update bundled_deps

bundled_deps/libigl/igl/svd3x3.h

@@ -0,0 +1,40 @@
+// 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_SVD3X3_H
+#define IGL_SVD3X3_H
+#include "igl_inline.h"
+#include <Eigen/Dense>
+
+namespace igl
+{
+  // Super fast 3x3 SVD according to http://pages.cs.wisc.edu/~sifakis/project_pages/svd.html
+  // The resulting decomposition is A = U * diag(S[0], S[1], S[2]) * V'
+  // BEWARE: this SVD algorithm guarantees that det(U) = det(V) = 1, but this 
+  // comes at the cost that 'sigma3' can be negative
+  // for computing polar decomposition it's great because all we need to do is U*V'
+  // and the result will automatically have positive determinant
+  //
+  // Inputs:
+  //   A  3x3 matrix
+  // Outputs:
+  //   U  3x3 left singular vectors
+  //   S  3x1 singular values
+  //   V  3x3 right singular vectors
+  //
+  // Known bugs: this will not work correctly for double precision.
+  template<typename T>
+  IGL_INLINE void svd3x3(
+    const Eigen::Matrix<T, 3, 3>& A, 
+    Eigen::Matrix<T, 3, 3> &U, 
+    Eigen::Matrix<T, 3, 1> &S, 
+    Eigen::Matrix<T, 3, 3>&V);
+}
+#ifndef IGL_STATIC_LIBRARY
+#  include "svd3x3.cpp"
+#endif
+#endif