strudel/packages/webaudio/prebake.mjs

import { Pattern, toMidi } from '@strudel.cycles/core';
import { samples } from '.';

let baking;

export function prebake(props) {
  if (baking) {
    return baking;
  }
  baking = prebaker(props);
  return baking;
}

async function prebaker(props = {}) {
  const { baseURL = './samples' } = props; // http://localhost:1234
  try {
    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://archive.org/details/SalamanderGrandPianoV3
      // License: CC-by http://creativecommons.org/licenses/by/3.0/ Author: Alexander Holm
      baseURL + '/piano/',
    );

    const maxPan = toMidi('C8');
    const panwidth = (pan, width) => pan * width + (1 - width) / 2;

    Pattern.prototype.piano = function () {
      return this.clip(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 };
        });
    };

    // ping sample server
    /* await fetch(samplerURL)
      .then(() => {
        console.log(`prebake: Using samples from "${baseURL}"`);
      })
      .catch(() => {
        throw new Error(
          `sample server not running at "${samplerURL}"... run "npm run sampler" from the strudel project root.`,
        );
      }); */
  } catch (e) {
    console.warn('prebake error', e);
  }
}