• 🎨 GPU-Accelerated Rendering — Powered by Metal for smooth performance with thousands of particles
• 🪟 Window Collision Physics — Snowflakes realistically melt when landing on window borders
• 🖱️ Mouse Interaction — Snowflakes react dynamically to cursor movement
• 🌬️ Wind Simulation — Adjustable wind strength affects snowflake trajectories
• 🖥️ Multi-Monitor Support — Works seamlessly across all connected displays

• 3 Built-in Presets: Light Snow, Comfortable Background, Blizzard
• Granular Controls:
  • Speed range (0.1–8.0)
  • Size range (1–25)
  • Particle count (100–10,000)
  • Wind strength (0–500)
• Privacy-Focused — All processing happens locally; no data collection

Get automatic updates via Homebrew:

brew install --cask barredewe/cask/snowfall

1. Download the latest release from Releases
2. Unzip and move Snowfall.app to /Applications
3. Launch and grant Screen Recording permission when prompted

Access settings via the menubar icon (❄️):

Window Interaction
Toggle collision physics for performance-critical workflows. When enabled:

• Uses CGWindowListCopyWindowInfo API to detect window positions
• Processes data in RAM only (no recording/storage)
• Snowflakes melt gradually upon contact

Mouse Influence Radius: 50px default

• Language: Swift 5.9+ with SwiftUI
• Graphics: Metal API for compute & render pipelines
• Physics: Custom particle system with SIMD2 vectors
• Platform: macOS 11.0+ (Big Sur and later)

SnowfallApp/
├── Common/
│   ├── Views/
│   │   ├── MenuBarSettings.swift      # SwiftUI preferences UI
│   │   └── MetalSnowViewController.swift  # MTKView controller
│   ├── Settings.swift                 # Codable configuration
│   ├── Snowflake.swift                # Particle data structure
│   ├── SnowRenderer.swift             # Metal pipeline manager
│   └── WindowInfo.swift               # CGWindowListCopyWindowInfo wrapper
├── SnowfallApp.swift                  # App entry point
└── SnowShader.metal                   # GPU kernels (compute + render)

• Compute Shader: Parallel particle updates on GPU
• Instanced Rendering: Single draw call for all particles
• Adaptive Caching: Window positions refreshed every 500ms
• Point Primitives: Efficient anti-aliased circles via fragment shader

• Xcode 15.0+
• macOS 13.0+ SDK
• Swift 5.9+

# Clone repository
git clone https://github.com/barredewe/snowfall.git
cd snowfall

# Open in Xcode
open Snowfall.xcodeproj

# Build & Run (⌘R)

Zero Data Collection Policy

Snowfall operates entirely offline:

• ✅ No network requests
• ✅ No analytics/tracking
• ✅ No third-party SDKs
• ✅ All settings stored locally (UserDefaults)

Permissions Explained:

• Screen Recording: Required only for window collision detection
• Accessibility: Alternative permission for older macOS versions

See PRIVACY.md for full policy.

Contributions are welcome!

Development Setup:

1. Fork the repository
2. Create feature branch (git checkout -b feature/amazing-feature)
3. Follow Swift API Design Guidelines
4. Submit PR with detailed description

Apache 2.0 License - see LICENSE for details.

• Metal framework by Apple
• Inspiration from classic screensavers
• Icon design: SF Symbols

Barredewe
📮 barredewe@gmail.com
🐙 GitHub