BeatDropX

BeatDropX is built on a professional-grade rhythm engine architecture, designed for players who demand precision. Technical Specifications: • Judgement accuracy: Perfect ±50ms / Good ±100ms / Miss ±150ms • Rendering engine: SpriteKit at 60fps real-time note fall • Audio-visual sync: AVAudioPlayer sampleTime-driven, frame-level alignment • Haptic system: CoreHaptics CHHapticEngine + UIImpactFeedbackGenerator dual-channel Beatmap System: • 3 built-in tracks (120/140/160 BPM), SplitMix64 PRNG for reproducibility • Difficulty scaling: Easy 1 note/beat, Normal 2/beat, Hard 4/beat + 18% chords • User import: AVAudioFile frame-level RMS differential + adaptive threshold onset detection • Auto-generates Easy/Normal difficulty beatmaps for imported songs Scoring Mechanics: • Perfect 1000pts / Good 500pts / Miss 0pts • Combo bonus: +5% per 10-hit streak, capped at +50% • S/A/B/C/D rank system (≥95% accuracy = S rank) • UserDefaults-persisted personal best records Interface & Adaptation: • SwiftUI + SpriteKit hybrid architecture • iPad adaptive layout (lane max width 500pt) • TimelineView-driven beat-breathing background animation • Runtime bilingual switching (dynamic Bundle lproj loading) Privacy: • Zero network requests, zero third-party SDKs • No data upload, 100% offline operation • Delete the app to delete all data