Store a fresh preview, replacing any previous entry for `fx_id`.

Apply `f(r,g,b) -> [r,g,b]` to every opaque pixel and blend the result back with `intensity`. Alpha is left untouched. Pixels that are fully transpare

When the user multi-selects several timeline clips and trims an edge of any one of them, every other peer should trim the same edge by the same scene-

Build a 256-entry LUT from a piecewise-linear tone curve. Each LUT entry is the curve's output for the corresponding 8-bit input clamped to 0..255. Id

Editable tone-curve widget. Click an empty area to add a point, drag a point to move it, right-click a point to delete it (endpoints stay permanent an

Directory holding PNG / image stickers.

Same as `overlay_bbox` but returns the actual on-disk dimensions of loaded image overlays when available. Used by the resize-handle math so the gizmo

World-space AABB of an overlay at the current playhead. Mirrors the math in `draw_canvas_overlays`. Returns `(min, max)` corners.

Range-aware lane picker for image / overlay clips.

Build a piecewise expression for a legacy-layout scalar against a configurable [`LayoutTimeBase`]. Convenience wrapper around [`piecewise_in_var`] tha

Strip characters that aren't safe in filenames (defence-in-depth — the server already restricts ids to a sane character class).

Clamp lane indices after undo/redo or legacy snapshots so every clip still maps to a valid video/audio row in the layers panel.

Save settings to disk. Errors are logged but never fatal.

Subdirectory name (relative to the asset root) that holds assets of this kind.

World-space AABB of an actor at the current playhead. Mirrors the math in `actor_screen_rect` but stays in world pixels (no canvas zoom multiplier, no

Spawn a scene element from a LibraryAsset at the current playhead / canvas centre. Used by double-click — drag-drop has its own handlers in `canvas_pr

Per-param breakpoint times on a canvas layout track (world-pixel motion).

Enable animation for one actor parameter: place the first keyframe at `seed_t` (already clamped to the element's visible range).

Locate a local thumbnail for a clip stem, mirroring server-side `find_thumbnail` resolution order.

Walk `root` (which is expected to contain `clips/`, `videos/`, `images/`, `sounds/`, `particles/`, `text/`) and rebuild the in-memory index from scrat

Same as `overlay_clip_local_time` but lets the caller pin the scene time explicitly. Used by the canvas drag setters so they can re-anchor every kf wr

After source duration becomes known, widen clips that still carry the drop placeholder length, clamp overstretched bars, and leave razor splits / manu

Sample an overlay's transform at clip-local time `t` (per-param tracks).

Save these chroma settings as JSON next to the source clip so they follow the asset across projects.

Sync `self.scene` into the active tab's stored scene.

Kick off a lazy clip download. Returns `true` when placement must wait for `ClipDownloaded` (caller should not spawn an actor/overlay yet).

Convert X pixel position back to time.

Normalised UV inset `(left, top, right, bottom)` from all enabled `Crop` entries on the stack (same accumulation as [`apply_effect_stack`]).

Per-param change times for an actor layout, merged with any matching `canvas_layouts` track (canvas drags write world-pixel motion there).

Indices of all audio tracks in screen order (top → bottom).

True when this element's canvas layout already authors motion for `param_id`.

Compute the X-range of a clip on the timeline given its (t_in, t_out) in scene-time. Returns `Some((x0, x1))` when at least part of the clip is visibl

All element ids in the parenting subtree rooted at `root_id` (includes `root_id` itself). Actors and overlays may parent each other; order is breadth-

Draw the curve editor panel for the given target. `selected_property` is only meaningful for Actor / Overlay targets (transform property index). For

World-pixel centre of an element, including parent position inheritance.

Enforce the "one clip per layer at a time" rule for the given mover. Returns the (possibly updated) mover identifier.

Locate ffprobe using the same rules as [`ffmpeg_binary`]. On Windows the extension matters: looking for a sibling named `ffprobe` misses the bundled

World centre used for image overlay hit-testing — matches the visible crop, not the uncropped layout anchor.

Borrow both the layout vec AND the per-overlay `animated_params` set at once. Used by canvas drag setters that route through `kf_anim::write_overlay_p

Per-param change times for an overlay layout, merged with canvas track.

Resolve the timeline track index for a given overlay (using the same fallback rule as the timeline panel).

Map a transform-property slot to the param-id used in `animated_params`.

One undo snapshot per canvas / timeline drag gesture (includes lane assignments so Ctrl+Z does not orphan clips from the panel).

Queue a timeline razor split at scene-time `cut_t` for `sel`.

Render a single frame at time `t` to a PNG file. Used by the GUI scrubber.

If the active tab has edits, queue destructive exit actions and return false. Switching/opening scenes is intentionally immediate: autosave keeps reco

Convert a screen-space pointer to UV (0..1) inside the selected element's image, **accounting for any rotation/scale applied to the element**. Returns

Rotation-aware screen gizmo for the current selection.

Materialise a placeholder audio file at `path` so the renderer's existence check (added defensively to skip stale references after asset rename/move)

Axis-aligned hit test in an oriented rectangle (world space).

Map a normalised time `t` in [0, 1] through the curve.