How to get the 4 world coordinates of the current viewport?

Questions
1

Is there any way to get 4 world coordinates of the current viewport?

I am using react-three/fiber but it returns width and height where the values are not expected.

const {viewpoint} = useThree()
const vp= viewpoint.getCurrentViewport()

Thanks

2

1: 0, 0
2: renderer.domElement.width, 0
3: 0, renderer.domElement.height
4: renderer.domElement.width, renderer.domElement.height

getBoxedCoordinate(0, 0);
getBoxedCoordinate(renderer.domElement.width, 0);
getBoxedCoordinate(0, renderer.domElement.height);
getBoxedCoordinate(renderer.domElement.width, renderer.domElement.height);

function getBoxedCoordinate(_clientX, _clientY)
{
let coordinate_ray = new THREE.Vector2();
coordinate_ray.x = (_clientX / renderer.domElement.width) * 2 - 1;
coordinate_ray.y = -(_clientY / renderer.domElement.height) * 2 + 1;

raycaster.setFromCamera( coordinate_ray, camera );
const intersects = raycaster.intersectObjects( [objects], false );

if ( intersects.length > 0 ) {

  // intersects

}
}