nesemu/crates/nesemu-adapter-headless/src/lib.rs

use nesemu_adapter_api::{
    AudioSink, BUTTONS_COUNT, ButtonState, InputSource, TimeSource, VideoSink,
};

#[derive(Default)]
pub struct NullInput;

impl InputSource for NullInput {
    fn poll_buttons(&mut self) -> ButtonState {
        [false; BUTTONS_COUNT]
    }
}

#[derive(Default)]
pub struct NullVideo;

impl VideoSink for NullVideo {
    fn present_rgba(&mut self, _frame: &[u8], _width: u32, _height: u32) {}
}

#[derive(Default)]
pub struct NullAudio;

impl AudioSink for NullAudio {
    fn push_samples(&mut self, _samples: &[f32]) {}
}

#[derive(Default)]
pub struct NoopTime;

impl TimeSource for NoopTime {
    fn wait_next_frame(&mut self) {}
}

#[cfg(test)]
mod tests {
    use super::{NoopTime, NullAudio, NullInput, NullVideo};
    use nesemu_adapter_api::{AudioSink, BUTTONS_COUNT, InputSource, TimeSource, VideoSink};

    #[test]
    fn null_adapters_are_noop() {
        let mut input = NullInput;
        let mut video = NullVideo;
        let mut audio = NullAudio;
        let mut time = NoopTime;

        assert_eq!(input.poll_buttons(), [false; BUTTONS_COUNT]);
        video.present_rgba(&[], 256, 240);
        audio.push_samples(&[]);
        time.wait_next_frame();
    }
}