Tilt-Shift Camera

A dedicated Android camera app for tilt-shift photography with real-time preview, touch-based controls, and proper EXIF handling.

Features

• Real-time tilt-shift effect preview - See the blur effect as you compose your shot
• Touch-based controls:
  • Single finger drag to move the focus line position
  • Two-finger rotation to adjust blur angle
  • Pinch gesture to adjust blur zone size
  • Pinch in center to zoom camera
• Zoom controls - Quick presets (0.5x, 1x, 2x, 5x) plus pinch-to-zoom
• Auto picture orientation detection - Photos saved with correct EXIF orientation
• GPS location tagging - Optional EXIF GPS data from device location
• Haptic feedback - Tactile response for all interactions
• Saves to gallery - Photos saved to Pictures/TiltShift/ folder

Requirements

• Android 15 (API 35) or higher
• Device with camera
• OpenGL ES 2.0 support

Building

1. Open the project in Android Studio
2. Sync Gradle files
3. Build and run on a physical device (camera preview won't work on emulator)

Or from command line:

./gradlew assembleDebug

Permissions

• Camera (required) - For capturing photos
• Location (optional) - For GPS tagging in EXIF data
• Vibrate - For haptic feedback

Architecture

The app uses:

• CameraX - Jetpack camera library for camera preview and capture
• OpenGL ES 2.0 - Real-time shader-based blur effect
• Jetpack Compose - Modern declarative UI
• Kotlin Coroutines & Flow - Asynchronous operations and state management

Project Structure

app/src/main/java/no/naiv/tiltshift/
├── MainActivity.kt           # Entry point with permission handling
├── camera/
│   ├── CameraManager.kt      # CameraX setup and control
│   ├── LensController.kt     # Lens/zoom switching
│   └── ImageCaptureHandler.kt # Photo capture with effect
├── effect/
│   ├── TiltShiftRenderer.kt  # OpenGL renderer
│   ├── TiltShiftShader.kt    # GLSL shader management
│   └── BlurParameters.kt     # Effect state
├── ui/
│   ├── CameraScreen.kt       # Main Compose screen
│   ├── TiltShiftOverlay.kt   # Touch gesture handling & visualization
│   ├── ZoomControl.kt        # Zoom UI component
│   └── LensSwitcher.kt       # Lens selection UI
├── storage/
│   └── PhotoSaver.kt         # MediaStore integration & EXIF handling
└── util/
    ├── OrientationDetector.kt
    ├── LocationProvider.kt
    └── HapticFeedback.kt

How the Tilt-Shift Effect Works

The tilt-shift effect simulates a selective focus lens that makes scenes appear miniature. The app achieves this through:

1. Camera Preview → OpenGL SurfaceTexture
2. Fragment Shader calculates distance from the focus line for each pixel
3. Gradient blur is applied based on distance - center stays sharp, edges blur
4. Two-pass Gaussian blur (optimized as separable passes) for quality and performance

License

MIT