Geometry_Engine: split at self intersections method added (#3292)

Author: Fraser Greenroyd

Geometry_Engine/Compute/SplitAtSelfIntersections.cs

@@ -0,0 +1,66 @@
+/*
+ * This file is part of the Buildings and Habitats object Model (BHoM)
+ * Copyright (c) 2015 - 2024, the respective contributors. All rights reserved.
+ *
+ * Each contributor holds copyright over their respective contributions.
+ * The project versioning (Git) records all such contribution source information.
+ *                                           
+ *                                                                              
+ * The BHoM is free software: you can redistribute it and/or modify         
+ * it under the terms of the GNU Lesser General Public License as published by  
+ * the Free Software Foundation, either version 3.0 of the License, or          
+ * (at your option) any later version.                                          
+ *                                                                              
+ * The BHoM is distributed in the hope that it will be useful,              
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of               
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 
+ * GNU Lesser General Public License for more details.                          
+ *                                                                            
+ * You should have received a copy of the GNU Lesser General Public License     
+ * along with this code. If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.      
+ */
+
+using BH.oM.Base.Attributes;
+using BH.oM.Geometry;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+
+namespace BH.Engine.Geometry
+{
+    public static partial class Compute
+    {
+        /***************************************************/
+        /****              Public Methods               ****/
+        /***************************************************/
+
+        [Description("Splits a closed planar polyline at self intersections and returns a collection of closed polylines.")]
+        [Input("polyline", "Closed planar polyline to split at self intersections.")]
+        [Input("distanceTolerance", "Distance tolerance used in geometrical processing.")]
+        [Output("splitOutlines", "Closed polylines representing the input polyline split at self intersections.")]
+        public static List<Polyline> SplitAtSelfIntersections(this Polyline polyline, double distanceTolerance = Tolerance.Distance)
+        {
+            if (polyline.IsNull())
+                return null;
+
+            if (!polyline.IsClosed(distanceTolerance))
+            {
+                BH.Engine.Base.Compute.RecordError("Splitting at self intersections works only on closed polylines.");
+                return null;
+            }
+
+            if (!polyline.IsPlanar(distanceTolerance))
+            {
+                BH.Engine.Base.Compute.RecordError("Splitting at self intersections works only on planar polylines.");
+                return null;
+            }
+
+            List<Line> segments = polyline.SubParts();
+            List<Point> selfIntersections = segments.LineIntersections(false, distanceTolerance).CullDuplicates();
+            segments = segments.SelectMany(x => x.SplitAtPoints(selfIntersections, distanceTolerance)).ToList();
+            return OutlinesFromLines(segments, distanceTolerance);
+        }
+
+        /***************************************************/
+    }
+}