utils.h

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/* utils.h
 
   Computer Music Toolkit - a library of LADSPA plugins. Copyright (C)
   2000 Richard W.E. Furse.
 
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public Licence as
   published by the Free Software Foundation; either version 2 of the
   Licence, or (at your option) any later version.
 
   This library is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307, USA. */
 
#ifndef CMT_UTILS_INCLUDED
#define CMT_UTILS_INCLUDED
 
/*****************************************************************************/
 
#include <cmath>
#include <cstdlib>
 
/*****************************************************************************/
 
#include "ladspa_types.h"
 
/*****************************************************************************/

inline LADSPA_Data 
calculate60dBDrag(const LADSPA_Data fTime,
                  const LADSPA_Data fSampleRate) {
  if (fTime <= 0)
    return 0;
  else 
    return pow(1e3, -1 / (fTime * fSampleRate));
}
 
/*****************************************************************************/
 
inline LADSPA_Data
BOUNDED_BELOW(const LADSPA_Data fData,
              const LADSPA_Data fLowerBound) {
  if (fData <= fLowerBound)
    return fLowerBound;
  else
    return fData;
}
 
inline LADSPA_Data BOUNDED_ABOVE(const LADSPA_Data fData,
                                 const LADSPA_Data fUpperBound) {
  if (fData >= fUpperBound)
    return fUpperBound;
  else
    return fData;
}
 
inline LADSPA_Data 
BOUNDED(const LADSPA_Data fData,
        const LADSPA_Data fLowerBound,
        const LADSPA_Data fUpperBound) {
  if (fData <= fLowerBound)
    return fLowerBound;
  else if (fData >= fUpperBound)
    return fUpperBound;
  else
    return fData;
}
 
/*****************************************************************************/
 
/* Take a reading from a normal RV. The algorithm works by repeated
   sampling of the uniform distribution, the lQuality variable giving
   the number of samples. */
inline double 
sampleNormalDistribution(const double dMean,
                         const double dStandardDeviation,
                         const long   lQuality = 12) {
 
  double dValue = 0;
  for (long lIter = 0; lIter < lQuality; lIter++)
    dValue += rand();
 
  double dSampleFromNormal01 = (dValue / RAND_MAX) - (lQuality * 0.5);
 
  return dMean + dStandardDeviation * dSampleFromNormal01;
}
 
/*****************************************************************************/
 
#endif
 
/* EOF */