Regenerate softer orchestral bgm

docs/roadmap.md

@@ -15,7 +15,7 @@ Build a small complete tactical RPG loop:
 - Vite, TypeScript, and Phaser project foundation
 - Cinematic title scene with an original Taoyuan Oath background, subtle motion, menu UI, and first-input audio
 - Cinematic prologue pages with high-resolution story backgrounds, character portraits, non-black scene transitions, and scenario data
-- File-based original orchestral BGM loops for title, prologue, oath, militia, and battle-prep scenes
+- File-based original soft stereo orchestral BGM loops for title, prologue, oath, militia, and battle-prep scenes
 - First battle scene with a high-resolution battlefield background, large 12x12 tactical grid, high-detail pixel-style unit sprites, movement range preview, click-to-move unit movement, cursor-adjacent post-move command popup, right-click move cancel, and grayscale acted-unit feedback
 - Flow verification script from title to first battle
 

scripts/generate-bgm.mjs

@@ -1,7 +1,8 @@
 import { mkdirSync, writeFileSync } from 'node:fs';
 import { join } from 'node:path';
 
-const sampleRate = 32000;
+const sampleRate = 44100;
+const channels = 2;
 const outputDir = 'src/assets/audio/bgm';
 
 mkdirSync(outputDir, { recursive: true });
@@ -10,84 +11,88 @@ const tracks = [
   {
     name: 'title-theme',
     root: 50,
-    tempo: 64,
+    tempo: 74,
     bars: 12,
+    mood: 'open',
     progression: [
-      [0, 5, 9],
+      [0, 7, 12],
+      [5, 9, 14],
       [2, 7, 11],
-      [-3, 2, 7],
-      [0, 5, 12]
+      [-3, 4, 9]
     ],
-    melody: [12, 14, 16, 19, 21, 19, 16, 14],
-    warmth: 1,
-    motion: 0.45
+    melody: [12, 16, 19, 21, 19, 16, 14, 12],
+    harp: [0, 7, 12, 19, 12, 7, 5, 12]
   },
   {
     name: 'story-dark',
     root: 45,
-    tempo: 56,
+    tempo: 62,
     bars: 10,
+    mood: 'quiet',
     progression: [
-      [0, 3, 7],
-      [-5, 0, 5],
-      [-2, 2, 7],
-      [-7, 0, 3]
+      [0, 7, 10],
+      [-5, 2, 7],
+      [-3, 4, 9],
+      [-7, 0, 7]
     ],
     melody: [10, 7, 5, 3, 5, 7],
-    warmth: 0.72,
-    motion: 0.18
+    harp: [0, 7, 10, 14, 10, 7]
   },
   {
     name: 'oath-theme',
     root: 52,
-    tempo: 60,
+    tempo: 68,
     bars: 12,
+    mood: 'warm',
     progression: [
-      [0, 5, 9],
-      [4, 9, 12],
-      [5, 9, 14],
-      [2, 7, 11]
+      [0, 7, 12],
+      [4, 9, 16],
+      [5, 12, 17],
+      [2, 9, 14]
     ],
     melody: [12, 16, 19, 21, 24, 21, 19, 16],
-    warmth: 1,
-    motion: 0.32
+    harp: [0, 7, 12, 16, 19, 16, 12, 7]
   },
   {
     name: 'militia-theme',
     root: 48,
-    tempo: 72,
+    tempo: 84,
     bars: 12,
+    mood: 'march',
     progression: [
-      [0, 5, 9],
-      [5, 9, 12],
-      [7, 11, 14],
-      [2, 7, 11]
+      [0, 7, 12],
+      [5, 12, 17],
+      [7, 14, 19],
+      [2, 9, 14]
     ],
     melody: [12, 14, 16, 19, 16, 14, 12, 14],
-    warmth: 0.9,
-    motion: 0.5
+    harp: [0, 7, 12, 7, 5, 12, 7, 12]
   },
   {
     name: 'battle-prep',
     root: 43,
-    tempo: 68,
+    tempo: 78,
     bars: 12,
+    mood: 'tense',
     progression: [
-      [0, 3, 7],
-      [2, 7, 10],
-      [-2, 3, 7],
-      [-5, 0, 5]
+      [0, 7, 10],
+      [2, 9, 14],
+      [-2, 5, 10],
+      [-5, 2, 7]
     ],
     melody: [12, 15, 17, 19, 17, 15, 12, 10],
-    warmth: 0.82,
-    motion: 0.42
+    harp: [0, 7, 10, 15, 10, 7, 2, 10]
   }
 ];
 
 for (const track of tracks) {
   const buffer = buildTrack(track);
-  normalize(buffer, 0.48);
+  removeLowRumble(buffer, 72);
+  applySmallRoom(buffer);
+  normalize(buffer, 0.34);
   applySoftLimiter(buffer);
+  smoothEdges(buffer, Math.floor(sampleRate * 1.6));
+
   const fileName = join(outputDir, `${track.name}.wav`);
   writeFileSync(fileName, encodeWav(buffer));
   console.log(`Generated ${fileName}`);
@@ -97,113 +102,264 @@ function buildTrack(track) {
   const beat = 60 / track.tempo;
   const bar = beat * 4;
   const duration = bar * track.bars;
-  const buffer = new Float32Array(Math.ceil(duration * sampleRate));
+  const buffer = createBuffer(duration);
 
   for (let barIndex = 0; barIndex < track.bars; barIndex += 1) {
     const start = barIndex * bar;
     const chord = track.progression[barIndex % track.progression.length];
-    const lift = 0.82 + Math.sin((barIndex / track.bars) * Math.PI) * 0.18;
-    const bass = track.root + chord[0] - 12;
+    const lift = 0.86 + Math.sin((barIndex / Math.max(1, track.bars - 1)) * Math.PI) * 0.14;
 
-    chord.forEach((step, index) => {
-      const midi = track.root + step + 12;
-      addPad(buffer, start + index * 0.04, bar * 1.08, midiToFrequency(midi), 0.07 * track.warmth * lift);
-      addPad(buffer, start + 0.06 + index * 0.03, bar * 1.02, midiToFrequency(midi + 12), 0.025 * track.warmth * lift);
-    });
+    addStringBed(buffer, start, bar * 0.96, track.root, chord, lift, track.mood);
+    addCelloPulse(buffer, start, beat, track.root + chord[0], track.mood);
+    addHarpFigure(buffer, start, beat, track.root, chord, track.harp, track.mood);
 
-    addLowPad(buffer, start, bar * 1.04, midiToFrequency(bass), 0.055 * lift);
-    addLowPad(buffer, start + beat * 2, bar * 0.54, midiToFrequency(bass + 7), 0.035 * lift);
-
-    if (track.motion > 0.25) {
-      addGentlePulse(buffer, start, beat, track.root, chord, track.motion * 0.026);
+    if (track.mood === 'march' || track.mood === 'tense') {
+      addSoftDrum(buffer, start, beat, track.mood);
     }
   }
 
-  addSoftMelody(buffer, track, beat, bar);
-  smoothEdges(buffer, Math.floor(sampleRate * 1.2));
+  addLeadLine(buffer, track, beat, bar);
   return buffer;
 }
 
-function addSoftMelody(buffer, track, beat, bar) {
-  for (let i = 0; i < track.bars * 2; i += 1) {
-    const barIndex = Math.floor(i / 2);
-    const start = barIndex * bar + (i % 2 === 0 ? beat * 0.38 : beat * 2.38);
+function createBuffer(duration) {
+  const length = Math.ceil(duration * sampleRate);
+  return {
+    left: new Float32Array(length),
+    right: new Float32Array(length)
+  };
+}
+
+function addStringBed(buffer, start, duration, root, chord, lift, mood) {
+  const baseGain = mood === 'quiet' ? 0.019 : mood === 'tense' ? 0.021 : 0.026;
+  const notes = [
+    { midi: root + chord[0] + 12, pan: -0.22, gain: baseGain * 0.72 },
+    { midi: root + chord[1] + 12, pan: 0.24, gain: baseGain * 0.64 },
+    { midi: root + chord[2] + 12, pan: -0.04, gain: baseGain * 0.56 },
+    { midi: root + chord[1] + 24, pan: 0.18, gain: baseGain * 0.28 }
+  ];
+
+  notes.forEach((note, index) => {
+    addTone(buffer, {
+      start: start + index * 0.045,
+      duration,
+      frequency: midiToFrequency(note.midi),
+      gain: note.gain * lift,
+      pan: note.pan,
+      attack: mood === 'tense' ? 1.1 : 1.45,
+      release: 1.25,
+      wave: softStringWave
+    });
+  });
+}
+
+function addCelloPulse(buffer, start, beat, midi, mood) {
+  const pulses = mood === 'quiet' ? [0] : [0, 2];
+  const gain = mood === 'tense' ? 0.024 : mood === 'march' ? 0.026 : 0.018;
+
+  pulses.forEach((beatOffset) => {
+    addTone(buffer, {
+      start: start + beat * beatOffset,
+      duration: beat * 1.35,
+      frequency: midiToFrequency(Math.max(43, midi + 12)),
+      gain,
+      pan: -0.08,
+      attack: 0.08,
+      release: 0.55,
+      wave: mellowCelloWave
+    });
+  });
+}
+
+function addHarpFigure(buffer, start, beat, root, chord, pattern, mood) {
+  const gain = mood === 'quiet' ? 0.011 : mood === 'tense' ? 0.014 : 0.016;
+  const stepDuration = beat * 0.46;
+  const stepGap = mood === 'quiet' ? beat : beat * 0.5;
+  const steps = mood === 'quiet' ? 4 : 8;
+
+  for (let i = 0; i < steps; i += 1) {
+    const offset = pattern[i % pattern.length];
+    const chordTone = chord[i % chord.length];
+    addPluck(buffer, {
+      start: start + i * stepGap + beat * 0.08,
+      duration: stepDuration,
+      frequency: midiToFrequency(root + offset + 12 + (i % 2 === 0 ? 0 : chordTone % 5)),
+      gain,
+      pan: i % 2 === 0 ? -0.32 : 0.32
+    });
+  }
+}
+
+function addLeadLine(buffer, track, beat, bar) {
+  const noteEvery = track.mood === 'quiet' ? 2 : 1;
+  const gain = track.mood === 'tense' ? 0.018 : track.mood === 'quiet' ? 0.016 : 0.021;
+
+  for (let i = 0; i < track.bars * noteEvery; i += 1) {
+    const barIndex = Math.floor(i / noteEvery);
+    const offsetInBar = noteEvery === 1 ? beat * 1.42 : beat * 1.85;
+    const start = barIndex * bar + offsetInBar + (i % noteEvery) * beat * 1.34;
     const midi = track.root + track.melody[i % track.melody.length] + 12;
-    addWoodwind(buffer, start, beat * 1.12, midiToFrequency(midi), 0.034);
+
+    addTone(buffer, {
+      start,
+      duration: beat * 1.05,
+      frequency: midiToFrequency(midi),
+      gain,
+      pan: 0.12,
+      attack: 0.13,
+      release: 0.5,
+      wave: woodwindWave
+    });
   }
 }
 
-function addGentlePulse(buffer, start, beat, root, chord, gain) {
-  const pattern = [0, 1, 2, 1, 0, 2, 1, 2];
+function addSoftDrum(buffer, start, beat, mood) {
+  const accents = mood === 'tense' ? [0, 2] : [0, 1.5, 2.5];
+  const gain = mood === 'tense' ? 0.034 : 0.026;
 
-  for (let i = 0; i < pattern.length; i += 1) {
-    const midi = root + chord[pattern[i] % chord.length] + 12;
-    addPluckedString(buffer, start + i * beat * 0.5, beat * 0.42, midiToFrequency(midi), gain);
-  }
+  accents.forEach((beatOffset, index) => {
+    addTone(buffer, {
+      start: start + beat * beatOffset,
+      duration: beat * 0.5,
+      frequency: index === 0 ? 92 : 122,
+      gain: gain * (index === 0 ? 1 : 0.62),
+      pan: 0,
+      attack: 0.006,
+      release: 0.16,
+      wave: drumWave,
+      pluck: true,
+      decay: 8.5
+    });
+  });
 }
 
-function addPad(buffer, start, duration, frequency, gain) {
-  addInstrument(buffer, start, duration, frequency, gain, (phase, t) => {
-    const slow = Math.sin(2 * Math.PI * 0.18 * t) * 0.03;
-    return (
-      Math.sin(phase + slow) * 0.72 +
-      Math.sin(phase * 2.001) * 0.12 +
-      Math.sin(phase * 0.5) * 0.08
-    );
-  }, 0.78, 1.05);
-}
-
-function addLowPad(buffer, start, duration, frequency, gain) {
-  addInstrument(buffer, start, duration, frequency, gain, (phase) => {
-    return Math.sin(phase) * 0.84 + Math.sin(phase * 2) * 0.1;
-  }, 0.46, 0.9);
-}
-
-function addWoodwind(buffer, start, duration, frequency, gain) {
-  addInstrument(buffer, start, duration, frequency, gain, (phase, t) => {
-    const vibrato = Math.sin(2 * Math.PI * 4.6 * t) * 0.012;
-    return Math.sin(phase + vibrato) * 0.82 + Math.sin(phase * 2) * 0.06;
-  }, 0.12, 0.42);
-}
-
-function addPluckedString(buffer, start, duration, frequency, gain) {
-  addInstrument(buffer, start, duration, frequency, gain, (phase) => {
-    return Math.sin(phase) * 0.75 + Math.sin(phase * 2) * 0.1;
-  }, 0.02, 0.18, true);
-}
-
-function addInstrument(buffer, start, duration, frequency, gain, wave, attack, release, pluck = false) {
+function addTone(buffer, options) {
+  const {
+    start,
+    duration,
+    frequency,
+    gain,
+    pan,
+    attack,
+    release,
+    wave,
+    pluck = false,
+    decay = 5
+  } = options;
   const startIndex = Math.max(0, Math.floor(start * sampleRate));
   const count = Math.max(1, Math.floor(duration * sampleRate));
+  const leftGain = Math.cos((pan + 1) * Math.PI * 0.25);
+  const rightGain = Math.sin((pan + 1) * Math.PI * 0.25);
 
   for (let i = 0; i < count; i += 1) {
     const index = startIndex + i;
-    if (index >= buffer.length) {
+    if (index >= buffer.left.length) {
       break;
     }
 
     const t = i / sampleRate;
     const env = pluck
-      ? Math.exp(-t * 5.8) * Math.min(1, t / attack)
+      ? Math.exp(-t * decay) * Math.min(1, t / Math.max(0.001, attack))
       : envelope(t, duration, attack, release);
     const phase = 2 * Math.PI * frequency * t;
-    buffer[index] += wave(phase, t) * gain * env;
+    const sample = wave(phase, t) * gain * env;
+    buffer.left[index] += sample * leftGain;
+    buffer.right[index] += sample * rightGain;
   }
 }
 
+function addPluck(buffer, options) {
+  addTone(buffer, {
+    ...options,
+    attack: 0.01,
+    release: 0.22,
+    wave: harpWave,
+    pluck: true,
+    decay: 4.6
+  });
+}
+
+function softStringWave(phase, t) {
+  const bow = 1 + Math.sin(2 * Math.PI * 0.7 * t) * 0.018;
+  return (
+    Math.sin(phase * bow) * 0.7 +
+    Math.sin(phase * 2) * 0.13 +
+    Math.sin(phase * 3) * 0.045
+  );
+}
+
+function mellowCelloWave(phase) {
+  return Math.sin(phase) * 0.78 + Math.sin(phase * 2) * 0.09 + Math.sin(phase * 0.5) * 0.04;
+}
+
+function woodwindWave(phase, t) {
+  const vibrato = Math.sin(2 * Math.PI * 4.2 * t) * 0.006;
+  return Math.sin(phase + vibrato) * 0.86 + Math.sin(phase * 2) * 0.045;
+}
+
+function harpWave(phase) {
+  return Math.sin(phase) * 0.82 + Math.sin(phase * 2) * 0.12 + Math.sin(phase * 3) * 0.035;
+}
+
+function drumWave(phase, t) {
+  const drop = 1 - Math.min(1, t * 5.2) * 0.42;
+  return Math.sin(phase * drop) * 0.92 + Math.sin(phase * 2.02) * 0.06;
+}
+
 function envelope(t, duration, attack, release) {
-  const attackLevel = Math.min(1, t / attack);
-  const releaseLevel = Math.min(1, (duration - t) / release);
-  const curved = Math.sin(Math.min(1, attackLevel) * Math.PI * 0.5);
-  return Math.max(0, Math.min(curved, releaseLevel));
+  const attackLevel = Math.min(1, t / Math.max(0.001, attack));
+  const releaseLevel = Math.min(1, (duration - t) / Math.max(0.001, release));
+  const attackCurve = Math.sin(attackLevel * Math.PI * 0.5);
+  return Math.max(0, Math.min(attackCurve, releaseLevel));
+}
+
+function removeLowRumble(buffer, cutoff) {
+  highPass(buffer.left, cutoff);
+  highPass(buffer.right, cutoff);
+}
+
+function highPass(samples, cutoff) {
+  const rc = 1 / (2 * Math.PI * cutoff);
+  const dt = 1 / sampleRate;
+  const alpha = rc / (rc + dt);
+  let previousOutput = 0;
+  let previousInput = samples[0] ?? 0;
+
+  for (let i = 0; i < samples.length; i += 1) {
+    const input = samples[i];
+    const output = alpha * (previousOutput + input - previousInput);
+    samples[i] = output;
+    previousOutput = output;
+    previousInput = input;
+  }
+}
+
+function applySmallRoom(buffer) {
+  const originalLeft = Float32Array.from(buffer.left);
+  const originalRight = Float32Array.from(buffer.right);
+  const delays = [
+    { samples: Math.floor(sampleRate * 0.075), gain: 0.09 },
+    { samples: Math.floor(sampleRate * 0.132), gain: 0.055 }
+  ];
+
+  delays.forEach(({ samples, gain }) => {
+    for (let i = samples; i < buffer.left.length; i += 1) {
+      buffer.left[i] += originalRight[i - samples] * gain;
+      buffer.right[i] += originalLeft[i - samples] * gain;
+    }
+  });
 }
 
 function smoothEdges(buffer, samples) {
-  for (let i = 0; i < Math.min(samples, buffer.length); i += 1) {
-    const fadeIn = Math.sin((i / samples) * Math.PI * 0.5);
-    const fadeOut = Math.sin((i / samples) * Math.PI * 0.5);
-    buffer[i] *= fadeIn;
-    buffer[buffer.length - 1 - i] *= fadeOut;
+  const limit = Math.min(samples, buffer.left.length);
+
+  for (let i = 0; i < limit; i += 1) {
+    const fadeIn = Math.sin((i / limit) * Math.PI * 0.5);
+    const fadeOut = Math.sin((i / limit) * Math.PI * 0.5);
+    buffer.left[i] *= fadeIn;
+    buffer.right[i] *= fadeIn;
+    buffer.left[buffer.left.length - 1 - i] *= fadeOut;
+    buffer.right[buffer.right.length - 1 - i] *= fadeOut;
   }
 }
 
@@ -213,8 +369,8 @@ function midiToFrequency(midi) {
 
 function normalize(buffer, target) {
   let peak = 0;
-  for (const value of buffer) {
-    peak = Math.max(peak, Math.abs(value));
+  for (let i = 0; i < buffer.left.length; i += 1) {
+    peak = Math.max(peak, Math.abs(buffer.left[i]), Math.abs(buffer.right[i]));
   }
 
   if (peak === 0) {
@@ -222,20 +378,23 @@ function normalize(buffer, target) {
   }
 
   const scale = target / peak;
-  for (let i = 0; i < buffer.length; i += 1) {
-    buffer[i] *= scale;
+  for (let i = 0; i < buffer.left.length; i += 1) {
+    buffer.left[i] *= scale;
+    buffer.right[i] *= scale;
   }
 }
 
 function applySoftLimiter(buffer) {
-  for (let i = 0; i < buffer.length; i += 1) {
-    buffer[i] = Math.tanh(buffer[i] * 1.15) / Math.tanh(1.15);
+  for (let i = 0; i < buffer.left.length; i += 1) {
+    buffer.left[i] = Math.tanh(buffer.left[i] * 1.08) / Math.tanh(1.08);
+    buffer.right[i] = Math.tanh(buffer.right[i] * 1.08) / Math.tanh(1.08);
   }
 }
 
 function encodeWav(buffer) {
   const bytesPerSample = 2;
-  const dataSize = buffer.length * bytesPerSample;
+  const frameCount = buffer.left.length;
+  const dataSize = frameCount * channels * bytesPerSample;
   const wav = Buffer.alloc(44 + dataSize);
 
   wav.write('RIFF', 0);
@@ -244,17 +403,20 @@ function encodeWav(buffer) {
   wav.write('fmt ', 12);
   wav.writeUInt32LE(16, 16);
   wav.writeUInt16LE(1, 20);
-  wav.writeUInt16LE(1, 22);
+  wav.writeUInt16LE(channels, 22);
   wav.writeUInt32LE(sampleRate, 24);
-  wav.writeUInt32LE(sampleRate * bytesPerSample, 28);
-  wav.writeUInt16LE(bytesPerSample, 32);
+  wav.writeUInt32LE(sampleRate * channels * bytesPerSample, 28);
+  wav.writeUInt16LE(channels * bytesPerSample, 32);
   wav.writeUInt16LE(16, 34);
   wav.write('data', 36);
   wav.writeUInt32LE(dataSize, 40);
 
-  for (let i = 0; i < buffer.length; i += 1) {
-    const value = Math.max(-1, Math.min(1, buffer[i]));
-    wav.writeInt16LE(Math.round(value * 32767), 44 + i * bytesPerSample);
+  for (let i = 0; i < frameCount; i += 1) {
+    const left = Math.max(-1, Math.min(1, buffer.left[i]));
+    const right = Math.max(-1, Math.min(1, buffer.right[i]));
+    const offset = 44 + i * channels * bytesPerSample;
+    wav.writeInt16LE(Math.round(left * 32767), offset);
+    wav.writeInt16LE(Math.round(right * 32767), offset + bytesPerSample);
   }
 
   return wav;

src/game/audio/SoundDirector.ts

@@ -10,7 +10,7 @@ class SoundDirector {
   private currentMusicKey?: string;
   private pendingMusicKey?: string;
   private musicFadeTimer?: number;
-  private readonly musicVolume = 0.2;
+  private readonly musicVolume = 0.14;
 
   registerMusicTracks(tracks: AudioTrackMap) {
     this.musicTracks = tracks;
@@ -29,7 +29,7 @@ class SoundDirector {
     if (AudioContextCtor) {
       this.context = new AudioContextCtor();
       this.master = this.context.createGain();
-      this.master.gain.value = this.muted ? 0 : 0.34;
+      this.master.gain.value = this.muted ? 0 : 0.3;
       this.master.connect(this.context.destination);
     }
 
@@ -58,7 +58,7 @@ class SoundDirector {
     }
 
     this.master.gain.cancelScheduledValues(this.context.currentTime);
-    this.master.gain.linearRampToValueAtTime(muted ? 0 : 0.34, this.context.currentTime + 0.18);
+    this.master.gain.linearRampToValueAtTime(muted ? 0 : 0.3, this.context.currentTime + 0.18);
   }
 
   isMuted() {