FR-DEV-5 asked for named snapshots of an edit state and FR-DEV-7 for a comparison against a chosen one, and neither existed. The history stack is per sitting and forgotten with it, on purpose — the gap that mattered was an automatically saved mis-drag with no way back, and that was closed first. What was left was the other half: a state the photographer wants to keep *because* it is worth keeping, which is a different thing from a step and is not served by making the steps last longer. A snapshot is an edit state, and an edit state is exactly what a sidecar version stores, so it is stored as one: a `[version]` block carrying `snapshot-of = <uuid>`. The parameters, the masks and their parts, the repairs and the film all arrive through the blocks that already carry them, a merge keys on the uuid as it does for any version, and a build that predates the key reads the block as a named version and keeps it — the right failure. Only the pointer is new. The one reader that has to know is `default_version`, which must never answer with a snapshot: a file whose edit is missing is not a file whose edit is one of its saved moments. The snapshots of an edit are listed by that pointer, oldest first, the same on every device. Writing them back removes what this sitting deleted and puts in what it holds, and leaves standing whatever it never saw — a snapshot the other device took since the photograph was opened here is not this device's to remove by not knowing about it. That is the rule the version merge already keeps, applied one level down, and it is why the save carries the deleted ids rather than replacing the list wholesale as the masks are. Each is re-pointed at the uuid the save settled on, because the default may have been fused onto its canonical identity since the snapshot was taken. Restoring is one history step, so undo takes it back whole, as a paste is. Taking and deleting are not steps: they change nothing about the photograph, and an undo that removed a snapshot would be undoing a decision to remember. Holding the eye beside one renders the snapshot and hands the edit straight back — the same suspension "Before" uses, against a point the photographer chose rather than the file. Two sessions on the same photograph get ids that cannot collide, stamped with the second and a random word, because the merge folds equal ids into one.
DarkRoom
A cross-platform, non-destructive RAW photo editor for Linux and Android.
Status: 0.9.0, and no longer a spike. A library opens, culls, develops and exports on both platforms, across eight tagged releases. What is not built is written down rather than merely absent — see docs/outstanding.md for the requirements that have no implementation and why, and docs/technical-debt.md for the compromises that were chosen.
Documentation
| Document | Contents |
|---|---|
| CONTRIBUTING.md | How to land a first change without reading the rest |
| requirements.md | What the software must do — 179 numbered requirements |
| architecture.md | How it is built — crates, GPU pipeline, data model, sync |
| technical-debt.md | Compromises taken deliberately, each with the condition that retires it |
| outstanding.md | What is not built, and whether that is a decision or a gap |
| code-health.md | What a contribution costs, per seam, measured |
| traceability.md | Generated: which requirement is claimed by which file |
| faces.md | Face detection and identity — the models, the licence problem, and what S14 measured |
Building
Desktop:
cargo run -p darkroom-desktop
Android (containerised toolchain, see docker/android):
./docker/android/build.sh cargo ndk -t arm64-v8a build --release
Git LFS is required for the model weights, and the toolchain pins itself. CONTRIBUTING.md has the details and the four commands CI will run against what you send.
Current state
Working. A catalog over a local folder, a Nextcloud account, or a folder a
sync client keeps in virtual-files mode — where a placeholder is treated as the
photograph rather than as a one-byte file. A virtualised library grid with a
capture-time timeline, ratings, labels, keywords, collections and a trash that
survives a crash mid-operation. Card ingest. Face detection and identity, with
the index syncing between devices. A develop pipeline of fifteen declared
operations fused into a single compute dispatch, plus the neighbourhood
operations that cannot be — clarity, texture, capture sharpening, noise
reduction, lens correction, spectral film simulation. Crop, straighten, spot
removal, gradient and subject-segmentation masks, named presets, and a
generated panel that no operation in ui/ is allowed to name. Export to JPEG,
PNG and 8- or 16-bit TIFF with resize and output sharpening.
The zero-copy display path works on desktop. The compute pass writes a texture that Slint composites directly, which is what ARCH §6.1 requires; the readback it forbids costs 96% of frame time at 4K, and
cargo run -p dr-gpu --example bench --features readback
still reproduces that measurement. The one exception is the Android develop view, which reads the frame back through the CPU because zero-copy there needs wgpu's Vulkan swapchain, and that tears a portrait window on a tablet whose panel is mounted landscape. It is debt, not a revision of the rule: the reasoning, the on-device measurements that forced it, and the three separate things any one of which would remove it are in technical-debt.md TD-1.
Not built. Plugins, compare and survey culling, focus peaking, burst grouping, AI denoise, tiled and progressive rendering, and most of the Android platform integration beyond running. The performance targets in §4.1 are unverified rather than unmet — the per-commit benchmark suite §8 requires does not exist, so nothing fails a build on a regression. docs/outstanding.md is the list, with the reasoning.
Licence
GPL-3.0-or-later.