threejs update horizontal fov projectionmatrix

gistfile1.txt

const DEG2RAD = Math.PI / 180;
    let updateProjectionMatrixHorizontalFOV = (camera)=>{

		const near = camera.near;
/*
		let top = near * Math.tan( DEG2RAD * 0.5 * camera.fov ) / camera.zoom;
		let height = 2 * top;
		let width = camera.aspect * height;
		let left = - 0.5 * width;
*/

		let left = -near * Math.tan( DEG2RAD * 0.5 * camera.fov ) / camera.zoom;
		let width = -2 * left;
		let height = width / camera.aspect ;
		let top = 0.5 * height;

		const view = camera.view;

		if ( camera.view !== null && camera.view.enabled ) {

			const fullWidth = view.fullWidth,
				fullHeight = view.fullHeight;

			left += view.offsetX * width / fullWidth;
			top -= view.offsetY * height / fullHeight;
			width *= view.width / fullWidth;
			height *= view.height / fullHeight;

		}

		const skew = camera.filmOffset;
		if ( skew !== 0 ) left += near * skew / camera.getFilmWidth();

		camera.projectionMatrix.makePerspective( left, left + width, top, top - height, near, camera.far );

		camera.projectionMatrixInverse.copy( camera.projectionMatrix ).invert();

	}

/// instead of:  perspectiveCamera.updateProjectionMatrix();            
//Call:
updateProjectionMatrixHorizontalFOV(perspectiveCamera)