The undo stack snapshotted a `Preset` — the parameter map — and a mask layer
is deliberately not a parameter. So drawing one changed nothing the history
could see: `record` returned `false`, no step opened, and the layer the
photographer had just painted had no way back. The interface went on calling
`record` in good faith, including from the mask controls, and nothing failed.
A film stock went missing the same way.
The snapshot is an `EditState` now, so the history is complete by
construction rather than by anyone keeping a list in their head.
`undo` and `redo` return a `Step` rather than a `bool`. Stepping is not the
only outcome a caller has to act on — a step across a change of film leaves
the graph without its tables, and only the caller can bake them — and a `bool`
would let that be dropped by writing nothing at all, which is the shape of
mistake this module had already made once. `DevelopSession` settles the debt
either way; a step that found nowhere to go is left alone, since clearing the
film because undo hit the floor would take the stock off the picture.
Five tests, all of which fail against the old snapshot: a drawn layer is
undoable and redoable, a layer's own settings are a step of their own, a
change of stock is a step and names what it needs baked back, clearing the
film is undoable, and an exposure move does not deep-copy the mask stack.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
A history state was a Preset — a map of scalars — which was right while
every edit in the graph was a parameter. A spot is not one, and undo is the
first thing anyone does with a repair: place it, dislike it, take it back.
Left as it was, that press would have stepped some unrelated slider and
left the spot on the photograph, which reads as undo being broken rather
than as undo being absent.
So a state is now the pair, params and spot set. The same door is the one
the mask stack will come through: mask edits are outside undo today for
exactly this reason, and FR-DEV-5 is not finished until they are not.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
A spot is a disc, a source offset and four numbers, and it lives beside
`ops` for the reason `masks` and `film` do: the operation trait is
ParamId -> f32, and a list of repairs is neither scalar nor fixed.
Two decisions here are not obvious. The id is derived from the position
rather than counted, because two devices editing offline would each mint
`spot3` for different marks and the sidecar merge would then treat two
repairs as one — from the position, two devices that removed the same
piece of dust agree, and two that removed different ones do not. And
every length is in the frame's isotropic units, not a mixture of those
and shorter-edge fractions: one unit for the radius, the feather and the
offset agrees on a landscape frame and on a portrait one, where a mixture
only agrees on the first.
`rounds` is the arithmetic that keeps a source from reading a
destination. Every spot in one pass reads the photograph as it stood
before that pass, so a spot sourcing from an earlier spot's destination
would copy the mark that spot was removing. Grouping is not a pass per
spot — that is sixty-four dispatches for a case that almost never arises
— it is a new round only when the sources actually collide.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
dtourolleandClaude Opus 5