use crate::*;

/// A currently playing instance of a sample.
#[derive(Default, Debug, Clone)] pub struct Voice {
    pub sample:   Arc<RwLock<Sample>>,
    pub after:    usize,
    pub position: usize,
    pub velocity: f32,
}

impl Iterator for Voice {
    type Item = [f32;2];
    fn next (&mut self) -> Option<Self::Item> {
        if self.after > 0 {
            self.after -= 1;
            return Some([0.0, 0.0])
        }
        let sample = self.sample.try_read().unwrap();
        if self.position < sample.end {
            let position = self.position;
            self.position += 1;
            return sample.channels[0].get(position).map(|_amplitude|[
                sample.channels[0][position] * self.velocity * sample.gain,
                sample.channels[0][position] * self.velocity * sample.gain,
            ])
        }
        None
    }
}