collect crates/ and deps/

crates/time/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name    = "tek_time"
+edition = "2021"
+version = "0.2.0"
+
+[dependencies]
+tengri = { workspace = true }
+tek_jack = { workspace = true }
+atomic_float = { workspace = true }

crates/time/src/clock.rs

@@ -0,0 +1,234 @@
+use crate::*;
+pub trait HasClock: Send + Sync {
+    fn clock (&self) -> &Clock;
+    fn clock_mut (&mut self) -> &mut Clock;
+}
+#[macro_export] macro_rules! has_clock {
+    (|$self:ident:$Struct:ident$(<$($L:lifetime),*$($T:ident$(:$U:path)?),*>)?|$cb:expr) => {
+        impl $(<$($L),*$($T $(: $U)?),*>)? HasClock for $Struct $(<$($L),*$($T),*>)? {
+            fn clock (&$self) -> &Clock { &$cb }
+            fn clock_mut (&mut $self) -> &mut Clock { &mut $cb }
+        }
+    }
+}
+#[derive(Clone, Debug, PartialEq)]
+pub enum ClockCommand {
+    Play(Option<u32>),
+    Pause(Option<u32>),
+    SeekUsec(f64),
+    SeekSample(f64),
+    SeekPulse(f64),
+    SetBpm(f64),
+    SetQuant(f64),
+    SetSync(f64),
+}
+provide_num!(u32: |self: Clock| {});
+provide!(f64: |self: Clock| {});
+atom_command!(ClockCommand: |state: Clock| {
+    ("play"        [] Some(Self::Play(None)))
+    ("play"        [t: u32] Some(Self::Play(t)))
+    ("pause"       [] Some(Self::Pause(None)))
+    ("pause"       [t: u32] Some(Self::Pause(t)))
+    ("toggle"      [] Some(if state.is_rolling() { Self::Pause(None) } else { Self::Play(None) }))
+    ("toggle"      [t: u32] Some(if state.is_rolling() { Self::Pause(t) } else { Self::Play(t) }))
+    ("seek/usec"   [t: f64] Some(Self::SeekUsec(t.expect("no usec"))))
+    ("seek/pulse"  [t: f64] Some(Self::SeekPulse(t.expect("no pulse"))))
+    ("seek/sample" [t: f64] Some(Self::SeekSample(t.expect("no sample"))))
+    ("set/bpm"     [t: f64] Some(Self::SetBpm(t.expect("no bpm"))))
+    ("set/sync"    [t: f64] Some(Self::SetSync(t.expect("no sync"))))
+    ("set/quant"   [t: f64] Some(Self::SetQuant(t.expect("no quant"))))
+});
+impl<T: HasClock> Command<T> for ClockCommand {
+    fn execute (self, state: &mut T) -> Perhaps<Self> {
+        self.execute(state.clock_mut())
+    }
+}
+impl Command<Clock> for ClockCommand {
+    fn execute (self, state: &mut Clock) -> Perhaps<Self> {
+        use ClockCommand::*;
+        match self {
+            Play(start)        => state.play_from(start)?,
+            Pause(pause)       => state.pause_at(pause)?,
+            SeekUsec(usec)     => state.playhead.update_from_usec(usec),
+            SeekSample(sample) => state.playhead.update_from_sample(sample),
+            SeekPulse(pulse)   => state.playhead.update_from_pulse(pulse),
+            SetBpm(bpm)        => return Ok(Some(SetBpm(state.timebase().bpm.set(bpm)))),
+            SetQuant(quant)    => return Ok(Some(SetQuant(state.quant.set(quant)))),
+            SetSync(sync)      => return Ok(Some(SetSync(state.sync.set(sync)))),
+        };
+        Ok(None)
+    }
+}
+
+#[derive(Clone, Default)]
+pub struct Clock {
+    /// JACK transport handle.
+    pub transport: Arc<Option<Transport>>,
+    /// Global temporal resolution (shared by [Moment] fields)
+    pub timebase:  Arc<Timebase>,
+    /// Current global sample and usec (monotonic from JACK clock)
+    pub global:    Arc<Moment>,
+    /// Global sample and usec at which playback started
+    pub started:   Arc<RwLock<Option<Moment>>>,
+    /// Playback offset (when playing not from start)
+    pub offset:    Arc<Moment>,
+    /// Current playhead position
+    pub playhead:  Arc<Moment>,
+    /// Note quantization factor
+    pub quant:     Arc<Quantize>,
+    /// Launch quantization factor
+    pub sync:      Arc<LaunchSync>,
+    /// Size of buffer in samples
+    pub chunk:     Arc<AtomicUsize>,
+    /// For syncing the clock to an external source
+    pub midi_in:   Arc<RwLock<Option<JackMidiIn>>>,
+    /// For syncing other devices to this clock
+    pub midi_out:  Arc<RwLock<Option<JackMidiOut>>>,
+    /// For emitting a metronome
+    pub click_out: Arc<RwLock<Option<JackAudioOut>>>,
+}
+impl std::fmt::Debug for Clock {
+    fn fmt (&self, f: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
+        f.debug_struct("Clock")
+            .field("timebase", &self.timebase)
+            .field("chunk",    &self.chunk)
+            .field("quant",    &self.quant)
+            .field("sync",     &self.sync)
+            .field("global",   &self.global)
+            .field("playhead", &self.playhead)
+            .field("started",  &self.started)
+            .finish()
+    }
+}
+impl Clock {
+    pub fn new (jack: &Jack, bpm: Option<f64>) -> Usually<Self> {
+        let (chunk, transport) = jack.with_client(|c|(c.buffer_size(), c.transport()));
+        let timebase = Arc::new(Timebase::default());
+        let clock = Self {
+            quant:     Arc::new(24.into()),
+            sync:      Arc::new(384.into()),
+            transport: Arc::new(Some(transport)),
+            chunk:     Arc::new((chunk as usize).into()),
+            global:    Arc::new(Moment::zero(&timebase)),
+            playhead:  Arc::new(Moment::zero(&timebase)),
+            offset:    Arc::new(Moment::zero(&timebase)),
+            started:   RwLock::new(None).into(),
+            timebase,
+            midi_in:   Arc::new(RwLock::new(Some(JackMidiIn::new(jack, "M/clock", &[])?))),
+            midi_out:  Arc::new(RwLock::new(Some(JackMidiOut::new(jack, "clock/M", &[])?))),
+            click_out: Arc::new(RwLock::new(Some(JackAudioOut::new(jack, "click", &[])?))),
+        };
+        if let Some(bpm) = bpm {
+            clock.timebase.bpm.set(bpm);
+        }
+        Ok(clock)
+    }
+    pub fn timebase (&self) -> &Arc<Timebase> {
+        &self.timebase
+    }
+    /// Current sample rate
+    pub fn sr (&self) -> &SampleRate {
+        &self.timebase.sr
+    }
+    /// Current tempo
+    pub fn bpm (&self) -> &BeatsPerMinute {
+        &self.timebase.bpm
+    }
+    /// Current MIDI resolution
+    pub fn ppq (&self) -> &PulsesPerQuaver {
+        &self.timebase.ppq
+    }
+    /// Next pulse that matches launch sync (for phrase switchover)
+    pub fn next_launch_pulse (&self) -> usize {
+        let sync  = self.sync.get() as usize;
+        let pulse = self.playhead.pulse.get() as usize;
+        if pulse % sync == 0 {
+            pulse
+        } else {
+            (pulse / sync + 1) * sync
+        }
+    }
+    /// Start playing, optionally seeking to a given location beforehand
+    pub fn play_from (&self, start: Option<u32>) -> Usually<()> {
+        if let Some(transport) = self.transport.as_ref() {
+            if let Some(start) = start {
+                transport.locate(start)?;
+            }
+            transport.start()?;
+        }
+        Ok(())
+    }
+    /// Pause, optionally seeking to a given location afterwards
+    pub fn pause_at (&self, pause: Option<u32>) -> Usually<()> {
+        if let Some(transport) = self.transport.as_ref() {
+            transport.stop()?;
+            if let Some(pause) = pause {
+                transport.locate(pause)?;
+            }
+        }
+        Ok(())
+    }
+    /// Is currently paused?
+    pub fn is_stopped (&self) -> bool {
+        self.started.read().unwrap().is_none()
+    }
+    /// Is currently playing?
+    pub fn is_rolling (&self) -> bool {
+        self.started.read().unwrap().is_some()
+    }
+    /// Update chunk size
+    pub fn set_chunk (&self, n_frames: usize) {
+        self.chunk.store(n_frames, Relaxed);
+    }
+    pub fn update_from_scope (&self, scope: &ProcessScope) -> Usually<()> {
+        // Store buffer length
+        self.set_chunk(scope.n_frames() as usize);
+
+        // Store reported global frame and usec
+        let CycleTimes { current_frames, current_usecs, .. } = scope.cycle_times()?;
+        self.global.sample.set(current_frames as f64);
+        self.global.usec.set(current_usecs as f64);
+
+        let mut started = self.started.write().unwrap();
+
+        // If transport has just started or just stopped,
+        // update starting point:
+        if let Some(transport) = self.transport.as_ref() {
+            match (transport.query_state()?, started.as_ref()) {
+                (TransportState::Rolling, None) => {
+                    let moment = Moment::zero(&self.timebase);
+                    moment.sample.set(current_frames as f64);
+                    moment.usec.set(current_usecs as f64);
+                    *started = Some(moment);
+                },
+                (TransportState::Stopped, Some(_)) => {
+                    *started = None;
+                },
+                _ => {}
+            };
+        }
+
+        self.playhead.update_from_sample(started.as_ref()
+            .map(|started|current_frames as f64 - started.sample.get())
+            .unwrap_or(0.));
+
+        Ok(())
+    }
+
+    pub fn bbt (&self) -> PositionBBT {
+        let pulse = self.playhead.pulse.get() as i32;
+        let ppq   = self.timebase.ppq.get() as i32;
+        let bpm   = self.timebase.bpm.get();
+        let bar   = (pulse / ppq) / 4;
+        PositionBBT {
+            bar:              1 + bar,
+            beat:             1 + (pulse / ppq) % 4,
+            tick:             (pulse % ppq),
+            bar_start_tick:   (bar * 4 * ppq) as f64,
+            beat_type:        4.,
+            beats_per_bar:    4.,
+            beats_per_minute: bpm,
+            ticks_per_beat:   ppq as f64
+        }
+    }
+}

crates/time/src/lib.rs

@@ -0,0 +1,57 @@
+mod clock;         pub use self::clock::*;
+mod microsecond;   pub use self::microsecond::*;
+mod moment;        pub use self::moment::*;
+mod note_duration; pub use self::note_duration::*;
+mod perf;          pub use self::perf::*;
+mod pulse;         pub use self::pulse::*;
+mod sample_count;  pub use self::sample_count::*;
+mod sample_rate;   pub use self::sample_rate::*;
+mod timebase;      pub use self::timebase::*;
+mod unit;          pub use self::unit::*;
+
+pub(crate) use ::tek_jack::{*, jack::{*, contrib::*}};
+pub(crate) use std::sync::{Arc, RwLock, atomic::{AtomicBool, AtomicUsize, Ordering::*}};
+pub(crate) use std::ops::{Add, Sub, Mul, Div, Rem};
+pub(crate) use ::tengri::{input::*, dsl::*};
+pub use ::atomic_float; pub(crate) use atomic_float::*;
+
+/// Standard result type.
+pub(crate) type Usually<T> = Result<T, Box<dyn std::error::Error>>;
+/// Standard optional result type.
+pub(crate) type Perhaps<T> = Result<Option<T>, Box<dyn std::error::Error>>;
+
+pub trait Gettable<T> {
+    /// Returns current value
+    fn get (&self) -> T;
+}
+
+pub trait Mutable<T>: Gettable<T> {
+    /// Sets new value, returns old
+    fn set (&mut self, value: T) -> T;
+}
+
+pub trait InteriorMutable<T>: Gettable<T> {
+    /// Sets new value, returns old
+    fn set (&self, value: T) -> T;
+}
+
+impl Gettable<bool> for AtomicBool {
+    fn get (&self) -> bool { self.load(Relaxed) }
+}
+
+impl InteriorMutable<bool> for AtomicBool {
+    fn set (&self, value: bool) -> bool { self.swap(value, Relaxed) }
+}
+
+impl Gettable<usize> for AtomicUsize {
+    fn get (&self) -> usize { self.load(Relaxed) }
+}
+
+impl InteriorMutable<usize> for AtomicUsize {
+    fn set (&self, value: usize) -> usize { self.swap(value, Relaxed) }
+}
+
+#[cfg(test)] #[test] fn test_time () -> Usually<()> {
+    // TODO!
+    Ok(())
+}

crates/time/src/microsecond.rs

@@ -0,0 +1,15 @@
+use crate::*;
+
+/// Timestamp in microseconds
+#[derive(Debug, Default)] pub struct Microsecond(AtomicF64);
+
+impl_time_unit!(Microsecond);
+
+impl Microsecond {
+    #[inline] pub fn format_msu (&self) -> Arc<str> {
+        let usecs              = self.get() as usize;
+        let (seconds, msecs)   = (usecs / 1000000, usecs / 1000 % 1000);
+        let (minutes, seconds) = (seconds / 60, seconds % 60);
+        format!("{minutes}:{seconds:02}:{msecs:03}").into()
+    }
+}

crates/time/src/moment.rs

@@ -0,0 +1,70 @@
+use crate::*;
+
+#[derive(Debug, Clone)]
+pub enum Moment2 {
+    None,
+    Zero,
+    Usec(Microsecond),
+    Sample(SampleCount),
+    Pulse(Pulse),
+}
+
+/// A point in time in all time scales (microsecond, sample, MIDI pulse)
+#[derive(Debug, Default, Clone)]
+pub struct Moment {
+    pub timebase: Arc<Timebase>,
+    /// Current time in microseconds
+    pub usec:   Microsecond,
+    /// Current time in audio samples
+    pub sample: SampleCount,
+    /// Current time in MIDI pulses
+    pub pulse:  Pulse,
+}
+
+impl Moment {
+    pub fn zero (timebase: &Arc<Timebase>) -> Self {
+        Self { usec: 0.into(), sample: 0.into(), pulse: 0.into(), timebase: timebase.clone() }
+    }
+    pub fn from_usec (timebase: &Arc<Timebase>, usec: f64) -> Self {
+        Self {
+            usec:     usec.into(),
+            sample:   timebase.sr.usecs_to_sample(usec).into(),
+            pulse:    timebase.usecs_to_pulse(usec).into(),
+            timebase: timebase.clone(),
+        }
+    }
+    pub fn from_sample (timebase: &Arc<Timebase>, sample: f64) -> Self {
+        Self {
+            sample:   sample.into(),
+            usec:     timebase.sr.samples_to_usec(sample).into(),
+            pulse:    timebase.samples_to_pulse(sample).into(),
+            timebase: timebase.clone(),
+        }
+    }
+    pub fn from_pulse (timebase: &Arc<Timebase>, pulse: f64) -> Self {
+        Self {
+            pulse:    pulse.into(),
+            sample:   timebase.pulses_to_sample(pulse).into(),
+            usec:     timebase.pulses_to_usec(pulse).into(),
+            timebase: timebase.clone(),
+        }
+    }
+    #[inline] pub fn update_from_usec (&self, usec: f64) {
+        self.usec.set(usec);
+        self.pulse.set(self.timebase.usecs_to_pulse(usec));
+        self.sample.set(self.timebase.sr.usecs_to_sample(usec));
+    }
+    #[inline] pub fn update_from_sample (&self, sample: f64) {
+        self.usec.set(self.timebase.sr.samples_to_usec(sample));
+        self.pulse.set(self.timebase.samples_to_pulse(sample));
+        self.sample.set(sample);
+    }
+    #[inline] pub fn update_from_pulse (&self, pulse: f64) {
+        self.usec.set(self.timebase.pulses_to_usec(pulse));
+        self.pulse.set(pulse);
+        self.sample.set(self.timebase.pulses_to_sample(pulse));
+    }
+    #[inline] pub fn format_beat (&self) -> Arc<str> {
+        self.timebase.format_beats_1(self.pulse.get()).into()
+    }
+}

crates/time/src/note_duration.rs

@@ -0,0 +1,35 @@
+pub struct NoteDuration;
+
+/// (pulses, name), assuming 96 PPQ
+pub const NOTE_DURATIONS: [(usize, &str);26] = [
+    (1,    "1/384"), (2,    "1/192"),
+    (3,    "1/128"), (4,    "1/96"),
+    (6,    "1/64"),  (8,    "1/48"),
+    (12,   "1/32"),  (16,   "1/24"),
+    (24,   "1/16"),  (32,   "1/12"),
+    (48,   "1/8"),   (64,   "1/6"),
+    (96,   "1/4"),   (128,  "1/3"),
+    (192,  "1/2"),   (256,  "2/3"),
+    (384,  "1/1"),   (512,  "4/3"),
+    (576,  "3/2"),   (768,  "2/1"),
+    (1152, "3/1"),   (1536, "4/1"),
+    (2304, "6/1"),   (3072, "8/1"),
+    (3456, "9/1"),   (6144, "16/1"),
+];
+
+impl NoteDuration {
+    /// Returns the next shorter length
+    pub fn prev (pulses: usize) -> usize {
+        for (length, _) in NOTE_DURATIONS.iter().rev() { if *length < pulses { return *length } }
+        pulses
+    }
+    /// Returns the next longer length
+    pub fn next (pulses: usize) -> usize {
+        for (length, _) in NOTE_DURATIONS.iter() { if *length > pulses { return *length } }
+        pulses
+    }
+    pub fn pulses_to_name (pulses: usize) -> &'static str {
+        for (length, name) in NOTE_DURATIONS.iter() { if *length == pulses { return name } }
+        ""
+    }
+}

crates/time/src/perf.rs

@@ -0,0 +1,22 @@
+use crate::*;
+use tengri::tui::PerfModel;
+
+pub trait JackPerfModel {
+    fn update_from_jack_scope (&self, t0: Option<u64>, scope: &ProcessScope);
+}
+
+impl JackPerfModel for PerfModel {
+    fn update_from_jack_scope (&self, t0: Option<u64>, scope: &ProcessScope) {
+        if let Some(t0) = t0 {
+            let t1 = self.clock.raw();
+            self.used.store(
+                self.clock.delta_as_nanos(t0, t1) as f64,
+                Relaxed,
+            );
+            self.window.store(
+                scope.cycle_times().unwrap().period_usecs as f64,
+                Relaxed,
+            );
+        }
+    }
+}

crates/time/src/pulse.rs

@@ -0,0 +1,71 @@
+use crate::*;
+
+pub const DEFAULT_PPQ: f64 = 96.0;
+
+/// FIXME: remove this and use PPQ from timebase everywhere:
+pub const PPQ: usize = 96;
+
+/// MIDI resolution in PPQ (pulses per quarter note)
+#[derive(Debug, Default)] pub struct PulsesPerQuaver(AtomicF64);
+impl_time_unit!(PulsesPerQuaver);
+
+/// Timestamp in MIDI pulses
+#[derive(Debug, Default)] pub struct Pulse(AtomicF64);
+impl_time_unit!(Pulse);
+
+/// Tempo in beats per minute
+#[derive(Debug, Default)] pub struct BeatsPerMinute(AtomicF64);
+impl_time_unit!(BeatsPerMinute);
+
+/// Quantization setting for launching clips
+#[derive(Debug, Default)] pub struct LaunchSync(AtomicF64);
+impl_time_unit!(LaunchSync);
+impl LaunchSync {
+    pub fn next (&self) -> f64 {
+        NoteDuration::next(self.get() as usize) as f64
+    }
+    pub fn prev (&self) -> f64 {
+        NoteDuration::prev(self.get() as usize) as f64
+    }
+}
+
+/// Quantization setting for notes
+#[derive(Debug, Default)] pub struct Quantize(AtomicF64);
+impl_time_unit!(Quantize);
+impl Quantize {
+    pub fn next (&self) -> f64 {
+        NoteDuration::next(self.get() as usize) as f64
+    }
+    pub fn prev (&self) -> f64 {
+        NoteDuration::prev(self.get() as usize) as f64
+    }
+}
+
+/// Iterator that emits subsequent ticks within a range.
+pub struct TicksIterator {
+    pub spp:    f64,
+    pub sample: usize,
+    pub start:  usize,
+    pub end:    usize,
+}
+impl Iterator for TicksIterator {
+    type Item = (usize, usize);
+    fn next (&mut self) -> Option<Self::Item> {
+        loop {
+            if self.sample > self.end { return None }
+            let spp    = self.spp;
+            let sample = self.sample as f64;
+            let start  = self.start;
+            let end    = self.end;
+            self.sample += 1;
+            //println!("{spp} {sample} {start} {end}");
+            let jitter = sample.rem_euclid(spp); // ramps
+            let next_jitter = (sample + 1.0).rem_euclid(spp);
+            if jitter > next_jitter { // at crossing:
+                let time = (sample as usize) % (end as usize-start as usize);
+                let tick = (sample / spp) as usize;
+                return Some((time, tick))
+            }
+        }
+    }
+}

crates/time/src/sample_count.rs

@@ -0,0 +1,5 @@
+use crate::*;
+
+/// Timestamp in audio samples
+#[derive(Debug, Default)] pub struct SampleCount(AtomicF64);
+impl_time_unit!(SampleCount);

crates/time/src/sample_rate.rs

@@ -0,0 +1,23 @@
+use crate::*;
+
+/// Audio sample rate in Hz (samples per second)
+#[derive(Debug, Default)] pub struct SampleRate(AtomicF64);
+impl_time_unit!(SampleRate);
+impl SampleRate {
+    /// Return the duration of a sample in microseconds (floating)
+    #[inline] pub fn usec_per_sample (&self) -> f64 {
+        1_000_000f64 / self.get()
+    }
+    /// Return the duration of a sample in microseconds (floating)
+    #[inline] pub fn sample_per_usec (&self) -> f64 {
+        self.get() / 1_000_000f64
+    }
+    /// Convert a number of samples to microseconds (floating)
+    #[inline] pub fn samples_to_usec (&self, samples: f64) -> f64 {
+        self.usec_per_sample() * samples
+    }
+    /// Convert a number of microseconds to samples (floating)
+    #[inline] pub fn usecs_to_sample (&self, usecs:   f64) -> f64 {
+        self.sample_per_usec() * usecs
+    }
+}

crates/time/src/timebase.rs

@@ -0,0 +1,118 @@
+use crate::*;
+
+/// Temporal resolutions: sample rate, tempo, MIDI pulses per quaver (beat)
+#[derive(Debug, Clone)]
+pub struct Timebase {
+    /// Audio samples per second
+    pub sr:  SampleRate,
+    /// MIDI beats per minute
+    pub bpm: BeatsPerMinute,
+    /// MIDI ticks per beat
+    pub ppq: PulsesPerQuaver,
+}
+
+impl Timebase {
+    /// Specify sample rate, BPM and PPQ
+    pub fn new (
+        s: impl Into<SampleRate>,
+        b: impl Into<BeatsPerMinute>,
+        p: impl Into<PulsesPerQuaver>
+    ) -> Self {
+        Self { sr: s.into(), bpm: b.into(), ppq: p.into() }
+    }
+    /// Iterate over ticks between start and end.
+    #[inline] pub fn pulses_between_samples (&self, start: usize, end: usize) -> TicksIterator {
+        TicksIterator { spp: self.samples_per_pulse(), sample: start, start, end }
+    }
+    /// Return the duration fo a beat in microseconds
+    #[inline] pub fn usec_per_beat (&self) -> f64 { 60_000_000f64 / self.bpm.get() }
+    /// Return the number of beats in a second
+    #[inline] pub fn beat_per_second (&self) -> f64 { self.bpm.get() / 60f64 }
+    /// Return the number of microseconds corresponding to a note of the given duration
+    #[inline] pub fn note_to_usec (&self, (num, den): (f64, f64)) -> f64 {
+        4.0 * self.usec_per_beat() * num / den
+    }
+    /// Return duration of a pulse in microseconds (BPM-dependent)
+    #[inline] pub fn pulse_per_usec (&self) -> f64 { self.ppq.get() / self.usec_per_beat() }
+    /// Return duration of a pulse in microseconds (BPM-dependent)
+    #[inline] pub fn usec_per_pulse (&self) -> f64 { self.usec_per_beat() / self.ppq.get() }
+    /// Return number of pulses to which a number of microseconds corresponds (BPM-dependent)
+    #[inline] pub fn usecs_to_pulse (&self, usec: f64) -> f64 { usec * self.pulse_per_usec() }
+    /// Convert a number of pulses to a sample number (SR- and BPM-dependent)
+    #[inline] pub fn pulses_to_usec (&self, pulse: f64) -> f64 { pulse / self.usec_per_pulse() }
+    /// Return number of pulses in a second (BPM-dependent)
+    #[inline] pub fn pulses_per_second (&self) -> f64 { self.beat_per_second() * self.ppq.get() }
+    /// Return fraction of a pulse to which a sample corresponds (SR- and BPM-dependent)
+    #[inline] pub fn pulses_per_sample (&self) -> f64 {
+        self.usec_per_pulse() / self.sr.usec_per_sample()
+    }
+    /// Return number of samples in a pulse (SR- and BPM-dependent)
+    #[inline] pub fn samples_per_pulse (&self) -> f64 {
+        self.sr.get() / self.pulses_per_second()
+    }
+    /// Convert a number of pulses to a sample number (SR- and BPM-dependent)
+    #[inline] pub fn pulses_to_sample (&self, p: f64) -> f64 {
+        self.pulses_per_sample() * p
+    }
+    /// Convert a number of samples to a pulse number (SR- and BPM-dependent)
+    #[inline] pub fn samples_to_pulse (&self, s: f64) -> f64 {
+        s / self.pulses_per_sample()
+    }
+    /// Return the number of samples corresponding to a note of the given duration
+    #[inline] pub fn note_to_samples (&self, note: (f64, f64)) -> f64 {
+        self.usec_to_sample(self.note_to_usec(note))
+    }
+    /// Return the number of samples corresponding to the given number of microseconds
+    #[inline] pub fn usec_to_sample (&self, usec: f64) -> f64 {
+        usec * self.sr.get() / 1000f64
+    }
+    /// Return the quantized position of a moment in time given a step
+    #[inline] pub fn quantize (&self, step: (f64, f64), time: f64) -> (f64, f64) {
+        let step = self.note_to_usec(step);
+        (time / step, time % step)
+    }
+    /// Quantize a collection of events
+    #[inline] pub fn quantize_into <E: Iterator<Item=(f64, f64)> + Sized, T> (
+        &self, step: (f64, f64), events: E
+    ) -> Vec<(f64, f64)> {
+        events.map(|(time, event)|(self.quantize(step, time).0, event)).collect()
+    }
+    /// Format a number of pulses into Beat.Bar.Pulse starting from 0
+    #[inline] pub fn format_beats_0 (&self, pulse: f64) -> Arc<str> {
+        let pulse = pulse as usize;
+        let ppq   = self.ppq.get() as usize;
+        let (beats, pulses) = if ppq > 0 { (pulse / ppq, pulse % ppq) } else { (0, 0) };
+        format!("{}.{}.{pulses:02}", beats / 4, beats % 4).into()
+    }
+    /// Format a number of pulses into Beat.Bar starting from 0
+    #[inline] pub fn format_beats_0_short (&self, pulse: f64) -> Arc<str> {
+        let pulse = pulse as usize;
+        let ppq   = self.ppq.get() as usize;
+        let beats = if ppq > 0 { pulse / ppq } else { 0 };
+        format!("{}.{}", beats / 4, beats % 4).into()
+    }
+    /// Format a number of pulses into Beat.Bar.Pulse starting from 1
+    #[inline] pub fn format_beats_1 (&self, pulse: f64) -> Arc<str> {
+        let mut string = String::with_capacity(16);
+        self.format_beats_1_to(&mut string, pulse).expect("failed to format {pulse} into beat");
+        string.into()
+    }
+    /// Format a number of pulses into Beat.Bar.Pulse starting from 1
+    #[inline] pub fn format_beats_1_to (&self, w: &mut impl std::fmt::Write, pulse: f64) -> Result<(), std::fmt::Error> {
+        let pulse = pulse as usize;
+        let ppq   = self.ppq.get() as usize;
+        let (beats, pulses) = if ppq > 0 { (pulse / ppq, pulse % ppq) } else { (0, 0) };
+        write!(w, "{}.{}.{pulses:02}", beats / 4 + 1, beats % 4 + 1)
+    }
+    /// Format a number of pulses into Beat.Bar.Pulse starting from 1
+    #[inline] pub fn format_beats_1_short (&self, pulse: f64) -> Arc<str> {
+        let pulse = pulse as usize;
+        let ppq   = self.ppq.get() as usize;
+        let beats = if ppq > 0 { pulse / ppq } else { 0 };
+        format!("{}.{}", beats / 4 + 1, beats % 4 + 1).into()
+    }
+}
+
+impl Default for Timebase {
+    fn default () -> Self { Self::new(48000f64, 150f64, DEFAULT_PPQ) }
+}

crates/time/src/unit.rs

@@ -0,0 +1,59 @@
+use crate::*;
+
+/// A unit of time, represented as an atomic 64-bit float.
+///
+/// According to https://stackoverflow.com/a/873367, as per IEEE754,
+/// every integer between 1 and 2^53 can be represented exactly.
+/// This should mean that, even at 192kHz sampling rate, over 1 year of audio
+/// can be clocked in microseconds with f64 without losing precision.
+pub trait TimeUnit: InteriorMutable<f64> {}
+
+/// Implement an arithmetic operation for a unit of time
+#[macro_export] macro_rules! impl_op {
+    ($T:ident, $Op:ident, $method:ident, |$a:ident,$b:ident|{$impl:expr}) => {
+        impl $Op<Self> for $T {
+            type Output = Self; #[inline] fn $method (self, other: Self) -> Self::Output {
+                let $a = self.get(); let $b = other.get(); Self($impl.into())
+            }
+        }
+        impl $Op<usize> for $T {
+            type Output = Self; #[inline] fn $method (self, other: usize) -> Self::Output {
+                let $a = self.get(); let $b = other as f64; Self($impl.into())
+            }
+        }
+        impl $Op<f64> for $T {
+            type Output = Self; #[inline] fn $method (self, other: f64) -> Self::Output {
+                let $a = self.get(); let $b = other; Self($impl.into())
+            }
+        }
+    }
+}
+
+/// Define and implement a unit of time
+#[macro_export] macro_rules! impl_time_unit {
+    ($T:ident) => {
+        impl Gettable<f64> for $T {
+            fn get (&self) -> f64 { self.0.load(Relaxed) }
+        }
+        impl InteriorMutable<f64> for $T {
+            fn set (&self, value: f64) -> f64 {
+                let old = self.get();
+                self.0.store(value, Relaxed);
+                old
+            }
+        }
+        impl TimeUnit for $T {}
+        impl_op!($T, Add, add, |a, b|{a + b});
+        impl_op!($T, Sub, sub, |a, b|{a - b});
+        impl_op!($T, Mul, mul, |a, b|{a * b});
+        impl_op!($T, Div, div, |a, b|{a / b});
+        impl_op!($T, Rem, rem, |a, b|{a % b});
+        impl From<f64>   for $T    { fn from (value: f64)   -> Self { Self(value.into()) } }
+        impl From<usize> for $T    { fn from (value: usize) -> Self { Self((value as f64).into()) } }
+        impl From<$T>    for f64   { fn from (value: $T)    -> Self { value.get() } }
+        impl From<$T>    for usize { fn from (value: $T)    -> Self { value.get() as usize } }
+        impl From<&$T>   for f64   { fn from (value: &$T)   -> Self { value.get() } }
+        impl From<&$T>   for usize { fn from (value: &$T)   -> Self { value.get() as usize } }
+        impl Clone for $T { fn clone (&self) -> Self { Self(self.get().into()) } }
+    }
+}