AgoraVideoViewController.swift

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return remoteUserIDs.count + 1
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "videoCell", for: indexPath)

    if indexPath.row == remoteUserIDs.count { //Put our local video last
        if let videoCell = cell as? VideoCollectionViewCell {
            let videoCanvas = AgoraRtcVideoCanvas()
            videoCanvas.uid = callID
            videoCanvas.view = videoCell.videoView
            videoCanvas.renderMode = .fit
            getAgoraEngine().setupLocalVideo(videoCanvas)
        }
    } else {
        let remoteID = remoteUserIDs[indexPath.row]
        if let videoCell = cell as? VideoCollectionViewCell {
            let videoCanvas = AgoraRtcVideoCanvas()
            videoCanvas.uid = remoteID
            videoCanvas.view = videoCell.videoView
            videoCanvas.renderMode = .fit
            getAgoraEngine().setupRemoteVideo(videoCanvas)
            print("Creating remote view of uid: \(remoteID)")
        }
    }

    return cell
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {

    let numFeeds = remoteUserIDs.count + 1

    let totalWidth = collectionView.frame.width - collectionView.adjustedContentInset.left - collectionView.adjustedContentInset.right
    let totalHeight = collectionView.frame.height - collectionView.adjustedContentInset.top - collectionView.adjustedContentInset.bottom

    if numFeeds == 1 {
        return CGSize(width: totalWidth, height: totalHeight)
    } else if numFeeds == 2 {
        return CGSize(width: totalWidth, height: totalHeight / 2)
    } else {
        if indexPath.row == numFeeds {
            return CGSize(width: totalWidth, height: totalHeight / 2)
        } else {
            return CGSize(width: totalWidth / CGFloat(numFeeds - 1), height: totalHeight / 2)
        }
    }
}