Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/covariance_scatter_matrix.cpp

@@ -0,0 +1,76 @@
+// 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 "covariance_scatter_matrix.h"
+#include "arap_linear_block.h"
+#include "cotmatrix.h"
+#include "diag.h"
+#include "sum.h"
+#include "edges.h"
+#include "verbose.h"
+#include "cat.h"
+#include "PI.h"
+
+IGL_INLINE void igl::covariance_scatter_matrix(
+  const Eigen::MatrixXd & V, 
+  const Eigen::MatrixXi & F,
+  const ARAPEnergyType energy,
+  Eigen::SparseMatrix<double>& CSM)
+{
+  using namespace Eigen;
+  // number of mesh vertices
+  int n = V.rows();
+  assert(n > F.maxCoeff());
+  // dimension of mesh
+  int dim = V.cols();
+  // Number of mesh elements
+  int m = F.rows();
+
+  // number of rotations
+  int nr;
+  switch(energy)
+  {
+    case ARAP_ENERGY_TYPE_SPOKES:
+      nr = n;
+      break;
+    case ARAP_ENERGY_TYPE_SPOKES_AND_RIMS:
+      nr = n;
+      break;
+    case ARAP_ENERGY_TYPE_ELEMENTS:
+      nr = m;
+      break;
+    default:
+      fprintf(
+        stderr,
+        "covariance_scatter_matrix.h: Error: Unsupported arap energy %d\n",
+        energy);
+      return;
+  }
+
+  SparseMatrix<double> KX,KY,KZ;
+  arap_linear_block(V,F,0,energy,KX);
+  arap_linear_block(V,F,1,energy,KY);
+  SparseMatrix<double> Z(n,nr);
+  if(dim == 2)
+  {
+    CSM = cat(1,cat(2,KX,Z),cat(2,Z,KY)).transpose();
+  }else if(dim == 3)
+  {
+    arap_linear_block(V,F,2,energy,KZ);
+    SparseMatrix<double>ZZ(n,nr*2);
+    CSM = 
+      cat(1,cat(1,cat(2,KX,ZZ),cat(2,cat(2,Z,KY),Z)),cat(2,ZZ,KZ)).transpose();
+  }else
+  {
+    fprintf(
+     stderr,
+     "covariance_scatter_matrix.h: Error: Unsupported dimension %d\n",
+     dim);
+    return;
+  }
+
+}