L
ling-daw
↓ 0 downloadsLing DAW engine: synth, physical-modeling drums, effects, mixer, sequencer, project I/O
lingfu install ling-dawCode / Files (91)
src/engine.rs
//! Realtime engine: transport, event scheduling, audio-clip playback, routing,
//! clip launcher (session), automation and the mixer.
use crate::dsp::Instrument;
use crate::model::*;
use std::sync::{Arc, Mutex};
const SUB: usize = 64; // frames per scheduling slice
pub type SharedEngine = Arc<Mutex<Engine>>;
/// Tiny helper so the per-track `Vec<Option<_>>` fields can be edited uniformly.
trait VecOps {
fn remove_at(&mut self, i: usize);
fn move_item(&mut self, i: usize, j: usize);
}
impl<T> VecOps for Vec<T> {
fn remove_at(&mut self, i: usize) {
if i < self.len() {
self.remove(i);
}
}
fn move_item(&mut self, i: usize, j: usize) {
if i < self.len() && j < self.len() && i != j {
let v = self.remove(i);
self.insert(j, v);
}
}
}
#[derive(Clone, Copy)]
struct Playing {
clip: usize,
scene: i32,
start: f64, // session beats
}
#[derive(Clone, Copy, PartialEq)]
enum QCmd {
Start(usize, i32),
Stop,
}
#[derive(Clone, Copy)]
struct Queued {
cmd: QCmd,
at: f64,
}
pub struct Engine {
pub project: Project,
pub sr: f32,
pub playing: bool,
pub position: f64, // beats (arrangement)
tmp: Vec<f32>,
mix: Vec<f32>,
outs: Vec<Vec<f32>>,
/// Per-track pre-fader peak of the last slice (sidechain key tap).
key_pk: Vec<f32>,
order: Vec<usize>,
/// `order` grouped into dependency levels (tracks within a level are independent)
levels: Vec<Vec<usize>>,
route_sig: u64,
audible: Vec<bool>,
sample_clock: u64,
/// Output latency (render-ahead + device buffer) in seconds: recorded notes/audio are shifted back by it.
pub rec_latency_s: f64,
/// Parameters being moved by hand while recording automation: (track, param, last beat, clock of last move).
touched: Vec<(Option<usize>, String, f64, u64)>,
/// Track armed for MIDI recording (live notes while playing are captured).
pub rec_arm: Option<usize>,
rec_clip: Option<(usize, usize)>,
rec_held: Vec<(u8, f64, f32)>,
/// When true, moving a parameter while playing writes automation points.
pub auto_rec: bool,
/// Bumped whenever the engine itself edits the project (recording, launcher capture).
pub rec_rev: u64,
/// Session (launcher) clock in beats.
pub spos: f64,
sess_play: Vec<Option<Playing>>,
sess_queue: Vec<Option<Queued>>,
/// Record launched clips into the arrangement.
pub perf_rec: bool,
/// Per track: (launcher clip index, arrangement beat where it started) while recording.
perf_open: Vec<Option<(usize, f64)>>,
/// Offline rendering: arrangement only, launcher ignored.
offline: bool,
/// master limiter gain state and the deepest reduction since last read (linear)
lim_gain: f32,
pub lim_min: f32,
/// audio-device test tone: samples left (L then R) and phase
tone_left: u32,
tone_ph: f32,
}
/// Schedule the notes of one clip whose absolute time falls inside [w0, w1).
/// `base` is the beat of note-time zero; `limit` the usable clip length.
#[allow(clippy::too_many_arguments)]
fn sched_notes(inst: &mut Option<Box<dyn Instrument>>, held: &mut Vec<(u8, u64)>, notes: &[Note], base: f64, limit: f64, w0: f64, w1: f64, t0: f64, bps: f64, start_clock: u64) {
for n in notes {
if n.start >= limit {
continue;
}
let ns = base + n.start;
if ns >= w0 && ns < w1 {
if let Some(i) = inst.as_mut() {
i.note_on_lyric(n.key, n.vel, n.pan, n.cutoff, n.reso, &n.lyric, (n.len.min(limit - n.start) / bps) as f32);
}
let end_beat = ns + n.len.min(limit - n.start);
let end_clock = start_clock + ((end_beat - t0) / bps).max(0.0) as u64;
held.push((n.key, end_clock));
}
}
}
/// Play an audio clip, using the pre-rendered warp / pitch variant when it is ready
/// (otherwise falls back to varispeed pitch on the original).
#[allow(clippy::too_many_arguments)]
fn mix_clip_audio(dst: &mut [f32], sample: &Arc<Sample>, offset_s: f64, gain: f32, pitch: f32, warp: f32, bpm: f64, local0: f64, bps: f64, spb: f64, frames: usize, len: f64, wrap: f64) {
let key = variant_key(pitch, warp, bpm);
if key == (0, 1000) {
mix_audio(dst, sample, offset_s, gain, 0.0, local0, bps, spb, frames, len, wrap);
} else if let Some(v) = sample.cached(key) {
mix_audio(dst, &v, offset_s * key.1 as f64 / 1000.0, gain, 0.0, local0, bps, spb, frames, len, wrap);
} else {
mix_audio(dst, sample, offset_s, gain, pitch, local0, bps, spb, frames, len, wrap);
}
}
#[allow(clippy::too_many_arguments)]
fn mix_audio(dst: &mut [f32], sample: &Sample, offset_s: f64, gain: f32, pitch: f32, local0: f64, bps: f64, spb: f64, frames: usize, len: f64, wrap: f64) {
let speed = 2f64.powf(pitch as f64 / 12.0);
let rate = sample.rate as f64;
let nfr = sample.frames();
for f in 0..frames {
let mut l = local0 + bps * f as f64;
if l < 0.0 {
continue;
}
if l >= len {
continue;
}
if wrap > 0.0 {
l %= wrap;
}
let src = (l * spb * speed + offset_s) * rate;
let i = src as usize;
if i + 1 >= nfr {
continue;
}
let fr = (src - i as f64) as f32;
for c in 0..2 {
let a = sample.stereo[i * 2 + c];
let b = sample.stereo[(i + 1) * 2 + c];
dst[f * 2 + c] += (a + (b - a) * fr) * gain;
}
}
}
impl Engine {
pub fn new(sr: f32) -> Engine {
Engine {
project: Project::new(),
sr,
playing: false,
position: 0.0,
tmp: vec![],
mix: vec![],
outs: vec![],
key_pk: vec![],
order: vec![],
levels: vec![],
route_sig: u64::MAX,
audible: vec![],
sample_clock: 0,
rec_latency_s: 0.0,
touched: vec![],
rec_arm: None,
rec_clip: None,
rec_held: vec![],
auto_rec: false,
rec_rev: 0,
spos: 0.0,
sess_play: vec![],
sess_queue: vec![],
perf_rec: false,
perf_open: vec![],
offline: false,
lim_gain: 1.0,
lim_min: 1.0,
tone_left: 0,
tone_ph: 0.0,
}
}
pub fn shared(self) -> SharedEngine {
Arc::new(Mutex::new(self))
}
/// Start the device test tone (440 Hz, left then right).
pub fn start_test_tone(&mut self) {
self.tone_left = (2.0 * self.sr) as u32;
self.tone_ph = 0.0;
}
fn beats_per_sample(&self) -> f64 {
self.project.bpm_at(self.position) / 60.0 / self.sr as f64
}
pub fn play(&mut self) {
self.playing = true;
}
pub fn pause(&mut self) {
self.finish_perf_all();
self.finish_recording();
self.playing = false;
self.release_all();
}
pub fn stop(&mut self) {
self.pause();
self.position = 0.0;
self.spos = 0.0;
for p in self.sess_play.iter_mut() {
*p = None;
}
for q in self.sess_queue.iter_mut() {
*q = None;
}
}
pub fn seek(&mut self, beat: f64) {
self.release_all();
self.position = beat.max(0.0);
}
fn release_all(&mut self) {
for t in self.project.tracks.iter_mut() {
if let Some(i) = t.inst.as_mut() {
i.all_off();
}
t.held.clear();
}
}
// ── live notes / recording ──────────────────────────────────────────────
/// Live (keyboard/preview) note on the given track. Captured into a clip
/// when the track is armed and the transport is running.
pub fn live_note(&mut self, track: usize, key: u8, vel: f32, on: bool) {
if let Some(i) = self.project.tracks.get_mut(track).and_then(|t| t.inst.as_mut()) {
if on {
i.note_on(key, vel)
} else {
i.note_off(key)
}
}
if self.playing && self.rec_arm == Some(track) {
self.record_note(track, key, vel, on);
}
}
/// Transport position as the player heard it (the engine renders ahead of the speakers).
pub fn heard_position(&self) -> f64 {
(self.position - self.rec_latency_s * self.project.bpm_at(self.position) / 60.0).max(0.0)
}
fn record_note(&mut self, track: usize, key: u8, vel: f32, on: bool) {
let pos = self.heard_position();
if self.rec_clip.is_none() {
if !on {
return;
}
let start = (pos / 4.0).floor() * 4.0;
let Some(t) = self.project.tracks.get_mut(track) else { return };
t.clips.push(Clip::midi(start, 4.0, "Recording"));
self.rec_rev += 1;
self.rec_clip = Some((track, t.clips.len() - 1));
}
let Some((rt, rc)) = self.rec_clip else { return };
if rt != track {
return;
}
if on {
self.rec_held.push((key, pos, vel));
} else if let Some(i) = self.rec_held.iter().position(|h| h.0 == key) {
let (k, start, v) = self.rec_held.remove(i);
self.push_recorded(rt, rc, k, start, pos, v);
}
}
fn push_recorded(&mut self, t: usize, c: usize, key: u8, start: f64, end: f64, vel: f32) {
self.rec_rev += 1;
if let Some(clip) = self.project.tracks.get_mut(t).and_then(|t| t.clips.get_mut(c)) {
let rel = (start - clip.start).max(0.0);
let len = (end - start).max(0.06);
if let ClipData::Midi(n) = &mut clip.data {
n.push(Note::new(rel, len, key, vel));
}
let need = ((rel + len) / 4.0).ceil() * 4.0;
if need > clip.len {
clip.len = need;
}
}
}
/// Close any notes still held and end the recording pass.
pub fn finish_recording(&mut self) {
let pos = self.heard_position();
if let Some((t, c)) = self.rec_clip.take() {
let held = std::mem::take(&mut self.rec_held);
for (k, s, v) in held {
self.push_recorded(t, c, k, s, pos, v);
}
}
self.rec_held.clear();
}
// ── automation ──────────────────────────────────────────────────────────
fn apply_lane(track: &mut Track, lane_idx: usize, beat: f64) {
let (param, v) = {
let lane = &track.auto[lane_idx];
match lane.value_at(beat) {
Some(v) => (lane.param.clone(), v),
None => return,
}
};
match param.as_str() {
"vol" => track.volume = v.clamp(0.0, 2.0),
"pan" => track.pan = v.clamp(-1.0, 1.0),
p if p.starts_with("fx") => {
// "fx<i>.<p>"
if let Some((a, b)) = p[2..].split_once('.') {
if let (Ok(i), Ok(pi)) = (a.parse::<usize>(), b.parse::<usize>()) {
if let Some(e) = track.effects.get_mut(i) {
e.set(pi, v);
}
}
}
}
name => {
if let Some(i) = track.inst.as_mut() {
i.set_param(name, v);
}
}
}
}
fn apply_automation(&mut self, beat: f64) {
// a parameter moved by hand in the last moment is "touched": the lane must not fight the hand
let hold = (self.sr as f64 * 0.4) as u64;
let clock = self.sample_clock;
self.touched.retain(|t| clock.saturating_sub(t.3) < hold);
let touched = &self.touched;
for (ti, t) in self.project.tracks.iter_mut().enumerate() {
for li in 0..t.auto.len() {
if !t.auto[li].points.is_empty() && !touched.iter().any(|x| x.0 == Some(ti) && x.1 == t.auto[li].param) {
Self::apply_lane(t, li, beat);
}
}
}
for li in 0..self.project.master_auto.len() {
let param = self.project.master_auto[li].param.clone();
if touched.iter().any(|x| x.0.is_none() && x.1 == param) {
continue;
}
let Some(v) = self.project.master_auto[li].value_at(beat) else { continue };
if param == "vol" {
self.project.master_volume = v.clamp(0.0, 2.0);
} else if let Some((a, b)) = param.strip_prefix("fx").and_then(|r| r.split_once('.')) {
if let (Ok(i), Ok(pi)) = (a.parse::<usize>(), b.parse::<usize>()) {
if let Some(e) = self.project.master_effects.get_mut(i) {
e.set(pi, v);
}
}
}
}
}
/// Record a parameter move as an automation point at the playhead.
pub fn record_auto(&mut self, track: Option<usize>, param: &str, value: f32) {
if !(self.auto_rec && self.playing) || !value.is_finite() {
return;
}
let beat = self.position;
let clock = self.sample_clock;
// continuing a touch: the stretch just passed over replaces whatever the lane held there
let mut from = beat;
match self.touched.iter_mut().find(|x| x.0 == track && x.1 == param) {
Some(x) => {
if beat >= x.2 && beat - x.2 < 2.0 {
from = x.2;
}
x.2 = beat;
x.3 = clock;
}
None => self.touched.push((track, param.to_string(), beat, clock)),
}
let lanes = match track {
Some(t) => match self.project.tracks.get_mut(t) {
Some(t) => &mut t.auto,
None => return,
},
None => &mut self.project.master_auto,
};
let li = match lanes.iter().position(|l| l.param == param) {
Some(i) => i,
None => {
lanes.push(AutoLane { param: param.to_string(), points: vec![] });
lanes.len() - 1
}
};
let pts = &mut lanes[li].points;
pts.retain(|p| (p.0 - beat).abs() > 0.04 && !(p.0 > from && p.0 < beat));
let at = pts.partition_point(|p| p.0 < beat);
pts.insert(at, (beat, value));
}
// ── launcher (session) ──────────────────────────────────────────────────
fn ensure_sess_len(&mut self) {
let n = self.project.tracks.len();
self.sess_play.resize(n, None);
self.sess_queue.resize(n, None);
self.perf_open.resize(n, None);
}
/// Turn a recorded launcher pass on track `t` into arrangement clips (one copy per loop).
fn finish_perf(&mut self, t: usize) {
let Some((ci, start)) = self.perf_open.get_mut(t).and_then(|o| o.take()) else { return };
let end = self.position;
let Some(track) = self.project.tracks.get_mut(t) else { return };
let Some(src) = track.session.get(ci).cloned() else { return };
self.rec_rev += 1;
let len = src.len.max(0.25);
let mut k = 0.0;
while start + k * len < end - 0.01 {
let mut c = src.clone();
c.start = start + k * len;
c.len = len.min(end - c.start);
track.clips.push(c);
k += 1.0;
}
}
fn finish_perf_all(&mut self) {
for t in 0..self.perf_open.len() {
self.finish_perf(t);
}
}
fn quant_boundary(&self) -> f64 {
let q = self.project.quant;
if q <= 0.0 {
self.spos
} else {
(self.spos / q - 1e-9).ceil().max(0.0) * q
}
}
fn queue_at(&self) -> f64 {
if self.playing {
self.quant_boundary()
} else {
self.spos
}
}
pub fn launch(&mut self, track: usize, scene: usize) {
self.ensure_sess_len();
let c = self.project.slot(scene, track);
if c < 0 || track >= self.sess_queue.len() {
return;
}
let at = self.queue_at();
self.playing = true;
self.sess_queue[track] = Some(Queued { cmd: QCmd::Start(c as usize, scene as i32), at });
}
pub fn launch_scene(&mut self, scene: usize) {
self.ensure_sess_len();
let at = self.queue_at();
self.playing = true;
for t in 0..self.project.tracks.len() {
let c = self.project.slot(scene, t);
self.sess_queue[t] = Some(if c >= 0 { Queued { cmd: QCmd::Start(c as usize, scene as i32), at } } else { Queued { cmd: QCmd::Stop, at } });
}
}
pub fn stop_track(&mut self, track: usize) {
self.ensure_sess_len();
let at = self.queue_at();
if track < self.sess_queue.len() {
self.sess_queue[track] = Some(Queued { cmd: QCmd::Stop, at });
}
}
pub fn stop_all_session(&mut self) {
self.ensure_sess_len();
for p in self.sess_play.iter_mut() {
*p = None;
}
for q in self.sess_queue.iter_mut() {
*q = None;
}
self.release_all();
}
/// (scene playing or -1, queued: -1 none / -2 stop / scene, progress 0..1)
pub fn sess_state(&self, track: usize) -> (i32, i32, f64) {
let play = self.sess_play.get(track).copied().flatten();
let q = self.sess_queue.get(track).copied().flatten();
let queued = match q {
None => -1,
Some(Queued { cmd: QCmd::Stop, .. }) => -2,
Some(Queued { cmd: QCmd::Start(_, s), .. }) => s,
};
match play {
Some(p) => {
let len = self.project.tracks.get(track).and_then(|t| t.session.get(p.clip)).map(|c| c.len).unwrap_or(4.0).max(0.25);
(p.scene, queued, ((self.spos - p.start).max(0.0) % len) / len)
}
None => (-1, queued, 0.0),
}
}
/// Cheap fingerprint of the routing graph (no allocation).
fn route_signature(&self) -> u64 {
let mut h: u64 = self.project.tracks.len() as u64 + 0x9E37_79B9_7F4A_7C15;
for r in &self.project.routes {
h = h.rotate_left(7) ^ ((r.from as u64) << 20 | (r.to as u64) << 4 | r.kind as u64);
h = h.wrapping_mul(0x100_0000_01B3);
}
h
}
/// Keep engine-side per-track state aligned after a track was removed.
pub fn on_track_removed(&mut self, i: usize) {
if let Some((t, _)) = self.rec_clip {
if t == i {
self.finish_recording();
}
}
for v in [&mut self.sess_play as &mut dyn VecOps, &mut self.sess_queue, &mut self.perf_open] {
v.remove_at(i);
}
if i < self.outs.len() {
self.outs.remove(i);
}
if i < self.key_pk.len() {
self.key_pk.remove(i);
}
self.rec_arm = match self.rec_arm {
Some(t) if t == i => None,
Some(t) if t > i => Some(t - 1),
other => other,
};
if let Some((t, c)) = self.rec_clip {
if t > i {
self.rec_clip = Some((t - 1, c));
}
}
self.route_sig = u64::MAX;
}
/// Keep engine-side per-track state aligned after track `i` moved to index `j`.
pub fn on_track_moved(&mut self, i: usize, j: usize) {
let map = |old: usize| -> usize {
if old == i {
j
} else if i < j && old > i && old <= j {
old - 1
} else if i > j && old >= j && old < i {
old + 1
} else {
old
}
};
for v in [&mut self.sess_play as &mut dyn VecOps, &mut self.sess_queue, &mut self.perf_open] {
v.move_item(i, j);
}
self.outs.clear();
self.key_pk.clear();
self.rec_arm = self.rec_arm.map(map);
if let Some((t, c)) = self.rec_clip {
self.rec_clip = Some((map(t), c));
}
self.route_sig = u64::MAX;
}
/// A clip on track `t` was removed / moved away: stop a recording pass that pointed into it.
pub fn on_clips_changed(&mut self, t: usize) {
if matches!(self.rec_clip, Some((rt, _)) if rt == t) {
self.finish_recording();
}
}
/// Group a render order into levels: a track sits one level below the deepest track that feeds it.
fn route_levels(&self, order: &[usize], routes: &[Route]) -> Vec<Vec<usize>> {
let n = self.project.tracks.len();
let mut pos = vec![usize::MAX; n];
for (i, &t) in order.iter().enumerate() {
if t < n {
pos[t] = i;
}
}
let mut lvl = vec![0usize; n];
for &t in order {
if t >= n {
continue;
}
for r in routes.iter().filter(|r| r.to == t && r.from < n && r.from != t && pos[r.from] < pos[t]) {
lvl[t] = lvl[t].max(lvl[r.from] + 1);
}
}
let depth = lvl.iter().copied().max().map(|m| m + 1).unwrap_or(0);
let mut out = vec![Vec::new(); depth];
for &t in order {
if t < n {
out[lvl[t]].push(t);
}
}
out
}
/// Topological render order: sources before the tracks they feed.
fn route_order(&self) -> Vec<usize> {
let n = self.project.tracks.len();
let mut indeg = vec![0usize; n];
for r in &self.project.routes {
if r.from < n && r.to < n {
indeg[r.to] += 1;
}
}
let mut order = Vec::with_capacity(n);
let mut done = vec![false; n];
loop {
let mut progressed = false;
for i in 0..n {
if !done[i] && indeg[i] == 0 {
done[i] = true;
order.push(i);
progressed = true;
for r in &self.project.routes {
if r.from == i && r.to < n {
indeg[r.to] = indeg[r.to].saturating_sub(1);
}
}
}
}
if !progressed {
break;
}
}
for i in 0..n {
if !done[i] {
order.push(i);
}
}
order
}
// ── rendering ───────────────────────────────────────────────────────────
/// Fill `out` (interleaved stereo) with the next block of audio.
pub fn render(&mut self, out: &mut [f32]) {
out.fill(0.0);
let mut off = 0;
while off < out.len() {
let n = (SUB * 2).min(out.len() - off);
self.render_slice(&mut out[off..off + n]);
off += n;
}
}
fn render_slice(&mut self, out: &mut [f32]) {
let frames = out.len() / 2;
let bps = self.beats_per_sample();
// audio clips follow the project's base tempo (they are not re-timed by tempo changes)
let bps_a = self.project.bpm / 60.0 / self.sr as f64;
let spb = 60.0 / self.project.bpm;
let n = self.project.tracks.len();
let dur = bps * frames as f64;
let (p0, p1) = (self.position, self.position + dur);
let (s0, s1) = (self.spos, self.spos + dur);
let playing = self.playing;
let any_solo = self.project.tracks.iter().any(|t| t.solo);
let start_clock = self.sample_clock;
let arr_on = playing && (self.offline || !self.project.session_only);
let sess_on = playing && !self.offline;
self.ensure_sess_len();
if self.outs.len() < n {
self.outs.resize(n, vec![]);
}
if self.key_pk.len() < n {
self.key_pk.resize(n, 0.0);
}
self.mix.clear();
self.mix.resize(out.len(), 0.0);
if playing {
self.apply_automation(p0);
}
// activate queued launcher commands that fall inside this slice
if sess_on {
for t in 0..n {
if let Some(q) = self.sess_queue[t] {
if q.at < s1 {
self.finish_perf(t);
match q.cmd {
QCmd::Start(c, sc) => {
self.sess_play[t] = Some(Playing { clip: c, scene: sc, start: q.at });
if self.perf_rec {
self.perf_open[t] = Some((c, self.position));
}
}
QCmd::Stop => {
self.sess_play[t] = None;
if let Some(i) = self.project.tracks[t].inst.as_mut() {
i.all_off();
}
self.project.tracks[t].held.clear();
}
}
self.sess_queue[t] = None;
}
}
}
}
let sig = self.route_signature();
if sig != self.route_sig {
self.order = self.route_order();
self.levels.clear();
self.route_sig = sig;
}
let order = std::mem::take(&mut self.order);
let routes = std::mem::take(&mut self.project.routes);
let mut audible = std::mem::take(&mut self.audible);
audible.clear();
audible.extend(self.project.tracks.iter().map(|t| !t.mute && (!any_solo || t.solo)));
// Tracks that do not feed each other render side by side: one pass per dependency level
let n_cov: usize = self.levels.iter().map(|l| l.len()).sum();
if n_cov != n {
self.levels = self.route_levels(&order, &routes);
}
let levels = std::mem::take(&mut self.levels);
let duck = duck_events(&self.project.tracks, &routes, p0, p1, bps, frames, arr_on);
let ctx = SliceCtx { p0, p1, s0, s1, bps, bps_a, spb, bpm: self.project.bpm, frames, out_len: out.len(), start_clock, arr_on, sess_on, n, routes: &routes, audible: &audible, duck: &duck };
for level in &levels {
let mut in_level = vec![false; n];
for &t in level {
in_level[t] = true;
}
let results: Vec<(usize, TrackResult)> = {
let (outs, key_pk, sess_play) = (&self.outs, &self.key_pk, &self.sess_play);
let items: Vec<(usize, &mut Track)> = self.project.tracks.iter_mut().enumerate().filter(|(i, _)| in_level[*i]).collect();
run_parallel(items, |(ti, track)| (ti, render_track(track, ti, &ctx, sess_play[ti], outs, key_pk)))
};
for (ti, r) in results {
self.key_pk[ti] = r.key_pk;
if audible[ti] {
for (d, s) in self.mix.iter_mut().zip(r.out.iter()) {
*d += *s;
}
}
self.outs[ti] = r.out;
}
}
self.levels = levels;
self.order = order;
self.project.routes = routes;
self.audible = audible;
for e in self.project.master_effects.iter_mut().filter(|e| !e.bypass) {
e.fx.process(&mut self.mix);
scrub(&mut self.mix);
}
let mv = self.project.master_volume;
let mut pk = [0.0f32; 2];
let limiter = self.project.limiter;
// ~60 ms release; the gain drops instantly when a peak would pass the ceiling
let rel = 1.0 - (-1.0 / (0.06 * self.sr)).exp();
const CEIL: f32 = 0.97;
for f in 0..frames {
let mut v = [self.mix[f * 2] * mv, self.mix[f * 2 + 1] * mv];
// device test tone: 1 s on the left channel, then 1 s on the right
if self.tone_left > 0 {
let total = (2.0 * self.sr) as u32;
let idx = total.saturating_sub(self.tone_left);
let ch = if (idx as f32) < self.sr { 0 } else { 1 };
let age = (idx as f32 % self.sr) / self.sr;
let env = (age * 20.0).min(1.0) * ((1.0 - age) * 20.0).min(1.0);
self.tone_ph = (self.tone_ph + 440.0 / self.sr).fract();
v[ch] += (self.tone_ph * std::f32::consts::TAU).sin() * 0.2 * env;
self.tone_left -= 1;
}
if limiter {
let peak = v[0].abs().max(v[1].abs());
if peak * self.lim_gain > CEIL {
self.lim_gain = CEIL / peak.max(1e-9);
} else {
self.lim_gain += (1.0 - self.lim_gain) * rel;
}
self.lim_min = self.lim_min.min(self.lim_gain);
v[0] *= self.lim_gain;
v[1] *= self.lim_gain;
}
for c in 0..2 {
let raw = v[c];
let s = if raw.is_finite() { raw.clamp(-1.0, 1.0) } else { 0.0 };
out[f * 2 + c] = s;
pk[c] = pk[c].max(s.abs());
}
}
let m = &mut self.project.master_meter;
m[0] = pk[0].max(m[0] * 0.995);
m[1] = pk[1].max(m[1] * 0.995);
self.sample_clock += frames as u64;
if self.playing {
self.position = p1;
self.spos = s1;
if !self.offline && self.project.loop_on && self.position >= self.project.loop_end {
// wrap without cutting sounding notes (they release on their own schedule)
self.position = self.project.loop_start.max(0.0);
}
}
}
/// Offline render from beat 0 to the end of the last clip (+ tail seconds).
pub fn bounce(&mut self, tail_s: f64) -> Vec<f32> {
let end = self.project.end_beat();
self.bounce_range(0.0, end, tail_s)
}
/// Offline render of `[start, end)` beats plus a release tail, ignoring loop and launcher.
/// Like `bounce_range`, reporting progress (0..1000) and stopping early when `cancel` is set.
pub fn bounce_range_progress(&mut self, start: f64, end: f64, tail_s: f64, progress: &std::sync::atomic::AtomicU32, cancel: &std::sync::atomic::AtomicBool, lo: u32, hi: u32) -> Option<Vec<f32>> {
use std::sync::atomic::Ordering::Relaxed;
self.project.loop_on = false;
self.release_all();
self.offline = true;
self.position = start;
self.playing = true;
let secs = self.project.beats_to_secs(start, end.max(start)) + tail_s;
let secs = if secs.is_finite() { secs.clamp(0.0, 4.0 * 3600.0) } else { 0.0 };
let frames = (secs * self.sr as f64) as usize;
let mut out = vec![0.0f32; frames * 2];
let mut done = 0usize;
for chunk in out.chunks_mut(2048) {
if cancel.load(Relaxed) {
return None;
}
self.render(chunk);
done += chunk.len() / 2;
progress.store(lo + (done as u64 * (hi - lo) as u64 / frames.max(1) as u64) as u32, Relaxed);
}
self.release_all();
Some(out)
}
pub fn bounce_range(&mut self, start: f64, end: f64, tail_s: f64) -> Vec<f32> {
let was = (self.playing, self.position, self.spos, self.project.loop_on);
self.project.loop_on = false;
self.release_all();
self.offline = true;
self.position = start;
self.playing = true;
let secs = self.project.beats_to_secs(start, end.max(start)) + tail_s;
let secs = if secs.is_finite() { secs.clamp(0.0, 4.0 * 3600.0) } else { 0.0 };
let frames = (secs * self.sr as f64) as usize;
let mut out = vec![0.0f32; frames * 2];
for chunk in out.chunks_mut(2048) {
self.render(chunk);
}
self.release_all();
self.offline = false;
self.playing = was.0;
self.position = was.1;
self.spos = was.2;
self.project.loop_on = was.3;
out
}
pub fn bounce_wav(&mut self, path: &str, tail_s: f64) -> Result<(), String> {
let data = self.bounce(tail_s);
let spec = hound::WavSpec { channels: 2, sample_rate: self.sr as u32, bits_per_sample: 16, sample_format: hound::SampleFormat::Int };
let mut w = hound::WavWriter::create(path, spec).map_err(|e| e.to_string())?;
for s in data {
w.write_sample((s * 32767.0) as i16).map_err(|e| e.to_string())?;
}
w.finalize().map_err(|e| e.to_string())
}
}
/// The triggers of every Duck route in one slice: for each target track the (frame, velocity) of each note of the source track that the route
/// lets through (its `keys`, or all notes). Read from the source's arrangement clips, so a muted kick still ducks, and exact to the frame.
fn duck_events(tracks: &[Track], routes: &[Route], p0: f64, p1: f64, bps: f64, frames: usize, arr_on: bool) -> Vec<Vec<(u32, f32)>> {
let n = tracks.len();
let mut out: Vec<Vec<(u32, f32)>> = vec![Vec::new(); n];
if !arr_on || frames == 0 || !(bps > 0.0) {
return out;
}
for r in routes.iter().filter(|r| r.kind == RouteKind::Duck && r.from < n && r.to < n && r.from != r.to) {
for clip in &tracks[r.from].clips {
let (cstart, clen) = (clip.start, clip.len);
if p1 <= cstart || p0 >= cstart + clen {
continue;
}
let ClipData::Midi(notes) = &clip.data else { continue };
let ll = if clip.loop_len >= 0.25 && clip.loop_len < clen { clip.loop_len } else { 0.0 };
let mut visit = |base: f64, limit: f64| {
for note in notes {
if note.start >= limit {
continue;
}
let ns = base + note.start;
if ns >= p0 && ns < p1 && (r.keys.is_empty() || r.keys.contains(¬e.key)) {
let f = (((ns - p0) / bps).floor().max(0.0) as usize).min(frames - 1) as u32;
out[r.to].push((f, (note.vel * r.amount).clamp(0.0, 1.0)));
}
}
};
if ll > 0.0 {
let k0 = (((p0 - cstart) / ll).floor() as i64).max(0);
let k1 = (((p1 - cstart) / ll).floor() as i64).max(0);
for k in k0..=k1 {
let off = k as f64 * ll;
if off >= clen {
break;
}
visit(cstart + off, ll.min(clen - off));
}
} else {
visit(cstart, clen);
}
}
}
out
}
/// Everything one slice of rendering needs besides the tracks themselves.
struct SliceCtx<'a> {
p0: f64,
p1: f64,
s0: f64,
s1: f64,
bps: f64,
bps_a: f64,
spb: f64,
bpm: f64,
frames: usize,
out_len: usize,
start_clock: u64,
arr_on: bool,
sess_on: bool,
n: usize,
routes: &'a [Route],
audible: &'a [bool],
/// per track: (frame, velocity) of every trigger the Duck routes into it fire in this slice
duck: &'a [Vec<(u32, f32)>],
}
struct TrackResult {
/// post-fader, post-pan stereo block
out: Vec<f32>,
/// pre-fader peak (sidechain key)
key_pk: f32,
}
thread_local! {
static TRACK_TMP: std::cell::RefCell<Vec<f32>> = const { std::cell::RefCell::new(Vec::new()) };
}
/// Render one track for one slice: its clips and notes, the instrument, sends from earlier tracks, its effect chain,
/// fader and pan. Touches only this track plus read-only data, so tracks in one dependency level can run in parallel.
fn render_track(track: &mut Track, ti: usize, c: &SliceCtx, play_state: Option<Playing>, outs: &[Vec<f32>], key_pk: &[f32]) -> TrackResult {
let SliceCtx { p0, p1, s0, s1, bps, bps_a, spb, bpm, frames, out_len, start_clock, arr_on, sess_on, n, routes, audible, duck } = *c;
TRACK_TMP.with(|cell| {
let mut tmp_buf = cell.borrow_mut();
let mut tmp: Vec<f32> = std::mem::take(&mut *tmp_buf);
tmp.clear();
tmp.resize(out_len, 0.0);
if arr_on {
for clip in track.clips.iter() {
let (cstart, clen) = (clip.start, clip.len);
if p1 <= cstart || p0 >= cstart + clen {
continue;
}
let ll = if clip.loop_len >= 0.25 && clip.loop_len < clen { clip.loop_len } else { 0.0 };
match &clip.data {
ClipData::Midi(notes) => {
if ll > 0.0 {
let k0 = (((p0 - cstart) / ll).floor() as i64).max(0);
let k1 = (((p1 - cstart) / ll).floor() as i64).max(0);
for k in k0..=k1 {
let off = k as f64 * ll;
if off >= clen {
break;
}
sched_notes(&mut track.inst, &mut track.held, notes, cstart + off, ll.min(clen - off), p0, p1, p0, bps, start_clock);
}
} else {
sched_notes(&mut track.inst, &mut track.held, notes, cstart, clen, p0, p1, p0, bps, start_clock)
}
}
ClipData::Audio { sample, offset_s, gain, pitch, warp } => {
mix_clip_audio(&mut tmp, sample, *offset_s, *gain, *pitch, *warp, bpm, p0 - cstart, bps_a, spb, frames, clen, ll);
}
}
}
}
if sess_on {
if let Some(pl) = play_state {
if let Some(clip) = track.session.get(pl.clip) {
let len = clip.len.max(0.25);
let (l0, l1) = ((s0 - pl.start).max(0.0), (s1 - pl.start).max(0.0));
if l1 > l0 || s1 > pl.start {
match &clip.data {
ClipData::Midi(notes) => {
// widen by a hair: the [w0, w1) test in sched_notes is the exact filter
let k0 = (((l0 - 1e-6) / len).floor() as i64).max(0);
let k1 = (((l1 + 1e-6) / len).floor() as i64).max(0);
for k in k0..=k1 {
let base = pl.start + k as f64 * len;
sched_notes(&mut track.inst, &mut track.held, notes, base, len, s0.max(pl.start), s1, s0, bps, start_clock);
}
}
ClipData::Audio { sample, offset_s, gain, pitch, warp } => {
mix_clip_audio(&mut tmp, sample, *offset_s, *gain, *pitch, *warp, bpm, s0 - pl.start, bps_a, spb, frames, f64::MAX, len);
}
}
}
}
}
}
// note-offs due within this slice
let end_clock = start_clock + frames as u64;
let mut k = 0;
while k < track.held.len() {
if track.held[k].1 <= end_clock {
let key = track.held.swap_remove(k).0;
if let Some(i) = track.inst.as_mut() {
i.note_off(key);
}
} else {
k += 1;
}
}
if let Some(i) = track.inst.as_mut() {
i.set_tempo(bpm);
i.render(&mut tmp);
}
// sends into this track (post-fader from already-processed sources)
let mut sc_level: Option<f32> = None;
let mut aux: Option<Vec<f32>> = None;
for r in routes.iter().filter(|r| r.to == ti && r.from < n && r.from != ti) {
if r.kind == RouteKind::Duck {
continue; // note-triggered: handled through `duck`
}
if r.kind == RouteKind::Mod {
// the modulator input of this track's effects: audible or not, the source feeds it
let src = &outs[r.from];
if src.len() == tmp.len() {
let a = aux.get_or_insert_with(|| vec![0.0; tmp.len()]);
for (d, s) in a.iter_mut().zip(src.iter()) {
*d += *s * r.amount;
}
}
continue;
}
if r.kind == RouteKind::Sidechain {
// key is tapped pre-fader / pre-mute so a muted trigger track still keys
let pk = key_pk[r.from] * r.amount;
sc_level = Some(sc_level.map_or(pk, |c: f32| c.max(pk)));
continue;
}
if !audible[r.from] {
continue;
}
let src = &outs[r.from];
match r.kind {
RouteKind::Send => {
if src.len() == tmp.len() {
for (d, s) in tmp.iter_mut().zip(src.iter()) {
*d += *s * r.amount;
}
}
}
RouteKind::Sidechain | RouteKind::Duck | RouteKind::Mod => {}
}
}
for e in track.effects.iter_mut() {
e.fx.set_sidechain(sc_level);
e.fx.set_aux(aux.as_deref());
e.fx.set_triggers(&duck[ti]);
}
for e in track.effects.iter_mut().filter(|e| !e.bypass) {
e.fx.process(&mut tmp);
scrub(&mut tmp);
}
let kpk = tmp.iter().fold(0.0f32, |a, b| a.max(b.abs()));
// fader + equal-power pan + meter
let ang = (track.pan + 1.0) * std::f32::consts::FRAC_PI_4;
let (gl, gr) = (ang.cos() * track.volume * std::f32::consts::SQRT_2, ang.sin() * track.volume * std::f32::consts::SQRT_2);
let mut pk = [0.0f32; 2];
let mut ob = vec![0.0f32; out_len];
for f in 0..frames {
let (l, r) = (tmp[f * 2] * gl, tmp[f * 2 + 1] * gr);
ob[f * 2] = l;
ob[f * 2 + 1] = r;
pk[0] = pk[0].max(l.abs());
pk[1] = pk[1].max(r.abs());
}
track.meter[0] = pk[0].max(track.meter[0] * 0.995);
track.meter[1] = pk[1].max(track.meter[1] * 0.995);
*tmp_buf = tmp;
TrackResult { out: ob, key_pk: kpk }
})
}
static PARALLEL: std::sync::atomic::AtomicBool = std::sync::atomic::AtomicBool::new(true);
/// Switch parallel track rendering on or off (on by default; the result is identical either way).
pub fn set_parallel_render(on: bool) {
PARALLEL.store(on, std::sync::atomic::Ordering::Relaxed);
}
/// Run `f` over `items`, side by side on the render pool when there is enough work, in order otherwise.
fn run_parallel<T: Send, R: Send>(items: Vec<T>, f: impl Fn(T) -> R + Sync + Send) -> Vec<R> {
use rayon::prelude::*;
match render_pool() {
Some(pool) if items.len() >= 3 && PARALLEL.load(std::sync::atomic::Ordering::Relaxed) => pool.install(|| items.into_par_iter().map(f).collect()),
_ => items.into_iter().map(f).collect(),
}
}
/// A small pool of high-priority DSP threads (one fewer than the cores, the audio thread is the other one).
/// A NaN or infinity out of any effect would travel on through the mix and the sound card driver (and stay in every feedback path):
/// a non-finite sample becomes silence, and everything is held inside +-32.
#[inline]
fn scrub(buf: &mut [f32]) {
for x in buf.iter_mut() {
if !x.is_finite() {
*x = 0.0;
} else if x.abs() > 32.0 {
*x = x.signum() * 32.0;
}
}
}
fn render_pool() -> Option<&'static rayon::ThreadPool> {
static POOL: std::sync::OnceLock<Option<rayon::ThreadPool>> = std::sync::OnceLock::new();
POOL.get_or_init(|| {
let cores = std::thread::available_parallelism().map(|n| n.get()).unwrap_or(1);
if cores < 3 {
return None;
}
rayon::ThreadPoolBuilder::new()
.num_threads((cores - 1).min(8))
.thread_name(|i| format!("lsx-dsp-{i}"))
.start_handler(|_| crate::audio::prepare_dsp_thread())
.build()
.ok()
})
.as_ref()
}