Profile samples added inside a flattened chord used the chord's direction for their normal, so a zoomed outline jogged at every flatten vertex. Keep the source segment that drew each flattened piece and ask it for the exact tangent at added samples; fit runs with coordinate-wise Fritsch-Carlson tangents. Adds a regression test and records the change in the parity evidence.
When a constant profile's half-width reaches the local radius of curvature, the smooth inner offset crosses the centre and the non-zero fill leaves a hole. Cut through the centre at those samples; the cut is inside the painted stroke. Varying profiles keep the offset because their crossings can be real caustics, where a cut would show as a slit. Regression test: a radius-5 circle with a 30 pt stroke contains its centre.
Offset smooth points along the curve's normal instead of the flattened polyline's miter (w/cos), which spiked the edge at every sample on tight curves. Fit runs with chord-length Catmull-Rom tangents so a short sample cannot flatten the long segment beside it, and add a coarse wide-circle regression test.
A width profile's sides now run as a cubic Hermite curve through the
points, its slope at each one the weighted harmonic mean of the secants
either side (Fritsch-Carlson). That is C1 continuous and monotone
between points, so it never overshoots them, a width change eases in and
out instead of making a corner, and moving one point only reshapes the
two segments beside it. The ends are flat; two points at one t are still
a step.
The outline samples the curve along the path (densify subdivides each
profile segment) so the smooth width draws on straight runs too, and a
flat profile keeps its old straight pieces.
Hit testing now counts every segment near enough to reach the point, as
the wider side of a farther one can paint past the nearest; gradient
strips reach over projecting dash caps. Tests updated for the new
sampled widths; new tests cover smoothing, monotonicity, locality and
steps.
The Gradient panel's Stroke buttons now work: with the Stroke proxy on a
linear or radial gradient they lay it within the stroke (placed on the
page, as before), along the path (start to end of each subpath) or across
it (left edge to right edge; inside/outside strokes span their visible
side). `paint.editGradient {stroke: true, strokeMode}` sets it (new art
too with nothing selected); `document.inspect` reports
strokeOptions.gradientMode. Model: StrokeLayer.gradient_mode (default
Within, not written).
Shared geometry in effects::stroke::gradient: ribs on the bisectors of
the flattened path (fans round sharp corners, widened under arrowheads,
following width profiles) cut slices each painted with a linear piece of
the gradient (Gradient::span). The canvas and raster export clip them to
the stroke's outline and arrowheads, grown a pixel and composited with
copy so there are no seams and translucent stops paint once. SVG and PDF
write the same slices clipped to the outline, with a warning (new
vectorcraft_svg::export_with_report). Outline Stroke and Expand make
gradient meshes clipped to the outline. Mesh quads now grow along their
edges so thin quads show no seams. Dashes, profiles and arrowheads keep
working in both modes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Double-clicking a width point opens Width Point Edit (Side 1, Side 2, Total Width, a link
keeping the sides equal, Adjust Adjoining Width Points, Delete; dialog `widthPoint`, also
`ui.widthPointEdit`). Shift-click selects several width points, which drag and widen together
as one undo step; Alt-dragging a point's centre copies it (`stroke.widthPoint.copy`); dropping a
point onto another makes a discontinuous point (two points at the same t), and the stroke's
width steps there. `stroke.widthPoint.set` takes `adjustAdjoining`, keeps a discontinuous point
when only its widths change, and `stroke.widthPoint.remove` takes `indices`. Flipping a profile
along the path swaps the sides of its steps; `document.inspect` reports `widthPoints`.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Each dash and dot of a profile stroke is as wide as the profile where it sits
along the whole path (before, dashes dropped the profile). Corners of profile
strokes take the stroke's miter (within the miter limit), round or bevel join on
the outer side and stay clean on the inner side, instead of a miter clamped at
4x; smooth points of curves bend round. Canvas, SVG/PDF outlines and Outline
Stroke share the geometry.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Arrowheads, width-profile outlines and dashed line outlines now come from
vectorcraft_effects::stroke (stroke_pieces, line_outline, width_outline), used by
the canvas and PDF export alike; the renderer caches profile outlines too. Width
profiles are a doc-level catalogue (WidthProfile::PRESETS, preset, preset_id,
id_of) shared by stroke.set and the Stroke panel; stroke.set rejects unknown
profile ids and its params doc lists the arrowhead names.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Adam