declarative vertices in React-three-fiber

reactThreeFiber-declarativeVertices.tsx

const Line = () => {
  const vertices = useMemo(() => {
    let p = [
      [0, 0, 0],
      [0, 1, 1],
      [0, 1, -1]
    ];
    const flatArr = p.reduce((ac, cv) => [...cv, ...ac], []);
    return new Float32Array(flatArr);
  }, []);
  return (
    <line>
      <bufferGeometry attach="geometry">
        <bufferAttribute
          attachObject={["attributes", "position"]}
          array={vertices}
          itemSize={3}
          count={vertices.length / 3}
        />
      </bufferGeometry>
      <lineBasicMaterial color="red" />
    </line>
  );
};