Function decodeCameraFromBytes

src/utils/urlCameraStateCodec.ts:77–106

(bytes: Uint8Array)

 * Decode camera state from raw bytes (72 bytes).
 */
export function decodeCameraFromBytes(bytes: Uint8Array): CameraViewState | null {
  if (bytes.length !== 72) return null;

  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);

  const px = view.getFloat64(0, true);
  const py = view.getFloat64(8, true);
  const pz = view.getFloat64(16, true);
  const tx = view.getFloat64(24, true);
  const ty = view.getFloat64(32, true);
  const tz = view.getFloat64(40, true);
  const qx = view.getFloat64(48, true);
  const qy = view.getFloat64(56, true);
  const qz = view.getFloat64(64, true);

  const qwSquared = 1 - qx * qx - qy * qy - qz * qz;
  if (qwSquared < 0) return null;
  const qw = Math.sqrt(qwSquared);

  return {
    position: [px, py, pz],
    target: [tx, ty, tz],
    quaternion: [qx, qy, qz, qw],
    distance: Math.sqrt(
      (px - tx) * (px - tx) +
      (py - ty) * (py - ty) +
      (pz - tz) * (pz - tz)
    ),
  };
}

/**
 * Decode camera state from Base64URL binary format.