48 lines
1.1 KiB
Rust
48 lines
1.1 KiB
Rust
pub struct FIRFilter<'a> {
|
|
coeffs: &'a [f32],
|
|
state: Vec<f32>,
|
|
pos: usize,
|
|
iterator: Box<dyn Iterator<Item = f32> + 'a>,
|
|
}
|
|
|
|
impl<'a> FIRFilter<'a> {
|
|
pub fn from<I>(iterator: I, coeffs: &'a [f32]) -> FIRFilter<'a>
|
|
where
|
|
I: Iterator<Item = f32> + 'a,
|
|
{
|
|
let mut state = Vec::new();
|
|
for _ in 0..coeffs.len() {
|
|
state.push(0.0);
|
|
}
|
|
|
|
FIRFilter {
|
|
coeffs,
|
|
state,
|
|
pos: 0,
|
|
iterator: Box::new(iterator),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a> Iterator for FIRFilter<'a> {
|
|
type Item = f32;
|
|
|
|
fn next(&mut self) -> Option<Self::Item> {
|
|
let cur = match self.iterator.next() {
|
|
Some(x) => x,
|
|
None => return None,
|
|
};
|
|
|
|
self.pos = (self.pos + 1) % self.coeffs.len();
|
|
self.state[self.pos] = cur;
|
|
|
|
let mut result = 0.0;
|
|
for i in 0..self.coeffs.len() {
|
|
let pos = (self.pos + self.coeffs.len() - i) % self.coeffs.len();
|
|
result += self.state[pos] * self.coeffs[i];
|
|
}
|
|
|
|
Some(result)
|
|
}
|
|
}
|