update bundled_deps

bundled_deps/libigl/igl/snap_to_canonical_view_quat.cpp

@@ -0,0 +1,117 @@
+// 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 "snap_to_canonical_view_quat.h"
+
+#include "canonical_quaternions.h"
+#include "normalize_quat.h"
+
+#include <cstdio>
+#include <cassert>
+
+// Note: For the canonical view quaternions it should be completely possible to
+// determine this anaylitcally. That is the max_distance should be a
+// theoretical known value
+// Also: I'm not sure it matters in this case, but. We are dealing with
+// quaternions on the 4d unit sphere, but measuring distance in general 4d
+// space (i.e. not geodesics on the sphere). Probably something with angles
+// would be better.
+template <typename Q_type>
+IGL_INLINE bool igl::snap_to_canonical_view_quat(
+  const Q_type* q,
+  const Q_type threshold,
+  Q_type* s)
+{
+  // Copy input into output
+  // CANNOT use std::copy here according to:
+  // http://www.cplusplus.com/reference/algorithm/copy/
+  s[0] = q[0];
+  s[1] = q[1];
+  s[2] = q[2];
+  s[3] = q[3];
+
+  // Normalize input quaternion
+  Q_type qn[4];
+  bool valid_len =
+    igl::normalize_quat(q,qn);
+  // If normalizing valid then don't bother
+  if(!valid_len)
+  {
+    return false;
+  }
+
+  // 0.290019
+  const Q_type MAX_DISTANCE = 0.4;
+  Q_type min_distance = 2*MAX_DISTANCE;
+  int min_index = -1;
+  double min_sign = 0;
+  // loop over canonical view quaternions
+  for(double sign = -1;sign<=1;sign+=2)
+  {
+    for(int i = 0; i<NUM_CANONICAL_VIEW_QUAT; i++)
+    {
+      Q_type distance = 0.0;
+      // loop over coordinates
+      for(int j = 0;j<4;j++)
+      {
+        // Double cast because of bug in llvm version 4.2 with -O3
+        distance +=
+          (qn[j]-sign*igl::CANONICAL_VIEW_QUAT<Q_type>(i,j))*
+          (qn[j]-sign*igl::CANONICAL_VIEW_QUAT<Q_type>(i,j));
+      }
+      if(min_distance > distance)
+      {
+        min_distance = distance;
+        min_index = i;
+        min_sign = sign;
+      }
+    }
+  }
+
+  if(MAX_DISTANCE < min_distance)
+  {
+    fprintf(
+      stderr,
+      "ERROR: found new max MIN_DISTANCE: %g\n"
+      "PLEASE update snap_to_canonical_quat()",
+      min_distance);
+  }
+
+  assert(min_distance < MAX_DISTANCE);
+  assert(min_index >= 0);
+
+  if( min_distance/MAX_DISTANCE <= threshold)
+  {
+    // loop over coordinates
+    for(int j = 0;j<4;j++)
+    {
+      s[j] = min_sign*igl::CANONICAL_VIEW_QUAT<Q_type>(min_index,j);
+    }
+    return true;
+  }
+  return false;
+}
+
+template <typename Scalarq, typename Scalars>
+IGL_INLINE bool igl::snap_to_canonical_view_quat(
+  const Eigen::Quaternion<Scalarq> & q,
+  const double threshold,
+  Eigen::Quaternion<Scalars> & s)
+{
+  return snap_to_canonical_view_quat<Scalars>(
+    q.coeffs().data(),threshold,s.coeffs().data());
+}
+
+#ifdef IGL_STATIC_LIBRARY
+// Explicit template instantiation
+// generated by autoexplicit.sh
+template bool igl::snap_to_canonical_view_quat<double>(const double*, double, double*);
+// generated by autoexplicit.sh
+template bool igl::snap_to_canonical_view_quat<float>(const float*, float, float*);
+template bool igl::snap_to_canonical_view_quat<float, float>(Eigen::Quaternion<float, 0> const&, double, Eigen::Quaternion<float, 0>&);
+template bool igl::snap_to_canonical_view_quat<double, double>(Eigen::Quaternion<double, 0> const&, double, Eigen::Quaternion<double, 0>&);
+#endif