Get cell percent visibility inside its collection view

Extension+UICollectionViewCell.swift

//
//  Extension+UICollectionViewCell.swift
//  @aguilarpgc
//
//  Created by aguilarpgc on 5/07/21.
//

import UIKit

extension UICollectionView {
    func percentVisibility(of cell: UICollectionViewCell) -> CGFloat {
        guard let indexPathForCell = self.indexPath(for: cell),
              let layoutAttributes = self.layoutAttributesForItem(at: indexPathForCell) else {
            return CGFloat.leastNonzeroMagnitude
        }
        
        let cellFrameInSuper = self.convert(layoutAttributes.frame, to: self.superview)
        
        let interSectionRect = cellFrameInSuper.intersection(self.frame)
        let percentOfIntersection: CGFloat = (interSectionRect.height * interSectionRect.width) /
            (cellFrameInSuper.height * cellFrameInSuper.width)
        
        return percentOfIntersection
    }
}