midix 3.2.0

MIDI structures designed for humans
Documentation 
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use super::Bytes;

/// (in microseconds per MIDI quarter-note)
///
/// FF 51 03 tttttt
#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
pub struct Tempo(u32);

impl Default for Tempo {
    fn default() -> Self {
        Self(500000)
    }
}

impl Tempo {
    /// Interprete a byte slice as a tempo
    pub fn new_from_bytes<'a, B: Into<Bytes<'a>>>(v: B) -> Self {
        let mut val = [0; 4];
        for (i, byte) in v.into().iter().enumerate() {
            if i > 3 {
                break;
            }
            val[i] = *byte;
        }

        let val = [0, val[0], val[1], val[2]];

        Self(u32::from_be_bytes(val))
    }

    /// The count of microseconds per midi quarter-note
    pub fn micros_per_quarter_note(&self) -> u32 {
        self.0
    }
}

#[test]
fn known_tempo() {
    let tempo = [0x07, 0xA1, 0x20];

    let tempo = Tempo::new_from_bytes(tempo);

    assert_eq!(tempo.micros_per_quarter_note(), 500000);
}