/* University College London Dept of P&A Course in C++ 3C59 
| all rights reserved 1999 
|
| class: RanCom
|
| 
| This class provides a method to generates an angle in the range 0-180 degrees
| which has the correct probability distribution for Compton scattering.
|
| The method is:
|     float scatter( )
|
| To use this class you need to copy RanCom.h and RanCom.cpp into your directory.
| Then you need to: 
|     #include RanCom.h into any file where you need to use this class
|     #include RanCom.cpp somewhere - typically at the bottom of your file containing main()
|
|
| NOTE: In this class the angles are in degrees !
|
| Author: P.Clarke 
*/

#ifndef  _rancom_hpp
#define  _rancom_hpp 1

#include <stdlib.h>
#include <cmath>



class RanCom {

  public:

    //Constructor which takes two parameters
    //- the electron mass is in KeV
    //- the incident photon energy in KeV
    RanCom( float emass, float incident ) ;

    //This is the method the user needs. 
    //It returns an angle picked randomly using the Compton scattering 
    //probability distribution.
    float scatter( ) ;

  private:

    // Member variable to store electron mass in KeV
    float electronMass ;

     // Member variable to store the incident photon energy in KeV
    float incidentEnergy ;

    // Method to calculate the Compton probability functin for a givven 
    // scattering angle
    float probability( float phi ) ;

    // Private method to return a uniform random number in the range 0-1
    float uniform( ) ;


};

#endif