dtourolle
7c3e1d2c54
The colour mixer is the only chromatic control in the chain, and it can only turn a hue that is already in the frame. Ask it for cool shadows against warm highlights and it has nothing to take hold of: the shadows of a correctly balanced photograph are near enough neutral that there is no band there to turn, and a monochrome conversion hands it a picture with no hue in it at all. Split toning is the oldest look in the book and every developer worth comparing against ships it; there was no way to reach it from here. So colour_grading, declared like any other node — a hue and a strength for the shadows, the midtones and the highlights, and a global cast over the frame. It targets a tonal range rather than a hue, which is the whole difference between the two controls: it puts colour where none was rather than turning what it finds. It sits at 105, after the mixer has had the last word on the colours that are in the picture and before the detail stage. The mechanism is one helper. Three cosines 120 degrees apart are the hue wheel written directly as an RGB direction, and their sum is zero at every angle, so exp2 turns them into three gains whose product is exactly one — a cast tilts the balance without moving the level. A grade that doubled as an exposure change is the failure that has the photographer chasing brightness with a colour slider, and it is corrected with a control that cannot reach it. The three tonal weights partition the scale rather than overlapping, the midtones being whatever the two ends leave, so setting all three to one hue is exactly the global cast and a split tone does not colour its own midtones as a side effect of its halves meeting. Full strength is half a stop on the leading channel, the ceiling white balance already holds itself to. Neutral is declared rather than inferred, which is what `active:` is for. A hue with no strength behind it is a direction with no distance, so under the default rule nudging one would have put the node into every fused shader for a change nobody can see. Summing the strengths is zero exactly when all four are, and they cannot go negative to cancel each other. The opposite reading — neutral as "nothing has been touched" — fails the other way round: red is hue zero, so a grade toward red never moves a hue off its default and would never have been applied at all. It asks for a colour wheel, the widget the descriptor vocabulary has been carrying with no operation behind it. Nothing draws one yet, and that is fine by construction: the panel takes the first widget it implements and falls through to sliders otherwise, so this arrives as eight ordinary controls that work. Each parameter is named for its own range for exactly that reason — in a flat list, four sliders called "Hue" are four controls nobody can tell apart. FR-DEV-12 is written into requirements.md beside it. A TRACES tag naming a requirement that is not defined there is an orphan, and the traceability gate fails on those rather than quietly counting them. The label catalogue gets one line for the operation's display name; the eight parameters derive correctly and are left to.
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.