Tutorial C# Rotate GMAP.NET Marker from Heading IMU or digital Compass

If you have a marker on Google Map which moves on a flight path/ road track but you want it to rotate when it turns. To rotate the image marker Icon from GMap.NET C#, in first create new class, add public class function named "GMapMarkerPlane"

	using GMap.NET;
	using GMap.NET.WindowsForms;
	using GMap.NET.WindowsForms.Markers;
	using System;
	using System.Drawing;
	using System.Drawing.Drawing2D;
	namespace GMap_offline
	{
	/// <summary>
	/// used to override the drawing of the waypoint box bounding
	/// </summary>
	public class GMapMarkerPlane : GMapMarker
	{
	private readonly Bitmap icon = Resource.planetracker;
	float heading = 0;
	public GMapMarkerPlane(PointLatLng p, float heading)
	: base(p)
	{
	this.heading = heading;
	Size = icon.Size;
	}
	public override void OnRender(Graphics g)
	{
	Matrix temp = g.Transform;
	g.TranslateTransform(LocalPosition.X, LocalPosition.Y);
	g.RotateTransform(-Overlay.Control.Bearing);
	try
	{
	g.RotateTransform(heading);
	}
	catch { }
	g.DrawImageUnscaled(icon, icon.Width / -2, icon.Height / -2);
	g.Transform = temp;
	}
	}
	}

view raw common.cs hosted with ❤ by GitHub

For icon picture, create the icon and add it into resource folder.

              private readonly Bitmap icon = Resources.planetracker;

In the declaration, create new layer name from GMapOverlay:

             public static GMapOverlay routesoverlay;

Next, in main form create new layer and add it to the gmap:

            routesoverlay = new GMapOverlay("routes");
            gMap.Overlays.Add(routesoverlay);

and then, add the code below in the GPS heading function (use timer 1 second or more):

            routesoverlay.Markers.Clear();

            // Get the most up-to-date data received from the sensor.
            var curMeas = vn200.CurrentMeasurements;

            PointLatLng point = new PointLatLng((float)curMeas.LatitudeLongitudeAltitude.X,
                                                                           (float)curMeas.LatitudeLongitudeAltitude.Y);
            gMap.Position = point;

            var plane = new GMapMarkerPlane(point, (float)curMeas.YawPitchRoll.YawInDegs);
            routesoverlay.Markers.Add(plane);

and finally, the Plane Marker heading will following your heading data sensor.

Keyword: Rotate GMap.NET marker, C#, heading Marker, IMU, google map marker, GPS tracking heading marker.