FFTW.h

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//# $Id: FFTW.h 21069 2011-05-06 13:59:44Z gervandiepen $

#ifndef SCIMATH_FFTW_H
#define SCIMATH_FFTW_H

#include <casa/Arrays/Array.h>
#include <casa/Arrays/ArrayLogical.h>
#include <casa/Arrays/VectorIter.h>
#include <casa/Arrays/Matrix.h>
#include <casa/OS/Mutex.h>

namespace casa {

//# Forward Declarations.
class FFTWPlan;
class FFTWPlanf;

// <summary> C++ interface to the FFTWw library </summary>
// <reviewed reviewer="NONE" date="" tests="" demos="">
// </reviewed>
// <synopsis>
// This is a wrapper of FFTW3.
// It is only active if FFTW3 was found during the build.
// If not found, all functions won't do anything at all.
// 
// The interface is such that the presence of FFTW3 is only visible
// in the implementation. The header file does not need to know.
// In this way external code using this class does not need to set HAVE_FFTW.
// </synopsis>

class FFTW
{
public:
  FFTW() ;
  
  ~FFTW() ;

  // polymorphic interface to fftw[f]_plan...
  void plan_r2c(const IPosition &size, Float *in, Complex *out) ;
  void plan_r2c(const IPosition &size, Double *in, DComplex *out) ;
  void plan_c2r(const IPosition &size, Complex *in, Float *out) ;
  void plan_c2r(const IPosition &size, DComplex *in, Double *out) ;
  void plan_c2c_forward(const IPosition &size, DComplex *in) ;
  void plan_c2c_forward(const IPosition &size, Complex *in) ;
  void plan_c2c_backward(const IPosition &size, DComplex *in) ;
  void plan_c2c_backward(const IPosition &size, Complex *in) ;
  
  // polymorphic interface to fftw[f]_execute...
  void r2c(const IPosition &size, Float *in, Complex *out) ;
  void r2c(const IPosition &size, Double *in, DComplex *out) ;
  void c2r(const IPosition &size, Complex *in, Float *out);
  void c2r(const IPosition &size, DComplex *in, Double *out);
  void c2c(const IPosition &size, Complex *in, Bool forward);
  void c2c(const IPosition &size, DComplex *in, Bool forward);

private:
  FFTWPlanf* itsPlanR2Cf;
  FFTWPlan*  itsPlanR2C;
  
  FFTWPlanf* itsPlanC2Rf;
  FFTWPlan*  itsPlanC2R;
  
  FFTWPlanf* itsPlanC2CFf;   // forward
  FFTWPlan*  itsPlanC2CF;
  
  FFTWPlanf* itsPlanC2CBf;   // backward
  FFTWPlan*  itsPlanC2CB;
  
  unsigned flags;

  static volatile Bool is_initialized_fftw;  // FFTW needs initialization
                                             // only once per process,
                                             // not once per object
  static Mutex theirMutex;          // Initialization mutex
};    
    
} //# NAMESPACE CASA - END

#endif