Method get_level_index

src/lasquadtree.cpp:277–320

returns the (sub-)level index of the cell that x & y fall into at the specified level

// returns the (sub-)level index of the cell that x & y fall into at the specified level
U32 LASquadtree::get_level_index(const F64 x, const F64 y, U32 level) const
{
  volatile float cell_mid_x;
  volatile float cell_mid_y;
  float cell_min_x, cell_max_x;
  float cell_min_y, cell_max_y;
  
  cell_min_x = min_x;
  cell_max_x = max_x;
  cell_min_y = min_y;
  cell_max_y = max_y;

  U32 level_index = 0;

  while (level)
  {
    level_index <<= 2;

    cell_mid_x = (cell_min_x + cell_max_x)/2;
    cell_mid_y = (cell_min_y + cell_max_y)/2;

    if (x < cell_mid_x)
    {
      cell_max_x = cell_mid_x;
    }
    else
    {
      cell_min_x = cell_mid_x;
      level_index |= 1;
    }
    if (y < cell_mid_y)
    {
      cell_max_y = cell_mid_y;
    }
    else
    {
      cell_min_y = cell_mid_y;
      level_index |= 2;
    }
    level--;
  }

  return level_index;
}

// returns the (sub-)level index of the cell that x & y fall into
U32 LASquadtree::get_level_index(const F64 x, const F64 y) const