Im programming a SpriteKit based game in Swift. The SKScene contains a SKSpriteNode which contains SKShapeNodes. One of those shapes is the "player". The user should be able to drag and drop the player. I implemented different methods to get this working user touchesBegan, touchesMoved, touchesCanceled and touches Ended. Basically everything works fine, as long as the user drags the "player" at a normal speed. But if the user drags the "player" really quickly the touchesMoved method is not called often enough. I thought it maybe due to the fact that I use SKShapeNodes but based on the output (below) that does not seem to be the case.
The code:
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
let touchLocation = touches.first!.locationInNode(self)
if(self.player.containsPoint(touchLocation)){
self.startedTouchingPlayer()
}
super.touchesBegan(touches, withEvent: event)
print("TOUCHES BEGAN")
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
let touchLocation = touches.first!.locationInNode(self)
if(self.player.containsPoint(touchLocation)){
self.isTouchingPlayer(touchLocation)
print("TOUCHES MOVED \(touchLocation)")
}
super.touchesMoved(touches, withEvent: event)
}
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
self.endedTouchingHelper()
super.touchesEnded(touches, withEvent: event)
print("TOUCHES ENDED")
}
override func touchesCancelled(touches: Set<UITouch>?, withEvent event: UIEvent?) {
print("TOUCHES CANCELED")
self.endedTouchingHelper()
super.touchesCancelled(touches, withEvent: event)
}
Print statements:
Normal Movement:
TOUCHES BEGAN
TOUCHES MOVED (-4.0, -241.499984741211)
TOUCHES MOVED (0.500015258789062, -239.0)
TOUCHES MOVED (4.0, -237.000015258789)
TOUCHES MOVED (11.0, -234.0)
TOUCHES MOVED (19.5, -229.499984741211)
TOUCHES MOVED (27.0000152587891, -225.499984741211)
TOUCHES MOVED (34.0, -221.499984741211)
TOUCHES MOVED (41.0, -217.499984741211)
TOUCHES MOVED (48.0, -213.499984741211)
TOUCHES MOVED (53.4999847412109, -210.0)
...
TOUCHES MOVED (77.5, -177.000015258789)
TOUCHES MOVED (77.5, -178.0)
TOUCHES ENDED
Fast movement:
TOUCHES BEGAN
TOUCHES MOVED (6.5, -277.5)
TOUCHES MOVED (3.0, -261.000030517578)
[*** at this point the finger is at a different position as the "player" ***] TOUCHES ENDED
Any kind of help is appreciated. Thanks.
Darvydas pointed me in the right direction and I was able to solve the problem like that:
The problem was not in the way I moved the player around it was this line in touchesMoved:
if(self.player.containsPoint(touchLocation))
When the user moves really quickly the touchLocation is not inside the player (because the position could not be updated that quickly). I changed the condition in the statement so it would just check if the player is currently being dragged (or allowed to be dragged).
Thanks.