Updating parameter of an SKAction that is repeating forever swift - ios

Question

I have a function that animates a ball in a game that I am designing right now. However, I want the animation speed to change with the balls actual velocity, which I have achieved but only after each iteration of the animation. That makes it come out a little choppy, I am looking for a more elegant solution that could update the timePerFrame argument mid-action. I originally had it set to repeatforever but realized that timePerFrame wouldn't update once the action had started. Is there a way to make this animation speed change more smoothly?
func animBall() {
//This is the general runAction method to make our ball change color
var animSpeedNow = self.updateAnimSpeed()
println(animSpeedNow)
var animBallAction = SKAction.animateWithTextures(ballColorFrames, timePerFrame: animSpeedNow,resize: false, restore: true)
self.runAction(animBallAction, completion: {() -> Void in
self.animBall()
})
}
func updateAnimSpeed() -> NSTimeInterval{
// Update the animation speed based on the velocity to syncrhonize animation with ball velocity
var velocX = self.physicsBody!.velocity.dx
var velocY = self.physicsBody!.velocity.dy
if abs(velocX) > 0 || abs(velocY) > 0 {
var veloc = sqrt(velocX*velocX + velocY*velocY)
var animSpeedNow: NSTimeInterval = NSTimeInterval(35/veloc)
let minAS = NSTimeInterval(0.017)
let maxAS = NSTimeInterval(0.190)
if animSpeedNow < minAS {
return maxAS
}
else if animSpeedNow > maxAS {
return minAS
}
else {
return animSpeedNow
}
}
else {
return NSTimeInterval(0.15)
}
}
If it isn't possible to directly manipulate a parameter of an SKAction that is running forever, I supposed I

Answer 1

In your case, a simpler way would be to remove the old animation action and replace it with a new one.