- Island detection style (group 75) picks the loops that take part: outer keeps the
outermost loops and their first islands, ignore only the outermost loops.
- A pattern hatch's background colour is filled under its pattern lines.
- Gradients blend colour 1 to colour 2 (LINEAR, CYLINDER, CURVED, SPHERICAL,
HEMISPHERICAL and the INV forms) along their angle, shifted when not centred, drawn as
bounded colour steps; ByLayer / ByBlock gradient colours resolve to the hatch's layer /
block colour instead of colour 7.
- DXF HATCH pattern definition lines (78, 53, 43-46, 79, 49) of a pattern the library
doesn't define are kept on the hatch (new `patternLines` field), drawn and written back;
hostile counts are capped.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
