Large documents stay interactive: the canvas re-renders only what a pan uncovers or an edit
touches, the layers panel lays out only the rows in view, and per-frame work no longer walks the
whole page.
- Benchmark: `cargo xtask bench [SIZES]` builds synthetic pages (`figcraft_engine::synthetic`:
screens with an auto layout header, a card group, button instances and shapes/text) at
1k/10k/50k layers and prints engine/render timings (`figcraft-cli perf --layers 1000,10000`) and
headless whole-UI frame timings (an ignored ui-egui test).
- Retained canvas rendering (`figcraft_render::Retained`, used by the render worker): views snap
to whole device pixels, so a pan shifts the previous image in place and renders only the
uncovered strips; an edit renders only where changed layers were and are
(`Document::changed_ids` diffs the two versions skipping shared structure; ancestors that paint
from their children's pixels - booleans, effects, masks - count whole; background blur reach
and noise are allowed for). Zoom, page, options, font or page-level changes, or large changes,
render the whole view as before. `ui.inspect` reports `canvas.renderWork`.
- The texture image is converted on the render thread, not the UI thread.
- Layers panel: only visible rows are laid out (stable ids while scrolling); rows are cached per
document version, page, expanded set and filter.
- Frame labels and layout grids of off-screen top-level frames are skipped; the Prototype tab's
connection sources are cached per document version.
- Text: the layout cache keys by a cheap fingerprint confirmed by `TextData` equality (no Debug
formatting per lookup, 32k entries) and hands out shared layouts; a layout generation marks
renders stale when fonts arrive. Overflowing text is culled by its glyphs, so it no longer
vanishes while its box is off screen.
Before -> after (release, Windows, 1440x900 view, ms; 10k / 50k layers):
- move one layer, re-render @100%: 7.65 / 6.49 -> 0.18 / 0.81
- move one layer, re-render zoomed out: 11.95 / 24.10 -> 0.16 / 0.77
- pan 40 px @100%: 7.53 / 6.82 -> 0.69 / 0.81
- pan 40 px zoomed out: 12.07 / 24.30 -> 1.62 / 4.17
- full render @100% / zoomed to fit: 7.78 / 44.22 -> 6.56 / 38.83 (10k @100%, 50k fit)
- UI frame, every screen expanded in layers: 6.16 / 39.07 -> 0.24 / 0.57
- UI frame, scrolling that panel: 6.11 / 40.18 -> 0.43 / 0.40
- UI frame, layers filtered by name: 1.03 / 6.92 -> 0.17 / 0.36
- UI frame, Prototype tab: 0.89 / 6.45 -> 0.18 / 0.80
- UI frame, idle: 0.31 / 1.43 -> 0.11 / 0.39
Unchanged and within budget: single-layer edits through the engine ~0.01 ms, normalize after a
one-node edit < 0.01 ms, hit test 26 / 93 us. Left: save/load at 50k (~0.7 s each), zoomed-out
renders at 50k (~40 ms).
Tests: retained renders match full renders after pans, moves, recolours, hide/remove/add, undo,
masks, overflowing text, edits under a background blur and an inner-shadow/noise layer, a drop-
shadowed group, and a blur panned in from the view's edge; zoom/page/options/page background
render full; junk views don't panic. Layer-row and prototype-source caches follow edits, undo,
page switches, expansion and the filter. `changed_ids`, the text cache, and the perf CLI.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
- New `figcraft_format::rest`: imports the public REST API file JSON (`GET /v1/files/:key`, and
the nodes endpoint's response) using the published reference only. Pages (name, background,
flow starting points), the layer tree, names, visibility, lock, opacity, blend mode, masks.
- Geometry from `relativeTransform` (children of groups/booleans checked against
`absoluteBoundingBox` to settle their space), else absolute bounds + rotation; sizes, corner
radii (uniform and per corner), smoothing, clip content, constraints, export settings, layout
grids.
- Paints: solid, linear/radial/angular/diamond gradients (handles map 1:1), image fills (fill,
fit, tile, stretch, rotation, filters) with bytes from a resolver or a grey placeholder keyed by
the imageRef; paint opacity, visibility and blend. Strokes: weight, per-side weights, align,
caps, join, dashes, miter angle. Effects: drop/inner shadow (offset, radius, spread, show behind),
layer and background blur.
- Vectors from `fillGeometry` (stroke-only vectors use the `strokeGeometry` outline), ellipse arc
data, stars/polygons, boolean operations. Text: characters, type style (family, style or weight
+ italic, size, line height px/%/auto, letter spacing, case, decoration, alignment, auto resize,
truncation, paragraph spacing/indent, OpenType flags, links), per-character overrides → styled
runs (UTF-16 aware), list type.
- Auto layout: direction incl. grid, alignment, padding, gaps, wrap, hug/fixed/fill sizing (legacy
and per-axis fields), absolute positioning, min/max, grid cells.
- Components and sets with descriptions and property definitions (names lose their `#id`
suffix); instances of components in the file become instances with their property values and
listed overrides; outside components and component cycles stay frames. Shared styles are created
from the layers that use them, named from the metadata.
- Unknown types and fields are skipped with a counted warning list; sizes, depth (256), layer count
(200,000), path length and list lengths are capped; nothing panics on junk.
- Engine: `file.open` / `file.import` / CLI detect the JSON by content, link imported instances to
their mains (sources and overrides), read image fills from an `images` folder next to the file,
never save over the JSON, and return `warnings`. `file.import` now remaps ids across all
imported pages at once (instances keep their main and layer sources) and brings styles and page
backgrounds along. `figcraft-cli info` prints load notes.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
BFlat
Brandon Thomas