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Levi Neuwirth 7d61271069 Push 3 (slur quality) 3/3: measure slur_shape_penalty (off the 0.0 placeholder) 
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>
 		2026-07-08 17:28:28 -04:00
..
src Push 3 (slur quality) 3/3: measure slur_shape_penalty (off the 0.0 placeholder) 2026-07-08 17:28:28 -04:00
Cargo.toml Phase 3 tranche 1: casting-off, K1 schema-fill, value-restoring undo 2026-07-02 21:55:26 -04:00
DECISIONS.md Push 3 (slur quality) 3/3: measure slur_shape_penalty (off the 0.0 placeholder) 2026-07-08 17:28:28 -04:00
README.md Phase 3 tranche 1: casting-off, K1 schema-fill, value-restoring undo 2026-07-02 21:55:26 -04:00

README.md

epiphany-engrave

Agent I's engraving constraint solver (spec Chapter 9): turns a ConstrainedLayoutIR into a ResolvedLayoutIR with real geometry. It is the production-side replacement for epiphany-layout-ir's interface-only StubSolver; the two live in separate crates so the spec's core/product boundary stays sharp.

Status: Minimal tier, with casting-off

  • Engraver runs a deterministic horizontal spacing pass (the first axis of the two-pass spring layout): each spring slot is placed left-to-right by a collision-aware advance derived from real glyph bearings.
  • A casting-off pass (Phase 3's layout track) then breaks the spaced line into systems at measure boundaries (greedy first-fit against a PageGeometry — default A4 portrait at an 8 mm staff), stacks systems vertically at the vertical-band model's inter-system gap, assigns pages by content height, and populates the real ResolvedPage/ResolvedSystem tree. Every position is baked into a single y-up world frame (pages stacked vertically), so the SVG renderer and hit-testing consume the flat glyph/stroke lists unchanged.
  • The IR's declared constraints are evaluated — geometric families against the pre-casting spaced frame, break constraints against the final break structure (hard breaks are always honoured; a pathological soft break is skipped and recorded as an IrOverride decision). Chosen breaks are recorded as EngravingDecisions with SynthesisKind::EngravedBreak targets, attributed to the user override that requested them when one did.
  • It reports SolverTier::Minimal: hard constraints (break family included) satisfied, no optimality claim — the quality-metric vector stays the honest all-worst placeholder until the Quality Metric Catalog lands.

Deferred: the vertical soft-spring solve, per-system justification/stretch, optimal break search, widow/orphan control, and casting-off caching. See DECISIONS.md.

use epiphany_engrave::Engraver;
use epiphany_layout_ir::{ConstraintSolver, SolverConfig};

let report = Engraver::default().solve(&constrained_ir, &SolverConfig::default());
assert!(report.satisfied_hard_constraints);
let resolved = report.layout; // real pages/systems; hand to epiphany-render-svg