label background

Author: SK21

RateAppSource/RateController/RateMap/ElevationOverlayCreator.cs

@@ -7,6 +7,7 @@
 using System.Diagnostics;
 using System.Drawing;
 using System.Linq;
+using System.Windows.Forms;
 
 namespace RateController.RateMap
 {
@@ -72,7 +73,7 @@ public void Build()
                 var bounds = ComputeBounds();
                 var grid = BuildGrid(bounds);
 
-                grid = SmoothGrid(grid, passes: 2);
+                grid = SmoothGrid(grid, passes: 1);
 
                 var contours = GenerateContours(grid, bounds);
 
@@ -142,6 +143,7 @@ private void ApplySimulatedElevations()
             Readings = simulatedReadings;
             ShowReadings();
         }
+
         private double[,] BuildGrid((double minLat, double maxLat, double minLon, double maxLon) b)
         {
             gridRows = (int)(MetersBetweenLat(b.minLat, b.maxLat) / GridResolutionMeters) + 1;
@@ -212,7 +214,6 @@ private void DrawContours(List<ContourLine> contours)
                         .Select(ratio => contour.Points[(int)(contour.Points.Count * ratio)])
                         .ToList();
 
-                    bool labelPlaced = false;
                     foreach (var labelPos in candidates)
                     {
                         bool tooClose = allPlacedLabels.Any(p =>
@@ -221,10 +222,9 @@ private void DrawContours(List<ContourLine> contours)
                         if (!tooClose)
                         {
                             _labelOverlay.Markers.Add(
-                                new TextMarker(labelPos, $"{group.Key:0} m"));
+                                new TextMarker(labelPos, group.Key));
                             allPlacedLabels.Add(labelPos);
                             labelCountThisLevel++;
-                            labelPlaced = true;
                             break; // Successfully placed, move to next contour
                         }
                     }
@@ -233,6 +233,7 @@ private void DrawContours(List<ContourLine> contours)
                 }
             }
         }
+
         private List<ContourLine> GenerateContours(
             double[,] grid,
             (double minLat, double maxLat, double minLon, double maxLon) b)
@@ -242,7 +243,10 @@ private List<ContourLine> GenerateContours(
             double minElev = Readings.Min(r => r.Elevation);
             double maxElev = Readings.Max(r => r.Elevation);
 
-            for (double level = minElev; level <= maxElev; level += ContourInterval)
+            double start = Math.Floor(minElev / ContourInterval) * ContourInterval;
+            double end = Math.Ceiling(maxElev / ContourInterval) * ContourInterval;
+
+            for (double level = start; level <= end + 1e-9; level += ContourInterval)
             {
                 var lines = MarchingSquares(grid, b, level);
 
@@ -309,7 +313,8 @@ private double Haversine(double lat1, double lon1, double lat2, double lon2)
         private double InterpolateElevation(double lat, double lon)
         {
             var nearest = Readings
-                .Select(r => new {
+                .Select(r => new
+                {
                     Reading = r,
                     Dist = Haversine(lat, lon, r.Latitude, r.Longitude)
                 })
@@ -330,7 +335,6 @@ private double InterpolateElevation(double lat, double lon)
             return valueSum / weightSum;
         }
 
-
         private List<List<PointLatLng>> MarchingSquares(
             double[,] grid,
             (double minLat, double maxLat, double minLon, double maxLon) b,
@@ -391,7 +395,6 @@ private double MetersBetweenLat(double lat1, double lat2)
         private double MetersBetweenLon(double lon1, double lon2, double lat)
             => Haversine(lat, lon1, lat, lon2);
 
-
         private double PolylineLengthMeters(List<PointLatLng> line)
         {
             double length = 0;
@@ -413,7 +416,7 @@ private void ShowReadings()
             {
                 if (reading.Elevation > 280) count++;
             }
-            Debug.Print("total: "+Readings.Count.ToString()+ ", above 280: " + count.ToString());
+            Debug.Print("total: " + Readings.Count.ToString() + ", above 280: " + count.ToString());
         }
 
         private double[,] SmoothGrid(double[,] grid, int passes = 2)
@@ -538,30 +541,73 @@ private struct Segment
 
     public class TextMarker : GMapMarker
     {
-        private readonly Brush _brush = Brushes.Black;
-        private readonly Font _font = new Font("Segoe UI", 12, FontStyle.Bold);
-        private readonly Pen _outline = new Pen(Color.White, 3);
+        private static readonly Font TextFont =
+            new Font("Segoe UI", 11, FontStyle.Bold);
+
+        // Fully opaque tooltip-style yellow
+        private static readonly Brush BgBrush =
+            new SolidBrush(Color.FromArgb(255, 255, 255, 200));
+
+        private static readonly Brush TextBrush =
+            new SolidBrush(Color.Black);
+
+        private static readonly Pen BorderPen =
+            new Pen(Color.FromArgb(255, 160, 160, 120), 1);
+
+        // Minimal padding
+        private const int PadX = 3;
+        private const int PadY = 1;
+
+        public double ElevationMeters { get; }
 
-        public TextMarker(PointLatLng pos, string text) : base(pos)
+        public TextMarker(PointLatLng position, double elevationMeters)
+            : base(position)
         {
-            Text = text;
+            ElevationMeters = elevationMeters;
         }
 
-        public string Text { get; set; }
+        private string GetDisplayText()
+        {
+            if (Props.UseMetric)
+            {
+                return $"{ElevationMeters:F1} m";
+            }
+            else
+            {
+                double feet = ElevationMeters * 3.28084;
+                return $"{Math.Round(feet):0} ft";
+            }
+        }
 
         public override void OnRender(Graphics g)
         {
-            if (string.IsNullOrEmpty(Text))
+            string text = GetDisplayText();
+            if (string.IsNullOrEmpty(text))
                 return;
 
-            SizeF size = g.MeasureString(Text, _font);
+            // Prevent yellow washout in GMap.NET
+            var oldMode = g.CompositingMode;
+            g.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceCopy;
+
+            SizeF textSize = g.MeasureString(text, TextFont);
+
+            float w = textSize.Width + PadX * 2;
+            float h = textSize.Height + PadY * 2;
+
+            float x = LocalPosition.X - w / 2;
+            float y = LocalPosition.Y - h / 2;
+
+            RectangleF rect = new RectangleF(x, y, w, h);
+
+            // Background
+            g.FillRectangle(BgBrush, rect);
 
-            // Center text
-            float x = LocalPosition.X - size.Width / 2;
-            float y = LocalPosition.Y - size.Height / 2;
+            // Restore normal blending
+            g.CompositingMode = oldMode;
 
-            // Outline for readability
-            g.DrawString(Text, _font, _brush, x, y);
+            // Border + text
+            g.DrawRectangle(BorderPen, rect.X, rect.Y, rect.Width, rect.Height);
+            g.DrawString(text, TextFont, TextBrush, rect.X + PadX, rect.Y + PadY);
         }
     }
 }