From b699eab1942314f7ce210ad7489ca23f8d4ccf40 Mon Sep 17 00:00:00 2001
From: Morten Nielsen <mn@iter.dk>
Date: Fri, 31 Jul 2020 15:23:12 -0700
Subject: [PATCH] Use bitmap for rendering plot view + allow zoom + improve ui

---
 src/SampleApp.WinDesktop/PointPlotView.xaml   |  38 +++--
 .../PointPlotView.xaml.cs                     | 158 +++++++++++++-----
 2 files changed, 139 insertions(+), 57 deletions(-)

diff --git a/src/SampleApp.WinDesktop/PointPlotView.xaml b/src/SampleApp.WinDesktop/PointPlotView.xaml
index 991b1f7..55362ad 100644
--- a/src/SampleApp.WinDesktop/PointPlotView.xaml
+++ b/src/SampleApp.WinDesktop/PointPlotView.xaml
@@ -4,11 +4,18 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
              xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
              xmlns:local="clr-namespace:SampleApp.WinDesktop"
+             xmlns:sys="clr-namespace:System;assembly=mscorlib"
              mc:Ignorable="d" 
              d:DesignHeight="450" d:DesignWidth="800">
+    <UserControl.Resources>
+        <SolidColorBrush x:Key="GridLinesBrush" Color="#AAFFFFFF" />
+        <DoubleCollection x:Key="GridLinesDash">4 4</DoubleCollection>
+        <sys:Double x:Key="GridLinesWidth">.5</sys:Double>
+    </UserControl.Resources>
     <Grid SizeChanged="Grid_SizeChanged" Background="Black" >
         <Grid Margin="10" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" x:Name="PlotMap" SizeChanged="PlotMap_SizeChanged">
             <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="50" />
                 <ColumnDefinition Width="1*" />
                 <ColumnDefinition Width="1*" />
                 <ColumnDefinition Width="1*" />
@@ -17,10 +24,10 @@
                 <ColumnDefinition Width="1*" />
                 <ColumnDefinition Width="1*" />
                 <ColumnDefinition Width="1*" />
-                <ColumnDefinition Width="1*" />
-                <ColumnDefinition Width="1*" />
+                <ColumnDefinition Width="50" />
             </Grid.ColumnDefinitions>
             <Grid.RowDefinitions>
+                <RowDefinition Height="50" />
                 <RowDefinition Height="1*" />
                 <RowDefinition Height="1*" />
                 <RowDefinition Height="1*" />
@@ -29,27 +36,28 @@
                 <RowDefinition Height="1*" />
                 <RowDefinition Height="1*" />
                 <RowDefinition Height="1*" />
-                <RowDefinition Height="1*" />
-                <RowDefinition Height="1*" />
+                <RowDefinition Height="50" />
             </Grid.RowDefinitions>
-            <Ellipse HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Stroke="White" StrokeThickness="1" Grid.ColumnSpan="8" Grid.RowSpan="8" Grid.Row="1" Grid.Column="1" StrokeDashArray="2 2" x:Name="OuterRing" />
-            <Ellipse HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Stroke="White" StrokeThickness="1" Grid.ColumnSpan="6" Grid.RowSpan="6" Grid.Row="2" Grid.Column="2" StrokeDashArray="2 2" />
-            <Ellipse HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Stroke="White" StrokeThickness="1" Grid.ColumnSpan="4" Grid.RowSpan="4" Grid.Row="3" Grid.Column="3" StrokeDashArray="2 2" />
-            <Ellipse HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Stroke="White" StrokeThickness="1" Grid.ColumnSpan="2" Grid.RowSpan="2" Grid.Row="4" Grid.Column="4" StrokeDashArray="2 2" />
-            <Path Data="M0,0 L1,0" HorizontalAlignment="Stretch" VerticalAlignment="Center" Stroke="White" StrokeThickness="1" Grid.RowSpan="8" Grid.ColumnSpan="8"  Grid.Row="1" Grid.Column="1" StrokeDashArray="2 2" Stretch="Fill" />
-            <Path Data="M0,0 L0,1" HorizontalAlignment="Center" VerticalAlignment="Stretch" Stroke="White" StrokeThickness="1" Grid.RowSpan="8" Grid.ColumnSpan="8"  Grid.Row="1" Grid.Column="1" StrokeDashArray="2 2" Stretch="Fill" />
+            <Ellipse HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Stroke="{StaticResource GridLinesBrush}" StrokeThickness="{StaticResource GridLinesWidth}" Grid.ColumnSpan="8" Grid.RowSpan="8" Grid.Row="1" Grid.Column="1" StrokeDashArray="{StaticResource GridLinesDash}" x:Name="OuterRing" />
+            <Ellipse HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Stroke="{StaticResource GridLinesBrush}" StrokeThickness="{StaticResource GridLinesWidth}" Grid.ColumnSpan="6" Grid.RowSpan="6" Grid.Row="2" Grid.Column="2" StrokeDashArray="{StaticResource GridLinesDash}" />
+            <Ellipse HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Stroke="{StaticResource GridLinesBrush}" StrokeThickness="{StaticResource GridLinesWidth}" Grid.ColumnSpan="4" Grid.RowSpan="4" Grid.Row="3" Grid.Column="3" StrokeDashArray="{StaticResource GridLinesDash}" />
+            <Ellipse HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Stroke="{StaticResource GridLinesBrush}" StrokeThickness="{StaticResource GridLinesWidth}" Grid.ColumnSpan="2" Grid.RowSpan="2" Grid.Row="4" Grid.Column="4" StrokeDashArray="{StaticResource GridLinesDash}" />
+            <Path Data="M0,0 L1,0" HorizontalAlignment="Stretch" VerticalAlignment="Center" Stroke="{StaticResource GridLinesBrush}" StrokeThickness="{StaticResource GridLinesWidth}" Grid.RowSpan="8" Grid.ColumnSpan="8"  Grid.Row="1" Grid.Column="1" StrokeDashArray="{StaticResource GridLinesDash}" Stretch="Fill" />
+            <Path Data="M0,0 L0,1" HorizontalAlignment="Center" VerticalAlignment="Stretch" Stroke="{StaticResource GridLinesBrush}" StrokeThickness="{StaticResource GridLinesWidth}" Grid.RowSpan="8" Grid.ColumnSpan="8"  Grid.Row="1" Grid.Column="1" StrokeDashArray="{StaticResource GridLinesDash}" Stretch="Fill" />
             <TextBlock x:Name="FirstMeterLabel" Text="5m"  Margin="0,15,0,0" FontSize="12" HorizontalAlignment="Center" VerticalAlignment="Center" Foreground="White" Grid.RowSpan="10" Grid.Column="6" Grid.ColumnSpan="2" Background="#55000000" />
-            <TextBlock x:Name="SecondMeterLabel" Text="10m" Margin="0,15,0,0" FontSize="12" HorizontalAlignment="Center" VerticalAlignment="Center" Foreground="White" Grid.RowSpan="10" Grid.Column="8" Grid.ColumnSpan="2" Background="#55000000" />
+            <TextBlock x:Name="SecondMeterLabel" Text="10m" Margin="0,15,-10,0" FontSize="12" HorizontalAlignment="Right" VerticalAlignment="Center" Foreground="White" Grid.RowSpan="10" Grid.Column="8" Grid.ColumnSpan="1" Background="#55000000" />
             <TextBlock Text="N" Margin="10" FontSize="9" HorizontalAlignment="Center" VerticalAlignment="Bottom" Foreground="White" Grid.ColumnSpan="10" />
             <TextBlock Text="S" Margin="10" FontSize="9" HorizontalAlignment="Center" VerticalAlignment="Top" Foreground="White" Grid.ColumnSpan="10" Grid.Row="9" />
             <TextBlock Text="W" Margin="10" FontSize="9" HorizontalAlignment="Right" VerticalAlignment="Center" Foreground="White" Grid.RowSpan="10" Grid.Column="0" />
             <TextBlock Text="E" Margin="10" FontSize="9" HorizontalAlignment="Left" VerticalAlignment="Center" Foreground="White" Grid.RowSpan="10" Grid.Column="9" />
-            <Canvas Grid.RowSpan="10" Grid.ColumnSpan="10" x:Name="canvas">
-                <Ellipse Fill="LightGreen" Canvas.Left="10" Width="3" Height="3" Canvas.Top="20" />
+            <Canvas Grid.RowSpan="10" Grid.ColumnSpan="10" x:Name="canvas" Opacity="0">
+                
             </Canvas>
+            <Image x:Name="plot" Grid.RowSpan="8" Grid.ColumnSpan="8" Grid.Row="1" Grid.Column="1" MouseWheel="plot_MouseWheel" />
         </Grid>
-        <StackPanel HorizontalAlignment="Left" VerticalAlignment="Bottom" Margin="20">
-            <Button Content="Clear" FontSize="10" Padding="2" HorizontalAlignment="Stretch" Click="ClearButton_Click"/>
+        <StackPanel HorizontalAlignment="Left" VerticalAlignment="Bottom" Margin="20" Orientation="Horizontal">
+            <Button Content="Clear" Padding="2" Margin="5" Click="ClearButton_Click" />
+            <ToggleButton IsChecked="True" x:Name="autoFitToggle" Content="Autofit" Padding="2" Margin="5" Unchecked="ToggleButton_Unchecked" Checked="ToggleButton_Checked" />
         </StackPanel>
         <StackPanel HorizontalAlignment="Right" VerticalAlignment="Top" Margin="20">
             <TextBlock x:Name="Status" Foreground="White" FontSize="12" />
diff --git a/src/SampleApp.WinDesktop/PointPlotView.xaml.cs b/src/SampleApp.WinDesktop/PointPlotView.xaml.cs
index 7e5bc28..4148875 100644
--- a/src/SampleApp.WinDesktop/PointPlotView.xaml.cs
+++ b/src/SampleApp.WinDesktop/PointPlotView.xaml.cs
@@ -21,7 +21,8 @@ namespace SampleApp.WinDesktop
     /// </summary>
     public partial class PointPlotView : UserControl
     {
-        List<double[]> locations = new List<double[]>();
+        private List<double[]> locations = new List<double[]>();
+
         public PointPlotView()
         {
             InitializeComponent();
@@ -31,34 +32,47 @@ namespace SampleApp.WinDesktop
         {
             PlotMap.Width = PlotMap.Height = Math.Min(e.NewSize.Width, e.NewSize.Height);
         }
-
+        Size size = new Size();
         private void PlotMap_SizeChanged(object sender, SizeChangedEventArgs e)
         {
+            size = e.NewSize;
             UpdatePlot();
         }
 
+        private void ClearButton_Click(object sender, RoutedEventArgs e)
+        {
+            Clear();
+        }
+
         public void Clear()
         {
             locations.Clear();
-            UpdatePlot();
+            if(!autoFit)
+                autoFitToggle.IsChecked = true;
+            else
+                UpdatePlot();
         }
+
         public void AddLocation(double latitude, double longitude, double altitude)
         {
-            Dispatcher.Invoke(() =>
-            {
-                locations.Add(new double[] { latitude, longitude, altitude });
-                UpdatePlot();
-            });
+            locations.Add(new double[] { latitude, longitude, altitude });
+            UpdatePlot();
         }
-        static SolidColorBrush dotFill = new SolidColorBrush(Color.FromRgb(0, 255, 0));
+
+        
         private void UpdatePlot()
         {
-            if (canvas.ActualWidth == 0 || canvas.ActualHeight == 0 || !IsVisible)
+            if (size.Width == 0 || size.Height == 0 || !IsVisible)
                 return;
-            Status.Text = "";
-            canvas.Children.Clear();
             if (locations.Count == 0)
+            {
+                Dispatcher.Invoke(() =>
+                {
+                    Status.Text = "";
+                    plot.Source = null;
+                });
                 return;
+            }
             var latAvr = locations.Select(l => l[0]).Average();
             var lonAvr = locations.Select(l => l[1]).Average();
             
@@ -86,45 +100,70 @@ namespace SampleApp.WinDesktop
             var lonAvr2 = locations2.Select(l => l[1]).Average();
             var maxDifLat = Math.Max(latAvr2 - latMin, latMax - latAvr2);
             var maxDifLon = Math.Max(lonAvr2 - lonMin, lonMax - lonAvr2);
-            var maxDif = Math.Max(maxDifLat, maxDifLon);
-            if (maxDif < .1)
-                maxDif = .1;
-            if (maxDif < .25)
-                maxDif = .25;
-            else if (maxDif < .5)
-                maxDif = .5;
+            //var maxDif = Math.Max(maxDifLat, maxDifLon);
+            double maxDif = 1;
+            if (autoFit)
+            {
+                maxDif = distances.Max();
+                if (maxDif < .1)
+                    maxDif = .1;
+                if (maxDif < .25)
+                    maxDif = .25;
+                else if (maxDif < .5)
+                    maxDif = .5;
+                else
+                    maxDif = Math.Ceiling(maxDif);
+                currentScale = maxDif / (Math.Min(size.Width, size.Height) * .5);
+            }
             else
-                maxDif = Math.Ceiling(maxDif);
-            //if(maxDif < 1)
-            SecondMeterLabel.Text = $"{maxDif}m";
-            FirstMeterLabel.Text = $"{maxDif/2}m";
-            double scale = maxDif / Math.Min(OuterRing.ActualWidth, OuterRing.ActualHeight) / .5;
+            {
+                maxDif = currentScale * (Math.Min(size.Width, size.Height) * .5);
+            }
+            double scale = currentScale;
             if (scale == 0)
                 scale = 1;
-            var MAXCOUNT = 1000;
-            for (int i = Math.Max(0, locations2.Count - MAXCOUNT); i < locations2.Count; i++) // Only draw the last 1000 points
+             int width = (int)size.Width;
+             int height = (int)size.Height;
+            int stride = width * 4;
+             byte[] pixels = new byte[width * height * 4];
+            double[][] stamp = new double[][] {new double[] { .3, .5, .3 }, new double[] { .5, 1, .5 }, new double[] { .3, .5, .3 } };
+                
+            for (int i = 0; i < locations2.Count; i++) 
             {
                 var l = locations2[i];
-                var x = canvas.ActualWidth * .5 + (l[1] - lonAvr2) / scale;
-                var y = canvas.ActualHeight * .5 - (l[0] - latAvr2) / scale;
-                Ellipse e = new Ellipse() { Width = 3, Height = 3, Fill = dotFill };
-
-                if (canvas.Children.Count == locations2.Count - 1 || canvas.Children.Count == MAXCOUNT - 1)
+                var x = (int)(width * .5 + (l[1] - lonAvr2) / scale);
+                var y = (int)(height * .5 - (l[0] - latAvr2) / scale);
+                var index = ((int)y) * stride + ((int)x) * 4;
+                for (int r = -1; r < stamp.Length-1; r++)
                 {
-                    e.Fill = new SolidColorBrush(Colors.Red);
-                    e.Width = 5;
-                    e.Height = 5;
+                    for (int c = -1; c < stamp[r + 1].Length-1; c++)
+                    {
+                        if (x + c >= width || x + c < 0 ||
+                           y + r >= width || y + r < 0)
+                            continue;
+                        var p = index + r * stride + c * 4;
+                        var val = stamp[r + 1][c + 1];
+                        pixels[p + 1] = 0;
+                        pixels[p + 1] = 255;
+                        pixels[p + 2] = 0;
+                        pixels[p + 3] = (byte)Math.Min(255, pixels[p + 3] + val * 255); //Multiply alpha
+                    }
                 }
-
-                Canvas.SetLeft(e, x - e.Width * .5);
-                Canvas.SetTop(e, y - e.Height * .5);
-                canvas.Children.Add(e);
             }
             var stdDevLat = Math.Sqrt(locations2.Sum(d => (d[0] - latAvr2) * (d[0] - latAvr2)) / locations2.Count);
             var stdDevLon = Math.Sqrt(locations2.Sum(d => (d[1] - lonAvr2) * (d[1] - lonAvr2)) / locations2.Count);
             var zAvr = locations.Select(l => l[2]).Where(l => !double.IsNaN(l)).Average();
             var stdDevZ = Math.Sqrt(locations.Select(l => l[2]).Where(l => !double.IsNaN(l)).Sum(d => (d - zAvr) * (d - zAvr)) / locations.Select(l => l[2]).Where(l => !double.IsNaN(l)).Count());
-            Status.Text = $"Measurements: {locations.Count}\nAverage:\n - Latitude: {latAvr.ToString("0.0000000")}\n - Longitude: {lonAvr.ToString("0.0000000")}\n - Elevation: {zAvr.ToString("0.000")}m\nStandard Deviation:\n - Latitude: {stdDevLat.ToString("0.###")}m\n - Longitude: {stdDevLon.ToString("0.###")}m\n - Horizontal: {distances.Average().ToString("0.###")}m\n - Elevation: {stdDevZ.ToString("0.###")}m";
+            Dispatcher.Invoke(() =>
+            {
+                SecondMeterLabel.Text = $"{maxDif.ToString("0.###")}m";
+                FirstMeterLabel.Text = $"{(maxDif / 2).ToString("0.###")}m";
+                // Specify the area of the bitmap that changed.
+                var writeableBitmap = new WriteableBitmap((int)size.Width, (int)size.Height, 96, 96, PixelFormats.Bgra32, null);
+                writeableBitmap.WritePixels(new Int32Rect(0, 0, width, height), pixels, stride, 0);
+                plot.Source = writeableBitmap;
+                Status.Text = $"Measurements: {locations.Count}\nAverage:\n - Latitude: {latAvr.ToString("0.0000000")}\n - Longitude: {lonAvr.ToString("0.0000000")}\n - Elevation: {zAvr.ToString("0.000")}m\nStandard Deviation:\n - Latitude: {stdDevLat.ToString("0.###")}m\n - Longitude: {stdDevLon.ToString("0.###")}m\n - Horizontal: {distances.Average().ToString("0.###")}m\n - Elevation: {stdDevZ.ToString("0.###")}m";
+            });
         }
 
         internal static class Vincenty
@@ -193,10 +232,45 @@ namespace SampleApp.WinDesktop
                 return s;
             }
         }
-
-        private void ClearButton_Click(object sender, RoutedEventArgs e)
+        bool autoFit = true;
+        double currentScale = 1;
+        private void ToggleButton_Unchecked(object sender, RoutedEventArgs e)
         {
-            Clear();
+            autoFit = false;
+        }
+
+        private void ToggleButton_Checked(object sender, RoutedEventArgs e)
+        {
+            autoFit = true;
+            UpdatePlot();
+        }
+
+        private void plot_MouseWheel(object sender, MouseWheelEventArgs e)
+        {
+            var maxDif = Math.Round(currentScale * (Math.Min(size.Width, size.Height) * .5), 3);
+            var dif = 1;
+            if (maxDif < 1)
+                maxDif = e.Delta < 0 ? maxDif * 2 : maxDif / 2;
+            else
+                maxDif = e.Delta < 0 ? maxDif + 1 : maxDif - 1;
+            if (maxDif < .1)
+                maxDif = .1;
+            if (maxDif < .25)
+                maxDif = .25;
+            else if (maxDif < .5)
+                maxDif = .5;
+            else
+                maxDif = Math.Ceiling(maxDif);
+            currentScale = maxDif / (Math.Min(size.Width, size.Height) * .5);
+
+            if (autoFitToggle.IsChecked == true)
+            {
+                autoFitToggle.IsChecked = false;
+            }
+            else
+            {
+                UpdatePlot();
+            }
         }
     }
 }
\ No newline at end of file