proxim.h

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/*
  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
*/
 
#ifndef CALOGEOHELPER_PROXIM
#define CALOGEOHELPER_PROXIM
 
// inline function for handling two phi angles, to avoid 2PI wrap around. 
//
 
#include <math.h> 
#include <numbers>
#include "CxxUtils/AthUnlikelyMacros.h"
 
 
 
inline double proxim(double b,double a)
{
  using std::numbers::pi;
  const double aplus = a + pi;
  const double aminus = a - pi;
  if (ATH_UNLIKELY(b > aplus)) {
    do {
      b -= 2*pi;
    } while(b > aplus);
  }
  else if (ATH_UNLIKELY(b < aminus)) {
    do {
      b += 2*pi;
    } while(b < aminus);
  }
  return b;
}
 
 
#endif