From f23639cdda4a36da01d45b1f062148790ab18e13 Mon Sep 17 00:00:00 2001
From: Ryan Schmidt <rms@rms80.com>
Date: Thu, 10 May 2018 15:52:23 -0400
Subject: [PATCH] utility fn

---
 mesh_selection/MeshConnectedComponents.cs | 27 +++++++++++++++++++
 mesh_selection/MeshVertexSelection.cs     | 32 +++++++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/mesh_selection/MeshConnectedComponents.cs b/mesh_selection/MeshConnectedComponents.cs
index 3c95befb..2c71559a 100644
--- a/mesh_selection/MeshConnectedComponents.cs
+++ b/mesh_selection/MeshConnectedComponents.cs
@@ -224,5 +224,32 @@ public static DMesh3 LargestT(DMesh3 meshIn)
             return submesh.SubMesh;
         }
 
+
+
+
+        /// <summary>
+        /// Utility function that finds set of triangles connected to tSeed. Does not use MeshConnectedComponents class.
+        /// </summary>
+        public static HashSet<int> FindConnectedT(DMesh3 mesh, int tSeed)
+        {
+            HashSet<int> found = new HashSet<int>();
+            found.Add(tSeed);
+            List<int> queue = new List<int>(64) { tSeed };
+            while ( queue.Count > 0 ) {
+                int tid = queue[queue.Count - 1];
+                queue.RemoveAt(queue.Count - 1);
+                Index3i nbr_t = mesh.GetTriNeighbourTris(tid);
+                for ( int j = 0; j < 3; ++j ) {
+                    int nbrid = nbr_t[j];
+                    if (nbrid == DMesh3.InvalidID || found.Contains(nbrid))
+                        continue;
+                    found.Add(nbrid);
+                    queue.Add(nbrid);
+                }
+            }
+            return found;
+        }
+
+
     }
 }
diff --git a/mesh_selection/MeshVertexSelection.cs b/mesh_selection/MeshVertexSelection.cs
index 9fb8f0a2..cda76921 100644
--- a/mesh_selection/MeshVertexSelection.cs
+++ b/mesh_selection/MeshVertexSelection.cs
@@ -149,6 +149,38 @@ public void SelectInteriorVertices(MeshFaceSelection triangles)
 
 
 
+        /// <summary>
+        /// Select set of boundary vertices connected to vSeed.
+        /// </summary>
+        public void SelectConnectedBoundaryV(int vSeed)
+        {
+            if ( ! Mesh.IsBoundaryVertex(vSeed))
+                throw new Exception("MeshConnectedComponents.FindConnectedBoundaryV: vSeed is not a boundary vertex");
+
+            HashSet<int> found = (Selected.Count == 0) ? Selected : new HashSet<int>();
+            found.Add(vSeed);
+            List<int> queue = temp; queue.Clear();
+            queue.Add(vSeed);
+            while (queue.Count > 0) {
+                int vid = queue[queue.Count - 1];
+                queue.RemoveAt(queue.Count - 1);
+                foreach (int nbrid in Mesh.VtxVerticesItr(vid)) {
+                    if (Mesh.IsBoundaryVertex(nbrid) && found.Contains(nbrid) == false) {
+                        found.Add(nbrid);
+                        queue.Add(nbrid);
+                    }
+                }
+            }
+            if ( found != Selected ) {
+                foreach (int vid in found)
+                    add(vid);
+            }
+            temp.Clear();
+        }
+
+
+
+
         public void SelectEdgeVertices(int[] edges)
         {
             for (int i = 0; i < edges.Length; ++i) {