Merge pull request #364 from GSharker/dev/peli/Segment-At-Length

Dev/peli/segment at length

src/GShark.Test.XUnit/Geometry/PolyCurveTests.cs

@@ -33,10 +33,8 @@ public PolyCurveTests(ITestOutputHelper testOutput)
  Line line = new Line(new Point3(5, 5, 0), new Point3(5, 5, -2.5));
  Arc arc = Arc.ByStartEndDirection(new Point3(5, 5, -2.5), new Point3(10, 5, -5), new Vector3(0, 0, -1));
 
- _polycurve = new PolyCurve();
- _polycurve.Append(curve);
- _polycurve.Append(line);
- _polycurve.Append(arc);
+ List<NurbsBase> curves = new List<NurbsBase>{ curve, line, arc};
+ _polycurve = new PolyCurve(curves);
  #endregion
  }
 
@@ -81,5 +79,21 @@ public void It_Returns_The_Length_At_Parameter(double t, double expectedLength)
  // Assert
  length.Should().BeApproximately(expectedLength, GSharkMath.MinTolerance);
  }
+
+ [Theory]
+ [InlineData(23.769824635278, 2)]
+ [InlineData(21.269824635278, 1)]
+ [InlineData(20, 0)]
+ public void It_Returns_The_Segment_At_Length(double length, int segmentIndex)
+ {
+ //Arrange
+ NurbsBase expectedSegment = _polycurve.Segments[segmentIndex];
+
+ //Act
+ NurbsBase segmentResult = _polycurve.SegmentAtLength(length);
+
+ //Assert
+ segmentResult.Should().BeSameAs(expectedSegment);
+ }
  }
 }

src/GShark/Geometry/NurbsBase.cs

@@ -521,8 +521,7 @@ public static PolyCurve Join(IList<NurbsBase> curves)
  }
  }
 
- PolyCurve polyCurve = new PolyCurve();
- polyCurve.Append(sortedCurves);
+ PolyCurve polyCurve = new PolyCurve(sortedCurves);
 
  return polyCurve;
  }

src/GShark/Geometry/PolyCurve.cs

@@ -1,7 +1,5 @@
 using GShark.Core;
 using GShark.ExtendedMethods;
-using GShark.Interfaces;
-using GShark.Operation;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -19,10 +17,19 @@ public class PolyCurve : NurbsBase
  private readonly List<NurbsBase> _segments = new List<NurbsBase>();
 
  /// <summary>
- /// Initializes a new empty polyCurve.
+ /// Initializes a new polyCurve with a list of curves
  /// </summary>
- public PolyCurve()
- { }
+ /// <param name="curves">a list of curves</param>
+ public PolyCurve(IList<NurbsBase> curves)
+ {
+ _segments.Add(curves[0]);
+ for (int i = 1; i < curves.Count; i++)
+ {
+ HealthChecks(curves[i - 1], curves[i]);
+ _segments.Add(curves[i]);
+ }
+ ToNurbsForm();
+ }
 
  /// <summary>
  /// Appends and matches the start of the arc to the end of polycurve.
@@ -31,7 +38,7 @@ public PolyCurve()
  /// <param name="line">The line to append.</param>
  public void Append(Line line)
  {
- HealthChecks(line);
+ HealthChecks(this, line);
  _segments.Add(line);
  ToNurbsForm();
  }
@@ -43,7 +50,7 @@ public void Append(Line line)
  /// <param name="arc">The arc to append.</param>
  public void Append(Arc arc)
  {
- HealthChecks(arc);
+ HealthChecks(this, arc);
  _segments.Add(arc);
  ToNurbsForm();
  }
@@ -59,7 +66,7 @@ public void Append(NurbsCurve curve)
  {
  throw new InvalidOperationException("The curve is closed.");
  }
- HealthChecks(curve);
+ HealthChecks(this, curve);
  _segments.Add(curve);
  ToNurbsForm();
  }
@@ -75,7 +82,7 @@ public void Append(PolyCurve polyCurve)
  {
  throw new InvalidOperationException("The polycurve is closed.");
  }
- HealthChecks(polyCurve);
+ HealthChecks(this, polyCurve);
  _segments.Add(polyCurve);
  ToNurbsForm();
  }
@@ -85,7 +92,7 @@ public void Append(PolyCurve polyCurve)
  /// No health checks are made, you are responsible of the collection of curve you are passing.
  /// </summary>
  /// <param name="curves"></param>
- internal void Append(List<NurbsBase> curves)
+ internal void Append(IEnumerable<NurbsBase> curves)
  {
  _segments.AddRange(curves);
  ToNurbsForm();
@@ -96,6 +103,33 @@ internal void Append(List<NurbsBase> curves)
  /// </summary>
  public List<NurbsBase> Segments => _segments;
 
+ /// <summary>
+ /// Find Curve Segment At a given Length.
+ /// When there is no curve segments in the PolyCurve, return null;
+ /// If the provided length is greater than the PolyCurve Length, then it return the last segment in PolyCurve;
+ /// </summary>
+ /// <param name="length">Segment Length</param>
+ public NurbsBase SegmentAtLength(double length)
+ {
+ NurbsBase segment = null;
+ if (length > Length) return _segments.Last();
+ if (_segments.Count == 1) return _segments.First();
+
+ double temp = 0;
+ foreach (NurbsBase curve in _segments)
+ {
+ double cumulativeLength = curve.Length + temp;
+ if (length >= temp && length < cumulativeLength)
+ {
+ segment = curve;
+ break;
+ }
+ temp = cumulativeLength;
+ }
+
+ return segment;
+ }
+
  /// <summary>
  /// Defines the NURBS form of the polyline.
  /// </summary>
@@ -141,18 +175,18 @@ private void ToNurbsForm()
  }
 
  /// <summary>
- /// Checks to define if the curve can be appended to the polycurve.
+ /// Checks to define if the curve can be appended.
  /// </summary>
- private void HealthChecks(NurbsBase curve)
+ private void HealthChecks(NurbsBase curve, NurbsBase curveToAppend)
  {
  if (_segments.Count <= 0) return;
 
- if (IsClosed)
+ if (curve.IsClosed)
  {
- throw new InvalidOperationException($"The polyCurve is closed can not be possible to connect the {curve.GetType()}.");
+ throw new InvalidOperationException($"The polyCurve is closed can not be possible to connect the {curveToAppend.GetType()}.");
  }
 
- if (EndPoint.DistanceTo(curve.StartPoint) > GSharkMath.Epsilon)
+ if (curve.EndPoint.DistanceTo(curveToAppend.StartPoint) > GSharkMath.Epsilon)
  {
  throw new InvalidOperationException("The two curves can not be connected.");
  }