GMSMarker with Drop Shadow

gmsmarker.swift

import Foundation
import GoogleMaps

func getShadowMarker() -> GMSMarker {
  let marker = GMSMarker()
        
  let image = UIImageView(image: UIImage(named: "marker"))
  marker.iconView = image
  marker.iconView?.contentMode = .center
  marker.iconView?.bounds.size.width *= 2
  marker.iconView?.bounds.size.height *= 2
  marker.groundAnchor = CGPoint(x: 0.5, y: 0.75)
        
  marker.iconView?.layer.shadowColor = UIColor.black.cgColor
  marker.iconView?.layer.shadowOffset = CGSize.zero
  marker.iconView?.layer.shadowRadius = 1.0
  marker.iconView?.layer.shadowOpacity = 0.5
        
  let size = image.bounds.size
  let rect = CGRect(x: size.width/2 - size.width/8, y: size.height*0.75 - 2, width: size.width/4, height: 4)
  marker.iconView?.layer.shadowPath = UIBezierPath(ovalIn: rect).cgPath
        
  marker.appearAnimation = .pop
  marker.position = kCLLocationCoordinate2DInvalid

  return marker
}