The boolean's answer went through orient(), which judges each ring's
side from its first point. The boolean often starts a contour where it
touches another, so a triangle whose tip rests on a square's edge was
dropped, and an even-odd hole touching its outline was filled. The
boolean already runs holes against their outlines, so its rings are now
only turned as a whole.
Other fixes:
- A bowtie drawn as one contour has no area of its own. It was dropped
before the meet check and built nothing, although it fills both lobes.
Sampling now keeps rings with no area, and orient() drops them after
the check. Flat rings, every point on one line, fill nothing and are
still dropped, so a stray flat contour doesn't send separate art
through the boolean.
- An open subpath was closed along its end handles when the profile went
through the boolean, but straight otherwise, as the renderer fills it.
It is now closed straight before the boolean too.
- An empty union was taken as a refusal. Contours that cancel (a square
drawn twice under even-odd) built a square. They now build nothing.
- Contours meet within twice the boolean's own sweep tolerance,
computed by its rule from every anchor and handle of the path it is
given. pathops snaps anchors onto nearby heights before the sweep
joins edges within that tolerance, so contours up to about 1.4 times
it apart can come out as one; within twice it, every contour it
might join goes through it, even far from the origin, and the few it
leaves apart cost a boolean that builds the same shape.
- A one-anchor subpath draws nothing, so it is skipped, as the renderer
and the boolean skip it.
- A profile the boolean refuses reuses the rings already sampled.
Tests:
- touching parts and holes;
- an open subpath with handles, alone and beside crossing bars;
- a flat contour beside separate squares;
- contours joined far from the origin, including by handles alone,
and contours a few millionths apart near it kept apart;
- triangles snapped together and joined at 1.4 times the tolerance,
the same triangles left apart and kept whole, and the factor pinned
between 1.9 and 2.2 times, with the worst case just past twice the
tolerance left apart by pathops;
- a 24-bar grid: too complex for Extrude and Inflate, whole under Rotate;
- the merged rings turned as a whole;
- a one-anchor loop;
- the bowtie and the cancelling squares under all three effects;
- a 3,001-point star that the boolean refuses (TooComplex), built as
drawn.
Docs: the pathops README's Limits section now says only the try_
functions refuse, lists OpenPath and the caught panic, and describes
unite_all's answers, and which calls take a precision. three-d.md and effects-parity.md (the 3D row, its
history and status line) describe the merge and its limits.
The boolean that merges crossing contours cost about as much as the rest
of a plain extrusion, and it ran on every profile. Most art has no
contours that meet, so the profile is now sampled first (its point limit
checked there, before any boolean) and resolved only when two edges
cross, touch, run along each other or fold back, in one contour or
across two. Edges are swept by their left ends, within a pair budget past
which the boolean decides. Touching counts: squares sharing an edge
inflate as one puff, not two with a seam.
On a release build, Extrude of 120 separate contours takes 0.31 ms
instead of 4.18 ms; profiles that do cross cost what they did.
Tests: the meeting cases, squares sharing an edge, the fallback for a
profile the boolean refuses, Inflate's extent and area for the crossing
k, and the coincident circles' area. The hairline test now holds a
crossing pair so that its profile still goes through the boolean.
Docs: the merge is described once for all three effects, linking to a new
Limits section in the pathops README instead of repeating its limits,
and the point limit notes that a merged outline can have more points.
try_normalize refits its result at Pathfinder's default precision and
drops every contour thinner than 0.01 pt on average as a sliver. A
hairline beside a larger shape is art, not debris, and resolved() only
fell back to the input when nothing at all was left, so the hairline lost
its cap, walls and surface.
Resolve with try_unite_all_with at a precision far below any art, which
still drops the debris a boolean leaves where curves coincide: a circle
drawn twice, exactly or 1e-7 pt off, stays one outline.
Extrude & Bevel, Inflate and Rotate broke on shapes whose contours cross.
Type often draws a glyph that way: Roboto Slab's "k" has its arm and leg
as one contour that crosses both the stem and the leg's foot serif.
rings() decided each contour's role (outline, hole, or no edge at all
under nonzero) from the contour's first point only. A contour that starts
inside another was dropped or flipped into a hole, cutting part of the
glyph away. A contour that starts outside was kept whole, so its walls and
bevels ran through the overlap and the overlapping parts drew as separate
boxes.
The profile now goes through vectorcraft_pathops::try_normalize first, so
rings() only ever sees simple contours that do not cross. A path the
boolean refuses is used as it was.
Drew Dibble