//
// ********************************************************************
// * DISCLAIMER                                                       *
// *                                                                  *
// * The following disclaimer summarizes all the specific disclaimers *
// * of contributors to this software. The specific disclaimers,which *
// * govern, are listed with their locations in:                      *
// *   http://cern.ch/geant4/license                                  *
// *                                                                  *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work  make  any representation or  warranty, express or implied, *
// * regarding  this  software system or assume any liability for its *
// * use.                                                             *
// *                                                                  *
// * This  code  implementation is the  intellectual property  of the *
// * GEANT4 collaboration.                                            *
// * By copying,  distributing  or modifying the Program (or any work *
// * based  on  the Program)  you indicate  your  acceptance of  this *
// * statement, and all its terms.                                    *
// ********************************************************************
//
//
// $Id: G4Para.hh,v 1.6.4.1 2001/06/28 19:08:59 gunter Exp $
// GEANT4 tag $Name:  $
//
//
// --------------------------------------------------------------------
// GEANT 4 class header file
//
// G4Para
//
// Class description:
//
//   A G4Parallepiped, essentially a box with half lengths dx,dy,dz
//   `skewed' so that there are angles theta & phi of the polar line
//   joining the faces at +-dz in z, and alpha formed by the y axis
//   and the plane joinng the centre of the faces G4Parallel to the
//   z-x plane at -dy and +dy.
//
//   A G4Para is defined by:
//	dx,dy,dz	Half-length in x,y,z
//	alpha		Angle formed by the y axis and by the plane joining
//			the centre of the faces G4Parallel to the z-x plane
//			at -dy and +dy
//	theta		Polar angle of the line joining the centres of the
//			faces at -dz and +dz in z
//	phi		Azimuthal angle of the line joining the centres of the
//			faces at -dz and +dz in z
//   Member data:
//
//   Note that the angles parameters are not stored - precomputed trig is
//   stored instead.
//
//      fDx   Half-length in x
//      fDy   Half-length in y
//      fDz   Half-length in z
//
//      fTalpha       Tan of alpha
//      fTthetaCphi   Tan theta * Cos phi
//      fTthetaSphi   Tan theta * Sin phi

// History:
// 21.3.94 P.Kent Old C++ code converted to tolerant geometry
// 31.10.96 V.Grichine Modifications according G4Box/Tubs before to commit
// 18.11.99 V.Grichine , kUndefined was added to ESide
// --------------------------------------------------------------------

#ifndef G4Para_HH
#define G4Para_HH

#include "G4CSGSolid.hh"

class G4Para : public G4CSGSolid
{
  public:

    G4Para(const G4String& pName,
	         G4double pDx, G4double pDy, G4double pDz,
	         G4double pAlpha, G4double pTheta, G4double pPhi);
		 
    G4Para( const G4String& pName,
	    const G4ThreeVector pt[8]) ;

    virtual ~G4Para() ;
    
  // Access functions

    G4double GetZHalfLength() const { return fDz ; }
    G4ThreeVector GetSymAxis() const
    {
       G4double cosTheta = 1.0/sqrt(1+fTthetaCphi*fTthetaCphi +
                                      fTthetaSphi*fTthetaSphi) ;
     
       return G4ThreeVector(fTthetaCphi*cosTheta,
                            fTthetaSphi*cosTheta,
			    cosTheta) ;
    }
    G4double GetYHalfLength() const { return fDy ; }
    G4double GetXHalfLength() const { return fDx ; }
    G4double GetTanAlpha()    const { return fTalpha ; }
    
  // Set  functions

    void SetXHalfLength(G4double val) { fDx= val; }
    void SetYHalfLength(G4double val) { fDy= val; }
    void SetZHalfLength(G4double val) { fDz= val; }
    void SetAlpha(G4double alpha)  { fTalpha= tan(alpha); }
    void SetTanAlpha(G4double val) { fTalpha= val; }
    void SetThetaAndPhi(double pTheta, double pPhi)    
    {
	fTthetaCphi=tan(pTheta)*cos(pPhi);
	fTthetaSphi=tan(pTheta)*sin(pPhi);
    }
    void SetAllParameters(G4double pDx, G4double pDy, G4double pDz, 
                          G4double pAlpha, G4double pTheta, G4double pPhi);
    
  // Methods
    
    void ComputeDimensions(G4VPVParameterisation* p,
                           const G4int n,
                           const G4VPhysicalVolume* pRep);

    G4bool CalculateExtent(const EAxis pAxis,
                           const G4VoxelLimits& pVoxelLimit,
                           const G4AffineTransform& pTransform,
                           G4double& pMin, G4double& pMax) const;    
        
    EInside Inside(const G4ThreeVector& p) const;

    G4ThreeVector SurfaceNormal( const G4ThreeVector& p) const;

    G4double DistanceToIn(const G4ThreeVector& p,
                          const G4ThreeVector& v) const;
    G4double DistanceToIn(const G4ThreeVector& p) const;
    
    G4double DistanceToOut(const G4ThreeVector& p,const G4ThreeVector& v,
			   const G4bool calcNorm=G4bool(false),
			   G4bool *validNorm=0,G4ThreeVector *n=0) const;
    G4double DistanceToOut(const G4ThreeVector& p) const;

             // Naming method (pseudo-RTTI : run-time type identification

    G4GeometryType  GetEntityType() const { return G4String("G4Para"); }

  // Visualisation functions

    void          DescribeYourselfTo (G4VGraphicsScene& scene) const;
    G4Polyhedron* CreatePolyhedron   () const;
    G4NURBS*      CreateNURBS        () const;

  protected:

    G4ThreeVectorList*
    CreateRotatedVertices(const G4AffineTransform& pTransform) const;

  private:

    G4double fDx,fDy,fDz;
    G4double fTalpha,fTthetaCphi,fTthetaSphi;
};
   	
#endif