When the room left in the result limit is too small for the lines of a
curved segment to stay within the tolerance, the loop stays as it is
instead of taking fewer lines that can pass it.
When a flat closed loop becomes the lines between samples of its curved
segments, the line segments it keeps now count toward the 2,097,152-line
limit before the rest is shared among the curved segments. When that
leaves no line for some curved segment, the loop stays as it is.
Follows #6651. When the refits of a closed subpath enclose no area,
Simplify splits its curves until straight lines between the pieces
enclose one. That split stopped at 65,536 pieces in all, and a loop
with many anchors then came back as the flat refit, with no outline.
- Only curved segments are split; line segments stay one piece each.
- When no split within the limits encloses an area, the loop stays as
it is. With Convert to Straight Lines, each curved segment becomes
the lines between its samples instead.
Follows #6614. When a closed subpath's refit in two and in three parts is
still lines that enclose no area, for example an S curve closed by a
straight edge whose cut points all lie on that edge, Simplify now splits
each segment in 2, 4, 8 and so on (up to 1,024 pieces, 65,536 in all)
until every piece is within the tolerance of the line between its ends
and those lines enclose an area. With Convert to Straight Lines those
lines are the result; without it the subpath stays as it is. A subpath
whose points are all in line keeps the refit's lines, so its extra
anchors are still removed. Lines count as enclosing no area when every
point is within 1e-6 pt of one line.
A closed subpath that refits to a single curve has one anchor, which is
not a subpath, so Simplify dropped it: a small circle inside a compound
path was lost and the result ended hundreds of points from the original,
and a small closed path on its own came out empty. Such a subpath is now
refitted in two parts, cut at the point farthest from its start, or in
three when two parts would still enclose no area (two lines that retrace
each other with Convert to Straight Lines). A closed subpath of a single
segment stays as it is.
`rdp` measured each sample to the infinite line through the ends of the
line that would replace it. A sample beyond either end could be far from
that line segment and still be dropped: a line to (100, 0), a 0.2 pt
U-turn and a line back to (50, 0.2) became one line at a tolerance of
1 pt, leaving the tip 50 pt away. `rdp` now measures to the segment, so a
sample beyond an end is measured to that end, and a zero-length chord
measures to its point as before.
The test `a_path_that_turns_back_past_its_end_converted_to_straight_lines_keeps_its_tip`
covers that path.
Object > Path > Smooth weighed every sample within three spreads of each
point, so the work grew with the square of the anchor count on traced
paths: 360 steps per sample for 1,000 anchors and 2,949 for 16,000.
Consecutive samples within 1/16 of a spread of each other are now
weighed together as their count at their mean place, found through a
tree of sums over the run's samples. A traced outline takes 203 to 286
steps per sample from 1,000 to 64,000 anchors, and every smoothed point
stays within a thousandth of a spread of weighing the samples one by
one (300 random runs).
The curve fitter split a piece over the tolerance at its worst point and
accepted any piece at depth 41 whatever its error. A worst point near the
end of a piece peels off a few points, so a long path refitted nearly all
of its points at every level. A serpentine of 200,000 anchors kept pieces
with a fitted error of up to about 1,598 pt at a tolerance of 1 pt.
Simplify also took at most 256 samples per segment, so the lines between
the samples on a long arc could be farther from it than the tolerance.
- `fit_rec` moves a split that is near an end of its piece to two fifths
of the piece from that end, so the depth is logarithmic, and it keeps no
piece over the tolerance. A piece of 32 points or more is first fitted
to about 16 of them, and it is split when that fit is over the tolerance.
- A curve is also rejected when it is over the tolerance from the lines
between the points it fits, with samples close enough that it stays
within 1% of the tolerance of the chord between them. A pair of points
that would need more than 1,024 samples counts as too far.
- `join_pieces` joins neighboring pieces when one curve fits them, up to
33 pieces per curve.
- `sample_steps` takes enough samples of a curved segment to keep it within
0.5% of the tolerance of the lines between them. A segment that would
need more than 65,536 samples stays as it is, and so does a segment
after a run's first 16,777,216 samples or 2,097,152 result segments. With
Convert to Straight Lines such a segment becomes evenly spaced lines, up
to 65,536. A fit holds at most 1,048,576 samples, so a longer run is
fitted in parts.
- Simplify fits at 98% of the tolerance, since turning a nearly straight
curve into a line moves it by up to 1.5%.
- Above slider level 0, Object > Path > Smooth fits a whole closed path
with no corner along one direction across its start, when no segment
stays as it is and the path is fitted as one part. A direct-selected
section does not get this. The start can still have a kink: a first or
last fitted curve that is nearly straight becomes a line, which leaves
along its chord, and a refit with more anchors than the path is
discarded, so the path stays as it is.
A closed subpath that refits to one curve is still dropped, as on main, so
it can end up farther than the tolerance from the result. docs/mcp.md
states this.
The anchors of every simplified path can differ from before, and so can
the results of the Pencil, Blob Brush and Smooth, which use the same fit.
Add Anchor Points builds the new anchor list in one pass, Swatch Library add looks names up in sets, full_documents dedups placed keys with a set, width profile lookups and mark insertion use binary search, and the symbolism tools cap and thin the previews of a long drag as Liquify does.
Found while testing crates/pathops/src/edit.rs:342-364 (smooth_level calls smooth_seam after the fit)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The Simplify help page says a path can be simplified whole or "a specific
path region with the Direct Selection tool"
(https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/modify-paths/manually-simplify-paths.html).
Simplify refitted every selected path whole, whatever part of it was
direct-selected.
object.path.simplify now looks at each path's direct selection: the
segments picked as segments, or else every segment with both anchors
selected. Each run of consecutive selected segments is refitted on its own
(vectorcraft_pathops::simplify_part) between its two end anchors, which stay
where they are with their handles on the side away from the run; every
other anchor and segment stays exactly as it was. A closed path's run may
cross its start point (the path then starts at the run's end anchor),
separate runs on one path simplify independently in one undo step, and the
runs stay direct-selected (as segments when segments were picked). A path
with only lone anchors selected still simplifies whole, as before, and
wholePaths: true simplifies partly selected paths whole. The slider, its
preview, Auto-Simplify and the Simplify dialog all run the command, so
they act on the part too. simplify_with now shares its run fitting with
the part refit (same results).
Verification: crates/engine/src/tests_simplify_part.rs (unselected anchors
and segments equal bit for bit, run end anchors fixed, the run within the
tolerance, two runs equal to each simplified alone in one undo step, a
closed run across the start point, picked segments, wholePaths, slider
preview and Auto-Simplify, a run that can't be simpler records no step)
and simplify_slider_and_dialog_simplify_only_the_direct_selected_part_of_a_path
(the slider's preview, Enter and the dialog's OK). Live: the release build's
slider at level 20 on a 91-anchor wave with anchors 30–60 selected refits
only that stretch.
The Simplify help page says the slider starts at an auto-simplified value
(https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/modify-paths/manually-simplify-paths.html).
The slider opened at a fixed level 50 (1 pt), whatever the size of the
selection, so the first preview was the same tolerance for a 30 pt icon as
for a 1000 pt drawing.
The level Auto-Simplify picks for the selection is now one engine function,
vectorcraft_engine::auto_simplify_level (the existing 1/400-of-the-longer-
side rule in vectorcraft_pathops), which object.path.simplify {auto: true}
and the slider's opening fields both use. Object › Path › Simplify (and
ui.menuDialog, the Properties and contextual task bar buttons, which go
through the same menu dialog) opens the slider there, and the canvas
previews that result; Auto-Simplify still moves the slider back to it.
The retained Simplify dialog path is unchanged.
Verification: simplify_slider_opens_at_the_auto_simplify_level_of_the_selection
opens the slider on 1140, 285 and 28.5 pt waves (levels 35, 55, 89) and
checks the preview is exactly object.path.simplify {auto: true}'s result;
without the change it fails with level 50 != 35, and
simplify_opens_a_slider_whose_drag_previews_fewer_or_more_points fails with
{"level": 50} != {"level": 55}. cargo xtask ci: all 10 steps passed.
Object > Path > Split Into Grid took a number of rows and columns and one gutter, and split each
selected path on its own. The dialog now has the documented options, the rows beside the columns:
number, height or width, gutter and total, with Add Guides and Preview. Several selected paths
become one grid over them all, painted as the topmost one, as documented.
object.path.splitIntoGrid takes rowGutter and columnGutter (gutter still sets both), totalHeight
and totalWidth, height and width (the size of each row and column, which sets the total) and
addGuides, which adds ruler guides along the row and column edges on the grid's layer.
Behaviour reference:
https://helpx.adobe.com/illustrator/desktop/manage-objects/edit-objects/divide-or-split-objects.html
- Parity: Object › Path › Remove Anchor Points now runs the new command (`path.removeAnchors`,
the menu's feature name) instead of `path.deleteAnchors`, which deleted the anchors with their
segments and opened closed paths; that stays the Delete key's command ("Delete Anchor Points",
off the menu). No second "Smart" item.
- Geometry: the refit moves to `vectorcraft_pathops::remove_anchor` on the existing least-squares
fitter (fixed end tangents, a golden-section search for where the curve passes the removed
point) instead of a ~1,000-candidate grid search in geom (about 4 ms per anchor, now well under
0.1 ms). Two straight sides stay one straight side (a rectangle loses a corner and becomes a
triangle), as Illustrator does; non-finite input leaves the handles alone.
- The Delete Anchor Point tool (`path.removeAnchor`) uses the same function, replacing its
heuristic handle stretch; the explicit id/anchor and `fit` params of the new command are dropped
as duplicates of it. The command is enabled by direct-selected anchors (`has_anchors`), not a
UI override.
- The Control bar shows an icon button (the Delete Anchor Point icon, tooltip "Remove Anchor
Points") instead of a 204 pt text button; the labels reuse the translated "Remove Anchor
Points"; zh-hant gains "Delete Anchor Points". The Pen test that pinned Alt-click as plain Pen
(Illustrator's Alt over an anchor is Convert Anchor Point) is dropped.
- Tests for the refit, closed paths, straight sides and bad input; docs/mcp.md and ROADMAP.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Shipped code no longer unwraps, expects or panics: every one of the 124
unwrap()/expect()/panic!/unreachable! sites outside tests now handles the
failure (Result/Option, ?, let-else, defaults) and reports errors to the user.
- Lints: workspace clippy denies unwrap_used, expect_used, panic, todo,
unimplemented and unreachable; clippy.toml allows them in tests, and
integration tests, examples and testkit opt out explicitly.
- Safety net (vectorcraft_engine::guard): a panic in a top-level command rolls
the document back and returns EngineError::Internal; a panicking tool is
reset; the MCP server answers with an internal error and keeps serving; the
UI frame and each control request are guarded.
- APIs that hid failures now return them: Rendered::to_png/to_jpeg/to_webp
return Result (JPEG/WebP errors used to write empty files),
FontDb::face returns Option, Region::top returns Option.
- Fuzzing: engine/tests/import_fuzz.rs feeds garbage, hostile and mutated SVG
and PDF through import → render → export (30k cases locally, no panics).
- Docs: AGENTS.md/CLAUDE.md rule, docs/development.md "Robustness" section,
README pointer and a PR template checklist.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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