An earlier commit claimed to move `film_sim` from `[tone, colour]` to
`[effect]` and did not. It edited `ops/film_sim.yaml`, where `attributes:` is
read, validated against the vocabulary, and then dropped: a `rust:` node
publishes its own descriptor, and the type still said tone and colour. The
stock went on appearing in the Light group beside exposure and again in Colour
beside white balance, exactly as before, and every test passed.
Nothing caught it because nothing could. The declaration parsed, the parity
tests compare ids rather than attributes, and an operation filed under the
wrong groups renders perfectly. It surfaced only on screen, as a missing
Effects tab — which is indistinguishable from a category that genuinely has
nothing in it, and is precisely how `Optics` looked for as long as it was
empty.
So three changes rather than one:
`FilmSim`'s descriptor declares `Attribute::Effect`, which is the move the
earlier commit described.
`attributes:` joins the keys a `rust:` node may not carry, beside `params`,
`uniforms`, `wgsl`, `helpers`, `define` and `label`. The rule was already
written — "its descriptor comes from the type" — and attributes were the one
field that slipped past it. A key that is silently ignored is worse than one
that is rejected, because it reads as though it worked; the eight hand-written
declarations lose a line that never did anything.
And a test asserts that every attribute the chain carries reaches the tab
strip. That is the property that was actually broken, and its failure mode is
invisible from every direction: the controls exist, they are in the shader,
and there is no way to filter to them.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
`ops/vignetting.rs` has carried a complete descriptor, polynomial, helper
and test suite without an entry in `ops/`, so it was never in `chain()`.
It reached no photograph and no panel, and `Attribute::Optics` was an empty
category in consequence — filtered out of the tab strip for having no rows,
by a chain that had never been given its only member.
Declaring it needs the one thing the operation was written against and
which did not exist. `wgsl_body` reads `radius`, and the module claimed
"the composer publishes `radius` in the shader prologue for exactly this
reason". It did not. `sample_source` now does, in both sampling branches,
beside the `source_px` it already published for the same class of caller.
It is corner-normalised there, which is the part that is easy to leave out.
`p` spans ±0.5·aspect, so its length at the corner is 0.5·length(aspect) —
about 0.901 on a 3:2 frame, not 1. Lensfun's polynomials are fitted against
a corner radius of 1, so passing `length(p)` straight in evaluates every one
of them short of where it was measured, by a factor that changes with the
aspect ratio. It would have read as a correction that is simply too weak,
which is indistinguishable from a bad profile. Both `lens.rs` and
`framing.rs` asserted the normalisation `p` does not have; corrected.
`order: 5` puts the correction ahead of the tonal stages, and the ordering
is load-bearing rather than tidy. Recovering a corner means dividing by an
attenuation below one — about two stops for a fast prime wide open — so run
after the highlights have been rolled off and clipped, the lift has nowhere
to go and the corners posterise instead of brightening.
`layer_chain` now drops `Optics` as well as the neighbourhood operations.
A local vignetting slider would have worked, which is what makes it worth
excluding: `radius` measures from the centre of the whole photograph and a
mask cannot move the optical axis, so it would lay a frame-centred radial
ramp across the picture and multiply it by the mask. The existing exclusion
covers operations that move and do nothing; this one covers an operation
that moves and does something its name does not promise. The rule both
share is now written down.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
dtourolleandClaude Opus 5