A layer offered the film's sliders and they moved nothing: its copy of
the node was never given the stock, so it stayed inactive. Film now
works in a layer the way the other adjustments do, as offsets to the
photograph's settings, but blended as settings rather than as results,
since a film is a rendering and cross-fading two developments is not
what a region on a pushed film looks like.
- dr-film bakes no slider. Exposure is a gain in the shader; push
interpolates the stock's measured processes, one curve row each; the
print is split at the paper's log exposure, so print exposure is an
addition between two lookups and exact at any setting. The enlarger
stays balanced at the photograph's exposure.
- film_sim reads all four settings as uniforms, format one-hot over a
grain count per format, so every uniform is linear in what it does.
- Operation::blends_settings lets the composer average each overlapping
layer's uniforms with the global ones by mask weight, the global
setting taking whatever weight the layers leave, and run the fragment
once. Three layers at full weight give the mean of their settings.
- The stock picker is hidden on a layer. Only the photograph's exposure
re-solves the print balance; push, print exposure and format need no
rebake at all now.
An edit used to be a bag of scalars. That stopped being true when the mask
stack and the film stock arrived, both deliberately held apart from `ops`
because a layer is not a scalar and a stock is not a scalar — and nothing
announced the change. What happened instead is that three routines each
captured "the edit" and each captured a different subset of it.
`EditState` is all of it: the parameter map, the masks, the stock. What keeps
it complete is not a comment. `EditGraph::state` destructures the graph
exhaustively, `EditGraph::set_state` destructures the state exhaustively, and
the fields are public so every construction site is a struct literal naming
all of them. Adding a fifth kind of graph state — FR-DEV-8's spot removal is
the one already asked for — fails to compile until somebody has decided
whether an undo has to put it back. Verified both ways round by adding a field
to each type and watching five call sites refuse to build.
A compiler error rather than a runtime check, because the failure being
prevented is silence: the missing halves produced no panic, no warning and no
failing test.
The stack is now shared rather than owned, and that is about the drag path
rather than memory: `state` runs on every parameter change, which during a
drag is once a frame, and deep-copying a painted brush sixty times a second to
record an exposure move would be a cost paid for nothing. `masks_mut` is the
one door a stack is modified through, so it clones on write.
`FilmRebake` is the one thing a caller is still owed. Restoring a stock always
needed the profile database this crate does not link (ARCH §6.5a); it was a
comment before, and it is a `#[must_use]` return value now.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
dtourolle
