SKEase action, how to use Float changing Action Se

问题:

In the following use case, I'm trying to animate the lineWidth of an SKShapeNode.

SKEase is part of the wonderful SpriteKitEasing github repo from Craig Grummitt.

One of its facilities is a Float changing ease action that appears to change the value of a float over time.

However I can't figure out how to use it. Xcode gives the following suggestions when typing it in:

 let lineWeight = SKEase.createFloatTween(<start: CGFloat, end: CGFloat, time: TimeInterval, easingFunction: AHEasingFunction, setterBlock: ((SKNode, CGFloat) -> Void))

With other SKEase actions from this library, Xcode is very helpful with ease types, and helping to figure out what to enter.

With this one, I have no idea what options are available for AHEasingFunctions... which I can probably find.

But I have absolutely no idea what or how to use the final part, the setterBlock seemingly expecting a function taking a pair of parameters unrelated to the activity. XCode won't accept SKShapeNodes or SKSpriteNodes here, only an SKNode, but I can't get beyond that.

---

Here's how the docs for SKEase describe it:

回答1:

If you type let fn = SKEase.getEaseFunction( and then a dot for the enum types for curve-type and ease-type you'll get completion.

With the SKNode to SKShapeNode you'll have to cast.

Here's some code:

    let fn = SKEase.getEaseFunction(.curveTypeQuadratic, easeType: .easeTypeInOut)
    let easeFat = SKEase.createFloatTween(2.5, end: 30.0, time: easeTime/2, easingFunction: fn) { (node: SKNode, param: CGFloat) in
        let spinny = node as! SKShapeNode
        spinny.lineWidth = param
    }
    let easeThin = SKEase.createFloatTween(30.0, end: 2.5, time: easeTime/2, easingFunction: fn) { (node: SKNode, param: CGFloat) in
        let spinny = node as! SKShapeNode
        spinny.lineWidth = param
    }

    if let spinnyNode = self.spinnyNode {
        spinnyNode.lineWidth = 2.5

        let rotate = SKAction.rotate(byAngle: CGFloat(M_PI) * CGFloat(2.0), duration: easeTime)
        let easeFatThin = SKAction.sequence([easeFat, easeThin])
        let rotateAndEase = SKAction.group([rotate, easeFatThin])

        spinnyNode.run(SKAction.repeatForever(rotateAndEase))
        spinnyNode.run(SKAction.sequence([SKAction.wait(forDuration: easeTime),
                                          SKAction.fadeOut(withDuration: easeTime),
                                          SKAction.removeFromParent()]))
    }

And a complete project on my GitHub.