Everything this application knew about a failure went to stderr on the desktop and to logcat on Android, and both are gone the moment the terminal closes or the ring buffer wraps. That is fine when the person debugging is sitting at the machine. It is useless for the case NFR-OPS-1 actually describes, and the one Android makes normal: somebody reproduces a bug on a tablet, and then sends us a file. A large amount of Android behaviour has never run on a device — image intents read over JNI, an ExportProvider, a class loaded through the activity's class loader, memory-pressure eviction, lost-root recovery — and the single most likely failure of the lot, the activity's loader not resolving our classes from android_main's thread, produces one line that scrolls past. That line is now in a file, with the thread that emitted it named beside it. dr_plat::state answers "where does this platform keep state for this app": $XDG_STATE_HOME/darkroom on Linux, and on Android whatever the entry point declares. Separate from configuration and from the catalog for the reason XDG separates them — state is the thing nobody backs up and the user may delete without consequence. dr_plat::diagnostics is the sink. Two files of 4 MiB, so the worst case is a number rather than a discovery on a full phone; one line per write with no BufWriter anywhere, because on Android processes are killed rather than ended and a buffered log loses exactly the line it was kept for; and redaction applied at the sink rather than at the call sites, since a rule every author has to remember is not a rule. It tees the platform's own logger rather than replacing it, so logcat is unchanged — losing that while debugging would have made this a downgrade. Android logs to external_data_path, not internal. Both are app-private and both survive backgrounding; what separates them is that /data/data/<pkg>/files needs run-as against a debuggable build to read and /sdcard/Android/data/<pkg>/files is a plain adb pull from any build. A log nobody can retrieve is not a diagnostic. The consequence is that anyone holding the tablet can read it, which is why the redaction is where it is, and why configuration stays on internal_data_path. What is redacted is what NFR-SEC-2 and NFR-OPS-1 name: credentials and tokens, found by the keyword that nearly always sits next to them, plus the two forms that carry one with no keyword at all — an Authorization scheme and a URL's userinfo. What is deliberately not redacted is filesystem paths and the names of the user's photographs. They are in neither requirement's list, and "failed to decode <redacted>" is not a diagnostic; the preview-and-consent step NFR-OPS-1 asks for governs those better than scrubbing would, because it lets the user look. The over-redaction failure is tested as carefully as the under-redaction one. A scrubber that eats "using basic sRGB as the fallback" makes a log useless without ever being caught.
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.