Criterion 6 (the Chapter 7 layout round-trip) and the render goldens previously
exercised only the verbatim StubSolver, so a regression in the real Engraver's
geometry could land unseen. I-3 drives both through the Engraver.
- round_trip_with<S: ConstraintSolver> factors the solver-agnostic provenance
contract out of round_trip (now a one-line stub wrapper): coverage, the
complete Provenance surviving constrained -> resolved -> render, the source
surjection, and no duplicate stable ids hold for *any* conformant solver. The
Stub tier's verbatim-geometry clause is gated behind solver.tier() == Stub;
every other tier re-spaces. The status gate accepts any renderable status
(Solved / SolvedWithWarnings / PartialBudgetExhausted), not exactly Solved, so
the helper matches its "arbitrary conformant solver" contract while still
rejecting the diagnostic-only statuses that carry no authoritative layout.
- criterion_six_round_trips_through_the_engravers_respacing (epiphany-engrave)
runs the full graph -> logical -> constrained -> *engraved* -> render round
trip over the criterion-6 hand-off fixtures -- ten_measure_single_staff (the
measured fixture) and valid_score_rich (cross-cutting tuplet/tie/spanner),
plus valid_score for breadth -- and asserts the whole provenance contract
survives the Engraver's re-spacing. A non-vacuity check confirms the Engraver
genuinely moved geometry, so provenance is preserved *through* a real geometry
change -- the statement the verbatim stub can never make. This adds an
epiphany-testkit dev-dep (no cycle: testkit does not depend on this crate).
- The render-svg engraver acceptance test is upgraded from invariant-only to
byte-locked: new .engrave.snapshot.txt / .engrave.svg goldens for both
fixtures capture the Engraver's re-spaced output (e.g. ten_measure view_box
width 82.26 vs the stub's 88.88, same glyph/stroke/class counts), so an
Engraver geometry regression is caught at the byte level. A companion test
asserts the engrave goldens genuinely differ from the stub goldens, catching
the degeneracy where the Engraver echoes the stub (which would otherwise pass
both golden checks independently).
Also corrects the epiphany-engrave package description, which still claimed it
reports SolverTier::Stub until it earns Minimal (it earned Minimal in I-2).
Full gate green: build, fmt, clippy, 580 tests, conformance scale 1.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Lands the renderer-against-stub slice of Agent I's visible engraving work
(spec/PHASE2_QUICKSTART.md). Two new crates; prerequisites (G Pass 11, H
spelling/decomposition) are in place. Real engraving + Minimal-tier solver
follow next phase.
epiphany-render-svg (the deliverable this phase):
- Renders a ResolvedLayoutIR to well-formed SVG 1.1, drawing each glyph as a
GENUINE Bravura SMuFL outline <path>. Outlines are extracted reproducibly
from the official OFL Bravura.otf by a committed generator
(tools/extract_bravura_outlines.py, OFL.txt); the font is not vendored, only
the generated Rust (src/outlines_generated.rs). Staff-space/y-up coords with
one global y-flip wrapper; viewBox in staff spaces, px scale on the root.
- Non-overreach: every element traces to a ResolvedGlyph (data-prov) or a
declared wrapper; a glyph lacking an outline is surfaced as a diagnostic and
drawn as a fallback rect, never silently dropped.
- Hand-rolled xml::check_well_formed (no XML dep); acceptance tests cross-check
with system xmllint when present.
- examples/render_fixture.rs demo (fixture name -> SVG stdout, --solver=stub|real).
- Golden-locked machine acceptance snapshot + full-SVG golden for
ten_measure_single_staff and valid_score_rich; deterministic output.
epiphany-engrave (honest scaffold):
- Engraver: a deterministic horizontal-spacing pass (first axis of the planned
two-pass spring layout). Reports SolverTier::Stub — NOT Minimal — until it
evaluates the declared hard constraints, guarded by a regression test. The
demo's --solver=real exercises it end to end.
Honesty notes (recorded as Pass-12 candidates P12-I1..I3 in spec/PASS12_BATCH.md
and the crates' DECISIONS.md): the v0 to_logical/to_constrained pipeline is a
structural placeholder (arbitrary glyph per object, y=0), so stub output is not
yet recognizable notation and the QUICKSTART human visual gate is a next-phase
gate; MUSCLOID layout-id derivation stays unwired; bundled BRAVURA_METRICS are
approximations that disagree with the real outlines.
Gates: cargo fmt + clippy -D warnings clean; cargo test --workspace 504 passed,
0 failed, 0 ignored (criterion 6 layout round-trip still green).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Levi Neuwirth