[help] how to control const_hz or hz?

[lukassup]

Hello,

Thank you for this project.
So far I've had quite a bit of fun and figuring out how things works (which is appreciated a lot)

I am trying to create a simple synth that I want to control the pitch of using an external parameter - let's say keyboard, or GUI, or MIDI, etc...

At the current moment I am a bit stuck how to provide pitch as input control for my oscillator - could you help me guide in the right direction?

fn run<T: SizedSample + FromSample<f32>>(
    device: &Device,
    config: &StreamConfig,
) -> anyhow::Result<()> {
    let one_sec = config.sample_rate as usize;
    let rate = signal::rate(config.sample_rate as f64);

    let mut synth = rate
        .const_hz(440.)
        .sine()
        .take(5 * one_sec)
        .map(|s| s.to_sample::<f32>() * 0.2);

    let (complete_tx, complete_rx) = mpsc::sync_channel::<()>(1);
    let err_fn = |err| eprintln!("an error occured on stream: {}!", err);
    let channels = config.channels as usize;
    let stream = device.build_output_stream(
        config,
        move |data: &mut [T], _| write_data(data, channels, &complete_tx, &mut synth),
        err_fn,
        None,
    )?;
    stream.play()?;
    complete_rx.recv().unwrap();
    stream.pause()?;
    Ok(())
}

Thanks!