如何基于Xcode内部2点之间移动的动画计算角度？

Question

我正在尝试在Google Maps iOS sdk中制作一个应用程序，该应用程序具有将汽车从一个位置移动到另一个位置的动画，并希望在移动汽车时找到正确的角度。

这是我到目前为止编写的代码：

func spawnRandomCarAround(location:CLLocation) {
    let range:Double = 0.002
    let carSpeed:Double = 0.0002
    let randomPointX:Double = Double.random(in: -range...range)
    let randomPointY:Double = Double.random(in: -range...range)
    let latitude = location.coordinate.latitude + randomPointX
    let longitude = location.coordinate.longitude + randomPointY
    let carLocation = CLLocation(latitude: latitude, longitude: longitude)
    let carMarker = GMSMarker(position: carLocation.coordinate)
    carMarker.isFlat = true
    carMarker.map = self.mapView
    Timer.scheduledTimer(withTimeInterval: 3.0, repeats: true) { (timer) in
        let newRandomPointX:Double = Double.random(in: -carSpeed...carSpeed)
        let newRandomPointY:Double = Double.random(in: -carSpeed...carSpeed)
        let newLatitude = carLocation.coordinate.latitude + newRandomPointX
        let newLongitude = carLocation.coordinate.longitude + newRandomPointY
        carMarker.rotation = Double.random(in: 0...360) //here I want to find the correct rotation.
        CATransaction.begin()
        CATransaction.setAnimationDuration(2.0)
        carMarker.position = CLLocationCoordinate2D(latitude: newLatitude, longitude: newLongitude)
        CATransaction.commit()
    }
}

我相信在CALayer中工作可能是相同的。因此，任何答案将不胜感激。