#ifndef  GENTRAPEZOID_HH
#define  GENTRAPEZOID_HH
//============================================================================
//
//   Class     : GenTrapezoid
//   Created   : 20-DEC-1997 by Stephen Kahn
//   Purpose   : Characterize a GeometryElement as a TRAPezoid
//
//============================================================================
#include <geometry_system/components/GeometryElement.hpp>
#include <geometry_system/components/CartesianCoordinate.hpp>

namespace dgs {
/// A generalized trapezoid.
class  GenTrapezoid :  public  GeometryElement
{  
private :
  /// half length along local z-direction
  double  _dz_bot;
  double  _dz_top;
  /// polar angle of line joining faces
  double  _thet;
  /// azimuth angle of line joining faces
  double  _phi; 
  /// y half length for face
  double  _h1;
  /// y half length for face
  double _h2; 
  /// x half length at bottom
  double  _bl1;
  /// x half length at bottom
  double _bl2;
  /// x half length at top
  double  _tl1;
  /// x half length at top
  double _tl2;
  /// angle of median y tilt wrt y-axis
  double  _alp1;
  /// angle of median y tilt wrt y-axis
  double _alp2;
  /// angle of median z tilt wrt z-axis
  double _beta;

  /// Trapezoid center.
  CartesianCoordinate  _TrapCenter;

  /// Support for positioning children.
  CartesianCoordinate  xform_to_local(const GeometryXform&) const;
		
  /// Support for positioning children.
  GeometryXform  local_to_xform(const CartesianCoordinate&) const;

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

public :

  ///  Default constructor.
  GenTrapezoid(): _cvers("Revision:$") {}

  ///  Construct trapezoid with specified size.
  GenTrapezoid(double dz, double thet, double phi, double h1,
	       double h2, double bl1, double bl2, double tl1, 
	       double tl2, double alp1, double alp2) : _dz_bot(dz), 
    _dz_top(dz), _thet(thet), _phi(phi), _h1(h1), _h2(h2), _bl1(bl1),
    _bl2(bl2), _tl1(tl1), _tl2(tl2), _alp1(alp1),
    _alp2(alp2), _cvers("Revision:$") {}
  ///  Construct trapezoid with different lengths on top and bottom
  GenTrapezoid(double dz1, double dz2, double thet, double phi, double h1,
	       double h2, double bl1, double bl2, double tl1, 
	       double tl2, double alp1, double alp2, double beta) : 
    _dz_bot(dz1), _dz_top(dz2), _thet(thet), _phi(phi), _h1(h1), _h2(h2), 
    _bl1(bl1), _bl2(bl2), _tl1(tl1), _tl2(tl2), _alp1(alp1),
    _alp2(alp2), _beta(beta), _cvers("Revision:$") {}

  ///  Fill trapezoid.
  void fill_Trap(double, double, double, double,
		 double, double, double, double, double, double, double);
  ///  Fill trapezoid with different lengths on top and bottom
  void fill_Trap(double, double, double, double, double, double,
		 double, double, double, double, double, double, double);
  ///  Get dz. ( defaults to dz_bot)
  double  get_dz() const;
  ///  Get dz on top
  double  get_dz_top() const;
  ///  Get dz on bottom
  double  get_dz_bot() const;
  ///  Get theta.
  double  get_thet() const;
  ///  Get phi.
  double  get_phi() const;
  ///  Get h1.
  double  get_h1() const;
  ///  Get h2.
  double  get_h2() const;
  ///  Get bl2.
  double  get_bl2() const;
  ///  Get bl1.
  double  get_bl1() const;
  ///  Get tl1.
  double  get_tl1() const;
  ///  Get tl2.
  double  get_tl2() const;
  ///  Get alp1.
  double  get_alp1() const;
  ///  Get alp2.
  double  get_alp2() const;
  ///  Get beta.
  double  get_beta() const;

  ///  Convert local point to global one.
  SpacePoint local_to_global( const CartesianCoordinate&) const;

  ///  Convert global point to local one.
  CartesianCoordinate global_to_local(const SpacePoint&) const;

  ///  Set center of trapezoid to specified Cartesian point.
  void  set_center_xyz( double, double, double);
  void  set_center_xyz();  // set from Xform

  ///  Set Xform.
  void  set_Xform(double, double, double, double);

  ///  Position child surface at specfied local point.
  bool  position_child_at( const CartesianCoordinate&, GeometryElement& );
  bool  position_child_at( const GeometryXform&, GeometryElement&);

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

  D0_OBJECT_SETUP(GenTrapezoid);    // persistent class	
};
}
#endif  // GENTRAPEZOID_HH