migrate to encapsulated out

packages/webaudio/webaudio.mjs

@@ -23,6 +23,21 @@ export const getAudioContext = () => {
   return audioContext;
 };
 
+let destination;
+export const getDestination = () => {
+  const ctx = getAudioContext();
+  if (!destination) {
+    destination = ctx.createGain();
+    destination.connect(ctx.destination);
+  }
+  return destination;
+};
+
+export const panic = () => {
+  getDestination().gain.linearRampToValueAtTime(0, getAudioContext().currentTime + 0.01);
+  destination = null;
+};
+
 const getFilter = (type, frequency, Q) => {
   const filter = getAudioContext().createBiquadFilter();
   filter.type = type;
@@ -99,7 +114,7 @@ const getSampleBufferSource = async (s, n, note) => {
   }
   const bank = samples?.[s];
   if (!bank) {
-    throw new Error('sample not found:', s, 'try one of ' + Object.keys(samples));
+    throw new Error(`sample not found: "${s}", try one of ${Object.keys(samples).join(', ')}`);
   }
   if (typeof bank !== 'object') {
     throw new Error('wrong format for sample bank:', s);
@@ -172,13 +187,17 @@ function gainNode(value) {
 }
 const cutGroups = [];
 
-Pattern.prototype.out = function () {
+// export const webaudioOutput = async (t, hap, ct, cps) => {
-  return this.onTrigger(async (t, hap, ct, cps) => {
+export const webaudioOutput = async (hap, deadline, hapDuration) => {
-    const hapDuration = hap.duration / cps;
   try {
     const ac = getAudioContext();
+    if (typeof hap.value !== 'object') {
+      throw new Error(
+        `hap.value ${hap.value} is not supported by webaudio output. Hint: append .note() or .s() to the end`,
+      );
+    }
     // calculate correct time (tone.js workaround)
-      t = ac.currentTime + t - ct;
+    let t = ac.currentTime + deadline;
     // destructure value
     let {
       freq,
@@ -306,8 +325,10 @@ Pattern.prototype.out = function () {
       const adsr = getADSR(attack, decay, sustain, release, 1, t, t + duration);
       chain.push(adsr);
     }
-      // level down before effects
+    // master out
-      chain.push(gainNode(gain));
+    const master = ac.createGain();
+    master.gain.value = gain;
+    chain.push(master);
 
     // filters
     cutoff !== undefined && chain.push(getFilter('lowpass', cutoff, resonance));
@@ -324,18 +345,18 @@ Pattern.prototype.out = function () {
       panner.pan.value = 2 * pan - 1;
       chain.push(panner);
     }
-
     // last gain
     const post = gainNode(1);
     chain.push(post);
-      post.connect(ac.destination);
 
+    post.connect(getDestination());
     if (delay > 0 && delaytime > 0 && delayfeedback > 0) {
       const dly = ac.createFeedbackDelay(delay, delaytime, delayfeedback);
       dly.start(t);
       post.connect(dly);
-        dly.connect(ac.destination);
+      dly.connect(getDestination());
     }
+
     // connect chain elements together
     chain.slice(1).reduce((last, current) => last.connect(current), chain[0]);
     // disconnect all nodes when source node has ended:
@@ -343,5 +364,9 @@ Pattern.prototype.out = function () {
   } catch (e) {
     console.warn('.out error:', e);
   }
-  });
+};
+
+Pattern.prototype.out = function () {
+  // TODO: refactor (t, hap, ct, cps) to (hap, deadline, duration) ?
+  return this.onTrigger((t, hap, ct, cps) => webaudioOutput(hap, t - ct, hap.duration / cps));
 };