Build a native iPhone version of GIF Cleanup Studio in SwiftUI. Do not wrap the Electron app. Port the core behavior from the existing TypeScript app:
Source files to study:
- outputs/gif-cleanup-studio/src/App.tsx for product workflow and screen structure
- outputs/gif-cleanup-studio/src/sprite.ts for sprite-sheet parsing, alignment, color snapping, resizing, starter frame creation
- outputs/gif-cleanup-studio/src/gif.ts for GIF export behavior
- outputs/gif-cleanup-studio/src/midi.ts for MIDI Fighter pad ordering and frame mapping
- outputs/gif-cleanup-studio/src/classicHeroSprites.ts for the CC0 starter cycle
Target:
- iOS 17+ SwiftUI app, iPhone first, usable on iPad by layout scaling.
- Import sprite sheets from Photos and Files.
- Parse sheets into up to 64 frames with selectable columns, rows/auto rows, background tolerance, color snap tolerance, bottom/center/cell alignment, frame size presets 24/48/64/124/128.
- Edit one frame at a time with a zoomed pixel canvas, pencil, eraser, eyedropper, grid toggle, and color picker.
- Show the MIDI Fighter model as 4 banks x 16 pads. On iOS, implement CoreMIDI input for real hardware where available; keep touch selection fully usable when hardware is absent.
- Export animated GIF at 8/16/24/30/60 FPS.
- Include a ChatGPT prompt drawer equivalent that reflects the chosen frame size, frame count, FPS, style notes, and learned starter cycle metadata.
Implementation requirements:
- Model PixelFrame as width, height, RGBA [UInt8], sourceIndex, id, name.
- Implement SpriteSheetParser with the same algorithm as sprite.ts: sample background from corners/edges, copy grid cells, compute non-background bounding boxes, align into a consistent target canvas, then normalize colors by nearest cluster within tolerance.
- Use PhotosUI and UTType.image for imports. Use CoreGraphics/ImageIO to read source pixels. Use CGImageDestination with kUTTypeGIF for export.
- Use CoreMIDI for MIDI devices. Map MIDI Fighter input to frame indices with the same four orientation modes from midi.ts: bottom-left, top-left, top-right, bottom-right.
- Keep rendering pixel-perfect: no smoothing when drawing frames, stable square pixel cells, no blurry scaling.
Suggested file layout:
- GIFCleanupStudioApp.swift
- Models/PixelFrame.swift
- Models/MidiBinding.swift
- Sprite/SpriteSheetParser.swift
- Sprite/FrameRenderer.swift
- Sprite/ClassicHeroStarter.swift
- Export/GifExporter.swift
- MIDI/MidiFighterController.swift
- Views/ContentView.swift
- Views/FrameBankGrid.swift
- Views/PixelEditorView.swift
- Views/PromptDrawerView.swift
- Tests/SpriteSheetParserTests.swift
- Tests/MidiMappingTests.swift
- Tests/GifExporterTests.swift
Checks before calling it done:
- xcodebuild -scheme GIFCleanupStudio -destination 'generic/platform=iOS Simulator' build
- xcodebuild -scheme GIFCleanupStudio -destination 'generic/platform=iOS Simulator' test
- Unit test that a 4x4 sheet produces 16 frames.
- Unit test that bottom alignment keeps all non-empty frames on the same baseline.
- Unit test that MIDI pad orientation maps frame 1 and frame 16 correctly for all four modes.
- Manual device note: CoreMIDI hardware selection must be tested on a real iPhone/iPad with the MIDI Fighter connected through a supported USB/MIDI path.