strudel/packages/midi/midi.mjs

/*
midi.mjs - <short description TODO>
Copyright (C) 2022 Strudel contributors - see <https://github.com/tidalcycles/strudel/blob/main/packages/midi/midi.mjs>
This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

import * as _WebMidi from 'webmidi';
import { Pattern, getEventOffsetMs, isPattern, logger, ref } from '@strudel/core';
import { noteToMidi } from '@strudel/core';
import { Note } from 'webmidi';

// if you use WebMidi from outside of this package, make sure to import that instance:
export const { WebMidi } = _WebMidi;

function supportsMidi() {
  return typeof navigator.requestMIDIAccess === 'function';
}

function getMidiDeviceNamesString(devices) {
  return devices.map((o) => `'${o.name}'`).join(' | ');
}

export function enableWebMidi(options = {}) {
  const { onReady, onConnected, onDisconnected, onEnabled } = options;
  if (WebMidi.enabled) {
    return;
  }
  if (!supportsMidi()) {
    throw new Error('Your Browser does not support WebMIDI.');
  }
  WebMidi.addListener('connected', () => {
    onConnected?.(WebMidi);
  });
  WebMidi.addListener('enabled', () => {
    onEnabled?.(WebMidi);
  });
  // Reacting when a device becomes unavailable
  WebMidi.addListener('disconnected', (e) => {
    onDisconnected?.(WebMidi, e);
  });
  return new Promise((resolve, reject) => {
    if (WebMidi.enabled) {
      // if already enabled, just resolve WebMidi
      resolve(WebMidi);
      return;
    }
    WebMidi.enable(
      (err) => {
        if (err) {
          reject(err);
        }
        onReady?.(WebMidi);
        resolve(WebMidi);
      },
      { sysex: true },
    );
  });
}

function getDevice(indexOrName, devices) {
  if (!devices.length) {
    throw new Error(`🔌 No MIDI devices found. Connect a device or enable IAC Driver.`);
  }
  if (typeof indexOrName === 'number') {
    return devices[indexOrName];
  }
  const byName = (name) => devices.find((output) => output.name.includes(name));
  if (typeof indexOrName === 'string') {
    return byName(indexOrName);
  }
  // attempt to default to first IAC device if none is specified
  const IACOutput = byName('IAC');
  const device = IACOutput ?? devices[0];
  if (!device) {
    throw new Error(
      `🔌 MIDI device '${device ? device : ''}' not found. Use one of ${getMidiDeviceNamesString(devices)}`,
    );
  }

  return IACOutput ?? devices[0];
}

// send start/stop messages to outputs when repl starts/stops
if (typeof window !== 'undefined') {
  window.addEventListener('message', (e) => {
    if (!WebMidi?.enabled) {
      return;
    }
    if (e.data === 'strudel-stop') {
      WebMidi.outputs.forEach((output) => output.sendStop());
    }
    // cannot start here, since we have no timing info, see sendStart below
  });
}

/**
 * MIDI output: Opens a MIDI output port.
 * @param {string | number} output MIDI device name or index defaulting to 0
 * @example
 * note("c4").midichan(1).midi("IAC Driver Bus 1")
 */
Pattern.prototype.midi = function (output) {
  if (isPattern(output)) {
    throw new Error(
      `.midi does not accept Pattern input. Make sure to pass device name with single quotes. Example: .midi('${
        WebMidi.outputs?.[0]?.name || 'IAC Driver Bus 1'
      }')`,
    );
  }
  let portName = output;
  let isController = false;
  let mapping = {};

  //TODO: MIDI mapping related
  if (typeof output === 'object') {
    const { port, controller = false, ...remainingProps } = output;
    portName = port;
    isController = controller;
    mapping = remainingProps;
  }

  enableWebMidi({
    onEnabled: ({ outputs }) => {
      const device = getDevice(portName, outputs);
      const otherOutputs = outputs.filter((o) => o.name !== device.name);
      logger(
        `Midi enabled! Using "${device.name}". ${
          otherOutputs?.length ? `Also available: ${getMidiDeviceNamesString(otherOutputs)}` : ''
        }`,
      );
    },
    onDisconnected: ({ outputs }) =>
      logger(`Midi device disconnected! Available: ${getMidiDeviceNamesString(outputs)}`),
  });

  return this.onTrigger((time_deprecate, hap, currentTime, cps, targetTime) => {
    if (!WebMidi.enabled) {
      console.log('not enabled');
      return;
    }
    const device = getDevice(portName, WebMidi.outputs);
    hap.ensureObjectValue();
    //magic number to get audio engine to line up, can probably be calculated somehow
    const latencyMs = 34;
    // passing a string with a +num into the webmidi api adds an offset to the current time https://webmidijs.org/api/classes/Output
    const timeOffsetString = `+${getEventOffsetMs(targetTime, currentTime) + latencyMs}`;
    // destructure value
    let {
      note,
      nrpnn,
      nrpv,
      ccn,
      ccv,
      midichan = 1,
      midicmd,
      midibend,
      miditouch,
      polyTouch, //??
      gain = 1,
      velocity = 0.9,
      progNum,
      sysexid,
      sysexdata,
    } = hap.value;

    velocity = gain * velocity;

    // note off messages will often a few ms arrive late, try to prevent glitching by subtracting from the duration length
    const duration = (hap.duration.valueOf() / cps) * 1000 - 10;
    if (note != null && !isController) {
      const midiNumber = typeof note === 'number' ? note : noteToMidi(note);
      const midiNote = new Note(midiNumber, { attack: velocity, duration });
      device.playNote(midiNote, midichan, {
        time: timeOffsetString,
      });
    }

    // Handle mapped parameters if mapping exists
    if (mapping) {
      Object.entries(mapping).forEach(([name, paramSpec]) => {
        if (name in hap.value) {
          const value = hap.value[name];

          if (paramSpec.cc) {
            if (typeof value !== 'number') {
              throw new Error(`Expected ${name} to be a number for CC mapping`);
            }
            // ccnLsb will only exist if this is a high-resolution CC message
            const [ccnMsb, ccnLsb] = Array.isArray(paramSpec.cc) ? paramSpec.cc : [paramSpec.cc];

            const ccvMsb = ccnLsb === undefined ? Math.round(value * 127) : Math.round(value * 16383) >> 7;
            device.sendControlChange(ccnMsb, ccvMsb, paramSpec.channel || midichan, { time: timeOffsetString });

            if (ccnLsb !== undefined) {
              const ccvLsb = Math.round(value * 16383) & 0b1111111;
              device.sendControlChange(ccnLsb, ccvLsb, paramSpec.channel || midichan, { time: timeOffsetString });
            }
          } else if (paramSpec.progNum !== undefined) {
            if (typeof value !== 'number' || value < 0 || value > 127) {
              throw new Error(`Expected ${name} to be a number between 0 and 127 for program change`);
            }
            device.sendProgramChange(value, paramSpec.channel || midichan, { time: timeOffsetString });
          }
        }
      });
    }

    // Handle program change
    if (progNum !== undefined) {
      if (typeof progNum !== 'number' || progNum < 0 || progNum > 127) {
        throw new Error('expected pc (program change) to be a number between 0 and 127');
      }
      device.sendProgramChange(progNum, midichan, { time: timeOffsetString });
    }
    // Handle sysex
    // sysex data is consist of 2 arrays, first is sysexid, second is sysexdata
    // sysexid is a manufacturer id it is either a number or an array of 3 numbers.
    // list of manufacturer ids can be found here : https://midi.org/sysexidtable
    // if sysexid is an array the first byte is 0x00

    if (sysexid !== undefined && sysexdata !== undefined) {
      if (Array.isArray(sysexid)) {
        if (!sysexid.every((byte) => Number.isInteger(byte) && byte >= 0 && byte <= 255)) {
          throw new Error('all sysexid bytes must be integers between 0 and 255');
        }
      } else if (!Number.isInteger(sysexid) || sysexid < 0 || sysexid > 255) {
        throw new Error('A:sysexid must be an number between 0 and 255 or an array of such integers');
      }

      if (!Array.isArray(sysexdata)) {
        throw new Error('expected sysex to be an array of numbers (0-255)');
      }
      if (!sysexdata.every((byte) => Number.isInteger(byte) && byte >= 0 && byte <= 255)) {
        throw new Error('all sysex bytes must be integers between 0 and 255');
      }

      device.sendSysex(sysexid, sysexdata, { time: timeOffsetString });
      //device.sendSysex(0x43, [0x79, 0x09, 0x11, 0x0A, 0x00,0x1e], { time: timeOffsetString });
    }

    // Handle control change
    if (ccv !== undefined && ccn !== undefined) {
      if (typeof ccv !== 'number' || ccv < 0 || ccv > 1) {
        throw new Error('expected ccv to be a number between 0 and 1');
      }
      if (!['string', 'number'].includes(typeof ccn)) {
        throw new Error('expected ccn to be a number or a string');
      }
      const scaled = Math.round(ccv * 127);
      device.sendControlChange(ccn, scaled, midichan, { time: timeOffsetString });
    }

    // Handle NRPN non-registered parameter number
    if (nrpnn !== undefined && nrpv !== undefined) {
      if (Array.isArray(nrpnn)) {
        if (!nrpnn.every((byte) => Number.isInteger(byte) && byte >= 0 && byte <= 255)) {
          throw new Error('all nrpnn bytes must be integers between 0 and 255');
        }
      } else if (!Number.isInteger(nrpv) || nrpv < 0 || nrpv > 255) {
        throw new Error('A:sysexid must be an number between 0 and 255 or an array of such integers');
      }

      device.sendNRPN(nrpnn, nrpv, midichan, { time: timeOffsetString });
    }

    // Handle midibend
    if (midibend !== undefined) {
      if (typeof midibend == 'number' || midibend < 1 || midibend > -1) {
        device.sendPitchBend(midibend, midichan, { time: timeOffsetString });
      } else {
        throw new Error('expected midibend to be a number between 1 and -1');
      }
    }

    // Handle miditouch
    if (miditouch !== undefined) {
      if (typeof miditouch == 'number' || miditouch < 1 || miditouch > 0) {
        device.sendChannelAfterTouch(miditouch, midichan, { time: timeOffsetString });
      } else {
        throw new Error('expected miditouch to be a number between 1 and 0');
      }
    }

    // Handle midicmd
    if (hap.whole.begin + 0 === 0) {
      // we need to start here because we have the timing info
      device.sendStart({ time: timeOffsetString });
    }
    if (['clock', 'midiClock'].includes(midicmd)) {
      device.sendClock({ time: timeOffsetString });
    } else if (['start'].includes(midicmd)) {
      device.sendStart({ time: timeOffsetString });
    } else if (['stop'].includes(midicmd)) {
      device.sendStop({ time: timeOffsetString });
    } else if (['continue'].includes(midicmd)) {
      device.sendContinue({ time: timeOffsetString });
    } else if (Array.isArray(midicmd)) {
      if (midicmd[0] === 'progNum') {
        if (typeof midicmd[1] !== 'number' || midicmd[1] < 0 || midicmd[1] > 127) {
          throw new Error('expected pc (program change) to be a number between 0 and 127');
        } else {
          device.sendProgramChange(midicmd[1], midichan, { time: timeOffsetString });
        }
      } else if (midicmd[0] === 'cc') {
        if (midicmd.length === 2) {
          if (typeof midicmd[0] !== 'number' || midicmd[0] < 0 || midicmd[0] > 127) {
            throw new Error('expected ccn (control change number) to be a number between 0 and 127');
          }
          if (typeof midicmd[1] !== 'number' || midicmd[1] < 0 || midicmd[1] > 127) {
            throw new Error('expected ccv (control change value) to be a number between 0 and 127');
          }
          device.sendControlChange(midicmd[0], midicmd[1], midichan, { time: timeOffsetString });
        }
      } else if (midicmd[0] === 'sysex') {
        if (midicmd.length === 3) {
          const [_, id, data] = midicmd;
          if (Array.isArray(id)) {
            if (!id.every((byte) => Number.isInteger(byte) && byte >= 0 && byte <= 255)) {
              throw new Error('all sysex id bytes must be integers between 0 and 255');
            }
          } else if (!Number.isInteger(id) || id < 0 || id > 255) {
            throw new Error('sysex id must be a number between 0 and 255 or an array of such integers');
          }
          if (!Array.isArray(data) || !data.every((byte) => Number.isInteger(byte) && byte >= 0 && byte <= 255)) {
            throw new Error('sysex data must be an array of integers between 0 and 255');
          }
          device.sendSysex(id, data, { time: timeOffsetString });
        }
      }
    }
  });
};

let listeners = {};
const refs = {};

/**
 * MIDI input: Opens a MIDI input port to receive MIDI control change messages.
 * @param {string | number} input MIDI device name or index defaulting to 0
 * @returns {Function}
 * @example
 * let cc = await midin("IAC Driver Bus 1")
 * note("c a f e").lpf(cc(0).range(0, 1000)).lpq(cc(1).range(0, 10)).sound("sawtooth")
 */
export async function midin(input) {
  if (isPattern(input)) {
    throw new Error(
      `midin: does not accept Pattern as input. Make sure to pass device name with single quotes. Example: midin('${
        WebMidi.outputs?.[0]?.name || 'IAC Driver Bus 1'
      }')`,
    );
  }
  const initial = await enableWebMidi(); // only returns on first init
  const device = getDevice(input, WebMidi.inputs);
  if (!device) {
    throw new Error(
      `midiin: device "${input}" not found.. connected devices: ${getMidiDeviceNamesString(WebMidi.inputs)}`,
    );
  }
  if (initial) {
    const otherInputs = WebMidi.inputs.filter((o) => o.name !== device.name);
    logger(
      `Midi enabled! Using "${device.name}". ${
        otherInputs?.length ? `Also available: ${getMidiDeviceNamesString(otherInputs)}` : ''
      }`,
    );
    refs[input] = {};
  }
  const cc = (cc) => ref(() => refs[input][cc] || 0);

  listeners[input] && device.removeListener('midimessage', listeners[input]);
  listeners[input] = (e) => {
    const cc = e.dataBytes[0];
    const v = e.dataBytes[1];
    refs[input] && (refs[input][cc] = v / 127);
  };
  device.addListener('midimessage', listeners[input]);
  return cc;
}