CADisplayLink?

[eonist]

Hey,

First of all Awesome concept!

Couple of questions:

1. Does your Library use CADisplayLink or?
2. 60fps?
3. Support for interactions while animation is happening?
4. Could you talk a little about what drives the animation?

Thanks.

[eonist]

I first read about the implications of CADisplayLink here: https://blog.bigspaceship.com/the-holy-grail-of-ios-animation-intervals-e9e663ea93c4 Pretty good article. I recently implemented the CVDisplayLink which is the macOS equivalent.

[RamonGilabert]

Hey @eonist, thanks for the issue.

1. & 4. The way Walker works is basically by taking the initial point and the final point and drawing the curve that the object should take, calculating all the points with a small step at the time, that way, a CAKeyframeAnimation is configured and will run the animation. The reason for that was for simplicity. I know there are some libraries that build the entire animation without using any sort of default API.
2. For the question of the 60fps, the answer is I am not sure. The performance of it relies in CAKeyframeAnimation, so it should be 60fps, since the calculation in points shouldn't take that long and, when a curve that is not a spring is used, the calculation is much simpler.
3. This is the reason why the library is in 0.10.0 and not in 1.0.0. I wanted to explore something different and not rely on CAKeyframeAnimation completely. Maybe build my own animation that moves ever x ms sending a notification or a delegate method – not sure. I haven't done much on it in a while, but I might definitely come back to it, this issue is mainly a motivation for it now – so thanks.

I'll read more about CADisplayLink, do you have a link to your macOS project? 😊

[eonist]

Thanks for the reply/answers!

I have a few blog posts about the AnimLib I've built for macOS:

http://stylekit.org/blog/2016/02/24/CVDisplayLink/
http://stylekit.org/blog/2016/02/20/Core-animation/
http://stylekit.org/blog/2016/03/09/Demo-app/

And here is the AnimLib (the important class being Animator.swift)

https://github.com/eonist/swift-utils/tree/master/misc/animation

In the example bellow, a clock pointer rotates 3 times:

let line:LineGraphic = addSubView(LineGraphic())
let animator = LoopingAnimator(Animation.sharedInstance,3,1,0,1,progress,Easing.easeLinear)
func progress(value:CGFloat){
   let angle = π * 2  * value
   line.p2 = line.p1.polarPoint(50,angle)
   line.draw()
}
animator.start()

The reason I asked about your lib was in terms of Interaction + animation which seems to be the tricky part. I want to attempt something similar for iOS, but looking through what other people has made first. Let me know if something is unclear with CADisplayLink. I'd be happy to help.

[eonist]

Hey, im lending som inspiration from your walker lib. Really liked the chaining you used. https://github.com/eonist/Element-iOS/wiki/anim-lib-ios