Core Technologies
Frameworks & Libraries
UI Framework
SwiftUI + UIKit Hybrid
Modern declarative UI with complex camera integration
GPU Acceleration
Metal GPU Framework
Real-time light painting effects and rendering
Camera & Video
AVFoundation
Professional camera capture and video processing
Data Storage
Core Data
Local persistence with migration support
Image Processing
Core Image
Advanced image processing pipeline
Voice Control
AppIntents
Siri integration for voice control
Platform Requirements
- iOS Target: 16.6+
- Xcode Version: 16.2+
- Swift Version: 5.0
- Device Support: iPhone only
- Bundle ID: com.shutterspeedapps.lightpainted
- Analytics: Firebase integration
Architecture Patterns
MVVM (Model-View-ViewModel)
Primary design pattern for clean separation of concerns:
Architecture Benefits
- • Observable view models manage business logic
- • Reactive UI updates through @Published
- • Clear separation of concerns
- • Testable business logic
Key ViewModels
- •
EasyViewModel- Main app state - •
TimelapseCameraViewModel- Camera session - •
TimelapseListViewModel- Media organization - •
SharedObjectsController- Resources
Singleton Pattern
Core singletons for shared resources:
CoreDataManager.sharedDatabase persistence
SharedMetalCIContext.sharedGPU rendering context
OrientationManager.sharedDevice orientation
TaskManager.sharedBackground processing
Metal Rendering Pipeline
GPU Processing Flow
Camera Input → Metal Texture Cache → Frame Blending Engine → Light Trail Composition → Display/Export
MetalRendererContext
Device and pipeline management
SharedMetalCIContext
Optimized Core Image context
FrameBlendingEngine
Real-time light trail blending
Blending Modes Implementation
enum BlendMode: String, CaseIterable {
case additive = "additiveBlendFragment"
case screen = "screenBlendFragment"
case lighten = "lightenBlendFragment"
case starTrail = "starTrailBlendFragment"
case steelWool = "steelWoolBlendFragment"
}Data Persistence
Core Data Architecture
Features
- • Dynamic container creation
- • Fresh install vs. migration support
- • Seeded data (pre-populated profiles)
- • Seamless TimeLapsed Pro transition
Thread Safety
- • Background context management
- • Main thread UI updates
- • Concurrent queue operations
- • Automatic save coordination
Modern Settings (@AppStorage)
@MainActor class AppSettings: ObservableObject {
@AppStorage("selectedTheme") var selectedTheme: String = "dark"
@AppStorage("enableMetalAcceleration") var enableMetalAcceleration: Bool = true
@AppStorage("lightThreshold") var lightThreshold: Float = 0.5
@AppStorage("trailFadeAmount") var trailFadeAmount: Float = 0.002
}Background Processing
TaskManager System
class TaskManager {
private let maxConcurrentTasks: Int = 8
private let semaphore: DispatchSemaphore
private let queue: DispatchQueue // .utility QoS
}Task Types
- •
timelapseRender- Video composition - •
imageStackRender- Light trail processing - •
importFiles- Media import operations - •
createOptimizedFiles- Asset optimization
Features
- • Concurrent task limiting
- • Progress tracking
- • Cancellation support
- • Memory pressure handling
Memory Management
Resource Cleanup
- • Automatic camera resource management
- • Image cache with memory pressure handling
- • Proper Metal texture lifecycle
- • Weak references prevent retain cycles
Performance Optimizations
- • Lazy loading for on-demand resources
- • Cache eviction on memory pressure
- • Non-blocking background operations
- • Metal command queue optimization
Device Orientation & Build Configuration
Dynamic Orientation System
class OrientationManager: ObservableObject {
@Published var isPortraitUpsideDown: Bool = false
@Published var rotationAngle: Double = 0.0
private var isOrientationLocked: Bool
}- • Orientation locking for stable capture
- • Smooth animated transitions (0.3s)
- • User-configurable preferences
- • Camera session coordination
Build Configuration
Development Settings
- • Optimization:
-Ononefor debugging - • Metal Debugging: Source-level enabled
- • Memory Tools: Full debug symbols
- • Assertion behavior: Enabled
Release Optimization
- • Whole Module Optimization
- • Metal Performance: Fast math
- • Code Signing: Automatic
- • dSYM Generation: Crash symbolication