dtourolle
7421837c8a
Tool tabs need a taxonomy, and the taxonomy was the problem: a table in `ui/` mapping operation to tab breaks FR-DEV-3a, and a `group:` field risks what `ui-refinement.md` condemned `starts-group` for — the core deciding where the panel draws things. `Attribute` threads the needle. It says what an operation *is* — tone, colour, detail, optics, geometry, effect — which is the same category as `ParamKind` and squarely on the core's side of ARCH §4.3a's line. What is drawn, where it sits and whether it is visible stay the frontend's. There is no attribute for "the third tab", the enum's order is declaration order rather than screen order, and a frontend may render these as tabs, as headings, or ignore them. The payoff is that a tab strip can be *derived*: the groups are the attributes present in the capability list, so the interface names no operation and needs no table to keep in step. An operation joins the right group by declaring what it is, which is the one thing its author is well placed to say. Plural, because the tone curve is genuinely both — an RGB curve is tonal and the per-channel curves are chromatic, and filing it under one would hide it from half the people looking for it. Required and non-empty, enforced in `build.rs`, and the failure was checked by removing the line rather than assumed. An operation with no attribute is invisible to a panel that groups by them; a build that stops costs ten seconds, a control nobody can find costs more. The vocabulary is closed for the same reason: a typo would otherwise invent a category holding exactly one operation, which looks like a deliberate one until somebody counts. Six tests over the real chain, including the hand-written operations that `build.rs` never sees and so cannot check.
59 lines
1.5 KiB
YAML
59 lines
1.5 KiB
YAML
# TRACES: FR-DEV-3a | FR-DEV-3c
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id: exposure
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label: op.exposure
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order: 20
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attributes: [tone]
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doc: |
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Exposure — a linear gain, expressed in stops.
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The simplest operation in the pipeline and the one that most justifies
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working in linear light: a stop is a doubling, so exposure is a single
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multiply. Applied to gamma-encoded data it would be neither a doubling nor
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reversible, which is why this stage sits where it does (ARCH §5.2).
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placement: |
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A correction to how the scene was captured, so it precedes every operation
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that interprets tone.
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params:
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exposure:
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label: param.exposure
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kind: stops
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min: -5
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max: 5
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doc: |
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±5 stops. Wider than most edits need, but recovering a badly
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underexposed frame is a real use and raw data often supports it.
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uniforms:
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gain:
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value: exp2(exposure)
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doc: The linear gain for the current setting.
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wgsl: |
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c = c * gain;
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tests:
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- name: one_stop_is_a_doubling
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why: |
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The definition of a stop. If this is wrong, every exposure adjustment is
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subtly off and no test of "looks right" would catch it.
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set: { exposure: 1 }
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expect: { gain: 2.0 }
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- name: one_stop_down_is_a_halving
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set: { exposure: -1 }
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expect: { gain: 0.5 }
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- name: stops_compose_additively
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why: +2 stops must equal +1 applied twice.
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set: { exposure: 2 }
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expect: { gain: 4.0 }
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- name: neutral_is_unity_gain
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why: |
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An unedited image must be the image, not an interpretation of it.
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expect: { gain: 1.0 }
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expect_active: false
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