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Working FFTs

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This commit is contained in:
Albin Chaboissier
2025-09-24 09:03:13 +02:00
parent d191b912b0
commit bd7ae2b19e
9 changed files with 15071 additions and 5003 deletions
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23
src/fft/rader.rs
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@ -5,7 +5,7 @@ use std::{f32::consts::PI, ops::Deref};
use super::mixed_radix;
use crate::{
complex::Complex32,
fft::{DFT, create_fft, dft::NaiveDFT, is_prime, windows},
fft::{DFT, FFTDirection, create_fft, dft::NaiveDFT, is_prime, windows},
};
pub struct RaderFFT {
@ -14,13 +14,14 @@ pub struct RaderFFT {
permutations: Box<[usize]>,
convolution_op: Box<[Complex32]>,
conv_fft: Box<NaiveDFT>,
inv_fft: Box<dyn DFT>,
conv_fft: Box<dyn DFT>,
size: usize,
}
impl DFT for RaderFFT {
fn create(size: usize) -> Self
fn create(size: usize, direction: FFTDirection) -> Self
where
Self: Sized,
{
@ -28,14 +29,16 @@ impl DFT for RaderFFT {
let g = compute_prime_primitive_root(size);
let permutations: Box<[usize]> = (0..(size - 1)).map(|i| exp_mod(g, i + 1, size)).collect();
let mut conv_fft = Box::new(NaiveDFT::create(size - 1));
let mut conv_fft = create_fft(size - 1, FFTDirection::Forward);
//let mut conv_fft = create_fft(size - 1);
conv_fft
.get_input()
.iter_mut()
.enumerate()
.for_each(|(i, x)| {
*x = Complex32::cexp(-2. * PI * (permutations[i] as f32) / (size as f32))
*x = Complex32::cexp(
-2. * direction.sign() * PI * (permutations[i] as f32) / (size as f32),
)
});
conv_fft.execute(windows::rectanguar);
@ -45,6 +48,7 @@ impl DFT for RaderFFT {
permutations,
convolution_op: conv_fft.get_output().iter().copied().collect(),
inv_fft: create_fft(size - 1, FFTDirection::Inverse),
conv_fft,
size,
@ -61,21 +65,20 @@ impl DFT for RaderFFT {
self.conv_fft.execute(windows::rectanguar);
for i in 0..(self.size - 1) {
self.output_buffer[i] =
self.conv_fft.get_output()[i] * self.convolution_op[i];
self.output_buffer[i] = self.conv_fft.get_output()[i] * self.convolution_op[i];
}
for i in 0..(self.size - 1) {
//self.conv_fft.get_input()[i] = self.output_buffer[i];
self.conv_fft.get_input()[i] = -self.output_buffer[self.size - 1 - i - 1];
self.inv_fft.get_input()[i] = self.output_buffer[i];
}
self.conv_fft.execute(windows::rectanguar);
self.inv_fft.execute(windows::rectanguar);
for i in 0..(self.size - 1) {
let k = self.permutations[i];
self.output_buffer[k] =
(self.conv_fft.get_output()[i] / (self.size - 1) as f32) + self.input_buffer[0];
(self.inv_fft.get_output()[i] / (self.size - 1) as f32) + self.input_buffer[0];
}
self.output_buffer[0] = self.input_buffer.iter().copied().sum();