RandomNumberGenerator.cc

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//=============================================================================
//
//  Helper Functions for generating a random number between 0.0 and 1.0 with
//  a garantueed resolution
//
//=============================================================================
 
 
//== INCLUDES =================================================================
 
 
#include <OpenMesh/Core/Utils/RandomNumberGenerator.hh>
 
 
//== NAMESPACES ===============================================================
 
 
namespace OpenMesh {
 
 
//== IMPLEMENTATION ===========================================================
 
RandomNumberGenerator::RandomNumberGenerator(const size_t _resolution) :
  resolution_(_resolution),
  iterations_(1),
  maxNum_(RAND_MAX + 1.0)
{
  double tmp = double(resolution_);
  while (tmp > (double(RAND_MAX) + 1.0) ) {
    iterations_++;
    tmp /= (double(RAND_MAX) + 1.0);
  }
 
  for ( unsigned int i = 0 ; i < iterations_ - 1; ++i ) {
    maxNum_ *= (RAND_MAX + 1.0);
  }
}
 
//-----------------------------------------------------------------------------
 
double RandomNumberGenerator::getRand() const {
  double randNum = 0.0;
  for ( unsigned int i = 0 ; i < iterations_; ++i ) {
    randNum *= (RAND_MAX + 1.0);
    randNum += rand();
  }
 
  return randNum / maxNum_;
}
 
double RandomNumberGenerator::resolution() const {
  return maxNum_;
}
 
//=============================================================================
} // namespace OpenMesh
//=============================================================================