The Standard-tier spacing floor warned on short healthy scores: three
reference-suite entries measured spacing_distortion 0.36-0.41, above the
0.32 warning floor (0.8 x 0.40), a spurious diagnostic (every score still
passed Minimal). Root cause: the CV folded in the clef-to-first-note lead
advance, which is sized by notational-furniture width, not by rhythm.
Unlike P12-I11 (an engrave-side fix, no spec change), the defect here lived
in the metric's own normative definition, so the honest fix is a catalog
change - the mirror of I11: correct the measurement rather than relax the
threshold.
Quality Metric Catalog 0.1.0 -> 0.2.0: spacing_distortion is scoped to the
system's rhythmic columns (spring slots bearing a notehead or rest). The
clef / key-signature / time-signature lead and barlines contribute no
column, so a note-to-note advance spans them. quality::census now builds its
spacing columns only from a precomputed rhythmic-slot set (is_rhythmic: a
notehead*/rest* glyph anywhere in the slot); the CV and the >= 3-column
contributing-unit rule are otherwise unchanged.
Results: RS-3/5/6 drop to 0.2188 / 0.0819 / 0.0856 (all below the floor),
and the axis stays honest on real irregularity (RS-3 keeps 0.2188 from a
mid-line accidental). RS-2/RS-4 go vacuous-0.0 (their systems carry < 3
rhythmic columns - honestly "too little to measure," cleaner than the old
furniture noise). RS-1 0.1341 -> 0.1967 (cross-barline note advances).
The 1.0 anchor, orientation, range, tier thresholds, and the eight other
axes are unchanged. This is measurement-only: the resolved layout, canonical
bytes, render goldens, and ENGRAVER_VERSION are all untouched - only the
reported spacing_distortion value moves. The duration-aware optical-spacing
open question (deviation from duration-proportional spacing) stays open; it
needs the pipeline's deferred duration-aware preferred widths.
- catalog: spacing_distortion requirement (req:qmc:spacing) redefined over
rhythmic columns, rationale + open-question note updated, version 0.2.0,
revision-history row; PDF rebuilt clean (0 undefined refs).
- engrave: quality::census rhythmic-column filter + is_rhythmic; module and
spacing_raw docs; the floor-column contrast test re-pointed from b-flat's
spacing (no longer warns) to RS-1's casting-off (still between the Standard
0.28 and Minimal 0.72 floors); new short_scores_do_not_trip_the_standard_
spacing_floor locks the fix.
- QMC version breadcrumbs bumped to 0.2.0 (engrave + layout-ir quality.rs,
both DECISIONS.md, testkit RS-1 comment); reference suite companion
unchanged (cites the catalog by name, no pinned values).
- process trail: PASS12_BATCH I12 struck; PASS12_RATIFICATION_LOG I12
section (Version movements: QMC 0.1.0 -> 0.2.0); engrave DECISIONS quality
decision 8 + item 7 + candidate.
861 workspace tests pass; clippy -D warnings, fmt --check, rustdoc
-D warnings, and the catalog PDF build all clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NEs4aYiu8MXjdYdMxw8PTd
Levi Neuwirth
9d28dd6615