touch transparent area of spritenode - sprite-kit

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

Related

Touch duration in SpriteKit

I am currently working with SpriteKit and I want to run a code block in the update-loop as long as the user is touching a certain SpriteNode. I tried to achieve this by using a Boolean, that gets set to true, when the touchesBegan() method recognises a touch on this node and gets set to false, when the touchesEnded() method recognises a touch ending on this node. However, when the user touches the node and then moves his finger outside of the boundaries, the touchesEnded() method does not recognise this.
Is there a simple way to check if a touch, that began in this node, but then moved outside of it, still exists? Or can I check in general if a UITouch instance still exists?
It's not clear what behavior you want, but in general you probably want to use touch identity to track what's happening.
For example, if you're handling touches in the scene containing the node, and if the desire is simply to have the action start when the node is touched and stop when that touch ends, then something like:
// Whatever touch initiated the action
var activeTouch: UITouch?
// Checked by update loop
var doingSomething = false
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
// Ignore new touches if one is already active
guard activeTouch == nil else { return }
let location = touch.location(in: self)
let touchedNodes = self.nodes(at: location)
for node in touchedNodes {
if <some test for the interesting node> {
activeTouch = touch
doingSomething = true
}
}
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
if touch == activeTouch {
// Finished
activeTouch = nil
doingSomething = false
}
}
}
If you also want the action to stop if the user moves their finger off the node and restart if they move back on, then also override touchesMoved, e.g.:
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
if touch == activeTouch {
let location = touch.location(in: self)
let touchedNodes = self.nodes(at: location)
// Assume they moved off the node
doingSomething = false
for node in touchedNodes {
if <some test for the interesting node> {
// Nope, still touching it
doingSomething = true
}
}
}
}
}
(You should also handle touchesCancelled in some appropriate way, maybe stopping the action and clearing activeTouch as in touchesEnded)
Perhaps you have some other behavior in mind for the case when there are multiple touches active. You might need to keep track of all the active touches and their status of being on or off the node, and then set doingSomething = true if any active touch is on the node. Or maybe you want touchesMoved to discard an active touch as soon as it moves off the node, so moving that touch back on again won't reactivate.
The main point is that keeping track of touch identity gives you a lot of flexibility, but you have to decide on how you want the game to react.

Moving SKSpriteNode with finger only if it is of type Fruit (subclass of SKSpriteNode)

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.

Determine if UITouch is within SKLabelNode frame

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!

Spritekit move camera only if not dragging from sprite

In a game I'm building a user is able to move the camera around by dragging around the screen similar to a scrollview. This is all handled in the main scene file by the touchesBegan and touchesMoved method. However I also want the ability for a user to drag from an SKSpriteNode (not actually moving it) to another SKSpriteNode - I then perform an action based on the 2 nodes. I can do both of these fine separately. But when a user is dragging from one node to another, I don't want the camera to pan.
Again I've managed to resolve this using a boolean flag that's set on touchesBegan if they have touched a node. However the screen then doesn't pan if a user starts touching on one of the sprites but finishes off of one e.g they actually quickly performed a pan that happened to start on a node. Does anyone have any good solutions for this?
One thought I had was to store all the touch events in touchesMoved, and then loop through them in touchesEnded performing the same movement logic, provided they didn't start and end on a sprite. e.g
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
movingTouches.append(touch)
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
if startedOnSprite && !endedOnSprite || !(startedOnSprite && endedOnSprite) {
let location = movingTouches.last().location(in: self)
let previousLocation = movingTouches.first().location(in: self)
let deltaY = location.y - previousLocation.y
let deltax = location.x - previousLocation.x
gameCamera?.position.y -= deltaY
view.frame.size.height
gameCamera?.position.y = (gameCamera?.position.y)! > viewHeight/2 ? viewHeight/2 : (gameCamera?.position.y)!
gameCamera?.position.y = (gameCamera?.position.y)! < -(viewHeight/2) ? -(viewHeight/2) : (gameCamera?.position.y)!
gameCamera?.position.x -= deltax
gameCamera?.position.x = (gameCamera?.position.x)! < -(viewWidth/2) ? -(viewWidth/2) : (gameCamera?.position.x)!
gameCamera?.position.x = (gameCamera?.position.x)! > (viewWidth/2) ? (viewWidth/2) : (gameCamera?.position.x)!
}
movingTouches = [UITouch]()
endedOnSprite = false
startedOnSprite = false
}
To complicate matters I also want the Sprites to have a tap event on them as well as dragging. I'm struggling to find a good way to do all this in SpriteKit
Unfortunately the above isn't very smooth at all, and in think it appears to not even scroll the distance I would expect either (the exact same code does scroll correctly if I'm not bothered about whether or not it starts on a Sprite)
So to be clear, I want scrolling behaviour, provided a user isn't actually using a finger to 'draw' from one sprite to another
Gesture recognisors on your scene would do what you need, keeping taps and swipes separated.

touchesMoved not functioning properly

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.