My goal is to find out if a UITouch took place within a SpriteKit label node. The view is an SKView. The issue with the code that I am using (below) is that the touch and the rectangle seem to be in different coordinate systems.
I could use simple math to correct this, but is there a simple way to correct this issue? Or is there another way I should be doing this?
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for t in touches {
let position = t.location(in: view)
//if inside startButton
if (startButton?.frame.contains(position))! {
debugPrint("yes")
}
}
}
I assume that you are are overriding touchesBegan within a scene. If so, then try using let position = t.location(in: self), i.e. replace view with self. That way you get the position within the scene itself, rather than the position within the view that holds the scene.
Hope that helps!
Related
I am creating a game where the user can move some fruits around in the scene. I want to user to be able to move only the fruits and not any other SKSpriteNode in the scene, so I wrote the code below to implement it. However the code doesn't work properly as I can't seem to be able to drag any of my sprites around, but rather they change position only when I stop touching the screen and they don't move by much anyway.
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
let touch = touches.first
if let location = touch?.location(in: self){
let nodesTouched = nodes(at: location)
for node in (nodesTouched) {
if node is Fruit{
for t in touches {
let locationMoved = t.location(in: self)
node.position.x = locationMoved.x
node.position.y = locationMoved.y
}
}
}
}
}
Anyone knows what's wrong with it?
Thanks in advance!
I found a solution to this, which was to basically set the physicsBody.affectedByGravity property to false for that specific Fruit instance every time I touch it, and then set it back to true as soon as I stop touching it. that makes it possible to drag all the fruits everywhere I want.
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 a few button with amorphous look. (the Rect of the buttons are intersecting) First I evaluated the BeganTouch in the GameScene. Then I get several touches.
Since I have in my buttons still child nodes, they have swallowed the touchs. Ok, I have made with the help of here a subclass of the SpriteNodes and processed the touch inside the subclass. Now I have the problem that the first button does not pass the touch to the underlying sprites.
But now I would like top ignore the transparent areas of the buttons, how can I do that?
I have read that one can work with physicsbody, I have tried, gravitiy = 0 but since I move and scale the buttons via actions there were violent effects.
Why can I check for the alpha in the touch location and pass the touch to the next sprite.
by the way: how can I get a reference to the view? to get the global loc.
let loc = touch.location(in: view)
with the global touch location I could check all sprites under this point for the alpha!
you can try passing the touch to it's parent (presumably the scene) from your subclass.
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first as UITouch! {
//handle whatever code you want your subclass to do
...
//pass the touch event to the parent
super.touchesBegan(touches, with: event)
}
}
and then in your scene, cycle through the your buttons (in this example I have the buttons in a button array)
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first as UITouch! {
let touchLocation = touch.location(in: self)
for button in buttons {
if button.contains(touchLocation) {
//handle all other buttons
...
}
}
}
}
although this seems a little redundant to do the touches in two different locations. #Knight0fDragon is correct, it seems odd to have a button have transparent areas.
ok, it's simple, all buttons are from the same subclass. this subclass delegates to an method in the GameScene. here I can check with
allNodes = nodes(at: globalLocation)
now I can check for the name of the node, calculate the point of the pixel inside each node and get the alpha value.
thanxs all
I am trying to implement an overriden touchesMoved func to enable SKSpriteNodes to be moved around by the user. However, I have to move the node very slowly for it to follow my touches when I drag. In addition, there are three SKSpriteNodes in the background (which you will see I explicitly set to .userInteractionEnabled = false) and these nodes will occasionally respond to the touches. Any help would be greatly appreciated. Let me know if there are any other parts of the code you need.
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
var positionInScene = CGPoint(x: 375.0, y: 400.0) //sets a default position
titleLabel.userInteractionEnabled = false
drawingBoard.userInteractionEnabled = false
sideBar.userInteractionEnabled = false
for touch in touches {
positionInScene = touch.locationInNode(self)
if self.nodeAtPoint(positionInScene) is SKSpriteNode {
if (self.nodeAtPoint(positionInScene)).name == movableNodeName { //movableNodeName is the name assigned to all SKSpriteNodes that should be draggable
//I know this might be a strange way of doing it
(self.nodeAtPoint(touch.previousLocationInNode(self))).position = positionInScene
}
}
}
}
I've managed to fix this issue by just setting the coordinates of the node that shouldn't move back to what they were originally whenever it is moved. This seems to work as I haven't been able to replicate the bug again in testing. If anyone could come up with a better solution though, I would love to hear it.
Your problem is you are using touch.locationInNode(self), where self is your SKSpriteNode. This means that your touch move code will only respond to what is going on inside of your SKSpriteNode. What you need to do, is use either the parent of the sprite, or the scene, based on how you want to apply this logic.
I have an SKShapeNode that I have created and given a CGPath to. This is in my GameScene.swift in didMoveToView:
let myNode = SKShapeNode()
let lineToDraw = CGPathCreateMutable()
CGPathMoveToPoint(lineToDraw, nil, 0, 0)
CGPathAddLineToPoint(lineToDraw, nil, 87, 120)
myNode.path = lineToDraw
myNode.strokeColor = SKColor.redColor()
myNode.lineWidth = 20
myNode.name = "My Node!"
world.addChild(myNode) // World is a higher-level node in my scene
And this is how I'm detecting touches, again in the Scene:
override func touchesEnded(touches: NSSet!, withEvent event: UIEvent!) {
if let touch = touches.anyObject() as? UITouch {
if let shapeNode = nodeAtPoint(touch.locationInNode(self)) as? SKShapeNode {
println("Touched \(shapeNode.name)")
} else {
println("Nothing here")
}
}
}
The line node is showing up with no issues. However, it is not registering touchesEnded at all.
Really, I have three questions nebulous to this:
Is there a better way to create an SKShapeNode that is a line between two points without calling a convenience initializer? I plan on subclassing SKShapeNode to add additional logic to the node, and the subclass doesn't have access to convenience initializers of the superclass.
More importantly, how do I get the scene to recognize my line node there and trigger touchesEnded?
Is there a way, using that mechanism, I can make it a bit more "fuzzy", so it handles touches close to the line, instead of on the line? My eventual plan is to make it thinner, but I'd still like to have a large touch zone. I figure if nothing else, I can create two nodes: one clear/thick and the other red/thin, and handle touch events on the clear one, but I would like to know if there's a better way.
In answer to your main question, there is a problem in your touchesEnded method. The template shown by apple recommends the following layout:
override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
for touch: AnyObject in touches {
let location = touch.locationInNode(self)
}
}
You can then use this method to see if the location value is inside the lines frame (in order to do this, i created the "myNode" variable outside of the didMoveToView so that i could access it from the rest of the functions):
override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
for touch: AnyObject in touches {
let location = touch.locationInNode(world)
if CGRectContainsPoint(myNode.frame, location) {
println("Touched \(myNode.name)")
} else {
println("Nothing here")
}
}
}
As for a "fuzzier" line, you can simply check a larger CGRect. In the code above, i check myNode.frame but you could create a variable with a CGRect which is slightly larger than the line so that you can detect touches which don't directly hit it.
As for more concise code, i cannot think of any at the moment but that isn't to say that there isn't a way. However, I don't quite understand what you mean about subclasses not having access to convenience methods as they can have access to whatever the superclass does so long as you import correctly.
I hope this helps.