epiphany/crates/epiphany-engrave
Levi Neuwirth 029039bf35 Straighten the QMC version story in the docs that assert it
Review follow-up on 5b016f3. Bumping the catalog to 0.3.0, I ran a mechanical
find-and-replace over the version string and did not reread the sentences around
it. Result: layout-ir's quality.rs credited the spacing_distortion refinement to
v0.3.0 when that was v0.2.0, and engrave's quality.rs still announced v0.2.0
while implementing the v0.3.0 unit set.

Each version now says what it actually did: v0.2.0 narrowed spacing_distortion's
measurement DOMAIN to rhythmic columns; v0.3.0 narrowed vertical_density_penalty's
CONTRIBUTING UNITS to one per realization of a gap band. Both narrowed what is
measured over, not what it is normalized against -- so the transcribed constants
(anchors, thresholds, warning fraction) have not moved since v0.1.0, which is the
invariant worth stating and the reason the two revisions were safe.

Swept for the same rot rather than fixing only the two reported. Three more
present-tense claims pinned a version that will keep going stale: engrave and
layout-ir DECISIONS both said "the companion (v0.2.0) ratifies/pins the nine
axes", and the reference suite claimed RS-1 passes "under engrave v3, QMC v0.2.0
anchors" -- engrave is at 11. All three now cite the current version and name what
is actually invariant across revisions. The remaining "QMC 0.1.0 -> 0.2.0"
mentions are historical records of what that revision did and stay as they are.

Docs only. Gate green; zero golden churn.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-09 11:54:25 -04:00
..
src Straighten the QMC version story in the docs that assert it 2026-07-09 11:54:25 -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 Straighten the QMC version story in the docs that assert it 2026-07-09 11:54:25 -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