What is swiftglow?

SwiftGlow is a Swift Package that adds animated glowing borders and neon capsule-style effects to SwiftUI views. You attach it to any view with a single modifier call, and the library handles rendering a color-cycling border that animates around the edges of rounded rectangles. The glow can be placed behind, inside, or on top of the view, and you can stack multiple glow layers with independent colors, speeds, and opacity. The rendering uses Metal, Apple's low-level graphics API, rather than stacking SwiftUI blur or shadow effects. This keeps CPU use low and lets the animation stay smooth even when multiple glow layers are active at once. The library computes the glow in a fragment shader, which runs directly on the GPU. The configuration design intentionally mirrors an existing React Native library called react-native-animated-glow. If you are building apps on both Apple platforms and React Native, you can write a single glow preset once and reuse it across both codebases, with minimal translation work. You define one or more named states -- default, hover, and press -- each with its own speed, colors, and layer setup. The modifier accepts a status value that selects which state is active, or you can use auto mode and the library switches states automatically as the user interacts with the view. The package ships with ready-made presets you can apply without writing any configuration. SwiftGlow works on iOS 15 and later, macOS 12 and later, and tvOS 15 and later. It installs through Swift Package Manager. The repository also includes a macOS demo app with a live parameter inspector where you can tune the glow in real time, and a one-click import workflow for bringing React Native glow presets into Apple platform projects.