From 08aab9d4d80099d4330549ee732c0ba9ec701297 Mon Sep 17 00:00:00 2001
From: Raphael Forment <raphael.forment@gmail.com>
Date: Wed, 20 Sep 2023 19:44:32 +0200
Subject: [PATCH] Adding vibrato to Superdough sampler

Modulating the `playbackRate` to simulate a vibrato!
---
 packages/superdough/sampler.mjs | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/packages/superdough/sampler.mjs b/packages/superdough/sampler.mjs
index 76b6a542..365d397c 100644
--- a/packages/superdough/sampler.mjs
+++ b/packages/superdough/sampler.mjs
@@ -22,7 +22,7 @@ function humanFileSize(bytes, si) {
   return bytes.toFixed(1) + ' ' + units[u];
 }
 
-export const getSampleBufferSource = async (s, n, note, speed, freq, bank, resolveUrl) => {
+export const getSampleBufferSource = async (s, n, note, speed, freq, vib, vibmod, bank, resolveUrl) => {
   let transpose = 0;
   if (freq !== undefined && note !== undefined) {
     logger('[sampler] hap has note and freq. ignoring note', 'warning');
@@ -57,8 +57,20 @@ export const getSampleBufferSource = async (s, n, note, speed, freq, bank, resol
   const bufferSource = ac.createBufferSource();
   bufferSource.buffer = buffer;
   const playbackRate = 1.0 * Math.pow(2, transpose / 12);
-  // bufferSource.playbackRate.value = Math.pow(2, transpose / 12);
-  bufferSource.playbackRate.value = playbackRate;
+  if (vib > 0) {
+    let vibrato_oscillator = getAudioContext().createOscillator();
+    vibrato_oscillator.frequency.value = vib;
+    const gain = getAudioContext().createGain();
+    // Vibmod is the amount of vibrato, in semitones
+    bufferSource.playbackRate.value = Math.pow(2, transpose / 12);
+    gain.gain.value = vibmod / 4;
+    vibrato_oscillator.connect(gain);
+    gain.connect(bufferSource.playbackRate);
+    vibrato_oscillator.start(0);
+  } else {
+    bufferSource.playbackRate.value = Math.pow(2, transpose / 12);
+    bufferSource.playbackRate.value = playbackRate;
+  }
   return bufferSource;
 };
 
@@ -211,6 +223,8 @@ export async function onTriggerSample(t, value, onended, bank, resolveUrl) {
     begin = 0,
     loopEnd = 1,
     end = 1,
+    vib,
+    vibmod = 0.5,
   } = value;
   // load sample
   if (speed === 0) {
@@ -224,7 +238,7 @@ export async function onTriggerSample(t, value, onended, bank, resolveUrl) {
   //const soundfont = getSoundfontKey(s);
   const time = t + nudge;
 
-  const bufferSource = await getSampleBufferSource(s, n, note, speed, freq, bank, resolveUrl);
+  const bufferSource = await getSampleBufferSource(s, n, note, speed, freq, vib, vibmod, bank, resolveUrl);
 
   // asny stuff above took too long?
   if (ac.currentTime > t) {
@@ -255,7 +269,7 @@ export async function onTriggerSample(t, value, onended, bank, resolveUrl) {
   bufferSource.connect(envelope);
   const out = ac.createGain(); // we need a separate gain for the cutgroups because firefox...
   envelope.connect(out);
-  bufferSource.onended = function () {
+  bufferSource.onended = function() {
     bufferSource.disconnect();
     envelope.disconnect();
     out.disconnect();