/*
* Copyright (c) 2015-2024 Sergey Bakhurin
* Digital Signal Processing Library [http://dsplib.org]
*
* This file is part of libdspl-2.0.
* is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* DSPL 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 Lesser General Public License
* along with Foobar. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <float.h>
#include "dspl.h"
#include "dft.h"
#ifdef DOXYGEN_ENGLISH
#endif
#ifdef DOXYGEN_RUSSIAN
int fft_krn(complex_t* t0, complex_t* t1, fft_t* p, int n, int addr)
{
int n1, n2, k, m, i;
complex_t *pw = p->w+addr;
complex_t tmp;
n1 = 1;
if(n % 4096 == 0) { n1 = 4096; goto label_size; }
if(n % 2048 == 0) { n1 = 2048; goto label_size; }
if(n % 1024 == 0) { n1 = 1024; goto label_size; }
if(n % 512 == 0) { n1 = 512; goto label_size; }
if(n % 256 == 0) { n1 = 256; goto label_size; }
if(n % 128 == 0) { n1 = 128; goto label_size; }
if(n % 64 == 0) { n1 = 64; goto label_size; }
if(n % 32 == 0) { n1 = 32; goto label_size; }
if(n % 16 == 0) { n1 = 16; goto label_size; }
if(n % 7 == 0) { n1 = 7; goto label_size; }
if(n % 8 == 0) { n1 = 8; goto label_size; }
if(n % 5 == 0) { n1 = 5; goto label_size; }
if(n % 4 == 0) { n1 = 4; goto label_size; }
if(n % 3 == 0) { n1 = 3; goto label_size; }
if(n % 2 == 0) { n1 = 2; goto label_size; }
label_size:
if(n1 == 1)
for(k = 0; k < n; k++)
RE(t1[k]) = IM(t1[k]) = 0.0;
for(m = 0; m < n; m++)
i = (k*m) % n;
RE(tmp) = CMRE(t0[m], pw[i]);
IM(tmp) = CMIM(t0[m], pw[i]);
RE(t1[k]) += RE(tmp);
IM(t1[k]) += IM(tmp);
}
else
n2 = n / n1;
if(n2>1)
memcpy(t1, t0, n*sizeof(complex_t));
matrix_transpose_cmplx(t1, n2, n1, t0);
if(n1 == 4096)
for(k = 0; k < n2; k++)
dft4096(t0+4096*k, t1+4096*k, p->w4096, p->w256);
if(n1 == 2048)
dft2048(t0+2048*k, t1+2048*k, p->w2048, p->w32, p->w64);
if(n1 == 1024)
dft1024(t0+1024*k, t1+1024*k, p->w1024, p->w32);
if(n1 == 512)
dft512(t0+512*k, t1+512*k, p->w512, p->w32);
if(n1 == 256)
dft256(t0+256*k, t1+256*k, p->w256);
if(n1 == 128)
dft128(t0+128*k, t1+128*k, p->w128);
if(n1 == 64)
dft64(t0+64*k, t1+64*k, p->w64);
if(n1 == 32)
dft32(t0+32*k, t1+32*k, p->w32);
if(n1 == 16)
dft16(t0+16*k, t1+16*k);
if(n1 == 7)
dft7(t0+7*k, t1+7*k);
if(n1 == 8)
dft8(t0+8*k, t1+8*k);
if(n1 == 5)
dft5(t0+5*k, t1+5*k);
if(n1 == 4)
dft4(t0+4*k, t1+4*k);
if(n1 == 3)
dft3(t0+3*k, t1+3*k);
if(n1 == 2)
dft2(t0+2*k, t1+2*k);
if(n2 > 1)
for(k =0; k < n; k++)
RE(t0[k]) = CMRE(t1[k], pw[k]);
IM(t0[k]) = CMIM(t1[k], pw[k]);
matrix_transpose_cmplx(t0, n1, n2, t1);
for(k = 0; k < n1; k++)
fft_krn(t1+k*n2, t0+k*n2, p, n2, addr+n);
matrix_transpose_cmplx(t0, n2, n1, t1);
return RES_OK;