Dywane

_waveHeight! -= duration / Double(label!.font.lineHeight)
_translate! += 0.1
if !_reverse {
    _zoom! += 0.02
    if _zoom! >= 1.2 {
        _reverse = true
    }
} else {
    _zoom! -= 0.02
    if _zoom! <= 1.0 {

Dywane

let originY = (label.bounds.size.height + label.font.lineHeight) / 2
let path = UIBezierPath()
path.move(to: CGPoint(x: 0, y: _waveHeight!))
var yPosition = 0.0
for xPosition in 0..<Int(label.bounds.size.width) {
    yPosition = _zoom! * sin(Double(xPosition) / 180.0 * Double.pi - 4 * _translate! / Double.pi) * 5 + _waveHeight!
    path.addLine(to: CGPoint(x: Double(xPosition), y: yPosition))
}
path.addLine(to: CGPoint(x: label.bounds.size.width, y: originY))
path.addLine(to: CGPoint(x: 0, y: originY))

Dywane

var percent = (CGFloat(currentTime - beginTime) - CGFloat(delayArray[index])) / CGFloat(durationArray[index])
percent = fmax(0.0, percent)
percent = fmin(1.0, percent)
attributedString.addAttribute(.baselineOffset, value: (percent - 1) * label!.font.lineHeight, range: range)

Dywane

case .fade:
    attributedString.addAttribute(.foregroundColor, value: label.textColor.withAlphaComponent(0), range: NSRange(location: 0, length: attributedString.length))
    let displayInterval = duration / TimeInterval(attributedString.length)
    for index in 0..<attributedString.length  {
        delayArray.append(TimeInterval(index) * displayInterval)
        durationArray.append(duration - delayArray[index])
    }

Dywane

case .shine:
    attributedString.addAttribute(.foregroundColor, value: label.textColor.withAlphaComponent(0), range: NSRange(location: 0, length: attributedString.length))
    for index in 0..<attributedString.length {
        delayArray.append(TimeInterval(arc4random_uniform(UInt32(duration) / 2 * 100) / 100))
        let remain = duration - Double(delayArray[index])
        durationArray.append(TimeInterval(arc4random_uniform(UInt32(remain) * 100) / 100))
    }

Dywane

case .typewriter:
    attributedString.addAttribute(.baselineOffset, value: -label.font.lineHeight, range: NSRange(location: 0, length: attributedString.length))
    let displayInterval = duration / TimeInterval(attributedString.length)
    for index in 0..<attributedString.length {
        durationArray.append(displayInterval)
        delayArray.append(TimeInterval(index) * displayInterval)
    }

Dywane

private func setup() {
    _displayLink = CADisplayLink(target: self, selector: #selector(update))
    _displayLink?.isPaused = true
    _displayLink?.add(to: RunLoop.main, forMode: .commonModes)
}