add_barycenter --> false_barycentric_subdivision

Former-commit-id: 676383ee274fae4b6861b6c200e03b16951fac20

include/igl/false_barycentric_subdivision.cpp

@@ -0,0 +1,57 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include "false_barycentric_subdivision.h"
+
+#include "verbose.h"
+#include <algorithm>
+#include <igl/barycenter.h>
+
+template <typename Scalar, typename Index>
+IGL_INLINE void igl::false_barycentric_subdivision(
+    const Eigen::PlainObjectBase<Scalar> & V, 
+    const Eigen::PlainObjectBase<Index> & F, 
+    Eigen::PlainObjectBase<Scalar> & VD, 
+    Eigen::PlainObjectBase<Index> & FD)
+{
+  using namespace Eigen;
+  // Compute face barycenter
+  Eigen::MatrixXd BC;
+  igl::barycenter(V,F,BC);
+
+  // Add the barycenters to the vertices
+  VD.resize(V.rows()+F.rows(),3);
+  VD.block(0,0,V.rows(),3) = V;
+  VD.block(V.rows(),0,F.rows(),3) = BC;
+
+  // Each face is split four ways
+  FD.resize(F.rows()*3,3);
+
+  for (unsigned i=0; i<F.rows(); ++i)
+  {
+    int i0 = F(i,0);
+    int i1 = F(i,1);
+    int i2 = F(i,2);
+    int i3 = V.rows() + i;
+
+    Vector3i F0,F1,F2;
+    F0 << i0,i1,i3;
+    F1 << i1,i2,i3;
+    F2 << i2,i0,i3;
+
+    FD.row(i*3 + 0) = F0;
+    FD.row(i*3 + 1) = F1;
+    FD.row(i*3 + 2) = F2;
+  }
+
+
+}
+
+
+#ifdef IGL_STATIC_LIBRARY
+// Explicit template specialization
+#endif

include/igl/false_barycentric_subdivision.h

@@ -0,0 +1,38 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#ifndef IGL_ADD_BARYCENTER_H
+#define IGL_ADD_BARYCENTER_H
+#include "igl_inline.h"
+
+#include <Eigen/Dense>
+
+namespace igl
+{
+  // Refine the mesh by adding the barycenter of each face
+  // Inputs:
+  //   V       #V by 3 coordinates of the vertices
+  //   F       #F by 3 list of mesh faces (must be triangles)
+  // Outputs:
+  //   VD      #V + #F by 3 coordinate of the vertices of the dual mesh
+  //           The added vertices are added at the end of VD
+  //   FD      #F*3 by 3 faces of the dual mesh
+  //
+  template <typename Scalar, typename Index>
+  IGL_INLINE void false_barycentric_subdivision(
+    const Eigen::PlainObjectBase<Scalar> & V,
+    const Eigen::PlainObjectBase<Index> & F,
+    Eigen::PlainObjectBase<Scalar> & VD,
+    Eigen::PlainObjectBase<Index> & FD);
+
+}
+
+#ifndef IGL_STATIC_LIBRARY
+#  include "false_barycentric_subdivision.cpp"
+#endif
+
+#endif