Question

我有一个类型为[UIBezierPath]的数组，我将其转换为cgPaths，然后动画到CAShapeLayer上，我称之为shapeLayer。由于某种原因，我的所有路径都是颠倒的，所以所有路径都被颠倒了。我怎么能解决这个问题，我尝试了几种方法，但遗憾的是没有一种方法可行......但我确实想弄清楚如何扩展路径。这是我绘制swiftPath的代码，swiftPath是一个由函数swiftBirdForm（）下的Forms类中的UIBezierPaths组成的路径。绘制路径工作正常，我只是无法弄清楚如何将它翻转180度。

    @objc func drawForm() {
    var swiftPath = Forms.swiftBirdForm()
    let shapeLayer = CAShapeLayer()
    shapeLayer.fillColor = UIColor.clear.cgColor
    shapeLayer.strokeColor = UIColor.black.cgColor
    shapeLayer.lineWidth = 1
    shapeLayer.frame = CGRect(x: -120, y: 120, width: 350, height: 350)

    var paths: [UIBezierPath] = swiftPath

    guard let path = paths.first else {
        return
    }

    paths.dropFirst()
        .forEach {
            path.append($0)
    }

    shapeLayer.transform = CATransform3DMakeScale(0.6, 0.6, 0)
    shapeLayer.path = path.cgPath

    self.view.layer.addSublayer(shapeLayer)

    let strokeEndAnimation = CABasicAnimation(keyPath: "strokeEnd")
    strokeEndAnimation.duration = 1.0
    strokeEndAnimation.fromValue = 0.0
    strokeEndAnimation.toValue = 1.0
    shapeLayer.add(strokeEndAnimation, forKey: nil)
}

Answer 1

使用CATransform3D

shapeLayer.transform = CATransform3DMakeScale(1, -1, 1)

转化路径，

let shapeBounds = shapeLayer.bounds
let mirror = CGAffineTransform(scaleX: 1,
                                  y: -1)
let translate = CGAffineTransform(translationX: 0,
                                  y: shapeBounds.size.height)
let concatenated = mirror.concatenating(translate)

bezierPath.apply(concatenated)

shapeLayer.path = bezierPath.cgPath

转换图层

let shapeFrame = CGRect(x: -120, y: 120, width: 350, height: 350)
let mirrorUpsideDown = CGAffineTransform(scaleX: 1,
                                              y: -1)
shapeLayer.setAffineTransform(mirrorUpsideDown)
shapeLayer.frame = shapeFrame

如何翻转动画到CAShapeLayer上的UIBezierPath或cgPath？

1 个答案: