feat: implement free-field CPU beamforming

packages/acoustics-core/math.js

@@ -0,0 +1,62 @@
+export const TAU = Math.PI * 2;
+
+export function distance3(a, b) {
+  return Math.hypot(a[0] - b[0], a[1] - b[1], a[2] - b[2]);
+}
+
+export function dbToLinear(decibels) {
+  return 10 ** (decibels / 20);
+}
+
+export function powerToDb(power, floorDb = -120) {
+  if (!(power > 0)) return floorDb;
+  return Math.max(floorDb, 10 * Math.log10(power));
+}
+
+export function clamp(value, minimum, maximum) {
+  return Math.min(maximum, Math.max(minimum, value));
+}
+
+export function lerp(start, end, amount) {
+  return start + (end - start) * amount;
+}
+
+export function createScanPoints(scan) {
+  const points = new Float32Array(scan.columns * scan.rows * 4);
+  let offset = 0;
+  for (let row = 0; row < scan.rows; row += 1) {
+    const y = scan.rows === 1 ? scan.yMax : lerp(scan.yMax, scan.yMin, row / (scan.rows - 1));
+    for (let column = 0; column < scan.columns; column += 1) {
+      const x = scan.columns === 1 ? scan.xMin : lerp(scan.xMin, scan.xMax, column / (scan.columns - 1));
+      points[offset] = x;
+      points[offset + 1] = y;
+      points[offset + 2] = scan.z;
+      points[offset + 3] = 0;
+      offset += 4;
+    }
+  }
+  return points;
+}
+
+export function scanIndexToPosition(index, scan) {
+  const row = Math.floor(index / scan.columns);
+  const column = index % scan.columns;
+  return [
+    scan.columns === 1 ? scan.xMin : lerp(scan.xMin, scan.xMax, column / (scan.columns - 1)),
+    scan.rows === 1 ? scan.yMax : lerp(scan.yMax, scan.yMin, row / (scan.rows - 1)),
+    scan.z,
+  ];
+}
+
+export function findPeak(values) {
+  if (values.length === 0) throw new Error("빈 map에서는 peak를 찾을 수 없습니다.");
+  let peakIndex = 0;
+  let peakValue = values[0];
+  for (let index = 1; index < values.length; index += 1) {
+    if (values[index] > peakValue) {
+      peakValue = values[index];
+      peakIndex = index;
+    }
+  }
+  return { index: peakIndex, value: peakValue };
+}