Using Swipe Recognizer in SpriteKit - swift

I'm trying to implement swipe gestures left and right into a game in SpriteKit where the player collects falling objects spawning from the top of the screen. The problem I'm facing is trying to keep a continuous movement of the player while the finger is on the screen until the touch is ended and the player stays where the last touch ended. There might be a better way to implement this other than swipe gestures hence why I'm asking you guys! Any help would be great, thank you all!

This is not something you want to use a swipe (I think you are using pan) gesture for. What you want to do is override the touchesBegan, touchesMoved, and touchesEnded calls on the scene, and plan your movement according to these 3 methods.
You are probably going to want to use SKAction.move(to:duration:) with these methods, and figure out the math to keep a constant speed.
E.G.
func movePlayer(to position:CGPoint)
{
let distance = player.position.distance(to:position)
let move = SKAction.move(to:position, duration: distance / 100) // I want my player to move 100 points per second
//using a key will cancel the last move action
player.runAction(move,withKey:"playerMoving")
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?)
{
let touch = touches.first
let position = touch.location(in node:self)
movePlayer(to:position)
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?)
{
let touch = touches.first
let position = touch.location(in node:self)
movePlayer(to:position)
}
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
let touch = touches.first
let position = touch.location(in node:self)
movePlayer(to:position)
}

Related

Spritekit: Dragging a SKCameraNode()

I am rather new to Swift and SpriteKit. I made a plane move around on a big background. What I am trying to do now is DRAG the "camera" so i can see the plane when its outside my view.
I made a SKCameraNode()
I can change its position without problem. And then I tried this for drag:
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
let location = touch.location(in: self)
camera?.position = CGPoint(x: location.x, y: location.y)
}
}
The camera moves when i drag, but super fast and far far far away...
Some ideas? Thanks!

Swift - Delay for dragging sknode

My SceneKit app has both
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
...
}
#objc func handleButtonMovement(recognizer : UIPanGestureRecognizer) {
...
}
The SKSpriteNode when touched doesn't trigger the handleButtonMovement unless you move slightly in any direction - but TouchesBegan is launched.
Also, if I touch the SKSpriteNode and move too quickly, the handleButtonMovement isn't triggered either.
Is there some way to adjust the sensitivity so that as soon as you touch the SKSpriteNode, it triggers handleButtonMovement as a drag event?

TouchEvents in watchOS 3 SpriteKit?

When using SpriteKit in watchOS 3, how do you handle the touch events? I am porting the SpriteKit games from iOS and the codes below won't work. Or you have to control the WKInterfaceController somehow?
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {}
override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {}
After a lot of frustration with the same issue, I wound up using gesture recognizers, and calculating the position from there.
#IBAction func handleSingleTap(tapGesture: WKTapGestureRecognizer) {
let location = tapGesture.locationInObject()
if yourSpriteNodeRect.contains(location) {
//do stuff
}
}
One tip though: A strange bug I found though when creating the method to handle the gesture recognizer was that the gesture wasn't being passed by default into the method. I had to ctrl + drag to create the method, and then modify the signature to contain the gesture. If I created the method with the gesture in the signature, Xcode wouldn't allow me to attach the gesture recognizer to it.
It would seem that there would be a better way to detect the touches, but that's the workaround I found for now.
To get something close to touch down events use a WKLongPressGestureRecognizer with super-short duration (0.001). The IBAction connected to this recognizer will get touch down events pretty much right away. The location is found in the locationInObject property of the recognizer. If the goal is to get moving touches then use the pan recognizer.
So to do this I first hooked up a gesture recognizer in the watch storyboard. Created an IBAction, then called a method on the SpriteKit Scene passing in gesture.locationInObject(). Then within the scene method for the conversion, here's some code.
let screenBounds = WKInterfaceDevice.current().screenBounds
let newX = ((location.x / screenBounds.width) * self.size.width) - (self.size.width / 2)
let newY = -(((location.y / screenBounds.height) * self.size.height) - (self.size.height / 2))
The newX and newY are the touch coordinates in the scene.

SpriteKit Scale on tap

im trying to create a "button touch" effect for one of my sprites, it works well but then I tap with 2 or more fingers at the same time, i get really weird results, here is my code:
let buttonPressAction = SKAction.scaleBy(0.8, duration: 0)
var button = SKNode()
override func didMoveToView(view: SKView) {
//assign sprite to node
button = self.childNodeWithName("button") as! SKSpriteNode!
}
for touch: AnyObject in touches {
let location = touch.locationInNode(self)
if button.containsPoint(location) {
button.runAction(buttonPressAction)
}
}
}
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
button.runAction(buttonPressAction.reversedAction())
}
Try changing the SK scale action from
...scaleBy
to
...scaleTo
to ensure it will always scale to the same size. With scaleBy it will scale it by 0.8, not to 0.8. That most likely causes the weird results on multiple touches because you are scaling by 0.8 for each finger/tap.
I never used reverseAction before so I am not sure if that might cause issues. If it does just reset the button by scaling it back to 1
...scaleTo(1, duration: 0)
As as side note you can just say
for touch in touches
instead of
for touch: AnyObject in touches

How to recognize continuous touch in Swift?

How can I recognize continuous user touch in Swift code? By continuous I mean that the user has her finger on the screen. I would like to move a sprite kit node to the direction of user's touch for as long as the user is touching screen.
The basic steps
Store the location of the touch events (touchesBegan/touchesMoved)
Move sprite node toward that location (update)
Stop moving the node when touch is no longer detected (touchesEnded)
Here's an example of how to do that
Xcode 8
let sprite = SKSpriteNode(color: SKColor.white, size: CGSize(width:32, height:32))
var touched:Bool = false
var location = CGPoint.zero
override func didMove(to view: SKView) {
/* Add a sprite to the scene */
sprite.position = CGPoint(x:0, y:0)
self.addChild(sprite)
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
touched = true
for touch in touches {
location = touch.location(in:self)
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
location = touch.location(in: self)
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
// Stop node from moving to touch
touched = false
}
override func update(_ currentTime: TimeInterval) {
// Called before each frame is rendered
if (touched) {
moveNodeToLocation()
}
}
// Move the node to the location of the touch
func moveNodeToLocation() {
// Compute vector components in direction of the touch
var dx = location.x - sprite.position.x
var dy = location.y - sprite.position.y
// How fast to move the node. Adjust this as needed
let speed:CGFloat = 0.25
// Scale vector
dx = dx * speed
dy = dy * speed
sprite.position = CGPoint(x:sprite.position.x+dx, y:sprite.position.y+dy)
}
Xcode 7
let sprite = SKSpriteNode(color: SKColor.whiteColor(), size: CGSizeMake(32, 32))
var touched:Bool = false
var location = CGPointMake(0, 0)
override func didMoveToView(view: SKView) {
self.scaleMode = .ResizeFill
/* Add a sprite to the scene */
sprite.position = CGPointMake(100, 100)
self.addChild(sprite)
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
/* Start moving node to touch location */
touched = true
for touch in touches {
location = touch.locationInNode(self)
}
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
/* Update to new touch location */
for touch in touches {
location = touch.locationInNode(self)
}
}
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
// Stop node from moving to touch
touched = false
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
if (touched) {
moveNodeToLocation()
}
}
// Move the node to the location of the touch
func moveNodeToLocation() {
// How fast to move the node
let speed:CGFloat = 0.25
// Compute vector components in direction of the touch
var dx = location.x - sprite.position.x
var dy = location.y - sprite.position.y
// Scale vector
dx = dx * speed
dy = dy * speed
sprite.position = CGPointMake(sprite.position.x+dx, sprite.position.y+dy)
}
The most difficult thing about this process is tracking single touches within a multitouch environment. The issue with the "simple" solution to this (i.e., turn "istouched" on in touchesBegan and turn it off in touchesEnded) is that if the user touches another finger on the screen and then lifts it, it will cancel the first touch's actions.
To make this bulletproof, you need to track individual touches over their lifetime. When the first touch occurs, you save the location of that touch and move the object towards that location. Any further touches should be compared to the first touch, and should be ignored if they aren't the first touch. This approach also allows you to handle multitouch, where the object could be made to move towards any finger currently on the screen, and then move to the next finger if the first one is lifted, and so on.
It's important to note that UITouch objects are constant across touchesBegan, touchesMoved, and touchesEnded. You can think of a UITouch object as being created in touchesBegan, altered in touchesMoved, and destroyed in touchesEnded. You can track the phase of a touch over the course of its life by saving a reference to the touch object to a dictionary or an array as it is created in touchesBegan, then in touchesMoved you can check the new location of any existing touches and alter the object's course if the user moves their finger (you can apply tolerances to prevent jitter, e.g., if the x/y distance is less than some tolerance, don't alter the course). In touchesEnded you can check if the touch in focus is the one that ended, and cancel the object's movement, or set it to move towards any other touch that is still occurring. This is important, as if you just check for any old touch object ending, this will cancel other touches as well, which can produce unexpected results.
This article is in Obj-C, but the code is easily ported to Swift and shows you what you need to do, just check out the stuff under "Handling a Complex Multitouch Sequence": https://developer.apple.com/library/ios/documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/multitouch_background/multitouch_background.html
Below is the code to drag the node around on X position (left and right), it is very easy to add Y position and do the same thing.
let item = SKSpriteNode(imageNamed: "xx")
var itemXposition = 50
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
// updates itemXposition variable on every touch
for touch in touches {
let location = touch.location(in: self)
itemXposition = Int(location.x)
}
}
// this function is called for each frame render, updates the position on view
override func update(_ currentTime: TimeInterval) {
spaceShip.position = CGPoint(x: self.itemXposition , y: 50 )
}