Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/flip_avoiding_line_search.h

@@ -0,0 +1,49 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2016 Michael Rabinovich
+//
+// 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_FLIP_AVOIDING_LINE_SEARCH_H
+#define IGL_FLIP_AVOIDING_LINE_SEARCH_H
+#include "igl_inline.h"
+#include "PI.h"
+
+#include <Eigen/Dense>
+
+namespace igl
+{
+  // A bisection line search for a mesh based energy that avoids triangle flips as suggested in
+  // 		"Bijective Parameterization with Free Boundaries" (Smith J. and Schaefer S., 2015).
+  //
+  // The user specifies an initial vertices position (that has no flips) and target one (that my have flipped triangles).
+  // This method first computes the largest step in direction of the destination vertices that does not incur flips,
+  // and then minimizes a given energy using this maximal step and a bisection linesearch (see igl::line_search).
+  //
+  // Supports both triangle and tet meshes.
+  //
+  // Inputs:
+  //   F  #F by 3/4 				list of mesh faces or tets
+  //   cur_v  						#V by dim list of variables
+  //   dst_v  						#V by dim list of target vertices. This mesh may have flipped triangles
+  //   energy       			    A function to compute the mesh-based energy (return an energy that is bigger than 0)
+  //   cur_energy(OPTIONAL)         The energy at the given point. Helps save redundant computations.
+  //							    This is optional. If not specified, the function will compute it.
+  // Outputs:
+  //		cur_v  						#V by dim list of variables at the new location
+  // Returns the energy at the new point
+  IGL_INLINE double flip_avoiding_line_search(
+    const Eigen::MatrixXi F,
+    Eigen::MatrixXd& cur_v,
+    Eigen::MatrixXd& dst_v,
+    std::function<double(Eigen::MatrixXd&)> energy,
+    double cur_energy = -1);
+
+}
+
+#ifndef IGL_STATIC_LIBRARY
+#  include "flip_avoiding_line_search.cpp"
+#endif
+
+#endif