Loop playback — the transport repeating the open symbol — is editor state and
the document has never heard of it. A looping INSTANCE is a node repeating the
symbol it places, which is the four-frame tire turning for the hundred and
twenty frames it is on screen, and it lives in the document as
`:playback {:end :loop}`. Same word, two scopes; named apart here before
anything is built on either.
The status of the second one is the surprise: it already works and cannot be
asked for. `node/placed-frame` does the modulo, `node/problems` already admits
`:end :loop`, `audio-tracks` already expands the periods — and no control sets
it anywhere in the UI. So the tire is three pieces of work, not one: somewhere
to edit an instance's playback, a block that draws its repeats rather than
only its first pass as the timeline's own docstring admits it does, and the
audio period guard.
This also pins down when the held cel can be torn out. Turning every drawing
into a one-frame looping instance is only safe once a looping instance can be
seen and edited; otherwise every drawing in the document quietly acquires a
property with no control on it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Holding a drawing and looping a one-frame symbol are the same picture, and the
second is a case the model already carries, so the first is a special case
kept for nothing. Speed 0 goes; a cel becomes a one-frame symbol with
`:end :loop` and a span. Looping and span are already properties of the
instance and `:frames` already belongs to the symbol, so nothing moves — a
mode is deleted. Two spellings of looping collapse to one, `:time :loop?`
giving way to `:playback :end :loop`, and `extend-hold` collapses into
`resize-out`, since it exists only to refuse anything that is not frozen
before editing a span.
What it buys is one rule where there were three refusals. `nest/inside` has no
invertible clock for a hold, for `:end :hold`, or for a loop, so
shift-to-reparent refuses all three — which is most of what anybody would drag
onto. Resolving the move with the destination's map at the CURRENT frame
covers every one: a loop is affine within the period the frame falls in, a
one-frame loop is that rule with a period of one — which lands exactly where
the nesting notes argued it should from first principles — and `:end :hold` is
affine in the played part and frozen in the tail.
The trap is written down beside it, because it would be found the hard way:
`audio-tracks` expands a loop into one walk per period, and is saved today
only by the `(pos? speed)` guard that a held cel fails. Make every drawing a
loop and a drawing held for 120 frames becomes 120 walks emitting any nested
sound 120 times. An audibility precheck has to land in the same change.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The plan asked what to draw when a symbol in lane mode holds overlapping
children, and offered to report it as a decision waiting for a person. Wrong
question: they never overlap. Placement claims time — anything placed, moved
or grown over occupied time trims, removes or splits what it lands on — so the
operation that could have made an overlap did not, and `span/finish`, which is
already the single commit path and already refuses rather than half-applying,
is where that is enforced. An overlap is then a bug in a command and not a
state to design around.
The check stays, named `symbol/overlaps` and used three ways: the commit path
refuses one, a property test asserts no command can produce one, and a
document that somehow holds one still LOADS and is drawn visibly wrong with
the status saying so. Not `problems`, which stops a document loading, and not
`conflicts`, which means somebody has a decision to make — a display hint must
never be able to keep a document from opening.
The one place a person can ask for the impossible is toggling lane mode on
over children that already overlap. That refuses and offers to trim them into
a sequence, through the `:required-frames` retry the model already uses.
Also written down, because it is the pair the modifier exists to separate:
a plain body drag is temporal and replaces, trimming extents as needed; shift
is structural and goes through `nest/move-node` into the symbol under the
pointer, which has to keep working for symbols held in a lane.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The lane model put a second container in the node map — a group with
`:layout :sequence`, with its own membership, its own validation and its own
fourteen commands — and every part of the editor then had to ask which kind of
container it was looking at. The decision recorded here is to delete all of
it: a lane becomes a way of DRAWING a symbol whose children are sequential and
non-overlapping, the display goes back to a row per symbol, and the word
survives only in the timeline and in the drag handling that re-spans a
symbol's children while it is drawn that way.
The commands are not the part being thrown away. `extend-hold`, `resize-out`,
`roll`, `blank` and the rest are what endpoint dragging IS, and their
arithmetic is right; what changes is their subject, from "the children of lane
L in symbol S" to "the children of symbol S". They belong in `span.cljs`,
which already owns re-spanning and `finish`.
The plan takes a position on the one question that decides whether this is a
simplification or a circle: lane mode is a saved hint on the symbol rather
than unsaved view state, because the drag rules follow the mode, and a toggle
the document does not record would make one gesture do two different things
to it. Nothing outside the timeline may read the hint.
It also lists what must not be lost on the way, all of which broke at least
once today: a held clip's contents reachable with no keys and no draggable
edges, double-click to open surviving the selection it leaves behind,
selection waiting for pointer-up, no drop silently deleting what it lands on,
and a sound drawn once.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
