/* RTcmix - Copyright (C) 2005  The RTcmix Development Team   See ``AUTHORS'' for a list of contributors. See ``LICENSE'' for   the license to this software and for a DISCLAIMER OF ALL WARRANTIES.*/ #include "Offt.h"#ifndef FFTW#include "FFTReal.h"#endif  Offt::Offt(int fftsize, unsigned int flags)	: _len(fftsize){#ifdef FFTW	_plan_r2c = _plan_c2r = NULL;	_buf = (float *) fftwf_malloc(sizeof(float) * _len);	int csize = sizeof(fftwf_complex) * ((_len / 2) + 1);	_cbuf = (fftwf_complex *) fftwf_malloc(csize);	if (flags & kRealToComplex)		_plan_r2c = fftwf_plan_dft_r2c_1d(_len, _buf, _cbuf, FFTW_ESTIMATE);	if (flags & kComplexToReal)		_plan_c2r = fftwf_plan_dft_c2r_1d(_len, _cbuf, _buf, FFTW_ESTIMATE);#else // !FFTW	_buf = new float [_len];	_tmp = new float [_len];	_fftobj = new FFTReal(_len);#endif // !FFTW} Offt::~Offt(){#ifdef FFTW	if (_plan_r2c)		fftwf_destroy_plan(_plan_r2c);	if (_plan_c2r)		fftwf_destroy_plan(_plan_c2r);	fftwf_free(_buf);	fftwf_free(_cbuf);#else // !FFTW	delete [] _buf;	delete [] _tmp;	delete _fftobj;#endif // !FFTW}  #ifdef FFTW void Offt::r2c(){	fftwf_execute(_plan_r2c); 	// _cbuf has complex result in real,imaginary pairs from DC to Nyquist;	// copy into _buf while reordering to...	//    re(0), re(len/2), re(1), im(1), re(2), im(2)...re(len/2-1), im(len/2-1)	// and normalizing by 1 / fftlen.	float scale = 1.0 / _len;	int last = _len / 2;	_buf[0] = _cbuf[0][0] * scale;	_buf[1] = _cbuf[last][0] * scale;	for (int i = 1; i < last; i++) {		_buf[i + i] = _cbuf[i][0] * scale;		_buf[i + i + 1] = _cbuf[i][1] * scale;	}} void Offt::c2r(){	// _buf has complex data; copy into _cbuf while reordering from...	//    re(0), re(len/2), re(1), im(1), re(2), im(2)...re(len/2-1), im(len/2-1)	// to real,imaginary pairs from DC to Nyquist;	int last = _len / 2;	_cbuf[0][0] = _buf[0];	_cbuf[last][0] = _buf[1];	for (int i = 1; i < last; i++) {		_cbuf[i][0] = _buf[i + i];		_cbuf[i][1] = _buf[i + i + 1];	} 	fftwf_execute(_plan_c2r);} #else // !FFTW void Offt::r2c(){	_fftobj->do_fft(_tmp, _buf); 	// _tmp has complex result; copy into _buf while reordering from...	//    re(0), re(1), re(2)...re(len/2), im(1), im(2)...im(len/2-1)	// to...	//    re(0), re(len/2), re(1), im(1), re(2), im(2)...re(len/2-1), im(len/2-1)	// and normalizing by 1 / fftlen. 	float scale = 1.0 / _len;	int j = _len / 2;	_buf[0] = _tmp[0] * scale;	_buf[1] = _tmp[j] * scale;#if 0	for (int i = 1; i < j; i++) {		_buf[i + i] = _tmp[i] * scale;				// real		_buf[i + i + 1] = _tmp[j + i] * scale;		// imag	}#else	int i = j - 1;	float *bp = &_buf[_len - 1];	float *tp = &_tmp[j + i];	do {		*bp-- = *tp-- * scale;         // imag		*bp-- = _tmp[i--] * scale;     // real	} while (i > 0);#endif} void Offt::c2r(){	// _buf has complex data; copy into _tmp while reordering from...	//    re(0), re(len/2), re(1), im(1), re(2), im(2)...re(len/2-1), im(len/2-1)	// to...	//    re(0), re(1), re(2)...re(len/2), im(1), im(2)...im(len/2-1) 	int j = _len / 2;	_tmp[0] = _buf[0];	_tmp[j] = _buf[1];#if 0	for (int i = 1; i < j; i++) {		_tmp[i] = _buf[i + i];				// real		_tmp[j + i] = _buf[i + i + 1];	// imag	}#else	int i = j - 1;	float *bp = &_buf[_len - 1];	float *tp = &_tmp[j + i];	do {		*tp-- = *bp--;         // imag		_tmp[i--] = *bp--;     // real	} while (i > 0);#endif 	_fftobj->do_ifft(_tmp, _buf); 	// _buf now holds real output} #endif // !FFTW  #include <stdio.h> void Offt::printbuf(float *buf, char *msg){	printf("\n%s\n", msg);	for (int i = 0; i < _len; i++)		printf("\t[%d] = %f\n", i, buf[i]);}