AemiSDR

A lightweight, App Store-safe library for adding dynamic, GPU-accelerated blurs and masks to your SwiftUI views.

AemiSDR is designed to work seamlessly with ScrollView and other dynamic content, providing high-performance effects with a simple, modifier-based API.

• Variable Blur: Apply blurs as a gradient.
• Alpha Masks: Fade view content with alpha masks.
• Advanced Shapes: Use standard rounded rectangles or iOS-style superellipses (squircles).
• Optimized: Effects are powered by Metal shaders (compiled automatically via build plugin) and cache their results to ensure smooth performance.

Example

Example.mp4

Requirements

• iOS 14+
• 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")
]

Example

Apply blurs and masks directly to your views. The library is perfect for fading the edges of a ScrollView, as shown in the project's preview:

import SwiftUI
import AemiSDR

struct AemiSDRPreview: View {
    var body: some View {
        ScrollView(showsIndicators: false) {
            LazyVStack(spacing: 16) {
                ForEach(1 ... 6, id: \.self) { index in
                    Image("Image_\(index)", bundle: .module)
                        .resizable()
                        .aspectRatio(contentMode: .fit)
                        .clipShape(clippingShape)
                }
            }
            .padding(.horizontal)
        }
        .fancyBlur()
    }

    private var clippingShape: some Shape {
        .rect(cornerRadius: UIScreen.displayCornerRadius - 16)
    }
}

private extension View {
    @ViewBuilder func fancyBlur() -> some View {
        if #available(iOS 15.0, *) {
            roundedRectMask()
                .verticalEdgeMask(height: 32)
                .roundedRectBlur()
                .verticalEdgeBlur(height: 48, maxBlurRadius: 5)
        } else {
            self
        }
    }
}

API

The library provides four main SwiftUI modifiers (iOS 15+):

• roundedRectBlur(...): An overlay blur shaped like a rounded rectangle or superellipse.
• verticalEdgeBlur(...): A blur applied only to the top and bottom edges of a view.
• roundedRectMask(...): An alpha mask to fade content, shaped as a rounded rectangle or superellipse.
• verticalEdgeMask(...): An alpha mask for the top and bottom edges, perfect for scroll views.

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

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.