clean interface

src/lib/utils/pitch.ts

@@ -0,0 +1,33 @@
+const NOTE_NAMES = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B'];
+const A4_FREQUENCY = 440;
+const A4_MIDI_NOTE = 69;
+
+export function noteToFrequency(noteName: string): number | null {
+  const match = noteName.match(/^([A-G]#?)(-?\d+)$/i);
+  if (!match) return null;
+
+  const [, note, octave] = match;
+  const noteIndex = NOTE_NAMES.indexOf(note.toUpperCase());
+  if (noteIndex === -1) return null;
+
+  const octaveNum = parseInt(octave, 10);
+  const midiNote = (octaveNum + 1) * 12 + noteIndex;
+  const semitonesDiff = midiNote - A4_MIDI_NOTE;
+
+  return A4_FREQUENCY * Math.pow(2, semitonesDiff / 12);
+}
+
+export function parseFrequencyInput(input: string): number | null {
+  const trimmed = input.trim();
+
+  const asNumber = parseFloat(trimmed);
+  if (!isNaN(asNumber) && asNumber > 0 && asNumber < 20000) {
+    return asNumber;
+  }
+
+  return noteToFrequency(trimmed);
+}
+
+export function formatFrequency(frequency: number): string {
+  return frequency.toFixed(2);
+}

src/lib/utils/settings.ts

@@ -1,9 +1,13 @@
 const DEFAULT_VOLUME = 0.7;
 const DEFAULT_DURATION = 1.0;
+const DEFAULT_PITCH_LOCK_ENABLED = false;
+const DEFAULT_PITCH_LOCK_FREQUENCY = 440;
 
 const STORAGE_KEYS = {
   VOLUME: 'volume',
   DURATION: 'duration',
+  PITCH_LOCK_ENABLED: 'pitchLockEnabled',
+  PITCH_LOCK_FREQUENCY: 'pitchLockFrequency',
 } as const;
 
 export function loadVolume(): number {
@@ -23,3 +27,21 @@ export function loadDuration(): number {
 export function saveDuration(duration: number): void {
   localStorage.setItem(STORAGE_KEYS.DURATION, duration.toString());
 }
+
+export function loadPitchLockEnabled(): boolean {
+  const stored = localStorage.getItem(STORAGE_KEYS.PITCH_LOCK_ENABLED);
+  return stored ? stored === 'true' : DEFAULT_PITCH_LOCK_ENABLED;
+}
+
+export function savePitchLockEnabled(enabled: boolean): void {
+  localStorage.setItem(STORAGE_KEYS.PITCH_LOCK_ENABLED, enabled.toString());
+}
+
+export function loadPitchLockFrequency(): number {
+  const stored = localStorage.getItem(STORAGE_KEYS.PITCH_LOCK_FREQUENCY);
+  return stored ? parseFloat(stored) : DEFAULT_PITCH_LOCK_FREQUENCY;
+}
+
+export function savePitchLockFrequency(frequency: number): void {
+  localStorage.setItem(STORAGE_KEYS.PITCH_LOCK_FREQUENCY, frequency.toString());
+}