libigl_Martin/include/igl/embree/unproject_in_mesh.cpp

#include "unproject_in_mesh.h"
#include "EmbreeIntersector.h"
#include <igl/unproject.h>
#include <vector>

template <
  typename PointMatrixType,
  typename FaceMatrixType,
  typename RowVector3,
  typename Derivedobj>
bool igl::unproject_in_mesh(
  const int x,
  const int y,
  const igl::EmbreeIntersector<PointMatrixType,FaceMatrixType,RowVector3> & ei,
  Eigen::PlainObjectBase<Derivedobj> & obj)
{
  using namespace igl;
  using namespace std;
  using namespace Eigen;
  // Source and direction on screen
  Vector3d win_s = Vector3d(x,y,0);
  Vector3d win_d(x,y,1);
  // Source, destination and direction in world
  Vector3d s,d,dir;
  unproject(win_s,s);
  unproject(win_d,d);
  dir = d-s;
  // Shoot ray, collect all hits (could just collect first two)
  int num_rays_shot;
  vector<embree::Hit > hits;
  ei.intersectRay(s,dir,hits,num_rays_shot);
  switch(hits.size())
  {
    case 0:
      return false;
    case 1:
    {
      obj = s + dir*hits[0].t;
      break;
    }
    case 2:
    default:
    {
      obj = 0.5*((s + dir*hits[0].t) + (s + dir*hits[hits.size()-1].t));
      break;
    }
  }
  return true;
}

#ifndef IGL_HEADER_ONLY
template bool igl::unproject_in_mesh<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<double, 3, 1, 0, 3, 1>, Eigen::Matrix<double, 3, 1, 0, 3, 1> >(int, int, igl::EmbreeIntersector<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<double, 3, 1, 0, 3, 1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<double, 3, 1, 0, 3, 1> >&);
#endif