94 lines
2.8 KiB
Rust
94 lines
2.8 KiB
Rust
// Copyright (c) 2021 Weird Constructor <weirdconstructor@gmail.com>
|
|
// This file is a part of HexoDSP. Released under GPL-3.0-or-later.
|
|
// See README.md and COPYING for details.
|
|
|
|
const VALUE_SAMPLING_FILTER_SIZE: usize = 10;
|
|
|
|
/// Accumulates the values for a single visible feedback value,
|
|
/// like an LED ([crate::Matrix::led_value_for]) or the
|
|
/// output feedbacks [crate::Matrix::out_fb_for] from the [crate::Matrix].
|
|
#[derive(Debug, Clone, Copy)]
|
|
pub struct VisualSamplingFilter {
|
|
/// Holds a state bit, that is used to check if this
|
|
/// filter needs to recalculate or not.
|
|
recalc_state: bool,
|
|
|
|
/// Current write head into the sample buffer.
|
|
write_ptr: usize,
|
|
|
|
/// Holds a set of the most recent samples to calculate
|
|
/// the output.
|
|
sample_buffer: [f32; VALUE_SAMPLING_FILTER_SIZE],
|
|
|
|
/// Holds the last output, will only be recalculated
|
|
/// when necessary.
|
|
last_output: (f32, f32),
|
|
}
|
|
|
|
impl VisualSamplingFilter {
|
|
pub fn new() -> Self {
|
|
Self {
|
|
recalc_state: false,
|
|
write_ptr: 0,
|
|
sample_buffer: [0.0; VALUE_SAMPLING_FILTER_SIZE],
|
|
last_output: (0.0, 0.0),
|
|
}
|
|
}
|
|
|
|
/// Used to check if we need to update this filter.
|
|
#[inline]
|
|
fn needs_recalc(&mut self, recalc_value: bool) -> bool {
|
|
if self.recalc_state != recalc_value {
|
|
self.recalc_state = recalc_value;
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
|
|
/// Retrieves the current output value of the filter.
|
|
/// Negate the input for `recalc_value` one each frame,
|
|
/// to reduce access to the `retrieve_fn` to be done only
|
|
/// once per frame and per [VisualSamplingFilter].
|
|
///
|
|
///```
|
|
/// use hexodsp::nodes::visual_sampling_filter::*;
|
|
///
|
|
/// let mut vsf = VisualSamplingFilter::new();
|
|
///
|
|
/// let inputs = [-0.87, -0.8, 0.2, 0.75, 0.5, 0.0, 0.22];
|
|
/// let mut recalc = true;
|
|
///
|
|
/// let mut last_output = (0.0, 0.0);
|
|
/// for ip in inputs {
|
|
/// last_output = vsf.get(recalc, ip);
|
|
/// recalc = !recalc;
|
|
/// }
|
|
///
|
|
/// assert_eq!(last_output, (0.87, 0.75));
|
|
///```
|
|
pub fn get(&mut self, recalc_value: bool, sample: f32) -> (f32, f32) {
|
|
if self.needs_recalc(recalc_value) {
|
|
let write_ptr = (self.write_ptr + 1) % self.sample_buffer.len();
|
|
self.write_ptr = write_ptr;
|
|
|
|
self.sample_buffer[write_ptr] = sample;
|
|
|
|
let mut neg_max: f32 = 0.0;
|
|
let mut pos_max: f32 = 0.0;
|
|
|
|
for v in self.sample_buffer.iter() {
|
|
if *v >= 0.0 {
|
|
pos_max = pos_max.max((*v).abs());
|
|
} else {
|
|
neg_max = neg_max.max((*v).abs());
|
|
}
|
|
}
|
|
|
|
self.last_output = (neg_max, pos_max);
|
|
}
|
|
|
|
self.last_output
|
|
}
|
|
}
|