I'm using Google Maps in my iOS application. It will draw the line between two coordinates and also add start and end position as "Markers" on the map.
I'm using below code to add start and end markers
//myLatLngArrayList is array of coordinates with latitude and longitude positions
markerA.position = (curDrill.myLatLngArrayList.first)! as CLLocationCoordinate2D
markerA.map = mapView
markerA.icon = UIImage(named: markerImages.0)
markerB.position = (curDrill.myLatLngArrayList.last)! as CLLocationCoordinate2D
markerB.map = mapView
markerB.icon = UIImage(named: markerImages.1)
I'm using below code for drawing line:
let path = GMSMutablePath()
for coord in curDrill.myLatLngArrayList {
path.add(coord)
}
let drillPath = GMSPolyline.init(path: path)
drillPath.strokeWidth = 2.0
drillPath.strokeColor = UIColor(Utility.getDrillColor(type: curDrill.type))
drillPath.map = mapView
The problem is that Marker positions are not matching with line start and end points. Marker A is not touching start of the line and Marker B is not touching end of the line.
I couldn't identify what is missing in my code.
Try adding all the steps coordinates which you receives from google API from First point to Last point.
Try to play with groundAnchor of your marker.
The ground anchor specifies the point in the icon image that is anchored to the marker's position on the Earth's surface. This point is specified within the continuous space [0.0, 1.0] x [0.0, 1.0], where (0,0) is the top-left corner of the image, and (1,1) is the bottom-right corner.
This working for me:
marker.groundAnchor = CGPoint(x: 0.5, y: 0.5)
Related
I need to zoom NMAMapView to specific point inside map bounds. Let's say we have some marker as subview of this map with position pinPoint: CGPoint.
I tried to use transformCenter property of NMAMapView like this:
let transformCenter = CGPoint(x: pinPoint.x / mapView.bounds.width, y: pinPoint.y / mapView.bounds.height) // x and y are in range [0, 1]
mapView.transformCenter = transformCenter
mapView.set(zoomLevel: mapView.zoomLevel + 1, animation: .linear)
But this code zooms map to its frame center, not to pinPoint.
I also tried to zoom map to needed point with code below:
guard let coordinates = mapView.geoCoordinates(from: pinPoint) else {
return
}
mapView.set(coordinates: coordinates, to: pinPoint, animation: .linear, zoomLevel: mapView.zoomLevel + 1)
But this also doesn't work correctly: after zooming, geo coordinates below marker were changed after each zoom step.
Please try to with this code, this code is just for your reference, You need to modify as per your requirements.
// create geo coordinate
let geoCoordCenter = NMAGeoCoordinates(latitude: 49.260327, longitude: -123.115025)
// set map view with geo center
self.mapView.set(geoCenter: geoCoordCenter, animation:NMAMapAnimation.none)
// set zoom level
self.mapView.zoomLevel = 13.2
Please check more example GitHub.
I am using google map in the application. When I do not rotate map everything works fine. But when I rotate map I am getting problem as shown in image. To solve that I need to get the google map currently rotated angle by the user. I need to get this so that I can place the marker back on the map at the same angle. Currently my map angle after rotation and my overlay seems to be different after placing plan image on map even when I am getting correct top left & bottom right corner coordinates.
My code
let topCoordinate = CLLocationCoordinate2D(latitude: topLattitude, longitude: topLongitude)//top
let bottomCoordinate = CLLocationCoordinate2D(latitude: bottomLattitude, longitude: bottomLongitude)//bottom
overlayBounds = GMSCoordinateBounds(coordinate: topCoordinate, coordinate:
bottomCoordinate)
let overlay = GMSGroundOverlay(bounds: overlayBounds, icon: planImage)
overlay.map = mapView
GMSMapViewDelegate
Bearing of the camera, in degrees clockwise from true north.
func mapView(_ mapView: GMSMapView, idleAt position: GMSCameraPosition) {
print(position.bearing)
}
I have solved my problem by changing the overlay method as
let zoomLevel = (object["image_zoom_level"] as? NSString)?.doubleValue
let overlay = GMSGroundOverlay(position: centreCoordinate, icon: planImage, zoomLevel: CGFloat(zoomLevel!))
overlay.map = mapView
if let angle = (object["rotation_angle"] as? NSString)?.doubleValue{
overlay.bearing = angle
}
Instead of using Overlay bounds I have just used center coordinate and placed overlay image using image zoom level and rotation angle. By this, my image is placing in proper angle and at a proper place. This works fine if the Image size is correct as you want place and the center point is accurate and precise.
I need to draw lines to demonstrate transportation of goods on apple maps. To clarify start- and end-point, I draw a little arrowhead on the destination side.The arrowhead is drawn separately but it is reversed in one case.
>-->-->-->-
instead of
<--<--<--<-
I am using MKMapView and MKPolyline to draw lines. I am using MKOverlay to add direction arrows. The steps I follow are,
calculate bearing of
Source : CLLocationCoordinate2D(latitude: -33.8392932, longitude: 151.21519799999999)
Destination: CLLocationCoordinate2D(latitude: 39.645516999999998, longitude: -104.598724)
using the following function
open static func getDirectionOf( _ supplyLineWithCoordinates: [CLLocationCoordinate2D]) -> CGFloat {
guard let sourceCoordniate = supplyLineWithCoordinates.first,
let destinationCoordniate = supplyLineWithCoordinates.last else {
fatalError("Coordinates of supply line not found")
}
let sourcePoint: MKMapPoint = MKMapPointForCoordinate(sourceCoordniate)
let destinationPoint: MKMapPoint = MKMapPointForCoordinate(destinationCoordniate)
let x: Double = destinationPoint.x - sourcePoint.x
let y: Double = destinationPoint.y - sourcePoint.y
var arrowDirection = CGFloat(fmod(atan2(y, x), 360.0))
if arrowDirection < 0.0 {
arrowDirection += 2 * .pi
}
return arrowDirection
}
Rotate the arrow image and add it as the map overlay. The directions are calculated correctly in most of the cases, however, when I select the line shown below the direction is displayed 180 opposite. It starts from Sydney, Australia and ends in Denver, US
When trying to display the region with this two locations in mapView.setVisibleMapRect these region is not displayed, mapview tries to display region starting from Sydney (Australia) to Denver(US) through Asia and Europe, while it should display the map area I have attached above. If you have suggestions for optimisation, feel free to mention it.
I think this might be the reason, the direction should be calculated along the red line but it being calculated along the green line. Both lines are drawn by connecting same location coordinates in map. Any known workaround for this?
I solved it in a dirty way by converting coordinate to CGPoint and then calculating bearing between Points.
let destinationPoint = mapView.convert(destination, toPointTo: nil)
let sourcePoint = mapView.convert(source, toPointTo: nil)
let bearing = atan2(sourcePoint.y - destinationPoint.y, sourcePoint.x - destinationPoint.x) - .pi
Caution: This calculation will go wrong when map is rotated
I draw a circle on an MKMapView. But how do I calculate the radius of this circle such that it equals the value of the radius used to draw the circle in the first place?
func setArea(_ center:CLLocationCoordinate2D, radius:CLLocationDistance) {
let area = MKCircle(center:center, radius:radius / LocationViewController.kRadiusInset)
mapView.setVisibleMapRect(mapView.mapRectThatFits(area.boundingMapRect), animated:false)
}
I've tried the following but it returns a value very slightly larger than radius passed to setArea. It calculates the distance from the center of the map to the left-hand edge.
// getRadius
let distance = middle.distance(from: edge)
let middle = CLLocation(latitude: mapView.region.center.latitude, longitude: mapView.region.center.longitude)
let edge = CLLocation(latitude: mapView.region.center.latitude, longitude: mapView.centerCoordinate.longitude - (mapView.region.span.longitudeDelta * 0.5))
let distance = middle.distance(from: edge)
If I pass in '4000' metres to setArea() and then afterwards calculate the map's radius (say, within mapViewDidFinishRenderingMap() I get 4010.61219348448
Why the discrepancy?
I replaced the use of a MKCircle with the following:
let region = MKCoordinateRegionMakeWithDistance(center, radius * 2, radius * 2)
mapView.region = region
This is less inaccurate. With radius == 4000 fed into this I get 4000.00048143541 after I set my MKMapView's region. This difference will creep into the user-interface but not nearly as quickly as my first approach.
Can anyone get closer?
How can I center a map between two points? Sort of like when the native map application generates directions between location A and location B. I'm got a start coordinate and an end coordinate and I'll like to show two pins. I can place the pins in place, but I'm not sure how to set the center of the map.
Do I need to find the math to work out the exact distance from the points and set the map to that location? Is there a built in function for this?
this.currentMapView.SetCenterCoordinate (annotation.Coordinate, true);
Calculating the midpoint between two coordinates needs a simple formula. For example, let's say you have two coordinates: (x1,y1) and (x2,y2).
Their midpoint coordinate is: ( (x1+x2)/2, (y1+y2)/2 ).
So for example, in map coordinates, let's say you have the following start/end points:
a. long: 40, lat: 39
b. long: 41, lat: 38
Their midpoint coordinate is: ( (40+41)/2, (39+38)/2 ) = (40.5, 38.5)
So you set the map view's center coordinate to the outcome of this formula.
I am not aware of a built-in function for calculating this.
Taken from: http://codisllc.com/blog/zoom-mkmapview-to-fit-annotations/
BasicMapAnnotation is inherit class from MKAnnotation
private void GetRegion(MKMapView mapView)
{
var userWasVisible = mapView.ShowsUserLocation;
mapView.ShowsUserLocation = false; // ignoring the blue blip
// start with the widest possible viewport
var tl = new CLLocationCoordinate2D(-90, 180); // top left
var br = new CLLocationCoordinate2D(90, -180); // bottom right
foreach (var an in mapView.Annotations)
{
// narrow the viewport bit-by-bit
CLLocationCoordinate2D coordinate = ((BasicMapAnnotation) an).Coordinate;
tl.Longitude = Math.Min(tl.Longitude, coordinate.Longitude);
tl.Latitude = Math.Max(tl.Latitude, coordinate.Latitude);
br.Longitude = Math.Max(br.Longitude, coordinate.Longitude);
br.Latitude = Math.Min(br.Latitude, coordinate.Latitude);
}
var center = new CLLocationCoordinate2D
{
// divide the range by two to get the center
Latitude = tl.Latitude - (tl.Latitude - br.Latitude)*0.5
,
Longitude = tl.Longitude + (br.Longitude - tl.Longitude)*0.5
};
var span = new MKCoordinateSpan
{
// calculate the span, with 20% margin so pins aren’t on the edge
LatitudeDelta = Math.Abs(tl.Latitude - br.Latitude)*1.2
,
LongitudeDelta = Math.Abs(br.Longitude - tl.Longitude)*1.2
};
var region = new MKCoordinateRegion {Center = center, Span = span};
region = mapView.RegionThatFits(region); // adjusts zoom level too
mapView.SetRegion(region, true); // animated transition
mapView.ShowsUserLocation =
userWasVisible;
}
} ``