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use super::Float;
use log::{info, debug, trace, warn};
use rustfft::FFTplanner;
use rustfft::num_complex::Complex;
use rustfft::num_traits::Zero;
use std::cmp;
use std::sync::Arc;
pub struct Wavetable {
pub num_tables: usize,
pub num_octaves: usize,
pub num_values: usize,
pub num_samples: usize,
pub table: Vec<Vec<Float>>,
}
pub type WavetableRef = Arc<Wavetable>;
impl Wavetable {
pub fn new(num_tables: usize, num_octaves: usize, num_samples: usize) -> Wavetable {
let num_values = num_samples + 1;
let table = vec!(vec!(0.0; num_values * num_octaves); num_tables);
debug!("New Wavetable: {} tables for {} octaves, {} samples",
num_tables, num_octaves, num_samples);
Wavetable {
num_tables,
num_octaves,
num_values,
num_samples,
table
}
}
pub fn new_from_vector(num_tables: usize, num_octaves: usize, num_samples: usize, table: Vec<Vec<Float>>) -> WavetableRef {
let num_values = num_samples + 1;
debug!("New Wavetable: {} tables for {} octaves, {} samples",
num_tables, num_octaves, num_samples);
Arc::new(Wavetable {
num_tables,
num_octaves,
num_values,
num_samples,
table
})
}
pub fn get_wave(&self, wave_id: usize) -> &Vec<Float> {
&self.table[wave_id]
}
pub fn get_wave_mut(&mut self, wave_id: usize) -> &mut Vec<Float> {
&mut self.table[wave_id]
}
pub fn calc_num_harmonics(base_freq: Float, sample_freq: Float) -> usize {
let nyquist_freq = sample_freq / 2.0;
if base_freq > nyquist_freq {
return 0;
}
let num_harmonics = (nyquist_freq / base_freq) as usize - 1;
debug!("Base frequency {}: {} harmonics, highest at {} Hz with sample frequency {}",
base_freq, num_harmonics, base_freq * (num_harmonics + 1) as Float, sample_freq);
num_harmonics
}
pub fn convert_to_harmonics(&self, num_harmonics: usize) -> Vec<Vec<Float>> {
let mut harmonics = vec![vec![0.0; num_harmonics]; self.table.len()];
let mut input: Vec<Complex<Float>> = vec![Complex::zero(); 2048];
let mut output: Vec<Complex<Float>> = vec![Complex::zero(); 2048];
let mut planner = FFTplanner::new(false);
let fft = planner.plan_fft(2048);
let mut value: Float;
for i in 0..self.table.len() {
let table = &self.table[i];
for j in 0..2048 {
input[j].re = table[j];
}
fft.process(&mut input, &mut output);
let mut max: Float = 0.0;
for j in 0..output.len() {
max = max.max(output[j].im.abs());
}
for j in 0..num_harmonics {
value = output[j].im;
harmonics[i][j] = if value < 0.001 && value > -0.001 {
0.0
} else {
(value / max) * -1.0
};
}
}
harmonics
}
fn add_wave(table: &mut [Float], freq: Float, amplitude: Float, wave_func: fn(Float) -> Float) {
let extra_sample = table.len() & 0x01;
let num_samples = table.len() - extra_sample;
let num_samples_f = num_samples as Float;
let mult = freq * 2.0 * std::f64::consts::PI;
let mut position: Float;
for i in 0..num_samples {
position = mult * (i as Float / num_samples_f);
table[i] = table[i] + wave_func(position) * amplitude;
}
if extra_sample > 0 {
table[table.len() - 1] = table[0];
}
}
pub fn add_sine_wave(table: &mut [Float], freq: Float, amplitude: Float) {
Wavetable::add_wave(table, freq, amplitude, f64::sin);
}
pub fn add_cosine_wave(table: &mut [Float], freq: Float, amplitude: Float) {
Wavetable::add_wave(table, freq, amplitude, f64::cos);
}
pub fn insert_tables(&mut self,
table_id: usize,
start_freq: Float,
sample_freq: Float,
insert_wave: fn(&mut [Float], Float, Float)) {
info!("Creating table {}", table_id);
let num_octaves = self.num_octaves;
let num_values = self.num_values;
let table = self.get_wave_mut(table_id);
let mut current_freq = start_freq;
for i in 0..num_octaves {
let from = i * num_values;
let to = (i + 1) * num_values;
insert_wave(&mut table[from..to], current_freq, sample_freq);
current_freq *= 2.0;
}
}
pub fn get_start_frequency(base_freq: Float) -> Float {
let two: Float = 2.0;
(base_freq / 32.0) * (two.powf((-9.0) / 12.0))
}
pub fn insert_harmonics(&mut self, harmonics: &[Vec<Float>], sample_freq: Float) -> Result<(), ()> {
if harmonics.len() != self.table.len() {
info!("Wrong number of tables");
return Err(());
}
let mut amp: Float;
let num_values = self.num_values;
for i in 0..harmonics.len() {
let table = &mut self.table[i];
let mut start_freq = Wavetable::get_start_frequency(440.0);
for j in 0..self.num_octaves {
start_freq *= 2.0;
let num_harmonics = Wavetable::calc_num_harmonics(start_freq, sample_freq);
let num_harmonics = cmp::min(num_harmonics, harmonics[i].len());
let from = j * num_values;
let to = (j + 1) * num_values;
for freq in 0..num_harmonics {
amp = harmonics[i][freq];
Wavetable::add_sine_wave(&mut table[from..to], freq as Float, amp);
}
Wavetable::normalize(&mut table[from..to]);
}
}
Ok(())
}
pub fn combine_tables(&mut self,
table_id: usize,
table_a: &[Float],
table_b: &[Float],
offset_b: Float) {
let num_octaves = self.num_octaves;
let num_values = self.num_values;
let num_samples = self.num_samples;
let table = self.get_wave_mut(table_id);
let offset_b = (num_samples as Float * offset_b) as usize;
info!("Combining source tables into table {}, offset {}", table_id, offset_b);
let mut index_b: usize;
for i in 0..num_octaves {
let from = i * num_values;
let to = (i + 1) * num_values;
for j in from..to {
index_b = j + offset_b;
if index_b >= to {
index_b -= num_samples;
}
table[j] = table_a[j] - table_b[index_b];
}
Wavetable::expand(&mut table[from..to]);
}
}
pub fn normalize(table: &mut [Float]) {
let mut max = 0.0;
let mut current: Float;
for i in 0..table.len() {
current = table[i].abs();
if current > max {
max = current;
}
}
for i in 0..table.len() {
table[i] = table[i] / max;
}
}
pub fn shift(table: &mut [Float], num_values: usize, offset: usize) {
let mut temp = vec!(0.0; num_values);
let mut offset = offset;
for i in 0..num_values {
temp[offset] = table[i];
offset += 1;
if offset == num_values {
offset = 0;
}
}
for i in 0..num_values {
table[i] = temp[i];
}
table[num_values] = table[0];
}
fn get_extremes(table: &[Float]) -> (Float, Float) {
let mut max = -1.0;
let mut min = 1.0;
let mut current: Float;
for i in 0..table.len() {
current = table[i];
if current > max {
max = current;
} else if current < min {
min = current;
}
}
(min, max)
}
pub fn expand(table: &mut [Float]) {
let (min, max) = Wavetable::get_extremes(table);
let scale = 2.0 / (max - min);
let offset = (max + min) / 2.0;
let mut new_val: Float;
for i in 0..table.len() {
new_val = (table[i] - offset) * scale;
table[i] = new_val;
}
}
pub fn show(&self) {
for t in &self.table {
for (i, s) in t.iter().enumerate() {
info!("{}: {}", i, s);
}
}
}
}