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// ********************************************************************
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///////////////////////////////////////////////////////////////////////////////
//
// MODULE:        G4SPSPosDistribution.hh
//
// Version:      1.0
// Date:         5/02/04
// Author:       Fan Lei 
// Organisation: QinetiQ ltd.
// Customer:     ESA/ESTEC
//
///////////////////////////////////////////////////////////////////////////////
//
// CHANGE HISTORY
// --------------
//
//
// Version 1.0, 05/02/2004, Fan Lei, Created.
//    Based on the G4GeneralParticleSource class in Geant4 v6.0
//
///////////////////////////////////////////////////////////////////////////////
//
//
// Class Description:
//
// To generate the position of a primary vertex according to the defined distribution 
//
///////////////////////////////////////////////////////////////////////////////
//
// MEMBER FUNCTIONS
// ----------------
//
// G4SPSPosDistribution ()
//    Constructor: Initializes variables and instantiates the Navigator class
//
// ~G4SPSPosDistribution ()
//    Destructor: 
//
// void SetPosDisType(G4String)
//    Allows user to choose Point, Plane, Surface or Volume source
//    position distributions.
//
// void SetPosDisShape(G4String)
//    Allows the user to choose the particular shape they wish for the
//    position distribution. Choices are Square, Circle, Ellipse, Rectangle,
//    Sphere, Ellipsoid, Cylinder, Parallelepiped.
//
// void SetCentreCoords(G4ThreeVector)
//    Sets the co-ordinates of the centre of the position distribution.
//
// void SetPosRot1(G4ThreeVector)
//    Used to specify the co-ordinate system for the position distribution
//    along with SetPosRot2. SetPosRot1 sets the vector x' and need not be
//    a unit vector.
//
// void SetPosRot2(G4ThreeVector)
//    Used in connection with SetPosRot1. This sets a vector in the plane
//    x'y'. By a series of cross products x', y', z' are generated. Again
//    need not be a unit vector.
// 
// void SetHalfX(G4double)
//    Sets the half length in x.
//
// void SetHalfY(G4double)
//    Sets the half length in y.
//
// void SetHalfZ(G4double)
//    Sets the half length in z.
//
// void SetRadius(G4double)
//    Sets the radius where appropriate for source distribution shapes.
//
// void SetRadius0(G4double)
//    Sets the inner radius where appropriate for source distribution shapes.
//
//  void SetBeamSigmaInR(G4double);
//    Sets the sigma for 1D beam
//
//  void SetBeamSigmaInX(G4double);
//    Sets the first sigma for 2D beam
// 
//  void SetBeamSigmaInY(G4double);
//    Sets the second sigma for 2D beam
//
// void SetParAlpha(G4double)
//    Sets the angle Alpha in the Parallelepiped shapes.
//
// void SetParTheta(G4double)
//    Sets the angle Theta in the Parallelepiped shapes.
//
// void SetParPhi(G4double)
//    Sets the angle Phi in the Parallelepiped shapes.
//
// void ConfineSourceToVolume(G4String)
//    Used to confine the start positions to a particular volume.
//
//  void SetBiasRndm (G4SPSRandomGenerator* a) { posRndm = a ; };
//    Sets the biased random number generator
//
//  G4ThreeVector GenerateOne();
//    Generate one random position
//
// void SetVerbosity(G4int)
//    Sets the verbosity level.
//
///////////////////////////////////////////////////////////////////////////////
//
#ifndef G4SPSPosDistribution_h
#define G4SPSPosDistribution_h 1

#include "G4Navigator.hh"
#include "G4SPSRandomGenerator.hh"

class G4SPSPosDistribution
{
  //
  friend class G4SPSAngDistribution;
public:
  G4SPSPosDistribution (); 
  ~G4SPSPosDistribution ();

  // methods to create source position dist.
  void SetPosDisType(G4String); // Point, Plane, Surface, Volume
  inline G4String GetPosDisType() { return SourcePosType; };
  void SetPosDisShape(G4String);
  inline G4String GetPosDisShape() { return Shape; };
  // SetPosDisShape - Square, Circle, Annulus, Ellipse, Rectangle, Sphere,
  // Ellipsoid, Cylinder, Right (parallelepiped).
  void SetCentreCoords(G4ThreeVector);
  inline G4ThreeVector GetCentreCoords() { return CentreCoords; } ;
  void SetPosRot1(G4ThreeVector); 
  void SetPosRot2(G4ThreeVector); 
  void SetHalfX(G4double);
  inline G4double GetHalfX() { return halfx; } ;
  void SetHalfY(G4double);
  inline G4double GetHalfY()  { return halfy; } ;
  void SetHalfZ(G4double);
  inline G4double GetHalfZ()  { return halfz; } ;
  void SetRadius(G4double);
  inline G4double GetRadius()  { return Radius; };
  void SetRadius0(G4double);
  void SetBeamSigmaInR(G4double);
  void SetBeamSigmaInX(G4double);
  void SetBeamSigmaInY(G4double);
  void SetParAlpha(G4double);
  void SetParTheta(G4double);
  void SetParPhi(G4double);
  void ConfineSourceToVolume(G4String);
  //
  void SetBiasRndm (G4SPSRandomGenerator* a) { posRndm = a ; };
  // Set the verbosity level.
  void SetVerbosity(G4int a) {verbosityLevel = a; } ;
  //
  G4ThreeVector GenerateOne();

private:

  void GenerateRotationMatrices();
  // the following routines generate the source position
  void GeneratePointSource();
  void GeneratePointsInBeam();
  void GeneratePointsInPlane();
  void GeneratePointsOnSurface();
  void GeneratePointsInVolume();

  G4bool IsSourceConfined();

private:

  // Position distribution Variables
  G4String SourcePosType; //Point,Plane,Surface,Volume
  G4String Shape; //Circle,Square,Rectangle etc..
  G4double halfx, halfy, halfz; //half lengths
  G4double Radius; //Radius for circles or spheres
  G4double Radius0; // The inner radius of an annulus
  G4double SR,SX,SY; // Standard deviation in raduial, x, y for beam type source
  G4ThreeVector CentreCoords; // Coords of centre of input shape
  G4ThreeVector Rotx, Roty, Rotz; // Unit vectors defining rotation matrix
  G4double ParAlpha, ParTheta, ParPhi; //Angle for Right Parallellepipeds
  G4bool Confine; //If true confines source distribution to VolName
  G4String VolName;
  G4ThreeVector SideRefVec1,SideRefVec2,SideRefVec3; //Side rotation matrices
  G4ThreeVector particle_position; // the final particle position to be returned
  //  
  G4Navigator *gNavigator;
  //
  G4SPSRandomGenerator* posRndm; // biased random generator
  // Verbosity
  G4int verbosityLevel;

};

#endif