[2022/05/27]

* Added the Matrix3.Reflection method that builds a reflection matrix for a mirror plane that passes through the origin. See sample ReflectionMatrix().
* Added the Matrix4.Reflection method that builds a reflection matrix for a mirror plane that passes through an arbitrary point. See sample ReflectionMatrix().
* Corrected the comments in the Ellipse.Center property.
* (fixed) In the Ellipse.SetAxis method the validity checks must be performed with the arguments of the method not the actual major and minor axis of the ellipse.

TestDxfDocument/Program.cs

@@ -31,7 +31,7 @@ public class Program
     {
         public static void Main()
         {
-            DxfDocument doc = Test(@"sample.dxf");
+            DxfDocument doc = Test(@"sample.dxf"); 
 
             #region Samples for GTE classes
 
@@ -48,6 +48,7 @@ public static void Main()
 
             #region Samples for new and modified features 3.0.0
 
+            //ReflectionMatrix();
             //PolygonMesh();
             //UcsTransform();
             //SmoothPolyline2D();
@@ -710,6 +711,38 @@ public static void NURBSSurface()
 
         #region Samples for new and modified features 3.0.0
 
+        public static void ReflectionMatrix()
+        {
+            Polyline2D polyline = new Polyline2D(new []{
+                new Polyline2DVertex(-5,-5), 
+                new Polyline2DVertex(-5,5), 
+                new Polyline2DVertex(0,0),
+                new Polyline2DVertex(5,5), 
+                new Polyline2DVertex(5,-5)}, true) {Color = AciColor.Blue};
+
+            polyline.TransformBy(Matrix3.Identity, new Vector3(20,20,0));
+
+            Line mirrorLine = new Line(new Vector3(20,5,0), new Vector3(0,15,0)) {Color = AciColor.Yellow};
+            Vector3 mirrorNormal = Vector3.CrossProduct(mirrorLine.Direction, Vector3.UnitZ);
+
+            Polyline2D reflection = (Polyline2D) polyline.Clone();
+            reflection.Color = AciColor.Red;
+
+            // reflection matrix of a mirror plane given its normal and a point on the plane
+            Matrix4 reflectionMatrix = Matrix4.Reflection(mirrorNormal, mirrorLine.StartPoint);
+
+            // for a mirror plane that passes through the origin, you can also use
+            //Matrix3 reflectionMatrix = Matrix3.Reflection(mirrorNormal);
+            reflection.TransformBy(reflectionMatrix);
+
+            DxfDocument doc = new DxfDocument();
+            doc.Entities.Add(polyline);
+            doc.Entities.Add(mirrorLine);
+            doc.Entities.Add(reflection);
+
+            doc.Save("test.dxf");
+        }
+
         public static void PolygonMesh()
         {
             short u = 4;

doc/Changelog.txt

@@ -1,5 +1,11 @@
 ## Change history
 
+### [2022/05/27]
+* Added the Matrix3.Reflection method that builds a reflection matrix for a mirror plane that passes through the origin. See sample ReflectionMatrix().
+* Added the Matrix4.Reflection method that builds a reflection matrix for a mirror plane that passes through an arbitrary point. See sample ReflectionMatrix().
+* Corrected the comments in the Ellipse.Center property.
+* (fixed) In the Ellipse.SetAxis method the validity checks must be performed with the arguments of the method not the actual major and minor axis of the ellipse.
+
 ### [2022/04/19]
 * Added more GTE classes. See the Samples for GTE classes
 * Deleted the SplineVertex class. Now the Spline constructors take two lists: a Vector3 to define the controls points and a double array to define the weights.

netDxf/Entities/Circle.cs

@@ -85,7 +85,7 @@ public Circle(Vector2 center, double radius)
         #region public properties
 
         /// <summary>
-        /// Gets or sets the circle <see cref="netDxf.Vector3">center</see> in world coordinates.
+        /// Gets or sets the circle <see cref="Vector3">center</see> in world coordinates.
         /// </summary>
         public Vector3 Center
         {

netDxf/Entities/Ellipse.cs

@@ -263,9 +263,8 @@ public Ellipse(Vector3 center, double majorAxis, double minorAxis)
         #region public properties
 
         /// <summary>
-        /// Gets or sets the ellipse <see cref="Vector3">center</see>.
+        /// Gets or sets the ellipse <see cref="Vector3">center</see> in world coordinates.
         /// </summary>
-        /// <remarks>The center Z coordinate represents the elevation of the arc along the normal.</remarks>
         public Vector3 Center
         {
             get { return this.center; }
@@ -364,17 +363,17 @@ public bool IsFullEllipse
         /// <param name="minor">Ellipse minor axis.</param>
         public void SetAxis(double major, double minor)
         {
-            if (majorAxis <= 0)
+            if (major <= 0)
             {
-                throw new ArgumentOutOfRangeException(nameof(majorAxis), majorAxis, "The major axis value must be greater than zero.");
+                throw new ArgumentOutOfRangeException(nameof(major), major, "The major axis value must be greater than zero.");
             }
 
-            if (minorAxis <= 0)
+            if (minor <= 0)
             {
-                throw new ArgumentOutOfRangeException(nameof(minorAxis), minorAxis, "The minor axis value must be greater than zero.");
+                throw new ArgumentOutOfRangeException(nameof(minor), minor, "The minor axis value must be greater than zero.");
             }
 
-            if ( minorAxis > majorAxis)
+            if ( minor > major)
             {
                 throw new ArgumentException("The ellipse major axis must be greater than the minor axis.");
             }

netDxf/Entities/Spline.cs

@@ -38,12 +38,12 @@ public class Spline :
     {
         #region private fields
 
-        private Vector3[] fitPoints;
+        private readonly Vector3[] fitPoints;
         private readonly SplineCreationMethod creationMethod;
         private Vector3? startTangent;
         private Vector3? endTangent;
-        private Vector3[] controlPoints;
-        private double[] weights;
+        private readonly Vector3[] controlPoints;
+        private readonly double[] weights;
         private double[] knots;
         private readonly short degree;
         private bool isClosedPeriodic;
@@ -505,9 +505,9 @@ public double[] Knots
         /// </summary>
         public void Reverse()
         {
-            this.fitPoints = this.fitPoints.Reverse().ToArray();
-            this.controlPoints = this.controlPoints.Reverse().ToArray();
-            this.weights = this.weights.Reverse().ToArray();
+            Array.Reverse(this.fitPoints);
+            Array.Reverse(this.controlPoints);
+            Array.Reverse(this.weights);
             Vector3? tmp = this.startTangent;
             this.startTangent = -this.endTangent;
             this.endTangent = -tmp;

netDxf/GTE/BSplineCurve.cs

@@ -1,4 +1,29 @@
-// This is a translation to C# from the original C++ code of the Geometric Tool Library
+#region netDxf library licensed under the MIT License
+// 
+//                       netDxf library
+// Copyright (c) Daniel Carvajal (haplokuon@gmail.com)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+// 
+#endregion
+
+// This is a translation to C# from the original C++ code of the Geometric Tool Library
 // Original license
 // David Eberly, Geometric Tools, Redmond WA 98052
 // Copyright (c) 1998-2022

netDxf/GTE/BSplineCurveFit.cs

@@ -1,4 +1,31 @@
-// David Eberly, Geometric Tools, Redmond WA 98052
+#region netDxf library licensed under the MIT License
+// 
+//                       netDxf library
+// Copyright (c) Daniel Carvajal (haplokuon@gmail.com)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+// 
+#endregion
+
+// This is a translation to C# from the original C++ code of the Geometric Tool Library
+// Original license
+// David Eberly, Geometric Tools, Redmond WA 98052
 // Copyright (c) 1998-2022
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt

netDxf/GTE/BSplineReduction.cs

@@ -1,4 +1,31 @@
-// David Eberly, Geometric Tools, Redmond WA 98052
+#region netDxf library licensed under the MIT License
+// 
+//                       netDxf library
+// Copyright (c) Daniel Carvajal (haplokuon@gmail.com)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+// 
+#endregion
+
+// This is a translation to C# from the original C++ code of the Geometric Tool Library
+// Original license
+// David Eberly, Geometric Tools, Redmond WA 98052
 // Copyright (c) 1998-2022
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt

netDxf/GTE/BSplineSurface.cs

@@ -1,4 +1,29 @@
-// This is a translation to C# from the original C++ code of the Geometric Tool Library
+#region netDxf library licensed under the MIT License
+// 
+//                       netDxf library
+// Copyright (c) Daniel Carvajal (haplokuon@gmail.com)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+// 
+#endregion
+
+// This is a translation to C# from the original C++ code of the Geometric Tool Library
 // Original license
 // David Eberly, Geometric Tools, Redmond WA 98052
 // Copyright (c) 1998-2022

netDxf/GTE/BSplineSurfaceFit.cs

@@ -1,4 +1,31 @@
-// David Eberly, Geometric Tools, Redmond WA 98052
+#region netDxf library licensed under the MIT License
+// 
+//                       netDxf library
+// Copyright (c) Daniel Carvajal (haplokuon@gmail.com)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+// 
+#endregion
+
+// This is a translation to C# from the original C++ code of the Geometric Tool Library
+// Original license
+// David Eberly, Geometric Tools, Redmond WA 98052
 // Copyright (c) 1998-2022
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt

netDxf/GTE/BandedMatrix.cs

@@ -1,4 +1,31 @@
-// David Eberly, Geometric Tools, Redmond WA 98052
+#region netDxf library licensed under the MIT License
+// 
+//                       netDxf library
+// Copyright (c) Daniel Carvajal (haplokuon@gmail.com)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+// 
+#endregion
+
+// This is a translation to C# from the original C++ code of the Geometric Tool Library
+// Original license
+// David Eberly, Geometric Tools, Redmond WA 98052
 // Copyright (c) 1998-2022
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt

netDxf/GTE/BasisFunction.cs

@@ -1,4 +1,29 @@
-// This is a translation to C# from the original C++ code of the Geometric Tool Library
+#region netDxf library licensed under the MIT License
+// 
+//                       netDxf library
+// Copyright (c) Daniel Carvajal (haplokuon@gmail.com)
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+// 
+#endregion
+
+// This is a translation to C# from the original C++ code of the Geometric Tool Library
 // Original license
 // David Eberly, Geometric Tools, Redmond WA 98052
 // Copyright (c) 1998-2022
@@ -141,10 +166,10 @@ public UniqueKnot[] UniqueKnots
     // for 1 <= i <= d.
     public class BasisFunction
     {
-        private struct Key
+        private readonly struct Key
         {
-            private double knotValue;
-            private int knotIndex;
+            private readonly double knotValue;
+            private readonly int knotIndex;
 
             public Key(double knotValue, int knotIndex)
             {
@@ -229,7 +254,7 @@ public void Create(BasisFunctionInput input)
             int mult0 = this.uniqueKnots[0].Multiplicity;
             Debug.Assert(mult0 >= 1 && mult0 <= this.degree + 1, "Invalid first multiplicity.");
 
-            int mult1 = this.uniqueKnots[this.uniqueKnots.Length -1].Multiplicity;
+            int mult1 = this.uniqueKnots[this.uniqueKnots.Length - 1].Multiplicity;
             Debug.Assert(mult1 >= 1 && mult1 <= this.degree + 1, "Invalid last multiplicity.");
 
             for (int i = 1; i <= input.NumUniqueKnots - 2; i++)