#ifndef HALFSPACECONTAINER_H
#define HALFSPACECONTAINER_H

#include <list>
#include <iostream>
using namespace std;

#include <typedefs.h>

/*!
\brief Half space and a container of integer indexes to 
       points.
*/
template<typename HS, typename PT >
class halfspaceContainer 
{
public:

  /** The half space. */
  HS halfspace;

  /** Indexes into a vector of T. */
  list<uint> index;

  /** Global points. */
  vector< PT > const & pts;

  /** Needs a half space and a reference to the points to 
      be operated on. */
  halfspaceContainer
  (
    HS const & halfspace_,
    vector< PT > const & pts_
  ) : halfspace(halfspace_), pts(pts_) {} 

  /** Copies the targets indexes which the half-space can 
      see, or is on the boundary. ie populates index. */
  void isInsideOrOnBoundary(list<uint> const & target);

  /** Moves the target indexes which the half-space can
      see into index.  Includes the boundary. */
  void subtractfrom( list<uint> & target );

};

//---------------------------------------------------------
//  Implementation

template< typename HS, typename PT >
void halfspaceContainer<HS,PT>::subtractfrom
(
  list<uint> & target
)
{
  list<uint>::iterator i=target.begin();
  for ( ; i!=target.end(); ++i)
  {
    if (halfspace.isInsideOrOnBoundary(pts[*i]))
    {
      index.push_back(*i);
      i=target.erase(i);
    }
  }
}

template< typename HS, typename PT >
void halfspaceContainer<HS,PT>::isInsideOrOnBoundary
(
  list<uint> const & target
)
{
  list< uint >::const_iterator i=target.begin();
  list< uint >::const_iterator iend=target.end();
  for ( ; i!=iend; ++i)
  {
    if (halfspace.isInsideOrOnBoundary(pts[*i]))
      index.push_back(*i);
  }
}

#endif