BookFun Features

BookFun (悅讀/悦读) is a beautifully crafted personal reading sanctuary for iOS, built natively with SwiftUI and SwiftData. Inspired by modern digital reading experiences, BookFun delivers an elegant, distraction-free, and feature-rich experience for literature lovers.

✨ Core Features & Innovations

1. Dynamic Layout Engine (BookPageSplitter)

• Pixel-Accurate Pagination: Built on CoreText to perform sub-millisecond page splitting and precise character boundary calculations.
• Advanced Typography Rules: Supports mixed Chinese-English layout, orphan control, and line wrap optimization, avoiding awkward text cuts.
• High-Performance Caching: Caches rich-text layouts to minimize CPU usage during long reading sessions, keeping your device cool and battery-efficient.

2. Smooth Physical Transitions

• 3 Physical Page-Turn Modes:
  • 3D Cover Flip — Realistic page curl with physics-based lighting and shadow creases for paper-like reading.
  • Horizontal Slide — Clean push transition for modern magazine-style reading.
  • Continuous Vertical Scroll — Seamless infinite scrolling for uninterrupted reading.
• Seamless Chapter Transition: Uses a single-container multi-page ID switching design that eliminates lag between chapter boundaries.

3. Text-to-Speech (TTS) & Narration

• Native High-Fidelity Voices: Powered by AVSpeechSynthesizer (including natural Siri voices) with auto-matching English and Chinese speech rates.
• Smooth Streaming: 3-layer text chunking algorithm flattens soft linebreaks, delivering uninterrupted continuous narration and background playback.
• Sentence-Level Highlighting: Synchronized sentence highlighting with 6 preset color themes (Yellow, Warm Orange, Mint Green, Sky Blue, Sakura Pink, Orchid Purple) or custom ColorPicker tinting.
• Double-Tap Quick Launch: Double-tap any sentence to instantly start TTS playback, complete with mini floating controls and a sleep timer.

4. Eye Protection & Color Temperature System

• Backlight Dimming Overlay: Adjustable dimming for comfortable reading in low-light environments.
• Kelvin Color Temperature Filter: Physics-based Kelvin color warmness adjustment to reduce blue-light strain during extended reading.
• 4 Preset Themes: Parchment, Eye-Care Green, Dark Mode, and Pure White.

5. Smart Bookshelf & Text Purification

• Adaptive Grid View: Beautiful gradient cover generator for imported TXT and EPUB books with duplicate collision detection.
• Background Text Purification: Silent Regex pipeline that filters out garbage characters, ads, and formatting errors on the fly.

6. Seamless iCloud Sync & Architecture

• Decoupled SwiftData Architecture: Built on a 3-tier data model (Book - Chapter - ChapterContent) with @Attribute(.externalStorage) for large text blobs.
• Private iCloud Sync: Real-time background sync across iOS devices via private iCloud (CloudKit) without third-party servers.

BookFun v1.0.0 — Read more. Worry less.