refactor(engine): flatten

- add `just stats`
- add basic doctests

engine/engine_structs.rs

@@ -0,0 +1,156 @@
+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,
+}
+
+/// Iterator that emits subsequent ticks within a range.
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Default)] pub struct TicksIterator {
+    pub spp:    f64,
+    pub sample: usize,
+    pub start:  usize,
+    pub end:    usize,
+}
+
+///
+/// ```
+/// let model = MidiSelection::from((1, false));
+///
+/// let _ = model.get_time_len();
+/// let _ = model.get_time_zoom();
+/// let _ = model.get_time_lock();
+/// let _ = model.get_time_start();
+/// let _ = model.get_time_axis();
+/// let _ = model.get_time_end();
+///
+/// let _ = model.get_note_lo();
+/// let _ = model.get_note_axis();
+/// let _ = model.get_note_hi();
+/// ```
+#[derive(Debug, Clone)] pub struct MidiCursor {
+    /// Time coordinate of cursor
+    pub time_pos: Arc<AtomicUsize>,
+    /// Note coordinate of cursor
+    pub note_pos: Arc<AtomicUsize>,
+    /// Length of note that will be inserted, in pulses
+    pub note_len: Arc<AtomicUsize>,
+}
+
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Clone, Default)] pub struct MidiSelection {
+    pub time_len:   Arc<AtomicUsize>,
+    /// Length of visible time axis
+    pub time_axis:  Arc<AtomicUsize>,
+    /// Earliest time displayed
+    pub time_start: Arc<AtomicUsize>,
+    /// Time step
+    pub time_zoom:  Arc<AtomicUsize>,
+    /// Auto rezoom to fit in time axis
+    pub time_lock:  Arc<AtomicBool>,
+    /// Length of visible note axis
+    pub note_axis:  Arc<AtomicUsize>,
+    // Lowest note displayed
+    pub note_lo:    Arc<AtomicUsize>,
+}
+
+/// 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,
+}
+
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Clone, Default)]
+pub enum Moment2 {
+    #[default] None,
+    Zero,
+    Usec(Microsecond),
+    Sample(SampleCount),
+    Pulse(Pulse),
+}
+
+/// MIDI resolution in PPQ (pulses per quarter note)
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Default)] pub struct PulsesPerQuaver (pub(crate) AtomicF64);
+
+/// Timestamp in MIDI pulses
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Default)] pub struct Pulse (pub(crate) AtomicF64);
+
+/// Tempo in beats per minute
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Default)] pub struct BeatsPerMinute (pub(crate) AtomicF64);
+
+/// Quantization setting for launching clips
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Default)] pub struct LaunchSync (pub(crate) AtomicF64);
+
+/// Quantization setting for notes
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Default)] pub struct Quantize (pub(crate) AtomicF64);
+
+/// Timestamp in audio samples
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Default)] pub struct SampleCount (pub(crate) AtomicF64);
+
+/// Audio sample rate in Hz (samples per second)
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Default)] pub struct SampleRate (pub(crate) AtomicF64);
+
+/// Timestamp in microseconds
+///
+/// ```
+///
+/// ```
+#[derive(Debug, Default)] pub struct Microsecond (pub(crate) AtomicF64);