Notes above or below the staff now get ledger lines — the gap the GUI surfaced
the moment a note is moved off the staff. Each notehead carries its StaffStep;
to_constrained emits one short horizontal stroke per whole step between the
staff (lines at steps 0..=8) and the note, reaching LEDGER_LINE_EXTENSION past
each side of the note's actual bounding box (so a wide whole note gets a wider
ledger), synthesized from the pitch so the strokes are deterministic and
hit-testable. The synthesis key splits component (high 64 bits) from signed step
(low 64) so two components of a very low note can never collide.
Ledger lines are fixed-width marks, not system-spanning lines, so the Engraver's
horizontal spacing must not scale them. is_rigid_width_stroke marks them; the
remap translates such a stroke rigidly by its *owning glyph's* column delta
(found by source, not the stroke midpoint — which for a wide head can fall nearer
a neighbouring column), so it keeps both its length and its offset from the
notehead. The spacing pass folds each ledger's extent into its notehead's slot,
so adjacent off-staff notes' ledgers reserve room and do not overlap. The stub
solver passes ledgers through unchanged.
Tests cover the step geometry, key distinctness (incl. steps below -128), the
bbox span, width preservation and offset (no-drift) through the Engraver, the
adjacent-overlap spacing, and an explicit two-whole-note off-staff drift case.
Render goldens regenerated.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NAtEiJtt9yKVV1zjKYmZhS
Levi Neuwirth
9539b1652b