OpenGlass

Apple's Liquid Glass, on any iOS version

Every visual detail matched against Apple's native implementation. The optical behavior, the lighting, the way glass adapts to what's behind it. Ships with Apple's exact tuning out of the box. Every parameter is exposed and configurable

Installation

dependencies: [
    .package(url: "https://github.com/mi11ione/OpenGlass", from: "2.0.0")
]

import OpenGlass

Quick Start

Text("Hello, Glass")
    .padding()
    .openGlassEffect()

The API mirrors Apple's. .glassEffect() becomes .openGlassEffect(). If you know the native API, you already know OpenGlass

Styles

Text("Regular").openGlassEffect(.regular)  // standard glass
Text("Clear").openGlassEffect(.clear)      // transparent, minimal blur
Text("Identity").openGlassEffect(.identity) // no effect, animate in/out

Shapes

Text("Circle").openGlassEffect(in: Circle())
Text("Rounded").openGlassEffect(in: RoundedRectangle(cornerRadius: 16))
Text("Sharp").openGlassEffect(in: Rectangle())
Text("Custom").openGlassEffect(cornerRadius: 24)

Default is capsule

Physics

Spring-based touch interactions. Press scales on touch. Anchored stretches toward your finger but stays in place. Free moves with velocity-based squash-stretch and rotation

Text("Press").openGlassEffect(.regular.press())
Text("Anchored").openGlassEffect(.regular.anchored())
Text("Free").openGlassEffect(.regular.free())

Buttons

Button("Glass") { }
    .buttonStyle(.openGlass)

Button("Clear") { }
    .buttonStyle(.openGlass(.clear))

Configuration

For full control, pass a GlassConfiguration directly:

var config = GlassConfiguration()
config.refractionStrength = 0.6
config.chromeStrength = 4.5
config.blurRadius = 0.0
config.glassTintStrength = 0.0
config.zoom = 1.06
config.physicsMode = .anchored

Text("Custom").openGlassEffect(configuration: config)

All physics parameters are configurable too: velocity sensitivity, stretch limits, spring stiffness, damping, rotation, pressed-state scale and opacity

UIKit

let glassView = OpenGlassView(configuration: .regular)
glassView.frame = CGRect(x: 100, y: 200, width: 200, height: 50)
parentView.addSubview(glassView)

Under the Hood

A custom layer-tree compositor built in Metal and Obj-C++. Instead of screenshotting the view hierarchy, OpenGlass traverses the CALayer tree, reconstructs the scene on the GPU, and renders glass on top

The traversal handles transforms, masks, clipping, gradients, content gravity, z-ordering, presentation layers mid-animation. The compositor batches everything into Metal draw calls with texture atlasing, gradient LUT caching, and mask stack management

Each glass element gets GPU-computed background luminance with hysteresis-based regime switching. Glass adapts its tinting to light and dark backgrounds in real time. Text color follows automatically

Handles dozens of glass elements without dropping a frame

Known Limitations

• When dynamically changing a glass element's size without changing its SwiftUI view identity (e.g., same view with different .frame() values), the glass may not resize. Add .id() to force a fresh instance when the size changes
• TimelineView or CAGradientLayer with continuous animations may cause frame rate drops when used as content behind glass elements
• Rapidly switching tabs containing glass elements may cause temporary frame rate drops. Performance returns to normal once navigation settles

Demo

See OpenGlassDemo for a standalone demo app with every feature and parameter tweakable in real time

Roadmap

• MacOS support
• Color tinting with blend modes (multiply, overlay, screen, color dodge, soft light)
• GlassEffectContainer
• Prominent button style

License

MIT. See LICENSE for details