CAEmitterLayer

Because despite their reputation as the workhorse of UIKit, UIView delegates the vast majority of its functionality to CALayer. Sure, views handle touch events and autoresizing, but beyond that, nearly everything else between your code and the pixels on screen is the responsibility of layers.

→ nshipster.com/caemitterlayer/

The article introduces CAEmitterLayer for creating a confetti effect on iOS, explaining its role as a high-performance particle system within the Quartz Core framework for rendering effects like confetti, fire, or rain.

It contrasts views and layers, noting that UIView delegates most functionality to CALayer, with CAEmitterLayer managing particle emission and CAEmitterCell defining particle properties like size, colour, and velocity. A custom ConfettiView implementation is provided, using an enum for confetti shapes and images, a CAEmitterLayer subclass for configuration, and animation techniques to control emission duration and cleanup.

Alternative approaches include SpriteKit, SceneKit, UIKit Dynamics, HEVC video with alpha, animated PNGs, WebGL, and emoji. The article highlights Swift’s expressive syntax and Core Animation’s capabilities for creating engaging UI effects, encouraging community contributions to enhance the implementation.