Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/circulation.cpp

@@ -0,0 +1,71 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2015 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 "circulation.h"
+#include "list_to_matrix.h"
+
+IGL_INLINE std::vector<int> igl::circulation(
+  const int e,
+  const bool ccw,
+  const Eigen::MatrixXi & F,
+  const Eigen::MatrixXi & E,
+  const Eigen::VectorXi & EMAP,
+  const Eigen::MatrixXi & EF,
+  const Eigen::MatrixXi & EI)
+{
+  // prepare output
+  std::vector<int> N;
+  N.reserve(6);
+  const int m = F.rows();
+  const auto & step = [&](
+    const int e, 
+    const int ff,
+    int & ne, 
+    int & nf)
+  {
+    assert((EF(e,1) == ff || EF(e,0) == ff) && "e should touch ff");
+    //const int fside = EF(e,1)==ff?1:0;
+    const int nside = EF(e,0)==ff?1:0;
+    const int nv = EI(e,nside);
+    // get next face
+    nf = EF(e,nside);
+    // get next edge 
+    const int dir = ccw?-1:1;
+    ne = EMAP(nf+m*((nv+dir+3)%3));
+  };
+  // Always start with first face (ccw in step will be sure to turn right
+  // direction)
+  const int f0 = EF(e,0);
+  int fi = f0;
+  int ei = e;
+  while(true)
+  {
+    step(ei,fi,ei,fi);
+    N.push_back(fi);
+    // back to start?
+    if(fi == f0)
+    {
+      assert(ei == e);
+      break;
+    }
+  }
+  return N;
+}
+
+IGL_INLINE void igl::circulation(
+  const int e,
+  const bool ccw,
+  const Eigen::MatrixXi & F,
+  const Eigen::MatrixXi & E,
+  const Eigen::VectorXi & EMAP,
+  const Eigen::MatrixXi & EF,
+  const Eigen::MatrixXi & EI,
+  Eigen::VectorXi & vN)
+{
+  std::vector<int> N = circulation(e,ccw,F,E,EMAP,EF,EI);
+  igl::list_to_matrix(N,vN);
+}