main.rs

// This example is a Rust port of 'link_hut' from the 'abl_link' extension (written in C).
// Source: https://github.com/Ableton/link/blob/master/extensions/abl_link/examples/link_hut/main.c

#![allow(clippy::new_without_default)]

use crossterm::{
    cursor,
    event::{poll, read, Event, KeyCode},
    queue,
    style::Print,
    terminal,
};
use rusty_link::{AblLink, SessionState};
use std::{
    io::{self, Write},
    time::Duration,
};

pub struct State {
    pub link: AblLink,
    pub session_state: SessionState,
    pub running: bool,
    pub quantum: f64,
}

impl State {
    pub fn new() -> Self {
        Self {
            link: AblLink::new(120.),
            session_state: SessionState::new(),
            running: true,
            quantum: 4.,
        }
    }

    pub fn capture_app_state(&mut self) {
        self.link.capture_app_session_state(&mut self.session_state);
    }

    pub fn commit_app_state(&mut self) {
        self.link.commit_app_session_state(&self.session_state);
    }
}

/// Prints SessionState and AblLink Data to the terminal.
fn print_state(state: &mut State) {
    state.capture_app_state();

    let time = state.link.clock_micros();
    let enabled = match state.link.is_enabled() {
        true => "yes",
        false => "no ",
    }
    .to_string();
    let num_peers = state.link.num_peers();
    let start_stop = match state.link.is_start_stop_sync_enabled() {
        true => "yes",
        false => "no ",
    };
    let playing = match state.session_state.is_playing() {
        true => "[playing]",
        false => "[stopped]",
    };
    let tempo = state.session_state.tempo();
    let beats = state.session_state.beat_at_time(time, state.quantum);
    let phase = state.session_state.phase_at_time(time, state.quantum);
    let mut metro = String::with_capacity(state.quantum as usize);
    for i in 0..state.quantum as usize {
        if i > phase as usize {
            metro.push('O');
        } else {
            metro.push('X');
        }
    }

    let mut stdout = io::stdout();
    queue!(
        stdout,
        cursor::SavePosition,
        terminal::Clear(terminal::ClearType::FromCursorDown),
        Print(format!("{:<7} | ", enabled)),
        Print(format!("{:<9} | ", num_peers)),
        Print(format!("{:<7} | ", state.quantum.trunc())),
        Print(format!("{:<3}   {:<9} | ", start_stop, playing)),
        Print(format!("{:<7.2} | ", tempo)),
        Print(format!("{:<8.2} | ", beats)),
        Print(metro.to_string()),
        cursor::RestorePosition,
    )
    .unwrap();
    stdout.flush().unwrap();
}

/// Poll keyboard input (Blocking function -> Thread "sleeps" here for `duration`)
/// Use a separate input thread for non-blocking input. (See `link_hut` example)
fn poll_input(state: &mut State, duration: Duration) -> io::Result<()> {
    if poll(duration)? {
        if let Event::Key(event) = read()? {
            state.capture_app_state();
            let tempo = state.session_state.tempo();
            let time_stamp = state.link.clock_micros();
            let enabled = state.link.is_enabled();

            match event.code {
                // Quit
                KeyCode::Char('q') => state.running = false,

                // Enable Link Toggle
                KeyCode::Char('a') => state.link.enable(!enabled),

                // Tempo
                KeyCode::Char('w') => {
                    state
                        .session_state
                        .set_tempo((tempo - 1.).max(20.), time_stamp);
                    state.commit_app_state();
                }
                KeyCode::Char('e') => {
                    state
                        .session_state
                        .set_tempo((tempo + 1.).min(999.), time_stamp);
                    state.commit_app_state();
                }

                // Quantum
                KeyCode::Char('r') => state.quantum = (state.quantum - 1.).max(1.),
                KeyCode::Char('t') => state.quantum = (state.quantum + 1.).min(16.),

                // Start Stop Sync Toggle
                KeyCode::Char('s') => state
                    .link
                    .enable_start_stop_sync(!state.link.is_start_stop_sync_enabled()),

                // Play / Stop Toggle
                KeyCode::Char(' ') => {
                    if state.session_state.is_playing() {
                        state.session_state.set_is_playing(false, time_stamp as u64);
                    } else {
                        state.session_state.set_is_playing_and_request_beat_at_time(
                            true,
                            time_stamp as u64,
                            0.,
                            state.quantum,
                        );
                    }
                    state.commit_app_state();
                }
                _ => {}
            }
        }
    }
    Ok(())
}

fn main() {
    println!("\n\n < L I N K  H U T  S I L E N T >\n");

    println!("usage:");
    println!("  enable / disable Link: a");
    println!("  start / stop: space");
    println!("  decrease / increase tempo: w / e");
    println!("  decrease / increase quantum: r / t");
    println!("  enable / disable start stop sync: s");
    println!("  quit: q");

    println!("\nenabled | num peers | quantum | start stop sync | tempo   | beats    | metro");

    let mut state = State::new();

    terminal::enable_raw_mode().unwrap();

    '_main_loop: while state.running {
        poll_input(&mut state, Duration::from_millis(50)).expect("Input Fn Error");
        print_state(&mut state);
    }

    state.link.enable(false);

    terminal::disable_raw_mode().unwrap();
    println!("\n");
}