added is_border_vertex

Former-commit-id: 32a33b18177fc72e62f4a42ae4fa23f163e2e2f1

is_border_vertex.h

@@ -0,0 +1,37 @@
+//
+//  IGL Lib - Simple C++ mesh library 
+//
+//  Copyright 2011, Daniele Panozzo. All rights reserved.
+
+#ifndef ISBORDERVERTEX_H
+#define ISBORDERVERTEX_H
+
+#include <Eigen/Core>
+#include <string>
+
+#include <vector>
+#include "tt.h"
+
+namespace igl 
+{
+  template<typename T>
+  inline std::vector<bool> is_border_vertex(const T& V, const Eigen::MatrixXi& F)
+  {
+    Eigen::MatrixXi FF;
+    igl::tt(V,F,FF);
+    vector<bool> ret(V.rows());
+    for(int i=0; i<ret.size();++i)
+      ret[i] = false;
+    
+    for(int i=0; i<F.rows();++i)
+      for(int j=0;j<F.cols();++j)
+        if(FF(i,j) == -1)
+        {
+          ret[F(i,j)]       = true;
+          ret[F(i,(j+1)%3)] = true;
+        }
+    return ret;
+  }
+}
+
+#endif