void fft2d(double **xtre, double **xtim, int width, int height)
{
double **xint_re = Matrix::allocateMatrixData(height, width);
if (!xint_re)
return;
double **xint_im = Matrix::allocateMatrixData(height, width);
if (!xint_im){
Matrix::freeMatrixData(xint_re, height);
return;
}
#ifdef Q_CC_MSVC
QVarLengthArray<double> x_int_l(width), x_int2_l(width), x_int_c(height), x_int2_c(height);
#else
double x_int_l[width], x_int2_l[width], x_int_c[height], x_int2_c[height];
#endif
for(int k=0; k<height; k++){
for(int j=0; j<width; j++){
//x_int_l[j] = x[k][j];
//x_int2_l[j] = 0.0;
x_int_l[j] = xtre[k][j];
x_int2_l[j] = xtim[k][j];
}
#ifdef Q_CC_MSVC
fft(x_int_l.data(), x_int2_l.data(), width);
#else
fft(x_int_l, x_int2_l, width);
#endif
for(int j=0; j<width; j++){
xint_re[k][j]=x_int_l[j];
xint_im[k][j]=x_int2_l[j];
}
}
for(int k=0; k<width; k++){
for(int i=0; i<height; i++){
x_int_c[i]=xint_re[i][k];
x_int2_c[i]=xint_im[i][k];
}
#ifdef Q_CC_MSVC
fft(x_int_c.data(),x_int2_c.data(), height) ;
#else
fft(x_int_c,x_int2_c, height) ;
#endif
for(int i=0; i<height; i++){
xtre[(i+(height>>1))%height][(k+(width>>1))%width]=x_int_c[i];
xtim[(i+(height>>1))%height][(k+(width>>1))%width]=x_int2_c[i];
}
}
Matrix::freeMatrixData(xint_re, height);
Matrix::freeMatrixData(xint_im, height);
}
void fft2d_inv(double **xtre, double **xtim, double **xrec_re, double **xrec_im,
int width, int height) {
double **xint_re = Matrix::allocateMatrixData(height, width);
if (!xint_re)
return;
double **xint_im = Matrix::allocateMatrixData(height, width);
if (!xint_im) {
Matrix::freeMatrixData(xint_re, height);
return;
}
QVarLengthArray<double> x_int_l(width), x_int2_l(width), x_int_c(height),
x_int2_c(height); // double x_int_l[width], x_int2_l[width],
// x_int_c[height], x_int2_c[height];
for (int k = 0; k < height; k++) {
for (int j = 0; j < width; j++) {
int idx_h = (k + (height >> 1)) % height;
int idx_w = (j + (width >> 1)) % width;
x_int_l[j] = xtre[idx_h][idx_w];
x_int2_l[j] = xtim[idx_h][idx_w];
}
fft_inv(x_int_l.data(), x_int2_l.data(),
width); // fft_inv(x_int_l, x_int2_l, width) ;
for (int j = 0; j < width; j++) {
xint_re[k][j] = x_int_l[j];
xint_im[k][j] = x_int2_l[j];
}
}
for (int k = 0; k < width; k++) {
for (int i = 0; i < height; i++) {
x_int_c[i] = xint_re[i][k];
x_int2_c[i] = xint_im[i][k];
}
fft_inv(x_int_c.data(), x_int2_c.data(),
height); // fft_inv(x_int_c,x_int2_c, height) ;
for (int i = 0; i < height; i++) {
xrec_re[i][k] = x_int_c[i];
xrec_im[i][k] = x_int2_c[i];
}
}
Matrix::freeMatrixData(xint_re, height);
Matrix::freeMatrixData(xint_im, height);
}