animatePolylineDashAnimation.swift

    @objc func animatePolylineDashAnimation() {
        //Iterate each valid coordinate on the path
        if i < path.count() {
            newPath.add(path.coordinate(at: i))
            newPolyline.path = newPath
            newPolyline.strokeWidth = 4

            let dashLength = calculateDashLength(zoomLevel: mapView.camera.zoom)
            let clearDashLength = Int(Double(dashLength) * 0.5)
            let lengths = [dashLength, clearDashLength] // Play with this for dotted line
            let greenSpan = GMSStrokeStyle.solidColor(UIColor(rgb: 0x38726E))
            let clearSpan = GMSStrokeStyle.solidColor(UIColor.clear)
            newPolyline.spans = GMSStyleSpans(newPolyline.path!, [greenSpan, clearSpan], lengths as [NSNumber], .rhumb)
            newPolyline.map = mapView
            i += 1
        } else {
            resetTimer()
            startAnimationTimer()
        }
    }
    
    func calculateDashLength(zoomLevel: Float) -> Int {
        let maxDashLength : Float = 750000.0
        let a = zoomLevel < 18.0 ? powf(2.0, zoomLevel - 1) : powf(2.0, zoomLevel - 2)
        return Int(maxDashLength / a) > 50 ? Int(maxDashLength / a) : 50
    }