cpal/examples/beep.rs

56 lines
1.8 KiB
Rust

extern crate cpal;
fn main() {
let endpoint = cpal::default_endpoint().expect("Failed to get default endpoint");
let format = endpoint
.supported_formats()
.unwrap()
.next()
.expect("Failed to get endpoint format")
.with_max_sample_rate();
let event_loop = cpal::EventLoop::new();
let voice_id = event_loop.build_voice(&endpoint, &format).unwrap();
event_loop.play(voice_id);
let sample_rate = format.sample_rate.0 as f32;
let mut sample_clock = 0f32;
// Produce a sinusoid of maximum amplitude.
let mut next_value = || {
sample_clock = (sample_clock + 1.0) % sample_rate;
(sample_clock * 440.0 * 2.0 * 3.141592 / sample_rate).sin()
};
event_loop.run(move |_, buffer| {
match buffer {
cpal::UnknownTypeBuffer::U16(mut buffer) => {
for sample in buffer.chunks_mut(format.channels as usize) {
let value = ((next_value() * 0.5 + 0.5) * std::u16::MAX as f32) as u16;
for out in sample.iter_mut() {
*out = value;
}
}
},
cpal::UnknownTypeBuffer::I16(mut buffer) => {
for sample in buffer.chunks_mut(format.channels as usize) {
let value = (next_value() * std::i16::MAX as f32) as i16;
for out in sample.iter_mut() {
*out = value;
}
}
},
cpal::UnknownTypeBuffer::F32(mut buffer) => {
for sample in buffer.chunks_mut(format.channels as usize) {
let value = next_value();
for out in sample.iter_mut() {
*out = value;
}
}
},
};
});
}