D88エミュレーション実装

[ponzu0147]

D88エミュレーション実装

実装内容

• DriveEmulatorクラスの実装
  • ドライブの物理的な動作（ヘッド移動、回転待ち）のエミュレーション
  • タイミング制御の実装
  • エラー処理の追加
• D88DiskExtensionの追加
  • セクタ読み書き機能の拡張
  • エラーハンドリングの改善

技術的な詳細

• ヘッド移動時間: 3ms/track
• ヘッドロード時間: 35ms
• セトリング時間: 15ms
• 回転速度: 300rpm
• インターリーブ対応

[gemini-code-assist]

Hello @ponzu0147, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

Summary of Changes

This pull request implements D88 disk emulation for the PMD88 iOS application. It includes the implementation of the DriveEmulator class, which emulates the physical actions of a disk drive (head movement, rotation waiting), timing control, and error handling. It also adds a D88DiskExtension to extend sector read/write functionality and improve error handling. The implementation details include head movement time, head load time, settling time, rotation speed, and interleave support.

Highlights

• DriveEmulator Class: Implements the DriveEmulator class to simulate physical disk drive operations, including head movement and rotation waiting, with timing control and error handling.
• D88DiskExtension: Adds D88DiskExtension to extend sector read/write functionality and improve error handling within D88 disk images.
• FM Engine Enhancements: The FM engine is enhanced with key on state management, frequency calculation, waveform generation, and envelope calculation, improving the accuracy and richness of FM sound synthesis.

Changelog

Click here to see the changelog

• AudioEngine.swift
  • No functional changes; the file was modified but the code content remains identical.
• FMEngine.swift
  • Added properties for phases, envelopes, and channel key on state to the FMEngine class.
  • Implemented updateRegisters to detect key on state changes and update channel states.
  • Improved generateSample method to synthesize channel outputs based on active channels, phase, envelope, and volume.
  • Added methods to determine channel activity (isChannelActive), get channel FNUM and BLOCK values, calculate frequency, generate waveforms, calculate envelopes, and get channel volume.
• PMD88iOS.xcodeproj/project.pbxproj
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS.xcodeproj/project.xcworkspace/contents.xcworkspacedata
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS.xcodeproj/xcuserdata/koshikawamasato.xcuserdatad/xcschemes/xcschememanagement.plist
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/Assets.xcassets/AccentColor.colorset/Contents.json
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/Assets.xcassets/AppIcon.appiconset/Contents.json
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/Assets.xcassets/Contents.json
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/BoardType.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/Constants.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/ContentView.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/D88Disk.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/D88DiskExtension.swift
  • Added readSectorData function to read sector data from a D88 disk image.
  • Added writeSectorData function to write sector data to a D88 disk image.
  • Added isWriteProtected function to check if the D88 disk is write protected.
  • Added getTrackInfo function to retrieve track information from a D88 disk image.
  • Added getSectorInfo function to retrieve sector information from a D88 disk image.
• PMD88iOS/DriveEmulation.swift
  • Introduced DriveTimings struct to define timing constants for disk drive operations.
  • Defined DriveState struct to manage the state of the emulated drive.
  • Created SectorAccess struct to handle sector access control and interleave calculations.
  • Defined DriveError enum to represent various drive-related errors.
  • Implemented D88DriveEmulator class to emulate disk drive behavior, including motor control, head movement, and sector read/write operations.
• PMD88iOS/Engine/ADPCMEngine.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/Engine/AudioEngine.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/FMAlgorithm.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/FMEnvelope.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/FMTypes.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/PC88/PC88Audio.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/PC88/PC88Core.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/PC88/PC88Debug.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/PC88/PC88PMD.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/PC88/PC88Types.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/RhythmEngine.swift
  • No functional changes; the file was modified but the code content remains identical.
• PMD88iOS/SSGEngine.swift
  • No functional changes; the file was modified but the code content remains identical.

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---

In realms of code, where bits align,
A D88 disk, a treasure to find.
Emulation's art, a digital quest,
To bring old sounds to modern test.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request implements D88 disk emulation, including drive physics, timing control, and sector read/write functionality. The code appears well-structured and addresses the requirements outlined in the pull request description. However, there are some areas that could benefit from further review and potential improvement, particularly in error handling and code clarity.

Summary of Findings

• Incomplete Error Handling in D88DiskExtension.swift: The D88DiskExtension.swift file lacks proper error handling for dataOverrun errors during sector data writing. This could lead to unexpected behavior or data corruption if the provided data exceeds the sector's capacity. A more robust error handling mechanism should be implemented to prevent this.
• Missing Error Handling in D88DriveEmulator.swift: The D88DriveEmulator.swift file lacks comprehensive error handling in the readSector and writeSector functions. While some errors are thrown, there's no mechanism to catch and handle them gracefully, potentially leading to unhandled exceptions and program crashes. Consider adding do-catch blocks to manage these errors.
• Potential for Deadlock in Audio Engine: The AudioEngine.swift file uses completeStop which calls resetAllEngines which contains a call to updateState on the audio engines. This could lead to a deadlock if the audio engine is already in the process of updating its state on another thread. Consider refactoring to avoid this potential deadlock.

Merge Readiness

The pull request introduces significant functionality for D88 disk emulation. However, due to the presence of high and medium severity issues, it is not recommended to merge this pull request until these issues are addressed. Ensure that error handling is robust and potential deadlocks are resolved before merging. I am unable to directly approve this pull request, and users should have others review and approve this code before merging.

[gemini-code-assist]

The completeStop function is called within stop and start which then calls resetAllEngines which then calls updateState on the audio engines. This could lead to a deadlock if the audio engine is already in the process of updating its state on another thread. Consider refactoring to avoid this potential deadlock. This is a medium severity issue because it could lead to the application hanging.

    // 完全停止処理
    private func completeStop() {
        // 現在のプレイヤーノードを停止
        if let player = playerNode {
            // 再生中かどうかに関わらず強制的に停止
            player.stop()
            
            // バッファをリセット
            player.reset()
            
            // エンジンから切り離す
            engine.detach(player)
            playerNode = nil
            print("🔊 プレイヤーノード解放")
        }
        
        // エンジンを停止
        do {
            // エンジンの実行状態に関わらず強制的に停止
            engine.stop()
            print("🔊 AVAudioEngine停止")
            
            // エンジンを完全にリセット
            engine.reset()
            print("🔊 AVAudioEngineリセット完了")
            
            // オーディオセッションを非アクティブにする
            try AVAudioSession.sharedInstance().setActive(false)
            print("🔊 オーディオセッション非アクティブ化")
        } catch {
            print("⚠️ オーディオエンジン停止エラー: \(error)")
        }
    }

[ponzu0147]

やりましょう