add prebake script with piano

repl/src/App.jsx

@@ -12,6 +12,7 @@ import React, { useCallback, useEffect, useLayoutEffect, useRef, useState } from
 import './App.css';
 import logo from './logo.svg';
 import * as tunes from './tunes.mjs';
+import { prebake } from './prebake.mjs';
 import * as WebDirt from 'WebDirt';
 import { loadWebDirt } from '@strudel.cycles/webdirt';
 import { resetLoadedSamples, getAudioContext } from '@strudel.cycles/webaudio';
@@ -46,6 +47,8 @@ loadWebDirt({
   sampleFolder: 'EmuSP12',
 });
 
+prebake();
+
 async function initCode() {
   // load code from url hash (either short hash from database or decode long hash)
   try {
@@ -218,6 +221,7 @@ function App() {
                 cleanupDraw();
                 cleanupUi();
                 resetLoadedSamples();
+                prebake();
                 const parsed = await evaluate(_code);
                 setPattern(parsed.pattern);
                 setActiveCode(_code);

repl/src/prebake.mjs

@@ -0,0 +1,55 @@
+import { Pattern, toMidi } from '@strudel.cycles/core';
+import { samples } from '@strudel.cycles/webaudio';
+
+export function prebake() {
+  samples(
+    {
+      piano: {
+        A0: 'A0v8.mp3',
+        C1: 'C1v8.mp3',
+        Ds1: 'Ds1v8.mp3',
+        Fs1: 'Fs1v8.mp3',
+        A1: 'A1v8.mp3',
+        C2: 'C2v8.mp3',
+        Ds2: 'Ds2v8.mp3',
+        Fs2: 'Fs2v8.mp3',
+        A2: 'A2v8.mp3',
+        C3: 'C3v8.mp3',
+        Ds3: 'Ds3v8.mp3',
+        Fs3: 'Fs3v8.mp3',
+        A3: 'A3v8.mp3',
+        C4: 'C4v8.mp3',
+        Ds4: 'Ds4v8.mp3',
+        Fs4: 'Fs4v8.mp3',
+        A4: 'A4v8.mp3',
+        C5: 'C5v8.mp3',
+        Ds4: 'Ds4v8.mp3',
+        Fs5: 'Fs5v8.mp3',
+        A5: 'A5v8.mp3',
+        C6: 'C6v8.mp3',
+        Ds6: 'Ds6v8.mp3',
+        Fs6: 'Fs6v8.mp3',
+        A6: 'A6v8.mp3',
+        C7: 'C7v8.mp3',
+        Ds7: 'Ds7v8.mp3',
+        Fs7: 'Fs7v8.mp3',
+        A7: 'A7v8.mp3',
+        C8: 'C8v8.mp3',
+      },
+    },
+    'https://tambien.github.io/Piano/audio/',
+  );
+}
+
+const maxPan = toMidi('C8');
+const panwidth = (pan, width) => pan * width + (1 - width) / 2;
+
+Pattern.prototype.piano = function () {
+  return this.choke(1)
+    .s('piano')
+    .fmap((value) => {
+      // pan by pitch
+      const pan = panwidth(Math.min(toMidi(value.note) / maxPan, 1), 0.5);
+      return { ...value, pan: (value.pan || 1) * pan };
+    });
+};