Neuerstellung

- Quelle: https://github.com/oxyplot/oxyplot

Source/Examples/ExampleLibrary/CustomSeries/LineSegmentSeries.cs

@@ -0,0 +1,165 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="LineSegmentSeries.cs" company="OxyPlot">
+//   Copyright (c) 2014 OxyPlot contributors
+// </copyright>
+// <summary>
+//   Represents a line series where the points collection define line segments.
+// </summary>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace ExampleLibrary
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using OxyPlot;
+    using OxyPlot.Series;
+
+    /// <summary>
+    /// Represents a line series where the points collection define line segments.
+    /// </summary>
+    public class LineSegmentSeries : LineSeries
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="LineSegmentSeries" /> class.
+        /// </summary>
+        public LineSegmentSeries()
+        {
+            this.ShowVerticals = true;
+            this.Epsilon = 1e-8;
+        }
+
+        /// <summary>
+        /// Gets or sets a value indicating whether to show vertical lines where there is no gap in x-coordinate.
+        /// </summary>
+        /// <value><c>true</c> if verticals should be shown; otherwise, <c>false</c>.</value>
+        public bool ShowVerticals { get; set; }
+
+        /// <summary>
+        /// Gets or sets the x-coordinate gap tolerance.
+        /// </summary>
+        /// <value>The epsilon value.</value>
+        public double Epsilon { get; set; }
+
+        /// <summary>
+        /// Renders the series on the specified rendering context.
+        /// </summary>
+        /// <param name="rc">The rendering context.</param>
+        public override void Render(IRenderContext rc)
+        {
+            if (Points.Count == 0)
+            {
+                return;
+            }
+
+            if (Points.Count % 2 != 0)
+            {
+                throw new InvalidOperationException("The number of points should be even.");
+            }
+
+            if (this.XAxis == null || this.YAxis == null)
+            {
+                throw new InvalidOperationException("Axis has not been defined.");
+            }
+
+            var screenPoints = Points.Select(this.Transform).ToList();
+            var verticalLines = new List<ScreenPoint>();
+
+            for (int i = 0; i < screenPoints.Count; i += 2)
+            {
+                if (screenPoints[i].DistanceToSquared(screenPoints[i + 1]) < this.StrokeThickness)
+                {
+                    screenPoints[i] = new ScreenPoint(screenPoints[i].X - (this.StrokeThickness * 0.5), screenPoints[i].Y);
+                    screenPoints[i + 1] = new ScreenPoint(screenPoints[i].X + (this.StrokeThickness * 0.5), screenPoints[i].Y);
+                }
+
+                if (this.ShowVerticals && i > 0 && Math.Abs(screenPoints[i - 1].X - screenPoints[i].X) < this.Epsilon)
+                {
+                    verticalLines.Add(screenPoints[i - 1]);
+                    verticalLines.Add(screenPoints[i]);
+                }
+            }
+
+            if (this.StrokeThickness > 0)
+            {
+                if (this.LineStyle != LineStyle.None)
+                {
+                    rc.DrawLineSegments(screenPoints, this.ActualColor, this.StrokeThickness, this.EdgeRenderingMode, this.LineStyle.GetDashArray(), this.LineJoin);
+                }
+
+                rc.DrawLineSegments(verticalLines, this.ActualColor, this.StrokeThickness / 3, this.EdgeRenderingMode, LineStyle.Dash.GetDashArray(), this.LineJoin);
+            }
+
+            rc.DrawMarkers(screenPoints, this.MarkerType, null, this.MarkerSize, this.MarkerFill, this.MarkerStroke, this.MarkerStrokeThickness, this.EdgeRenderingMode);
+        }
+
+        /// <summary>
+        /// Gets the point on the series that is nearest the specified point.
+        /// </summary>
+        /// <param name="point">The point.</param>
+        /// <param name="interpolate">Interpolate the series if this flag is set to <c>true</c>.</param>
+        /// <returns>A TrackerHitResult for the current hit.</returns>
+        public override TrackerHitResult GetNearestPoint(ScreenPoint point, bool interpolate)
+        {
+            var points = this.Points;
+
+            if (points == null)
+            {
+                return null;
+            }
+
+            var spn = default(ScreenPoint);
+            var dpn = default(DataPoint);
+            double index = -1;
+
+            double minimumDistance = double.MaxValue;
+
+            for (int i = 0; i + 1 < points.Count; i += 2)
+            {
+                var p1 = points[i];
+                var p2 = points[i + 1];
+                if (!this.IsValidPoint(p1) || !this.IsValidPoint(p2))
+                {
+                    continue;
+                }
+
+                var sp1 = this.Transform(p1);
+                var sp2 = this.Transform(p2);
+
+                // Find the nearest point on the line segment.
+                var spl = ScreenPointHelper.FindPointOnLine(point, sp1, sp2);
+
+                if (ScreenPoint.IsUndefined(spl))
+                {
+                    // P1 && P2 coincident
+                    continue;
+                }
+
+                double l2 = (point - spl).LengthSquared;
+
+                if (l2 < minimumDistance)
+                {
+                    double u = (spl - sp1).Length / (sp2 - sp1).Length;
+                    dpn = new DataPoint(p1.X + (u * (p2.X - p1.X)), p1.Y + (u * (p2.Y - p1.Y)));
+                    spn = spl;
+                    minimumDistance = l2;
+                    index = i + u;
+                }
+            }
+
+            if (minimumDistance < double.MaxValue)
+            {
+                return new TrackerHitResult
+                {
+                    Series = this,
+                    DataPoint = dpn,
+                    Position = spn,
+                    Item = this.GetItem((int)index),
+                    Index = index
+                };
+            }
+
+            return null;
+        }
+    }
+}