cpal/examples/beep.rs

extern crate cpal;

fn main() {
    let mut channel = cpal::Voice::new();

    // producing a sinusoid
    let mut data_source =
        std::iter::iterate(0.0f32, |f| f + 0.03)
            .map(|angle| {
                use std::num::Float;
                use std::num::Int;

                let angle = angle.sin();

                let max: u16 = Int::max_value();
                let value = (max as f32 / 2.0) + (angle * (max as f32 / 2.0));
                value as u16
            });

    loop {
        {
            let mut buffer = channel.append_data(1, cpal::SamplesRate(44100), 32768);

            for sample in buffer.iter_mut() {
                let value = data_source.next().unwrap();
                *sample = value;
            }
        }

        channel.play();
    }
}