fft_halfcomplex.hpp

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/*
 * $Id: fft_halfcomplex.hpp 283 2012-08-26 15:36:43Z jdl3 $
 * Copyright (C) 2012 John D Lamb
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 * 
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
 
#ifndef CCGSL_FFT_HALFCOMPLEX_HPP
#define CCGSL_FFT_HALFCOMPLEX_HPP
 
#include <gsl/gsl_fft_halfcomplex.h>
#include "complex.hpp"
#include "vector_complex.hpp"
#include "fft_real.hpp"
 
namespace gsl {
  namespace fft {
    namespace halfcomplex {
      namespace radix2 {
    inline int backward( double data[], size_t const stride, size_t const n ){
      return gsl_fft_halfcomplex_radix2_backward( data, stride, n ); }
 
    inline int inverse( double data[], size_t const stride, size_t const n ){
      return gsl_fft_halfcomplex_radix2_inverse( data, stride, n ); }
    
    inline int backward( double data[], size_t const n ){
      return gsl_fft_halfcomplex_radix2_backward( data, 1, n ); }
 
    inline int inverse( double data[], size_t const n ){
      return gsl_fft_halfcomplex_radix2_inverse( data, 1, n ); }
 
    template<typename DATA>
    inline int backward( DATA& data, size_t const stride = 1 ){
      return gsl_fft_halfcomplex_radix2_backward( data.data(), stride, data.size() / stride ); }
 
    template<typename DATA>
    inline int inverse( DATA& data, size_t const stride = 1 ){
      return gsl_fft_halfcomplex_radix2_inverse( data.data(), stride, data.size() / stride ); }
      }
 
      class wavetable {
      public:
    wavetable(){
      ccgsl_pointer = 0;
      count = 0; // initially nullptr will do
    }
    // Refines random access container
    // Refines assignable
    explicit wavetable( size_t const n ){
      ccgsl_pointer = gsl_fft_halfcomplex_wavetable_alloc( n );
      // just plausibly we could allocate wavetable but not count
      try { count = new size_t; } catch( std::bad_alloc& e ){
        // try to tidy up before rethrowing
        gsl_fft_halfcomplex_wavetable_free( ccgsl_pointer );
        throw e;
      }
      *count = 1; // initially there is just one reference to ccgsl_pointer
    }
    explicit wavetable( gsl_fft_halfcomplex_wavetable* v ){
      ccgsl_pointer = v;
      // just plausibly we could fail to allocate count: no further action needed.
      count = new size_t;
      *count = 1; // initially there is just one reference to ccgsl_pointer
    }
    // copy constructor
    wavetable( wavetable const& v ){ ccgsl_pointer = v.ccgsl_pointer;
      count = v.count; if( count != 0 ) ++*count; }
    // assignment operator
    wavetable& operator=( wavetable const& v ){
      // first, possibly delete anything pointed to by this
      if( count == 0 or --*count == 0 ){
        if( ccgsl_pointer != 0 ) gsl_fft_halfcomplex_wavetable_free( ccgsl_pointer );
        delete count;
      } // Then copy
      ccgsl_pointer = v.ccgsl_pointer; count = v.count; if( count != 0 ) ++*count; return *this;
    }
    // destructor
    ~wavetable(){
      if( count == 0 or --*count == 0 ){
        // could have allocated null pointer
        if( ccgsl_pointer != 0 ) gsl_fft_halfcomplex_wavetable_free( ccgsl_pointer );
        delete count;
      }
    }
#ifdef __GXX_EXPERIMENTAL_CXX0X__
    wavetable( wavetable&& v ) : ccgsl_pointer( v.ccgsl_pointer ), count( nullptr ){
      std::swap( count, v.count );
      v.ccgsl_pointer = nullptr;
    }
    wavetable& operator=( wavetable&& v ){
      wavetable( std::move( v ) ).swap( *this );
      return *this;
    }
#endif
    // Refines equality comparable
    // == operator
    bool operator==( wavetable const& v ) const { return ccgsl_pointer == v.ccgsl_pointer; }
    // != operator
    bool operator!=( wavetable const& v ) const { return not operator==( v ); }
    // Refines forward container
    // Refines less than comparable
    // operator<
    bool operator<( wavetable const& v ) const { return ccgsl_pointer < v.ccgsl_pointer; }
    // operator>
    bool operator>( wavetable const& v ) const { return ccgsl_pointer > v.ccgsl_pointer; }
    // operator<=
    bool operator<=( wavetable const& v ) const { return ccgsl_pointer <= v.ccgsl_pointer; }
    // operator>=
    bool operator>=( wavetable const& v ) const { return ccgsl_pointer >= v.ccgsl_pointer; }
    bool empty() const { return ccgsl_pointer == 0; }
    // swap() --- should work even if sizes don't match
    void swap( wavetable& v ){
      std::swap( ccgsl_pointer, v.ccgsl_pointer );
      std::swap( count, v.count );
    }
      private:
    gsl_fft_halfcomplex_wavetable* ccgsl_pointer;
    size_t* count;
      public:
    // shared reference functions
    gsl_fft_halfcomplex_wavetable* get() const { return ccgsl_pointer; }
    bool unique() const { return count != 0 and *count == 1; }
    size_t use_count() const { return count == 0 ? 0 : *count; }
#ifdef __GXX_EXPERIMENTAL_CXX0X__
    explicit
#endif
    operator bool() const { return ccgsl_pointer != 0; }
      };
 
      inline int backward( gsl::complex_packed_array data, size_t const stride, size_t const n,
               wavetable const& wavetable, real::workspace& work ){
    return gsl_fft_halfcomplex_backward( data, stride, n, wavetable.get(), work.get() ); }
 
      inline int inverse( gsl::complex_packed_array data, size_t const stride, size_t const n,
              wavetable const& wavetable, real::workspace& work ){
    return gsl_fft_halfcomplex_inverse( data, stride, n, wavetable.get(), work.get() ); }
 
      inline int unpack( double const real_coefficient[], double complex_coefficient[],
             size_t const stride, size_t const n ){
    return gsl_fft_halfcomplex_unpack( real_coefficient, complex_coefficient, stride, n ); }
      
      template<typename DATA>
      inline int backward( DATA& data, size_t const stride, wavetable const& wavetable,
              real::workspace& work ){
    return gsl_fft_halfcomplex_backward( data.data(), stride, data.size(),
                         wavetable.get(), work.get() ); }
 
      template<typename DATA>
      inline int inverse( DATA& data, size_t const stride, wavetable const& wavetable, 
              real::workspace& work ){
    return gsl_fft_halfcomplex_inverse( data.data(), stride, data.size(),
                        wavetable.get(), work.get() ); }
      
      template<typename R, typename C>
      inline int unpack( R const& real_coefficient, C& complex_coefficient, size_t const stride ){
    size_t n = std::max( real_coefficient.size(), complex_coefficient.size() / 2);
    return gsl_fft_halfcomplex_unpack( real_coefficient.data(), complex_coefficient.data(),
                       stride, n ); }
      // Partial specialisation
      
      template<>
      inline int unpack( vector const& real_coefficient, vector_complex& complex_coefficient,
             size_t const stride ){
    size_t n = std::max( real_coefficient.size(), complex_coefficient.size() );
    return gsl_fft_halfcomplex_unpack( real_coefficient.data(), complex_coefficient.data(),
                       stride, n ); }
      
      // stride-free versions
      
      inline int backward( gsl::complex_packed_array data, size_t const n,
               wavetable const& wavetable, real::workspace& work ){
    return gsl_fft_halfcomplex_backward( data, 1, n, wavetable.get(), work.get() ); }
 
      inline int inverse( gsl::complex_packed_array data, size_t const n,
              wavetable const& wavetable, real::workspace& work ){
    return gsl_fft_halfcomplex_inverse( data, 1, n, wavetable.get(), work.get() ); }
 
      inline int unpack( double const real_coefficient[], double complex_coefficient[], size_t const n ){
    return gsl_fft_halfcomplex_unpack( real_coefficient, complex_coefficient, 1, n ); }
      
      template<typename DATA>
      inline int backward( DATA& data, wavetable const& wavetable,
              real::workspace& work ){
    return gsl_fft_halfcomplex_backward( data.data(), 1, data.size(),
                         wavetable.get(), work.get() ); }
 
      template<typename DATA>
      inline int inverse( DATA& data, wavetable const& wavetable, 
              real::workspace& work ){
    return gsl_fft_halfcomplex_inverse( data.data(), 1, data.size(),
                        wavetable.get(), work.get() ); }
      
      template<typename R, typename C>
      inline int unpack( R const& real_coefficient, C& complex_coefficient ){
    size_t n = std::max( real_coefficient.size(), complex_coefficient.size() / 2);
    return gsl_fft_halfcomplex_unpack( real_coefficient.data(), complex_coefficient.data(), 1, n ); }
      
      template<>
      inline int unpack( vector const& real_coefficient, vector_complex& complex_coefficient ){
    size_t n = std::max( real_coefficient.size(), complex_coefficient.size() );
    return gsl_fft_halfcomplex_unpack( real_coefficient.data(), complex_coefficient.data(), 1, n ); }
 
      
    }
  }
}
 
#endif