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>
Land the two real pre-passes as canonical *derived annotations* (pure
functions of the materialized Score + profile, recomputed on
materialization, never serialized into canonical Score bytes), exposed via
`derive_annotations`:
- Spelling: a Temperley-style line-of-fifths centre-of-gravity preference
rule (key-free, deterministic), preserving authored CMN letters and only
inferring spelling for chromatic/integer input. `resolve_spelling`
layers authored overrides above the inferred default (the RespellPitch
precedence rule). `spell` now takes `&Pitch` and delegates to
`simplest_spelling`.
- Decomposition: metric greedy-aligned splitting on a 1/4096 integer grid
(barline + dyadic-boundary ties), with exact sounding->notated tuplet
conversion before gridding. Components reconstruct the event duration
(invariant 15).
- A per-event-kind eligibility `TaxonomyReport` so "ineligible" is always
explicit and counted, never silently absent.
Test infrastructure (Agent F): a 29-fixture representative corpus +
taxonomy harness (corpus.rs), the H spelling/decomposition merge gate
(prepass_harness.rs), a discrete `tests/prepass.rs` CI target, conformance
stage [7b], a dedicated CI job, and the Pass-12 batch tracker.
Review hardening folded in (nine findings):
- Guard `decompose_metric` against a zero-length measure (was a
divide-by-zero panic; now reported ungriddable).
- Resolve spelling-override priority via `Reverse` instead of negation
(was an i32::MIN overflow).
- Verify spelling *register* (octave), not just pitch class, in the gate.
- Close the decomposition under-emission gap: the unusual-outcome
taxonomy buckets are an exact per-fixture whitelist (classify_corpus
step 5b).
- Generalize `accidental_ids` to a glyph stack so authored extreme
alterations (triple-sharp+) reconstruct exactly instead of being clamped.
- Per-fixture spread checks in the non-vacuity tripwire and broad-bucket
coverage, so no single rich fixture can carry a signal (partial-stub
resistance); added a `mixed_rhythm` fixture for margin.
- Pin the integer-grid note-value math to the canonical rational helpers
via an exhaustive test; cross-reference comments.
- Replace the O(n^2) tuplet innermost-resolution scan with an id index.
fmt + clippy -D warnings clean; 199 tests pass; conformance suite green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011giSRaHCFCGm1Z2SWv6JHt
Levi Neuwirth