I'm trying to apply a CIBumpDistortion Core Image filter to a view that contains a UILabel (my storyLabel). The goal is to create a visual bump/magnifying glass effect over the text.
However, despite my attempts, the filter doesn't seem to render at all. The view and the label appear as normal, with no distortion effect. I've tried adjusting the filter parameters and reviewing the view hierarchy, but without success. I also haven't been able to find clear documentation or examples for applying this filter to a UIView's layer.
//
// TVView.swift
// Mistery
//
// Created by Joje on 31/07/25.
//
import CoreImage
import CoreImage.CIFilterBuiltins
import UIKit
import AVFoundation
final class TVView: UIView {
// propriedades animacao texto
private var textAnimationTimer: Timer?
private var fullTextToAnimate: String = ""
private var currentCharIndex: Int = 0
// propriedades video estatica
private var player: AVQueuePlayer?
private var playerLayer: AVPlayerLayer?
private var playerLooper: AVPlayerLooper?
var onNextButtonTap: () -> Void = {}
// MARK: - Subviews
// imagem da TV
private(set) lazy var tvImageView: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.image = UIImage(named: "tvFinal")
imageView.contentMode = .scaleAspectFit
return imageView
}()
// texto que passa dentro da TV
private(set) lazy var storyLabel: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
//label.backgroundColor = .gray
label.textColor = .red
label.font = UIFont(name: "MeltedMonster", size: 30)
label.textAlignment = .left
label.numberOfLines = 0
label.text = ""
return label
}()
private(set) lazy var nextButton: UIButton = {
let button = UIButton(type: .system)
button.translatesAutoresizingMaskIntoConstraints = false
//button.backgroundColor = .darkGray
button.addTarget(self, action: #selector(didPressNextButton), for: .touchUpInside)
return button
}()
// MARK: - Lifecycle
override init(frame: CGRect) {
super.init(frame: frame)
backgroundColor = .black
setupVideoPlayer()
addSubviews()
setupConstraints()
}
override func layoutSubviews() {
super.layoutSubviews()
playerLayer?.frame = tvImageView.frame.insetBy(dx: tvImageView.frame.width * 0.05, dy: tvImageView.frame.height * 0.18)
setupFisheyeEffect()
}
private func setupFisheyeEffect() {
// cria o filtro
guard let filter = CIFilter(name: "CIBumpDistortion") else {return print("erro")}
storyLabel.layer.shouldRasterize = true
storyLabel.layer.rasterizationScale = UIScreen.main.scale
// define os parametros
filter.setDefaults()
// centro do efeito
let center = CIVector(x: storyLabel.bounds.midX, y: storyLabel.bounds.midY)
filter.setValue(center, forKey: kCIInputCenterKey)
// raio de distorção
filter.setValue(storyLabel.bounds.width, forKey: kCIInputRadiusKey)
// intensidade de distorção
filter.setValue(7, forKey: kCIInputScaleKey)
storyLabel.layer.filters = [filter]
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
// MARK: - Button actions
@objc private func didPressNextButton() {
onNextButtonTap()
}
@objc private func animateNextCharacter() {
guard currentCharIndex < fullTextToAnimate.count else {
textAnimationTimer?.invalidate()
return
}
let currentTextIndex = fullTextToAnimate.index(fullTextToAnimate.startIndex, offsetBy: currentCharIndex)
let partialText = String(fullTextToAnimate[...currentTextIndex])
storyLabel.text = partialText
currentCharIndex += 1
}
public func updateStoryText(with text: String) {
textAnimationTimer?.invalidate()
storyLabel.text = ""
fullTextToAnimate = text
currentCharIndex = 0
textAnimationTimer = Timer.scheduledTimer(timeInterval: 0.12, target: self, selector: #selector(animateNextCharacter), userInfo: nil, repeats: true)
}
// MARK: - Setup methods
private func setupVideoPlayer() {
guard let videoURL = Bundle.main.url(forResource: "static-video", withExtension: "mov") else {
print("Erro: Não foi possível encontrar o arquivo de vídeo static-video.mov")
return
}
let playerItem = AVPlayerItem(url: videoURL)
player = AVQueuePlayer(playerItem: playerItem)
// LINHA COM POSSIVEL ERRO
playerLooper = AVPlayerLooper(player: player!, templateItem: playerItem)
playerLayer = AVPlayerLayer(player: player)
playerLayer?.videoGravity = .resizeAspectFill
if let layer = playerLayer {
self.layer.addSublayer(layer)
}
player?.play()
}
private func addSubviews() {
self.addSubview(storyLabel)
self.addSubview(tvImageView)
self.addSubview(nextButton)
}
private func setupConstraints() {
NSLayoutConstraint.activate([
// TV Image
tvImageView.centerXAnchor.constraint(equalTo: centerXAnchor),
tvImageView.centerYAnchor.constraint(equalTo: centerYAnchor),
tvImageView.widthAnchor.constraint(equalTo: widthAnchor),
// TV Text
storyLabel.centerXAnchor.constraint(equalTo: tvImageView.centerXAnchor, constant: -50),
storyLabel.centerYAnchor.constraint(equalTo: tvImageView.centerYAnchor, constant: -25),
storyLabel.widthAnchor.constraint(equalTo: tvImageView.widthAnchor, multiplier: 0.35),
storyLabel.heightAnchor.constraint(equalTo: tvImageView.heightAnchor, multiplier: 0.42),
//TV Button
nextButton.topAnchor.constraint(equalTo: tvImageView.centerYAnchor, constant: -25),
nextButton.centerXAnchor.constraint(equalTo: self.centerXAnchor, constant: 190),
nextButton.widthAnchor.constraint(equalToConstant: 100),
nextButton.heightAnchor.constraint(equalToConstant: 160)
])
}
}
#Preview{
ViewController()
}
