80938b05274e99fc3a293f4276061cfb8ad460db
5
Commits
| Author | SHA1 | Message | Date | |
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 dtourolle
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acab0d7abb |
A linear DNG in and out: the writer, and a three-sample RawImage
dr-export gains write_linear_dng — LinearRaw, DNG 1.4, u16 samples at the sensor's scale, the body's matrices with their illuminants, the as-shot neutral, the EXIF block an export writes — streamed strip by strip through a closure so the composite is never held (FR-MRG-11). The tiff crate's directory is a map, so PhotometricInterpretation is written over what new_image set, which is the trick the S15.1 spike thought it had to hand-roll around. The test reads the file back through rawler. dr-decode's RawImage carries samples_per_pixel (a linear DNG is 3), the body's profile with its calibrations mapped back to EXIF illuminant codes, and the cleaned make and model. The GPU uploads a three-sample image as it is, normalised by black and white like a photosite, through a full f16 conversion — subnormals kept, because a 14-bit LSB sits at f16's smallest normal and rounding it to zero would crush exactly the shadows the file was written to keep. |
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 dtourolleandClaude Opus 5
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4b2ee0ac50 |
Count the silver instead of adding noise
An emulsion is a suspension of crystals. Light sensitises some; development
turns a sensitised one opaque, all or nothing. So a patch of film's density
is a *count* of developed grains, and a count of independent yes/no events
has a variance whether or not anyone wanted texture:
mean = D
variance = D * (Dmax - u * D) / N
That expression is the whole feature. It peaks in the middle of the density
range and vanishes at both ends -- clear film has nothing developed to vary,
black film has nothing left to develop -- so grain lives in the midtones as a
consequence rather than as a "midtone bias" slider.
I was wrong earlier that this needs the detail stage. Nothing in it reads a
neighbouring pixel; the only reason to move it was that grain must be fixed in
film space rather than screen space, and that solves itself: N is grains *per
pixel*, so it scales with the film a pixel covers. Zoom out, each pixel
averages more grains, less variance -- correct, with nothing super-sampled and
nothing filtered. It stays in the fused pass.
Grain goes on the density and *before* the dye, which is the physical order
and not cosmetic. Perturbing the finished colour -- what an effect does --
tints highlights wrong, because that noise never passes through the dye.
Crystal habit lives in `rms_granularity`, the number every datasheet
publishes, now a profile field. It measures exactly what differs between a
cubic emulsion and a tabular one: at equal speed, tabular crystals present
more area per unit silver, so the film reads finer. Delta 100 is quoted near 9
where HP5 is near 12, and that gap *is* the habit. Adding a stock whose grain
is its whole reputation is therefore editing one line, not writing a model.
Three things this cost, all of them worth writing down:
- The default granularity is a colour negative's, blue coarsest. Applied to
Tri-X it put *colour* speckle on a black and white photograph. Monochrome
stocks collapse it at parse, where every other per-layer table is already
replicated from the one measured channel.
- Helpers cannot read uniforms. The composer prefixes a uniform with its
operation's id and rewrites references inside a fragment body only;
helpers are shared and deduplicated, so a bare `gn0` names nothing.
`film_lut` already took its size as an argument for this reason, and now
says so.
- The end-to-end test compares the shader against the CPU model, and grain
is stochastic, so that comparison now runs with grain off. Which means a
grain that never left the CPU would look exactly like a passing suite --
hence a second test that grain off is bit-identical, one grain per pixel
moves it, and ten thousand move it less.
Not here, deliberately: no grain slider. The parameters are physical and
`rms_granularity` is the honest place to scale one from, but its range wants
choosing rather than guessing. Nor a film format -- 35 mm is assumed, and
medium format at the same stock is far less grainy per unit of picture.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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dtourolleandClaude Opus 5
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3b5952769b |
Emit floats an f32 can hold, and drop the format! that formats nothing
CI runs cargo fmt --check and clippy -D warnings, and this branch had never been through either. Both would have failed it. The bulk was the generated colour tables: eight significant figures where an f32 carries about 7.2, so the eighth is noise that rounds away at compile time and clippy's excessive_precision says so 109 times over. Fixed in the generator rather than only in the file, so it stays fixed -- and the file is trimmed in place rather than re-derived, because regenerating it needs a colour-science stack that has nothing to do with the defect. The format! in the composer is mine too, from extracting the rendering tail: the braces in it were escaped because the text used to live inside a larger template, and once extracted the escapes are noise and the call formats nothing. Also here, and clearly not mine: an unused import and a shadowed binding in dr-gpu, and an unused import in a test. They are pre-existing -- clippy has been failing on master before this branch existed, on lints like is_multiple_of that arrived with a toolchain rather than with anyone's code. Fixed because CI cannot go green around them, and called out because a merge commit is a bad place to quietly edit someone else's crate. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> |
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dtourolleandClaude Opus 5
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baa8957e80 |
Let a photographer choose the film, and remember which one
The stock model rendered correctly and nothing could ask for it. This is the picker, and the sidecar key that makes the choice outlive the session. How the choice persists was the open question, and the answer was already written down twice in sidecar.rs: `rating` is a top-level key "because a rating is not an edit", and `masks` are one "because a layer is not a scalar". A stock is that kind of thing -- a choice of material, not a number a slider moves -- so it is a top-level key too. It stores the **id**, not an index. Stocks are files that users add, so an index would mean installing a profile silently changed which film every existing photograph had been developed on. A name this build has no profile for still round-trips untouched, because the alternative is that syncing to an older phone quietly un-develops the picture. Only the names travel. Turning one back into tables needs the profile database, which dr-pipeline deliberately does not link, so `Version::apply` clears the film and the session re-bakes -- after the parameters, because the bake reads the film's own exposure sliders and the print balance is solved against them. That is also why moving those sliders rebuilds the lookup where no other control in the panel does: an enlarger's filtration depends on how the negative was exposed. The panel keeps its rule. It still names no operation and still generates every control from a declared parameter kind; the stock gets a bespoke control beside those, exactly as the mask stack does, and for the same reason. The film's exposure and print exposure arrive as ordinary generated sliders. Two defaults worth stating. Picking a colour negative prints it, because an unprinted one is an orange strip and offering that as the first thing somebody sees after choosing Portra reads as a bug rather than as a choice -- the toggle is there for anyone who wants the scan. And a paste carries no film: a preset is a parameter map, and a stock is not a parameter, so pasting one would paste a choice the clipboard never took. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> |
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dtourolleandClaude Opus 5
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4a2fcb6d22 |
Render a film stock on the GPU, and let it take over the rendering
The stock model landed in dr-film with no way to see it. This is the pipeline node, the two texture bindings it reads, and the end-to-end test that proves the shader agrees with the model. The design point is that a film simulation is not an adjustment. Every other node changes a picture; this one makes it. A stock's characteristic curve does the camera profile's base curve's job -- from measurements rather than from a curve somebody drew -- so running both renders the scene twice: the camera's rendering, and then a film's rendering of that. It looks like neither, and it reads as a colour-management bug with no colour-management bug to find. So `Operation::renders` is new. A node declaring it takes camera RGB and hands back linear sRGB, and the composer emits neither the base curve nor the conversion out of camera space. Both halves move together, and the composer keeps them as one string precisely so that getting half of it right is impossible. The tables are not parameters, for the reason vignetting's coefficients are not: they are measurements. dr-pipeline declares the layout as a plain struct and keeps its no-dependency property; the two crates share no types on purpose. `EditGraph::set_film_tables` offers them to every node rather than to the one that wants them, because knowing which concrete type is which is what the graph is organised not to know. Bindings 4 and 5 follow the masks precedent: declared unconditionally so one bind group layout serves every generated shader, bound to 1x1 placeholders when no stock is loaded. Both are interpolated by hand with textureLoad -- this pipeline binds no sampler, and adding one for two lookups would cost a binding in every shader. Uploads are keyed on content so an unchanged stock does not push half a megabyte across the bus per frame. The end-to-end test earned its place immediately: it found the density lookup being filled z-fastest while a 3D texture upload wants x-fastest, so the red and blue axes were transposed. Green matched exactly, which is what that bug looks like -- a plausible photograph of the wrong colour, and one that every unit test on either side of the seam passes. dr-film now pins the layout in a test that needs no device, and states it where the field is declared. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> |