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DarkRoom/core/dr-pipeline/ops/film_sim.yaml
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dtourolleandClaude Opus 5 e235e99cce Move the film to Effect in the descriptor that is actually read
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>
2026-09-05 18:28:59 +02:00

26 lines
1.2 KiB
YAML

id: film_sim
order: 25
# What this node is *about* is not written here, and cannot be: a `rust:` node
# publishes its own descriptor, so `attributes:` in this file would be read,
# validated and then ignored. See `Attribute::Effect` on `FilmSim`'s descriptor
# in `../src/ops/film_sim.rs`.
rust: FilmSim
why_rust: |
It carries a stock's measured tables — an exposure matrix, three
characteristic curves and a density lookup — which are not parameters and
which no `uniforms:` expression could produce. Its neutral is "no stock
loaded" rather than a set of values, and it is the one node that declares
`Operation::renders`, so the composer omits the camera profile's base curve
and the conversion out of camera space on its behalf.
placement: |
After white balance and exposure, and before everything else.
Those two are what the camera did — interpreting the sensor, and correcting
the amount of light that reached it — and they are only meaningful on
scene-linear values, which is what a film has to be handed. Everything below
is a decision about the picture, and a decision about the picture belongs
after the film has rendered it, exactly as it does when you scan a frame and
then work on the scan.