Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/rotate_by_quat.cpp

@@ -0,0 +1,55 @@
+// 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 "rotate_by_quat.h"
+
+#include "quat_conjugate.h"
+#include "quat_mult.h"
+#include "normalize_quat.h"
+#include <cassert>
+
+template <typename Q_type>
+IGL_INLINE void igl::rotate_by_quat(
+  const Q_type *v,
+  const Q_type *q,
+  Q_type *out)
+{
+  // Quaternion form of v, copy data in v, (as a result out can be same pointer
+  // as v)
+  Q_type quat_v[4] = {v[0],v[1],v[2],0};
+
+  // normalize input 
+  Q_type normalized_q[4];
+
+#ifndef NDEBUG
+  bool normalized = 
+#endif
+  igl::normalize_quat<Q_type>(q,normalized_q);
+#ifndef NDEBUG
+  assert(normalized);
+#endif
+
+  // Conjugate of q
+  Q_type q_conj[4];
+  igl::quat_conjugate<Q_type>(normalized_q,q_conj);
+
+  // Rotate of vector v by quaternion q is:
+  // q*v*conj(q)
+  // Compute q*v
+  Q_type q_mult_quat_v[4];
+  igl::quat_mult<Q_type>(normalized_q,quat_v,q_mult_quat_v);
+  // Compute (q*v) * conj(q)
+  igl::quat_mult<Q_type>(q_mult_quat_v,q_conj,out);
+}
+
+#ifdef IGL_STATIC_LIBRARY
+// Explicit template instantiation
+// generated by autoexplicit.sh
+template void igl::rotate_by_quat<double>(double const*, double const*, double*);
+// generated by autoexplicit.sh
+template void igl::rotate_by_quat<float>(float const*, float const*, float*);
+#endif