music.js

// Music synthesizer (`playTabs`) and tabs
// Tab format:
// whitespace is irrelevant
// pauses: _x4 (pause 4x); _ (pause 1x)
// notes:  f#x2 (play f# 2x); f# (play f# 1x)

let audioCtx

// let drumTempo = (60_000 / (120 * 2)) / 2;

// A register to avoid Terser writing 'let' sometimes
let UNUSED_VAR;

let VOLUME_MOD = 1
let DRUM_VOLUME_MOD = 0.04;

let trimSplit = s => {
  return s.trim().split(/\s+/g)
}
let notes_names = trimSplit('_ c c# d d# e f f# g g# a a# b')
let getNoteFreq = (note, octave) => {
  note = notes_names.indexOf(note);
  return note && 32.7 * (2 ** (1/12)) ** ((note - 1) + (octave * 12));
};

let setValue = (thing, value) => {
  thing.value = value;
};

let instrument = (volume, waveShape) => {
  let oscillator = audioCtx.createOscillator();
  let gainNode = audioCtx.createGain();
  let gainNode2 = audioCtx.createGain();

  document.addEventListener("visibilitychange", () => {
    // "visible" becomes true, becomes 1.0
    setValue(gainNode2.gain, document.visibilityState > 'v');
  });
  setValue(oscillator.frequency, 0);
  setValue(gainNode.gain, log2(1 + 0.025 * volume));
  oscillator.type = waveShape;
  oscillator.start();
  oscillator.connect(gainNode).connect(gainNode2).connect(audioCtx.destination);
  return [oscillator.frequency, gainNode.gain];
};

let playTabs = async (tabs) => {
  while (1) {
    for (let [tab, delay] of tabs) {
      sleep_native(delay).then(() => tab.next())
    }
    await sleep_native(drumTempo, 0);
  }
}

let drumWavePlan = async (plan, freqStart, freqEnd, frequency, gain, mod) => {
  for (UNUSED_VAR of plan) {
    setValue(frequency, lerp(freqStart, freqEnd, UNUSED_VAR[0]) * mod)
    setValue(gain, (UNUSED_VAR[1] || UNUSED_VAR[0]) * DRUM_VOLUME_MOD)
    await sleep_native(10)
  }
}

let tabPlayer = function*([frequency, gain], tempo, mod, tab, endingSolo) {
  for (;;) {
    for (UNUSED_VAR of trimSplit(tab)) {
      let [,note, octave, count = 1] = UNUSED_VAR.match(/^(\w#?|_)(\d?)x?(\d+)?$/)

      let should_mute =
        currently_paused
        || ENDING_CUTSCENE && !endingSolo
      if (!should_mute) {
        if (note === 'x') {
          drumWavePlan([
            [1],
            [.75, .7],
            [.75, .7],
            [.7],
            [.57, .6],
            [.27, .6],
            [.17, .5],
            [.1, .4],
            [.1, .2],
            [0],
          ], 111, 255, frequency, gain, mod)
        } else if (note === 'o') {
          drumWavePlan([
            [.4],
            [.8],
            [1],
            [.75, .7],
            [.7],
            [.57, .6],
            [.27, .6],
            [.17, .5],
            [.1, .4],
            [.1, .2],
            [0],
          ], 15, 70, frequency, gain, mod)
        } else {
          let freq = getNoteFreq(note, octave);
          setValue(frequency, freq * mod);
        }
      } else {
        setValue(frequency, 0)
      }

      for (UNUSED_VAR of range(tempo * count)) yield;
    }
  }
}

/*
// mechanical turk fight music
let motif = 'a3x4 c4x4 b3x4 a#3x4';
let response = 'a3x2 _ a3';

let tab =
`${motif} ${response} _x4 ${response} _x4
a3x4 c4x4 d#4x4 g3x4 ${response} _x4 ${response} _x4
${motif} ${response} _x4 ${response} _x4
a3x2 b3x2 c4x2 d4x2 e4x2 d4x2 g4x2 g3x2 a3x2 _ a3 _x4 ${response} _x4
${motif} ${motif}
a4 g4 f4 e4 f4 e4 d4 c4 b3 a3 g3 a3 b3 c4 g3 _ a3x8 ${response} _x4`;
let drumTab = `x _ o _ x _ o _ x _ o _ x x o _`
firstUserInteraction.then(() => {
  audioCtx = new AudioContext();
  playTabs([
    [tabPlayer(instrument(0.3, 'square'), 2, 1, tab), 0],
    [tabPlayer(instrument(0.3), 2, 2, tab), 34],
    [tabPlayer(instrument(0.0, 'square'), 1, 1, drumTab), 34],
  ])
})
*/

/*
// mechanical turk cafe music
let tab = ''
+ `_x2 _x2 d3x2 d3x2 e3x2 f3x2 d3x2 a3x6 d3x2 d3x2 e3x2 f3x2 d3x2 _x2 d3x4 d3x4 e3x2 f3x2 d3x2 a3x6 d3x2 e3x2 f3x2 d3x2 e3x2 _x2 `
+ `d3x3 c3x3 a2x2 d3x3 c3x3 a2x2 d3x3 c3x3 a2x2 d3x3 c3x3 c#3x2 d3x13 _x19 `
+ `d4x2 a3x2 d4x2 a3x2 d4x2 a3x2 d4x2 a3x2 c4x2 g3x2 c4x2 g3x2 c4x2 g3x2 c4x2 g3x2 b3x2 f#3x2 b3x2 f#3x2 b3x2 f#3x2 b3x2 g3x2 a3x8 _ _ a3 _ a3 _ a3 _ `
+ `d4x2 a3x2 d4x2 a3x2 d4x2 a3x2 d4x2 a3x2 c4x2 g3x2 c4x2 g3x2 c4x2 g3x2 f4x2 c#4x2 d4x2 a3x2 d4x2 a3x2 d4x2 a3x2 d4x2 c4x2 d4x8 _ _ d4 _ d4 _ d4 _`;
let tab2 = ''
+ `_x14 a2x6 _x12 d2x4 _x10 a2x6 _x12 `
+ `d4x2 _ d4x2 _ d4x2 c4x2 _ c4x2 _ c4x2 b3x2 _ b3x2 _ b3x2 a3x2 _ a3x2 _ a3x2 d4x13 _x19 `
+ `_x48 a2x8 _ _ a2 _ a2 _ a2 _ `
+ `_x48 d3x8 _ _ d3 _ d3 _ d3 _`;
let drumTab = `o o o x _ o o x _ o o x x _ x _`


firstUserInteraction.then(() => {
  audioCtx = new AudioContext();
  playTabs([
    [tabPlayer(instrument(0.3, 'square'), 1, 1, tab), 34],
    [tabPlayer(instrument(0.3), 1, 2, tab), 64],
    [tabPlayer(instrument(0.1, 'sawtooth'), 1, 2, tab), 16],
  
    [tabPlayer(instrument(0.15, 'sawtooth'), 1, 4, tab2), 34],
    [tabPlayer(instrument(0.3), 1, 1, tab2), 64],
  
    [tabPlayer(instrument(0.0, 'square'), 2, 1, drumTab), 36],
  ])
})

*/

let musicInitialize = () => {
  audioCtx = new AudioContext();
}

// Original game music
let drumTempo = (60_000 / (165 * 2)) / 2;

let musicStartMainTheme = () => {
  let stopX3 = '_x24 '
  let stopX4 = stopX3 + '_x8 '

  let drum1 = 'o o x o o o x o '
  let drum2 = 'o o x o x o x o '
  let drumTab = ''
  // part 1
  + drum1
  + drum2
  // part 2
  + drum2
  + drum2

  let mainInstrumentPart1Motif = ''
  + 'e3x2 _x2 e3x2 d3x2 e3x2 _x2 e3x2 _x2 '
  + 'g3x2 _x2 g3x2 d3x2 g3x2 _x2 g3x2 _x2 '
  let mainInstrumentPart1Motif2 = ''
  + 'e4x2 _x2 e4x2 _x2 e4 _ g4 _ b4x2 _x2 '

  let mainInstrumentPart2Cadence = note => (note + ' _ ').repeat(7) + note + 'x2 '
  let mainInstrumentPart2Bit1 = mainInstrumentPart2Cadence('e4')
  let mainInstrumentPart2Bit2 = 'e3 _ e3 _ g3 _ a3 _ b3 _ b3 _ a3 _ g3x2 '
  let mainInstrumentPart2Motif = ''
  + mainInstrumentPart2Bit1
  + mainInstrumentPart2Cadence('d4')
  let mainInstrumentPart2Motif2 = ''
  + mainInstrumentPart2Bit1
  + mainInstrumentPart2Cadence('g4')
  let mainInstrumentPart2Response = ''
  + mainInstrumentPart2Bit2
  + mainInstrumentPart2Bit2
  let mainInstrumentPart2Response2 = ''
  + mainInstrumentPart2Bit2
  + mainInstrumentPart2Cadence('e3')
  let mainInstrumentPart2Finish = ''
  + mainInstrumentPart2Bit2
  + 'b3 _ a3 _ a3x2 _x2 b3 _ a3 _ d3x2 _x2 '
  let mainInstrumentTab = ''
  // part 1
  + mainInstrumentPart1Motif
  + mainInstrumentPart1Motif2
  + mainInstrumentPart1Motif2
  + mainInstrumentPart1Motif
  + mainInstrumentPart1Motif2
  + 'e4x2 _x2 e4x2 _x2 e4 _ d4 _ e4x2 _x2 '
  // part 2
  + mainInstrumentPart2Motif
  + mainInstrumentPart2Response
  + mainInstrumentPart2Motif
  + mainInstrumentPart2Response2
  + mainInstrumentPart2Motif2
  + mainInstrumentPart2Response
  + mainInstrumentPart2Motif
  + mainInstrumentPart2Finish

  let secondInstrumentBit = 'b3x2 _x2 b3x2 _x2 b3 _ d4 _ e4x2 _x2 '
  let secondInstrumentPhrase = ''
  + mainInstrumentPart2Cadence('b3')
  + mainInstrumentPart2Cadence('a3')
  + stopX4
  let secondInstrumentResponse = ''
  + mainInstrumentPart2Cadence('b3')
  + mainInstrumentPart2Cadence('d4')
  + stopX4
  let secondInstrumentTab = ''
  // part 1
  + stopX4
  + secondInstrumentBit
  + secondInstrumentBit
  + stopX4
  + secondInstrumentBit
  + 'b3x2 _x2 b3x2 _x2 b3 _ a3 _ b3x2 _x2 '
  // part 2
  + secondInstrumentPhrase
  + secondInstrumentPhrase
  + secondInstrumentResponse
  + secondInstrumentPhrase

  let highPitchedSlowStart = ''
  + 'b5x2 _x2 g5x2 _x2 e5x2 _x2 '
  + 'b5x2 _x2 g5x2 _x2 e5x2 _x2 '
  let highPitchedPart1A = ''
  + highPitchedSlowStart
  + 'b5x2 _x2 g5x2 _x2 e5x8 '
  + stopX3
  let highPitchedPart1B = ''
  + highPitchedSlowStart
  + 'b5x2 _x2 c6x2 _x2 e5x8 '
  + stopX3

  let highPitchedFastStart = ''
  + 'e5 _ g5 _ b5 _ e5 _ g5 _ b5 _ e5 _ g5 _ b5 _ e5 _ g5 _ b5 _ '
  let highPitchedPart2A = ''
  + highPitchedFastStart
  + 'b5 _ b5 _ b5x4 '
  + stopX4
  let highPitchedPart2B = ''
  + highPitchedFastStart
  + 'b5 _ a5 _ b5x4 '
  + stopX4
  let highPitchedPart2C = ''
  + highPitchedFastStart
  + 'd6 _ e6 _ b5x4 '
  + stopX4
  let highPitchedTab = ''
  + highPitchedPart1A
  + highPitchedPart1B
  + highPitchedPart2A
  + highPitchedPart2B
  + highPitchedPart2C
  + highPitchedPart2A

  playTabs([
    [tabPlayer(instrument(0.3 * VOLUME_MOD, 'sawtooth'), 1, 1, mainInstrumentTab), 34],
    [tabPlayer(instrument(0.3 * VOLUME_MOD), 1, 1, mainInstrumentTab), 16],

    [tabPlayer(instrument(0.1 * VOLUME_MOD, ''), 1, 1, secondInstrumentTab), 16],

    // High pitched backing track
    [tabPlayer(instrument(0.125 * VOLUME_MOD, ''), 1, 1/2, highPitchedTab), 16],
    [tabPlayer(instrument(0.3 * VOLUME_MOD), 1, 1, highPitchedTab), 16],

    // Drum
    [tabPlayer(instrument(0.0, 'square'), 2, 1, drumTab, 1), 0],
  ])
}