Directed polyline function

DirectedPolylineViewController.swift

func drawPolyline() {
        
        //Step 1:
        let coordinates = self.geoJson.map({CLLocationCoordinate2D(latitude: $0.last!, longitude: $0.first!)})
        
        //Step 2:
        let chunkSize = 3
        let chunkedCoordinates = coordinates.chunked(into: chunkSize)
        
        //Step 3:
        let path = GMSMutablePath()
        
        //Step 4:
        for chunk in chunkedCoordinates {
            for coordinate in chunk {
                path.add(coordinate)
            }
            
            if chunk.count == 3 {
                let location1 = CLLocation(latitude: chunk[1].latitude, longitude: chunk[1].longitude)
                let location2 = CLLocation(latitude: chunk[2].latitude, longitude: chunk[2].longitude)
                
                if !GMSGeometryIsLocationOnPath(chunk[1], path, false) ||
                    !GMSGeometryIsLocationOnPath(chunk[2], path, false) ||
                    location2.distance(from: location1) < 1.5 {
                    continue
                }
                    
                let angle = GMSGeometryHeading(chunk[1], chunk[2])// chunk[1].heading(to: chunk[2])

                var arrowImage = UIImage(named: "icon_navigation")!
                arrowImage = arrowImage.withColor(UIColor.orange.withAlphaComponent(0.8))
                
                let marker = GMSMarker(position: chunk[1])
                marker.icon = arrowImage
                marker.groundAnchor = CGPoint(x: 0.5, y: 0.5)
                marker.isFlat = true
                marker.rotation = angle
                marker.map = self.mapView
            }
        }
        
        //Step 5:
        let polyline = GMSPolyline(path: path)
        polyline.strokeColor = UIColor.orange
        polyline.strokeWidth = 5.0
        polyline.map = self.mapView
        
        //Step 6:
        let bounds = GMSCoordinateBounds(path: path)
        self.mapView.animate(with: GMSCameraUpdate.fit(bounds, withPadding: 50.0))
    }