AemiSDR

A lightweight, App Store-safe SwiftUI library for GPU-accelerated blurs, masks, visual effects, and physics-based lens distortion.

AemiSDR works seamlessly with ScrollView and dynamic content, providing high-performance effects through a modifier-based API.

• Variable Blur: Gradient-driven blur with rounded rectangle and superellipse shapes (iOS)
• Alpha Masks: Fade content edges with configurable mask shapes (iOS)
• Visual Effect: Customizable backdrop blur with tint, saturation, and system material presets (iOS + macOS)
• Liquid Lens: Physics-based refraction with chromatic aberration and Sellmeier dispersion (iOS)
• Display Corner Radius: Retrieve the device's actual screen corner radius (iOS)
• Optimized: Metal shaders compiled automatically via SPM build plugin, with result caching and zero-copy texture bridging

Example

Example.mp4

Requirements

• iOS 14+ / macOS 11+
• Swift 6.2 Toolchain
• SwiftUI

Installation

Add the package in Xcode (File → Add Package Dependencies…) using the repository URL, or add it to your Package.swift:

.dependencies = [
    .package(url: "https://github.com/Aemi-Studio/AemiSDR.git", branch: "main")
]

Usage

Scroll View Edge Fade

Combine blurs and masks to fade the edges of a ScrollView:

import SwiftUI
import AemiSDR

struct ContentView: View {
    var body: some View {
        ScrollView {
            // your content
        }
        .roundedRectMask()
        .verticalEdgeMask(height: 32)
        .roundedRectBlur()
        .verticalEdgeBlur(height: 48, maxBlurRadius: 5)
    }
}

Frosted Glass Background

Text("Hello")
    .padding()
    .frostedGlassBackground(blurRadius: 20, tintOpacity: 0.15)

System Material Blur

// Use a system material preset
VisualEffectView(configuration: .ultraThinMaterial)

// Or customize fully
Text("Overlay")
    .padding()
    .visualEffectBackground(blurRadius: 25, colorTint: .blue, colorTintAlpha: 0.1)

Liquid Lens Distortion

Image("photo")
    .resizable()
    .aspectRatio(contentMode: .fit)
    .liquidLens(
        center: SIMD2(200, 300),
        halfSize: SIMD2(150, 150),
        material: .flintGlass,
        clipShape: Circle()
    )

Or use auto-capture mode to distort live content (e.g. a scroll view underneath):

ScrollView {
    // content
}
.liquidLens(
    center: SIMD2(Float(position.x), Float(position.y)),
    halfSize: SIMD2(120, 120),
    strength: 1.5,
    material: .diamond,
    continuousCapture: true,
    refreshRate: 30
)

API

Variable Blur (iOS 15+)

Modifier	Description
roundedRectBlur(...)	Overlay blur shaped as a rounded rectangle or superellipse
verticalEdgeBlur(...)	Blur applied to the top and/or bottom edges of a view

Alpha Mask (iOS 15+)

Modifier	Description
roundedRectMask(...)	Alpha mask shaped as a rounded rectangle or superellipse
verticalEdgeMask(...)	Alpha mask for vertical edges, ideal for scroll views

Visual Effect (iOS 15+ / macOS 12+)

Modifier	Description
visualEffectBackground(...)	Customizable blur as a background layer
visualEffectOverlay(...)	Customizable blur as an overlay layer
frostedGlassBackground(...)	Convenience frosted glass effect
tintedBlurBackground(...)	Colored blur background

Configuration-based API with system presets:

// System presets (iOS): .light, .dark, .extraLight, .ultraThinMaterial,
//                       .thinMaterial, .material, .thickMaterial, .chromeMaterial
VisualEffectView(configuration: .material)

// Custom configuration
var config = VisualEffectConfiguration()
config.blurRadius = 20
config.saturationDeltaFactor = 1.8
config.colorTint = .blue
config.colorTintAlpha = 0.1
VisualEffectView(configuration: config)

Liquid Lens (iOS 15+)

Modifier	Description
liquidLens(configuration:...)	Lens distortion from a LiquidLensConfiguration
liquidLens(center:halfSize:...)	Lens distortion with inline parameters
liquidLens(image:...)	Lens distortion using an explicit source image

Key configuration options:

• Materials: .crownGlass, .flintGlass, .water, .acrylic, .diamond — each with physically-based Sellmeier dispersion coefficients
• Falloff curves: .linear, .easeIn, .easeOut, .easeInOut, .cubic, .exponential
• Corner radius: .proportional(Float) or .points(Float)
• Clip shapes: Any SwiftUI Shape (iOS 16+), or use LiquidLensClipShape.circle, .capsule, .roundedRect(cornerRadius:)

Display Corner Radius (iOS)

// Static accessor
let radius = UIScreen.displayCornerRadius

// From a specific view context
let radius = myView.screenCornerRadius

All modifiers come with sensible defaults and can be customized for corner style, transition smoothness, and more.

Demo App

A full demo app is included in Examples/AemiSDRDemo/ with tabbed views showcasing each effect:

• Blur: Variable blur configurations
• Mask: Alpha mask examples
• Glass: Visual effect presets and custom blurs
• Lens: Interactive liquid lens with drag gesture

Development

Metal Shaders

The Metal shader source files are located in Sources/AemiSDR/Shaders/. The package uses a Swift Package Manager build plugin that automatically compiles shaders during the build process.

When you build the package (via swift build or Xcode), the AemiSDRShaderPlugin will:

1. Find all .metal files in the target
2. Compile them using xcrun metal with Core Image kernel flags (-fcikernel)
3. Generate platform-specific Metal libraries:
   • AemiSDR.iOS.metallib (iOS 14.0+)
   • AemiSDR.macOS.metallib (macOS 11.0+)

No manual compilation is required. Simply edit the .metal files and rebuild — the plugin handles the rest.

Build Plugin Details

The plugin is located in Plugins/AemiSDRShaderPlugin/ and uses MetalCompilerTool (in Sources/MetalCompilerTool/) to invoke the Metal toolchain. Key features:

• Incremental builds: Shaders are only recompiled when source files change
• Xcode Cloud compatible: Uses -fmodules=none to avoid sandbox issues
• Cross-platform: Generates libraries with correct deployment targets for each platform

License

This software is provided under the Mozilla Public License 2.0.