The slur_shape quality axis was pinned at 0.0 (vacuous, then "by construction").
It now MEASURES, per the Quality Metric Catalog (req:qmc:slur): each drawn slur
Curve's arc ratio ρ = apex height / chord length is penalized by its distance
outside the shallow-arc band [0.08, 0.25] (max(0, 0.08-ρ, ρ-0.25)), meaned over
curves, normalized by R_worst=0.25. Apex is the max perpendicular distance from
the sampled cubic (32 points) to its endpoint chord; translation-invariant, so
the post-cast curves are measured directly.
Honest outcome: the Minimal tier's mid-span slurs sit at ρ = SLUR_HEIGHT_FACTOR
= 0.16 (in band → 0), but the fixed min/max height clamps push short slurs above
the band (bulgy) and very long ones below it (flat) — a genuine non-zero value a
duration-aware Standard-tier height would improve. A curve-free layout measures
0 by the vacuous-geometry rule.
No ENGRAVER_VERSION bump — measurement-only, resolved geometry / canonical bytes
/ render goldens untouched (quality-decision-8 rule); no RS entry carries a slur
so the reference suite is unaffected. Test: an adjacent-event slur is penalized
(>0), a wide-span slur is in-band (0). 935 tests, 8/8.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Levi Neuwirth
7d61271069