using System;  
 using System.Collections.Generic;  
 using System.Linq;  
 using System.Windows.Forms;  
 
 namespace CenteringOnMovingFeature  
 {  
     static class Program  
     {  
         /// <summary>  
         /// The main entry point for the application.  
         /// </summary>  
         [STAThread]  
         static void Main()  
         {  
             Application.EnableVisualStyles();  
             Application.SetCompatibleTextRenderingDefault(false);  
             Application.Run(new TestForm());  
         }  
     }  
 }  
 

 using System;  
 using System.Collections.ObjectModel;  
 using System.Drawing;  
 using System.Windows.Forms;  
 using System.IO;  
 using System.Data;  
 using ThinkGeo.MapSuite.Core;  
 
 namespace CenteringOnMovingFeature  
 {  
     public partial class TestForm : Form  
     {  
         private MapEngine mapEngine = new MapEngine();  
         private Bitmap bitmap = null;  
         private StreamReader mGPSData = new StreamReader(@"..\..\data\GPSinfo.txt");  
         private Timer timer;  
         private double previousLong;  
         private double previousLat;  
 
        public TestForm()  
         {  
             InitializeComponent();  
             timer = new Timer();  
         }  
 
         private void TestForm_Load(object sender, EventArgs e)  
         {  
             //Sets timers properties.  
             timer.Interval = 2000;  
             timer.Tick += new EventHandler(timer_Tick);  
 
             // Set the extent and the background color  
             mapEngine.CurrentExtent = ExtentHelper.GetDrawingExtent(new RectangleShape(-97.7591, 30.3126, -97.7317, 30.2964), Map.Width, Map.Height);  
             mapEngine.BackgroundFillBrush = new GeoSolidBrush(GeoColor.GeographicColors.ShallowOcean);  
 
             //Displays the World Map Kit as a background.  
             ThinkGeo.MapSuite.Core.WorldMapKitLayer worldMapKitLayer = new ThinkGeo.MapSuite.Core.WorldMapKitLayer();  
             mapEngine.StaticLayers.Add(worldMapKitLayer);  
 
             //InMemoryFeatureLayer for vehicle.  
             InMemoryFeatureLayer inMemoryFeatureLayer = new InMemoryFeatureLayer();  
             inMemoryFeatureLayer.ZoomLevelSet.ZoomLevel01.DefaultPointStyle.PointType = PointType.Bitmap;  
             inMemoryFeatureLayer.ZoomLevelSet.ZoomLevel01.DefaultPointStyle.Image = new GeoImage(@"..\..\data\sedan.png");  
             inMemoryFeatureLayer.ZoomLevelSet.ZoomLevel01.DefaultPointStyle.RotationAngle = 45;  
             inMemoryFeatureLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;  
             inMemoryFeatureLayer.InternalFeatures.Add("Car", new Feature(new PointShape()));  
 
            //Adds the InMemoryFeatureLayer for the car to the second mapengine to have it draw on separate bitmap  
             mapEngine.DynamicLayers.Add("CarLayer", inMemoryFeatureLayer);  
 
             DrawImage();  
 
             timer.Start();  
         }  
 
         void timer_Tick(object sender, EventArgs e)  
         {  
             //Gets the GPS info from the textfile.  
             DataTable carData = GetCarData();  
 
             double angle;  
             InMemoryFeatureLayer inMemoryFeatureLayer = (InMemoryFeatureLayer)mapEngine.DynamicLayers["CarLayer"];  
             PointShape pointShape = inMemoryFeatureLayer.InternalFeatures[0].GetShape() as PointShape;  
 
             // Get the Row of Data we are working with.  
             DataRow carDataRow = carData.Rows[0];  
 
             double Lat = Convert.ToDouble(carDataRow["LAT"]);  
             double Long = Convert.ToDouble(carDataRow["LONG"]);  
 
             if (previousLong == 0)  
             {  
                 previousLong = Long;  
                 previousLat = Lat;  
             }  
 
             double Xdiff = previousLong - Long;  
             double Ydiff = previousLat - Lat;  
 
             //Gets the angle based on the current GPS position and the previous one to get the direction of the vehicle.  
             angle = GetAngleFromTwoVertices(new Vertex(previousLong, previousLat), new Vertex(Long, Lat));  
 
             inMemoryFeatureLayer.ZoomLevelSet.ZoomLevel01.DefaultPointStyle.RotationAngle = 90 - (float)angle;  
 
             pointShape.X = Long;  
             pointShape.Y = Lat;  
             pointShape.Id = "Car";  
 
             inMemoryFeatureLayer.Open();  
             inMemoryFeatureLayer.EditTools.BeginTransaction();  
             inMemoryFeatureLayer.EditTools.Update(pointShape);  
             inMemoryFeatureLayer.EditTools.CommitTransaction();  
             inMemoryFeatureLayer.Close();  
 
             previousLong = Long;  
             previousLat = Lat;  
 
             //Function to center the map to a point (the moving moving vehicle feature)  
             mapEngine.CenterAt(new PointShape(Long, Lat), Map.Width, Map.Height);  
 
             DrawImage();  
         }  
 
         private DataTable GetCarData()  
         {  
             DataTable datatable = new DataTable();  
             datatable.Columns.Add("LAT");  
             datatable.Columns.Add("LONG");  
 
             string strLattitude = "";  
             string strLongitude = "";  
 
             // Read the next line from the text file with GPS data in it.  
             string strCurrentText = mGPSData.ReadLine();  
 
             if (strCurrentText == "")  
             {  
                 mGPSData.BaseStream.Seek(0, SeekOrigin.Begin);  
                 strCurrentText = mGPSData.ReadLine();  
             }  
 
             while (strCurrentText != null)  
             {  
                 // Every other line is a "/" and we want to skip those.  
                 if (strCurrentText.Trim() != "/")  
                 {  
                     string[] strSplit = strCurrentText.Split(','); // (':');  
                     strLongitude = strSplit[0];  
                     strLattitude = strSplit[1];  
                     break;  
                 }  
                 strCurrentText = mGPSData.ReadLine();  
             }  
 
             object[] objs = new object[2] { strLattitude, strLongitude };  
 
             datatable.Rows.Add(objs);  
 
             return datatable;  
         }  
 
         //We assume that the angle is based on a third point that is on top of b on the same x axis.  
         private double GetAngleFromTwoVertices(Vertex b, Vertex c)  
         {  
             double alpha = 0;  
             double tangentAlpha = (c.Y - b.Y) / (c.X - b.X);  
             double Peta = Math.Atan(tangentAlpha);  
 
             if (c.X > b.X)  
             {  
                 alpha = 90 - (Peta * (180 / Math.PI));  
             }  
             else if (c.X < b.X)  
             {  
                 alpha = 270 - (Peta * (180 / Math.PI));  
             }  
             else  
             {  
                 if (c.Y > b.Y) alpha = 0;  
                 if (c.Y < b.Y) alpha = 180;  
             }  
             return alpha;  
         }  
 
 
 
         private void DrawImage()  
         {  
             if (bitmap != null) { bitmap.Dispose(); }  
             bitmap = new Bitmap(Map.Width, Map.Height);  
             mapEngine.OpenAllLayers();  
             mapEngine.DrawStaticLayers(bitmap, GeographyUnit.DecimalDegree);  
             mapEngine.DrawDynamicLayers(bitmap, GeographyUnit.DecimalDegree);  
             mapEngine.CloseAllLayers();  
 
             Map.Image = bitmap;  
         }  
 
         private void ToolBar_ButtonClick(object sender, ToolBarButtonClickEventArgs e)  
         {  
             switch (e.Button.Tag.ToString())  
             {  
                 case "Zoom In":  
                     mapEngine.CurrentExtent.ScaleDown(50);  
                     break;  
                 case "Zoom Out":  
                     mapEngine.CurrentExtent.ScaleUp(50);  
                     break;  
                 case "Full Extent":  
                     mapEngine.CurrentExtent = ExtentHelper.GetDrawingExtent(new RectangleShape(-180.0, 83.0, 180.0, -90.0), Map.Width, Map.Height);  
                     break;  
                 case "Pan Left":  
                     mapEngine.CurrentExtent = ExtentHelper.Pan(mapEngine.CurrentExtent, PanDirection.Left, 20);  
                     break;  
                 case "Pan Right":  
                     mapEngine.CurrentExtent = ExtentHelper.Pan(mapEngine.CurrentExtent, PanDirection.Right, 20);  
                     break;  
                 case "Pan Up":  
                     mapEngine.CurrentExtent = ExtentHelper.Pan(mapEngine.CurrentExtent, PanDirection.Up, 20);  
                     break;  
                 case "Pan Down":  
                     mapEngine.CurrentExtent = ExtentHelper.Pan(mapEngine.CurrentExtent, PanDirection.Down, 20);  
                     break;  
                 default:  
                     break;  
             }  
             DrawImage();  
         }  
 
         private void btnClose_Click(object sender, EventArgs e)  
         {  
             this.Close();  
         }  
 
         private void Map_MouseMove(object sender, MouseEventArgs e)  
         {  
             //Displays the X and Y in screen coordinates.  
             statusStrip1.Items["toolStripStatusLabelScreen"].Text = "X:" + e.X + " Y:" + e.Y;  
 
             //Gets the PointShape in world coordinates from screen coordinates.  
             PointShape pointShape = ExtentHelper.ToWorldCoordinate(mapEngine.CurrentExtent, new ScreenPointF(e.X, e.Y), Map.Width, Map.Height);  
 
             //Displays world coordinates.  
             statusStrip1.Items["toolStripStatusLabelWorld"].Text = "(world) X:" + Math.Round(pointShape.X, 4) + " Y:" + Math.Round(pointShape.Y, 4);  
         }  
 
 
     }  
 }