Some fixes, added new events and properties

Author: Alexander Krutov

DemoApp/FormMain.cs

@@ -137,7 +137,7 @@ private ICollection<GeoPoint> ReadPointsFromResource(string resourceName)
         private void UpdateWindowTitle()
         {
             GeoPoint g = mapControl.Mouse;
-            this.Text = $"Longitude = {DegreeToString(g.Longitude, "W", "E")} / Latitude = {DegreeToString(g.Latitude, "S", "N")} / Zoom = {mapControl.ZoomLevel}";
+            this.Text = $"Mouse = {g} / Zoom = {mapControl.ZoomLevel} / Bounding Box = TL:{mapControl.TopLeft}, TR:{mapControl.TopRight}, BR:{mapControl.BottomRight}, BL:{mapControl.BottomLeft}";
         }
 
         private void mapControl_MouseMove(object sender, MouseEventArgs e)
@@ -184,26 +184,8 @@ private void mapControl_DoubleClick(object sender, EventArgs e)
         {
             var coord = mapControl.Mouse;
             StringBuilder sb = new StringBuilder();
-            sb.AppendLine($"Latitude: {DegreeToString(coord.Latitude, "S", "N")}");
-            sb.AppendLine($"Longitude: {DegreeToString(coord.Longitude, "W", "E")}");
+            sb.AppendLine($"Location: {coord}");
             MessageBox.Show(sb.ToString(), "Info");
         }
-
-        private string DegreeToString(double coordinate, string negativeSym, string positiveSym)
-        {
-            string sym = coordinate < 0d ? negativeSym : positiveSym;
-            coordinate = Math.Abs(coordinate);
-            double d = Math.Floor(coordinate);
-            coordinate -= d;
-            coordinate *= 60;
-            double m = Math.Floor(coordinate);
-            coordinate -= m;
-            coordinate *= 60;
-            double s = coordinate;
-            string dd = d.ToString();
-            string mm = m.ToString().PadLeft(2, '0');
-            string ss = s.ToString("00.00", CultureInfo.InvariantCulture);
-            return $"{dd}° {mm}' {ss}\" {sym}";
-        }
     }
 }

MapControl/GeoPoint.cs

@@ -1,4 +1,6 @@
-namespace System.Windows.Forms
+using System.Globalization;
+
+namespace System.Windows.Forms
 {
     /// <summary>
     /// Represents point on the Earth surface with geographical coordinates
@@ -25,5 +27,28 @@ public GeoPoint(float longitude, float latitude)
             Longitude = longitude;
             Latitude = latitude;
         }
+
+        /// <inheritdoc/>
+        public override string ToString()
+        {
+            return $"{DegreeToString(Longitude, "W", "E")}, {DegreeToString(Latitude, "S", "N")}";
+        }
+
+        private static string DegreeToString(double coordinate, string negativeSym, string positiveSym)
+        {
+            string sym = coordinate < 0d ? negativeSym : positiveSym;
+            coordinate = Math.Abs(coordinate);
+            double d = Math.Floor(coordinate);
+            coordinate -= d;
+            coordinate *= 60;
+            double m = Math.Floor(coordinate);
+            coordinate -= m;
+            coordinate *= 60;
+            double s = coordinate;
+            string dd = d.ToString();
+            string mm = m.ToString().PadLeft(2, '0');
+            string ss = s.ToString("00.00", CultureInfo.InvariantCulture);
+            return $"{dd}° {mm}' {ss}\" {sym}";
+        }
     }
 }

MapControl/MapControl.cs

@@ -4,6 +4,7 @@
 using System.Diagnostics;
 using System.Drawing;
 using System.Drawing.Drawing2D;
+using System.Drawing.Imaging;
 using System.IO;
 using System.Linq;
 using System.Threading;
@@ -93,7 +94,8 @@ public int ZoomLevel
                 if (value < 0 || value > 19)
                     throw new ArgumentException($"{value} is an incorrect value for {nameof(ZoomLevel)} property. Value should be in range from 0 to 19.");
 
-                SetZoomLevel(value, new Point(Width / 2, Height / 2));
+                SetZoomLevel(value, new Point(Width / 2, Height / 2));
+                CenterChanged?.Invoke(this, EventArgs.Empty);
             }
         }
 
@@ -205,7 +207,8 @@ public ITileServer TileServer
                         ZoomLevel = TileServer.MinZoomLevel;
                 }
 
-                Invalidate();
+                Invalidate();
+                TileServerChanged?.Invoke(this, EventArgs.Empty);
             }
         }
 
@@ -218,8 +221,8 @@ public GeoPoint Center
         {
             get
             {
-                float x = NormalizeTileNumber(-(_Offset.X - Width / 2) / TILE_SIZE);
-                float y = -(_Offset.Y - Height / 2) / TILE_SIZE;
+                float x = NormalizeTileNumber(-(float)(_Offset.X - Width / 2) / TILE_SIZE);
+                float y = -(float)(_Offset.Y - Height / 2) / TILE_SIZE;
                 return TileToWorldPos(x, y);
             }
             set
@@ -228,11 +231,11 @@ public GeoPoint Center
                 _Offset.X = -(int)(center.X * TILE_SIZE) + Width / 2;
                 _Offset.Y = -(int)(center.Y * TILE_SIZE) + Height / 2;
                 _Offset.X = (int)(_Offset.X % FullMapSizeInPixels);
-                Invalidate();
+                Invalidate();
+                CenterChanged?.Invoke(this, EventArgs.Empty);
             }
         }
 
-
         /// <summary>
         /// Gets geographical coordinates of the current position of mouse.
         /// </summary>
@@ -248,6 +251,66 @@ public GeoPoint Mouse
             }
         }
 
+        /// <summary>
+        /// Gets geographical coordinates of the top left point of the map
+        /// </summary>
+        [Browsable(false)]
+        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
+        public GeoPoint TopLeft
+        {
+            get
+            {
+                float x = NormalizeTileNumber(-(float)(_Offset.X) / TILE_SIZE);
+                float y = -(float)(_Offset.Y) / TILE_SIZE;
+                return TileToWorldPos(x, y);
+            }
+        }
+
+        /// <summary>
+        /// Gets geographical coordinates of the top right point of the map
+        /// </summary>
+        [Browsable(false)]
+        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
+        public GeoPoint TopRight
+        {
+            get
+            {
+                float x = NormalizeTileNumber(-(float)(_Offset.X - Width) / TILE_SIZE);
+                float y = -(float)(_Offset.Y) / TILE_SIZE;
+                return TileToWorldPos(x, y);
+            }
+        }
+
+        /// <summary>
+        /// Gets geographical coordinates of the bottom left point of the map
+        /// </summary>
+        [Browsable(false)]
+        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
+        public GeoPoint BottomLeft
+        {
+            get
+            {
+                float x = NormalizeTileNumber(-(float)(_Offset.X) / TILE_SIZE);
+                float y = -(float)(_Offset.Y - Height) / TILE_SIZE;
+                return TileToWorldPos(x, y);
+            }
+        }
+
+        /// <summary>
+        /// Gets geographical coordinates of the bottom right point of the map
+        /// </summary>
+        [Browsable(false)]
+        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
+        public GeoPoint BottomRight
+        {
+            get
+            {
+                float x = NormalizeTileNumber(-(float)(_Offset.X - Width) / TILE_SIZE);
+                float y = -(float)(_Offset.Y - Height) / TILE_SIZE;
+                return TileToWorldPos(x, y);
+            }
+        }
+
         /// <summary>
         /// Gets collection of markers to be displayed on the map.
         /// </summary>
@@ -332,6 +395,12 @@ public override Color ForeColor
             }
         }
 
+        /// <summary>
+        /// Image attributes to be applied to a tile image when drawing.
+        /// </summary>
+        [Description("Image attributes to be applied to a tile image when drawing."), Category("Appearance")]
+        public ImageAttributes TileImageAttributes { get; set; } = null;
+
         /// <summary>
         /// Raised when marker is drawn on the map.
         /// </summary>
@@ -346,6 +415,21 @@ public override Color ForeColor
         /// Raised when polygon is drawn on the map.
         /// </summary>
         public event EventHandler<DrawPolygonEventArgs> DrawPolygon;
+
+        /// <summary>
+        /// Raised when <see cref="Center"/> property value is changed.
+        /// </summary>
+        public event EventHandler<EventArgs> CenterChanged;
+
+        /// <summary>
+        /// Raised when <see cref="Mouse"/> property value is changed.
+        /// </summary>
+        public event EventHandler<EventArgs> MouseChanged;
+
+        /// <summary>
+        /// Raised when <see cref="TileServer"/> property value is changed.
+        /// </summary>
+        public event EventHandler<EventArgs> TileServerChanged;
 
         /// <summary>
         /// Creates new <see cref="MapControl"/> control.
@@ -439,7 +523,8 @@ protected override void OnSizeChanged(EventArgs e)
             _LinkLabel.Top = Height - _LinkLabel.Height;
 
             AdjustMapBounds();
-            Invalidate();
+            Invalidate();
+            CenterChanged?.Invoke(this, EventArgs.Empty);
         }
 
         /// <summary>
@@ -487,12 +572,14 @@ protected override void OnMouseMove(MouseEventArgs e)
                     _Offset.Y = Height;
 
                 AdjustMapBounds();
-
-                Invalidate();
+                Invalidate();
+                CenterChanged?.Invoke(this, EventArgs.Empty);
             }
 
             _LastMouse.X = e.X;
             _LastMouse.Y = e.Y;
+
+            MouseChanged?.Invoke(this, EventArgs.Empty);
 
             base.OnMouseMove(e);
         }
@@ -513,8 +600,8 @@ protected override void OnMouseWheel(MouseEventArgs e)
             SetZoomLevel(z, new Point(e.X, e.Y));
 
             AdjustMapBounds();
-
-            base.OnMouseWheel(e);            
+            base.OnMouseWheel(e);
+            CenterChanged?.Invoke(this, EventArgs.Empty);          
         }
 
         /// <summary>
@@ -744,7 +831,6 @@ private void DrawPolygons(Graphics gr)
                 using (GraphicsPath gp = new GraphicsPath())
                 {
                     gp.StartFigure();
-
                     for (int i = 0; i < polygon.Count; i++)
                     {
                         GeoPoint g = polygon.ElementAt(i);
@@ -754,9 +840,12 @@ private void DrawPolygons(Graphics gr)
                             p = p0.Nearest(p, new PointF(p.X - FullMapSizeInPixels, p.Y), new PointF(p.X + FullMapSizeInPixels, p.Y));
                             gp.AddLine(p0, p);
                         }
+
                         p0 = p;
                     }
 
+                    gp.CloseFigure();
+
                     var eventArgs = new DrawPolygonEventArgs()
                     {
                         Graphics = gr,
@@ -812,8 +901,15 @@ private void DrawTilePart(Graphics gr, int x, int y, int xRemainder, int yRemain
             Rectangle srcRect = new Rectangle(TILE_SIZE / frac * xRemainder, TILE_SIZE / frac * yRemainder, TILE_SIZE / frac, TILE_SIZE / frac);
 
             // Destination rectangle
-            Rectangle destRect = new Rectangle(p.X, p.Y, TILE_SIZE, TILE_SIZE);
-            gr.DrawImage(image, destRect, srcRect, GraphicsUnit.Pixel);
+            Rectangle destRect = new Rectangle(p.X - frac, p.Y - frac, TILE_SIZE + 2 * frac, TILE_SIZE + 2 * frac);
+
+            var state = gr.Save();            
+            gr.SmoothingMode = SmoothingMode.HighSpeed;
+            gr.InterpolationMode = InterpolationMode.NearestNeighbor;
+            gr.PixelOffsetMode = PixelOffsetMode.HighSpeed;
+            gr.CompositingQuality = CompositingQuality.HighSpeed;
+            gr.DrawImage(image, destRect, srcRect.X, srcRect.Y, srcRect.Width, srcRect.Height, GraphicsUnit.Pixel, TileImageAttributes);
+            gr.Restore(state);
         }
 
         /// <summary>
@@ -828,7 +924,8 @@ private void DrawTile(Graphics gr, int x, int y, Image image)
             Point p = new Point();
             p.X = _Offset.X + x * TILE_SIZE;
             p.Y = _Offset.Y + y * TILE_SIZE;
-            gr.DrawImageUnscaled(image, p);
+
+            gr.DrawImage(image, new Rectangle(p, new Drawing.Size(TILE_SIZE, TILE_SIZE)), 0, 0, TILE_SIZE, TILE_SIZE, GraphicsUnit.Pixel, TileImageAttributes);
         }
 
         /// <summary>

MapControl/MapControl.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>net451</TargetFrameworks>
-    <Version>1.0.1</Version>
+    <Version>1.0.2</Version>
     <Product>System.Windows.Forms.MapControl</Product>
     <Description>Map control for WindowsForms</Description>
     <Copyright>© Alexander Krutov 2020</Copyright>