#ifndef ANNULARSURFACESECTION_HH
#define ANNULARSURFACESECTION_HH
//
// $Id: AnnularSurfaceSection.hpp,v 1.7 1998/10/23 14:32:48 hobbs Exp $
//
// File: disk.hh
// Purpose: 
// Created: 16-SEP-1997   John Hobbs
//
// $Revision: 1.7 $
//
//

// Include files
#include <iostream>
#include <geometry_system/components/GeometryElement.hpp>

namespace dgs {
class CylindricalCoordinate;
/**  A section of an annular surface.

     {\bf AnnularSurfaceSection} is an annulus (section of a plane)
     that does not form a full circle.  The radial extent is from
     $r_{min}$ to $r_{max}$, and angular range is from $0$ to
     $\phi_{max}$.

*/
class AnnularSurfaceSection : public GeometryElement {
public:

  ///  Default constructor.
  AnnularSurfaceSection(): _rmin(0.0), _rmax(0.0), _phimax(0.0),
    _cvers("Revision:$") {}

  ///  Construct an annulus with specified rmin, rmax and phimax.
  AnnularSurfaceSection(const double rmin, const double rmax, const double phimax):
    _rmin(rmin), _rmax(rmax), _phimax(phimax), _cvers("Revision:$") {}

  ///  Convert local point to global one.
  virtual SpacePoint local_to_global(const CylindricalCoordinate& lpt) const;

  ///  Convert global point to local one.
  virtual CylindricalCoordinate global_to_local(const SpacePoint & gpt) const;
  
  ///  Resize annulus by specified changes to rmin, rmax and phimax.
  bool resize(const double drmin, const double drmax, const double dphimax);

  ///  Position child surface at specified local point.
  bool position_child_at(const CylindricalCoordinate& lpt,
			 GeometryElement& kid);

  ///  Access rmin.
  double get_rmin() const { return _rmin; }

  ///  Access rmax.
  double get_rmax() const { return _rmax; }

  ///  Access phimax.
  double get_phimax() const { return _phimax; }

  ///  Stream insertion operator.
  friend std::ostream& operator<<(std::ostream& os, const AnnularSurfaceSection& me);

  /// Get source code version. Kept to allow following code changes
  const std::string& code_version() const { return _cvers; }

private:

  ///  rmin.
  double _rmin;

  ///  rmax.
  double _rmax;

  ///  phimax.
  double _phimax;

  ///  Support for placing children.
  CylindricalCoordinate xform_to_local(const GeometryXform& xf) const;

  ///  Support for placing children.
  GeometryXform local_to_xform(const CylindricalCoordinate& lpt) const;

  /// RCS version
  std::string _cvers;  // Replaced at checkout

public:

  D0_OBJECT_SETUP(AnnularSurfaceSection);

};
}
#endif //ANNULARSURFACESECTION_HH