* Fix internal bridges over Hilbert Curve/Octagram Spiral sparse infill
For patterns with curved/turning anchor lines (Hilbert Curve, Octagram
Spiral), the bridge_over_infill algorithm produced incorrect results:
1. determine_bridging_angle: sampling curved anchor orientations
produced noise across all turning directions (0/90/180/270°)
instead of a single dominant one, yielding unstable bridge angles
with 180° spread. Fix: use the configured infill_direction + 90°
directly, bypassing the noisy sampling. The old blind +0.25*PI
(Hilbert) and +1/16*PI (Octagram) offsets are removed.
2. construct_anchored_polygon: curved Hilbert/Octagram anchors
intersected each vertical scan line many times at wildly different
Y positions, producing chaotic polygon sections — holes in random
places, bridges over air, rotated bridges. Fix: replace the curved
infill polylines with synthetic straight lines parallel to
infill_direction, spaced at the real infill line spacing
(flow_spacing / density). Lines are centered on the limiting_area
bbox center so that after rotation they span the full bridged_area.
Anchors are left at full bbox length (not clipped) to guarantee
every scan line finds an anchor.
Rectilinear and other straight-line patterns are unaffected.
Known limitation: some bridge edges may still terminate over air in
edge cases where the nearest synthetic anchor line is more than one
infill spacing away from the bridge boundary. This will be addressed
in a follow-up.
* fix: anchor internal bridges to actual sparse infill
Preserve real anchors across regions and align plane-path anchor origins with printed infill. Respect lower-layer rotation templates and model alignment, and sample curved bridge boundaries more finely.
Add regression coverage for anchor alignment, bridge angles and region isolation, with Orca comments explaining the geometry constraints. Verified 175 FFF tests before the comment-only follow-up; preserve CRLF in modified files.
* Fix internal bridge support contacts and separated infill origins
Restore anchor contact after bridge smoothing and share per-body pattern origins between anchors and printed infill. Recompute origins when preparation settings change.
Cover multiline counts 1, 2 and 3 and add regressions for printed bridge support, separated infill alignment and reslicing.
* Add explicit standard headers to PrintObject tests
* test: cover surface centering when infill settings change
Verify top and bottom Archimedean Chords and Octagram Spiral paths after switching centering modes or toggling separated infills. Compare reslicing against fresh slicing and document dependent infill invalidation.
* test: preserve directional surface infill when settings change
* perf: index layer islands for connected-body detection
* test: use public print pipeline for body centering checks
Valerii Bokhan