algorithm/utils/motion.hpp

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//
// Copyright (c) 2020 INRIA
//
 
#ifndef __pinocchio_algorithm_utils_motion_hpp__
#define __pinocchio_algorithm_utils_motion_hpp__
 
#include "pinocchio/spatial/se3.hpp"
#include "pinocchio/spatial/motion.hpp"
#include "pinocchio/multibody/fwd.hpp"
 
namespace pinocchio
{
 
  template<typename Scalar, int Options, typename MotionIn, typename MotionOut>
  void changeReferenceFrame(
    const SE3Tpl<Scalar, Options> & placement,
    const MotionDense<MotionIn> & m_in,
    const ReferenceFrame rf_in,
    const ReferenceFrame rf_out,
    MotionDense<MotionOut> & m_out)
  {
    if (rf_in == rf_out)
    {
      m_out = m_in;
      return;
    }
 
    // case: LOCAL/WORLD and WORLD/LOCAL
    if (rf_in == LOCAL && rf_out == WORLD)
    {
      m_out = placement.act(m_in);
      return;
    }
    if (rf_in == WORLD && rf_out == LOCAL)
    {
      m_out = placement.actInv(m_in);
      return;
    }
 
    // case: LOCAL/LOCAL_WORLD_ALIGNED and LOCAL_WORLD_ALIGNED/LOCAL
    if (rf_in == LOCAL && rf_out == LOCAL_WORLD_ALIGNED)
    {
      m_out.linear().noalias() = placement.rotation() * m_in.linear();
      m_out.angular().noalias() = placement.rotation() * m_in.angular();
      return;
    }
    if (rf_in == LOCAL_WORLD_ALIGNED && rf_out == LOCAL)
    {
      m_out.linear().noalias() = placement.rotation().transpose() * m_in.linear();
      m_out.angular().noalias() = placement.rotation().transpose() * m_in.angular();
      return;
    }
 
    // case: WORLD/LOCAL_WORLD_ALIGNED and LOCAL_WORLD_ALIGNED/WORLD
    if (rf_in == WORLD && rf_out == LOCAL_WORLD_ALIGNED)
    {
      m_out.angular() = m_in.angular();
      m_out.linear().noalias() = m_in.linear() + m_in.angular().cross(placement.translation());
      return;
    }
    if (rf_in == LOCAL_WORLD_ALIGNED && rf_out == WORLD)
    {
      m_out.angular() = m_in.angular();
      m_out.linear().noalias() = m_in.linear() - m_in.angular().cross(placement.translation());
      return;
    }
 
    assert(false && "This must never happened.");
  }
 
  template<typename Scalar, int Options, typename MotionIn>
  typename MotionIn::MotionPlain changeReferenceFrame(
    const SE3Tpl<Scalar, Options> & placement,
    const MotionDense<MotionIn> & m_in,
    const ReferenceFrame rf_in,
    const ReferenceFrame rf_out)
  {
    typedef typename MotionIn::MotionPlain ReturnType;
    ReturnType res;
 
    changeReferenceFrame(placement, m_in, rf_in, rf_out, res);
 
    return res;
  }
 
} // namespace pinocchio
 
#endif // #ifndef __pinocchio_multibody_fwd_hpp__