The Live Paint Bucket now fills areas enclosed by any paths. Crossing
lines enclose faces it can fill, a line across a shape splits that shape's
face in two, and an area enclosed by paths becomes a face even when nothing
fills it (it starts unfilled). Edges are the paths cut wherever another path
meets them, keeping their stroke, so Shift-click paints each piece. Closed
shapes give the same faces as before.
Root cause: Live Paint built its faces from the Pathfinder regions, which
divide the filled areas of closed shapes. An open path counted only as the
area it would fill if closed, which for a straight line is nothing, so lines
divided nothing and the bucket found no face to fill. A new planar map in
vectorcraft-pathops (live_paint) sweeps every path as an edge: an open path
goes in traced there and back, with crossing counts that never cancel; faces
are walked on the resulting graph (holes included), and their fills and the
edges' sources are found geometrically. The sweep runs in an exactly sheared
frame, because it mishandles a horizontal line traced there and back.
Make, Merge, the bucket and Live Paint Selection all use it;
interior_point moves to vectorcraft-pathops with it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The sweep compares a curve with another segment over a y-span shorter than
its tolerance by bounding boxes only, so an edge rising by less than that
tolerance (e.g. a rectangle edge cut through a circle's cap, whose computed
intersection end sits ~1e-12 off the horizontal) was mis-ordered and the
result lost a corner: xor/difference/area disagreed by up to 10%. Every
sweep input now snaps on-curve y values within the tolerance to one level
(handles follow and are levelled with their anchor), so such edges become
exact horizontals, which the sweep handles exactly.
- tests/regressions.rs: the six minimal failures found by the properties,
the root cause in isolation, and the self-crossing "star" polygon.
- The star-polygon strategy rejected no angular step of half a turn or
more, so it sometimes drew self-crossing polygons (the shoelace failure).
- Property suites run from a fixed seed (PROPTEST_CASES / PROPTEST_RNG_SEED
still override), so CI cannot fail at random.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
