Created
February 27, 2017 12:19
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type Freq = f32; | |
#[derive(Clone, Debug)] | |
pub struct Note(u8, u8, Freq); | |
impl Note { | |
pub fn number(&self) -> u8 { | |
self.0 | |
} | |
pub fn octave(&self) -> u8 { | |
self.1 | |
} | |
#[inline] | |
pub fn freq(&self) -> f32 { | |
self.2 | |
} | |
} | |
const NOTES: &'static [Note] = &[ | |
Note(0, 0, 32.70), Note(1, 0, 36.71), Note(2, 0, 41.20), Note(3, 0, 43.65), Note(4, 0, 49.00), Note(5, 0, 55.00), Note(6, 0, 61.74), | |
Note(0, 1, 65.41), Note(1, 1, 73.42), Note(2, 1, 82.41), Note(3, 1, 87.31), Note(4, 1, 98.00), Note(5, 1, 110.00), Note(6, 1, 123.47), | |
Note(0, 2, 130.81), Note(1, 2, 146.83), Note(2, 2, 164.81), Note(3, 2, 174.61), Note(4, 2, 196.00), Note(5, 2, 220.00), Note(6, 2, 246.94), | |
Note(0, 3, 261.63), Note(1, 3, 293.66), Note(2, 3, 329.63), Note(3, 3, 349.23), Note(4, 3, 392.00), Note(5, 3, 440.00), Note(6, 3, 493.88), | |
Note(0, 4, 523.25), Note(1, 4, 587.33), Note(2, 4, 659.26), Note(3, 4, 698.46), Note(4, 4, 783.99), Note(5, 4, 880.00), Note(6, 4, 987.77), | |
Note(0, 5, 1046.50), Note(1, 5, 1174.66), Note(2, 5, 1318.51), Note(3, 5, 1396.91), Note(4, 5, 1567.98), Note(5, 5, 1760.00), Note(6, 5, 1975.53), | |
Note(0, 6, 2093.00), Note(1, 6, 2349.32), Note(2, 6, 2637.02), Note(3, 6, 2793.83), Note(4, 6, 3135.96), Note(5, 6, 3520.00), Note(6, 6, 3951.07), | |
Note(0, 7, 4186.01), Note(1, 7, 4698.64), Note(2, 7, 5274.04), Note(3, 7, 5587.65), Note(4, 7, 6271.93), Note(5, 7, 7040.00), Note(6, 7, 7902.13) | |
]; | |
#[derive(Default, Clone)] | |
struct Tuner { | |
current_note: Option<Note>, | |
} | |
impl Tuner { | |
pub fn new() -> Self { | |
Self::default() | |
} | |
pub fn set_note(&mut self, note: Option<&Note>) { | |
self.current_note = note.map(Note::clone); | |
} | |
pub fn get_difference(&self, freq: Freq) -> (&Note, Freq) { | |
let note = match self.current_note { | |
Some(ref note) => note, | |
None => self.get_closest(freq) | |
}; | |
(note, note.freq() - freq) | |
} | |
fn get_closest(&self, freq: Freq) -> &'static Note { | |
let mut closest: &Note = &NOTES[0]; | |
let mut closest_diff = (closest.freq() - freq).abs(); | |
for note in NOTES.iter() { | |
let diff = (note.freq() - freq).abs(); | |
if diff < closest_diff { | |
closest_diff = diff; | |
closest = note; | |
} | |
} | |
closest | |
} | |
} | |
fn main() { | |
let mut tuner = Tuner::new(); | |
tuner.set_note(Some(&Note(3, 3, 349.23))); | |
let (note, diff) = tuner.get_difference(440.0); | |
println!("Note = {:?} ({})", note, diff); | |
} |
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