Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/partition.cpp

@@ -0,0 +1,59 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2014 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 "partition.h"
+#include "mat_min.h"
+
+IGL_INLINE void igl::partition(
+  const Eigen::MatrixXd & W,
+  const int k,
+  Eigen::Matrix<int,Eigen::Dynamic,1> & G,
+  Eigen::Matrix<int,Eigen::Dynamic,1> & S,
+  Eigen::Matrix<double,Eigen::Dynamic,1> & D)
+{
+  // number of mesh vertices
+  int n = W.rows();
+
+  // Resize output
+  G.resize(n);
+  S.resize(k);
+
+  // "Randomly" choose first seed
+  // Pick a vertex farthest from 0
+  int s;
+  (W.array().square().matrix()).rowwise().sum().maxCoeff(&s);
+
+  S(0) = s;
+  // Initialize distance to closest seed
+  D = ((W.rowwise() - W.row(s)).array().square()).matrix().rowwise().sum();
+  G.setZero();
+
+  // greedily choose the remaining k-1 seeds
+  for(int i = 1;i<k;i++)
+  {
+    // Find maximum in D
+    D.maxCoeff(&s);
+    S(i) = s;
+    // distance to this seed
+    Eigen::Matrix<double,Eigen::Dynamic,1> Ds =
+      ((W.rowwise() - W.row(s)).array().square()).matrix().rowwise().sum();
+    // Concatenation of D and Ds: DDs = [D Ds];
+    Eigen::Matrix<double,Eigen::Dynamic,Eigen::Dynamic> DDs;
+    // Make space for two columns
+    DDs.resize(D.rows(),2);
+    DDs.col(0) = D;
+    DDs.col(1) = Ds;
+    // Update D
+    // get minimum of old D and distance to this seed, C == 1 if new distance
+    // was smaller
+    Eigen::Matrix<int,Eigen::Dynamic,1> C;
+    igl::mat_min(DDs,2,D,C);
+    G = (C.array() ==0).select(G,i);
+  }
+
+
+}