projectPoint(SCNVector3(0, 0, 0))
let scenePoint = gameScene.unprojectPoint(SCNVector3(location.x, location.y, CGFloat(projectedPoint.z)))
gameControl.airStrike(position: scenePoint)
}
else
{
let hitResults = gameScene.hitTest(location, options: hitTestOptions)
for vHit in hitResults
{
if(vHit.node.name?.prefix(5) == "Panel")
{
// May have selected an invalid panel or auto upgrade was on
if(gameControl.selectPanel(vPanel: vHit.node.name!) == false) { return }
return
}
}
}
}
So I am not completely satisfied with this answer, however it is a work around for what I need.
What I have done is added two variables ‘touchesStart’ and ‘touchesEnd’ to my tiles class.
Then in touchesBegan() I add a call to update touchesStart with CACurrentMediaTime() and update touchesEnd via the touchesEnded() function.
Then in the touchesEnded() I subtract touchesStart from touchesEnd. If the difference is more than 1.0 I call the function for long press. If less than 1.0 I call the function for tap.
Related
Desired behavior is: when an action is removed from a node (with removeAction(forKey:) for instance) it stops to animate and all the changes caused by action are discarded, so the node returns back to pervious state. In other words, I want to achieve behavior similar to CAAnimation.
But when a SKAction is removed, the node remains changed. It's not good, because to restore it's state I need to know exactly what action was removed. And if I then change the action, I also will need to update the node state restoration.
Update:
The particular purpose is to show possible move in a match-3 game. When I show a move, pieces start pulsating (scale action, repeating forever). And when the user moves I want to stop showing the move, so I remove the action. As the result, pieces may remain downscaled. Later I would like to add more fancy and complicated animations, so I want to be able to edit it easily.
Thanks to the helpful comment and answer I came to my own solution. I think the state machine would be bit too heavy here. Instead I created a wrapper node, which main purpose is run the animation. It also has a state: isAimating property. But, first of all, it allows to keep startAnimating() and stopAnimating() methods close to each other, incapsulated, so it's more difficult to mess up.
class ShowMoveAnimNode: SKNode {
let animKey = "showMove"
var isAnimating: Bool = false {
didSet {
guard oldValue != isAnimating else { return }
if isAnimating {
startAnimating()
} else {
stopAnimating()
}
}
}
private func startAnimating() {
let shortPeriod = 0.2
let scaleDown = SKAction.scale(by: 0.75, duration: shortPeriod)
let seq = SKAction.sequence([scaleDown,
scaleDown.reversed(),
scaleDown,
scaleDown.reversed(),
SKAction.wait(forDuration: shortPeriod * 6)])
let repeated = SKAction.repeatForever(seq)
run(repeated, withKey: animKey)
}
private func stopAnimating() {
removeAction(forKey: animKey)
xScale = 1
yScale = 1
}
}
Usage: just add everything that should be animated to this node. Works well with simple animations, like: fade, scale and move.
As #Knight0fDragon suggested, you would be better off using the GKStateMachine functionality, I will give you an example.
First declare the states of your player/character in your scene
lazy var playerState: GKStateMachine = GKStateMachine(states: [
Idle(scene: self),
Run(scene: self)
])
Then you need to create a class for each of these states, in this example I will show you only the Idle class
import SpriteKit
import GameplayKit
class Idle: GKState {
weak var scene: GameScene?
init(scene: SKScene) {
self.scene = scene as? GameScene
super.init()
}
override func didEnter(from previousState: GKState?) {
//Here you can make changes to your character when it enters this state, for example, change his texture.
}
override func isValidNextState(_ stateClass: AnyClass) -> Bool {
return stateClass is Run.Type //This is pretty obvious by the method name, which states can the character go to from this state.
}
override func update(deltaTime seconds: TimeInterval) {
//Here is the update method for this state, lets say you have a button which controls your character velocity, then you can check if the player go over a certain velocity you make it go to the Run state.
if playerVelocity > 500 { //playerVelocity is just an example of a variable to check the player velocity.
scene?.playerState.enter(Run.self)
}
}
}
Now of course in your scene you need to do two things, first is initialize the character to a certain state or else it will remain stateless, so you can to this in the didMove method.
override func didMove(to view: SKView) {
playerState.enter(Idle.self)
}
And last but no least is make sure the scene update method calls the state update method.
override func update(_ currentTime: TimeInterval) {
playerState.update(deltaTime: currentTime)
}
I have an app thats spawn ball on the screen every 1 second. now, I want the user to touch those balls what make them disappear (removeFromParent()). as I understand I have to set the touch function via touchesBegan and I do so, here is my code:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch: AnyObject in touches{
let positionOfTouch = touch.location(in: self)
enumerateChildNodes(withName: "BALL") { (node: SKNode, nil) in
if positionOfTouch == node.position {
print("just touched the ball")
}
else{
print("error")
}
}
}
the problem is that when I touch the screen/ ball the console print error instead of just touched the ball, which mean that my code doesn't work. moreover, the console print the error message as the number of the balls in my view. i don't relay understand what I am doing wrong and how to really set this function.
here is my createBall function which implement from my BallNode class (type SKShapeNode):
func createBall(){
let ball = BallNode(radius: 65)
print(ball.Name)
print(ball._subName!)
ball.position.y = ((frame.size.height) - 200)
let ballXPosition = arc4random_uniform(UInt32(frame.size.width)) // set the ball a randon position from the top of the screen
ball.position.x = CGFloat(ballXPosition)
ball.physicsBody?.categoryBitMask = PhysicsCategory.ball // ball's category bitMask
ball.physicsBody?.collisionBitMask = PhysicsCategory.ball // prevent objects from intersecting
ball.physicsBody?.contactTestBitMask = PhysicsCategory.topBorder // when need to know if two objects touch each other
addChild(ball)
}
can you help me with that? because I am quit new for swift I also would like to get some explanation about this touch detection (and touches in general - the apple doc is poor).
every time you touch the screen you are cycling through all balls to see if you're touching one of them. if you have 50 balls on the screen it goes through them all to see if you are touching 1. that's not an efficient way of figuring out if you are touching 1.
There are many ways you can do this but what I would do is handle the touches inside of the Ball class. That way you don't have to figure out if you are touching a ball and which one it might be.
Explanation of protocol (to the best of my ability) this may seem a little much right now, but the faster you learn and understand protocols that better off you will be (IMO).
In this example we will use a protocol to setup a delegate of the
BallNode class. A protocol is a set user defined "rules" that must be
followed by any class that you designate compliant to that protocol.
In my example I state that for a class to be compliant to the
BallNodeDelegate protocol it must contain the didClick func. When you
add the BallNodeDelegate after GameScene you are stating that this
class will be compliant to that protocol. So if in GameScene you did
not have the didClick func it will cause an error. All this is put in
place so that you have an easy way to communicate between your
BallNode instances and your GameScene class (without having to pass
around references to your GameScene to each BallNode). Each BallNode
then has a delegate (GameScene) which you can pass back the
information to.
inside your BallNode class make sure you have isUserInteraction = true
outside of your BallNode class create a protocol that will send the touch info back to the GameScene
protocol BallNodeDelegate: class {
func didClick(ball: BallNode)
}
create a delegate variable in your BallNode class
weak var delegate: BallNodeDelegate!
move the touches began to you BallNode class
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
self.delegate?.didClick(ball: self)
}
in GameScene add the compliance to the BallNode protocol
class GameScene: SKScene, BallNodeDelegate
in GameScene when you create a Ball make sure you set it's delegate
let ball = BallNode()
ball.delegate = self
in GameScene add the nest. func to handle the clicks
func didClick(ball: BallNode) {
print("clicked ball")
}
You are comparing the exact touch point with the exact position of the node, which are very unlikely to ever be the same.
if positionOfTouch == node.position {
Instead, you'll need to test to see if the user's touch is close enough to the position of the ball.
One option is to use SKNode's contains function, which will handle this for you.
if node.contains(positionOfTouch) {
Side note: You'll probably want to use SKSpriteNode instead of SKShapeNode, as SKShapeNode has poor performance in SpriteKit.
Take a look at nodes(at:CGPoint) defined at SKNode to retrieve a list of the nodes at the touched position. You'll need to convert in between view coordinates and scene coordinates, though, using convertPoint(fromView). Documentation here and here.
I have reviewed countless references to try to understand why my scene is not behaving the way i expected it to, such as this.
Here is my very simple SKScene (2 child nodes):
The scene has a SpriteNode (which covers the entire scene as a background image). This has a zPosition = 0.
The scene has a 2nd node (SKNode) which itself has another child (up to 2 levels). This has a zPosiiton - 2.
ALL nodes have .userInteractionEnabled = false
Issue:
When i click anywhere all i see is that the 1st child (SpriteNode) is touched. The 2nd child (SKNode) is never touch-detected.
Note that the z-ordering of the Nodes are being rendered as I expect them. It is the touch-detection that doesnt appear to be working.
Snippet of my touchesBegan method:
for touch in touches {
let touchLocation = touch.locationInNode(self)
let sceneTouchPoint = self.convertPointToView(touchLocation)
let touchedNode = self.nodeAtPoint(sceneTouchPoint)
if (touchedNode.name != nil) {
print("Touched = \(touchedNode.name! as String)")
}
}
I had a similar issue (background in z: 999 + spawning "ducks" nodes in z: <999) that I solved with the following code in Swift 4:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let touch:UITouch = touches.first!
let positionInScene = touch.location(in: self)
let touchedNodes = self.nodes(at: positionInScene)
for touch in touchedNodes {
let touchName = touch.name
if (touchName != nil && touchName!.hasPrefix("pato_")) {
touch.removeFromParent()
}
}
}
I had several layers of nodes because I used a mask over my game with buttons to make selections and move forward. I had issues with the buttons not working until I made a "startState:Bool = true" and updated this to false when the start screen was clicked through. I then had each of my buttons on that start page to have && startState==true for there clicks to be taken. It may be that your clicks are being recorded - but its not the node you think you are using. I would put print("NodeXXX") on each entry in touches and give it a unique name so you can see where the touches are actually happening.
Hope that helps.
Best regards,
mpe
I'm making a game using Sprite Kit and I want to be able to drag and drop boxes as they travel down the screen.
Here's the gist of the code: I spawn the boxes on a timer and they move down the screen.
override func didMoveToView(view: SKView) {
let timer = NSTimer.scheduledTimerWithTimeInterval(2.0, target: self, selector: Selector("spawnBox"), userInfo: nil, repeats: true)
}
func spawnBox() {
/* Set up the box */
addChild(box)
let boxMoveDown = SKAction.moveToY(-100, duration: 5.0)
let actionDone = SKAction.removeFromParent()
box.runAction(SKAction.sequence([boxMoveDown, actionDone]))
}
But the problem is I how can I move a specific child which I am touching without affecting all the other 'children'? I understand that at the moment, every time I spawn a box it's exactly the same so I can't be specific when I set a individual child's position.
Here's what's inside my touchesBegan and touchesMoved functions
if let touch = touches.first {
let location = touch.locationInNode(self)
let objects = nodesAtPoint(location) as [SKNode]
if objects.contains(nodeAtPoint(location)) && nodeAtPoint(location).name == "box" {
box.position = location
box.removeAllActions()
}
}
The - box.position = location is what
needs changing.
Hopefully you understand my idea. I've tried to keep included code to what's necessary. I'm quite new to Sprite Kit which you can probably tell.
If I were you, I would handle it this way:
Create a custom class for your box nodes that extends SKSpriteNode.
In this custom class, override the touch property.
Then set the position inside this function based on location.
Now all you need to worry about is your zPosition, whatever child has the highest zPosition will be the one that gets called on touch.
You do not need to worry about nodesAtPoint or what not anymore, the API will handle all that for you.
I'm in the process of learning swift (and spritekit) and trying to make a simple game.
In my game, the hero should jump or duck...
The hero needs to jump when the screen is tapped,or duck if the screen is tap+held (long gesture)
So basic pseudo code:
if tapped
heroJump()
else if tappedAndHeld
heroDuck()
I have a func which is seen in almost all tutorials, which handles the touch event:
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
for touch in touches {
let location = touch.locationInNode(self) //need location of tap for something
switch gameState {
case .Play:
//do in game stuff
break
case .GameOver:
//opps game ended
}
break
}
}
super.touchesBegan(touches, withEvent: event)
}
Is there a way, to include in this touch event, to decide if it was tapped or held? I can't seem to get my head around the fact, the program will always recognise a tap before a long gesture?!?
Anyway, in an attempt to solve my problem, I found THIS question, which introduced to me recognisers, which I tried to implement:
override func didMoveToView(view: SKView) {
// other stuff
//add long press gesture, set to start after 0.2 seconds
let longPressRecognizer = UILongPressGestureRecognizer(target: self, action: "longPressed:")
longPressRecognizer.minimumPressDuration = 0.2
self.view!.addGestureRecognizer(longPressRecognizer)
//add tap gesture
let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: "tapped:")
self.view!.addGestureRecognizer(tapGestureRecognizer)
}
And these are the functions the gestures call:
func longPressed(sender: UILongPressGestureRecognizer)
{
if (sender.state == UIGestureRecognizerState.Ended) {
print("no longer pressing...")
} else if (sender.state == UIGestureRecognizerState.Began) {
print("started pressing")
// heroDuck()
}
}
func tapped(sender: UITapGestureRecognizer)
{
print("tapped")
// heroJump()
}
How can I combine these two things?
Can I add a way to determine whether it was tapped or hold in my touchBegins event, or can I scrap that method and use only the two functions above?
One of many problems being getting the location if using the latter?
Or maybe I'm looking at this completely wrong, and there's a simple and/or built in way in swift/spritekit?
Thanks.
You only need the UITapGestureRecognizer and the UILongPressRecognizer. You do not need to do anything with touchesBegan and touchesEnded, because the gesture recognizer analyses the touches itself.
To get the location of the touch you can call locationInView on the gesture recognizer to get the location of the gesture or locationOfTouch if you are working with multitouch gestures and need the location of each touch. Pass nil as parameter when you want the coordinates in the window’s base coordinate system.
Here is a working example:
func setupRecognizers() {
let tapRecognizer = UITapGestureRecognizer(target: self, action: Selector("handleTap:"))
let longTapRecognizer = UILongPressGestureRecognizer(target: self, action: Selector("handleLongPress:"))
view.addGestureRecognizer(tapRecognizer)
view.addGestureRecognizer(longTapRecognizer)
}
func handleLongPress(recognizer: UIGestureRecognizer) {
if recognizer.state == .Began {
print("Duck! (location: \(recognizer.locationInView(nil))")
}
}
func handleTap(recognizer: UIGestureRecognizer) {
print("Jump! (location: \(recognizer.locationInView(nil))")
}
If a long press is recognized handleTap: tap is not called. Only if the user lifts his finger fast enough handleTap: will be called. Otherwise handleLongPress will be called. handleLongPress will only be called after the long press duration has passed. Then handleLongPress will be called twice: When the duration has passed ("Began") and after the user has lifted his finger ("Ended").
you do the same thing you are doing for longpress, wait till the .Ended event
func tapped(sender: UITapGestureRecognizer)
{
if sender.state == .Ended {
print("tapped")
}
}
A tap event will always happen, this can't be prevented because lets face it, you need to touch the screen. What should be happening though is when you enter the long press event, the tap event should go into a Cancel state instead of an Ended state