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Levi Neuwirth 7045a13a18 Schema major 1 Phase F: ratify engrave I8/I9/I10 + process trail 
Spec/process only, no code. Closes the schema-major-1 track (Phases A-F): the
two data-model batch rows parked behind the frozen-layout rule (P12-I7, P12-K7)
landed via Phases C/D1, and the three engrave/layout-ir dispositions the
implementation already made are ratified into the core spec.

- core_spec: three normative requirements ratifying the implemented behavior --
  break-constraint satisfaction (req:layoutir:break-satisfaction, I8: a
  SystemBreakAt/PageBreakAt is satisfied iff the final ResolvedLayoutIR starts a
  system/page at that slot), break-override attribution via a
  ConstrainedLayoutIR.break_origins sidecar declining to widen the constraint
  record (req:layoutir:break-origin-attribution, I9), and system-continuation
  synthesis Registered(SYSTEM_CONTINUATION_SYNTHESIS) with an (original, ordinal)
  instance key (req:layoutir:continuation-synthesis, I10). Revision-history row.
  PDF rebuilt (latexmk -xelatex, 0 undefined refs).
- PASS12_RATIFICATION_LOG: schema-major-1 tranche (I7/K7 landed + I8/I9/I10
  adopt), with the open cross-region-slur item flagged.
- PASS12_BATCH: struck I7/K7/I8/I9/I10; added P12-K12 (which region governs a
  cross-region slur's spanning permission -- implemented as conservative AND).
- engrave/layout-ir DECISIONS: ratification cross-refs; the P12-I7 note reworded
  so deferred Phase C' does not read as landed.
- .gitignore: spec/*.xdv (xelatex intermediate; the tracked PDF is committed).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NEs4aYiu8MXjdYdMxw8PTd
 		2026-07-06 17:40:38 -04:00
..
src Clear P12-I12: scope spacing_distortion to rhythmic columns (QMC 0.2.0) 2026-07-05 13:57:10 -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 Schema major 1 Phase F: ratify engrave I8/I9/I10 + process trail 2026-07-06 17:40:38 -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