Clavier à lumières notes and noteToFrequency function

src/constants/colorScale.ts

@@ -0,0 +1,45 @@
+export type ColorNote = {
+    note: string;
+    color: string;
+    label: string;
+};
+
+export const colorScale: ColorNote[] = [
+    { note: "C", color: "#ff0000", label: "C" },
+    { note: "C#", color: "#caa3ff", label: "C#" },
+    { note: "D", color: "#ffff00", label: "D" },
+    { note: "D#", color: "#5b5f8b", label: "D#" },
+    { note: "E", color: "#dff8ff", label: "E" },
+    { note: "F", color: "#8b1a0e", label: "F" },
+    { note: "F#", color: "#18bffb", label: "F#" },
+    { note: "G", color: "#ff7a00", label: "G" },
+    { note: "G#", color: "#ff00ff", label: "G#" },
+    { note: "A", color: "#39c52a", label: "A" },
+    { note: "A#", color: "#8a8a8a", label: "A#" },
+    { note: "B", color: "#0c2bff", label: "B" },
+];
+
+const SEMITONES: Record<string, number> = {
+    C: 0,
+    "C#": 1,
+    D: 2,
+    "D#": 3,
+    E: 4,
+    F: 5,
+    "F#": 6,
+    G: 7,
+    "G#": 8,
+    A: 9,
+    "A#": 10,
+    B: 11,
+};
+
+export function noteToFrequency(note: string, octave: number): number {
+    const semitone = SEMITONES[note];
+    if (semitone === undefined) {
+        throw new Error(`Unsupported note: ${note}`);
+    }
+
+    const midi = (octave + 1) * 12 + semitone;
+    return 440 * 2 ** ((midi - 69) / 12);
+}