6 functions, 53 lines. highway.js 4,158 -> 4,105. NOT ONE CALL SITE CHANGES.
project, roundRect, bnvNormalizedPoints, teachingFingerLabel, teachingDegreeLabel,
chordHarmonyLabels — the shared primitives every drawing function leans on.
━━━ PURITY IS THE WHOLE POINT OF THIS SLICE ━━━
Every one of these is a pure function of its arguments. None touches hwState. None closes over
the canvas context — roundRect() already took `ctx` explicitly, and the rest need nothing but
numbers. project() reads only the module-level constants from #914.
That matters because createHighway() is a FACTORY: a plugin can build a second highway for its
own panel, so anything holding per-instance state must be PASSED hwState rather than importing
it, or two panels silently share one clock and palette. These six hold no state at all, so
they move VERBATIM — the module boundary is invisible to every caller.
The asserts are mechanical and in the extractor: it REFUSES to move a function whose body
mentions hwState, or that references `ctx` without taking it as a parameter. Purity is
checked, not assumed.
━━━ WHAT IS DELIBERATELY LEFT BEHIND ━━━
The four primitives that DO need hwState — fretX, fillTextReadable, _noteState, _paintGemGlow
— stay in the factory for now. They need an explicit hwState parameter threaded through 53
call sites, which is a real behavioural change and belongs in its own commit rather than
smuggled in beside a provably-identical move. Separating the provable from the risky is the
whole discipline of this epic.
TESTS. Three harnesses brace-match these functions out of the source and run them in a
sandbox; they now read static/js/highway-geometry.js. `export function x` still contains
`function x`, so the extractor needed no change — only the path.
VERIFIED. A/B against origin/main: 15 probes IDENTICAL, zero page errors. PERF GATE PASSES AT
1.91ms against its 12ms budget — and this is the one that could plausibly have cost something:
project() runs for every visible note on every frame and is now a CROSS-MODULE call. It costs
nothing measurable. That is the answer #910 was built to give.
node 1045, pytest 2416, ESLint 0, Codex 0.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Post-merge Codex review of the bend-curve PRs (#531/#532) surfaced edge cases:
- GP8 (#531 P2): bnv timing used rn.sustain, which is zeroed for notes <= 0.2s,
so short GP8 bends kept the scalar bn but lost bt/bnv. Use the beat duration
`dur` (matching the GP5 path) so the curve survives.
- 2D highway (#532 P2): bnvNormalizedPoints mapped x over the curve's own t-range
[first,last] instead of the note span, so curves not starting at 0 / ending at
sus were time-distorted. Now maps over [0, sus] (clamped), with a curve-span
fallback when sus<=0 (existing no-sus callers unaffected).
- 3D highway (#532 P3): the sustain ribbon + bend chevron were gated on bn>0, so a
note carrying an authoritative bnv with bn==0 drew no ribbon/marker. Both now
also fire on bnv presence; chevron steps derived from max(bn, bnv peak).
Codex-reviewed: clean (no findings). +1 JS test (sus-relative mapping + fallback).
JS 8/8, 250 core GP/song tests pass.
NB: GP8's short-bend path still lacks a dedicated synthetic-GPIF fixture (same gap
as the GP8 offset-prop-names P3) — _gpx_bend_shape units cover the function; the
fix is the one-line caller change.
Part of got-feedback/feedback#334.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
PR-B of the bend-shape feature (feedpak §6.2.1). Both highways drew a bend
from the scalar `bn` only; now they trace the authoritative `bnv` curve
([{t, v}]) when present and fall back to the `bn` arc/envelope otherwise.
2D (static/highway.js drawNote): when a note carries `bnv`, draw the real
shape as a contour above the gem (round-trip rises then falls, pre-bend
starts high, release descends — `bt` is implicit in the point shape), with
an arrowhead only when the gesture ends rising. `bnvNormalizedPoints` maps
{t,v} to a 0..1 x span. The scalar-arrow path is preserved unchanged as the
fallback; the peak label is unchanged.
3D (plugins/highway_3d/screen.js): `bnvSampleAt` linearly interpolates the
curve (clamped to its endpoints) and `bendSemisAtTime` samples it when
present, else keeps the synthetic rise→hold→release envelope from `bn`. The
chevron count still comes from the peak. Fixed a stale-scratch hazard: the
reused `_scrChordNote` now resets `bnv`/`bt` (omit-when-default) after
Object.assign, mirroring the existing `fhm` reset, so a chord note without a
curve can't inherit the previous note's contour.
Render-only — no wire/schema change. Pure helpers covered by
tests/js/highway_bend_curve.test.js (interp, clamping, round-trip,
degenerate/empty); node --check passes on both files; full tests/js green.
Part of got-feedback/feedback#334
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
